Cooperative activity of alpha4beta1 and alpha4beta7 integrins in mediating human B-cell lymphoma adhesion and chemotaxis on fibronectin through recognition of multiple synergizing binding sites within the central cell-binding domain

We have quantitated the relative contributions of the constitutively active alpha4beta1 and alpha4beta7 integrins and the domains embodying their cognate binding sites in mediating human B-cell lymphoma adhesion and chemotaxis on fibronectin. By cooperating, the central cell-binding and IIICS carboxy-terminal domains were entirely responsible for the adhesion activity displayed by fibronectin, and their relative contribution to this process was estimated to be 30% versus 70%. Assessment of the leukocyte-substrate binding strength (ie, dynes/cell) indicated a 10-fold higher avidity of the cell-IIICS domain interaction. The two integrins interchangeably recognized both domains, but differed quantitatively in their participation in the adhesive event, as well as in domain preference. The use of 3Fn (according to the nomenclature proposed by Bork and Koonin [Curr Opin Struct Biol 6:366, 1996] for the type III fibronectin modules) module-specific antibodies and recombinant polypeptides showed that alpha4 integrins recognized both the RGD sequence (3Fn10) and an apparently novel synergistic site located within the 3Fn8 module; even in this case, the integrins displayed a distinct binding site preference. Interleukin-1beta (IL-1beta)/IL-2-induced chemotaxis also involved cooperative function of the central cell-binding and IIICS domains, but the mechanisms regulating this phenomenon differed markedly from those controlling cell adhesion. First, the relative contribution of the individual domains was comparable, but neither of the individual domains promoted migration to the extent observed on intact fibronectin. Secondly, alpha4beta1 and alpha4beta7 integrins were both involved in the domain-binding necessary for initiation of migration, but the relative contribution of each receptor in the chemotactic process was less disparate than for initial cell adhesion. Thirdly, the mode by which chemotactic B-lymphoma movement was supported by the central cell-binding domain differed from that sustaining cell adhesion in that it involved independent recognition of either the 3Fn8 or the 3Fn9 module, which acted in synergy with the 3Fn10 module. Our data provide novel evidence concerning the relative importance of the constitutively active alpha4beta1 and alpha4beta7 integrins for the interaction of B-cell lymphoma cells with fibronectin, and they emphasize a multiple and diverse recognition of sites responsible for either anchorage or locomotion of tumor leukocytes on this matrix molecule.

Modulating the Th1/Th2 balance in inflammatory arthritis

The balance between Th1 and Th2 cells regulates the choice between inflammatory and antibody-mediated immune responses. To an increasing extent this balance is thought to involve the participation of antigen-presenting cells, rather than the entirely autonomous activity of T cells and their cytokines. Here we survey current opinion concerning the working of this balance, and its condition in rheumatoid arthritis and the other inflammatory arthritides. The contrast between Lyme arthritis and reactive arthritis is particularly illuminating, since one is triggered by extracellular and the other by intracellular infection. We describe current approaches to the modulation of this balance. Guided by the principles that genetic polymorphism is likely to identify relevant genes, that any cytokine gene picked up by a virus must matter and that natural immunosuppressive activity at mucosal surfaces should be worth exploiting, we identify as particularly worthy of attention: (i) IL-10, (ii) inhibitors of IL-12 production, (iii) inhibitors of CD40 ligand expression and (iv) oral and nasal tolerance. Other protective T cell subsets are touched on, and the impact of oligonucleotide arrays mentioned.

