Chloride channel CLCN5 mutations in Japanese children with familial idiopathic low molecular weight proteinuria

BACKGROUND

Familial idiopathic low molecular weight proteinuria (FILMWP) is a renal proximal tubulopathy characterized by mild proteinuria consisting of low molecular weight proteinuria and relatively conserved renal function in young patients, but without rickets. Mutations in the renal chloride channel CLCN5 gene have been reported in three disorders of hypercalciuric nephrolithiasis and in FILMWP.

METHODS

To assess the relationship between molecular defects and phenotypic variations, we analyzed the CLCN5 gene from three additional Japanese families with FILMWP using single-strand conformation polymorphism and sequencing.

RESULTS

We identified three mutations: a single base insertion at codon 514; a single base deletion at codon 116; and a nonsense mutation, R704X. The R704X mutation is identical to that found in X-linked recessive nephrolithiasis, but there was no renal failure in our patient. The first two mutations caused a shift in the reading frame, and all introduced a premature stop codon, resulting in synthesis of truncated CLC-5 proteins that lacked 220 (29%), 610 (82%), and 43 (6%) amino acids, respectively. These mutations were demonstrated to cosegregate with the disease in each of the three families.

CONCLUSIONS

We conclude that the CLCN5 gene is responsible for the renal proximal tubulopathy in many Japanese families and suggest that molecular defects, environmental factors, or other modifying genes may account for the different phenotypes.

A controlled trial of combined therapy for newly diagnosed severe childhood IgA nephropathy. The Japanese Pediatric IgA Nephropathy Treatment Study Group

The most appropriate treatment for patients with IgA nephropathy is controversial. Treatment with prednisolone, azathioprine, heparin-warfarin, and dipyridamole early in the course of disease may prevent immunologic renal injury in children with severe IgA nephropathy. To determine whether similar results can be obtained with a combination of just heparin-warfarin and dipyridamole, the effects of such treatment were compared to those of treatment with prednisolone, azathioprine, heparin-warfarin, and dipyridamole in 78 children with newly diagnosed IgA nephropathy showing diffuse mesangial proliferation. The patients were randomly assigned to receive either prednisolone, azathioprine, heparin-warfarin, and dipyridamole for 2 yr (group 1) or heparin-warfarin and dipyridamole for 2 yr (group 2). All of the 40 patients in group 1 and 34 of the 38 patients in group 2 completed the trial. The mean urinary protein excretion fell in group 1 patients (P < 0.0001), but remained unchanged in group 2 patients. The mean serum IgA concentration was reduced in group 1 patients (P = 0.0002), but was unchanged in group 2 patients. BP and creatinine clearance were normal at the end of the trial in all but one group 2 patient, who developed chronic renal insufficiency. The percentage of glomeruli showing sclerosis was unchanged in group 1 patients, but increased in group 2 patients (P = 0.006). The intensity of mesangial IgA deposits decreased in group 1 patients (P = 0.02), but remained unchanged in group 2 patients. In conclusion, the present study shows that treatment of children with severe IgA nephropathy with prednisolone, azathioprine, heparin-warfarin, and dipyridamole for 2 yr early in the course of disease reduces immunologic renal injury and prevents increase of sclerosed glomeruli.

A novel human RasGAP-like gene that maps within the prostate cancer susceptibility locus at chromosome 1q25

We report the molecular cloning of a human cDNA that encodes a molecule having striking homology with Ras-specific GTPase-activating proteins (RasGAPs). Among previously described RasGAPs, the cDNA product is most closely related to Caenorhabditis elegans GAP-2, including a predicted coiled-coil structure near the carboxyl terminus. Expression of the cDNA in Saccharomyces cerevisiae defective in one of two RasGAPs, Ira2, complemented loss of the Ira2 function, indicating that the cDNA product functions as a RasGAP. The RasGAP-like gene is located on the human chromosome 1q25, the locus that appears to contain a hereditary prostate cancer susceptible gene, HPC1.

[Standard versus long-term prednisolone with sairei-to for initial therapy in childhood steroid-responsive nephrotic syndrome: a prospective controlled study]

The most appropriate initial treatment for children with steroid-responsive nephrotic syndrome is controversial. Initial treatment with 18-week prednisolone and the Chinese herbal medicine. Sairei-to, may prevent subsequent relapse. To determine whether similar results can be obtained with a combination of just initial 8-week prednisolone and Sairei-to, we compared the effects of such treatment with those of treatment with 18-week prednisolone and Sairei-to in 196 children with steroid-responsive nephrotic syndrome. The patients were randomly assigned to receive 8-week (group 1) or 18-week (group 2) prednisolone for the initial therapy. All patients received Sairei-to for 2 years in addition to prednisolone. Eighty-eight of the 98 patients in group 1 and 83 of the 98 patients in group 2 completed their trial. At entry, the two groups of patients did not differ in their clinical and laboratory findings. During the 2-year trial, 62 group 1 patients (70%) and 54 group 2 patients (65%) had relapses, and 19 group 1 patients (21%) and 20 group 2 patients (24%) had frequent relapses. The present study demonstrates that a combination of initial 8-week prednisolone and 2-year Sairei-to is effective in children with steroid-responsive nephrotic syndrome.

The G protein G alpha12 stimulates Bruton's tyrosine kinase and a rasGAP through a conserved PH/BM domain

Heterotrimeric guanine-nucleotide-binding proteins (G proteins) are signal transducers that relay messages from many receptors on the cell surface to modulate various cellular processes. The direct downstream effectors of G proteins consist of the signalling molecules that are activated by their physical interactions with a G alpha or Gbetagamma subunit. Effectors that interact directly with G alpha12 G proteins have yet to be identified. Here we show that G alpha12 binds directly to, and stimulates the activity of, Bruton's tyrosine kinase (Btk) and a Ras GTPase-activating protein, Gap1m, in vitro and in vivo. G alpha12 interacts with a conserved domain, composed of the pleckstrin-homology domain and the adjacent Btk motif, that is present in both Btk and Gap1m. Our results are, to our knowledge, the first to identify direct effectors for G alpha12 and to show that there is a direct link between heterotrimeric and monomeric G proteins.

L-selectin-specific autoantibodies in murine lupus: possible involvement in abnormal homing and polarization of CD4+ T cell subsets

One notable functional abnormality in murine and human systemic lupus erythematosus (SLE) is the defect in the production of IL-2 in association with the deficit in naive CD4+ T cells. The mechanism is unknown, but one idea is that naturally occurring autoantibodies with specificities to the naive CD4+ T cell subpopulation are related to this event. We selected hybridoma monoclonal autoantibodies from SLE-prone (New Zealand Black (NZB) x New Zealand White (NZW))F1 mice that reacted with restricted populations of CD4+ T cells. One of these, H32, was specific for L-selectin, as determined by 1) distribution of Ag H32 on lymphoid cells similar to Mel-14, an epitope of L-selectin; 2) shedding of 80-kDa molecules with epitope H32 from the surface of lymph node cells coincidentally with Mel-14, when stimulated with phorbol ester; 3) cross-inhibitory activities on Ag binding between H32 and Mel-14; and 4) reactivity of H32 with recombinant mouse L-selectin. Pretreatment of 51Cr-labeled lymphocytes from BALB/c mice with H32 significantly inhibited their homing to lymph nodes in vivo. The BALB/c splenic H32+ CD4+ T cell subset produced few cytokines except IL-2, thus corresponding to naive ThP-type cells. This subset was markedly selectively depleted in aged (NZB x NZW)F1 mice. There was an age-associated increase in frequencies and titers of anti-L-selectin autoantibodies in sera from (NZB x NZW)F1 mice. Thus, abnormalities of naive CD4+ T cell subset, including IL-2 production in subjects with SLE, are at least partly attributed to the generation of autoantibodies to L-selectin.

