Hepatitis G virus (HGV) infection in voluntary and commercial blood donors in India

The prevalence of hepatitis G virus (HGV) has been determined in commercial as well as voluntary blood donors from India by detecting viral RNA genome using reverse transcription polymerase chain reaction (RT-PCR) assay. 45 professional blood donors from private blood banks and 50 healthy controls who opted for voluntary blood donation were recruited for the study. Both the groups were also screened serologically for HBV and HCV infection. The prevalence of HGV in the general population in India was found to be 4% but significantly a higher frequency (46.6%; p<0.001) of HGV was observed in commercial blood donors.

Modified standard pancreaticoduodenectomy for the treatment of pancreatic head cancer

Since 1980 extended surgery has been used to treat pancreatic cancer in many institutions in Japan in the hope of achieving curative resection and a good outcome. The resection rate increased, but the final outcome was unsatisfactory, and the question of postoperative quality of life (QOL) following extended surgery has instead become the central issue. During the past 22 years (October 1976 to June 1998) 169 of the 188 patients with invasive pancreatic ductal carcinoma at Mie University Hospital were treated surgically. A standard operation was performed in the early period (October 1976 to April 1981, n = 34), an extended operation was performed in the middle period (May 1981 to March 1993, n = 100), and a modified standard operation was performed in the late period (April 1993 to June 1998, n = 35). 'Standard operation' means pancreaticoduodenectomy (PD) with D1 lymph node dissection (regional), and 'extended operation' means PD with D2-D3 lymph node dissection. Our 'modified standard operation' consists of PD with lymph node dissection limited to the anterior pancreaticoduodenal (APD), posterior pancreaticoduodenal (PPD), pyloric (PY), hepatoduodenal ligament (HDL), common hepatic artery (CH) and right half of the superior mesenteric (SM) nodes. Thus, the extent of lymph node dissection in the modified standard procedure lies between the level in the standard and extended procedure, but the PD is the same, with only slight modification in the reconstruction procedure. We consider the standard operation to be a less curative procedure and the extended operation to be a very stressful procedure and accordingly we have modified it (modified standard operation) in our recent cases out of consideration for patients' QOL. We found that postoperative QOL and survival were much better in the late period than in the early and middle periods.

P53 tumor suppressor gene mutations in hepatocellular carcinoma patients in India

BACKGROUND

Specific mutations of the p53 tumor suppressor gene in hepatocellular carcinoma (HCC) have been reported from several parts of the world, but to the authors' knowledge to date the status of this gene has not been studied in HCC patients in India, where HCC is one of the major cancers and the frequency of chronic hepatitis B virus (HBV) as well as hepatitis C virus (HCV) infection and exposure to dietary aflatoxin B(1) is very high. The most frequent mutation of the p53 gene in HCC is an AGG(Arg) to AGT(Ser) missense mutation at codon 249 of exon 7.

METHODS

Liver biopsy specimens from 21 HCC patients and 10 healthy controls were obtained through surgery or by needle biopsy technique. Phenol-chloroform-extracted DNA specimens were employed for the detection of HBV infection and p53 gene mutations. Nucleotide mutations of exons 4-9 of the p53 gene were analyzed by polymerase chain reaction (PCR), single strand confirmation polymorphism, and direct sequencing. Third-generation sandwich enzyme-linked immunosorbent assay (ELISA) was used for the serologic detection of HBV and HCV infection.

RESULTS

Analysis of exons 4-9 of the p53 gene revealed only 3 mutations (3 of 21 specimens, 14.28%; 95% confidence interval, -0.7-29.3), 2 mutations at codon 249 showing G-->T transversions, and 1 mutation (4.7%) at codon 250 with a C-->T transition. The base substitutions at the third base of codon 249 resulted in a missense mutation leading to a change in amino acid from arginine to serine whereas at codon 250 it caused a change from proline to serine. Dot blot hybridization and PCR for HBV DNA from HCCs revealed 58.8% (10 of 17 specimens) and 90. 47% (19 of 21 specimens), positivity, respectively. ELISA for hepatitis B virus surface antigen in serum showed a positivity of 71. 42% (15 of 21 specimens), but there was only 40% positivity (8 of 20 specimens) for hepatitis B virus envelope antigen whereas 6 of 17 patients (35.29%) showed the presence of antibodies against hepatitis B virus envelope protein. No patient was found to be positive for the HCV antibody.

CONCLUSIONS

The very low frequency of p53 mutations and the extremely high frequency of HBV infection (> 90%) in HCC indicate that the mutations in the p53 gene frequently found in HCC reported from different endemic areas of the world may not play a direct role in the development of HCC in India. HBV infection and, possibly, exposure to the dietary aflatoxin B(1) appear to play major roles in the molecular pathogenesis of HCC in India.

