Phagocytic response in rats following chemical sympathectomy with 6-hydroxydopamine. Wistar rats were injected i.p. at 2, 4 and 7 days after birth with 6-OHDA (50 mg/kg). At maturity the phagocytic response of neutrophils was elicited by Escherichia coli (EC) lipopolysaccharide (LPS). Before and at 3 and 24 hours after the injection of LPS (1 mg/kg i.v.) the leucocyte (L) and neutrophil (N) counts and the phagocytic activity of N in blood against EC have been tested. In controls (6 female and 7 male rats) the number of N increases significantly after 3 h. The L and N responses were similar in controls and in treated (SyX) animals. In controls the percentage of phagocytic active N(PA) and the number of bacteria incorporated by 100 n(IB) shows significant rises at 3 h. In the SyX groups (7 females and 7 males) PA does not increase; the IB decreases significantly in females at 3 and 24 h. In conclusion chemical sympathectomy depresses the PR to LPS in rats; this suggests a stimulatory action of the sympathetic system on the phagocytic immune reaction. An immunological sexual dimorphism exists.


The stimulation of fibronectin synthesis by high peak power electromagnetic energy (Diapulse). The effect of Diapulse therapy (pulsed electromagnetic energy of 27.12 MHz frequency) on post-operative wound healing and plasma fibronectin concentration is investigated. Patients treated with Diapulse, locally and over hepatic area present higher fibronectin levels starting 3d day after surgery. These higher values correlate well with a clear improvement of wound healing processes.


The action of Cu2+ on the frog epithelium. The mechanism of action of Cu2+ when applied to the external side of the frog skin preparation was investigated. Cu2+ acts most probably on the external barrier of this preparation, since it increases the transport pool of Na proportionally to the increase in the short-circuit current (I(sc)). Cu2+ does not open new routes for the Na+ entry since the stimulated I(sc) is still completely abolished by amiloride. The I(sc) dependence of Na concentration in the external medium is modified by cooper, since the Ksm value increases in addition to changes in I(sc).


The MSH-like activity of pineal hormone E5 in vivo and in vitro experiment. Further experiments have revealed that the polypeptidic hormone E5 has a MSK-like effect, as experimentally demonstrated on the frog skin. In Rana esculenta, 30-120 min after a subcutaneous injection of 0.2 mg purified E5B or E5P/100 g b.w., the skin blackened and the effect lasted for about two hours. A comparable effect was induced by incubating the fragment of frog abdominal skin with a similar solution of E5. This MSK-like effect appears to be identical upon mammalian melanocytes in C57/B16 mice strain valves in vitro experiment. The results obtained indicate that pineal gland can influence melanocyte activity directly and suggest the possible implication in such pathological conditions as melanomas, vitiligo, etc.


Ethnic differences in the lung cancer risk associated with smoking. Mortality trends and ecological data strongly suggest that the lung cancer risk associated with smoking is greater among Hawaiians than among the other ethnic groups in Hawaii. The authors combined data from two consecutive population-based case-control studies to formally test this hypothesis among 740 cases and 1616 controls. A multiple logistic regression analysis adjusting for pack-years of smoking, occupation, education, and age revealed that Hawaiian, Filipino, and Caucasian male smokers were at 121%, 53%, and 46% greater risk for lung cancer than Japanese male smokers. These risk differences were statistically significant, were consistent across sexes and histological types, and were not explained by the type of cigarettes, the level of inhalation, or by cholesterol or beta-carotene intake. Additionally, an increased lung cancer risk unrelated to smoking was observed among Chinese women. The possibility that other dietary antioxidants and/or genetic risk factors are responsible for these ethnic differences needs to be investigated.


Nicotine and cotinine in the cervical mucus of smokers, passive smokers, and nonsmokers. Although epidemiological studies suggest that cigarette smoking is a risk factor for cervical cancer, further evidence is required to document the biological plausibility of this relationship. This study obtained cervical mucus, using a cervical flush technique, from 50 patients in a neoplasia clinic. Nicotine was detected in the cervical mucus of all 25 smokers and cotinine in the mucus of 84% of the smokers; nicotine and cotinine levels were correlated (P < or = 0.10) with both the number of cigarettes usually smoked and the number smoked in the last 24 h. Nicotine and cotinine levels for passive smokers and nonexposed women were much lower than for women who currently smoked, with little difference found between the nonsmoking women who did and did not report passive smoke exposure. In the one woman who reported smokeless tobacco use, both nicotine and cotinine were detected at much higher levels than for other nonsmoking women. These results indicate that tobacco constituents do indeed reach the uterine cervix, suggesting that they could play a causal role in the development of cervical cancer.


Polyamine contents in rectal and buccal mucosae in humans treated with oral difluoromethylornithine. Difluoromethylornithine (DFMO) is an investigational chemopreventive agent that inhibits ornithine decarboxylase (ODC) activity, lowers cellular polyamine concentrations, and decreases cell proliferation in vivo and in vitro. In five subjects we have compared the polyamine concentrations in rectal mucosal biopsies and in exfoliated buccal mucosal cells (EBM) before and after DFMO treatment to assess the suitability of EBM as an easily accessible marker tissue for DFMO suppression of polyamine synthesis in the rectal mucosa. One month of 3 g/m2/day of DFMO treatment caused a statistically significant decrease in putrescine and spermidine concentrations in rectal mucosa biopsy specimens but not in EBM samples. ODC activity in EBM was high (approximately 1 mumol/min/mg protein), resistant to DFMO inhibition (Ki = 4200 microM), dependent on GTP concentration (maximal at 0.1 mM), and was reduced concomitantly with bacterial concentration by antiseptic mouthwashing. Bacteria adherent to EBM were visible by electron microscopy. Forty bacterial colonies/ng protein were culturable from washed EBM samples. Oral bacteria preclude the use of EBM samples as a marker tissue of DFMO effect in the rectal mucosa, but oral DFMO therapy is effective in depleting polyamines in rectal mucosa.


Risk factors for stomach cancer in sixty-five Chinese counties. Stomach cancer mortality data were compared with dietary and biochemical data from 65 Chinese counties to provide clues to reasons for the marked geographic variation of stomach cancer mortality rates in China. Sex-specific correlation and multivariate regression analyses showed significant positive associations with consumption of salted vegetables and eggs, prevalence of antibodies to Helicobacter pylori, and levels of plasma albumin; and significant negative associations with intake of green vegetables and levels of plasma selenium and beta-carotene. Limitations of ecological data preclude causal inferences, but these findings suggest factors that may contribute to making stomach cancer the leading cause of cancer death in China and other countries.


Identification of women at increased risk for breast cancer in a population-based screening program. A multivariate model to assess breast cancer risk was developed by Gail et al. (M. H. Gail, L. A. Brinton, D. B. Byar, D. K. Corle, S. B. Green, C. Schairer, and J. J. Mulvihill, J. Natl. Cancer Inst., 81: 1879-1886, 1989) based on data analysis of the Breast Cancer Detection and Demonstration Project. We evaluated the model's usefulness for assigning women to risk groups for counseling and follow-up by applying it to the 1987 Texas Breast Screening Project data. We identified 3165 women with one or more first-degree relatives affected with breast cancer. The mean risk score for the group was 3.3 (range, 2.7-11.8), indicating a greater than 3-fold elevated risk. The mean risk score for the remaining 27,439 women without affected first-degree relatives was 1.5 (range, 1.24-3.2). Risk perception was found to be a motivator for participation. Women with a risk score greater than 5 perceived themselves to be at high risk for breast cancer. The perception of risk was related to the type of affected first-degree relatives: 80.0% of the women with three affected first-degree relatives and 71.5% of women whose mother and sister were both affected with breast cancer perceived themselves to be at high risk. The Gail model is potentially useful in the clinical setting because women at high risk for breast cancer can be entered into etiological studies, enrolled in primary prevention trials, or referred to programs seeking to improve compliance with screening mammography. The Gail model needs validation, but it is useful for estimating the risk of breast cancer in large populations.


Expression of the CYP1A1 gene in peripheral lymphocytes as a marker of exposure to creosote in railroad workers. We have conducted a pilot study to assess levels of cytochrome CYP1A1 gene expression in human peripheral lymphocytes as a molecular biomarker assay for polycyclic hydrocarbon exposure. Basal and 3-methylcholanthrene-induced levels of gene expression were measured by standard slot-blot mRNA analyses in mitogen-stimulated cultures of peripheral blood lymphocytes from creosote-exposed railroad workers and unexposed control subjects. Dermal and inhalation exposure of workers to creosote may vary substantially as a function of working conditions related to temperature. Therefore, blood specimens were collected from separate groups during the winter, fall, and summer. Basal and induced CYP1A1 gene expression levels were not elevated in workers from any of the three seasonal studies. However, induced/basal (inducibility) CYP1A1 mRNA ratios from workers sampled in the summer (when actual exposures were greatest) were significantly higher when compared to those of controls (P < 0.01). These studies demonstrate the potential usefulness of specific gene expression assays in human peripheral lymphocytes for the assessment of carcinogen exposure in human populations.


Folate, vitamin C, and cervical intraepithelial neoplasia. A case-control study was designed to assess the relationship between cervical intraepithelial neoplasia (CIN) and folate in serum, red blood cells, and diet. The association between CIN and dietary vitamin C was also investigated. Cases were selected from women with biopsy-confirmed CIN. Controls were age-, race-, and clinic-matched women with normal cervical (Pap) smears. Study participants completed self-administered food frequency (n = 100 matched pairs) and health (n = 102 matched pairs) questionnaires. Fasting venous blood samples were collected for serum (n = 98 matched pairs) and red cell (n = 68 matched pairs) folate assays. Conditional logistic regression models were used to estimate crude odds ratios and odds ratios adjusted for smoking, income, number of sexual partners, frequency of cervical smear, use of spermicidal contraceptive agents, history of genital warts, and Quetelet index. Dietary intake variables were adjusted for total energy intake prior to logistic regression. A protective effect of red cell folate was evident with adjusted odds ratios (95% confidence intervals) of 0.1 (0.0-0.4), 0.6 (0.2-2.0), and 0.5 (0.2-1.9) for those in quartiles 4 (highest), 3, and 2 compared to quartile 1 (lowest). Supporting evidence for the protective effect of folate was provided by inverse associations between CIN and folate in both serum and diet. An inverse association was also found between CIN and dietary vitamin C with adjusted odds ratios (95% confidence intervals) of 0.2 (0.0-0.7), 0.6 (0.2-1.6), and 0.6 (0.2-1.8) for those in quartiles 4, 3, and 2, respectively, compared to quartile 1. These findings support dietary recommendations, such as those of the American Cancer Society, the National Cancer Institute, and the U.S. Dietary Guidelines, which allow for adequate intake of folate and vitamin C, both of which are found in good quantity in fruits and vegetables. Increased consumption of legumes and whole grains is also in accord with current dietary recommendations, and both of these types of foods are good sources of folates.


