Reactive hypoglycemia owing to an intrahepatic congenital portosystemic shunt in an older patient

An 85-year-old woman was admitted to our hospital because of hypoglycemia and impairment of consciousness several hours after breakfast. Because the hypoglycemia predominantly occurred 2-4 h after meals, we diagnosed reactive hypoglycemia. An oral glucose tolerance test showed prolonged hyperinsulinemia following the postprandial hyperglycemia, with a subsequent rapid decrease in blood glucose concentration. The post-stimulus plasma C-peptide concentration was relatively low compared to the plasma insulin concentration. Abdominal computed tomography revealed an intrahepatic congenital portosystemic shunt (CPSS). On the basis of these findings, we concluded that the reactive hypoglycemia was induced by the CPSS, via a reduction in hepatic insulin extraction. Treatment with an alpha-glucosidase inhibitor resolved the reactive hypoglycemia. CPSS comprises anomalous vascular connections between the portal vein and the systemic venous circulation, and reactive hypoglycemia is a rare complication of this malformation, which has most frequently been reported in children, with only a few cases reported in adults. However, this case indicates that even in adult patients, imaging studies should be conducted to rule out CPSS as the cause of the reactive hyperglycemia.

Effect of Ezetimibe on LDL-C Lowering and Atherogenic Lipoprotein Profiles in Type 2 Diabetic Patients Poorly Controlled by Statins

Background

There exists a subpopulation of T2DM in whom first-line doses of statin are insufficient for optimally reducing LDL-C, representing a major risk of CVD. The RESEARCH study focuses on LDL-C reduction in this population along with modifications of the lipid profiles leading to residual risks.

Methods

Lipid changes were assessed in a randomized, multicenter, 12-week, open-label study comparing a high-potency statin (10mg of atorvastatin or 1mg of pitavastatin) plus ezetimibe (EAT: n = 53) with a double dose of statin (20mg of atorvastatin or 2mg of pitavastatin) (DST: n = 56) in DM subjects who had failed to achieve the optimal LDL-C targets. Lipid variables were compared with a primary focus on LDL-C and with secondary focuses on the percentage of patients who reached the LDL-C targets and changes in the levels of RLP-C (remnant like particle cholesterol) and sd-LDL-C, two characteristic atherogenic risks of DM.

Results

The reduction of LDL-C (%), the primary endpoint, differed significantly between the two groups (-24.6 in EAT vs. -10.9 in DST). In the analyses of the secondary endpoints, EAT treatment brought about significantly larger reductions in sd-LDL-C (-20.5 vs. -3.7) and RLP-C (-19.7 vs. +5.5). In total, 89.4% of the patients receiving EAT reached the optimized treatment goal compared to 51.0% of the patients receiving DST. The changes in TC (-16.3 vs. -6.3) and non-HDL-C (-20.7 vs. -8.3) differed significantly between the two groups.

Conclusion

Ezetimibe added to high-potency statin (10 mg of atorvastatin or 1 mg of pitavastatin) was more effective than the intensified-dose statin (20 mg of atorvastatin or 2 mg of pitavastatin) treatment not only in helping T2DM patients attain more LDL-C reduction, but also in improving their atherogenic lipid profiles, including their levels of sd-LDL-C and RLP-C.

We thus recommend the addition of ezetimibe to high-potency statin as a first line strategy for T2DM patients with insufficient statin response.

Trial Registration

The UMIN Clinical Trials Registry UMIN000002593

Myocardial Injury without Electrocardiographic Changes after a Suicide Attempt by an Overdose of Glimepiride and Zolpidem: A Case Report and Literature Review

A 40-year-old diabetic man was admitted to our hospital for poor glycemic control. During hospitalization, he took 42 mg glimepiride and 50 mg zolpidem as a suicide attempt. The following day, the creatine kinase-MB fraction and troponin I levels were elevated to 112 IU/L and 8.77 ng/mL, respectively, without any electrocardiographic abnormalities. The patient recovered completely without any complications. Four weeks later, coronary computed tomography angiography and myocardial perfusion scintigraphy revealed moderate one-vessel coronary disease without the evidence of myocardial ischemia or old infarction. Cardiac-specific markers must be considered in sulfonylurea-induced hypoglycemic patients, particularly when the patient is unconscious and does not exhibit any clinical manifestations.

Assessment of muscle blood flow volume in elderly poststroke hemiplegic patients using near-infrared spectroscopy

This study assessed the changes in blood flow volume in elderly hemiplegic patients before and after rehabilitation training. Total hemoglobin accumulation (blood flow volume) was measured using near-infrared spectroscopy (NIRS) in both the affected and unaffected gastrocnemius muscles before and after walking. In the gastrocnemius on the affected side, the blood flow volume was larger during the recovery period than during the rest period, and the blood flow volume did not decrease during the recovery period after the subjects walked a corridor. By contrast, the blood flow volume recovered faster on the unaffected side than on the affected side. After the subjects walked the stairs, the blood flow volume increased in the gastrocnemius muscles on both sides. These results suggested that the level of training involved in walking a corridor was too light for the unaffected side, although it was effective for the affected side. In our subjects, walking the stairs was effective rehabilitation training for both the unaffected and affected sides. Our results suggested that NIRS was an objective tool useful for planning rehabilitation training.

Adrenomedullin inhibits insulin exocytosis via pertussis toxin-sensitive G protein-coupled mechanism

Direct effects of adrenomedullin on insulin secretion from pancreatic beta-cells were investigated using a differentiated insulin-secreting cell line INS-1. Adrenomedullin (1-100 pM) inhibited insulin secretion at both basal (3 mM) and high (15 mM) glucose concentrations, although this inhibitory effect was not observed at higher concentrations of adrenomedullin. The inhibition of glucose-induced insulin secretion by adrenomedullin was restored with 12-h pretreatment with 1 microg/ml pertussis toxin (PTX), suggesting that this effect could be mediated by PTX-sensitive G proteins. Cellular glucose metabolism evaluated by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide colorimetric assay was not affected by adrenomedullin at concentrations that inhibited insulin secretion. Moreover, electrophysiological studies revealed that 10 pM adrenomedullin had no effect on membrane potential, voltage-gated calcium currents, or cytosolic calcium concentration induced by 15 mM glucose. Finally, insulin release induced by cAMP-raising agents, such as forskolin plus 3-isobutyl-1-methylxanthine or the calcium ionophore ionomycin, was significantly inhibited by 10 and 100 pM adrenomedullin. In conclusion, adrenomedullin at picomolar concentrations directly inhibited insulin secretion from beta-cells. This effect is likely due to the inhibition of insulin exocytosis through the activation of PTX-sensitive G proteins.

