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A Taylor

Publications and source records attributed to A Taylor.

At least 847 records · Page 47Linked to original sources
PubMed1976

Analysis of muscle receptor connections by spike-triggered averaging. 2. Spindle group II afferents.

1. The spike-triggered averaging (STA) method has been used to study synaptic connections of nine spindle group II afferents from medial gastrocnemius to 151 motoneurons of leg muscles in the cat. 2. EPSPs were found in 40 cells, predominantly of triceps surae with latency from cord entry ranging from 0.3 to 4.2 ms. Those with latency less than or equal to 1.4 ms were deduced to be monosynaptic in confirmation of Kirkwood and Sears (13). Mean amplitude for MG-LGS cells was 30.1 muV and mean rise time 1.0 ms (compared with 65.4 muV and 1.0 ms for monosynaptic Ia EPSPs from the preceding report (26)). It is argued that monosynaptic latency for spindle group II afferents could be as large as 1.65 ms. 3. The occurrence of a presynaptic spike permitted the division of EPSP latencies into central conduction time and synaptic delay components. Sindle group II central conduction times were significantly longer than those of Ia afferents, while there were no differences in the synaptic delays associated with the two afferent types. 4. EPSPs of longer latency were judged to be di- or trisynaptic. They were smaller and had longer rise times than the monosynaptic effects. Evidence is presented to show that short rise time of an individual PSP does not guarantee that it is monosynaptic. Rise times are different only on a population basis. 5. Inhibitory responses were found with latencies and mean rise times appropriate for di- and trisynaptic connections. Their mean amplitude was 4.6 muV. 6. The distribution of EPSPs and IPSPs was generally consistent with their exerting stretch reflex effects similar to that of Ia afferents and inconsistent with the inclusion of them in the grouping known as "flexor reflex afferents."

Animals↗
PubMed1976

Lack of gallium uptake in primary hepatic amyloidosis.

99mTc-sulfur colloid and 67Ga citrate hepatic scintigrams showed matching defects in a patient with diffuse primary amyloidosis. Amyloidosis should be added to the usual differential diagnosis of such matching lesions which includes cysts, fibrosis, most benign tumors, and occasional metastatic lesions which do not concentrate gallium.

Aged↗
PubMed1976

A potential error in the quantitation of fecal blood loss: concise communication.

Chromium-51-labeled red cells were used to quantitate fecal blood loss in a patient with chronic upper gastrointestinal hemorrhage. On Day 1, the stool guaiac was positive but the blood loss indicated by 51Cr was less than 1 cm3. Blood loss in the stool by 51Cr did not become significant until Day 3, when it measured 23 cm3. The failure to detect abnormal blood loss on Day 1, and probably on Day 2, appears to be due to a long intestinal transit time from a proximal bleeding site. The problem of slow intestinal transit is not uncommon and could lead to a false-negative study or falsely low estimates of fecal blood loss. This problem could be minimized by beginning stool collection on Day 3 or by delaying stool collection until the appearance in the stool of an oral nonabsorbable marker swallowed when the 51Cr-tagged red cells are injected.

Aged↗
PubMed1976

Tumor-associated thymidine kinase in the sera of rats with transplanted hepatomas.

A cytoplasmic form of thymidine kinase was detected in sera from rats bearing Morris hepatoma 7777. Polyacrylamide electrophoretic properties demonstrate similarity between the serum enzyme extracted from hepatoma tissue. This form of thymidine kinase has also been described in normal human fetal tissue and a variety of human tumor cells. The results suggest that serum isoenzymes of thymidine kinase may be a useful adjunctive test for the presence of certain types of malignant tumors.

Animals↗
PubMed1976

Tissue distribution of 203 Pb-acetate: comparison with 67 Ga-citrate as an abscess-localizing agent.

