Inhibition of farnesyltransferase with A-176120, a novel and potent farnesyl pyrophosphate analogue

Farnesylation of Ras is required for its transforming activity in human cancer and the reaction is catalysed by the enzyme farnesyltransferase. Recently, we discovered a novel chemical series of potent farnesyl pyrophosphate (FPP) analogues which selectively inhibited farnesyltransferase. Our most potent compound to date in this series, A-176120, selectively inhibited farnesyltransferase activity (IC(50) 1.2+/-0.3 nM) over the closely related enzymes geranylgeranyltransferase I (GGTaseI) (IC(50) 423+/-1.8 nM), geranylgeranyltransferase II (GGTaseII) (IC(50) 3000 nM) and squalene synthase (SSase) (IC(50)>10000 nM). A-176120 inhibited ras processing in H-ras-transformed NIH3T3 cells and HCT116 K-ras-mutated cells (ED(50) 1.6 and 0.5 microM, respectively). The anti-angiogenic potential of A-176120 was demonstrated by a decrease in Ras processing, cell proliferation and capillary structure formation of human umbilical vein endothelial cells (HUVEC), and a decrease in the secretion of vascular endothelial growth factor (VEGF) from HCT116 cells. In vivo, A-176120 reduced H-ras NIH3T3 tumour growth and extended the lifespan of nude mice inoculated with H- or K-ras-transformed NIH3T3 cells. A-176120 also had an additive effect in combination with cyclophosphamide in nude mice inoculated with K-ras NIH3T3 transformed cells. Overall, our results demonstrate that A-176120 is a potent FPP mimetic with both antitumour and anti-angiogenic properties.

Histopathological examination of chemo-sympathectomy in cats

In recent decades, there has been an increase in both the number of sympathectomy techniques, as well as the surgical findings of sympathetic anatomy. Currently the advanced technique of C-arm guided percutaneous thoracic chemo-sympathectomy is widely used for the treatment of palmar hyperhidrosis. However, a better understanding of chemical agents in sympathectomy is required. In this study, chemo-sympathectomy was performed in cats, using alcohol, glycerol and various concentrations of phenol, to determine the chronic neurotoxic effects of these chemical agents on the stellate ganglia. The stellate ganglia of 24 cats were exposed under endotracheal general anesthesia, then injected with about 0.02 ml of absolute alcohol, glycerol and phenol (10%, 25%, 50%, and 75% concentration) solutions, respectively. The stellate ganglia were taken for histological examination three weeks after the chemical injection. The results showed that the degenerative changes in the cytoplasm and nucleus of ganglionic cells and intercellular tissue were moderate and relatively moderate after the injection of alcohol and glycerol, respectively. Meanwhile, the stellate ganglia revealed mild, relatively moderate, serious and extremely serious degeneration after injection of 10%, 25%, 50%, and 75% phenol, respectively. In conclusion, we recommend a high concentration of phenol, in the least volume, as a chemical agent for clinical injection in the upper thoracic sympathetic ganglion.

Molecular diagnosis of fragile X syndrome and distribution of CGG repeats in the FMR-1 gene in Taiwanese

BACKGROUND AND PURPOSE

Fragile X syndrome, the most frequent form of inherited mental retardation, is caused by abnormal expansion of the CGG trinucleotide repeats in the 5' untranslated region of the FMR-1 gene. In this study, we describe the prenatal diagnosis of fragile X syndrome and the distribution of CGG repeat numbers in the FMR-1 gene, which has not been previously reported in Taiwanese.

METHODS

Using polymerase chain reaction (PCR), we determined the range of the CGG repeats in the FMR-1 gene in 316 normal individuals (350 X chromosomes) and 349 mentally retarded patients (429 X chromosomes). For prenatal diagnosis of fragile X syndrome, DNA extracted from amniotic fluid cells was used for PCR determination of CGG repeats.

