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Biomedical subjects

F Gigliotti

Publications and source records attributed to F Gigliotti.

At least 91 records · Page 5Linked to original sources

Control of breathing in patients with short-term primary hypothyroidism.

In 8 patients (3 men and 5 women) with short-term primary hypothyroidism before and during replacement therapy, and in an age-matched control group (9 men and 7 women), we assessed maximal inspiratory muscle force (Pimax) and the ventilatory control system at neural (EMG), muscular (P0.1), and ventilatory (VE and Vt/Ti) levels. While hypothyroid, patients exhibited a significantly lower Pimax. During a CO2 rebreathing test, hypothyroid patients exhibited similar diaphragmatic electromyographic (EMGd) and ventilatory (VE) response slopes to increasing end-tidal CO2 tension (delta EMGd/delta Pet CO2 and delta VE/delta PetCO2), but significantly less delta P0.1/delta PetCO2 (p less than 0.05) and delta(Vt/Ti)/delta PetCO2 (p less than 0.05) response slopes. During replacement therapy with L-triiodothyronine (L-T3), Pimax (p less than 0.05), delta P0.1/delta PetCO2, and delta(Vt/Ti)/delta PetCO2 response slopes were found to be significantly increased (p less than 0.05 for both) while neither EMGd nor VE response changed significantly. We concluded that short-term hypothyroidism does not seem to be associated with blunted neural inspiratory output (EMGd), the respiratory control system seems to be affected mostly at a peripheral (muscular) level, and L-T3 increases both force (P0.1 and Pimax) and velocity (Vt/Ti) of inspiratory muscle contraction.

Adult↗

Neural respiratory drive and neuromuscular coupling during CO2 rebreathing in patients with chronic interstitial lung disease.

In 12 patients with CILD and 18 age-matched normal subjects we assessed the ventilatory control system at three levels: (a) neural, as assessed by EMGd (XP/Ti) and EMGint muscles via surface electrodes; (b) muscular, as assessed by mouth occlusion pressure (P0.1); and (c) ventilatory, as assessed by both ventilation (VE) and the related parameters, tidal volume (VT) and respiratory frequency (f). Compared with a normal control group, patients exhibited a significant decrease in lung volumes and in MIP; VT and inspiratory time (Ti) were significantly lower, while VT/Ti, P0.1, and both EMGd and EMGint were significantly greater in patients. During a CO2 rebreathing test, patients exhibited significantly greater EMGd, EMGint, and P0.1 responses to increasing PETCO2 than the control group. VE response slopes were similar in the two groups. For a given EMGd response slope (delta XP/Ti/delta PETCO2), the average P0.1 response slope (delta P0.1/delta PETCO2) was found to be significantly lower in patients than in the normal control group. Compared with normal subjects, CILD patients have a normal or increased neural component of respiratory activity and relatively low neuromuscular coupling (delta P0.1/delta XP/Ti). The decreased neuromuscular coupling could be explained in these patients by a reduced inspiratory muscle strength.

Aged↗

Vancomycin, ticarcillin, and amikacin compared with ticarcillin-clavulanate and amikacin in the empirical treatment of febrile, neutropenic children with cancer.

We assessed two antibiotic regimens--vancomycin, ticarcillin, and amikacin, as compared with a vancomycin placebo, ticarcillin-clavulanate, and amikacin--as initial empirical therapy for febrile, neutropenic children with cancer. In a randomized, double-blind clinical trial, the planned 10-day treatment was unsuccessful in 15 percent of the vancomycin, ticarcillin, and amikacin group (n = 53), as compared with 38 percent of the group receiving ticarcillin-clavulanate and amikacin (n = 48) (P = 0.010). Of 10 episodes of breakthrough bacteremia, 9 (1 fatal) occurred in patients treated with ticarcillin-clavulanate and amikacin (P = 0.006). Each of the 10 microbial isolates was a gram-positive bacterium with similar susceptibilities to vancomycin and ticarcillin-clavulanate in vitro. Both regimens were well tolerated. None of the patients had detectable renal dysfunction, but those receiving vancomycin, ticarcillin, and amikacin were more likely to have twofold increases in serum hepatic-enzyme activity. Rashes consistent with the "red-man" syndrome occurred in three patients upon the infusion of vancomycin and in three others who received a placebo. We conclude that the combination of vancomycin, ticarcillin, and amikacin is more effective than ticarcillin-clavulanate and amikacin as empirical antibiotic therapy in clinical settings in which gram-positive bacteremias are a serious problem.

