Inactivation of wild-type and rad mutant Caenorhabditis elegans by 8-methoxypsoralen and near ultraviolet radiation

Survival of wild-type and four radiation-sensitive (rad) mutants of the nematode Caenorhabditis elegans was determined after near-UV irradiation in the presence of 8-methoxypsoralen (8-MOP). Three sets of inactivation profiles were generated for each strain by irradiating synchronous populations of either early embryos, late embryos or first-stage larvae (L1s). Late embryos were consistently the most sensitive. Curiously, none of the four rad mutants were even moderately hypersensitive. Split-dose experiments indicated that DNA-DNA crosslinks were primarily responsible for lethality. Crosslink induction and repair were determined using two different assays. In both cases, little if any repair was observed in wild-type. This lack of repair thus explains why the rad mutants were not hypersensitive to 8-MOP photoinactivation. Since early embryos undergo extensive cell cycling, their resistance to 8-MOP photoinactivation suggests that replication is highly refractory to both monoadducts and crosslinks, as has been demonstrated previously for UV radiation-induced photoproducts (Hartman et al., 1991, Mutat. Res., 255, pp. 163-173).

O(-•) chemical ionization of carbonyl compounds

The negative ion chemical ionization mass spectra of twentyeight C4 to C7 carbonyl compounds were recorded using the oxide radical anion O(-•) as reagent ion. As noted earlier, the reactions occurring include H(+) abstraction, H 2 (+•) abstraction, H- atom displacement, and alkyl radical displacement. In addition, the [M-2H](-) ions fragment further by alkyl radical elimination. The relative importance of these reactions depends strongly on molecular structure, with the result that isomer distinction frequently is possible. Where this is not possible, as for isomeric aldehydes, the collisional charge inversion mass spectra of common product ions provides isomer distinction. The H 2 (+•) abstraction reaction is shown to involve abstraction not only of two hydrogens from the same α-carbon but also, in part, abstraction of one hydrogen from each α-carbon.

The DNF15S2 locus at 3p21 is transcribed in normal lung and small cell lung cancer

Small cell lung cancer (SCLC) has been associated with a deletion of the short arm of chromosome 3. One SCLC cell line, H748, has an interstitial deletion of chromosome 3p and shows allele loss for the DNF15S2 locus detected by the probe lambda H3. Conservation of DNF15S2 sequences in mouse indicated that this human genomic fragment may contain coding sequences. Screening of a normal lung cDNA library with chromosome 3-specific fragments of the lambda H3 probe resulted in the isolation of 18 positive clones. The cDNA clones detect an additional DNA polymorphism that is in linkage disequilibrium with the HindIII polymorphism of the DNF15S2 locus. Sequence analysis indicated that the DNF15S2 locus could potentially code for a previously unreported protein of 67 kDa which has 26 cysteine residues. DNF15S2 is part of the coding region of a 3.3-kb mRNA expressed in lung. Northern analysis indicated that this mRNA was not detectable in one of five SCLC lines. This SCLC line, H128, also lacks the enzyme aminoacylase 1.

Rat clusterin isolated from primary Sertoli cell-enriched culture medium is sulfated glycoprotein-2 (SGP-2)

Clusterin, a glycoprotein originally isolated from ram rete testis fluid, is a dimer composed of monomers with non-identical NH2-terminal amino acid sequences. In view of its possible role in cell-cell interactions in the seminiferous epithelium, we sought to identify such a protein in the rat. Using the bioassay developed for the ovine protein, rat clusterin was purified to apparent homogeneity by HPLC from primary Sertoli cell-enriched culture media. This protein is also a heterodimer consisting of monomers of Mr 43,000 (alpha) and Mr 35,000 (beta). NH2-Terminal amino acid sequence analysis indicated that the alpha subunit has a sequence of NH2-SLMPLSHYGPLSFHNMFQPFFDMIHQAQQA and the beta subunit, NH2-EQEFSDNELQELSTQGSRYVNKEIQNAVQG. These two subunits show marked similarity with the corresponding subunits of ram clusterin isolated from rete testis fluid. Using an antibody against the alpha subunit of rat clusterin, a cDNA clone was isolated from a rat testicular lambda gt11 cDNA library. Analyses of the amino acid sequence derived from the isolated rat clusterin cDNA and of the NH2-terminal amino acid sequences indicate that rat clusterin is identical to a Sertoli cell glycoprotein previously designated sulfated glycoprotein-2.

