Optimum and sub-optimal temperature effects on stomata and photosynthesis rate of determinate soybeans

Stomatal frequency, length and width were studied in two determinate type soybean (Glycine max L. Merr.) cultivars at 15, 20 and 25 degrees C on 60th day after emergence. The stomatal frequency on the adaxial leaf surface did not show any consistent trend for the increase of growing temperatures but on the abaxial surface, stomatal frequency significantly decreased for every increase of 5 degrees C. Akishirome had 503, 454 and 379 stomata mm-2 and Akiyoshi had 471, 442 and 384 mm-2 at 15, 20 and 25 degrees C respectively. The stomatal lengths of both surfaces increased toward optimum temperature and were longer in the adaxial surface Maintaining this trend, the lengths varied between 16.3 to 23.4 micrometers on the adaxial surface and from 14.2 to 21.5 micrometers on the abaxial surface. Width of the whole stomatal apparatus at noon time did not show any significant variation due to environmental temperature. Net photosynthesis rate of 4th leaf from top significantly increased in higher temperatures in both cultivars and showed similar trend at 32nd day after emergence and on 62nd day after emergence. Stomatal conductance increased and dark respiration decreased with increasing temperature. Plants grown in 25 degrees C were transferred to 15, 20 and 30 degrees C temperature chambers. On the 30th day after emergence, 4 hours of treatment resulted similar significant effects on net photosynthesis (ranging between 12.55 and 31.37 micromoles CO2 m-2 s-1 in Akishirome, and between 16.26 to 34.53 micrometers CO2 m-2 s-1 in Akiyoshi). 72 hours of similar treatments at 60 day after emergence also produced identical results. Therefore, higher temperature increased stomatal size but decreased its frequency, and increased net photosynthesis and stomatal conductance.

Subpopulations of T lymphocytes in the peripheral blood and lymph nodes of Indian kala-azar patients

Distribution of T cells in the peripheral blood and lymph nodes of Indian kala-azar (KA) patients was studied by using appropriate phenotypic markers for CD2+, CD4+ and CD8+ cells. Significant reduction in the CD2+, CD4+ cell numbers as well as CD4+/CD8+ cell ratio was noted in the peripheral blood of active KA cases. Such alteration in the T cell population appeared to be a manifestation of the disease process as it showed a tendency to return close to normalcy several months after successful chemotherapy. Histopathological studies of KA patients with lymphadenopathy demonstrated gradual destruction of lymph node follicular architecture which correlated well with the severity and duration of illness. Massive infiltration of CD2+ cells in the cortical region of lymph node was evident. The observed preponderance of CD4+ cells over CD8+ ones in these infiltrates was in sharp contrast to the distribution pattern of these cells in the periphery. Significance of these findings is discussed in relation to the current concepts on the immunology of leishmaniasis and related diseases.

Molecular cloning and characterization of human FGF8 alternative messenger RNA forms

Three alternatively spliced mRNA isoforms of the human fibroblast growth factor-8 (FGF8) gene, expressed in a prostatic carcinoma cell line, have been isolated as cDNA clones and characterized by DNA sequencing. The clones, designated FGF8a, FGF8b, and FGF8e, differ from each other at the NH2-terminal region of the mature proteins and share extensive nucleotide sequence homology in the protein coding region to the corresponding mouse cDNA isoforms that were previously reported. FGF8a and FGF8b exhibit identical amino acid sequences to those of their murine counterparts. FGF8e displays partial sequence variation from the corresponding mouse clone only in the extra exon sequence found in this isoform in both species. There is extensive sequence diversity between FGF8 (human) and Fgf8 (murine) genes in the 3'-untranslated region of the mRNAs. Northern blot analyses revealed FGF8 mRNA expression only in fetal kidney tissue among the various fetal and adult human tissues tested. The reverse transcription-PCR amplification method, however, detected FGF8 mRNA expression in adult prostate, kidney, and testes (the tissues that were tested) and in all normal and tumor prostatic epithelial cell lines examined; although expression of both FGF8a and FGF8b was seen in kidney and testes, FGF8b appeared to be the predominantly expressed species in the prostatic tissue and cell lines analyzed by reverse transcription-PCR. To address the biological effect of specific isoform expression, NIH3T3 cells were transfected with a eukaryotic expression vector containing cDNA for FGF8a, FGF8b, or FGF8e. Consistent with previous reports on differences in the transforming potential of mouse FGF8 isoforms, human FGF8b was found to induce marked morphological transformation to NIH3T3 cells and strong tumorigenicity of the transfected cells in nude mice. Human FGF8a and FGF8e were moderately transforming in NIH3T3 cells, and the transfected cells were moderately tumorigenic in vivo. These results document the production of three alternatively spliced FGF8 mRNAs in human tissues and the transforming and tumorigenic potential of their protein products. Moreover, these data, combined with the tissue-specific expression of these isoforms, suggest that they may have different biological functions.