Adolescent↗

Measles and rubella antibody status in previously vaccinated children with cancer.

Measles and rubella antibody status were determined by ELISA for 115 previously vaccinated children with cancer. Seventy subjects were receiving chemotherapy, and 45 had successfully completed treatment for their malignancy. Overall, 18% of the subjects were seronegative for measles antibody and 8% for rubella antibody. Only 3% of patients lacked both. In general, seronegative individuals were over age 10 years. Subjects born before 1976 were significantly more likely to be seronegative to measles, 29% vs. 11% (P = 0.02) and to rubella, 16% vs. 4% (P = 0.03) than those born afterwards. Antibody status showed no apparent relationship to the duration of anticancer therapy. Stored serum samples were available for nine seronegative subjects, of whom five were initially seropositive and then lost antibody during or after the completion of anticancer therapy. Our observations suggest that cancer and its associated therapy interfere with antibody production. In view of the increasing survival rates for childhood cancers, additional studies are needed to assess the immune status of these subjects for all vaccine-preventable infections. Pending the outcome of further studies, we suggest that long-term survivors, particularly those born before 1976, or known to be vaccinated at less than 13 months of age, be tested after the completion of therapy for antibody to measles and rubella (and mumps). Also, immune serum globulin should be considered for any previously immunized patient with a close exposure to an active case of measles.

Antibodies, Viral↗

Purification and initial characterization of a ferret Pneumocystis carinii surface antigen.

The purification and initial characterization of a ferret Pneumocystis carinii surface glycoprotein is described. Previous studies have demonstrated that passive administration of monoclonal antibody recognizing this glycoprotein reduces the severity of P. carinii pneumonitis in animal models of infection. This acidic glycoprotein (approximate isoelectric point, 5.0-5.7) contains both mannose (and/or glucose) and N-acetyl-glucosamine residues. The cross-reactive surface antigen on P. carinii of human origin is also a mannose- (and/or glucose-) containing glycoprotein. Initial biochemical characterization of these surface molecules should aid in understanding the immunobiology of this organism and in developing reliable diagnostic assays for P. carinii pneumonitis.

Animals↗

Immunolabeling of lipopolysaccharide liberated from antibiotic-treated Escherichia coli.

Increased anti-core glycolipid antibody binding was visualized by immunoelectron microscopy after incubation of Escherichia coli K1:O7 cells with a bacteriolytic antibiotic and compared with binding in control cells. The findings suggest that the core glycolipid regions of the lipopolysaccharides of some gram-negative bacilli can be effectively sequestered until liberated by antibiotic-induced cell lysis.

Anti-Bacterial Agents↗

Passive immunoprophylaxis with specific monoclonal antibody confers partial protection against Pneumocystis carinii pneumonitis in animal models.

Pneumocystis carinii is an important cause of pneumonitis in the immunosuppressed host. Little is known, however, about the biology of this organism. This report demonstrates that a MAb, M5E12, previously shown to be directed against a surface antigen that is present on rat-, rabbit-, ferret-, and human-derived P. carinii, is capable of hindering the development of P. carinii pneumonitis in animal models of this infection when administered throughout the period of immunosuppression. It appears that MAb M5E12 thus has identified a surface antigen of P. carinii that is important in host-parasite interactions.

Animals↗

Influence of exercise and CO2 on breathing pattern in patients with chronic obstructive lung disease (COLD).

In ten eucapnic patients with chronic obstructive lung disease (COLD) we evaluated the breathing pattern during induced progressive hypercapnia (CO2 rebreathing) and progressive exercise on an ergometric bicycle (30 W/3 min). The time and volume components of the respiratory cycle were measured breath by breath. When compared to hypercapnia, the increase in ventilation (VE) during exercise was associated with a smaller increase in tidal volume (VT) and a greater increase in respiratory frequency (fR). Plots of tidal volume (VT) against both inspiratory time (TI) and expiratory time (TE) showed a greater decrease in both TI and TE during exercise than with hypercapnia. Analysis of VE in terms of flow (VT/TI) and timing (TI/TT) showed VE to increase by a similar increase to that in VT/TI during both exercise and hypercapnia, while TI/TT did not change significantly. When the patients were matched for a given VE (28 l.min-1), exercise induced a smaller increase in VT (p less than 0.05), a greater increase in fR (p less than 0.025); TI (p less than 0.025) and TE (p less than 0.01) were found to be smaller during exercise than hypercapnia. The change in the off-switch mechanism during exercise and hypercapnia could account for our results.