Restriction fragment length polymorphism studies show consistent loss of chromosome 3p alleles in small cell lung cancer patients' tumors

Previous karyotypic analysis of human small cell lung cancer cell lines has demonstrated a consistent deletion of a portion of the short arm of chromosome 3(p14-23). DNA prepared from tumors and normal tissues obtained from 24 small cell lung cancer and two extrapulmonary small cell cancer patients was hybridized to four probes that detect restriction fragment length polymorphisms within chromosome region 3p14-21. Of the 25 patients who were heterozygous for at least one marker in this region in the DNA from normal tissue, 23 (92%) showed an unequivocal loss of heterozygosity in the DNA from their tumor tissue. From these studies we conclude that loss of alleles from the short arm of chromosome 3 is a consistent finding in unselected small cell lung cancer patients' tumor DNA.

Adult polyglucosan body disease (APBD)

Three patients aged 63, 63 and 74 years had various combinations of progressive lower and upper motor neuron dysfunction, sensory loss, urinary incontinence and dementia. Postmortem examinations in two cases showed moderate cerebral and spinal atrophy, ill-defined areas of incomplete myelin loss in white matter and small necrotic foci in the white matter of gyri, around the basal ganglia and near the dentate nuclei. The main microscopic abnormality was a massive accumulation of PAS-positive polyglucosan bodies (PB) of various sizes and shapes in the cerebral hemispheres, brainstem, cerebellum, spinal cord, nerve roots and nerves. These PB were found in the processes of nerve cells and astrocytes, but not in their perikarya. Similar PB were present in peripheral nerves and in the lungs, heart, liver and kidneys. In the third case, a nerve biopsy revealed several, unusually large, PB in the axons of myelinated fibers. These clinicopathologic features are consistent with adult polyglucosan body disease (APBD) and are distinctive from other conditions in which PB may accumulate. Twelve similar cases have been reported previously. The diagnosis can be made by nerve biopsy. The pathogenesis of APBD is not known, but it may be a polysaccharide storage disease.

Genes for human vitamin K-dependent plasma proteins C and S are located on chromosomes 2 and 3, respectively

cDNAs encoding human proteins C and S have been used to screen a panel of mouse-human somatic cell hybrids to determine the chromosomal location of their respective genes. The gene for human protein C is located on chromosome 2, whereas that for protein S is located on chromosome 3. Analysis of human genomic DNA restriction endonuclease fragmentation patterns suggests that the human protein S gene is greater than 40 kb in size and contains a minimum of 11 introns.

Assignment of the lactotransferrin gene to human chromosome 3 and to mouse chromosome 9

Lactotransferrin (LTF), a member of the transferrin family of genes, is the major iron-binding protein in milk and body secretions. The amino acid sequence of LTF consists of two homologous domains homologous to proteins in the transferrin family. Recent isolation of cDNA encoding mouse LTF has expedited the mapping of both mouse and human LTF genes. Southern blot analysis of DNA from mouse-Chinese hamster and human-mouse somatic cell hybrids maps the LTF gene to mouse chromosome 9 and to human chromosome 3, respectively. Furthermore, analysis of cell hybrids containing defined segments of human chromosome 3 demonstrates that the gene is located in the 3q21-qter region. These results suggest that LTF and associated genes of the transferrin family have existed together on the same chromosomal region for 300-500 million years.

Chromosomal assignments of genes for tissue plasminogen activator and urokinase in mouse

The genes encoding the two plasminogen activators, tissue plasminogen activator and urokinase, were mapped to mouse chromosomes using probes derived from the respective mouse cDNAs. DNA from mouse-Chinese hamster and mouse-rat somatic cell hybrids was digested with BamHI and EcoRI, respectively, and analyzed by Southern blot hybridization for the segregation of the two genes. Tissue plasminogen activator and urokinase cosegregated with mouse chromosomes 8 and 14, respectively. The plasminogen activator genes thus fall into two syntenic groups that are conserved in human and mouse.

Hemopexin is localized to human chromosome 11

Hemopexin, a plasma protein that migrates during electrophoresis with the beta-globulins, transports free heme to sites of its catabolism in the liver. A hemopexin cDNA clone has been utilized for mapping the hemopexin (HPX) gene to human chromosome 11 in the region pter----p11 by somatic cell hybrid analysis.