RESULTS

Because there were no significant differences between the distribution of the (CGG)n alleles between the mentally retarded and normal subjects, the data were pooled. Among the 779 X chromosomes studied, 24 different alleles were identified with a low of 16 and a high of 45 CGG repeats. The 29 repeat allele was the most common, followed by the 30 and the 28 repeat alleles. We effectively amplified slightly expanded premutation alleles of up to about 90 CGG repeats. In the prenatally diagnosed fetus, a normal 29 repeat allele was found.

CONCLUSIONS

Determination of the distribution of the CGG repeats in the FMR-1 gene in Taiwanese is useful in genetic counseling regarding fragile X syndrome. Prenatal molecular diagnosis of the syndrome can be successfully performed using amniotic fluid cells.

Correlation of genetic instability with mismatch repair protein expression and p53 mutations in non-small cell lung cancer

To examine the etiological association of genetic instability in lung tumorigenesis, we investigated the frequency of microsatellite instability (MI) of eight dinucleotide repeat markers in 68 patients with non-small cell lung cancer. Twenty-eight patients (41.2%) evidenced instability in multiple tested microsatellite markers ranging from 3-7 and were defined as MI-positive patients. MI occurred more frequently in patients suffering from squamous cell lung carcinoma (P = 0.004). We examined the association between MI and expression of hMLH1 mismatch repair protein by immunohistochemical analysis of hMLH1 protein in paraffin-embedded tumors from 64 patients. Twenty MI-positive patients (76.9%) had no expression of hMLH1 protein. The data showed that MI was associated with altered hMLH1 expression (P = 0.03). To examine the role of genetic instability in the previous identified small intragenic deletion of the p53 gene, we explored the association between MI and p53 gene mutations. All patients, except one, containing small intragenic deletion in p53 gene showed MI (P = 0.018). In addition, we found that MI was not associated with the prognosis. Our data suggest that MI plays a significant role in non-small cell lung cancer tumorigenesis in Taiwan and that MI is associated with the altered expression of hMLH1 mismatch repair protein. In addition, MI may be involved in frequent small intragenic deletions of p53 gene.

Antagonism between members of the CNC-bZIP family and the immediate-early protein IE2 of human cytomegalovirus

The HCMV IE2 protein negatively autoregulates its own expression as well as represses the transactivation activity of p53. Using the repression domain of IE2 as bait in the yeast two-hybrid system, Nrf1 and Nrf2, members of the CNC-bZIP family, were found to be IE2-interacting proteins. Residues 331-448 encompassing the DNA-binding and the dimerization domains of Nrf1 are sufficient for the interaction. The interaction was further confirmed in vitro by a glutathione S-transferase pull-down assay and in vivo by co-immunoprecipitation. In transient transfection studies, transcription driven by six copies of an NF-E2 site or by chimeric proteins between the DNA-binding domain of LexA and members of the CNC-bZIP family is repressed by IE2. Importantly, the DNA binding activity of the Nrf1/MafK heterodimer is not impeded by IE2. In a parallel study, CNC-bZIP factors attenuate the negative autoregulation of IE2. The attenuation could be explained by the finding that Nrf1 functions alone and synergistically with its heterodimerization partner, MafK, in inhibiting the DNA binding activity of IE2. Taken together, these results demonstrate the existence of antagonism between members of the CNC-bZIP family and IE2.

Endoscopic endonasal transsphenoidal surgery for pituitary tumors

BACKGROUND

The traditional transsphenoidal approach for pituitary surgery can be performed via transnasal, transseptal, or sublabial routes through unilateral or bilateral nostrils. It requires wide mucosal and septal dissection and postoperative nasal packing. Endoscopic surgery has been widely used because it allows excellent visualization with minimal invasion. Recently, it has also been applied to pituitary surgery.

METHODS

From January, 1997 to February, 1999, 40 patients with pituitary adenomas underwent the transsphenoidal approach using a rigid endoscope via one nostril. Among the 40 cases, 18 were prolactinomas, seven were growth hormone-secreting adenomas and 15 were nonfunctional adenomas.