Effect of additional general anesthesia with propofol, midazolam or sevoflurane on stress hormone levels in hysterectomy patients, receiving epidural anesthesia

Hormonal responses after surgery are characterized by increased pituitary-adrenal axis hormones. We undertook this study to determine whether the choice of anesthesia influences stress hormone levels. Twenty-three adult females scheduled for hysterectomy for benign disease under general anesthesia were randomly assigned to one of three groups: epidural/propofol anesthesia (Group P), epidural/midazolam anesthesia (Group M), and epidural/sevoflurane anesthesia (Group S). The concentrations of ACTH and cortisol in group P and group M were significantly less than that of group S at 60 min after the incision. The concentrations of beta-endorphin and aldosterone in group P and group M were significantly less than that of group S at 60 min after the incision and after extubation. We conclude that combined epidural and general anesthesia with propofol or midazolam has a greater suppressive effect than sevoflurane on the stress response of the pituitary-adrenal axis during hysterectomy.

Moyamoya disease with concurrent von Recklinghausen's disease and cerebral arteriovenous malformation

We present a rare autopsy case of von Recklinghausen's disease with Moyamoya vessels and arteriovenous malformation. A 58-year-old female patient suffered from dysarthria and dysphagia. On examination, Parkinson's signs, pseudobulbar palsy, and muscular weakness of the left extremity and pyramidal tract signs were observed. An enhanced brain computed tomography revealed abnormal high-density network vessels at the thalamus and midbrain. By cerebral angiography, the following changes were observed; occlusion of the right internal carotid artery at the bifurcation, and abrupt narrowing and occlusion of the left internal carotid artery at the bifurcation and siphon. A lateral vertebral arteriography revealed telangiectasia at the basilar tip. The patient died of pulmonary thromboembolism at age 61. The vessels of the circle of Willis were hypoplastic. The optic nerves, infundibulum and mammillary body were covered with a large number of ectastic vessels. Arteriovenous malformations were observed in the bilateral occipital lobes. Histopathologically, the elastic lamina of Moyamoya vessel was conspicuously wavy and often duplicated or triplicated, and discontinued occasionally. Discontinuity of the elastic lamina of the perforating arteries and circumferential arteries supplied by the middle cerebral artery (MCA), anterior CA (ACA) and posterior CA (PCA), was also occasionally observed. It is likely that the Moyamoya vessels in this patient were compensatorily formed by congenital hypoplasia of the internal artery, MCA, ACA and PCA.

Involvement of prolonged ras activation in thrombopoietin-induced megakaryocytic differentiation of a human factor-dependent hematopoietic cell line

Thrombopoietin (TPO) is a hematopoietic growth factor that plays fundamental roles is both megakaryopoiesis and thrombopoiesis through binding to its receptor, c-mpl. Although TPO has been shown to activate various types of intracellular signaling molecules, such as the Janus family of protein tyrosine kinases, signal transducers and activators of transcription (STATs), and ras, the precise mechanisms underlying TPO-induced proliferation and differentiation remain unknown. In an effort to clarify the mechanisms of TPO-induced proliferation and differentiation, c-mpl was introduced into F-36P, a human interleukin-3 (IL-3)-dependent erythroleukemia cell line, and the effects of TPO on the c-mpl-transfected F-36P (F-36P-mpl) cells were investigated. F-36P-mpl cells were found to proliferate and differentiate at a high rate into mature megakaryocytes in response to TPO. Dominant-negative (dn) forms of STAT1, STAT3, STAT5, and ras were inducibly expressed in F-36P-mpl cells, and their effects on TPO-induced proliferation and megakaryocytic differentiation were analyzed. Among these dn molecules, both dn ras and dn STAT5 reduced TPO- or IL-3-induced proliferation of F-36P-mpl cells by approximately 30%, and only dn ras could inhibit TPO-induced megakaryocytic differentiation. In accord with this result, overexpression of activated ras (H-rasG12V) for 5 days led to megakaryocytic differentiation of F-36P-mpl cells. In a time course analysis on H-rasG12V-induced differentiation, activation of the ras pathway for 24 to 28 h was required and sufficient to induce megakaryocytic differentiation. Consistent with this result, the treatment of F-36P-mpl cells with TPO was able to induce prolonged activation of ras for more than 24 h, whereas IL-3 had only a transient effect. These results suggest that prolonged ras activation may be involved in TPO-induced megakaryocytic differentiation.

Structural elements of Trimeresurus flavoviridis serum inhibitors for recognition of its venom phospholipase A2 isozymes

Five inhibitors (PLI-I-V) against Trimeresurus flavoviridis (Tf, habu snake, Crotalinae) venom phospholipase A2 (PLA2) isozymes have been isolated from its serum. PLI-I, which is composed of two repeated three-finger motifs, and PLI-IV and PLI-V, which contain a sequence similar to the carbohydrate recognition domain (CRD) of C-type lectins, were expressed in the forms fused with glutathione S-transferase (GST). The resulting GST-PLIs showed ability to bind to three Tf venom PLA2 isozymes. The binding study with the truncated forms indicated that one of two three-finger motifs of PLI-I was able to bind to PLA2 isozymes. The N-terminal 37-amino acid fragment and the CRD-like domain of PLI-IV and PLI-V were bound to PLA2 isozymes. On the other hand, their C-terminal 12-amino acid segment also associated with PLA2 isozymes. When either of two units of a hydrophobic tripeptide in this sequence was replaced by trialanine, the binding was completely abolished, indicating that the C-terminal hydrophobic cores of PLI-IV and PLI-V were critically responsible for the binding to venom PLA2 isozymes.

Diagnosis of squamous cell carcinoma arising from mature cystic teratoma of the ovary

BACKGROUND

The prognoses of patients with squamous cell carcinoma of the ovary are quite poor. However, preoperative diagnosis is difficult due to the rarity of this tumor and its similarity to mature cystic teratoma (MCT). The objective of this study was to assess the value of tumor markers and clinical characteristics in making a differential diagnosis between MCT and squamous cell carcinoma arising from MCT.

METHODS

Between September 1979 and June 1996, 37 patients with ovarian squamous cell carcinoma arising from MCT were treated by the Tokai Ovarian Tumor Study Group. The authors evaluated tumor markers, tumor size, and age as parameters for differentiation between MCT and squamous cell carcinoma arising from MCT. Diagnostic efficiency was calculated as the sensitivity multiplied by the specificity.

