[A study on the mechanism of the cardiac adenylyl cyclase activity alteration in septic rats]

The present work showed that cardiac sarcolemmal (SL) adenylyl cyclase (AC) and purified AC maximal activity of septic rat (cecal ligaation and puncture, CLP) were significantly increased during the early sepsis (ES, CLP 9 h) but decreased in the late sepsis (LS, CLP 18 h). Similar alterations were observed in cardiac sarcolemmal protein kinase C (PKC) activity. Sensitization and desensitization of rat SL adenylyl cyclase during ES and LS were respectively correlated with activition and inhibition of PKC. The biphasic changes of AC and PKC were independent of beta- and alpha 1-adrenergic receptor systems. The rat cardiac sarcolemmal PKC activation and AC sensitization during ES is related to M-cholinergic receptor system. The system, however, is not involved during the LS PKC inhibition and AC desensitization.

Cooperatively between an upstream TATA-like sequence and a CAA repeated element mediates E1A-dependent negative repression of the H-2Kb class I gene

In primary rodent cells transformed by the E1A region of the highly oncogenic adenovirus type 12, repression of transcription mediated by the far upstream TATA-like element was observed only in conjunction with either possible juxtaposition of a CAA repeated element in the presence of E1A and was dependent upon the relative arrangement of both the TATA-like and CAA repeated motifs in both homologous and heterologous promoter constructs. A gel shift competition study demonstrated that the TATA-binding protein (TBP) or a TBP-like protein can bind to both the upstream TATA-like sequence and the regular TATA box on the H-2Kb basal promoter. Moreover, employing immunoselection and cyclic amplification and selection of targets (CASTing) methods with nuclear extracts derived from Ad12-E1A transformants, we have identified a high affinity binding site in the H-2Kb class I promoter for E1A-associated DNA-binding proteins. The sequences of the binding sites were identified and were found to contain both the upstream TATA-like motif and the CAA repeated motifs. Our results suggest that the TATA-like sequence in the far upstream region of the H-2Kb gene is one of the elements that is required for Ad12-E1A-mediated negative repression.

Degeneration of Sertoli and spermatogenic cells in homozygous and heterozygous weaver mice

In the neurological mutant mouse weaver (wv/wv), the majority of males are infertile due to hypospermatogenesis. Heterozygous weaver mice (wv/+) cease mating successfully when males reach an average age of 3.5 months. The contents of epididymal fluid were scored for the number of sperm and sperm motility in wv/wv, wv/+ and controls. Testes were examined in mice of the three genotypes at various ages using light and electron microscopy. In wv/+ males, sperm counts were significantly lower than in controls and were significantly higher than in wv/wv. The seminiferous epithelium in weaver mice appears depleted soon after puberty and a wide range of degenerative changes was identified in both germ cells and Sertoli cells. Analogous cellular aberrations were detected in heterozygous males, but they appeared at an older age and were not as severe as in wv/wv. We hypothesize that in weaver homo- and heterozygosity the damage of Sertoli cells may induce degeneration of germinal cells and particularly affect the most advanced spermatogenic cells.

Reticular crypt epithelium and intra-epithelial lymphoid cells in the hyperplastic human palatine tonsil: an immunohistochemical analysis