Since 203Pb-acetate accumulates in necrotic tumor tissue, the possibility was raised that it might also accumulate in other necrotic tissue such as abscess. We first studied the tissue distribution and excretion of 203Pb-acetate in control rats at 4, 24, 48, 72, and 96 hr. An enterohepatic circulation for lead is suggested. We then compared the uptakes of 203Pb-acetate and 67Ga-citrate in experimental abscesses in rats. The mean gallium accumulation in the abscess was 10 times that of lead at 24 hr and 12 times that of lead at 72 hr. The abscess-to-tissue ratios were greater for gallium for every tissue examined, although the abscessed areas were clearly visualized by scanning at 24 and 72 hr with both agents. With the exception of blood, abscess-to-tissue ratios for 67Ga at 24 hr were higher than or equal to those at 72 hr. However, the 67Ga ratios for the inflamed tissue surrounding the abscess to muscle and blood were higher at 72 hr than at 24 hr, which suggests that inflammation without abscess might be better identified by gallium scanning at 72 hr.

Abscess↗
PubMed1975

On the effects of propionate and other short-chain fatty acids on sodium transport by the toad bladder.

1. Propionate and other unbranched short-chain fatty acids, butyrate, pentanoate, hexanoate and octanoate were found to both stimulate and inhibit active sodium transport by the toad bladder, as measured by the short-circuit current (s.c.c.). 2. Stimulation alone followed addition of low concentrations of fatty acids (0.1-1.0 mM) to either the serosal or mucosal bathing medium; stimulation was also seen after an initial period of inhibition in response to higher concentrations (approx. 5 mM) of some compounds. 3. Inhibition alone followed addition of high concentrations (5-20 mM) of these compounds. The duration and magnitude of the inhibition varied with increasing concentration and chain length of the fatty acid, and was greater following mucosal addition than serosal addition. 4. The inhibitory effect of mucosal propionate increased with decreasing pH of the mucosal bathing medium. 5. Inhibition by the fatty acids was completely reversed upon removing the compound from the bathing medium, and stimulation characteristically followed. 6. In studies designed to evaluate the role of metabolism of the fatty acids in their mucosal inhibitory effects it was found that 14-c-labelled propionate, when added to the mucosal surface of the bladder, was converted to 14-CO2, and mucosal succinate and alpha-oxoglutaric acid at 20 mM inhibited the s.c.c. slightly. However, malonate did not interfere with inhibition by mucosal propionate and two non-metabolizable acids, dimethylpropionate and benzoate, induced inhibition (and no stimulation) of the s.c.c. 7. In the presence of an inhibitory concentration of fatty acid, the ability of the bladder to respond to added pyruvate was reduced in proportion to the reduction in the level of the s.c.c., whereas the natriferic response to vasopressin was largely intact. 8. We conclude that stimulation of sodium transport by propionate and other short-chain fatty acids is due to metabolism of the compounds and provision of energy to the sodium transport mechanism. The basis of the inhibition appears complex. It may in part depend on metabolism of the fatty acids and/or uncoupling of oxidative phosphorylation, with resultant reduction in net ATP production for the sodium transport mechanism. However, the inhibition may also be caused in part by a direct effect on the mucosal entry of sodium into the transporting epithelial cells.

Animals↗
PubMed1975

Prognostic antecedents and outcome in a follow-up study of children with a diagnosis of childhood psychosis.

Records of the initial period of observation and the early history of 59 children with a diagnosis of childhood psychosis during the preschool years were examined for possible predictive variables. The children, now age 10 years or older, were divided into two groups--those that are presently successful and those that are presently unsuccessful, according to the criteria of this study. A cluster of 23 items was found significantly to differentiate the two groups.

Adaptation, Psychological↗
PubMed1975

Serum complement profiles in infants and children.

The purpose of this study was to examine normal serum values for the complement components, C3, C4, and C5, and total hemolytic complement (CH50) activity in 163 healthy infants and children, in the age range from birth through 14 years. There were statistically significant relationships of C3, C4, and C5, but not CH50 with age. None of the complement components or CH50 could be differentiated by sex or race. Tolerance limits for high and low values were projected for each complement measurement for 75%, 90%, and 95% of the general population. Our data confirm the differences in complement levels between children and adults and demonstrate a wide range of values within each group, reflecting the biologic variability of complement measurements. These results emphasize the importance of establishing normal pediatric values in any laboratory that measures complement profiles in various diseases of childhood.

Adolescent↗