RESULTS

There were significant differences (P < or = 0.0002) in age, tumor size, and levels of squamous cell carcinoma antigen (SCC), CA125, and CEA, as well as a significant difference (P < or = 0.0396) in the CA19-9 level between MCT and squamous cell carcinoma arising from MCT. Diagnostic efficiency was highest for SCC (63.0%), followed by CA125 (50.7%). Receiver operating characteristic (ROC) curves demonstrated that CEA was the best screening marker for squamous cell carcinoma arising from MCT, whereas age and tumor size were better markers than CA125 or CA19-9. The optimal cutoff values for age and tumor size were 45 years and 99 mm, respectively, according to ROC analysis.

CONCLUSIONS

These findings demonstrate that age and tumor size are important factors in making a differential diagnosis. In addition, SCC and CEA levels should be measured in patients age 45 years or older who have an MCT-like ovarian tumor larger than 99 mm in greatest dimension.

Retrotransposable CR1-like elements in crotalinae snake genomes

A part of the 3'-flanking region of BP-II gene, which is one of Trimeresurus flavoviridis venom gland phospholopase A2 (PLA2) isozyme genes, has a region homologous to avian chicken repeat 1 (CR1)-element. In the present study, ten CR1-like elements were further identified in T. gramineus venom gland PLA2 isozyme genes, T. flavoviridis PLA2 inhibitor (PLI) genes, and T. flavoviridis and T. gramineus TATA-box binding protein (TBP) genes. Southern blot analysis using a probe for CR1 showed that Crotalinae snake genomes contain a number of CR1-like elements.

Diagnosis of squamous cell carcinoma arising from mature cystic teratoma of the ovary

BACKGROUND

The prognoses of patients with squamous cell carcinoma of the ovary are quite poor. However, preoperative diagnosis is difficult due to the rarity of this tumor and its similarity to mature cystic teratoma (MCT). The objective of this study was to assess the value of tumor markers and clinical characteristics in making a differential diagnosis between MCT and squamous cell carcinoma arising from MCT.

METHODS

Between September 1979 and June 1996, 37 patients with ovarian squamous cell carcinoma arising from MCT were treated by the Tokai Ovarian Tumor Study Group. The authors evaluated tumor markers, tumor size, and age as parameters for differentiation between MCT and squamous cell carcinoma arising from MCT. Diagnostic efficiency was calculated as the sensitivity multiplied by the specificity.

RESULTS

There were significant differences (P < or = 0.0002) in age, tumor size, and levels of squamous cell carcinoma antigen (SCC), CA125, and CEA, as well as a significant difference (P < or = 0.0396) in the CA19-9 level between MCT and squamous cell carcinoma arising from MCT. Diagnostic efficiency was highest for SCC (63.0%), followed by CA125 (50.7%). Receiver operating characteristic (ROC) curves demonstrated that CEA was the best screening marker for squamous cell carcinoma arising from MCT, whereas age and tumor size were better markers than CA125 or CA19-9. The optimal cutoff values for age and tumor size were 45 years and 99 mm, respectively, according to ROC analysis.

CONCLUSIONS

These findings demonstrate that age and tumor size are important factors in making a differential diagnosis. In addition, SCC and CEA levels should be measured in patients age 45 years or older who have an MCT-like ovarian tumor larger than 99 mm in greatest dimension.

Developmental changes in carbonic anhydrase II in the rat kidney

We examined the distribution and maturational changes of carbonic anhydrase I (CAI) and carbonic anhydrase II (CAII) in microdissected nephron segments of Sprague-Dawley rats. CAI and CAII proteins were measured by enzyme-linked immunosorbent assay. CAI was not detected in any nephron segment in 7-week-old rats. CAII was present in the collecting ducts, proximal tubules, and thick ascending limbs of loop of Henle in 7-week-old rats. CAII contents were significantly higher in the early proximal tubules (S1) than in second (S2) and late (S3) portions of the proximal tubules, while the contents in S1 were less than in cortical collecting ducts (CCD), outer stripe and inner stripes of the outer medullary collecting ducts (OMCDo and OMCDi). CAII content in each of S1, CCD, and OMCD of 1-week-old rats was only 14% or less of that of adults, but increased steeply during the 2nd and 3rd weeks of life, reaching almost 40% at 3 weeks of age and 97% at 7 weeks. Our results indicate that CAII is present throughout the entire nephron of the rat, and that CAII content in S1, CCD, and OMCD increases exponentially during the first 7 weeks of life. Our data suggest that the immature low levels of CAII may explain, at least in part, the limited capacity of urinary acidification during neonatal life. Further studies are necessary to establish the role of such changes in CAII content in acid-base homeostasis during neonatal life.

Specific detection of phosphatidylinositol 3,4,5-trisphosphate binding proteins by the PIP3 analogue beads: an application for rapid purification of the PIP3 binding proteins

Phosphatidylinositol (PI) 3-kinase is known as one of the key molecules involved in the various biological events such as vesicle trafficking, cytoskeletal rearrangements and cell survival. T clarify the molecular basis underlying these events, we have tried to identify the proteins that can interact with phosphatidylinositol 3,4,5-trisphosphate (PIP3), the lipid product of PI3-kinase. Using a new PIP3 analogue, PIP3-APB, we synthesized an affinity column for PIP3 binding proteins. This enabled us to purify and identify several PIP3 binding proteins such as Tec tyrosine kinase, Gap1m, and Akt, as the candidates for the downstream molecules of PI3-kinase. All of these proteins contain PH domains, possible binding sites for phospholipids. Studies with various deletion mutants of Tec or Gap1m revealed that their PH domains are indeed the binding sites for PIP3. These results demonstrate that this PIP3-analogue binds various PIP3 binding proteins with high specificity and may be useful to elucidate the downstream mechanisms of PI3-kinases-mediated signaling pathways.

The complete cDNA coding sequence for the bovine proalpha2(I) chain of type I procollagen

The complete sequence of the cDNA for the pro alpha2(I) chain of bovine type I procollagen is presented. The encoded amino acid sequence shows 92.0% identity to the human pro alpha2(I) collagen chain.

Liver bilirubin UDP-glucuronosyltransferase activity in chronic nonhemolytic unconjugated hyperbilirubinemia of adults

Ten adult patients with chronic nonhemolytic unconjugated (indirect) hyperbilirubinemia were analyzed by determining bilirubin uridine diphosphate-glucuronosyltransferase activity according to a more physiological and sensitive method (9 control cases, 0.457 +/- 0.163 nmole/mg protein/min). There was no overlap of the enzyme activities of 2 cases with Crigler-Najjar syndrome (type II) (0.006 nmole/mg protein/min on average) and 6 cases with Gilbert's syndrome (0.051 +/- 0.016 nmole/mg protein/min). The enzyme activities in 2 patients with post-hepatitic hyperbilirubinemia were within the normal range. A new classification of nonhemolytic unconjugated hyperbilirubinemia in adults is proposed according to the results of this enzyme activity and the recent data on the gene mutation of this enzyme.

Loss of neurofibromin in the leptomeningeal astroglial heterotopia of NF-1

Neurofibromin, the protein product of the neurofibromatosis type 1 (NF-1) gene, has important roles in tumor suppression or normal embryogenesis. Cerebellar leptomeningeal astroglial heterotopia (LAH) is a proliferation of heterotopic astroglial cells and fibers in the cerebellar leptomeninges, which is characteristically demonstrated in the NF-1 patients. In this study, neurofibromin expression was investigated in NF-1 and non-NF-1 human tissues, especially in the cerebellum of NF-1 patients. Neurofibromin was found by immunoblotting in the CNS but not in the heart, liver, and kidney. Immunohistochemistry in the normal areas of the brains with NF-1 demonstrated neurofibromin immunoreactivity as did the brains of unaffected controls. Cerebellar LAH showed no neurofibromin immunoreactivity. The results of this study suggest that neurofibromin expression remains unchanged in the nonproliferated region of the CNS of the NF-1 patient but changes occur in the abnormally proliferated region, resulting in cerebellar LAH. Loss of neurofibromin may result in the excessive migration and growth of astrocytes in the early fetal period.

