PMCC PMCC

Search tips
Search criteria

Advanced
Results 1-25 (73)
 

Clipboard (0)
None

Select a Filter Below

Journals
more »
Year of Publication
more »
2.  Endosulfatases SULF1 and SULF2 limit Chlamydia muridarum infection 
Cellular microbiology  2013;15(9):1560-1571.
Summary
The first step in attachment of Chlamydia to host cells is thought to involve reversible binding to host heparan sulfate proteoglycans (HSPGs), polymers of variably sulfated repeating disaccharide units coupled to diverse protein backbones. However, the key determinants of HSPG structure that are involved in Chlamydia binding are incompletely defined. A previous genome-wide Drosophila RNAi screen suggested that the level of HSPG 6-O sulfation rather than the identity of the proteoglycan backbone maybe a critical determinant for binding (Elwell et al., 2008). Here, we tested in mammalian cells whether SULF1 or SULF2, human endosulfatases which remove 6-O sulfates from HSPGs, modulate Chlamydia infection. Ectopic expression of SULF1 or SULF2 in HeLa cells, which decreases cell surface HSPG sulfation, diminished C. muridarum binding and decreased vacuole formation. ShRNA depletion of endogenous SULF2 in a cell line that primarily expresses SULF2 augmented binding and increased vacuole formation. C. muridarum infection of diverse cell lines resulted in downregulation of SULF2 mRNA. In a murine model of acute pneumonia, mice genetically deficient in both endosulfatases or in SULF2 alone demonstrated increased susceptibility to C. muridarum lung infection. Collectively, these studies demonstrate that the level of HSPG 6-O sulfation is a critical determinant of C. muridarum infection in vivo and that 6-O endosulfatases are previously unappreciated modulators of microbial pathogenesis.
doi:10.1111/cmi.12133
PMCID: PMC3722241  PMID: 23480519
3.  Managing malaria in the intensive care unit 
BJA: British Journal of Anaesthesia  2014;113(6):910-921.
The number of people travelling to malaria-endemic countries continues to increase, and malaria remains the commonest cause of serious imported infection in non-endemic areas. Severe malaria, mostly caused by Plasmodium falciparum, often requires intensive care unit (ICU) admission and can be complicated by cerebral malaria, respiratory distress, acute kidney injury, bleeding complications, and co-infection. The mortality from imported malaria remains significant. This article reviews the manifestations, complications and principles of management of severe malaria as relevant to critical care clinicians, incorporating recent studies of anti-malarial and adjunctive treatment. Effective management of severe malaria includes prompt diagnosis and early institution of effective anti-malarial therapy, recognition of complications, and appropriate supportive management in an ICU. All cases should be discussed with a specialist unit and transfer of the patient considered.
doi:10.1093/bja/aeu157
PMCID: PMC4235570  PMID: 24946778
ARDS; ICU; imported infections; malaria
4.  Audit of bacteraemia management in a university hospital ICU 
Critical Care  2014;18(Suppl 1):P357.
doi:10.1186/cc13547
PMCID: PMC4069552
5.  Pretubulysin: a new option for the treatment of metastatic cancer 
Cell Death & Disease  2014;5(1):e1001-.
