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Biomedical subjects

J Katz

Publications and source records attributed to J Katz.

At least 343 records · Page 19Linked to original sources
PubMed1993

Protective salivary immunoglobulin A responses against Streptococcus mutans infection after intranasal immunization with S. mutans antigen I/II coupled to the B subunit of cholera toxin.

The B subunit of cholera toxin (CTB) has been shown to augment mucosal responses to microbial virulence antigens, including those of Streptococcus mutans, which is the principal etiologic agent of dental caries. In the present study, the surface fibrillar protein antigen of S. mutans, antigen I/II (Ag I/II), was chemically coupled to CTB (Ag I/II-CTB), and the conjugate was examined for its effectiveness in inducing salivary immune responses protective against S. mutans infection. Weanling Fischer rats were given Ag I/II-CTB (50 micrograms) by the intranasal route and then orally infected with a virulent strain of S. mutans. Gnotobiotic or conventional rats were given two or three additional immunizations, respectively, at about 2-week intervals. One week after each immunization, individual serum, saliva, and fecal samples were collected and stored frozen until assayed for antibody activity to Ag I/II and cholera toxin (CT) by an enzyme-linked immunosorbent assay. The rats were sacrificed 1 week after the last immunization, when mandibles were also collected from individual rats for assessment of S. mutans levels in plaque and caries activity. Rats immunized only or both immunized and infected showed a salivary immunoglobulin A (IgA) anti-Ag I/II response which reached significantly (P < 0.05) higher levels than those seen in nonimmunized, infected controls. A salivary IgA anti-Ag I/II response was also seen in rats infected only with S. mutans. Essentially no salivary antibody activity to CT was detected. Some serum anti-Ag I/II and anti-CT responses were seen in immunized animals. Serum IgG anti-Ag I/II responses were seen in immunized, infected rats and also in infected-only rats, suggesting that the responses were a result of infection with S. mutans. The immunized and infected rats had significantly (P < 0.05) lower levels of S. mutans in plaque and lower caries activity than nonimmunized, infected rats. These results indicated that intranasal immunization of rats with Ag I/II-CTB induced a protective salivary immune response which was associated with a reduction in S. mutans colonization and S. mutans-induced dental caries.

Animals↗
PubMed1993

Comparison of nucleic acid hybridization and nucleic acid amplification using conserved sequences from the 5' noncoding region for detection of bovine viral diarrhea virus.

Primers and probes derived from conserved sequences located in the 5' noncoding region of pestiviruses were evaluated for detection of bovine viral diarrhea virus. With these reagents, hybridization and polymerase chain reaction tests detected 62 of 90 and 90 of 90 bovine viral diarrhea virus isolates, respectively. A quick lysis method for preparing RNA for use in polymerase chain reaction amplification also was evaluated.

Animals↗
PubMed1993

Postoperative pain: the effect of low-dose ketamine in addition to general anesthesia.

In a randomized, double-blind study, postoperative pain was assessed in 22 patients undergoing elective open cholecystectomy with two types of anesthesia: standardized general anesthesia (control group), and low-dose ketamine as an addition to the same method of general anesthesia, before surgical incision (ketamine group). After the operation we found that the time from the end of surgery to the first request for analgesic was longer in the ketamine group. Postoperatively, patients in both groups were treated with patient-controlled analgesia (PCA) in exactly the same way. The major difference in the study was the reduced dose requirement of morphine in the ketamine group compared with the control group after the operation. The mean dose of morphine given in patients of the control group during the first 24 h was 48.7 mg vs 29.5 mg in the ketamine group. Mean visual analog scale (VAS) and verbal rating scale (VRS) were higher in patients in the control group during the first 5 h after surgery (P < 0.02), but between 5 and 24 h after surgery VAS and VRS were not significantly different (P > 0.05). Our results indicate that postoperative pain can be decreased when ketamine in low doses is added to general anesthesia before surgical stimulation.

Adult↗
PubMed1993

Automated suprathreshold screening for glaucoma: the Baltimore Eye Survey.

