Risk factors for substance use by Mexican American youth with and without learning disabilities

This survey study was designed to (a) investigate the prevalence of minor and major substance use among low socioeconomic status elementary and middle school Mexican American students identified with learning disabilities (LD; n = 150) and without LD (n = 150), and (b) identify psychosocial and environmental risk factors that may lead to the use of various substances among both non-learning disabled (non-LD) students and students with LD in an all-Mexican American sample. No differences were found in the use of substances between the two groups. Risk factors that were found to influence the use of minor substances for students identified as learning disabled, as opposed to the non-LD students, included use of substances by close friends and susceptibility to peer influence. Risk factors that were found to affect the use of major substances for students identified as learning disabled, as opposed to the non-LD students, included the number of minor substances used and stressful life events. Findings are discussed in the context of differing pathways leading to the use of substances for non-LD students and students with LD within an intraethnic group study.

[Expression and regulation of milk protein gene in mammalia]

On the basis of introducing the structures and relations of evolution in milk protein genes, the factors involved in gene expression including cis-acting elements, trans-acting factors as well as induction of hormones were discussed. Finally the applicable prospect of mammary gland as a bioreactor was estimated.

[Transsphenoidal microsurgical removal of GH-secreting pituitary adenoma in: a report of 200 cases]

From July 1979 to April 1992, 212 cases of GH-secreting pituitary adenoma were treated transsphenoidally by microsurgical technique, of whom two hundred cases monitored with their GH levels at preoperative and postoperative periods. The majority of cases totally 132 cases were of macroadenoma, and 68 cases were of microadenoma. 138 cases were operated on after April 1986. The cure and remission rate averaged to 72.5%, rising from 44.4% (before 1986) to 80.5% for microadenoma and from 31.4% to 69.1% for macroadenoma due to improvement of technique and accumulation of experience. One patient died of angiocardiopathy suddenly during operation. Mortality rate was 0.5%. The follow-up observation of postoperative GH levels in 52 cases revealed that the GH levels within 2 weeks after operation were the same as in 3-6 months. It is thought that the early GH levels may represent the surgical results. The surgical technique is described and factors influencing the surgical results, prevention and treatment of operative complications are discussed in this paper.

Illegal drug use, alcohol and aggressive crime among Mexican-American and white male arrestees in San Antonio

This research explores the relationship between use of certain drugs and aggressive crimes among Mexican-American and White male arrestees in San Antonio, Texas, for 1992. This is based on a Drug Use Forecasting (DUF) sample of 534 male arrestees administered a drug urine analysis test and questionnaire by the Department of Justice and the city of San Antonio. Using a four-way asymmetrical analysis, logit-models were tested to examine the relationships between the response variable, the types of crimes charged (nonaggressive versus aggressive) and a set of exploratory variables, ethnicity (White versus Hispanic), drug test results (positive versus negative), and alcohol use (infrequent versus frequent). The logit-analysis allows the specification of a subset of relevant models to be tested for their adequacy of fit. Findings indicate a complex but interpretable pattern between drug use, alcohol use patterns, and aggressive crimes. A surprising finding was that more aggressive crimes were committed by all men testing negative for drugs. Mexican-Americans with frequent alcohol use and testing positive for drugs were twice as likely to commit an aggressive crime (a crime associated with violence) than Whites in the same subgroup. The implication of these findings for prevention strategies aimed at alcohol and other drug users involved in violent behavior is discussed.