Localization of human SAA gene(s) to chromosome 11 and detection of DNA polymorphisms

A human serum amyloid A (SAA) cDNA was used as a probe in chromosome mapping studies to detect human SAA gene sequences in DNA isolated from human/mouse somatic cell hybrids. Southern analysis of DNA from 20 hybrid cell lines, including some with translocations of human chromosomes, placed the SAA gene(s) in the p11----pter region of chromosome 11. Screening of human DNA from unrelated individuals by Southern analysis using the SAA cDNA probe revealed restriction fragment polymorphisms for HindIII and PstI. An analysis of the segregation of these polymorphisms with other markers on the short arm of chromosome 11 should more precisely map the SAA gene(s).

Outbreak of Salmonella eimsbuettel in newborn infants spread by rectal thermometers

Over a six-week period there were 25 episodes of Salmonella eimsbuettel infection in newborn infants, mothers, and staff in a modern maternity hospital with 3600 annual deliveries. The probable source was a mother and her child, and the organism was spread by rectal thermometers in the labour suite and one of the wings (wards). When the thermometers were withdrawn from use and correctly disinfected the outbreak in babies ceased. Environmental cross-infection of staff was halted by closure, cleaning, and disinfection of the clinical area mainly affected. Some babies had diarrhoea but quickly recovered, and none came to harm. The infected staff had no symptoms and returned to duty after three negative cultures. Measurement of temperature is still an important observation in the care of newborn infants, but for everyday care it is recommended that rectal thermometry be discontinued and replaced by axillary measurement.

Nicotine chewing gum in general practice: effect of follow up appointments

Two hundred smokers who were judged by their general practitioner to be motivated to stop smoking were allocated to one of two groups. All were offered an initial appointment at which they were advised to stop smoking and offered nicotine gum. One group then received no further appointments. The other was offered four further appointments over three months. Both groups were followed up at six and 12 months. At one year follow up 15.5% overall had stopped smoking, 14% in the low and 17% in the high contact group. This is better than most results so far reported for nicotine chewing gum in general practice, suggesting that general practitioners can use it to good effect. We compare this result with others achieved in general practice.

Improved Prognosis in Congenital Diaphragmatic Hernia: Experience of 62 Cases over 2-Year Period

During 1979 and 1980, 62 babies with congenital diaphragmatic hernia were admitted to the Hospitals for Sick Children. All 62 babies underwent surgical closure of the anatomical defect. There were 44 survivors and 18 deaths, a survival rate of 71%. Both the number treated and the overall survival rate were greater than any series reported for a similar period. The number of admissions may reflect earlier diagnosis and improved resuscitation, with safer and more rapid transfer to our units. The improved survival must be mainly attributed to our experience over the past few years which has consolidated understanding and methods of management and led to a close cooperation between surgeon and anaesthetist both in immediate management and in postoperative care.

High-pressure liquid chromatographic determination of ranitidine, a new H2-receptor antagonist, in plasma and urine

An assay is described for the determination of a new H2-receptor antagonist, ranitidine, and its desmethyl metabolite in human plasma and urine. Alkalinized plasma or urine was extracted with methylene chloride, the organic phase was evaporated, and the reconstituted residue was analyzed by high-pressure liquid chromatography using a reversed-phase column. Two other identified metabolites of ranitidine, the S-oxide and N-oxide, were separated chromtographically from both ranitidine and the desmethyl metabolite. However, these metabolites could not be quantitative due to poor analytical recovery and interference from endogenous components. The sensitivity limits were 5 ng/ml for ranitidine and 15 ng/ml for desmethylranitidine. Plasma samples from two volunteers who were given oral ranitidine (0.1, 0.2, and 0.4 mg/kg) at 1-week intervals were assayed. Peak levels of 30--130 ng/ml were achieved between 40 and 120 min after dosage, followed by an elimination half-life of 2.9-3.9 hr. Plasma levels of ranitidine were still detectable at 8 hr but were below the sensitivity of the assay by 24 hr. Plasma levels of the desmethyl metabolite were seldom above the threshold sensitivity of the assay. Urinary excretion of unmetabolized ranitidine accounted for 77% of the administered dose, whereas only 4% appeared as desmethylranitidine.

Hypertrichosis due to minoxidil

A case of hypertrichosis due to the hypotensive drug minoxidil is described. A review of the literature suggests that this complication appears in nearly all patients treated with this drug. The mechanism is unknown, but the similarity to the cases of hypertrichosis due to diazoxide, another potent vasodilator, suggests that increased cutaneous blood flow may be a factor.

