The status of the p53 gene in human papilloma virus positive or negative cervical carcinoma cell lines

We have analyzed p53 gene alterations in five cervical cancer derived cell lines. Two of the five cervical cancer cell lines, HTB31 (C-33A) and 32 (HT-3), harbored missense mutations in codons 273 and 245 respectively, whereas the other three tumor cell lines, HTB33 (ME180), 34 (MS751) and 35 (SIHA), did not reveal any mutation in the p53 coding sequence spanning codons 126-307. Although all the tumor cell lines express comparable levels of p53 RNA, only HTB31 and HTB32 contain high or detectable levels respectively of p53 protein. The other three tumor cell lines, where neither p53 mutation nor the expression of p53 protein could be detected, were found to harbor human papilloma virus (HPV) 16 or 18. The inactivation of the wild-type p53 function resulting from a missense mutation, or the lack of detectable wild-type p53 protein due to the translational/post-translational deregulation of p53 protein levels may be the contributing factor in the tumorigenicity of these five cases of cervical cancer. The lack of detectable p53 protein in HTB33, 34 and 35 associates with the presence of either HPV16 or -18 in these cell lines.

A survey of chronic bronchitis among brassware workers

A stratified random sample of 580 workers aged between 18 and 50 years representing each sub-occupation in the brassware industry was studied for the prevalence of chronic bronchitis in relation to occupational and environmental factors. The findings were compared with those obtained in a reference group (N = 131) belonging to similar socio-economic status and unexposed to a dusty environment. Although the exposed group showed higher prevalence of chronic bronchitis in comparison to that observed in the controls (10.5 vs 5.3%), the difference was not significant at the 5% level. It was observed that the workers engaged in non-dusty occupations such as brass sheet cutting and engraving showed the lowest prevalence of the disease (5.0%) while those engaged in the dusty occupations viz., casting, soldering, electroplating and polishing showed the highest prevalence (12.0%). The smoking adjusted odds ratios calculated in various sub-occupations showed the highest risk of developing chronic bronchitis among the polishers (2.74). Though the risk in other occupational sub-groups was double, it did not attain a level of significance. The smoking adjusted odds ratios in relation to length of exposure showed that the risk was significantly higher among the workers exposed for over 10 years compared to those who worked for less than 10 years in the grinding, soldering and brass ingot making operations. The study thus showed a dose-response relationship between length of exposure and chronic bronchitis while effect of age on the disease was not discernible probably due to the small number of cases and the young age of the study group. The concentration of various metals in the air samples drawn from the work environment where main processes were in operation, was low compared to the prescribed level by ACGIH.

Quantitative evaluation of the growth of established cell lines on the surface of collagen, collagen composite and reconstituted basement membrane

As a step in the development of a system for assessing growth of human urothelium and transitional cell carcinoma, the growth of two established cell lines on collagen-based membranes has been evaluated. HT1080 (metastatic human fibrosarcoma) and WI38 VA13 (virus-transformed human fibroblasts) were grown on substrates of collagen, collagen/hyaluronic acid or chondroitin sulphate and reconstituted basement membrane (Matrigel). Cell growth was quantified using a new fluorimetric assay utilizing carboxyfluorescein diacetate. There were differences in morphology between cells grown on collagen and those grown on polystyrene. There were, however, no differences in growth of the WI38 VA13 cells on collagen compared with polystyrene, but growth of the HT1080 cells was increased on membranes of collagen/2.5% hyaluronic acid and collagen/5% chondroitin sulphate, and decreased on Matrigel. Adequate growth on collagen substrates is dependent on cell line. The fluorimetric assay used was suitable for quantifying cell growth on such substrates.

Detection of both mutant and wild-type p53 protein in normal skin fibroblasts and demonstration of a shared 'second hit' on p53 in diverse tumors from a cancer-prone family with Li-Fraumeni syndrome

Germline transmission of mutant p53 gene in cancer-prone families with Li-Fraumeni syndrome has revealed a new role for p53 in the genetic predisposition to cancer. The studies reported here focus on the analysis of the expression of normal and mutant p53 RNA and protein in germline configuration and demonstrate that normal skin fibroblasts derived from members of a family with Li-Fraumeni syndrome express mutant p53Gly----Asp(245) protein and RNA at levels similar to the wild-type p53. Thus, these fibroblasts represent a unique biological system in which endogenous promoters are utilized for the expression of both mutant and normal p53. We have further extended the earlier observations on the analysis of mutant p53 with a limited number of tumors derived from individuals with Li-Fraumeni syndrome. Tumors arising from two different germ layers in four individuals in a single family clearly exhibited the loss of the wild-type allele and the retention of the mutant allele observed in the normal skin fibroblasts derived from the same individuals. These observations further support the notion that germline p53 mutation plays a key role in the tumorigenesis of individuals with Li-Fraumeni syndrome.

