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Biomedical subjects

J Silva

Publications and source records attributed to J Silva.

At least 271 records · Page 15Linked to original sources

Abnormalities of lymphocyte transformations in women with intraepithelial carcinoma of the vulva.

Cellular immunity of the delayed type in women with intraepithelial carcinoma (carcinoma is situ) of the vulva was investigated by an in vitro assay of mitogen-induced lymphocyte transformations. Test results from 9 patients were compared to those of 23 age-matched control subjects. Lymphocyte transformation responses in counts per minute were significantly lower for women with carcinoma in situ of the vulva than for control subjects for phytohemagglutinin-P (at 50 microgram/ml) 6238 and 28,102 (P less than 0.0001); for phytohemagglutinin-P (at 165 microgram/ml 7222 and 21,417 (P less than 0.001); for concanavallin A, 14,988 and 41,888 (P less than 0.0001); and pokeweed mitogen, 20,861 and 49,601 (P less than 0.001). No significant differences in lymphocyte transformations were noted between these two groups to the specific antigens, Candida or streptokinase-streptodornase. Four patients with carcinoma in situ of the vulva were also found to have intraepithelial carcinoma of the cervix and/or vegina. The occurrence and clinical course of carcinoma in situ of the vulva in some women may be related to an underlying defect in cellular immunity. Immunosuppression may also explain the frequent association noted between carcinoma of the vulva and the development of other malignant neoplasms.

Adolescent↗

Antibiotic-induced colitis implication of a toxin neutralised by Clostridium sordellii antitoxin.

A toxin(s) has been demonstrated in the stools of two patients with antibiotic-associated colitis. This toxin(s) was heat-labile, was rapidly lethal for hamsters, increased vascular permeability in rabbit skin, and was cytotoxic for cells in tissue-culture. It was neutralised by Clostridium sordellii antitoxin but not by antitoxins prepared against other clostridia; Escherichia coli, and Vibrio cholerae toxins. These characteristics were identical to those of a toxin implicated in the aetiology of antibiotic-induced colitis in the hamster. One patient improved rapidly after treatment with oral vancomycin, and at the same time the toxin disappeared from the stool.

Adolescent↗

The relative proliferation index as a more sensitive parameter for evaluating lymphoproliferative responses of cancer patients to mitogens and alloantigens.

Lymphocyte proliferation (LP) assays were performed in microculture using the T-cell mitogens phytohemagglutinin (PHA) and concanavalin A (Con A); the T + B cell mitogens, pokeweed mitogen (PWM) and staphylococcal phage lysate (SPL); and a pool of allogeneic stimulating leukocytes in one-way mixed leukocyte cultures (MLC) in lung and breast cancer patients and normal individuals. The resultant data were expressed in three different ways: (1) as mean counts per minute (CPM) of tritiated thymidine incorporation; (2) as a stimulation index (SI) and (3) as a relative proliferation index (RPI). The RPI is defined as the ratio of net CPM (nCPM) in experimental cultures with stimulant (E) minus medium control cultures (C) of a test individual to the mean nCPM of three or more normal individuals examined in the same assay on the same day. These expressions were then compared for their ability to discriminate between LP responses in cancer patients and normal individuals. The RPI value and selected cut-off values gave the most sensitive measure for the determination of depressed proliferative responses. These analyses demonstrated that lung carcinoma patients were depressed to PHA (50%), MLC (47%), PWM (43%) and Con A (40%). To a lesser degree, breast carcinoma patients were also depressed to MLC (36%), PHA (31%), PWM (27%) and Con A (19%). Our data indicate that the use of the RPI in the analysis of LP response represents an improved method for detecting impaired response of lymphocytes to general mitogens and alloantigens which can consistently reveal immunosuppression in many cancer patients and may be useful for serial monitoring of individual patients.

Antigens, Bacterial↗

Gastrointestinal side effects of clindamycin and ampicillin therapy.

