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Biomedical subjects

J Birnbaum

Publications and source records attributed to J Birnbaum.

At least 37 records · Page 2Linked to original sources
PubMed1998

Splanchnic oxygen transport and lactate metabolism during normothermic cardiopulmonary bypass in humans.

UNLABELLED: The effect of normothermic (36.2 degrees C +/- 0.6 degree C) nonpulsatile cardiopulmonary bypass (CPB) on splanchnic (hepatic) blood flow (SBF), splanchnic oxygen transport (DO2spl) and oxygen consumption (VO2spl), splanchnic lactate uptake and gastric mucosal pH (pHi, gastric tonometry) was studied in 12 adults (New York Heart Association class II, ejection fraction > or = 0.4) undergoing coronary artery surgery. SBF was estimated with the constant-infusion indocyanine green (ICG) technique using a hepatic venous catheter. DO2spl, VO2spl, and splanchnic lactate uptake were calculated using the Fick principle after the induction of anesthesia, during aortic cross-clamping, after CPB, and 2 and 7 h after admission to the intensive care unit (ICU). SBF, DO2spl, and VO2spl did not decrease during CPB but increased after ICU admission, whereas pHi decreased 7 h after ICU admission. Initial ICG extraction was 0.78, which decreased to 0.54 during aortic clamping and remained low thereafter. The increased arterial blood lactate concentrations were not associated with a decreased splanchnic lactate uptake. We conclude that normothermic CPB is not associated with deterioration in the global intestinal oxygen supply. The increase of blood lactate levels and the decrease in ICG extraction, as well as in pHi, are consistent with a systemic inflammatory response to CPB. IMPLICATIONS: This study demonstrated that normothermic cardiopulmonary bypass (at flows > 2.4 L.min-1.m-2) was not associated with deterioration in global intestinal oxygen delivery, which suggests that increased blood lactate concentrations and decreased gastric mucosal pH and indocyanine green extraction are manifestations of a systemic inflammatory response to cardiopulmonary bypass.

Adult↗
PubMed1997

A phase I trial of humanized anti-interleukin 2 receptor antibody in renal transplantation.

The efficacy of murine monoclonal anti-interleukin 2 alpha chain receptor (Tac) antibodies is limited by a short half-life and the development of antibodies to the heterologous protein. The safety, pharmacokinetics-dynamics, and immunosuppressive effect of a humanized anti-Tac antibody (HAT) was evaluated in 12 renal transplant recipients. Ten patients received living related transplants (three HLA-identical matches and seven one-haplotype or zero-haplotype matches) and two patients received cadaver organs. The patients were divided into four HAT treatment arms: 0.5 mg/kg/week (n=4), 1 mg/kg/week (n=2), 0.5 mg/kg every other week (n=3), and 1 mg/kg every other week (n=3). The first dose of HAT was given within 12 hr before transplantation, and four additional doses were given after transplantation. Patients were also placed on cyclosporine, steroids, and azathioprine. Only one patient, a recipient of a cadaver kidney in the lowest HAT treatment arm, had a reversible rejection episode. The 10 recipients of living related transplants were compared with 17 historical controls treated with an identical immunosuppressive regimen except for HAT. Whereas none of the HAT-treated living related donor recipients had a rejection episode, 6 of 17 (41%) of the historical controls had a rejection episode in the first year after transplantation. There were no first-dose reactions after HAT therapy or other subsequent side effects. None of the patients experienced opportunistic infections or malignancies. One patient developed low-titer anti-HAT antibodies, although the patient maintained high serum HAT concentrations throughout the study. Immune monitoring showed that there were no changes in the percentage or absolute counts of CD3 cells or T-cell subsets after HAT therapy. However, there was a significant decrease in the number of circulating lymphocytes that expressed free Tac. The overall harmonic mean half-life of HAT was 273 hr. The results of this study indicate that HAT given at 1 mg/kg every other week for a total of five doses may provide therapeutic HAT concentration levels and result in good saturation of Tac receptors for at least 12 weeks after transplantation. In summary, HAT is safe and is well tolerated by patients. Its long half-life and lack of immunization could make it a very useful immunosuppressive drug.

Adult↗
PubMed1997

Association between latex sensitization and repeated latex exposure in children.

