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Biomedical subjects

J M Joseph

Publications and source records attributed to J M Joseph.

At least 55 records · Page 3Linked to original sources
PubMed1989

Clinical experience with electroneurography in the pediatric patient.

Electroneurography (ENoG) has demonstrated utility in adults with facial nerve paralysis. We wished to evaluate the possible usefulness of this test in children. Twenty-six patients, aged 3 months through 16 years, were studied. Initial measurements were obtainable in all but two patients; they were successfully tested on a second attempt. All subsequent patient testing efforts were completed, for an overall successful test rate of 95%. Waveform amplitude and morphology were consistent with adult values, except in infants. The most clinically helpful use of this test was to objectively assess facial nerve function, once spontaneous motion was lost in acquired paralysis or if it had never been seen in congenital paralysis. Surprisingly, analysis of the "normal" side of the face proved most informative for three patients. Use of the test as an absolute predictor for return of function is not possible; however, the ENoG results add data that can be incorporated into the clinical information to make such predictions more rational. We conclude that ENoG can be performed on children, and that the measurements, within bounds of interpretation, can offer objective data not usually available in this age population.

Action Potentials↗
PubMed1988

Direct detection of Chlamydia trachomatis in clinical specimens by a dot-immunobinding technique using monoclonal antibody.

A dot-immunobinding technique (DIBT) has been developed to permit detection of Chlamydia trachomatis organisms or antigen in clinical specimens. This method was evaluated for the rapid diagnosis of chlamydia infections using monoclonal antibody. The membrane antigen extracted from reticulate bodies was used for the production of species-specific monoclonal antibodies by an in vitro immunization procedure. The DIBT involved spotting clinical specimen directly onto a nitrocellulose membrane followed by reaction with monoclonal antibody and a biotin-avidin-peroxidase indicator system. Specimens were tested for the presence of chlamydia by the cell culture method. Of these, 361 positives and 317 negatives were selected for detection of antigen using the DIBT method. Of 678 clinical specimens that were evaluated by DIBT, 654 (96.7%) gave identical results to the cell culture method, whereas 24 (3.5%) were positive by the DIBT but culture negative. The overall sensitivity was 100% with a specificity of 92.4%. The test could detect as little as 75 pg of chlamydial antigen.

Animals↗
PubMed1988

Effect of the fatty acid oxidation inhibitor 2-tetradecylglycidic acid (TDGA) on glucose and fatty acid oxidation in isolated rat soleus muscle.

1. The effect of 2-tetradecylglycidic acid (TDGA), a potent, specific inhibitor of long-chain fatty acid oxidation, on fatty acid and glucose oxidation by isolated rat soleus muscle was studied. 2. TDGA inhibited [1-14C]palmitate oxidation by soleus muscle in a concentration-dependent manner. 3. TDGA inhibited the activity of soleus muscle mitochondrial carnitine palmitoyltransferase A (CPT-A). 4. Added palmitate (0.5 mM) significantly inhibited D-[U-14C]glucose oxidation and, under conditions where TDGA inhibited palmitate oxidation, the oxidation of D-[U-14C]glucose by isolated soleus muscle was significantly stimulated. 5. TDGA stimulation of glucose oxidation was reversed by octanoate, a medium-chain fatty acid whose oxidation is not inhibited by TDGA. 6. When nondiabetic rats were treated with TDGA (10 mg/kg p.o./day x 3 days), fasting plasma glucose was significantly lowered and the ability of isolated contralateral soleus muscles to oxidize palmitate was inhibited while glucose oxidation was significantly stimulated.

Animals↗
PubMed1988

Hypoglycaemic and hypoketonaemic effects of single and repeated oral doses of methyl palmoxirate (methyl 2-tetradecylglycidate) in streptozotocin/alloxan-induced diabetic dogs.

