Mutation in PMR1, a Ca(2+)-ATPase in Golgi, confers salt tolerance in Saccharomyces cerevisiae by inducing expression of PMR2, an Na(+)-ATPase in plasma membrane

Sodium tolerance in yeast is enhanced by continuous activation of calcineurin, a Ca(2+)/calmodulin-dependent protein phosphatase that is required for modulation of the Na(+) efflux mechanism. We isolated several salt-tolerant mutations with the treatment of ethylmethane sulfonate under high salt stress. One of the mutations was mapped in the PMR1 gene. Pmr1p, the P-type Ca(2+)-ATPase in the Golgi apparatus, regulates a cytosolic Ca(2+) level in various responses. Cytosolic Ca(2+) concentration in the pmr1 mutant is highly maintained, and thus calcineurin is activated continuously. The treatment of FK506, a specific inhibitor of calcineurin, abolishes the salt-tolerant phenotype of the pmr1 mutant. Activated calcineurin induces the expression of PMR2, encoding the P-type Na(+)-ATPase, through the specific transcription factor, Tcn1p/Crz1p. Also, expression of the PMR2::lacZ reporter gene in the pmr1 mutant was higher than that in wild type. We propose that the pmr1 mutation confers salt tolerance through continuous activation of calcineurin and that Pmr1p might act as a major Ca(2+)-ATPase under high salt stress.

Inconsistent association of esophageal symptoms, psychometric abnormalities and dysmotility

OBJECTIVES

The aim of this study was to characterize the psychometric profiles of symptomatic patients with abnormal esophageal motility and symptomatic patients with normal manometric findings compared to asymptomatic controls.

METHODS

A total of 113 patients with abnormal esophageal motility (7 achalasia, 8 diffuse esophageal spasm, 27 nutcracker esophagus, 37 hypertensive lower esophageal sphincter, 21 hypotensive peristalsis, 13 failed peristalsis), 23 symptomatic controls with similar esophageal symptoms but normal manometry, and 27 asymptomatic controls were enrolled. Validated questionnaires assessing depression (Beck Depression Inventory), anxiety (Spielberger State Anxiety Inventory or Trait Anxiety Inventory), and somatization (Psychosomatic Symptom Checklist) were administered to all subjects.

RESULTS

Patients with both esophageal symptoms and either hypertensive lower esophageal sphincter, nutcracker esophagus, or hypotensive contractions exhibited increased somatization, acute anxiety, or depression compared to asymptomatic controls but not compared to symptomatic controls. On the other hand, the psychometric profiles of patients with achalasia and diffuse esophageal spasm were strikingly normal. Among esophageal symptoms, chest pain was closely correlated with psychometric abnormalities.

CONCLUSIONS

The esophageal symptoms of patients with abnormal esophageal motility may relate to the underlying psychological abnormalities, independent of manometric abnormalities.

Molecular cloning of a novel pathogen-inducible cDNA encoding a putative acyl-CoA synthetase from Capsicum annuum L

By means of differential display, a pool of salicylic acid (SA)-induced mRNAs were identified and subsequently their cDNAs were isolated from a cDNA library prepared from SA-induced leaf tissues of hot pepper. One of these cDNA clones, designated CaSIG4, was 1900 bp and contained an open reading frame encoding 523 amino acids with a calculated molecular mass of 56.3 kDa. The predicted amino acid sequence of CaSIG4 showed high sequence similarity to the AMP-binding protein family of both prokaryotic and eukaryotic acyl-CoA synthetases. CaSIG4 transcripts accumulated rapidly after SA treatment and in response to both incompatible and compatible interactions with Xanthomonas campestris pv. vesicatoria race 1. To investigate the cis-acting elements mediating CaSIG4 expression, the CaSIG4 5'-flanking region was isolated by inverse PCR. Database searches indicated that a potential cis-regulatory element is almost identical to the consensus core sequences ACC(A/T)ACC(A/C) which are conserved among promoters of other phenylpropanoid biosynthetic genes. The subcellular localization of the CaSIG4 protein was studied by using a soluble modified GFP gene fusion delivered into epidermal cells of onion by biolistic bombardment. The CaSIG4-smGFP fusion protein was localized to the plasma membrane. Taken together, CaSIG4 encoding a putative acyl-CoA synthetase could function as a plasma membrane-bound protein with a role in signaling in plant defense.