Rat ribosomal RNA gene can utilize primate RNA polymerase I transcription machinery: lack of absolute species specificity in rDNA transcription

The transcriptional activity of rodent ribosomal RNA gene (rDNA) in the primate cell was examined in the light of reported species specificity of eukaryotic ribosomal RNA synthesis. The present study showed that rat rDNA can be transcribed in HeLa nuclear extract whereas mouse rDNA was not transcribed in the heterologous extract. Rat and mouse rDNA transcription factors were interchangeable with respect to efficiency and accuracy of transcription. The initiation of rat ribosomal gene transcription by RNA polymerase I occurred at the +1 site in the heterologous extract. Initiation of transcription at the correct site also occurred in vivo following transfection of cloned rat rDNA into the primate (COS-7) cells. These data indicate that rat ribosomal RNA gene can be expressed in the primate system in vitro and in vivo. The absolute lack of species specificity in rDNA transcription has been discussed based on the present data and other reports.

Nonpeptidal P2 ligands for HIV protease inhibitors: structure-based design, synthesis, and biological evaluation

Design and synthesis of nonpeptidal bis-tetrahydrofuran ligands based upon the X-ray crystal structure of the HIV-1 protease-inhibitor complex 1 led to replacement of two amide bonds and a 10 pi-aromatic system of Ro 31-8959 class of HIV protease inhibitors. Detailed structure-activity studies have now established that the position of ring oxygens, ring size, and stereochemistry are all crucial to potency. Of particular interest, compound 49 with (3S,3aS,6aS)-bis-Thf is the most potent inhibitor (IC50 value 1.8 +/- 0.2 nM; CIC95 value 46 +/- 4 nM) in this series. The X-ray structure of protein-inhibitor complex 49 has provided insight into the ligand-binding site interactions. As it turned out, both oxygens in the bis-Thf ligands are involved in hydrogen-bonding interactions with Asp 29 and Asp 30 NH present in the S2 subsite of HIV-1 protease. Stereoselective routes have been developed to obtain these novel ligands in optically pure form.

Characterisation of an acid trehalase of Saccharomyces cerevisiae present in trehalase-sucrase aggregate

An acid trehalase-sucrase aggregate was purified (by 780-fold) from Saccharomyces cerevisiae, following conventional protein purification techniques, to an apparent yield of 18.5%. The aggregate was electrophoretically homogeneous but contained 175, 90, 68, 60, 40 molar mass (kDa) bands on SDS-electrophoresis. The purified aggregate had a specific activity (acid trehalase) of 22 U/mg; a Km value of 5.0 mM but contained 3-times more sucrase activity. Only sucrose and trehalose were hydrolysed by this aggregate and both activities were inhibited by acetate or phosphate. Temperature and pH optima for trehalose hydrolysis appeared to be 40-45 degrees C and 5.0, respectively. The purified aggregate appeared to be disaggregating spontaneously resulting in inactivation of both enzymes, which was enhanced either at pH 3.5 or at pH 7.0. Separation of acid trehalase from the aggregate by hydrophobic interaction chromatography resulted in inactivation. Rechromatography (HPGPLC) of the purified aggregate also gave disaggregation as well as inactivation of both enzymes. Disaggregated acid trehalase and sucrase contained 20-fold and 13-fold lower specific activities, respectively, and appeared to be unstable. Based on these observations we suggest that acid trehalase is stabilised by aggregation with sucrase.

Calculation of van't Hoff enthalpy associated with aspirin-induced change in liposomal membrane anisotropy

The lipid disordering effect of aspirin on the liposomal membrane of dipalmitoyl phosphatidyl choline has recently been studied using the fluorescence polarization method. From the anisotropy-temperature curve, we have calculated here the associated change in van't Hoff enthalpy. Since the fluorescence technique requires a very small amount of sample (10(-4) M), this method of enthalpy calculation compares well and is advantageous over the standard calorimetric methods.