Adult↗

Changes in neural drive (EMGd) and neuromuscular coupling during histamine-induced bronchoconstriction in patients with asthma.

This study was undertaken in order to assess the neural drive to the respiratory muscles and the inspiratory neuromuscular coupling in patients with bronchial asthma during histamine-induced bronchoconstriction. Bronchoconstriction was produced in a graded fashion, with histamine phosphate aerosol of increasing dose, in twelve asymptomatic asthmatic patients and was measured by FEV1. Inspiratory drive was measured by electromyographic activity of the diaphragm (EMGd) and the coupling of the neural drive to the respiratory muscles was assessed by the relationship of mouth occlusion pressure (P0.1) to EMGd. During the test we also measured electromyographic activity of the inspiratory intercostal (EMGint), sternomastoid (EMGsm) and expiratory abdominal (EMGab) muscles. Histamine caused a significant decrease in FEV1, a significant increase in P0.1, EMGd, EMGint, and a relevant increase in EMGsm, with no substantial increase in EMGab. An inverse significant relationship between the change in FEV1 and changes in P0.1, EMGd and EMGint and a significant correlation between the change in FEV1 and in the P0.1/EMGd ratio were observed. We conclude that a progressive increase in bronchospasm is accompanied by a progressive increase in respiratory neural drive and decrease in neuromuscular coupling. This could be caused both by an increase in lung volume and a lack of abdominal expiratory muscle recruitment.

Adult↗

Cryptosporidiosis in ferrets.

The diagnosis of cryptosporidiosis in two ferrets who died from unrelated causes prompted a survey to determine the prevalence and incidence of the infection in ferrets at our facility. The survey of the existing ferret population and all new arrivals indicated cryptosporidiosis occurred as a subclinical disease in a high percentage of young ferrets: 40% of the ferret population and 38 to 100% of the new arrivals had cryptosporidial oocysts in their feces. The infection was found to persist for several weeks in both immunocompetent and immunosuppressed ferrets. The interspecies transmission of Cryptosporidium implies that infected ferrets should be considered a potential source of infection for the general population.

Animals↗

Effects of aminophylline on respiratory drive and neuromuscular coupling in normal man and in patients with chronic airflow obstruction.

In order to evaluate the separate effects of aminophylline on the neural and muscular components of the respiratory control system, assessed by electromyographic activity of the diaphragm (EMGd) and mouth occlusion pressure (P0.1), respectively, 6 normal subjects and 14 patients with mild or moderate chronic airflow obstruction (8 asthmatics and 6 COPD) were studied during CO2 rebreathing, before and after administration of a therapeutic dose of aminophylline 5.6 mg/kg. Compared to normal subjects, before aminophylline administration both asthmatic and COPD patients exhibited a significantly greater value in EMGd response slope to CO2. In no group did aminophylline modify P0.1 or EMGd activity response slope to CO2, nor did it significantly affect neuromuscular coupling, assessed by plotting change in P0.1 against change in EMGd activity with increasing CO2. The data appear to indicate that aminophylline in therapeutic concentrations does not modify respiratory drive or neuromuscular coupling in normal subjects, or in patients with mild or moderate chronic airflow obstruction.

Action Potentials↗

Induction of prostaglandin synthesis as the mechanism responsible for the chills and fever produced by infusing amphotericin B.

Amphotericin B produces chills and fever in a significant proportion of patients who receive this drug. The mechanism for this adverse effect is unknown. Amphotericin B suspension at a concentration of 1.0 microgram/ml was demonstrated to be a potent inducer of prostaglandin E2 synthesis by human and murine mononuclear cells in vitro. A double-blind, placebo-controlled clinical trial demonstrated that ibuprofen (10 mg/kg), a potent inhibitor of prostaglandin synthesis, administered 30 min before amphotericin B administration reduced the incidence of chilling from 87% to 49% (P = .01); the incidence of chilling reactions considered severe was reduced from 69% to 15% (P = .008). We postulate that the chills and fever produced by an infusion of amphotericin B are mediated through prostaglandin E2 synthesis. Ibuprofen is therapeutically useful in ameliorating the chills and fever caused by amphotericin B.

Adolescent↗