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Biomedical subjects

R L Nichols

Publications and source records attributed to R L Nichols.

At least 109 records · Page 6Linked to original sources
PubMed1978

Use of enteric vaccines in protection against chlamydial infections of the genital tract and the eye of guinea pigs.

Guinea pigs in a test group were fed living guinea pig inclusion conjunctivitis (GPIC) organisms classified as Chlamydia psittaci in 60% yolk-sac suspensions as enteric vaccines, while animals in a control group received uninfected yolk sac. Seven test animals and 14 control animals were challenged 11 or 22 days later with 1,000 50% infectious doses of GPIC organisms in either the conjunctiva or the vagina. Evidence of protection from mucosal infection in both sites was noted in test animals. Clinically, the disease was less severe, and microbiologically, lower percentages of mucosal cells were infected. The results suggest that enteric vaccination against mucosal infections of the eye and the genital tract with chlamydial agents is possible.

Administration, Oral↗
PubMed1978

Veterans Administration Cooperative Study on Bowel Preparation for Elective Colorectal Operations: impact of oral antibiotic regimen on colonic flora, wound irrigation cultures and bacteriology of septic complications.

A ten hospital cooperative study comparing prophylactic oral neomycin and erythromycin base versus placebo demonstrated clinical efficacy of the antibiotics in preventing septic complications following elective colon operations. The present report concerns microbiological studies accomplished during this trial. Cultures of colon contents during surgery showed the antibiotic prep reduced concentrations of both aerobes and anaerobes by approximately 10(5) bacteria/ml. Virtually all major bacterial components of the normal flora were affected. Wound irrigation specimens at the time of closure failed to predict subsequent wound infection, but significantly fewer antibiotic recipients had positive irrigation cultures. Postoperative stool specimens showed that the oral antibiotics did not cause an emergence in resistant forms. Bacteriological studies of postoperative infections indicated that most postoperative infections involved a mixed aerobic-anaerobic flora, and that Bacteroides fragilis accounted for six of eight episodes of bacteremia.

Bacteria↗
PubMed1978

Immunity to vaginal reinfection in female guinea pigs infected sexually with Chlamydia of guinea pig inclusion conjunctivitis.

Guinea pig boars were inoculated intraurethrally with the chlamydial agent of guinea pig inclusion conjunctivitis (GPIC). At the heights of their urethral infections, they were caged with sows in estrus. Whereas some of the sows had not been previously exposed to GPIC agent, others had received an intravaginal inoculation 5 to 8 weeks earlier. Those sows for which infected boars provided the first exposure were challenged by intravaginal inoculation 5 to 8 weeks later. Vaginal and conjunctival scrapings were taken regularly and stained for chlamydial inclusions. Titers of serum anti-GPIC antibodies and of vaginal secretory IgA anti-GPIC antibodies were determined by immunofluorescence. Our results show for the first time that a sexually acquired vaginal GPIC infection induces immunity to manual reinfection of the vagina. Because of the high incidence of secondary conjunctival infections among the vaginally infected sows, we could not provide a sound statistical basis for our tentative conclusion that manual infection of the vagina induces immunity to sexual reinfection. The results of our antibody titrations confirm previous work showing that vaginal GPIC infection induces formation of both serum antibody and vaginal secretory immunoglobulin A antibody.

Animals↗
PubMed1977

Intraabdominal sepsis: characterization and treatment.

Intraabdominal sepsis is frequently present after trauma, surgical resection, or intrinsic diseases of the gastrointestinal tract. When infection occurs it may be generalized or localized in intraperitoneal or extraperitoneal locations as well as in solid organs. The offending microflora is polymicrobial, consisting of both aerobes and anaerobes. Adequate, prompt surgical drainage and the appropriate choice of parenteral antibiotics aimed at both types of bacteria will result in a more favorable postoperative course and will reduce the possibility of local infection and secondary septicemia.

Abdomen↗
PubMed1977

Environmental air and airborne infections.