Roles of CTPL/Sfxn3 and Sfxn family members in pancreatic islet

Pancreatic AR42J cells have the feature of pluripotency of the precursor cells of the gut endoderm. Betacellulin (BTC) and activin A (Act) convert them into insulin-secreting cells. Using mRNA differential display techniques, we have identified a novel mitochondrial transporter, which is highly expressed during the course of differentiation, and have designated it citrate transporter protein-like protein (CTPL). Recently sideroflexin 1 (Sfxn1) was shown to be a susceptible gene of flexed-tail (f/f) mice, and CTPL has turned out to be a rat orthologous protein of Sfxn3, a member of sideroflexin family. CTPL/Sfxn3 was targeted to mitochondrial membrane like Sfxn1. The expression levels of CTPL/Sfxn3, Sfxn2, and Sfxn5 were upregulated in the early phase of differentiation into insulin-secreting cells but the expression levels of Sfxn1 and Sfxn3 did not change. All Sfxn family members were expressed in rat pancreatic islet. The expression levels of CTPL/Sfxn3, Sfxn2, and Sfxn5 were also upregulated in islets of streptozotocin-induced diabetic rats compared to normal rats. The downregulation of CTPL/Sfxn3 in a rat insulinoma cell line, INS-1, with the antisense oligonucleotide did not affect the insulin secretion. Taken together, CTPL/Sfxn3 and some other family members might be important in the differentiation of pancreatic beta-cells as a channel or a carrier molecule and be related to the regeneration of pancreatic endocrine cells.

Dispersive terahertz gain of a nonclassical oscillator: BLOCH oscillation in semiconductor superlattices

We have directly determined the spectral shape of the complex conductivities of Bloch oscillating electrons by using the time-domain terahertz (THz) electro-optic sampling technique, and presented experimental evidence for a dispersive Bloch gain in superlattices. This unique dispersive gain without population inversion arises from a nonclassical nature of Bloch oscillations; that is, the phase of the Bloch oscillation is shifted by pi/2 from that of the semiclassical charged harmonic oscillation when driven by the same ac field. By increasing the bias electric field, the gain bandwidth reached approximately 3 THz in our particular sample.

Role of uncoupling protein-2 up-regulation and triglyceride accumulation in impaired glucose-stimulated insulin secretion in a beta-cell lipotoxicity model overexpressing sterol regulatory element-binding protein-1c

Triglyceride (TG) accumulation in pancreatic beta-cells is thought to be associated with impaired insulin secretory response to glucose (lipotoxicity). To better understand the mechanism of the impaired insulin secretory response to glucose in beta-cell lipotoxicity, we overexpressed a constitutively active form of the sterol regulatory element-binding protein- 1c (SREBP-1c), a master transcriptional factor of lipogenesis, in INS-1 cells with an adenoviral vector. This treatment was associated with strong activation of transcription of the genes involved in fatty acid biosynthesis, increased cellular TG content, severely blunted glucose-stimulated insulin secretion, and enhanced expression of the uncoupling protein-2 (UCP-2), which supposedly dissipates the mitochondrial electrochemical potential. To decrease the up-regulated UCP-2 expression, small interfering RNA for UCP-2 was used. Introduction of the small interfering RNA increased the ATP/ADP ratio and partially rescued the glucose-stimulated insulin secretion in the cells overexpressing SREBP-1c, but did not affect the cellular TG content. Next, the effect of the AMP-activated protein kinase (AMPK) agonist, 5-amino-4-imidazolecarboxamide riboside, was examined in the lipotoxicity model. Exposure of the cells with lipotoxicity to 5-amino-4-imidazolecarboxamide riboside increased free fatty acid oxidation, partially reversed the TG accumulation, phosphorylated AMPK and acetyl-coenzyme A carboxylase, and improved the impaired glucose-stimulated insulin secretion. These results suggest that UCP-2 down-regulation and AMPK activation could be candidate targets for releasing beta-cells from lipotoxicity.

Application of synchrotron X-ray imaging to phase objects in orthopedics

Novel imaging of the fine structures of the ribs of a pig and a specimen of human osteosarcoma utilizing the spatial coherence of X-rays was successfully performed with an incident X-ray energy of 30 keV at SPring-8, Japan. The image contrast appearing at the periphery of trabecular bone, small calcifications and small fractures is caused by the phase shift of the X-rays at the boundary of these objects that have different X-ray refractive indices. The image is recorded on mammography film without an intensifying screen. Comparison of the image contrast using different sample-to-film distances, Z, such as Z = 5 m and Z approximately 0 m, showed that the former images were always more informative, i.e. better in resolution and/or image contrast when imaging trabecular bone, bone marrow and small fractures in compact bone, and for imaging cartilage. Radiography using synchrotron X-rays for phase objects should be a powerful tool for diagnosis in orthopedics, especially for bone disease.

GH inhibits interferon-gamma-induced signal transducer and activator of transcription-1 activation and expression of the inducible isoform of nitric oxide synthase in INS-1 cells

Interferon-gamma and TNFalpha synergistically induce the inducible isoform of nitric oxide synthase and elicit severe cytotoxicity in pancreatic beta-cells. We demonstrate here that GH, the well known beta-cell mitogen, inhibits nitric oxide production by reducing inducible nitric oxide synthase gene induction by the two cytokines and counteracts their cytotoxic effect in insulin-secreting INS-1 cells. To elucidate the underlying mechanism, we examined activation of the transcription factors implicated in the induction of inducible nitric oxide synthase, signal transducer and activator of transcription-1, and nuclear factor-kappa B. GH inhibited tyrosine phosphorylation and DNA binding of signal transducer and activator of transcription-1 promoted by interferon-gamma, whereas nuclear factor-kappa B activation by TNFalpha was not affected by GH. GH was found to induce suppressor of cytokine signaling-1 and -3, both of which are able to inhibit interferon-gamma activation of signal transducer and activator of transcription-1, suggesting that they are likely to mediate the inhibitory action of GH. Finally, exposure of INS-1 cells to interferon-gamma resulted in the impairment of insulin secretion in response to glucose, which was restored by the addition of GH. These results indicate that GH counteracts the effect of interferon-gamma through the inhibition of signal transducer and activator of transcription-1. This action of GH may be sufficient to suppress the synergistic induction of inducible nitric oxide synthase by interferon-gamma and TNFalpha, thereby preventing the cytotoxicity to beta-cells.