RESULTS

After surgery, complete resolution or improvement of symptoms and restoration of normal hormone levels were achieved in 16 patients with prolactinomas, five with growth hormone-secreting adenomas and 12 with nonfunctional macroadenomas. One patient with a recurrent microprolactinoma needed a second operation to remove the cavernous portion of the tumor. Another male patient with a macroprolactinoma who experienced galactorrhea and gynecomastia showed improvement of clinical symptoms after the operation. Two patients with residual growth hormone-secreting macroadenomas in the cavernous sinus needed Sandostatin treatment. Three patients with nonfunctional macroadenomas underwent nearly total resection leaving residual tumor in the cavernous sinus, which then required adjuvant radiotherapy. No complications related to this approach were encountered in the patients during the follow-up period.

CONCLUSIONS

Endonasal transsphenoidal endoscopic surgery can be employed for treating pituitary tumors without septal or sublabial complications. Postoperative suffering was reduced and hospitalization was shortened by this mini-invasive procedure. This surgical procedure can be used for both microadenomas and macroadenomas.

Comparison testing of current (PPD-S1) and proposed (PPD-S2) reference tuberculin standards

Since 1951, the tuberculin PPD-S1 has been used to standardize commercial PPD reagents and perform special tuberculin surveys. PPD-S1 is now in short supply and a new standard (PPD-S2) has been manufactured. To determine if PPD-S2 is equivalent and can replace PPD-S1, we conducted a double-blind clinical trial. Between May 14 and October 28, 1997, 69 subjects with a history of culture-proven tuberculosis (TB patients) and 1,189 subjects with a very low risk for TB infection were enrolled, received four skin tests (with PPD-S1, PPD-S2, and one each of the commercially available PPDs), and had reactions measured by two trained observers. Among the TB patients, we found statistically indistinguishable immunogenicity (mean reaction size +/- standard deviation): 15.6 +/- 6.6 mm for PPD-S1 and 14.8 +/- 5.6 mm for PPD-S2. Among low-risk subjects, the tests had equally high specificities (PPD-S1, 98.7% and PPD-S2, 98. 5%), using a 10-mm cutoff. The number of discordant (negative versus positive) interpretations for PPD-S2, assuming that low-risk subjects who had a >/= 10 mm reaction to PPD-S1 were truly infected, was low (0.5%) and indistinguishable from the rate of discordant interpretations of the same test when read by two different observers (0.8%). The study results indicate that PPD-S2 is qualified to be used as the new U.S. reference standard for PPD tuberculin.

[Cardiovascular reactions to gravitational force in different directions]

OBJECTIVE

To observe the features of the cardiovascular reactions to gravitational forces along different axes of the body.

METHOD

Dogs were exposed to gravitational forces along axes of body on an animal centrifuge.

RESULT

It was found that when the direction of G force changed from +Gz to +Gx, the predominating effect on the cardiovascular system changed from the drop of eye level blood pressure to the increase of central venous pressure, and the reactions of the organism changed from a presson reflex of the arterial system to the inhibition of cardiac activities at higher G levels. The turning point was found to be at the back angle of 75 degrees with respect to the direction of the gravitational force.

CONCLUSION

These findings provide an important reference for choosing the optimal seat back angle in a manned space vehicle.

A viscoelasticity index for cheese meltability evaluation

A device especially designed for uniaxial creep test was used in this study. Cheddar cheeses of different fat content were used. To study the linear viscoelastic response of the cheese, temperature of 40 degrees C and stress of 1119.5 Pa were chosen. Tests were carried out at cheese ages of 1, 3, 6, and 12 wk after production date. A six-element Kelvin model was used to model the creep data. Instantaneous slope of the creep curve was defined as the viscoelasticity index. The results showed that the viscoelasticity index based on viscoelastic parameters could be used for predicting cheese meltability. From the analysis of variance test, it was evident that that the viscoelasticity index can be used to distinguish the meltability of Cheddar cheeses of different ages and fat levels.

