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Biomedical subjects

B Herz

Publications and source records attributed to B Herz.

12 recordsLinked to original sources
PubMed1998

A small protein (Ags1p) and the Pho80p-Pho85p kinase complex contribute to aminoglycoside antibiotic resistance of the yeast Saccharomyces cerevisiae.

We identified the AGS1 and AGS3 genes by their ability to partially complement an ags mutant (RC1707) which is supersensitive to various aminoglycoside antibiotics (J. F. Ernst and R. K. Chan, J. Bacteriol. 163:8-14, 1985). AGS1 is located in proximity to the centromere of chromosome III and encodes a small protein of 88 amino acids. The size of the AGS1 transcript, which in wild-type cells is 1 kb, is reduced to 0.75 kb in mutant RC1707. Disruption of AGS1 rendered strains supersensitive to hygromycin B and increased their resistance to vanadate. In addition, ags1delta strains underglycosylated invertase but had normal carboxypeptidase Y glycosylation, suggesting that Ags1p is required for the elaboration of outer N-glycosyl chains. AGS3 was found to be identical to PHO80 (TUP7), which encodes a cyclin activating the Pho85p protein kinase. Deletion of either PHO80 or PHO85 led to aminoglycoside supersensitivity; pho80delta ags1delta strains showed an enhanced-sensitivity phenotype compared to single mutants. pho80 and pho85 mutants were rendered resistant by deletion of PHO4, indicating that activation of the Pho4p transcription factor is required for increased aminoglycoside sensitivity. Thus, both the Pho80p-Pho85p kinase complex (by Pho4p phosphorylation) and a novel component of the N glycosylation pathway contribute to basal levels of aminoglycoside resistance in Saccharomyces cerevisiae.

Amino Acid Sequence↗
PubMed1997

Noninvasive quantification of muscle oxygen in subjects with and without claudication.

The disabling pain of intermittent claudication (IC) arises from oxygen deprivation in the lower limbs during walking. Measurement of the oxygen deficiency within the limb tissue now appears possible with recently expanded understanding of the photon transport through tissue for photons in the visible and near infrared range. Noninvasive measurement consists of preferentially measuring photons that have traveled more deeply into limb tissues and that, therefore, may reach locations of ischemic tissue. Oxygen measurements appear to be possible up to a depth approaching 1.5 cm beneath the surface of the skin. The present study reports on data acquired from the limbs of 11 subjects with IC and 12 subjects without IC. The subjects with IC are patients with clinical findings of claudication based upon segmental Doppler pressure profiles and subjective reports by the patient of pain during exercise. The subjects without IC are individuals with no prior history of ischemic vascular disease. The results consist of photon reflectance measurements at red and infrared wavelengths (approximately 660 nm and 880 nm respectively) taken before, during, and after exercise. Infrared reflectance indices are plotted as well as oxygenation indices generated from combining red and infrared reflectances. A compilation of exercise data shows responses that are generally consistent with the expected physiological responses to mild exercise in subjects with and without IC. We anticipate that the findings of this study may lead to an objective noninvasive testing procedure for measuring the ischemic and exercise-induced changes in muscle oxygenation in the presence of claudication. If the testing of ischemic hypoxia continues to show consistency and accuracy in determining the disability of the subjects with IC, future studies can more effectively test modes of conservative management, such as cessation of smoking, alternative exercise regimens, weight loss, and alternative pharmacological agents.

Exercise↗
PubMed1996

Detection of Clonal Rearrangement of the T-cell Receptor Gamma Gene by Polymerase Chain Reaction and Single-strand Conformation Polymorphism (PCR-SSCP).

