[Heterogeneity of the immunoreactivity of A14, A19, B16 and B26- (125I) monoiodoinsulin to different species of anti-insulin immuno sera]

By using lactoperoxidase oxidation with 6 mol. urea in the reaction medium, the four tyrosine residues contained in insulin molecule were iodinated as monoiodoinsulins. These tracers, namely A14, A19, B16 and B26- (125I) monoiodoinsulins were separated with polyacrylamide gel electrophoresis+QAE-Sephadex A25 chromatography. The present study demonstrated that the radiochemical purity of these tracers was high (> 98%) and the specific radioactivity also high. The binding of these tracers to surplus insulin antibody was more than 95%. These our tracers were tested in two RIA systems against 35 species of guinea-pig anti-insulin immuno sera to compare their immunoreactivity (Ka, Scatchard analysis) to each immunoserum. The two RIA systems were antibody dilution and self displacement, and in both of them, only iodinated insulin and insulin antibody were present in the reaction fluid. The results showed that for 16 antiinsulin immuno sera, Ka for A14, A19, B16 or B26-monoiodoinsulin were significantly different, and for the rest 19 immuno sera no significant difference could be detected. The possible mechanism and implication of this phenomenon were discussed.

[Determination of serum pancreatic polypeptide and its clinical significance in patients with end state renal failure]

Serum levels of pancreatic polypeptide (SPP) responding to 75g glucose (oral) challenge were observed in 27 patients with end state renal failure (ESRF) and 27 normal subjects as a control. The results showed that the levels of SPP were significantly higher in ESRF patients than in normal subjects. Dialysis therapy seemed to have no effect on the levels of SPP. The elevated levels of SPP could return to normality after kidney transplantation. There was no positive correlation between the levels of SPP, the blood sugar, and the serum insulin. It is suggested that kidneys are the important sites for the metabolism of PP. The elevated SPP concentration in patients with ESRF may result from their renal failure, and may contribute to some gastrointestinal symptoms which are frequently associated with ESRF.

[Transplantation of islets of Langerhans in man]

Islet of Langerhans transplantation is an alternative to whole pancreas transplantation for type I diabetic patients, in whom exogenous insulin therapy has not prevented the occurrence of systemic complications. Thanks to a new isolation technique of human islets, 45 patients have been transplanted worldwide since 1988, of whom only 7 have become totally insulin-independent. Rejection and quality of the islet preparations are problems which remain to be solved. Autotransplantation of islets has been proposed in patients undergoing a pancreatectomy for benign disease. The present report concerns two of our patients who had a pancreatectomy with islet autotransplantation. Both patients are insulin-independent 3 and 11 months postoperatively, with satisfactory metabolic tests. Islet autotransplantation can be proposed when pancreatectomy for non-malignant disease is performed. This method may prevent the development of insulin-dependent diabetes, known to be particularly labile. Because of the sophisticated technical procedures required, human islet isolation is at present only performed in a small number of medical centers and still is in the field of medical experimentation.

Kinetics of proinsulin conversion in human islets

Islets isolated from human cadaver pancreas were pulse-labeled (10 min with [3H]leucine) and then incubated for a 180-min chase. Islets and chase medium were collected every 15 min and analyzed by reversed-phase HPLC to quantify the percentage of radioactively labeled proinsulin, conversion intermediates, and fully processed insulin. Release of proinsulin-related labeled products into the chase medium was < 10% of total. Whereas 50% of labeled proinsulin had been lost by conversion within 45 min, fully processed insulin only appeared with a half-time of 100 min. This discrepancy is attributable to accumulation of radioactive conversion intermediates. Des 64.65 split proinsulin was a minor component, reaching a maximum of 5.2 +/- 1.7% (n = 4) at 60 min of chase. By contrast, des 31.32 split proinsulin--and a truncated form lacking the first three residues of C-peptide--rose progressively to 29.3 +/- 1.4% by 75 min, and declined thereafter. The accumulation of des 31.32 split proinsulin rather than the des 64.65 split form during the conversion of human proinsulin reflects slower conversion at the C-peptide/A-chain than at the B-chain/C-peptide junction, and is consistent with the appearance of this particular conversion intermediate in the circulation.

[Islet of Langerhans transplantation in humans]

Islet of Langerhans transplantation is an alternative to whole pancreas transplantation for type I diabetic patients, in whom exogenous insulin therapy has not prevented the occurrence of systemic complications. Thanks to a new isolation technique of human islets, 45 patients have been transplanted worldwide since 1988, of whom only 7 have become totally insulin-independent. Rejection and quality of the islet preparations are problems which remain to be solved. Autotransplantation of islets has been proposed in patients undergoing a pancreatectomy for benign disease. The present report concerns two of our patients who had a pancreatectomy with islet autotransplantation. Both patients are insulin-independent 3 and 11 months postoperatively, with satisfactory metabolic tests. Islet autotransplantation can be proposed when pancreatectomy for non-malignant disease is performed. This method may prevent the development of insulin-dependent diabetes, known to be particularly labile. Because of the sophisticated technical procedures required, human islet isolation is at present only performed in a small number of medical centers and still is in the field of medical experimentation.

[Isolation and purification of alpha fetal protein utilizing Act-Ultrogel AcA 22 affinity chromatography]

In the present communication, we report a method for the isolation and purification of alpha FP from fetal corpse homogenate in a single-step procedure using Act-Ultrogel AcA 22 affinity chromatogrpahy column. This method proves to be better than the conventional method in simplicity, fastness and validity with recovery, purity and immunoreactivity. The immunoreactivity of the purified alpha FP labelled by the method of Hunter and Greenwood (1962) was 50-60% (B/T%). This was similar to alpha FP standard (WHO). The results indicate that the 125I-alpha FP is suitable for alpha FP radioimmunoassay.

