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Biomedical subjects

S Kohl

Publications and source records attributed to S Kohl.

At least 145 records · Page 8Linked to original sources
PubMed1980

Ontogeny of murine cellular cytotoxicity to herpes simplex virus-infected cells.

Mice infected with herpes simplex virus either orally or intraperitoneally had a markedly age-related mortality. All animals under 3 weeks of age died, whereas all those over 3 weeks of age survived. The ability of murine peritoneal cells to kill herpes simplex virus-infected target cells in the absence (natural killer cytotoxicity) or presence (antibody-dependent cellular cytotoxicity) of antiviral antibody was similarly correlated with age and survival. This correlation is further support for the relevance of these antiviral defense mechanisms, and it may help explain the profound susceptibility of neonatal mice to herpes simplex virus infection.

Age Factors↗
PubMed1980

The relationship between maternal hypertensive disease of pregnancy and the incidence of idiopathic respiratory distress syndrome.

The relationship between maternal hypertensive disease of pregnancy (HDOP) and idiopathic respiratory distress syndrome (IRDS) was analyzed in 2,105 premature infants weighing between 1,000 and 2,199 gm and born between January 1968 and December 1975 at the Kings County Hospital Center and State University Hospital. HDOP was diagnosed in 250 mothers of 2,105 infants studied. The incidence of IRDS (15.2%) in the HDOP group was significantly lower than the 29.9% in the non-HDOP group (P less than .001). In infants whose gestational age was 32 weeks or less, the incidence of IRDS was 26.1% in the HDOP group and 40.8% in the non-HDOP group (P less than .01). In infants whose gestational age was 33 weeks or more, the incidence (9.3%) in the HDOP group was significantly lower than the 18.4% in the non-HDOP group (P less than .005). The low incidence of IRDS in the HDOP group remained even after eliminating infants with known predisposing and protecting factors from the development of IRDS. The incidence of IRDS was inversely related to the severity of maternal toxemia. The total mortality and mortality with IRDS were not significantly different in both HDOP and non-HDOP groups. When the infants did not develop IRDS, the mortality rate in the HDOP group was significantly higher than that in the non-HDOP group especially in the lower gestational age group. These data suggest that chronic stress accelerates fetal lung maturation and severe chronic stress is even more effective in accelerating fetal lung maturation. When maternal toxemia was severe enough to accelerate the fetal lung maturation, the mortality rate of the infants without IRDS increased.

Female↗
PubMed1979

Current concepts of bacteremia in children with malignancies.

One hundred fifteen episodes of bacteremia occurred among 2790 children with malignancies hospitalized during a 45-month period. The mean age was 9.3 years with a male predilection (62%). A greater (p less than .025) number of children over 10 years of age died with bacteremia when compared to younger children. The majority of episodes occurred in children with leukemia (56%); however, once bacteremia developed, a significantly (p less than .05) greater number of children with lymphoma died when compared to children with other malignancies. Absolute polymorphonuclear leukocyte counts were greater in survivors (p less than .025) than in children who died. Thirty-seven different microorganisms were isolated with E. coli, S. Aureus, P. aeruginosa, and K. pneumoniae accounting for 50% of the episodes. Anaerobes were isolated from blood of 12 (10%) children. Twelve children had polymicrobial bacteremia and 14 had recurrent bacteremia which occurred during antibiotic therapy. Mortality (78%) in these children was significantly (p less than .001) greater then in children from whom one microorganism was isolated (47%). Interesting aspects include the resurgence of S. aureus, failure of development of meningitis in children with bacteremia, and unchanged antibiotic susceptibility since the last review of bacteremia in this institution. Polymicrobial and recurrent bacteremia necessitate obtaining simultaneous and sequential blood cultures to facilitate administration of appropriate antimicrobial therapy until bone marrow function improves.

Adolescent↗
PubMed1979

Multiple-dose amikacin kinetics in pediatric oncology patients.

Amikacin kinetics was studied in 8 pediatric oncology patients who received the drug by intravenous infusion over 30 or 60 min at a dose of 5 mg/kg every 6 or 8 hr. This regimen is recommended but, due to patient variability, patients should be monitored. Dosing intervals during 1 or 2 and 3 or 4 days of therapy were studied with serum samples collected before and at the end of the infusion and serially to the end of the dosing interval. The data appeared consistent with and were analyzed according to 1-compartment model. An equation describing serum concentration with time for the multiple-dose case was fit to each patient's multiple-interval data with nonlinear regression. Half-life averaged 1.2 hr. volume of distribution 0.24 l/kg, and total body clearance 109 ml/min/1.73 m2 or 2.51 ml/min/kg. The volume of distribution and the clearance are greater than reported for adults and probably account for the larger dose needed to achieve and maintain therapeutic levels. Although the total daily dose was greater than previously reported, there were no signs of toxicity, although therapuetic concentrations were maintained.

Adolescent↗
PubMed1979

Human rotavirus in an adult population with travelers' diarrhea and its relationship to the location of food consumption.