Extensive immunohistochemical analyses of the hyperplastic human palatine tonsil disclosed variegated B cell phenotypes on the lymphoid cells among the crypt epithelium. The reticular epithelial network was evident by cytokeratin immunostaining. The reticular epithelium near the crypt lumen was positive for lysozyme. Secretory component was negative, while HLA-DR was frequently expressed. Intramucosal small lymphocytes, densely distributed in the luminal side, consisted mainly of B cells expressing CD19, CD20, CD21, CD22, CD45R, CD74, DBB42, HLA-DR, HLA-DQ, bcl-2 protein and surface IgM. Some B cells revealed mantle zone phenotypes (surface IgD+, CD5+, CD24+, DBA44+, CD10-, DNA7-). Cells of germinocyte phenotype (CD10+, DNA7+) were sparsely seen. A good number of intramucosal lymphoid cells were further labeled for CD11b, a phenotype of so-called B-1 cells. Plasma cells were clustered within the basal half. IgG was their major immunoglobulin class, followed by IgA, IgM and IgD classes. A smaller number of T cells (CD2+, CD3+, CD5+, CD45RO+, TCR alpha beta+) were identified among the epithelium. CD4+ cells predominated over CD8+ cells. TCR gamma delta+ cells were rare. Macrophages (CD68+), dendritic histiocytes (S-100 protein+, CD1+), and natural killer cells (CD16+ or CD57+) were also dispersed. Another unique feature of this lymphoepithelial complex was the existence of HLA-DR- intramucosal intramucosal microvasculature, where lymphocyte recirculation was suggested. Proliferating cell nuclear antigen was detected commonly in the epithelial cells but rarely in the lymphoid cells. Possible lymphoepithelial interactions and morphologic similarities to the thymic medulla are discussed.

Changes in the resistance of Plasmodium falciparum to chloroquine in Hainan, China

In 1979, in view of the widespread resistance of Plasmodium falciparum to chloroquine in the island of Hainan, China, it use as an antimalarial was suspended throughout the island. A longitudinal survey of the chloroquine-sensitivity of P. falciparum was carried out over the period 1981-91 to investigate whether its resistance had changed from the 1979 level. In-vitro assays were carried out every 2-3 years, while in-vivo tests were performed annually over the period 1981-83 and also in 1991. Resistance to chloroquine declined progressively after its use had stopped. The in-vitro tests indicated that the rate of chloroquine-resistant P. falciparum was 97.9% in 1981, but dropped to 60.9% in 1991 (P < 0.001). The mean concentration of chloroquine for complete inhibition of schizont formation was 10.4 pmol/microliters in 1981, but decreased to 3.0 pmol/microliters in 1991 (P < 0.001). The proportion of samples taken from malaria cases that required high concentrations ( > 6.4 pmol/microliters) of chloroquine for complete inhibition of schizont formation was 83.3% in 1981, but only 17.4% in 1991 (P < 0.001); at low concentrations ( > 1.6 pmol/microliters), the corresponding proportions increased from 4.2% in 1981 to 60.8% in 1991 (P < 0.001). In the 4-week in-vivo test, the rate of chloroquine-resistant P. falciparum decreased from 84.2% in 1981 to 40% in 1991 (P < 0.001). RII + RIII cases represented 59.4% of the total resistant cases in 1981, but decreased to 37.5% in 1991 (0.02 > P > 0.01).

Genomic structure and chromosomal localization of processed pseudogenes for human RBP-Jk

The functional gene for human recombination signal sequence-binding protein (RBP-Jk) and corresponding processed psudogenes have been isolated from various species, such as Drosophila, Xenopus, mouse, and human. Here we report the isolation of another two genomic pseudogenes of human RBP-Jk, named K2 and K7, from a cosmid library of Hela cells. The nucleotide sequences of both genes exhibited more than 95% homology to the functional human gene for RBP-Jk. Moreover, they did not contain any intron sequences and were interrupted by several stop codons in all frames. In situ hybridization demonstrated that the pseudogenes, K2 and K7, were localized at chromosomes 9p13 and 9q13, respectively. Their physical maps differed from those of the true functional gene and of the pseudogenes reported previously by Amakawa et al. (1993).

DNA fingerprinting involving fluorescence-labeled termini of any enzymatically generated fragments of DNA

We have developed a new fluorescence-based method for DNA fingerprinting that does not require a fluorescent linker or a synthetic oligonucleotide primer, both of which are normally used for labeling of DNA. Cosmid DNAs are digested with appropriate restriction enzymes and the 3' termini of DNA fragments are labeled with the corresponding, fluorescent dye-conjugated dideoxynucleotide triphosphate terminator (dye-ddNTP) by the Klenow fragment of DNA polymerase I from Escherichia coli, which has 3'-->5' exonuclease and replacement activities as well as its main 5'-->3' polymerase activity. Samples are separated on a DNA-sequencing gel and data are analyzed by application of both the Version 0.3.8a mapper program (Applied Biosystem Inc., Foster City, CA) and our Overlap I program that facilitate rapid analysis of the frequency of overlapping of cosmid DNAs. Using this method we have determined the overlap frequency of DNA fragments of each cosmid clone from the mouse MHC class I gene cluster.

