Antibacterial properties of Ro 40-6890, a broad-spectrum cephalosporin, and its novel orally absorbable ester, Ro 41-3399.

Ro 41-3399 is a novel orally active ester of Ro 40-6890, an aminothiazolyl cephalosporin with potent in vitro activities against commonly encountered aerobic gram-positive bacteria (streptococci and methicillin-susceptible staphylococci) and gram-negative bacteria (members of the family Enterobacteriaceae, haemophili, meningococci, and gonococci). In terms of the MICs determined by the methods recommended by the National Committee for Clinical Laboratory Standards, for 50 and 90% of gram-positive organisms, the water-soluble free carboxylic acid Ro 40-6890 proved to be at least as active as or two- to fourfold more active than cefpodoxime, cefuroxime, cefaclor, amoxicillin, amoxicillin-clavulanic acid, and ceftriaxone; against aerobic gram-negative organisms, Ro 40-6890 was usually two- to fourfold more active than cefpodoxime, the next most potent of the oral drugs under comparison, but remained usually two- to fourfold weaker than ceftriaxone. Ro 40-6890 showed a high affinity for the essential penicillin-binding proteins of susceptible bacteria and was resistant to hydrolysis by a broad array of beta-lactamases. Ro 41-3399 bopentil was well absorbed in mice when administered by oral gavage and proved effective in several experimental bacterial infections. Further studies with Ro 41-3399 and Ro 40-6890 are in progress.


In vitro activities of Ro 40-6890 against 164 predominantly intestinal members of the families Enterobacteriaceae and Vibrionaceae.

The in vitro activities of Ro 40-6890, the active metabolite of a novel orally absorbable cephalosporin ester, Ro 41-3399, against 164 nonfastidious aerobic gram-negative rods of predominantly intestinal origin from patients with diarrhea were evaluated by the agar dilution method recommended by the National Committee for Clinical Laboratory Standards. Ro 40-6890 was inhibitory (MIC for 90% of isolates [MIC90], 0.12 micrograms/ml) against the majority of intestinal members of the families Enterobacteriaceae and Vibrionaceae (Vibrio spp., Aeromonas spp., and Plesiomonas shigelloides). The potency of Ro 40-6890 was very similar to that of cefotaxime (MIC90, 0.12 micrograms/ml) and distinctly higher than those of cefadroxil (MIC90, > or = 128 micrograms/ml) and amoxicillin-clavulanic acid (MIC90, 32 micrograms/ml-2 micrograms/ml).


Selection of resistant mutants of Mycobacterium avium in beige mice by clarithromycin monotherapy.

Beige mice were inoculated intravenously with 10(7.90) CFU of Mycobacterium avium 101. Among the untreated control mice, when the mean CFU per spleen increased to a level greater than 10(8), small numbers of organisms resistant to clarithromycin (CLARI) were isolated from some of the spleens; the frequency of CLARI-resistant mutants was estimated to be between 10(-8) and 10(-9). In mice treated with 200 mg of CLARI per kg of body weight six times weekly, however, CLARI-resistant organisms were isolated from the spleens of all mice examined after treatment for 8 weeks; the mean CFU per spleen and the frequency of resistant mutants were significantly greater than those of control mice and increased further after treatment for 16 weeks. The MICs of CLARI against the resistant organisms isolated from both control and treated mice were > or = 512 micrograms/ml.


Effect of pH on radiometric MICs of clarithromycin against 18 species of mycobacteria.

The antimycobacterial spectrum of clarithromycin, a new macrolide drug, was screened against 26 strains belonging to 18 species of mycobacteria by determining radiometric MICs by Bactec methodology at three different pHs, i.e., pH 6.0, 6.8, and 7.4. The MICs obtained at pH 7.4 were 1 to 2 or more dilutions lower in some of the species than those obtained at pH 6.8, whereas they were significantly higher at pH 6.0. The numbers of species for which MICs were below the Cmax levels of clarithromycin (i.e., 4 micrograms/ml) at different pHs were 8 of 18 species at pH 6.0, 13 of 18 species at pH 6.8, and 14 of 18 species at pH 7.4. The drug possessed promising activity against such potential pathogens as M. avium, M. scrofulaceum, M. szulgai, M. malmoense, M. xenopi, M. marinum, and M. kansasii and rare pathogens like M. chelonei.


Activity of clarithromycin compared with those of other drugs against Mycobacterium paratuberculosis and further enhancement of its extracellular and intracellular activities by ethambutol.

Radiometric MICs of clarithromycin, a new macrolide drug, were determined against five mycobactin-dependent strains of Mycobacterium paratuberculosis (including two Crohn's disease clinical isolates) and compared with those of other drugs which included rifampin, ethambutol, amikacin, ofloxacin, ciprofloxacin, and sparfloxacin. Among the drugs screened, clarithromycin was the drug for which MICs were lowest against the five strains tested. As MICs were significantly below the reported Cmax levels (about 4 micrograms/ml), the intracellular activity of clarithromycin against the type strain of M. paratuberculosis maintained in cultured macrophages was screened. Clarithromycin was able to kill the initial inoculum by more than 1 log within 7 days, and this activity was further potentiated by ethambutol. Extracellular drug combination screened by using sublethal concentrations of the drugs showed that ethambutol was able to enhance clarithromycin activity in three out of four M. paratuberculosis strains instead of only one out of four strains (or none in the case of ofloxacin) when associated with other drugs. These results suggest that clarithromycin may be fruitful to treat human disease in which M. paratuberculosis may be etiologically involved.


Antimicrobial susceptibilities of Campylobacter jejuni and Campylobacter coli isolated in Sweden: a 10-year follow-up report.

Resistance to erythromycin and doxycycline and more recently to fluoroquinolones has been reported to occur in Campylobacter spp. both in vitro and in patients treated with these antibiotics. The frequency of resistance to 14 antimicrobial agents in Campylobacter jejuni and Campylobacter coli isolated from patients infected in Sweden or abroad is described. For some agents, a comparison of susceptibility in strains of Campylobacter spp. isolated in 1978 with those isolated in 1988 is made. No general increase in in vitro resistance to antibiotics commonly used for the treatment of human gastroenteritis caused by C. jejuni or C. coli has occurred during the last 10 years in Sweden, which might be a consequence of strict antibiotic control. The numbers of strains from 1988 to 1989 resistant to ciprofloxacin and to norfloxacin included in this study (0.7 and 1.4%, respectively) are still fewer than those that were resistant to erythromycin (7.3%) or doxycycline (12.4%). There is, however, since 1989 to 1990 an indication of increasing resistance to these antibiotics.


Influence of ceftriaxone on emergence of Clostridium difficile.

The influence of long-term ceftriaxone administration on the emergence of Clostridium difficile was studied with 80 patients receiving ceftriaxone for 14 days. In five patients (6.3%) C. difficile was cultured. The appearance of gastrointestinal disturbances during treatment with ceftriaxone was common, but the rate of emergence of C. difficile in immunocompetent patients was not high.


Synergistic activity of clarithromycin and minocycline in an animal model of acute experimental toxoplasmosis.

The efficacy of clarithromycin in a murine model of acute toxoplasmosis was studied. Clarithromycin was administered alone and concurrently with minocycline, and efficacy was assessed by survival rates and sequential determination of parasite burden in blood, brains, and lungs. Limited protection resulted from administration of each drug alone, whereas a remarkable synergistic effect followed concurrent administration. Survival of mice treated with 200 mg of clarithromycin plus 20 mg of minocycline per kg of body weight daily was 95%; that of mice treated with 50 mg of clarithromycin plus 50 mg of minocycline per kg daily was 93%. The parasite burden in the blood and organ tissues of these mice was markedly reduced compared with that in mice treated with a single agent. In mice treated with 200 mg of clarithromycin plus 50 mg of minocycline per kg per day, survival was 100% during the 30-day experiment; no parasites were found in blood and tissues.


Taste and food preference changes across the course of pregnancy.

The present study investigates taste and specific food consumption changes across the course of pregnancy. These variables could potentially play a role in excess pregnancy-associated weight gains. Pregnant and postpartum women were asked to consume a series of everyday foods in the laboratory. Consumption and taste perception of each food were measured. In contrast to the self-report literature on cravings and aversions during pregnancy, which emphasizes changes in the first trimester, this study found that women in the second trimester consumed significantly more sweet food, but not salty or non-sweet/non-salty food, as compared with women at any other point in pregnancy. Subjects were restrained eaters, and so possibly refrained from daily consumption of excess sweet foods. This study suggests that psychological variables may interact with behavioral and physiological variables to control food preferences and eating in pregnancy.


Effects of eating an uncooked vegetable diet for 1 week.

Biochemical and metabolic indicators were monitored in a group of volunteers suffering from a variety of chronic illnesses participating in a week's course on a special uncooked vegetable diet, known as "living food". Unmatched healthy controls ate the same diet cooked for 2 min in a microwave oven. After 1 week on the regimen, serum protein and urea contents decreased and alanine aminotransferase (ALAT) activity increased in both groups, although all within the normal range. Blood glucose increased in both groups to slightly above normal limits but total serum cholesterol dropped about 1 mmol/l from normal starting levels. Serum tocopherol and retinol increased only in the group eating the uncooked diet. In both groups urinary sodium dropped drastically without a significant change in potassium. Serum and urinary phenol and p-cresol diminished also significantly. It is concluded that this vegetable diet may be of some benefit in the short term but any longer-term use requires evaluation.


Economic analysis of the effects of caloric alternatives and reinforcer magnitude on "demand" for food in baboons.

In a study examining "demand" for food, the responses of six adult male baboons (Papio c. anubis) were maintained under a fixed ratio schedule of food reinforcement during daily 22-h experimental sessions. Completion of the ratio requirement resulted in the delivery of a single 1-g food pellet. Caloric intake was studied under four food-access conditions: a single source of 1-g food pellets, two sources of pellets with different response costs, one source of pellets and one source of dextrose solutions with different response costs, or a single source of multiple pellets. Total daily caloric intake under minimal response-cost conditions did not vary across these four conditions. Increasing the response requirement for a single pellet decreased daily food intake. Compared to this single-pellet condition, increasing the response requirement: (a) decreased intake of multiple pellets to a much smaller extent; (b) decreased pellet intake to a larger extent when dextrose was available on an alternate lever and (c) decreased pellet intake to the greatest extent when pellets were available on an alternate lever. Changes in pellet intake were fitted to a theoretical equation derived by Hursh et al. (1988) to describe changes in demand for a commodity. Increasing the number of pellets per delivery decreased the rate of change in intake as cost increased, indicating decreased elasticity. Dextrose availability increased the rate of change in intake as cost increased, indicating increased elasticity. Availability of an identical food source increased the initial slope of intake without effecting the rate of change, thus also increasing elasticity. Mathematical analysis of demand curves provide a means of comparing the effects of diverse environmental manipulations on feeding behavior.


Underreporting of food intake in obese "small eaters".

