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Biomedical subjects

W B Karp

Publications and source records attributed to W B Karp.

At least 19 recordsLinked to original sources
PubMed1998

Effect of sodium metabisulfite on hydrogen peroxide production in light-exposed pediatric parenteral amino acid solutions.

The effect of sodium metabisulfite (MBS) on hydrogen peroxide (HP) production in model and commercial amino acid solutions exposed to phototherapy light was studied. Model and commercial pediatric amino acid solutions were prepared such that the amino acid concentration was 1%. MBS concentration, riboflavin concentration, and duration of exposure to phototherapy light were varied to determine the effect on HP production. Control solutions were kept in the dark. HP production was assayed in the model amino acid solutions by using potassium iodide in the presence of ammonium molybdate. In all experiments, HP production was measured at 360 nm in the presence and absence of catalase. In light-exposed solutions, HP production increased linearly for several hours and reached a plateau by eight hours. A mean maximum of 940 microM was produced (data pooled for all solutions). No detectable HP was generated in the solutions kept in the dark. After two hours of light exposure, it was necessary to add at least 10 times more MBS than is typically found in commercial total parenteral nutrient solutions to scavenge all the HP produced. An average of up to 940 microM of HP was produced in model and commercial pediatric parenteral 1% amino acid solutions in the presence of phototherapy light and clinically relevant concentrations of riboflavin and MBS. Light exposure decreased the antioxidant effect of MBS.

Amino Acids↗
PubMed1997

Ventilator management of infants before extracorporeal membrane oxygenation.

The aim of this project was to review the course of infants referred for consideration of extracorporeal membrane oxygenation (ECMO) to identify maximal ventilator settings that, when exceeded, did not provide clinical benefit to the patient. These settings might then be used in defining failure of conventional mechanical ventilation. We reviewed referral records and hospital charts of all infants treated for severe respiratory failure due to meconium aspiration syndrome during the 52.5 month period from March 15, 1985, to August 1, 1989. At an inspiratory pressure > 35 cm H2O, 75% (43/57) of patients eventually required ECMO, and 28% (4/14) of the infants who did not receive ECMO died. When the inspiratory pressure was > or = 40 cm H2O, 39/49 patients required ECMO, and 30% (3/10) of those not treated with ECMO died. Once the inspiratory pressure was > 45 cm H2O, 91% (29/32) of patients required ECMO, and only one third of those not treated with ECMO survived. Although the limitations for conventional therapy suggested in this paper may be helpful to clinicians, each center needs to establish guidelines for maximal conventional ventilator support. If these guidelines are clearly defined, alternative methods of therapy can be used once these criteria are achieved.

Apgar Score↗
PubMed1995

Intrapartum prophylaxis with ceftriaxone decreases rates of bacterial colonization and early-onset infection in newborns.

Because of high rates of neonatal gram-negative sepsis in many Latin American countries, we prospectively enrolled 784 high-risk pregnant women in a study designed to evaluate the effect of a single 1-g dose of ceftriaxone (n = 390) vs. that of no antibiotic prophylaxis (n = 394) on oral, rectal, and umbilical colonization and fatality rates among newborn infants. The mean ceftriaxone concentration in cord blood samples was 26 microgram/mL (range, 9-40 microgram/mL). Compared with infants of untreated mothers, children born to women who were given ceftriaxone were colonized at a lesser rate by gram-negative bacilli (54% vs. 35%; P < .001) and by group B streptococci (54% vs. 21%; P = .03) and endured significantly fewer sepsis-like illnesses in the first 5 days of life (8.1% vs. 3.1%; P = .004). There was also a tendency for them to have fewer episodes of culture-proven early-onset sepsis (2.8% vs. 0.5%; P = .06). Sepsis-related case-fatality rates (0.8% and 0.3%, respectively) were not significantly different. Although intrapartum administration of a single dose of ceftriaxone to high-risk mothers could be a safe and potentially useful strategy for reducing early-onset neonatal infections, additional information is required before this approach can be recommended for routine prophylaxis.

Bacterial Infections↗
PubMed1994

Nutrition update for the dental health professional.

