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Biomedical subjects

M D Yow

Publications and source records attributed to M D Yow.

At least 37 records · Page 2Linked to original sources
PubMed1984

Use of deglycerolized red blood cells to prevent posttransfusion infection with cytomegalovirus in neonates.

In an effort to reduce the rate of posttransfusion infection with cytomegalovirus (CMV), 157 CMV-seronegative neonates were given deglycerolized red blood cells as their only source of red blood cells. Other blood products given to these patients received no special preparation. The 106 (67.5%) infants available for adequate evaluation received an average of 5.7 units (range, one to 39 units). Three hundred thirteen (51.4%) of the 609 transfused units were CMV-seropositive. When evaluated three months after their last transfusion, none of the 106 infants had virological or serological evidence of CMV infection. These results suggest that regardless of the serological status of the donor, deglycerolized red blood cells can reduce or possibly eliminate posttransfusion CMV infection and can serve as a safe alternative to CMV-seronegative blood. Freezing, depletion, and physical disruption of leukocytes may be responsible for the decreased infectivity of the deglycerolized product.

Birth Weight↗
PubMed1982

Pharmacology of kanamycin in the newborn.

We studied the pharmacologic effects of kanamycin in three groups of newborn infants: group 1--birth weight (BW) less than or equal to 2,000 gm, chronologic age (CA) less than 7 days; group 2--BW greater than 2,000 gm, CA less than 7 days; and group 3--BW greater than 2,000 gm, CA 7 to 28 days. The dose of kanamycin was 15 mg/kg/day, administered in two intramuscular doses. Serum kanamycin levels were measured 15 minutes before the dose and 1/2, 1, 6, and 8 hours after the dose. Infants in group 1 had a mean peak concentration of 18.7 micrograms/ml, those in group 2, 19.6 micrograms/ml, and those in group 3, 15.6 micrograms/ml. The mean peak concentrations varied inversely with chronologic age but were not influenced by birth weight. Mean serum half-life varied inversely with birth weight, gestational age, and chronologic age. We recommend a standard dose of 15 mg/kg/day for newborn infants. Modification of this dose may be required for individual infants.

Age Factors↗
PubMed1982

Adherence of Haemophilus influenzae to buccal epithelial cells.

The role of adherence of Haemophilus influenzae to epithelial surfaces in the pathogenesis of infection is unknown. Fluorescent-antibody and radiolabeled adherence methods were adapted to study H. influenzae adherence to human buccal epithelial cells. By the fluorescent-antibody method, 19 of 21 (90%) nontypable H. influenzae strains were found to be adherent compared with 2 of 42 (5%) type b strains (P less than 0.0001). Using a radiolabeled adherence method, we found that 9 of 12 (75%) nontypable H. influenzae strains were adherent to buccal epithelial cells whereas only 3 of 32 (9%) type b strains were adherent (P = 0.001). Results of H. influenzae adherence examined by both methods correlated significantly (P = 0.01). H. influenzae adherence to adult pharyngeal, nasal, and buccal epithelial cells was comparable. Type b H. influenzae did not adhere to the buccal epithelial cells of well children, children with H. influenzae type b disease, or children with upper respiratory infections. In contrast, nontypable H. influenzae did adhere to the buccal epithelial cells of well children and children with upper respiratory infections. These observed in vitro differences in adherence between nontypable and type b H. influenzae strains may explain differences in colonization, pathogenesis, and types of infection due to nontypable and type b H. influenzae.

Adhesiveness↗
PubMed1982

Use of restriction enzymes to investigate the source of a primary cytomegalovirus infection in a pediatric nurse.

The risk of transmission of cytomegalovirus (CMV) infection from congenitally infected infants to nonimmune medical attendants is unknown. The case of a CMV-seronegative, pregnant nurse who seroconverted after caring for an infant with symptomatic CMV infection is reported. She elected to be aborted and the fetal tissue contained CMV. Isolates from the nurse, the fetal tissue, and the infant to whom the nurse was exposed were examined for genetic relatedness by restriction enzyme analysis. As expected, the isolates from the nurse and the fetal tissue were identical. However, the virus isolated from the symptomatic infant was different from the strain infecting the nurse. These data indicate that the nurse acquired her infection from a source other than the index infant, either within the hospital or within the community.

Abortion, Therapeutic↗
PubMed1980

The natural history of group B streptococcal colonization in the pregnant woman and her offspring. I. Colonization studies.