Thirty sedentary and stable weight obese women were classified as small, normal or large eaters depending on their report of 24 h energy intake (EI) through a dietary history questionnaire. For each subject, resting metabolic rate (RMR) was assessed through indirect calorimetry, physical activity through a self-administered questionnaire and psychological evaluation through psychometric tests. Neither RMR nor indices of physical activity were different between the three groups; however for small eaters, RMR was higher than reported EI (p < 0.001). Thus, the low EI reported by obese small eaters reflected an underreporting of food intake. Psychometric evaluation was not different between normal and large eaters. Small eaters exhibited a better perception of food size than normal or large eaters, and no difference in tests assessing memory or attention; their score (2.8 +/- 1.3) in a nutritional dissimulation test was higher (p = 0.015) than that of normal (1.0 +/- 0.7) or large eaters (1.5 +/- 0.09). This suggests that underreporting in obese small eaters might be due to specific nutritional concealment; because small eaters reported a low intake particularly in foods which are often perceived as unhealthy (fats, sugars, extra-prandial consumption), they probably reported what, in their opinion, they should have eaten, instead of what they did eat.


Consumer liking for sausages affected by sensory quality and information on fat content.

The sensory quality of sausages containing 12 and 20% fat (the usual level) was assessed by descriptive profiling in a trained sensory panel. The effects of information on fat level and sensory differences on liking or dislike by consumers were assessed in 347 eaters of sausages recruited in food stores. The knowledge of a 40% reduction in fat content did not affect the hedonic responses to sausages with different sensory quality, whereas the sensory differences had major effects on liking scores. Fat-reduced sausages were liked as much as standard sausages when their texture and saltiness were similar to the more familiar quality. When sensory quality was similar, false information that the fat content of the 20%-fat sausages was 12% increased the liking for them although correct information on fat content of the sensorily similar 12%-fat sausages decreased liking. Thus, to avoid reducing the acceptability of reduced-fat sausages, it seems necessary to have a profile similar to the sausages containing usual levels of fat.


Effects of intraruminal infusions of sodium acetate and sodium chloride on silage intake by lactating cows.

Lactating dairy cows prepared with rumen fistulas were fed on grass silage and concentrates and used in two experiments to compare the effects of sodium acetate and sodium chloride infused over 3 h into the rumen on the voluntary intake of silage. Silage intake was depressed in an approximately linear manner by increasing amounts (6-15 mol) of sodium acetate (NaOAc) and 15 mol NaCl had an effect similar to that of 12 mol NaOAc. Sodium in rumen fluid was significantly correlated with intake as was osmolality. 5.5, 7.4 or 9.1 mol of NaOAc significantly depressed silage intake, while 7.4 and 9.1 mol NaCl had significant effects. There were significant negative relationships between intake and the level of NaOAc or NaCl. It is concluded that the major effect of either salt was via the elevation of osmolality of rumen fluid and the relevance to normal control of feeding is discussed.


Discrimination of Listeria monocytogenes from other Listeria species by ligase chain reaction.

A ligase chain reaction assay based on a single-base-pair difference in the V9 region of the 16S rRNA gene (16S rDNA) was developed to distinguish between Listeria monocytogenes and other Listeria species. For this purpose, two pairs of primers were designed, with one primer of each pair being radioactively labeled. The ligated product was separated from the primers by denaturing polyacrylamide gel electrophoresis and then detected by autoradiography. To achieve a higher sensitivity, the 16S rDNA was initially amplified by polymerase chain reaction prior to the ligase chain reaction. The ligase chain reaction was tested on 19 different Listeria species and strains and proved to be a highly specific diagnostic method for the detection of L. monocytogenes.


Cloning, characterization, and nucleotide sequence of a gene encoding Microbispora bispora BglB, a thermostable beta-glucosidase expressed in Escherichia coli.

Genomic DNA fragments encoding beta-glucosidase activities of the thermophilic actinomycete Microbispora bispora were cloned into Escherichia coli. Transformants expressing beta-glucosidase activity were selected by their ability to hydrolyze the fluorogenic substrate 4-methylumbelliferyl-beta-D-glucoside. Two genes encoding beta-glucosidase activity were isolated and distinguished by restriction analysis, Southern hybridization, and the substrate specificities of the encoded enzymes. One gene, bglB, encoded a beta-glucosidase that was expressed intracellularly in E. coli. It exhibited a molecular mass of approximately 52,000 Da by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (PAGE) and 51,280 Da by nondenaturing gradient PAGE, a pI of 4.6, and temperature and pH optima of 60 degrees C and 6.2, respectively. Cloned BglB showed greater activity against cellobiose than against aryl-beta-D-glucosides and was thermostable, retaining about 70% of its activity after 48 h at 60 degrees C. BglB activity is activated two- to threefold in the presence of 2 to 5% (0.1 to 0.3 M) glucose. The DNA sequence of the 2.2-kb insert carrying bglB has been determined. An open reading frame which codes for a protein of 473 amino acids with a predicted molecular mass of 52,227 Da showed significant homology (40 to 47% identity) with beta-glucosidases from glycosal hydrolase family 1.


Predicting the growth of Salmonella typhimurium on beef by using the temperature function integration technique.

Lag and generation times for the growth of Salmonella typhimurium on sterile lean beef were modeled as functions of cooling time under various carcass-chilling scenarios. Gompertz growth models were fit to the log10 colony counts over time at each of six temperatures in the range of 15 to 40 degrees C. Lag and generation times were defined as the points at which the second and first derivatives, respectively, of each growth curve attained a maximum. Generation time and lag time parameters were modeled as functions of temperature by use of exponential-decay models. The models were applied to typical beef carcass-cooling scenarios to predict the potential growth of S. typhimurium during the cooling of beef. Validation studies indicated no significant difference between the observed and predicted bacterial populations on inoculated lean and fatty beef tissues cooled at either 6 or 9 degrees C/h.


Viability of Cryptosporidium parvum oocysts: correlation of in vitro excystation with inclusion or exclusion of fluorogenic vital dyes.

A viability assay for oocysts of Cryptosporidium parvum based on the inclusion or exclusion of two fluorogenic vital dyes, 4',6-diamidino-2-phenylindole (DAPI) and propidium iodide, was developed by using several different isolates of oocysts. Correlation of this assay with viability measured by in vitro excystation was highly statistically significant, with a calculated correlation coefficient of 0.997. In this research, two similar excystation protocols were utilized, and no significant difference between excystation protocols was detected. Percent excystation of oocyst suspensions could be increased or reduced by inclusion of a preincubation treatment in either excystation protocol, and this alteration was also demonstrated in the viability assay. Oocysts which excluded both dyes would not excyst in vitro unless a further trigger was provided and were more resistant to acid or alkali treatment. The results of this research provide a reproducible, user-friendly assay which is applicable to individual oocysts and also provides a useful adjunct for identification of oocysts in water and environmental samples.


Survival of Cryptosporidium parvum oocysts under various environmental pressures.

The survival of various isolates of Cryptosporidium parvum oocysts under a range of environmental pressures including freezing, desiccation, and water treatment processes and in physical environments commonly associated with oocysts such as feces and various water types was monitored. Oocyst viability was assessed by in vitro excystation and by a viability assay based on the exclusion or inclusion of two fluorogenic vital dyes. Although desiccation was found to be lethal, a small proportion of oocysts were able to withstand exposure to temperatures as low as -22 degrees C. The water treatment processes investigated did not affect the survival of oocysts when pH was corrected. However, contact with lime, ferric sulfate, or alum had a significant impact on oocyst survival if the pH was not corrected. Oocysts demonstrated longevity in all water types investigated, including seawater, and when in contact with feces were considered to develop an enhanced impermeability to small molecules which might increase the robustness of the oocysts when exposed to environmental pressures.


Production of bacteriocin inhibitory to Listeria species by Enterococcus hirae.

A bovine intestinal bacterial isolate, identified as Enterococcus hirae, was found to produce a bacteriocin (designated hiraecin S) inhibitory to Listeria monocytogenes and other Listeria spp. Identification to species level was determined by comprehensive biochemical and morphological tests which were verified by DNA-DNA homology assays. The antimicrobial agent was inactivated by pronase and papain and was insensitive to catalase. The antimicrobial activity was not due to hydrogen peroxide or acid formation, nor was lysozyme or muramidase activity observed in cell-free bacteriocin preparations. Inhibition of selected gram-negative bacteria was not observed. Other enterococci were sensitive to the bacteriocin, and except for Listeria spp., no other gram-positive bacteria tested were inhibited.


Efficacy of activated sludge in removing Cryptosporidium parvum oocysts from sewage.

Primary clarifier effluent (procedure B) and final effluent (procedure A) from a wastewater treatment plant were enriched with Cryptosporidium parvum oocysts obtained from the feces of naturally infected calves. Procedure B samples alone were subjected to a laboratory simulation of activated-sludge treatment. Coccidium-free neonatal CD-1 mice were then inoculated intragastrically with procedure A or procedure B samples. Seven days after inoculation, the intensity of oocyst infection in procedure B mice was 91% less than in procedure A mice (controls).


Sensitive and species-specific detection of Erwinia amylovora by polymerase chain reaction analysis.

Detection and identification of the fire blight pathogen, Erwinia amylovora, can be accurately done by polymerase chain reaction (PCR) analysis in less than 6 h. Two oligomers derived from a 29-kb plasmid which is common to all strains of E. amylovora were used to amplify a 0.9-kb fragment of the plasmid. By separation of the PCR products on agarose gel, this fragment wa specifically detected when E. amylovora DNA was present in the amplification assay. It was not found when DNA from other plant-pathogenic bacteria was used for the assay. A visible band specific to the 0.9-kb fragment was produced with DNA from fewer than 100 E. amylovora cells. A signal of similar strength was also obtained from E. amylovora cell lysates in the presence of the mild detergent Tween 20. Signals were weaker when bacteria were added to the PCR mixture without the detergent. As with results obtained from hybridization experiments using pEA29 DNA< the PCR signal was obtained with E. amylovora isolates from various geographic regions. This technique could also be used for detection of the fire blight pathogen in extracts of tissue obtained from infected plant material.


Application of gas chromatography-mass spectrometry for rapid detection of Mycobacterium xenopi in drinking water.

Gas chromatography-mass spectrometry (GC-MS) was used to detect 2-docosanol, a secondary alcohol characteristic of Mycobacterium xenopi, in 7 of 10 analyzed drinking water samples culture positive for that species. GC-MS was also used to detect tuberculostearic acid. Both of these chemical markers were analyzed as halogenated derivatives in the negative-ion-chemical-ionization mode. The numbers of CFU of M. xenopi were lowest in the three GC-MS-negative samples. The described GC-MS method is useful for the rapid detection of M. xenopi in drinking water.


The anaerobic degradation of 3-chloro-4-hydroxybenzoate in freshwater sediment proceeds via either chlorophenol or hydroxybenzoate to phenol and subsequently to benzoate.

