Effects of commonly used non steroidal anti-inflammatory drugs on gastric mucosa. A clinical, endoscopic and histopathological study

Non steroidal anti-inflammatory drugs (NSAIDS) are known to produce gastro-intestinal lesions. In the present work we found that aspirin, indomethacin and oxyphenbutazone caused gastric mucosal damage in 90.9%, 100% and 100% respectively, while ibuprofen and paracetamol caused damage in 33.3% and 37.5% of cases respectively. Thus the latter two drugs were much safer NSAIDs. Furthermore we demonstrated that endoscopic monitoring of patients on NSAIDs is a sensitive method for early detection of gastric mucosal damage. This monitoring may be particularly valuable in high risk subjects on NSAIDs.

Platelet ionic calcium and serum total calcium in essential hypertension

A total of 44 cases comprising hypertensive (31) and normotensive group (13) were studied. Serum total calcium concentrations remained unaltered in hypertensives. Platelet cytosolic calcium in hypertensive group was significantly higher as compared to the normotensive controls. Platelet cytosolic calcium correlated with systolic and diastolic blood pressure and mean arterial pressure significantly.

Brainstem auditory evoked potentials (BAEPs) in pregnant women

The electrophysiological correlate of change in sensory function during pregnancy has not been reported. The brain stem auditory evoked potentials were recorded in eight pregnant women during third trimester from CZ-A1 and CZ-A2 position, with alternating 90 dB sound pressure click stimuli delivered at 10/sec and -40 dB (white noise) masking of contralateral ear. Two thousand and forty eight responses were analysed and replicated. The noise and other artefacts were rejected with filter bandpass setting 150 to 3000 Hz. The evoked responses in pregnant women were compared with ten age matched normal subjects using Student's 't' test. The threshold for eliciting wave V of the brainstem auditory response was higher in pregnant women (28.1 +/- 2.1 dB). The absolute peak latencies of waves I to V were similar in both groups. However, Inter peak latencies (IPLs) I-III, III-V were on higher side in the pregnant women, and I-V, in particular (3.9 +/- 0.14) was significantly higher when compared with controls (3.73 +/- 0.16). These findings suggest that besides an increase in evoking wave V threshold, neural conduction process in brainstem auditory pathways during pregnancy is also delayed within + 2SD of the mean central conduction time in nonpregnant state.

Recombination mediates production of an extrachromosomal circular DNA containing a transposon-like human element, THE-1

An abundant class of HeLa extrachromosomal circular DNA containing the transposon-like element, THE-1, is shown to arise via site specific recombination. The chromosomal locus from which these circles are derived, however, is single-copy. Northern blot analysis detects homology to two polyadenylated RNAs in HeLa cells. The possible presence of an origin of replication and its role in generating these small polydisperse circles is discussed.

A novel mutation, cog, which results in production of a new porin protein (OmpG) of Escherichia coli K-12

A mutant of Escherichia coli K-12 which produces a new outer membrane protein, OmpG, was isolated and genetically and biochemically characterized. The presence of OmpG allows growth on maltodextrins in the absence of the LamB maltoporin. The data obtained from in vivo growth and uptake experiments suggested that the presence of the OmpG protein results in an increase in outer membrane permeability for small hydrophilic compounds. In light of these findings, we suggest that OmpG is a porinlike protein. The mutation which results in the expression of OmpG has been termed cog (for control of OmpG) and mapped to 29 min on the E. coli chromosome. Diploid analysis shows that the mutant cog-192 allele is recessive for both the Dex+ and OmpG+ phenotypes. We propose that the cog mutation destroys a negative regulatory function and therefore derepresses ompG expression.

Ultrastructural changes in parietal cells in iron deficiency anemia

Eighteen patients with iron deficiency anemia (IDA) and 14 age and sex matched control subjects were studied with regard to ultrastructural changes in parietal cells. The control subjects had normal hemoglobin and serum iron levels and endoscopic examination of the upper gastrointestinal tract. Thirteen cases of iron deficiency anemia had chronic superficial gastritis on light microscopy. Ultrastructural abnormalities in the parietal cells, such as indented or pyknotic nucleus with irregular outline, grossly distorted canalicular system, abnormal large empty spaces in the cytoplasm and paucity of mitochondria, were demonstrated in all IDA patients but not in controls. The presence of superficial gastritis and ultrastructural changes were not related either to hemoglobin or serum iron levels in the IDA group.

