Search tips
Search criteria

Results 1-20 (20)

Clipboard (0)

Select a Filter Below

Year of Publication
more »
1.  Streptococcus suis Meningoencephalitis with Seizure from Raw Pork Ingestion: A Case Report 
Streptococcus suis meningoencephalitis is a rare but increasingly important condition. Good history taking will give clues to the diagnosis. This is the fourth case report in the United States.
A 52-year-old Filipino man who recently returned from a trip to the Philippines was admitted with classic symptoms of bacterial meningitis. His cerebrospinal fluid culture grew Streptococcus suis. His clinical course was complicated by seizures, hearing loss, and permanent tinnitus.
Clinicians should be aware of this emerging disease especially in patients with recent travel history to endemic areas. Early recognition and appropriate management could potentially prevent complications.
PMCID: PMC4175935  PMID: 25285249
Case Report; Streptococcus suis meningoencephalitis; seizure; hearing loss; tinitus
2.  Mycobacterium avium Complex Empyema in a Patient with Interferon Gamma Autoantibodies 
Interferon gamma (IFN-γ) autoantibodies are a relatively recently discovered clinical entity, which have been shown to be associated with disseminated non-tuberculous mycobacterial (NTM) infections and other opportunistic infections. Interestingly, isolated NTM infections (without disseminated NTM infection) have not been shown to be a good predictor of the presence of IFN-γ autoantibodies. This case describes an isolated NTM empyema in a patient with IFN-γ autoantibodies and makes the argument that the development of an NTM empyema in a patient with no known immunodeficiency should prompt consideration for IFN-γ testing. Additionally, this case underscores the importance for clinicians to recognize that an unusual infection without the typical cause of impairment in immunity should prompt a more thorough investigation of the patient's immune system.
PMCID: PMC4175962  PMID: 25285250
3.  Euthermic Endocarditis 
PLoS ONE  2013;8(11):e80144.
Most patients with infective endocarditis (IE) manifest fever. Comparison of endocarditis patients with and without fever, and whether the lack of fever in IE is a marker for poorer outcomes, such as demonstrated in other severe infectious diseases, have not been defined.
Methods and Results
Cases from the Mayo Clinic, Rochester, Minnesota, Division of Infectious Diseases IE registry, a single-center database that contains all cases of IE treated at our center. Diagnosis date between 1970 and 2006, which met the modified Duke criteria for definite endocarditis, without fever was included. There were 240 euthermic endocarditis cases included in this analysis, with 282 febrile controls selected by frequency matching on gender and decade of diagnosis. Euthermic patients had a median age of 63.6 years (±16.1) as compared to 59.0 years (±16.4) in the febrile control group (p=0.001). Median (IQR) symptom duration prior to diagnosis was 4.0 (1.0, 12.0) weeks in the euthermic group compared to 3.0 (1.0, 8.0) weeks in the febrile controls (p= 0.006). From unadjusted analyses, survival rates were 87% in euthermic cases versus 83% in febrile controls across 28-day follow-up (p=0.164), and 72% in euthermic group cases versus 69% in febrile controls across 1-year follow-up (p=0.345). Also unadjusted, the 1-year cumulative incidence rate of valve surgery was higher in euthermic cases versus febrile controls (50% vs. 39%, p= 0.004).
Patients with euthermic endocarditis are older, and lack of fever was associated with longer symptom duration and delayed diagnosis prior to IE diagnosis. Despite a higher unadjusted rate of valve surgery in euthermic patients, the result was not significant when adjusting for baseline confounders. Differences in survival rates at both 28-days and 365-days were not statistically significant between the two groups.
PMCID: PMC3823819  PMID: 24244630
4.  Superior Orbital Fissure Syndrome: A Case Report 
Superior orbital fissure syndrome is an infrequently encountered entity with a unique presentation and significant morbidity. This article reviews the background of the syndrome, treatments in the literature, and discusses a recent case with treatment strategy.
PMCID: PMC3444026  PMID: 23730429
trauma; midface; superior orbital fissure syndrome; zygomaticomaxillary complex fracture
5.  Chemokine receptor usage by human eosinophils. The importance of CCR3 demonstrated using an antagonistic monoclonal antibody. 
Journal of Clinical Investigation  1997;99(2):178-184.