P53 tumor suppressor gene mutations in hepatocellular carcinoma patients in India

BACKGROUND

Specific mutations of the p53 tumor suppressor gene in hepatocellular carcinoma (HCC) have been reported from several parts of the world, but to the authors' knowledge to date the status of this gene has not been studied in HCC patients in India, where HCC is one of the major cancers and the frequency of chronic hepatitis B virus (HBV) as well as hepatitis C virus (HCV) infection and exposure to dietary aflatoxin B(1) is very high. The most frequent mutation of the p53 gene in HCC is an AGG(Arg) to AGT(Ser) missense mutation at codon 249 of exon 7.

METHODS

Liver biopsy specimens from 21 HCC patients and 10 healthy controls were obtained through surgery or by needle biopsy technique. Phenol-chloroform-extracted DNA specimens were employed for the detection of HBV infection and p53 gene mutations. Nucleotide mutations of exons 4-9 of the p53 gene were analyzed by polymerase chain reaction (PCR), single strand confirmation polymorphism, and direct sequencing. Third-generation sandwich enzyme-linked immunosorbent assay (ELISA) was used for the serologic detection of HBV and HCV infection.

RESULTS

Analysis of exons 4-9 of the p53 gene revealed only 3 mutations (3 of 21 specimens, 14.28%; 95% confidence interval, -0.7-29.3), 2 mutations at codon 249 showing G-->T transversions, and 1 mutation (4.7%) at codon 250 with a C-->T transition. The base substitutions at the third base of codon 249 resulted in a missense mutation leading to a change in amino acid from arginine to serine whereas at codon 250 it caused a change from proline to serine. Dot blot hybridization and PCR for HBV DNA from HCCs revealed 58.8% (10 of 17 specimens) and 90. 47% (19 of 21 specimens), positivity, respectively. ELISA for hepatitis B virus surface antigen in serum showed a positivity of 71. 42% (15 of 21 specimens), but there was only 40% positivity (8 of 20 specimens) for hepatitis B virus envelope antigen whereas 6 of 17 patients (35.29%) showed the presence of antibodies against hepatitis B virus envelope protein. No patient was found to be positive for the HCV antibody.

CONCLUSIONS

The very low frequency of p53 mutations and the extremely high frequency of HBV infection (> 90%) in HCC indicate that the mutations in the p53 gene frequently found in HCC reported from different endemic areas of the world may not play a direct role in the development of HCC in India. HBV infection and, possibly, exposure to the dietary aflatoxin B(1) appear to play major roles in the molecular pathogenesis of HCC in India.

Ultrastructural study of the remnant liver after extensive hepatectomy in dogs; especially morphological alterations of sinusoidal endothelial cells

BACKGROUND/AIMS

To investigate the role of sinusoidal endothelial cells in the mechanism of the remnant liver dysfunction after extensive hepatectomy, morphological alteration of sinusoidal endothelial cells and cytoprotective effects of prostaglandin I2 analog were studied by ultrastructural analysis.

METHODOLOGY

Mongrel dogs (n = 24) were divided into 3 groups according to the extent of hepatectomy and the use of prostaglandin I2 analog preoperatively. Group 1: 70% hepatectomy (n = 8), Group 2: 84% hepatectomy (n = 8), and Group 3: 84% hepatectomy with administration of prostaglandin I2 analog, preoperatively (n = 8). Morphology of hepatic sinusoidal endothelial cells was examined after hepatectomy in all cases.

RESULTS

Group 2: Enlargement of the sinusoidal endothelial fenestrations was transitorily occurred immediately after hepatectomy, but were dramatically decreased in size 24 h after the operation. Most sinusoidal endothelial cells were destroyed and separated from the sinusoidal wall. Fibrin deposits and sludge were found in the Disse's space and sinusoidal lumens, resembling liver failure at 24 h after the operation. Group 1 and 3: sinusoidal endothelial fenestrations remained slightly enlarged at 24 h after the operation, but fibrin deposits or sludge were not observed in sinusoidal lumens.

CONCLUSIONS

Our data suggest that extensive hepatectomy changed the morphology of sinusoidal endothelial cells. Administration of prostaglandin I2 analog helped maintain structural integrity of sinusoidal endothelial cells, improved hepatic microcirculation and thus served to reduce remnant liver dysfunction.