PURPOSE: To evaluate automated suprathreshold perimetric screening for glaucoma in a population-based survey of ocular disorders in east Baltimore, Maryland. METHODS: A population-based sample of persons > or = 40 years of age residing in 16 clusters was selected for an ocular screening examination that included automated suprathreshold testing with the Full Field 120 program of the Humphrey Field Analyzer. Subjects who failed the test underwent manual testing to confirm the defect. Subjects were referred for definitive examination by an ophthalmologist if they had an abnormal field, visual acuity worse than 20/30, intraocular pressure > 21 mm Hg, optic disc damage, a history of glaucoma, or shallow angles. The sensitivity and specificity of the automated visual field testing for identifying glaucoma was estimated and compared with other methods to screen for glaucoma. RESULTS: Of 5,341 subjects > or = 40 years of age who underwent a screening eye examination at neighborhood centers, 4,735 (89%) completed the automated field test. The median test time was 7.25 minutes per eye. Screening test results were abnormal in one or both eyes in 1,234 (26%) of the subjects. Kinetic perimetry was performed on 95% of these subjects, and defects were confirmed for 448 (36%) of them. Hence, 9.5% of the 4,735 subjects who completed the automated test were referred for definitive examination because the defect on automated perimetry was confirmed on manual testing. For a specificity of 90%, the sensitivity of the screening visual field test to detect glaucoma was 52% for 17 or more relative or absolute defects, higher than that of intraocular pressure at 39% for a cut-off of 20.5 mm Hg, vertical cup-to-disc ratio at 45% for a cut-off of 0.53, narrowest remaining rim width at 42% for a cut-off of 0.16, and was comparable to a combination of these and other nonfield parameters. CONCLUSION: Suprathreshold testing performed better than nonperimetry-based screening tests for glaucoma. However, a number of logistical weaknesses of this visual field screening method were identified.

Adult↗
PubMed1992

Motive to sin.

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Humans↗
PubMed1992

Quantitation of positional isomers of deuterium-labeled glucose by gas chromatography/mass spectrometry.

A method for determining the site and extent of deuterium (D) labeling of glucose by GC/MS and mass fragmentography was developed. Under chemical and electron impact ionization, ion clusters m/z 328, 242, 217, 212, and 187 of glucose aldonitrile pentaacetate and m/z 331 and 169 of pentaacetate derivative were produced. From the mass spectra of 13C- and D-labeled reference compounds, glucose carbon and hydrogen (C-H) positions included in these fragments were deduced to be m/z 328 = C1-C6, 2,3,4,5,6,6-H6; m/z 331 = C1-C6, 1,2,3,4,5,6,6-H7; m/z 169 = C1-C6, 1,3,4,5,6,6-H6; m/z 187 = C3-C6, 3,4,5,6,6-H5; m/z 212 = C1-C5, 2,3,4,5-H4; m/z 217 = C4-C6, 4,5,6,6-H4; and m/z 242 = C1-C4, 2,3,4-H3. After correction for isotope discrimination and deuterium-hydrogen exchange, the D enrichment of these fragments can be quantitated using selective ion monitoring, and the D enrichment of all C-H positions can be obtained by the difference in enrichment of the corresponding ion pairs. The validity of this approach was tested by examining D enrichment of known mixtures of 1-d1-, 2-d1-, 3-d1-, and 5,6,6-d3-glucose with unlabeled glucose and D enrichment of perdeuterated glucose using these fragments. This method was used to determine deuterium incorporation in C1 through C6 of blood glucose in fasted (24 h) rats infused with deuterated water. The distribution of deuterium was similar to that found by Postle and Bloxham (1980, Biochem. J. 192, 65-73). Approximately one deuterium atom was incorporated into C5 and only 75% deuterium atom was incorporated into C2. The enrichment of C2 and C6 of glucose relative to that of water indicated that 74 +/- 9% of plasma glucose was newly formed 4 h after the onset of deuterium infusion, and gluconeogenesis accounted for about 76 +/- 7% of the glucose 6-phosphate flux.

Animals↗
PubMed1992

Esterase-1: developmental expression in the mouse and distribution of related proteins in other species.

Esterase 1 (Es-1) is a sexually dimorphic 65-kDa glycoprotein present in plasma and other murine tissues able to hydrolyze a variety of esters including fatty acid esters of estradiol. Like most other carboxylesterases, its function is unknown. To gain insight into the function of Es-1 and by analogy other carboxylesterases, we have examined the developmental regulation of Es-1 in the mouse and have looked for the presence of related proteins in the plasma of other species. Northern blot analysis of total RNA from the livers of mice of various ages using a 32P-labeled 470-bp Es-1 cDNA probe showed clear postpartum induction with no detectable Es-1 mRNA in fetal liver. Similarly, immunoblotting after sodium dodecyl sulfate-polyacrylamide gel electrophoresis with an affinity-purified rabbit antibody to Es-1 showed no cross-reacting proteins in the plasma until after birth. Northern blot analysis of total RNA from a variety of adult mouse tissues showed the presence of substantial levels of Es-1 mRNA only in liver with lower levels in kidney, testes, and ovaries. Liver mRNA and plasma protein levels rose in parallel attaining full adult levels between 15 and 20 days of age. When plasma proteins were electrophoresed on 7% polyacrylamide gels under nondenaturing conditions, the antibody to Es-1 recognized a low mobility protein in mouse, rat, human, baboon, guinea pig, bovine, horse, and canine but not in chicken plasma. Consistent with the immunoblotting results, the Es-1 cDNA probe hybridized to restriction fragments from human, monkey, rat, and rabbit as well as mouse genomic DNA but not from chicken DNA indicating conservation of the esterase (or esterase-like) gene in mammalian species. The low mobility antigens in mouse and human plasma appeared also to cross-react with antibodies to human thyroglobulin, although antibodies to human thyroglobulin did not appear to recognize Es-1 under these conditions.

