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Biomedical subjects

M J Carter

Publications and source records attributed to M J Carter.

At least 109 records · Page 6Linked to original sources
PubMed1981

Antigenic characterization of measles and SSPE virus haemagglutinin by monoclonal antibodies.

Hybrid cells secreting monoclonal antibodies directed against the haemagglutinin (H) protein of measles virus (Edmonston) were produced by fusion of mouse myeloma cells with spleen cells derived from immunized mice. Measles antibodies secreted by these cells were tested for their ability to react with measles virus in immunoprecipitation experiments and assays of binding, neutralization, haemagglutination inhibition and haemolysin inhibition. On this basis 21 out of 75 hybridomas could be defined and divided into five functional groups with different properties. However, when tested against other measles virus strains, including those isolated from subacute sclerosing panencephalitis (SSPE) patients, normalized radioimmunoassay (RIA) binding titres showed that the extent to which a given antibody bound could vary greatly with the virus strain examined. Moreover, the biological actions within a group were found to be very heterogeneous, even when high antibody binding titres were observed. These results suggest that different measles virus strains, which are not distinguishable by polyvalent sera, do in fact possess antigenic differences. Furthermore, the functional significance of a given virus epitope may vary from strain to strain. Hybridoma antibodies were also used to demonstrate the occurrence of antigenic changes within the H polypeptide of SSPE virus during the course of non-productive, persistent infection in vitro.

Antibodies, Monoclonal↗
PubMed1981

Moxalactam (LY127935) in treatment of meningitis due to gram-negative bacilli.

Moxalactam (LY127935; 6059S), a new broad-spectrum beta-lactam antibiotic, was used successfully with an aminoglycoside in a patient with Serratia marcescens meningitis complicating a neurosurgical procedure. With a bioassay method, peak and trough serum and cerebrospinal; fluid concentrations of moxalactam were determined during therapy. Mean peak and trough serum levels were 100.6 and 35.5 micrograms/ml, respectively. Corresponding mean peak and trough cerebrospinal fluid levels were 12.4 and 10.38 micrograms/ml. Cerebrospinal fluid levels of moxalactam exceeded the minimal bactericidal concentration for the infecting organism by more than 30-fold throughout therapy. No untoward effects of moxalactam were observed. Moxalactam may be a useful agent in the treatment of meningitis due to susceptible gram-negative bacilli.

Cephalosporins↗
PubMed1980

Pseudomonas pseudomallei in an anopthalmic orbit.

A 21-year old man sustained multiple facial fractures and skin lacerations during an automobile accident, with resultant necrosis of the left upper eyelid and exposure of the cornea. Bacterial and secondary fungal corneal ulceration and perforation occurred, leading to enucleation. Cultures from the noninfected anophthalmic orbit approximately eight weeks after enucleation yielded Pseudomonas pseudomallei. This is the second isolate of this domallei. This is the second isolate of this organism in the United States and the first apparent association with the ocular adnexa.

Accidents, Traffic↗
PubMed1979

Changing phage typing patterns of epidemic gentamicin-resistant Staphylococcus aureus. Evidence for transmission of gentamicin resistance.

In a 10-week period, infection with gentamicin resistant Staphylococcus aureus appeared in 24 adults and infants in one hospital. Medical staff were affected first, and subsequently 16 infants in the neonatal intensive-care unit. The gentamicin-resistant staphyloccal isolates showed three distinct phage susceptibility patterns in two distinct phage groups during the early, middle, and late phases of the outbreak. Although not confirmed with in-vitro or in-vivo laboratory data, this outbreak suggests that gentamicin resistance may be transferred between different strains of Staph. aureus in vivo.

Adult↗
PubMed1978

Aminoglycoside modification by gentamicin-resistant isolates of Staphylococcus aureus.

Three clinical isolates of Staphylococcus aureus, which were previously shown to contain a 50S plasmid conferring resistance to several aminoglycosides, were examined for modifying enzymes. Both the wild-type and heat-cured derivatives of the isolates were screened for acetyl-, adenylyl-, and phosphotransferase activities. The substrates were gentamicin, amikacin, and netilmicin; the results indicated that even though all three activites were present, the phosphotransferase reaction was most responsible for resistance to these antibiotics. The absence of any of the modifying activites in cured derivatives of the three isolates supports the conclusion that aminoglycoside resistance in these strains is conferred by a plasmid.

Aminoglycosides↗
PubMed1977

Plasmid-mediated resistance to gentamicin in Staphylococcus aureus.

Two strains isolated from a recent outbreak of infections by gentamicin-resistant Staphylococcus aureus were examined to determine whether genetic control of this resistance is plasmid or chromosomally mediated. Curing techniques indicated a plasmid location in both strains. Physical isolation and characterization of the plasmid deoxyribonucleic acid from one strain revealed that the determinant for gentamicin resistance resides on a 50S plasmid.

DNA, Bacterial↗
PubMed1977

72 kidney transplants at the Medical College of Georgia 1968-1976.