Chemokines bind and signal through G-protein coupled seven transmembrane receptors. Various chemokine receptors are expressed on leukocytes, and these may impart selective homing of leukocyte subsets to sites of inflammation. Human eosinophils express the eotaxin receptor, CCR3, but respond to a variety of CC chemokines apart from eotaxin, including RANTES, monocyte chemotactic protein (MCP)-2, MCP-3, and MCP-4. Here we describe a mAb, 7B11, that is selective for CCR3 and has the properties of a true receptor antagonist. 7B11 blocked binding of various radiolabeled chemokines to either CCR3 transfectants, or eosinophils. Pretreatment of eosinophils with this mAb blocked chemotaxis and calcium flux induced by all CCR3 ligands. In all individuals examined, including allergic and eosinophilic donors, > 95% of the response of eosinophils to eotaxin, RANTES, MCP-2, MCP-3, and MCP-4 was shown to be mediated through CCR3. The IL-8 receptors, particularly CXCR2, were induced on IL-5 primed eosinophils, however these eosinophils responded to CC chemokines in the same manner as unprimed eosinophils. These results demonstrate the importance of CCR3 for eosinophil responses, and the feasibility of completely antagonizing this receptor.
PMCID: PMC507784  PMID: 9005985
6.  The Lysostaphin Endopeptidase Resistance Gene (epr) Specifies Modification of Peptidoglycan Cross Bridges in Staphylococcus simulans and Staphylococcus aureus 
Volume 61, no. 4, p. 1478, Table 2, column 4: The diameters (in milliliters) of the zones of inhibition for 5-(mu)g methicillin disks given (from top to bottom), "116," "72," "107," and "32," should read "33.5," "22.6," "34.2," and "21.0," respectively.
PMCID: PMC1390749  PMID: 16535087
7.  The lysostaphin endopeptidase resistance gene (epr) specifies modification of peptidoglycan cross bridges in Staphylococcus simulans and Staphylococcus aureus. 
Staphylococcus simulans biovar staphylolyticus produces an extracellular glycylglycine endopeptidase (lysostaphin) that lyses other staphylococci by hydrolyzing the cross bridges in their cell wall peptidoglycans. The genes for endopeptidase (end) and endopeptidase resistance (epr) reside on plasmid pACK1. An 8.4-kb fragment containing end was cloned into shuttle vector pL150 and was then introduced into Staphylococcus aureus RN4220. The recombinant S. aureus cells produced endopeptidase and were resistant to lysis by the enzyme, which indicated that the cloned fragment also contained epr. Treatments to remove accessory wall polymers (proteins, teichoic acids, and lipoteichoic acids) did not change the endopeptidase sensitivity of walls from strains of S. simulans biovar staphylolyticus or of S. aureus with and without epr. Immunological analyses of various wall fractions showed that there were epitopes associated with endopeptidase resistance and that these epitopes were found only on the peptidoglycans of epr+ strains of both species. Treatment of purified peptidoglycans with endopeptidase confirmed that resistance or susceptibility of both species was a property of the peptidoglycan itself. A comparison of the chemical compositions of these peptidoglycans revealed that cross bridges in the epr+ cells contained more serine and fewer glycine residues than those of cells without epr. The presence of the 8.4-kb fragment from pACK1 also increased the susceptibility of both species to methicillin.
PMCID: PMC167404  PMID: 7747966
8.  Familial benign hypercalcemia--from clinical description to molecular genetics. 
Western Journal of Medicine  1994;160(6):554-561.
Familial benign hypercalcemia (or familial hypocalciuric hypercalcemia), a syndrome of lifelong hypercalcemia inherited as an autosomal dominant trait, is distinct from the multiple endocrine neoplasia syndromes and other forms of inherited parathyroid disease. Familial benign hypercalcemia results from the inappropriate secretion of parathyroid hormone despite hypercalcemia, enhanced renal tubular reabsorption of calcium (independent of parathyroid hormone), and apparent tissue resistance to adverse effects of hypercalcemia. Heterozygosity for the familial hypercalcemia trait is benign, although homozygosity for the trait may lead to severe neonatal primary hyperparathyroidism. Genetic linkage studies show that most persons affected with familial hypercalcemia have a mutation on the long arm of chromosome 3 (3cen-q21), although one phenotypically indistinguishable family appears to have a mutation on the short arm of chromosome 19 (19p), and another family has neither 3q nor 19p mutations. One group has recently shown mutations in a putative parathyroid cell-surface calcium receptor that are plausible causes for the chromosome 3q variant of the familial hypercalcemia syndrome. Perhaps the other genes for this syndrome encode proteins representing hitherto-unknown regulators of systemic calcium metabolism independent of parathyroid cell calcium sensing or proteins involved in signal transduction from the calcium receptor.
PMCID: PMC1022558  PMID: 8053177
9.  A simple and generally applicable procedure for releasing DNA from bacterial cells. 
Treatment of Staphylococcus simulans biovar staphylolyticus cells with acetone before digestion with lysozyme made the cells susceptible to lysis by sodium dodecyl sulfate. This technique was found to be useful for releasing DNA from a wide variety of gram-positive and gram-negative organisms.