Effect of styrene on testicular enzymes of growing rat

Effect of styrene (100 or 200 mg/kg body wt/day) for 60 days was observed on testicular enzymes of postnatally maturing rats. A significant decrease in epididymal spermatozoa count was observed only at 200 mg/kg body weight dose. Activities of testicular sorbitol dehydrogenase and acid phosphatase decreased while activities of lactate dehydrogenase, beta-glucuronidase, glucose-6-phosphate dehydrogenase, and gamma-glutamyl transpeptidase significantly increased only in animals exposed to styrene at a dose of 200 mg/kg body weight. The results suggest that exposure to high dose of styrene during developmental period alters the activities of enzymes associated with specific cell type of testis.

Conformational studies on cimetidine and ranitidine by PCILO calculations and NMR spectroscopy

The conformational characteristics of two H2-receptor antagonists, cimetidine and ranitidine, have been investigated by quantum mechanical PCILO method and the results indicate a folded conformation for cimetidine stabilized by intramolecular hydrogen bonding and an extended backbone conformation for ranitidine. NMR investigations carried out on these two drugs in solution, however, indicate a predominance of an extended conformation for both the molecules. The significance of this result has been discussed in terms of the activity of these two drugs. Besides these studies, NMR experiments have also been carried out on the drugs incorporated into the lipid bilayers to investigate the drug-lipid interaction. The results from this study suggest that the hydrophobic portion of the drugs is buried in the hydrophobic hydrocarbon chains of the lipid bilayer, while the terminal hydrophilic end of the drug lies at the lipid-water interface.

Induction of Xenopus oocyte meiotic maturation by the dbl oncogene product

The dbl oncogene was originally identified by transfection of NIH3T3 cells with DNA from a human diffuse B-cell lymphoma. The dbl oncogene product is a cytoplasmic phosphoprotein distributed between the cytosolic and cytoskeletal matrix-associated membrane fractions. Nucleotide sequence analysis has indicated that the predicted dbl product is very hydrophilic with no detectable similarity to known oncogene products. We have more recently discovered that a region of dbl essential for its transforming activity shows significant sequence similarity to a yeast cell cycle gene, CDC24, which is involved in cell polarity and bud formation in the division cycle of Saccharomyces cerevisiae. This sequence similarity suggests a possible role for dbl in cell division. We report here that the dbl oncogene product is able to induce maturation of Xenopus oocytes. Germinal vesicle breakdown (GVBD) was observed when oocytes were microinjected with the soluble fraction of SF9 insect cells infected with a dbl recombinant baculovirus as well as with the in vitro-transcribed dbl mRNA. Moreover, extracts of oocytes microinjected with dbl mRNA showed activation of H1 histone kinase activity. These findings define a new biologic activity of the dbl product and provide the opportunity to analyse dbl interactions with other components of signaling pathways involved in oocyte maturation.

Occupational morbidity among children employed in brassware industry

Fifty seven male children between ages of 10-16 years engaged in the brassware industry at Moradabad in Northern India were studied for occupational morbidity. The finding were compared with those obtained in the children (n = 29) engaged in other ancillary units which did not involve exposure to the metal fumes and dust in their work environment. The study showed a high prevalence of respiratory morbidity in the children engaged in the main units in comparison to those employed in the ancillary units (40.3 vs 27.6%; p less than 0.05). This was associated with significantly higher prevalence of pulmonary impairment in the former group (21.0%) particularly demonstrating restrictive ventilatory abnormality (10.5%) followed by bronchial obstruction (7.0%). The high respiratory morbidity may be attributed to chronic exposure to the fumes and dust of the metals such as nickel, chromium and cadmium. The children employed in the ancillary as well as in the main units showed high prevalences of musculo-skeletal disorders (27.6 and 22.8%) which may be caused by sustained faulty posture adopted during work and physical stress.

Altered activity of hepatic mixed function oxidase, cytochrome P-450 and glutathione-S-transferase by styrene in rat fetal liver

The effect of in utero exposure to styrene 200 or 400 mg/kg/day orally was studied on mixed function oxidase activities, cytochrome P-450 and glutathione contents and on the glutathione-S-transferase activity in rat fetal liver. Activities of aminopyrene-N-demethylase, aniline hydroxylase, aryl hydrocarbon hydroxylase and the cytochrome P-450 contents were significantly decreased in the fetal liver. A significant decrease in the glutathione contents and the glutathione-S-transferase activity was also observed in the liver of the fetuses of styrene exposed animals. The current data show that prenatal exposure to styrene could adversely affect the developing biotransformation process.