Intracellular distribution of the Wilson's disease gene product (ATPase7B) after in vitro and in vivo exogenous expression in hepatocytes from the LEC rat, an animal model of Wilson's disease

In patients with Wilson's disease, both copper incorporation into ceruloplasmin and excretion of this metal into bile are impaired. These conditions are caused by a genetic defect in the Wilson's disease gene (ATP7B). To investigate the Wilson's disease gene protein (ATPase7B) in hepatocytes, we constructed an expression plasmid carrying full-length complementary DNA for human Wilson's disease gene and attempted to express the gene in hepatocytes of LEC rats, an animal model of Wilson's disease. Transfection of hepatocytes, either in vitro or in vivo, was done using a newly developed cationic liposome containing 1,4-bis(3-(N-hexadecyl) aminopropyl) piperazine. Immunological analyses of human ATPase7B with specific monoclonal antibodies showed human ATPase7B to be a membrane protein with a molecular mass of 155 kd. Analysis of human ATPase7B expressed in hepatocytes from LEC rats suggested that this protein is present in the trans-Golgi network and at the plasma membrane, a distribution pattern similar to that of Menkes' disease protein (ATPase7A). These findings suggest that these two putative copper-transporting P-type ATPases function similarly at the cellular level. Cotransfection and coexpression of the human Wilson's disease gene and ceruloplasmin gene in cultured hepatocytes indicate that the distribution of ceruloplasmin is always accompanied by ATPase7B at the perinuclear region, but that part of ATPase7B localizes irrespective of the distribution of ceruloplasmin. Based on these investigations, we propose that ATPase7B exists in the trans-Golgi network and transports copper into this compartment. This seems to ensure an appropriate delivery of copper to the apoceruloplasmin. On the other hand, part of ATPase7B that is not accompanied by ceruloplasmin in the perinuclear region and at the plasma membrane seems to contribute to efflux of this metal from the hepatocytes. Thus the distribution patterns of ATPase7B in hepatocytes may explain the dual roles of this P-type ATPase in hepatocytes.

Distribution of platinum in human gynecologic tissues and pelvic lymph nodes after administration of cisplatin

BACKGROUND

Defining tissue accumulation of platinum may be of importance, since it may provide a pharmacological explanation for organ-specific cisplatin activity. This study was conducted to evaluate the efficacy of cisplatin at the tissue level in different gynecologic organs. The doses administered were equivalent to those used in neoadjuvant chemotherapy regimens.

STUDY DESIGN

Cisplatin was administered intravenously to patients with cervical or endometrial cancer 1 h before operation, and platinum accumulations in tissues were assayed by the atomic absorption method.

RESULTS

Platinum accumulation was highest in the cervix and next highest in the myometrium in both cancers. Platinum accumulation in ovary and lymph node was only 0.58 and 0.57 times that in the myometrium, respectively. In patients with cervical cancer, the platinum accumulations in the myometrium and cervix were significantly higher than in the ovary and lymph node. Platinum accumulation in cervical cancer tissue was lower than in the myometrium and cervix, suggesting that delivery of cisplatin to a cervical cancer is somewhat more difficult than to the normal cervix. In patients with endometrial cancer, there was significantly more accumulation in the cervix than in the ovary and lymph node.

CONCLUSIONS

These data indicated that cisplatin was easily distributed to the cervix and myometrium, but not to the ovary, lymph node, and cancer tissues.

Neurotrophin-3 prevents death of axotomized Clarke's nucleus neurons in adult rat

In the present investigation, we studied whether neurotrophin-3 (NT-3) contributes to the rescue of axotomized Clarke's nucleus (CN) neurons in adult rats. A significant (24%) loss of CN neurons occurred at L-1 ipsilateral to T-8 hemisection by 14 days, which reached 31% at 2 months and then stabilized. Axotomized CN neurons had also atrophied by 14 days, but mean cell size did not decrease further. Animals that received gelfoam soaked in nerve growth factor, brain derived neurotrophic factor, or ciliary neurotrophic factor at the lesion site also showed a 30% neuron loss at 2 months, and a 40% reduction in average cell area. Rats receiving NT-3 showed a 15% neuron loss, which was not improved by additional neurotrophins in combination with NT-3. None of the treatments prevented neuron atrophy. Bioassay of the gelfoam showed that NT-3 bioactivity remained at 5 days after surgery but not at 14 days. Additional rats with hemisections that received NT-3 continuously via mini-pump for 2 months showed a 15% neuron loss, the same as with NT-3 given via gelfoam. These results indicate that even limited exposure of axotomized CN neurons to NT-3 produces permanent rescue of 50% of the neurons. The virtually complete rescue that we had previously observed with transplants of fetal central nervous system (CNS) tissues may, therefore, be due at least in part to NT-3, but the exogenous administration of a single neurotrophic factor or a combination of neurotrophic factors is less effective than transplants in producing long-term survival of axotomized CNS neurons.

Geographical variation of mandible size and shape in the Ryukyu wild pig (Sus scrofa riukiuanus)

We measured adult mandibles of Ryukyu wild pigs from Amami-Oshima, Kakeroma, Okinawa, Ishigaki and Iriomote Islands. The size cline was not statistically recognized among the populations of Nansei Islands. The Ishigaki population was significantly larger than Iriomote one in mandible length. Some measurement ratios indicated that the ramus is enlarged laterally and that the body of mandible is dorso-ventrally developed in Ishigaki and Iriomote populations. The Amami-Oshima mandibles were relatively smaller than those of Okinawa and Iriomote populations in length item of body of mandible. These results will contribute to the zoo-archaeology on the historical change of size and shape in the island populations, and to the evolutionary biology on the morphological adaptation of this animal.

Necrotizing funisitis: clinical significance and association with chronic lung disease in premature infants

OBJECTIVES

Our purpose was to analyze the clinical significance of necrotizing funisitis, an unusual type of chronic inflammation of the umbilical cord, and to determine whether necrotizing funisitis is associated with chronic lung disease in premature infants.

STUDY DESIGN

A total of 52 perinatal factors were prospectively assessed in 18 pregnant women and their fetuses in cases of chorioamnionitis at delivery occurring at 22 to 30 gestational weeks; a statistical comparison between the necrotizing funisitis group (n = 5) and the group without necrotizing funisitis (n = 18) was carried out.

RESULTS

Significant correlations were found between necrotizing funisitis and the following factors: maternal serum C-reactive protein level on admission (p = 0.014), fetal distress (p = 0.044), umbilical artery blood pH value (p = 0.037) and polynuclear neutrophilic leukocyte count at birth (p = 0.014), chronic lung disease (p = 0.035), need for dexamethasone therapy for chronic lung disease (p = 0.029), duration of oxygen supplementation (p = 0.026), and length of hospital stay (p = 0.026).

