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Biomedical subjects

J Mendelson

Publications and source records attributed to J Mendelson.

At least 19 recordsLinked to original sources

Left ventricular morphologic features and function in nonhospitalized cocaine users: a quantitative two-dimensional echocardiographic study.

To determine whether left ventricular (LV) hypertrophy or dysfunction is present in nonhospitalized cocaine users, we performed quantitative two-dimensional echocardiography in 20 intravenous cocaine users and 20 age- and sex-matched controls. Cocaine users were normotensive, had begun taking cocaine an average of 14 years earlier, and had used cocaine an average of 8 times/mo during the preceding year. There were no significant differences between cocaine users and control subjects for LV mass index (79 vs 74 gm/m2, respectively), mean wall thickness (0.95 vs 0.91 cm), end-diastolic volume index (55 vs 56 ml/m2), end-systolic volume index (17 vs 19 ml/m2), or ejection fraction (70 vs 66%; p > or = 0.09 for all comparisons). Moreover, none of the cocaine users or control subjects had significant regional wall motion abnormalities, and none of the subjects or controls had ejection fractions < 55%. Thus we found little evidence that significant LV hypertrophy or dysfunction is present in nonhospitalized cocaine users. From these results we speculate that cocaine-associated LV hypertrophy and dysfunction may be restricted to certain high-risk groups of chronic cocaine users.

Adult

Methamphetamine and ethanol interactions in humans.

OBJECTIVE: Methamphetamine and ethanol are commonly used together. We examined the effects of intravenous methamphetamine (30 mg), oral ethanol (1 gm/kg), and the combination of methamphetamine (30 mg) and ethanol (1 gm/kg). METHODS: Eight methamphetamine and ethanol users were studied in a double-blind, double-placebo, within-subject, balanced Latin-square design. Ethanol was administered in six drinks over 30 minutes. Methamphetamine was injected 60 minutes after the first drink was begun. Cardiovascular, subjective, and neuropsychologic effects of the drug combinations were measured for 6 hours. Methamphetamine and amphetamine in plasma and urine were measured by capillary gas chromatography for 48 hours. Data were analyzed by repeated-measures ANOVA. RESULTS: Compared with methamphetamine alone, the combination increased heart rate but decreased systolic blood pressure. The net cardiovascular effect was an increase in rate pressure product, an index of cardiac work and myocardial oxygen consumption. The combination diminished the subjective effects of ethanol while not affecting the subjective effects of methamphetamine. Methamphetamine pharmacokinetics were not altered by the concurrent administration of ethanol, with the exception of lowering the apparent volume of distribution at steady state for methamphetamine. CONCLUSIONS: As a potent sympathomimetic drug with alpha-agonist-like effects, methamphetamine increased systolic blood pressure, with minimal change in heart rate. The concurrent administration of methamphetamine and ethanol increased cardiac work, which could produce more adverse cardiovascular effects than either drug taken alone. The increased perceived global intoxication may explain the popularity of this drug combination.

Administration, Oral

Anterior chamber contamination after uncomplicated phacoemulsification and intraocular lens implantation.

PURPOSE: To determine the frequency of anterior chamber contamination occurring during uncomplicated cataract surgery with intraocular lens implantation using phacoemulsification through a scleral tunnel incision. METHODS: In a prospective study, anterior chamber aspirates of one eye each of 103 consecutive ambulatory patients who underwent uncomplicated cataract surgery with lens implantation were cultured. The anterior chamber aspirate was withdrawn immediately upon the completion of surgery. Conjunctival cultures of the same eye were taken immediately before surgery, after the eye and periocular area had been prepared and draped. Multiple use topical medications used preoperatively on all patients were cultured at the end of the surgical day. RESULTS: Intraocular aspirates yielded positive cultures in five specimens (5%), four of which were identified as Staphylococcus epidermidis. Quantification disclosed colony counts ranging between 100 and 200 colony forming units per milliliter. Results of conjunctival cultures were positive in ten specimens (10%). Staphylococcus epidermidis was the most common isolate, identified in seven of the ten positive cultures. Positive intraocular and conjunctival culture results were not present concurrently in any patient. Microorganisms were recovered from the multiple use topical medications on nine of the 26 successive surgical days. Neisseria species was the most frequent isolate (7,44%), followed by S. epidermidis (5,31%). The frequency of contamination of the anterior chamber was independent of wound width (chi 2 = 0.869) and operative time (chi 2 = 4.77). CONCLUSION: Bacterial contamination of the anterior chamber was detected in five (5%) of the patients. This reduced incidence of contamination compared with that of previous studies may be related to the preoperative preparation, the surgical technique, or both. Contamination of the multiple use topical medications and bulbar conjunctiva define possible sources of pathogens that may enter the anterior chamber. The absence of any clinical ocular infection in all patients attests to the small inoculum sizes, as well as the ability of the anterior chamber to clear small bacterial loads.