Mucosa-associated lymphoid tissue (MALT) lymphoma of the stomach progressing to overt B cell malignancy

A 70 year old man, who underwent subtotal gastrectomy under the diagnosis of reactive lymphoid hyperplasia 6 years earlier, suffered from diffuse large-cell-type B cell lymphoma in the remnant stomach. Retrospectively reviewed, the initial lesion was consistent with mucosa-associated lymphoid tissue (MALT) lymphoma, a low-grade B cell malignancy, based upon histologic, cytologic and immunohistochemical features. Both the initial and recurrent tumors revealed the phenotypes of mantle zone cells, DBA44-positive. It is noteworthy that the overt lymphoma cells retained the capacity for inducing germinal center-like nodules consisting of LN1 and DNA7-positive cells even in the invading site. The diagnosis of reactive lymphoid hyperplasia of the stomach should be made after careful exclusion of the possibility of MALT lymphoma.

Pistil-Specific and Ethylene-Regulated Expression of 1-Aminocyclopropane-1-Carboxylate Oxidase Genes in Petunia Flowers

The differential expression of the petunia 1-aminocyclopropane-1-carboxylate (ACC) oxidase gene family during flower development and senescence was investigated. ACC oxidase catalyzes the conversion of ACC to ethylene. The increase in ethylene production by petunia corollas during senescence was preceded by increased ACC oxidase mRNA and enzyme activity. Treatment of flowers with ethylene led to an increase in ethylene production, ACC oxidase mRNA, and ACC oxidase activity in corollas. In contrast, leaves did not exhibit increased ethylene production or ACC oxidase expression in response to ethylene. Gene-specific probes revealed that the ACO1 gene was expressed specifically in senescing corollas and in other floral organs following exposure to ethylene. The ACO3 and ACO4 genes were specifically expressed in developing pistil tissue. In situ hybridization experiments revealed that ACC oxidase mRNAs were specifically localized to the secretory cells of the stigma and the connective tissue of the receptacle, including the nectaries. Treatment of flower buds with ethylene led to patterns of ACC oxidase gene expression spatially distinct from the patterns observed during development. The timing and tissue specificity of ACC oxidase expression during pistil development were paralleled by physiological processes associated with reproduction, including nectar secretion, accumulation of stigmatic exudate, and development of the self-incompatible response.

Protein kinase domain of twitchin has protein kinase activity and an autoinhibitory region

Twitchin is a 753-kDa polypeptide located in the muscle A-bands of the nematode, Caenorhabditis elegans. It consists of multiple copies of both fibronectin III and immunoglobulin C2 domains and, near the C terminus, a protein kinase domain with greatest homology to the catalytic domains of myosin light chain kinases. We have expressed and purified from Escherichia coli twitchin's protein kinase catalytic core and flanking sequences that do not include fibronectin III and immunoglobulin C2 domains. The protein was shown to phosphorylate a model substrate and to undergo autophosphorylation. The autophosphorylation occurs at a slow rate, attaining a maximum at 3 h with a stoichiometry of about 1.0 mol of phosphate/mol of protein, probably through an intramolecular mechanism. Sequence analysis of proteolytically derived phosphopeptides revealed that autophosphorylation occurred N-terminal to the catalytic core, predominantly at Thr-5910, with possible minor sites at Ser5912 and/or Ser-5913. This portion of twitchin (residues 5890-6268) was also phosphorylated in vitro by protein kinase C in the absence of calcium and phosphotidylserine, but not by cAMP-dependent protein kinase. By comparing the activities of three twitchin segments, the enzyme appears to be inhibited by the 60-amino acid residues lying just C-terminal to the kinase catalytic core. Thus, like a number of other protein kinases including myosin light chain kinases, the twitchin kinase appears to be autoregulated.

