Hypoleptinemia, but not hypoinsulinemia, induces hyperphagia in streptozotocin-induced diabetic rats.

To assess the dominance between hypoinsulinemia and hypoleptinemia as factors in the development of hyperphagia in streptozotocin (STZ)-induced diabetes mellitus (STZ-DM) rodents with respect to hormone-neuropeptide interactions, changes in gene expression of agouti gene-related protein (AGRP) in the arcuate nucleus of the hypothalamus were investigated using STZ-DM rats, fasting Zucker fa/fa rats and STZ-DM agouti (STZ-DM A(y)/a) mice. AGRP mRNA and neuropeptide Y mRNA were both significantly up-regulated in STZ-DM rats, which are associated with body weight loss, hyperglycemia, hypoinsulinemia and hypoleptinemia. We proceeded to analyze whether insulin or leptin played the greater role in the regulation of AGRP using Zucker fa/fa rats. The AGRP mRNA did not differ significantly between fasted fa/fa rats, which have both leptin-insensitivity and hypoinsulinemia, and fed Zuckers, which have leptin-insensitivity and hyperinsulinemia. We further found that up-regulation of AGRP expression was normalized by infusion of leptin into the third cerebroventricle (i3vt), but not by i3vt infusion of insulin, although up-regulation of AGRP was partially corrected by systemic insulin infusion. The latter finding supports hypoleptinemia as a key-modulator of STZ-DM-induced hyperphagia because systemic insulin infusion, at least partially, restored hypoleptinemia through its acceleration of fat deposition, as demonstrated by the partial recovery of lost body weight. After STZ-DM induction, A(y)/a mice whose melanocortin-4 receptor (MC4-R) was blocked by ectopic expression of agouti protein additionally accelerated hyperphagia and up-regulated AGRP mRNA, implying that the mechanism is triggered by a leptin deficit rather than by the main action of the message through MC4-R. Hypoleptinemia, but not hypoinsulinemia per se, thus develops hyperphagia in STZ-DM rodents. These results are very much in line with evidence that hypothalamic neuropeptides are potently regulated by leptin as downstream targets of its actions.

Tissue-specific expression of the uncoupling protein family in streptozotocin-induced diabetic rats.

The vulnerability of streptozotocin (STZ)-induced diabetic rats to cold stress has been established. One of the elements controlling body temperature is thermogenesis, in which uncoupling protein (UCP) is known to play an important role. We have examined UCP2 and UCP3 expressions in brown adipose tissue (BAT), white adipose tissue (WAT), and skeletal muscle (MSL) during the acute and chronic phases of STZ-induced diabetes in rats. The long-term effect and the effect of insulin treatment thereafter were also unexplored previously and are examined in this study. In the acute phase of diabetes (2.5 days after STZ injection), UCP2 gene expression in BAT, WAT, and MSL, and UCP3 expression in the muscle were significantly increased. In the chronic phase of diabetes (21 days after STZ injection), UCP2 and UCP3 expression in the MSL were restored to the control levels without insulin supplementation. UCP2 in BAT and WAT remained high in the chronic phase, whereas UCP3 expression in BAT and WAT, which did not change in the acute phase, was significantly decreased. Insulin supplementation restored UCP2 expression in BAT and WAT, but over-corrected UCP3 in WAT above the control and did not affect UCP3 expression in BAT. Insulin supplementation depressed UCP3 expression in the MSL below control. These results indicate that the effects of STZ-induced diabetes on UCPs gene expression are tissue-specific as well as dependent on the duration of diabetes.

Molecular cloning of rat brain mitochondrial carrier protein-1 cDNA and its up-regulation during postnatal development.