Insulin resistance with enhanced insulin signaling in high-salt diet-fed rats

Previous clinical studies showed an apparent correlation between hypertension and insulin resistance, and patients with diabetes are known to have increased blood pressure responsiveness to salt loading. To investigate the effect of high salt intake on insulin sensitivity and the insulin signaling pathway, a high-salt diet (8% NaCl) or a normal diet was given to 7-week-old SD rats for 2 weeks. High salt-fed rats developed slightly but significantly higher systolic blood pressure than controls (133 +/- 2 vs. 117 +/- 2 mmHg, P < 0.001), with no change in food intake or body weight. High salt-fed rats were slightly hyperglycemic (108.5 +/- 2.8 vs. 97.8 +/- 2.5 mg/dl, P = 0.01) and slightly hyperinsulinemic (0.86 +/- 0.07 vs. 0.61 +/- 0.06 ng/ml, P = 0.026) in the fasting condition, as compared with controls. Hyperinsulinemic-euglycemic clamp study revealed a 52.7% decrease in the glucose infusion rate and a 196% increase in hepatic glucose production in high salt-fed rats, which also showed a 66.4% decrease in 2-deoxyglucose uptake into isolated skeletal muscle and a 44.5% decrease in insulin-induced glycogen synthase activation in liver, as compared with controls. Interestingly, despite the presence of insulin resistance, high salt-fed rats showed enhanced insulin-induced tyrosine phosphorylation of insulin receptor substrate (IRS)-1, IRS-2 (liver and muscle), and IRS-3 (liver only). Phosphatidylinositol (PI) 3-kinase activities associated with IRS and phosphotyrosine in the insulin-stimulated condition increased 2.1- to 4.1-fold, as compared with controls. Insulin-induced phosphorylation of Ser-473 of Akt and Ser-21 of glycogen synthase kinase-3 also increased 2.9- and 2-fold, respectively, in the liver of the high salt-fed rats. Therefore, in both the liver and muscle of high salt-fed rats, intracellular insulin signaling leading to PI 3-kinase activation is enhanced and insulin action is attenuated. The hyperinsulinemic-euglycemic clamp study showed that decreased insulin sensitivity induced with a high-salt diet was not reversed by administration of pioglitazone. The following can be concluded: 1) a high-salt diet may be a factor promoting insulin resistance, 2) the insulin-signaling step impaired by high salt intake is likely to be downstream from PI 3-kinase or Akt activation, and 3) this unique insulin resistance mechanism may contribute to the development of diabetes in patients with hypertension.

[Sentinel node detection of patients with breast cancer by radionuclide method: consideration of radiation safety]

Sentinel node was detected by 99mTc labeled nanocolloid in five patients with breast cancer. Surgery of breast cancer was done at 16 hours after the administration of 74 MBq of 99mTc labeled nanocolloid. Sentinel node was searched by scintigraphy prior to surgery and by gamma-probe during surgery. Radioactivity of injected site, sentinel nodes, blood contaminated gauze, and other garbage was measured by GM detector. Radiation to medical staffs was monitored by a pocket radiation detector and film batches. Sentinel nodes were successfully detected both by scintigraphy and gamma-detector. More than 70% of radioactivity remained in the administered site at 16 hours. Small amount of radioactivity was detectable in the sentinel node. Almost no radioactivity was detectable in blood-contaminated gauze and other garbage. Radiation dose to the main surgeon was 4 to 6 microSv per surgery by a pocket radiation detector. Radiation dose to the assistant surgeon was 2 microSv per surgery. Radiation dose by labeling or injection was 0 to 1 microSv per procedure. No detectable radiation was measured by film batches. It is concluded that the detection of sentinel node by 99mTc labeled nanocolloid is a safe procedure from the point of radiation safety consideration.

Synergistic activation of NF-kappab and inducible isoform of nitric oxide synthase induction by interferon-gamma and tumor necrosis factor-alpha in INS-1 cells

Interferon-gamma (IFN-gamma) is known to exert deleterious effects on pancreatic beta-cells and is implicated in the development of type 1 (autoimmune) diabetes mellitus. In this study, we investigated signaling mechanisms mediating the effects of IFN-gamma in pancreatic beta-cells using a differentiated rat insulin-secreting cell line, INS-1, with special reference to the activation of transcription factors STAT (signal transducers and activators of transcription)1 and NF-kappaB. Exposure of INS-1 cells to 100 IU/ml IFN-gamma for 24 h resulted in significant inhibition of nutrient-induced insulin secretion associated with impaired metabolism. In combination with tumor necrosis factor-alpha (TNF-alpha) (50 ng/ml), IFN-gamma elicited severe cytotoxicity and induced the expression of the inducible isoform of nitric oxide synthase (iNOS) mRNA. IFN-gamma promoted tyrosine phosphorylation and DNA-binding of STAT1 through Janus kinase (JAK)1 activation without apparent phosphorylation of JAK2. TNF-alpha did not affect STAT1 activation, but stimulated DNA-binding and transcriptional activity of NF-kappaB, both of which were further increased by IFN-gamma. These effects of IFN-gamma and TNF-alpha seem physiologically relevant, because either inhibition of STAT1 by the tyrosine kinase inhibitor herbimycin A or that of NF-kappaB by sulfasalazine resulted in the reduction of iNOS mRNA expression. In conclusion, IFN-gamma activates STAT1 and potentiates TNF-alpha-induced NF-kappaB activation in INS-1 cells, thereby inducing iNOS and cell destruction.

Prostaglandin A1 enhances c-fos expression and activating protein-1 activity

Prostaglandin A1 (PGA1) increases heat shock element (HSE)-mediated transcription, thereby enhancing expression of HSE-bearing genes, including heat shock proteins. Because we recently found functional HSEs in the human and rodent c-fos promoters, we hypothesized that PGA1 might increase c-fos expression through the HSE. In this study, we revealed that PGA1 induces c-fos expression at least partly by increasing the binding between heat shock factor-1 and the HSE, and that PGA1 enhances activity of activating protein-1 (AP-1). Interestingly, so far as PGA, is present in the medium, AP-1-mediated transcription enhanced by PGA1 cannot be detected by the standard luciferase reporter gene assay. Instead, it can be detected by either checking luciferase mRNA levels in the presence of PGA1 or measuring luciferase activities just after removal of PGA1. These results showed that protein products of some stress-responsive genes can increase, not during the stressful condition, but immediately after recovery from stress.

Magnetic resonance imaging of experimentally-induced sialadenitis in rat submandibular glands

OBJECTIVES

To correlate the features of magnetic resonance (MR) images of experimentally induced obstructive sialadenitis in rat submandibular glands with the histopathological changes.

METHODS

Changes in MR images of ligated and non-ligated rat submandibular glands were compared with the histopathological changes and wet weight ratios. Spin echo T1 weighted images (SE T1WI), fast spin echo T2 weighted images (FSE T2WI), and gradient echo T2 weighted images (GE T2WI) were obtained at 1, 2, 3, 4, 5, 7 and 21 days after duct ligation with a 0.3 T MR imaging system.

