Biomedical subjects

M Lesser

Publications and source records attributed to M Lesser.

At least 55 records · Page 3Linked to original sources

PubMed1996

Airway hyperresponsiveness to methacholine in subjects with spinal cord injury.

Previously, we found that never-smokers with quadriplegia were hyperresponsive to aerosolized methacholine. To further explore the phenomenon, we compared responsiveness to methacholine in never-smokers with that of smokers and ex-smokers. We also evaluated responsiveness in subjects with high paraplegia (lesions at T-1 to T-6) or low paraplegia (lesions at T-7 and below). We found that smokers and ex-smokers with quadriplegia were hyperresponsive to methacholine (provocative concentration causing a 20% fall in FEV1 = 1.9 mg/mL), and that the response was comparable to that found in never-smokers, revealing that hyperresponsiveness among never-smokers cannot be attributed to preinjury airway hyperreactivity that precluded cigarette use. In contrast, subjects with low paraplegia were not hyperresponsive to methacholine. Among subjects with high paraplegia, the three subjects demonstrating airway hyperresponsiveness had significantly lower FEV1 (percent predicted). The findings support the hypothesis that airway hyperresponsiveness in subjects with quadriplegia represents loss of sympathetic innervation of the lung, thereby leaving intact unopposed bronchoconstrictor cholinergic activity. However, reduced lung volumes in these subjects also suggest the possibility that airway hyperresponsiveness is due to loss of ability to stretch airway smooth muscle by deep breathing.

Adult↗

PubMed1995

Isolated fetal hydronephrosis: beware the effect of bladder filling.

The aim was to assess the role that fetal bladder size has in the determination of fetal hydronephrosis. Forty-three fetuses were evaluated for fetal hydronephrosis in the second trimester of pregnancy. Anteroposterior measurements of the renal pelvis were obtained with a full bladder and again when the bladder emptied in each fetus. Statistical analysis was performed using the Spearman rank order correlation coefficient to assess the relationship between bladder status and renal dilation. The anteroposterior size of the fetal renal pelvis diminished from 6.8 +/- 1.8 mm on a full bladder scan to 4.5 +/- 1.6 mm when the bladder was emptied (P < 0.001). Fifty-three per cent of the fetuses whose renal pelvic measurements were 5 mm or more on a full bladder scan had normal-appearing renal pelvises when their bladders emptied. The status of the fetal bladder should be considered when evaluating fetal hydronephrosis.

Diagnostic Errors↗

PubMed1995

Pulmonary function survey in spinal cord injury: influences of smoking and level and completeness of injury.

Spirometry was performed on 165 subjects with spinal cord injury (84 with quadriplegia and 81 with paraplegia). Subjects were characterized by level of lesion as: high quadriplegia (HQ, C4 and above not requiring mechanical ventilation), low quadriplegia (LQ, C5-8), high paraplegia (HP, T1-7), and low paraplegia (LP, T8-L3). Thirty-nine subjects had complete motor lesions, and 126 had incomplete motor lesions. Nonsmokers (54 with quadriplegia and 53 with paraplegia) were defined as those who had never smoked or those who had stopped smoking for 1 year. Current smokers (28 with quadriplegia and 28 with paraplegia) were defined as those who currently smoked cigarettes, cigars, and/or pipe or those who had quit for < or = 1 year. We found by linear regression analysis that forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), peak expiratory flow (PEF), and maximal voluntary ventilation (MVV) were inversely correlated with the level of injury (i.e., the higher the level of injury, the lower the parameter). In the HQ group, those with complete injury had significantly lower pulmonary function parameters than those with incomplete lesions. In contrast, there were no significant differences in pulmonary function parameters between complete and incomplete lesions in subjects in the LQ, HP, and LP groups. In the LQ, HP, and LP groups, the FEV1 and PEF were significantly lower in smokers than in nonsmokers. Thus, this study demonstrates the effects of completeness of injury and smoking on pulmonary function in a large group of subjects with spinal cord injury.

Adolescent↗

PubMed1995

The fertility of women after cervical laser surgery.