Background: Diagnosis of T-lymphoid neoplasms frequently requires molecular studies of T-cell receptor (TCR) gene rearrangements. The Southern blot technique traditionally used for these analyses lacks the sensitivity and speed necessary for the routine clinical laboratory. The authors have developed a method using polymerase chain reaction (PCR) amplification with single-strand conformation polymorphism (SSCP) analysis that is rapid, sensitive, and semiautomated. Methods and Results: Polymerase chain reaction of the TCR gamma gene is done with consensus primers to the V and J regions. Amplicons thus include the N region, which serves as a marker of clonal T-cell population. Clonal populations having identical N-region sequences are identified by SSCP analysis, using a semiautomated electrophoresis system with silver staining for gel visualization. A series of 46 DNA samples from normal controls and various hematopoietic malignancies was comparatively analyzed by both Southern blot of the TCR beta locus and PCR-SSCP of the of the TCR gamma gene. The PCR-SSCP technique was rapid and reproducible, and detected clonal T-cell populations constituting 1% of the cell sample: The PCR-SSCP technique detected clones in eight cases that were negative by Southern blot. Conclusions: PCR-SSCP analysis of the TCR gamma gene is a rapid and sensitive method for the detection of clonal T-cell populations.

Journal Article↗
PubMed1996

Molecular detection of prostate epithelial cells from the surgical field and peripheral circulation during radical prostatectomy.

PURPOSE: Prostate cancer progression despite organ confined pathological assessment has been reported in a variable number of men after radical retropubic prostatectomy. To study this phenomenon, we used the prostate specific antigen (PSA) reverse transcriptase-polymerase chain reaction assay. MATERIALS AND METHODS: We prospectively assayed the peripheral venous blood before, during and after surgical manipulation as well as the intraoperative field blood for PSA reverse transcriptase-polymerase chain reaction-positive cells in 22 men undergoing radical retropubic prostatectomy. RESULTS: PSA reverse transcriptase-polymerase chain reaction-positive cells were identified in 20 of the 22 operative field samples (91%) and 4 of 16 (25%) had evidence of intraoperative hematogenous dissemination (p = 0.046). No significant association was identified among Gleason score, pathological stage and the PSA reverse transcriptase-polymerase chain reaction result. CONCLUSIONS: Our results suggest that tumor cell spillage and less frequently hematogenous dissemination may be associated with operative manipulation of the prostate during radical retropubic prostatectomy and may potentially represent mechanisms of failure after radical retropubic prostatectomy.

Adenocarcinoma↗
PubMed1994

Laparoscopic gastrojejunostomy: a case presentation.

Laparoscopic gastrojejunostomy is demonstrated as an alternative to open gastric bypass procedures. We performed the operative procedure safely and with reasonable anesthesia time, using stapling devices. It is hoped that further patient benefit will be obtained from this laparoscopic procedure in the future.

Adenocarcinoma↗
PubMed1988

Stercoral perforation of the colon: report of a new location.

Stercoral perforations of the colon unassociated with obstructive lesions are rarely reported. With the exception of one case report which described a stercoral perforation of the cecum, all the reported perforations occurred at the sigmoid or rectosigmoid colon. This report describes a new location of perforation which hitherto has not been reported.

Aged↗
PubMed1987

Diagnosis of arylsulfatase A deficiency in intact cultured cells using a fluorescent derivative of cerebroside sulfate.

A fluorescent derivative of cerebroside sulfate (12-(1-pyrene)dodecanoyl-sphingosylgalactosyl-0-3-sulfate (P12-sulfatide) has been synthesized as a potential substrate for the determination of cerebroside sulfatidase (or arylsulfatase A) activity. It was administered into cultured human skin fibroblasts and thereby utilized for the diagnosis of arylsulfatase A deficiency. Cultured skin fibroblasts from normal individuals and healthy persons suffering from a pseudoarylsulfatase A deficiency (PD) degraded the P12-sulfatide, while in cells derived from a metachromatic leukodystrophy (MLD) patient it remained essentially intact. This contrasts with in vitro determinations of enzymatic activity, where the MLD or PD-derived arylsulfatase A exhibit similar deficiency, in spite of a profoundly different clinical course. Administration of the fluorescent sulfatide into the intact cells permitted a sensitive and rapid diagnosis of MLD and its distinction from the PD-phenomenon. This might be of particular importance for cases in which a rapid diagnosis is required and for prenatal diagnosis of fetuses from families afflicted with both MLD and pseudo-deficiency mutant genes.

Cell Line↗
PubMed1984

Arylsulfatase A in pseudodeficiency.