To study the anaerobic degradation of the chimera 3-chloro-4-hydroxybenzoate (3-Cl,4-OHB), anaerobic freshwater sediment samples from the vicinity of Athens, Ga., were adapted for the transformation of 4-hydroxybenzoate (4-OHB), 3-chlorobenzoate (3-CB), 2-chlorophenol (2-CP), and 2,4-dichlorophenol (2,4-DCP). In nonadapted samples, both 4-OHB (product of aryl dechlorination) and 2-CP (product of aryl decarboxylation) were observed as intermediates in the transformation of 3-Cl,4-OHB to phenol. The accumulated phenol was subsequently transformed to benzoate, an intermediate in the conversion to methane and CO2. In 4-OHB-adapted samples (i.e., samples adapted for aryl decarboxylation), 2-CP was the first intermediate which was subsequently dechlorinated to phenol. In 3-CB-adapted samples (i.e., samples adapted for meta-chlorobenzoate dehalogenation), 3-Cl,4-OHB was stoichiometrically dechlorinated to 4-OHB. In 2-CP-adapted samples (i.e., samples adapted for ortho-chlorophenol dehalogenation), 4-OHB was the first major intermediate. Furthermore, 3-CB was not dechlorinated in 2-CP-adapted sediment samples, suggesting the possibility that different 3-Cl,4-OHB dechlorinating systems were induced in the 2-CP- and 3-CB-adapted sediments. Adaptation of sediment samples for dechlorination of 2,4-DCP did not lead to adaptation for dechlorination of 3-Cl,4-OHB. However, 3-Cl,4-OHB was dechlorinated to 4-OHB in our stable, sediment-free 2,4-DCP-dechlorinating enrichment, isolated previously from the same environment.(ABSTRACT TRUNCATED AT 250 WORDS)


Properties of a genetically reconstructed Prevotella ruminicola endoglucanase.

A pUC19-derived plasmid was constructed that coded for a hybrid cellulase with the Thermomonospora fusca E2 cellulose-binding domain at its C terminus joined to the Prevotella ruminicola 40.5-kDa carboxymethyl cellulase (CMCase). The hybrid enzyme was purified and characterized enzymatically. It bound tightly to cellulose, and its specific activities on carboxymethyl cellulose, amorphous cellulose, and ball-milled cellulose were 1.5, 10, and 8 times that of the 40.5-kDa CMCase, respectively. Furthermore, the modified enzyme gave synergism with an exocellulase in the degradation of filter paper, while the 40.5-kDa CMCase did not.


Mineralization of sulfonated azo dyes and sulfanilic acid by Phanerochaete chrysosporium and Streptomyces chromofuscus.

Five 14C-radiolabeled azo dyes and sulfanilic acid were synthesized and used to examine the relationship between dye substitution patterns and biodegradability (mineralization to CO2) by a white-rot fungus and an actinomycete. 4-Amino-[U-14C]benzenesulfonic acid and 4-(3-sulfo-4-aminophenylazo)-[U-14C]benzenesulfonic acid were used as representative compounds having sulfo groups or both sulfo and azo groups. Such compounds are not known to be present in the biosphere as natural products. The introduction of lignin-like fragments into the molecules of 4-amino-[U-14C]benzenesulfonic acid and 4-(3-sulfo-4-aminophenylazo)-[U-14C]benzenesulfonic acid by coupling reactions with guaiacol (2-methoxyphenol) resulted in the formation of the dyes 4-(3-methoxy-4-hydroxyphenylazo)-[U-14C]benzenesulfonic acid and 4-(2-sulfo-3'-methoxy-4'-hydroxy-azobenzene-4-azo)-[U-14C]benzenesulf oni c acid, respectively. The synthesis of acid azo dyes 4-(2-hydroxy-1-naphthylazo)-[U-14C]benzenesulfonic acid and 4-(4-hydroxy-1-naphthylazo)-[U-14C]benzenesulfonic acid also allowed the abilities of these microorganisms to mineralize these commercially important compounds to be evaluated. Phanerochaete chrysosporium mineralized all of the sulfonated azo dyes, and the substitution pattern did not significantly influence the susceptibility of the dyes to degradation. In contrast, Streptomyces chromofuscus was unable to mineralize aromatics with sulfo groups and both sulfo and azo groups. However, it mediated the mineralization of modified dyes containing lignin-like substitution patterns. This work showed that lignocellulolytic fungi and bacteria can be used for the biodegradation of anionic azo dyes, which thus far have been considered among the xenobiotic compounds most resistant to biodegradation.(ABSTRACT TRUNCATED AT 250 WORDS)


Influence of aromatic substitution patterns on azo dye degradability by Streptomyces spp. and Phanerochaete chrysosporium.

Twenty-two azo dyes were used to study the influence of substituents on azo dye biodegradability and to explore the possibility of enhancing the biodegradabilities of azo dyes without affecting their properties as dyes by changing their chemical structures. Streptomyces spp. and Phanerochaete chrysosporium were used in the study. None of the actinomycetes (Streptomyces rochei A10, Streptomyces chromofuscus A11, Streptomyces diastaticus A12, S. diastaticus A13, and S. rochei A14) degraded the commercially available Acid Yellow 9. Decolorization of monosulfonated mono azo dye derivatives of azobenzene by the Streptomyces spp. was observed with five azo dyes having the common structural pattern of a hydroxy group in the para position relative to the azo linkage and at least one methoxy and/or one alkyl group in an ortho position relative to the hydroxy group. The fungus P. chrysosporium attacked Acid Yellow 9 to some extent and extensively decolorized several azo dyes. A different pattern was seen for three mono azo dye derivatives of naphthol. Streptomyces spp. decolorized Orange I but not Acid Orange 12 or Orange II. P. chrysosporium, though able to transform these three azo dyes, decolorized Acid Orange 12 and Orange II more effectively than Orange I. A correlation was observed between the rate of decolorization of dyes by Streptomyces spp. and the rate of oxidative decolorization of dyes by a commercial preparation of horseradish peroxidase type II, extracellular peroxidase preparations of S. chromofuscus A11, or Mn(II) peroxidase from P. chrysosporium. Ligninase of P. chrysosporium showed a dye specificity different from that of the other oxidative enzymes.(ABSTRACT TRUNCATED AT 250 WORDS)


Hydrogen as an electron donor for dechlorination of tetrachloroethene by an anaerobic mixed culture.

Hydrogen served as an electron donor in the reductive dechlorination of tetrachloroethene to vinyl chloride and ethene over periods of 14 to 40 days in anaerobic enrichment cultures; however, sustained dechlorination for more extended periods required the addition of filtered supernatant from a methanol-fed culture. This result suggests a nutritional dependency of hydrogen-utilizing dechlorinators on the metabolic products of other organisms in the more diverse, methanol-fed system. Vancomycin, an inhibitor of cell wall synthesis in eubacteria, was found to inhibit acetogenesis when added at 100 mg/liter to both methanol-fed and hydrogen-fed cultures. The effect of vancomycin on dechlorination was more complex. Methanol could not sustain dechlorination when vancomycin inhibited acetogenesis, while hydrogen could. These results are consistent with a model in which hydrogen is the electron donor directly used for dechlorination by organisms resistant to vancomycin and with the hypothesis that the role of acetogens in methanol-fed cultures is to metabolize a portion of the methanol to hydrogen. Methanol and other substrates shown to support dechlorination in pure and mixed cultures may merely serve as precursors for the formation of an intermediate hydrogen pool. This hypothesis suggests that, for bioremediation of high levels of tetrachloroethene, electron donors that cause the production of a large hydrogen pool should be selected or methods that directly use H2 should be devised.


Adaptation of model genetically engineered microorganisms to lake water: growth rate enhancements and plasmid loss.

When a genetically engineered microorganism (GEM) is released into a natural ecosystem, its survival, and hence its potential environmental impact, depends on its genetic stability and potential for growth under highly oligotrophic conditions. In this study, we compared plasmid stability and potential for growth on low concentrations of organic nutrients of strains of Pseudomonas putida serving as model GEMs. Plasmid-free and plasmid-bearing (NAH7) prototrophic isogenic strains and two amino-acid auxotrophs, all containing antibiotic resistance markers, were held physically separate from but in chemical contact with lake water containing the natural bacterium-sized microbial populations. Cells were reisolated at intervals over a 2-month period to determine the percent retaining the plasmid and the specific growth rate on various media. Plasmid stability in lake water was strongly strain specific; the NAH7 plasmid was stably maintained by the prototrophic strain for the duration of the test but was lost within 24 h by both of the auxotrophs. Specific growth rates of reisolates, compared with those of the corresponding non-lake water-exposed strains (i.e., parental strains), were not different when measured in rich medium (Luria-Bertani broth). However, specific growth rates were 42, 55, and 63% higher in reisolates of auxotrophs and the plasmid-free prototroph, respectively, when measured in 10-fold-diluted medium after exposure of 15 days or longer to lake water. Moreover, lake water-exposed strains grew actively when reintroduced into sterile lake water (28- to 33-fold increase in numbers over 7 days), while the corresponding unadapted parental strains exhibited no growth over the same period.(ABSTRACT TRUNCATED AT 250 WORDS)


Fungal metabolism of acenaphthene by Cunninghamella elegans.

The filamentous fungus Cunninghamella elegans ATCC 36112 metabolized within 72 h of incubation approximately 64% of the [1,8-14C]acenaphthene added. The radioactive metabolites were extracted with ethyl acetate and separated by thin-layer chromatography and reversed-phase high-performance liquid chromatography. Seven metabolites were identified by 1H nuclear magnetic resonance, UV, and mass spectral techniques as 6-hydroxyacenaphthenone (24.8%), 1,2-acenaphthenedione (19.9%), trans-1,2-dihydroxyacenaphthene (10.3%), 1,5-dihydroxyacenaphthene (2.7%), 1-acenaphthenol (2.4%), 1-acenaphthenone (2.1%), and cis-1,2-dihydroxyacenaphthene (1.8%). Parallel experiments with rat liver microsomes indicated that the major metabolite formed from acenaphthene by rat liver microsomes was 1-acenaphthenone. The fungal metabolism of acenaphthene was similar to bacterial and mammalian metabolism, since the primary site of enzymatic attack was on the two carbons of the five-member ring.


An uncooked vegan diet shifts the profile of human fecal microflora: computerized analysis of direct stool sample gas-liquid chromatography profiles of bacterial cellular fatty acids.