OBJECTIVE: To retrospectively survey our population of women who had undergone cervical laser surgery to determine if it adversely affected their ability to conceive or to carry a pregnancy to term. METHODS: Women who had undergone laser surgery during the period 1979-1989 were contacted and surveyed regarding each of their pregnancies. Information obtained included their age at the time of each pregnancy, pregnancy outcome, how long they were trying to conceive, and their use of contraception. The post-laser experience of the study group was matched individually for age and parity with a control population taken from the pre-laser interval of the same patients. RESULTS: We contacted 1069 women; 512 responded to the survey and 433 were matched with controls. The mean study interval was 3.8 years. The study group had significantly more total pregnancies (277 versus 177 for controls, P < .001), total births (163 versus 112 for controls, P < .002), full-term pregnancies (145 versus 100 for controls, P < .005), and terminations of pregnancy (75 versus 28 for controls, P < .001). There was no significant difference in the number of spontaneous abortions (31 for the study group and 33 for controls), premature deliveries (18 for the study group and 12 for controls) or ectopic pregnancies (eight for the study group and four for controls). There was no difference in the pregnancy rate (compared with controls) between laser vaporizations and excisions. CONCLUSION: Cervical laser surgery does not appear to impair a woman's ability to conceive or carry a pregnancy to term. There is no difference in the effect on fertility between laser vaporization and laser excisional cone biopsies.

Adult↗

PubMed1995

Degradation of lysylbradykinin by endopeptidase 24.11 and endopeptidase 24.15.

Lysylbradykinin (LBK), a potent bioactive peptide with pleiotropic actions, is the major kinin generated in the extravascular space. To explore possible mechanisms of inactivation of this peptide in tissues, we evaluated its degradation by endopeptidase 24.11 (EP 24.11) and endopeptidase 24.15 (EP 24.15), two zinc metalloenzymes widely distributed in tissues. EP 24.11 cleaved LBK at the Gly5-Phe6 and Pro8-Phe9 bonds, whereas EP 24.15 cleaved the Phe6-Ser7 bond. Determination of kinetic constants for degradation of LBK by the two enzymes yielded kcat/Km ratios of 5.2 x 10(5) and 8.4 x 10(5) for EP 24.15 and EP 24.11, respectively, indicating that LBK is a good substrate for both enzymes. The findings demonstrate that both EP 24.11 and EP 24.15 efficiently degrade LBK and thus may contribute to the inactivation of this peptide in tissues.

Amino Acid Sequence↗

PubMed1995

Unmet analgesic needs in cancer patients.

This study was designed to characterize unmet analgesic needs in a group of cancer patients. One hundred one inpatients were surveyed to document pain prevalence and intensity, satisfaction with pain control and factors associated with unmet analgesic needs during the week prior to admission. Forty-four percent had unmet analgesic needs, defined as pain of moderate or greater than moderate intensity. These patients had a significantly greater prevalence of bone and axillary node involvement, higher than pain intensity, and less satisfaction with pain control. Fifty-nine percent were satisfied with pain control. Dissatisfaction was associated with higher usual pain intensity, less satisfaction with physician information about pain etiology, less frequent attribution of pain to disease, sharp pain, constant and intermittent pain, patient perceptions of less physician concern about pain, patient and physician belief that the patient is receiving insufficient analgesic, and patient wanting more control over analgesic regimen. Patients may benefit from improved treatment of specific syndromes and by attention to communication.

Aged↗

PubMed1995

CPR knowledge, self-efficacy, and anticipated anxiety as functions of infant/child CPR training.

STUDY OBJECTIVE: To determine the effect of infant/child CPR training on CPR knowledge, self-efficacy, and anticipated anxiety among parents of healthy infants/children. PARTICIPANTS: Parents (n = 36) undergoing a 4-hour training program in infant/child CPR at a tertiary-care hospital located in a suburb of a large metropolitan region and a control group of parents (n = 47) without CPR training were enrolled in the study. DESIGN: Two parallel forms developed specifically to assess the impact of infant/child CPR training on CPR knowledge, self-efficacy, and anticipated anxiety were independently evaluated for their psychometric characteristics before being administered to the parents with and without CPR training. The CPR-trained parents were requested to complete one form immediately before and the other 1 month after CPR training, and the control group completed the two forms over a 1-month interval. Estimates of the likelihood of infant/child CPR situations were also rated by the parents at the same times. Demographic data were obtained during administration of the second form. RESULTS: Self-efficacy had increased significantly and anticipated anxiety about CPR had decreased significantly 1 month after CPR training among CPR-trained parents, compared with controls. We found no significant changes in the CPR-trained parents' CPR knowledge or estimates of the likelihood of experiencing CPR situations over the 1-month interval on comparison with data from the controls. CONCLUSION: Community-based infant/child CPR training programs affect parents on a variety of levels but may not effect changes in CPR knowledge.