The glutamine synthetase from the hyperthermoacidophilic crenarcheon Sulfolobus acidocaldarius: isolation, characterization and sequencing of the gene

The glutamine synthetase (EC 6.3.1.2) from the hyperthermoacidophilic crenarcheon Sulfolobus acidocaldarius (DSM 639) was purified to homogeneity, characterized and the glnA gene isolated and sequenced. The amount of enzyme present in the cytosolic fraction from Sulfolobus cells showed a strong variation depending on the carbon and nitrogen sources in the growth medium. The enzyme was found to be a dodecameric protein composed of identical subunits of 52 kDa. It was stable at 78 degrees C in the presence of Mn2+ ions. The catalytic activity was regulated solely by feed-back inhibition through L-alanine and glycine and not by adenylylation. No evidence for the presence of isoenzymes was found. Sequence comparison showed that the Sulfolobus protein is most closely related to the glutamine synthetases of the I-beta type despite its regulatory properties and the finding that the known euryarcheal glutamine synthetase sequences belong to the I-alpha subgroup of these enzymes. Our phylogenetic analysis suggests that the gene duplication leading to the development of the I-alpha and I-beta enzymes preceded the separation of the archea and the bacteria.

The legal importation of prescription drugs into the United States from Mexico: a study of Customs declaration forms

The nature and magnitude of the problem of the diversion of prescription drugs from legal to illegal markets have been identified as a high priority by the federal government. This study was based on a random sample (2,005) of declaration forms of persons declaring Mexican prescription drugs at the US Customs office in Laredo, Texas. Of the 75 different types of drugs, the most frequently declared drugs were Valium (71%), Rohypnol (46%), and Tafil (25%), drugs highly associated with nonmedicinal use among United States teenagers and young adults. These data reinforce a documented need for more transnational cooperative efforts between the United States and Mexico.

[Clinical application of hydrogel membrane of silicone rubber for preventing adhesion in orthopedics]

Grafting hydrogels onto silicone rubber membranes were prepared by radiation technique for medical application. This material is characterized by high purity, hydrophilia, formation of stable hydrogel after water absorption, good biocompatibility, etc. Clinical application was initiated on the basis of animal experiments. The material was used in 47 cases of joint and tendon injuries, in 9 cases of rheumatoid arthritis, and in 4 other cases; totaling 60 cases. All patients were followed up for three and a half years after surgical operation. A general effectiveness of above 86% was noted.

JNK targets p53 ubiquitination and degradation in nonstressed cells

In this study we elucidated the role of nonactive JNK in regulating p53 stability. The amount of p53-JNK complex was inversely correlated with p53 level. A peptide corresponding to the JNK binding site on p53 efficiently blocked ubiquitination of p53. Similarly, p53 lacking the JNK binding site exhibits a longer half-life than p53(wt). Outcompeting JNK association with p53 increased the level of p53, whereas overexpression of a phosphorylation mutant form of JNK inhibited p53 accumulation. JNK-p53 and Mdm2-p53 complexes were preferentially found in G0/G1 and S/G2M phases of the cell cycle, respectively. Altogether, these data indicate that JNK is an Mdm2-independent regulator of p53 stability in nonstressed cells.

A two-year study of patterns and predictors of substance use among Mexican American youth

This study investigated the incidence and patterns of substance use in a school-age population, as well as predictive risk factors that may play an important role in understanding its initiation. Low socioeconomic status Mexican American fourth-, fifth-, and sixth-grade students were surveyed for two consecutive years in order to obtain information on their substance use and its relationship to specific demographic, environmental, and psychological risk factors. Results capture patterns of substance use among this population over the two years, as well as the relationship between reported risk factors in year one and the use of minor and major substances in year two.

The protective effect of procaine blocking on nerve-electrophysiological study during operation

OBJECTIVE

To clinically evaluate the protective effect of procaine blocking on nerves.

METHODS

Electrophysiological examination before and after procaine blocking was conducted on 32 nerves during operation, 18 of which were donor nerves and 14 were injured ones.

RESULTS

The latency of somatosensory evoked potentials (SEPs) was lengthened (15.30%) and the amplitude was lowered (18.47) after procaine blocking. Compared with the values before procaine blocking, the differences were significant (P < 0.01 and P < 0.05, respectively). SEP waves disappeared after procaine blocking in some cases (28.13%).

CONCLUSION

Latency of SEP is lengthened and amplitude is lowered after procaine blocking. In some cases, SEPs even disappear.