The results of a study on the epidemiology of airborne (aerobic) surgical infections are presented. The first phase of the study was carried out in a surgical suite which contained no environmental or traffic control systems. The second phase of the study took place within a modern "up to date" operating room suite containing multiple air screens as well as an elaborate ventilation system utilizing HEPA type filters which provided the operating room with clinically sterile air. One hundred and fifty-six patients were also studied. All patients underwent major procedures. The ratio of clean, clean-contaminated, and dirty cases was the same in both groups. Preoperatively, a nasal swab, clean voided urine (or vaginal swab) and a rectal swab were obtained on each patient. Daily nasal cultures and cultures of suspected sites of infection were obtained postoperatively. Daily nasal cultures and "glove sweat" cultures were obtained on all personnel attending the patient. Environmental cultures of the operating room, the operating room hallway, recovery room and patients' rooms were also taken. All samples were checked for the presence of staphylococci, streptococci, Escherichia coli, proteus species, enterobacter, klebsiella, and pseudomonas. In all, 15,000 cultures were taken during the study. The rate of infection was essentially the same in both phases of the study. Environmental air only occasionaly served as the source of infecting organisms. The results of the study support the conclusion that the most common source of infecting organisms in surgical infections is thepatient or those around him. The most common time of contamination is during the surgical procedure itself. Surgical infections can best be minimized by meticulous observation of fundamental principles of antisepsis rather than by dependence on elaborate and costly ventilation and air control systems.

Adolescent↗
PubMed1977

Comparison of the fecal microflora of Seventh-Day Adventists with individuals consuming a general diet. Implications concerning colonic carcinoma.

Qualitative and quantitative fecal microflora was studied in a double blind fashion in 28 subjects. Fourteen were Seventh-Day Adventists, who were strict vegetarians, while the remaining 14 subjects were individuals consuming a general western diet. No statistically significant differences were identified in the fecal microflora of the two groups. The bacteriologic analysis included total aerobes and total anaerobes as well as each of the major fecal aerobes and anaerobes. This study seems to indicate that the dietary intake of animal fat and protein does not significantly alter the fecal microflora, a possibility which has previously been suggested as being part of the explanation for the higher incidence of colonic carcinoma in those who consume meat compared with vegetarians. It does not, however, invalidate the concept that dietary animal fat does increase bile acid degradation within the gastrointestinal tract, a factor which has been related to colon cancer. Future studies should be directed at identifying the factors that may be present in the gastrointestinal tracts of vegetarians which modify the ability of their colonic microflora to degrade bile acids, an essential step in the production of intraluminal carcinogens or co-carcinogens.

Adolescent↗
PubMed1977

Preoperative oral antibiotics reduce septic complications of colon operations: results of prospective, randomized, double-blind clinical study.

The effectiveness of short-term, low-dose, preoperative oral administration of neomycin and erythromycin base combined with vigorous purgation in reducing the incidence of wound infections and other septic complications of elective colon and rectal operations has been studied in a prospective, randomized, double-blind, clinical trial. One hundred and sixteen patients completed the study; all received mechanical preparation; 56 received neomycin-erythromycin base while 60 received an identical appearing placebo. The two patient groups were comparable in age distribution, clinical diagnoses, associated systemic diseases, types of operation performed and similar clinical features. The overall rate of directly related septic complications was 43 per cent in the placebo group and 9% in the group receiving neomycin and erythromycin base. The wound infection rates were 35% in placebo and 9% in antibiotic treated patients. Oral administration of neomycin and erythromycin base together with vigorous mechanical cleansing reduces the risk of septic complications after elective colo-rectal operations.

Abscess↗
PubMed1977

Technique for specimen collection of postsurgical exudate of wounds.

Postsurgical sepsis due to anaerobic microoganisms is often difficult to diagnose. The difficulty arises primarily because of inadequate specimen collection techniques and because of delays in the transport of the specimen to the microbiologic laboratory. Three acceptable techniques for anaerobic specimen collection and transportation have been offered. All of these techniques have in common the minimization of contact between the collected specimen and the atmosphere, a step which helps to preserve the viability of many of the fastidious anaerobic bacteria frequently implicated in surgical sepsis.

Anaerobiosis↗
PubMed1977

A technique for isolation of ileostomy drainage during abdominal operations.

An abdominal operation performed upon a patient with an existing ileostomy carries an increased risk of postoperative infection due to the escape of ileal effluent from the stoma during the course of the operation. The bacteriologic sample of this effluent has been shown to contain high cocentrations of both aerobic and anaerobic bacteria qualitatively similar to that of the microflora of the colon. A nontraumatic technique for effective isolation of the effluent using Foley catheter occlusion between the balloon and the fascial ring has been devised.

Catheterization↗
PubMed1976

Trachoma in a rural Haitian community.