RESULTS

There was a significant difference (P<0.05) between the signal intensity ratios of both ligated and non-ligated glands on each day, except at 21 days on GE T2WI. On SE T1WI, small interval changes of signal intensity ratios were observed on both glands, whereas there were large interval changes at 1 - 2 days, 4 - 7 days and 21 days after duct ligation with FSE T2WI. These three periods correlated highly with three phases of histopathological changes, swelling of acinar cells at 1 - 2 days, atrophy of acinar cells and increase of duct-like structures at 3 - 7 days, and proliferation of connective tissue at 21 days, and the changes in wet weight ratios. A similar tendency was observed on GE T2WI to FSE T2WI.

CONCLUSIONS

As FSE T2WI showed large changes in signal intensity that correlated highly with histopathological three phases, it is recommended as the MR sequence of choice for diagnosing the degree of damage in obstructive sialadenitis.

Clinical evaluation of repeat apheresis donors in Japan

BACKGROUND AND OBJECTIVES

To ascertain the safety of repeat apheresis donation, hematological and biochemical tests were performed on 511 donors with a donation rate of over 6 times per year for a period of 12-19 months.

MATERIALS AND METHODS

Repeat donors who had apheresis more than 6 times in the previous year were chosen. Data for the repeat donors at the start of the experiments were compared with those at the end of the study. Blood samples were taken prior to donation. Serum protein, albumin, immunoglobulin G, A, and M, serum ferritin levels were determined by biochemical tests.

RESULTS

When compared to prospective donors of 400 ml, WBC, lymphocytes, and serum ferritin levels were lower in a roughly frequency-dependent manner in female and male donor groups at the beginning of the study. All the data for the male group remained almost constant with increasing frequency of apheresis donation. However, in the female group, ferritin levels significantly decreased with over 21 donations.

CONCLUSIONS

The present data showed that the serum ferritin level of the female donors decreased the most with increasing frequency of apheresis donation. The cumulative RBC left in the collecting chamber and for the laboratory test is discussed in relation to a possible cause of iron deficiency in frequent apheresis donors.

Influence of monoclonal antiplatelet glycoprotein antibodies on in vitro human megakaryocyte colony formation and proplatelet formation

The influence of antiplatelet glycoprotein (GP) antibodies on megakaryocytopoiesis in patients with idiopathic or immune thrombocytopenic purpura (ITP) has been well studied. However, the influence of GP antibodies on proplatelet formation is poorly understood. Here we investigated whether in vitro human megakaryocyte colony formation and proplatelet formation are affected by various monoclonal antiplatelet GP antibodies (MoAb). The megakaryocyte colony formation inhibition assay was performed by methylcellulose culture with modifications, using peripheral blood nonadherent mononuclear cells. The proplatelet formation inhibition assay was performed by megakaryocytes derived from CD34(+) cells, stimulated with thrombopoietin + stem cell factor, which were then incubated with antiplatelet GP MoAb for 24 or 48 hours. Anti-GP-Ibalpha MoAb (CD42b; HIP1) slightly inhibited megakaryocyte colony formation (P < .05). and strongly inhibited proplatelet formation (after 24 hours incubation, P < .0002; after 48 hours incubation, P < .0007). Anti-GP-IIb MoAb (CD41; 5B12) inhibited only proplatelet formation (only after 24 hours incubation, P <. 03). Anti-integrin alphavbeta3 MoAb (CD51/CD61; 23C6) only slightly inhibited colony size (P < .05). However, anti-GP-IIIa MoAb (CD61; Y2/51) did not inhibit either colony formation or proplatelet formation. These results suggest that antiplatelet GP MoAbs have differing effects on in vitro megakaryocyte colony formation and proplatelet formation.

Free radical modulation of insulin release in INS-1 cells exposed to alloxan

Generation of free radicals is thought to mediate the cytotoxic action of alloxan on the pancreatic beta-cell. In this investigation, the early effects of alloxan on cell function were studied. When INS-1D insulinoma cells were exposed to alloxan (1 mM) for 45 min followed by a 3-hr recovery period, the drug increased basal insulin release while abolishing the effect of glucose in static incubations. This was associated with impaired stimulation of cellular metabolism by glucose and reduced viability, both monitored colorimetrically with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). These alterations were largely counteracted by the antioxidant butylated hydroxyanisol (BHA). Similar changes occurred when glucose was added directly after 5 min of alloxan treatment, whereas KCl-induced secretion was only partially inhibited. In perifusion, alloxan caused transient insulin secretion to 50% of the rates obtained with glucose 30 min later. Under these conditions, epinephrine abolished the stimulation due to both agents. Membrane potential and cytosolic calcium concentrations ([Ca2+]i) were recorded to clarify the action of alloxan. Alloxan-induced insulin release correlated with depolarization of INS-1D cells and a rise in [Ca2+]i. Alloxan did not augment [Ca2+]i in the presence of BHA or the absence of extracellular calcium. Nickel chloride blocked the effect of alloxan on [Ca2+]i, whereas verapamil was ineffective. This suggests that alloxan promotes Ca2+ influx through channels distinct from L-type channels, perhaps through non-selective cation channels. Thus, alloxan causes changes in INS-1D cells prevented by antioxidant treatment, suggesting that free radicals may modulate the ionic permeability leading to functional activation.

Growth hormone-induced tyrosine phosphorylation of EGF receptor as an essential element leading to MAP kinase activation and gene expression

GH binding to its receptor, which belongs to the cytokine receptor superfamily, activates Janus kinase (JAK) 2 tyrosine kinase, thereby activating a number of intracellular key proteins such as STAT (signal transducers and activators of transcription) proteins and mitogen-activated protein (MAP) kinases, which finally lead to GH's biological actions including gene expression. In contrast to receptor tyrosine kinases, the signalling pathways leading to MAP kinase activation by GH are poorly understood but appear to involve Grb2 and Shc. We now show that GH stimulated tyrosine phosphorylation of epidermal growth factor receptor (EGFR) and its association with Grb2, and concomitantly stimulated MAP kinase activity in liver, a major target tissue. Expression of EGFR and its mutants into CHO-GH receptor (GHR) cells revealed that GH-induced full activation of MAP kinase and c-fos expression required tyrosine phosphorylation sites of EGFR but not its intrinsic tyrosine kinase activity. Moreover, by also using dominant negative JAK2 and in vitro kinase assay, we demonstrated that tyrosine 1068 of EGFR was evidently one of the major phosphorylation and Grb2 binding sites stimulated by GH via JAK2. These data suggest that the role of EGFR in GH signalling is to be phosphorylated by JAK2, thereby providing docking sites for Grb2 and activating MAP kinases and gene expression. This novel cross talk pathway may provide the first example of the hormone and cytokine receptor superfamily transducing signals via associated nonreceptor tyrosine kinase by phosphorylating growth factor receptor and utilizing it as a docking protein independent of its receptor tyrosine kinase activity.

