PMCC PMCC

Search tips
Search criteria

Advanced
Results 1-25 (38)
 

Clipboard (0)
None

Select a Filter Below

Year of Publication
more »
1.  Comparative transcriptome analysis reveals candidate genes for the biosynthesis of natural insecticide in Tanacetum cinerariifolium 
BMC Genomics  2017;18:54.
Background
Pyrethrins are monoterpenoids and consist of either a chrysanthemic acid or pyrethric acid with a rethrolone moiety. Natural pyrethrins are safe and eco-friendly while possessing strong insecticidal properties. Despite such advantages of commercial value coming with the eco-friendly tag, most enzymes/genes involved in the pyrethrin biosynthesis pathway remain unidentified and uncharacterized. Since the flowers of Tanacetum cinerariifolium are rich in major pyrethrins, next generation transcriptome sequencing was undertaken to compare the flowers and the leaves of the plant de novo to identify differentially expressed transcripts and ascertain which among them might be involved in and responsible for the differential accumulation of pyrethrins in T. cinerariifolium flowers.
Results
In this first tissue specific transcriptome analysis of the non-model plant T. cinerariifolium, a total of 23,200,000 and 28,500,110 high quality Illumina next generation sequence reads, with a length of 101 bp, were generated for the flower and leaf tissue respectively. After functional enrichment analysis and GO based annotation using public protein databases such as UniRef, PFAM, SMART, KEGG and NR, 4443 and 8901 unigenes were identified in the flower and leaf tissue respectively. These could be assigned to 13344 KEGG pathways and the pyrethrin biosynthesis contextualized. The 2-C-methyl-D-erythritol 4-phosphate (MEP) pathway was involved in the biosynthesis of acid moiety of pyrethrin and this pathway predominated in the flowers as compared to the leaves. However, enzymes related to oxylipin biosynthesis were found predominantly in the leaf tissue, which suggested that major steps of pyrethrin biosynthesis occurred in the flowers.
Conclusions
Transcriptome comparison between the flower and leaf tissue of T. cinerariifolium provided an elaborate list of tissue specific transcripts that was useful in elucidating the differences in the expression of the biosynthetic pathways leading to differential presence of pyrethrin in the flowers. The information generated on genes, pathways and markers related to pyrethrin biosynthesis in this study will be helpful in enhancing the production of these useful compounds for value added breeding programs. Related proteome comparison to overlay our transcriptome comparison can generate more relevant information to better understand flower specific accumulation of secondary metabolites in general and pyrethrin accumulation in particular.
Electronic supplementary material
The online version of this article (doi:10.1186/s12864-016-3409-4) contains supplementary material, which is available to authorized users.
doi:10.1186/s12864-016-3409-4
PMCID: PMC5220608  PMID: 28068903
De novo assembly; MEP pathway; MVA pathway; Oxylipin pathway; pyrethrins; Tanacetum cinerariifolium; Transcriptome; Unigenes
2.  Midbrain tuberculoma presenting as partial ptosis 
BMJ Case Reports  2014;2014:bcr2014207686.
doi:10.1136/bcr-2014-207686
PMCID: PMC4244482  PMID: 25404254
3.  Evaluation of melatonin levels in saliva in gingivitis and periodontitis cases: A pilot study 
Contemporary Clinical Dentistry  2016;7(4):519-523.
Objective:
To evaluate the melatonin levels in saliva in gingivitis and periodontitis cases.
Background:
Melatonin has strong antioxidant, free radical scavenging, and immunomodulating properties, acts on osteoblasts directly to stimulate cell proliferation and synthesis of Type I collagen, and promotes bone formation.
Materials and Methods:
A total of thirty participants were selected and divided into three groups (control group, gingivitis group, and periodontitis group). In each group, ten participants were taken. Salivary melatonin was estimated in each of the three groups.