PMCID: PMC239025  PMID: 3524454
10.  Structural requirements for parathyroid hormone action in mature bone. Effects on release of cyclic adenosine monophosphate and bone gamma-carboxyglutamic acid-containing protein from perfused rat hindquarters. 
Journal of Clinical Investigation  1985;76(6):2348-2354.
To determine the structural requirements for parathyroid hormone (PTH) activity in mature bone, we perfused the surgically isolated hindquarters of adult male rats with either native bovine PTH-(1-84) [bPTH-(1-84)] or the synthetic amino-terminal fragment, bovine PTH-(1-34) [bPTH-(1-34)]. Changes in the release of cyclic AMP (cAMP) and bone Gla protein (BGP) were monitored as evidence of bone-specific response to PTH; tissue specificity of the cAMP response was confirmed through in vitro examination on nonskeletal tissue response to PTH. Biologically active, monoiodinated 125I-bPTH-(1-84) was administered to determine if mature murine bone cleaves native hormone. We found that perfused rat bone continuously releases BGP, and that both bPTH-(1-84) and bPTH-(1-34) acutely suppress this release. In addition, both hormones stimulate cAMP release from perfused rat hindquarters. When examined on a molar basis, the magnitude of the cAMP response was dose-dependent and similar for both hormones, with doses yielding half-maximal cAMP responses. The response for bPTH-(1-34) was 0.5 nmol and for bPTH-(1-84) was 0.7 nmol. Moreover, biologically active 125I-bPTH-(1-84) was not metabolized in our hindquarter perfusion system. These findings indicate that PTH-(1-84) does not require extraskeletal or skeletal cleavage to an amino-terminal fragment in order to stimulate cAMP generation in, or suppress BGP release from, mature rat bone.
PMCID: PMC424371  PMID: 3001148
11.  Simple screening method for identification of nonpleiotropic mutants for exoenzyme production. 
A differential medium that distinguishes between pleiotropic and nonpleiotropic mutants for exoenzyme production has been developed for Staphylococcus simulans biovar staphylolyticus. The medium will facilitate genetic analysis of exoenzyme production by this organism. Generally useful strategies for increasing the sensitivity of indicator plates for detection of exoenzyme activities are presented.
PMCID: PMC238553  PMID: 4004249
12.  Impaired vitamin D metabolism with aging in women. Possible role in pathogenesis of senile osteoporosis. 
Journal of Clinical Investigation  1984;73(6):1668-1672.
Calcium absorption decreases with aging, particularly after age 70 yr. We investigated the possibility that this was due to abnormal vitamin D metabolism by studying 10 normal premenopausal women (group A), 8 normal postmenopausal women within 20 yr of menopause (group B), 10 normal elderly women (group C), and 8 elderly women with hip fracture (group D) whose ages (mean +/- SD) were 37 +/- 4, 61 +/- 6, 78 +/- 4, and 78 +/- 4 yr, respectively. For all subjects, serum 25-hydroxyvitamin D [25(OH)D] did not decrease with age, but serum 1,25-dihydroxyvitamin D [1,25(OH)2D], the physiologically active vitamin D metabolite, was lower (P = 0.01) in the elderly (groups C and D; 20 +/- 3 pg/ml) than in the nonelderly (groups A and B; 35 +/- 4 pg/ml). The increase of serum 1,25(OH)D after a 24-h infusion of bovine parathyroid hormone fragment 1-34, a tropic agent for the enzyme 25(OH)D 1 alpha-hydroxylase, correlated inversely with age (r = -0.58; P less than 0.001) and directly with glomerular filtration rate (r = 0.64; P less than 0.001). The response was more blunted (P = 0.01) in elderly patients with hip fracture (13 +/- 3 pg/ml) than in elderly controls (25 +/- 3 pg/ml). We conclude that an impaired ability of the aging kidney to synthesize 1,25(OH)2D could contribute to the pathogenesis of senile osteoporosis.
PMCID: PMC437077  PMID: 6327768
13.  Rapid development of renal resistance to low doses of synthetic bovine parathyroid hormone fragment 1-34. Dissociation of urinary cyclic adenosine monophosphate, phosphaturic, and calciuric responses. 
Journal of Clinical Investigation  1983;72(3):1106-1113.