Accessing NCI's SEER cancer data base with SeerQuery and CD-ROM

The National Cancer Institute operates the Surveillance, Epidemiology, and End Results (SEER) cancer data base. SEER data are obtained from participating population-based registries that monitor cancer incidence and patient survival in a representative 10 percent sample of the general population. The data cover all cancers (except superficial skin cancers) in the defined regional populations. SeerQuery is a personal computer program for accessing that data on IBM-compatible personal computer compact diskettes in read-only memory (CD-ROM) form. SeerQuery facilitates rapid access to cancer data at minimal cost and effort to the user. SeerQuery is menu-driven, enabling physicians and other health care professionals to query the data base directly. They can use the data to determine cancer frequency, perform cross-tabulation, determine incidence, and calculate survival using such variables as primary cancer site, histologic type, stage, sex, age, and race. The comprehensive data base lacks many selection biases that are inherent in data reported from other sources. SeerQuery has applications in professional education and in cancer control program planning and resource allocation.

Mobilization of cadmium by liposome-encapsulated meso-2,3-dimercaptosuccinic acid in pre-exposed mice

meso-2,3-Dimercaptosuccinic acid (DMSA) treatment in free of liposome-encapsulated form was given to mice pre-exposed to cadmium as CdCl2 (2 intraperitoneal injections; 0.5 mg Cd/kg along with 5 microCi 109CdCl2 in 4 ml volume within 24 h). Both treatments removed cadmium from liver, spleen, testis and blood with liposomal DMSA exhibiting higher efficacy in mobilizing cadmium not only from whole organs but also from liver proteins. It also resulted in higher excretion of cadmium via urine as compared with free DMSA or saline treatment. Whereas this treatment eliminated significantly higher amounts of cadmium via the fecal route throughout the period examined, free DMSA responded only 48 h after treatment and was less effective. The results suggest mobilization of cadmium from intracellular sites of deposition. However, DMSA in the dose administered (24 mumol/kg i.v.) in either form was ineffective in decorporating cadmium from the kidney, the critical organ in cadmium intoxication.

Three-dimensional reconstruction of the 70S Escherichia coli ribosome in ice: the distribution of ribosomal RNA

A reconstruction, at 40 A, of the Escherichia coli ribosome imaged by cryo-electron microscopy, obtained from 303 projections by a single-particle method of reconstruction, shows the two subunits with unprecedented clarity. In the interior of the subunits, a complex distribution of higher mass density is recognized, which is attributed to ribosomal RNA. The masses corresponding to the 16S and 23S components are linked in the region of the platform of the small subunit. Thus the topography of the rRNA regions responsible for protein synthesis can be described.

Effect of di(2-ethylhexyl)phthalate on 17 beta-hydroxysteroid dehydrogenase activity in testis of rat

The purpose of the present study was to demonstrate the effects of di(2-ethylhexyl)phthalate (DEHP) on 17 beta-hydroxysteroid dehydrogenase (17 beta-HSD) activity in the testis of adult rat. DEHP was administered to rats by gavage at doses of 250, 500, 1000 and 2000 mg/kg body wt./d for 15 days. The absolute and relative weights of testes were significantly decreased only at the highest dose level. The activity of 17 beta-HSD was decreased in animals exposed to 1000 and 2000 mg/kg of DEHP. The data suggest that DEHP may affect testicular steroidogenesis adversely.

Long-term effects of soldering fumes upon respiratory symptoms and pulmonary function

To evaluate the long-term effect of soldering gases and fumes, and of cigarette smoke on lung function, and the prevalence of respiratory symptoms, a comparative study of spirometric measurements in 57 solderers engaged in acetylene gas soldering of brassware joints in the brass industry (mean exposure: 12.4 +/- 1.1 years) and in 131 controls was performed. The two groups were similar in age, height, smoking habits and social class. The prevalence of respiratory symptoms in the solderers did not differ significantly from that in the unexposed controls (59.6 vs 56.4%). However, solderers who smoked showed higher prevalence of respiratory symptoms than those who did not smoke; a similar trend was observed in the controls. The study failed to demonstrate any association between the respiratory symptoms and length of exposure. The respiratory status of the solderers was unaffected as the results of spirometric measurements of lung function did not show any significant differences between the exposed and the control groups, indicating the absence of an additive effect of cigarette smoking and exposure to soldering fumes.