Tubulin-binding agents such as taxol, vincristine or vinblastine are well-established drugs in clinical treatment of metastatic cancer. However, because of their highly complex chemical structures, the synthesis and hence the supply issues are still quite challenging. Here we set on stage pretubulysin, a chemically accessible precursor of tubulysin that was identified as a potent microtubule-binding agent produced by myxobacteria. Although much simpler in chemical structure, pretubulysin abrogates proliferation and long-term survival as well as anchorage-independent growth, and also induces anoikis and apoptosis in invasive tumor cells equally potent to tubulysin. Moreover, pretubulysin posseses in vivo efficacy shown in a chicken chorioallantoic membrane (CAM) model with T24 bladder tumor cells, in a mouse xenograft model using MDA-MB-231 mammary cancer cells and finally in a model of lung metastasis induced by 4T1 mouse breast cancer cells. Pretubulysin induces cell death via the intrinsic apoptosis pathway by abrogating the expression of pivotal antiapoptotic proteins, namely Mcl-1 and Bcl-xL, and shows distinct chemosensitizing properties in combination with TRAIL in two- and three-dimensional cell culture models. Unraveling the underlying signaling pathways provides novel information: pretubulysin induces proteasomal degradation of Mcl-1 by activation of mitogen-activated protein kinase (especially JNK (c-Jun N-terminal kinase)) and phosphorylation of Mcl-1, which is then targeted by the SCFFbw7 E3 ubiquitin ligase complex for ubiquitination and degradation. In sum, we designate the microtubule-destabilizing compound pretubulysin as a highly promising novel agent for mono treatment and combinatory treatment of invasive cancer.
doi:10.1038/cddis.2013.510
PMCID: PMC4040707  PMID: 24434509
microtubule-targeting agents; natural compounds; metastatic cancer; Fbw7; Mcl-1; TRAIL
7.  Generalized Schemes for High-Throughput Manipulation of the Desulfovibrio vulgaris Genome▿† 
Applied and Environmental Microbiology  2011;77(21):7595-7604.
The ability to conduct advanced functional genomic studies of the thousands of sequenced bacteria has been hampered by the lack of available tools for making high-throughput chromosomal manipulations in a systematic manner that can be applied across diverse species. In this work, we highlight the use of synthetic biological tools to assemble custom suicide vectors with reusable and interchangeable DNA “parts” to facilitate chromosomal modification at designated loci. These constructs enable an array of downstream applications, including gene replacement and the creation of gene fusions with affinity purification or localization tags. We employed this approach to engineer chromosomal modifications in a bacterium that has previously proven difficult to manipulate genetically, Desulfovibrio vulgaris Hildenborough, to generate a library of over 700 strains. Furthermore, we demonstrate how these modifications can be used for examining metabolic pathways, protein-protein interactions, and protein localization. The ubiquity of suicide constructs in gene replacement throughout biology suggests that this approach can be applied to engineer a broad range of species for a diverse array of systems biological applications and is amenable to high-throughput implementation.
doi:10.1128/AEM.05495-11
PMCID: PMC3209177  PMID: 21908633
10.  Survival of HIV‐infected patients in the intensive care unit in the era of highly active antiretroviral therapy 
Thorax  2007;62(11):964-968.
Background
Several studies have described improved outcomes for HIV‐infected patients admitted to the intensive care unit (ICU) since the introduction of highly active antiretroviral therapy (HAART). A study was undertaken to examine the outcome from the ICU for HIV‐infected patients and to identify prognostic factors.
Methods
A retrospective study of HIV‐infected adults admitted to a university affiliated hospital ICU between January 1999 and December 2005 was performed. Information was collected on patient demographics, receipt of HAART (no patient began HAART on the ICU), reason for ICU admission and hospital course. Outcomes were survival to ICU discharge and to hospital discharge.
Results
102 patients had 113 admissions to the ICU; HIV infection was newly diagnosed in 31 patients. Survival (first episode ICU discharge and hospital discharge) was 77% and 68%, respectively, compared with 74% and 65% for general medical patients. ICU and hospital survival was 78% and 67% in those receiving HAART, and 75% and 66% in those who were not. In univariate analysis, factors associated with survival were: haemoglobin (OR = 1.25, 95% CI 1.03 to 1.51, for an increase of 1 g/dl), CD4 count (OR = 1.59, 95% CI 0.98 to 2.58, for a 10‐fold increase in cells/µl), APACHE II score (OR = 0.51, 95% CI 0.29 to 0.90, for a 10 unit increase) and mechanical ventilation (OR = 0.29, 95% CI 0.10 to 0.83).
