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Biomedical subjects

G Alpert

Publications and source records attributed to G Alpert.

At least 19 recordsLinked to original sources
PubMed1993

Risk of infection during adrenocorticotropic hormone treatment in infants with infantile spasms.

We reviewed the clinical features and laboratory findings of 27 infants with infantile spasms treated with adrenocorticotropic hormone or prednisone during febrile episodes in order to evaluate the incidence of bacteremia, the risk of serious infection, determination of whether serious infections can be identified at presentation and the outcome of febrile episodes. There were 75 febrile episodes including 4 episodes of identified bacteremia (5.3%). Three children who were treated with adrenocorticotropic hormone dosage larger than recommended died. Leukocytosis and a differential count with many immature granulocytes predicted bacteremia in this population. Chest radiography was useful in identifying the cause of fever. The pathogens isolated were similar to those found in this age range. We conclude that the frequency of bacteremia in our patient population is similar to that observed in infants of the same age; however, the outcome is frequently fatal. In addition this increased mortality may be associated with the use of a larger dosage of adrenocorticotropic hormone than recommended.

Adrenocorticotropic Hormone↗
PubMed1992

K+ current stimulation by Cl- in the midgut epithelium of tobacco hornworm (Manduca sexta). I. Kinetics and effect of Cl(-)-site-specific agents.

Goblet cells in the midgut epithelium of the tobacco hornworm (Manduca sexta larva, 5th instar) actively secrete K+. This can be measured as short-circuit current (Isc) when the tissue is mounted in an Ussing chamber and bathed in K(+)-rich standard saline containing 32 mmol K+.l-1. Isc depends strictly on basolateral (i.e. haemolymph side) K+ and is therefore termed K+ current, IK. Basolateral, but not apical, chloride, bromide and iodide stimulate IK when compared to the baseline current recorded with gluconate-, nitrate- or thiocyanate-containing salines. So-called "Cl(-)-specific" transport inhibitors (frusemide, 9-anthracene carboxylic acid, diphenylamine carboxylic acid and 4,4'-diisothiocyana-to-stilbene-2,2'-disulphonic acid) reduce IK when added to the basolateral bath, whether Cl- or gluconate is the principal ambient anion. Cl- stimulates IK according to saturation kinetics. The Michaelis-Menten-type, K+ concentration-dependent, saturation of IK is altered in a highly specific manner when gluconate is replaced by Cl-: maximal K+ current, as well as the apparent Michaelis constant, are increased by a factor of 4. Since IK develops in these conditions exclusively via basolateral, Ba(2+)-blockable K+ channels, these results can be understood if it is assumed that haemolymph Cl- interferes with the K+ channel by simultaneously lowering the binding affinity for K+ ions and increasing their subsequent transfer rate across the basolateral goblet cell membrane.

Animals↗
PubMed1992

Limulus antilipopolysaccharide factor protects rabbits from meningococcal endotoxin shock.

Limulus antilipopolysaccharide factor (LALF), an 11.8-kDa peptide isolated from amebocytes of Limulus polyphemus, neutralizes meningococcal lipooligosaccharide (LOS)-induced gelation of limulus amebocyte lysate. Rabbits challenged with an LD90 of LOS (10 micrograms/kg) premixed with LALF in vitro (n = 10) had significantly higher mean arterial pressure, arterial pH, serum bicarbonate concentrations, and survival (90% vs. 8%, P = .005) than did rabbits challenged with LOS alone. Relative to untreated controls, rabbits pretreated with LALF intravenously (iv) at 1.2 mg/kg (n = 21) also had significant improvements in physiologic measurements and higher survival (52% vs. 8%, P = .003). Even when LALF (1.2 mg/kg iv) was given 1/2 h after LOS challenge, animals showed significant improvements in physiologic measurements and survival (33% vs. 8% in untreated controls P = .028). LALF-treated animals also had significantly lower circulating endotoxin activity and tumor necrosis factor concentrations. Thus, LALF attenuates the toxic effects of meningococcal LOS in rabbits even when administered after LOS challenge and deserves further evaluation as a potential therapeutic agent for treating gram-negative septic shock.

Animals↗
PubMed1992

Effect of a human immunoglobulin preparation for intravenous use in a rabbit model of meningococcal endotoxin-induced shock.