Hospitalized patients who received clindamycin or ampicillin were evaluated for gastrointestinal side effects for a period of up to six weeks after therapy was discontinued. Of 104 patients receiving clindamycin therapy, 31 (29.8%) developed diarrhea, and two (1.9%) developed pseudomembranous colitis (PMC). Of 138 patients receiving ampicillin, 24 (17.3%) developed diarrhea, and one (0.7%) developed PMC. Diarrhea persisting for three days or more was noted in 13 (12.5%) of the patients receiving clindamycin and in seven (5.1%) of those receiving ampicillin. The tendency to develop diarrhea was positively correlated with serious illness, abdominal or pelvic sepsis, and total dosage of clindamycin. Examination of stools from a patient with PMC that was associated with clindamycin therapy showed a decrease in the number of anaerobic bacteria from the numbers found in stool cultures of normal controls. Those patients who did not develop diarrhea also had fewer anaerobic bacteria and coliform organisms. Lymphocytes from the patient with PMC were hyporeactive to phytohemagglutinin and hyperreactive to clindamycin.

Adult↗

Tuberculin-specific transfer factor in dogs.

Five mongrel dogs were sensitized to tuberculoprotein with Freund adjuvant, as determined by responses to tuberculin skin tests and by in vitro lymphocyte cultures. These animals served as blood donors for production of transfer factor. Nine mongrel dogs received single doses of transfer factor that was tuberculin specific. Successful transfer of tuberculin sensitivity as measured by lymphocyte transformations was achieved in five of nine animals. Canine lymphocyte cultures frequently showed relatively low transformations to mitogens as compared with responses noted in other animals. Dissociation between skin test reactivity and in vitro lymphocyte transformation to tuberculoprotein was noted in two of nine animals. Increases in lymphocyte transformations to phytochemagglutinin were seen in three of nine recipient animals after transfer factor administration. Successful transfer from an animal sensitized by prior transfer factor administration was achieved in one instance. These data indicate that transfer factor-like substances are present in dogs. The reasons why successful transfer was achieved in only half of the recipient animals needs further explanation.

Animals↗

Pulmonary phycomycetoma in a patient with diabetes mellitus.

Phycomycetes are ubiquitous saprophytic fungi sharing with other fungi a propensity for invasion and disease production in immunologically compromised hosts. Diabetes mellitus, in particular diabetic ketoacidosis, is a common clinical setting for phycomycosis. A pulmonary phycomycetoma was diagnosed in a diabetic patient from material obtained by bronchial brushing was treated successfully with a combination of surgery and amphotericin B.

Diabetes Complications↗

Aanerobic isolates in hemovac lines.

Seventeen of 68 patients (25 percent) who required the use of hemovac drainage system after major head and neck procedures had positive anaerobic islates. Co-isolation of aerobic (94 percent) and other anaerobic (29 percent) microorganisms are common. There was an increased rate of psoitive anaerobic islates with procedures requiring exposure of mucosa. Radiotherapy, except in doses greater than 6,800 rads, did not affect the culture rate. Eight of 17 patients (47 percent) with positive anaerobic isolates had infectious-related complications while five of 51 patients (10 percent) with negative cultures had similar complications. Positive anaerobic isolates in hemovac lines can be correlated with pathogens isolated from subsequent complications.

Adult↗

Antibiotic agranulocytosis: association with cephalothin and carbenicillin.

A 65-year-old woman developed agranulocytosis on two separate occasions following prophylactic administration of antibiotics before cardiac surgery. In the first leukopenic episode, large doses of cephalosporin derivatives were the only drugs implicated, and in the second, carbenicillin was believed responsible. Life-threatening septicemia occurred with Pseduomonas aeruginosa and later with Escherichia coli. Erythrocytes, platelets, and lymphocytes were not affected during these granulocytopenias. Bone marrow examination revealed an arrest of maturation in the granulocytic series. Review of the hematologic complications of cephalosporins, particularly agranulocytosis, suggests an interesting association between carbenicillin-induced neutropenia and previous administration of cephalosporins.

Aged↗

Nosocomial outbreak of Candida parapsilosis fungemia related to intravenous infusions.