Chlamydia trachomatis and human papillomavirus infection in Indian women with sexually transmitted diseases and cervical precancerous and cancerous lesions

OBJECTIVES

Sexually transmitted diseases (STDs) and anogenital cancers are the major health problems in Indian women but no reliable estimate of the prevalence of either genital chlamydial infection or human papillomavirus (HPV) infection in STD patients is available. The aim of this study was to detect the frequency of Chlamydia trachomatis and the most prevalent high-risk HPV type 16 (HPV 16) infection in Indian women, with STDs and precancerous and cancerous lesions of the uterine cervix by polymerase chain reaction (PCR), and their comparison with those of conventional serology and antigen tests used for C. trachomatis detection.

METHODS

Endocervical swabs or scrapes were collected from 50 women with STDs and 30 normal healthy women attending the STD clinics of Smt. Sucheta Kripalani Hospital, New Delhi. Scraped cervical cell specimens were also collected from 50 women with precancerous and cancerous lesions of the uterine cervix. Detection of C. trachomatis and HPV was carried out by PCR using chlamydia and HPV genome-specific oligonucleotide primers. The detection of chlamydial antigen and IgG-specific antibodies was carried out by enzyme immunoassay (EIA) and serological enzyme-linked immunosorbent assay (ELISA), respectively.

RESULTS

A chlamydia plasmid-based PCR assay detected 50% (25 of 50) positivity of C. trachomatis in STD patients and HPV 16 DNA was found in 30% (15 of 50) of these cases which are significantly higher than those found in healthy controls. The PCR estimate of chlamydia was found to be higher than its reported frequency by tissue culture. The EIA could detect chlamydial antigen in only 13 cases (26%) while serological ELISA revealed evidence of chlamydia IgG-specific antibodies in 26 (52%) cases. Interestingly, in women with precancerous and cancerous lesions, the rate of HPV 16 infection was very high (52% and 72%, respectively), whereas the frequency of chlamydia infection was found to be 12-22% only. Occurrence of other sexually transmitted agents was also evaluated in the women.

CONCLUSIONS

This is the first PCR estimate of genital chlamydial (50%) and HPV 16 (30%) infection in STD patients and women with precancerous and cancerous lesions of the uterine cervix in India. The PCR method seems to be a good alternative to tissue culture.

Surgical anatomy of the medial segment (S4) of the liver with special reference to bile ducts and vessels

BACKGROUND/AIMS

Resection of the inferior area of the medial segment (S4a) plus S5 with preservation of the superior area of the medial segment (S4b) is being performed to manage hilar bile duct carcinoma and pT2 type gallbladder carcinoma, and thus, attention has been focused on the surgical anatomy of the medial segment of the liver to identify the specific vessels and bile ducts of the areas of that segment to be resected and to be preserved.

METHODOLOGY

Anatomical study of the bile duct, portal vein, middle hepatic vein, and middle hepatic artery to the medial segment branches of the liver (S4) was performed in a total of 171 specimens comprised of 71 adult cadavers, and 100 liver casts.

RESULTS

1) Two main types of bile duct branches of the medial segment (B4) were recognized. Type I included the branches which joined to the left hepatic duct on the hilar duct side (35.5%), and type II included the branches that joined on the peripheral side (54.6%). Several subtypes were also found in both types. The B2-B3 confluence was mostly on the left (41.7%) or posterior (42.7%) to the umbilical portion (UP) of the portal vein, and to the right of the UP (hilar side) in only 15.6%. 2) The portal vein of the medial segment branches (P4): P4a branched from the right angle and upper right border of the UP in every specimen. The most common morphology was 1 large and 2-3 small branches (41%). P4b was almost always found to branch posterior to the UP and lower than P4a, and the most common morphology was 1 large and 0-1 small branches (57.8%). 3) The middle hepatic vein: In 83.2% a common trunk was observed at the confluence with the inferior vena cava, and 8 types of the middle hepatic vein were recognized. 4) The middle hepatic artery: It arose from the left hepatic artery in 61.5%, from of the right hepatic artery in 27.5%, from the proper hepatic artery in 5.5%, and from both the left and the right hepatic artery in 5.5%.

CONCLUSIONS

The detailed vascular and bile duct anatomy of S4 is described. This study should be helpful in identifying the specific vessels and bile ducts of the areas of the medial segment to be resected and to be preserved, thereby facilitating resection of the medial segment.