Molecular authentication of Panax ginseng species by RAPD analysis and PCR-RFLP

In order to develop convenient and reproducible methods for the identification of ginseng drugs at a DNA level, randomly amplified polymorphic DNA (RAPD) and PCR-restriction fragment length polymorphism (PCR-RFLP) analyses were applied within Panax species. To authenticate Panax ginseng among ginseng populations, RAPD analysis was carried out using a 20 mer-random primer. The similarity coefficients among the DNA of ginseng plants analyzed were low, ranging from 0.197 to 0.491. In addition, by using PCR-RFLP analysis, very different fingerprints were obtained within Korean ginseng plants. These results suggest that these methods are able to authenticate the concerned Panax species. Broader application of this approach to authenticate other morphologically similar medicinal materials is rationalized.

Sclerotherapy with picibanil (OK-432) for congenital lymphatic malformation in the head and neck

HYPOTHESIS/OBJECTIVES

Congenital lymphatic malformations of the head and neck (LMHN) present special challenges to the otolaryngologist-head and neck surgeon. Recently, a number of sclerotherapy trials have shown promising results. In this study, we present our experiences with picibanil (OK-432) sclerotherapy for this lesion.

STUDY DESIGN

Retrospectively review.

METHODS

We retrospectively reviewed 21 patients who have undergone sclerotherapy with picibanil for LMHN.

RESULTS

Satisfactory response with complete or nearly complete shrinkage of the lesions was observed in 15 cases after repeated sclerotherapy (average, two times). We did not observe any significant morbidity or complications in the patients treated with picibanil. Reduction in size of the mass was achieved in weeks to months. Some of the patients who had not had any other previous treatment showed remarkable reductions in size even after the first therapy. When we used picibanil sclerotherapy as a primary treatment for the LMHN, most of our patients showed satisfactory results regardless of the size or location of the lesions.

CONCLUSION

Given with our experience and the reports that failure of picibanil sclerotherapy does not hinder subsequent surgical salvage procedures, we recommend trying picibanil sclerotherapy as a primary treatment for the LMHN and performing surgical excision as a secondary modality if the response to the sclerotherapy is not satisfactory.

Systemic coagulation and fibrinolysis after laparoscopic and open gastric bypass

HYPOTHESIS

Laparoscopic gastric bypass (GBP) induces a postoperative hypercoagulable state that is similar or reduced compared with open GBP.

SETTING

University hospital.

PATIENTS

Between May 1999 and June 2000, 70 patients were randomly assigned to laparoscopic (n = 36) or open (n = 34) GBP. Deep venous thrombosis (DVT) prophylaxis consisted of antiembolism stockings and sequential pneumatic compression devices.

MAIN OUTCOME MEASURES

Plasminogen, thrombin-antithrombin complex (TAT), prothrombin fragment 1.2 (F1.2), fibrinogen, D-dimer, antithrombin III (AT), and protein C levels were measured at baseline and at 1, 24, 48, and 72 hours postoperatively. A venous duplex examination of both lower extremities was performed preoperatively and between the third and fifth day postoperatively.

RESULTS

The 2 groups were similar in age, weight, and body mass index. Plasminogen levels decreased, and TAT, F1.2, and fibrinogen levels increased after laparoscopic and open GBP. There was no significant difference in these levels between groups. D-dimer levels increased in both groups, but the levels were significantly higher after open GBP than after laparoscopic GBP (P<.01). Antithrombin III and protein C levels decreased in both groups. The reduction of AT (at 1 hour) and protein C (at 72 hours) was significantly less after laparoscopic GBP than after open GBP (P<.05). Postoperative venous duplex examination revealed DVT in 1 (2.9%) of 34 patients after open GBP but in none of 36 patients after laparoscopic GBP. One patient developed pulmonary embolism after open GBP.