Smad proteins act in combination with synergistic and antagonistic regulators to target Dpp responses to the Drosophila mesoderm

Dorsal mesoderm induction in arthropods and ventral mesoderm induction in vertebrates are closely related processes that involve signals of the BMP family. In Drosophila, induction of visceral mesoderm, dorsal muscles, and the heart by Dpp is, at least in part, effected through the transcriptional activation and function of the homeobox gene tinman in dorsal mesodermal cells during early embryogenesis. Here we present a functional dissection of a tinman enhancer that mediates the Dpp response. We provide evidence that mesoderm-specific induction of tinman requires the binding of both activators and repressors. Screens for binding factors yielded Tinman itself and the Smad4 homolog Medea. We show that the binding and synergistic activities of Smad and Tinman proteins are critical for mesodermal tinman induction, whereas repressor binding sites prevent induction in the dorsal ectoderm and amnioserosa. Thus, integration of positive and negative regulators on enhancers of target genes appears to be an important mechanism in tissue-specific induction by TGF-beta molecules.

Blood volume redistribution on fluid treatments after burn-blast combined injury, especially with respect to the regulation role of microcirculation due to the Fåhraeus effect

Considering the Fåhraeus effect and the blood volume regulation role of the microcirculation, we used a new method for calculating the blood volume change in microcirculation, macrocirculation as well as the whole circulation (delta Vmic, delta Vmac, delta Vb), to compare fluid therapy effects of hypertonic saline dextran solution (HSD) and lactic Ringer's solution at the early stage after burn-blast combined injury (BBI). The measurement of plasma viscosity was used in this calculation. The results showed that, with calculation of the blood volume change in microcirculation and macrocirculation, this method could more exactly and distinctly display the change and distribution of blood volume during the therapy. It confirms that HSD treatment can increase blood pressure and attenuate tissue edema, by significantly increasing total blood volume, recouping delta Vmac. The study suggests that a desirable and practical clinical method for blood volume change can be developed based on the present study.

Relationship between apoptosis of brain cells and free radical scavenging ability in rats during acute intermittent hypoxia

It has been found that plateau hypoxia could induce apoptosis in rats' brain, but the mechanism was not clear. In order to study it further, we utilized acute intermittent hypoxia model to investigate reduced gliutathione (GSH), oxidized gliutathione(GSSG), super-oxide dismutase (SOD) and programmed cell death (PCD) or apoptosis (AP) in rats' brain. The results showed that with the increase of hypoxic exposure duration, apoptotic cells increased, the ratio of GSH/GSSG and the activity of SOD dropped. Regression analysis showed that there was a negative power relationship between the number of apoptotic cells and the ratio of GSH/GSSG or between the number of apoptotic cells and the activity of SOD in a limited range. It was concluded that there would be an intrinsic relationship between apoptosis and free radical scavenging ability in the organ.

The method of micro-displacement measurement to improve the space resolution of array detector

This paper introduces the method of micro-displacement measurement to improve the space resolution of limited size array detector. This method could also be applied in various research areas, especially in image measurement of nuclear detection.

Characterization of the synovial T cell response to various recombinant Yersinia antigens in Yersinia enterocolitica-triggered reactive arthritis. Heat-shock protein 60 drives a major immune response

OBJECTIVE

In Yersinia enterocolitica-triggered reactive arthritis (Yersinia ReA), the synovial T cell response is primarily directed against bacterial components, which are mostly unknown. This study was performed to investigate the synovial proliferative T cell response to a panel of recombinant Yersinia antigens in patients with Yersinia ReA and in controls.

METHODS

Synovial fluid mononuclear cells (SFMC) were obtained from 4 patients with Yersinia ReA and from 14 patients with arthritides of different etiology. SFMC were stimulated with 5 recombinant Yersinia antigens (the 19-kd urease beta subunit, 13-kd ribosomal L23 protein, 32-kd ribosomal L2 protein, 18-kd outer membrane protein H, and Y. enterocolitica heat-shock protein 60 [hsp60]), and with human, Chlamydia trachomatis, and Borrelia burgdorferi hsp60. Three T cell clones specific for Y. enterocolitica hsp60 were generated from 1 patient with Yersinia ReA. Antigen-induced cytokine release was measured by enzyme-linked immunosorbent assay.