Candida parapsilosis is rarely isolated from blood cultures. Our hospital surveillance detected an increased rate of isolation of C parapsilosis during a four month period. Fourteen postoperative patients receiving intravenous (IV) hyperalimentation and eight burn patients receiving IV albumin were involved. Hectic fever, the major clinical manifestation, was seen in 61% of cases. Therapy in the postoperative patients consisted merely of discontinuing IV catheters and hyperalimentation, while amphotericin B was needed in five of eight burn patients to control persistent fungemia. Epidemiologic analysis identified a source of the organism in the IV-additive preparation room where C parapsilosis was found contaminating a vacuum system. Organisms apparently refluxed into IV bottles when aliquots were removed to accommodate additives. Of 103 patients who received fluids prepared with the contaminated system, 21% became infected with C parapsilosis. Infection surveillance was instrumental in detection and control of the outbreak. Routine guideline should be established to insure the sterility of IV fluids containing additives.

Adult↗

Therapy of Pseudomonas aeruginosa infections with tobramycin.

The efficacy of tobramycin in doses of 2.7 to 5.6 mg/kg per day in 29 courses of therapy in 25 hospitalized patients with serious Pseudomonas aeruginosa infections was studied. Eighty-three percent of the P. aeruginosa strains showed zones of inhibition of 16 mm or more around a 10-mug tobramycin disk in the Bauer-Kirby disk method. Tobramycin minimal inhibitory concentration ranged from <0.05 to 1.5 mug/ml (microtiter twofold dilution method); for gentamicin they ranged from 0.05 to 6.2 mug/ml; corresponding geometric means were 0.19 and 0.49 mug/ml. Therapy was given for a median of 10 days (mean 19, range 1 to 83). The clinically satisfactory response rate for the 29 courses of therapy was 52%: critically ill, 44%; seriously ill, 50%; moderately ill, 80%. The response rates for various sites of infection were bone and cartilage, 100%; urinary tract infection, 56%; wound, 50%; respiratory tract, 67%; septicemia, 40%; abscess, 0%; burns, 44%. No adverse reactions were seen. Serum concentration (mug/ml +/- standard deviation) of tobramycin determined by an agar-well plate method, were 4.81 +/- 2.17 (1 h); 3.24 +/- 1.43 (2 h); 2.35 +/- 1.30 (4 h); and 1.40 +/- 1.09 (8 h). Tobramycin appears to be as effacacious as gentamicin in the treatment of serious P. aeruginosa infections and has a theoretical advantage of lower minimal inhibitory concentration for P. aeruginosa. The data suggest that, for life-threatening infections, dosages of tobramycin may need to be increased over those used in this study.

Adolescent↗

Neisseria meningitidis: a cause of nosocomial pneumonia.

A 24-year-old man developed coma and many neurologic abnormalities for 2 weeks after ingesting phencyclidine. On admission, pulmonary aspiration occurred, for which he was given large doses of methylprednisolone, clindamycin, and gentamicin. These antimicrobial drugs were continued for 2 weeks until new pulmonary infiltrates were recognized. Neisseria meningitidis was subsequently isolated from cultures of conjunctival discharge, sputum, and blood and found to be resistant to clindamycin and gentamicin. N. meningitidis as a cause of nosocomial pneumonia in the setting of broad spectrum antimicrobial drugs is discussed.

Adult↗

Quantitative nitro blue tetrazolium test in febrile patients. Correlation with diagnosis and bacterial activity of leukocytes.

The quantitative nitro blue tetrazolium (NBT) test did not show increased NBT reduction in bacterial infections as frequently as has been reported with the qualitative NBT test in untreated infections. Lower than normal values were seen in septic shock and bacterial endocarditis, and normal results were seen in most other bacterial infections. Increased NBT reduction was seen with reticulum cell sarcoma, Hodgkin disease, postoperative wound infections, and upper respiratory tract infections. Thus, the quantitative NBT was of little use in diagnosis of acute infections. The correlation between quantitative tests and tests of bactericidal capacity of leukocytes was poor. These data suggest that NBT reduction and bactericidal activity are dissociative events within phagocytes. Patients with low NBT results usually had bactericidal activity within normal limits.

Adult↗