Adult↗

PubMed1995

Immunological characteristics of HIV-infected children: relationship to age, CD4 counts, disease progression, and survival.

We have evaluated immunologic markers of disease progression in 79 children perinatally infected with HIV. Laboratory testing included T lymphocyte subsets and lymphoproliferative responses (LPR) to mitogens (PHA, Con A, and PWM), antigens (Candida, Tetanus), and alloantigens (MLC). Patients were graded into grades I, II, and III based on results of CD4 counts, and into grades A, B, and C based on results of LPR, with grades I and grades A being normal, III and C being the lowest, and II and B falling in-between. CD4 counts, CD4/CD8 ratio, and lymphoproliferative responses were markedly decreased in a majority of children. Grade III CD4 counts were almost always associated with decreased LPR. A majority of the children with grade I CD4 numbers, however, also had abnormal lymphoproliferative responses. Results of laboratory testing were analyzed in relation to clinical disease progression and survival. The first AIDS defining illnesses (ADI), especially opportunistic infections (OI), was usually associated with Grade III/C results in immunologic assays. Survival was significantly decreased in children with grade III CD4 cell counts, and grade C LPR, and was poorest if these abnormalities developed within the first year of life. In this latter age group, if the CD4 counts fell to grade III, the risk for dying was at least five times greater than those children with higher CD4 counts (grades II and I); if the proliferative responses to PHA and MLC were in Grade C, the survival was 22 months. Severe immune defects in the first year of life in children with HIV infection, as assessed by CD4 counts and a battery of functional tests, predicted rapid disease progression.

Age Factors↗

PubMed1995

Prevalence of cigarette smoking in a group of male veterans with chronic spinal cord injury.

Male veterans with spinal cord injury (SCI) were surveyed regarding their smoking history. Subjects (n = 250) were placed in one of two categories: never smokers (smoked < or = 100 cigarettes in lifetime), or ever smokers (divided into former smokers, quit smoking for > 1 year, or current smokers). Never smokers constituted 23.2%, and ever smokers constituted 76.8% of the sample. Among the ever smokers, 59.4% had quit, compared with 49.1% in the general population (p < 0.05). In the former smokers, 23% had quit before injury, 24% quit within 1 year of injury, and the remaining 53% quit > 1 year after injury. In this sample veteran SCI population, the number of current smokers is comparable to that found in the general population. The lower number of never smokers with SCI (23.2%) compared with the general population (49.9%) most likely reflects the smoking habits of a veteran population.

Adult↗

PubMed1994

Method of tumor detection influences disease-free survival of women with breast carcinoma.

BACKGROUND: Screening mammography provides the primary means of reducing breast cancer mortality. Clinical breast examination (CBE) and breast self-examination (BSE) may be complementary screening modalities enabling palpation of interval cancers and detection of tumors not visualized by mammography; however, their combined contribution to improving prognosis has not been evaluated adequately. METHODS: Disease-free survival was assessed in relation to method of tumor detection among 729 consecutive patients treated by mastectomy and axillary dissection for primary breast carcinoma between 1976 and 1978. RESULTS: Disease-free survival at 10 years was significantly higher after detection by mammography (77% of 30 patients) or CBE (78% of 101 patients) compared to self-detection (64%). The hazard ratio of recurrence associated with clinical examination or mammography in contrast to self-detection was significantly reduced to 0.55 (95% CI, 0.37-0.81; P = 0.001). In addition, annual CBE, compared to less frequent clinical palpation, reduced the risk of recurrence controlling for detection modality (P = .03). In multivariate analyses, the method of detection and frequency of clinical breast examination remained statistically significant prognostic factors after controlling for number of screening mammograms, history of prior breast surgery, family history of breast cancer, and age at diagnosis. Differences in self-examination frequency were not associated with prognosis. CONCLUSIONS: Among patients diagnosed before widespread mammography screening, tumor detection by CBE was associated with a significant reduction in recurrence compared with detection by self-palpation. Improvement in the frequency and quality of CBE and BSE may enhance the contribution of these modalities to early detection, complementing the role of screening mammography in reducing breast cancer mortality rates.

Adult↗

PubMed1994

Effects of peptidase inhibitors on bradykinin-induced bronchoconstriction in the rat.