BACKGROUND: Children with spina bifida are at greater risk for latex and ethylene oxide sensitization. The authors' aim in this study was to evaluate the role of previous surgical procedures in the development of sensitization to latex and ethylene oxide. METHODS: The authors investigated 80 children 1-16 yr old, separated into 3 groups. Two groups had a history of 3 or more general anesthetics: 29 children had spina bifida (spina bifida group) and 31 had undergone multiple surgeries for another disease (multiple surgeries group). A control group of 20 children had undergone less than 1 anesthetic. Clinical manifestations with latex, perioperative anaphylactic reactions, and number of previous anesthetics were recorded. Skin prick tests with a commercial extract of latex, four common inhalant allergens, and radioallergosorbent test to latex and ethylene oxide were performed. RESULTS: The three groups did not differ significantly with respect to age, sex, and atopic status. Mean number of anesthetics was comparable in the spina bifida and the multiple surgeries group. Latex sensitization was common in the spina bifida group (59%) and in the multiple surgeries group (55%) but not in the control group (0%, P < 0.05). Ethylene oxide sensitization was significantly more frequent in the spina bifida group than in the multiple surgeries group (44% vs. 19%; P = 0.052) and strongly associated with latex sensitization. Mean number of previous anesthetics was greater in children sensitized to latex (8.4 vs. 3.9; P < 0.05). CONCLUSION: Results suggest that it is the number of surgical procedures rather than spina bifida per se that is related to sensitization to latex.

Adolescent↗
PubMed1997

Prevalence of latex sensitization in subjects attending health screening: implications for a perioperative screening.

BACKGROUND: Because latex is a common allergen, the rate of latex sensitization may be high in the general population. A major issue would then be to determine whether a systematic preoperative screening in the general population should be recommended. OBJECTIVE: The purpose of the study was to evaluate the prevalence of latex sensitization in a sample of the general population and to assess the role of possible risk factors. METHODS: The subjects were 258 people, aged from 20 to 40 yr, visiting a health care centre for a check-up. The protocol included: a questionnaire (occupation, symptoms of atopy, use of latex goods and possible reactions, history of previous surgery), a skin-prick test, and a CAP RAST to latex. Atopy was evaluated by a skin-prick test to common allergens and a Phadiatop test. RESULTS: Some 6.6% of the study group had either a positive skin test or a positive RAST to latex. These subjects had a four-fold higher prevalence of symptoms when wearing gloves. The rate of latex sensitization was higher by fivefold in subjects with a history of reactions to latex goods and by fourfold in atopic subjects. CONCLUSIONS: Because the rate of latex sensitization is much higher than the anticipated rate of perioperative reactions due to latex allergy, a systematic preoperative screening for latex allergy should not be recommended for adults.

Adult↗
PubMed1996

Sex difference in Fel d 1 allergen production.

BACKGROUND: Previous experiments have shown that in vivo Fel d 1 production is under hormonal control. It strongly decreased 1 month after castration of male cats and increased after testosterone injection. OBJECTIVE: These results led us to put forward the hypothesis that Fel d 1 production could be more important in male that in female cats. Five adult male and five adult female cats were studied. METHODS: On day 0 three separate sites of each cat's trunk were shaved, and a 5.72 cm2 area in each site was washed twice (D0a and D0b) with 5 ml of distilled water. Then a collar was attached to the neck to prevent contamination from saliva. Twenty-four hours later on day 1, all areas were washed again once (D1a). Skin washes and fur extracts from the shaved areas were evaluated for Fel d 1 content. The same procedures (apart from collection of fur) were repeated 5 months later. RESULTS: The Fel d 1 level was higher in the first skin wash of male cats compared with that of female cats on each separate site of the trunk in both experiments, initially and 5 months later. Results were significant in the first experiment (median Fel d 1 per milliliter: 69.4 and 28.9 mU, respectively, for the combined three sites; p < 0.05). Fel d 1 production over a 24-hour period was higher in male cats, but the difference did not reach statistical significance. Furthermore, correlation between Fel d 1 levels in washes D0a and in fur was highly significant (p < 0.01). CONCLUSION: These results confirm that Fel d 1 originates from skin. Furthermore, they suggest that Fel d 1 production is higher in male than in female cats.

Allergens↗
PubMed1996

Clinical manifestation and outcome of tuberculosis in children with acquired immunodeficiency syndrome.