The relationship between nutrition and dentistry has been longstanding. Today, dental healthcare providers need to broaden the definition of "dental nutrition" from a narrow focus on the relationship of foods to caries, periodontal disease and oral lesions, to concerns about the overall nutritional adequacy of a patient's diet. This article discusses some of the latest nutrition recommendations put forth by major United States' health organizations and comments on their applicability to dental patients.

Dental Care↗
PubMed1993

Hydrogen peroxide generation in a model paediatric parenteral amino acid solution.

1. Parenteral amino acid solutions undergo photooxidation, which may be an important factor in total parenteral nutrition-associated hepatic dysfunction. Light-exposed parenteral solutions containing amino acids, in addition to vitamins and trace minerals, generate free radicals, which, in turn, may contribute to this type of injury. This study examined the characteristics of H2O2 production in a parenteral amino acid solution modelled on a commercially available paediatric parenteral amino acid solution. 2. The solution was exposed to light in the presence of riboflavin-5'-monophosphate (riboflavin), and peroxide formation in the presence and absence of catalase (H2O2 formation) was assayed using potassium iodide/molybdate. 3. Peak H2O2 production occurred at a light intensity of 8 microW cm-2 nm-1 in the 425-475 nm waveband and was linear to 2 h of light exposure. H2O2 production reached 500 mumol/l at 24 h. 4. H2O2 was directly related to a riboflavin concentration of up to 20 mumol/l and was maximal at 30 mumol/l. 5. H2O2 production was greatest in the amino acid/riboflavin solution at a pH of between 5 and 6. 6. Under the conditions of light exposure intensity, light exposure time, riboflavin concentration and pH found during the administration of parenteral nutrition in neonatal intensive care units, net H2O2 production occurs in solutions modelled on a paediatric parenteral amino acid preparation.

Amino Acids↗
PubMed1990

Dentists' and physicians' attitudes on the role of the dental health care team in a cardiovascular risk factor reduction program.

This study examines the attitudes of both dentists and physicians on the role of the dental health care team in a cardiovascular risk factor reduction program directed at a general "well" population. A questionnaire was sent to a stratified sample of primary care dentists and physicians in the Augusta, Georgia, metropolitan area. The questionnaire was divided into four parts: the demographic component and three attitude components (the affective component, the cognitive component, and the action component). Results showed that dentists tended to have a positive attitude about performing cholesterol screening, nutrition counseling, and blood pressure screening in the dental office. Physicians tended to be negative about the idea of dentists performing cholesterol screening and nutrition counseling and were undecided about this role for dentists in a cardiovascular risk factor reduction program. Both dentists and physicians had positive attitudes about the idea of dentists referring high cardiovascular risk patients to physicians, as well as about the role of dentists in blood pressure screening. Overall, although dentists and physicians expressed concerns about the role of dentists in a cardiovascular risk factor reduction program, responses of both groups demonstrated a willingness to explore this concept further.

Adult↗
PubMed1990

Impact of a public cholesterol screening program.

The National Cholesterol Education Program (NCEP) has endorsed physician case finding as the primary method to detect individuals with elevated cholesterol levels. Despite this recommendation, promotional and for-profit public screening programs have flourished. We surveyed participants of a mall-based cholesterol screening program 1 year after their screening. Sixty-four percent of those screened had not previously known their cholesterol levels. Those who were newly screened were less likely to benefit from this testing than the general public, since they were older (mean age, 55.3 years), more likely to be female (67.4%), and nonsmokers (88%). Screenees had excellent recall of their cholesterol level (mean absolute reporting error, 0.24 mmol/L [9 mg/dL]) and a good understanding of cholesterol as a coronary heart disease risk. Those with elevated cholesterol levels reported high distress from screening but no reduction in overall psychosocial well-being and an actual decrease in absenteeism. Only 53.7% of all who were advised to seek follow-up because of an elevated screening value had done so within the year following the screening program. However, of those with values greater than 6.2 mmol/L (240 mg/dL), 68% had sought follow-up. Many of those who participate in public screening programs have been previously tested, fall into low-benefit groups, or fail to comply with recommended follow-up. We therefore conclude that cholesterol screening programs of the type now commonly offered are unlikely to contribute greatly to the national efforts to further reduce coronary heart disease.

Adult↗
PubMed1987

The effect of hydrocortisone, thyroxine, and phenobarbital on diamine oxidase activity in newborn rat intestine.

