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Biomedical subjects

I Brook

Publications and source records attributed to I Brook.

At least 469 records · Page 26Linked to original sources
PubMed1977

Leukopenia and granulocytopenia after oxacillin therapy.

Two cases of granulocytopenia and leukopenia developing after high-dosage oxacillin therapy given intravenously are described. One patient developed leukopenia and granulocytopenia after 17 days of therapy. The conditions were reversible when oxacillin therapy was discontinued. In the other case, the adverse reaction developed within 48 hours after therapy began and the patient died from heart failure. Leukopenia and granulocytopenia as adverse effects of oxacillin therapy should be kept in mind, especially when high dosages are used.

Adolescent↗
PubMed1977

Mixed bacterial meningitis: a complication of ventriculo- and lumboperitoneal shunts.

Infectious complications of ventriculo- and lumboperitoneal shunts in two patients are presented. Cerebrospinal fluid infection due to aerobic and anaerobic enteric flora was characteristic of each case. Both infections occurred several months after shunt surgery and were associated with colonic perforation by the distal limb of the peritoneal catheter. These cases emphasize this unusual hazard of peritoneal shunts and demonstrate methods for diagnosis and effective therapy.

Adult↗
PubMed1973

Increased reactivity of mouse spleen cells sensitized in vitro against syngeneic tumor cells in the presence of a thymic humoral factor.

Unprimed mouse spleen cells cultured in vitro on syngeneic tumor cell monolayers have been previously shown to become specifically sensitized and to mediate cytotoxicity against the same type of tumor cells. This complete in vitro system of cell-mediated response has been presently used to test the effect of a thymic humoral factor (THF) upon the differentiation process leading to the generation of specifically committed lymphocytes. Culture media were supplemented with 2% THF during either the sensitization or effector phase, or both phases of the reaction. Whereas the addition of THF during both phases or during sensitization only resulted in a significant increase in the cytotoxicity index, THF added during the effector phase was ineffective. The behavior of unsensitized spleen cells and of spleen cells sensitized against nonrelated transplantation antigens remained unmodified by THF. After showing that the entire reaction is mediated by lymphocytes of thymic origin, THF was directly tested on T or B spleen cells. It was found that only T cells reacted to THF by an increased cytotoxic capacity, while B cells remained inactive after addition of THF. It was therefore concluded that THF activates a postthymic population of lymphoid cells, transforming them into fully competent lymphocytes.

Animals↗
PubMedDate not supplied

Synovial fluid lactic acid. A diagnostic aid in septic arthritis.

Lactic acid concentrations in the synovial fluid of 84 patients with acute monoarticular arthritis were determined by gas liquid chromatography. Lactic acid values in 27 cases of nongonococcal septic arthritis were strikingly higher (mean 1170 mg/100ml) than in 45 cases of inflammatory or degenerative arthritis (mean 34 mg/100 ml), as well as in 12 cases of gonococcal arthritis (mean 27 mg/100 ml). With the proper equipment, determination of lactic acid can be a relatively rapid, reliable procedure. Synovial fluid lactic acid concentrations therefore can be used as a rapid, supplemental diagnostic aid in differentiating nongonococcal septic arthritis from both gonococcal and nonseptic acute arthritis.

Adult↗
PubMedDate not supplied

Medical treatment of non-streptococcal recurrent tonsillitis.

Forty patients with a history of recurrent non-beta-hemolytic streptococcal tonsillitis (RNST) participated in a prospective randomized study comparing penicillin and clindamycin in the treatment of acute non-group A streptococcal infection. The efficiency of each antibiotic was evaluated according to its ability to alleviate acute infection and prevent recurrence. Surface tonsillar cultures were obtained both before and ten days after the termination of therapy, and specimens were processed for aerobic and anaerobic bacteria. Beta-lactamase-producing bacteria (BLPB) were present in 36 (90%) tonsillar cultures. Thirty-one BLPB were isolated in 17 patients before penicillin therapy and 42 BLPB were recovered from 19 after such treatment. Thirty-three BLPB were recovered in 19 patients before clindamycin therapy, after which four BLPB were isolated in three patients (P less than .05). From the second day posttherapy onward, significantly fewer patients who received clindamycin had fever, pharyngeal injection, and sore throat. In a 1-year follow-up period, recurrent tonsillitis was noted in 13 of the patients who received penicillin and in two treated with clindamycin (P less than .001). The data clearly demonstrate the superiority of clindamycin therapy over penicillin in patients with RNST.

Adolescent↗
PubMedDate not supplied

Aerobic and anaerobic bacteriology of intracranial abscesses.