Brain mitochondrial carrier protein-1 (BMCP1), a new member of the mitochondrial uncoupling carrier, has been shown to be expressed predominantly in the brain of the mice and humans. We cloned rat BMCP1 cDNA and investigated its mRNA level during postnatal development and under various metabolic conditions. The nucleotide sequence of the cDNA revealed that rat BMCP1 protein was composed of 322 amino acid residues, and was 99 and 96% identical to the mouse and human proteins and 29, 33 and 35% identical to rat uncoupling protein (UCP) 1, UCP2 and UCP3, respectively. The molecular weight was predicted to be 36017 Da and the protein of this size was detectable when the cDNA was expressed in vitro. Using Northern blot analysis, the corresponding mRNA, approximately 1.8-kb in size, was found expressed predominantly in the cerebrum, cerebellum and hypothalamus. A unique developmental pattern was identified in the brain, where BMCP1 expression was low in their fetal life, but significantly elevated in the first postnatal week. Thereafter BMCP1 mRNA was maintained to be gradually increased. In 48-h fasted or insulin-induced hypoglycemic rats, BMCP1 mRNA expression in the hypothalamus slightly, but significantly, decreased compared with that in their appropriate controls. The present results indicate that BMCP1 may be involved in pathogenesis of mitochondrial dysfunction in neurons induced by aging or neurodegenerative disorders, and perhaps in energy balance in the brain.

Hypothalamic neuronal histamine as a target of leptin in feeding behavior.

Leptin, an ob gene product, has been shown to suppress food intake by regulating hypothalamic neuromodulators. The present study was designed to examine the involvement of brain histamine in leptin-induced feeding suppression. A bolus infusion of 1.0 microg leptin into the rat third cerebroventricle (i3vt) elevated the turnover rate of hypothalamic neuronal histamine (P < 0.05) as assessed by pargyline-induced accumulation of tele-methylhistamine (t-MH), a major metabolite of histamine. No remarkable change in the mRNA expression of histidine decarboxylase (HDC), a histamine-synthesizing enzyme, was observed in the hypothalamus after i3vt infusion of leptin. These results indicate that leptin increases histamine turnover by affecting the posttranscriptional process of HDC formation or histamine release per se. As expected, concomitant suppression in 24-h cumulative food intake was also observed after infusion of leptin. Systemic depletion of brain histamine levels by pretreatment with an intraperitoneal injection of 224 micromol/kg alpha-fluoromethylhistidine (FMH), a suicide inhibitor of HDC, attenuated the leptin-induced feeding suppression by 50.7% (P < 0.05). This attenuation of feeding suppression was mimicked by the i3vt infusion of 2.24 micromol/kg FMH before leptin treatment (P < 0.05). In addition, concentrations of hypothalamic histamine and t-MH were lowered in diabetic (db/db) mice, which are known to be deficient in leptin receptors (P < 0.05 vs. lean littermates for each amine), although the amine levels were higher in diet-induced obese rats (P < 0.05 for each amine). Leptin-deficient obese mice (ob/ob) showed lower histamine turnover (P < 0.05 vs. lean littermates), which recovered after leptin infusion. Thus, a growing body of results points to an important role for the hypothalamic histamine neurons in the central regulation of feeding behavior controlled by leptin.

The inhibitory properties and primary structure of a novel serine proteinase inhibitor from the fruiting body of the basidiomycete, Lentinus edodes.

A novel proteinase inhibitor, Lentinus proteinase inhibitor, has been purified from the fruiting bodies of the edible mushroom, Lentinus edodes, by buffer extraction and affinity chromatography on immobilized anhydrotrypsin. The protein simultaneously inhibits bovine beta-trypsin and alpha-chymotrypsin at independent sites, with apparent dissociation constants of 3.5 x 10(-10) M and 4 x 10(-8) M, respectively. The purified protein is eluted as two well-separated peaks on reversed-phase HPLC, one of which is inhibitory-active and the other inactive, and they are interconvertible under folding/unfolding conditions. Among the mammalian and microbial serine proteinases examined, including human enzymes of blood coagulation and fibrinolysis, activated factor XI was inhibited by the Lentinus proteinase inhibitor. Chemical modification studies suggest involvement of one or more arginine residues in the inhibition of trypsin. The complete primary structure composed of 142 amino acids with an acetylated N-terminus was determined by protein analysis. The theoretical molecular mass (15999.2) from the sequence is close to the experimental value of 15999.61 +/- 0.61 determined by mass spectrometry. Although there are no apparently homologous proteinase inhibitors in the protein database, there is a rather striking similarity to the propeptide segment of a microbial serine proteinase, as well as to the N-terminal region of the mature enzyme.