CONCLUSIONS

There was a significant association between necrotizing funisitis and development of chronic lung disease, suggesting that necrotizing funisitis is an important risk factor for the development of chronic lung disease.

Defective adenoassociated viral-mediated transfection of insulin gene by direct injection into liver parenchyma decreases blood glucose of diabetic mice

The present study assessed the feasibility of transferring the insulin gene into liver cells of diabetic individuals using a defective adenoassociated viral (AAV) vehicle. AAV offers several advantages over other viral vectors, since this vehicle can facilitate transfection in vivo without cell division and without any viral coding sequences (thus minimizing inflammation). The rat insulin gene and lacZ were each packed into a defective AAV vehicle (AAV-INS and AAV-lacZ, respectively). Successful AAV-mediated transfection and expression of lacZ into hepatocytes in primary cell culture were demonstrated by chemiluminescent assay of beta-galactosidase. Similarly, AAV-mediated transfection and expression of the insulin gene into hepatocytes was demonstrated by immunocytochemistry and reverse-transcriptase polymerase chain reaction (RT-PCR). After AAV-mediated transfection of the insulin gene into hepatocytes, glucose in the medium was significantly reduced for up to 5 days. After direct injection of AAV-INS into liver parenchyma of diabetic mice, successful transfection was demonstrated by RT-PCR, and blood glucose was significantly decreased for at least 6 days. These studies suggest that the AAV vector may be used to transfer the insulin gene into liver cells in vitro and in vivo.

Induction of ST-segment elevation by regional myocardial stretch in normal canine hearts in vivo

The purpose of this study was to evaluate ST-segment elevation induced by regional myocardial stretch without myocardial ischemia in canine hearts. A strain gauge arch (TH-601T) was sutured to the left ventricular epicardium, parallel to the short axis, to shorten the end-diastolic length of the myocardium beneath the arch (stretch zone; SZ) and to produce regional myocardial stretch in each of 6 dogs. An increase in preload caused by altering the height of a saline-filled reservoir affected prolongation or shortening of the myocardium both in the SZ and outside the arch (normal zone; NZ) to increase myocardial stretch. An epicardial electrocardiogram was recorded in both the SZ and the NZ. After suture of the strain gauge arch, the ST segment was elevated in the SZ. An increase in preload augmented stretch during systole in the SZ, resulting in additional ST-segment elevation. These results suggest that regional myocardial stretch itself plays an important role in ST-segment elevation.

[Etiological analysis of thrombophilia]

We have established a system for etiological analysis of thrombophilia which includes assays of antithrombin III, protein C, protein S, plasminogen, fibrinogen, heparin cofactor II and lupus anticoagulants as well as gene analysis. The analysis conducted on 115 patients with venous thrombosis, arterial thrombosis and small vessel thrombosis revealed that forty-one patients(36% of the examined patients) were accompanied with decreased activities of protein S, protein C, antithrombin III and plasminogen. Eleven candidate causal mutations were found by gene analysis. These studies indicate that a comprehensive examination is instrumental in identifying and confirming the etiology in patients with thrombophilia.

Differential effects of thiopental on neuronal nicotinic acetylcholine receptors and P2X purinergic receptors in PC12 cells

BACKGROUND

PC12 cells, derived from rat pheochromocytoma, express neuronal nicotinic acetylcholine receptors (nAchRs) and P2X purinergic receptors, both of which resemble the receptors in postganglionic sympathetic neurons. The former is the established and the latter is the putative receptor to mediate fast synaptic transmission. The authors investigated effects of thiopental on these two ligand-gated ion channels.

METHODS

Whole cell currents were recorded in PC12 cells without treatment of nerve growth factor, using conventional whole cell patch clamp technique. Nicotine or adenosine triphosphate (ATP) 30 microM was applied for 4-5 s in the absence or presence of thiopental 3-300 microM.

RESULTS

Nicotine induced the rapidly decaying inward current at -60 mV, which exhibited the characteristics of the neuronal nAchR-mediated current. Thiopental inhibited the nicotine-induced inward current and accelerated the current decay in a dose-dependent manner, resulting in the greater effects on the steady current than the peak current. IC50s for the peak and steady current were 56.7 and 7.4 microM, when the anesthetic was coapplied with nicotine. Thiopental's inhibition was not associated with a change in the reversal potential and was voltage-independent at membrane potential of -30 to -70 mV. Most of thiopental's effects seemed to require channel opening. In contrast to the nicotine-induced current, thiopental had little effect on the current elicited by ATP.

CONCLUSIONS

Thiopental, whose reported EC50 for general anesthesia is 25 microM, inhibited the neuronal nAchR-mediated current but not the P2X receptor-mediated response in PC12 cells at clinically relevant concentrations. Inhibition may result in suppression of synaptic transmission in sympathetic ganglia.

Characterization and evolution of a gene encoding a Trimeresurus flavoviridis serum protein that inhibits basic phospholipase A2 isozymes in the snake's venom

The proteins that bind phospholipase A2 (PLA2) isozymes of Trimeresurus flavoviridis (habu snake, crotalinae) venom were fractionated from sera on four columns, each conjugated with one of four PLA2 isozymes. Five proteins, termed PLA2 inhibitors (PLI) I-V, were obtained as the binding components. The combinations of the binding components differed depending on the PLA2 isozymes. PLI-IV and PLI-V correspond to PLI-A and PLI-B, respectively, which were known to bind to a major [Asp49]PLA2, PLA2, and contained a segment similar to the carbohydrate-recognition domain of C-type lectins. PLI-I, which is a major component of inhibitory proteins against three basic PLA2 isozymes, PLA-B (a basic [Asp49]PLA2) and basic proteins I and II (both [Lys49]PLA2s), has been isolated, and its partial amino acid sequence has been determined. A cDNA encoding PLI-I was isolated from a T. flavoviridis liver cDNA library and sequenced. PLI-I cDNA encoded 200 amino acid residues, including a signal peptide of 19 amino acid residues. One sugar chain was predicted to occur at position 157. A gene coding for PLI-I was isolated. It is 9.6-kb long and consists of five exons and four introns. Comparison of the exon-intron structure of the PLI-I gene with those of genes encoding urokinase-type-plasminogen-activator receptor (uPAR), Ly-6, CD59 and neurotoxins showed that they have characteristic unit encoding approximately 90 amino acid residues, which is divided over two exons. This strongly suggests that the PLI-I gene belongs to the uPAR, Ly-6, CD59 and neurotoxin gene family. There are two types of structurally different inhibitors against PLA2 isozymes in T. flavoviridis serum with different evolutionary origins.

Mutations in the CLCN5 gene in Japanese patients with familial idiopathic low-molecular-weight proteinuria

Familial idiopathic low-molecular-weight proteinuria (FILMWP) is a renal proximal tubulopathy that occurs predominantly in males. FILMWP is characterized by mild proteinuria consisting of low-molecular-weight proteinuria, aminoaciduria and relatively conserved renal function, but without rickets. To determine whether FILMWP is related to the CLCN5 gene, which is responsible for Dent's disease and two related disorders, we analyzed the CLCN5 gene from four Japanese families with FILMWP. We identified two novel mutations: one was a single base insertion at codon 520 serine in exon 10 and the other was a single base deletion at codon 403 tyrosine in exon 8. These mutations caused a shift in the reading frame, resulting in synthesis of truncated CLC5 proteins that lacked 220 (29%) and 314 (42%) amino acids, respectively. These mutations were demonstrated to cosegregate with the disease in two families, respectively. We conclude that the CLCN5 gene is responsible for this proximal renal tubulopathy in some Japanese families and that FILMWP is possibly a variant of Dent's disease.

