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Biomedical subjects

J F Cooper

Publications and source records attributed to J F Cooper.

At least 19 recordsLinked to original sources
PubMed1991

Action of taurine, 3-aminopropanesulfonic acid, and GABA on the hindgut and heart of the cockroach, Leucophaea maderae.

Taurine, glycine, glutamate, and gamma-aminobutyric acid (GABA) were all present in concentrations of greater than 1% of the total free amino acid content in the brain, thoracic, and abdominal ganglia of Leucophaea maderae. Hemolymph, subesophageal ganglia, and hindgut had substantial amounts of glutamate and glycine, but less than 0.3% taurine or GABA. Taurine, 3-aminopropanesulfonic acid (3-APS), cysteine-sulfinic acid (CSA), and GABA each had myotropic activity on the isolated cockroach hindgut, with 3-APS having the most consistent effect (ED50 = 0.63 mM), while taurine and CSA activities were similar to that of GABA on the hindgut. Both taurine and 3-APS had anti-arrhythmic effects on semi-isolated heart preparations of L. maderae, while GABA was inhibitory and induced arrhythmia. Bicuculline was antagonistic to the effects of GABA, taurine, and 3-APS on the hindgut, and induced arrhythmia in heart preparations; this arrhythmia was reversible by taurine, but not by GABA or 3-APS.

Amino Acids↗
PubMed1990

Endogenous colonization by gentamicin-resistant gram-negative bacilli elaborating aminoglycoside (3)-5-acetyltransferase.

Members of the family Enterobacteriaceae that elaborate aminoglycoside 3-5-acetyltransferase [AAC(3)-5] caused a nosocomial outbreak at the Vanderbilt University Medical Center and have persisted. To see whether the gene for AAC(3)-5 was present in the community, stool cultures of newly admitted patients and ambulatory persons were examined with a specific gene probe. AAC(3)-5-positive strains were present in the intestinal flora examined.

Acetyltransferases↗
PubMed1989

Mycobacterium chelonae: a cause of nodular skin lesions with a proclivity for renal transplant recipients.

PURPOSE: Infections due to Mycobacterium chelonae are uncommon. Several renal transplant recipients at our medical center have developed M. chelonae infections during the past several years, so we decided to review our recent experience with M. chelonae infections. PATIENTS AND METHODS: The clinical microbiology laboratory records of four Vanderbilt University Affiliated Hospitals were reviewed. Ten patients with M. chelonae tissue or blood infections were identified between 1982 and July 1988. RESULTS: All infections involved the skin and subcutaneous tissue. Three infections developed at the sites of medical injections. The remaining seven infections occurred in renal transplant recipients and produced a clinically distinctive syndrome. All were indolent tender nodular lesions on the extremities, usually the lower legs. Systemic symptoms were absent, and white blood cell counts were within normal limits. Diagnosis required tissue biopsy and cultures that were incubated for a month. Therapy consisted of surgical excision combined with long-term antibiotics. Even so, some patients had a chronic, relapsing course. CONCLUSION: Although other diagnoses must be considered, the presumptive diagnosis of M. chelonae infection is suggested by the appearance of nodular erythematous lesions on the legs of a renal transplant recipient.

Adult↗
PubMed1989

Recurrent meningitis in a black man.

A 43-year-old black man had recurrence of acute bacterial meningitis caused by Neisseria meningitidis. He had had three previous episodes of acute meningitis, starting at age 27 years. The patient's serum was found to have an undetectable level of the sixth component of complement. Congenital absence of one of the terminal proteins in the complement system impairs a patient's ability to eradicate bacteria, and increases susceptibility to recurring infections caused by meningococci and other Neisseria species. Though the serum of complement-deficient patients promotes normal opsonization of bacteria, it is unable to kill meningococci directly. The currently available meningococcal vaccine may augment type-specific antibody, but it does not correct the underlying complement deficiency. The role of self-administered antibiotics in preventing recurrent Neisseria infection remains uncertain.

Adult↗
PubMed1988

Effect of patient positioning on distribution of tetracycline in the pleural space during pleurodesis.

Thoracostomy tube drainage with tetracycline (TCN) instillation is an effective technique for management of recurrent, symptomatic, malignant pleural effusions. Although patient rotation through various positions after instillation of TCN has been advocated empirically, it has not been shown scientifically to be necessary and is often uncomfortable for the patient and time-consuming for personnel. Five patients with symptomatic, malignant pleural effusions were studied during pleurodesis using radiolabelled TCN. Scintigraphic imaging was done immediately after TCN instillation prior to patient rotation. Patients were rotated through six positions and multiple images were obtained at 30 and 120 minutes. Tetracycline dispersed throughout the pleural space within seconds. Patient positioning had no effect on the intrapleural distribution of TCN in four of the five patients. In one patient with loculated hydropneumothorax and trapped lung, rotation minimally improved distribution of TCN to the apex. Rotation during pleurodesis does not appear to be necessary in patients with a relatively normal pleural space. However, patient rotation enhances distribution of TCN when the lung is separated substantially from the chest wall, as with trapped lung. Possibly, in this situation the properties of fluid mechanics and capillary action no longer apply.