[Detection of serum p53 antibodies in colorectal cancer patients and the clinical significance of postoperative monitoring].

p53 protein overexpression was found to induce the production of antibodies in patient serum and, recently, the easy detection of serum antibodies has been made possible. The aim of this study is to determine the significance of serum p53 antibodies in patients with primary colorectal adenocarcinoma in comparison with their clinicopathological features, and the tumor marker sensitivities of carcinoembryonic antigen (CEA), carcinoma antigen 19-9 (CA19-9) and alpha-fetoprotein (AFP). Thirty-nine of 86 patients (45.3%) were positive for serum p53 antibodies. However, there was no relation with the cancer progression or clinicopathological findings. The sensitivities of CEA, CA19-9 and AFP were 36.0%, 38.4%, and 8.1% respectively, but there was no relation between serum p53 antibodies and these three markers. When the sensitivity of serum p53 antibodies and CEA was evaluated according to clinical stage, the presence of serum p53 antibodies was more significantly associated with stage 0, I and II colorectal cancer than was CEA. Thirty-three patients who showed preoperative positivity for serum p53 antibodies were followed by serial evaluation of circulating antibodies after resection. Negative conversions after resection were significantly higher in the "Cur A" group than in the "Cur B" or "Cur C" groups. Serum p53 antibodies appear to be a useful tumor marker independent of the other markers, especially in the early stage, and are expected to be useful in the development of a method of early diagnosis for mass screening, and as a postoperative monitoring marker for colorectal cancer.

[Acute renal failure in non-fulminant acute hepatitis without hepatitis A, B or C virus infection].

Here, we report a 35-year-old man with non-fulminant acute non A, non B, non C hepatitis which developed into acute renal failure. The patient was admitted to hospital with the chief complaints of general fatigue, nausea and a high-grade fever of 40 degrees C. Laboratory examination revealed severe liver dysfunction and renal insufficiency on admission: his serum glutamic oxaloacetic transaminase was 3.203 IU/ml, serum glutamic pyruvic transaminase was 3.825 IU/ml, lactic dehydrogenase was 2.840 IU/ml, blood urea nitrogen was 65 mg/dl, and creatinine was 7.6 mg/dl. Hemodialysis was conducted during the initial 19-day period after admission because anuria was manifested on admission. On the 36th day after onset, renal functions returned to normal and the patient was negative for IgM-HA antibody. HBs antigen, IgM-HBC antibody, HCV antibody, cytomegalovirus antibody, and Epstein-Barr virus antibody. However, liver biopsy for histological examination on the 44th day after onset revealed no specific findings except the healing stage of acute hepatitis. Renal biopsy on the 49th day showed the healing stage of acute tubular necrosis without any glomerular change. It has been infrequently reported that acute renal failure develops following a non-fulminant acute state without hepatitis A, B or C virus infection. It is necessary to take acute renal failure into account in the clinical course of non-fulminant non A, non B, non C hepatitis.

Intracranial germinoma with Down's syndrome: a case report and review of the literature.

BACKGROUND: Down's syndrome's association with malignancies such as leukemia is well known, but its association with brain tumor appears to be rare. We reviewed such rare cases of Down's syndrome and intracranial germ-cell tumor. CASE REPORT: A 10-year-old boy with Down's syndrome and intracranial germinoma located in the left basal ganglia is reported. The patient presented with right hemiparesis and was treated with a combination of surgery, chemotherapy with cisplatin and etoposide, and irradiation. CONCLUSIONS: We speculate that the percentage of germ-cell tumors is high among Down syndrome patients with brain tumors and that the most common site is the basal ganglia.