Feline leukemia virus variants in experimentally induced thymic lymphosarcomas

This study was initiated to evaluate the in vivo infectivity and pathogenicity of a group of recombinant feline leukemia viruses (rFeLVs) previously generated by in vitro forced recombination between a FeLV subgroup A virus (FeLV-A) and an endogenous FeLV (enFeLV) envelope (env) element (Sheets et al., 1992, Virology 190, 849-855). To determine infectivity of rFeLVs, neonatal cats were inoculated with rFeLVs alone or in combination with FeLV-A. The recombinant viruses were able to replicate efficiently in vivo only when administered along with FeLV-A. Of six co-infected cats, three developed thymic lymphosarcomas, one severe aplastic anemia, and two cachexia and depression; all were viremic and seroconverted shortly after inoculation. While both virus types were detected in virtually all tissues examined from these tumor-bearing cats, there was a particularly noteworthy sequence reversion in the rFeLVs. It is known that exogenous FeLV isolates carry a conserved neutralizing MGPNL epitope in the middle of the surface glycoprotein domain of the env gene. In contrast, the parental recombinant viruses used to inoculate these cats harbored the enFeLV-derived MGPNP sequence at this position. However, all in vivo-propagated recombinants displayed the MGPNL sequence, while the env-encoded backbone flanking the MGPNL sequence was that of the parental recombinant virus. These results suggest that viruses with the MGPNL epitope have an in vivo proliferative advantage. The data also provide an explanation for the conservation of this epitope in exogenous FeLVs despite the existence of variant forms in enFeLV proviral elements with which they can recombine.

Heart rate & blood lactate response in amateur competitive boxing

The heart rate (HR) and blood lactate response were studied on 26 senior national level boxers in competitive bouts to explore the aerobic-anaerobic metabolism as well as the training status of the players. The aerobic capacity (VO2 max) of the players were determined using graded running protocol on a treadmill. Heart rate and blood lactate concentration were measured during warm up and boxing rounds. The mean relative VO2 max of the heavy weight category boxers was lower (P < 0.05) than the other two weight categories. No interweight category as well as inter-round differences were observed in the heart rate and blood lactate concentration of the boxers, excepting in the 48-57 kg category, the mean lactate levels in the second and third rounds were higher (P < 0.05) than in the first round. When all weight categories were pooled the mean HR and blood lactate levels were 178 beats/min and 8.24 mMol/l respectively. The study highlights that in amateur boxing, irrespective of the weight category and aerobic capacity, the anaerobic adaptability of the boxers was the same. The training requirements of the boxers demand that they should be also to tolerate a high blood lactate level (approx. 9.0 mMol/l) and a high HR (approx. 180 beats/min) over a total duration of one bout.

cDNA encoding a functional feline liver/bone/kidney-type alkaline phosphatase

Feline alkaline phosphatase (FeALP) was copurified with the putative 70-kDa feline leukemia virus subgroup-A (FeLV-A) receptor protein from feline T-lymphocyte cells (FeT) by two-dimensional gel electrophoresis. The sequence of the N-terminal 17 amino acids and five other internal tryptic peptides revealed that it is homologous to the liver/bone/kidney (L/B/K)-type alkaline phosphatase of other mammalian species. Corresponding oligonucleotides were synthesized and used for amplification of a 1.2-kb segment of the FeALP gene by polymerase chain reaction, using phage DNA from a FeT cell cDNA library as template. The 1.2-kb FeALP gene fragment generated was then used as a probe to isolate a 2127-bp L/B/K-type FeALP cDNA clone from the same library harboring a large, intact open reading frame. This cDNA possessed an open reading frame encoding a 524-amino-acid protein including a putative signal peptide of 17 amino acids followed by 14-amino-acid residues identical to the N-terminal sequence determined from the purified protein. Sequences closely related to five tryptic peptides from the purified protein were also contained within the cDNA-encoded protein. Homology with the human, bovine, rat and mouse L/B/K-type ALP was found to be 88-90% at both the nucleotide and the amino acid levels. The cDNA was transferred into a eukaryotic expression vector and expressed following transfection into murine and mink lung fibroblast cell lines. High levels of enzymatically active ALP were detected, along with a 70-kDa protein reactive in immunoblot assay using a polyclonal antibody against the original crude FeALP preparation. FeALP was specifically released from intact cells by treatment with phosphoinositol-specific phospholipase-C. By Northern blot analysis, only one species of mRNA was detected using a 32P-labeled cDNA probe. These results indicate that the 2127-bp cDNA encodes a functional feline L/B/K-type ALP expressed on cell surfaces via phosphatidylinositol-glycan linkage. Despite electrophoretic comigration in two dimensions and following deglycosylation in a third dimension, FeALP failed to function as an FeLV receptor since its expression failed to provide for attachment or entry of virus into cells.