Lack of evidence of association of p21WAF1/CIP1 polymorphism with lung cancer susceptibility and prognosis in Taiwan

An association between the Arg allele of the p21WAF1/CIP1 codon 31 polymorphism and lung cancer has been reported. However, the genotype distribution of the p21 codon 31 polymorphism, as well as the association of this polymorphism with lung cancer risk and prognosis, remain undefined in the Taiwanese population. Therefore, we investigated the genotype distribution of the p21 codon 31 polymorphism in 155 lung cancer patients and 189 non-cancer controls. The genotype frequencies in the Taiwanese non-cancer controls were 0.51 (Ser) and 0.49 (Arg). Chi2 analysis indicated significant differences in Taiwanese genotype distribution of p21 from those reported for Swedes (P=0.001), Caucasians (P=0.001), Indians (P=0.001), and African-Americans (P=0.001). However, our data did not demonstrate an association of the Arg allele of the p21 polymorphism with lung cancer risk in Taiwan. Lung cancer patients with Ser/Arg and Arg/Arg genotypes were at a nonsignificant 1.15-fold increased risk of lung cancer when compared to individuals with the Ser/Ser genotype (95%CI, 0.70-1.86). In addition, although p21 is a downstream target of p53, we found no significant correlation of the p21 polymorphism with the p53 polymorphism and p53 gene mutation in lung cancer patients. We further investigated the association of the p21 polymorphism with prognosis in 154 lung cancer patients. Patients with the Ser/Ser genotype tended to have a poorer prognosis than those with the Ser/Arg and Arg/Arg genotypes (P=0.097, by the log rank test). Our data suggest that the p21 codon 31 polymorphism may not play a significant role in cancer susceptibility and the prognosis of lung cancer patients in Taiwan.

[The signal transduction and regulation mechanism of interleukin-1 on embryo implantation]

This article elaborates the signal transduction pathway of interleukin-1 (IL-1) and its regulatory mechanism on embryo implantation. IL-1 is an important factor, but not the sole determinant in the regulation of embryo implantation. The cytokines are also crucial on embryo implantation.

Tryptophan hydroxylase gene polymorphism (A218C) and suicidal behaviors

Serotonergic dysfunction is implicated in mood disorders and suicidal behaviors. Genetic variants of tryptophan hydroxylase (TPH), a rate-limiting enzyme in the biosynthesis of serotonin, were associated with suicidal behaviors in three reports, but were not found in other studies. We investigated the TPH A218C polymorphism in 151 subjects with mood disorders and 200 control subjects. The results demonstrated a significant difference in genotypic distribution between controls and depressed patients, but not bipolar patients. A positive association between TPH polymorphism and suicidal behaviors was found in depressed patients and not in bipolar patients. We suggest that the association of TPH variants and suicide might depend on the diagnosis, and TPH mutation plays no major role in the pathogenesis of bipolar disorders.

Association analysis of the 5-HT6 receptor polymorphism C267T in Alzheimer's disease

Serotonergic dysfunction has been implicated in the pathogenesis of Alzheimer's disease (AD). This association study explores whether the serotonin 6 receptor (5-HT6) polymorphism (C267T) is a susceptibility factor for AD. Statistical analysis showed a significant difference in the genotype and gene frequencies between the AD group and the normal controls (P = 0.006; and P = 0.023, respectively). These findings indicate that the 267C allele of the 5-HT6 gene is a risk factor for AD.

[Effects of inhibition of PKC alpha on breast cancer cell phenotype and expressions of cyclin E and CDK2]

Human breast cancer cell line Bcap-37 was stably transfected with the plasmid expressing antisense PKC alpha RNA, and cells, in which PKC alpha was inhibited due to antisense PKC alpha RNA, were isolated. Changes in serum-dependent growth in cell culture, cell clonogenicity in soft agar and growth in nude mice were tested, and the expressions of cyclin E and CDK2 were analyzed. After PKC alpha was inhibited, the cells showed that serum-dependent growth and anchorage-dependent growth enhanced, tumorigenicity in nude mice decreased. The results suggest that less aggressive breast cancer phenotypes may be induced by inhibition of PKC alpha. Levels of cyclin E and CDK2 mRNA in cells with antisense PKC alpha RNA were lower than those in control cell. These indicate that signal transduction system with PKC alpha is closely related to cell cycle control system with cyclin/CDK in the functions.