Duodenal obstruction due to annular pancreas associated with pancreatic head carcinoma.

A patient with obstructive jaundice due to carcinoma of the pancreas head showed painless vomiting from the supra-papillary duodenal obstruction. Computed tomography demonstrated a space-occupying lesion in the head of the pancreas, which was not so large as to make an obstruction of the proximal portion of the duodenum. Pylorus preserving pancreatoduodenectomy was performed and the surgical specimen showed that the duodenal obstruction was caused by a swollen annular pancreas associated with obstructive pancreatitis by the carcinoma of the pancreas head. Duodenal obstruction is a rare symptom of annular pancreas in adults. It is thought to be necessary to remind of the coexistence of the annular pancreas, when patients with pancreatic or periampullary malignancies are complicated with unexpected obstruction of the second portion of the duodenum in proportion to the size.

Reinnervation of peripheral nerve segments implanted into the hemisected spinal cord estimated by transgenic mice.

We investigated how far Schwann cells, which are the peripheral nerve elements supporting axonal regrowth, penetrate into the hemisected recipient spinal cord. C57BL/6 mice, which carry carcinoembryonic antigen as transgene, were used for transplantation study. These CEA transgenic mice were syngenic to C57BL/6 mice except for the expression of human CEA DNA. In the syngenic transplantation study, C57BL/6 mice were transplanted with the sciatic nerve of CEA-transgenic mice to the hemisected spinal cord. Schwann cell migration into the recipient spinal cord was detected by the PCR method. Transplanted Schwann cells migrated into the recipient spinal cord both rostrally and caudally at a distance of 2 mm from the graft-host interface until 21 days after transplantation. At 28 days after transplantation, the Schwann cells migrated rostrally at a distance of 2 mm and caudally at a distance of 4 mm. C57BL/6-CEA sciatic nerve was transplanted to BALB/C mice as the allogenic transplant. CEA DNA was detected until 14 days after transplantation, but disappeared at 21 days. In addition, C57BL/6-CEA sciatic nerves were transplanted into Wistar rats to study xenogenic transplantation. The CEA band disappeared at 10 days after transplantation. In conclusion, by using CEA transgenic mice and the PCR method, we could evaluate the mobility of Schwann cells which are thought to play an important role in axonal regeneration.

[Immunohistochemical study of collagen in gastric cancer tissue].

The distribution and localization of collagen types were studied immunohistochemically in resected tissues obtained from gastric cancer patients. The expression of transforming growth factor (TGF) -alpha, TGF-beta 1 and TGF-beta 2 on cancer cells as well as the aggregation of T lymphocytes in the cancer tissue were also studied, in order to determine the differences between differentiated and undifferentiated type cancer. The interstitial tissues of differentiated type cancer showed intense staining for types I and III collagen, while those of undifferentiated type cancer showed intense staining for types I and III collagen, in addition to the stronger staining for types IV, V and VI collagen. Characteristically, type IV collagen was intensely stained in the interstitium in 18 of 20 undifferentiated type cancer (90%), but was stained in only one of 15 differentiated type cancer (6%). CD 3+ T lymphocytes were aggregated in the interstitial tissue of both the tumors, where the density of CD 4+ cells and the ratio of CD 4 to CD 8 were significantly higher in undifferentiated type cancer than in differentiated type cancer. TGF-alpha was detected in cancer cells in 80% of the differentiated cases and in 45% of the undifferentiated cases. The staining of TGF-beta 1 was also detected in 80% of the undifferentiated cases, which was significantly higher than 47% in differentiated cases. There were no differences in the incidences of staining for TGF-beta 2 between differentiated (33%) and undifferentiated type cancer (40%). These results suggest that there exist different mechanisms in the regulation of collagen production between differentiated and undifferentiated types of gastric cancer.