The bacteriologic and clinical findings of 39 pediatric patients with intracranial abscess are presented. Twenty-three children presented with brain abscess and 16 with subdural empyema. Predisposing conditions were present in all instances. Sinusitis was present in 25 children and 4 patients each had chronic otitis media, dental abscess, and congenital heart disease. The abscess was located in the frontal area in 14 patients, parietal in 13, and temporal in 12. Anaerobic organisms alone were recovered in 22 patients (56%), aerobic bacteria alone in 7 (18%), and mixed aerobic and anaerobic bacteria in 10 (26%) patients. There were 79 anaerobic isolates (2 per specimen). The predominant anaerobes were anaerobic Gram-positive cocci (29 isolates); Bacteroides sp. (12, including 5 Bacteroides fragilis group), Fusobacterium sp. (14 isolates); and Prevotella sp. and Actinomyces sp. (6 isolates each). A total of 17 aerobic or facultative isolates (0.4 per specimen), including 11 Gram-positive cocci and 6 Haemophilus sp., were recovered. Antimicrobial therapy was administered to all patients. Nine patients (i.e., 6 with sinusitis and subdural empyema, 3 with sinusitis and brain abscess) did not respond to antimicrobial therapy and aspiration of the abscess, and required surgical drainage of inflamed sinuses. These findings indicate the major role of anaerobic organisms in the polymicrobial etiology of intracranial abscess in children.

Adolescent↗
PubMedDate not supplied

Aerobic and anaerobic bacteriologic features of serous otitis media in children.

Aspirates of serous ear fluids from 57 children were examined for aerobic and anaerobic bacteria. Bacterial growth was noted in 23 patients (40 per cent). Aerobic organisms only were recovered in 13 aspirates (57 per cent of the culture-positive aspirates); anaerobic bacteria in four (17 per cent); and mixed aerobic and anaerobic bacteria in six (26 per cent). A total of 45 bacterial isolates were recovered, accounting for 2.0 isolates per specimen (1.4 aerobes and 0.6 anaerobe). There were a total of 31 aerobic isolates, including Hemophilus influenzae (eight isolates), Staphylococcus aureus and Streptococcus pneumoniae (five of each), and Staphylococcus epidermidis and alpha-hemolytic streptococcus (four of each). Fourteen anaerobes were recovered, including anaerobic gram-positive cocci and Bacteroides melaninogenicus (five isolates each) and Propionibacterium acnes (three isolates).

Bacteria, Aerobic↗
PubMedDate not supplied

The presence of beta-lactamase-producing bacteria as a guideline in the management of children with recurrent tonsillitis.

Thirty-eight children who had recurrent tonsillitis and who were chronic carriers of group A beta-hemolytic streptococci (GABHS) were treated with oral clindamycin. Surface tonsillar cultures, obtained prior to therapy and two weeks after the termination of therapy, were processed for aerobic and anaerobic microorganisms. Mixed aerobic and anaerobic flora were obtained from all cultures. Prior to therapy, the average yield was 9.3 isolates (5.2 aerobes and 4.1 anaerobes) per specimen; after the completion of therapy, the average yield was 5.5 isolates (3.0 aerobes and 2.5 anaerobes). The GABHS were completely eliminated after clindamycin therapy, and the numbers of isolates of Bacteroides spp and Staphylococcus aureus were reduced. Beta-lactamase production was detected prior to therapy in 57 isolates recovered from all tonsillar surfaces. This group included all isolates of S. aureus (15) and Bacteroides fragilis (eight), 19 of 34 Bacteroides melaninogenicus isolates (56 per cent), and seven of 12 Bacteroides oralis isolates (58 per cent). Only four isolates of beta-lactamase-producing bacterial strains were recovered after the conclusion of therapy. Follow-up study of 33 children for eight to 16 months (average, 13 months) showed no recurrence of GABHS in 31.

Adolescent↗
PubMedDate not supplied

Bacterial flora of airline headset devices.

External otitis caused by Staphylococcus aureus was observed in two patients after they wore airline headset devices. The bacterial flora of 40 headset devices was evaluated. Bacteria were recovered from all headsets, and the number of organisms ranged from 10 to 1,200 (mean 138 +/- 246 organisms per headset). The predominant organisms recovered were S. aureus (in 12 headsets), Bacillus sp. and S. epidermidis (ten headsets each), alpha-hemolytic streptococci (in eight) and Corynebacterium sp. (in six). The effect of wearing a sterile headset for an hour was investigated using 20 volunteers. After wearing the headsets, an increase of at least two log10 colony-forming units was observed in 11 (55 per cent) of the volunteers, a decrease was observed in one (5 per cent), and no significant change in the bacterial flora was noticed in eight (40 per cent). The study demonstrates the presence of potential pathogens in headset devices and the increase in the number of endogenous flora in individuals who wear these devices.

Adolescent↗
PubMedDate not supplied

The role of anaerobic bacteria in otitis media: microbiology, pathogenesis, and implications on therapy.