1. The hypoglycaemic and hypoketonaemic effects of orally administered methyl palmoxirate were studied in streptozotocin/alloxan-induced diabetic dogs. 2. Single oral 50 mg doses (approximately 7.5 mg kg-1) of methyl palmoxirate produced statistically significant reductions of plasma glucose (32 +/- 6% maximum reduction from baseline) and ketones (74 +/- 12% maximum reduction from baseline), with the peak effect on plasma ketones (3.5 h) preceding that for plasma glucose (6.0 h). 3. Lower doses (0.7-2.0 mg kg-1 daily) of methyl palmoxirate given repeatedly for seven days produced reductions of blood glucose and ketones equivalent to those produced with the higher single dose. Maximal reductions of plasma ketones were generally observed following the first dose of drug, whereas significant lowering of plasma glucose required several days of continuous dosing. 4. Repeated daily doses of methyl palmoxirate markedly reduced the overnight fasting ketone levels but not glucose levels of diabetic dogs. 5. In conclusion, administration of the fatty acid oxidation inhibitor methyl palmoxirate, in the absence of concomitant insulin therapy, was able to lower the plasma glucose and ketone levels of insulin-deficient streptozotocin/alloxan diabetic dogs. Only the plasma ketones were decreased to normal by this treatment.

Animals↗
PubMed1987

Antibody response after a two-year intradermal booster of rabies human diploid cell vaccine.

A study was undertaken to evaluate the effectiveness of a low dose of rabies human diploid cell vaccine administered intradermally for preexposure booster inoculation. Seventy-six volunteers received a 0.1-ml dose of rabies human diploid cell vaccine intradermally, approximately 2 years after their primary series. Though only 25 (32.9%) had a titer less than 0.5 IU/ml before the booster, all had a postbooster titer of greater than or equal to 4.0 IU/ml 3 weeks later. Five of 73 (6.8%) reported an allergic reaction after the booster.

Adolescent↗
PubMed1986

An enzyme immunoassay for immunoglobulin M antibodies to Toxoplasma gondii which is not affected by rheumatoid factor or immunoglobulin G antibodies.

An enzyme-linked immunosorbent assay (ELISA) for total antibodies to Toxoplasma gondii was modified to measure specific immunoglobulin M (IgM) antibodies. The assay requires three incubation periods totaling 2 h and enzyme-labeled-heavy-chain-specific antibodies to human IgM. The objective read-out in absorbance was normalized to percent of a standardized positive control for interpretations. No difference was observed between the assay results with or without previous absorption of the samples by Staphylococcus aureus protein A to remove most of the IgG antibodies. Addition of serum containing very high levels of IgG antibodies to another containing both IgG and IgM antibodies did not change the IgM assay values for the latter. None of the 22 sera containing high levels of IgM rheumatoid factor (RF) gave positive ELISA IgM results, even though 8 of them also had high levels of IgG toxoplasma antibodies. Mixtures of sera containing high concentrations of RF with sera having high levels of IgG toxoplasma antibodies also failed to show any false-positive reactions in the IgM toxoplasma assay. Thus, this ELISA for T. gondii IgM antibodies was not affected by IgG toxoplasma antibodies and RF.

Adult↗
PubMed1986

An outbreak of influenza A in a nursing home.

An outbreak of influenza A occurred in an elderly population in a Maryland nursing home between December 8, 1980 and January 13, 1981 and involved 76 of the 170 residents. Throat swabs from two of 10 acutely ill residents yielded influenza A virus similar to the A/Taiwan/1/79 strain. Fourfold or greater increases in the titer of complement-fixing (CF) or hemagglutination-inhibiting (HI) antibodies were detected in paired sera from four of five ill residents and from none of four well residents. One hundred (62.9 per cent) of 159 residents with known vaccination histories had been vaccinated with trivalent influenza virus vaccine in October and November 1980. Crude illness attack rates and mortality rates were similar in vaccinees and nonvaccinees. Various risk factors and hypotheses were examined in an attempt to explain the apparent lack of vaccine efficacy.

Aged↗
PubMed1983

Evaluation of latex-Rickettsia rickettsii test for Rocky Mountain spotted fever in 11 laboratories.