Aging↗
PubMed1992

Why cheat?

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Fraud↗
PubMed1992

Thrombospondin levels in patients with malignancy.

Thrombospondin (TSP), a large glycoprotein present in platelets, and various normal and tumor tissues, has recently been shown to promote cell adhesion and platelet aggregation. Most importantly because TSP has been shown to promote metastasis of melanoma tumor cells to the lung in a murine model (1) and since thromboembolic events commonly occur in patients afflicted with metastatic tumors, we explored the role of TSP in human cancer by measuring TSP blood levels in patients with various malignant neoplasms. Blood TSP levels were measured by indirect enzyme-linked immunoadsorbent assay (ELISA) from 20 control subjects, 22 patients with gastrointestinal (GI) cancer, 18 patients with breast cancer, and 17 patients with lung cancer. Control subjects consisted both of healthy subjects and acutely ill patients with no malignancies. TSP levels of both healthy and acutely ill controls were found to range between 245-440 ng/ml with a mean of 365 ng/ml. In contrast, elevated levels of TSP greater than the mean value of 400 ng/ml for controls ranging between 590-3,650 ng/ml were found in 20/22 (91%) patients with GI malignancies, 13/18 (72%) patients with breast cancer, and 15/17 (88%) with lung cancer. Mean TSP levels of GI, breast, and lung cancer patients were 3, 2, and 3 fold greater than controls, respectively. Increased blood TSP levels in patients were not due to increased levels of platelets since both control and patient groups had platelet counts within the normal range. These results suggest that TSP may play a role in tumor cell metastasis in man and could serve as a blood marker for metastasis.

Adult↗
PubMed1992

Left ventricular dimensions and mass using magnetic resonance imaging in female endurance athletes.

Few published studies of left ventricular (LV) mass in female endurance athletes have been performed with M-mode echocardiography, which involves assumptions of LV geometry. Therefore, magnetic resonance imaging, a 3-dimensional technique, was used to examine LV mass, LV end-diastolic volume and mean wall thickness in female long distance runners (n = 13; mean age 29 years), cyclists (n = 12; mean age 26 years) and cross-country skiers (n = 11; mean age 24 years), and the findings were compared with sedentary control subjects (n = 10; mean age 27 years) matched for height and body weight. The physical characteristics for all subjects included height (mean 166 cm, and body weight (mean 56 kg). The percent body fat (mean 11.7) and maximal oxygen uptake (VO2max, mean 63 ml.kg-1.min-1) were similar (p greater than 0.05) among all athletic groups, but significantly different from the control group (body fat, mean 22.5%; VO2max, mean 35 ml.kg-1.min-1). LV mass (mean 159 kg), LV end-diastolic volume (mean 122 ml), and mean wall thickness (mean 11.5 mm) were also similar among the athletic groups and significantly larger than the following control values: LV mass (mean 115 g), LV end-diastolic volume (mean 93 ml) and mean wall thickness (mean 9.8 mm). Ratios of LV mass to lean body weight were similar among all athletic groups, although athletic groups had larger ratios (p less than 0.05) than the sedentary control subjects. LV mass/LV end-diastolic volume ratio was similar (p greater than 0.05) among all groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of Variance↗
PubMed1992

The increased risk of ulcerative keratitis among disposable soft contact lens users.

Previous controlled studies on contact lens-associated ulcerative keratitis were performed before the widespread use of disposable contact lenses. Therefore, a controlled study was undertaken to determine the relative risk of ulcerative keratitis among users of disposable soft contact lenses compared with the risk among users of other lens types. Forty-six consecutive cases of contact lens-associated ulcerative keratitis were identified between January 1990 and June 1992 at a corneal specialty practice in western Michigan. Five controls, matched to each case patient according to the dispensing data and prescribing practitioner, were obtained for 42 cases (91%). Users of daily-wear rigid gas-permeable lenses had the lowest risk of developing ulcerative keratitis. Relative to users of daily-wear soft contact lenses, users of extended-wear soft contact lens had an age-adjusted and sex-adjusted relative risk of 1.87 (95% confidence interval, 0.61 to 5.71). Disposable soft contact lens users had the highest risk of developing ulcerative keratitis, with an adjusted relative risk of 14.16 (95% confidence interval, 5.47 to 37.63) compared with daily-wear soft contact lens users and 7.66 (95% confidence interval, 2.27 to 25.83) compared with conventional extended-wear soft contact lens users.