Oral ciprofloxacin as antibacterial prophylaxis after allogeneic bone marrow transplantation: a reappraisal

The efficacy of ciprofloxacin as antibacterial prophylaxis for allogeneic bone marrow transplantation has been well documented, and it virtually eliminated bacteremias caused by gram-negative pathogens in early reports. Ciprofloxacin was therefore incorporated into the prophylactic antibiotic regimen during allogeneic bone marrow or peripheral blood stem cell transplantation at Veterans General Hospital, Kaohsiung from February 1997. In 12 consecutive patients receiving allogeneic bone marrow or peripheral blood stem cell transplantation, ciprofloxacin-resistant Escherichia coli bacteremia developed in three (25%). In addition to our data, increasing evidence suggests that the widespread use of a fluoroquinolone is associated with the emergence of resistant isolates as well as documented infections caused by these resistant strains. The incidence of Escherichia coli bacteremia in our transplant patients was 25%, which was similar to that in patients not receiving preventive therapy or in those receiving trimethoprim-sulfamethoxazole prophylaxis. The prophylactic efficacy of ciprofloxacin in allogeneic bone marrow transplant or peripheral blood stem cell transplant recipients should therefore be reassessed.

Alpha-1-antichymotrypsin polymorphism in schizophrenia: frequency, age at onset and cognitive function

A common polymorphism in the alpha1-antichymotrypsin (ACT) gene is associated with Alzheimer's disease. ACT is also a trophic factor in the hippocampal neurons. In order to examine if the ACT gene plays a role in the pathogenesis of schizophrenic disorders, patients (n = 175) and control subjects (n = 114) were genotyped for ACT. We also investigated the relationship between genotypes and patients' cognitive function as evaluated by the Clinical Dementia Rating Scale and the Mini-Mental State Examination. The results demonstrated no association between schizophrenia and/or cognitive deficit in schizophrenia and ACT polymorphism. The data suggest that the ACT gene is not of major importance for the genesis of schizophrenia. Further studies measuring ACT expression as messenger RNA or serum ACT level may help to exclude the role of ACT in the pathogenesis of schizophrenia.

No association between alpha-1-antichymotrypsin polymorphism and Alzheimer's disease in Chinese

A recent observation has shown that a common polymorphism in the alpha1-antichymotrypsin (ACT) confers a significant risk for Alzheimer's disease (AD). Furthermore, the apolipoprotein E epsilon4 allele (APOE*4) effect associated with AD risk is modified by the ACT polymorphisms. To evaluate the role of ACT polymorphism in AD, we conducted an association study of ACT polymorphisms in Chinese AD patients and normal controls. We found that the ACT polymorphism had no effect on the development of AD either alone or in combination with the APOE*4 allele.

Effect of novel CAAX peptidomimetic farnesyltransferase inhibitor on angiogenesis in vitro and in vivo

Ras oncogenes can contribute to tumour development by stimulating vascular endothelial growth factor (VEGF)-dependent angiogenesis. The effect of Ras on angiogenesis may be affected by farnesyltransferase inhibitors (FTI) since farnesylation of Ras is required for its biological activity. In this paper we evaluated the effect of A-170634, a novel and potent CAAX FTI on angiogenesis. Human umbilical vein endothelial cell (HUVEC) tube formation and VEGF secretion were used to assess the effect of A-170634 on angiogenesis in vitro. In vivo, nude mice were injected with the K-ras mutant colon carcinoma cell line HCT116 and treated subcutaneously with A-170634 using osmotic minipump infusion for 10 days. The effect of A-170634 on corneal angiogenesis in vivo was assessed using pellets containing hydron, VEGF, A-170634 or vehicle. In vitro, A-170634 selectively inhibited farnesyltransferase activity over the closely related geranylgeranyltransferase I, inhibited Ras processing, blocked anchorage-dependent and -independent growth of HCT116 K-ras mutated cells, decreased HUVEC capillary structure formation, decreased VEGF secretion from tumour cells and HUVEC growth stimulating activity in a dose-dependent manner. In vivo, tumour growth was decreased by 30% and vascularisation in and around the tumours was reduced by 41% following drug-treatment with no apparent toxicity to the animals. VEGF-induced corneal neovascularisation was reduced by 80% following A-170634 treatment for 7 days. The data presented here demonstrated that A-170634 was a potent and selective peptidomimetic CAAX FTI with anti-angiogenic properties. These results implied that A-170634 may affect tumour growth in vivo by one or more antitumour pathways.