RESULTS

SFMC from all 4 patients with Yersinia ReA responded to each of the Yersinia antigens except the 13-kd protein. These antigens were also recognized by SFMC from a subgroup of patients with undifferentiated arthritis (n = 4), but not by SFMC from other patients with arthritis of different etiology (n = 10). Y. enterocolitica hsp60 induced the strongest proliferative response in all cases. Two types of hsp60-reactive T cell clones could be obtained. One clone responded to all hsp60 variants, including the human variant, and showed a type 2 T helper (Th2)-like cytokine-secretion pattern. In contrast, another clone with specificity for the bacterial hsp60 proteins, but not the human equivalent, reacted with a more Th1-like pattern.

CONCLUSION

In Y. enterocolitica-triggered ReA, at least 4 immunodominant T cell antigens exist, which might be used in lymphocyte proliferation assays to identify patients with Yersinia ReA. The hsp60 is a strong antigen, inducing both bacteria-specific and potentially autoreactive CD4+ T cells of both the Th1 and Th2 type.

Regulation of the twist target gene tinman by modular cis-regulatory elements during early mesoderm development

The Drosophila tinman homeobox gene has a major role in early mesoderm patterning and determines the formation of visceral mesoderm, heart progenitors, specific somatic muscle precursors and glia-like mesodermal cells. These functions of tinman are reflected in its dynamic pattern of expression, which is characterized by initial widespread expression in the trunk mesoderm, then refinement to a broad dorsal mesodermal domain, and finally restricted expression in heart progenitors. Here we show that each of these phases of expression is driven by a discrete enhancer element, the first being active in the early mesoderm, the second in the dorsal mesoderm and the third in cardioblasts. We provide evidence that the early-active enhancer element is a direct target of twist, a gene encoding a basic helix-loop-helix (bHLH) protein, which is necessary for tinman activation. This 180 bp enhancer includes three E-box sequences which bind Twist protein in vitro and are essential for enhancer activity in vivo. Ectodermal misexpression of twist causes ectopic activation of this enhancer in ectodermal cells, indicating that twist is the only mesoderm-specific activator of early tinman expression. We further show that the 180 bp enhancer also includes negatively acting sequences. Binding of Even-skipped to these sequences appears to reduce twist-dependent activation in a periodic fashion, thus producing a striped tinman pattern in the early mesoderm. In addition, these sequences prevent activation of tinman by twist in a defined portion of the head mesoderm that gives rise to hemocytes. We find that this repression requires the function of buttonhead, a head-patterning gene, and that buttonhead is necessary for normal activation of the hematopoietic differentiation gene serpent in the same area. Together, our results show that tinman is controlled by an array of discrete enhancer elements that are activated successively by differential genetic inputs, as well as by closely linked activator and repressor binding sites within an early-acting enhancer, which restrict twist activity to specific areas within the twist expression domain.

Differential cation regulation of the alpha 5 beta 1 integrin-mediated adhesion of leukemic cells to the central cell-binding domain of fibronectin