Results:
Results from this study showed that the mean levels of salivary melatonin increased as severity increased from control to periodontitis, i.e., the mean levels were highest in periodontitis followed by gingivitis and least in control group. The melatonin level of all participants was positively and significantly (P < 0.01) correlated with their gingival index (r = 0.85, P < 0.01) and probing depth (r = 0.72, P < 0.01).
Conclusion:
Salivary melatonin level varied with the severity of gingivitis and periodontitis. With increased severity of periodontal disease, the level of salivary melatonin also increased suggesting that salivary melatonin may act as a diagnostic biomarker for periodontal diseases.
doi:10.4103/0976-237X.194115
PMCID: PMC5141668  PMID: 27994421
Gingivitis; melatonin; periodontitis; saliva
4.  Pontine stroke and bladder dysfunction 
BMJ Case Reports  2014;2014:bcr2013200787.
We report the case of a 54-year-old hypertensive woman who presented with sudden onset left hemiparesis with facial asymmetry and inability to pass urine. Her bladder was distended and she had to be catheterised. MRI of her brain showed a large infarct in the right pontine region. Antiplatelet therapy was instituted and the patient showed good recovery and was able to walk with support after a fortnight at the time of discharge. She was discharged with a catheter in situ. After 6 months, she could walk with the support of a stick, but had increased frequency and urgency of micturition along with nocturia. Urodynamic study revealed detrusor hyper-reflexia, possibly due to involvement of the pontine micturition centre.
doi:10.1136/bcr-2013-200787
PMCID: PMC4039818  PMID: 24876208
5.  Phlyctenular conjunctivitis: a rare association with spinal intramedullary tuberculoma 
BMJ Case Reports  2014;2014:bcr2013202010.
We present a case of a 33-year-old woman who presented with phlyctenular conjunctivitis while on treatment for spinal intramedullary tuberculosis. She was treated with topical steroids along with continuation of antitubercular therapy, and improved on this treatment.
doi:10.1136/bcr-2013-202010
PMCID: PMC3962859  PMID: 24642174
6.  Spinal cord tuberculosis: a paradoxical response to antituberculous therapy 
BMJ Case Reports  2014;2014:bcr2014203639.
doi:10.1136/bcr-2014-203639
PMCID: PMC3948148  PMID: 24604804
7.  Hirayama Disease with Periscapular Involvement: A Rare Association 
Annals of Neurosciences  2016;23(1):56-59.
Hirayama disease (HD) is a rare disease commonly seen in India and Japan typically presenting in adolescent age group with male predominance and asymmetrical distal pure motor, lower-motor neuron-type weakness. We report a patient of HD who had significant involvement of proximal periscapular muscles along with typical distal involvement. The patient also had scapular winging, which is rare in HD. He was treated conservatively with physiotherapy and hard cervical collar and is presently under follow-up during the static phase of disease.
doi:10.1159/000443557
PMCID: PMC4934413  PMID: 27536023
Hirayama disease; MRI; Anterior horn cell disorder
8.  Paroxysmal kinesigenic dyskinesia: a frequently misdiagnosed movement disorder 
BMJ Case Reports  2014;2014:bcr2014203681.
doi:10.1136/bcr-2014-203681
PMCID: PMC3939411  PMID: 24569354
9.  Laryngeal carcinoma presenting as polymyositis: A paraneoplastic syndrome 
Laryngeal carcinoma is rarely associated with paraneoplastic syndrome. Inflammatory myopathy presenting as paraneoplastic event is commonly associated with carcinomas of ovary, lung, pancreas, stomach, colorectal, and non-Hodgkin's lymphoma. We report a case of elderly male, who presented with proximal muscle weakness and found to be associated with laryngeal carcinoma. Diagnosis of polymyositis (PM) was confirmed based on clinical features, laboratory test, and muscle biopsy. Exclusion of other commonly associated malignancies was done. This patient improved gradually after 6 months of immunosuppressive therapy and management of underlying cancer.