HCV seroreactivity and detection of HCV RNA in cirrhotics

This study was carried out to determine the presence of HCV infection in cirrhotic patients and to compare their serologic profiles with detection of HCV RNA by RT-PCR. Liver function profiles were assessed and correlated with infection. Coinfection of HCV with HBV was studied in the Indian context Sera from 62 patients of biopsy confirmed cirrhosis and an equal number of asymptomatic controls were tested for HCV by two ELISA (third generation) kits and nested reverse transcription PCR using primers from the 5'NCR. Other tests included HBV serology (ELISA for HBsAg and anti-HBc) and liver function tests. Twenty-four (38.7%) cases were HCV infected, of which 17 (70.8%) had past exposure to HBV or were coinfected with HBV (either being chronically infected or carriers of HBV). There was no significant difference in the clinical and liver function profiles of HCV infected and uninfected cirrhotics. Similarly, no difference was observed in cases coinfected with both HCV and HBV compared with those infected with HCV alone. Although the difference between positivity of HCV RNA and of anti-HCV was not significant, HCV RNA and anti HCV were present together in only 7/62 (11.3%) cases. Thus testing for both antibody and HCV RNA would be more appropriate than either test alone. HBV infection was seen in about one-fourth of HCV infected cirrhotics. About one-fourth (25.8%) patients had non-B, non-C cirrhosis in whom testing for HCV variants and other recently characterized hepatitis viruses could be performed.

Hepatitis C virus infection in sporadic fulminant viral hepatitis in North India: cause or co-factor?

INTRODUCTION

The role of hepatitis C virus (HCV) infection in fulminant hepatitis (FH) is poorly understood and the available data are conflicting. We have examined the aetiological role of HCV in 50 consecutive patients with sporadic FH by employing serology and reverse transcription-polymerase chain reaction (RT-PCR).

MATERIALS AND METHODS

A total of 50 consecutive patients with sporadic FH were included. After an initial clinical and biochemical assessment, tests were performed for detection of HBsAg, IgM anti-HBc, IgM anti-HAV, IgM anti-HEV and anti-HCV. RT-PCR was carried out for detection of HCV RNA in sera of all the patients and in post mortem liver biopsy tissue of 20 subjects, using primers selected from the conserved 5' non-coding region of the HCV genome.

RESULTS

Hepatitis E virus (HEV) was found to be the most common viral infection (21/50; 42%) followed by HBV (14/50; 28%), HCV (7/50; 14%) and HAV (2/50; 4%). No viral markers could be detected in nine patients (18%) and multiple infections were seen in seven (14%). Of the seven subjects who tested positive for HCV-related markers, two had both anti-HCV and HCV RNA, three had HCV RNA alone and the remaining two had anti-HCV alone. Interestingly, all the HCV-infected subjects were co-infected with other hepatotropic viruses and the most common co-infecting agent was found to be HBV (5/7). Liver tissue was available in 20 cases and HCV RNA was detected in three of them. All of these patients were also positive for the viral genome in their serum samples. Comparison of the biological attributes of HCV-positive and HCV-negative cases revealed that haemorrhagic symptomatology (haematemesis, melaena and purpurae) was significantly more common, prothrombin time more deranged and mortality was much higher in the former group. The overall mortality was 68% and the most common cause of death was cerebral oedema (70.6%). No significant correlation was observed between mortality and the duration of the icterus-encephalopathy interval. The study included a total of 21 pregnant females; HEV infection was found to be significantly greater in this group and was associated with a higher mortality rate.

CONCLUSIONS

The results clearly suggest that HCV is not an important aetiological factor for FH in North India. However, it may act as a co-factor in the development of FH leading to a higher mortality. HEV appears to contribute substantially to the causation of sporadic FH in India and advanced stage pregnancy is a potential risk factor for HEV-induced FH and high rate of mortality. Our study also suggests that the length of the icterus-encephalopathy period may not have significant prognostic implications in Indian patients with FH.

Hepatitis G virus (HGV) infection & its pathogenic significance in patients of cirrhosis

In the present study the hepatitis G virus (HGV) infection and its pathogenic significance in patients of cirrhosis were assessed using reverse transcription plus nested polymerase chain reaction (RT-PCR). Serum samples were collected from a total of 50 patients of histologically proven non-alcoholic cirrhosis and from a control group consisting of 50 healthy voluntary blood donors. HGV RNA was detected by RT-PCR using primer sequences located in the conserved NS3 helicase region of HGV genome. Serological evaluation for markers of chronic infection with HBV (HBsAg, IgG anti-HBc, HBeAg) and HCV (anti-HCV) was carried out using commercially available kits. HBV DNA and HCV RNA were also tested by PCR in those samples that were found to be non-B, non-C by serological assays. Serological evidence of exposure to HBV was found in 31 (62%) and to HCV in 15 (30%) patients. HGV RNA was detected in 6 (12%) cirrhosis patients and in 2 (4%) healthy blood donors but the difference between the two groups was not statistically significant. Of the 6 HGV positive patients, 2 were coinfected with HBV, 1 with HCV, while the remaining 3 belonged to non-B, non-C category. No significant difference was observed in the clinical and biochemical profiles of HGV-positive and HGV-negative patients except that a history of blood transfusion was significantly (P < 0.005) more common in the former. The findings indicate that the HGV infection is commonly observed in both cirrhosis patients as well as healthy blood donors. A significant association of the virus with blood transfusion is indicative of a parenteral route of transmission. The observations of this study also suggest that the pathogenic role of HGV in the causation of liver disease may be insignificant.