There is a reported association between administration of prenatal glucocorticoids and a decreased incidence of necrotizing enterocolitis in human infants. In rats, the degree of ischemic bowel disease correlates negatively with intestinal diamine oxidase (E.C. 1.4.3.6) activity. Since the administration of hydrocortisone, thyroxine, or phenobarbital to newborn rat pups affects the development of intestinal enzymes, we were interested in knowing whether hydrocortisone, thyroxine, or phenobarbital specifically affect intestinal diamine oxidase activity. We injected rat pups with hydrocortisone sodium succinate, 1-thyroxine pentahydrate, sodium salt, sodium phenobarbital, or the control solution on days 4, 6, 8, or 10 of life (phenobarbital, days 3, 5, 7, or 9). Pups were injected 3 days consecutively (phenobarbital, 4 days), and all were sacrificed on days 7, 9, 11, and 13. Intestinal diamine oxidase and intestinal invertase (E.C. 3.2.1.26) activities were measured. Invertase was used as a control enzyme because it is known to be induced by glucocorticoid hormones. We found that the hydrocortisone-injected pups had 10-fold higher specific activity of invertase than the saline-injected animals. Diamine oxidase activity was significantly higher in the group receiving hydrocortisone and sacrificed on days 7, 9, and 11. Enzyme activity in both the hydrocortisone-injected and saline-injected groups was equal on day 13, as was enzyme activity on all days in the thyroxine-injected and sodium hydroxide-injected groups, and the phenobarbital-injected and the saline-injected groups. Our results suggest that diamine oxidase activity may be induced by hydrocortisone, but is not affected by thyroxine or phenobarbital.

Amine Oxidase (Copper-Containing)↗
PubMed1987

The dietitian as a member of the dental health care team.

Our short-term pilot study suggests that a dietitian can play an important role in the dental office. Patients, staff, and dentists perceived a need for nutrition counseling in the dental setting that is not presently being met. We suggest that a dietitian might effectively meet this need without putting a financial burden on the practice.

Dental Care↗
PubMed1986

Quality control of laboratory tests run in a neonatal intensive care unit.

We examined the accuracy of laboratory screening tests in eight neonatal intensive care units. Analytes were provided by the EXCEL proficiency testing program of the College of American Pathologists (CAP), Skokie, III, samples were analyzed for hematocrit values and urine specific gravity. "Dipstick" tests were also performed for urinary protein, bilirubin, blood, glucose, pH, and ketones. The one intensive care unit that adhered to a formal quality control program for all these tests uniformly reported results well within statistically acceptable limits as defined by CAP. The seven other centers reported 14 instances of results that were either greater than 1 SD of the mean or considered by the consensus method to be outside acceptable CAP limits. Three of these results may have led to inappropriate clinical action in neonates. We conclude that there is a real potential for errors to be made in screening tests run by nurses in a neonatal intensive care unit when a formalized quality control program is not in effect.

Clinical Laboratory Techniques↗
PubMed1986

Vitamin E in neonatology.

It is difficult to maintain an objective attitude toward the use of vitamin E in neonatology. On the one hand, the desire to ameliorate iatrogenic diseases, such as BPD and ROP, makes one grasp hopefully at any theory or clinical trial that suggests a role for vitamin E in decreasing the handicaps that patients take with them from the intensive care nursery. On the other hand, when the question of toxicity arises, one tends to be negative, remembering the unfortunate experiences with oxygen, chloramphenicol, sulfisoxazole, and now, E-Ferol Aqueous Solution. We like to think that if this review had been written 2 years ago, our conclusions, based on the analysis of the data, would have been the same. But, probably, in the absence of data on the severe toxicity of one vitamin E preparation, we would have been more liberal in our recommendations for the use of vitamin E in neonatology. At this time, however, any use of supplemental vitamin E beyond the guidelines of the American Academy of Pediatrics cannot be recommended. Nor can the monitoring of blood Vitamin E levels be recommended as an assurance of nontoxic tissue concentrations in sick, premature infants. All physicians caring for premature infants are urged to review their nursery policies to make sure that excessive doses of vitamin E are not being administered. It is hoped that additional clinical trials will provide more definite answers to the questions about the efficacy of vitamin E in ROP and IVH.

Humans↗