Search PubMed⌕ Search

Biomedical subjects

J Lewis

Publications and source records attributed to J Lewis.

At least 379 records · Page 21Linked to original sources

Formes frustes in myeloproliferative disorders. Identification by the growth of an endogenous erythroid clone in vitro in patients with arterial vascular disease.

The myeloproliferative disorders, including polycythaemia rubra vera, arise as a result of a single-cell mutation. A characteristic of the abnormal haemopoietic clone is that it can form erythroid colonies in vitro in the absence of added erythropoietin. Such endogenous erythroid clones were consistently found in two of seven patients with peripheral vascular disease. These two patients had mean platelet counts of 600 X 10(9)/l and 630 X 10(9)/l. Culture of blood and bone-marrow cells from patients with raised platelet counts secondary to a variety of other disorders failed to yield such colonies. The presence of endogenous erythroid clones provides early evidence of a myeloproliferative disorder.

Adult↗

Hepatobiliary scanning in hemobilia-induced acute cholecystitis.

Radionuclide scanning of the hepatobiliary tree is highly accurate for the detection of patients with acute cholecystitis. Hemobilia, a rare complication of percutaneous liver biopsy, may result in blood clots within the biliary canaliculi. Such clots, like gallstones, may occlude the ducts and produce a clinical syndrome indistinguishable from acute cholecystitis. A patient with acute cholecystitis resulting from hemobilia following percutaneous biopsy of the liver is described. The diagnosis of acute cholecystitis secondary to blood clots was made with technetium 99mTc Iprofenin (Pipida [Sn]) scintigraphy. The patient was treated conservatively, and follow-up Pipida scan 6 weeks later demonstrated normal hepatobiliary function.

Adult↗

Comparison of in vivo and in vitro SCE induction.

In vivo and in vitro sister-chromatid exchange (SCE) induction and cell replication kinetics were compared in P388 cells exposed to 4 mutagens. While concordance was observed between SCE induction and inhibition of cell replication kinetics, certain mutagens were more potent in vivo while others were more potent in vitro. These results indicate that caution should be applied before equating in vivo and in vitro mutagen exposures.

Animals↗

A case of acute esophageal variceal hemorrhage.

All those who deal with patients suffering from this discouraging and lethal disease are constantly searching for the ideal method in which to control active hemorrhage from esophageal varices. Continued nonoperative management in those whose hemorrhage does cease on purely conservative measures results in an unacceptably high mortality, the most common cause of which is recurrent bleeding. Those patients who undergo portoazygos disconnection via the transabdominal or transthoracic route are equally prone to recurrent hemorrhage unless an elective portosystemic shunt is performed. Whether such a shunt is done as an elective or as an emergency procedure, the postoperative mortality and morbidity are high. Although protection against recurrent bleeding can be expected in most, the natural history of liver disease progression (and prognosis therefrom) remains unaltered, if not occasionally aggravated. Resurgence of interest in injection sclerotherapy for immediate control of hemorrhage, with subsequent longterm control of varices by repeated injections at intervals of several months, has received enthusiastic support. Preservation of existing hepatocellular function, the simplicity of the technique, especially with the fibreoptic endoscope, and its likely impact on medical care costs in this disease are attractive benefits. It is not perfect, and prospective randomized controlled trials are required to prove its superiority over other forms of treatment, but it currently appears to be the most viable alternative. We are not alone in fervently hoping that portoazygos disconnection will rarely be required and that portosystemic shunting will become a superfluous procedure, comfortably consigned to the history books.

Acute Disease↗

Pharmacokinetics of standard (lithicarb) and sustained-release (Priadel) lithium carbonate preparations in patients.

Equivalent oral dosages (800 mg, 21.6 mmol) of a standard (Lithicarb) and a sustained-release (Priadel) lithium carbonate preparation were administered to six patients receiving lithium maintenance treatment using a randomized cross-over design. There were no significant differences in the two preparations for 24 hour plasma level curves, 24 hour bioavailability, peak plasma concentrations (Cmax), time to peak plasma concentrations (Tmax) or urinary excretion rates. These results are in agreement with a previous study using Priadel in healthy volunteers, and indicate that Priadel is a delayed-release, rather than a true sustained-release preparation. In order to maintain therapeutic plasma levels and to minimise adverse effects that may occur with high plasma lithium levels, Priadel needs to be administered in divided dosages rather than as a single daily dose.

Administration, Oral↗

The timetable of innervation and its control in the chick wing bud.

How is the timing of nerve outgrowth controlled during development? This question has been examined by grafting early limb buds between chick embryos of different ages, before innervation, and assessing the morphological pattern of nerves at later stages. Grafted limbs continued to develop according to their own timetable and were invaded by nerves from the host. Irrespective of the age of the host, the development of the pattern of innervation followed the time course appropriate to the age of the grafted limb. Young nerves in an old limb showed accelerated development; old nerves in a young limb showed retarded development. The process of innervation is apparently governed not by the intrinsic developmental timetable of the neurons, but rather by the rate of construction of pathways for them in the peripheral tissue, and by the times at which their specific targets, such as muscles, differentiate.

Animals↗

Mortality and cancer morbidity among workers in the rubber tire industry.

A retrospective follow-up study was conducted to evaluate mortality and cancer incidence between 1954 and 1976 among 1,792 white male production workers employed for at least 2 years at a tire manufacturing plant. There were no marked excesses in overall or site-specific cancer deaths or incident cases. Compared to U.S. white males, men employed for at least 10 years experienced small increases in deaths from cancers of the large intestine, pancreas, and lung. Results obtained by comparing observed incident cancer cases to the numbers expected based on age- and calendar time-specific incidence rates of Connecticut males also suggested excesses of these three malignancies. These findings were based on small numbers and therefore do not necessarily indicate causal associations between cancer excesses and employment in the rubber tire industry. However, because the workers studied comprised a relatively young population that may not have experienced the full impact of carcinogenic occupational exposures, further follow-up is warranted.

Adult↗