Seventy-two kidneys have been transplanted-47 from related donors, and 25 from cadaver donors-into 63 recipients. No donor died or experienced a complication requiring more than one extra week of hospitalization. Six recipients died. Three of the six recipients died from complications. Two of the six died only because they declined to resume hemodialysis, and one died in prison of unusual circumstances after seven and one-half years of good health and kidney function. Five patients are surviving by virtue of a second transplant. Eight patients are now on hemodialysis. Seven patients with transplants are not in excellent physical health and five other patients with excellent health and renal function are nonetheless frequently depressed and easily upset over minor physical disabilities. A majority of the recipients have been rehabilitated to a gratifying extent.

ABO Blood-Group System↗
PubMed1972

The isoenzymes of carbonic anhydrase: kinetic properties with particular reference to the functions in the intestinal tract.

1. Details are given of an electrometric method for measuring the activity of isoenzymes of carbonic anhydrase (EC 4.2.1.1) in catalysing the hydration of carbon dioxide under different conditions at 0 degrees C. In the method, a measured volume of water saturated with carbon dioxide at a known partial pressure and appropriate temperature is introduced into a buffered solution. Using a sensitive electrometer and recording instrument, the subsequent change in hydrogen ion concentration is recorded as a function of time. Under the conditions of assay, the pH change induced in the presence of substrate is very small (DeltapH < 0.05 units) and the period of observation need not exceed 10 sec.2. For enzymes isolated from guinea-pig tissues, it is found that the specific activity of the ;high activity' isoenzyme (carbonic anhydrase C, carbonic anhydrase II, HACA) is about eighteen times that of the ;low activity' counterpart (carbonic anhydrase B, carbonic anhydrase I, LACA) when measured at 0 degrees C, pH 7.2, and ionic strength 0.19. Under the same conditions, the K(m) was found to be 10 mM for the ;high activity' isoenzyme and 23 mM for the ;low activity' isoenzyme. No differences were found between the equivalent kinetic parameters of the corresponding isoenzymes isolated from different tissues.3. The isoenzymes isolated from guinea-pig tissues are found to be inhibited by acetazolamide in a non-competitive manner. It is also found that the ;high activity' isoenzyme is many times more sensitive to this inhibitor than is the ;low activity' isoenzyme. Evidence is presented which indicates that one acetazolamide binding site is present on each molecule of either isoenzyme.4. While chloride ions specifically inhibit the ;low activity' component of guinea-pig carbonic anhydrase (I(0.5) = 40 mM), acetate, butyrate and pyruvate inhibit both isoenzymes. Under the conditions employed, acetate and pyruvate are more strongly inhibitory to the ;low activity' isoenzyme than to the ;high activity' isoenzyme, while butyrate is more strongly inhibitory to the ;high activity' isoenzyme.5. The findings are discussed with particular reference to the physiological significance of the presence of the isoenzymes in the gastro-intestinal tract. Also considered are possible relationships between the distribution of the ;low activity' isoenzyme in these tissues and the transport and metabolism of products of fermentation occurring in the intestinal lumen.

Acetates↗
PubMed1971

The isoenzymes of carbonic anhydrase: tissue, subcellular distribution and functional significance, with particular reference to the intestinal tract.

1. The total carbonic anhydrase activity in some guinea-pig tissues has been measured using a pH-stat procedure. Stomach, gall bladder, proximal colon and caecum all possess more carbonic anhydrase activity per unit amount of protein than does whole blood.2. The carbonic anhydrase activity of the small intestine is low. Reasons are given for supposing that activity found there is not entirely due to contamination by whole blood, and it is suggested that in this tissue the enzyme may be localized in some cell type other than the columnar absorbing cells.3. Evidence is presented which indicates that heavy metals interfere with the activity of the enzyme as measured in tissue homogenates.4. The distribution and concentration of the two major isoenzymes of carbonic anhydrase have been measured in different tissues. Blood and proximal colon contain both isoenzymes in comparable concentrations, the ratio of the concentration of the ;low activity' isoenzyme to that of the ;high activity' being about 2. The gastric mucosa contains much ;high activity' carbonic anhydrase, but only a negligible amount of the ;low activity' isoenzyme. In the caecal mucosa, the ;low activity' isoenzyme is predominant, the ratio of its concentration to that of the ;high activity' isoenzyme being about 9. It is also found that more than 1.5% of the protein in the caecal mucosa is accounted for as carbonic anhydrase enzymes.5. It is found that some 45% of the total carbonic anhydrase activity of sucrose homogenates of the guinea-pig colon is bound to particles. The activity is located mainly in the nuclear and microvillous fraction and in the ;high-speed supernatant' fraction. The form of enzyme bound is largely of the ;high activity' variety. When the tissue is homogenized in potassium chloride solutions less than 4% of the total activity is recovered in particulate fractions. The amount of activity which is bound to particulate fractions increases as the ionic strength or pH of the homogenate is lowered.6. The findings are discussed in relation to the possible physiological roles of the isoenzymes in tissues other than blood. Possible relationships between the presence of the enzymes and the metabolism and transport of ammonium and fatty acids are considered.

Animals↗