[Prophylactic effect of refined amorphophallus konjac on MNNG-induced lung cancers in mice]

Three hundred and seventy LACA mice of seven weeks old were used in 2 batches for studying the prophylactic effect of Konjaku powder on MNNG-induced lung cancers. These mice (within each batch) were randomly allocated to four groups, namely positive control (MNNG), refined Amorphophallus Konjac (R.A.K.), complex (MNNG + R.A.K.), and blank control (C). In MNNG group, MNNG (250 micrograms) was injected intravenously once five days for seven times in each mouse, the total dosage of MNNG was 1.75 mg. In R.A.K. group, according to w/w, 8% R.A.K. was well mixed into 92% common diet for long-term term breeding. In complex group, MNNG was given as that in MNNG group and the mice were reared as those in R.A.K. group. The mice in MNNG group and in C group were all reared by common diet. The results of experiments showed different degrees of preventive effect of R.A.K. on MNNG-induced lung cancers in LACA mice. R.A.K. not only exerted effect on the number of induced cancer, causing a drop of the cancerous rate from 79.75% to 20.00% and the mean number of cancer in each animal, but also prolonged the survival time of animals. At the same time, the constituent ratio of the kinds of tumor denoted a decrease in malignancy (adenoma with malignant change), an absence of adenocarcinoma and relative increase in benign adenoma. The results of experiments also exhibited good duplication as well as absence of adverse reactions to Konjaku powder.

[The preparation of highly purified insulin and its clinical use. Insulin Cooperative Study Group]

Antigenicity of insulin preparations is obviously related to their purity. The average contents of proinsulin, glucagon and pancreatic polypeptide in highly purified insulin (HP-I) produced by us are 76.0, 2.11 and 0.11 ppm respectively. These results are superior to those for domestic conventional crystalline insulin and single peak insulin (SP-I). The antibodies to insulin, proinsulin and pancreatic polypeptide in serum were examined in 24 diabetic patients treated with HP-I for more than 6 months. The positive rates for the above three antibodies were 37.5%, 0% and 0% respectively. The results showed that the antigenicity of HP-I was much lower than that of domestic conventional crystalline insulin and almost the same as that of MC-I from Nordisk, Denmark.

[An observation on growth hormone levels in patients with chronic renal failure]

Serum levels of growth hormone (GH) in the fasting and postprandial state were observed in 27 patients with chronic renal failure (CRF) [and in 27 normal controls. The results showed that serum levels of GH were significantly higher in CRF patients than in normal controls. Most patients exhibited a "paradoxical rise" of GH following an oral glucose load. There was no difference between GH concentrations in those with impaired glucose tolerance (IGT) and those with normal glucose tolerance (NGT) in the CRF cases. Elevation of GH could be returned to normal by kidney transplantation with the disappearance of the "paradoxical rise" of GH. The mechanism of these abnormalities and the relationship between abnormalities of GH and IGT were discussed.

Acupuncture treatment of syncope based on differentiation of signs and symptoms

1. The three typical cases reported above were syncopic patients of different types. Case 1 belonged to yin-depletion syndrome, case 2 pertained to yang-depletion syndrome, and case 3 Jue syndrome due to disturbance between qi and the blood induced by deficiency of qi and accumulation of phlegm. All of the three cases were satisfactorily cured with acupuncture and moxibustion though they did not respond to western medicines. 2. The rationale of acupuncture treatment for syncope includes: 1) Regulating yin and yang: For yin-depletion syndrome, reinforcing method is mainly adopted for nourishing water to promote reproduction of the body fluids and replenishing yin to restore yang; in case of yang-depletion syndrome, moxibustion and needle-warming methods are mainly used for recuperating the depleted yang to rescue the patient from collapse and for invigorating yang to restore yin. 2) Resuscitating the patient by regulating qi and the blood and dredging the channels to activate the circulation. After a successful resuscitation, the patient should be radically treated with appropriate herbal medicines so as to consolidate the therapeutic efficacy. 3. An emergency treatment for syncopal patients with acupuncture and moxibustion must be based on a conscientious differentiation of the signs and symptoms. The treatment should strictly follow the therapeutic principles: reinforce for the deficiency, reduce for the excess, cool the heat and warm the cold.

[Pancreatic glucagon receptor radioassay with liver cell plasma membrane in normal and streptozotocin-induced diabetic rats]

Pancreatic glucagon receptor radioassay has been developed with rat liver cell plasma membrane prepared with sucrose gradient centrifugation. 125I-glucagon was prepared in this laboratory and the separation of B/F was done by low speed centrifugation with addition of PEG (W/V, 20%) and normal human serum. The specific binding of 125I-glucagon was 25%-35% and nonspecific binding was less than 5%. Reproducibility within and between- assay was 6.83% and 8.40% (CV%), respectively. Binding characteristics of glucagon receptor of normal and streptozotocin-induced diabetic rats were determined by using two methods, receptor dilution and conventional competitive binding assay. The results showed that there were no marked differences concerning high and low binding affinities between normal and diabetic rats, but the concentration of binding sites for both high and low affinity receptors was significantly higher for diabetic rats than normal rats. The possible mechanisms for the above results have been discussed.