The lipid composition of bovine sebum and dermis.
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Biomedical subjects
Publications and source records attributed to R C Noble.
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A study has been made of the comparative distribution and fatty acid compositions of the major lipid fractions of maternal plasma, placenta and fetal plasma of the sheep at approximately 120 days of gestation. Cholesteryl esters and phospholipids constituted the major lipid fractions present in both maternal and fetal plasmas. In the placenta, phospholipids accounted for some 60 per cent of the total lipid present. Within the phospholipids of the maternal and fetal plasmas and placenta, phosphatidylcholine comprised the largest component. Whereas maternal plasma contained high levels of linoleic and arachidonic acids, fetal plasma contained a low proportion only a linoleic acid and high proportions of delta 5,8,11 eicosatrienoic acid and arachidonic acid. In the maternal plasma the arachidonic acid:linoleic acid ratio was only 0.17, but in the fetal plasma the ratio was 3.32. The differences in the lipid and fatty acid compositions between the maternal plasma, fetal plasma and placenta are discussed in relationship to the distinctive polyunsaturated fatty acid metabolism of the fetal and newborn lamb.
This report describes a young woman with a ventriculoperitoneal shunt who developed gonococcal meningitis and ventriculitis. Her infection responded to treatment with antimicrobial agents without removal of the shunt.
We studied the incidence of gonorrhea, gonococcal recidivism and related factors in venereal disease clinic patients. A sample of 2029 records, which were selected randomly, were reviewed. Gonorrhea and gonococcal recidivism were more common in nonwhite patients, particularly in nonwhite men. Gonorrhea occurred more than once in 23% of the patients with gonorrhea and those patients accounted for 48% of all cases of gonorrhea. We also interviewed 627 new patients attending the venereal disease clinic. Gonococcal recidivism was reported more often by older men and younger women. Use of contraceptives was less frequent among white women who were gonococcal recidivists. However, contraception was not used by 40% of the patients or their partners. Gonococcal isolation rates were lowest in men who used condoms. The number of sexual partners did not correlate with age, use of contraceptives or results of cultures for gonococci. Men had more sexual partners than women and white women had more partners than non-white women. Nine percent of patients took oral antibiotics prior to their visit to the clinic; antibiotic ingestion did not correlate with the patients' race or the results of their cultures.
Before 1978, isolates of Neisseria gonorrhoeae from white patients attending a venereal disease clinic were more susceptible to penicillin G than were isolates from black patients, because the whites were more frequently infected with the Arg- Hyx- Ura- auxotype that was highly susceptible to penicillin. Recent isolates from the same clinic show a change both in the auxotypes and in the penicillin susceptibility of N. gonorrhoeae infecting the two patient groups. Of 211 isolates studied in 1978, the four most common auxotypes were, in decreasing frequency: Pro-, nonrequiring, Arg- Hyx- Ura- and Arg-. In the present study of 265 isolates, the order of frequency was nonrequiring; Pro-; Pro- Arg-(Orn*) Ura-; and Arg- Hyx- Ura-. The Pro- Arg-(Orn*) Ura- auxotype was new to the clinic and was significantly more frequent in white than in black patients and significantly more resistant to penicillin than were gonococci of the remaining auxotypes. With the appearance of the Pro- Arg-(Orn*) Ura- auxotype among white patients, there was no significant difference in the susceptibility to penicillin of isolates of N. gonorrhoeae from the two groups of patients.
Isolates of Neisseria gonorrhoeae from 304 patients attending a venereal disease clinic were examined by a plate dilution method for their susceptibility to six antibiotics: penicillin G, spectinomycin, tetracycline, cefaclor, cefoxitin, and moxalactam. The isolates were also characterized by gonococcal auxotyping. The most frequent auxotypes were Nonrequiring, 58%; Pro-, 14%; Pro- Arg (Orn*) Ura-, 14%; Arg- Hyx- Ura-, 6%; and a miscellaneous group consisting of 8% of the isolates. If the entire group of isolates were examined, moxalactam was the most active of the antibiotics; 94% of the isolates were inhibited by less than or equal to 0.25 microgram/ml. The Pro- Arg (Orn*) Ura- isolates were relatively resistant to penicillin G and cefoxitin. The Arg- Hyx- Ura- group of isolates was the most susceptible of the auxotypes to all of the antibiotics except spectinomycin. The uncommon auxotype Arg (Orn*) Ura- has a requirement for arginine that is satisfied by citrulline but not by ornithine. The results of the present study indicate that the nutritional requirements of gonococci may be associated with their response to certain antibiotics.
