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Biomedical subjects

D Brown

Publications and source records attributed to D Brown.

At least 1,081 records · Page 60Linked to original sources
PubMed1976

Virus infections and acute renal transplant rejection.

The date of onset of 360 acute renal transplant rejection episodes from 1969 to 1973 have been compared with the prevalence of various common viral infections and infections due to Mycoplasma pnuemoniae. A positive correlation was found for influenza B infections (r=0.43, p less than 0.01) up to 5 months before transplantation and for adenovirus infections (r=0.32, p less than 0.05) at 1 month before kidney grafting.

Acute Disease↗
PubMed1976

Spina bifida, exencephaly, and cranial bleb produced in hamsters by the solanum alkaloid solasodine.

Solasodine, one of the spirosolone structured solanum alkaloids, was gavaged to hamsters at 1184 - 1628 mg/kg once on the 7th or 8th day of gestation. About one-third of all litters from surviving, pregnant dams had one or more deformed offspring. There were 50 abnormals among 727 offspring from 84 dams at sacrifice. Abnormalities included 9 spina bifida, 13 major exencephaly, 25 cranial bleb, 2 hare lip, and 1 anophthalmic types. There were 5 abnormals among 1948 total offspring from 192 control dams. Malformation incidence in controls was 1/10 that in solasodine-gavaged animals. Solasodine gavage also resulted in a large increase in resorptions. Spina bifidas had a protuberance of the skin and other soft tissue in the dorsal mid-line of the lumbosacral region of the fetus. Exencephalics had a prominent dorsocranial defect that fully exposed the brain. Cranial blebs consisted of a soft protuberance of the skin in the mid-line of the interparietal region. The solasodine analogs tomatidine and diosgenin were not teratogenic at dose levels twice as high as the teratogenic dose of solasodine.

Abnormalities, Drug-Induced↗
PubMed1976

Hypoxic protection in paraquat poisoning.

Ingestion or injection of the herbicide paraquat (1,1'-dimethyl-4,4'-dipyridylium dichloride) has caused more than 120 deaths in humans. Most have been due to respiratory failure caused by pulmonary edema, hemorrhage, and atelectasis, or subsequent pulmonary fibrosis. Paraquat is concentrated in lung tissue and is believed to cause superoxide radical formation in the presence of oxygen and suitable electron donors. Exposure to increased concentrations of oxygen has been reported to accelerate the toxicity of paraquat. The therapeutic efficacy of a reduced oxygen environment was investigated by exposing paraquat-poisoned mice to 10% oxygen after stepwise drops from 14% oxygen. Sixty-one mice were given intraperitoneal injections of 27 mg. per kg. of paraquat. The 25 mice in hypoxia for 7 days had a 32% mortality rate versus a 78% mortality rate for the remainder of the mice in room air, p less than 0.01. After a dose of 20 mg. per kg. of paraquat administered intraperitoneally, 24 mice in hypoxia had a 25% mortality rate versus 51% for 35 animals in room air. Brief exposures of the hypoxic group to "normoxia" (room air) led to pulmonary edema and death. The continuous exposure of paraquat-poisoned animals to hypoxic environments was protective. This approach may be useful in other oxidant lung injuries.

Animals↗
PubMed1975

Parathyroid function in infants of diabetic mothers.

Serum parathyroid hormone and total and ionized Ca, Mg, and P levels were determined serially from birth to 96 hr of age in 28 infants of diabetic mothers (IDM, 15 Class A, 13 Class B, C, D) and their respective mothers at the time of delivery. In spite of marked decreases in concentrations of serum total and ionized Ca from birth to 24 to 48 hr, there was an insignificant increase in serum PTH values over this period in infants of insulin-dependent mothers. Infants of Class A diabetic mothers had an equivocal PTH response. Nineteen term control infants were similarly examined and had a significant increase in serum PTH postnatally. Relatively higher values of serum ionized Ca at birth in IDM were followed by greater decreases in ionized Ca from birth to 24-48 hr of age, and by decreased neonatal parathyroid function. The data support functional hypoparathyroidism as a basis for the hypocalcemia and hyperphosphatemia of IDM. It is speculated that increased concentrations of serum ionized Ca in utero and suppression of activity in the fetal parathyroid glands may be a cause for the functional hypoparathyroidism.

Blood↗
PubMed1975

State response to federal policy: children, EPSDT, and the Medicaid Muddle.