Conclusions
The outcome for HIV‐infected patients admitted to the ICU was good and was comparable to that in general medical patients. More than a quarter of patients had newly diagnosed HIV infection. Patients receiving HAART did not have a better outcome.
doi:10.1136/thx.2006.072256
PMCID: PMC2117109  PMID: 17517829
11.  Pharmacological optimization of tissue perfusion 
After fluid resuscitation, vasoactive drug treatment represents the major cornerstone for correcting any major impairment of the circulation. However, debate still rages as to the choice of agent, dose, timing, targets, and monitoring modalities that should optimally be used to benefit the patient yet, at the same time, minimize harm. This review highlights these areas and some new pharmacological agents that broaden our therapeutic options.
doi:10.1093/bja/aep135
PMCID: PMC2700012  PMID: 19460775
arterial pressure, drug effects; cardiovascular system, effects; heart, cardiac output; oxygen, therapy; pharmacology, agonists adrenergic
13.  Improved survival for HIV infected patients with severe Pneumocystis jirovecii pneumonia is independent of highly active antiretroviral therapy 
Thorax  2006;61(8):716-721.
Background
Despite a decline in incidence of Pneumocystis jirovecii pneumonia (PCP), severe PCP continues to be a common cause of admission to the intensive care unit (ICU) where mortality remains high. A study was undertaken to examine the outcome from intensive care for patients with PCP and to identify prognostic factors.
Methods
A retrospective cohort study was conducted of HIV infected adults admitted to a university affiliated hospital ICU between November 1990 and October 2005. Case note review collected information on demographic variables, use of prophylaxis and highly active antiretroviral therapy (HAART), and hospital course. The main outcome was 1 month mortality, either on the ICU or in hospital.
Results
Fifty nine patients were admitted to the ICU on 60 occasions. Thirty four patients (57%) required mechanical ventilation. Overall mortality was 53%. No patient received HAART before or during ICU admission. Multivariate analysis showed that the factors associated with mortality were the year of diagnosis (before mid 1996 (mortality 71%) compared with later (mortality 34%; p = 0.008)), age (p = 0.016), and the need for mechanical ventilation and/or development of pneumothorax (p = 0.031). Mortality was not associated with sex, ethnicity, prior receipt of sulpha prophylaxis, haemoglobin, serum albumin, CD4 count, Pao2, A‐ao2 gradient, co‐pathology in bronchoscopic lavage fluid, medical co‐morbidity, APACHE II score, or duration of mechanical ventilation.
Conclusions
Observed improved outcomes from severe PCP for patients admitted to the ICU occurred in the absence of intervention with HAART and probably reflect general improvements in ICU management of respiratory failure and ARDS rather than improvements in the management of PCP.
doi:10.1136/thx.2005.055905
PMCID: PMC2104703  PMID: 16601092
AIDS; intensive care; mechanical ventilation;  Pneumocystis jirovecii ; opportunistic infections; respiratory failure
16.  Gene expression of interleukin 18 in unstimulated peripheral blood mononuclear cells of patients with alcoholic cirrhosis 
Gut  2001;49(1):106-111.
BACKGROUND—Most patients with alcohol induced cirrhosis (AC) and chronic endotoxinaemia are not suffering from clinically evident systemic inflammatory reactions. This may be due to altered gene expression of cytokines, possibly related to endotoxin (for example, tolerance and sensitisation). Interleukin 18 (IL-18; interleukin γ inducing factor) modulates local cytokine production in response to endotoxin (lipopolysaccharide (LPS)).
AIM—To investigate the systemic immune response of patients with AC and to see if unstimulated peripheral blood mononuclear cells (PBMC) from patients with AC are activated and contribute to gene expression of IL-18.
METHODS—Plasma levels of endotoxin (LPS) and serum levels of IL-18 were measured by enzyme linked immunoassay and the amoebocyte lysate test in 74 abstinent patients with different stages of AC (Child-Pugh stage A, n=18; B, n=22; C, n=34) and compared with healthy controls (n=43). Gene expression of IL-18 was assessed by semiquantitative reverse transcription-polymerase chain reaction in freshly isolated unstimulated PBMC of a subgroup of 14 patients with AC compared with five healthy controls.