CONCLUSIONS

Laparoscopic GBP induces a hypercoagulable state similar to that of open GBP. Our findings suggest that DVT prophylaxis should be used during laparoscopic GBP as in open GBP.

IGF-I as a mediator of VIP/activity-dependent neurotrophic factor-stimulated embryonic growth

IGF-I and the IGF-I receptor are necessary for normal embryonic growth. VIP is an important regulator of early postimplantation growth and acts indirectly through the release of other factors, including activity-dependent neurotrophic factor. The relationship of IGF-I growth regulation to VIP/activity-dependent neurotrophic factor-stimulated growth was examined with whole cultured embryonic d 9.5 mouse embryos. Somite numbers and DNA and protein contents were measured in embryos treated with IGF-I, anti-IGF-I, VIP, activity-dependent neurotrophic factor, and anti-activity-dependent neurotrophic factor-14 (antiserum to an activity-dependent neurotrophic factor agonist). IGF-I mRNA content was measured after incubation with and without VIP for 30 and 60 min using competitive RT-PCR. IGF-I induced a significant, dose-dependent increase in growth as measured by somite number, DNA levels, and protein content. Furthermore, anti-IGF-I inhibited embryonic growth and also prevented exogenous IGF-mediated growth. Both VIP- and activity-dependent neurotrophic factor-stimulated growth were blocked by anti-IGF-I, whereas anti-activity-dependent neurotrophic factor-14 had no detectable effect on IGF-I-induced growth. Treatment with VIP resulted in a 2-fold increase in embryonic IGF-I mRNA. These data suggest that IGF-I is a downstream mediator of VIP and activity-dependent neurotrophic factor in a regulatory pathway coordinating embryonic growth and that VIP may function as a regulator of IGF-I gene expression in the embryo.

Choroidal tuberculoma with membranous glomerulonephritis

We report treatment of a 24-year-old man with membranous glomerulonephritis (MGN) who developed a solitary choroidal tuberculoma in association with miliary tuberculosis during steroid therapy. In June 1995, the patient had developed nephrotic syndrome. He had refused renal biopsy at that time. So we treated him with corticosteroids having assumed a diagnosis of minimal change nephrotic syndrome. After initial corticosteroids and diuretics therapy for 5 months, his generalized edema resolved but proteinuria (3 positive) continued, suggesting the presence of other forms of glomerulonephritis. Renal biopsy performed in January 1996. The patient was diagnosed as having MGN. The patient was closely observed over a period of 34 months and remained stable without steroid therapy. However at 34 months, generalized edema was again noted and steroid therapy at high dosage was initiated. After 5 months of steroid therapy, he developed miliary tuberculosis and a solitary choroidal mass. An antituberculosis chemotherapeutic regimen was started and after a further 5 months, all clinical symptoms and signs of the pulmonary lesion were resolved and a measurable shrinking of the choroidal mass was recorded.

Costs of mobile screening for diabetic retinopathy: a practical framework for rural populations

Australia's rural and remote residents experience considerably higher hospitalisation and death rates due to diabetes than their metropolitan counterparts. There is clearly a need for improved diabetes care services in these areas and interventions that target conditions associated with diabetes will yield beneficial results for the community. All people with diabetes are at risk for diabetic retinopathy, which can cause vision loss and blindness. Although vision loss and blindness due to diabetes is nearly 100% preventable through regular eye examinations, 35% of Victoria's rural population with diabetes do not have their eyes examined on a regular basis. A pilot, mobile screening program for the early detection of diabetic eye disease was conducted in rural Victoria and proved to be a successful model of adjunct eye care for people with diabetes. Actual costs from the pilot screening were applied to a permanent model for rural eye care. At A$41 per participant, costs for mobile screening were competitive with Medicare rebate costs for eye examinations. The model addresses barriers of accessibility and availability, targets a portion of the rural population with diabetes that is not otherwise having eye examinations, and is cost-saving to the Government.

Evaluation of survival rate after follicular unit transplantation using the KNU implanter

BACKGROUND

Many hair transplant surgeons have advocated the use of micrograft megasessions for the purpose of a more natural looking end result, especially in the Oriental with higher skin/hair color contrast and darker, coarse, straight hairs. But it also has some fundamental limitations. Most important are a low graft yield and a low density after transplantation. There are several reports about the survival rate of micrografts in Caucasians, though the results are variable, but few reports about the survival rate and fate of micrografts in Orientals.

