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Biomedical subjects

J F Williams

Publications and source records attributed to J F Williams.

At least 235 records · Page 13Linked to original sources
PubMed1979

The ghetto emergency room.

A study of Emergency Room use by members of the Southside Community Health Plan was conducted to assess patterns and economies affected in health care delivery to the population. An analysis of the 141 patient visits is presented.

Chicago↗
PubMed1978

Psoroptic ear mites in dairy goats.

Of 24 adult dairy goats examined at necropsy, 21 were found to be infected with ear mites (Psoroptes cuniculi), but none had gross signs of ear scab. Clinical examination of approximately 200 live adult goats on 23 farms revealed ear scabs in only one animal; however, the frequency of head shaking and ear scratching was high. On one farm with 170 lactating does, most of 25 kids examined within 6 weeks of birth were found to be infested. Serial examination of growing kids on another farm revealed mites in the ears of kids by 10 days of age. The onset of clinical signs of ear mite infestation was evident in all kids on the property during the 3rd week of life. In one instance when infested adult goats and kids were penned with adult sheep and lambs, there was no evidence of cross infestation.

Animals↗
PubMed1978

The fate of 14C in glucose 6-phosphate synthesized from [1-14C]Ribose 5-phosphate by enzymes of rat liver.

1. Glucose 5-phosphate was synthesized from ribose 5-phosphate by an enzyme extract prepared from an acetone-dried powder of rat liver. Three rates of ribose 5-phosphate utilization were observed during incubation for 17 h. An analysis of intermediates and products formed throughout the incubation revealed that as much as 20% of the substrate carbon could not be accounted for. 2. With [1-14C]ribose 5-phosphate as substrate, the specific radioactivity of [14C]glucose 6-phosphate formed was determined at 1, 2, 5 and 30 min and 3, 8 and 17 h. It increased rapidly to 1.9-fold the initial specific radioactivity of [1-14C]ribose 5-phosphate at 3 h and then decreased to a value approximately equal to that of the substrate at 6 h, and finally at 17 h reached a value 0.8-fold that of the initial substrate [1-14C]ribose 5-phosphate. 3. The specific radioactivity of [14C]ribose 5-phosphate decreased to approx. 50% of its inital value during the first 3 h of the incubation and thereafter remained unchanged. 4. The distribution of 14C in the six carbon atoms of [14C]glucose 6-phosphate formed from [1-14C]ribose 5-phosphate at 1, 2, 5 and 30 min and 3, 8 and 17 h was determined. The early time intervals (1--30 min) were characterized by large amounts of 14C in C-2 and in C-6 and with C-1 and C-3 being unlabelled. In contrast, the later time intervals (3--17 h) were characterized by the appearance of 14C in C-1 and C-3 and decreasing amounts of 14C in C-2 and C-6. 5. It is concluded that neither the currently accepted reaction sequence for the non-oxidative pentose phosphate pathway nor the 'defined' pentose phosphate-cycle mechanism can be reconciled with the labelling patterns observed in glucose 6-phosphate formed during the inital 3 h of the incubation.

Animals↗
PubMed1978

New reaction sequences for the non-oxidative pentose phosphate pathway.

1. Reactions leading to the formation of 14C-labelled volatile compounds and compounds volatile under acid conditions were investigated in a system actively synthesizing hexose 6-phosphates from [U-14C]ribose 5-phosphate by reactions catalysed by enzymes prepared from acetone-dried powder of rat liver; no reactions involving 14C-labelled volatile compounds were detected. Similarly the fixation of 14C-labelled volatile compounds into hexose 6-phosphate could not be detected. 2. A complete carbon balance was made for the reactants, intermediates and products of the reactions involved in the conversion of ribose 5-phosphate into hexose 6-phosphate by enzymes of rat liver. Five additional intermediates of pentose 5-phosphate metabolism in liver were detected, namely D-manno-heptulose 7-phosphate, D-altro-heptulose 1,7-bisphosphate, D-glycero-D-ido-octulose 1,8-bisphosphate, D-glycero-D-altro-octulose 1,8-bisphosphate and D-arabinose 5-phosphate. 3. D-Arabinose 5-phosphate was found to be utilized by a rat liver enzyme preparation to produce both hexose 6-phosphate and triose phosphate. 4. D-Arabinose 5-phosphate was reversibly converted into other pentose 5-phosphates. Paper chromatographic and enzymic evidence indicated that the conversion involved an enzyme tentatively named arabinose phosphate 2-epimerase, which catalyses the following reaction: D-arabinose 5-P in equilibrium D-ribose-5-P. 5. A variety of rat tissues also utilized D-arabinose 5-phosphate to produce both hexose 6-phosphate and triose phosphate and at a rate comparable with that obtained with D-ribose 5-phosphate. 6. A new reaction sequence for the non-oxidative pentose phosphate pathway in liver is proposed.