Heterogeneity in intratumor distribution of p53 mutations in human prostate cancer

Prostatic carcinoma from 65 patients have been examined for the occurrence of point mutations in the p53 tumor suppressor gene locus within the region of exons 5 to 8. Overall, only a small fraction of tumors (12.3%) was found to contain p53 mutations. No significant correlation was detected between the presence of the mutant gene and either tumor volume or histopathological grade. However, metastatic prostatic tumors are found to display a higher percentage (21.4%) of p53 mutations compared with primary adenocarcinomas (9.8%). Analysis of the topographical distribution of the p53 mutant genotype revealed two remarkable findings. First, multifocal tumors within a prostate appear to differ in harboring the mutant gene, and second, evidence is obtained for intratumor heterogeneity in the distribution of the mutant p53 allele. Together these findings appear to explain, at least in part, why there has been a wide discrepancy in the reported detection frequency of p53 mutations in prostate cancer specimens. It appears that the outcome of mutation analysis would depend not only on which tumors but also which regions of the tumors are included in the study. Furthermore, the observed heterogeneous topographical distribution of the mutation, if confirmed to be unique to prostate cancer, may have important implications in the understanding of the biology of prostate carcinogenesis.

Immunoglobulin G subclass-specific antileishmanial antibody responses in Indian kala-azar and post-kala-azar dermal leishmaniasis

Antileishmanial antibody responses in the sera of Indian kala-azar (KA) and post-KA dermal leishmaniasis (PKADL) patients were analyzed by enzyme-linked immunosorbent assay (ELISA) and immunoblot experiments using immunoglobulin G (IgG) class- and subclass-specific reagents. All sera showed antileishmanial reactivities in IgG ELISA which followed the order IgG1 > IgG2 > IgG3, with very little IgG4. Immunoblot analysis with IgG class-specific reagents revealed variable patterns of reactivity by KA and PKADL sera, although certain common bands around the 60- to 63-kDa regions were discernible. Sera from antimony-unresponsive KA cases, on the other hand, strongly recognized two bands at around 20 to 22 kDa, in addition to other bands in the high-molecular-mass region. Further analysis showed that the 28-kDa band was preferentially recognized by the IgG2 isotype, while 20- to 22-kDa and 60- to 63-kDa bands were recognized by the IgG1 isotype. Antibodies belonging to the IgG3 isotype reacted to antigens primarily in the region of 14 to 34 kDa and persisted in patients even several months after cure. Immunoblot studies also revealed the presence of a nonspecific band which arose as a result of binding between a 66-kDa leishmanial antigen and streptavidin. Finally, the results presented in this study suggest that certain leishmanial antigens preferentially stimulate the synthesis of a particular IgG subclass(es), depending on the nature of such antigens or their epitopes.

The RNA polymerase I promoter-activating factor CPBF is functionally and immunologically related to the basic helix-loop-helix-zipper DNA-binding protein USF

Analysis of the core promoter sequence of the mammalian ribosomal RNA genes revealed an E-box-like sequence (CACGCTG) to which the upstream stimulatory factor (USF) binds. Because the core promoter binding factor (CPBF) binds specifically to the core promoter sequence of the ribosomal RNA gene (Liu, Z., and Jacob, S. T. (1994) J. Biol. Chem. 269, 16618-16626) and resembles USF in some respects, we explored the potential relationship between USF and CPBF. Competition electrophoretic mobility shift assay using labeled core promoter probe and several unlabeled competitor oligonucleotides showed that USF can indeed bind to the core promoter and that only those oligonucleotides with an E-box sequence could compete in the promoter-protein complex formation characteristic of CPBF. This complex formation was thermostable, a unique property of USF. Furthermore, antibodies raised against USF cross-reacted with the 44-kDa component of rat CPBF. To prove further the relationship between CPBF and USF, we examined the effects of the unlabeled USF and ribosomal gene core promoter oligonucleotides on polymerase (pol) I and pol II transcription. Both oligonucleotides inhibited rDNA transcription as well as transcription from the adenovirus major late promoter. Only the oligonucleotides that contain the E-box sequence competed in the transcription. These data indicate that the promoter sequence of mammalian ribosomal RNA gene contains an USF-binding site, that the 44-kDa polypeptide of CPBF is related to the 44/43-kDa polypeptide of human USF, and that USF or USF-related protein can transactivate both pol I and pol II promoters.