The role of human rotavirus in adult diarrhea was evaluated in 164 newly arrived US students attending summer school at an urban Mexican university. Rotavirus was identified in stool samples by electron microscopy. Rotavirus was found in 26 of 109 students with diarrhea (24%) and in 8 of 55 asymptomatic control students (15%). Although bacterial pathogens were recovered from virus positive students with diarrhea, viral shedding also occurred independently of other agents. Clinical disease in students excreting only rotavirus tended to be mild and was accompanied by a low density of viral shedding. Food consumption in the home and at public eating establishments was examined the week before illness. While the location of food consumption was found to be important in the acquisition of diarrhea, there was no apparent relationship of the site where meals were eaten and the acquisition of rotavirus by students newly arrived in Mexico. These data support our previous study in a US student population residing in a rural setting in Mexico and implicate rotavirus as a cause of diarrhea among students traveling to Mexico from the United States. The present study offers additional evidence that rotavirus infection in this population might be spread by a nonfood vehicle of transmission which differs from spread of enterotoxigenic E coli, Shigella, or Salmonella strains in the same population.

Adolescent↗
PubMed1979

Inhibition of human monocyte-macrophage and lymphocyte cytotoxicity to herpes simplex-infected cells by glucan.

The effect of short term in vitro incubation of glucan--a reticuloendothelial system stimulator--on subsequent cytotoxicity of human monocyte-macrophages (MP) and lymphocytes (L) to Herpes simplex virus-infected cells in a 51Cr-release assay was analyzed. Particulate, cell-associated glucan irreversibly inhibited MP antibody-dependent cellular cytotoxicity (ADCC). In contrast, the inhibition of L-ADCC and L-natural killer cytotoxicity could be reversed by dissociation of glucan and cells utilizing serum gradient centrifugation, a process which did not remove the glucan. These experiments reveal further basic differences between MP and L-ADCC using the reagent glucan.

Cytotoxicity, Immunologic↗
PubMed1979

Yersinia enterocolitica infections in children.

Y. enterocolitica has been increasingly associated with a wide range of age-related clinical manifestations in children and adults, including febrile gastroenteritis, pseudoappendicitis, arthritis, sepsis, and focal suppurative disease. Although definite patterns of incidence, prevalence, transmission, and pathophysiology are emerging, much remains to be explained. The alert clinician who notifies his clinical laboratory colleagues that special isolation techniques are required to recover this organism from stool samples, and who submits mesenteric lymph nodes for bacteriologic examination in cases of mesenteric adenitis, will aid attempts to further delineate the significance of this emerging pathogen in the United States. Therapy depends on the form and severity of illness and must be guided by in vitro sensitivity, pending animal and epidemiologic studies.

Animals↗
PubMed1979

Enhancement of nitroblue tetrazolium dye reduction by leucocytes exposed to a factor released from sensitised lymphocytes.

Leucocytes from purified protein derivative (PPD) skin test positive individuals, after exposure to PPD in vitro, show a significant increase in nitroblue tetrazolium (NBT) dye reduction when compared to leucocytes from PPD negative donors. The active principle was shown to be soluble, and was released from lymphocytes after a rapid, immunologically specific interaction with the sensitising antigen.

Cells, Cultured↗
PubMed1979

Amikacin pharmacokinetics in pediatric patients with malignancy.

The pharmacokinetics of amikacin were evaluated in 50 pediatric patients (1 to 17 years of age) with malignancies and normal renal function. Dosage regimens of 5 mg/kg per dose were administered intravenously (i) over 30 min every 8 h, (ii) over 60 min every 8 h, and (iii) over 60 min every 6 h. Administration of amikacin over 30 min produced concentrations in serum of 29.3 +/- 5.7 micrograms/ml at the end of the infusion and subtherapeutic concentrations 4 h after the infusion. The regimen of 20 mg/kg per 24 h, divided into doses given every 6 h infused over 60 min, achieved concentrations in serum at the end of the infusion of 17.2 +/- 1.7 micrograms/ml and at 6 h of 1.2 +/- 0.3 microgram/ml. The serum half-life was 1.24 +/- 0.09 h, volume of distribution was 0.26 +/- 0.02 liter/kg, and total body clearance rate was 131 +/- 10 ml/min per 1.73 m2. No accumulation of amikacin was noted, and no significant side effects could be attributed to the drug. This study suggests that the optimal initial dosage regimen of amikacin in children is 20 mg/kg per 24 h administered in equal doses every 6 h over 60 min; however, optimal therapy requires individualization of dosage based on measured serum concentrations and susceptibility data on bacterial pathogens isolated.

Adolescent↗
PubMed1979

Murine antibody-dependent cellular cytotoxicity to herpes simplex virus-infected target cells.