S4a + S5 with caudate lobe (S1) resection using the Taj Mahal liver parenchymal resection for carcinoma of the biliary tract

Recently we have been performing S4a + S5 with total resection of the caudate lobe (S1) by using a dome-like dissection along the root of the middle hepatic vein at the pinnacle, which we refer to as the Taj Mahal liver parenchymal resection, for carcinoma of the biliary tract. This procedure offers the following advantages: (1) It allows total resection of the caudate lobe, including the paracaval portion (S9), and (2) because the cut surface of the liver is large, it allows intrahepatic jejunostomy to be performed more easily with a good field of view. The indications for this procedure include hilar bile duct carcinoma, gallbladder carcinoma, and choledochal cyst (type IVA). Because of the high rate of hilar liver parenchyma and caudate lobe invasion associated with hilar bile duct carcinoma, the liver must be resected. The Taj Mahal procedure is indicated in cases where extended liver resection is impossible. The dissection limits of this procedure are, on the left side, the B2+3 bifurcation at the right margin of the umbilical portion of the portal vein and, on the right side, the B8 of the anterior branch and the B6+7 bifurcation of the right posterior branch. This procedure could also be described as a reduced form of extended right hepatectomy and extended left hepatectomy. For gallbladder carcinoma, this procedure is indicated to ensure an adequate surgical margin and eradicate transvenous liver metastasis, particularly in cases of pT2 lesions. Hilar and caudate lobe invasion also occurs in liver bed-type gallbladder carcinoma, and bile duct resection and caudate lobe resection are required for the surgery to be curative. We performed this procedure in four cases of hilar bile duct carcinoma, five cases of gallbladder carcinoma, and one case each of choledochal cyst (type IVA) with carcinoma of the bile duct and gallbladder adenomyomatosis. Curative resection was possible in all except the patient with adenomyomatosis, and all of the patients are alive and recurrence free 10 to 37 months postoperatively. This procedure, in addition to preserving liver function, provides a wide field of view and facilitates reconstruction of multiple intrahepatic bile ducts. Thus it can be said to be a curative operation not only in patients considered high risk but also in those whose hilar bile duct carcinoma is limited to the bifurcation area (Bismuth type IIIa and IIIb) and in gallbladder carcinoma up to pT2 with slight extension on the hepatic side.

Conversion of HPV 18 positive non-tumorigenic HeLa-fibroblast hybrids to invasive growth involves loss of TNF-alpha mediated repression of viral transcription and modification of the AP-1 transcription complex

AP-1 represents a transcription factor, which plays a pivotal role in initiating and maintaining the expression of human papillomavirus (HPV) oncoproteins E6 and E7 during HPV-linked carcinogenesis of the uterine cervix. AP-1 stands as a synonym for different proteins such as c-Jun, JunB, JunD, c-Fos, FosB as well as the Fos-related antigens Fra-1 and Fra-2, which can either homo- or heterodimerize to build up a functional transcription complex. AP-1 is mainly considered as a positive regulator, which binds to cognate DNA sequences within the viral upstream regulatory region. By using non-tumorigenic HeLa-fibroblast hybrids ('444'), their tumorigenic segregants ('CGL3') as well as HPV 18 positive HeLa cells as a experimental model system, evidence is provided that AP-1 composition differs considerably between these cell lines. In nuclear extracts obtained from non-tumorigenic cells, Jun-family members (in the order c-Jun>JunD>JunB) were mainly heterodimerized with Fra-1, a protein, known to be involved in the abrogation of AP-1 activity under certain experimental conditions. In contrast, Fra-1 concentration is low in extracts from tumorigenic cells. Conversely, c-Fos, the canonical dimerization partner of Jun proteins is expressed in substantial quantity in HeLa- and 'CGL3' cells, but it is completely absent in AP-1 complexes from non-tumorigenic '444' cells. Ectopical expression of c-fos under a heterologous promoter in '444'-cells induces tumorigenicity and a change of the Jun/Fra-1 ratio towards a constellation initially detected in 'CGL3'-and HeLa cells. Furthermore, conversion to tumorigenicity is accompanied with a resistance against TNF-alpha, a cytokine, capable to selectively suppress HPV 18 transcription in formerly non-malignant cells. These data propose a novel role for AP-1 as an essential component of an inter- and intracellular surveillance mechanism negatively controlling HPV transcription in non-tumorigenic cells.