Arylsulfatase A (ASA) is found to be deficient in healthy individuals (pseudo arylsulfatase A deficiency) who usually show in vitro ASA levels in the range of metachromatic leukodystrophy patients. The in vitro properties of ASA in pseudodeficiency were studied in cultured fibroblasts. The residual ASA activity showed apparent Km with the synthetic substrate (2.6 mM), pH optimum of activity (pH 5.0), and sensitivity to heat denaturation at 65 degrees C (T1/2, 10 min) similar to those found in controls. To test whether the low in vitro activity is a result of extreme sensitivity to the homogenization procedure, cells were disrupted by five different techniques, including rapid freezing and thawing, hand homogenization, ultrasonication, mild osmotic shock, and nitrogen cavitation; all yielded similar ASA ratio of the pseudodeficient to control. The use of antiproteases phenylmethylsulfonyl fluoride and leupeptin did not affect the residual ASA activity in the pseudodeficient line. These results imply that the ASA that is formed in this condition has properties similar to those of the normal hydrolase, so that even if it is synthesized in lower amounts, it is still sufficient to promote normal catabolism of sulfatide. Screening for ASA activity in lymphocyte extracts of a random sample of 250 individuals revealed 7 individuals with enzyme level in the MLD heterozygote range or lower. These individuals apparently represent homozygosity for pseudodeficiency (pd/pd). This implies that the frequency of the pseudodeficient allele is about 15% in the general population, leading to polymorphism of the ASA.

Adult↗
PubMed1984

Nutritional support in a general urological service.

A nutritional support team was used in the assessment and management of patients on a general urological service. Indications for nutritional evaluation included history of weight loss, anorexia, significant infection, chronic neoplastic disease, trauma or major surgery. The fat and protein status of the patient was assessed by anthropomorphic and laboratory determinations. The patient then was categorized as having mild, moderate or severe degrees of nutritional depletion. Deficiencies in vitamins, trace elements or essential fatty acids were not noted. Caloric and protein needs were calculated by multiplication of the basal energy expenditure by a metabolic activity factor, which was derived from the degree of illness or stress. Nutritional support was provided by enteral feedings via oral, nasogastric or jejunal feeding tubes and/or intravenous hyperalimentation via peripheral or central venous nutrient lines. During a 6-month interval nutritional consultation was requested for 50 patients, who represented 7 per cent of the urological admissions. Nutritional support was provided for patients who had obstructive uropathy with or without neoplasms, radiation cystitis, sepsis, urinary fistulas, mental depression, end stage renal disease or neurological dysfunction. In patients in whom urological treatment controlled the disease nutritional support maintained the weight, and stabilized serum albumin and lymphocyte counts. We concluded that a nutritional support program has a significant and, often, unappreciated role in the management of urological patients.

Aged↗
PubMedDate not supplied

Randomized, prospective comparison of cefoxitin and gentamicin-clindamycin in the treatment of acute colonic diverticulitis.

In a randomized, prospective study, single-drug antibiotic therapy with cefoxitin (CFX) was compared to combination therapy with gentamicin and clindamycin (G/C) as definitive treatment for acute colonic diverticulitis. Excluding individuals requiring immediate operation, 51 patients with a clinical diagnosis of diverticulitis, who were hospitalized at five different medical centers, were randomized to receive CFX (30 patients) or G/C (21 patients). Age, sex, and the severity of diverticulitis were similar in the two groups. The cure rates of 90% and 85.7% observed for CFX and G/C, respectively, did not differ significantly. Leukocytosis resolved in a shorter time period in patients treated with CFX than in those treated with G/C (2.5 +/- 0.4 vs 4.1 +/- 0.6 days, respectively) (P = 0.03, Student's t test, unpaired data). Two cases of possibly antibiotic-related toxicity occurred in the CFX group versus three cases in the G/C group. The average cost of a course of CFX therapy was $417 compared with $488 for G/C. In this study, cefoxitin demonstrated efficacy and tolerability similar to that of gentamicin-clindamycin in the treatment of acute colonic diverticulitis and may be preferred in view of its narrower antimicrobial spectrum and lower cost.

Acute Disease↗