doi:10.4103/0972-2327.170571
PMCID: PMC4782538  PMID: 27011653
Laryngeal carcinoma; muscle biopsy; polymyositis
10.  WRKY Transcription Factors: Molecular Regulation and Stress Responses in Plants 
Plants in their natural habitat have to face multiple stresses simultaneously. Evolutionary adaptation of developmental, physiological, and biochemical parameters give advantage over a single window of stress but not multiple. On the other hand transcription factors like WRKY can regulate diverse responses through a complicated network of genes. So molecular orchestration of WRKYs in plant may provide the most anticipated outcome of simultaneous multiple responses. Activation or repression through W-box and W-box like sequences is regulated at transcriptional, translational, and domain level. Because of the tight regulation involved in specific recognition and binding of WRKYs to downstream promoters, they have become promising candidate for crop improvement. Epigenetic, retrograde and proteasome mediated regulation enable WRKYs to attain the dynamic cellular homeostatic reprograming. Overexpression of several WRKYs face the paradox of having several beneficial affects but with some unwanted traits. These overexpression-associated undesirable phenotypes need to be identified and removed for proper growth, development and yeild. Taken together, we have highlighted the diverse regulation and multiple stress response of WRKYs in plants along with the future prospects in this field of research.
doi:10.3389/fpls.2016.00760
PMCID: PMC4891567  PMID: 27375634
WRKY; multiple response; proteasome-mediated degradation; retrograde signaling
11.  Pure motor monoparesis: solitary cysticercus granuloma 
BMJ Case Reports  2013;2013:bcr2013201808.
Solitary cysticercus granuloma (SCG) is the most common form of neurocysticercosis in India and usually presents with seizures. Pure motor monoparesis (PMM) due to cerebral cysticercus lesions has been rarely reported and it has not been seen with SCG. We describe a young girl with SCG who presented with PMM without any other neurological manifestations. The lesion was located in the Penfield homunculus area of the opposite leg. The patient was treated with steroids and antihelminthic drugs. She responded well to the treatment.
doi:10.1136/bcr-2013-201808
PMCID: PMC3888544  PMID: 24343804
12.  Segmental neuromyotonia 
Unilateral focal neuromyotonia has been rarely reported in fingers or extraocular muscles. We report a case of segmental neuromyotonia in a 20-year-old boy who presented to us with intermittent tightness in right upper limb. Electromyography revealed myokymic and neuromyotonic discharges in proximal as well as distal muscles of the right upper limb. Patient's symptoms responded well to phenytoin therapy. Such an atypical involvement of two contiguous areas of a single limb in neuromyotonia has not been reported previously. Awareness of such an atypical presentation of the disease can be important in timely diagnosis and treatment of a patient.
doi:10.4103/0976-3147.154579
PMCID: PMC4481806  PMID: 26167035
Myokymia; myotonia; neuromyotonia
13.  Aneurysmal bone cyst of thoracic spine: case report and brief review of literature 
BMJ Case Reports  2013;2013:bcr2013009265.
A 16-year-old girl was admitted with insidious onset, gradually progressive spastic sensori-motor paraparesis, with a sensory level at D10 dermatome without bowel or bladder involvement for the last 2 months following trivial trauma on the lower back. MRI of the spine showed a low-to-intermediate signal intensity, heterogeneous mass with multiple fluid levels. A diagnosis of aneurysmal bone cyst was made. A D8-D9 laminectomy with near total excision of mass was performed. Histopathology of the mass showed cyst cavity filled with haemorrhage surrounded by bony trabeculae confirming the diagnosis. Following excision the patient had excellent recovery. We report this case owing to its rarity and to emphasise the importance of surgery if there is cord compression.
doi:10.1136/bcr-2013-009265
PMCID: PMC3702870  PMID: 23814197
14.  Hepatic myelopathy: an unusual neurological complication of chronic liver disease presenting as quadriparesis 
BMJ Case Reports  2013;2013:bcr2013009078.