Adult↗
PubMed1988

Symptomatic sclerosing cholangitis in patients with a normal alkaline phosphatase: two case reports and a review of the literature.

The diagnosis of sclerosing cholangitis is usually not considered in the absence of an elevation of serum alkaline phosphatase. The purpose of this paper is to report two symptomatic cases of primary sclerosing cholangitis (PSC) which presented with a normal alkaline phosphatase, and to review the literature regarding alkaline phosphatase in PSC. A total of 172 patients with PSC were identified in the literature; six of these patients (3%) presented with a normal alkaline phosphatase. Patients with diseases known to be associated with primary sclerosing cholangitis and having a compatible clinical presentation should be considered for evaluation with endoscopic retrograde cholangiography, even in the presence of a normal level of serum alkaline phosphatase.

Adult↗
PubMed1985

Comparison of several control standard endotoxins to the National Reference Standard Endotoxin--an HIMA collaborative study.

A collaborative study, initiated under the auspices of the Health Industry Manufacturers Association (HIMA), was designed to establish the relationship of Escherichia coli O55:B5 endotoxin (the control standard endotoxin of HIMA and the Food and Drug Administration's Office of Medical Devices) to the U.S. National Reference Standard Endotoxin and to two internationally used control standard endotoxins. By using two Limulus amoebocyte lysate test systems, it was established that the E. coli O55:B5 endotoxin lot originally used by HIMA and the Office of Medical Devices to establish Limulus amoebocyte lysate release test criteria for pyrogen testing of medical devices contains approximately 4.5 endotoxin units (EU) per ng. Thus, the 1.0-ng/kg endotoxin dose limit currently established for medical devices is approximately the same as the 5.0-EU/kg endotoxin limit (on an activity basis) established by several other Food and Drug Administration agencies for human and animal parenteral drugs and biological products.

Endotoxins↗
PubMed1985

Ideal properties of a LAL reagent for pharmaceutical testing.

Evaluation of medical devices and pharmaceutical products for endotoxin content is the most significant biomedical application of Limulus amebocyte lysate (LAL). This review summarizes the means by which LAL reagent suppliers have introduced different production techniques and formulation additives to uniquely optimize their products for industry. Pharmaceutical testing requires a LAL reagent that is buffered, stabilized to a sensitivity of 0.12 EU/ml, optimized to detect E. coli-derived LPS in water, formulated to produce firm opaque gels, designed specifically to detect bacterial endotoxin, and is economical. Unique LAL reagent characteristics produce nonuniformity in drug compatibility testing but does not significantly alter detection of unsafe levels of native endotoxin. Design of a clinical LAL reagent may require additional means for standardization and exclusion of additives which are only useful for pharmaceutical testing. A cooperative effort between clinical investigators and the LAL industry should resolve these issues in a reasonable period of time.

Drug Industry↗
PubMed1984

Identification of structural and secretory lectin-binding glycoproteins of normal and cancerous human prostate.

We have utilized the technique of lectin-loading of SDS gels with iodinated concanavalin A and wheat germ agglutinin to identify glycoproteins in prostatic and seminal fluids as well as in prostate tissue fractions. The following subunits which bound both lectins were detected: (a) 50, 43 and 38 kDa subunits common to prostatic and seminal fluids, and an additional 55 kDa subunit which predominates only in prostatic fluid; (b) 78, 55, 50 and 43 kDa subunits in prostatic tissue cytosol and (c) 195, 170, 135, 116 and 95 kDa subunits present in the particulate fractions of prostatic tissue. Immunoblotting using specific rabbit antibodies revealed the 50 kDa band to be prostatic acid phosphatase and the 38 kDa band to be prostate-specific antigen. Interestingly, antibodies directed toward prostatic acid phosphatase were found to cross-react with the 43 kDa band. Fractionation on sucrose gradients showed that several of these particulate glycoproteins were associated with a vesicle fraction enriched in adenylate cyclase activity, implying that they are plasma membrane glycoproteins. Comparison of soluble and particulate fractions of normal and cancerous tissue homogenates was made by densitometric scanning of autoradiograms of lectin-loaded gels. Similar relative intensities of lectin-binding were obtained for corresponding proteins in normal and cancerous tissue fractions. Also, immunoblotting showed no differences in prostatic acid phosphatase or prostate-specific antigen between normal and cancerous soluble homogenate fractions. Our results suggest that major lectin-binding proteins are conserved in the transition from normal to cancerous tissue. These results may be useful in developing a multiple-marker profile of metastatic prostate cancer and for the design of imaging agents, such as monoclonal antibodies, to prominent soluble and particulate prostate glycoproteins.