Epidemiological models of carcinogenesis: the example of bladder cancer. Epidemiological studies have clearly shown that smokers have an increased risk of bladder cancer. Chemical, biochemical, and molecular investigations indicate that such risk might be due to aromatic amines which are present in tobacco smoke. In particular, collaborative studies have shown that smokers have increased levels of hemoglobin-4-aminobiphenyl adducts in their blood and that these levels show a dose-response relationship and an association with the most carcinogenic variety of tobacco, air-cured or black tobacco. Adduct concentrations were also modulated by the genetically based slow acetylator phenotype. In addition, investigations in dogs and humans have described a DNA adduct in bladder biopsies and in exfoliated bladder cells that is a derivative of 4-aminobiphenyl. This paper summarizes the epidemiological, biochemical, and molecular evidence concerning the possible mechanisms of bladder cancer induction in smokers and in occupationally exposed workers. The case of bladder cancer is an example of integration between epidemiological studies, mathematical modeling, and laboratory investigations aiming at the elucidation of mechanisms of carcinogenesis.


HLA and multiple myeloma among black and white men: evidence of a genetic association. To evaluate the possibility that genetic factors contribute to the excess rates of multiple myeloma among blacks, serological typing of human leukocyte antigens (HLA) was conducted for black and white male patients and controls who participated in a large population-based case-control interview study. Forty-six black cases, 88 black controls, 85 white cases, and 122 white controls were typed for the Class I antigens (HLA-A, -B, -C) and for the Class II antigens (HLA-DR, HLA-DQ). Black cases had significantly higher gene frequencies than black controls for Bw65, Cw2, and DRw14, while white cases had higher gene frequencies than white controls for A3 and Cw2 and blanks at the DR and DQ loci. Further analysis of the association between Cw2 and multiple myeloma revealed relative risks of 5.7 (95% confidence interval = 1.5-26.6) and 2.6 (95% confidence interval = 1.0-7.2) for blacks and whites, respectively. The frequency of Cw2 in black and white controls was similar. These findings suggest that the Cw2 allele enhances the risk of myeloma in blacks and whites but do not explain the higher incidence of this cancer among blacks. The study also suggests that undefined DQ antigens may play an etiological role, supporting the need for further research into the immunogenetic determinants of myeloma.


Is histological subtype a marker for environmental exposures in acute myelogenous leukemia? The association between occupational and other environmental exposures was evaluated in 60 acute myelogenous leukemia cases and controls. Odds ratios and 95% confidence intervals for prior cytotoxic therapy and benzene exposure, adjusted for age, sex, and race by logistic regression, were 3.7 (0.7, 19.9) and 2.6 (0.4, 15.2), respectively. No other work-related associations, including employment in electrical occupations, were present. Other associations were suggestive but may have been due to biases in control selection or small numbers of subjects. The risks for prior cytotoxic therapy (odds ratio = 10.2) and benzene exposure (odds ratio = 11.4) were concentrated in 13 patients with French-American-British M4 leukemia; no environmental exposures were associated with French-American-British subtypes M1 and M2. These findings support the concept that French-American-British histological subtypes of AML may have different etiologies.


A prospective comparison of prostate cancer at autopsy and as a clinical event: the Hawaii Japanese experience. Prostate cancer was diagnosed in life among 274 of 8006 (3.6%) members of a cohort of Japanese men in Hawaii between 1965 and 1990. Only 55 (20%) of the 274 diagnosed cases died with prostate cancer, and they accounted for only 2% of the 2893 deaths that occurred among the men during this period. None of the 61 men whose tumor was found incidentally to a transurethral resection died as a result of this cancer, while it was the cause of death of 9 of 106 (8%) men with clinical cancer localized to the prostate. Forty-six of the 107 (43%) men with more extensive disease at the time of diagnosis died from prostate cancer. Step sectioning of the prostate identified prostate cancer in 80 of 293 (27%) autopsied Hawaii Japanese men who died after 50 years of age, reaching a frequency of 63% (10 of 16) among men over 80 years of age. The volume of 48 (60%) of these cancers was less than 150 mm3. These small tumors would probably not have been discovered in a screening program. Tumors larger than 1000 mm3 would probably be discovered using modern diagnostic procedures but were found in only 13 (4.4%) of the autopsied men. It is likely that a screening program to detect and treat such large, unsuspected tumors in this population would have had little impact upon the already low proportion of deaths due to prostate cancer among these Japanese men.


Levels of colorectal ornithine decarboxylase activity in patients with colon cancer, a family history of nonpolyposis hereditary colorectal cancer, and adenomas. Ornithine decarboxylase (ODC), a key enzyme in mammalian polyamine biosynthesis, has been proposed to be a marker of colonic epithelial cell proliferation and risk for colorectal cancer. We investigated the basal levels of ODC activity in sigmoid and rectal mucosae, and basal and tumor promoter 12-O-tetradecanoylphorbol-13-acetate-induced levels of skin ODC activity in individuals with a personal history of colon cancer (n = 9 colon; n = 58 skin), a family history of nonpolyposis hereditary colorectal cancer (n = 49; n = 42), adenomas (n = 16; n = 40), and healthy, family history-negative control subjects (n = 40; n = 79). Using a fresh tissue assay and samples obtained after a standard colon lavage preparation, colon mucosal ODC levels ranged from 0 to 192 pmol/mg/h (sigmoid, 0-163 pmol/mg/h; mean, 36 +/- 32 pmol/mg/h; rectum, 0-192 pmol/mg/h; mean, 35 +/- 32 pmol/mg/h). No differences among the four groups of subjects were found for either colon or skin ODC levels, and there were no sex differences overall or in any group. These results are not compatible with the suggestion that ODC levels are a useful marker of risk for colorectal cancer.


Estimation of interhemispheric dynamics from simple unimanual reaction time to extrafoveal stimuli. This essay reviews research on interhemispheric transfer time derived from simple unimanual reaction time to hemitachistoscopically presented visual stimuli. Part 1 reviews major theoretical themes including (a) the significance of the eccentricity effect on interhemispheric transfer time in the context of proposed underlying neurohistological constraints; (b) the significance of gender differences in interhemispheric transfer time and findings in dyslexics and left-handers in the context of a fetal brain testosterone model; and (c) the significance of complexity effects on interhemispheric transfer time in a context of "dynamic" vs. "hard-wired" concepts of the underlying interhemispheric communication systems. Part 2 consists of a meta-analysis of 49 published behavioral experiments, in view of drawing a portrait of the best set of experimental conditions apt to produce salient, reliable, and statistically significant measures of interhemispheric transfer time, namely (a) index rather than thumb response, (b) low rather than high target luminance, (c) short rather than prolonged target display, and (d) very eccentric rather than near-foveal stimulus location. Part 3 proposes a theoretical model of interhemispheric transfer time, postulating the measurable existence of fast and slow interhemispheric channels. The proposed mechanism's evolutionary adaptive value, the neurophysiological evidence in its support, and favorable functional evidence from studies of callosotomized patients are then presented followed by proposals for critical experimental tests of the model.


Prospective study of Lewis antigen alterations in the gastric precancerous process. A prospective study with two gastric biopsies taken several years apart was carried out in 117 subjects with intestinal metaplasia who are of the Lewis(a-b+) phenotype. They are residents of a rural Andean region in Colombia displaying very high rates of gastric cancer. The anomalous expression of Lewis(a) antigens in the metaplastic epithelium carried a significantly increased risk of colonic metaplasia and dysplasia. Such risk was much higher when the simultaneous expression of sulfomucins and Lewis(a) antigen was observed.


Partial sequence and polymerase chain reaction-mediated analysis of expression of the human CYP2C18 gene. We describe the isolation of the human CYP2C18 gene, a new member in the complex CYP2C subfamily, associated with the genetically-determined polymorphism for (S)-mephenytoin hydroxylase. The 5' end of CYP2C18 gene was isolated from a human genomic library using a probe derived from the CYP2C10 cDNA and the 5' flanking region, exons 1 to 4 and intron-exon junctions were sequenced. With respect to intron-exon boundaries, the partial gene structure was identical to that of rat and rabbit CYP2C genes. Consensus sequences for putative 'glucocorticoid responsive elements' were observed in the 5' flanking region and in intron 1, an interesting feature in a so-called constitutively-expressed gene subfamily. The knowledge of CYP2C gene sequences is a prerequisite to genomic analysis by PCR techniques. Using oligonucleotides derived from the gene sequence, we were able to specifically detect CYP2C18 mRNAs in human liver.


A model for the formation and removal of hemoglobin adducts. Hemoglobin adducts formed by chemical carcinogens can be used as biomarkers of exposure. The kinetics of adduct formation and removal is complex and depends on the processes involved in erythrocyte removal, adduct stability, and the duration and extent of exposure. In order to relate the formation of adducts to the extent of exposure in complex exposure scenarios, a model has been developed to describe the kinetics of accumulation and removal of adducts formed in vivo. The exposure scenario, lifetime of erythrocytes, and extent of adduct formation following a single exposure are required input parameters. Predictions of adduct accumulation have been generated for a wide variety of exposure scenarios and compared with both the solutions to equations derived for adduct formation and removal and experimental observations. Loss of adduct by removal of erythrocytes from circulation, both by senescence and random removal and as a result of chemical instability, has been simulated. Equations have been derived to describe the removal of hemoglobin adducts under conditions of exposure for less than the lifetime of the erythrocyte, when removal is initially a linear function of time. This model makes possible the comparison of data obtained from different exposure scenarios and in different species.


