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Biomedical subjects

J Lough

Publications and source records attributed to J Lough.

At least 73 records · Page 4Linked to original sources
PubMed1984

Effects of estradiol on myointimal thickenings from catheter injury and on organizing white mural non-occlusive thrombi.

The objective of this present study was to determine the effect of estradiol on the organization of white, mural, nonocclusive thrombus produced with a permanent, indwelling catheter in the abdominal aortae of rabbits and on myointimal thickenings produced by catheter injury but with only transient adhesion of platelets and no thrombosis in the thoracic aorta. Estradiol did not significantly alter the weight of thrombus or myointimal thickenings produced nor did it qualitatively or quantitatively alter Evans Blue uptake by the 7-day myointimal thickenings from injury or alter Evans Blue uptake by the 7-day thrombus. DNA synthesis measured in terms of [3H]thymidine incorporation into biochemical extractable DNA and expressed as dpm/mg DNA was 9 519 for the normal rabbit aortic wall without adventitia; 358 261 for myointimal thickenings including underlying aortic wall without estradiol treatment and 196 336 with estradiol; 55 840 for thrombus without estradiol and 55 250 with estradiol. Expressed as dpm/mg delipidated tissue the values were 62 for the normal rabbit aortic wall; 4 590 for myointimal thickenings without estradiol and 2 037 with estradiol; 1 421 for thrombus without estradiol and 1 403 with estradiol. Estradiol was effective in reducing DNA synthesis in the myointimal thickenings from injury but was not effective in reducing DNA synthesis in the 7-day thrombi. Estradiol significantly increased the influx or retention of [14C]cholesterol found at autopsy in both the organizing thrombi and the myointimal thickenings from injury after an oral dose of 14C-labelled cholesterol was administered 4 days prior to autopsy; however, estradiol did not significantly modify the final cholesterol concentration in the lesions.

Animals↗
PubMed1983

Declining histone phosphorylation during myogenesis revealed by in vivo and in vitro labeling.

To investigate histone phosphate levels during myogenesis, proliferation (d 1), pre-fusion postmitotic (d 2) and myotube (d 3) stage cultured chicken myoblasts were phosphorylated in vivo with [32P]orthophosphate or in vitro by incubating isolated nuclei with 32P-gamma-ATP. Incorporation of radioactive phosphate into histone was assessed by SDS and acid/urea/Triton-X-100 (AUT) gel electrophoresis and radioautography. During proliferation, in vivo labeling with [32P]orthophosphate revealed that all histones except H2b were phosphorylated in the following order of decreasing modification: H1 a greater than H2a greater than H1 b greater than H3 greater than H4. In pre-fusion post-mitotic cells phosphorylation of histones H1 a, H3 and H4 declined, whereas all histones exhibited significantly decreased modification at the myotube stage. It is unlikely that these changes resulted from decreased specific radioactivity of intracellular inorganic phosphate pools, since uptake of [32P]orthophosphate by myotubes increased six-fold, compared with proliferating cells. Isolated nuclei incubated with 32P-gamma-ATP displayed similar decreases during myogenesis; however, 1 a, H1 b and H3 were the only histones modified by in vitro phosphorylation.

Animals↗
PubMed1983

Modulation of in vitro myogenesis by submillimolar concentrations of sodium butyrate.

The effects of submillimolar concentrations of sodium butyrate on the differentiation of cultured chick myoblasts have been studied. The continuous presence of 0.5 mM butyrate inhibited myoblast fusion, creatine kinase (CK) isozyme transition, and synthesis of total RNA and protein until the 4th day of myogenesis, after which the fusion index reached control values and total CK activity was elevated. The latter continued to exhibit daily increases over control levels, largely reflecting activity of the MM-CK muscle-specific isozyme which increased to twice the control level by the 8th day. Similar but less striking patterns of early inhibition followed by stimulation were observed for total protein content and synthesis of total protein and RNA. On the other hand, DNA content was slightly but significantly depressed in treated cultures at all times. Butyrate treatment did not reverse 5'-bromodeoxyuridine (BUdR) inhibition of MM-CK differentiation. It was also noted that continuous treatment with 0.5 mM butyrate prevented the unexplained sporadic deterioration of myotubes sometimes observed at the 4th day.

Animals↗
PubMed1982

Giant hemangioma of the liver.

Six patients with hemangioma of the liver larger than 5 cm in diameter were treated at the Montreal General Hospital between 1968 and 1981. Two patients were symptomatic, complaining of nonspecific right upper quadrant pain. One man presented in a dramatic fashion when he bled from a ruptured hemangioma after a fall. Arteriography in three of the patients revealed characteristic filling of the vascular spaces commencing in the arterial phase with persistent dense accumulation in the venous phase. A timed, infusion computerized axial tomogram in one case revealed prolonged opacification, occurring from the periphery of the lesion towards the centre over several minutes. All six hemangiomas were benign; they consisted of large blood spaces separated by fine fibrous septae. They appeared to expand by incorporating marginal liver sinusoids. Organizing thrombus was often seen; this could account for the right upper quadrant pain. The patients were treated by partial or total hepatic lobectomy to relieve symptoms and prevent hemorrhage due to trauma. On two occasions, nodules of hemangioma were left behind but none of the six patients showed evidence of recurrence on follow-up.