The implementation in Connecticut of Early and Periodic Screening, Diagnosis and Treatment (EPSDT), a program of comprehensive medical care for needy children, illustrates the complexities engendered by federally mandated state-administered health programs. The EPSDT amendments to Title V and Title XIX (Medicaid) were ambiguous on four major issues: administrative responsibility, costs, eligibility, and scope of services. The problems experienced by federal, regional, state, and local administrators in resolving these issues illustrate the weaknesses inherent in federal-state relations, and the contrasting roles health and welfare agencies under Medicaid have played in the development of health policy. Connecticut may represent maximum limits to state performance in carrying out EPSDT because it is a rich state, ranking high in medical resources and in the provision of Medicaid services. During the first year of implementation of EPSDT, the program had little impact: less than 5 percent of eligible children were served. State policies, which contravened federal policy, precluded effective resolution of the legislative ambiguities; no new services were added, the organization of health services remained unchanged and fragmented; and the State Health Department played only a limited role.

Child Health Services↗
PubMed1975

Relation between changes in plasma calcium in first week of life and renal function.

(1) Of 71 infants fed on reconstituted dried or evaporated cow's milk, 31 showed a fall in plasma calcium between the 1st and 6th days of life, whereas in 35 breast-fed infants this occurred in only 5. (2) Those artificially-fed infants who had shown a rise in plasma calcium over this period had significantly lower plasma creatinine values and significantly higher excretion of creatinine than those infants who showed a fall in calcium levels. (3) Artificially-fed infants who had shown a rise in calcium had significantly lower plasma osmolality and significantly higher osmolar excretion in the urine than those infants who showed a fall in plasma calcium. (4) It is suggested that a delay in the normal increase in glomerular filtration rate during the first week of life in some infants leads to phosphate retention. This, together with a higher dietary intake of phosphate, leads to a decrease of the plasma calcium to hypocalcaemic levels.

Animals↗
PubMed1975

The 'rapid filling wave' of the apex cardiogram. Its relation to echocardiographic and cineangiographic measurements of ventricular filling.

In order to study the relation between the 'rapid filling wave' of the apex cardiogram and left ventricular filling, simultaneous apex cardiograms, phonocardiograms, and echocardiograms were recorded in 57 patients. Continuous measurements of left ventricular dimension were derived from the echocardiograms by digitization using manual tracing and a computer. Possible errors in the use of a single dimension to assess left ventricular filling were investigated by frame-by-frame analysis of cineangiocardiograms in 37 patients, and the timing of changes in transverse diameter found to correlate closely with those in cavity area. Mitral valve opening, shown as the initial separation of the valve cusps by echocardiography, preceded the 'O' point of the apex cardiogram in all except 3 patients, the 'O' point appearing to correlate more closely with the time of peak rate of outward wall movement. A third heart sound was present in 29 patients, and in 25 of these it occurred later than the peak rate of wall movement (ment interval 51 ms). The end of rapid filling derived from the dimension trace occurred in relation to the third heart sound after a mean interval of 9 ms, with a range from 50 ms before to 80 ms after the third sound. Peak rates of wall movement were similar in patients with and without third heart sounds. The results show that outward left ventricular wall movement begins with a period of acceleration, with peak rates occurring synchronous with the 'O' point of the apex cardiogram and thus with the nadir of the ventricular pressure trace. Outward wall movement becomes less rapid thereafter, so that the rapid filling wave of the apex cardiogram does not reflect the time of rapid filling of the left ventricle. The 'O' point is not related to mitral valve movement nor does the third heart sound bear a consitent relation to any aspect of left ventricular wall movement.

Adolescent↗
PubMed1975

Hepatocyte function in long-term organ culture of Amphimuma means liver.

Fragments of liver from the adult urodele Amphiuma means, the Congo eel, were maintained in organ culture for up to 70 days. The normal electrophoretic patterns of several enzymes were retained. The activities of ornithine transcarbamylase, arginase, glutamate oxalacetate transaminase and glutamate pyruvate transaminase, and urea production, glucose uptake and tissue glycogen content remained relatively constant throughout the culture period. Histological organization and hepatocyte ultrastructure were also retained. Liver fragments survived better in media based on MEM or BME than in medium based on Leibovitz L15. Since many aspects of tissue-specific structure and function are retained, long-term amphibian organ culture is well suited to studies on the control of hepatocyte function and on the effects of metabolites, hormones, drugs and toxins.

Alanine Transaminase↗