BACKGROUND: Atypical clinical manifestations and rapid progression of tuberculous disease (TB) are well-recognized in adults with the acquired immunodeficiency syndrome (AIDS). There are few reports of children with AIDS and TB. We report the manifestations, clinical course and outcome of 12 pediatric patients with AIDS and TB. METHODS: The charts of all children admitted to our institution, from 1989 through 1994, with the diagnoses of AIDS and culture-proved TB were reviewed. RESULTS: Twelve children between the ages of 2 months and 13 years fit the criteria. The mean time between the diagnosis of AIDS and TB was 20 months. The most frequent presenting symptoms were fever (75%) and tachypnea (33%). All had negative Mantoux tests (5 tuberculin units of purified protein derivative). Extrapulmonary TB was present in 3 (25%). A source case was identified for 4 (33%). Previous pulmonary disease was present in 7 (58%). Chest roentgenograms were abnormal in 11 (91%), with diffuse interstitial infiltration the most common finding. Susceptibility tests were performed on 10 strains, 3 of which were resistant to 1 or more antituberculosis drugs. Three patients (25%) died of TB, 1 of whom was appropriately treated with antituberculosis drugs but had a strain resistant to isoniazid and rifampin. CONCLUSION: Children with AIDS and TB most frequently present with atypical manifestations of TB. A high index of suspicion is needed to correctly diagnose TB in this group of children. Early diagnosis is important because most respond well when treated appropriately.

AIDS-Related Opportunistic Infections↗
PubMed1996

Fel d I levels in cat anal glands.

BACKGROUND: Major cat allergen Fel d I is produced consistently by skin and by sebaceous glands before being spread on the fur. OBJECTIVE: Since cats have tubular anal glands secreting sebum, proteins and lipids, we looked at the possible presence of Fel d I in these secretions and compared the levels found to those already reported in other cat tissues or secretions. METHODS: Thirty-seven cats were studied. Fel d I dosage in the anal sacs' secretions was performed using an enzyme linked immunosorbent assay (ELISA) method and total protein evaluation by the Bradford's method. RESULTS: The geometric mean Fel d I concentration was 41 U/g secretion which represents 3.4% of the total protein levels. This amount is the highest ever reported in cat tissues or secretions. CONCLUSION: The close association of Fel d I protein with skin sebaceous glands and anal sacs both with holocrine function and lipids' secretions in one hand, and the homology of chain I of Fel d I with some steroid-binding proteins in other hand, suggest a possible physiological role for Fel d I in the regulation of lipids on skin and cat fur.

Allergens↗
PubMed1995

Indoor allergen levels in day nurseries.

BACKGROUND: Because allergic sensitization seems to occur especially during infancy, we decided to evaluate such an exposure in day nurseries. METHODS: Thirty day nurseries in Marseilles, which were selected at random, were visited during 2 weeks in April 1993. Routine cleaning includes daily cleaning of smooth floors, weekly laundering of sheets, and monthly cleaning of soft toys. Mattresses are encased in synthetic covers. Dust samples were collected from four settings: infants' mattresses and pillows, smooth floors, and soft toys. Levels of mite, cockroach, cat, and dog allergens were analyzed with a monoclonal antibody-based ELISA. RESULTS: Mite allergen levels were lower than the proposed threshold level for sensitization (2 micrograms/gm of dust) on 94% of mattresses and soft toys and on 100% of floors and pillows. Cat allergen levels in mattresses ranged from less than 0.1 to 4.5 micrograms/gm dust. On floors, cat allergen levels ranged from less than 0.1 to 2.4 micrograms/gm dust. Only 10% of pillows and soft toys had levels greater than 2 micrograms/gm of dust. Fel d I levels were significantly higher (p < 0.03) in mattresses from nurseries with curtains and were correlated with the percentage of children with a cat at home. In almost all day nurseries, cockroach allergen (Bla g I and Bla g II) levels were very low. Only three samples from mattresses had dog allergen levels greater than 2 micrograms of Can f I allergen per gram of dust. On floors the level was always lower than 2 micrograms/gm. CONCLUSIONS: These data clearly show that indoor allergen levels are much lower in day nurseries than in most houses. Most samples contain allergen levels below threshold levels for sensitization. Thus children of atopic parents are less likely to become sensitized to indoor allergens in day nurseries than in their own homes. In addition, this study emphasizes the efficacy of avoidance measures such as use of synthetic protective mattress covers, frequent washing of sheets and soft toys, and avoidance of carpets and curtains.

Allergens↗
PubMed1995

Housing and house-dust mites.

