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Biomedical subjects

A Fahmy

Publications and source records attributed to A Fahmy.

9 recordsLinked to original sources

The effect of glucose on insulin release and ion movements in isolated pancreatic islets of rats in old age.

1. The effect of glucose on 86Rb+ efflux, 45Ca2+ net uptake and insulin secretion of pancreatic islets from 3- and 24-month-old rats was studied. 2. Raising the glucose concentration from 3 to 5.6 and 16.7 mM had no effect on 86Rb+ efflux from islets of 24-month-old male rats whereas that from 24-month-old female rats was decreased. 3. At 16.7 mM-glucose, net uptake of 45Ca2+ was significantly diminished in islets of 24-month-old rats compared to islets of 3-month-old rats. 4. In the presence of 16.7 mM-glucose, islets of 24-month-old rats exhibited only 60-70% of the insulin release obtained with islets from 3-month-old rats. 5. Neither net uptake of 45Ca2+ nor insulin secretion appear to differ between the sexes. 6. These data suggest that the decreased insulin secretory response to glucose during old age is due, at least in part, to inadequate inhibition of K+ efflux and diminished net uptake of Ca2+.

Aging

Muir-Torre syndrome. Histologic spectrum of sebaceous proliferations.

The sebaceous proliferations seen in patients with Muir-Torre syndrome are unique and difficult to classify. Having reviewed over 50 skin biopsies from five patients with Muir-Torre syndrome, we conclude that the primary proliferation involves the hair follicle and most often resembles either a keratoacanthoma or a sebaceous proliferation, but may have histologic features of both lesions. Unusual patterns seen in the sebaceous components may include solid basaloid sheets, mucinous areas, and convoluted glands.

Adenoma

Failure of glucose to affect 86rubidium efflux and 45calcium uptake of fetal rat pancreatic islets.

Ion movements and insulin secretion of pancreatic islets of adult and fetal rats have been studied at three glucose concentrations. In islets of adult rats, 86Rb efflux is maximally decreased by 5.6 mM-glucose. 16.7 mM-glucose caused a biphasic efflux pattern which may be due to glucose-stimulated Ca uptake. In islets of fetal rats elevation of the glucose concentration from 3 to 5.6 or 16.7 mM does not cause a change of 86Rb efflux, and the fractional efflux from fetal islets in the presence of 3 mM-glucose is similar to that from adult rat islets in the presence of 5.6 mM-glucose. Elevation of the glucose concentration from 3 to 16.7 mM is not associated with an increase in 45Ca uptake into fetal islets, although this change in glucose concentration doubles 45Ca uptake into adult islets. When challenged with 16.7 mM-glucose, fetal islets exhibit no insulin secretory response; however, they do respond to theophylline. It is concluded that the failure of fetal islets to exhibit an insulin-secretory response when challenged with glucose might be related to the inability of glucose to affect 86Rb efflux and Ca uptake. The present data are discussed in light of differences between pancreatic islets of fetal and adult rats with respect to the redox state of pyridine nucleotides, thiols and glucose metabolism.

Animals

Adenocarcinoma of rete testis.

Adenocarcinoma of the rete testis is a rare tumor of the genital tract. An advanced case of adenocarcinoma thought to arise from the rete testis is presented. We believe this is the eighteenth reported case.

Adenocarcinoma, Papillary

Macrocheilia due to lymphangiectasia.

A case of symmetrical, diffuse macrocheilia due to lymphangiectasia is presented. No primary cause for this case or for many other pathologic forms of macrocheilia has been established. Tranverse mucosal wedge resection of the lip with mucosal advancement, however, is a satisfactory method of treatment.

Adolescent

Platelet function by afibrinogenemia.

Platelet function was studied in two cases with congenital afibrinogenemia. In these two cases there was no aggregation by ADP, while, there was increased calcium-induced platelet aggregation and decreased platelet adhesiveness to glass. Platelet aggregation was corrected in vitro, by addition of fibrinogen. It can be concluded from the above findings that the fibrinogen is an important factor for platelet aggregation by ADP and for platelet adhesion to glass surfaces, while platelet aggregation by thrombin does not need fibrinogen. The increased calcium-induced aggregation can be explained by postulating that thrombin finds no substrate to act upon except the platelets.

Afibrinogenemia

Studies on platelet function in cases of hemophiliac Egyptian children.

Eleven cases of hemophilia were studied for detection of any change in the platelet function. The results showed hyperfunction in 5 cases, normal function in 4, and hypofunction in the remaining two. The hyperfunction of the platelets was shown in the case with acute hemorrhage and it might be a compensation mechanism. The normal function was shown in cases during the quiescent phase. The hypofunction of the platelets was associated with the presence of AHg inhibitor and platelet antibody. Normal function returned after Cortisone administration. It may be postulated that the inhibitor of factor VIII and the platelet antibody are one and the same thing.

Adolescent