A longitudinal study of colonization by group B streptococcus (GBS) was conducted in 93 pregnant women and 92 of their infants. Positive cultures were obtained from vaginal swab specimens on at least one occasion during pregnancy from 20.4% of the women. Three types of carriage were observed: chronic, transient, and intermittent. At the time of delivery, 12.9% of the mothers were colonized by GBS. GBS colonization occurred in 41.7% of the infants of the mothers colonized intrapartum. Only 1.2% of infants intrapartum culture-negative mothers were colonized. Infants colonized at birth were culture negative by 4 months of age. This study suggests that interruption of vertical transmission of GBS from mother to infant not only would influence the incidence of early-onset GBS disease but also might reduce the incidence of late-onset GBS disease.

Adolescent↗
PubMed1980

The natural history of group B streptococcal colonization in the pregnant woman and her offspring. II. Determination of serum antibody to capsular polysaccharide from type III, group B Streptococcus.

An investigation of the prevalence and persistence of the concentration of antibody to capsular polysaccharide from type III, group B Streptococcus in sera from 93 pregnant women and their newborn infants is reported. In the majority of women, the concentrations of antibody detected in the sera were low (less than 1 microgram/ml). However, sera from women who were colonized with type III strains of group B streptococci contained significantly higher concentrations of antibody than those from noncolonized women (p = 0.027). No appreciable change in antibody concentration was found in sera collected early in gestation when compared to delivery sera. When maternal-cord serum pairs were analyzed, a significant correlation between concentrations of antibody was found, which indicates that this antibody is transplacentally transferred.

Antibodies, Bacterial↗
PubMed1980

Community acquisition of group B Streptococcus by infants of colonized mothers.

Forty-six infants of women known to be colonized by group B Streptococcus (GBS) during the third trimester of pregnancy were not colonized by GBS at the time of discharge from the hospital nursery. At 6 to 8 weeks of age, two of these infants (4.3%) were found to harbor GBS. The rate of community acquisition of GBS by uncolonized infants appears to be low.

Female↗
PubMed1979

Failure of penicillin to eradicate group B streptococcal colonization in the pregnant woman. A couple study.

Prophylactic treatment of couples with oral penicillin has been recommended as a means of eradicating GBS from the parturient female. In 1977 and 1978 this hypothesis was tested in an investigation of couples from a middle and upper socioeconomic group in Houston, Texas. A group of 40 women, known to be colonized with GBS during the third trimester of pregnancy, and their husbands were treated simultaneously with oral penicillin. Patients were recultured 3 weeks following completion of therapy and at the time of delivery. At the time of delivery 67% of the women remained colonized with GBS. This percentage does not differ substantially from that obtained in a series of untreated colonized women. This study demonstrates that oral penicillin treatment of couples is not an effective means of reducing maternal colonization at the time of delivery.

Delivery, Obstetric↗
PubMed1979

Ampicillin prevents intrapartum transmission of group B streptococcus.

Early-onset group B streptococcus (GBS) disease in the infant is acquired by vertical transmission from the mother colonized with GBS. Thirty-four women colonized with GBS were treated with intravenous ampicillin sodium during labor. None of their infants were colonized with GBS at birth or within 48 hours. Twenty-four women colonized with GBS received no antibiotic therapy; 14 (58%) of their infants were colonized with GBS at birth or by 48 hours. This difference was highly significant. Mechanisms by which this may have occurred were temporary suppression of GBS vaginal and rectal colonization, high concentration of ampicillin in the amniotic fluid, and transplacental transport of the antibiotic to the infant. In areas where GBS disease is prevalent, we recommend screening pregnant women (34 to 36 weeks' gestation) and treating those colonized with GBS (with no history of penicillin hypersensitivity) with intravenous ampicillin during labor.

Ampicillin↗
PubMed1979

Group B streptococcal colonization and antibody status in lower socioeconomic parturient women.

This investigation was undertaken to determine the prevalence of group B streptococcal vaginal and throat colonization among lower socioeconomic pregnant women and the antibody concentration to the capsular polysaccharide antigen of type III group B streptococcus in their sera. Group B streptococci were recovered from 28.6 per cent of the 112 women studied; vaginal colonization was detected in 23.4 per cent, throat colonization in 4.7 per cent, and colonization at both sites in 0.9 per cent of the patients, respectively. Among these isolates of group B streptococci, serotypes III (39.5 per cent) and II (30.3 per cent) predominated. No differences were found between colonized and noncolonized women with respect to age, race, marital status, or parity. The majority of all women studied had low concentration of antibody in serum (less than 1.0 microgram per milliliter). However, women with isolation of type III group B streptococci from cultures at the time sera were collected had significantly higher concentrations than did women without group B streptococci from cultures at the time sera were collected had significantly higher concentrations than did women without group B streptococcal colonization.