The effect of an uncooked extreme vegan diet on fecal microflora was studied by direct stool sample gas-liquid chromatography (GLC) of bacterial cellular fatty acids and by quantitative bacterial culture by using classical microbiological techniques of isolation, identification, and enumeration of different bacterial species. Eighteen volunteers were divided randomly into two groups. The test group received an uncooked vegan diet for 1 month and a conventional diet of mixed Western type for the other month of the study. The control group consumed a conventional diet throughout the study period. Stool samples were collected. Bacterial cellular fatty acids were extracted directly from the stool samples and measured by GLC. Computerized analysis of the resulting fatty acid profiles was performed. Such a profile represents all bacterial cellular fatty acids in a sample and thus reflects its microflora and can be used to detect changes, differences, or similarities of bacterial flora between individual samples or sample groups. GLC profiles changed significantly in the test group after the induction and discontinuation of the vegan diet but not in the control group at any time, whereas quantitative bacterial culture did not detect any significant change in fecal bacteriology in either of the groups. The results suggest that an uncooked extreme vegan diet alters the fecal bacterial flora significantly when it is measured by direct stool sample GLC of bacterial fatty acids.


Introduction of a de novo bioremediation ability, aryl reductive dechlorination, into anaerobic granular sludge by inoculation of sludge with Desulfomonile tiedjei.

Methanogenic upflow anaerobic granular-sludge blanket (UASB) reactors treat wastewaters at a high rate while simultaneously producing a useful product, methane; however, recalcitrant environmental pollutants may not be degraded. To impart 3-chlorobenzoate (3-CB)-dechlorinating ability to UASB reactors, we inoculated granular sludge in UASB reactors with either a pure culture of Desulfomonile tiedjei (a 3-CB-dechlorinating anaerobe) or a three-member consortium consisting of D. tiejei, a benzoate degrader, and an H2-utilizing methanogen. No degradation occurred in an uninoculated control reactor which was started with the same granular sludge, but inoculated reactors and granules from the inoculated UASB systems rapidly transformed 3-CB (54 mumol/day/g of granule biomass). After several months at a hydraulic retention time of 0.5 day, much shorter than the generation time of D. tiedjei, the reactors still dechlorinated 3-CB. This indicated that the bacteria were immobilized in the reactor granules, and by using an antibody probe for D. tiedjei, we demonstrated that this microorganism had colonized the sludge granules. These results represent the first addition of a pure culture or a defined microbial mixture to a viable waste treatment process to introduce a specific de novo degradative pathway into a granular-sludge consortium.


A lactococcal expression system for engineered nisins.

The nisin-producing Lactococcus lactis strain FI5876 has been modified and developed for use as an expression system for engineered nisin variants. Insertional inactivation of the resident nisA gene had a polar effect on downstream genes, including those involved in nisin immunity. However, subsequent chromosomal rearrangements in this region involving a newly discovered insertion element (IS905) generated a strain that was deficient in the nisA gene product but expressed those nisin determinants necessary for prenisin maturation, secretion, and immunity. Complementation of the lesion in the nisA gene by plasmid-encoded nisA genes containing site-specific mutations resulted in the exclusive production of altered nisins containing specific amino acid substitutions.


Development of monoclonal antibodies that identify Vibrio species commonly isolated from infections of humans, fish, and shellfish.

Monoclonal antibodies (MAbs) against Vibrio species that infect humans, fish, and shellfish were developed for application in rapid identifications. The pathogens included Vibrio alginolyticus, V. anguillarum, V. carchariae, V. cholerae, V. damsela, V. furnissii, V. harveyi, V. ordalii, V. parahaemolyticus, and V. vulnificus. Three types of MAbs were selected. The first important group included MAbs that reacted with only a single species. A second group comprised a number of MAbs that reacted with two, taxonomically closely related Vibrio species. For example, of 22 MAbs raised against V. alginolyticus, 6 recognized a 52-kDa flagellar H antigen common to both V. alginolyticus and V. parahaemolyticus; V. anguillarum and V. ordalii also shared antigens. A third group included three genus-specific MAbs that reacted with almost all Vibrio species but did not react with other members of the family Vibrionaceae (e.g., members of the Aeromonas, Photobacterium, and Plesiomonas genera) or a wide range of gram-negative bacteria representing many genera. This last group indicated the possible existence of an antigenic determinant common to Vibrio species. Two of these three genus-specific MAbs reacted with heat-stable antigenic determinants of Vibrio species as well as lipopolysaccharide extracted from Vibrio species. The use of the MAbs in blind tests and diagnosis of clinical isolates indicated that three different types of bacteria, viz., live, formalin-fixed, and sodium azide-killed bacteria, were detected consistently. Overall, it was found that the genus-specific MAbs were very useful for rapidly identifying vibrios in the screening of acute infections, while the species-specific MAbs and others were useful for completing the diagnosis.


Flocculence of Saccharomyces cerevisiae cells is induced by nutrient limitation, with cell surface hydrophobicity as a major determinant.

Initiation of flocculation ability of Saccharomyces cerevisiae MPY1 cells was observed at the moment the cells stop dividing because of nitrogen limitation. A shift in concentration of the limiting nutrient resulted in a corresponding shift in cell division and initiation of flocculence. Other limitations also led to initiation of flocculence, with magnesium limitation as the exception. Magnesium-limited S. cerevisiae cells did not flocculate at any stage of growth. Cell surface hydrophobicity was found to be strongly correlated with the ability of the yeast cells to flocculate. Hydrophobicity sharply increased at the end of the logarithmic growth phase, shortly before initiation of flocculation ability. Treatments of cells which resulted in a decrease in hydrophobicity also yielded a decrease in flocculation ability. Similarly, the presence of polycations increased both hydrophobicity and the ability to flocculate. Magnesium-limited cells were found to be strongly affected in cell surface hydrophobicity. A proteinaceous cell surface factor(s) was identified as a flocculin. This heat-stable component had a strong emulsifying activity, and appears to be involved in both cell surface hydrophobicity and in flocculation ability of the yeast cells.


Biosynthesis of the lantibiotic nisin: genomic organization and membrane localization of the NisB protein.

Nisin produced by Lactococcus lactis 6F3 is used as a food preservative and is the most important member of a group of peptide-antibiotics containing lanthionine bridges (lantibiotics) (N. Schnell, K.-D. Entian, U. Schneider, F. Götz, H. Zähner, R. Kellner, and G. Jung, Nature [London] 333:276-278, 1988). Nisin is ribosomally synthesized, and its structural gene, nisA, encodes a prepeptide that is posttranslationally modified, revealing the active lantibiotic (C. Kaletta and K.-D. Entian, J. Bacteriol. 171:1597-1601, 1989). Adjacent to nisA, the additional genes nisB, nisT, and nisC were identified. Over their entire sequences, these genes were homologous to genes recently identified as important for the biosynthesis of lantibiotics, that is, subtilin from Bacillus subtilis ATCC 6633 and epidermin from Staphylococcus epidermidis Tü 3298. Genes nisB, nisT, and nisC corresponded to open reading frames of 993, 600, and 418 amino acid residues, respectively. The nisT open reading frame is homologous to proteins of the HlyB (hemolysin B protein of Escherichia coli) subfamily. Proteins of this subfamily are responsible for the secretion of a variety of compounds, including large polypeptides, polysaccharides, and anti-drug tumors, indicating that NisT may be involved in nisin transport. Northern (RNA) blot analysis revealed a 0.3-kb transcript for the nisA structural gene, and the transcriptional start point of the nisA gene was determined by primer extension. Additionally, a mRNA of at least 3 kb was identified by using a hybridization probe specific to nisB. Antibodies were raised against the NisB protein, and Western blot (immunoblot) analysis revealed a molecular weight of about 115 kDa, which is in accordance with the theoretical protein size of 117.5 kDa as calculated from the nisB open reading frame. Several amphipathic transmembrane alpha-helices indicated that NisB is associated with the membrane. This was confirmed by preparing L. lactis vesicles. The NisB protein was tightly associated with the vesicle fraction and was released by sodium dodecyl sulfate treatment only. These results suggest that NisB is membrane associated and that nisin biosynthesis occurs at the cell membrane.


Isolation of a Pseudomonas solanacearum-specific DNA probe by subtraction hybridization and construction of species-specific oligonucleotide primers for sensitive detection by the polymerase chain reaction.

A subtraction hybridization technique was employed to make a library enriched for Pseudomonas solanacearum-specific sequences. One cloned fragment, PS2096, hybridized under stringent conditions to DNA of 82 P. solanacearum strains representing all subgroups of the species. Other plant-associated bacteria, including closely related species such as Pseudomonas capacia, Pseudomonas picketti, or Pseudomonas syzygii, did not hybridize to PS2096. A minimum number of between 4 x 10(5) and 4 x 10(6) P. solanacearum cells could routinely be detected with PS2096 labelled either with [32P]dCTP or with digoxigenin-11-dUTP. To improve the sensitivity of detection, PS2096 was sequenced to allow the construction of specific oligonucleotide primers to be used for polymerase chain reaction (PCR) amplification. After 50 cycles of amplification, 5 to 116 cells, depending on the strain, could reproducibly be detected by visualization of a 148-bp PCR product on an agarose gel. A preliminary field trial in Burundi with the probe and PCR primers has confirmed that they are sensitive tools for specifically detecting low-level infections of P. solanacearum in potato tubers.


Use of tRNA consensus primers to indicate subgroups of Pseudomonas solanacearum by polymerase chain reaction amplification.

Polymerase chain reaction amplification of DNA from 112 Pseudomonas solanacearum strains with the tRNA consensus primers T3A and T5A divided the species into three fingerprint groups. These groups correspond well with previous divisions made by restriction fragment length polymorphism analysis. This polymerase chain reaction test is a facile method for rapidly classifying P. solanacearum strains.


Purification and partial characterization of two feruloyl esterases from the anaerobic fungus Neocallimastix strain MC-2.

Two extracellular feruloyl esterases (FAE-I and FAE-II) produced by the anaerobic fungus Neocallimastix strain MC-2 which cleave ferulic acid from O-(5-O-[(E)-feruloyl]-alpha-L- arabinofuranosyl)-(1-->3)-O-beta-D-xylopyranosyl-(1-->4)-D-xylopyranose (FAXX) were purified. The molecular masses of FAE-I and FAE-II were 69 and 24 kDa, respectively, under both denaturing and nondenaturing conditions. Apparent Km and maximum rate of hydrolysis with FAXX were 31.9 microM and 2.9 mumol min-1 mg-1 for FAE-I and 9.6 microM and 11.4 mumol min-1 mg-1 for FAE-II. FAE-II was specific for FAXX, but FAE-I hydrolyzed FAXX and PAXX, the equivalent p-coumaroyl ester, at a maximum rate of metabolism ratio of 3:1.


Electrical enhancement of biocide efficacy against Pseudomonas aeruginosa biofilms.

When applied within a low-strength electric field (+/- 12 V/cm) with a low current density (+/- 2.1 mA/cm2), several industrial biocides exhibited enhanced killing action against Pseudomonas aeruginosa biofilms grown on stainless steel studs. Biocide concentrations lower than those necessary to kill planktonic cells of P. aeruginosa (1, 5, and 10 ppm of the active ingredients of kathon, glutaraldehyde, and quaternary ammonium compound, respectively) were bactericidal within 24 h when applied within our electrified device.


Relationship between bacterial counts and endotoxin concentrations in the air of wastewater treatment plants.

