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Biomedical subjects

C M Martin

Publications and source records attributed to C M Martin.

At least 73 records · Page 4Linked to original sources
PubMed1985

Antenatal diagnosis of cystic adenomatoid malformation: effect on patient management.

Congenital adenomatoid malformation (CAM) of the lung was diagnosed at 30 weeks gestation. The mother presented with preterm labor and polyhydramnios. A complex cystic mass was seen in the right lung of the fetus. Additional radiographic and sonographic investigations prior to delivery allowed differentiation of this rare lesion from other cystic thoracic pathology of the fetal period. Careful hospital obstetric management of the mother and fetus for over 3 weeks allowed the delivery of an infant with adequate pulmonary maturity to permit stabilization and surgery on the baby in the first days of life.

Adult↗
PubMed1983

Hepatitis B vaccine--what to expect.

Following up the pioneering work of Dr. Saul Krugman of New York University School of Medicine, scientists have spent more than 10 years developing a hepatitis B vaccine. Vaccine consists of purified, inactivated, noninfectious surface protein of hepatitis B virus; it is derived from particles of incomplete virus surface protein extracted from plasma collected from human carriers of hepatitis B virus. Observations in more than 13,000 human vaccinees indicate that the vaccine is highly effective and extremely safe. The recommended three-dose vaccination regimen produces protective antibody in the large majority of persons 3 months of age and older. Available data suggest that immunity will last for at least 5 years in persons who have received all three vaccine doses. Supplied as a liquid and administered intramuscularly, the vaccine is generally well tolerated, with no serious adverse reactions attributable to the vaccine yet reported. The vaccine is quite stable; when stored at refrigerator temperature, it remains potent for 3 years. However, the vaccine should never be frozen, since freezing destroys potency.

Adult↗
PubMed1980

Loop of Henle during the water-to-antidiuresis transition in Brattleboro rats.

A mathematical model of the renal medulla predicted patterns of NaCl and urea concentration and flow rate when a rat undergoing water diuresis receives antidiuretic hormone (ADH), We tested these predictions with micropuncture and clearance experiments in Brattleboro rats lacking endogenous ADH. The model successfully predicted urine flow rate, urea excretion rate, and ascending vasa recta (AVR) solute concentration patterns. A novel result the model correctly foresaw was that AVR urea concentration lagged behind NaCl, because ADH temporarily interrupted urea recycling. The model suggested that this lag would be carried over to descending limb of Henle's loop (DLH) fluid only if DLH permeabilities allowed solutes as well as water to move across the DLH wall, but not if solute movement was negligible. Experimental results showed the lag, therby suggesting significant solute entry into DLH fluid during the transition, and, by extension, in other conditions as well, As shown in a companion paper (Am. J. Physiol. 239 (Renal Fluid Electrolyte Physiol. 8): F57-F71, 1980), solute permeation across DLH limits hypertonic urine formation in the inner medulla unless thin ascending limbs perform active transport of NaCl.

Animals↗
PubMed1978

Verbal and spatial encoding of visual stimuli: the effects of sex, hemisphere and yes-no judgements.

Six male and six female subjects were given 112 trials on each of two tasks requiring a yes-no comparison of pairs of letters presented to the right and left hemispheres. One task was predominantly visual (detection of curved letter segments) and the other was predominantly verbal (detection of rhyming "ee" sounds). It was found that for "yes" decisions, females were faster in the right hemisphere than in the left, while the reverse was the case for males. Also for females "no" decisions were faster than "yes" decisions in the left hemisphere but "yes" decisions were faster than "no" decisions in the right hemiphere.

Decision Making↗
PubMed1977

Effect of lidocaine on the absorption, disposition and tolerance of intramuscularly administered cefoxitin.

The use of lidocaine HCL solution at concentrations of 0.5 and 1.0% to reconstitute sodium cefoxitin relieves the pain associated with intramuscular injections of the antibiotic. Cefoxitin absorption by the intramuscular route is initially rapid and is virtually complete. Peak serum concentrations, corresponding to about one-half those of a comparable intravenous infusion, are achieved in 30 min. Continuing absorption tends to maintain higher serum concentrations for longer times. Renal clearance and serum half-life of cefoxitin do not appear to be affected by lidocaine at its effective anaesthetic concentrations.

Absorption↗
PubMed1977

Origin of electrical PD's in hamster thin ascending limbs of Henle's loop.