Phenotypic heterogeneity of persistent expansions of CD4+ CD8+ T cells

A group of 18 individuals is described that manifest persistent (follow up between 4 and 57 months) expansions (ranging from 10 to 70%) of CD4+ CD8+ peripheral T cells. In nine individuals there was no apparent underlying disease whereas the remaining displayed a wide range of unrelated diseases. Analysis of the cell surface immunophenotype showed that all individuals express high densities of CD2, CD3, CD5, and TCR alpha/beta on their CD4+ CD8+ subset. On the contrary, these cells did not express CD25, CD38, CD71, HLA-DR, and the beta chain of the interleukin-2 receptor (p75) but expressed high density of CD29 and low density or absence of CD7. CD8 was "dim" in most individuals and consisted only of the CD8 alpha chain isoform. These individuals could be further divided into two subgroups based on the following parameters: in eleven cases CD4+ CD8+ cells had an LGL morphology and expressed the CD11b, CD56 and CD57 NK-associated antigens; in addition, a high percentage of CD4+ CD8- cells from the same individuals also expressed NK-associated antigens on their cell surface (subgroup A). The CD4+ CD8+ cells of the remaining individuals had small lymphocyte morphology, expressed little or no CD11b and CD56 and their CD4+ CD8- cells did not express NK-associated antigens at all (subgroup B). Finally, CD8 was "bright" on the CD4+ CD8+ cells of three individuals and in these cells also the CD8 beta chain isoform was present (subgroup C). Southern blot hybridization of genomic DNA with a T-cell receptor beta probe revealed that of the sixteen individuals examined four had a monoclonal, seven an oligoclonal, and five a polyclonal molecular configuration. The present data indicate that persistent CD4+ CD8+ expansions represent a novel heterogeneous subset of T cells.

Evaluation of laboratory methods for cystic fibrosis carrier screening: reliability, sensitivity, specificity, and costs

We report a comparative evaluation of three different laboratory methods for screening large numbers of mouthwash DNA samples for common cystic fibrosis mutations. Sensitivity, specificity, and costs of ARMS (allele refractory mutation detection system), dot blotting, and a deletion/digest/PAGE method (multiplex PCR of exons 10 and 11, digest with HincII followed by polyacrylamide gel electrophoresis (PAGE)) were assessed. ARMS was the most reliable and sensitive method and so was considered more suitable than the cheaper deletion/digest/PAGE. As well as being less reliable than ARMS, the dot blotting method assessed was considerably more costly. ARMS was the best laboratory method for CF screening tested.

Primary cilia in cultured mammalian cells: detection with an antibody against detyrosinated alpha-tubulin (ID5) and by electron microscopy

A fluorescent-labelled antibody against detyrosinated alpha-tubulin, ID5 (Wehland and Weber, 1987), allows primary cilia and centrioles to be detected rapidly and accurately for analysis in cell cultures. Many features of primary cilia have been re-examined, including frequency of expression in relation to levels of confluency, different sera, different cell cycle stages, and following trypsinization and centrifugation procedures. The detection of multiple ciliation per cell, and the precise positioning of cilia in cells in monolayers are readily recorded. The findings are discussed in relation to cilium expression in cell growth and cycling, to previous findings based on ultrastructural analysis, and to their potential role in sensing the local environment.

Sensitivity of 3T3 cells to low serum concentration and the associated problems of serum withdrawal

The sensitivity of cells to serum deprivation depends upon whether they are transformed. Most supplies of 3T3 cells are of this type and are considerably less sensitive than untransformed cells. In addition, the apparently simple manoeuvre of reducing serum levels has considerable effects on cell fragility, viability, growth rate and metabolism, which were found to be due to small changes in pH, substrate availability, cell density and other parameters, many of which cannot be attributed to the absence of growth factors from the medium. Supplementation of medium with bovine serum albumin (BSA) to compensate for low normal serum protein did not aid growth nor offset the disturbances caused by low serum levels themselves. Problems associated with the altered precursor availability for DNA, RNA and protein synthesis are also discussed.