OBJECTIVE

To compare the survival rate of one-hair follicular units with that of two-hair follicular units using the KNU implanter, to ascertain the average survival rate of micrografts (one- and two-hair follicular units), and to evaluate the fate of grafted hair according to time.

METHODS

Two templates of 1.5 cm2 were made by tattooing on both sides of the frontoparietal recess areas in 11 patients with male pattern baldness (beyond Norwood type IIIa). The authors planted one-hair unit micrografts in the left template and two-hair unit micrografts in the right template, which were prepared by the concept of follicular unit, and counted the surviving number of follicular units at 1 and 3 months and total hairs at 6 and 12 months after transplantation.

RESULTS

The mean survival rate by the number of follicular units was 47.3 and 57.4% at 1 and 3 months after transplantation, respectively. The mean survival rate by the total number of hairs was 92.0 and 90.4% at 6 and 12 months after transplantation, respectively.

CONCLUSION

About 50% of the transplanted hairs fell out in 1 month, but at 6 months the survival rate of follicular unit transplantation using the KNU implanter showed a good result (92%), and there were no significant differences in the mean survival rate of follicular unit and total hairs between one-hair and two-hair units at 1, 3, 6, and 12 months after transplantation.

Regulation of myostatin activity and muscle growth

Myostatin is a transforming growth factor-beta family member that acts as a negative regulator of skeletal muscle mass. To identify possible myostatin inhibitors that may have applications for promoting muscle growth, we investigated the regulation of myostatin signaling. Myostatin protein purified from mammalian cells consisted of a noncovalently held complex of the N-terminal propeptide and a disulfide-linked dimer of C-terminal fragments. The purified C-terminal myostatin dimer was capable of binding the activin type II receptors, Act RIIB and, to a lesser extent, Act RIIA. Binding of myostatin to Act RIIB could be inhibited by the activin-binding protein follistatin and, at higher concentrations, by the myostatin propeptide. To determine the functional significance of these interactions in vivo, we generated transgenic mice expressing high levels of the propeptide, follistatin, or a dominant-negative form of Act RIIB by using a skeletal muscle-specific promoter. Independent transgenic mouse lines for each construct exhibited dramatic increases in muscle mass comparable to those seen in myostatin knockout mice. Our findings suggest that the propeptide, follistatin, or other molecules that block signaling through this pathway may be useful agents for enhancing muscle growth for both human therapeutic and agricultural applications.

Malignant obstruction of gastric outlet and duodenum: palliation with flexible covered metallic stents

PURPOSE

To assess the usefulness of flexible covered metallic stents in the palliation of malignant obstruction of the gastric outlet and duodenum.

MATERIALS AND METHODS

Twenty-four consecutive patients with malignant obstruction of the gastric outlet (n = 22) or duodenum (n = 2) underwent palliative treatment with self-expandable flexible covered metallic stents. Fourteen patients had advanced gastric carcinoma at the antrum and/or pylorus, and eight had obstruction at the anastomosis site of previous gastrojejunostomy. Complications and clinical status were investigated during the study period.

RESULTS

The technical success rate was 75% (18 of 24 patients). Twenty-one stents were placed in 18 patients by using an introducer 6 (n = 7) or 8 mm (n = 14) in diameter. The mean follow-up period was 3.4 months (range, 1 week to 9 months). Symptoms improved in 12 (67%) patients after the procedure. There was no change in symptoms in five and a decrease in one. Twelve patients died during the follow-up period (mean survival, 4.3 months). The complication rate was 25% (six of 24 patients), including stent migration (n = 5) and fracture (n = 3).

CONCLUSION

Flexible covered metallic stent placement can be useful for palliation in patients with malignant obstruction of the gastric outlet or duodenum.