Normal and neoplastic leukocytes interact with the central cell-binding and carboxyl-terminal regions of fibronectin (FN) primarily via the alpha(4) beta(1) and alpha(5) beta(1) integrins. By using a unique centrifugation-based cell adhesion assay and affinity chromatography of the cell surface-labeled integrins, we show in this study that the constitutive alpha(5) beta(1)-dependent attachment of three leukemic cell lines, BV-173, K562, and Nalm-6, to FN or to a 110-kDa central cell-binding fragment of FN was totally inhibited at 37 degrees C by preincubation of the substrate with either antibodies to the arginine-glycine-aspartic acid-containing region (3Fn-9 module) or to the synergistic region (3Fn-9 module) of FN. Similar results were obtained when assays were carried out at 4 degrees C, suggesting that energy-dependent events were not involved. On the other hand, only the antibody against the 3Fn-10 module was able to detach most firmly adherent cells. Constitutive cell attachment to the 110-kDa fragment was cation dependent, with the order of efficacy of the cation being Mn2+ > Mg2+ > Ca2+, and Ca2+ was only effective for BV-173 cells. Antibodies against the alpha(5) beta(1) integrin or the alpha(5) subunit completely impaired cell attachment of all cell lines, whereas several blocking anti-beta(1) subunit antibodies, including 4B4, P4C10, and AIIB2, differentially perturbed cell adhesion of BV-173, depending on which cation was present. These anti-beta(1) blocking antibodies, whose epitopes map to a region distant from the one expected to contain the beta(1) putative cation binding sites, seemed to lock the higher activation state of this integrin attained in the presence of Mg2+ and to preserve it during the subsequent adhesion events irrespectively of the presence of the low avidity state-inducing Ca2+ ion. Because the higher binding avidity displayed by BV-173 could not be explained by a higher degree of preclustering of alpha(5) beta(1) integrin in this cell line compared to K562, these findings suggest that cations might act as allosteric activators of integrin function. Whether this novel cation-dependent parameter of alpha(5) beta(1) integrin-FN interaction might contribute to the growth control and/or tissue dissemination of leukemic cells remains to be determined.

Crucial role of interleukin-10/interleukin-12 balance in the regulation of the type 2 T helper cytokine response in reactive arthritis

OBJECTIVE

To investigate whether a predominant type 1 T helper (Th1) or Th2 cytokine pattern is present in the joints of patients with reactive arthritis (ReA), and whether the cytokine pattern can be modulated by cytokines or anticytokines.

METHODS

Eleven patients with ReA following infection with either Chlamydia trachomatis, Yersinia enterocolitica, or Salmonella enteritidis were investigated for the presence of Th1/Th2 cytokines in the joints. Release of the bacteria-specific cytokines interferon-gamma (IFN gamma), tumor necrosis factor alpha (TNF alpha), interleukin-10 (IL-10), and IL-4 was measured in synovial fluid mononuclear cells (SFMC) using enzyme-linked immunosorbent assay and polymerase chain reaction. In the synovial membrane, secretion of IFN gamma and IL-4 was determined by immunohistologic analysis. Cytokine regulation was studied by adding cytokines and anticytokines to the cultures.

RESULTS

Upon stimulation with specific bacteria, SFMC secreted low amounts of IFN gamma and TNF alpha, but high amounts of IL-10. IL-10 was responsible for the suppression of IFN gamma and TNF alpha, as judged by the effect of adding either anti-IL-10 antibodies or exogenous IL-10 to these cultures. The addition of neutralizing anti-IL-12 to the cultures completely abolished the effects of anti-IL-10, suggesting that inhibition of the Th1-like cytokines by IL-10 is mediated through suppression of IL-12 synthesis. Exogenous IL-12 clearly enhanced IFN gamma and TNF alpha secretion. In the synovial membrane, a higher number of cells were positive for the Th2 cytokine IL-4, compared with the amount of IFN gamma-secreting cells.

CONCLUSION

These data indicate that a Th2 cytokine pattern predominates in the joints of patients with ReA. Since Th1 cytokines are necessary for the elimination of ReA-associated bacteria, Th2 cytokines might contribute to bacterial persistence in the joint. Therefore, the IL-10/IL-12 balance appears to be crucial for regulation of the cytokine pattern in the joints of patients with ReA.

[Laser transnasal dacryocystorhinostomy under head mirror]

Laser transnasal dacryocystorhinostomy under head mirror is a new approach for surgical treatment of chronic lacrimal obstruction. This technique has several advantages, such as less damage, less operative complications and so on. This paper presented the results of 37 cases who had undergone transnasal dacryocystorhinostomy for chronic dacryocystitis under head mirror. The postoperative follow-up time was 3-24 months. The effective rate was 95.6%. The operative technique was also discussed in this paper.