Epithelial inclusion cysts in an intrapancreatic accessory spleen

A 38 year old male underwent distal pancreatectomy for benign cystic pancreatic tumor. The pancreas tail contained a 2.3 x 2.1 cm accessory spleen associated with multiple epithelial inclusion cysts. The cysts were of varying sizes (max: 1.4 cm), lined by non-keratinizing squamous epithelium with a few mucin-producing cells, and filled with serous material. This is the fifth reported case of so-called 'epidermoid' cysts in the intrapancreatic accessory spleen.

The optimization of preparations of competent cells for transformation of E. coli

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[Risk factors of prostate cancer--a matched case-control study]

A 1:2 matched case-control study was used to determine the risk factors of prostate cancer. Twenty-seven cases of prostate cancer were matched with an equal number of other malignant tumor cases (non-urological tumor) and other urological cases (non-malignant tumor). Both study and control groups were the same in age, sex, race, and day of admission. All of these patients were treated in the First Affiliated Hospital of West China University of Medical Sciences. The questionnaire was used to survey the both groups of patients. Such data as diet, lifestyle, marital status and past history of other prostate diseases were obtained. Single factor analysis and multiple conditional logistic regression analysis were used to estimate the relative risk (RR), 95% confidence interval (95% CI) and P values. Statistical analysis was performed using the Egret, Epilog soft ware. The results were as follows: 1. Increasing dietary vitamin A was associated with a significant decrease in the risk of prostate cancer (RR = 0.948, 95% CI = 0.9309-0.9947, P = 0.029). This factor also showed dose response gradients. The relative risk was decreasing with exposure dose increasing. 2. The positive previous prostate history, such as prostatitis and benign prostate hyperplasia, increased the risk of prostate cancer (RR = 6.385, 95% CI = 1.046-38.97, P = 0.045). 3. Another finding in the widower, divorce and remarried men (RR = 4.312, 95% CI = 1.367-13.6, P = 0.013). And 4. There was no relationship between the risk of prostate cancer and dietary fat intake, vasectomy, socioeconomic status, familial malignant tumor history, smoking and alcohol consumption.(ABSTRACT TRUNCATED AT 250 WORDS)

Screening anti-HIV Chinese materia medica with HIV and equine infectious anemic virus reverse transcriptase

The inhibitory activities of human immunodeficiency virus reverse transcriptase (HIV-RT) inhibitors PFA and Suramin against HIV-RT and equine infectious anemic virus reverse transcriptase (EIAV-RT) were studied in this paper. The 50% inhibitory concentration (IC50) of HIV-RT and EIAV-RT treated by PFA and Suramin were 0.2 mumol, 9.8 mumol and 17 mumol, 19.9 mumol, respectively. More than thirty Chinese medicines, including recipes, herbs, extracts of traditional materia medica and isolated compounds were tested using HIV-RT and EIAV-RT as target enzymes. It was found that 5 crude extracts such as Rhizoma Polygoni Cuspidati, and Radix Notoginseng, 7 isolated compounds like Flavone of Ramulus Visci, Flavone of Ajuga Decumbens Thumb, and Aristolochic acid, as well as the extract of the complex prescription Xiao Chai Hu Tang have shown various inhibitory actions on these two enzymes. The activities of the two enzymes were comparable, but HIV-RT was more sensitive, suggesting that HIV-RT can be used as index for the screening of anti-aids drugs.

Mixed tumor of the external auditory canal

A mixed tumor with apocrine differentiation seen in the external auditory canal of a 39 year old male is reported. The well demarcated polypoid tumor showed proliferation of elongated gland-like or duct-like structures lined by two rows of epithelial cells, occasionally accompanied by foci of keratinization. There were fat cells in the myxoid stroma, in which no chondroid elements were seen. This neoplasm is considered to have arisen from the ceruminous gland, the modified apocrine gland of the skin.