Prospective study on the diagnosis of hepatocellular carcinoma by using alpha-fetoprotein reactive to lentil lectin

In order to study the changes in AFP reactive to lentil lectin (AFP-R-L) during the development of hepatocellular carcinoma (HCC) and its clinical significance, AFP-R-L was monitored in 64 patients by using 20-400 ng/L AFP and negative imaging localization. AFP-R-L was determined by using affino-crossed-immunoelectrophoresis autoradiography. AFP-R-L above 25% was considered positive for the diagnosis of HCC. Over a follow-up of 3-31 months, 32 patients developed HCC. The positivity of AFP-R-L was 59.4% in the HCC group at the first assay. The accuracy of using positive AFP-R-L values to predict HCC was 95.0%. Increased AFP-R-L levels appeared 3-24 months earlier than did positive imaging location. The results suggest that positive AFP-R-L values can predict the development of HCC.

[Preparation and cytotoxicity of McAb-HSA-MTX conjugates]

In the present study, methotrexate (MTX), was conjugated with a murine monoclonal antibody (79) to human common acute lymphoblastic leukemia antigen (CALLA), with human serum albumin (HSA) as an intermediary. The highest molar ratio of McAb 79:HSA:MTX in the conjugates was 1:2. 63:117. The conjugates obtained retained both antibody binding and drug activities. Although there was some loss of drug activity in binding to antibody, the toxicity of McAb79-HSA-MTX was entirely specific for the target cell, and the cytotoxicity of McAb79-HSA-MTX against CALLA+ cells was greater than that of control S13 (Anti-human urokinase)-HSA-MTX. The ratio of 79-HSA-MTX cytotoxicity to the target and non-target cells was 66:1, whereas there was no cytotoxicity to target cells when McAb79 was used only. There was no cytotoxic difference between 79-HSA-MTX and S13-HSA-MTX against CALLA- SB cells. These results suggest that the cytotoxicity of 79-HSA-MTX against CALLA leukemia cells is specific and this specificity is mediated by McAb79.

[Effect of ke-tang-Ling administration on the function of pancreatic islets cells in non-insulin-dependent diabetes mellitus]

Radioimmunoassay methods were modified for insulin(IRI), C-peptide (IRCP) and glucagon (IRG) in the clinical investigation on normal subjects and 38 patients with non-insulin-dependent diabetes mellitus (NIDDM). In the control group, the peaks of glucose and IRI appeared 1 hour after glucose was taken. IRCP peak, however, appeared 1 hour later. IRG showed its maximum value on fasting and then reached its lowest point at the second hour after glucose loading. The authors' interests were focused on the changes of blood glucose, IRI, IRCP, and IRG in oral glucose tolerance test (OGTT) before and after Ke-Tang-Ling (KTL) was administered in NIDDM. The results demonstrate that the glucose levels and undercure areas at various phases in OGTT were significantly decreased (P less than 0.01) in comparison of before and after the treatment with KTL in NIDDM (including obese and non-obese groups). In non-obese group, however, IRI, IRCP, and their undercure were remarkably increased (P less than 0.01). In obese group their values were decreased. It suggests that KTL plays a therapeutic role in decreasing blood glucose in non-obese NIDDM. The mechanism involved in this process may be related to its stimulating effect. IRG levels were decreased also (P less than 0.01) after the treatment with KTL in both obese and non-obese NIDDM, suggesting an inhibitory effect on glucagon secretion from alpha cells in pancrease.

Induction by butylated hydroxyanisole of specific molecular forms of glutathione S-transferase and UDP-glucuronyltransferase and inhibition of development of gamma-glutamyl transpeptidase-positive foci in rat liver