Lichenysins G, a novel family of lipopeptide biosurfactants from Bacillus licheniformis IM 1307: production, isolation and structural evaluation by NMR and mass spectrometry

A series of 9 lactonic lipopeptide biosurfactants was isolated from Bacillus licheniformis IM 1307 as representatives of the lichenysin group and we propose to name them lichenysins G. They were recovered from the culture medium as complex mixtures of molecules having different peptide sequences and different structures of beta-hydroxy fatty acids. Their separation was achieved by a reversed-phase HPLC method leading to eight well-separated compounds. The complete structure of individual isoforms was proposed following the results of amino acid and fatty acid analysis, LSI-MS and 2D NMR spectroscopies. Compared to surfactin, lichenysins G are at least 10 fold more efficient biosurfactants.

Screening for Chlamydial infection in women attending STD clinic by polymerase chain reaction, ELISA and cell cytology

Thirty five female patients with endocervicitis attending STD clinic were studied for the presence of Chlamydial infection by Polymerase Chain Reaction (PCR), Enzyme Immunoassay (EIA) and Cell Cytology. PCR was found to be positive in 54.2% of patients, Enzyme-Linked Immunosorbent Assay (ELISA) in 25.7% of patients, but cell cytology revealed the presence of inclusion bodies only in 3% of the cases, thereby showing that polymerase chain reaction is a better method for detection of Chlamydia trachomatis than EIA and cell cytology.

Effect of PTU treatment on histone acetylation pattern in the developing rat brain

The effect of hypothyroidism induced m female rats on histone acetylation pattern m the neonatal rat brain was studied. It is likely that thyroid hormone regulates the acetylation of histones and thereby influence their interaction with DNA and modulates transcription. Propylthiouracil (PTU), administered to induce hypothyroidism, resulted in a significant reduction m the thyroid and brain weight of neonatal rats. The circulating thyroxine levels were undetectable in both 14 and 21 day old pups. The hypothyroid condition was further confirmed by low levels of T4 (94.31 ng/g brain tissue vs 1811.29 ng/g in controls and 144.67 ng/g vs 1087.72 ng/g in controls at 14 and 21 days, respectively) and T3 (42.19 ng/g brain tissue vs 879.97 ng/g in controls and 60.62 ng/g vs 766.68 ng/g in controls at 14 and 21 days, respectively) in the neonatal rat brain. Histone acetylation pattern was similar in treated and control groups m the 14 day old rats. PTU treatment, however, resulted in significant (p<0.01) reduction in acetylation in the H3 fraction at 21 days whereas no such changes were recorded in other histone fractions. Lower histone acetylation in the 21 day old pups suggest a reduction m the transcriptional activity due to fewer initiation sites for RNA polymerase. It may be concluded that thyroid hormone may stimulate transcription of specific genes by increasing the acetylation of nucleosomal histones.

Stepwise building of a 115-kDa macromolecular edifice monitored by electrospray mass spectrometry. The case of acetohydroxy acid isomeroreductase

The macromolecular complexes formed by the enzyme acetohydroxy acid isomeroreductase with NADPH, magnesium ions and the competitive inhibitor N-hydroxy-N-isopropyloxamate (IpOHA) were analysed by electrospray mass spectrometry. Each ligand was added successively to a protein solution, allowing the stoichiometry of the whole macromolecular edifice (115 583 Da) to be unambiguously determined. The combination of an electrospray ion source with the high mass range magnetic instrument used in the present studies proved to be a very powerful tool for characterizing, in a specific manner, the quaternary structures of proteins by single mass measurements.

Association of hepatitis C virus & hepatitis B virus in chronic liver disease

Hepatitis C virus (HCV) as a cause of chronic liver disease (CLD) was assessed by testing anti-HCV antibodies in the serum samples of 55 patients of chronic hepatitis (17), cirrhosis (32) and hepatocellular carcinoma (6). All the samples were also tested for the presence of HCV RNA by reverse transcription polymerase chain reaction (RT-PCR) using primers from the 5' non-coding region (NCR) and the relationship between the serological parameters and presence of HCV RNA was studied. The association of hepatitis B virus (HBV) with HCV in this group was evaluated by testing for the anti HBc antibodies (IgG and IgM separately) and HBsAg. The biochemical parameters and involvement of other risk factors were also studied. Twenty two (40%) patients were found to be HCV positive and 17 (77.3%) of these had evidence of infection or past exposure to HBV. On comparing the sensitivities of ELISA with that of PCR for the detection of HCV, we observed no significant difference between the two methods (P > 0.05, McNemar's test). Eighteen patients had no evidence of HBV or HCV infection. Our results indicate that HCV is next only to HBV in the causation of CLD. It is suggested that RT-PCR be used with antibody detection by ELISA for reliable detection of HCV infection.