Objectives of this study were to determine if aerosolized bradykinin causes bronchoconstriction in anesthetized, mechanically ventilated rats, and if pretreatment with enalaprilat, an inhibitor of angiotensin-converting enzyme (ACE), or phosphoramidon, an inhibitor of endopeptidase 24.11 (EP 24.11), alters the response. We found that aerosolized bradykinin elicited a reproducible bronchoconstrictor response that was significantly amplified by pretreatment with aerosolized enalaprilat or phosphoramidon. Neither inhibitor alone affected airway tone or caused nonspecific airway hyperreactivity. These findings indicate that both ACE and EP 24.11 contribute to bradykinin degradation in rat airways.

Aerosols↗

PubMed1993

Pulmonary mechanics and gas exchange: effect of lateral positioning during recovery from respiratory distress syndrome.

Sixteen stable intubated premature infants without a clinically significant patent ductus arteriosus were studied during recovery from respiratory distress syndrome in order to determine the effects of left and right lateral, as compared to supine, positioning. Pulmonary mechanics were measured for spontaneous breaths 5 and 15 minutes after positioning, and arterial blood gases 15 minutes after positioning. Infants were randomized to 1 of 2 position sequences: (1) supine, left, supine, right or (2) supine, right, supine, left. No significant differences were detected between positions for dynamic compliance, tidal volume/kg, and total, inspiratory and expiratory pulmonary resistance. Likewise, no significant differences in PaO2 or PaCO2 were detected between the positions. The sequence of positions did not affect the pulmonary mechanics of spontaneous breaths or arterial blood gases. This suggest that short-term lateral positioning as well as supine positioning can be utilized without deleterious effects on pulmonary mechanics and gas exchange in neonates recovering from respiratory distress syndrome.

Analysis of Variance↗

PubMed1993

Colonic mucosal pH in humans.

Mucosal pH was measured at specific anatomic segments within the colon using a flexible pH probe in patients prepared for colonoscopy. The data revealed similar pH measurements along the length of the colon, irrespective of the presence or absence of colorectal neoplasia. Patients exhibited a relatively acidic right colon; a more alkaline transverse, left, and sigmoid colon; and a relatively acidic rectum. There were no apparent gender- or age-related effects on colonic mucosal pH.

Colon↗

PubMed1993

Effect of phenytoin on acute lung injuries in unanesthetized sheep.

OBJECTIVE: To determine if the intravenous administration of phenytoin attenuates or prevents acute experimental lung injury. DESIGN: Placebo-controlled, longitudinal animal investigative study. SETTING: University research laboratory. SUBJECTS: Sixteen yearling female lambs weighing 30 +/- 3 kg. INTERVENTION: After administration of anesthesia, the animals were endotracheally intubated and mechanically ventilated. Using sterile techniques, four thoracotomies were performed. Through the left fourth intercostal space, cannulas for pressure measurements were inserted directly into the main pulmonary artery and left atrium. An ultrasound flow cuff for determination of cardiac output was placed around the main pulmonary artery. Through the left tenth intercostal space, the diaphragmatic and mediastinal parietal pleura were widely cauterized. Through the right tenth intercostal space, the caudal mediastinal lymph node was identified and divided at the caudal margin of the right pulmonary ligament, and a 1- to 2-cm portion of the node distal to the ligament was resected. The diaphragmatic and mediastinal parietal pleura were widely cauterized. Through the right sixth intercostal space, the efferent duct (or ducts) was identified, ligated at the site of entry into the thoracic duct, and cannulated. The lymph cannula was brought to the outside of the thorax through a separate stab wound. MEASUREMENTS AND MAIN RESULTS: Unanesthetized sheep were studied 7 to 10 days after surgery. Hemodynamic, lung fluid balance, and arterial blood variables were measured in uninjured sheep and in sheep injured by intravenous infusions of Escherichia coli endotoxin (1 microgram/kg iv over 30 mins), air bubbles (0.056 to 0.074 mL/kg/min over 4 hrs), or oleic acid (0.06 mL/kg over 1 hr). The sheep were studied when untreated and after pretreatment with phenytoin. We found that the expected increase in protein-rich lung lymph flow with injuries, resulting from increased microvascular permeability in the lungs, was attenuated by phenytoin when the lungs were injured by endotoxin or air bubbles. In contrast, phenytoin had no effect on oleic acid-induced lung injury or on uninjured lungs. CONCLUSIONS: Phenytoin attenuates acute lung injuries in sheep that are thought to be caused by stimulation of host inflammatory responses (e.g., endotoxin and air bubbles), but has no effect on direct injuries to the lungs (e.g., oleic acid). A plausible mechanism for this finding is phenytoin inhibition of polymorphonuclear leukocyte function.