Determination of CYP1A2 and NAT2 phenotypes in human populations by analysis of caffeine urinary metabolites. The wide variations in urinary bladder and colo-rectal cancer incidence in humans have been attributed in part to metabolic factors associated with exposure to carcinogenic aromatic and heterocyclic amines. Cytochrome P-4501A2 (CYP1A2), which catalyses N-oxidation, and acetyltransferase (NAT2) which catalyses N- and O-acetylation, both appear to be polymorphically distributed in human populations; and slow and rapid NAT2 phenotypes have been implicated as risk factors for these cancers. Caffeine has also been shown to undergo 3-demethylation by CYP1A2, and it is further acetylated to 5-acetylamino-6-formylamino-3-methyluracil (AFMU) by the polymorphic NAT2. In this report, we describe a metabolic phenotyping procedure that can be used to determine concomitantly the hepatic CYP1A2 and NAT2 phenotypes. For the NAT2 phenotype, we confirm the valid use of the urinary molar ratio of AFMU/1-methylxanthine, even in alkaline urines. For the CYP1A2 phenotype, the urinary molar ratio of [1,7-dimethylxanthine + 1,7-dimethyluric acid]/caffeine, taken at 4-5 h after caffeine ingestion, was identified from pharmacokinetic analyses of 12 subjects as being better correlated (r = 0.73; p = 0.007) with the rate constant for caffeine 3-demethylation than other previously suggested ratios. This procedure was then used to determine the CYP1A2 phenotype in subjects from Arkansas (n = 101), Italy (n = 95), and China (n = 78). Statistical and probit analyses of nonsmokers indicated that the CYP1A2 activity was not normally distributed and appeared trimodal. This trimodality allowed arbitrary designation of slow, intermediate, and rapid phenotypes, which ranged from 12-13% slow, 51-67% intermediate, and 20-37% rapid, in the different populations. A reproducibility study of 13 subjects over a 5 day or 5 week period showed that, with one exception, intraindividual variability did not alter this CYP1A2 phenotypic classification. Induction of CYP1A2 by cigarette smoking was also confirmed by the increased caffeine metabolite ratios observed in the Arkansas and Italian smokers (blonde tobacco). However, Italian smokers of black tobacco and Chinese smokers did not appear to be induced. Furthermore, probit analyses of Arkansas and Italian blonde tobacco smokers could not discriminate between phenotypes, apparently as a consequence of enzyme induction.


The ability to 4-hydroxylate debrisoquine is related to recurrence of bladder cancer. Oxidative metabolism by cytochrome P450 enzymes is often involved in the activation of environmental procarcinogens. Debrisoquine, mephenytoin, and dapsone were used as in vivo probes for the activities of P4502D6, 2CMP, and 3A4, respectively, as well as dapsone for N-acetyltransferase, in order to assess the relationship between such activities and the relative risk of recurrence of bladder cancer. Urinary recovery ratios of debrisoquine and dapsone and the R/S ratio of mephenytoin were measured in an 0-8 h urine sample after simultaneous administration of debrisoquine (10 mg) and racemic mephenytoin (100 mg), and the administration of dapsone (100 mg) one week later, to patients undergoing local surgical resection of transitional cell bladder cancer of G-I, G-II, or G-III histopathology. In addition, plasma levels of dapsone and mono-acetyldapsone were determined in an 8 h plasma sample to determine the N-acetylation phenotype. Patients were followed for 3 years, to the time of tumour recurrence, or death. Three patients were lost to follow-up; of the remaining 95 patients, 55 had tumour recurrence. The debrisoquine recovery ratio was significantly greater in patients with recurrence than in individuals who remained disease-free. Among the 65 patients with non-aggressive (G-I and G-II) histopathology, two patients were lost to follow-up and 32 had tumour recurrence. In this subgroup, the debrisoquine recovery ratio was again found to be significantly greater in those individuals with tumour recurrence (p < 0.003).(ABSTRACT TRUNCATED AT 250 WORDS)


Acculturation, education, and income as determinants of cigarette smoking in New Mexico Hispanics. Surveys of cigarette smoking among Hispanics in the Southwest have shown a pattern of smoking distinct from that of non-Hispanic whites, but determinants of smoking by Hispanics remain inadequately characterized. We have assessed household income, education, and language preference as predictors of cigarette smoking in 1072 Hispanic adults residing in a community in New Mexico. Cigarette smoking status (never, former, or current smoker) varied strongly with educational attainment, showing the anticipated gradient of increasing smoking as level of education declined. In contrast, cigarette smoking status did not vary in a consistent pattern with reported language preference. A composite measure of socioeconomic status, combining education and household income, predicted continued smoking among ever smokers, whereas language preference had no effect. In males, the age at which subjects started to smoke increased significantly with increasing education; a similar trend in females did not reach statistical significance. Determinants of numbers of cigarettes smoked daily were not identified. The findings suggest that, as in other U.S. populations, Hispanics in the Southwest with lower education and less income should be targeted for smoking prevention and cessation.


The novel bilirubin/phenol UDP-glucuronosyltransferase UGT1 gene locus: implications for multiple nonhemolytic familial hyperbilirubinemia phenotypes. At least three types of congenital nonhemolytic unconjugated hyperbilirubinemias, including the rare Crigler-Najjar (CN) diseases (Types I or II) and Gilbert's syndrome (affecting 6% of the population) are associated with either absent or reduced hepatic UDP-glucuronosyltransferase (transferase) activity towards the potentially toxic endogenous acceptor, bilirubin. Here, we review the biochemical studies associated with these deficiencies. Accumulated evidence from studies with an animal model of CN Type I syndrome, the Gunn strain of hyperbilirubinemic rats, suggested that multiple isozymes are absent. These confounding observations have been clarified by a flurry of reports which have revealed the molecular basis for the complex disease phenotype in the Gunn rat and by the isolation and description of a novel human gene complex, UGT1, which encodes multiple and independently-regulated transferase isozymes that contain identical carboxyl terminal regions (246 amino acids). Finally, we discuss the implications of the gene organization and genetic defects determined for four different CN Type I individuals as a basis for a model which explains the inheritance pattern and genotypes of other familial unconjugated hyperbilirubinemias.


Molecular genetics of human aldehyde dehydrogenase. Four non-allelic genes, which encode four different aldehyde dehydrogenase (ALDH) isozymes, have been cloned and characterized at the present time. The coding nucleotide sequences, and organization of introns and exons of these genes have been elucidated. The ALDH1 gene encodes the major cytosolic ALDH1 existing in the liver and other tissues. The genetic deficiency of this isozyme was found at a low frequency (<< 10%) in both Caucasians and Orientals. The deficiency and alcohol sensitivity character are inherited together in one large Caucasian family examined. The ALDH1 gene contains two hormone response elements in its upstream 5' region. The ALDH2 gene encodes the major liver mitochondrial ALDH2 which has a very low Km for acetaldehyde. The atypical ALDH2(2) allele is common (about 30%) in Orientals; and subjects with ALDH2(2) allele, both homozygous and heterozygous status, lack ALDH activity. These individuals are alcohol sensitive and have a markedly reduced risk in developing alcoholism and alcoholic liver diseases. The ALDH3 gene produces a cytosolic ALDH3 isozyme existing in the stomach and liver carcinoma but hardly in normal liver. The ALDH3 locus is polymorphic in Orientals and presumably other populations. The ALDH5 gene, which is expressed in testes and liver, is highly polymorphic in both Caucasians and Orientals. The variation of these two loci may affect the development of alcohol-related problems.


Human liver thiopurine methyltransferase pharmacogenetics: biochemical properties, liver-erythrocyte correlation and presence of isozymes. Thiopurine methyltransferase (TPMT) catalyses the S-methylation of thiopurine drugs such as 6-mercaptopurine (6-MP). TPMT activity in the human red blood cell (RBC) is controlled by a common genetic polymorphism. Gene frequencies for this polymorphism are such that approximately one in 300 subjects is homozygous for the allele for low activity and lacks RBC TPMT activity, 11% of subjects are heterozygous and have intermediate levels of enzyme activity and 89% are homozygous for the allele for high activity. Our experiments were performed to determine whether the properties of TPMT in an important human drug metabolizing organ, the liver, were similar to those of RBC TPMT and to test the hypothesis that the genetic polymorphism which controls TPMT activity in the human RBC might also regulate the level of this enzyme activity in hepatic tissue. Human liver TPMT is a cytoplasmic enzyme and the Km values for 6-MP and S-adenosyl-L-methionine, cosubstrates for the reaction, were 580 microM and 2.7 microM, respectively. These properties, as well as the sensitivity of human liver TPMT to a panel of methyltransferase inhibitors, were similar to those of RBC TPMT. The enzyme activity was then measured in 119 surgical biopsy samples of hepatic tissue. Average hepatic TPMT activity was 13.6% higher in samples from male than in those from female patients. Frequency distribution histograms demonstrated the presence of a subgroup with intermediate enzyme activity that included 8.4% of samples. In addition, when TPMT activity was measured in both RBCs and hepatic tissue for 35 patients, those with inherited intermediate levels of RBC TPMT activity also had intermediate hepatic enzyme activity. Finally, ion exchange chromatography demonstrated the presence of two isozymes of TPMT in human hepatic tissue, but the isozymes did not appear to explain the molecular mechanism responsible for the genetic polymorphism. These results were compatible with the conclusion that the genetic polymorphism which controls TPMT activity in the RBC also controls levels of this important enzyme activity in a major human drug metabolizing organ, the liver.


Induction of various cytochromes CYP2B, CYP2C and CYP3A by phenobarbitone in non-human primates. Male and female patas (Erythrocebus patas) and cynomolgus (Macaca fascicularis) monkeys were treated with phenobarbitone (PB) and examined for the induction of various cytochrome P450 (P450)-mediated drug metabolizing enzymes. Hydroxylation of testosterone at the 6 beta, 2 beta, and 15 beta positions, metabolites normally associated with CYP3A P450s increased 2- to 5-fold in PB-treated animals. Induction of this P450 family was confirmed by the use of polyclonal antisera directed against the human CYP3A enzymes which inhibited both induced and constitutive 6 beta- and 15 beta-hydroxylase activities in both species of monkeys. The enzymatic activities testosterone 16 beta-hydroxylation, pentoxyresorufin O-dealkylation [PROD], and benzyloxyresorufin O-dealkylation [BZROD] typically associated with the rodent CYP2B subfamily in rodents were also examined. Testosterone 16 beta-hydroxylation activity was highly induced up to 15-fold in both species of monkeys to maximal levels similar to those induced in PB-treated male rats. BZROD was similarly induced up to 10-fold in both species of monkeys, but the maximal levels of BZROD achieved were substantially lower than those obtained in PB-treated rats. Finally, PROD yielded an idiosyncratic response showing substantial induction (> 30-fold) in certain patas monkeys (4 out of 8) but minimal (< 5-fold) induction in the other patas monkeys (4 out of 8) or any of the cynomolgus monkeys (0 out of 8). Immunodetection of various cytochromes using polyclonal antisera directed against rat cytochromes confirmed the induction of CYP3A proteins as well as the induction of protein(s) immunologically cross-reactive with rat CYP2B P450s. BZROD, PROD, or testosterone 16 beta-hydroxylase activities, were not inhibited by antibody to CYP3A P450s. However, high concentrations of polyclonal antiserum directed against rat CYP2B inhibited all three activities in PB-induced patas monkeys. In contrast, this antiserum failed to inhibit the hydroxylation of testosterone at the 6 beta or 2 beta positions. Induction of the CYP2C subfamily was observed by immunochemical detection. Interestingly, induction of this subfamily appeared to be more pronounced in cynomolgus than in patas monkeys. Finally, we failed to observe significant sex-dependent differences in P450-mediated enzymatic activities in either control or induced monkeys. These results confirm the induction of a similar spectrum of P450 proteins by PB in non-human primates to that which has previously been observed in rodents.