Modulation of liposomal lipid peroxidation in presence of nickel by incorporation of alpha-tocopherol in the bilayer

alpha-Tocopherol is a well-known membrane associated chain-breaking phenolic antioxidant which functions as a trap for peroxyl and other free radicals and thus inhibits lipid peroxidation of membranes. Antioxidative effect of alpha-tocopherol when incorporated in liposomes was examined by the generation of Thiobarbituric acid (TBA) reacting species in the presence of nickel. The incorporation of alpha-tocopherol in the lipid bilayer resulted in the enhancement of lipid peroxidation at low concentration (1.0 mg) but at higher concentration (2.5 and 5.0 mg) considerably reduced the enhancement in lipid peroxidation of liposomes in the presence of nickel. When alpha-tocopherol was added (unincorporated) to liposomes in the presence of nickel, enhancement in lipid peroxidation was observed compared to nickel alone. Thus the antioxidative effect of alpha-tocopherol in the liposomes may depend on its mode of incorporation in the lipid bilayer.

Germ-line transmission of a mutated p53 gene in a cancer-prone family with Li-Fraumeni syndrome

Tumour suppressor genes, whose usual function seems to be controlling normal cell proliferation, have been implicated in many inherited and sporadic forms of malignancies Much evidence supports the concept of tumour formation by loss-of-function mutations in suppressor genes, as predicted by the two-hit model of Knudson and DeMars. The suppressor gene, p53, is affected in such a manner by numerous mutations, which occur in a variety of human tumours. These mutations usually represent the loss of one allele and the substitution of a single base in the other. We have now analysed the p53 gene in a family affected by Li-Fraumeni syndrome, a rare autosomal dominant syndrome characterized by the occurrence of diverse mesenchymal and epithelial neoplasms at multiple sites. In some instances the neoplasms seem to be related to exposure to carcinogens, including ionizing radiation. The Li-Fraumeni family that we studied had noncancerous skin fibroblasts (NSF) with an unusual radiation-resistant phenotype. DNA derived from the NSF cells of four family members, spanning two generations, had the same point mutation in codon 245 (GGC----GAC) of the p53 gene. This mutation leads to substitution of aspartic acid for glycine in one of the regions identified as a frequent target of point mutations in p53. The NSF cell lines with the mutation also retained the normal p53 allele. This inherited p53 mutation may predispose the members of this family to increased susceptibility to cancer.

Glycolysis and Entner-Doudoroff pathways in Halobacterium halobium: some new observations based on 13C NMR spectroscopy

13C NMR was used to study glucose metabolism in intact cells of Halobacterium halobium. Spectra of glucose grown cells incubated with [1-13C] glucose indicate the presence of gluconate as the initial product. The existence of glycolytic pathway is also indicated. In the extracts of these cells an NADP dependent glucose dehydrogenase was detected. Galactose grown cells failed to metabolise glucose but exhibited glucose dehydrogenase activity although about 20-50% less than that for glucose grown cells. Possible explanations of these experiments are discussed.

Facial clefting in Kuwait and England: a comparative study

A retrospective study of all new cases of facial clefts seen between January 1985 and December 1987 was carried out at the lbn Sina Hospital, Kuwait, and West Midlands Regional Plastic and Jaw Surgery Unit at Wordsley Hospital, Stourbridge, England; 234 arab children in Kuwait and 181 white Caucasian children in the West Midlands were studied. Despite vast differences in racial characteristics, environment and customs the pattern of clefting was very similar in the two groups. The incidence of clefts was calculated for the two regions and this demonstrated an increase in the incidence of cleft lip and palate (CL/P and CP) in the West Midlands since the last study was reported from this region in 1953.

Computer-automated structure evaluation of gastric antiulcer compounds: study of cytoprotective and antisecretory imidazo[1,2-a]pyridines and -pyrazines

A quantitative structure-activity relationship study of a set of antiulcer compounds has been performed using the computer-automated structure evaluation methodology. Computer-automated structure evaluation identified cyanomethyl and hydroxymethyl functionalities, substituted in the 3-position of imidazo[1,2-a]pyridine and -Pyrazine, as descriptors relevant to antisecretory activity. The phenoxy group at the 8-position and the methyl group at the 2-position were shown to be sterically involved in the activity. A parabolic relationship was observed between the antisecretory activity and the logarithm of the partition coefficient of the compounds. Thus, hydrophobicity is found to be a necessary criterion for the inhibition of acid secretion. An attempt has been made to provide a rationale for designing a more potent antiulcer agent in this series of congeneric compounds.