A comparison of alcohol, drugs, and aggressive crime among Mexican-American, black, and white male arrestees in Texas

Few comparative studies exist examining the relationship between substance abuse and aggressive behavior under different social conditions. We studied the relationship between aggressive crime and substance abuse among Mexican-American, black and white male arrestees in Dallas, Houston, and San Antonio, Texas using existing 1992 Drug Use Forecasting (DUF) data. The aim of the analysis was to predict the outcome of aggressive crime from drug and alcohol-related and ethnic group variables within the total male sample (n = 2,364). Results indicated that ethnicity was significantly related to aggressive crime. Mexican-American arrestees were more likely to be arrested for aggressive crimes than either blacks or whites. Drug and alcohol use effects were found across all ethnic groups. In general, the subgroup which drank frequently and tested positive for drug use was less likely to be charged with aggressive crimes than the other subgroups. The psychopharmacological influence of alcohol as a disinhibitor and drugs as a inhibitor provides one explantation of the results. Specific ethnic subcultural and ecological influences also affect the outcome. Our study strongly indicates the heterogeneous character of the drug using population in relation to aggression. The variability between subculturally defined subgroups requires detained ethnographic field studies in the future to describe the contexts of substance use and aggressive behavior.

Evaluation of immune response and protection in animals given mink parvovirus vaccines

In orthogonal and pair design tests, mink, guinea-pigs and rabbits were inoculated with inactivated mink enteritis virus (MEV) vaccine prepared with mineral oil or Al(OH)3 gel adjuvant. The animals were examined for serum haemagglutination-inhibition (HI) antibody during 6-55 days postvaccination (p.v.) and serum-neutralizing (SN) antibody for 11-31 days p.v. Differences between mineral oil and Al(OH)3 gel adjuvant vaccines in the induction of HI and SN antibodies during 6-55 days p.v. were not significant. There was significant positive rank correlation between HI antibody level and SN antibody index from 11 to 31 days p.v. in serum of mink inoculated with the mineral oil or Al(OH)3 gel adjuvant vaccine (P < 0.05). The results of experimental challenge tests with vaccines in 29 mink showed a positive correlation between HI antibody titres, SNI and immune protective rates. Levels of HI antibodies in guinea-pigs, rabbits or mink during 11-40 days p.v. were reliable indices for monitoring the humoral immune responses and immune protective rates. The criteria for virus vaccine potency and vaccine immune efficiency is an HA titre of 64 for the cell-cultured MEV and an HI antibody titre of 32 for guinea-pigs, rabbits or mink during 11-40 days p.v. The vaccine stimulates a protective response which lasts for a period of 12 months. The vaccine is stable for a period of 9 months at 4 degrees C. Economic, simple and scientific means have been developed to monitor the quality of MEV vaccines, of which more than 70,000 doses of the mineral oil vaccine and more than 18,000,000 doses of the Al(OH)3 gel vaccine have been used for the last 5 years.

[Identification and survey of commercial crude drug of Herba Cistanchis]

This paper deals with the morphological identification, TLC analysis and survey of commercial crude drug of Herba Cistanchis (Genus Cistinche). This results provide authentic methods for the identification of Herba Cistanchis.

A method to determine the filter matrix in four-dye fluorescence-based DNA sequencing

In a previous paper (Yin et al., Electrophoresis 1996, 17, 1143-1150), an automated method for matrix determination in four-dye fluorescence-based DNA sequencing was presented. As a continuation of that work, we have developed an alternative method to estimate the matrix from raw sequence data. The method uses an iterative clustering technique to associate each 4 x 1 data vector with one column of the desired filter matrix, using Kullback's I-divergence as a distance measure. The method requires less preprocessing of the data and less computation than the approach described by Yin et al. (Electrophoresis 1996, 17, 1143-1150). An example demonstrating applicability of the proposed method to Applied Biosystems sequencer data is given.

T cell cytokine pattern in the joints of patients with Lyme arthritis and its regulation by cytokines and anticytokines

OBJECTIVE

To investigate whether type 1 helper (Th1) or Th2 cytokines are found in the joints of patients with Lyme arthritis, and whether the cytokine pattern can be modulated by cytokines or anticytokines.