Hepatic myelopathy is a rare neurological complication of chronic liver disease, which is usually seen in adults, presenting as pure motor spastic paraparesis. It is almost always associated with portosystemic shunts and hepatic decompensation. We report a rare case of a young adult man presenting as rapidly progressive spastic quadriparesis because of hepatic myelopathy and associated spontaneous splenorenal shunt and early hepatic decompensation.
doi:10.1136/bcr-2013-009078
PMCID: PMC3702798  PMID: 23749858
15.  Isolated thalamic tuberculoma presenting as ataxic hemiparesis 
BMJ Case Reports  2013;2013:bcr2013009100.
Lacunar syndrome is a neurodeficit secondary to a deep cerebral lesion, usually because of microatheroma of small arteries. Ataxic hemiparesis (AH) is a lacunar syndrome with unilateral pyramidal weakness and ipsilateral ataxia. Thalamic tuberculoma, as a cause of AH, has not been previously described in the literature. We describe an elderly man who presented with left hemiparesis and ipsilateral ataxia. Clinical examination revealed upper motor neuron left facial paresis and left-sided hemiparesis. The patient had incoordination in left upper and lower limbs. Mantoux test was positive and erythrocyte sedimentation rate was elevated. MRI of brain showed a conglomerated hypointense lesion in the right thalamus with a peripheral hyperintensity on T1-weighted imaging and a hyperintense lesion in T2-weighted imaging with significant perilesional oedema, suggesting a tuberculoma. The patient was treated with antitubercular therapy and was symptomatically better at the 9 months follow-up.
doi:10.1136/bcr-2013-009100
PMCID: PMC3645337  PMID: 23580686
16.  De novo leaf and root transcriptome analysis identified novel genes involved in Steroidal sapogenin biosynthesis in Asparagus racemosus 
BMC Genomics  2014;15(1):746.
Background
Saponins are mainly amphipathic glycosides that posses many biological activities and confer potential health benefits to humans. Inspite of its medicinal attributes most of the triterpenes and enzymes involved in the saponin biosynthesis remains uncharacterized at the molecular level. Since the major steroidal components are present in the roots of A. racemosus our study is focussed on the comparative denovo transcriptome analysis of root versus leaf tissue and identifying some root specific transcripts involved in saponin biosynthesis using high-throughput next generation transcriptome sequencing.
Results
After sequencing, de novo assembly and quantitative assessment, 126861 unigenes were finally generated with an average length of 1200 bp. Then functional annotation and GO enrichment analysis was performed by aligning all-unigenes with public protein databases including NR, SwissProt, and KEGG. Differentially expressed genes in root were initially identified using the RPKM method using digital subtraction between root and leaf. Twenty seven putative secondary metabolite related transcripts were experimentally validated for their expression in root or leaf tissue using q-RT PCR analysis. Most of the above selected transcripts showed preferential expression in root as compared to leaf supporting the digitally subtracted result obtained. The methyl jasmonate application induces the secondary metabolite related gene transcripts leading to their increased accumulation in plants. Therefore, the identified transcripts related to saponin biosynthesis were further analyzed for their induced expression after 3, 5 and 12 hours of exogenous application of Methyl Jasmonate in tissue specific manner.
Conclusions
In this study, we have identified a large set of cDNA unigenes from A. racemosus leaf and root tissue. This is the first transcriptome sequencing of this non-model species using Illumina, a next generation sequencing technology. The present study has also identified number of root specific transcripts showing homology with saponin biosynthetic pathway. An integrated pathway of identified saponin biosynthesis transcripts their tissue specific expression and induced accumulation after methyl jasmonate treatment was discussed.
Electronic supplementary material
The online version of this article (doi:10.1186/1471-2164-15-746) contains supplementary material, which is available to authorized users.
doi:10.1186/1471-2164-15-746
PMCID: PMC4162912  PMID: 25174837
Asparagus racemosus; saponin; Transcriptome; De novo assembly; Unigenes
17.  De novo sequencing and comparative analysis of holy and sweet basil transcriptomes 
BMC Genomics  2014;15(1):588.