The relationship between bacterial counts and endotoxin concentrations in air samples was studied. Selective EMB medium favored the growth of a larger portion of airborne gram-negative bacteria than LES Endo or MacConkey medium and was a good predictor of the endotoxin levels determined with a chromogenic Limulus assay of the air of wastewater treatment plants. The bacterial counts determined with nonselective media correlated poorly with airborne endotoxin levels; however, R2A medium yielded higher viable bacterial counts than TYG medium. Direct counting by epifluorescence microscopy yielded the highest bacterial counts, but no correlation was obtained between total bacterial counts and endotoxin concentrations.


Alteration of specific activity and stability of thermostable neutral protease by site-directed mutagenesis.

On the basis of three-dimensional information, many amino acid substitutions were introduced in the thermostable neutral protease (NprM) of Bacillus stearothermophilus MK232 by site-directed mutagenesis. When Glu at position 143 (Glu-143), which is one of the proposed active sites, was substituted for by Gln and Asp, the proteolytic activity disappeared. F114A (Phe-114 to Ala), Y110W (Tyr-110 to Trp), and Y211W (Tyr-211 to Trp) mutant enzymes had higher activity (1.3- to 1.6-fold) than the wild-type enzyme. When an autolysis site, Tyr-93, was replaced by Gly and Ser, the remaining activities of those mutant enzymes were higher than that of the wild-type enzyme.


On-line visualization of the competitive behavior of antagonistic bacteria.

To study the interaction between cocultured Listeria monocytogenes and an antagonistic Leuconostoc strain producing an anti-Listeria bacteriocin, flow cytometry, a technique allowing on-line and real-time analysis, was used along with classical microbiological methods. Culture methods and flow cytometric measurements of the mixed culture over time point to a bactericidal action of the lactic acid-producing bacterial strain against L. monocytogenes cells.


[Prenatal chromosome study: cause, incidence and prevention of erroneous determination of various study samples].

False diagnoses in prenatal chromosomal analysis are rare; but the causes are numerous. They can be specific for amniocentesis, chorionic villus samples or independent of the tissue. The sources of mistake and their frequencies are discussed in detail.


[Noninvasive screening for chromosome abnormalities in young pregnant patients].

Two thirds of the patients with Down's syndrome are born by women below 35 years of age. An extension of invasive prenatal diagnosis to these women is problematical due to the operative risks and the relatively high costs. Therefore, non-invasive screening methods are sought, apt to identify groups at high risk. Biochemical screening methods applied at 16 weeks of pregnancy (triple test) and the new first trimester tests are discussed. Ultrasound screening at 10 to 12 weeks is dealt with in more detail. A large fluid cushion over most of the back was documented not only in most cases of trisomy 21 but in trisomies 18 and 13 and in Turner's syndrome as well. Only few chromosomally normal fetuses with the same peculiarity were observed. Systematic first trimester screening for nuchal fluid accumulation seems to be a recommendable method for the detection of chromosome anomalies. It compares favourably with current methods of maternal serum screening performed at 16-18 weeks which require a manyfold higher number of invasive procedures.


Treatment of immunological infertility by sperm washing and intrauterine insemination.

The purpose of this study is to review our experience with sperm washing and intrauterine insemination as a method to reduce the presence of sperm antibodies in serum of couples with immunological infertility. Our results support the premise that sperm washing and intrauterine insemination can diminish the level of sperm-bound immunoglobulins and can improve the chance of conception in a selected group of couples with a diagnosis of immunological infertility. Patients with > 50% attachment of IgG, IgA, or both antisperm antibodies in this study had a greater chance of achieving a pregnancy. The high level of antibody attachment seen in our study appears to represent true immunological infertility and therefore is more likely to respond to therapy that reduces antibody attachment and bypasses cervical mucus.


Syphilis serology in men attending the Andrology Clinic at Ga-Rankuwa Hospital.

The worldwide resurgence of syphilis may have serious implications on neonatal morbidity. The aim of this study was to evaluate the seroprevalence of syphilis in men attending an infertility clinic. Blood samples from 782 males were screened using the titrated RPR and TPHA tests. If either of these tests was positive, FTA-ABs IgG was performed. The RPR was positive in 63 (8%) cases. In 24 (3%) patients the titer was 1:8 with positive TPHA and FTA-Abs IgG tests and these were regarded as current infections. Thirty-nine (4.9%) cases had RPR titers 1:8 with positive specific tests. These were probably patients either treated inadequately or in the early stage of primary syphilis. In addition, 92 (12%) patients were RPR negative but TPHA and FTA positive. This was evidence of previous exposure to syphilis. The overall seropositivity in this group was 20% (155 cases). Six hundred and twenty-seven (80%) tested negative with RPR and TPHA. Syphilis may still have a major impact on health in Southern Africa. Since syphilis is significantly associated with HIV seropositivity, efforts to prevent and control syphilis may also be important in limiting the spread of HIV.


The importance of the hypoosmotic swelling test and acrosin activity assay for identifying subpopulations of idiopathic infertile men.

Semen samples collected from fertile donors (n = 13) and pooled samples from idiopathic infertile men (n = 19) were used in this study. Measurements of the total sperm acrosin activity and the hypoosmotic swelling test (HOST) were performed in all the samples. The percentage of swollen spermatozoa and acrosin profiles were significantly lower in the infertile men than in the fertile donors. Considering the lowest values of the outcome of the HOST and the acrosin activity assay in the group of fertile men as the lowest normal values, it was proven that HOST and acrosin activity assay could identify subpopulations of infertile men of 37 and 26%, respectively. The results tend to support the employment of the HOST and the acrosin activity assay in the evaluation of idiopathic infertile men.


Use of a sealed mini-chamber to investigate human sperm motility in real time under aerobic and anaerobic conditions.

To study the correlation between metabolism and motility, ejaculated human spermatozoa were washed in media containing glucose, pyruvate, and deoxyglucose in various combinations. Spermatozoa suspended in these media were incubated in sealed mini-chambers and subjected to aerobic or anaerobic conditions at 37 degrees C. The effect on the patterns of sperm motility was investigated in real time by direct observation and objective determination with the multiple exposure photography (MEP) method. The motility of spermatozoa incubated in media containing excess of glucose showed similar changes of motility quality with time, whether exposed to aerobic or anaerobic conditions, and in both cases motility lasted about 13 h. Motility of sperm incubated with pyruvate only was of a much lower quality, especially under anaerobic conditions, and in both circumstances lasted about 7 h. When glycolysis of fructose remnants was totally inhibited by deoxyglucose and sperm were incubated with pyruvate only, motility lasted for 2 h under aerobic conditions and only for about 1 h under anaerobic conditions. It is concluded that the main metabolic process that supplies energy for sperm motility is glycolysis, under both aerobic and anaerobic conditions. Oxidative respiration was less efficient as a source of energy for sperm motility. When glycolysis was inhibited and oxidative respiration was eliminated under anaerobic conditions, sperm motility lasted only for about 1 h, probably by using intracellular energy reserves.


Microinsemination of rabbit oocytes with heat-treated sperm: embryonic development.

A study was conducted to evaluate the ability of rabbit oocyte to develop to the pronuclear stage and subsequent development if injected with heat-treated sperm. The rate of fertilization of eggs after microinjection of cauda epididymal spermatozoa heated at 60 degrees C for 30 min was 36%; the rate of cleavage was 24%. The rate of fertilization after microinjection of heat-treated sperm nuclei was 43%; the rate of cleavage was 26%. On the other hand, the rate of fertilization of eggs injected with sperm without heat treatment was 43%, the rate of cleavage was 29%, and there was no difference between eggs microinjected with heat-treated spermatozoa or sperm nuclei and those not heat treated. Of the viable eggs injected with heat-treated sperm, 16% developed to the 6- to 8-cell stage 72 h after injection.


Stability of the hypoosmotic swelling test over time.

The results of the sperm count, motility, and hamster oocyte penetration (SPA) tests have been found to vary greatly in individuals who have had tests performed on more than one occasion. The study presented herein was designed to evaluate the stability of the hypoosmotic swelling (HOS) test over time. A total of 444 patients were classified into categories according to the time interval between HOS tests: 0-90 days (n = 267), 91-180 days (n = 35), 181-270 days (n = 37), 271-360 days (n = 30), 1-2 years (n = 54), and > 2 years (n = 21). A paired t test was used to compare mean HOS scores. The correlation between the HOS test of the first specimen and the HOS of the second specimen was calculated. For those who had 2 tests the only significant difference was found in the > 2 year group (69.67 +/- 9.13 vs. 64.23 +/- 12.83%), p < .05. When comparing the first and third HOS test in 74 patients, there was a significant (p < .05) decrease in the later test when the interval was greater than 270 days. The difference was not significant when the HOS results were classified as subnormal (< 50%) and normal (> or = 50%) for that same time period. It would appear that this test is reproducible, rarely fluctuates, but tends to become less dependable over longer intervals of time.


Acute effect of prolactin on ornithine decarboxylase activity in the rat testis.

A study was conducted to evaluate the effect of the acute treatment with prolactin (PRL) on ornithine decarboxylase (ODC) activity in the rat testis. Injection of a single SC dose of ovine PRL to puberal rats resulted in the activation of ODC from whole testis. This effect was maximal at 4 h after injection, and statistically significant at the dose of 500 micrograms. The effect of PRL was confined to the interstitial space; no change was observed in seminiferous tubules. PRL was unable to further increase testicular ODC activity when injected together with a stimulatory dose of human chorionic gonadotropin (hCG). The effect of PRL was mimicked by injection of a single dose of the dopamine antagonist sulpiride, which provoked a ninefold increase in serum PRL levels. In contrast, PRL did not stimulate testicular ODC activity in hypophysectomized rats, either under basal conditions or during treatment with PRL-hCG, indicating the requirement of a functional hypophysis for the expression of PRL action. These results suggest that the stimulation of testicular ODC activity by PRL is a marker of the trophic response of the testis to this hormone, different from the stimulation of steroidogenesis. This activity could be useful for the study of PRL action on the testis as well as of the interaction between PRL and LH at the testicular level.


Modification of the Wang tube to improve in vitro semen manipulation.

The Wang tube was modified to improve in vitro semen manipulation, by adding another two racks to the anterior (posterior) wall of the low component of the Wang tube and supplying another four convex lenses symmetrical to those on the bottom wall. The former provides a slanted position leading to a complete real-time sperm separation image and benefiting low-quality sperm preparation when the modified Wang tube is turned on its side. The latter converses the microscope's light better and gives a clearer objective image.


[Detection of early occlusion of aortocoronary by-passes. Usefulness of a non-angiographic method].