Association study of serotonin-6 receptor variant (C267T) with schizophrenia and aggressive behavior

The relative abundance of serotonin type 6 receptors (5-HT6) in some limbic regions and the high affinity of some antipsychotics to 5-HT6 receptors suggest that they might be involved in the pathogenesis of schizophrenic disorders. In a population-based association study, we tested the hypothesis that the allelic variant, C267T, of the human 5-HT6 gene confers susceptibility to schizophrenic disorders and associated aggressive behavior. We genotyped 5-HT6 receptors in 186 patients with schizophrenic disorders and 163 controls. The results demonstrated no significant difference in genotype or allele frequencies between patients with or without aggressive behaviors. However, genotype distribution was significantly different between schizophrenic patients and control subjects. This suggests that the 5-HT6 gene may play a role in the pathogenesis of schizophrenic disorders.

Influence of polymorphism at p53, CYP1A1 and GSTM1 loci on p53 mutation and association of p53 mutation with prognosis in lung cancer

BACKGROUND

We previously found that the majority (9/11) of p53 tumor suppressor gene mutations in 60 lung cancer patients in Taiwan were small intragenic deletions and nonsense mutations. To gain insights into the possible etiologic factors involved in these mutations and the prognostic significance of p53 gene mutations in lung cancer in Taiwan, we investigated the influence of polymorphism at p53, cytochrome p450 1A1 (CYP1A1) and glutathione S-transferase M1 (GSTM1) loci on p53 gene mutation, and the association of p53 gene mutation with prognosis in these lung cancer patients.

METHODS

The polymorphism of these genes was determined by polymerase chain reaction followed by restriction enzyme digestion. The Pearson chi 2 test was used to compare allelic distributions between lung cancer patients and controls. The log-rank test was used to assess the significance of the survival differences between patients with and without p53 mutations.

RESULTS

There was no significant difference with respect to the genotype distribution of p53, CYP1A1 and GSTM1 polymorphisms between patients with and without p53 mutations, although a tendency toward increasing frequency of the wild-type homozygote genotype of p53 polymorphism was noted in lung cancer patients containing p53 mutations. We further analyzed the association of p53 mutation with prognoses in lung cancer patients for whom postoperative survival data were available. The estimated median survival times for patients with and without p53 mutation were 25 and 28 months, respectively. There was no significant correlation between p53 mutation and survival.

CONCLUSIONS

Our data suggest that p53 gene mutation may not be associated with polymorphisms of p53, CYP1A1 and GSTM1 genes, and it may have no significant effect on the prognosis of lung cancer patients in Taiwan.

Protein transfer of glycosyl-phosphatidylinositol-B7-1 into tumor cell membranes: a novel approach to tumor immunotherapy

Modification of tumor cells with one or more costimulatory adhesion molecules has been proposed as a means to develop therapeutic cancer vaccines for use in human immunotherapy. Expression of B7-1 (CD80) in tumors by gene transfer creates an immunogenic tumor cell that induces antitumor immunity and protects mice from further challenge with wild-type tumor cells. In this report, we demonstrate that protein transfer of glycosyl-phosphatidylinositol (GPI)-anchored costimulatory molecules into tumor cell membranes could be used as an alternative to gene transfer for tumor immunotherapy. Incubation of isolated tumor membranes with purified GPI-anchored B7-1 results in stable incorporation of B7-1 on tumor cell membranes within a few hours. Immunization of C57BL/6 mice with EG7 tumor membranes modified to express GPI-B7-1 by protein transfer induces tumor-specific T-cell proliferation and CTLs. In addition, immunization with these EG7 membranes protects mice from parental tumor challenge. The protein transfer approach used here does not require foreign vectors or live tumor cells and is completed within a matter of hours. Irradiated cells or membrane preparations from fresh or frozen tumor tissue can be used. Therefore, protein transfer of glycolipid-anchored molecules provides an efficient and novel approach to modify tumor membranes for human immunotherapy. This approach is not limited to costimulatory molecules because any cell surface protein can be converted to a GPI-anchored form by recombinant techniques.