BetaPix-enhanced p38 activation by Cdc42/Rac/PAK/MKK3/6-mediated pathway. Implication in the regulation of membrane ruffling

betaPix (PAK-interacting exchange factor) is a recently identified guanine nucleotide exchange factor for Rho family small G protein Cdc42/Rac. The protein interacts with p21-activated protein kinase (PAK) through its SH3 domain. We examined the effect of betaPix on MAP kinase signaling and cytoskeletal rearrangement in NIH3T3 fibroblast cells. Overexpression of betaPix enhanced the activation of p38 in the absence of other stimuli and also induced translocation of p38 to the nucleus. This betaPix-induced p38 activation was blocked by coexpression of dominant-negative Cdc42/Rac or kinase-inactive PAK, indicating that the effect of betaPix on p38 is exerted through the Cdc42/Rac-PAK pathway and requires PAK kinase activity. The essential role of betaPix in growth factor-stimulated p38 activation was evidenced by the blocking of platelet-derived growth factor-induced p38 activation in the cells expressing betaPix SH3m (W43K) and betaPix DHm (L238R,L239R). In addition, SB203580, a p38 inhibitor, and kinase-inactive p38 (T180A,Y182F) blocked membrane ruffling induced by betaPix, suggesting that p38 might be involved in mediating betaPix-induced membrane ruffling. The results in this study suggest that betaPix might have a role in nuclear signaling, as well as in actin cytoskeleton regulation, and that some part of these cellular functions is possibly mediated by p38 MAP kinase.

Vesicle permeabilization by protofibrillar alpha-synuclein: implications for the pathogenesis and treatment of Parkinson's disease

Fibrillar alpha-synuclein is a component of the Lewy body, the characteristic neuronal inclusion of the Parkinson's disease (PD) brain. Both alpha-synuclein mutations linked to autosomal dominant early-onset forms of PD promote the in vitro conversion of the natively unfolded protein into ordered prefibrillar oligomers, suggesting that these protofibrils, rather than the fibril itself, may induce cell death. We report here that protofibrils differ markedly from fibrils with respect to their interactions with synthetic membranes. Protofibrillar alpha-synuclein, in contrast to the monomeric and the fibrillar forms, binds synthetic vesicles very tightly via a beta-sheet-rich structure and transiently permeabilizes these vesicles. The destruction of vesicular membranes by protofibrillar alpha-synuclein was directly observed by atomic force microscopy. The possibility that the toxicity of alpha-synuclein fibrillization may derive from an oligomeric intermediate, rather than the fibril, has implications regarding the design of therapeutics for PD.

C-type natriuretic peptide system in rabbit oviduct

C-type natriuretic peptide (CNP), a third member of the natriuretic peptide family, is known to be distributed mainly in brain and vascular endothelium and is considered to act as a local regulator in many tissues. The purpose of this study was to determine the presence of CNP system and its biological function in rabbit oviduct. The serial dilution curve of tissue extracts was parallel to the standard curve of CNP((1-22)) and a major peak of molecular profile of tissue extracts by HPLC was CNP((1-53)). mRNA of CNP which was the same size as positive control was also detected by Southern blot analysis. CNP increased the production of 3',5'-cyclic guanosine monophosphate (cGMP) in the purified membrane of oviduct, which was more in membranes derived from the isthmic portion than in the ampullar portion. The presence of mRNAs of natriuretic peptide receptor-A (NPR-A) and NPR-B was demonstrated by RT-PCR. Synthetic CNP((1-22)) inhibited both frequency and amplitude of basal motility of oviduct in a dose-dependent manner. The inhibitory effect of CNP on the basal motility was more potent in the isthmic portion than in the ampullar portion. These results demonstrate the presence of CNP system in the oviduct and regional differences in motility inhibition by CNP between isthmic and ampullar portions. Therefore, these findings suggest the possible existence of a CNP system that may exert a local regulator of basal motility, either alone or in concert with other hormones.