A total of 83 bypasses were studied. Angiographic results demonstrated occlusion in 3 of 24 bypass of internal mammary artery placed in the anterior descending artery, 2 in the right coronary artery, 1 in the posterolateral of the circumflex and 1 in the first diagonal branch, with a total occlusion average of 8.4% within the first 8 days. We found a good correlation between the coronarographic angiograms and the positivity or negativity of the echo-electrocardiographic tests, during atrial pacing. We believe that this simple method could be done routinely in all the patients after coronary surgery, to decide the need of a new coronary angiogram. Furthermore, this study shows that the occlusion of a single coronary bypass does not produce myocardial infarction, detectable by enzymatic measures or by resting EKG. This method also detects the early post-operatory sinus sick syndrome.


[Usefulness of magnetic resonance images in percutaneous angioplasty for aortic coarctation].

From October 1985 to February 1992, we performed 80 percutaneous transluminal angioplasty procedures (PTA) in 76 patients with Coarctation of the Aorta (CoAo). Twenty eight patients (aged 2.6 to 62 years; mean, 11.4) underwent Magnetic Resonance Imaging (MRI) during the follow-up period, 2 to 60 months (m = 16) after dilation. Three of these patients were also studied before PTA. We found mild residual coarctation in 11, minimal irregularities in the aorta in five and excellent results in twelve cases. No aneurysms were found. In those patients that underwent MRI before the angioplasty was possible to choose the balloon, thus reducing the time during dilatation. In conclusion we believe that MRI is an excellent and well suited alternative for the serial studies in patients with CoAo, before PTA and in the follow-up.


[Balloon valvuloplasty in stenotic bioprosthesis].

The results of balloon valvuloplasty performed on five patients with stenotic bioprosthesis treated in the Hospital de Cardiología Centro Médico Nacional Siglo XXI, are presented. All five bioprosthesis were right sided, two in tricuspid position, one in pulmonary valve position and two in valvulated conduits from right ventricle to pulmonary artery. In all cases a pressure gradient reduction was achieved, an improvement of clinical functional class and heart failure manifestations were obtained. Mansfields balloons were used. One in two patients, and two balloons in three. We had not complications with the procedure. We conclude that balloon valvuloplasty on bioprosthesis is a safe and dependable procedure to be used in right sided bioprosthesis.


[Role of adenosine in the digitalis action on atrio-ventricular conduction in the dog heart].

In order to explore the hypothesis about the existence of an adenylic component on ouabain effects on the atrioventricular node, we perform experiments on anesthetized and vagotomized dogs. Decremental propagation of impulses through atrioventricular conduction system was evaluated stimulating the right atria at frequencies from 3.5 to 5.0 per second. Aminophylline antagonized and dipyridamole synergized the atrioventricular decremental conduction induced by digitalis. The blockade of purinergic receptors produced by aminophylline and the inhibition of adenosine endocytosis by dipyridamole could explain these antagonic and synergistic interaction with ouabain, and constitute an experimental evidence favorable to the possibility of the existence of a purinergic component on the digitalis mechanism of action.


[Rehabilitation in ischemic cardiopathy. Results at the level of quality of life and prognosis].

Cardiac rehabilitation programs, by means of physical, psychosocial and risk control factors, intend to improve the life style and prognosis of coronary patients. In this study, we analyzed the results obtained from 349 patients, 310 with acute myocardial infarction and 39 after coronary artery surgery. The average follow up period was 36 months and the average age was 53.9 years. The results showed that 84.3% stopped smoking, 60% returned to work after a heart attack and 51.36% after coronary artery bypass. Functional capacity improved significantly with p < 0.001. Although 50% of the patients considered themselves sexually incapacitated, the number of coitus per month is similar to that of healthy people of the same age. There were 12 new infarctions (1.28 por 100 patients per year), and 11 cardiac-related deaths (1.18 per 100 patients per year). All the deaths occurred in the group of patients with myocardial infarction, and with a significant increase in the elevation of the ST in the necrosis area, during an exercise testing, indicating extensive areas of dyskinesis. Based on these results, we have reached the conclusion that steps must be taken to reduce the high percentage of patients who leave the program. In our study this was significantly low at 21.5%.


[Effect of transdermal therapy with clonidine on suppression symptoms secondary to smoking cessation].

For the purpose of evaluating the effectiveness of transdermal clonidine treatment (Catapres-TTS No. 2) on ameliorating withdrawal symptoms associated with smoking cessation, we carried out a prospective study on 375 patients who smoke, motivated to abandon smoking. Each patient acted as his own control at one moment receiving placebo and, at another, clonidine. Each patient was instructed to maintain his normal daily cigarette consumption during the first three days of study, and to stop smoking from the fourth to the seventh day. All of the withdrawal symptoms measured (craving, irritability, anxiety and restlessness) significantly increased (p = 0.001) in the placebo group during the days of abstinence. There was a 5 fold increase in craving and in irritability, in the placebo group, as compared with the transdermal clonidine group during the three days of smoking cessation. Anxiety and restlessness also augmented at 3 times greater extent. Regarding the side effects, these were slight and of a transitory nature. Transdermal clonidine treatment helps the heavy smoker to give up tobacco by means of a considerable drop of the short-term withdrawal symptoms, specially craving and irritability, associated with smoking cessation.


[Child abuse with fatal sequelae in an Essen autopsy sample].

In the Institute of Forensic Medicine in Essen/Germany 24 cases of lethal child battering or neglect have been observed over 17 years from 1973 to 1989. The medicolegal and morphologic findings in these cases are presented and compared to the literature. The patterns of abuse/neglect in Essen compare to those frequently reported in the literature: skull/brain traumas caused by blunt impact, multiple hematomas, bone fractures, and symptoms of malnutrition, vitamin deficiency, and general neglect. In many cases the abuse could be shown to have been chronic. In the seven years 1983-1989 the cases of lethal child mistreatment and neglect amounted to 0.18 percent of all autopsies. Five cases of lethal sexual assault in children during the same period are compared to the mistreated cases.


[Homicide of a supervisor simulating an occupational accident].

An unusual case of homicide is reported. A driver of an excavator killed his foreman by using the scoops of his machine and tried to feign an industrial accident. The man was convicted by the autopsy findings because his testimony could not explain the severe injuries.


[Left systolic ventricular function and metabolic disorders in untreated hypertensive patients].

Previous studies have shown that essential hypertension is frequently associated with insulin resistance and hyperinsulinism. Because insulin may exert a direct positive inotropic as well as chronotropic effect and controlled the initiation of peptide chains in the heart, we tested the hypothesis that insulin may be a determinant of myocardial hypertrophy and contractility. The relation between glucose metabolism (assessed by the oral glucose tolerance test) and left ventricular (LV) mass and function (assessed by echocardiography) was explored in 47 never-treated lean essential hypertensive patients (EH) of short duration and 19 normotensive subjects (NT). A greater number of EH versus NT (23 vs 5%) had an abnormal glucose tolerance. The fasting insulin-to-glucose ratio was significantly higher in EH as compared to NT. Fasting as well as integrated serum insulin to glucose values ratio were positively correlated with heart rate (r = 0.35, p < 0.05, r = 0.38, p < 0.05) and the LV end-systolic stress to volume ratio (r = 0.48, p < 0.001, r = 0.54, p < 0.001) but not with LV mass (r = 0.02, r = 0.02) in EH. When EH were divided into those with normal (n = 36) and supernormal (n = 11) LV contractility based on the relationship between LV fractional shortening and LV end-systolic stress, integrated insulin level and fasting insulin to glucose ratio were markedly higher in patients with supernormal LV contractility, whereas arterial pressure, heart rate, urinary sodium excretion, and plasma renin activity were similar in the two groups. We concluded that hyperinsulinemia and LV hypercontractility are associated in patients with hypertension of short duration. If chronic hyperinsulinemia is to be causally related to hypertension, one would have to postulate that the effects (inotropism and chronotropism) of insulin on the heart can be dissociated from the resistance to the glucose-lowering action of insulin.


[Cardiac output studied by a non invasive method in hypertensive patients].

We measured by thoracic bioimpedance (BoMed, NCCOM3-R7) non invasive cardiac index (CI), stroke index (SI) and systemic vascular resistance index (SVRI) in 48 hypertensive patients (OMS) compared to 30 normotensive. The mean arterial pressure (MAP) and the SVRI were significantly higher in the hypertensive group while the CI are significantly lower, as that was shown in previous invasive studies. We found an inverse correlation between age and CI (r = -.30, p < or = .05) in relation with a negative correlation between SI and age (r = -.35, p < or = .05) and no correlation between heart rate and age. Furthermore we divided normotensive and hypertensive patients in three groups of CI (low CI < 2.8 l/min/m2, 2.8 < or = normal CI < or = 4.2 l/min/m2, high CI > 4.2 l/min/m2) and in three groups of SVRI (low SVRI < 1660 Flohms/m2, 1660 < or = normal SVRI < or = 2580 Flohms/m2, high SVRI > 2580 Flohms/m2). Despite CI diminution in hypertension, high CI percentage's was the same in normotensive and hypertensive patients. In conclusion, these results confirm previous studies by using a simple, easy, non invasive and reproducible method.


[Electrocution accident with three-week survival].

A 55-year-old man was found unconscious with ventricular fibrillations at his working place near a power press. CPR was successful. After three weeks of intensive care the patient died of ischemic brain damage. The first suspected diagnosis of myocardial infarction was revised when typical current marks were detected on both palms. At the working place the top of a lubricating grease container was found to be energized due to a technical damage: There is a round, multiple-pole plug mounted upon the container top the proper orientation of which is coded by a set of five plastic nipples. All the nipples had been abraded by longlasting mechanical stress, so that the plug could be connected in a variety of possible orientations. In actual fact, the incorrect orientation caused a voltage of up to 240 V to the container top.


[Apropos of acute changes in left ventricular filling induced by antihypertensive treatment].

The purpose of the study was to interpret the acute improvement in left ventricular (LV) filling induced by a new calcium channel blocker (SR 33 557) using Doppler echocardiography. Thirteen patients, 29 to 68 years old (mean 52) with mild to moderate hypertension were examined by Doppler echocardiography before and 4 hours after treatment (SR 33 557: 300 mg). The LV filling parameters, E, A, A/E, VTIM, VTIA, VTIA/VTIM, pressure half time (PHT) and isovolumic relaxation time (IRT) were measured. An index of left atrial pressure was obtained by measuring the mean pulmonary arterial pressure (PAP). The following hemodynamic parameters were also obtained: systolic blood pressure (SBP), heart rate (HR), PR interval (PR), stroke volume (SV) at aortic origin, total systemic resistances (TSR), pulse wave velocity (PWV) at thoracic descending aorta, LV end systolic stress (ESS), LV geometry (thickness/radius: th/r) and systolic function indices: mean VCF and contractility (mean VCF-ESS relationship). Following acute treatment, E and VTIM increased, A, VTIA and PHT did not change, and A/E, VTIA/VTIM ans IRT decreased, both significantly (p < 0.05). PAP did not change, HR, SBP, TSR, PWV, ESS decreased and PR increased both significantly (p < 0.05). LV geometry and systolic function did not change. No significant relationship was found between LV filling changes and changes in hemodynamic parameters. In conclusion, the acute increase in early LV filling induced by the calcium blocker treatment may be interpreted as the consequence of the improvement in LV relaxation in the absence of any change in left atrial pressure.(ABSTRACT TRUNCATED AT 250 WORDS)


[Tattoo pigment in regional lymph nodes--an identifying marker?].