Background
Ocimum L. of family Lamiaceae is a well known genus for its ethnobotanical, medicinal and aromatic properties, which are attributed to innumerable phenylpropanoid and terpenoid compounds produced by the plant. To enrich genomic resources for understanding various pathways, de novo transcriptome sequencing of two important species, O. sanctum and O. basilicum, was carried out by Illumina paired-end sequencing.
Results
The sequence assembly resulted in 69117 and 130043 transcripts with an average length of 1646 ± 1210.1 bp and 1363 ± 1139.3 bp for O. sanctum and O. basilicum, respectively. Out of the total transcripts, 59648 (86.30%) and 105470 (81.10%) from O. sanctum and O. basilicum, and respectively were annotated by uniprot blastx against Arabidopsis, rice and lamiaceae. KEGG analysis identified 501 and 952 transcripts from O. sanctum and O. basilicum, respectively, related to secondary metabolism with higher percentage of transcripts for biosynthesis of terpenoids in O. sanctum and phenylpropanoids in O. basilicum. Higher digital gene expression in O. basilicum was validated through qPCR and correlated to higher essential oil content and chromosome number (O. sanctum, 2n = 16; and O. basilicum, 2n = 48). Several CYP450 (26) and TF (40) families were identified having probable roles in primary and secondary metabolism. Also SSR and SNP markers were identified in the transcriptomes of both species with many SSRs linked to phenylpropanoid and terpenoid pathway genes.
Conclusion
This is the first report of a comparative transcriptome analysis of Ocimum species and can be utilized to characterize genes related to secondary metabolism, their regulation, and breeding special chemotypes with unique essential oil composition in Ocimum.
Electronic supplementary material
The online version of this article (doi:10.1186/1471-2164-15-588) contains supplementary material, which is available to authorized users.
doi:10.1186/1471-2164-15-588
PMCID: PMC4125705  PMID: 25015319
Comparative transcriptomics; Chromosome; Ocimum sanctum; Ocimum basilicum; Phenylpropanoids; Terpenoids
19.  Standardized Extract of Bacopa monniera Attenuates Okadaic Acid Induced Memory Dysfunction in Rats: Effect on Nrf2 Pathway 
The aim of the present study is to investigate the effect of standardized extract of Bacopa monnieri (memory enhancer) and Melatonin (an antioxidant) on nuclear factor erythroid 2 related factor 2 (Nrf2) pathway in Okadaic acid induced memory impaired rats. OKA (200 ng) was administered intracerebroventricularly (ICV) to induce memory impairment in rats. Bacopa monnieri (BM-40 and 80 mg/kg) and Melatonin (20 mg/kg) were administered 1 hr before OKA injection and continued daily up to day 13. Memory functions were assessed by Morris water maze test on days 13–15. Rats were sacrificed for biochemical estimations of oxidative stress, neuroinflammation, apoptosis, and molecular studies of Nrf2, HO1, and GCLC expressions in cerebral cortex and hippocampus brain regions. OKA caused a significant memory deficit with oxidative stress, neuroinflammation, and neuronal loss which was concomitant with attenuated expression of Nrf2, HO1, and GCLC. Treatment with BM and Melatonin significantly improved memory dysfunction in OKA rats as shown by decreased latency time and path length. The treatments also restored Nrf2, HO1, and GCLC expressions and decreased oxidative stress, neuroinflammation, and neuronal loss. Thus strengthening the endogenous defense through Nrf2 modulation plays a key role in the protective effect of BM and Melatonin in OKA induced memory impairment in rats.