METHODS

The cytokine pattern in the joints of 10 patients with Lyme arthritis was investigated. Expression of interferon-gamma (IFN gamma), tumor necrosis factor alpha (TNF alpha), interleukin-4 (IL-4), and IL-10 was measured by enzyme-linked immunosorbent assay (ELISA), after stimulation of synovial fluid mononuclear cells (SFMC) with Borrelia burgdorferi (Bb) in the supernatant. Expression of cytokine messenger RNA and protein in synovial membrane (SM) and nonstimulated SFMC was studied using semiquantitative reverse transcriptase-polymerase chain reaction and immunohistologic techniques. The effects of recombinant cytokines or neutralizing anticytokine antibodies on cytokine production in Bb-stimulated SFMC were investigated by ELISA.

RESULTS

SFMC produced high amounts of IFN gamma and TNF alpha, but little or no IL-4, upon stimulation with Bb antigen, indicating a Th1-type cytokine pattern. In SM, IFN gamma was detectable in all patients, while the other cytokines were less frequently found. Serial sections of SM revealed that all cytokines were located in the same area. The Th1 response, especially the production of TNF alpha, could be down-regulated in vitro by both endogenous and exogenous IL-10, but not by IL-4 or anti-IL-12.

CONCLUSION

A Th1-type cytokine pattern was found in the joints of patients with Lyme arthritis. This Th1 response could be down-regulated by IL-10, suggesting insufficient IL-10 production in vivo.

Characterization of pathogenic fungi genomes using pulsed field gel electrophoresis

Pulsed field gel electrophoresis (PFGE) has been firstly introduced in characterization of the pathogenic fungi Penicillium marneffei and Exophiala dermatitidis genomes. The numbers and sizes of their chromosomes have been detected. Polymorphism was identified on the smallest chromosome of E. dermatitidis. The result shows that PFGE for characterization of large molecular DNA pathogenic fungi is very suitable, it is more simple and more efficacy. The result also shows the diversity of pathogenic fungi is relative common even in rare occurred pathogenic fungi such as E. dermatitidis.

Automatic matrix determination in four dye fluorescence-based DNA sequencing

The four dye fluorescence detection strategy is a widely used approach to automated DNA sequence analysis. An important aspect of data processing in this approach is the multicomponent analysis to deduce the concentrations of four fluorophores from fluorescence emission intensities at four different wavelengths. This requires knowledge of the correct transformation matrix M. The matrix M is a function both of the fluorophores employed and the fluorescence detection system. M is typically determined either by a calibration process with individual dyes, or by choosing four well-separated individual peaks corresponding to the four different dyes. Both are time-consuming and complicated procedures for routine use. An automatic scheme for finding M directly from raw sequence data is presented here. This facilitates data analysis and the underlying algorithm may also find utility in other multispectral applications.

Multiple signalling pathways trigger the exquisite sensitivity of yeast gluconeogenic mRNAs to glucose

The transcription of the yeast FBP1 and PCK1 genes, which encode the gluconeogenic enzymes fructose-1,6-bisphosphatase and phosphoenolpyruvate carboxykinase, is repressed by glucose. Here, we show that this repression is both very strong and exceptionally sensitive to glucose, being triggered by glucose at concentrations less than 0.005% (0.27 mM). This repression remains operative in yeast mutants carrying any one of the three hexose kinases, but is lost in a triple hxk1, hxk2, glk1 mutant. In addition, 2-deoxyglucose can trigger the repression, but 6-deoxyglucose cannot, suggesting that internalization and phosphorylation of the glucose is essential for repression to occur. While gluconeogenic gene transcription is subject to the Mig 1p-dependent pathway of glucose repression, the exquisite response to glucose is maintained in hxk2 and mig1 mutants, suggesting that this pathway is not essential for the response. The response can also be triggered by the addition of exogenous cAMP, suggesting that the Ras/cAMP pathway can mediate repression of the FPB1 and PCK1 mRNAs. However, the response is not dependent upon this pathway because it remains intact in Ras, adenyl cyclase and protein kinase A mutants. The data show that yeast cells can detect very low glucose concentrations in the environment, and suggest that several distinct signalling pathways operate to repress FPB1 and PCK1 transcription in the presence of glucose.

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.