Acid Phosphatase↗
PubMed1984

Distribution of prostatic acid phosphatase isoenzymes in normal and cancerous states.

We have studied the IEF (isoelectric focusing) profiles and the sedimentation characteristics of intracellular and secretory prostatic acid phosphatase (PAP) in normal and cancerous states. IEF studies show a similar relative distribution of tartrate inhibitable pI 4.9 (approximately 80%) and 5.6 (approximately 20%) forms of this enzyme in normal as well as cancerous prostate. The same IEF profile is obtained regardless of whether an enzymatic or RIA method is utilized for detection of PAP. Of these two isoenzymes, only the form of pI 4.9 predominates in prostatic and seminal fluids and in Stage IV serum. Sedimentation analysis shows that the purified enzyme is exceptionally stable since it retains an S020,w value of 5.7 at low concentrations (ng/ml). While only the 5.7S form is observed in normal and cancerous tissues as well as in prostatic fluid, analysis of Stage IV serum reveals an additional form at 8.7S. Control experiments suggest that the 8.7S form is not induced by non-specific association with normal serum proteins or by the inhibitor tartrate. Our results suggest that: (a) of the two major isoenzymes in tissue, only the pI 4.9 isoenzyme predominates in secretion, (b) this relationship of intracellular to secretory forms is unaltered in the transition from normal to cancerous tissue, and (c) the utility of PAP as a tumor marker is derived at least in part by the intrinsic stability of the 5.7S form. The significance of the 8.7S form is unknown at the present time, but it does not distort the clinical (RIA) measurement of PAP in serum.

Acid Phosphatase↗
PubMed1983

Purification of acetylcholine receptors from the muscle of Electrophorus electricus.

Muscle from the electric eel Electrophorus electricus contains acetylcholine receptors at 50 times the concentration of normal mammalian muscle and fully one-tenth the concentration of receptors in its electric organ tissue. Receptor is organized much more diffusely over the surface of Electrophorus muscle cells than is the case in normally innervated mammalian skeletal muscle. Receptor was purified from Electrophorus muscle by affinity chromatography on cobra toxin-agarose and found to contain subunits which correspond immunochemically to the alpha, beta, gamma, and delta subunits of receptor from electric organ tissue of Torpedo californica. Receptor purified from Electrophorus muscle appears virtually identical with receptor purified from Electrophorus electric organ tissue.

Animals↗
PubMed1982

Radiotherapy for prostatic carcinoma: post-irradiation prostatic biopsy and recurrence patterns with long-term followup.

From 1968 through 1975, 159 patients with stages A, B and C adenocarcinoma of the prostate were treated with supervoltage radiation therapy. A median dose of 7,200 rad was given. The influence upon survival of grade, stage and a positive biopsy result after irradiation is analyzed. Over-all survival is a patently imprecise test of local treatment because patients die of intercurrent disease and are alive with metastases for significant intervals. The classification of survival with no evidence of recurrent disease excluded those patients dying of intercurrent disease. Therefore, the rate of survival free of disease always will be greater than the over-all survival rate in these patients, and a certain percentage of the patients without evidence of cancer will harbor subclinical disease. The 5 and 10-year survival rates free of disease were 80 and 69 per cent, respectively, in 51 patients with stages A and B cancer, and 66 and 47 per cent, respectively, in 108 with stage C disease. The 5 and 10-year over-all survival rates were 72 and 56 per cent, respectively, in the former and 68 and 39 per cent, respectively, in the latter patients. Survival free of disease and death of prostatic carcinoma were influenced adversely by advancing grade and stage (p less than 0.05), while over-all survival was influenced adversely by grade (p equals 0.02) but not by stage (p greater than 0.05). A positive biopsy result after irradiation did not predict survival free of disease, over-all survival or death of prostatic cancer in patients followed for 10 years (p greater than 0.05).

Adenocarcinoma↗
PubMed1982

Formulae for maximum valid dilution.

The preparation of test specimens using the MVD calculation represents a reasonable approach to equating the sensitivity of the in vitro and in vivo tests for endotoxin. Labeling of LAL reagents and control standard endotoxins are a point of confusion for the parenterals industry. Government and reagent suppliers must work together expeditiously to provide test materials that are explicitly labeled as to reactivity in EU/ml and ng/ml. The relatively greater reactivity of LAL reagent to environmental endotoxin than the rabbit bioassay provides a greater margin of safety for the in vitro approach than previously anticipated, and suggests that rabbit retest of LAL failures may be appropriate for specific products.

Animals↗