A latex-Rickettsia rickettsii test for detection of antibodies to Rocky Mountain spotted fever (RMSF) was evaluated during the 1980 RMSF season in 11 laboratories in nine states where the disease is endemic. In a double-blind study, all sera submitted to each laboratory for RMSF testing were also examined by the latex-R. rickettsii test. A portion of each specimen was then sent to the New York State laboratory for testing by latex-R. rickettsii and by the reference microimmunofluorescence test. Results were exchanged at the end of the examination period. At the usual ratio of reactive to nonreactive sera encountered in a diagnostic laboratory on a day-to-day basis, the efficiency of the latex-R. rickettsii test relative to microimmunofluorescence was 96.79% for New York and 93.30% for the collaborating laboratories. Both the latex and microimmunofluorescence tests detected antibodies to RMSF within 7 to 9 days of onset. With the latex-R. rickettsii test--but not necessarily with microimmunofluorescence--a high titer (greater than or equal to 128) on a single serum was diagnostic of active RMSF. Changes in serum titer for patients with multiple sera were similar for both tests. The test detects rickettsial antibodies in patients with active infection, but in most cases it does not detect antibody in patients with past infection. Test reactivity could not be uniquely linked to a particular immunoglobulin class.

Antibodies, Bacterial↗
PubMed1982

A comparison of the biological properties of androst-5-en-3 beta-ol, a series of (20R)-n-alkylpregn-5-en-3 beta-ols and 21-isopentylcholesterol with those of cholesterol.

The delta 5-sterol, androst-5-en-3 beta-ol, which has no side chain at C-17, did not permit molting of the insect Heliothis zea, growth of either the protozoan Tetrahymena pyriformis, or the yeast Saccharomyces cerevisiae adapted to anaerobic conditions, nor was the sterol esterified by a mammalian microsomal ACAT preparation. However, the sterol did form a liposome with egg lecithin and, when fed to mice, did inhibit hepatic cholesterol synthesis. 21-Isopentylcholesterol also formed a liposome but neither supported the growth of the yeast nor was metabolized by the protozoan. When sterols, 20(R)-n-alkylpregn-5-en-3 beta-ols, with side chains of varying lengths were added to the medium of the protozoan, maximal esterification with fatty acids occurred with the 20(R)-n-pentyl derivative, and maximal inhibition of tetrahymanol formation occurred with the n-butyl, n-pentyl, and n-hexyl derivatives. In all of the assays cholesterol showed a positive response, either permitting molting or growth, being metabolized, inhibiting sterol or tetrahymanol synthesis, or forming a liposome.

Androstenols↗
PubMed1981

Steric effects at C-20 and C-24 on the metabolism of sterols by Tetrahymena pyriformis.

Cultures of Tetrahymena pyriformis were incubated with various sterols and the extent of dehydrogenation at C-7 and C-22 was determined. The sterols incubated were desmosterol, 22-dehydrodesmosterol, 24-methyldesmosterol, 24 alpha-methylcholesterol (campesterol), 24-methylene-cholesterol, isohalosterol (26,27-bisnorcampesterol, also known as 24,24-dimethylchol-5-en-e beta-ol, a naturally occurring C26-sterol), and 20-isohalosterol. 20-Isohalosterol was not metabolized, while products with delta 7- and delta 22-bonds were formed from isohalosterol and all of the other sterols studied. This confirms an earlier conclusion, based on results with 20-isocholesterol and cholesterol, that inversion of the configuration from 20(R) to 20(S) completely prevents metabolism both in the nucleus and the side chain. On the other hand, changes in the electronics or stereochemistry at C-24 had a direct affect only on metabolism in the side chain. The presence of a methyl group at C-24 reduced the yield of metabolites with a delta 22-bond relative to those with a delta 7-bond producing an accumulation of 7-dehydro metabolite. A double bond at position-24 counteracted this steric effect, presumably by enhancing the rate of dehydrogenation, and a delta 24(28)-bond was more effect than was a delta 24(25)-bond.

Animals↗
PubMed1980

The effects of branching, oxygen, and chain length in the side chain of sterols on their metabolism by Tetrahymena pyriformis.