BACKGROUND AND METHODS: Endotoxin shock is mediated by various cytokines, including tumor necrosis factor. Treatment of patients with i.v. immunoglobulin has been shown to reduce the concentration of circulating cytokines. The purpose of this study was to determine the protective effects of immunoglobulin for i.v. use on meningococcal endotoxin-induced shock in a rabbit model. Experimental animals were challenged with i.v. meningococcal endotoxin (lipo-oligosaccharide) 10 micrograms/kg, and treated with either a 2-hr i.v. immunoglobulin infusion (400 mg/kg) or a similar saline infusion that was initiated 30 mins before endotoxin challenge. Control animals were challenged with saline alone. RESULTS: Compared with untreated control animals, pulse rate increased (p less than .007) and mean arterial pressure and serum bicarbonate concentrations decreased (p less than .02) in both experimental groups, but did not differ between immunoglobulin-treated and saline-treated animals (p greater than .05) at any time after the endotoxin challenge. Geometric mean serum endotoxin concentrations were significantly (p less than .03) lower in the immunoglobulin-treated animals at 60, 120, 180, 240, 300, and 360 mins after the endotoxin challenge. The geometric mean serum tumor necrosis factor level at 1 hr after the endotoxin challenge in the immunoglobulin-treated experimental animals was lower than in saline-treated animals (5.53 vs. 8.47 tumor necrosis factor enzyme-linked immunosorbent assay U/mL), but not significantly so (p greater than .05). Mortality rate was similar in both experimental groups; eight (67%) of 12 saline-treated experimental rabbits and seven (70%) of ten immunoglobulin-treated rabbits died. All untreated control animals survived 24 hrs. CONCLUSIONS: In this model of circulatory shock in rabbits, i.v. immunoglobulin: a) does not significantly alter the physiologic responses to endotoxin challenge; b) significantly reduces endotoxin concentrations; c) reduces tumor necrosis factor concentrations, but not significantly; and d) does not improve survival rate.

Analysis of Variance↗
PubMed1992

Dehydroepiandrosterone protects mice from endotoxin toxicity and reduces tumor necrosis factor production.

Recent reports have demonstrated an immunomodulating activity of dehydroepiandrosterone (DHEA) different from that described for glucocorticoids. The present study was designed to test DHEA's activity in endotoxic shock and to investigate its effect on endotoxin-induced production of tumor necrosis factor (TNF). Mortality of CD-1 mice exposed to a lethal dose of lipopolysaccharide (LPS; 800 micrograms per mouse) was reduced from 95 to 24% by treatment with a single dose of DHEA, given 5 min before LPS. LPS administration resulted in high levels of TNF, a response that was significantly blocked by DHEA, both in vivo and in vitro. DHEA treatment also reduced LPS-induced increments in serum corticosterone levels, a parameter considered not to be mediated by TNF. In another experimental model, mice sensitized with D-galactosamine, followed by administration of recombinant human TNF, were subjected to 89% mortality rate, which was reduced to 55% in DHEA-treated mice. These data show that DHEA protects mice from endotoxin lethality. The protective effect is probably mediated by reduction of TNF production as well as by effecting both TNF-induced and non-TNF-induced phenomena.

Animals↗
PubMed1992

Effect of meningococcal endotoxin in a rabbit model of shock.

Endotoxin in the form of a lipooligosaccharide (LOS) plays a key role in the development of shock in meningococcal sepsis. To examine hemodynamic and biochemical alterations during meningococcal endotoxic shock, we established a rabbit model. Thirty-nine rabbits, weighing 2.5-4.4 kg, were studied. After anesthesia with intramuscular ketamine (20 mg/kg) and xylazine (4 mg/kg), femoral venous and arterial catheters were inserted. Control animals received only saline, while rabbits in each of four additional groups were given LOS in 10-fold increments from 0.1 microgram/kg to 100 microgram/kg. Mean arterial pressure (MAP), heart rate (HR), respirations (RR), temperature (T), urine output, and arterial blood gases (pH, PCO2, PO2, and bicarbonate) were determined at baseline and hourly. Endotoxin levels and TNF levels were measured at 30, 60, 120, 180, 240, 300, and 360 min post-LOS. Survival was recorded. One-way analysis of variance (ANOVA) and the Scheffe procedure, paired samples t-test, two-tailed t-test, and Fisher's exact test were used. Pearson's coefficients were calculated. Animals receiving meningococcal LOS developed tachycardia and compensated metabolic acidosis with an initially normal pH and MAP. With progression of the shock state, the pH decreased and hypotension ensued. Maximal levels of endotoxin were measured 30 min after LOS injection and declined during the ensuing 6 hr. TNF rose from undetectable to markedly elevated levels and peaked at 60-120 min post-LOS. Increasing the amount of injected endotoxin produced more profound degrees of shock until a dose of 10.0 micrograms/kg was reached. There was no correlation between serum TNF at 60 min and survival at 6 hr or 24 hr.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Effect of polymyxin B on experimental shock from meningococcal and Escherichia coli endotoxins.

