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Biomedical subjects

J C Robinson

Publications and source records attributed to J C Robinson.

At least 145 records · Page 8Linked to original sources
PubMed1982

A color-matching technique for monitoring tar/nicotine yields to smokers.

We describe a technique that enables individuals to detect the number of puffs taken on a filter cigarette by comparing the "color" of the spent filter to a color scale that simulates the appearance of filters exposed to low-, standard-, or high-yield smoking-machine regimens. Average ratings of filters by 11 subjects correlated almost perfectly with the number of standard puffs to which the filters had been exposed. (Am J Public Health 1982; 72:597-599.)

Colorimetry↗
PubMed1982

Substernal gastric bypass for palliation of esophageal carcinoma: rationale and technique.

A review of sixteen consecutive patients who underwent substernal gastric bypass (SSGB) for middle and upper thoracic esophageal cancer is presented. All patients were alcoholics and heavy smokers with significant medical risk factors. All had locally advanced, long, circumferential, obstructing lesions with regional metastases. The operative mortality rate was 36% in this group of high-risk patients with advanced disease. This high mortality rate may decrease with the modifications discussed. The previously described technique of SSGB is detailed with special reference to a modification for widening the thoracic inlet. The palliation afforded was excellent in all survivors, and the median survival time was a surprisingly long 10 months. Alternative approaches are discussed in a review of the literature. SSGB provides quite possibly the superior approach for palliative management of these difficult lesions.

Aged↗
PubMed1981

How good are the numbers for cigarette tar at predicting deliveries of carbon monoxide, hydrogen cyanide, and acrolein?

Simple and multiple linear regression analyses were performed on the tar, nicotine, CO, HCN, and acrolein deliveries of 98 brands of commercially available Canadian cigarettes. Simple linear regressions of CO, HCN, and acrolein on tar and of acrolein on CO were not significant at the 5% level for plain cigarettes; all other regressions were very strongly significant (p less than 0.01). In addition there was strong statistical evidence that filter, vented filter, and plain cigarettes have different regression relations and different levels of precision associated with the regression parameters. With respect to CO, tar level could predict the corresponding CO value only within 3.9 mg (filter), 1.9 mg (vented filter), and 3.1 mg (plain). These results show that tar delivery alone is an inadequate predictor of gas-phase constituents such as CO. Information concerning these constituents is best conveyed by an analytically determined value for each component.

Acrolein↗
PubMed1981

Assays of immunocompetence in the staging and prognosis of cancer.

There are definite immunologic abnormalities associated with the cancer bearing state which are apparent on both in vitro and in vivo testing. The weight of evidence presented suggests an increasing loss of immunocompetence with increasing disease stage and a degree of positive correlation of immunologic responsiveness with prognosis. Unfortunately the correlation is not absolute for any one individual, although it is often fairly well defined for a large group of patients. This is a failure of all other prognostic studies as well. The critical question as to whether or not this loss of immune integrity reported represents a cause or a result of cancer progression remains largely unanswered. The data suggests that the measured impairment of immunologic responsiveness stems from conditions brought about by the tumor bearing state. Regardless of which precedes the other, the cancer or the immunoincompetence, the additional question as to the effect of immune impairment on the disease progression also remains uncertain. Results of tests to monitor immunocompetence appear to be of some value if used as additional data on which to base prognostic conclusions. Dinitrochlorobenzene skin testing is an assay that is easily performed and probably yields the most easily obtained significant prognostic information.

Dinitrochlorobenzene↗
PubMed1980

Have tar and nicotine yields of cigarettes changed?

In official assays of the tar and nicotine yields of 12 popular brands of cigarettes, smoking machines took fewer puffs, on the average, in 1974 than in 1969. The decline in puffs appears to have been a major cause of the reported reductions in tar and nicotine yields during this period.

Canada↗
PubMed1980

The inhibition of premature labor with indomethacin.

We administered indomethacin orally for the treatment of premature labor in a prospective, randomized, double-blind fashion, and all infants were followed up. Indomethacin was significantly more effective than placebo in inhibition of premature labor during a 24-hour course of therapy, with treatment failure during therapy occurring in only one of 15 indomethacin-treated patients compared to nine of 15 placebo-treated patients (p less than 0.01). Mean plasma concentrations of indomethacin were approximately 0.8 micrograms/ml at both 4 and 12 hours after administration. Mean plasma levels of 15-oxo-13,14-dihydroprostaglandin F2 alpha (PGFM) were similar in the two groups before treatment, decreased markedly in the indomethacin group by 4 hours, and were not detected at 12 hours in all but the one indomethacin-treated patient who was delivered within 24 hours. Patients in the placebo group who were delivered prematurely had higher pretreatment PGFM levels (mean +/- SE, 83 +/- 18 pg/ml, n = 9) than the patients who responded to placebo (25 +/- 6 pg/ml, n = 6) (p less than 0.05). There was no difference between the indomethacin and placebo groups with respect to gestational age at delivery, birth weight, and neonatal morbidity and deaths. In particular, we found no evidence of premature closure of the ductus arteriosus, pulmonary hypertension, or increase in bleeding problems among the infants exposed to indomethacin in utero. Although no difference in neonatal outcome was observed in this small number of patients, it would seem prudent still to consider indomethacin as an experimental therapy.

Dinoprost↗
PubMed1980

Estimating the hazards of "less hazardous" cigarettes. I. Tar, nicotine, carbon monoxide, acrolein, hydrogen cyanide, and total aldehyde deliveries of Canadian cigarettes.