Gonococci of the Arg-, Hyx-, Ura- auxotype are isolated most commonly from white patients and seldom from black patients. Five gonococcal isolates of the Arg-, Hyx-, Ura- auxotype and five of the Pro- auxotype were tested for their ability to attach to buccal epithelial cells or to attach or be ingested by polymorphonuclear leukocytes taken from two individuals each of three different racial backgrounds: European-American (caucasian), black American, and Indian from India. Despite the differences in race of the six individuals, there were no differences in the attachment or ingestion of the two gonococcal auxotypes to the two different cell types. The study does not explain why the Arg-, Hyx-, Ura- auxotype is isolated more frequently from whites.
Rosoxacin, a beta-lactamase-resistant, pyridyl quinolone derivative with in vitro activity against Neisseria gonorrhoeae, was compared to an oral regimen of ampicillin plus probenecid for the treatment of uncomplicated gonococcal infection. Fifty-seven patients were evaluated for the effectiveness of the two antibiotics. Thirty (97%) of 31 patients receiving rosoxacin were cured of their infection as were 25 (96%) of 26 patients who received the oral regimen of ampicillin plus probenecid. Both drug regimens were associated with a significant number of side effects. Of the ampicillin-treated group, 29% had diarrhea and/or abdominal cramping. Of the rosoxacin-treated patients, 52% had reactions classified as central nervous system effects; these included headaches, dizziness, euphoria, and drowsiness.
Strains of Neisseria gonorrhoeae requiring arginine, hypoxanthine, and uracil (AHU) may cause disseminated gonococcal infection (DGI). A significant epidemiologic association was noted between the incidence of disseminated gonococcal infection and the presence of gonococci of the AHU auxotype in the community over a nine-year period. Thirty-nine patients with DGI were identified from hospital records of January 1974-December 1982. During this interval, gonococcal isolates from patients in the community were collected at a venereal disease clinic and a hospital emergency room. The incidence of patients hospitalized for DGI dropped significantly after 1978. The year of highest incidence of DGI was 1977, when there were 429 cases of DGI per 100,000 cases of uncomplicated gonorrhea; the incidence of gonococcal isolates of the AHU auxotype in that year was 26.3%. In contrast, this auxotype accounted for only 4.6% of gonococcal isolates in 1980, when the incidence of DGI had decreased to 58 cases per 100,000 cases of uncomplicated gonorrhea. When DGI and gonococci of the AHU auxotype from the community were ranked for incidence by year, a significant correlation between the two was found (P less than .001). Thus the incidence of patients with DGI in the hospital reflected the presence of gonococci of the AHU auxotype in the community.
Isolates of Neisseria gonorrhoeae from 150 patients attending a venereal disease clinic were examined for their susceptibility to four antibiotics (norfloxacin, cefotaxime, cefuroxime, and erythromycin) by a plate-dilution method. The isolates were also characterized by gonococcal auxotyping. The most frequent auxotypes were nonrequiring, 50%; Pro-, 16.7%; Pro-, Arg-, (Orn*), Ura-, 10.7%; Arg-, Hyx-, Ura-, 12.7%; and a miscellaneous group consisting of 10% of the isolates. Norfloxacin was the most active of the antibiotics; all of the isolates were inhibited by less than or equal to 0.06 microgram/ml. The Arg-, Hyx-, Ura- group of isolates was the most susceptible of the auxotypes to antibiotics. In the present study N. gonorrhoeae of the Arg-, Hyx-, Ura- auxotype fell into two groups with respect to erythromycin, one highly susceptible and one less susceptible. The results of the present study provide further evidence that the nutritional requirements of gonococci are associated with their response to certain antibiotics.