The current knowledge of the recovery of anaerobic bacteria from cases of acute and chronic otitis media is reviewed. Although techniques for cultivation of anaerobes were used in the studies presented, the methodologies of collection, transportation, and cultivation of the specimens varied. Consequently, there were differences in the rates of recovery of these organisms and the species isolated. Anaerobes, mainly gram-positive cocci, were recovered from a quarter of ear aspirates in acute otitis media in about one third mixed with aerobic and facultative bacteria. In a study of otitis media with effusion, anaerobic bacteria were recovered in 12% of the culture-positive aspirates. The predominant anaerobes were gram-positive cocci and Bacteroides melaninogenicus. Several studies reported the recovery of anaerobes in about half of the patients with chronic otitis media and in those with cholesteatoma. The predominant anaerobes were gram-positive cocci, Bacteroides sp, and Fusobacteria sp. Many of these organisms produced beta-lactamase and might have contributed to the failure of these patients to respond to penicillins. The potential synergistic relationships between the various aerobic and anaerobic bacteria and the role of the capsule of anaerobic bacteria as a virulence factor are discussed.

Acute Disease↗
PubMedDate not supplied

Toxocariasis in an institution for the mentally retarded.

A seroepidemiologic investigation was conducted in order to determine the cause of an apparent increase in rates of eosinophilia among 1400 institutionalized children during 1976-1977. The annual serologic survey during this period revealed 283 (20%) individuals with eosinophilia that exceeded 600 cells/cu mm of blood. During a five-month period in 1977, five patients who were hospitalized in adjacent wards developed acute pneumonia with eosinophilia. Because laboratory tests of sputum, bone marrow, and stool failed to identify the etiologic agent, it was thought that these pneumonia cases might be related to the increased rates of eosinophilia. Analyses of random samples of sera from patients with eosinophilia revealed seroprevalence rates of 12% for Ascaris, 20% for Toxocara canis, 24% for Strongyloides stercoralis, and 32% with increased antibody to Entamoeba histolytica. Further investigation showed a statistically significant positive association between occurrence of eosinophilia and pica behavior, and eosinophilia and contact with dogs. Although the serologic survey showed patients to have had previous exposure to a variety of parasites, we hypothesize that a principal cause of eosinophilia among institutionalized children may be Toxocara infestation, due to their frequent pica behavior and, in this case, contact with resident animals. We recommend that children in similar facilities have limited contact with pet dogs, and only after frequent and vigorous examination of the animals for infectious parasites.

Animals↗
PubMedDate not supplied

Use of selective decontamination in the prevention of infection after accidental irradiation. A review.

Exposure to radiation induces a reduction in the number of gastrointestinal, anaerobic bacterial flora, and an increase in the number of Enterobacteriaceae that are associated with sepsis and mortality. Antimicrobials that suppress anaerobic flora have a deleterious effect on survival by promoting earlier enterobacterial sepsis. In contrast, in studies of animals and immunosuppressed patients, antimicrobials that inhibit gram-negative enteric bacteria and preserve the anaerobic flora have shown a beneficial effect by preventing bacterial translocation and fatal sepsis. The quinolone antimicrobials hold potential for therapy of endogenous and exogenous infection after irradiation.

Anti-Infective Agents↗
PubMedDate not supplied

The effects of amoxicillin therapy on skin flora in infants.

In order to determine the effect of amoxicillin therapy on the perineal skin microbial flora in infants, we took quantitative bacterial and fungal cultures of perineal and sternal areas from 25 infants treated with amoxicillin (40 mg/kg/day) for 10 days. Specimens were obtained prior to therapy, within 3 days of conclusion of therapy, and 14-16 days later. Immediately following therapy, a decline in the number of bacterial isolates occurred on both the perineum (89 to 47) and sternum (84 to 39). The greatest decline occurred in the number of anaerobic bacteria (mostly Peptostreptococcus spp. and Propionibacterium acnes). Other organisms that were less often isolated were aerobic streptococci and Staphylococcus epidermidis. The number of Candida albicans isolates increased from 3 to 11 (p < 0.05) on the perineum, and 1 to 7 (p < 0.025) on the sternum. Four of the infants developed diaper dermatitis. The density of C. albicans increased more than 14-fold following amoxicillin therapy. Cultures done 14-16 days after cessation of therapy revealed an increase in the number of bacterial isolates on the perineum (47 to 72) and on the sternum (39 to 61) and a decline in recovery of C. albicans. This study demonstrates the effects of amoxicillin on the ecology of skin microbial flora in infants-a decrease in the number of bacterial isolates and an increase in recovery of C. albicans.

Amoxicillin↗
PubMedDate not supplied

Inoculum effect.