Adult↗
PubMed1980

Focal nodular hyperplasia of the liver. An electron microscopic study of the vascular lesions.

Localized myointimal proliferation with narrowing of blood vessels is frequently seen associated with focal nodular hyperplasia of the liver. The apparent increase in the incidence of focal nodular hyperplasia in women may be associated with the oral use of contraceptive medications, and it has been suggested that the nodules could be areas of focal cirrhosis following liver infarction. A light and electron microscopic study was undertaken to try to determine the pathogenesis of the vascular abnormalities. The observation of intravascular coagulation, recurrent endothelial damage, and myointimal proliferation about bifurcations suggests that the changes could be produced by repeated platelet-fibrin aggregate embolic injury.

Arteries↗
PubMed1979

Recurrent obstipation as a complication of partial pancreatectomy for non-beta cell adenoma of the pancreas.

Verner and Morrison, in 1958, reported non-insulin-secreting tumours of the pancreas that were associated with a syndrome of refractory diarrhea, achlorhydria and hypokalemia. Surgical resection of such tumours results in rebound acid hypersecretion and cessation of the watery diarrhea. The authors report the case of an 84-year-old man who had three of the four major criteria for diagnosis of the Verner Morrison syndrome. Hypokalemia was absent, but this was possibly due to the large doses of potassium chloride that he was taking in conjunction with diuretics. After resection of the tumour severe obstipation with resultant bowel obstruction developed in addition to rebound hypersecretion and relief of watery diarrhea. Treatment, consisting of bulk laxatives in appropriate amounts, alleviated the obstipation.

Achlorhydria↗
PubMed1978

Focal nodular hyperplasia of the liver and oral contraceptives.

The increased incidence of liver tumors in women of childbearing age who have been using oral contraceptives for many years suggests an environmental causation. The causative agent may be the steroidal oral contraceptives. Two lesions are recognized: focal nodular hyperplasia and hepatic adenoma. This paper concentrates on focal nodular hyperplasia, with two cases added to the four previously described cases. It is postulated that the estrogen component causes vascular lesions characterized by myointimal hyperplasia and thrombosis, leading to infarct, necrosis, and subsequent nodular hepatic regeneration. The clinical feature highlighted is the long history of gastrointestinal disturbance associated with negative gastrointestinal investigation with the possible exception of cholelithiasis. It is suggested that gray-scale ultrasonography is an effective screening method that also aids in a definitive diagnosis. As these tumors are often incidental findings it is emphasized that the liver should always be inspected at laparoscopy. Ultimately, diagnosis by biopsy or excision is essential as it may well be possible to treat cases of focal nodular hyperplasia of the liver conservatively, once oral contraceptives have been discontinued.

Adult↗
PubMed1978

Cardiomyopathy produced by cigarette smoke. Ultrastructural observations in guinea pigs.

Guinea pigs were restrained in a smoking machine and were exposed to the smoke of eight cigarettes a day, five days a week for 12 to 15 weeks. One group of animals inhaled filtered smoke from which most of the tar and nicotine had been removed. Heart weight of the smoking animals was found to be significantly increased in both the filtered and unfiltered groups. Toxic changes were evident in myocardial mitochondria that were associated with edema, increased lipid and enhanced autophagolysosomal activity. The observed cardiomyopathy is probably caused by carbon monoxide and resembles the changes of chronic intermittent hypoxia.

Animals↗
PubMed1977

Hepatic toxicity associated with gold therapy.

Three patients with rheumatoid arthritis developed jaundice after initiation of chrysotherapy. Gold sodium thiomalate had been administered in dosages of 37.5, 60, and 110 mg in these patients before the onset of jaundice. Liver function studies indicated a cholestatic jaundice in all subjects. One patient underwent exploratory laparotomy because of progressive jaundice. Liver biopsy was done in two patients. In one patient significant bile stasis and thrombi were seen in the biliary tree. In another patient liver biopsy showed ballooning of hepatocytes with minimal cholestasis. All patients recovered spontaneously. Awareness of this rare complication may prevent unnecessary diagnostic and surgical procedures in patients with rheumatoid arthritis who may develop jaundice while receiving chrysotherapy.

Arthritis, Rheumatoid↗
PubMed1976

Wilson disease. Comparative ultrastructure in a sibship of nine.

Comparative electron microscopy was done on liver tissue from a family of nine siblings to determine whether presymptomatic, affected patients with Wilson disease could be differentiated from heterozygous, normal carriers. Two of the nine had developed the neurologic manifestations of the disease; three others were considered to be homozygous but normal, two were heterozygous and normal, and two were classified as genotypically uncertain because of borderline biochemical abnormalities. Alterations of the mitochondria and endoplasmic reticulum suggestive of copper toxicity were present in both the heterozygous and the genotypically uncertain siblings, and a clear distinction could not be made on this basis. The severity of the abnormalities appeared to correlate with liver copper level, and organelle changes were found to precede lipid accumulation.

Adolescent↗