Conjunctival malignant melanoma with xeroderma pigmentosum.

A 10-year-old male patient with xeroderma pigmentosum had a recurrent, pigmented, conjunctival tumor. Conjunctival malignant melanoma was diagnosed from the histopathological examination of the resected biopsy specimens. To our knowledge, this case of conjunctival malignant melanoma in a patient with xeroderma pigmentosum may be the second such report in the literature. We believe that malignant melanoma must be considered with squamous cell carcinoma in the differential diagnosis of conjunctival tumors in patients with xeroderma pigmentosum. Fontana-Masson and S-100 staining techniques helped diagnose this conjunctival malignant melanoma.

[Immunomodulatory effects of interferons on target human gliosarcoma cells in the tumor-specific CTL- and LAK-mediated cytolysis].

We compared the regulatory effects of interferon (IFN)-beta and IFN-gamma on the susceptibility of a human gliosarcoma line GI-1 to the attack of autologous cloned tumor-specific cytotoxic T-lymphocytes (CTL) and lymphokine-activated killer (LAK) cells. Preincubation of GI-1 cells with IFN-gamma caused augmented susceptibility to the cytotoxic attack of two autologous CTL clones, whereas IFN-beta exhibited no such marked effect. On the other hand, preincubation with either IFN-beta or IFN-gamma made the GI-1 cells resistant to the attack of autologous LAK cells. Both IFNs augmented the surface expression of HLA class-I molecules on GI-1 cells. A monoclonal anti-HLA class-I antibody blocked the cytolysis by one CTL clone, but not by the other one. These results suggest that IFN-gamma exerts some different effect (s) from that of IFN-beta on the target GI-1 cells in their susceptibility to the CTL-mediated cytolysis, and that recognition mechanisms of target cells by the CTL are different from those by LAK cells. This draws our attention to IFN administration in adoptive immunotherapy against brain tumors using CTLs and LAK cells.

Structure and molecular analysis of RGR1, a gene required for glucose repression of Saccharomyces cerevisiae.

An RGR1 gene product is required to repress expression of glucose-regulated genes in Saccharomyces cerevisiae. The abnormal morphology of rgr1 cells was studied. Scanning and transmission electron microscopic observations revealed that the cell wall of the daughter cell remained attached to that of mother cell. We cloned the RGR1 gene by complementation and showed that the cloned DNA was tightly linked to the chromosomal RGR1 locus. The cloned RGR1 gene suppressed all of the phenotypes caused by the mutation and encoded a 3.6-kilobase poly(A)+ RNA. The RGR1 gene is located on chromosome XII, as determined by pulsed-field gel electrophoresis, and we mapped rgr1 between gal2 and pep3 by genetic analysis. rgr1 was shown to be a new locus. We also determined the nucleotide sequence of RGR1, which was predicted to encode a 123-kilodalton protein. The null mutation resulted in lethality, indicating that the RGR1 gene is essential for growth. On the other hand, a carboxy-terminal deletion of the gene caused phenotypes similar to but more severe than those caused by the original mutation. The amount of reserve carbohydrates was reduced in rgr1 cells. Possible functions of the RGR1 product are discussed.

[Clinico-pathological studies on Is, Ip polyps and flat elevations in the large intestine].

We histologically compared 3 types of adenoma and cancer of the large intestine using 620 adenoma specimens (509 Is type lesions, 83 Ip type lesions, and 28 flat type lesions) and 113 specimens of early stage cancer (51 Is type lesions, 39 Ip type lesions, and 23 flat type lesions) obtained during the past 5-year period at our department. More than 90% of the Is and Ip type polyps were adenoma or carcinoma in adenoma while 25.5% of the flat elevations were m or sm carcinoma. Flat elevations even less than 10 mm in diameter were frequently carcinomas (26.3%) compared with the other types (both Is and Ip types, 6.7%), and all of those 10 mm or more in size were carcinomas. The distribution of the flat type early cancers in the large intestine was similar to that of advanced cancer with high percentages of carcinoma at each site compared with the other types. These results suggest that the carcinogenesis and progression of flat type early stage cancer differ from those of the other types.