Meningococcemia is the most frequent cause of septic shock in healthy children. To determine whether polymyxin B (PMB) might improve mortality from meningococcal shock, its protective activity was evaluated in rabbits challenged with an LD90 of meningococcal lipooligosaccharide (LOS) and compared with an LD80 of Escherichia coli O111:B4 lipopolysaccharide (LPS). PMB (5 mg/kg) administered intravenously 30 min before meningococcal LOS challenge had no significant effect on heart rate, mean arterial pressure, serum bicarbonate, serum tumor necrosis factor (TNF) levels, or survival relative to controls. However, PMB premixed with LOS in vitro increased serum bicarbonate levels (P less than .05) and improved 24-h survival (P less than .05). In contrast, PMB given before E. coli LPS challenge increased serum bicarbonate levels, decreased TNF levels, and improved 24-h survival (all, P less than .05). In vitro studies confirmed that PMB at 10 micrograms/ml neutralized E. coli LPS but not meningococcal LOS activity. Thus, pretreatment with PMB apparently protects rabbits against shock induced by E. coli LPS but not by meningococcal LOS.

Animals↗
PubMed1990

Case-control study of hyperpyrexia in children.

To test the association of hyperpyrexia (temperature greater than or equal to 41.1 degrees C) with increased rates of bacteremia and serious bacterial illness in young children, we performed a retrospective case-control study. Seventy-six hyperpyrexic children and an equal number of control cases with temperatures of 39.1-40 degrees C and 40.1-41.0 degrees C were identified. A significantly larger number of diagnostic procedures including blood cultures, urine cultures, chest x-rays and white blood cell counts were performed in the hyperpyrexic children (P less than 0.05). The frequency of serious bacterial infections and bacteremia did not differ among the groups (P greater than 0.05). Hyperpyrexic children need to be evaluated as thoroughly and carefully as any other febrile child but do not merit special consideration.

Bacterial Infections↗
PubMed1989

Recurrent ascites in an infant with perinatally acquired cytomegalovirus infection.

We describe an infant with symptomatic perinatally-acquired cytomegalovirus (CMV) infection manifested by fever, anaemia, thrombocytopenia and hepatosplenomegaly. This infant developed recurrent episodes of severe ascites during which the virus was isolated from his urine. This rare hepatic manifestation of neonatal CMV infection has, to the best of our knowledge, only been reported twice in aborted fetuses with intrauterine systemic CMV infection.

Ascites↗
PubMed1989

A clinical model for diagnosis of urinary tract infection in young women.

To develop a clinical model for diagnosis of bacterial urinary tract infection, we conducted a prospective study on 266 dysuric young women, 147 of whom had urinary tract infections. Five variables were found to be significant and independent correlates to bacterial urinary tract infection on logistic regression analysis: sexual activity, absence of vaginal discharge, short duration of complaints, leukocyturia, and hematuria. An algorithm combining the logistic model and a Gram-stained urine specimen, which was used in only a third of our patients, afforded a sensitivity of 86% and a specificity of 84%. The algorithm was validated in a second set of 166 dysuric women, 77 of whom had urinary tract infections. The algorithm led to a diagnosis of bacterial urinary tract infection with a sensitivity of 91% and specificity of 79%; the only laboratory test needed except for urinalysis was a Gram's stain of urine, obtained for 30% of the patients.

Adolescent↗
PubMed1988

An outbreak of measles among young adults. Clinical and laboratory features in 461 patients.