Pharmacokinetic studies of 2-amino-9-(3-acetoxymethyl-4-isopropoxycarbonyl-oxybut-1-yl)purine, an oral prodrug for the antiviral agent penciclovir

2-Amino-9-(3-acetoxymethyl-4-isopropoxycarbonyloxybut-1-yl)- purine (SK1899) was tested as an oral prodrug for penciclovir. SK1899 was administered orally to rats and dogs at doses up to 2 and 0.68 mmol/kg, respectively. SK1899 was well absorbed, and the major metabolites detected in plasma and urine were penciclovir, the active antiviral compound, and 6-deoxypenciclovir (M4) in both species. In rats, SK1899 was rapidly and extensively metabolized to penciclovir, which reached the peak plasma concentration (C(max)) of 39.5 microM at 0.5 h after 0.2-mmol/kg dosing. The area under the plasma concentration-time curve (AUC) for penciclovir was 57.5 microM x h. After an oral dose of 0.034 mmol/kg to dogs, extensive conversion of SK1899 to penciclovir also occurred with slower rate of formation of penciclovir from M4 than in rats. The mean C(max) and AUC for penciclovir were 4.5 microM at 2.7 h and 28.2 microM x h, respectively. The 0- to 24-h urinary recovery of penciclovir represented 36.1 and 36.3% of dose to rats and dogs, respectively. Radioactivity was found in fetuses following an oral administration of [(14)C]SK1899 to pregnant rats, but no significant accumulation was observed. Although substantial milk transfer of [(14)C]SK1899 occurred in rats, the radioactivity in milk was rapidly cleared. The values of C(max), AUC, and urinary recovery of penciclovir after dosing with SK1899 to rats and dogs were similar or slightly higher than those from famciclovir. These data indicate that introduction of an isopropoxy carbonate group into one of the two hydroxyl groups of M4 did not significantly alter the oral bioavailability of penciclovir compared with famciclovir.

Both E6 and E7 oncoproteins of human papillomavirus 16 inhibit IL-18-induced IFN-gamma production in human peripheral blood mononuclear and NK cells

Cervical carcinoma is the predominant cancer among malignancies in women throughout the world, and human papillomavirus (HPV) 16 is the most common agent linked to human cervical carcinoma. The present study was performed to investigate the mechanisms of immune escape in HPV-induced cervical cancer cells. The presence of HPV oncoproteins E6 and E7 in the extracellular fluids of HPV-containing cervical cancer cell lines SiHa and CaSki was demonstrated by ELISA. The effect of HPV 16 oncoproteins E6 and E7 on the production of IFN-gamma by IL-18 was assessed. E6 and E7 proteins reduced IL-18-induced IFN-gamma production in both primary PBMCs and the NK0 cell line. FACS analysis revealed that the viral oncoproteins reduced the binding of IL-18 to its cellular surface receptors on NK0 cells, whereas there was no effect of oncoproteins on IL-1 binding to its surface IL-1 receptors on D10S, a subclone of the murine Th cell D10.G4.1. In vitro pull-down assays also revealed that the viral oncoproteins and IL-18 bound to IL-18R alpha-chain competitively. These results suggest that the extracellular HPV 16 E6 and E7 proteins may inhibit IL-18-induced IFN-gamma production locally in HPV lesions through inhibition of IL-18 binding to its alpha-chain receptor. Down-modulation of IL-18-induced immune responses by HPV oncoproteins may contribute to viral pathogenesis or carcinogenesis.

Intermonomer interactions in dimer of bovine heart cytochrome c oxidase

The X-ray structure of bovine heart cytochrome c oxidase solved for orthorhombic crystals showed a dimeric structure stabilized by four subunit-subunit contacts, namely, subunit Vb-subunit Vb on the matrix side, subunit I-subunit VIa, subunit VIa-subunit I in the transmembrane region and subunit VIb-subunit VIb on the intermembrane side. The same intermonomer contacts as in the orthorhombic crystals were observed in both hexagonal and tetragonal crystals, the X-ray structures of which were determined by the molecular-replacement method. These results suggest that the dimeric structure also exists under physiological conditions. These contacts, especially the subunit IVa-subunit I contact, in which the N-terminal portion of subunit IVa is placed on the surface of subunit I near the dioxygen-reduction site, indicate that the function of the bovine heart enzyme is likely to be controlled by perturbation of the monomer-monomer association.