GH signalling in pancreatic beta-cells

GH and its related peptide PRL are known to stimulate proliferation and insulin biosynthesis in pancreatic beta-cells, and assumed to be involved in their functional maturation. We investigated signal transduction of GH and PRL in insulin-secreting cells using the differentiated rat insulinoma cell line, INS-1. In these cells, both hormones stimulated proliferation and DNA synthesis, increased viability, cellular metabolism and insulin content. GH induced cytosolic Ca2+ ([Ca2+]i) rises, which appear to be due to Ca2+-influx through voltage-gated Ca2+-channels. GH also promoted tyrosine phosphorylation of several proteins in INS-1 cells, one of which was identified as JAK2 tyrosine kinase. Moreover, GH caused changes in DNA binding of nuclear proteins to some interferon-gamma-activated sites. Verapamil inhibited neither DNA synthesis nor JAK2 phosphorylation stimulated by GH, whereas a tyrosine kinase inhibitor, lavendustin A, blocked the mitogenic effect. Involvement of cAMP is also suggested because Rp-cAMPS, a competitive inhibitor of protein kinase A, abolished both [Ca2+]i rises and DNA synthesis stimulated by GH. The effects of GH and PRL on [Ca2+]i, JAK2 phosphorylation and DNA binding of the STATs were virtually identical in INS-1 cells. Since both hormones failed to activate MAP kinase in these cells, it is strongly suggested that activation of the JAK-STAT pathway is the major signalling event for the mitogenic effects of GH and PRL in beta-cells. It remains to be clarified whether the [Ca2+]i rise mediates other effects of these hormones.

Tyrosine phosphorylation of the EGF receptor by the kinase Jak2 is induced by growth hormone

When growth hormone binds to its receptor, which belongs to the cytokine receptor superfamily, it activates the Janus kinase Jak2 which has tyrosine-kinase activity and initiates an activation of several key intracellular proteins (for example, mitogen-activated protein (MAP) kinases) that eventually execute the biological actions induced by growth hormone, including the expression of particular genes. In contrast to receptors that themselves have tyrosine kinase activity, the signalling pathways leading to MAP kinase activation that are triggered by growth hormone are poorly understood, but appear to be mediated by the proteins Grb2 and Shc. We now show that growth hormone stimulates tyrosine phosphorylation of the receptor for epidermal growth factor (EGFR) and its association with Grb2 and at the same time stimulates MAP kinase activity in liver, an important target tissue of growth hormone. Expression of EGFR and its mutants revealed that growth-hormone-induced activation of MAP kinase and expression of the transcription factor c-fos requires phosphorylation of tyrosines on EGFR, but not its own intrinsic tyrosine-kinase activity. Moreover, tyrosine at residue 1,068 of the EGFR is proposed to be one of the principal phosphorylation sites and Grb2-binding sites stimulated by growth hormone via Jak2. Our results indicate that the role of EGFR in signalling by growth hormone is to be phosphorylated by Jak2, thereby providing docking sites for Grb2 and activating MAP kinases and gene expression, independently of the intrinsic tyrosine kinase activity of EGFR. This may represent a novel cross-talk pathway between the cytokine receptor superfamily and growth factor receptor.

Glucose-induced insulin secretion in INS-1 cells depends on factors present in fetal calf serum and rat islet-conditioned medium

To study the regulation of growth and differentiated function of insulin-secreting cells, the rat insulinoma cell line INS-1 was cultured in a defined serum-free medium containing prolactin, IGF-I, and triiodothyronine, which was originally reported to maintain insulin secretion of islet cells. Growth and viability, as well as cellular insulin content of INS-1 cells in the defined medium, were comparable to the control cells cultured in the complete medium containing 10% fetal calf serum. However, after a 3-day culture in this medium, insulin secretion in response to glucose, pyruvate, and leucine was markedly blunted compared with the control cells (-78, -68, and -56%, respectively), whereas the response to 30 mmol/l K+ was only slightly decreased. In these cells: 1) nutrient metabolism assessed by tetrazolium salt reduction was reduced in response to pyruvate and leucine, which are mainly metabolized in the mitochondria; 2) oxidation of both [3,4-(14)C]glucose and [1-(14)C]pyruvate was decreased (-22 and -32%, respectively); 3) glucose failed to depolarize the membrane potential, whereas tolbutamide was fully active; 4) video imaging analysis of cytosolic Ca2+ showed a decrease in the population of glucose-responsive cells, while the response to 30 mmol/l K+ was preserved; 5) serum replenishment for 3 days restored glucose-induced insulin secretion. Interestingly, conditioned serum-free medium from rat islets maintained the insulin secretory function of INS-1 cells, although glucagon, somatostatin, and some other factors failed to restore the function. In contrast, conditioned media from HepG2, PC12, and human umbilical vein endothelial cells did not substitute for serum. Thus, the impaired insulin secretion of the cells cultured in the defined medium is best explained by defective mitochondrial metabolism. Islet cells, but not INS-1 cells, produce factors required for normal signal generation by nutrient secretagogues.

[Comparison of retinal breaks between patients with atopic dermatitis and mentally retarded patients with self-inflicted ocular injury]

We compared the distribution of retinal breaks in retinal detachment between patients with atopic dermatitis (AD) and mentally retarded patients who had self-inflicted ocular injury (MR). The cases of AD were 16 eyes in 14 patients (six males and eight females, ranging in age from 15 to 52 years, mean 24.5) and the cases of MR were 6 eyes in 5 patients (5 males, ranging in age from 14 to 25 years, mean 20.2). There was no corneoscleral laceration in either group. In the patients with AD, 14 (87.5%) of 16 eyes had retinal breaks at the vitreous base, and 21 (87.5%) of 24 retinal breaks in 16 eyes were at the vitreous base. In the patients with MR, five (83.3%) of 6 eyes had retinal breaks at the vitreous base and 6(66.7%) of 9 retinal breaks in 6 eyes were at the vitreous base. In both groups, ciliary epithelial breaks and peripheral retinal tears were frequently observed, suggesting that retinal detachment in AD has a pathophysiology similar to traumatic retinal detachment with repeated ocular contusion (self-inflicted injury).