Caffeine as a probe for human cytochromes P450: validation using cDNA-expression, immunoinhibition and microsomal kinetic and inhibitor techniques. The molecular basis for the use of caffeine (CA; 1,3,7-trimethylxanthine) as a probe for specific human cytochromes P450 has been investigated. The CA 1-, 3- and 7-demethylations (to form theobromine, paraxanthine and theophylline, respectively) all followed biphasic kinetics in human liver microsomes. Mean apparent Km values for the high- and low-affinity components of the demethylations ranged from 0.13-0.31 nM and 19.2-30.0 mM, respectively. cDNA-expressed CYP1A2 catalysed all three CA demethylations, and the apparent Km for CA 3-demethylation (the major metabolic pathway in humans) by the expressed enzyme was similar to the Km for the high-affinity liver microsomal CA 3-demethylase. IC50 values for inhibition of the CA demethylations by alpha-naphthoflavone were similar for both expressed CYP1A2 and the high-affinity microsomal demethylases. Moreover, CA was a competitive inhibitor of expressed CYP1A2 catalysed phenacetin O-deethylation, with the apparent Ki (0.080 mM) closely matching the apparent Km (0.082 mM) for CA 3-demethylation by the expressed enzyme. Expressed CYP1A1 was additionally shown to catalyse the 3-demethylation of CA, although activity was lower than that observed for CYP1A2. While these data indicate that CYP1A2 is responsible for the high-affinity component of human liver CA 3-demethylation, two limitations associated with the use of CA as an in vitro probe for CYP1A2 activity have been identified: (i) CA 3-demethylation reflects hepatic CYP1A2 activity only at appropriately low substrate concentrations; and (ii) CA is a non-specific CYP1A substrate and CYP1A1 may therefore contribute to CA 3-demethylase activity in tissues in which it is expressed. An anti-CYP3A antibody essentially abolished the 8-hydroxylation of CA to form trimethyluric acid, suggesting formation of this metabolite may potentially serve as a marker of CYP3A isozyme(s) activity.


Metabolic, molecular genetic and toxicological aspects of the acetylation polymorphism in inbred mice. Over the past 10 years, much fascinating information has been obtained concerning the biochemistry, genetics, toxicological implications and molecular genetics of the N-acetylation polymorphism in mice. Using C57BL/6J (B6) mice as representative of rapid acetylation and A/J (A) mice as representing slow acetylation, it has been shown that the polymorphism observed in N-acetyltransferase (NAT) activity in liver also occurs in kidney, bladder, blood, and other tissues. The development of congenic acetylator mouse lines derived from B6 and A, have provided the necessary tools to study the role of the acetylation polymorphism, on either the B6 or A genetic background, free of nearly all other genetic differences between these strains. Eliminating genes which modify and complicate the differences due to the acetylator genes make the congenic lines very useful in toxicology studies, particularly those involving carcinogenesis. The molecular genetic basis of the acetylator polymorphism in B6 and A mice involves two Nat genes. Nat-1 encodes a protein termed NAT1 which is identical in rapid and slow acetylator strains. Nat-2, however, differs between rapid and slow strains by a single nucleotide change in the coding region. The corresponding NAT2 proteins differ by a single change at amino acid 99: an hydrophilic asparagine in rapid acetylator NAT2 to an hydrophobic isoleucine in NAT2 from slow acetylators. The mechanistic basis for the differences between rapid and slow acetylation in mice appears to be that NAT2 from the rapid B6 strain is 15-fold more stable at 37 degrees C and is transcribed/translated with a maximal efficiency twice that of the enzyme from slow acetylator A mice. Results discussed in this review indicate that mice provide an excellent system for studying the N-acetyltransferase polymorphism and also are useful for modelling several aspects of the human N-acetyltransferase polymorphism.


Guinea pig or rabbit lung flavin-containing monooxygenases with distinct mobilities in SDS-PAGE are allelic variants that differ at only two positions. Both guinea pig and rabbit express two variants of the 'lung' flavin-containing monooxygenase (FMO), observed as three distinct phenotypes based on mobility differences in SDS-PAGE. Samples of messenger RNA prepared from lungs of the two homozygous phenotypes of the guinea pig were used for the construction of two cDNA libraries. The libraries were screened with a cDNA encoding the rabbit lung FMO, and positive clones for each guinea pig lung FMO variant were isolated and sequenced. A full length clone from each library was found to encode a protein of 535 amino acids containing two pyrophosphate binding sites. Comparison of the sequences of the guinea pig and rabbit lung FMOs shows that their primary structures are 86% identical. The coding region sequences of the guinea pig variants differ at only two positions, and both differences result in amino acid substitutions. Sequence analysis has also been completed on a partially characterized variant of the rabbit lung FMO. As with the guinea pig, the nucleotide and amino acid sequences of the rabbit variants differ at only two positions. The cDNAs encoding the guinea pig variants were expressed in yeast. The activities of the enzymes are characteristic of the lung FMO, and the mobilities of the expressed enzymes are the same as those observed for the variants present in guinea pig pulmonary microsomal preparations. Similar to findings for the rabbit, analysis of genomic DNA indicates that the guinea pig lung FMO is associated with a single gene. The results of cDNA sequence analysis, expression in yeast, and analysis of genomic DNA indicate that the multiple lung FMOs in guinea pig and rabbit are allelic variants whose mobilities in SDS-PAGE are markedly altered by minimal changes in primary structure.


Genotyping human polymorphic arylamine N-acetyltransferase: identification of new slow allotypic variants. Arylamine N-acetyltransferase catalyses the N-acetylation of primary arylamine and hydrazine drugs and chemicals. N-acetylation is subject to a polymorphism and humans can be categorized as either fast or slow acetylators according to their ability to N-acetylate polymorphic substrates in vivo. Previously, slow acetylation has been linked to four distinct polymorphic N-acetyltransferase (pnat) alleles each of which contains one or more point mutations within the coding region of the pnat gene. One new rare slow variant of pnat has been identified by cloning and sequencing the pnat DNA from an individual whose NAT phenotype was determined by in vivo acetylation of the polymorphic substrate sulphamethazine. This allele, designated S1c, differs from the wild type fast allele at nucleotide positions 341 and 803. A second new rare slow allotypic variant, designated S3, has been identified by resistance of the pnat specific DNA to digestion with the restriction enzymes Fok I and Bam HI. A method of genotyping individuals for the arylamine N-acetyltransferase (NAT) polymorphism is presented which correctly predicts the phenotype of greater than 95% (21 of 22) of individuals as measured by the extent of acetylation of sulphamethazine in urine. This refined genotyping method was applied to a clinical population of 48 Caucasians with classical or definite rheumatoid arthritis each receiving daily between 150 and 500 mg of the anti-rheumatic drug, D-penicillamine. There is no difference in the N-acetyltransferase phenotype of the individuals who developed proteinuria and the control group with no adverse effects.


Interindividual variability of coumarin 7-hydroxylation in healthy volunteers. A test designed to estimate the extent and rate of formation of 7-hydroxycoumarin by measuring the urinary excretion of the metabolite in humans after administering 5 mg coumarin was developed. Coumarin was rapidly metabolized after oral administration and more than 95% of the 7OHC formed was excreted in 4 h. The total amount of 7OHC formed was 64 +/- 15% (mean +/- SD, variation 20-100%) of the dose given. The percentage of 7OHC excreted in 2 h, as compared with the 7OHC excretion in 4 h, was found to be a constant and stable individual characteristic for the rate of the formation of 7OHC ('2 h coumarin test'). In 110 volunteers, there was a great interindividual variability in the extent and rate of 7OHC formation. Four individuals had relatively 'slow' coumarin test values (50-60%), but much larger populations would be needed for the demonstration of polymorphism.


Structural basis of the butyrylcholinesterase H-variant segregating in two Danish families. The rare H-variant of human butyrylcholinesterase is a quantitative variant that reduces serum butyrylcholinesterase activity by about 90%. Individuals who are heterozygous for both the H-variant and the atypical variant are abnormally sensitive to the muscle relaxant succinylcholine. By using standard phenotypic serum assays, the Danish Cholinesterase Research Unit identified four individuals from two unrelated pedigrees who were heterozygous for both the H-variant (H) and the atypical (A) variant. DNA of these A/H individuals was extracted from white blood cells. Using the polymerase chain reaction and subsequent DNA sequencing, a point mutation was found at nucleotide 424 which changed amino acid 142 from valine to methionine. The previously identified atypical mutation, Asp 70 to Gly, was also seen, which segregated apart from the H-variant mutation in family studies. These two mutations were found in all four A/H individuals.


A methodological investigation on the estimation of the S-mephenytoin hydroxylation phenotype using the urinary S/R ratio. After a single oral dose of racemic mephenytoin the S/R ratio in urine can be used to phenotype extensive (EM) and poor metabolizers (PM) of S-mephenytoin. We confirmed the increased S/R ratio by storage time in EM because of the hydrolysis of a conjugate of S-mephenytoin excreted in EM, but not in PM. The S/R ratio in the 0-8 h urine increased 8- to 127-fold (from 0.22 +/- 0.16 to 9.9 +/- 11.3) after acid treatment of urine from 30 EM, but there was no effect of acid in that of 12 PM. We suggest that the phenotype of mephenytoin in combination with debrisoquine can be determined in the 0-8 h urine by estimating the mephenytoin S/R ratio before and after acid treatment.


The pharmacogenetics of chemical carcinogenesis. The human body is endowed with a large number of xenobiotic chemical metabolizing enzymes, a significant proportion of which are polymorphic and thus render one individual at greater or lesser risk than another of chemically-induced disease. All examples of genetic polymorphism of chemical metabolizing enzymes have been reviewed in relation to their potential to activate and detoxicate procarcinogens and promutagens. Many examples are cited whereby phenotype can act as a carcinogenic risk factor. With the availability of a large amount of DNA sequence data for chemical metabolizing enzymes there has emerged a number of polymerase chain reaction (PCR) strategies aimed at discerning one metabolic phenotype or another. This is seen as a very positive and democratic scientific development, widening the franchise for studies of disease risk. Nevertheless, it is argued that, at these early stages with many laboratory-based scientists scarcely familiar with epidemiological study design, a cautious approach should obtain when interpreting single studies.