Negative regulation of the gene for H-2Kb class I antigen by adenovirus 12-E1A is mediated by a CAA repeated element

Both positive and negative regulatory elements responsive to the product of the adenovirus type 12 E1A gene are located in the promoter region of the gene for mouse H-2Kbm1 major histocompatibility complex (MHC) class I antigen (1). We have analyzed the negative regulatory element that is affected by E1A and identified a target CAA repeated motif, CAA(A)CAAA, within -1725 to -1705 and -1591 to -1568 in a 316-bp sequence located in the far upstream region of H-2Kb promoter (-1837 to -1522; +1 refers to the cap site). The extent of cell surface expression of the MHC class 1 antigen was significantly decreased in the case of transfectants obtained by introducing an expression plasmid that included MHC class 1 cDNA with the CAA repeated element, as compared with that of a plasmid with mutated CAA repeats. We have also characterized the nuclear proteins that bind to this motif. The analysis of the effects of mutations during competition assays of in vivo and gel retardation competition assays demonstrated that the CAA repeated element is essential not only for E1A-dependent repression of transcription but also for the cell surface expression of the product of the mouse H-2Kb class I gene, presumably through nuclear proteins that specifically bind to it.

Organization and structure of the 1-aminocyclopropane-1-carboxylate oxidase gene family from Petunia hybrida

In this paper we present the structural analysis of the 1-aminocyclopropane-1-carboxylate (ACC) oxidase gene family from Petunia hybrida. Southern blot analysis and restriction endonuclease mapping showed that two cloned regions of the petunia genome contained sequences highly homologous to a previously isolated ACC oxidase cDNA clone. Nucleotide sequencing of these two regions of the genome showed that each contained two tandemly arranged genes designated ACO1, ACO2, ACO3 and ACO4. Comparison of the nucleotide sequences of the cloned genomic regions with the cDNA clone pPHEFE indicated that ACO1 encoded the transcript in 4 exons interrupted by 3 introns. The other three members of the petunia ACC oxidase gene family shared identical intron numbers and positions with ACO1 and their exons were greater than 80% homologous. Nucleotide substitutions and deletions in the ACO2 gene indicate that it likely represents a pseudogene. Overall homology between ACO1 and ACO2 indicates that this gene cluster arose by a more recent duplication event than the gene duplication giving rise to the ACO3 and ACO4 cluster. The 5-flanking sequences share little overall homology between members of this gene family. However, sequences which likely make up the core promoter of these genes including the TATA box are highly homologous. RNA-based PCR amplification of ACC oxidase cDNAs from ethylene-treated corollas and wounded leaves revealed transcripts for ACO1, ACO3 and ACO4 indicating that a least three of these genes are transcriptionally active. The proteins encoded by ACO1, ACO3 and ACO4 share more than 90% identity with one another and more than 70% identity with ACC oxidases from other species. The ACC oxidase proteins share significant sequence homology with other enzymes that require Fe(II) and ascorbate for catalytic activity.

A mathematically designed STS primer without any mismatches for direct sequencing of cosmid DNA clones

We report here a new method for the direct sequencing of large DNA inserts of cosmid clones from human chromosomes using STS primers of 14 nucleotides without any mismatches, which are designed from results of a mathematical analysis. It is clear that STS primer of 14 nucleotides is optimum for direct sequencing of cosmid recombinant DNA clones. We also provide examples of direct sequencing of cosmid clones of human chromosome 21 using these STS primers.

[Quantitative study of transmitral flow by spectral Doppler echocardiography]

The aim of this study is to find an accurate and simple method for measuring the transmitral flow by pulsed Doppler echocardiography (PDE). Four parameters were measured: (1) anteroposterior dimension of the mitral valve annulus (MVA) (a); (2) mediolateral dimension of MVA (b); (3) a and b of MVA to calculate the area of MVA (elliptical method); (4) the area of the mitral valve orifice (MVO). The transmitral flow calculated by the use of (3) and (4) were compared with the aortic blood flow. The findings suggested that the MVA calculated with elliptical method is accurate and simple in measuring the transmitral flow.