Acanthamoeba Keratitis↗
PubMed1992

Prenatal diagnosis of tetrasomy 12p by in situ hybridization: varying levels of mosaicism in different fetal tissues.

Prenatal diagnosis of tetrasomy 12p is complicated by the discrimination of the 12p isochromosome from the duplication 21q as well as the level of mosaicism demonstrated in the particular tissue sampled. In this disease, a high percentage of chromosomally abnormal cells are generally found in fibroblastic cells, but lymphocyte karyotypes from the same individual may be normal. We report on the pregnancy of a 37-year-old female who presented to our centre at 16 weeks' gestation for genetic amniocentesis. Sonography of the fetus revealed dextrocardia and diaphragmatic hernia. Chromosome analysis of amniocytes demonstrated mosaicism of a 47,XY,+i(12p) line in 80 per cent of cells and a normal male line (20 per cent), consistent with the Pallister-Killian syndrome. Following termination, a 220 g male fetus of 18 weeks was examined. A flattened nose and low-set ears were noted. In situ hybridization with a chromosome 12 centromeric probe in lymphocytes and skin cells unequivocally confirmed the karyotype and showed the presence of a single centromere in the abnormal chromosome, suggesting a true isochromosome. Chromosome analysis of various fetal tissues was performed and the following percentages of abnormal cells were found: skin 100 per cent, chorion 50 per cent, placenta 30 per cent, and blood 80 per cent. The high frequency of tetrasomic cells in fetal blood at this early gestational age is noteworthy, since most reports of this syndrome show a very low percentage of abnormal cells postnatally.

Adult↗
PubMed1992

Liposomes and conjugate vaccines for antigen delivery and induction of mucosal immune responses.

In this brief review, emphasis was placed on the effectiveness of liposomes as carriers/vehicles of soluble antigens and as adjuvants for use in oral vaccine development. Evidence was provided that oral administration of antigen in liposomes resulted in a mucosal response which was higher than that obtained when the oral vaccine consisted of antigen alone. Specific mucosal responses were enhanced by incorporating lipophilic MDP into the antigen/liposome vaccines. Antigens shown to be effective in inducing a protective mucosal response when given in an oral liposome vaccine were anti-idiotypic antibodies, purified S. mutans GTF, CHO and Ag I/II. Evidence is also provided that CTB may be an effective oral adjuvant when coupled to proteins or peptides by either chemical or genetic methods. Further studies, however, will be required to characterize the effectiveness and safety of CTB in conjugate vaccines for inducing specific mucosal responses and to develop practical means to prepare oral liposome vaccines for use in humans.

Animals↗
PubMed1992

Use of esterase inhibitors and zone electrophoresis to define bacterial esterases in amniotic fluid.

OBJECTIVE: The purpose of our study was to define further the role of bacterial esterases in amniotic fluid obtained from women with chorioamnionitis. STUDY DESIGN: Amniotic fluid samples from 39 patients with chorioamnionitis were submitted for bacterial cultures and in vitro assay. Esterase inhibitors diisopropyl fluorophosphate and iodoacetic acid were added and the degree of inhibition calculated. These results were compared with the amniotic fluid culture results. Chi square analysis was performed to compare the results of the esterase assay and the inhibition assay between the uninfected and infected amniotic fluid samples. RESULTS: Thirty-one patients had positive bacterial cultures, with 21 being infected with gram-negative organisms. All samples showed significant inhibition (range 55% to 82%) with diisopropyl fluorophosphate. There was partial inhibition with iodoacetic acid (range 10% to 30%) in the gram-negative samples but no inhibition in the gram-positive and uninfected samples. Six infected and two uninfected samples were analyzed by using zone electrophoresis with human plasma as a control. Minimal esterase motility was noted in the amniotic fluid samples as compared with that in plasma. CONCLUSION: The esterases in amniotic fluid appeared to be of bacterial, not human, origin. Furthermore, different groups of bacteria appeared to produce different esterases in infected amniotic fluid.

Amniotic Fluid↗
PubMed1992

Esterase activity in human breast cyst fluid: associations with steroid sulfates and cations.

Human breast cyst fluid (BCF) contains an esterase that on the basis of electrophoretic mobility and response to inhibitors differs from those found in the plasma. From a total of 384 BCF samples analyzed for esterase using p-nitrophenyl hexanoate as substrate, 149 (39%) showed significant activity. The samples had been analyzed for the concentrations of the sulfates of estrone, estriol, dehydroepiandrosterone, as well as the potassium and sodium cations (K+/Na+). The data were submitted to statistical analysis using the Spearman rank order test. The esterase-positive samples exhibited a significant positive association with each of the steroid sulfates and the K+/Na+ ratios. Except for protein concentration, there was no significant correlation between the esterase-positive and esterase-negative cysts. These observations may have physiological significance in that high K+/Na+ ratio cysts have been related to the histological status of the cyst.

Biomarkers↗