Administration, Topical

Growth curves of Staphylococcus aureus, Candida albicans, and Moraxella osloensis in propofol and other media.

Propofol, 2,6 diisopropylphenol, in an emulsion formulation (Diprivan), has been associated with postsurgical infections caused by Staphylococcus aureus, Moraxella osloensis and Candida albicans. These organisms were individually inoculated into each of the following media: (1) the emulsion preparation of propofol, (2) Intralipid 10%, (3) pure 2,6 diisopropylphenol, and (4) trypticase soy broth (TSB). The organisms were incubated and subcultured hourly for eight hours at room temperature. Propofol supported the growth of all three organisms, but for S. aureus and M. osloenis, the growth rate was slower in propofol than in TSB (P less than 0.05). There was no difference between the growth rate of any organism in propofol than in Intralipid 10%. The authors conclude that propofol, in the emulsion formulation, supports bacterial growth and, therefore, must be prepared for administration in an aseptic manner. Also, by administering propofol soon after preparation, the risk of introduction of a significant inoculum to the patient will be reduced.

Candida albicans

Recombinant alpha-2 interferon gel treatment of recurrent herpes genitalis.

Topical recombinant alpha-2 interferon treatment of recurrent genital herpes was studied in a randomized, double-blind, placebo controlled clinical trial. Three hundred and eighty-seven patients were treated at eight study centers with either interferon gel or placebo four times daily for four days. Interferon therapy caused a 26% decrease in the duration of viral shedding. For male patients, there were also significant decreases in the time to crusting (17%) and duration of pain (34%) and itching (21%). For patients with recurrent genital herpes, treatment with topical interferon was found to be effective in decreasing the duration of viral shedding and, for males, pain, itching and time to crusting.

Administration, Cutaneous

A comparison of brain perfusion SPECT in cocaine abuse and AIDS dementia complex.

Intravenous drug use is a major risk factor for HIV-1 infection. Since both AIDS dementia complex (ADC) and cocaine have been associated with abnormal brain perfusion imaging, we compared the scintigraphic patterns of ADC patients and cocaine polydrug users with normal control subjects using 99mTc-HMPAO SPECT. We found a high incidence of cortical defects in both ADC (100%) and cocaine-dependent (90%) subjects. In the cocaine and ADC patients, cortical defects were most frequent in the frontal, temporal and parietal lobes and occurred with similar frequency in the two populations. In both groups, the number of cortical defects per subject was higher than normal subjects (10.0 +/- 5.0 for ADC, 10.1 +/- 5.2 for cocaine and 0.7 +/- 1.5 for normal), background activity was high (a 65% and 60% incidence for ADC and cocaine, respectively), and basal ganglia involvement was frequent (40% and 65% for ADC and cocaine). We conclude that the brain perfusion pattern, while a sensitive indicator of ADC, cannot be distinguished from chronic cocaine polydrug use and caution should therefore be applied before entertaining a specific diagnosis.

AIDS Dementia Complex

Ability of National Committee for Clinical Laboratory Standards-recommended quality control strains from the American Type Culture Collection to detect errors in disk diffusion susceptibility tests.

The National Committee for Clinical Laboratory Standards (NCCLS) recommends, as a quality control for the disk diffusion susceptibility test, the use of three strains from the American Type Culture Collection: Staphylococcus aureus ATCC 25923, Pseudomonas aeruginosa ATCC 27853, and Escherichia coli ATCC 25922. This study assesses the capacity of these strains to detect errors in the overall method. ATCC strains were tested by comparing testing by the standard NCCLS-recommended procedure (ST) with testing under the following conditions: incubation at 25 degrees C, Mueller-Hinton agar depths of 2 mm (AD2) and 8 mm (AD8), agar pHs of 6.5 and 8, inocula with McFarland standards of 0.25 (0.25M) and 4.0 McFarland (4.0M), direct inoculation without preincubation of inoculum (DI), and a 2-h delay between inoculation and disk application (2HR). The frequency of zone measurements outside the NCCLS-recommended control zone limits were as follows: ST, 0%; AD2, 18%; AD8, 9.6%; pH 6.5, 7.9%; pH 8, 5.3%; 0.25M, 3.5%; 4.0M, 24%; DI, 3.4%; 2HR, 1.8%; 25 degrees C (only E. coli and P. aeruginosa were evaluable), 28%. These results suggest that the quality control strains are only partially effective in detecting single extreme laboratory errors and that careful laboratory supervision is necessary even in the setting of properly monitored quality control strains.