The designing of parathyroid hormone (PTH)-renal dose-response studies in human beings is complicated by the possibility of rapid homologous receptor down-regulation, a phenomenon that is clearly shown to occur in vitro. Large amounts of PTH given to human subjects as serial injections or prolonged infusions cause decreased urinary 3',5'-cyclic adenosine monophosphate (cAMP) responses to subsequent PTH doses, but it is uncertain whether lower doses given over shorter periods similarly cause renal tachyphylaxis to PTH action. Thus, in seven water-loaded adults, we infused in ascending order 10, 30, 75, 150, and 300 U of synthetic bovine PTH fragment 1-34 (bPTH 1-34) per 70 kg body wt over 15 min on widely separated days ("separate day administration"). On another day, each subject received all five 15-min doses in ascending order at 75-min intervals ("single day administration"). Urine collection intervals were control, 0-30 min (including the PTH infusion), and 30-60 min. Peak nephrogenous cAMP (NcAMP, nmol/100 ml glomerular filtrate) response was linearly related to the dose of PTH (separate day study, r = 0.94, P less than 0.001; single day study, r = 0.88, P less than 0.001). However, the slope of NcAMP responses plotted against PTH dose for the single day study was only 36% of that derived from separate day administration of the same PTH doses (P less than 0.001). After only 40 U (10 + 30) of bPTH 1-34/70 kg, the NcAMP response to 75 U was reduced 44%, and the effect of 300 U/70 kg, when given as the last of the sequential single day infusions, was 64% less than the response to 300 U of bPTH 1-34 given alone (P less than 0.001). The phosphaturic response (fractional excretion of phosphorus, FEP [percent]) was also linearly related to bPTH 1-34 dose, but combined administration of the PTH infusions on one day increased FEP at each dose identically with the effects of separate day administration. A transient, dose-related, early hypercalciuric response to bPTH 1-34 also occurred, and was of equal magnitude in both protocols. These studies demonstrate that significant blunting of the NcAMP response to bPTH 1-34 occurs rapidly and follows brief exposure to relatively low doses of hormone. In contrast, there is no effect of recent PTH administration on the phosphaturic and early hypercalciuric actions of bPTH 1-34. This seeming dissociation of PTH effects makes unclear the physiologic importance of PTH-induced cAMP tachyphylaxis in the regulation of final PTH actions. In any case, studies of NcAMP responses in which the occurrence of tachyphylaxis would be undesirable should be designed to avoid prolonged or closely spaced administrations of the hormone.
PMCID: PMC1129278  PMID: 6309905
14.  Biochemical genetics of tryptophan synthesis in Pseudomonas acidovorans. 
Journal of Bacteriology  1981;147(1):62-68.
Sixty independent tryptophan auxotrophs of Pseudomonas acidovorans were isolated and characterized for nutritional response to intermediates of the pathway, accumulation of intermediates, and levels of tryptophan-synthetic enzymes. Mutants for each of the seven proteins catalyzing the five steps of tryptophan synthesis were obtained. Transductional analysis established three unlinked chromosomal regions: trpE, trpGDC, and trpFBA. The order of the genes within the two clusters was not determined. The levels and enzymatic activities of wild-type and mutant strains indicated that trpE and trpGDC were repressed by tryptophan. In contrast, trpFBA was not derepressed significantly by starvation for tryptophan. The trpG mutants had an additional requirement for p-aminobenzoate, which suggested that anthranilate synthase subunit II also served as glutamine-binding protein in the analogous reaction catalyzed by p-aminobenzoate synthase. In addition, trpD mutants revealed the ability of P. acidovorans to degrade anthranilate via the beta-ketoadipate pathway.
PMCID: PMC216007  PMID: 7240095
15.  Production, degradation, and circulating levels of 1,25-dihydroxyvitamin D in health and in chronic glucocorticoid excess. 
Journal of Clinical Investigation  1980;66(4):664-669.
The decreased intestinal absorption of calcium and accelerated bone loss associated with chronic glucocorticoid excess may be mediated by changes in vitamin D metabolism, leading to decreased availability of circulating 1,25-dihydroxyvitamin D. This hypothesis was examined in 14 patients with either endogenous or exogenous glucocorticoid excess. Analysis of paired serum samples (mean +/- SE) in 13 patients during euglucocorticoidism and during hyperglucocorticoidism showed that glucocorticoid excess resulted in small decreases of plasma 25-hydroxy-vitamin D concentrations (22 +/- 2- 18 +/- 2 ng/ml; P < 0.05) but no significant changes in plasma 1,25-dihydroxyvitamin D (32 +/- 8- 23 +/- 6 pg/ml) or serum immunoreactive parathyroid hormone (21 +/- 2- 18 +/- 2 muleq/ml). Additionally, we studied plasma kinetics of [3H]1,25-dihydroxyvitamin D3 after intravenous bolus administration in 10 hyperglucocorticoid patients and in 14 normal controls. Assessment with a three-compartment model showed no significant abnormalities in production rates (hyperglucocorticoid patients 1.2 +/- 0.3 micrograms/d, controls 1.5 +/- 0.2 micrograms/d) or metabolic clearance rates (hyperglucocorticoid patients, 18 +/- 2%; controls, 14 +/- 2%) or feces (hyperglucocorticoid patients, 60 +/- 9%, controls, 54 +/- 6%). We conclude that glucocorticoid excess does not effect plasma levels, production, or degradation of 1,25(OH)2D in humans. Thus, other mechanisms must be postulated to explain satisfactorily the abnormalities of bone structure and intestinal calcium absorption that may occur after chronic glucocorticoid therapy.