Thrombophilia found in patients with moyamoya disease

Sixteen patients with Moyamoya disease and four with quasi-Moyamoya disease were investigated in order to elucidate the presence of thrombophilia. The assay system for diagnosing thrombophilia consisted of assessing both the activity and antigen levels of antithrombin III, protein C, protein S, fibrinogen and plasminogen as well as detecting lupus anticoagulants. The analysis revealed that one third (four definite cases and three quasi-cases) of the examined patients demonstrated either congenital or acquired thrombotic tendency. Protein C deficiency was found in two definite cases and in two quasi-cases among whom one quasi-case was identified to have a hereditary type I Protein C deficiency. Protein S deficiency was found in one definite case and in one quasi-case. Type II plasminogen deficiency was found in one quasi-case, and lupus anticoagulant was present in one quasi-case. Based on these findings, an evaluation of thrombophilia should thus be performed when both diagnosing and treating suspected cases of Moyamoya disease.

Up-regulation of oxytocin receptors in porcine endometrium by adenosine 3',5'-monophosphate

Porcine endometrial cells (a mixture of epithelial, stromal, and glandular cells) were examined for the presence of oxytocin (OT) receptors using a cell culture system and a 125I-labeled OT antagonist. Binding specificity was tested in displacement studies with various related peptides. Scatchard analyses revealed the presence of a binding site with a dissociation constant (Kd) = 0.9 nM and a capacity of 1.9 fmol/10(5) cells. These cells, which were obtained from prepubertal gilts and thus had not been exposed to endogenous ovarian steroids, were used as a model to evaluate the possible action of ovarian steroids and intracellular cAMP on OT receptors. Although ovarian steroids showed no effect on OT receptors, forskolin (an adenylate cyclase activator) and dibutyryl cAMP caused 1.5- to 1.6-fold increases in specific binding of OT without changing the binding affinity. When the endometrial cells were exposed to OT (0.1-1000 nM) in combination with arachidonic acid (10 microM), OT stimulated prostaglandin F2 alpha secretion in a dose-dependent manner. These results indicate the presence of functional OT receptors in prepubertal porcine endometrial cells and suggest that the concentration of OT receptors may be regulated by one or more substances that raise intracellular cAMP levels.

Complete rescue of lethal albino c14CoS mice by null mutation of 4-hydroxyphenylpyruvate dioxygenase and induction of apoptosis of hepatocytes in these mice by in vivo retrieval of the tyrosine catabolic pathway

Hereditary tyrosinemia 1 (HT1) is characterized by progressive liver damage, from infancy, and by a high risk for hepatocellular carcinoma. HT1 is due to mutations in the fumarylacetoacetate hydrolase gene Fah, encoding the last enzyme in the tyrosine catabolic pathway. Lethal albino deletion c14CoS mice and mice with target-disrupted Fah are models for HT1, but they die in the perinatal period, albeit with a different phenotype from that seen in HT1 in humans. We first asked whether homozygous null mutation of the 4-hydroxyphenylpyruvate dioxygenase gene Hpd could rescue the homozygous c14CoS mice (c14CoS/c14CoS or Fah-/-). The double mutant Fah-/- Hpd-/- mice appeared normal, at least until age 18 months, and there was no evidence of liver disease, findings that facilitated examination of the effect of Fah-/- on mature and unmodified hepatocytes in vivo. The hepatocytes of Fah-/- undergo rapid apoptosis, and acute death follows. Essentially the same phenomena were observed when Fah-/- Hpd-/- mice were administered homogentisate intraperitoneally. These changes in liver pathology in Fah-/- Hpd-/- mice after the administration of homogentisate were associated with massive urinary excretion of succinylacetone. These results suggest that accumulation of fumarylacetoacetate, maleylacetoacetate, or succinylacetone seems to trigger the endogenous process of apoptosis in hepatocytes that lack fumarylacetoacetate hydrolase activity. This apoptosis may be related to the development of hepatocellular carcinomas seen in HT1 patients and pharmaceutically treated fumarylacetoacetate hydrolase-deficient mice.

Neutrophil elastase inhibitor, ONO-5046, modulates acid-induced lung and systemic injury in rabbits

BACKGROUND

Acid instillation leads to direct lung and to secondary systemic organ injury, probably via activated macrophages and neutrophils. This study investigated the effects of neutrophil elastase on organ injury after unilateral lung acid instillation by administrating a specific neutrophil elastase inhibitor, ONO-5046, before acid instillation.

METHODS

Three groups of anesthetized rabbits (n = 12 in each group) underwent tracheostomies, and instillations were made into their right lower lobe airspaces with either phosphate buffered saline (pH, 7.4; volume, 1.2 ml/kg; n = 12) or HCl (pH, 1.25; volume, 1.2 ml/kg; n = 24). In half of the acid-instilled rabbits, ONO-5046, 10 mg/kg, was given intravenously 15 min before the HCl instillation, and then 10 mg x kg(-1) x h(-1) of the drug was continuously infused throughout the experiment. The other groups of animals received the vehicle intravenously. Anesthesia and mechanical ventilation was continued for 8 h, whereas arterial blood gases were sampled intermittently. Eight hours after saline or acid instillation, the animals were killed, and their lungs, heart, kidneys, liver, and small intestines were harvested. Wet-to-dry weight ratios (W/ D) and myeloperoxidase (MPO) assays of these organs were done, and elastase assays on the bronchoalveolar lavage fluids (BALF) obtained from each lung also were performed.

RESULTS

Pretreatment with ONO-5046 attenuated the physiologic changes seen in the vehicle-treated animals. Significant decreases in W/D of the noninstilled lungs and of the small intestine and normalization of the oxygenation of the experimental animals occurred. The ONO-5046 pretreatment did not affect the neutrophil sequestration in the lungs or in the other organs as determined by neutrophil counts in BALF and by the MPO assays.

CONCLUSIONS

A neutrophil elastase inhibitor, ONO-5046, administered immediately before acid instillation attenuated the physiologic changes seen in the vehicle-treated animals. The drug blocked neutrophil elastase but did not block neutrophil sequestration in the lungs, although the drug improved measurements of lung injury.

[Activation of Rap1, antagonist to ras, by Crk-C3G]

Rap1 was identified as gene whose overexpression suppressed transformation by ras. Rap1 belongs to the Ras family. The amino acid sequences of Rap1 and Ras show 55% identity to each other. Due to this high sequence similarity, Rap1 binds to effector molecules of Ras, however, Rap1 does not activate them. Thus, Rap1 functions are antagonistic to Ras in the cells. C3G was identified as a Crk SH3-binding guanine nucleotide exchange factor. Biochemical and cell biological analyses revealed that C3G is a Rap1 activator. Since it has been considered that Crk transduces signals from tyrosine kinases, this finding suggests that the activity of Rap1 is also under the control of tyrosine kinases. Overexpression of C3G in ras-transformed cells caused the morphology of the cells to revert to that of normal cells. Moreover, a mutant cell line that was resistant to EGF-dependent transformation was isolated. In the cell line a mutation was found in crk gene that was the cause of the resistance. These findings suggest that Crk-C3G-Rap1 pathway may function as an anti-transformation machinery.