Adolescent↗
PubMed1976

Failure of penicillin to eradicate the carrier state of group B Streptococcus in infants.

Serial cultures were obtained from 12 patients being treated with a form of penicillin for group B streptococcal disease or asymptomatic colonization. These cultures were collected prior to initiation of therapy, during therapy, and at the end of the treatment period. Pencillin eradicated GBS from the involved system (blood, CSF, bone, and joint). Cultures remained positive from at least one of three carrier sites (throat, umbilicus, and rectum) in 70% of patients cultured between days one and eight of treatment and 66% between days 10 and 21. These data demonstrate the failure of penicillin to eradicate GBS from mucous surfaces of young infants.

Arthritis↗
PubMed1976

Fulminant neonatal sepsis and necrotizing enterocolitis associated with a "nonenteropathogenic" strain of Escherichia coli.

During 1973 a nonendemic mucoid strain of Escherichia coli entered the nursery of a hospital in Houston. This organism caused septicemia and was associated with a high incidence of necrotizing enterocolitis. The illness was fulminant and characterized by apnea, abdominal distension, and shock. Diarrhea was not a feature of the symptom complex. The epidemic organism was nontypable. Assays for invasiveness, enterotoxin production, and Kl antigen were negative. Surveillance revealed a colonization rate of 14%, an attack rate in colonized infants of 19.5%, and a mortality rate of 87.5%. These data suggest that in certain instances the specific bowel flora may increase the incidence and severity of NEC.

Disease Outbreaks↗
PubMed1976

Prolonged pneumococcal meningitis due to an organism with increased resistance to penicillin.

For more than 30 years, penicillin has been the agent of choice for pneumococcal infections. During this time the majority of strains of Streptococcus pneumoniae have been highly susceptible to penicillin. However, during the last ten years there have been sporadic reports of pneumococci with increased resistance to penicillin. The case report of an 18-month-old white boy with meningitis due to a strain of S. pneumoniae with increased resistance to penicillin is presented. The MIC of the organism to penicillin was 0.2 mug/ml and the MBC 0.39 mug/ml. The patient had normal immunity and no demonstrable sequestered focus of infection but failed to respond to appropriate doses of intravenous penicillin. Treatment with chloramphenicol caused a dramatic bacteriologic and clinical response. This experience reemphasizes the existence of pneumococcal strains of intermediate penicillin sensitivity and the importance of in vitro susceptibility tests.

Humans↗
PubMed1976

A ten-year assessment of methicillin-associated side effects.

The exact incidence and importance of side effects associated with methicillin therapy in children is unknown. During the ten-year period from 1964 to 1974 approximately 3,000 Houston children who received methicillin were observed for side effects. The great majority of these patients received the drug for less than ten days; however, side effects were more common in patients receiving long-term therapy. In order to assess these side effects, experiences with 124 children who received methicillin for ten days or longer were reviewed in depth. The average dose of methicillin was 200 mg/kg/day and the average duration was 22 days. In this highly selected group there were no adverse side effects in 54.8% and only eosinophilia in an additional 13%. Leukopenia occurred in 16%, microscopic hematuria in 8%, gross hematuria in 4%, skin rash in 6%, and "drug fever" in 6%. In many instances several of these side effects occurred within a single patient so that the total number of patients with definite side effects was 39 of 124 (31.5%). The true incidence figure of overall side effects is much lower than 31.5%. Corrected incidence rates based on a conservative figure of 3,000 methicillin-treated children are less than 1.5% for all side effects. In some patients the mechanism producing the adverse reactions seemed to be chemical irritation or toxicity and in others hypersensitivity. In nine of the 39 patients follow-up studies were not optimal. In the other 30 patients all side effects were reversible.

Adolescent↗
PubMed1975

The influence of advancing gestation on group B streptococcal colonization in pregnant women.

An investigation to determine the throat and vaginal colonization rates of group B streptococci among second- and third-trimester pregnant women was performed. Group B streptococci were recovered from 25.4 per cent of third-trimester and 14.8 per cent of second-trimester parturient (p = less than 0.025). Serotype distribution of isolates was similar among these two study groups. No significant differences in colonization rates were noted on the basis of age, race, parity, or complications of pregnancy.However, postpartum fever occurred in 22 per cent of colonized and only 4 per cent of noncolonized second-trimester parturients. The reason for this significant increase in group B streptococcal colonization rates with advancing gestation remains speculative.

Abortion, Spontaneous↗