Metabolic cytochrome P450 genotypes and assessment of individual susceptibility to lung cancer. Three polymorphic cytochrome P450 genes that have attracted interest for their potential role in human pulmonary carcinogenesis, i.e. CYP1A1, CYP2D6 and CYP2E1, were studied in a population consisting of 106 lung cancer patients and 122 healthy controls. Polymorphism of the CYP2D6 gene encoding for debrisoquine hydroxylase was determined using XbaI restriction fragment length polymorphism (RFLP) analysis together with a PCR based method. All of the three most common presently known defective alleles of CYP2D6 were detected by this application. Subjects having genotypes either homozygous or heterozygous for the CYP2D6 wild type alleles were classified as extensive metabolizers (EMs) of debrisoquine whereas poor metabolizers (PMs) had two defective alleles. The PM individuals are thought to be less prone to develop lung cancer. The CYP1A1 and CYP2E1 genes were studied by RFLP analyses using Msp I and Dra I restriction enzymes, respectively, giving rise to two different sized hybridizable fragments in Southern blot analyses. In these RFPL analyses genotypes homozygous to the mutated allele have been presented as potent determinants of individual lung cancer risk. In the present study no association between polymorphic CYP1A1 and CYP2E1 genotypes and susceptibility to lung cancer was found. However, CYP2D6 polymorphism studies of the 122 healthy controls revealed seven poor metabolizer genotypes (5.7%), which compares well with the previously observed phenotypic distribution in the Finnish population, whereas only one PM genotype (1/106) was found among the lung cancer patients. These results agree with the previous suggestions that PMs of debrisoquine are less susceptible to lung cancer than EMs.


Genetic polymorphism of cytochromes P450: interethnic differences and relationship to incidence of lung cancer. The cytochromes P450 participate in the metabolic activation of precarcinogens. Recent results reveal that many P450 genes are polymorphically distributed. Different investigators have tried to link polymorphic variants of the CYP1A1, CYP2D6 and CYP2E1 genes to the incidence of cancer, particularly lung cancer, in Asian and Caucasian populations. In the current overview we briefly summarize this research. It appears that interesting functionally linked interindividual differences in the CYP1A1 gene have been found and could be of importance in understanding differences in susceptibility to lung cancer. On the other hand, the data presented regarding CYP2D6 and CYP2E1 are less promising. We also describe interethnic differences in the P450 gene structures as a major obstacle for extrapolation of results between different ethnic groups.


Epidemiology and pathophysiology of ethanol-associated gastrointestinal cancer. Various epidemiological studies have given evidence on the correlation between alcohol intake and different types of cancer, especially in the upper alimentary and respiratory tract and in the liver. This review discusses the tumour stimulating effects of ethanol associated mechanisms.


Sources of genotoxicity and cancer risk in ambient air. Products of incomplete combustion are identified as a major source of carcinogenic risk in urban areas, especially those from small non-industrial sources. The major ubiquitous emission sources outdoors in populated areas are residential home heating and motor vehicles. Indoors the major combustion source is environmental tobacco smoke. Polycyclic organic matter adsorbed onto the particles emitted from incomplete combustion are estimated to make the largest contribution to human genotoxic and cancer risk. Mutagenic emission factors combined with dispersion modelling indicated that automobiles and heating sources were major sources of mutagens. Ambient air studies to apportion the sources of mutagens in non-industrial areas confirmed this prediction. To apportion and estimate the cancer risk of ambient organic matter from particles in vivo animal tumour data, receptor modelling and human exposure data were combined. Tumourigenicity studies of the source apportioned ambient organic matter provided the relative tumour potencies of two ambient samples of different source composition. The human cancer unit risks were developed based on the comparative potency method using tumour data from these ambient samples. Residential wood combustion accounted for 75% of the exposure to particle associated organics, but only 20% of the estimated cancer risk. The remaining 80% of the risk appears to be associated with the mobile source component and atmospheric transformation products from these source emissions.


Risk assessment of urban air pollution.

Risk assessment of urban air pollution. Urban air pollution, originating in western countries mainly from automotive engine exhausts, contains thousands of components, many of which are genotoxic, i.e. are putative cancer initiators. Other pollution components, such as NO2 and certain particles, may have cocarcinogenic/promotive effects, at least at higher exposure levels. Cancer risk assessment of this complex mixture has to combine data from the exposure history, from epidemiological studies as well as from animal carcinogenicity tests, and from in vitro studies of fractions and individual components. Data for metabolism and pharmaco-kinetics have also to be considered. A multiplicative linear model is assumed to be valid for cancer initiation at low levels. Attempts are being made to determine the target dose from ultimate carcinogens (reactive metabolites) via macromolecule adduct levels, and to base the risk assessment on the radiation-dose equivalent to the chemical dose. So far this has been possible only for simple alkenes, which are metabolized to epoxides, and indirectly, via benzo(a)pyrene (BaP), for particle-bound polycyclic aromatic hydrocarbons (PAH). The lifetime risk of cancer (all sites) from ethene is estimated accordingly to 1.4 x 10(-4) per microgram m-3, and from PAH to 12 x 10(-4) per ng m-3 BaP. For other components indicated to give risk contribution (NOx, volatile PAH, benzene, aldehydes, butadiene) essential data are lacking and only very rough estimates can be given at this time.


Assessment of PAH-exposure among coke oven workers. Coke oven workers are exposed to high concentrations of polycyclic aromatic hydrocarbons. Only recently have methods been developed to try to assess the individual, biologically significant exposure. The only coke oven plant in Finland started to function in 1987, in Raahe, enabling the implementation of a cohort study among the workers to determine the usefulness of some currently available biomonitoring methods, e.g. methods of measuring PAH-DNA adducts. Urine and blood samples were taken several times from a sample of workers starting from before they worked at the plant. A questionnaire (smoking, diet, former and current occupations) was filled in by the workers at every sampling, and air samples (personal and stationary) were collected at the same time. The mean values of both benzo(a)pyrene diolepoxide (BPDE)-DNA adducts were measured by synchronous fluorescence spectrophotometry (SFS) and the antibodies to these adducts increased somewhat after the work at the plant started. However, all the adduct values were low, and no differences between the smokers and non-smokers at any time point were detected. Battery workers had slightly increased means of BPDE-DNA adducts compared to non-battery workers. Also, coke oven workers had slightly higher adduct values than age, sex and smoking matched controls.


Genetic changes in breast carcinomas in an Icelandic population. We have examined breast tumour samples from 109 unselected breast cancer patients for genetic changes on chromosomes 13 and 17. We have looked for allelic losses, firstly, at the retinoblastoma locus, RB1, on chromosome 13q, and secondly, on both arms of chromosome 17. We have also studied the same samples for amplification of the erbB2 oncogene. We searched for mutations in four well conserved areas of the p53 gene using constant denaturant gradient electrophoresis (CDGE). Allelic loss or rearrangement was detected in a large proportion of the tumours, affecting 37-51% of cases with different probes. The areas most frequently affected were 17p13.1 and 17p13.3. Point mutations and small deletions in the p53 gene on 17p13.1 were detected in 16% of the tumours. The data on genetic changes were then analyzed for three different correlations: 1) co-operation between different lesions, 2) association with family history of breast cancer, 3) correlation with clinical factors and prognosis. There was association between losses at the retinoblastoma locus and losses on 17p and 17q. We also found an association between p53 mutations and amplification of the erbB2 oncogene. Relatives of patients having deletions at the retinoblastoma locus and/or sites on chromosome 17 in the tumours have a significantly increased relative risk of developing breast cancer. No such correlation is found for p53 mutations or erbB2 amplification. No p53 germline mutations were detected. P53 mutations do, however, appear to be a strong indication of poor prognosis in this population.


Detection of DNA variation in cancer.

Detection of DNA variation in cancer. Detection of DNA variation in cancer is central to the identification of relevant genes and mutations involved in the tumourigenic process. Diverse methods exist for such detection. One category of methods is for the detection of frequent sites for larger DNA alterations in cancer. Such areas may provide clues to the positioning of relevant genes, such as loss of heterozygosity (LOH) as in the case of tumour suppressor genes. Another category of methods is for the detection of single base mutations within specific genes. Frequently, such mutations may obliterate normal protein function. Among the most well-known are DGGE, SSCP, the HOT-method and direct sequencing. The methods for detection of DNA variation of these different levels are discussed. Two methods are presented in more detail. At the large-scale level, two-dimensional DNA fingerprinting has the potential of revealing the extent and location of altered DNA regions. This method is demonstrated using a panel of breast cancer patients. As an example of methods for the small-scale level, a recent development from DGGE, constant denaturant gel electrophoresis (CDGE) is demonstrated. This method has successfully been applied for the detection of mutations in a number of genes. Results with this method in studies of the RB1 gene are given, and its applicability as a screening tool for base mutations is discussed.


Missense mutations and evolutionary conserved amino acids at the human hypoxanthine phosphoribosyl-transferase locus. Molecular characterization of in vivo mutation at the human hypoxanthine phosphoribosyltransferase (hprt) locus has revealed a broad spectrum of mutation, both with regard to germ-line mutation in Lesch-Nyhan and gout patients, and somatic mutation in 6-thioguanine resistant T-lymphocytes from healthy individuals. The pattern of missense mutation shows a non-random distribution with a preferential location to codons for amino acids which are identical in human and the two parasites Schistosoma mansoni and Plasmodium falciparum. Although these 'evolutionary conserved' amino acids account for only 32% of the amino acids in the human hprt protein, they are involved in 76% of the missense mutations at the hprt locus in human T-lymphocytes, 67% in Lesch-Nyhan patients (with severe hprt-deficiency), but only 43% in gout patients (with partial hprt deficiency). This observation supports the notion that evolutionary conserved amino acids constitute functionally important sites in the hprt enzyme, and missense mutations affecting these amino acids will often lead to complete loss of enzyme activity. Substitutions of 'non-conserved' amino acids cause less severe hprt-deficiency (as seen in the gout patients), or may even escape clinical diagnosis. These considerations are important for the understanding of structure-activity relationships in the hprt protein, possible differences between hprt mutational spectra in germ-line and somatic cells, and the mutational spectra induced by specific exogeneous mutagens.


Approaches to the prediction of human cancer risk. Epidemiological studies provide the only direct means of measuring the risk of cancer in humans and for investigating effects directly avoiding interspecies extrapolation. Epidemiology is, however, too insensitive to detect small increases in risk. Furthermore, traditional epidemiology cannot be used prospectively to indicate future problems nor to explore the current exposure situation. Ideally, cancer hazards should be identified before humans are exposed. For the foreseeable future, therefore, identification of carcinogens will necessarily depend heavily on data derived from studies in experimental animals. Emerging molecular biological techniques, if used critically, hold great promise for resolving many contemporary puzzles in cancer risk prediction.


Evolutionary aspects of human cancer.