Freshly collected peritoneal cells (PC) and cultured spleen cells (SC) (but not fresh SC) from nonimmune mice could mediate antibody-dependent cellular cytotoxicity (ADCC) against herpes simplex virus (HSV)-infected cells in the presence of mouse or human sera containing antibody to HSV. PC also demonstrated variable natural killer cell cytotoxicity to infected cells. Both PC and cultured SC required high concentrations of antibody and high effector to target cell ratios for optimal ADCC. The time kinetics of the reaction appeared to depend on the state of activation of the effector cells. In both PC and SC populations, ADCC activity was limited to adherent cells, and was profoundly inhibited by particulate latex or silica. The murine effector cell found in PC and SC able to mediate ADCC to HSV-infected cells appears to be a macrophage.

Animals↗
PubMed1978

Effect of chemotherapeutic agents on metabolic and bactericidal activity of polymorphonuclear leukocytes.

Blood was obtained on 36 occasions from 12 healthy adult volunteers and the polymorphonuclear leukocytes (PMNL) were separated. PMNL hexose monophosphate shunt activity of whole blood and ability of separated cells to phagocytize and kill E. coli were evaluated when the PMNL were incubated with normal pooled sera and sera containing therapeutic concentrations of either 15 cancer chemotherapeutic drugs singly and in combination or 9 antibiotics. Resting and stimulated HMPS activity was significantly (p less than 0.025 to p less than 0.001) decreased by cyclophosphamide, carmustine (BCNU), high dose prednisone (pred), vinblastine (vinbl) and vincristine (vinc) and significantly (p less than 0.025 to p less than 0.01) increased by combinations of vinc-pred, vinc-predasparaginase, 6-mercaptopurine (6MP)-methotrexate (Mtx) and 6MP-Mtx-pred when compared to controls. No significant differences in HMPS activity of PMNL were found when exposed to various antimicrobial agents singly or in combination. The killing of E. coli by PMNL was significantly (p less than 0.001) decreased when exposed to BCNU, high concentration pred or combinations of 6MP-Mtx-pred, 6MP-Mtx and vinc-vinbl-pred but not when exposed to other chemotherapeutic agents. This study shows a disparity in results obtained when evaluating PMNL function by HMPS activity and bactericidal assay. In addition, a functional impairment in PMNL exposed to various antimetabolites occurred at a time when they exhibited normal morphology.

Anti-Bacterial Agents↗
PubMed1978

Human neonatal and maternal monocyte-macrophage and lymphocyte-mediated antibody-dependent cytotoxicity to cells infected with herpes simplex.

We recently have described destruction of cells infected with herpes simplex virus by the combination of specific antibody and either lymphocytes or monocyte-macrophages. Because of the role of these cells in viral immunity and the severity of HSV in neonates and pregnant women, cord blood from 11 healthy neonates and peripheral blood from seven of their postpartum mothers were analyzed for MP and lymphocyte antibody-dependent cellular cytotoxicity against cells infected with HSV. Cord blood yielded more lymphocytes and maternal blood fewer lymphocytes than did blood from adult female control subjects. Baseline cytotoxicity of cord MP and lymphocytes and maternal lymphocytes was significantly lower than control values. There was no significant difference in MP or lymphocyte ADCC, although maternal ADCC tended to be lower than that of control subjects. Analysis of cord plasma indicated that antibody able to participate in lymphocyte and MP ADCC crosses the placenta. These data demonstrate intact ADCC but possible defects in baseline cytotoxicity with leukocytes obtained from neonates and pregnant women. Further consideration of the use of HSV antibody for prevention and therapy of neonatal HSV infection is suggested.

Antibodies, Viral↗
PubMed1978

Prospective study of enteropathogens in children with diarrhea in Houston and Mexico.

During a 22-month period, 595 children with diarrhea and 210 age-matched controls attending clinics in Houston (367 children) and Mexico (438) were prospectively evaluated for enteric pathogens. Enteropathogens associated with disease were Shigella (18%), rotavirus (14%), Salmonella (9%), toxigenic Escherichia coli (6%), and others (12%), including 14 Proteus isolates that caused rounding of adrenal cells. Enteropathogens were isolated from a greater (P less than 0.001) number of children with diarrhea (59%) than from asymptomatic controls (6%). Paired sera tested for antibody to heat-labile toxin of E. coli rarely demonstrated a fourfold rise during episodes of diarrhea. This study demonstrates: (1) more striking illness in children from Mexico; (2) more common occurrence of Shigella in Houston, and of rotavirus and Salmonella in Mexico; (3) lack of seasonal occurrence of rotavirus isolation in either population and a summertime occurrence of Shigella in Houston; (4) lack of toxigenic E. coli isolation in endemic diarrhea of either population; and (5) a significant (P less than 0.001) age-related acquisition of E. coli LT antibodies.

Antibodies, Bacterial↗
PubMed1978

Yersinia enterocolitica: a significant 'new' pathogen.

It thrives in the cold, defies conventional culture methods, does not respond to most antibiotics, and may mimic other disorders in its manifestations. Fortunately, most cases of yersinial enterocolitis are mild and self-limiting, but infection can be life-threatening, especially in neonates or when immunologic defenses are impaired. Clinical and laboratory diagnostic criteria and epidemiologic clues are described.

Adult↗