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Biomedical subjects

D J Williams

Publications and source records attributed to D J Williams.

At least 199 records · Page 11Linked to original sources

Increased incidence of retained placenta associated with heat stress in dairy cows.

A dairy herd experienced an increased incidence of retained placenta and postpartum metritis during late spring and summer of 1977 and 1978. The incidence of retained placenta and postpartum metritis was 24.05% during the period of May through September compared to 12.24% the rest of the year. The gestation period of cows having retained placenta and postpartum metritis was an average of 5.25 days shorter than that of cows not exhibiting these symptoms. The gestation period of cows calving during the warm season was an average of 2.82 days shorter than that of the cows calving during the cool season. Heat stress resulting in early parturition was the probable cause of this increased incidence of retained placenta and postpartum metritis. The number of days open was influenced both by abnormal postpartum period and season of calving. Cows having retained placenta and metritis were open an average of 31.69 days longer than cows with normal postpartum periods. Cows that calved during the warm season were open an average of 24.42 days longer than those calving during the cool season.

Journal Article↗

Pharyngoesophageal dysphagia in infancy.

Swallowing disorders in the first 12 months of life are often seen in pediatric practice. Infants with more persistent and severe disabilities with feeding, continued vomiting, regurgitation, or aspiration resulting in pulmonary disease may have correctable anatomical abnormalities. Full pediatric, neurological, radiological and endoscopic examination is required to distinguish the site of the disorder.

Cysts↗

The laser and the nasal septum--a histological study.

We studied the histopathological effects of CO2 laser use on the nasal septum of nine rabbits. In the rabbits irradiated with no more than three bursts at four watts, healing was prompt and complete; more than three bursts caused cartilage necrosis. The CO2 laser, using appropriate settings, is safe and effective in treating anterior septal lesions. These settings can be established only after histological examination of the lesions.

Animals↗

The separation of microsomal membranes and free polyribosomes by gel filtration.

The integrity of polyribosome-membrane complexes in microsomal preparations is dependent on the centrifugal conditions used for their preparation. This paper describes techniques based on gel filtration that enable the rapid and gentle separation of microsomal membranes from both free polyribosomes and soluble protein.

Chromatography, Gel↗

Synthesis and secretion of albumin in rats during treatment with a carcinogenic dose of N-2-acetylaminofluorene.

The chronic administration of N-2-acetylaminofluorene (N-2-AAF) to rats causes a loss of hepatic cytoplasmic RNA, particularly from the endoplasmic-membrane fractions. At the end of the complete carcinogenic dose, the level of amino-acid incorporation into proalbumin is normal, despite the loss of 35% of membrane-bound RNA. The secretion of albumin, however, is inhibited. This inhibition of secretion is apparently the result of a change in membrane flow and differentiation; transfer of nascent protein from smooth-surfaced vesicles to the Golgi apparatus is blocked. The significance of these findings is discussed.

2-Acetylaminofluorene↗

A sub-population of rat liver membrane-bound ribosomes that are detached in vitro by carcinogens and centrifugation.

The chemical-carcinogen-induced detachment of ribosomes from rat liver endoplasmic reticulum was studied in vitro. Incubation of postmitochondrial supernatant with 0.2 mM-diethylnitrosamine or N-2-acetylaminofluorene removed approx. 16% of membrane-bound ribosomes, measured as differences in RNA/protein values of membrane separated from unbound ribosomes by flotation. These ribosomes are also detached by exposure to high centrifugal forces (160000g) and are among those removed by NADPH-catalysed lipid peroxidation. Extensive lipid peroxidation prohibits any measurement. The ribosomes (polyribosomes) removed are not those detached from the membrane by exposure to high KC1 concentrations (loosely bound) or high KC1 concentrations in the presence of puromycin (tightly bound). It is concluded then that centrifugally labile and carcinogen-sensitive represent a previously unreported sub-population of membrane-bound ribosomes.

Animals↗

The efferent projections of the nucleus accumbens in the rat.

The efferent projections of the nucleus accumbens have been examined in the rat. This has been achieved by mapping the distribution of degenerating axons and terminals following the placement of small electrolytic lesions within the accumbens. Quantitatively, the majority of accumbens efferent fibres appear to terminate in the diencephalon, while there are also projections to cortical and brain stem structures. The evidence suggests that the nucleus accumbens sends efferent fibres to the cingulum, lateral hypothalamus, globus pallidus, thalamus (including the reuniens, gelatinosus, parataenial, medial and anteromedial nuclei) and the substantia nigra.

Animals↗

Attendance at a London casualty department.

Patients who attended the casualty department of the Middlesex Hospital during one week in 1973 were interviewed. A predominantly young and working population used the department. Relatively few patients lived close to the hospital but many worked nearby. One third of all attendances were by patients who had been asked to return by casualty doctors. About half the new patients came of their own accord; the next largest group had been sent directly from work by an employer or occupational health service. Half the patients came with injuries, many of them superficial, although there were also serious accident cases. One fifth of the patients had no general practitioner whom they could consult. Age and geographical mobility were related to whether or not patients were registered with a general practitioner. The main reasons for not consulting a general practitioner were that patients felt they needed hospital treatment or that it was more convenient to attend the casualty department. It is suggested that the view that casual attenders with relatively trivial complaints should be encouraged to go to a general practitioner is not always applicable since social as well as medical circumstances determine whether or not patients decide to visit casualty.

Emergency Service, Hospital↗

The formation of 2-hydroxymethylquinoline and quinaldine in greyhound urine.

2-Hydroxymethylquinoline and quinaldine are found in nonfresh greyhound urine as putrefactive bases. Their production as a function of time was investigated. This is affected by preservatives or refrigeration. 2-Hydroxymethylquinoline forms in greyhound urine, if non-preserved, in three or four days at room temperature while quinaldine takes as much as 10 days longer to form. Production of 2-hydroxymethylquinoline or quinaldine is not arrested but merely retarded by preservation or refrigeration. Sodium fluoride is one of the more effective preservatives. A method for the measurement of quinaldine and 2-hydroxymethylquinoline using gas chromatography is described. The columns used are Carbowax 6000 + potassium hydroxide on Chromosorb G and SE-30 on Chromosorb W.

Animals↗