Evolutionary aspects of human cancer. Evolutionary aspects of human cancer can be dealt with at two levels--on the one hand long-term evolution involving hereditary effects between generations; and on the other hand evolutionary processes operating within the organisms between tissues, cells and cell constituents, which also comprise genetic alterations, selection and adaptation. These two levels of evolution can be designated as phylogenetic and ontogenetic evolution, respectively. Concerning phylogenetic evolution there must have been a strong selection against neoplastic diseases occurring at reproductive age and a variety of protective mechanisms against carcinogenic agents have been developed. Cancer is therefore primarily a disease of old age, which does not constitute a significant risk in natural populations for the simple reason that the life length is too short. The development of an individual comprises selection forces between cells and tissues, which are particularly striking for the multistage development of tumours. The accumulation of several genetic alterations in the same cells, as illustrated by the analysis of colorectal tumours, must require a pronounced clonal expansion between each event. Such selective growth effect has recently been demonstrated for the tumour suppressor gene p53 in brain tumours. Cancer often implies a break down of between balanced systems antagonistic forces, such as oncogenes and suppressors of oncogenes. Examples of this are provided by the genetic regulation of metastasis, involving metalloproteinase as well as the inhibitor of metalloproteinase. The immortalization of cells by transformation points to the fact that programmed cell death and the balance between suicide genes and suppressors of such suicide genes is affected.


[Bronchoesophageal fistulae: apropos a case rarely seen]. One case of acquired oesophago-bronchial fistula is reported. Diagnostic images are presented. Pathogenesis, clinical and therapeutics features are discussed.


Suppression of tumor necrosis factor-alpha, interleukin-1 beta, interleukin-6 and granulocyte-monocyte colony stimulating factor secretion from human monocytes by an extract of Poria cocos. Fu-Ling, the sclederma of Poria cocos (Schw.) Wolf, has long been used as a sedative and diuretic. However, data in this report suggest that Fu-Ling is a potential suppressor of cytokine secretion from human peripheral blood monocytes under in vitro condition. Monocyte culture medium containing 10% of Fu-Ling extract significantly inhibited secretion of TNF-alpha, IL-beta, IL-6 and GM-CSF from the monocyte monolayer. However, as Fu-Ling extract content was gradually reduced, cytokine secretion was augmented in comparison with the cytokine secretion in drug-free controls. This augmentative effect resulted from the trace amount (1.24 ng/ml in 0.62% of Fu-Ling extract) of lipopolysaccharide (LPS) which contaminated the Fu-Ling extract during the preparation process, since TNF-alpha, IL-1 beta and IL-6 secretion induced by 0.62% Fu-Ling extract could be significantly inhibited by polymyxin B, an LPS inhibitor. Furthermore, the amounts of TNF-alpha IL-1 beta and IL-6 induced by 1 ng/ml of LPS without the presence of drug were more than that induced by 0.62% of Fu-Ling extract. Thus, cytokine secretion induced by LPS contamination (1.24 ng/ml) in the Fu-Ling extract was partially suppressed by 0.62% of the Fu-Ling extract itself. GM-CSF secretion in the medium containing 0.62% of Fu-Ling extract was not induced by LPS since: a) GM-CSF induced by 0.62% Fu-Ling extract could not be inhibited by polymyxin B; b) LPS at 1 ng/ml showed no activity indicating induction of GM-CSF secretion.


[A rare complication due to diverticulitis]. The AA. report about a case of hepatic abscess found in a operated patient for perforation of a sigmoid diverticulum. The AA. made some consideration on the rarity of the hepatic abscess as complication of diverticulum perforation.


[The complications of lumbotomies].

[The complications of lumbotomies]. After having described the surgical anatomy of the lumbar region, with particular regard to the relationships with pleura and peritoneum, as well as to the course of the nervous structures of the region (12th intercostal, ileohypogastric and ileoinguinal), the authors describe the possible complications related with the surgical approaches to the lumbar region. Pathogenesis of post-operatory pains and parietal hypotonies is especially evaluated; these complications may be caused by section, ligature or compression of one or more nervous trunks. The authors conclude that the respect of the anatomic structures located in the lumbar region represents the best way in order to prevent most complications related to lumbotomies.


The influence on pregnancy of anti-SSA/Ro antibodies in systemic lupus erythematosus. Excessive fetal morbidity and mortality have been noted in patients with systemic lupus erythematosus (SLE). The influence of anti-SSA/Ro antibodies on fetal outcome in SLE patients has rarely been reported, but its high association with congenital heart block or neonatal lupus syndrome is well known. In 430 pregnancies of the 154 SLE patients studied, there was an increased frequency of adverse fetal outcome compared with controls. There was no significant difference in the rates of adverse fetal outcome between anti-SSA/Ro positive and negative SLE patients, except that the incidence of intrauterine growth retardation increased in the positive patients. However, pregnant SLE patients with high titer of anti-SSA/Ro antibodies had more adverse fetal outcomes. All three infants who suffered congenital heart block/neonatal lupus syndrome were associated with maternal anti-SSA/Ro antibodies. The frequency of congenital heart block/neonatal lupus syndrome was 0.79% (3/379) in livebirths of all SLE patients and 1.17% (3/257) in live-births by anti-SSA/Ro positive SLE mothers.


[The surgery of liver trauma (clinical contribution)]. Authors perform a retrospective review of all hepatic injuries operated on between 1974 and 1990 at Clinica Chirurgica II (ex Patologia Chirurgica II, ex Semeiotica Chirurgica) of Policlinico San Matteo (IRCCS) of Pavia. Thirteen patients were treated, 9 men and 4 women, with age ranged from 13 to 68 years and a mean age of 38 years. They were 21% of all patients operated on for abdominal trauma. Penetrating wounds were present in only two cases (15%), the other patients (85%) were affected by blunt trauma. The mechanisms of injuries were: road accidents (77%), fall at work (8%), gun shot wound (8%), stab wound (8%). All patients had associated injuries. The mortality was 31%: one patient died for haemorrhagic shock and the other three for craniocerebral injuries. After reviewing the several haemostatic techniques advocated for the various types of hepatic injuries, the authors stress that, although most lesions are minor and can be managed by simple technique of haemostasis, often the prognosis is severe for the associated injuries.


[Obturator hernia].

[Obturator hernia]. Obturator hernia, which is a rare cause of intestinal occlusion, generally presents non-specific signs and symptoms. Radiology may be sometimes useful for the diagnosis. Four cases of obturator hernia are described, and the possible surgical access routes are illustrated, emphasizing the use of prosthetic mesh.


Exclusion probabilities of red cell antigen systems for Chinese. Little data are available in the literature for Chinese people, regarding genotype frequencies of red cell antigen systems. Furthermore, no recommendations for proper selection of red cell antigen systems for paternity testing have been established for a Chinese population. Consequently, calculating a paternity index is impossible. Blood typing of 336-1919 samples of Taiwanese Chinese was undertaken to determine various red blood cell antigens. Gene frequencies and probabilities of exclusion (PE) for the red cell antigen systems were then analyzed. The distributions of the red cell antigens were quite homogeneous. The incidence of D, s, k, Fya and Lub antigens was high, 99.6%, 99.7%, 100%, 99.8% and 99.4%, respectively. On the contrary, that for the K antigen was very low. The PE for the ABO, Rh, MNSs, Kell, Duffy, Kidd, P, and Lutheran systems was 0.1910, 0.1961, 0.2237, 0.0003, 0.0444, 0.1870, 0.0806, and 0, respectively. The cumulative PE (CPE) using ABO, Rh, MNSs, Kell, Duffy, Kidd, P and Lutheran systems was 0.6394, while CPE for ABO, Rh, MNSs, Duffy, Kidd, and P systems was 0.6394. Thus, it appears that the Kell and Lutheran systems are not suitable for paternity testing because of their low probability of exclusions. Duffy system may also be excluded for its low PE. The CPE for ABO, Rh, MNSs, Kidd and P systems was 0.6226.


Anti-Jo-1 antibody in patients with polymyositis/dermatomyositis. Interstitial lung disease (ILD) has been recognized as a manifestation of polymyositis or dermatomyositis (PM/DM). Patients with PM/DM with anti-Jo-1 antibody had a higher incidence of ILD. Thirty-five patients with PM/DM were studied the antibodies. Six (16.1%) were found to have them. ILD occurred in all 6 anti-Jo-1 positive patients, as opposed to 10 (34.5%) of 29 anti-Jo-1 negative patients. Only 2 cases of undifferentiated connective tissue disease among 1320 patients with various kinds of collagen vascular diseases other than PM/DM were positive for anti-Jo-1 antibody. These two patients also had lung involvement. Among six PM/DM patients with anti-Jo-1 antibody, dyspnea preceded proximal muscle weakness in three patients. In one case, the anti-Jo-1 antibody had been detected one month prior to the onset of myositis. Anti-Jo-1 antibody is a useful marker for PM/DM with ILD.


[Surgery and chemotherapy in the treatment of primary gastric lymphomas: case review]. Fifty-seven patients with primary gastric non-Hodgkin's lymphoma are here reported. All our patients were treated with surgery as first step procedure. Thirty-six were treated in addition with chemotherapy (four of them with radiotherapy also). Thirty-eight were stage IE and nineteen IIE. According to the Working Formulation, 12 cases were classified as low, 25 intermediate and 20 high malignancy. 55 patients achieved a complete remission (96%) and only 6 relapsed (11%). The 10-year disease-related survival is 89%. Patients treated with combined surgery and chemotherapy were mainly a high risk group (high grade histologic subtype, stage IIE, incomplete resection). Nevertheless the survival of this group was similar to the group initially treated with surgery alone (p = 0.17) in which such unfavorable prognostic factors were not present. Stage, presence of residual tumor after surgery, sex and age did not statistically correlate with survival. Furthermore, there was not statistical difference among the various histological subgroups (p = 0.16). We stress the importance of cooperation among surgeons and oncologists in order to plan an appropriate treatment.


The phenotype and gene frequencies of human platelet specific antigens among Chinese in Taiwan. Human platelet specific antigens (HPA) were serologically typed among 48 to 567 samples of blood from Chinese in Taiwan by using the mixed passive hemag-glutination method (MPHA). The prevalence found was: HPA-la (P1A1), > 99.9% (48/48); HPA-2b (Koa or Siba), 9.0% (51/567); HPA-3a (Baka), 84.8% (481/567); HPA-4a (Yukb), > 99.9% (567/567); HPA-4b (Yuka), 0.5% (3/567); HPA-5b (Br(a)), 32.6% (185/567); and Nak(a), 98.4% (558/567). The gene frequencies for these antigens were: HPA-la (P1A1), > 0.999; HPA-2b (Koa or Siba), 0.046; HPA-3a (Bak(a)), 0.611; HPA-4a (Yukb), 0.997; HPA-4b (Yuka), 0.003; HPA-5b (Br(a)), 0.179; and Nak(a), 0.874. The distribution of HPA's for Chinese differ from those for Caucasians and for Japanese. When compared to Caucasians, Chinese show a higher prevalence of HPA-la (P1A1), higher prevalence of HPA-5b (Br(a)), lower prevalence of HPA-2b (Koa or Siba) and lower prevalence of HPA-3a (Baka). Both Chinese and Japanese have a very high prevalence rate of HPA-la (P1A1), ie. close to 100%. However, the prevalence of HPA 2-2b (Koa or Siba) and HPA-4b (Yuka) is slightly lower in Chinese than in Japanese; and, the prevalence rate for HPA-3a (Baka) is slightly higher in Chinese than in Japanese.