RESULTS—Gene expression of IL-18 specific mRNA in unstimulated PBMC was significantly enhanced in patients with advanced AC (Child-Pugh stage C) and correlated with plasma LPS and serum CD14 levels (Spearman rank correlation factors r=0.76 and r=0.72). Serum concentrations of IL-18 were also elevated compared with healthy controls (p<0.001) but correlation with serum levels of CD14 and plasma levels of LPS was much weaker compared with mRNA data (Spearman rank correlation factors r=0.47 and r=0.26).
CONCLUSIONS—Our in vivo data suggest a presensitisation of "unstimulated" PBMC in the circulation of patients with AC by endotoxin. The term "unstimulated" may be inadequate in patients with AC. Further investigations are needed to define the exact mechanisms and localisation of sensitisation of PBMC in vivo.


Keywords: liver cirrhosis; peripheral blood mononuclear cells; interleukin 18; lipopolysaccharide
doi:10.1136/gut.49.1.106
PMCID: PMC1728343  PMID: 11413118
18.  Cardiac output in 1998 
Heart  1998;79(5):425-428.
PMCID: PMC1728678  PMID: 9659184
21.  Targeted mutagenesis of DNA with alkylating RecA assisted oligonucleotides. 
Nucleic Acids Research  1999;27(24):e38.
Site-specific mutation was demonstrated in a shuttle vector system using nitrogen mustard-conjugated oligodeoxyribonucleotides (ODNs). Plasmid DNA was modified in vitro by ODNs containing all four DNA bases in the presence of Escherichia coli RecA protein. Up to 50% of plasmid molecules were alkylated in the targeted region of the supF gene and mutations resulted upon replication in mammalian cells. ODNs conjugated with either two chlorambucil moieties or a novel tetrafunctional mustard caused interstrand crosslinks in the target DNA and were more mutagenic than ODNs that caused only monoadducts.
PMCID: PMC148761  PMID: 10572190
22.  Olfactory Receptor Database: a database of the largest eukaryotic gene family. 
Nucleic Acids Research  1999;27(1):343-345.
The Olfactory Receptor Database (ORDB) is a WWW-accessible database that stores data on Olfactory Receptor-like molecules (ORs) and has been open to the public since June 1996. It contains a public and a private area. The public area includes published DNA and protein sequence data for ORs, links to OR models and data on their expression, chromosomal localization and source organism, as well as (i) links to bibliography through PubMed and (ii) interactive WWW-based tools, such as BLAST homology searching. The private area functions as a service to laboratories that are actively cloning receptors. Source laboratories enter the sequences of the receptor clones they have characterized to the private database and can search for identical or near identical OR sequences in both public and private databases. If another laboratory has cloned and deposited an identical or closely matching sequence there are means for communication between the laboratories to help avoid duplication of work. ORDB is available via the WWW at http://crepe.med.yale.edu/ORDB/HTML
PMCID: PMC148178  PMID: 9847223
23.  The human LINE-1 reverse transcriptase:effect of deletions outside the common reverse transcriptase domain. 
Nucleic Acids Research  1998;26(15):3528-3535.
Heterologous expression of human LINE-1 ORF2 in yeast yielded a single polypeptide (Mr145 000) which reacted with specific antibodies and co-purified with a reverse transcriptase activity not present in the host cells. Various deletion derivatives of the ORF2 polypeptide were also synthesized. Reverse transcriptase assays using synthetic polynucleotides as template and primer revealed that ORF2 protein missing a significant portion of the N-terminal endonuclease domain still retains some activity. Deletion of the C-terminal cysteine-rich motif reduces activity only a small amount. Three non-overlapping deletions spanning 144 amino acids just N-terminal to the common polymerase domain of the ORF2 protein were analyzed for their effect on reverse transcriptase activity; this region contains the previously-noted conserved Z motif. The two deletions most proximal to the polymerase domain eliminate activity while the third, most-distal deletion had no effect. An inactive enzyme was also produced by substitution of two different amino acids in a highly-conserved octapeptide sequence, Z8, located within the region removed to make the deletion most proximal to the polymerase domain; substitution of a third had no effect. We conclude that the octapeptide sequence and neighboring amino acids in the Z region are essential for reverse transcriptase activity, while the endonuclease and cysteine-rich domains are not absolutely required.