Animals↗

PubMed1992

Phenotypic analysis of 1-B-D-arabinofuranosylcytosine deamination in patients treated with high doses and correlation with response.

Two phenotypes for 1-B-D-arabinofuranosylcytosine (ara-C) deamination corresponding to a ratio of distribution for "slow" (ratio, less than or equal to 14) vs "fast" (ratio, greater than 14) deaminators of 70%:30%, have been determined on the basis of studies on plasma ratios of 1-B-D-arabinofuranosyluracil/ara-C (ara-U/ara-C) in 56 subjects treated with high-dose ara-C (3 g/m2 infused i.v. over 3 h). A positive correlation of age with the concentration of ara-U was observed. In a subgroup of 36 patients with leukemia, the ara-U/ara-C pattern was similar to that observed for all 56 subjects. In these leukemic patients, who were treated with combinations of ara-C plus other conventional agents, a tendency toward a positive response (complete response + partial response) was found for those showing low ara-U/ara-C ratios (slow deaminators). The phenotypic effect of deamination in acute leukemia needs to be evaluated prospectively.

Adolescent↗

PubMed1992

Lipopolysaccharide-induced stimulation of alveolar macrophage opsonin-independent phagocytosis.

Alveolar macrophage (AM) opsonin-independent phagocytosis may be an important process by which bacteria are cleared from the airspaces. Although it has been shown that clearance of bacteria from the lung is altered in association with endotoxemia, the effect of endotoxemia on opsonin-independent phagocytosis is unknown. Because alterations in AM opsonin-independent phagocytosis could potentially influence bacterial clearance in the lung, we studied the effects of the intravenous injection of Escherichia coli lipopolysaccharide (LPS) into rats on AM opsonin-independent phagocytosis of latex particles. AM obtained by bronchoalveolar lavage (BAL) 2 or 4 hr after injection of LPS demonstrated phagocytosis comparable to AM from control animals. In contrast, AM obtained 12 hr after injection of LPS demonstrated a nearly threefold increase in phagocytosis. Depletion of serum complement with Naja naja cobra venom factor (CVF) did not alter LPS-induced augmentation of phagocytosis. Furthermore, phagocytosis of AM obtained by BAL 2 or 12 hr after activation of complement by injection of CVF was not significantly different from that of AM from control animals, indicating that complement activation alone was not sufficient to stimulate opsonin-independent phagocytosis. These observations suggest that opsonin-independent phagocytosis may represent an important route of bacterial uptake by AM following endotoxemia, and that LPS-induced stimulation of AM opsonin-independent phagocytosis may occur independently of activation of complement by LPS.

Animals↗

PubMed1992

Use of the Dementia Rating Scale as a test for neuropsychological dysfunction in HIV-positive i.v. drug abusers.

Intravenous drug abusers (IVDAs) represent an increasing proportion of the HIV epidemic. Forty-three IVDA's (22 HIV-negative, 21 HIV-positive) were studied using the Mattis Dementia Rating Scale (DRS). All subjects had used intravenous heroin, but reported that they were drug-free at the time of testing. HIV-positive subjects were predominantly symptomatic and were dichotomized into AIDS and non-AIDS groups. All subjects with abnormal DRS scores were HIV-positive (57% of all HIV-positives). All HIV-negative subjects had normal DRS scores while 43% of the positive group obtained such scores. The DRS reliably identifies neuropsychological impairment, and may be a useful screening tool in this population.

AIDS Dementia Complex↗

PubMed1992

Substance use in a school-based clinic population: use of the randomized response technique to estimate prevalence.

Students attending school-based clinics acknowledge only minimal involvement with drug or alcohol use. In order to explain this unanticipated finding, we used a statistical method called randomized response to study adolescents in one school-based clinic. The sample consisted of 133 students (57% female; 75% black, 20% Hispanic, 5% other; and 58% grades 9-10, 42% grades 11-12). Using both lifetime and 30-day prevalence rates, these students revealed more cigarette smoking and alcohol use on randomized response than they had on questionnaires completed earlier the same academic year, minimal involvement with either marijuana or cocaine use by either method, and a similar amount of sexual activity by both methods. This study demonstrates that randomized response can be a useful method to generate more truthful group responses from adolescents.

Adolescent↗