[Anastomotic complications in the surgical treatment of rectal neoplasms]. The authors review the problems relating to the healing of colorectal anastomotic complications following anterior resection. They report on their own experience with 328 anastomoses, 281 of which constructed manually and 47 using a mechanical suturing gun. Following manual anastomosis, the reported incidence of clinical dehiscence was 1%, as against a 10.3% incidence of radiologically detectable dehiscence. In the cases of mechanically produced anastomoses the incidence of clinical dehiscence was 6.4%. In 2 cases stenosis developed as a result of the clinically manifest dehiscence following manual anastomosis. In the patients undergoing mechanical anastomosis, occlusion occurred in one case and stenosis in another, without any concomitant peri-anastomotic inflammatory processes; these complications were caused by a membrane extending between the margins of the anastomosis. The authors ascribe the greater incidence of clinically important dehiscence following mechanical anastomosis to a greater sensitivity of the mechanical suture to colonic contamination compared to the manual suture. According to the authors, the stenosis is attributable to inflammatory processes resulting from the dehiscence in the manual anastomosis cases and from the anastomotic structure in the mechanical-suture case.


[Splenic arteriovenous fistula (a clinical case)]. A splenic arteriovenous fistula is a situation often presenting with signs of portal hypertension and with a characteristic murmur. Though rare, the possibility of a splenic arteriovenous fistula must be borne in mind in differential diagnosis, since it can be corrected surgically by resolving the portal hypertension.


Reoviruses: replication and molecular pathogenesis. The mammalian reoviruses serve as a model for understanding both how viruses multiply within cells and, at a higher level of complexity, how the virus is assembled to "deliver" the virus to the cells in the host in which they can multiply and cause disease. They thus serve as a model for the molecular determinants of viral pathogenesis.


Bactericidal activity of imipenem compared to erythromycin against intracellular Legionella pneumophila. Pneumonia is the leading cause of death due to nosocomial infections with mortality ranging from 30 to 70%. Because imipenem has potent in vitro activity against virtually all major causes of nosocomial pneumonia, including P. aeruginosa, S. aureus, members of the family Enterobacteriaceae, and anaerobic organisms, it is used by many physicians as the empirical therapy of choice in severe nosocomial pneumonias. Recognition of Legionella species as nosocomial pathogens has been increasing. The incidence of Legionnaires' disease among patients with nosocomial pneumonia is reported to be as high as 30% (1), but the real prevalence is unknown. Imipenem has bactericidal activity against Legionella in vitro but has not previously been tested for efficacy against intracellular Legionellae.


Efficacy of L-627, a new carbapenem, in the treatment of experimentally induced intra-abdominal infections in rats. A reproducible experimental model of intra-abdominal infections in rats has been devised in order to simulate intra-abdominal sepsis in patients. Pre-operatively, the rats were fed lean ground beef for two weeks in order to change the intestinal flora to one similar to that of humans. A 1-cm segment of ileum was isolated on its vascular pedicle. The intestine was then divided at each end of the segment and intestinal continuity was re-established by an end-to-end anastomosis. The segment of ileum was then returned to the abdominal cavity. This experimental model was used to compare the efficacy of L-627 with the combination of gentamicin plus metronidazole. Eighty per cent of the untreated animals died within three days. Animals treated with L-627 or gentamicin plus metronidazole had significantly decreased mortality and increased cure rates during the experimental period. Only two animals in the two treatment groups died. L-627 seems to be as useful as gentamicin plus metronidazole in the treatment of intra-abdominal infections.


Efficacy of subinhibitory concentration of pefloxacin in preventing experimental Staphylococcus aureus foreign body infection in mice. Adhesion is the first step leading to colonization and infection of a foreign body (FBI). To assess the ability of a subinhibitory concentration (subMIC) of pefloxacin (P) to prevent such infection, an experimental model was developed in Swiss albino mice. Subcuts of polyurethane catheters (Vygon) were placed in the peritoneal cavity of animals and 24 hours later, different inocula of an adherent strain of Staphylococcus aureus (SA) (MIC of P:0.8 mg/l) were injected i.p. Unexposed SA served as controls. Two days later the removed catheters, blood and spleen specimens were quantitatively cultured for bacterial content and identity. Infection was defined as more than 10 CFU/ml of SA recovered. Significant protection of mice, with lower dissemination, was found with inoculum sizes of 10(5) and 10(6). These results suggest that subMICs of P may confer protection against foreign body infection.


Experimental chemotherapy of leishmaniasis with adenosine analogue Formycin A, in combination with inhibitor of nucleoside transport, nitrobenzylthioinosinate. A single dose of the adenosine analogue Formycin A (FoA) (20 mg/kg), combined with nitrobenzyl mercaptopurine ribonucleoside 5'-monophosphate (NBMPR-P) (10 mg/kg), a prodrug of nitrobenzylthioinosine (NBMPR), was effective in reducing the size of the foot pad lesions from 7.4 +/- 0.2 to 3.9 +/- 0.2 of Syrian golden hamsters infected with Leishmania major. There was a statistical difference (p < 0.01) in the size of the foot pad by the fifth day between the infected groups that received treatment and the controls, as well as between the groups that were treated with combined drugs and FoA only. The initial reduction in size of the foot pad noted in the group that received only FoA was transient. The effect of FoA or FoA combined with NBMPR on the in vitro cultured promastigotes was similar, indicating that the transport inhibitor might be manipulating the availability of FoA in the host's macrophages where the leishmania amastigotes are resident. The results further indicate the need to explore the usefulness of combining cytotoxic nucleoside analogues with host protecting nucleoside transport inhibitors in the treatment of protozoan parasitic infections.


The efficacy of clarythromycin (A-56268, TE-031) in the treatment of genital chlamydial infection. The authors report the preliminary results of an experience of treatment with clarythromycin in Chlamydia trachomatis endocervicitis/endourethritis; 100% of 51 outpatients treated had negative ELISA results 7-10 days after the end of treatment with clarythromycin 500 mg. b.i.d. for 7 days. Among 64 female outpatients with chlamydial cervicitis treated with erythromycin 1 g b.i.d. for 7 days, 88% were negative at ELISA at the same intervals after therapy. The authors conclude that the efficacy of clarythromycin in this experience makes it use worthy of other and more extensive studies.


L-carnitine and coenzyme Q10 protective action against ischaemia and reperfusion of working rat heart. The protective effect of L-carnitine, coenzyme Q10 and their combination on haemodynamic and metabolic variables has been investigated in isolated perfused working rat hearts after 10 min of global normothermic ischaemia followed by 60 min of reperfusion. In untreated rats or in rats treated only with L-carnitine or with coenzyme Q10, this experimental condition did not induce any irreversible myocardial injury as measured by leakage of cardiac enzymes; however, it decreased some haemodynamic parameters such as cardiac output and minute work, as well as the ATP concentration and the total adenine nucleotide pool. No variations in haemodynamic and metabolic parameters were observed in the rats treated with L-carnitine plus coenzyme Q10. In the perfusate of the hearts of the rats treated with both compounds, a lower purine release (a good index of myocardial energy balance) was also obtained. Although the molecular mechanisms remain to be defined, it appears that the association of L-carnitine and coenzyme Q10 is more effective than using these compounds separately. The complementary and synergic actions of L-carnitine and coenzyme Q10 on metabolism and against peroxidation by oxygen reaction species may explain the efficacy of their association.


Effect of carnitine and coenzyme Q10 on the calcium uptake in heart sarcoplasmic reticulum of rats treated with anthracyclines. The effect of the association of carnitine and coenzyme Q10 on doxorubicin cardiotoxicity has been investigated. The two drugs administered to rats for two weeks have lower protective activity when they are administered separately rather than given in association (carnitine 200 mg/kg/day, coenzyme Q10 10 mg/kg/day) for the acute toxic effect of doxorubicin on perfused functioning isolated hearts. The sarcoplasmic reticulum damage measured by calcium-uptake is lower in rat hearts treated with the combined drugs. Deferoxamine and phosphocreatine, two compounds which protect from peroxidative damage due to iron and copper ions, show very strong protection from acute doxorubicin toxicity in isolated perfused hearts. Carnitine and coenzyme Q10 do not protect sarcoplasmic reticulum from iron ions damage, suggesting that their mechanism of protection is not directly related to peroxidation due to metal ion-dependent cardiotoxicity of doxorubicin.


Myelin palingenesis. 2. Immunocytochemical localization of myelin/oligodendrocyte glycolipids in multilamellar structures. Myelin is a membrane with unique characteristics that set it apart from any other membrane. It has a very high lipid:protein ratio (approximately 75:25) not found in other multilamellar membranes; it has a high content of two glycolipids--galactocerebrosides and sulfatides--which account for 26.5% of its lipids. The physiological role of these glycolipids in myelin and/or oligodendrocytes is unknown, but evidence that Abs directed against them interfere with myelination has been presented. Moreover, one of the early events in the process of oligodendrocyte differentiation prior to myelination is the acquisition of galactocerebroside on their surface. In earlier work, we have demonstrated that adhesion of oligodendrocytes to a positively charged substratum signals the commencement of myelinogenesis. Among the events that take place following adhesion are the rapid synthesis of glycolipids. Since over time in culture, oligodendrocytes elaborate multilamellar membranes that contain all the myelin characteristic proteins, we undertook to investigate whether these structures also accumulate myelin characteristic glycolipids. We have used three monoclonal antibodies--two are directed against galactocerebroside, the third one is an antisulfatide--in conjunction with the immunogold method, at the electron microscopic level, to examine the distribution of these glycolipids in the multilammelar structures that accumulate in long-term oligodendrocyte cultures. Our data show that galactocerebrosides and sulfatides are present in the multilamellar structures. Staining is easily demonstrated on the outermost membrane. However, as was the situation with myelin proteins, detection of these glycolipids on the inner lamellae is only achieved at the expense of destroying the ultrastructure. This is so, independent of whether the structures are compact or not.(ABSTRACT TRUNCATED AT 250 WORDS)


Expression of the PMP-22 gene in Trembler mutant mice: comparison with the other myelin protein genes. The Trembler mouse suffers from a dominantly inherited autosomal mutation affecting the Schwann cell activities, which results in an abnormal myelination of the peripheral nervous system. Very recently, it has been shown that the mutation is in the PMP-22 gene. However, the level of expression of the mutated gene in trembler mice has not been studied. Therefore, we measured the steady-state levels of mRNA encoding PMP-22 in the sciatic nerve of normal and trembler mice, and we compared these results with the steady-state levels of mRNAs encoding the major peripheral nervous system myelin proteins. Our results show that all the myelin protein genes studied are affected by the trembler mutation but to a different extent, and that the PMP-22 gene is expressed at very low levels in the trembler nerve. This suggests that regulation of the expression of the PMP-22 gene is altered in the Trembler mutant.