Rhabdomyosarcoma of the right ventricle associated with polyarthritis

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Analysis of the penetrable space within the nucleus

Radioactive glycogen molecules have been used as passive probes to compare cavity systems within nuclei and isolated chromatin. Isolated chromatin was found to possess a narrow range of microspaces with mean effective diameters between 4.0 and 4.5 nm (40 and 45 A) depending on shape assumptions. Intact nuclei contained a far larger class of free spaces with average diameters in the order of 11.0-15.0 nm. This clearly shows that DNase-I (diam. 4.1 nm) can penetrate and occupy a large proportion of nuclear space even though this enzyme does not readily attack the undisturbed nuclear structure. A structure which simulated the pattern of penetrability and incorporated other known properties of chromatin was used to explain this DNase-I resistance of intact nuclei in terms of an ordered, compact, local structure interspersed by much larger spaces. A system for this local packing is suggested and the functional implications of this type of organization considered.

Analgesic effects of 3-carboxysalsolinol alone and in combination with morphine

A biphasic dose-response pattern is generated by the isoquinoline, 3-carboxysalsolinol, in analgesia tests conducted in mice. Carbidopa pretreatment enhances this effect, as well as the morphine-induced analgesic increase by 3-carboxysalsolinol. Naloxone blockade of all of these responses suggests an interaction of the alcohol-based isoquinoline with central opiate receptors.

The effect of tablet formulation on the haemodynamic properties of glyceryl trinitrate

A non-invasive haemodynamic study was carried out in 13 normal subjects to compare the pharmacodynamics of glyceryl trinitrate when formulated as a moulded tablet ('Nitrostat') rather than as a generic compressed tablet. The glyceryl trinitrate moulded tablet, with a much more rapid and predictable dissolution time, produced an earlier onset of systolic blood pressure fall (p less than 0.01) and a greater maximum percentage change in peripheral blood flow (p less than 0.02). No other significant differences in effect on pulse rate, blood pressure or peripheral blood flow were noted.

Potentiation of ethanol narcosis by dopamine- and l-DOPA-based isoquinolines

The isoquinolines, salsolinol and 3-carboxysalsolinol, prolong ethanol-induced narcosis in mice. Pretreatment with carbidopa increases the effect of 3-carboxysalsolinol but not of salsolinol. These results suggest that ethanol sleeping-time potentiation by l-LOPA may involve a partial conversion to the isoquinoline in vivo. A central depressant action of salsolinol or the 3-carboxy analogue is suggested.

Sensory system involvement in infantile spinal muscular atrophy

Nine cases of infantile spinal muscular atrophy were studied post-mortem. Their ages at death ranged from 5 months to 10 years. In all cases severe loss of anterior horn cells in the spinal cord and neurogenic muscular atrophy were characteristic of this disease. In 6 cases there was also loss of myelin in the posterior columns particularly affecting the lumbar contribution. Sensory ganglia, especially from the lumbar region, contained nodules of Nageotte, indicating sensory neuron degeneration. These sensory abnormalities were more severe in the longer surviving cases. It seems possible that sensory neuron degeneration occurs more commonly in Werdnig-Hoffmann disease than has previously been supposed but that it is less severe and develops more slowly than motor neuron degeneration.

Oestradiol-17 beta and prolactin levels in rat peripheral plasma

Radioimmunoassay methods for the determination of oestradiol-17 beta and prolactin have been examined for their reliability and applied to the measurement of hormone concentrations in the plasmas from male and female rats. Prolactin was detectable in all samples (greater than 7 ng RP-1 ng/ml) but the concentration of oestradiol-17 beta was below the sensitivity of the method (greater than 0-10 ng/100 ml) in ovariectomized females. Plasma oestradiol-17 beta concentration rose gradually from metoestrus to proestrus and fell to barely detectable levels in oestrus. Plasma prolactin concentration was very variable even for rats in the same stage of the oestrous cycle but values were minimal in the afternoon of diestrus and a surge in secretion occurred in the afternoon of proestrus. In addition to the stage of the oestrous cycle, the prolactin concentration was influenced by mode of blood collection, degree of haemolysis and choice of serum or plasma. There was no correlation between the concentration of prolactin and that of oestradiol-17 beta in the same sample of plasma.