Animals↗
PubMed1978

Globin messenger RNA content in hepatomas: a test of retrogenesis.

The globin mRNA content of foetal, neonatal and normal adult liver and of the transplantable Morris hepatoma 5123C and host liver of animals carrying the tumour was measured using molecular hybridization of total nucleic acid extracts from these tissues with a complementary DNA copy of globin mRNA from rabbit reticulocytes. The purpose of these experiments was to determine, as a test at the molecular level of the retrogenesis hypothesis, if the gene for foetal globin is activated in neoplastic hepatic tissue or induced in host liver. These experiments did not detect any foetal globin mRNA in the hepatoma or host liver nucleic acid extracts in spite of the increase in haemopoietic activity induced in host animals as a consequence of tumour bearing.

Animals↗
PubMed1978

A host range mutant of human adenovirus type 5 defective for growth in hamster cells.

A host-range mutant of adenovirus type 5, which grows in human cells but not in hamster cells, has been isolated. This mutant is complemented in mixed infection in hamster cells at 38.5 degrees C by temperature-sensitive mutants of type 5 belonging to seventeen complementation groups, and may constitute a new group. In mixed infection of human cells at 32 degrees C with the host-range and temperature-sensitive mutants, recombination takes place and by a series of two factor crosses the host-range mutation has been approximately located on the adenovirus genetic map.

Adenoviruses, Human↗
PubMed1978

Interaction between Taenia taeniaeformis and the complement system.

Factors present in the cystic bladder fluid of metacestodes of Taenia taeniaeformis and released by these parasites maintained in vitro were shown to interact with the C system in vitro and in vivo. This interaction resulted in the depletion of hemolytic C in normal sera of several species, the generation of anaphylatoxin-like activity in vitro, the conversion of C3, and the production of vascular permeability changes in vivo. The substances appeared to initiate C fixation nonimmunologically via both the alternative and classical pathways. Intravenous administration of parasite factors in rats led to profound depression of circulating C levels and the rats did not become refractory to this effect after repeated dosing over a 3-week period. Circulating levels of hemolytic C were not altered in infected rats over the first 8 weeks of infection. C-dependent inflammatory responses in the skin of rats were inhibited in animals given i.v. doses of parasite factors. The possibility is raised that local consumption of C around the metacestode in vivo could contribute to its successful evasion of inflammation and immune rejection during infection.

Animals↗
PubMed1978

Surgical removal of the pyloric antrum in weanling rats.

A method was devised for surgical removal of the pyloric antrum in 3-week-old rats. Contrary to published experiences with older rats, it was found that ligation of right and left gastroepiploic arteries was not necessary in young animals. Erythrocytes and fluids were routinely administered postoperatively, and recovered animals were denied access to water and food for 2 and 3 days, respectively. When the rats were fasted overnight prior to surgery, the recovery rate was 87% (27 of 31 attempted). Surgical sites were intact and showed minimal adhesions 2 months later. When overnight fasting was omitted, only 57% survived (8 of 14 attempted), because extensive manipulations were necessary to remove gastric contents, and this often produced shock.

Animals↗
PubMed1977

Cerebral nematodiasis in captive nutria.

Of 35 nutria (Myocaster coypus) at a city zoo, 20 died or were killed because of a progressive central nervous system disease. On the basis of histopathologic findings, a diagnosis of cerebral nematodiasis complicated by nosematosis was made. The only significant management change prior to illness was the feeding of poplar tree branches from a lowland area inhabited by skunks and raccoons. Neurologic disturbances gradually ceased within 2 months after control measures were initiated and the practice of provided poplar branches as a source of roughage was discontinued.

Animals↗
PubMed1977

A mechanism of tumourigenesis: retrodifferentiation and reontogeny in cancer and its clinical significance.

A general theory for the origin and maintenance of the neoplastic state in tissues is presented. Cancer is described as a disease of abnormal cell and tissue differentiation, and its underlying cause is identified in the process of blocked reontogeny. Data are presented which support this hypothesis and show the striking similarities at the molecular level between neoplastic, embryonic and regenerating tissues. The hypothesis suggests that numerous potentially useful (in the clinical sense) proteins, all of them members of early development, may be associated with neoplasms. It is suggested that research aimed at extending the identification and measurement of these proteins will make a significant contribution to the clinical management of cancer and may lead to the development of easy and cheap screening techniques for the early diagnosis of neoplastic disease in man.

Alkaline Phosphatase↗
PubMed1977

Depression of hepatic drug-metabolizing enzyme activity by B. pertussis vaccination.

In vitro measurements are described on N-demethylation of aminopyrine and ethylmorphine, the hydroxylation of aniline as well as the level and activity of the electron transport system in hepatic microsomal fractions from pertussis vaccinated mice. Results indicate that pertussis vaccination of mice markedly decreases the level and activity of the hepatic drug-metabolizing system.

Aminopyrine↗