Nesidioblastosis, myelodysplastic syndrome and nodular diabetic glomerulosclerosis in an elderly nondiabetic woman: an autopsy report

Nesidioblastosis as the cause of hyperinsulinaemic hypoglycaemia in an adult is rare. We report here an additional case of nesidioblastosis, which resulted in fatal hyperinsulinaemic hypoglycaemia in a 72-year-old woman with an underlying myelodysplastic syndrome. The diagnosis of nesidioblastosis was established only after post-mortem examination with a careful exclusion of minute insulinoma. To our surprise, the renal pathology disclosed typical diabetic nodular glomerulosclerosis in the same patient who had no previous history of diabetes mellitus (DM). Nesidioblastosis has been reported to cause 'reversal' of Type 1 DM and insulinoma causing 'reversal' of Type 2 disease. We therefore hypothesize that our patient might have had an undiagnosed DM in the past, which resulted in the typical diabetic nodular glomerulosclerosis. The nesidioblastosis caused a 'reversal' of DM and even the ultimate development of hyperinsulinaemic hypoglycaemia.

Protein kinase C isoforms in the epidermal tissues of normal and postburn human skin

Because the expression of the isoforms of protein kinase C (PKC) in human basal keratinocytes is not understood, the expression of PKC isoforms were screened in specimens of epidermal tissue from postburn skin and the normal locations for skin grafts in patients with second or higher degrees of flame injury. The expression of individual isoform was determined by Western blot technique. Only PKC alpha and zeta were detected in the epidermal tissues of normal and postburn skin and translocation occurred in PKC alpha. Patients without antibiotic treatment after flame injury had higher expressions of PKC alpha and zeta. These findings indicate that the mechanisms of cellular differentiation and growth in postburn epidermal tissue may be related to the expression and translocation of PKC alpha induced by intra- and extracellular stimulation. These changes in PKC alpha further activate the DAG/PKC signal transduction pathways.

TWEAK induces angiogenesis and proliferation of endothelial cells

TWEAK is a recently described member of the Tumor Necrosis Factor (TNF) ligand family whose transcripts are present in a wide variety of human tissues (Chicheportiche, Y., Bourdon, P. R., Xu, H., Hsu Y. M., Scott, H., Hession, C., Garcia, I., and Browning, J. L. (1997) J. Biol. Chem. 272, 32401-32410). TWEAK is a weak inducer of apoptosis in transformed cells when administered with interferon-gamma or cycloheximide (Chicheportiche, Y., Bourdon, P. R., Xu, H., Hsu Y. M., Scott, H., Hession, C., Garcia, I., and Browning, J. L. (1997) J. Biol. Chem. 272, 32401-32410; Masters, S. A., Sheridan, J. P., Pitti, R. M., Brush, A. G., and Ashkenazi, A. (1998) Curr. Biol. 8, 525-528) and also promotes IL-8 secretion in cultured cells. We report here that picomolar concentrations of recombinant soluble TWEAK induce proliferation in a variety of normal human endothelial cells and in aortic smooth muscle cells and reduce culture requirements for serum and growth factors. Blocking antibodies to Vascular Endothelial Growth Factor (VEGF) do not significantly inhibit TWEAK-induced proliferation, indicating that TWEAK does not function indirectly through up-regulation of VEGF. Pellets containing TWEAK induce a strong angiogenic response when implanted in rat corneas, suggesting a role for TWEAK in vasculature formation in vivo.