Because the mite-allergen content in homes is highly variable even in the same geographic area, we tried to determine which variables influence mite infestation. We evaluated mite-allergen content in bedding relative to housing conditions and living habits. This cross-sectional study included 108 homes. Housing conditions were assessed by an architect and living habits by a researcher specialized in social and family economics. Group I allergen level was measured on the mattress dust with monoclonal antibodies, and relative humidity (RH) was monitored in the bedroom during a 2-week period. Homes with low RH did have low mite-allergen content. In contrast, homes with intermediate RH levels had very variable mite-allergen content. Using analysis of variance and a logistic regression analysis, we were unable to identify any variable predictive of mite-allergen content. Thus, factors other than relative humidity seem to influence mite infestation. Moreover, the absence of association between mite infestation and ventilation rate might be accounted for by the gentle climate in our area with notable outdoor RH.

Allergens↗
PubMed1995

Evaluation of a portable clinical blood analyzer in the emergency department.

OBJECTIVE: To assess the potential effects of rapid bedside blood analysis on patient management in the ED. METHODS: A prospective, nonrandomized clinical study was conducted over a consecutive ten-month period (August 1992 to May 1993). Blood samples drawn from a convenience sample of 960 patients for analysis of Na+, K+, Cl-, BUN, glucose, and/or hematocrit (Hct) were simultaneously analyzed by portable clinical analyzer (PCA) and by routine methods in the central laboratory. Caregivers were blinded to the PCA values; patient care was based solely on central laboratory results. Physicians were surveyed after the completion of patient care. RESULTS: The PCA results were available 31 minutes (mean) sooner than were the central laboratory results for Hct, 43 minutes faster for Na+, K+, and Cl-, and 44 minutes faster for BUN and glucose. Except for Hct and glucose, the values obtained from the PCA were not significantly different from the central clinical blood analyzer laboratory values. When surveyed, the physicians caring for the patients reported that had the PCA results been available, a different or an earlier therapeutic approach would have resulted in 9.5% of the cases. The decision to release or admit the patient was based on one or more of the laboratory values for 10.7% of patients sampled. In no case in this series did a physician report that final ED clinical outcome would have been affected. CONCLUSIONS: In our ED, the PCA yielded faster reporting of laboratory values. These earlier results might have reduced the length of stay in the ED for 17.3% of patients studied. Selective use of a handheld portable analyzer might decrease time to therapeutic interventions and time to disposition.

Adult↗
PubMed1995

House dust mite allergen content in two areas with large differences in relative humidity.

BACKGROUND: Striking differences in mite counts and mite-allergen levels have been documented between dwellings located at sea level and high altitude. Apart from relative humidity (RH), several other factors, ie, temperature, UV exposure, and altitude per se could account for this difference. OBJECTIVE: To evaluate whether RH by itself could influence mite infestation by comparing mite-allergens levels in two towns differing only with respect to RH. METHODS: We compared group I allergen content in two Moroccan towns: Casablanca, located on the seashore and Marrakech located at 1404 feet. Mean (+/- SD) RH in years 1990 and 1991 was 81.2 +/- 2.9% in Casablanca and 56.0 +/- 7.6% in Marrakech. Mean annual temperatures were 17.7 +/- 4.0 degrees C and 20.2 +/- 6.4 degrees C in Casablanca and Marrakech, respectively. In each town, 20 asymptomatic subjects agreed to participate in the study. Their mattresses were vacuum-cleaned for a standardized duration (2 min/m2). Mite allergen-content was evaluated using monoclonal antibodies and ELISA and results expressed as micrograms of group I (Der pI+Der f I) allergens per gram of dust (micrograms/g dust). RESULTS: Mean (+/- SD) group I allergen level was 8.3 +/- 8.8 micrograms/g in Casablanca and 0.6 +/- 0.6 micrograms/g dust in Marrakech, a difference that is highly significant (P = .001). In both areas, mean Der f I allergen level was low (0.7 +/- 0.5 and < 0.1 micrograms/g dust, in Casablanca and Marrakech, respectively). CONCLUSION: This study shows that house dust mite allergen content in households depends on RH rather than on temperature.

Allergens↗
PubMed1994

[Asthma-allergy. Altitude: a study model].

Several epidemiological studies have now established the relationship between atopy and bronchial asthma. The study of the role of altitude in sensitization, bronchial reactivity, clinical symptoms and allergen exposure in asthma is a good model for understanding the disease. It is now demonstrated that in altitude there is a major decrease in the number of mites (one of the major aeroallergens) and a low mite antigenic load (measured with monoclonal antibodies). In altitude, the climatic factor which has by far the greatest effect on the development of mites is indoor relative humidity which is much lower that at sea level. These findings explain the clinical improvement of some asthmatic patients and help understand the association between the presence of indoor allergens and asthma.

Allergens↗