[Hematological evaluation of megakaryocytic vacuolar degeneration in patients with idiopathic thrombocytopenic purpura]

Variable degrees of vacuolar degeneration of the cytoplasm of megakaryocytes(MEG) have been recognized in patients with idiopathic thrombocytopenic purpura(ITP). It has been questioned whether this degeneration is specific to the disease, as it is not seen in all patients, and few reports have examined its physiological relationship to the disease process. This study examined the vacuolation and its relationship to platelet count(PLTc) by image analysis, measuring the vacuolar area and the MEG area. However, it was inappropriate to evaluate the vacuolar area alone, since variations in the MEG area among patients influenced the vacuolar area. When the proportion of the vacuolar area relative to total MEG was defined as %VAC, the value for ITP patients was higher than in control cases (p < 0.05). However, there was no correlation between %VAC and PLTc. It was thought that this reflected the previous reports doubting the disease specificity of this feature. When all the ITP patients were generalized, the age at onset was wide, and both chronic type and repetitive type cases were included. However, in 4 ITP cases in which it was possible to follow the treatment progress, the %VAC was well correlated with the change in PLTc. It was concluded that MEG cytoplasmic vacuolation in ITP is morphologically meaningful if it can be followed over the course of treatment.

Postreceptor signalling of growth hormone and prolactin and their effects in the differentiated insulin-secreting cell line, INS-1

Signal transduction of two mitogens for pancreatic beta-cells, GH and PRL, was investigated using the differentiated insulin-secreting cell line, INS-1. Addition of human GH (hGH) or ovine PRL in a serum-substitute medium increased growth, insulin content, and nutrient metabolism evaluated by tetrazolium salt reduction. hGH, bovine GH (bGH), and PRL also stimulated [3H]thymidine incorporation in a dose-dependent manner (1 pM - 1 nM). hGH induced cytosolic Ca2+ ([Ca2+]i) rises, which were transient, dependent on the presence of extracellular Ca2+, blocked by verapamil, calciseptine, and the hyperpolarizing agent diazoxide, suggesting that hGH stimulates Ca(2+)-influx through L-type Ca(2+)-channels. Similar effects on [Ca2+]i were observed with bGH or PRL. hGH caused membrane depolarization in a small proportion of the cells ( < 25%) as detected by cell-attached patch-clamp analysis. However, hGH failed to stimulate acute insulin secretion. hGH, bGH, and PRL promoted tyrosine phosphorylation of JAK2 tyrosine kinase. Verapamil inhibited neither [3H]thymidine incorporation nor JAK2 phosphorylation stimulated by hGH, whereas a tyrosine kinase inhibitor, lavendustin A, blocked the mitogenic effect. Involvement of cAMP is suggested because Rp-cyclic adenosine-3', 5'-monophosphorothioate, a competitive inhibitor of protein kinase A, abolished hGH-induced [Ca2+]i rises and DNA synthesis. cAMP appears to play a permissive role, although hGH failed to raise cellular cAMP levels. These results support the idea that activation of JAK2 is a major signaling event, whereas the [CA2+]i rise is not a prerequisite, for the mitogenic effects of GH and PRL in insulin-secreting cells.

Attenuation of glycogenolytic action of activin A in intact rat liver

Activin A stimulates glucose production by causing glycogenolysis in isolated hepatocytes. To determine the physiological significance of this effect, we examined the effect of activin A on glucose production in the perfused liver. Unlike the effect in isolated cells, activin A did not enhance glucose production nor did it cause radiocalcium efflux in the perfused liver. There was no effect of activin A in the liver perfused in the opposite direction. Although activin A did not promote glucose production, it was recovered from the hepatic vein in a bioactive form. When liver perfusion was performed in partially hepatectomized rats, activin A increased radiocalcium efflux. In isolated hepatocytes, activin A increased inositol phosphates, and the effect of activin A was attenuated by the plasma membrane fraction of hepatocytes. The inhibitory effect of the plasma membrane was abolished by digestion of the membrane with trypsin. These results indicate that the effect of activin A on glucose production is attenuated in the intact liver and that a protein factor(s) in plasma membrane may be involved in the inhibition.

Glucose, other secretagogues, and nerve growth factor stimulate mitogen-activated protein kinase in the insulin-secreting beta-cell line, INS-1

The signaling pathways whereby glucose and hormonal secretagogues regulate insulin-secretory function, gene transcription, and proliferation of pancreatic beta-cells are not well defined. We show that in the glucose-responsive beta-cell line INS-1, major secretagogue-stimulated signaling pathways converge to activate 44-kDa mitogen-activated protein (MAP) kinase. Thus, glucose-induced insulin secretion was found to be associated with a small stimulatory effect on 44-kDa MAP kinase, which was synergistically enhanced by increased levels of intracellular cAMP and by the hormonal secretagogues glucagon-like peptide-1 and pituitary adenylate cyclase-activating polypeptide. Activation of 44-kDa MAP kinase by glucose was dependent on Ca2+ influx and may in part be mediated by MEK-1, a MAP kinase kinase. Stimulation of Ca2+ influx by KCl was in itself sufficient to activate 44-kDa MAP kinase and MEK-1. Phorbol ester, an activator of protein kinase C, stimulated 44-kDa MAP kinase by both Ca(2+)-dependent and -independent pathways. Nerve growth factor, independently of changes in cytosolic Ca2+, efficiently stimulated 44-kDa MAP kinase without causing insulin release, indicating that activation of this kinase is not sufficient for secretion. In the presence of glucose, however, nerve growth factor potentiated insulin secretion. In INS-1 cells, activation of 44-kDa MAP kinase was partially correlated with the induction of early response genes junB, nur77, and zif268 but not with stimulation of DNA synthesis. Our findings suggest a role of 44-kDa MAP kinase in mediating some of the pleiotropic actions of secretagogues on the pancreatic beta-cell.

[A case of cutaneous malignant melanoma metastatic to the choroid]

A case of metastasis of cutaneous malignant melanoma to the choroid was reported. The patient, a 61-year-old man, had undergone an amputation of his right first finger 3 years ago due to cutaneous malignant melanoma. Ophthalmoscopic examination revealed a whitish yellow elevated choroidal lesion and serous retinal detachment in the left eye. Fluorescein angiography demonstrated multiple pinpoint leaks in the early phase and progressive pooling of dye into the subretinal space in the late phase. In magnetic resonance imaging, the tumor showed a hyperintense image in both T1 and T2-weighted images. Autopsy was performed and histopathological examination of the eye showed that the tumor cells were polygonal in shape, and had round or oval nuclei, but the cytoplasms had little melanin pigment. Immunohistochemistry for S-100 and HMB-45 antibody showed positive staining in choroidal tumor and other metastatic lesions, indicating that they were metastatic tumors from cutaneous malignant melanoma (amelanotic melanoma cells).