31 of 275 unselected forensic autopsy cases revealed tattoos on one or both sides of the upper extremities, which were nearly always accompanied by pigmentations of the axillary lymph nodes. The deposits of tattoo pigment could already be identified with the naked eye. Their composition reflected the colour ingredients of the tattooed skin. So this easily practicable preparation and examination of the draining lymph nodes makes it possible to establish the identity of unknown corpses by drawing conclusions about former tattoos even if they have been removed or if, owing to postmortal changes of the skin, they cannot be recognized by the forensic pathologist.


[Fatal exsanguination from a small venous injury].

Report on a 34 year old man who bled to death sitting in an empty bath-tub by suicidal cutting in his groin. The source of the bleeding was a small lesion of the femoral vein with a diameter of 2 mm. No endogenous or exogenous coagulopathies could be established.


[Doppler echocardiographic evaluation of right and left ventricular filling in hypertension].

Left (LV) and right ventricular (RV) filling was evaluated by pulsed doppler echocardiography in 56 hypertensive (HTN) untreated patients and in 30 normotensive (N) subjects, matched for age, body surface and heart rate. HTN were classified in two groups: HTN1: with normal LV mass index (LV mi) (< 135 g.m-2 for men, < or = 115 g.m.-2 for women); HTN2: with increased LV mi (> or = 135 g.m-2 for men, > or = 115 g.m-2 for women). All subjects had normal systolic function by echo. We derived: LV wall thickness (h), antero-posterior radius (r), h/r ratio, LV mi, ratio of early to late filling (E/A) in both ventricle. RESULTS. h and h/r were significantly in HTN1 (p < 0.01 vs N) and particularly in HTN2 (p < 0.001 vs N and HTA1). E/ALV and E/ARV were significantly decreased (p < 0.001) in both HTA compared to N. There was no significant difference between HTN1 and HTN2 concerning E/ALV and E/ARV. Relations of E/ALV and E/ARV with age, systolic blood pressure (SBP), LV mi, h, h/r: [table: see text] E/ALV is correlated to E/ARV (r = 0.37; p < 0.01) only in HTA. CONCLUSIONS. 1) In HTN in comparison with N: h, h/r are higher in the presence but also in the absence of increased LV mi. 2) In N and HTN: E/ALV and E/ARV are better correlated to h (and also to h/r in N) than to LV mi. Though the respective values of E/ALV and E/ARV are identical, they are correlated significantly only in HTN. 3) In the absence of the direct measures of the RV pressures and volumes, the interpretation of the results concerning the RV filling in uncertain. Only in HTN, they could be explained at least in part by the diastolic interplay between the two ventricles.


[Medical and legal problems of multiple death certificates].

In cases of unnatural death and unclear manner of death the police has according to section 159 StPO to inform the prosecution. The prosecutor has to decide how the case shall be handled. Independent inquiries or even independent handling of the case by the police are not scheduled. For legal purposes it is not possible to induce another doctor to issue another death certificate with the manner of death certified as natural.


[Restoring normal coronary reserve in treated hypertension without left ventricular hypertrophy].

It has been previously demonstrated that coronary vascular reserve (CVR) was severely impaired in hypertensive patients with left ventricular hypertrophy (LVH), even after anti-hypertensive therapy. To assess if CVR was similarly depressed in hypertensive patients without LVH, peak-to-resting coronary flow velocity ratio (P/R) and a minimal coronary vascular resistance index (MCVRI) were determined with a coronary Doppler catheter placed into the left anterior descending coronary artery and maximally vasodilating dose of intracoronary papaverine (12 mg) in 16 control subjects (C), 7 untreated hypertensives without LVH (G1), and 7 hypertensives without LVH treated for at least one year (G2). All subjects and patients had normal left ventricular angiography and coronary arteriography. Left ventricular and aortic pressures, rate-pressure-product (RPP) were significantly elevated in G1 and were similar to those of control subjects in G2. Results evidenced that P/R was reduced and that MCVRI was increased in G1. However, these alterations were moderate. In G2, these two indices were similar to those of control subjects: [table: see text] These results suggest: 1) that alterations of coronary microcirculation occur before left ventricular hypertrophy in hypertensive patients; 2) that anti-hypertensive therapy may restore a normal coronary vascular reserve in hypertensive patients without LVH, when coronary vascular reserve remained severely impaired despite normalization of arterial pressure in patients with persistent LVH.


[Hypertensive cardiopathy and ventricular late potentials].

Ventricular arrhythmias occur with increased frequency in hypertensive patients with left ventricular hypertrophy (LVH). The aim of this work is to study the incidence of ventricular late potentials (LP) and their relation to ventricular arrhythmias in 148 hypertensive patients, 87 men and 55 women, without evidence of a coronaropathy. For each patient we carried out a signal-averaged electrocardiography, an echocardiogram to determine the LV mass index (LVMI) and the LV end-diastolic dimension (EDD), and 24 hours Holter monitoring to record ventricular arrhythmias filed according to Lown's classification. LP were considered present if the root-mean-square voltage during the last 40 ms of the QRS was: < 20 uV in absence of bundle branch block, or < or = 17 uV in presence of bundle branch block. [table: see text] The frequency of LP appears exceptional in hypertensive patients without LVH (5%) and remains uncommon in patients with concentric LVH (13%). The incidence of LP is only frequent at the end stage of hypertensive cardiopathy with eccentric LVH (48%). The severity of ventricular arrhythmias is only correlated to the presence of LP in patients with concentric LVH (p < 0.02).


[Evaluation of norepinephrine content in the myocardium in hypertensive patients with left ventricular hypertrophy].

The sympathetic nervous system seems to be a non hemodynamic factor involved in the development of hypertension and in left ventricular hypertrophy determinism. The aim of this study was to estimate the myocardial norepinephrine content in essential hypertensive patients, using a reliable radio-iodinated marker of norepinephrine: the 123I-meta-iodobenzylguanidine (123I-meta-iodobenzylguanidine). Eight male and female hypertensive patients with left ventricular hypertrophy and average age of 52 +/- 9 years underwent a resting, ambulatory and effort blood pressure measure. Echocardiographic parameters allowed measure of left ventricular mass index (according to Devereux, and we considered left ventricular hypertrophy as left ventricular mass index greater than 120g/m2. Plasma norepinephrine is measured at rest. Cardiac and mediastinal radioactivity is detected 4 h after a 4mCi i.v. injection of 123I-meta-iodobenzylguanidine and meta-iodobenzylguanidine myocardial uptake is definite as the cardiac/mediastinal ratio (N:1.78 +/- 0.19). Meta-iodobenzylguanidine-myocardial uptake average value of hypertensive patients was 1.89 +/- 0.19 (1.63 to 2.25) without statistical difference to control subjects. We found a significative correlation between meta-iodobenzylguanidine myocardial uptake and effort systolic blood pressure variation in one hand, and with heart rate increase with effort in the other hand. There is no correlation between meta-iodobenzylguanidine-myocardial uptake and left ventricular mass index or ambulatory blood pressure. In hypertensive patients with left ventricular hypertrophy, meta-iodobenzylguanidine myocardial uptake is normal or high, in agreement with experimental data in SHRs, model of human essential hypertension. Therefore myocardial scintigraphy with 123I-meta-iodobenzylguanidine can appreciate cardiac norepinephrine content in humans.


[Action of labetalol on norepinephrine myocardial content in left ventricular hypertrophy in hypertensive patients].

The high incidence of cardiovascular morbidity and mortality in hypertensive patients with left ventricular hypertrophy shows the great interest in understanding the pathophysiology of this process. Many reports suggest the role of catecholamines in generating left ventricular hypertrophy. The aim of this study is to evaluate the effect of labetalol on myocardial norepinephrine content in hypertensive subjects with left ventricular hypertrophy by using an isotopic norepinephrine marker, the 123I-meta-iodobenzylguanidine (123I-MIBG). Eight male and female hypertensive patients with left ventricular hypertrophy were investigated after a 30 day placebo period. Resting, ambulatory and effort blood pressure was measured. Echocardiographic parameters allowed measure of left ventricular mass index according to Devereux. And we considered left ventricular hypertrophy as left ventricular mass index greater than 120 g/m2. Cardiac and mediastinal radioactivity is detected 4 h after a 4 mCi i.v. injection of 123I-MIBG and MIBG myocardial uptake is definite as the cardiac/mediastinal ratio (N : 1.78 +/- 0.19). All subjects received at the beginning of the study (D0) 2 tablets of labetalol 200 mg, increased to 4 tablets if diastolic blood pressure during follow-up remained above 95 mmHg. Patients again underwent these explorations after 3 months of treatment (D90). Labetalol decreases in considerable manner MIBG myocardial uptake as it has been shown that it decreases tissular norepinephrine content in experimental studies. Therefore, MIBG myocardial uptake seems to be a reliable tool in evaluating drugs effect on cardiac sympathetic nervous system.


[Study and value of high amplification atrial signal in arterial hypertension].

The aim is the analysis of the P wave on the signal averaged ECG in 31 pts: 12 control pts (6 M, 6 W, 40 +/- 10 y) 12 HTA (9 M, 3 W, 60 +/- 7 y), 7 pts (5 M, 2W, 48 +/- 7 y) with sustained paroxystic atrial fibrillation (AF) without organic heart disease, without antiarrhythmic drugs. We measured the filtered P wave duration (Ad), the integral of Ad, the root mean square voltage of Ad for the last 10, 20, 30, 40, 60 msec and the duration of P wave on the ECG in lead II (P II) and the echocardiographic dimensions of the atria (LAd). HTA Ad (132 +/- 12 msec)* et > control Ad (116 +/- 10 msec) HTA LAd (38 +/- 3 mm) et > control LAd (31 +/- 0.7 mm) HTA PII (120 +/- 1.5 mm)* et > control PII (88 +/- 10 mm). The difference between HTA Ad (132 +/- 12 msec) and AF Ad (129 +/- 7 msec) is not significant. The linear regression tests don't show correlation between P II and Ad and between LAd and Ad in HTA group. There is a correlation between Ad and LAF in AF group (r = 0.83, p 0.02). HTA RMS 2o (2.2 + 0.6 microV), control RMS 2o (3.9 + 1.8 V) but HTA RMS 2o and AF RMS 2o (2.4 +/- 0.6 microV) are not significantly different and are not correlated with LAd and PII. A long duration of P filtered P wave and a low RMS 2o observed in HTA group and AF group would be a criteria of atrial vulnerability. p < 0.05.


[Prevalence of atrial arrhythmia in 48 hypertensive patients: research of predictive criteria].