Identification and characterization of a new gene of Escherichia coli K-12 involved in outer membrane permeability

Using a genetic selection for mutations which allow large maltodextrins to cross the outer membrane of Escherichia coli in the absence of the LamB maltoporin, we have obtained and characterized two mutations that define a new locus of E. coli. We have designated this locus imp for increased membrane permeability. Mapping studies show that the imp gene resides at approximately 1.2 min on the E. coli chromosome. The mutations alter the permeability of the outer membrane resulting in increased sensitivity to detergents, antibiotics and dyes. The mutations are nonreverting and codominant. Genetic analysis of the mutations suggest that the imp gene is an essential gene. We describe a general cloning strategy that can be used to clone both dominant and recessive alleles. Using this technique, we have cloned the wild-type and mutant imp alleles onto a low copy number plasmid.

Platelet serotonergic mechanisms and glomerulonephritis

Proven cases (28) of glomerulonephritis (GN) were evaluated for clinico-biochemical profile, bleeding time, platelet count, platelet aggregation and platelet serotonergic mechanisms. Inordinate increase in platelet aggregation and altered platelet serotonergic mechanisms (reduced 5-HT, uptake, reduced intraplatelet 5-HT and increased plasma 5-HT) were demonstrated in some histopathological types of GN. The mechanisms and importance of these alterations have been discussed.

Cancer cervix complicating pregnancy: a case report

A case of invasive carcinoma cervix in a 25 years woman complicating labour is presented with brief review of literature.

Detection of multiple, novel reverse transcriptase coding sequences in human nucleic acids: relation to primate retroviruses

A variety of chemically synthesized oligonucleotides designed on the basis of amino acid and/or nucleotide sequence data were used to detect a large number of novel reverse transcriptase coding sequences in human and mouse DNAs. Procedures involving Southern blotting, library screening, and the polymerase chain reaction were all used to detect such sequences; the polymerase chain reaction was the most rapid and productive approach. In the polymerase chain reaction, oligonucleotide mixtures based on consensus sequence homologies to reverse transcriptase coding sequences and unique oligonucleotides containing perfect homology to the coding sequences of human T-cell leukemia virus types I and II were both effective in amplifying reverse transcriptase-related DNA. It is shown that human DNA contains a wide spectrum of retrovirus-related reverse transcriptase coding sequences, including some that are clearly related to human T-cell leukemia virus types I and II, some that are related to the L-1 family of long interspersed nucleotide sequences, and others that are related to previously described human endogenous proviral DNAs. In addition, human T-cell leukemia virus type I-related sequences appear to be transcribed in both normal human T cells and in a cell line derived from a human teratocarcinoma.

Anti-cardiolipin antibodies in infectious mononucleosis react with the membrane of activated lymphocytes

To elucidate the mechanisms of autoantibody induction in infectious mononucleosis (IM), we have studied sera from 35 patients with IM with enzyme-linked immunosorbent assays using purified antigens. In the IM group 37% had IgM antibodies to cardiolipin above the normal range (mean plus 2 standard deviations of control sera). Significantly elevated frequencies of antibodies to actin (26%) and cytoskeletal antigens (97% versus 29% in normal sera) were also found, but levels of IgM rheumatoid factors, IgM antibodies to single-stranded DNA and antibodies to ribonucleoproteins (nRNP/Sm, Sm and La) were normal. Affinity purified anti-cardiolipin antibodies reacted with the cell membrane of transformed lymphocytes but not with resting cells, suggesting that cell activation was required for the expression of antigenic epitopes. Our data suggest that the autoantibody response in IM is restricted to two classes of autoantigens: cytoskeletal and cell membrane antigens. The appearance of antigenic epitopes on EBV-transformed lymphocytes could be a mechanism for the generation of anti-cardiolipin antibodies in infectious mononucleosis. Similar mechanisms could operate in autoimmune rheumatic disease.

Acceleration of growth rate in growth hormone-deficient children treated with human growth hormone-releasing hormone

Twenty-four growth hormone-deficient children were treated with growth hormone releasing hormone-40 (GHRH) for 6 months or longer. GHRH (1 to 4 micrograms/kg of body weight per dose) was administered subcutaneously every 3 h (n = 10); or every 3 h overnight only (n = 10); or by twice daily injections (n = 4). Twenty-one children had an increase in growth rate during GHRH treatment. The growth velocities (mean +/- SD; cm/yr) before and during treatment were, respectively: every 3 h 3.5 +/- 1.4 versus 10.0 +/- 2.2, p = 0.0001; overnight only 3.4 +/- 1.0 versus 6.2 +/- 2.1, p = 0.008; twice daily injections 3.2 +/- 1.8 versus 7.9 +/- 2.4, p = 0.06. Using these three modes of GHRH administration, different total daily amounts of GHRH were administered. Regression analysis of average daily dose versus growth velocity revealed a correlation coefficient (r) value of 0.57, p = 0.004. Sixteen children received extended treatment for periods varying from 9 to 30 months. Of these, seven children were treated continuously for 9 months with pump overnight only and 5 for 12 months with pump every 3 h. Their growth velocities were sustained at a similar rate as those observed at 6 months. Six children received both twice daily and three hourly treatments consecutively. The growth velocities were similar during both treatments. Eleven children developed circulating antibodies to GHRH during treatment, however, all 11 had accelerated growth rates during GHRH therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Genetic identification of the pore domain of the OmpC porin of Escherichia coli K-12

