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Biomedical subjects

J F Warner

Publications and source records attributed to J F Warner.

36 records · Page 2Linked to original sources

T cells may express multiple activities: specific allohelp, cytolysis, and delayed-type hypersensitivity are expressed by a cloned T-cell line.

A T-cell line that recognizes private specificities encoded in the H-2 IA subregion in the proliferative response, cytotoxic activity, delayed-type hypersensitivity, and allohelp reaction with B cells has been cloned. The individual clones were assayed for ability to express the activities of the parent line. Results show that the cloned sublines tested are able to perform all the activities of the parent line. It is suggested that T cells may express multiple activities and that the apparent monofunctionality of T cells is due to regulation of these activities.

Animals↗

A comparison of amphotericin B alone and combined with flucytosine in the treatment of cryptoccal meningitis.

We compared amphotericin B therapy for cryptococcal meningitis with a newer regimen containing both amphotericin B and flucytosine. In 50 patients with 51 courses of therapy adherent to the protocol, 27 courses were with amphotericin B and 24 with the combination. Even though the combination regimen was given for only six weeks and amphotericin B for 10 weeks, the combination cured or improved more patients (16 vs 11), produced fewer failures or relapses (three vs. 11), more rapid sterilization of the cerebrospinal fluid (P less than 0.001) and less nephrotoxicity (P less than 0.05) than did amphotericin B alone. The number of deaths was the same (five) with each regimen. Adverse reactions to flucytosine occurred in 11 of 34 patients but were not life threatening. We conclude that combined flucytosine-amphoericin B therapy is the regimen of choice in cryptococcal meningitis.

Adolescent↗

Metronidazole therapy of anaerobic bacteremia, meningitis, and brain abscess.

Four patients with Bacteroides fragilis bacteremia, one patient with a brain abscess due to Bacteroides species, Fusobacterium naviforme, and Peptostreptococcus species, and an infant with Bacteroides species ventriculitis and meningitis were treated with metronidazole. In all cases the anaerobic pathogens were eradicated. Five of the six patients recovered. One patient with leukemia in whom B fragilis bacteremia was eradicated by metronidazole treatment subsequently died of Pseudomonas aeruginosa bacteremia. Ventricular fluid and serum concentrations of metronidazole were determined in the case of meningitis and are reported.

Adult↗

F1 hybrid anti-parental H-2k cell-mediated lympholysis. I. Stimulator and target determinants controlled by the H-2K region.

H-2k-heterozygous F1 hybrid mouse spleen cells cultured with irradiated H-2k-homozygous stimulator cells generated specific anti-parent cytolytic effectors. The parental antigenic determinants recognized by responder cells during induction (afferent arm) and by effector cells during cytolysis (efferent arm) were coded for, or regulated by, the H-2K-Hh3 region of the MHC, according to recombinant analysis. There were no detectable influences by other linked or unlinked genes on the phenotypic expression of parental antigens; however, the anti-parent responsiveness was modulated by background genes of responder cells. These experiments establish that the K end of H-2 controls determinants of F1 anti-parental H-2k CML, like the D end controls those of F1 anti-parental H-2b CML, thus confirming the basic symmetry of the H-2 complex. The relationship of this primary in vitro cell-mediated response with natural in vivo resistance to parental and allogeneic bone marrow grafts is discussed.

Animals↗

Effects of Fusobacterium necrophorum leukotoxin on rabbit peritoneal macrophages in vitro.

A method to demonstrate leukotoxic activity of Fusobacterium necrophorum in vitro is described. Continuous dialysis sac culture system, using reduced liquid medium was used to grow F necrophorum for 7-day periods. The continuous culture dialysis filtrate contained leukotoxic substance(s) which appeared to be less than 10,000 in molecular weight, heat resistant, and stable at 4 C for at least 10 days. Leukotoxic activity was demonstrated in vitro by determining the percentage of macrophages taking up trypan blue dye after these were exposed to a 1:2 solution of continuous culture dialysis filtrate and Eagle's minimal essential medium at 1, 2, 4, and 6 hours. Approximately 90% of these macrophages were destroyed during the 6-hour incubation period.

Animals↗

Nafcillin treatment of Staphylococcus aureus meningitis.

Serial serum and cerebrospinal fluid nafcillin concentrations were determined in a patient successfully treated with nafcillin (200 mg/kg per day) for Staphylococcus aureus bacteremia and meningitis. Nafcillin and methicillin cerebrospinal fluid concentrations were compared.

Aged↗

Therapy of cryptococcosis with a combination of flucytosine and amphotericin B.