Enhancement of guanine-nucleotide exchange activity of C3G for Rap1 by the expression of Crk, CrkL, and Grb2

Crk is an adaptor protein that consists almost entirely of SH2 and SH3 domains. We have previously demonstrated, by using in vivo and in vitro systems, that C3G, which was identified as a Crk SH3 domain-binding guanine nucleotide exchange factor, specifically activates Rap1. C3G also binds to other adaptor proteins, including CrkL and Grb2. In the present study, we analyzed the effect of Crk, CrkL, and Grb2 on the C3G-Rap1 pathway. Expression of Crk, CrkL, and Grb2 with C3G in Cos1 cells significantly increased the ratio of GTP/GDP bound to Rap1. Both the SH2 and SH3 domains of Crk were required for this activity. However, Crk did not stimulate the guanine nucleotide exchange activity of C3G for Rap1 in vitro, suggesting that Crk does not activate C3G by an allosteric mechanism. The requirement of the SH2 domain of Crk for the enhancement of guanine nucleotide exchange activity for Rap1 could be compensated for by the addition of a farnesylation signal to Crk, indicating that Crk enhanced the guanine nucleotide exchange activity of C3G by membrane recruitment of C3G. These results demonstrate that Crk, CrkL, and Grb2 positively modulate the C3G-Rap1 pathway primarily by recruiting C3G to the cell membrane.

Activation of R-Ras GTPase by GTPase-activating proteins for Ras, Gap1(m), and p120GAP

The enzymatic properties of Gap1(m) were characterized using three Ras and R-Ras proteins as substrates and were compared with those of p120GAP. Gap1(m) stimulated the GTPase of Ras better than that of R-Ras, in contrast to p120GAP which promoted the GTPase of R-Ras better than that of Ras. The EC50 values of Gap1(m) for Ha-Ras and R-Ras were 0.48 +/- 0.02 and 1.13 +/- 0.12 nM, respectively, whereas the EC50 values of p120GAP for Ha-Ras and R-Ras were 23.1 +/- 1.9 and 3.86 +/- 0.38 nM, respectively. The affinities of Gap1(m) and p120GAP to the substrates determined by competitive inhibition by using Ha-Ras.GTPgammaS (guanosine 5'-O-(3-thiotriphosphate)) or R-Ras.GTPgammaS as a competitor agreed well with the substrate specificities of these GTPase-activating proteins. The Km values of Gap1(m) for Ha-Ras and R-Ras were 1.53 +/- 0.27 and 3.38 +/- 0.53 microM, respectively, which were lower than that of p120GAP for Ha-Ras (145 +/- 11 microM) by almost 2 orders of magnitude. The high affinity of Gap1(m) to the substrates and its membrane localization suggest that Gap1(m) may act as a regulator of the basal activity of Ha-Ras and R-Ras.

[Effects of loprinone hydrochloride on hemodynamics and respiratory oxygenation in patients after cardiac surgery]

Loprinone hydrochloride (Lop), a phosphodiesterase fraction III inhibitor and positive inotrope, was recently released in Japan. We evaluated its dose-related effects on hemodynamics and oxygenation as as well as on plasma levels of Lop in ten patients after cardiac surgery. Immediately after admission to the intensive care unit, baseline hemodynamics and arterial blood gas data were obtained; patients with inotropic support, were given 0.1, 0.2, 0.3 microgram.kg-1.min-1.lop over 1 hour incrementally, and additional data were obtained. CI increased significantly from baseline (2.1 +/- 0.3 l.min-1.m-2) to 3.2 +/- 0.8 at 0.3 microgram.kg-1.min-1. Systemic vascular resistance decreased significantly from baseline (2853 +/- 439 dynes.sec.cm-5.m-2) to 1554 +/- 440 at 0.3 micrograms. kg-1.min-1, and mean arterial pressure also decreased significantly from baseline. There were no significant changes in heart rate (HR), central venous pressure (CVP), pulmonary artery occlusion pressure (PAOP), or PaO2.FIO2(-1) in patients over the period evaluated. Plasma levels of Lop rapidly increased to 27.8 ng.ml-1 (effective level; 20 ng.ml-1) at 0.3 microgram.kg-1.min-1. In this study, Lop was shown to effectively increase CI in patients after cardiac surgery with no significant changes in HR, CVP, PAOP or PaO2/FIO2. Thus, Lop has a beneficial effect in the treatment of patients with low cardiac output immediately after cardiac surgery.

Induction of tetrahydrobiopterin synthesis in rat cardiac myocytes: impact on cytokine-induced NO generation

Because tetra-hydrobiopterin (BH4) is an essential cofactor for nitric oxide (NO) formation, we investigated whether BH4 synthesis is required for cytokine-induced NO production in cultured rat cardiac myocytes. The total biopterin content of untreated cardiac myocytes was below our limit of detection. However, treatment with interleukin-1 alpha (IL-1 alpha) + interferon-gamma (IFN-gamma) caused a significant rise in biopterin levels and induced NO synthesis. 2,4-Diamino-6-hydroxypyrimidine (DAHP), a selective inhibitor of GTP cyclohydrolase I (the rate-limiting enzyme for de novo BH4 synthesis), completely abolished the elevation in biopterin levels induced by IL-1 alpha + IFN-gamma. DAHP also caused a concentration-dependent inhibition of (IL-1 alpha + IFN-gamma)-induced NO synthesis. Similarly, N-acetylserotonin, an inhibitor of the BH4 synthetic enzyme sepiapterin reductase, blocked increases in biopterin levels as well as NO synthesis induced by IL-1 alpha + IFN-gamma. Sepiapterin, substrate for BH4 synthesis via the pterin salvage pathway, prevented this inhibition by DAHP or N-acetylserotonin, and this effect was blocked by methotrexate. Sepiapterin and, to a lesser extent, BH4 dose dependently enhanced (IL-1 alpha + IFN-gamma)-induced NO synthesis, suggesting that the concentration of BH4 limits the rate of NO production. Inducible NO synthase mRNA and GTP cyclohydrolase I mRNA were induced by IL-1 alpha + IFN-gamma in parallel. We thus demonstrate that BH4 synthesis is an absolute requirement for induction of NO synthesis by cytokines in cardiac myocytes.

Activation of R-Ras by Ras-guanine nucleotide-releasing factor

Ras-GRF/CDC25(Mm), mSos, and C3G have been identified as guanine nucleotide-releasing factors for Ras family proteins. We investigated in this study the guanine nucleotide-releasing activities of Ras-GRF, mSos, and C3G toward R-Ras, which shows high sequence similarity to Ras. Ras-GRF markedly stimulated the dissociation of GDP from R-Ras, and C3G also promoted the release of R-Ras-bound GDP. Under the same conditions, mSos little affected the reaction. When Ras-GRF and R-Ras were coexpressed in COS7 cells, the remarkable accumulation of the active GTP-bound form of R-Ras was observed. C3G also increased active R-Ras in COS7 cells, while mSos did not give any effect. These results indicated that Ras-GRF and C3G could activate R-Ras. Furthermore, the activation of R-Ras by Ras-GRF was enhanced when cells were treated with ionomycin, which is known to increase the intracellular calcium concentration. The examination of tissue distribution of R-Ras, Ras-GRF, and mSos by the reverse transcription-polymerase chain reaction revealed that Ras-GRF was expressed only in brain and testis, whereas R-Ras, C3G, and mSos were expressed rather ubiquitously. These findings raise the possibility that R-Ras is activated by Ras-GRF in brain and testis, and by C3G in other tissues, respectively.