doi:10.1155/2013/294501
PMCID: PMC3776558  PMID: 24078822
20.  A Cross Sectional Study of Oral Submucous Fibrosis in Central India and the Effect of Local Triamcinolone Therapy 
The use of processed arecanut is on the increase. In the impending danger of increased occurrence of oral submucous fibrosis and subsequent oral cancer following this habit is colossal. So an attempt is made to clinically evaluate the condition and to evaluate the effect of triamcinolone on this condition. Using the clinical data collected from the patients presenting in the ENT OPD of NSCB Medical College Hospital, Jabalpur, a cross sectional study was done and the effect of intralesional triamcinolone on this condition is noted by biweekly submucosal injections of 40 mg triamcinolone for 12 weeks and followed up for 1 year. The effect of therapy was evaluated subjectively by improvement in symptoms and objectively by increase in mouth opening. The age of occurrence and sex predilection also showed a significant change with more young males being affected by the condition. There was no significant correlation between effect of triamcinolone therapy and duration of addiction but a significant correlation (P < 0.0001) was noted with the frequency of addiction per day. A significant improvement in mouth opening is observed following local triamcinolone therapy. The results imply that the exposure and the frequency of chewing habits, and not mere the duration that is significant in producing the condition and affecting the treatment outcome. Local triamcinolone therapy has good effect in the initial stages of the disease. The fact that more youngsters are being affected needs serious consideration.
doi:10.1007/s12070-011-0365-9
PMCID: PMC3431518  PMID: 23998027
Oral submucous fibrosis; Triamcinolone; Arecanut; Tobacco; Gutkha; Trismus
21.  Association of psychiatric co-morbidity and efficacy of treatment in chronic daily headache in Indian population 
Objective:
To study the prevalence of psychiatric co-morbidity in patients of chronic daily headache (CDH) and compare the efficacy of treatment between various type of headache associated with psychiatric co-morbidity.
Materials and Methods:
Prospective case control cohort study, 92 consecutive patients of CDH meeting eligibility criteria. The diagnosis of various subtypes of CDH was made according to the IHS criteria. Age, sex, educational, marital and socioeconomic status, matched controls were also selected. Patients were evaluated with the Mini International Neuropsychiatric Interview (MINI) scale at the time of enrolment and at 3 months.
Results:
CDH accounted for 28% of all headache patients. The mean age of presentation was 30.2 ± 10.3 years, male: Female ratio of 28:64 and mean duration of 4.56 ± 0.56 years. Chronic migraine (CM) accounted for 59 patients, chronic tension type headache (CTTH) 22 patients, new daily persistent headache (NDPH) 3 patients and miscellaneous 8 patients. Psychiatric co-morbidity was present in 53.3% patients with CDH, and was more common in CM (62.7%) as compared to CTTH (36.4%). Single psychiatric co-morbidity was seen in 26 patients, while 23 patients had multiple co-morbidity. Major depressive episode, anxiety disorder, agoraphobia and dysthymia were significant psychiatric co-morbidities. Patients with CM were treated with topiramate or divalproex sodium ER and CTTH were treated with amitriptyline. 55 patients came for follow up at 3 months, improvement in headache was seen in 29 patients.
Conclusion:
Psychiatric co-morbidity was present in more than 50% patients with CDH and its presence along with a duration of ≥2 years was associated with a poor response to treatment.
doi:10.4103/0976-3147.112736
PMCID: PMC3724287  PMID: 23914085
Chronic daily headache; chronic migraine; chronic tension type headache; psychiatric co-morbidity
22.  Wound Induced Tanscriptional Regulation of Benzylisoquinoline Pathway and Characterization of Wound Inducible PsWRKY Transcription Factor from Papaver somniferum 
PLoS ONE  2013;8(1):e52784.