We studied atrial arrhythmias during a continue prospective work in 48 hypertensive patients referred to the OMS criteria. Hypertension was confirmed by a blood pressure ambulatory monitoring and stress testing blood pressure trend. All cardiovascular drugs were stopped at admission. Patients with associated valvular or coronary artery disease were excluded from analysis. In all patients, we realized a twelve lead-ECG, stress testing, 24 hour Holter monitoring, a blood pressure ambulatory monitoring, two-dimensional echocardiography with Doppler study and cardiac radio-nuclide angiography with diastolic function study. Atrial arrhythmias were considered significant if more than 100 premature atrial beats (PAB) and/or more than three successive PAB were present during Holter monitoring. Significant atrial arrhythmias were found in 39.5% of patients (group II, n = 19), not significant in 60.5% of patients (group I, n = 29). The duration of hypertension was longer in group II (140 vs 66 months, p < 0.05). There was no difference between the two populations considering left atrial size or blood pressure level. Furthermore, we were surprised to find a normal E/A ratio on mitral Doppler recording in patients with atrial arrhythmias (1.23 vs 0.9; p < 0.05). Others diastolic parameters didn't significantly differ. Left ventricular mass index was similar in the two groups but patients with atrial arrhythmias had more asymmetric hypertrophy (1.23 vs 1.13 septum/posterior wall ratio: p < 0.05). atrial arrhythmias in our study seem to be more dependent from duration of HTA and left ventricular asymmetric structure than from left atrial size.(ABSTRACT TRUNCATED AT 250 WORDS)


[Hypertension has no effect on coronary calcifications in asymptomatic patients with hypercholesterolemia].

Since calcium in coronary artery walls is considered as an indicator for atherosclerosis, we used ultrafast computed tomography to quantify it non invasively in 111 hypercholesterolemic men. They were selected at worksite by a cholesterol screening program, had total cholesterol (TC) above 5.2 (6.88 +/- 0.82, SD) mmol/l, were aged from 30 to 63 (46 +/- 5 years), had never been treated with lipid lowering or antihypertensive drug, and had no clinical coronary heart disease. Body mass index, blood pressure, smoking and other serum lipids as HDL cholesterol, triglyceride (TG) were evaluated. Calcium score of proximal coronary arteries was calculated on 30 contiguous 3 mm slices from areas and peak density of calcium lesions. The mean score was 30 +/- 69 and ranged from 0 to 440. A zero score was found in 39 subjects who differed from the 72 others only by TG levels (1.44 +/- 0.60 vs 1.85 +/- 0.80; p < 0.05). A multiple regression analysis showed that elevated calcium score was associated independently to age (F = 6.6; p < 0.05) and TG (F = 6; p < 0.05) but not to blood. Thus 65% of these asymptomatic subjects had a non-zero calcium score in coronary arteries. Elevated calcium score was influenced independently by age and triglyceride level, but not by other risk factors, such as blood pressure. This potential adverse effect of moderate triglyceride elevation on large coronary arteries merits attention in the assessment of the risk of coronary heart disease.


[Left ventricular involvement in Conn adenoma, renovascular hypertension and pheochromocytoma before and after etiological treatment].

Assessment of left ventricular (LV) structural modifications following etiologic treatment of secondary hypertension, in a group of 43 patients. M-Mode echocardiograms were independently analysed by 2 trained investigators before and 7.4 months (RV), 11 patients with COnn's adenoma (C) and 9 patients with phaeochromocytoma (PH). Age, sex ratio, antihypertensive treatment, and duration of hypertension before treatment were comparable among the 3 groups. Blood pressure was higher in C and RV than in PH for casual (C: 190/116; RV: 193/109; PH: 146/91; p < 0.01/0.05) as well as ambulatory blood pressure (C: 140/93; RV 153/89; PH: 126/80; p < 0.01/0.05). Before etiologic treatment, systolic function was normal in the 3 groups whereas LV mass index differed between the 3 groups (C: 147; RV: 118; PH: 85 g/m2). LV end diastolic diameter index was smaller in PH (26.4 mm/m2) than in C (29.1) and RV (28.8). After treatment, there was a significant reduction on office (C: -43/-20; RV: -39/-19; PH: -20/-12 mmHg) and ambulatory (C: -6.6/-5.6; R: -20/-9.9; PH: -4.7/- 4.5) blood pressure. Systolic function was not altered. LV mass index was significantly reduced in C and RV but not in PH (C: -18%; RV: -7%; PH: -5%). Changes in LV end diastolic diameter index were not significant (C: -2%; RV: 0%; PH: + 6%). There was no correlation between LV mass index changes and blood pressure differences. Etiologic treatment leads to significant regression of LV hypertrophy in patient with renovascular hypertension or Conn's adenoma, at least partly independently of blood pressure change. Humoral and volume factors may play a role in LV regression.


[Differential regulation of the release of norepinephrine and neuropeptide Y].

The release of catecholamines and their co-neurotransmitter neuropeptide Y was investigated in conscious dogs with neurogenic arterial hypertension elicited by sinoaortic denervation. One month after denervation, an elevation of catecholamine levels (measured by HPLC) without elevation of neuropeptide Y levels in plasma (evaluated by RIA) has been found. This dissociation could be explained by a transient release of neuropeptide Y during the first weeks after surgery; a depletion of neuronal neuropeptide Y due to the permanent sympathetic stimulation; or an insufficient increase in sympathetic tone. To test these three hypotheses, we investigated the time courses of catecholamine and neuropeptide Y levels in arterial plasma during the first five weeks after sinoaortic denervation; and the responses to yohimbine (an alpha 2 antagonist which enhances transmitter release). Resting neuropeptide Y levels in plasma remained normal during the first five weeks after sinoaortic denervation. In normal dogs, a high dose of yohimbine (0.5 mg/kg i.v.) elevated both catecholamine (6-fold) and neuropeptide Y levels (1.5-fold), whereas a lower dose (0.05 mg/kg i.v.) induced a two fold elevation of catecholamine levels without changing neuropeptide Y concentrations. In sinoaortically denervated dogs, yohimbine elicited elevation of both catecholamines and neuropeptide Y whatever the dose used. Thus, neurogenic arterial hypertension in dogs seams to involve catecholamines but not neuropeptide Y. Moreover, the present work suggests that a high level of sympathetic stimulation is required for a co-release of catecholamines and neuropeptide Y.


[Role of sympathetic nerve fibers in hemodynamic responses to stress in rats].

Hemodynamic responses to acute stress exposure were studied in normotensive control (C) and chronically sympathectomized (S) rats. Male Sprague-Dawley rats received daily sc injections of either saline (C) or guanethidine (S) from 1 to 13 weeks of age. Doppler flow probes were then implanted for the measurement of blood velocity in the sub-diaphragmatic aorta, superior mesenteric artery and distal aorta (hindquarters). After 10 days of recovery and 24 hours before the study, the caudal artery was cannulated. In the conscious freely moving rats, mean arterial pressure (MAP), heart rate (HR) and indices of regional blood flows and vascular conductances (G as blood flow/MAP ratio) were recorded beat to beat, before and during emotional stress (jet of air for 2 min). In basal conditions, mean values of MAP and HR were similar in C (107 +/- 2 mmHg; 399 +/- 8 bpm, n = 9) and S (106 +/- 3 mmHg; 384 +/- 12 bpm, n = 7) rats. The effects of stress on MAP, HR, aortic (AoG), mesenteric (MeG) and hindquarters (HqG) vascular conductances are expressed as percentage changes from baseline (delta): [table: see text] These results highlight the role of vascular sympathetic nerves in pressor responses and systemic and mesenteric vasoconstrictions induced by stress in the rat. They also indicate that vasodilatation in the hindquarters vascular bed is not secondary to withdrawal of sympathetic vasoconstrictor tone but rather to active phenomena which do not involve the stimulation of vascular beta 2-adrenoceptors by neuronal catecholamines nor the release of vasodilator cotransmitters from the sympathetic nerve endings.


[Methods of computerized approach of dysautonomia from a non-invasive pressure signal].

examination of an automated exploration of autonomic neuropathy using the Ewing score and evaluation of sympatho-vagal tone. continuous non-invasive collection of blood pressure (BP) data by means of Finapress fingerprobe. The signal was analysed after digitization at 500Hz, sampled and computerised. Values of systolic BP (SBP), diastolic BP (DBP) and heart rate (HR) are analysed by Anapres (Notochord). the pressure monitor is placed on the finger and the reading calibrated to the BP value recorded by auscultatory method on the contralateral arm to give a gap of less than 10 mmHg. BP and HR response to five different manoeuvres are recorded, namely: at rest over 7 minutes, after lying decubitus for 15 minutes; on rising suddenly over 3 seconds, and then over 9 minutes standing still; during 2 respiratory manoeuvres (a) deep breathing over 6 cycles per minute, (b) Valsalva pressure at 40 mmHg sustained over 20 seconds; isometric exercise with sustained handgrip at 30% maximal force sustained over 3 minutes. a dedicated computer programme displays in graphic form BP and HR over each manoeuvre and allows the operator to locate the exact cut-off of normality for each test of the Ewing score and also measure the balance of sympatho-vagal tone by Fourier transformation of the interval data of HR or BP peaks. this approach allows evaluation of autonomic function and sympatho-vagal tone by means of 40 minutes of clinical testing and two minutes of automated analysis. This approach seems useful in the assessment of the autonomic nervous system in diabetes.


[Pheochromocytoma, first manifestation of Von Hippel-Lindau disease: a possibility to be considered].

Von Hippel-Lindau (VHL) disorder is an autosomal dominant disease characterized by the almost constant development of hemangioblastomas in the central nervous system (cerebellum, spinal cord and retina). In addition, various types of tumors including renal cell carcinomas, pancreatic cysts and pheochromocytomas are frequently observed in VHL gene carriers. Linkage of the VHL locus to the RAF-1 oncogene on the short arm of chromosome 3 (3p25-26) has been recently reported. Pheochromocytoma is of particular interest because of the risk of inaugural malignant hypertensive crisis but especially because of a great degree of interfamily variability (from 0 to 92% of affected members in previously reported large kindreds). We have studied a French series of 25 pheochromocytoma (11 males, 14 females) in VHL affected patients. Twenty pheochromocytoma (80%) occurred in a familial context, whereas 5 (20%) were consistent with "apparent sporadic cases". The mean age at pheochromocytoma diagnosis was 27 years (5-55 years). Bilateral tumours have been documented in 13 cases (52%). The prevalence of pheochromocytoma revealing VHL was 14 out 25 (56%). In these cases, VHL diagnosis was considered up to 25 years later. In 6 cases (2 deceased) pheochromocytoma was the only manifestation of VHL. Thus, search for VHL must be systematic in the presence of pheochromocytoma, in the interest of the patients themselves and of potential at-risk family members (prevention of hypertensive crisis linked to latent tumours). Basic check-up (neurological and somatic examination, ophthalmoscopy, familial inquiry) may be completed with cerebral CT scan or MRI and abdominal ultrasonography followed, if positive or doubtful, by abdominal MRI or selective angiography.