The inoculum effect (IE) is a laboratory phenomenon that is described as a significant increase in the minimal inhibitory concentration of an antibiotic when the number of organisms inoculated is increased. The IE generally occurs with beta-lactam antibiotics in relation to beta-lactamase-producing bacteria. An IE occurs with the first- and second-generation cephalosporins against Staphylococcus aureus and less often with the quinolones, beta-lactam-resistant penicillins, cefoxitin, and aminoglycosides. An IE occurs with the penicillins against the Enterobacteriaceae and Pseudomonas species, and a variable IE occurs with cephalosporins; however, no IE occurs with aminoglycosides, quinolones, imipenem, and chloramphenicol against these organisms. An IE occurs with beta-lactam antibiotics against Haemophilus influenzae and with the penicillins and the cephalosporins against penicillinase-producing Neisseria gonorrhoeae and Branhamella catarrhalis. An IE occurs with the penicillins and cephalosporins against the Bacteroides fragilis group; no IE occurs with cefoxitin and imipenem. Although certain antibiotics exhibit an IE, they are still capable of eradicating infections when administered appropriately. Thus, the clinical significance of this laboratory phenomenon has yet to be elucidated.

Anti-Bacterial Agents↗
PubMedDate not supplied

Infections caused by Propionibacterium species.

Eight hundred and sixteen isolates of Propionibacterium species (725 of which were Propionibacterium acnes) were isolated from 3,971 specimens submitted for the identification of anaerobic bacteria over the course of 10 years. A total of 94 Propionibacterium isolates (12%) identified in 92 patients were considered to cause infection. The rest of the isolates were determined to be contaminants or of uncertain pathogenic significance. Significant infections caused by Propionibacterium species were associated with the blood in 15 patients, central nervous system in 11, lymph glands in 10, abscesses in eight, joints in seven, wounds in seven, cysts in six, and sinuses in five. Predisposing or underlying conditions were noted in 66 patients (70%). The most common conditions were the presence of foreign bodies (29 patients), diabetes (12), previous surgery (10), trauma (seven), malignancy (seven), immunodeficiency (seven), and steroid therapy (four). Antimicrobial therapy was administered to 83 patients; for 47 patients this therapy was given in conjunction with surgical drainage or correction. Surgical drainage alone was performed in nine patients. Five patients (5%) died. These data illustrate that although Propionibacterium species are rarely associated with infections, these organisms can occasionally cause serious infections.

Adolescent↗
PubMedDate not supplied

In vitro susceptibility vs. in vivo efficacy of various antimicrobial agents against the Bacteroides fragilis group.

In vitro susceptibility testing is only one step in the evaluation of the potential efficacy of antimicrobial agents against the Bacteroides fragilis group. An assessment of in vivo efficacy, with a consideration of the factors that can best be studied in an infected host, is also an integral part of this process. Abscess models in rodents have been used to correlate in vitro activity with in vivo efficacy against this group of microorganisms. For metronidazole, clindamycin, moxalactam, and cefoxitin, the correlation was strong; for chloramphenicol and carbenicillin, it was not. In vivo studies of mixed infection with the B. fragilis group and Escherichia coli showed that cefoxitin and imipenem were effective; in contrast, cefotetan was not effective against resistant strains. Only strains susceptible to ceftizoxime in the agar dilution test were also affected by this drug in vivo. The so-called inoculum effect noted with ceftizoxime may explain this finding. In vivo elimination of encapsulated organisms of the B. fragilis group was found to be more difficult than elimination of unencapsulated isolates. The beta-lactamase produced by Bacteroides species can protect the enzyme-producing organism as well as its partners in mixed infections from the effects of beta-lactam antibiotics. These data illustrate the complexity and difficulties encountered when in vitro activity is correlated with in vivo efficacy.

Abscess↗
PubMedDate not supplied

The importance of lactic acid levels in body fluids in the detection of bacterial infections.

Lactic acid can be formed as a "blind alley" in the metabolic degradation of glucose, especially under anaerobic conditions. The presence of bacterial infection in a closed body cavity induces elevated levels of lactic acid, as is evident in bacterial and fungal infections inthe meninges, joints, peritoneum, and pleura. Although measurement of lactate levels is not a test without faults, it is still a valuable tool in the early recognition of bacterial infections of various body cavities and can assist in the differentiation between infectious and noninfectious conditions. False-positive readings can be obtained with severe anoxia of the CNS, and with irritation of the peritoneal or pleural cavities due to metastases. False-negative values can be obtained in gonococcal arthritis. Table 1 presents accepted normal values for lactic acid in various body sites and the levels of lactic acid than can signify the presence of infection. Further work is still needed to provide better understanding of the mechanisms that cause changes in concentrations of lactic acid.

Ascitic Fluid↗