Clinical Laboratory Techniques

Brain perfusion is abnormal in cocaine-dependent polydrug users: a study using technetium-99m-HMPAO and ASPECT.

Cocaine abuse is widespread and has been associated with serious neurovascular complications. We studied a group of cocaine-dependent polydrug users with 99mTc-HMPAO and high-resolution SPECT and compared their perfusion pattern to cerebral perfusion in a group of older control subjects. Sixteen of 18 cocaine-dependent polydrug users had abnormal perfusion characterized primarily as small focal defects involving inferoparietal, temporal, and anterofrontal cortex and basal ganglia. Psychometric testing was abnormal in all 18 cocaine-dependent subjects. No relation was found between the severity of SPECT abnormalities and mode of administration or frequency or length of cocaine use. All 15 older normal subjects had normal cerebral perfusion. While the focal perfusion abnormalities to the cortex and basal ganglia could be explained by the profound vasoconstrictor effects of cocaine, the combinational use of multiple substances including cannabis and alcohol may play a contributory role. This study documents the high incidence of functional brain abnormalities in cocaine-dependent chronic polydrug users without corresponding abnormalities on imaging studies of cerebral anatomy and morphology.

Adult

Diagnosis of herpes simplex virus infection in a clinical setting by a direct antigen detection enzyme immunoassay kit.

A commercial 4-h direct herpes simplex virus (HSV) antigen detection enzyme immunoassay (EIA) kit (Du Pont Herpchek) was evaluated by using 273 clinical specimens obtained in a hospital-based infectious disease practice. The EIA was compared with a standard culture method in which WI38 cells were inoculated within 20 min of sample collection. Cultures were observed for 2 weeks, and positive findings were confirmed by fluorescein-labeled monoclonal antibody (FA) staining. The values for the overall HSV detection rate were 40.7% by the standard culture method and 41.4% by EIA. In eight cases, the EIA was positive, while the culture method was negative; however, clinical data and confirmatory blocking EIA suggested that a true HSV infection was present. For six FA-confirmed, culture-positive samples, the direct EIA was negative; however, an EIA performed on the supernatants of these cultures was positive, suggesting that the failure of the EIA to detect these samples was not due to lack of strain specificity of the test. After confirmatory tests of standard culture and EIA discrepant results, the overall sensitivity of the test was 95.0% (113 of 119) and the specificity was 100% (154 of 154).

Acyclovir

Dilated cardiomyopathy in children with acquired immunodeficiency syndrome: a pathologic study of five cases.

Clinicopathologic features with special reference to the heart are presented in five fatal cases of acquired immunodeficiency syndrome (AIDS) in children. Three children showed clinical evidence of cardiovascular compromise or congestive heart failure. Autopsy was performed in all cases. The enlarged heart showed biventricular dilatation with grossly unremarkable valves and coronary arteries and absence of mural thrombi. Microscopic examination of the heart revealed primarily myopathic abnormalities with hypertrophy of the myocardium and only rare foci of sparse inflammatory infiltrate. The pathogenesis of dilated cardiomyopathy in these children with AIDS is not known. Infection, immunologic factors, anemia, deficiency of nutritional factor(s), and longer survival may be related to the pathogenesis. Pediatricians should be alert to the possibility of cardiac involvement in pediatric AIDS.

Acquired Immunodeficiency Syndrome

Cefoperazone compared with ampicillin plus tobramycin for severe biliary tract infections.

In a prospective, randomized, multicenter study, the efficacy and safety of cefoperazone and the combination ampicillin-tobramycin as initial therapy for patients with severe acute biliary tract infections were compared. Of 77 patients initially entered in the study, definite severe biliary tract infection was confirmed in 67. Sixty-four patients completed treatment. At the end of treatment, 35 of 36 (97%) patients given cefoperazone and 23 of 28 (82%) given ampicillin-tobramycin were cured of their infection (P = 0.07). Pathogens were recovered from the bile in 32 patients; microbiological cures were observed in 18 of 19 (94%) patients receiving cefoperazone and 8 of 13 (62%) receiving ampicillin-tobramycin (P = 0.03). Thirteen patients had septicemia. None (0%) of the eight septicemic patients from the cefoperazone group, but two of five (40%) from the ampicillin-tobramycin group, were clinical failures. Of the isolated pathogens, 51% were resistant to ampicillin, while the resistance rate was 4% for tobramycin and 1% for cefoperazone (P less than 0.001). Biliary concentrations of cefoperazone were maintained at high levels--236 +/- 87 micrograms/ml up to 12 h after administration. Even in the presence of severe obstruction, cefoperazone levels in the bile and gallbladder wall were above MICs for most pathogens. Cefoperazone may be considered as an excellent alternative in the therapy of severe biliary tract infections.

Acute Disease