Effects of an antioxidant, butylated (3-tert-butyl-4-) hydroxyanisole (BHA) on the induction of specific molecular forms of glutathione S-transferase (GST), UDP-glucuronyltransferase (UDP-GT) and other glutathione-related enzymes in rat liver were investigated. The development of gamma-glutamyl transpeptidase (gamma-GTP)-positive foci and hyperplastic nodules induced by diethylnitrosamine, 200 mg/kg i.p., followed by 0.02% N-2-fluorenylacetamide (FAA) in diet plus partial hepatectomy was inhibited by the administration of 0.75% BHA in the FAA-containing diet. Inhibition was reflected in decreased area of gamma-GTP-positive foci which correlated with a decrease in gamma-GTP activity measured biochemically. Under the present experimental conditions, total activities of GSTs, especially that of GST-A form, and of UDP-GTs, especially that of the late fetal form (o-GT), were markedly increased, together with glutathione levels in the whole liver, within one week after BHA administration. Without BHA administration the activities of GST-A and o-GT, as well as glutathione levels, were also increased by FAA treatment, primarily localized within gamma-GTP-positive foci. These results suggest that the induction of specific molecular forms of detoxicating enzymes either in enzyme-altered foci or in the whole liver may play an important role in determining the extent of development of preneoplastic nodules from initiated foci under the short term induction conditions used.

Molecular forms of glutathione S-transferase and UDP-glucuronyltransferase as hepatic preneoplastic marker enzymes

Changes in molecular forms of glutathione S-transferase (GST) and UDP-glucuronyltransferase (UDP-GT) as hepatic detoxicating enzymes were investigated during chemical hepatocarcinogenesis in the rat. The activity and the protein amount (formula; see text) itself of the GST-A form, which has fetal characteristics and is separable from other forms by CM-Sephadex column chromatography and by immunologic techniques, was much increased in gamma-glutamyl transpeptidase (gamma-GTP)-positive foci or hyperplastic nodules (HNs) induced by diethylnitrosamine and 2-fluorenylacetamide or 3'-methyl-4-dimethylaminoazobenzene. The activity of enzyme 1 (late fetal form) of UDP-GT assayed with o-aminophenol (o-GT) also increased with increased number of the foci or HNs, while the activity of enzyme 2 (neonatal form) assayed with phenolphthalein (p-GT) changed but little. The foci and HNs were stained more strongly than the nonnodular areas immunohistochemically using the antibody against purified GST-A or o-GT. The two activities were also increased in well-differentiated hepatomas, but they were decreased in moderately and poorly differentiated hepatomas, and activating enzymes such as cytochrome P-450 were markedly decreased from HN. GST-A and o-GT differ from fetal enzymes such as those of carbohydrate metabolism in that they are inducible in the short-term by drugs, including carcinogens, and they show the highest activities in HNs, and so they may be considered as hepatic preneoplastic (PN) antigens.

Changes in activities of uridine diphosphate-glucuronyltransferases during chemical hepatocarcinogenesis

Changes in the activities of hepatic uridine diphosphate-glucuronyltransferases (UDP-GTs) were investigated during the induction of hyperplastic nodules (enzyme-altered foci) by a system consisting of diethylnitrosamine (DEN) followed by N-2-fluoroenylacetamide (FAA) and including partial hepatectomy. The activity of the late fetal form of UDP-GT, which was assayed towards o-aminophenol (o-GT activity), was induced rapidly by a single ip injection of DEN (200 mg/kg) or 3-methylcholanthrene (40 mg/kg) or by the continuous administration of FAA (0.02% in diet) alone. This activity further increased with the appearance of the nodules, while the activity of the neonatal form, which was assayed toward phenolphthalein (p-GT activity) and was inducible by phenobarbital, increased only slightly. The increased o-GT activity showed a good correlation with the increased number or area of enzyme-altered foci detected by gamma-glutamyltransferase activity staining, but the p-GT activity did not, though it was significantly increased. In hyperplastic nodules and well differentiated hepatomas induced by DEN (0.1% in drinking water, 3 weeks) but isolated long after cessation of DEN, o-GT activity was markedly increased, but p-GT activity was decreased or remained at the level of normal rat liver. These data indicate that the increased o-GT activity may be one of the enzyme markers for preneoplastic hepatic cells. An antioxidant, butylated hydroxyanisole (BHA) (0.75% in diet), markedly elevated the hepatic o-GT activity rapidly after being administered with FAA in the above system, and the induction of the nodules was inhibited.