Biomedical subjects
Publications and source records attributed to M Nishikawa.
Meglumine iocarmate (Dimer-X) may be accidentally put into the subarachnoid space because of suboptimal technique during ventriculography. This may cause status epilepticus. Two cases of this complication are reported. It is emphasized that this should be avoided. Treatment is mentioned briefly.
A case of spontaneous spinal epidural hematoma during pregnancy is reported. Although we operated the patient 14 hours after the initial symptoms, the functional prognosis was poor. It is believed that the spinal cord was damaged irreversibility because of the rapid development of spinal cord edema. Referring to the reported cases we discussed symptoms, diagnosis and therapy as well as etiology. As to our case it is supposed that the rise of epidural venous pressure due to the pregnancy caused the rupture of the epidural venous plexus. About spontaneous spinal epidural hematoma during pregnancy, so long as we examined, there is only one case report, which Bidzinski reported in 1966.
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Six cases of Cushing's syndrome with adrenocortical tumors which showed a variety of responsiveness to ACTH were investigated in relation to their clinical pictures and laboratory findings. Abnormal responses to ACTH in tumors was analyzed by in vitro experiments with surgically obtained tumor tissues, and the ACTH responsive mechanism of the tumors was discussed. An 8 hour intravenous ACTH infusion test showed that three of these patients were ACTH responsive, and the other three unresponsive. Histological observation of the tumors revealed that ACTH responsive tumors were adenomas and that ACTH unresponsive tumors were "black adenomas" in two and a carcinoma in one. To investigate possible factors which might account for these differences in ACTH responsiveness, tumor specimens of each one of the responsive and unresponsive adenomas, and a carcinoma were subjected to in vitro studies. When incubated with ACTH or cyclic AMP, tissue sections of a responsive adenoma enhanced cortisol secretion, while that of a black adenoma failed to show any change. Steroidogenesis by carcinoma sections were significantly suppressed in the presence of ACTH or cyclic AMP. Cycloheximide abolished a stimulatory effect of ACTH and cyclic AMP on steroidogenesis in a responsive adenoma without affecting its basal secretion of cortisol. Steroidogenesis by unresponsive tumors (an adenoma and a carcinoma) were decreased by cycloheximide. Since the conversion of cholesterol to pregnenolone, the rate limiting step in steroidogenesis, takes place in adrenal mitochondria, the effect of cyclic AMP on pregnenolone formation from 14C-cholesterol by mitochondrial fractions of these tumors was examined. Cyclic AMP stimulated pregnenolone formation by mitochondrial fraction of an ACTH responsive adenoma, while with that of an unresponsive adenoma pregnenolone formation was not affected. Pregnenolone formation by cancer mitochondria was significantly suppressed by cyclic AMP. These results suggest that the unresponsiveness to ACTH of these tumors might be explained by the ineffectiveness of cyclic AMP to stimulate pregnenolone formation by tumor mitochondria, and that the steroidogenic pathway in unresponsive tumors are in an enhanced state even without cyclic AMP. It should be mentioned that all unresponsive adenomas gave a characteristic appearance of a "black adenoma". Histologically, tumors were composed of compact cells with abundant lipofuscin granules. The possible relationship between the ACTH responsiveness of adrenocortical tumors and some clinical pictures caused by them was also noticed. ACTH unresponsive adenomas resulted in shorter duration, severer conditions of the disease and higher 17-ketosteroid excretion than responsive adenomas. The growth of unresponsive tumors seemed faster than that of responsive ones.
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Various preparations of glucagon treated with chloramine-T under different conditions have been studied with respect to their immunoreactivity toward two different glucagon antisera; one specific for pancreatic glucagon and the other capable of reacting with enteroglucagon as well. The glucagon preparations exposed to chloramine-T for different periods reacted almost identically with the nonspecific antibody whether they were used as tracer or standard. On the contrary, treatment with chloramine-T under severe conditions led to reduced immunoreactivity toward the specific antibody. Inclusion of dimethyl sulfoxide (DMSO) in the chloramine-T reaction resulted in preservation of the immunoreactivity of the treated preparations. The cyanogen bromide cleaved-glucagon, (1-26) homoserine lactone, showed little cross-reactivity with the specific antibody whereas it reacted to a similar extent with the nonspecific antibody as natural glucagon did. Amino acid analysis of the hormone exposed to chloramine-T demonstrated that the methionine residue at position 27 in the glucagon molecule had been oxidized to methionine sulfoxide. In addition, tryptophan had also been affected. DMSO protected methionine and tryptophan from the oxidative action of chloramine-T. We postulate from these results that the change in the immunoreactivity toward the specific antibody of glucagon exposed to chloramine-T is mainly due to oxidation of the methionine residue at position 27 in the molecule. The usefulness of DMSO in the iodination process is also discussed.
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The boiling method deviced in accordance with the extraction procedure of secretin was applied to the extraction of gut glucagon-like immunoreactive material (GLI) and compared with the acid alcohol method of Kenny with respect to efficiency of the extraction and property of the extracted materials. GLI was extracted from minced porcine small intestine by each method. The total amount of GLI extracted by the boiling method was 14.45+/-2.07 mug/10g small intestine (mean+/-SE), showing a high yield as compared to 4.07+/-0.29 mug/10 g small intestine obtained by the acid alcohol method. The difference was statistically significant (p less than 0.005). The gel chromatogram of the acid alcohol extract was separated into two peaks; peak 1 appeared before the the insulin marker, while peak II was eluted with the glucagon marker. The chromatogram of the boiling extract has a main broad fraction including insulin marker and a minor second peak corresponding to peak II of the acid alcohol extract. Boiling of the acid alcohol extract did not cause any shift of peak I in chromatogram. GLI present in the first half of the main fraction of the boiling extract was different from that in the latter half, but identical to peak I of the acid alcohol extract with respect to the immunoreactivity against glucagon antibody. It is concluded that in the extraction of GLI not only high yield is achieved but one or more new components is picked up by the boiling procedure as compared to the acid alcohol method.
The effect of phenformin (DBI) on the plasma intestinal glucagon-like immunoreactivity (GLI) and pancreatic glucagon (IRG) responses to oral and intravenous glucose loads were studied in 26 gastrectomized subjects, using a cross-reacting and an IRG-specific anti-serum. The drug produced no significant changes in fasting GLI and IRG levels. Thirty minutes after oral glucose alone, the total GLI level rose to a peak of 1.55 +/- 0.17 ng/ml in the untreated subjects and to a maximum level of 1.67 +/- 0.18 ng/ml in the DBI-pretreated subjects. However, the mean GLI levels obtained 120 and 180 min after oral glucose were significantly higher after treatment with DBI. The blood sugar and IRI responses to oral glucose were lowered significantly by DBI pretreatment. DBI did not alter the glucose, IRI, IRG and GLI response to intravenous glucose. These results suggest that the release of intestinal GLI is not related to the intestinal absorption of glucose.
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A case of spontaneous spinal epidural hematoma during pregnancy is reported. The patient, three weeks before term, was operated upon successfully. A healthy child was delivered with forceps three days after the operation.
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