The ciliated protozoan Tetrahymena pyriformis was incubated with delta 5-sterols which has side chains varying in degree of branching, polarity, and length. Branching at neither end of the side chain was obligatory for metabolism, although removal of C-21 did have a small quantitative effect. Both 21-norcholesterol and sterols lacking a terminal gem-dimethyl group, e.g. 26 (or 27)-norcholesterol, underwent conversion to the corresponding delta 5,7,22-trienols. However, replacement of C-21 with oxygen (20 xi-hydroxy- and 20-keto-21-norcholesterol) was very deleterious. In particular, introduction of a delta 22-bond was abolished, and dehydrogenation in Ring B was strongly reduced. The overall length of the side chain which permitted maximal metabolism corresponded closely to that in cholesterol and other natural sterols. Maximal metabolism was observed only with sterols bearing side chains which had 5 or 6 carbon atoms (other than C-21) attached to C-20. The extent of metabolism fell gradually to zero as the length of the chain was increased or decreased. No metabolism at all occurred with side chains of no carbon atoms (pregn-5-en-3 beta-ol) or as many as 12 carbon atoms (20(R)-n-dodecylpregn-5-en-3 beta-ol) on C-20 other than C-21. Dehydrogenation in the side chain was more sensitive to chain length than was dehydrogenation in Ring B. The data presented here reinforce the view that the enzymes involved in sterol metabolism are actually directed toward binding with sterols. Furthermore, since the sterols become components of the ciliary membrane of this protozoan, the observed structural requirements for metabolism presumably reflect the structural requirements for membrane architecture; and the evidence presented then suggests that the natural length of the sterol side chain is governed by the sterol's membranous function.

Animals↗
PubMed1980

Initial SEM observations of Herpes simplex virus infected chicken chorioallantoic membranes.

Chorioallantoic membranes (CAMs) of 10 day old embryonated chicken eggs were experimentally infected with types 1 and 2 Herpes simplex virus (HSV) and observed by scanning electron microscopy. This preliminary report examined CAMs at time periods ranging from 30 minutes to 24 hours post-infection. Samples also were taken for transmission electron microscopy to correlate topographic alterations with ultrastructural changes. Uninfected control CAMs, throughout the study, consisted of a homogeneous population of flattened chorionic ectodermal cells whose surface were covered with uniformly distributed microvilli of varying lengths and fairly constant diameter. At thirty minutes post infection, irrespective of infecting herpes type, microvilli were markedly decreased in numbers with those remaining showing noted blunting. Later stages of infection with type 1 HSV strains showed a cytopathic process consisting of a generalized rounding of individual cells and the presence of cells apparently containing multilobulated nuclei. CAMs infected with type 2 strains demonstrated a more focal spread of infection and the presence of intranuclear filamentous structures by transmission electron microscopy.

Allantois↗
PubMed1979

Laboratory-based surveillance of influenza virus in the United States during the winter of 1977-1978. I. Periods of prevalence of H1N1 and H3N2 influenza A strains, their relative rates of isolation in different age groups, and detection of antigenic variants.

Influenza A (H3N2) viruses were isolated from outbreaks and epidemics of disease during the period December 1977 to March 1978. For the last two months of this period, H1N1 strains of influenza A were also responsible for epidemics. In some regions (e.g., Hawaii) co-circulation of H1N1 AND H3N2 strains occurred, whereas in other regions (e.g., Wisconsin) isolation of H3N2 strains had almost ceased prior to isolation of H1N1 strains. Few influenza B isolates were reported. Analysis of the ages of patients from whom specimens were submitted for influenza virus isolation confirmed that, whereas H3N2 strains were isolated from persons of all ages, greater than 97 per cent of H1N1 isolates in six states analyzed were recovered from patients less than 26 years old, although specimens were tested from older persons who were ill during the period of prevalence of H1N1 influenza. The majority of H3N2 isolates tested by hemagglutinin-inhibition reaction were similar to A/Texas/1/77, and the majority of H1N1 isolates were similar to A/USSR/90/77. Antigenic analysis of isolates, however, identified a small number of variants of H3N2 and H1N1 strains.

Adolescent↗