We have isolated and characterized 31 mutations in the ompC gene which allow Escherichia coli to grow on maltotriose (Dex+) in the absence of the LamB and OmpF porins. These ompC(Dex) mutations include single-base-pair substitutions, small deletions, and small insertions. DNA sequence analysis shows that all of the alterations occur within the coding region for the first 110 amino acids of mature OmpC. The 26 independent point mutations repeatedly and exclusively alter residues R37, R74, and D105 of mature OmpC. In each case, a charged amino acid is changed to an uncharged residue. Biochemical and physiological tests suggest that these alterations increase the size of the pore channel. Starting with three different ompC(Dex) strains with alterations affecting R74, we isolated mutants that could grow on maltohexose (Hex+). These mutants each contained a second alteration in the ompC gene involving residues R37, D105, or R124. The combined effects on pore function of the two mutations appear to be additive. These experiments suggest that we have identified the important residues of OmpC peptide involved in pore function. On the basis of these mutations and general rules for membrane protein folding, a model for the topology of the OmpC protein is proposed.

Isolation and characterization of OmpC porin mutants with altered pore properties

The LamB protein is normally required for the uptake of maltodextrins. Starting with a LamB- OmpF- strain, we have isolated mutants that will grow on maltodextrins. The mutation conferring the Dex+ phenotype in the majority of these mutants has been mapped to the ompC locus. These mutants, unlike LamB- OmpF- strains, grew on maltotriose and maltotetraose, but not on maltopentaose, and showed a significantly higher rate of [14C]maltose uptake than the parent strain did. In addition, these mutants showed increased sensitivity to certain beta-lactam antibiotics and sodium dodecyl sulfate, but did not exhibit an increase in sensitivity to other antibiotics and detergents. The nucleotide sequence of these mutants has been determined. In all cases, residue 74 (arginine) of the mature OmpC protein was affected. The results suggest that this region of the OmpC protein is involved in the pore domain and that the alterations lead to an increased pore size.

Role of micF in the tolC-mediated regulation of OmpF, a major outer membrane protein of Escherichia coli K-12

Mutation in the tolC locus greatly reduces normal synthesis of OmpF, a major porin protein of Escherichia coli K-12. Experiments that use ompF-ompC chimeric genes demonstrate that a tolC mutation exerts its effect at either the promoter or the amino-terminal end of the ompF gene. Direct analysis of ompF mRNA from tolC+ and tolC strains showed that the amount of ompF transcript in the latter was greatly reduced. We have also observed that, in addition to reducing the amount of OmpF, a tolC mutation increases the level of OmpC protein to a much greater extent than occurs in an OmpF mutant and also increases micF RNA synthesis as shown by increased beta-galactosidase synthesis in a micF-lacZ fusion strain. Based on these observations, we suggest that an increased expression of the micF gene in a tolC mutant results in the reduced expression of ompF and that a major effect of the tolC mutation may be to push the porin-regulating system to favor ompC and micF to a greater extent than under high-osmolarity conditions.

Analysis of epidermal proteins for DNA-binding activity

A group of DNA-binding proteins from the soluble extract of newborn rat epidermis have been separated by chromatography using DNA-cellulose columns. The electrophoretogram of the DNA-binding proteins eluted from a single stranded DNA-cellulose column shows five major proteins of molecular weights ranging between 25K to 40K. Both the epidermal protein filaggrin and most keratins, except two high molecular weight keratins, do not show in vitro DNA-binding activity.

Cloned extrachromosomal circular DNA copies of the human transposable element THE-1 are related predominantly to a single type of family member

The 2300 base-pair transposon-like human element, THE-1, has been identified in the extrachromosomal circular DNA of the established human cell line HeLa as a relatively homogeneous population of covalently closed 1900 base-pair molecules. THE-1, which has been classified tentatively as a retroviral-like transposable element (a retrotransposon), is present in the extrachromosomal circular DNA of African green monkey (BSC-1) and human lymphoblastoid (Jurkat) cell lines. The 1900 base-pair extrachromosomal elements isolated and cloned from HeLa cells (1) appear to contain only THE-1-specific nucleotide sequences, (2) are circularized versions of the linear chromosomal sequence, and (3) are related predominantly to a single, or single type of, family member.