Bimodal effect of transforming growth factor-beta on insulin secretion in MIN6 cells

The effects of transforming growth factor-beta (TGF-beta) on insulin secretion were investigated using a glucose-responsive clonal cell line, MIN6. One hundred pM TGF-beta stimulated insulin release during 0.5-24 h of incubation in the presence of 5.5 mM glucose, but not after 48 h; 1 nM TGF-beta also stimulated insulin release up to 2 h of exposure, but the effect was not seen after 6 h of exposure. When cells were incubated with 25 mM glucose for 24 h, 100 pM TGF-beta significantly inhibited glucose-stimulated insulin release, whereas insulin release was not altered at 0 or 2.8 mM glucose. On the contrary, forskolin- (10 microM) and tolbutamide- (40 microM) induced insulin release were not affected by TGF-beta. TGF-beta affected neither the cell growth nor the cellular insulin content. An addition of 1 microM nitrendipine abolished TGF-beta-induced insulin secretion at 5.5 mM glucose. The presence study shows that TGF-beta exerts a bimodal effect on glucose-induced insulin secretion from MIN6 cells, depending on dose, time of exposure and concentrations of coexisting glucose. These effects might be mediated by the Ca(2+)-dependent mechanism.

Characterization of botulinum C3-catalyzed ADP-ribosylation of rho proteins and identification of mammalian C3-like ADP-ribosyltransferase

The exoenzyme C3 produced by Clostridium botulinum catalyzes ADP-ribosylation of rho gene products which belong to a family of small molecular-weight GTP-binding proteins. The C3 enzyme-catalyzed ADP-ribosylation of rho proteins partially purified from bovine brain was markedly activated by certain types of detergents or phospholipids and by endogenous factors present in the brain cytosol. Rho A protein that had been expressed in E. coli and subsequential purified was readily ADP-ribosylated by the C3 enzyme even in the absence of the activating factors. These results suggest that partially purified rho proteins contain an inhibitor, probably rho GDI (GDP-dissociation inhibitor for rho p21), of C3-catalyzed ADP-ribosylation. The activity of an endogenous enzyme, having the same substrate as botulinum C3 enzyme, was also found in brain cytosol. The enzyme activity was partially purified and characterized. The enzyme appeared to have a molecular mass of approximately 20,000 on a gel filtration and displayed unique properties similar to those observed with the botulinum C3 enzyme. The alpha-subunits of alpha beta gamma-trimeric G proteins which served as the substrates of cholera or pertussis toxin were not ADP-ribosylated by the brain enzyme.

[Incidence of cataract and retinal detachment associated with atopic dermatitis]

The incidence of cataract and retinal detachment associated with atopic dermatitis is reported. The subjects suffered from moderate or severe atopic dermatitis. Seventy-five patients (32 male and 43 female, age: 7-46, mean 19.7 years) had their initial examination at the Department of Ophthalmology, Sapporo Medical University Hospital, from 1981 to 1990. Cataract was found in 13 (6 male and 7 female) out of the 75 patients (17.3%). All cases except one already had cataract at the initial visit. The average age was 21.2 years. Nine had bilateral cataracts and four had unilateral. Type of cataract in 22 eyes was anterior subcapsular cataract (n = 3), posterior subcapsular cataract (n = 8), anterior and posterior cataract (n = 9), and mature cataract (n = 2). Retinal detachment was associated in six (8.0%) out of the 75 patients. Four were male and two were female. The average age was 21.6 years (range 18-29). Three cases were bilateral and 3 unilateral. Five of nine eyes with retinal detachment had no history of intraocular surgery. Four of the nine had a history of cataract extraction (3 eyes) and trabeculectomy (1 eye). Tears were observed in 5 out of 9 eyes (small tears in the peripheral retina (n = 1), oral dialysis (n = 3), and breaks at the pars plicata (n = 1). Tears could not be observed in four eyes (44%). Detachment of the pars plana was found in seven eyes. Retinal detachment was always associated with cataract.

Low lactate dehydrogenase and high mitochondrial glycerol phosphate dehydrogenase in pancreatic beta-cells. Potential role in nutrient sensing

Nutrient metabolism was examined with regard to insulin secretion in purified rat islet beta- and non-beta-cells, beta-cell lines, and hepatocytes. Lactate dehydrogenase (LDH) activity (nanomoles.min-1.mg protein-1) was remarkably low in the glucose-sensitive INS-1 cell line (15.7) and in beta-cells (22.3). Thus, beta-cell LDH was respectively 8-, 122-, 17-, and 136-fold lower than in islet non-beta, liver, HIT-T15, and RINm5F cells. Plasma membrane lactate transport activity was 3-10-fold lower in beta- or INS-1 cells than in the other cell types. Conversely, mitochondrial glycerol phosphate dehydrogenase was strongly expressed only in beta- and INS-1 cells. The significance of these findings to nutrient recognition was explored using INS-1 cells as a model of native beta-cells. Glucose-stimulated lactate output and glucose utilization were, respectively, 12- and 5-fold lower in INS-1 than in RINm5F cells. Each process was entirely blocked by respiratory chain inhibitors in INS-1 cells, whereas glucose utilization was barely affected and lactate output stimulated in RINm5F cells. Glucose oxidation represented 73% of total utilization in INS-1 cells, but only 9% in RINm5F cells. Absolute rates of glucose oxidation, and the extent of mitochondrial NAD(P) reduction, were similar in the two cell types, and glucose stimulated insulin secretion 1.9-fold in INS-1 and 1.4-fold in RINm5F cells. The mitochondrial substrates, monomethyl succinate, pyruvate, and leucine, each triggered secretion in INS-1 cells. The balance of LDH, plasma membrane lactate transport, and mitochondrial glycerol phosphate dehydrogenase activities therefore appear to be important in beta- and INS-1 cell glucose recognition to ensure that mitochondrial oxidation is the principle fate of pyruvate and NADH produced by glycolysis. The resultant close coupling of glycolysis with mitochondrial oxidation explains the absence in beta-cells of Crabtree and Pasteur effects.

Activin A increases intracellular free calcium concentrations in rat pancreatic islets

Activin A stimulated insulin secretion in rat pancreatic islets, an effect that was attenuated by reduction of extracellular Ca2+ and abolished by either nitrendipine or verapamil. Activin A increased intracellular the free Ca2+ concentration, [Ca2+]i in fura-2-loaded islets. Activin A-mediated elevation of [Ca2+]i was abolished by the reduction of extracellular Ca2+ or the addition of nifedipine. In addition, activin A did not increase [Ca2+]i in the presence of diazoxide, an opener of ATP-sensitive K+ channels. These results suggest that activin A increases insulin secretion by stimulating Ca2+ entry.