Developmental expression of glial fibrillary acidic protein and actin-encoding messages in quaking and control mice. Quaking is a neurological mutation leading to pleiotropic phenotypic expression, the most prominent being disturbed myelin formation in the central nervous system (CNS) with minor abnormalities in the peripheral nervous system. Previous immunochemical measurements of glial fibrillary acidic protein (GFAP) revealed a marked increase in the protein in several areas of the CNS. To further characterize the regulation parameters of GFAP synthesis, we analyzed the levels of GFAP mRNA in 5 regions of the CNS, some with elevated levels of GFAP and some without. This was compared to the developmental expression of GFAP transcripts in the same regions in normal mice. To establish the specificity of the variations observed with this astroglial specific message, we conducted a similar investigation with actin RNA which is expressed by several cell types in the CNS. Both the actin and the GFAP message were found to be increased in the adult mutant throughout the CNS. In 2-year-old normal mice the messengers for both cytoskeleton proteins were expressed in a higher amount than in young adults.


Neural cell adhesion molecules are present in the fetal human primary olfactory pathway. Olfactory tissues from human fetuses (17.5-28 weeks of gestation) were stained by immunofluorescence for neural cell adhesion molecules (N-CAMs). Staining for N-CAMs was most prominent in the olfactory nerve bundles in the lamina propria, while in the olfactory epithelium, it was present on the olfactory receptor neurons and globose basal cells. The basal cells proper and supporting cells lacked N-CAMs. In the olfactory bulb, only the olfactory nerve and glomerular layers showed moderate labeling for N-CAMs. Western blot analysis showed that the N-CAMs of the fetal human primary olfactory pathway consisted of three molecular isoforms, N-CAM180, N-CAM140 and N-CAM120.


Norepinephrine utilization in the hypothalamus of the male rat during adolescent development. This study examined the influence of adolescent development and pubertal changes in gonadal function on the development of norepinephrine (NE) turnover in the hypothalamus and cerebral cortex of rats from late juvenile to young adult ages. In one study, NE utilization was estimated in intact male rats and in male rats castrated at 14 days of age. NE levels were measured 15, 30, 45, 60, 120, and 240 min after inhibition of catecholamine synthesis at 28, 42, and 70 days of age. In a second study, male rats were made precocious by chronic testosterone exposure over days 14-28 and on the 28th day NE utilization was measured in both the hypothalamus and cerebral cortex. Turnover rates were calculated based on steady-state kinetics. The results indicate that in vivo NE levels and turnover rates in both the hypothalamus and cortex significantly increase from a late juvenile age to adulthood. However, when NE levels measured after synthesis inhibition were expressed as a percentage of the mean basal values, there was a significant effect of age only in the hypothalamus. Hence, the age-related increases in hypothalamic NE turnover appear to reflect age-related changes in NE utilization, whereas the increases in cortical turnover rates reflect the increasing basal levels and not age-related changes in NE utilization. During mid-puberty (42 days), NE utilization in the hypothalamus was markedly different from that observed in this region at either 28 or 70 days. At 28 and 70 days, NE levels decreased to 50% of basal levels by 4 h following synthesis inhibition.(ABSTRACT TRUNCATED AT 250 WORDS)


Development of the paramedian lobule of the cerebellum in wild-type and tottering mice. The mutant mouse tottering, (tg/tg), and the compound heterozygote mouse (tg/tg1a) exhibit three neurological disorders: ataxia, petit mal-like absence seizures and myoclonic intermittent movement disorders which are independent of the absence seizures. The tottering mouse carries an autosomal recessive single gene mutation on chromosome 8, and behavioral symptoms are first observed in the 3rd to 4th week of age. Using an additional genetic marker, Oligosyndactyly (Os), it is possible to distinguish tg/tg and tg/tg1a mice from wild-type mice at birth; nonaffected heterozygous littermates carry the Os mutation while tottering and compound heterozygous mice do not carry the Os gene. Similar to neurons found elsewhere in the brain, cerebellar Purkinje cells in both the wild-type and mutant mice were found to decrease in diameter with maturation. Forebrain weight, hindbrain weight, Purkinje cell dimensions and the thickness of the molecular layer in the paramedian lobule of the cerebellum in mutant mice were found to be reduced in mutants after, but not prior to the onset of behavioral symptoms.


Effects of neonatal asphyxia on the serotonin neuron system in the developing brain studied by immunohistochemistry. The effects of neonatal asphyxia on the serotonin neuron system were examined using the immunoperoxidase method. Male mice, 2 days of age, were exposed to total asphyxia (100% CO2) for 30 min. Mice that spontaneously survived were perfused transcardially with a fixative at 15, 30 and 60 days of age. Quantitative immunohistochemical analysis at 60 days of age demonstrated a significant decrease in the numbers of serotonin-immunoreactive cell bodies in the nucleus raphe dorsalis, the nucleus raphe pontis, the subpyramidal region, the total raphe system and the whole brain, while no significant reduction in the number of serotonin-immunoreactive cell bodies was observed in the caudal raphe system. Presumably degenerative changes in serotonin-immunoreactive fibers were observed in various parts of the brain of mice subjected to total asphyxia at 15 days of age, and the numbers of degenerated fibers decreased in almost all parts of the brain, the exception being the caudal portion of the brainstem, at 30 and 60 days of age. These results suggested that neonatal asphyxia induced permanent changes in the serotonin neuron system, with regional differences.


[The epidemiology and risk factors, in particular environmental, of malignant non-Hodgkin's lymphomas. The Working Group on the Epidemiology of Tumors of the Hemo- and Lymphopoietic Systems in Italy]. Malignant non-Hodgkin's lymphomas (NHL) represent a category of neoplasms that includes several types of tumours with different hystological and clinical characteristics. No large differences exist in incidence and mortality for the whole category of lymphomas among different countries. On the other hand data concerning different subclassifications of lymphomas in different countries are not available. The incidence of NHL increased in recent years in USA and in the European countries. Data from the Cancer Registry in the province of Varese, the registry with the longest high-quality registration period in Italy, indicate the same tendency. Also mortality rates show an increasing trend in Europe and in the USA. The cause of changing in incidence and in mortality rates for NHL are unknown. Anyhow many factors, viral, chemical and immunological are known to be associated to the occurrence of lymphomas. Risk factors and in particular environmental factors are reviewed. Problematic aspects, in relation to methodologies adopted in these studies, are focused.


Health effects of the Bhopal gas leak: a review. The methyl isocyanate (MIC) gas leak from the Union Carbide plant at Bhopal, India in 1984 was the worst industrial disaster in history. Exposure estimates of gas concentrations in the area range from 85 to 0.12 ppm. Of the approximately 200,000 persons exposed, 3598 deaths have resulted as of November 1989. Chronic inflammatory damage to the eyes and lungs appears to be the main cause of morbidity. Reproductive health problems in the form of increased spontaneous abortions and psychological problems have been reported. Questions about the nature of MIC toxicity have been raised by the persistence of multi-systemic symptoms in survivors. Animal studies using radio-labeled MIC given by the inhalation route have shown that the radio-label is capable of crossing the lung membranes and being distributed to many organs of the body. This paper reviews health effects of gas exposure from published studies and discusses some of the clinical and epidemiological issues being debated.


[The quality of the data on hospital discharge]. Methods and results of a study on quality of the hospital discharge data are described. The study has been performed in the Hospital of Padova (Italy) and carried out on charts of all patients discharged in 1988. The completeness of discharge forms compilation, the appropriateness of diagnosis and surgical procedures coding, the correspondence between discharge forms and medical record data, the correspondence between discharge forms and computerized data have been analyzed. Four thousand seven hundred seventy six discharge forms were analyzed and 1226 (26.2%) showed one or more errors. Coding procedures have been incorrect in 18.6% of the cases. Improvement actions which have been adopted are described.


[Major ambulatory surgery: organizational models]. In this essay, the authors provide a definition for those medical care facilities representing a consolidated alternative to traditional hospitalization. These facilities can be basically ascribed to the following patterns: day case surgery; day-hospital activity; home-care. Day case surgery is a complex and, in most cases, interdisciplinary procedure; this type of activity necessitates a pre-hospitalization period and often also a "protected discharge" or even a home-care service. Some specific criteria regarding day surgery activity have been defined as follows: the main criteria have a clinical nature, but they interact with others belonging to a social and structural-organizational order. The Royal College of Surgeons of United Kingdom has officially recognized in 1985 this medical care typology as one of the constituents of surgical care, and has evaluated that at least 1/3 of the overall operations could be carried out as day care surgery. In the United States, besides hospital and ambulatory surgery activity, a new pattern known as "free-standing center" has been promoted; in 1993, 35% of the operations is expected to be carried out in day case surgery centers. As far as Italy is concerned, in 1988 only day-hospital practice has been adequately recognized as an alternative medical care facility to traditional hospitalization. The Emilia Romagna region, in order to increase day case surgery activity, has issued in 1991 a list of 53 DRGs, in which day bed units treatment was possible. Up to now, however, only a small part of these diseases is treated on a day case surgery basis.


[An operating model for assessing the practical efficacy of screening tests: the case of amblyopia]. Standard for assessing the efficacy of screening programs are at present well-established. Nevertheless, the effectiveness of screening programs can reduced by several factors in real world conditions. The aim of this work is to check the feasibility of an operational model for the practical evaluation of the effectiveness of screening programs. In this model seven critical points are defined (recruitment, screening test sensitivity, access to diagnostic services, diagnosis, compliance to follow-up, treatment compliance, therapy) and their contribution to the reduction of potential effectiveness is calculated. For each point consequent problem(s) and possible solutions are predefined. The model was tested with the results of the screening program for amblyopia of the Community Health Service of USL 32 Treviglio (BG) assuming 40% and 97% sensitivity of the screening test. For this screening the reduction of effectiveness at the seven critical points ranged from 0 to 60%, with a total reduction of effectiveness to 15.6-37.8%. The operational model was used to identify causes of this reduction. This kind of analysis is proposed as a tool for evaluation and improvement of the effectiveness of efficacious screening program.