Role of inducible heat shock protein 70 in radiation-induced cell death

We previously demonstrated the protective effect of inducible heat shock protein 70 (Hsp70) against gamma radiation. Herein, we extend our studies on the possible role of Hsp70 to ionizing radiation-induced cell cycle regulation. The growth rate of inducible hsp70-transfected cells was 2-3 hours slower than that of control cells. Flow cytometric analysis of cells at G1 phase synchronized by serum starvation also showed the growth delay in the Hsp70-overexpressing cells. In addition, reduced cyclin D1 and Cdc2 levels and increased dephosphorylated phosphoretinoblastoma (pRb) were observed in inducible hsp70-transfected cells, which were probably responsible for the reduction of cell growth. To find out if inducible Hsp70-mediated growth delay affected radiation-induced cell cycle regulation, flow cytometric and molecular analyses of cell cycle regulatory proteins and their kinase were performed. The radiation-induced G2/M arrest was found to be inhibited by Hsp70 overexpression and reduced p21Waf induction and its kinase activity by radiation in the Hsp70-transfected cells. In addition, radiation-induced cyclin A or B1 expressions together with their kinase activities were also inhibited by inducible Hsp70, which represented reduced mitotic cell death. Indeed, hsp70 transfectants showed less induction of radiation-induced apoptosis. When treated with nocodazole, radiation-induced mitotic arrest was inhibited by inducible Hsp70. These results strongly suggested that inducible Hsp70 modified growth delay (increased G1 phase) and reduced G2/M phase arrest, subsequently resulting in inhibition of radiation-induced cell death.

Cloning and characterization of 5'-upstream region of human phospholipase C-beta2 gene

5'-upstream region of the phospholipase C-beta2 gene, 810 bp, was cloned and characterized. S1 nuclease mapping and primer extension analyses revealed that a single transcriptional start site locates at 284 nucleotides upstream from the beginning of translation. The 5-upstream region lacks both TATA motif and typical initiator sequence, but retains GC-rich segment. Two putative regulatory regions, a negative region (-636/-588) and a positive region (-98/ -13) were identified in the upstream region of PLC-beta2 gene. We suggest that the transcription of PLC-beta2 may be regulated by binding of regulatory proteins to the negative and/or positive regulatory regions located in the upstream of the gene.

Neurotrophic and neuroprotective actions of estrogens and their therapeutic implications

Originally known for its regulation of reproductive functions, estradiol, a lipophilic hormone that can easily cross plasma membranes as well as the blood-brain barrier, maintains brain systems subserving arousal, attention, mood, and cognition. In addition, both synthetic and natural estrogens exert neurotrophic and neuroprotective effects. There is increasing evidence that estrogen actions are mediated by nongenomic as well as direct and indirect genomic pathways. Although in vitro models have provided the most extensive evidence for neurotrophic and neuroprotective actions to date, there are also in vivo studies that support these actions.

Bounds on the CP asymmetry in b --> sgamma decays

We have measured the CP asymmetry A(CP) identical with[gamma(b-->sgamma)-gammab-->sgamma)]/[gamma(b-->sgamma)+gamma(b-->sgamma)] to be A(CP) = (-0.079+/-0.108+/-0.022) (1.0+/-0.030), implying that, at 90% confidence level, A(CP) lies between -0.27 and +0.10. These limits rule out some extreme non-standard-model predictions, but are consistent with most, as well as with the standard model.

Ca2+-independent activity of nitric oxide synthase

Ca2+-independent forms of nitric-oxide synthase have significant activity when the endogenous calmodulin subunit is Ca2+ free. Further activation is seen when Ca2+ is added. We have examined the activation of a Ca2+-independent nitric-oxide synthase variant and its two point mutants that are more dependent on Ca2+ for activation using mutant calmodulins containing non-functional Ca2+-binding sites. These studies provide evidence that the Ca2+-independent activity of these enzymes can be exerted through specific adapted interactions between the enzyme and the Ca2+-binding site 2 of calmodulin. Further, the results suggest that EGTA-sensitive metals other than Ca2+ complexed to calmodulin may be involved in maximal activation of these nitric-oxide synthase variants.