Chemical modifications of the vasoconstrictor peptide angiotensin II by nitrogen oxides (NO, HNO2, HOONO)--evaluation by mass spectrometry

Nitric oxide (NO) and angiotensin II are natural regulators of blood pressure. Under aerobic conditions, NO is transformed into its higher oxides (N2O4, NO2, NO/NO2 or N2O3) and oxoperoxonitrate (currently named peroxynitrite) by coupling with superoxide. Previous studies have shown that these reactive nitrogen species should be involved in vivo in the transformation of cysteine and tyrosine into the corresponding nitrosothiol and 3-nitrotyrosine. In the present study, attention has been focused on the relative reactivities of HNO2, peroxynitrite, and NO in the presence of dioxygen, towards the arginine and tyrosine residues of the peptide angiotensin II. Nitration of the tyrosine residue is clearly the main reaction with peroxynitrite. By contrast, besides 20% of nitration of the tyrosine residue, NO in the presence of dioxygen leads to nitrosation reactions with the arginine residue similar to those observed with HNO2 at pH 5, possibly through the intermediate N2O3 reactive species. Angiotensin II is converted for the most part to peptides having lost either a terminal amine function or the whole guanido group, leading respectively to citrulline-containing angiotensin II or to a diene derivative. Identification established mainly by tandem mass spectrometry of peptidic by-products allows us to propose a cascade of nitrosations of all the amine functions of the arginine residue. Further in vivo studies show that transformations of the arginine residue in angiotensin II do not alter its vasoconstrictive properties, whereas nitration of the tyrosine residue totally inhibits them.

Detection of hepatitis C and E virus genomes in sera of patients with acute viral hepatitis and fulminant hepatitis by their simultaneous amplification in PCR

A study was undertaken to investigate the role of hepatitis C virus (HCV) and hepatitis E virus (HEV), either alone or together, in the causation of sporadic acute viral hepatitis (AVH) and fulminant hepatitis (FH) by simultaneous detection of their genomes in serum samples using the reverse transcription and nested polymerase chain reaction (RT-PCR). A total of 50 patients were enrolled in the study of which 34 had AVH and 16 had sporadic FH. The serum samples were first tested for hepatitis B surface antigen (HBsAg) and immunoglobulin (Ig)M antibodies against hepatitis A virus (HAV), hepatitis B core antigen (HBcAg) and HEV and also antibodies against HCV using commercially available enzyme-linked immunosorbent assay (ELISA) kits. All samples were then subjected to RT-PCR using primers for both HCV and HEV simultaneously in the same reaction mixture. Hepatitis C or hepatitis E was diagnosed when either the antibodies or PCR or both were positive for the respective viruses. Evidence of hepatitis C was present in six of the 34 (17.6%) cases of AVH and two out of 16 (12.5%) cases of FH. Four patients in the AVH group and one of the fulminant hepatic failure (FHF) group were found to be positive by PCR and the rest by serology. But as a sole aetiological agent, HCV infection was found in only one (2.9%) case of AVH and in none of the FHF cases. Evidence of HEV infection was found in 22/34 (64.7%) and 8/16 (50%) cases of AVH and FHF, respectively. Excluding co-infection with other viruses, HEV was found to be the sole aetiological agent in 15/34 (44.1%) of AVH and 7/16 (43.7%) cases of FHF. In five (10%) (four AVH and one FHF) of the 50 cases, evidence of infection with both HCV and HEV was present. But only in two of these five cases, genomes of both HCV and HEV were co-amplified. In seven (four AVH and three FHF) out of 50 (14%) cases, no known viral agent could be detected. Our results suggest that HEV is the most common aetiological agent for both acute viral hepatitis and fulminant hepatic failure and that HCV is a rare cause of acute liver diseases although along with other viruses, evidence of either present or past HCV infection may be present in a substantial number of cases. Furthermore, advanced-stage pregnancy appears to be a potential risk factor for HEV infection and high rate of mortality in women. The study suggests that the method of simultaneous amplification of both HCV and HEV genomes could reduce the time, labour and cost involved in diagnostic work up of acute liver disease patients.