We report the clinical and laboratory characteristics of measles infection in an unselected group of 461 young adults. Otitis media was diagnosed in 9.8%, sinusitis in 4.1%, pneumonia in 3.7%, and keratitis in 3.3% of the patients. Minor T-wave changes on electrocardiogram were observed in only 0.7% and jaundice in 0.4%. Elevated liver enzymes were found in 51% of the patients. Creatine kinase (CK) MM fraction was high in 44%. Traces of myoglobin were found in the urine of 14% of those with a high CK, and of the 13 patients with the higher CKs, 12 had an abnormal serum aldolase. We emphasize several points of interest in this large and unselected group of young adults. There was 1) possible evidence of rhabdomyolisis in some of our patients; 2) a lower rate of electrocardiogram abnormalities than previously reported; 3) no evident correlation between initial laboratory values and subsequent complications; and 4) lack of a clinical or laboratory difference between patients who had been vaccinated with an attenuated virus during childhood and those who had not.

Adolescent↗
PubMed1988

Malassezia furfur skin colonization in infancy.

Malassezia furfur, a lipophilic yeast, has become recognized as a cause of sepsis in infants receiving parenteral fat emulsions via indwelling deep venous catheters. Colonization of infants' skin may be a prerequisite to colonization of the intravascular catheter and subsequent infection with M furfur. Three hundred ninety-three surveillance cultures were performed on 146 infants during their first 12 weeks of hospitalization in the intensive care unit (ICU) or the neonatal transitional unit (NTU). In addition, 47 full-term newborn infants and 38 healthy infants in the well-baby clinic were cultured. Colonization rates were greatest (48%) during the second month of hospitalization for the infants in the ICU/NTU group. In contrast, 0 of 47 newborn infants and 2 of 38 healthy infants were colonized. Prematurity and a prolonged length of stay were identified as risk factors for colonization.

Humans↗
PubMed1988

Single intramuscular dose of ceftriaxone as compared to 7-day amoxicillin therapy for acute otitis media in children. A double-blind clinical trial.

Fifty-two children (mean age 23 months) with acute otitis media were treated randomly with either a single intramuscular dose of ceftriaxone (Rocephin) 50 mg/kg (27 patients) or 7 days of amoxicillin 12.5 mg/kg t.i.d. (25 patients). The rate of resolution of acute symptoms and incidence of recurrences and relapses during the first months after commencement of the therapy was similar in the two groups. One week following the start of treatment no difference was observed in the proportion of patients with tympanometric evidence of middle ear effusion (MEE) in either of the two groups. On day 30, however, significantly more patients from the ceftriaxone group had flat tympanograms-83% as compared to 47% in the amoxicillin group. Therefore, single-dose ceftriaxone therapy cannot be suggested at present as routine therapy for acute otitis, although it may be considered a reasonable alternative in noncompliant patients.

Administration, Oral↗
PubMed1988

Nursing, nursing education, and anxiety.

One hundred seventy-one graduating students in associate degree, diploma, and baccalaureate nursing programs completed a questionnaire concerning various state and trait measures of emotions (including general anxiety, apprehension about communication, and anxiety about one's future nursing career). Differences among the three groups of nursing students on the various dimensions of emotions, anxiety, and communication apprehension were assessed from the perspective of Mehrabian's theory of emotion. Predictors of anxiety about one's nursing career were investigated for the overall sample and for the three groups separately. Findings indicate that baccalaureate students are least apprehensive about communicating and feel most dominant in their setting. In addition, associate degree students were most anxious about nursing if they did not feel dominant, diploma students were most anxious if they did not feel dominant or were apprehensive about communication, and baccalaureate students were most anxious if they were generally unhappy. The results are discussed in terms of Mehrabian's emotion theory, the current crisis in and future direction of nursing education, and the use of theory in designing a strategy for nursing as a profession.

Adult↗
PubMed1987

Malassezia furfur fungemia in infancy.

Malassezia furfur was recovered from blood cultures obtained through an indwelling line in seven severely ill infants hospitalized in a neonatal intensive care unit. While two of the patients were asymptomatic, the other patients had signs and symptoms compatible with sepsis. One patient had evidence of endocarditis.

Catheters, Indwelling↗
PubMed1987

Urinary tract infections and sexual activity in young women.

A group of 147 young women with symptomatic urinary tract infection (UTI) were compared with a control group of 105 symptom-free young women belonging to the same population. On logistic-regression analysis, sexual activity was the only significant and independent behavioral difference between the groups (87% of women with UTI were sexually active vs 32.7% of the control group). Of the 147 episodes of UTI, only 28.9% occurred within 24 hours of sexual intercourse; of 24 episodes that occurred during follow-up, the percentage that occurred within 24 hours of intercourse was 33.3%. This finding is in discordance with the close temporal association between UTI and sexual intercourse reported in previous studies.

Adolescent↗