Arginine-481 mutation abolishes ligand-binding of the AMPA-selective glutamate receptor channel alpha1-subunit

Arginine-481 is located in the putative agonist-binding region preceding the putative transmembrane segment M1 of the alpha1-subunit of the AMPA-selective glutamate receptor (GluR) channel. This amino acid is completely conserved among GluR proteins. A site-directed mutagenesis study using a baculovirus expression system showed that substitution of glutamate, glutamine and lysine for arginine-481 of the recombinant alpha1-subunit protein abolishes binding to [3H]AMPA completely. The present study provides the first direct experimental evidence that the conserved charged arginine-481 residue is essential, directly or indirectly, for the acquisition of ligand-binding activity by the receptor protein.

A randomized trial of cisplatin, vinblastine, and bleomycin versus cyclophosphamide, aclacinomycin, and cisplatin in epithelial ovarian cancer

After primary cytoreductive surgery, a randomized clinical trial was conducted in women with epithelial ovarian cancer to compare the impact on survival between PVB chemotherapy, consisting of cisplatin, vinblastine and bleomycin, and CAP chemotherapy, consisting of cyclophosphamide, aclacinomycin and cisplatin. There were 148 evaluable patients. One hundred and five patients with stage II, III and IV were analyzed in this study, 49 of them received PVB chemotherapy while the remaining 56 patients received CAP chemotherapy. Sixty-four patients fulfilled the criteria for clinical remission set by the Tokai Ovarian Tumor Study Group [Gynecol Oncol 1993;48:342-348]. The remission rate was 73 and 50% in the PVB and CAP groups, respectively, and showed a significant advantage for the PVB group (p = 0.0139). Moreover, the recurrence rate was 44% in the PVB group and 61% in the CAP group after clinical remission, although there was no significant difference between the two groups. The final survival rate was 32% in the PVB group and 24% in the CAP group. There was a significant difference of survival rate between both groups at 24 months (p = 0.0378) and 48 months (p = 0.0450), but finally no significant difference was found at 96 months (p = 0.0660). Compared to the CAP regimen, the PVB combination has a significantly higher efficacy in remission, but there was no significant difference in the long-term survival rate. Furthermore, multivariate analysis demonstrated that the PVB chemotherapy improved the survival, but it was not significant. The authors conclude that PVB chemotherapy may be more effective than CAP chemotherapy for epithelial ovarian cancer.

[A prospective controlled study of sairei-to in childhood IgA nephropathy with focal/minimal mesangial proliferation. Japanese Pediatric IgA Nephropathy Treatment Study Group]

To determine the effect of the Chinese herbal medicine, Sairei-to (TJ-114) in children with newly diagnosed IgA nephropathy showing focal/minimal mesangial proliferation, we undertook a prospective controlled study. One hundred and one patients were randomly assigned to receive Sairei-to for 2 years (group 1) or no drug for 2 years (group 2). Forty-six of the 50 patients in group 1 and 48 of the 51 patients in group 2 completed their trial. At entry, the two groups of patients did not differ in the clinical, laboratory and pathologic findings. At the end of the trial, urinary protein excretion and hematuria were significantly reduced in group 1, but were unchanged in group 2. Twenty-one group 1 patients (46%) had normal urine, but only 5 group 2 patients (10%) had normal urine at the end of the trial (p < 0.001). Blood pressure and creatinine clearance were normal at the end of the trial in all but one group 2 patient, who developed chronic renal failure. The present study demonstrates that 2-year Sairei-to treatment early in the course of disease is effective in children with IgA nephropathy showing focal/minimal mesangial proliferation.

Structures of genes encoding phospholipase A2 inhibitors from the serum of Trimeresurus flavoviridis snake

Inhibitors (PLIs) against snake venom gland phospholipases A2 (PLA2s) have been found in their sera. A cDNA encoding a PLI from Trimeresurus flavoviridis (Tf, habu snake, Crotalinae) serum, cPLI-A, was isolated from the Tf liver cDNA library and sequenced. Northern blot analysis with cPLI-A showed that PLIs are expressed only in liver. Genes for PLIs, gPLI-A and gPLI-B, were isolated from the Tf genomic DNA library and their nucleotide (nt) sequences were determined. The genes consisted of four exons and three introns, and exon 4 encoded the carbohydrate recognition domain (CRD)-like motif. Comparison of the nt sequences between gPLI-A and gPLI-B showed that these genes are highly homologous, including introns, except that exon 3 is rich in nonsynonymous nt substitutions which are almost four times as frequent as synonymous nt substitutions. This evolutionary feature of PLI genes is different from that of venom gland PLA2 isozyme genes in which nonsynonymous nt substitutions are spread over the entire mature protein-coding region.

A case of linear IgA disease: an immunofluorescent study using confocal laser scan microscopy

A 79-year-old Japanese woman presented with erythema and bullae on her trunk and limbs. Histological examination of the skin lesions showed subepidermal bullae and polymorphonuclear leukocyte infiltration into the papillary dermis. A direct immunofluorescent study showed the linear deposition of IgA, but not of IgG or IgM, in the basement membrane zone. Indirect immunofluorescence of the serum using confocal laser scan microscopy showed IgA, but not IgG, reactivity in the basement membrane zone. In double immunostaining experiments, IgA reactivity was also observed on the epidermal side; laminin 5 was detected on the dermal side.

A study on the biological significance of midregion and intact parathyroid hormone in hemodialysis patients

In this study, we investigated the relationship between the concentrations of intact parathyroid hormone (i-PTH) and midregion PTH (m-PTH) measured by an immunoradiometric assay and a radioimmunoassay, respectively, versus various demographic and biochemical parameters, bone mineral density (BMD) of the lumbar spine (LS) and radius, and the radiographic findings of osteosclerosis and aortic calcification in hemodialysis (HD) patients. m-PTH correlated positively and more significantly with serum calcium (Ca), serum phosphorus (P), Ca-P solubility products (Ca x P) and LS-BMD than i-PTH did (P = 0.024 vs. 0.531, 0.001 vs. 0.061, 0.0001 vs. 0.125, and 0.017 vs. 0.284, respectively). A positive correlation between the percent changes in serum P over the 1-month measurement period and those in m-PTH rather than in i-PTH was also observed (P = 0.021 vs. 0.869). These data indicate than m-PTH is distinct from i-PTH in its positive correlation with serum Ca, serum P, Ca [symbol: see text] P and LS-BMD in HD patients. Since m-PTH is known to consist mostly of the midregion and carboxyl-terminal fragments of PTH in HD patients, the present study suggests that these PTH fragments may be biologically significant in the patients in vivo.