Urethral gonorrhea is typified by the presence of large numbers of polymorphonuclear leukocytes, which are presumably attracted to the urethra by an as yet uncharacterized chemotaxin. Culture supernatants from three different auxotypes of Neisseria gonorrhoeae, one requiring arginine, hypoxanthine, and uracil (Arg-,Hyx-,Ura-), one requiring proline, arginine (not satisfied by ornithine), and uracil (Pro-,Arg-[Orn*],Ura-), and one requiring proline (Pro-), were tested for their chemotactic activity against leukocytes from men of two racial groups, white and black. These auxotypes were chosen because the Pro- auxotype is isolated more frequently from black patients, and the Arg-,Hyx-,Ura- and the Pro-,Arg-(Orn*),Ura- auxotypes are isolated more frequently from white patients. Chemotaxis was tested in blind-well chambers in the absence of complement; membranes with a pore size of 3 microns were used. The culture supernatants of the Pro- auxotype were the most chemotactic, while those of the Arg-,Hyx-,Ura- were the least chemotactic when analyzed by a three-way analysis of variance: F = 22.83, df = 2.6, P less than .001. There were no differences in migration with respect to the race of the donor. Gonococcal culture supernatants did not require complement for chemotaxis.
Some human urine is bactericidal for the F-62 strain of Neisseria gonorrhoeae. Gonococci of three auxotypes (Pro-; Arg-, Hyx-, Ura-; and Pro-, Arg-. (Orn*), Ura-) were tested by in-vitro exposure to 31 samples of urine from 14 men. Nineteen of the urine specimens were bactericidal, and 12 were not. Except for one sample, all cidal urines came from five men. Cidal activity was associated with acidic, concentrated urines; it was unaffected by exposure to lowered pH, pronase, heat or cold, and was dialyzable with use of a dialysis membrane with a cut-off molecular weight of 1000. Neutralization of the acid urines removed the antigonococcal activity. Noncidal acid urines became cidal urines when concentrated by lyophilization. Zinc, lysozyme, fluoride ions, and fatty acids are substances that have antibacterial activity and are also present in urine. These substances were examined for antigonococcal activity. Neither zinc salts, fluoride ions, lysozyme, nor fatty acids in concentrations exceeding those found in urine were bactericidal for the gonococci. These results show that sufficiently concentrated, acidic urines kill gonococci by an unknown mechanism.
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In the present study an attempt has been made to describe the morphometrical changes occurring in the microvilli of the duodenum of rats of different ages and periods of reproduction. The data showed that the microvillous surface area in the duodenum was greatest in senescent rats and lowest in adult and old animals. The values for lactating rats were similar to that for the senescent group. There was a direct correlation between the microvillous surface area with the height and density. By contrast, however, there was a negative correlation between the width and density of the duodenal microvilli.
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A relationship is discussed between free radicals, lipid metabolism, neurotransmitters, and aging. Almost all of the lipid fractions of nerve tissue are heavily exposed during aging to the deleterious effects of a continuous formation of free radicals. In comparative terms, brain tissue has less enzymatic capacity to lower or counteract the rate of lipid peroxidation. However, various defense mechanisms exist that enable phospholipid reconstitution to occur and their metabolic activity to be maintained through reutilization of products arising from their biosynthesis and turnover. The effect of hyperoxygenation or hypoxygenation in association with free radicals generation on neurone stability and neurotransmitters reveals different susceptibilities to neuronal stimuli- and release quotients related to aging. With respect to the relationship between the environment and aging, neurotransmitter mechanisms, exemplified by that of dopamine and its turnover, play an important role in coping with stress, iatrogenic and toxic factors during aging. Possible pharmacological and other ways of mitigating age-related changes by means of protective reactions, accelerated repair processes, and compensatory mechanisms are discussed.