PMCID: PMC371639  PMID: 7419714
16.  Metabolism of carbohydrate derivatives by Pseudomonas acidovorans. 
Journal of Bacteriology  1979;138(2):418-424.
Wild-type Pseudomonas acidovorans strain A1 was unable to grow on glycerol or glucose as sole source of carbon and energy although it grew well on gluconate. Spontaneous glycerol-positive mutants, which apparently had become permeable to glycerol, were readily isolated, but glucose-positive mutants did not occur. P. acidovorans lacked glucose dehydrogenase and glucokinase, which were sufficient to account for its inability to grow on glucose. Gluconate was degraded exclusively via a noncoordinately induced Entner-Doudoroff pathway. Phosphogluconate dehydrogenase was undetectable. In contrast to P. aeruginosa, P. acidovorans possessed a single glyceraldehyde-phosphate dehydrogenase activity, which was NAD+ specific and constitutive, and an inducible pyruvate kinase. Moreover, growth of glycerol-positive strain K2 on glycerol did not induce any of the enzymes related to metabolism of hexosephosphate derivatives as occurs in fluorescent pseudomonads.
PMCID: PMC218193  PMID: 220214
17.  Relationship between catabolism of glycerol and metabolism of hexosephosphate derivatives by Pseudomonas aeruginosa. 
Journal of Bacteriology  1978;136(2):638-646.
The relationship between catabolism of glycerol and metabolism of hexosephosphate derivatives in Pseudomonas aeruginosa was studied by comparing the growth on glycerol and enzymatic constitution of strain PAO with these characteristics of glucose-catabolic mutants and revertants. Growth of strain PAO on glycerol induced a catabolic oxidized nicotinamide adenine dinucleotide-linked glyceraldehyde-phosphate dehydrogenase and seven glucose-catabolic enzymes. The results indicated that these enzymes were induced by a six-carbon metabolite of glucose. All strains possessed a constitutive anabolic Embden-Meyerhof-Parnas pathway allowing limited conversion of glycerol-derived triosephosphate to hexosephosphate derivatives, which was consistent with induction of these enzymes by glycerol. Phosphogluconate dehydratase-deficient mutants grew on glycerol. However, mutants lacking both phosphogluconate dehydrogenase and phosphogluconate dehydratase were unable to grow on glycerol, although these strains possessed all of the enzymes needed for degradation of glycerol. These mutants apparently were inhibited by hexosephosphate derivatives, which originated from glycerol-derived triosephosphate and could not be dissimilated. This conclusion was supported by the fact that revertants regaining only a limited capacity to degrade 6-phosphogluconate were glycerol positive but remained glucose negative.
PMCID: PMC218589  PMID: 101528
The Journal of General Physiology  1948;31(3):249-258.
1. Paramecium caudatum is sensitized to heat by sublethal dosages of x-rays. Thus if paramecia are irradiated, then exposed to a sublethal dosage of heat they are killed, but if the same heat exposure precedes the same dosage of radiations, they are not. 2. Sensitivity to both heat and x-rays is much greater in paramecia from the log growth phase than in those from the stationary phase of a culture. 3. Recovery from heat sensitization in animals from the stationary phase of a culture is slow, requiring several days. 4. Division is readily retarded and even temporarily inhibited by sublethal dosage of x-rays. Recovery of the division rate is fairly slow requiring several days. 5. Paramecia can be killed by a dosage of 1,200,000 r (of which about one-half reach the animal) units of x-radiation alone. Smaller dosages are not lethal if the paramecia are transferred to fresh medium immediately upon completion of irradiation. 6. The possibility of utilization of heat sensitization in treatment of malignant growths is discussed.
PMCID: PMC2147107  PMID: 18920613
20.  Ether Clonus treated by Hexobarbitone Soluble 
British Medical Journal  1943;2(4324):646.
PMCID: PMC2285402  PMID: 20785136

Results 1-20 (20)