[Effectiveness of synthetic calcitonin derivative (elcatonin) on the bone pain and serum calcium concentration in multiple myeloma].

Fifteen patients (8 male and 7 female) with multiple myeloma, who were admitted to our hospital between July 1986 and August 1988 and suffering from pain and hypercalcemia, were treated with synthetic calcitonin derivative (elcatonin: ECT). ECT was administered intravenously at a dose of 10-640 units twice daily. Seven patients were treated with ECT (ECT group), and eight patients received combination treatment with ECT and other form of chemotherapy (combination group). With regard to the pain score (PS), significant analgesic effects in both groups were observed during 1-4 week treatments (p less than 0.05). There were no significant differences in PS between two groups. Serum calcium levels in the combination group at 1 and 4 weeks were significantly lower than the initial value (p less than 0.05). Hypocalcemia was not seen in any of the patients. Urinary excretion of calcium at 1 week in ECT group was higher than the initial value (p less than 0.05). The observed toxicities of ECT were slight nausea and vomiting in only 2 patients. These findings suggest that ECT is an useful agent for the treatment of pain and hypercalcemia accompanied with multiple myeloma.

Hepatocellular carcinoma and bladder cancer as complications following five years of chemotherapy for acute myeloblastic leukemia.

Acute myeloblastic leukemia (AML) was diagnosed in a 54-year-old male, a chronic hepatitis B surface antigen (HBsAg) carrier, in June, 1983. Prompt remission was achieved, and maintenance and intensification chemotherapy were given for five years. He was readmitted in March, 1988 because of a mass in the liver and was diagnosed as having hepatocellular carcinoma (HCC). Curative right segmentectomy was performed in May, 1988. In December, 1988, transitional cell carcinoma of the bladder was discovered, and resected transurethrally. These secondary neoplasms, HCC and bladder cancer, were thought to be associated with the long-term chemotherapy given for the AML.

[A clinicopathological study of recurrent gastric cancer cases treated by a resection of the remnant stomach].

Seventeen cases of a recurrent gastric cancer that were treated by a resection of the remnant stomach have been studied retrospectively. For first management 12 cases were given a Billroth 2 procedure, 4 cases a Billroth 1 procedure and 1 case a fundectomy. For the recurrent cancer, 13 cases were given a total resection of the gastric remnant and 4 cases a partial resection. The overall mortality rate was 12% and the survival rate was 58% at 1 year, and 8% at 5 years. We thus have concluded that a resection of the remnant stomach should be carried cut in cases of a recurrent gastric cancer whenever possible.

[Hepatocellular carcinoma treated with a curative segmentectomy five years after complete remission of acute myeloblastic leukemia].

Acute myeloblastic leukemia (AML) was diagnosed in a 54-year-old male who had been known to carry a chronic hepatitis B surface antigen (HBsAg) from June, 1983. Prompt remission was achieved with combination chemotherapy of BHAC-DMP. Follow-up maintenance and an intensification of this chemotherapy had been given for five years. He was readmitted to our hospital in March, 1988 because a mass was detected in the right lobe of the liver by ultrasonography. His serum alpha fetoprotein (AFP) level was found to be 180.1 ng/ml, and was diagnosed as having a hepatocellular carcinoma though there was no evidence of liver cirrhosis. A curative right hepatectomy was performed in May, 1988 after transcatheter arterial embolization and portal embolization. After resection of the tumor, the AFP level decreased to 10.7 ng/ml and no HbsAg was detected in the serum.