Wounding is required to be made in the walls of the green seed pod of Opium poppy prior exudation of latex. To withstand this kind of trauma plants regulate expression of some metabolites through an induced transcript level. 167 unique wound-inducible ESTs were identified by a repetitive round of cDNA subtraction after 5 hours of wounding in Papaver somniferum seedlings. Further repetitive reverse northern analysis of these ESTs revealed 80 transcripts showing more than two fold induction, validated through semi-quantitative RT-PCR & real time expression analysis. One of the major classified categories among identified ESTs belonged to benzylisoquinoline transcripts. Tissue specific metabolite analysis of benzylisoquinoline alkaloids (BIAs) in response to wounding revealed increased accumulation of narcotine and papaverine. Promoter analysis of seven transcripts of BIAs pathway showed the presence of W-box cis-element with the consensus sequence of TGAC, which is the proposed binding site for WRKY type transcription factors. One of the Wound inducible ‘WRKY’ EST isolated from our subtracted library was made full-length and named as ‘PsWRKY’. Bacterially expressed PsWRKY interacted with the W-box element having consensus sequence TTGACT/C present in the promoter region of BIAs biosynthetic pathway genes. PsWRKY further activated the TYDC promoter in yeast and transiently in tobacco BY2 cells. Preferential expression of PsWRKY in straw and capsule and its interaction with consensus W-box element present in BIAs pathway gene transcripts suggest its possible involvement in the wound induced regulation of BIAs pathway.
doi:10.1371/journal.pone.0052784
PMCID: PMC3559656  PMID: 23382823
24.  Statistical models for predicting number of involved nodes in breast cancer patients 
Health  2010;2(7):641-651.
Clinicians need to predict the number of involved nodes in breast cancer patients in order to ascertain severity, prognosis, and design subsequent treatment. The distribution of involved nodes often displays over-dispersion—a larger variability than expected. Until now, the negative binomial model has been used to describe this distribution assuming that over-dispersion is only due to unobserved heterogeneity. The distribution of involved nodes contains a large proportion of excess zeros (negative nodes), which can lead to over-dispersion. In this situation, alternative models may better account for over-dispersion due to excess zeros. This study examines data from 1152 patients who underwent axillary dissections in a tertiary hospital in India during January 1993-January 2005. We fit and compare various count models to test model abilities to predict the number of involved nodes. We also argue for using zero inflated models in such populations where all the excess zeros come from those who have at some risk of the outcome of interest. The negative binomial regression model fits the data better than the Poisson, zero hurdle/inflated Poisson regression models. However, zero hurdle/inflated negative binomial regression models predicted the number of involved nodes much more accurately than the negative binomial model. This suggests that the number of involved nodes displays excess variability not only due to unobserved heterogeneity but also due to excess negative nodes in the data set. In this analysis, only skin changes and primary site were associated with negative nodes whereas parity, skin changes, primary site and size of tumor were associated with a greater number of involved nodes. In case of near equal performances, the zero inflated negative binomial model should be preferred over the hurdle model in describing the nodal frequency because it provides an estimate of negative nodes that are at “high-risk” of nodal involvement.
doi:10.4236/health.2010.27098
PMCID: PMC3124077  PMID: 21720569
Nodal Involvement; Count Models; Breast Cancer
25.  Dynamic Bone Quality – A Non-invasive Measure of Bone’s Biomechanical Property in Osteoporosis 
We describe a novel approach to non-invasively characterize bone quality, a measurement that quantitates aggregate shock absorption capacity of load-bearing bones as a measure of mechanical structural integrity during exposure to real-time self-induced in-vivo loading associated with heel strike. The outcome measure, damping factor, was estimated at five load bearing anatomical sites: ankle, tibial tuberosity, femoral condyle, lower back (at 3rd lumbar vertebra) and upper back (7th thoracic vertebra) plus the forehead in 67 patients with postmenopausal osteoporosis with and without documented vertebral fractures. The damping value was significantly lower in patients with vertebral fractures compared with those without fracture (range −36% to −72%, median −44%). In these women with osteoporosis, damping factor was able to discriminate between patients with and without vertebral fractures, whereas traditional measures of bone density and biomechanical measures obtained from bone geometry were not significantly different between the groups.
doi:10.1016/j.jocd.2010.01.001
PMCID: PMC2862806  PMID: 20347363
dynamic bone quality; damping; osteoporosis; fracture; shock absorption

Results 1-25 (38)