PMCID: PMC147723  PMID: 9671814
24.  Pharmacy access to syringes among injecting drug users: follow-up findings from Hartford, Connecticut. 
Public Health Reports  1998;113(Suppl 1):81-89.
OBJECTIVE: To break the link between drug use and the human immunodeficiency virus (HIV), in 1992 the state of Connecticut rescinded a 14-year ban on pharmacy sales of syringes without a physician's prescription. In 1993, the Center for Disease Control and Prevention (CDC) evaluated the impact of the new legislation on access to syringes among injecting drug users (IDUs) and found an initial pattern of expanded access. However, it also found that some pharmacies, after negative experiences with IDU customers, reverted to requiring a prescription. This chapter reports findings from a four-year follow-up study of current IDU access to over-the-counter (OTC) pharmacy syringes in Hartford, Connecticut. METHODS: Through structured interviews, brief telephone interviews, and mailed surveys, data on nonprescription syringe sale practices were collected on 27 pharmacies, including 18 of the 21 pharmacies in Hartford and none from pharmacies in contiguous towns, during June and July 1997. Interview data on pharmacy syringe purchase from two sample of IDUs, a group of out-of-treatment injectors recruited through street outreach, and a sample of users of the Hartford Needle Exchange Program, also are reported. RESULTS: The study found that, while market trends as well as negative experiences have further limited pharmacy availability of nonprescription syringes, pharmacies remain an important source of sterile syringes for IDUs. However, the distribution of access in not even; in some areas of the city it is much easier to purchase nonprescription syringes than in other. All of the seven pharmacies located on the north end of Hartford reported that they had a policy of selling OTC syringes, whereas only six (54.5%) of the II pharmacies located on the south end have such a policy. Overt racial discrimination was not found to be a barrier to OTC access to syringes. CONCLUSIONS: To further decrease acquired immunodeficiency syndrome (AIDS) risk among IDUs, there is a need for public education to counter empirically unsupported stereotypes about IDUs that diminish their access to health care and AIDS prevention resources and services. In states or cities where pharmacy sale of nonprescription syringes is illegal, policy makers should examine the benefits of removing existing barriers to sterile syringe acquisition. In cases in which pharmacy sale of nonprescription syringes is legal, local health departments should implement educational programs to inform pharmacy staff and management about the critically important role low-cost (or cost-free), sterile syringe access can play in HIV prevention.
PMCID: PMC1307730  PMID: 9722813
25.  High dependency units in the UK: variable size, variable character, few in number. 
Postgraduate Medical Journal  1995;71(834):217-221.
An exploratory descriptive survey was conducted to determine the size and character of high dependency units (HDUs) in the UK. A telephone survey and subsequent postal questionnaire was sent to the 39 general HDUs in the UK determined by a recent survey from the Royal College of Anaesthetists; replies were received from 28. Most HDUs (82%, n = 23) were geographically distinct from the intensive care unit and varied in size from three to 13 beds, although only 64% (n = 18) reported that all beds were currently open. Nurse: patient ratios were at least 1:3. Fifty per cent of units had one or more designated consultants in charge, although only 11% (n = 3) had specifically designated consultant sessions. Junior medical cover was provided mainly by the on-call speciality term. Twenty units acted as a step-down facility for discharged intensive care unit patients and 21 offered a step-up facility for patients from general wards. Provision of facilities and levels of monitoring varied between these units. Few HDUs exist in the UK and they are variable in size and in the facilities and monitoring procedures which they provide. Future studies are urgently required to determine cost-effectiveness and outcome benefit of this intermediate care facility.
Images
PMCID: PMC2398078  PMID: 7784281

Results 1-25 (73)