We selected 43 patients, aged 15 days to 57 yesrs, for intensive study after screening 975 people for clinical evidence of trachoma in rural Haiti. Trachoma was present in Haiti with low endemicity and was followed by relatively mild sequelae. Laboratory studies confirmed the disease through demonstration of conjunctival inclusion bodies by immunofluoresence and serotyping of antibody in sera or eye secretions, or both. Of 23 patients (age 1 to 36 years) with active trachoma, all had serum antibody to chlamydia (range 1:10 to 1:640), nine had eye secretion antibody (range 1:10 to 1:1280), and one was inclusion positive. The remaining 20 patients (age 15 days to 57 years) had the following diagnosis: atypical follicles (eight), conjunctivitis with or without mucopurulent discharge (ten) innactive pannus only (one), and severe anemia (one). Only 16 of the 20 were tested for serum antibody and all were positive (1:10 to 1:5,120), 11 of 20 had eye secretion antibody (1:10 to less than or equal to 1:640), and one was inclusion positive. Serotyping attempted on 22 patients yielded 16 patients with antibodies specific for type A, one patient with type B, and five who were not typed.

Adolescent↗
PubMed1976

Animal model studies of genital chlamydial infections. Immunity to re-infection with guinea-pig inclusion conjunctivitis agent in the urethra and eye of male guinea-pigs.

A previous report demonstrated that male guinea-pigs could be infected in the urethra with guinea-pig inclusion conjunctivitis (GPIC) agent and that the infection was transmitted during mating from infected males to females. In the experiments reported here, inoculation of male guinea-pigs in the urethra with GPIC organisms resulted in infection which subsided spontaneously in about 2 weeks. Males were demonstrated to be completely resistant to urethral challenge with 10(3)ID50 when tested 6 weeks after urethral infection. These guinea-pigs, immune to re-infection of the urethra, remained susceptible to infection of the eye, but this ocular infection was shorter in duration than that in previously uninfected control animals. Infection in the eye resulted in immunity to both ocular and urethral infection when animals were challenged 6 weeks after the ocular infection.

Animals↗
PubMed1976

Anaerobic Infections.

Oxygen-sensitive anaerobic bacteria comprise the largest group of organisms among the human endogenous microflora. The oral cavity, the vagina and the colon are areas where the obligate anaerobes are predominant and can be isolated in high numbers. Clinical clues that indicate anaerobic sepsis include a putrid odor of the exudate and evidence of abscess, necrosis or associated gas formation. A Gram stain is highly valuable in early identification. Surgical drainage and appropriate antibiotics are essential.

Abdomen↗
PubMed1975

Modern approach to the diagnosis of anaerobic surgical sepsis.

Oxygen-sensitive anaerobic bacteria comprise the largest group of organisms among the human endogenous microflora. The oral cavity, the vagina, and the colon are the areas of the human body where the obligate anaerobes are predominant and can be isolated in very high numbers. Sepsis following surgery of any of these organs is frequently due to the escape of these endogenous bacteria during the course of the operative procedure. To enable the isolation and successful identification of most of these anaerobic microorganisms from clinical exudate, special collection and bacteriologic techniques are necessary. The acceptable anaerobic collection techniques have been reviewed in this paper. All of these techniques minimize the exposure of the clinical specimen to atmospheric oxygen during collection and transfer. The modern equipment used in sophisticated anaerobic bacteriologic workup has been discussed. Clinical clues that indicate anaerobic sepsis include a putrid odor of the exudate and evidence of abscess, necrosis, or associated gas formation. The importance and value of the gram-stain in the early identification of surgical sepsis has been stressed.

Anaerobiosis↗
PubMed1975

Gas in the wound: what does it mean?

Gas-forming infections on the surgical service are usually due to anaerobic microorganisms such as clostridia, peptostreptococci or bacteroides, or to one of the aerobic coliforms. Factors that predispose to the development of gas infections include lower extremity vascular disease and diabetes mellitus. Early treatment based on the inital Gram-stain study as well as the clinical presentation is helpful in reducing tissue losses and increasing overall survival. Treatment for nonclostridial gas infections includes prompt adequate surgical debridement and appropriate parenteral antibiotics. When available, hyperbaric oxygen should be added to the treatment plan in all extensive clostridial infections.

Chloramphenicol↗
PubMed1975

Septic complications following gastric surgery: relationship to the endogenous gastric microflora.

The microflora of the stomach is derived from both the ingestion of food and saliva and the reflux of proximal intestinal contents through the pylorus. Normally, this microflora is inhibited by gastric acid and normal gastric motility. In disease states, however, such as bleeding or obstructing duodenal ulcer, gastric ulcer or carcinoma, the level of gastric acid is reduced or the gastric motility is altered. Thus, endogenous microflora persists and often becomes the source of postoperative wound infections following gastric resection.

Gastrectomy↗