Development of high-molar-mass cellobiase complex by spontaneous protein-protein interaction in the culture filtrate of Termitomyces clypeatus

The 450 kDa cellobiase from Termitomyces clypeatus which migrates as a single band on IEF, PAGE and SDS-PAGE, was found to possess appreciable sucrase activity. The fungus produced sucrase and cellobiase constitutively in different media but with different activity ratios. The kinetics of secretion of the two enzymes was similar under in vivo and in vitro conditions. HPGPLC analysis of the culture filtrates indicated the presence of both sucrase and cellobiase in the same protein fractions of different molar mass, even in the 30-kDa protein fraction. No free sucrase or cellobiase could be detected in the culture filtrates. It was also observed that fractionation of cellobiase by (NH4)2SO4 precipitation was different with different amounts of associated sucrase activity present in the culture filtrate. The (NH4)2SO4-precipitated cellobiase fraction also contained cellobiases in proteins of widely varied molar mass ranges. However, none of the low-molar mass proteins other than the 450-kDa enzyme could be purified, as all low-molar-mass fractions spontaneously aggregated to the 450-kDa enzyme. Hydrophobic chromatography of the (NH4)2SO4-precipitated fractions followed by HPGPLC of the eluted active fraction yielded both cellobiase-free sucrase and a very low sucrase-containing cellobiase fraction. The cellobiase fraction, homogeneous in PAGE, was also a high-molar-mass protein complex dissociating into a number of protein bands on SDS-PAGE.(ABSTRACT TRUNCATED AT 250 WORDS)

Hepatic histology in chronic liver disease in hepatitis B surface antigen positive cases

The spectrum of histological changes in needle biopsies of the liver tissue was analysed in 43 patients with chronic liver disease who were positive for hepatitis B surface antigen (HBsAg) in their sera. Majority of the patients were around 40 years and there was a male predominance. According to histopathological pattern, there were 18 (41.8%) cases of chronic active hepatitis, 16 (37.2%) cases of inactive cirrhosis, 3 (6.9%) cases of chronic persistent hepatitis and 2 (4.7%) cases of chronic lobular hepatitis and hepatoma each. Two (4.7%) cases could not be exactly categorised into any particular histological entity. The inflammation, hepatic cell necrosis and fibrosis were more marked in cases of chronic active hepatitis without past history of jaundice. Micronodular cirrhosis was the most common histological pattern in the study. Shikata orcein stain for detection of HBsAg in the hepatocytes was positive in 8 (18.6%) cases only.

Influence of dietary vitamin A deficiency on rat digestive & absorptive functions during diabetes mellitus

Intestinal absorption of glucose and activities of amylases of intestinal and pancreatic origin were measured in animals vitamin A deficient, diabetic and combined state of vitamin A deficiency with diabetes. The vitamin A deficient diet caused a significant reduction in intestinal digestive and absorptive functions. On the other hand the digestive and absorptive functions were increased in the diabetic state. The combination of diabetes with vitamin A deficient diet caused a decrease in the digestive and absorptive functions along with blood glucose level in comparison to diabetic state alone. These findings suggest that the inhibition of digestive and absorptive functions observed in the combined state of vitamin A deficiency and diabetes may be due to the presence of vitamin A deficient diet.

Esophageal candidiasis after renal transplantation: comparative study in patients on different immunosuppressive protocols

OBJECTIVES

The incidence of esophageal candidiasis (EC) in renal allograft recipients has not been well documented. The present study was done to determine the incidence of EC in renal allograft recipients receiving different forms of immunosuppressive therapy and to identify patients at a high risk of developing Candida esophagitis.

METHODS

We conducted a retrospective study of 265 live related renal allograft recipients and compared three groups: patients given azathioprine and prednisolone (group I), those given cyclosporine, azathioprine, and prednisolone (group II), and those given cyclosporine and prednisolone (group III). EC was diagnosed by esophagogastroduodenoscopy.

RESULTS

The overall incidence of EC was 10.5%. Group II patients had a significantly higher incidence (28.6%) than those in group I (10.4%) and group III (3.8%). EC was noted earlier in patients in groups II and III, who were on higher doses of steroids than group I patients. Dysphagia (57.1%) was the most common presenting symptom of EC, but 21.4% of patients were asymptomatic. Oral thrush was present in 42.9%. The entire esophageal mucosa was affected in six (46.1%) patients in group II and one (20%) in group III. No correlation was found between fungal serology or daily dose of steroids and extent of esophageal involvement. Treatment included nystatin in seven, nystatin and ketoconazole in 10, ketoconazole alone in eight, amphotericin B in one, and ketoconazole and amphotericin B in two episodes. Treatment failure occurred in seven (25%). Three patients died of disseminated candidiasis. Serology and biopsy were poor predictors of dissemination.

CONCLUSIONS

In this retrospective study of renal allograft recipients, patients on triple drug immunosuppression, diabetics, and those with myelosuppression had an increased risk of developing EC. This high incidence calls for prophylactic use of antifungal agents in selected renal transplant recipients.