Microelectrodes with 2-micronm-tip diameters arranged to record differentially between this ascending limbs (ALH) and ascending vasa recta (AVR), gave values of 1.95 +/- 0.17 mV, ALH positive, in hydropenia with mineral oil bathing the kidney. Average values remained in the range of 1-2 mV when the ALH and AVR values were obtained sequentially, when the kidney was bathed in Ringer solution, when 5-8 Momega Ling-Gerard microelectrodes were used in the ALH, or when the hamsters were in saline diuresis. These results contradict reports of earlier studies with high impedance Ling-Gerard electrodes that the PD was -9 mV, ALH negative. Perfusion of ALH in saline diuresis with solutions of various compositions provided estimates of ionic transport numbers: tNa+ = 0.33 +/- 0.01, tK+ = 0.00 +/- 0.02, tC1- = 0.67 +/- 0.02. When the perfusion solution was designed to have the same Na+, K+, and C1- concentrations as AVR plasma, the PD was 1.36 +/- .20 mV; when ouabain or furosemide were included (10(-5) M), the PD declined 1.35 +/- 0.21 mV and 1.41 +/- 0.28 mV, respectively. The results suggest that active C1- transport is mainly responsible for the PD, but that diffusion potentials can contribute.

Animals↗
PubMed1976

Comparative clinical pharmacology of intravenous cefoxitin and cephalothin.

Intravenous doses of 0.5, 1, and 2 g cephalothin and cefoxitin, a semi-synthetic cephamycin antibiotic highly resistant to bacterial cephalosporinase, were infused over a period of 3 minutes into 18 normal adult males by a randomized, crossover design. Serum and urine data on cefoxitin best fit a two-compartment open model. Serum concentrations following cefoxitin were higher and more prolonged and urine recoveries higher than those following equal doses of cephalothin. The terminal serum half-life of cefoxitin was longer at all dose levels. Renal clearance of cephalothin-like activity exceeded that of cefoxitin, which may possess dose-dependent kinetics. Whereas cephalothin has been reported to metabolize by greater than 35% to the less active desacetyl form, cefoxitin was metabolized by 0.1 to 6% to the descarbamyl form in individual subjects.

Adult↗
PubMed1975

Human epidermal transamidase.

The possible presence of epsilon-(gamma-glutamyl) lysine covalent bonds in human epidermal proteins prompted a study of transamidase activity in human hair-free epidermis. Callus contains an enzyme which catalyzes the incorporation of radioactive putrescine into alpha-casein. The enzyme is active without prior treatment with exogenous proteolytic enzymes. The putrescine incorporation is calcium dependent and inhibited by iodoacetamide. The enzyme was partially purified (50-fold over starting material), and has an apparent molecular weight between 50,000 daltons and 55,000 daltons by agarose 0.5m gel filtration. The apparent molecular weight is unaltered by chromatography in the presence of 11 mMCaCl2, a condition known to dissociate plasma transglutaminase (Factor XIII) into its ultimate subunits. The enzyme is active over a wide pH range up to pH 10.4 The Km for putrescine varies by 1-fold over the pH range 6.0 to 10.2, although enzyme activity increases at least 20-fold over the same pH range. The human epidermal transamidase is similar to the guinea-pig hair follicle transglutaminase and cow snout transamidase in its ability to cross-link fibrin.

Animals↗
PubMed1975

Effects of diuretic states on collecting duct fluid flow resistance in the hamster kidney.

Hydrostatic pressures were measured in cortical tubules, long loops of Henle, terminal collecting ducts, and in vasa recta in hamsters. In hydropenia, the loops of Henle and terminal collecting ducts provided the major fluid flow resistances, as judged by the location of hydrostatic pressure drops. In mannitol or saline diuresis, hydrostatic pressures in all tubular segments increased, but pressure drops in loops of Henle disappeared, indicating dilatation of loops. The major pressure drop was in terminal collecting ducts, especially in ducts of Bellini, even though these tubular segments also dilated. At highest urine flows, cortical tubule pressures were higher with the ureter and renal pelvis intact than when they were excised, suggesting laminar flow in the ureter adds a flow resistance at high flows. The pressure drop across the medullary capillary bed was 1-2 mmHg. The summation of medullary capillary hydrostatic and colloid osmotic pressures favored fluid uptake from the interstitium, a relationship enhanced by vasa recta geometry which ensures that descending vasa recta offer 4 times the flow resistance of ascending vessels.

Animals↗