The tar, nicotine, CO, HCN, total aldehyde, and acrolein deliveries of 102 brands of Canadian cigarettes have been determined. On the basis of these deliveries, 15 brands (9% of sales) were categorized as low hazard and 9 brands (10% of sales) as high hazards. All six constituents were used for the classification since for most brands tar was a poor indicator of gas-phase deliveries. As a result, smokers who indiscriminately switch to a brand with a lower tar delivery may inadvertently increase their exposure to gas-phase constituents such as CO and increase their risk of smoking-related pathology. With respect to Canadian cigarettes, the choice of a 30-mm standard butt length may result in omission of some of the available tobacco from the testing procedure, thus reducing the value of tar level as a guide to choosing a less harmful cigarette.

Acrolein↗
PubMed1980

Studies on the nicotine exposure of individual smokers. II. An analysis of smoking habits during a one-week period.

The smoking habits of 30 smokers, consisting of monozygotic and dizygotic twins, were investigated in order to order check whether a subgroup of these smokers exhibited a pattern which could be associated with addiction to nicotine. The results showed that smoking patterns varied in the course of a day, although no consistent pattern emerged which indicated that a significant sub-group of smokers was addicted strongly to nicotine. Moreover, on the basis of the associations of mouth level exposure obtained from a specific cigarette, and the time intervals when a cigarette was smoked before or after a specific cigarette was smoked, it appears that the sub-groups of smokers which self-titrate nicotine to any appreciable extent is probably small.

Adolescent↗
PubMed1979

Characterization of alkaline phosphatases from human first trimester placentas.

Alkaline phosphatase from human first trimester placentas was purified, characterized, and compared with alkaline phosphatases from term placenta and liver. Three forms of first trimester placental alkaline phosphatase (I, IIa, and IIb) were isolated; their relative amounts were 35%, 39%, and 26%, respectively. Phosphatases I and IIa were found to be dimers, whereas phosphatase IIb appeared to be a tetramer consisting of two dimers of phosphatase I or IIa. Phosphatase I was indistinguishable from liver phosphatase by several criteria including apparent molecular weight (Mr = 165,000), size of the monomeric subunit (Mr = 77,000), heat liability, insensitivity to inactivation by antiserum against term placental alkaline phosphatase, and sensitivity to inactivation by antiserum against liver alkaline phosphatase. In addition, phosphatase I and liver phosphatase were equally sensitive to inhibition by amino acids, levamisole, l-p-bromotetramisole, and EDTA. Phosphatase IIa, in contrast, was indistinguishable from term placental alkaline phosphatase by the same criteria: apparent molecular weight (Mr = 115,000), size of the monomeric subunit (Mr = 63,000), heat stability, inactivation by antiserum against term placental alkaline phosphatase, and sensitivity to inhibition by various compounds. These findings clearly demonstrate the existence of two distinct placental alkaline phosphatases, one (phosphatase I) specific for the first trimester placenta and the other (phosphatase IIa) occurring in both first trimester and term placentas.

Alkaline Phosphatase↗
PubMed1978

Developmental changes in the enzymatic capacity for reduction and oxidation of alpha-ketoadipate in rat liver, heart, kidney, and brain.

alpha-Ketoadipate, an intermediate common to lysine and tryptophan metabolism, is a substrate for both alpha-ketoadipate reductase (alpha-KAR) and alpha-ketoadipate dehydrogenase (alpha-KADH). A comparison was made of the activities of these two enzymes in liver, heart, kidney, and brain of rats during the period from 5 days before birth to 56 days after birth. In general, both enzymes increased in activity during development in all tissues tested; however, different patterns of increase were observed (Figs. 1 and 2). The ratio of alpha-KADH to alpha-KAR (on the basis of activity/g tissue) did not change significantly in liver until day 10 and then increased 6.6-fold (from 0.08 to 0.53) in the period from day 10 to day 28. For other tissues the ratios increased 5.5-fold in hearts (from 0.2 to 1.1), 12-fold in kidney (from 0.2 to 2.4), and 5.3-fold in brain (from 0.3 to 1.6) during the period from day -5 to day 56. These results suggest that alpha-KAR has a major role in the metabolism of lysine and tryptophan during development.

Adipates↗
PubMed1978

Regulation of the synthesis of human chorionic gonadotrophin by 5-bromo-2'-deoxyuridine and dibutyryl cyclic AMP in trophoblastic and nontrophoblastic tumor cells.

Synthesis of hCG and its alpha subunit (hCG-alpha) by trophoblastic tumor cell lines (JEG-3, Reid, and BeWo) and by nontrophoblastic tumor cell lines [ChaGo and three HeLa lines (HeLa CCL2, HeLa S3, and HeLa 65)] was studied. cAMP, dibutyryl cAMP, and 8-bromo-cAMP induced, but 5-bromo-2'-deoxyuridine inhibited, the synthesis of hCG-alpha and hCG in trophoblastic tumor cells, Addition of 5-bromo-2'-deoxyuridine partially blocked the induction by dibutyryl cAMP in these cells. The synthesis of hCG-alpha and hCG in nontrophoblastic tumor cells was stimulated by dibutyryl cAMP. cAMP and 8-bromo-cAMP, however, did not affect the synthesis of hCG-alpha, although the synthesis of hCG was enhanced. 5-Bromo-2'-deoxyuridine induced hCG-alpha synthesis but did not affect hCG synthesis in nontrophoblastic tumor cells. In HeLa S3 and HeLa 65 cells, the amount of hCG-alpha and hCG produced in the presence of dibutyryl cAMP and 5-bromo-2'-deoxyuridine together was greater than the total hormone produced by each inducer separately. Our data indicate that the regulation of the production of hCG-alpha and hCG differs in trophoblastic and nontrophoblastic tumors.

Bromodeoxyuridine↗