Saponins from the stem bark of Filicium decipiens

Four new saponins have been isolated from the stem bark of Filicium decipiens and identified as 3-O-{beta-D-glucopyranosyl(1-->2)-beta- D-glucopyranosyl}-28-O-{[alpha-L-arabinopyranosyl(1-->2)-beta- D-xylopyranosyl (1-->6)]. [4-O-angeloyloxy-alpha-L-arabinopyranosyl(1-->2)-alpha-L- rhamnopyranosyl(1-->2)]}-beta-D-glucopyranosyl gypsogenic acid, 3-O-{beta-D-glucopyranosyl(1-->2)-beta-D- glucopyranosyl}-28-O-{[alpha-L-arabinopyranosyl(1-->2)- beta-D-xylopyranosyl(1-->6)] [4-O-angeloyloxy-alpha-L- arabinopyranosyl(1-->2)-alpha-L-rhamnopyranosyl(1-->2)]}-beta-D- glucopyranosyl medicagenic acid, 3-O-{beta-D-glucopyranosyl(1-->2)-beta-D- glucopyranosyl}-28-O-{[alpha-L-arabinopyranosyl(1-->2)] [beta-D-xylopyranosyl(1-->4)]alpha-L-rhamnopyranosyl(1-->2)-4-O-[3'- hydroxy-2'-methyl-butyroyloxy)-3-hydroxy-2-methyl-butyroyloxy++ +]-beta-D- fucopyranosyl} medicagenic acid and 3-O-beta-D-glucopyranosyl-28-O- {[alpha-L-arabinopyranosyl(1-->2)] [beta-D-xylopyranosyl(1-->4)] alpha-L-rhamnopyranosyl(1-->2)-4- O-[(3'-hydroxy-2'-methyl-butyroyloxy)-3-hydroxy-2-methyl-butyro yloxy]-beta- D-fucopyranosyl} zanhic acid. These structures were elucidated by analysis of 2D-NMR spectra and of electrospray ionization mass spectra.

DNA aneuploidy and infection of human papillomavirus type 16 in preneoplastic lesions of the uterine cervix: correlation with progression to malignancy

A microphotometric analysis of nuclear DNA ploidy and detection of human papillomavirus (HPV) type 16 DNA was carried out in 50 cases of mild, moderate and severe dysplasia of the uterine cervix along with an equal number of matched controls in order to understand their relative importance in malignant progression of the disease in women. Twenty-two (44.0%) cases of dysplasia showed an aneuploid DNA pattern while positivity for high risk HPV type 16 DNA was found in twenty-three (46.0%) cases. Thirty-four women with twice confirmed mild and moderate dysplasia have been followed up for 24 months. Follow-up data revealed that eight (72.7%) of the 11 patients having an aneuploid DNA pattern and positivity for HPV 16 progressed to carcinoma in situ (CIS) compared to only one (4.4%) case which was positive for HPV 16 with a non-aneuploid DNA pattern. This suggests that a combined analysis of infection of high risk HPV type 16 and aneuploid DNA pattern may serve as an important biological indicator to predict the potential of precancerous lesions of the uterine cervix for progression to malignancy.

Influences of pH and in-source collisional energy on the cationization of insulin

The influence of pH and in-source collisional energy variations on interactions between a model protein and sodium or cesium ions has been studied by electrospray ionization mass spectrometry. Behavioural differences regarding cationization have been observed and seem to be linked to the neutral of deprotonated form of carboxylic acids. At pH 8, cesium and sodium adducts totally disappear in the case of highest charge states. Increasing the cone voltage leads to an overall change loss that can be attributed to the loss of cesium, sodium ions and even protons.

Lipopeptides with improved properties: structure by NMR, purification by HPLC and structure-activity relationships of new isoleucyl-rich surfactins

The biosynthesis of bacterial isoleucyl-rich surfactins was controlled by supplementation of L-isoleucine to the culture medium. Two new variants, the [Ile4,7]- and [Ile2,4,7]surfactins, were thus produced by Bacillus subtilis and their separation was achieved by reverse-phase HPLC. Amino acids of the heptapeptide moiety were analysed by chemical methods, and the lipid moiety was identified by beta-hydroxy anteiso pentadecanoic acid by combined GC/MS. Sequences were established on the basis of two-dimensional NMR data. Because conformational parameters issuing from NMR spectra suggested that the cyclic backbone fold was globally conserved in the new variants, structure-activity relationships were discussed in details on the basis of the three-dimensional model of surfactin in solution. Indeed, both variants have increased surface properties compared with that of surfactin, and this improvement is assigned to an increase of the hydrophobicity of the apolar domain favouring micellization. Furthermore, the additional Leu-to-Ile substitution at position 2 in the [Ile2,4,7]surfactin leads to a substantial increase of its affinity for calcium, when compared with that of [Ile4,7]surfactin or surfactin. This effect is assigned, from the model, to an increase in the accessibility of the acidic side chains constituting the calcium binding site. Thus, the propensities of such active lipopeptides for both hydrophobic and electrostatic interactions were improved, further substantiating that they can be rationally designed.