Existence of activin-A in A- and D-cells of rat pancreatic islet

Activin-A, a member of the transforming growth factor-beta supergene family, stimulates insulin secretion in rat pancreatic islets and causes glycogenolysis in isolated rat hepatocytes. These observations prompted us to determine whether activin-A existed in rat pancreas by using an immunocytochemical method. Cells in pancreatic islets were stained by antibody against activin-A, whereas no immunoreactivity was observed in exocrine pancreas. Cells localized in the mantle of the islets were densely stained by the antibody. Immunoelectron microscopic study showed that activin-A existed in secretory granules in both A- and D-cells. Furthermore, studies using a double labeling method revealed that activin-A coexisted with glucagon in secretory granules in A-cells and with somatostatin in D-cells. Antibody against inhibin-A weakly stained cells in both the core and mantle of the islets only when the rat was pretreated with colchicine. Subtypes of activin subunit in islets were identified to be beta A by a reverse transcription-polymerase chain reaction method. In addition, mRNA for inhibin alpha-subunit was expressed in islets. However, mRNA for these inhibin subunits was not detected in exocrine pancreas. To further examine the action of activin-A on insulin secretion, we examined the effect of activin-A in a flow-through perifusion system. Activin-A induced a biphasic insulin secretory response in the presence of 2.8 mM glucose, and a low concentration of activin-A, which does not stimulate insulin secretion by itself, markedly enhanced glucose-mediated insulin secretion at concentrations above 2.8 mM glucose. Inhibin-A did not affect insulin secretion. These results suggest the existence of activin-A in A- and D-cells of rat pancreatic islets and raise the possibility that activin-A acts as a physiological regulator of carbohydrate metabolism.

Production of monoclonal antibodies that inhibit ADP-ribosylation of small GTP-binding proteins catalyzed by Clostridium botulinum ADP-ribosyltransferase C3

Four monoclonal antibodies that inhibited ADP-ribosylation of 23 kDa protein(s) of ascidian eggs catalyzed by Clostridium botulinum ADP-ribosyltransferase C3 were produced. They also inhibited C3-catalyzed ADP-ribosylation of the 24 kDa protein of rat liver cytosol. By the immunoprecipitation technique, it was found that they recognized small GTP-binding proteins of ascidian eggs and mammalian brains, but did not interact with the rat brain activator of the ADP-ribosyltransferase reaction. The antibody can also immunoprecipitate recombinant Rho A irrespective as to whether the Rho A is the GDP-bound form or the GTPrS-bound form. Thus the antibodies are novel and useful tools in analyzing the physiological roles of the Rho family of GTP-binding proteins.

Rhabdomyolysis and acute renal failure in a patient with hypothyroidism

A 61-year-old woman developed rhabdomyolysis and acute renal failure after strenuous walking. She had been treated for seven years with levothyroxine (T4) for hypothyroidism. On admission, her thyroid function test revealed marked hypothyroidism, suggesting poor drug compliance. Electromyographic and muscle biopsy findings were compatible with hypothyroid myopathy. Other diseases that could cause rhabdomyolysis were excluded. Her renal function completely recovered with peritoneal dialysis, and thyroid function normalized with 100 micrograms/day of T4. The present case suggests that rhabdomyolysis could occur in patients with hypothyroidism, especially those with poor drug compliance, in combination with other aggravating factors such as exercise.

[HTLV-I associated myelopathy with macular degeneration]

The authors report a case of macular involvement in a patient with HTLV-I associated myelopathy (HAM). The patient was a 10-year-old girl who noticed sudden decreased vision in her right eye in November 1987. The corrected visual acuity was 0.01 in the right eye and 1.0 in the left eye. Fundus examination of the right eye disclosed mild optic disc pallor. The macula appeared to have pigmentary mottling with superficial irregular retinal reflex that was three disc diameters in size. Fluorescein angiography revealed a discoid hypofluorescent area in the macula, surrounded by mottled hyperfluorescent areas. She had no contributory family history of ocular disease, but had a history of blood transfusion during an operation for patent ductus arteriosus and ventricular septal defect at the age of 8 months. In November 1990, she developed gait disturbance due to spastic paraparesis and was admitted to our hospital. Antibodies to HTLV-I were markedly elevated in serum (titer, 1:8192) and in cerebrospinal fluid (titer, 1: 1024). She was diagnosed as HAM. Two months later, she developed encephalopathy and bilateral optic disc atrophy.

A patient with protein-losing enteropathy associated with systemic lupus erythematosus

A 46-year-old woman previously diagnosed as having systemic lupus erythematosus presented with severe hypoalbuminemia and anasarca. She was demonstrated to have protein-losing enteropathy without any other active symptoms of SLE. Her bowel habit was normal and endoscopic examination revealed non-specific colitis and a small ulcer in the duodenum. Serum biochemistry showed an abnormal profile of the serum protein, including severe hyperlipoproteinemia and hyperfibrinogenemia. The process of protein-losing was not selective in terms of the molecular size. All of these symptoms and the abnormalities in laboratory data were improved by corticosteroid therapy.

Bilateral metastatic sclerochoroidal calcification in a patient with hyperparathyroidism

We present the case of a 39-year-old man with bilateral sclerochoroidal calcification with primary hyperparathyroidism. Both the calcium and parathyroid hormone levels were elevated. Funduscopic examination revealed slightly elevated, multiple yellow lesions in both eyes. Fluorescein angiography showed filling defects of the choroid. Ultrasonography showed elevated, highly reflective lesions, and a computed tomography scan of the globe disclosed sclerochoroidal lesions with high density. We discuss the mechanism of sclerochoroidal calcification.

Increase in susceptibility of Pseudomonas aeruginosa to carbapenem antibiotics in low-amino-acid media

The in vitro susceptibility of Pseudomonas aeruginosa PAO1 to carbapenem antibiotics, such as CS-533, was influenced by various concentrations of basic amino acids, i.e., L-lysine, L-histidine, and L-arginine, in agar media. P. aeruginosa PAO1 showed higher susceptibility to carbapenems in minimal medium than it did in rich media such as Mueller-Hinton II agar. The susceptibility was decreased by the addition of a basic amino acid to the minimal medium, whereas it was influenced less by other amino acids. The susceptibility of PAO1 to cephalosporins, piperacillin, quinolones, and gentamicin was not influenced by the addition of a basic amino acid to the minimal medium. A significant change in susceptibility to carbapenems by the addition of a basic amino acid was not observed with D2 protein-deficient mutants of PAO1. Clinical isolates of P. aeruginosa also showed an increase in susceptibility in minimal medium. L-Lysine in minimal medium did not have any influence on the production of D2 protein, beta-lactamases, or penicillin-binding proteins of PAO1 or on the chemical degradation of CS-533. These results strongly indicate that the increase in susceptibility of P. aeruginosa to carbapenems relates to less competition with basic amino acids for permeation through the D2 protein channel of P. aeruginosa.