In a prospective study from May 1971 to November 1973, 20 consecutive patients with a diagnosis of disseminated cryptococcosis were treated for six weeks with a combination of amphotericin B (20 mg daily) intravenously and flucytosine (150 mg/kg daily) orally. Fifteen patients has culturally docummented Cryptococcus neoformans meningitis, and three died of infection early in therapy. Of the remaining 12 patients, eight were alive and well eight to 34 months after therapy, and four died of other causes. None of the surviving patients has relapsed. Hematologic complications developed in nine patients, three of whom had no underlying lymphoreticular disorder or therapy with known cytotoxic agents. Renal insufficiency of mild degree occurred in only six patients. A shorter period of hospitalization and reduction in toxicity of amphotericin B suggest that combined therapy is a safe and efficacious alternative to other regimens.

Adult↗

Endotoxin from Fusobacterium necrophorum of bovine hepatic abscess origin.

The endotoxic activity of Fusobacterium necrophorum bov 5 was investigated. The supernatant (S) fluid and cell wall (CW) preparation, obtained after differential centrifugation of the ruptured cell mass, were lethal for mice. The toxicity of the S fluid was stable during prolonged storage, treatment with formalin, and heating for 15 minutes at 80, 100, and 121 C, but was destroyed by alkaline hydrolysis with 0.25 N NaOH. The toxic factor was found in a high molecular weight (MW) fraction after gel filtration. The properties exhibited by the toxic S fluid resembled those of endotoxic lipopolysaccharide (LPS). Extracted and partially purified LPS (endotoxin) from F necrophorum bov 5 demonstrated a mouse median lethal dose (mouse LD50) of 16.8 mg/kg of body weight. The toxic LPS material, a high molecular weight moiety as estimated by gel filtration, was resistant to ribonuclease (RNase), deoxyribonuclease (DNase), and pronase treatment. A positive Shwartzman reaction (median skin lesion dose (SLD50) equal to 3.32 mug/kg of body weight) and biphasic fever response (minimal dose required to produce a fever index of 40 sq cm which falls on the linear portion of dose-response curve (FL40) equal to 0.41 mug/kg of body weight) further indicated the toxin was endotoxin in nature. The LPS from F necrophorum bov 5 was less toxic than Salmonella typhimurium LPS; but had considerable toxicity for experimental animals. The toxic activity of the partially purified F necrophorum bov 5 endotoxin was separated into 2 fraction regions by diethylaminoethyl (DEAE)-cellulose chromatography. The data provide evidence for the production of a potent endotoxin, possibly composed of more than one toxic component, which may be released upon cell disruption.

Animals↗

Morphological alterations of Pseudomonas aeruginosa by ticarcillin: a scanning electron microscope study.

Pseudomonas aeruginosa was exposed to 0.1, 1.0, 10, 100, and 1,000 times the minimal inhibitory concentration of ticarcillin in vitro and subsequently examined with the scanning electron microscope. The morphological alterations observed were filamentation, mid-cell defects, and spheroplast formation, and these alterations were dependent upon the drug concentration.

Carboxylic Acids↗

Therapy of skin, soft tissue, and bone infections with cefoxitin sodium.

Twenty-seven patients with skin and soft tissue infections, including three with contiguous osteomyelitis, were given cefoxitin intravenously or intramuscularly; the infections of 25 (93%) were resolved with cefoxitin therapy. Etiologic agents included staphylococci, streptococci, Enterobacteriaceae, and anaerobes. Susceptible pathogens were inhibited by less than or equal to 8 micrograms of cefoxitin/ml. This level of drug was surpassed by mean peak serum concentrations eight- to 12-fold after intravenous infusions and two- to threefold after intramuscular injections and resulted in eradication of susceptible organisms from lesions during treatment. Intravenously administered cefoxitin was well tolerated, although eosinophilia, phlebitis, elevation of levels of hepatic enzymes, and a positive direct Coombs' test were observed. Intramuscular injections of cefoxitin in 0.5% lidocaine caused pain and induration and thus were poorly tolerated.

Abscess↗

Infected subfural hematoma: three case reports involving gram-negative organisms.

Three case reports of infected subdural hematoma are presented, two with Salmonellae and one with Escherichia. Infection of such hematomas most often occurs during bacteremia, and the area of infection is limited by the existing hematoma membrane. Clincally, fever, headache, nuchal rigidity, and focal neurological signs, especially in a patient with previous head trauma, suggest subdural infection. Treatment consists of drainage and systemic antibiotics. These case reports demonstrate the clinical features of this rarely reported entity, and especially illustrate the need for careful bacteriologic identification in suspected cases.

Adult↗