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Biomedical subjects

M Simmons

Publications and source records attributed to M Simmons.

At least 37 records · Page 2Linked to original sources
PubMed2000

Suburban versus urban: does it matter where the residency interview begins?

Geographic location is an important factor in students' ranking of residency programs. Our program's inner city location has a negative impact on our recruitment efforts. In an attempt to assess the impact of geography, we started half of the residency interview days at our suburban community medical center and then measured the effect on the applicant's perception of the program. During the 1998-1999 residency interview season we alternated the site at which the day began. Students were randomly assigned based on interview date requests to starting the day at the urban hospital or at the community hospital. At the conclusion of the day the students completed a questionnaire regarding various components of the interview day and how their perception of the program was influenced by the experience. Of 206 students asked to complete the questionnaire, 188 (91%) completed the survey. The degree to which the students' perception of the program was affected was remarkably similar regardless of where the interview day began; however, significant differences were found between the Chairman's Talk, the Teaching Session, and talking with current residents when compared by univariate analysis. We concluded that students' perception of the program at the conclusion of the interview day was similar regardless of whether the interview day began at an urban or suburban medical center.

Career Choice↗
PubMed1999

Lumbar agenesis with sacral sparing: a case report.

Caudal agenesis or caudal regression syndrome refers to a spectrum of malformations involving the lower spine, which can result in significant progressive or permanent neurologic defects. Caudal agenesis is frequently associated with other congenital anomalies of the axillary skeleton, hindgut and genitourinary systems. Described in this paper is a patient who presented with multiple clinical and radiographic findings consistent with caudal agenesis. This case is unique in that there is total absence of the lumbar vertebral column with an intact spinal cord and bony sacrum.

Abnormalities, Multiple↗
PubMed1999

Nocturnal increase in plasma cGMP levels in humans.

The circadian dynamics of responses to cyclic guanosine 3',5'-monophosphate (cGMP) in in vitro experiments and the stimulating effects of the pineal hormone melatonin on cGMP levels both in vitro and in vivo provoked an investigation into the diurnal pattern of occurrence of this second messenger in human plasma and its correlation with plasma melatonin levels. Plasma cGMP levels were measured in 9 normal human subjects who were over 50 years of age. Samples were obtained hourly through a 20-h period (11 a.m. to 7 a.m.) that included the subjects' habitual hours of nocturnal sleep; physical activity was kept to a minimum during the daylight hours. The area under the time-plasma cGMP concentration curve showed a significant increase during the period of nocturnal sleep compared to that observed during the period of daytime wakefulness. The individual temporal pattern of the nocturnal rise in plasma cGMP differed among the subjects; however, the initial increase typically was observed soon after bedtime. No significant correlation was observed between individual nocturnal plasma melatonin levels and cGMP levels.

Area Under Curve↗
PubMed1999

Using audit to monitor and improve the quality of anaesthesia for caesarean section.

OBJECTIVE: To improve the quality of anaesthesia for caesarean section by assessing the type and reason for using a particular anaesthetic; monitoring the incidence of anaesthetic complications or side effects; and measuring patient satisfaction with anaesthesia provided. DESIGN: Repeat audit undertaken retrospectively using a pre-designed database developed on EPI info public domain software. SETTING: Maternity unit of a district general hospital. SUBJECTS: 166 women undergoing emergency or elective caesarean section. RESULTS: An initial audit involving 79 patients undergoing emergency and elective caesarean section revealed the following: 58.0 per cent of emergency sections and 45.5 per cent of elective sections were given general anaesthesia; "failure to progress" was indicated as the main reason for caesarean section in 27.8 per cent of cases; 25.3 per cent of patients experienced an anaesthetic-related complication or side-effect; and 90.3 per cent of patients were satisfied with their anaesthesia rising to 97.2 per cent after technical adjustment. The main findings were presented to the multi-disciplinary team staffing the unit. It was agreed that the quality of care could be further improved and changes to anaesthetic practice were quickly introduced. A subsequent re-audit of a further 87 patients showed a number of significant improvements: the overall use of general anaesthesia had fallen to 23.8 per cent from 53.0 per cent (P < 0.05); a noticeable reduction in the number of anaesthetic side-effects and complications had occurred, down from 25.3 per cent to 17.2 per cent of all sections; and patient satisfaction rates with anaesthesia provided were maintained.

Anesthesia, Obstetrical↗
PubMed1998

Histopathologic and molecular alterations in bronchial epithelium in habitual smokers of marijuana, cocaine, and/or tobacco.

BACKGROUND: Tobacco smoking has been observed to cause molecular alterations in bronchial epithelium that antedate the development of lung carcinoma. The rising prevalence of marijuana and cocaine use among young adults in the United States prompted us to investigate whether similar molecular and histopathologic alterations occur in habitual smokers of marijuana and/or cocaine who may or may not also smoke tobacco. METHODS: Bronchoscopy was performed in 104 healthy volunteer subjects, including 28 nonsmokers and 76 smokers of one or more of the following substances: marijuana, tobacco, and/or cocaine. Bronchial mucosa biopsy specimens and brushings were analyzed for histopathologic changes, for immunohistopathologic expression of intermediate or surrogate end-point markers that are linked to an increased risk of cancer (Ki-67 [a marker of cell proliferation], epidermal growth factor receptor, p53, Her-2/neu [also known as erbB-2 and ERBB2], globular actin, and abnormal DNA ploidy). Reported P values are two-sided. RESULTS: Smokers of any one substance or of two or more substances exhibited more alterations than nonsmokers in five to nine of the 10 histopathologic parameters investigated (all P < .05), and they exhibited more molecular abnormalities than nonsmokers. Differences between smokers and nonsmokers were statistically significant (all P < or = .01) for Ki-67, epidermal growth factor receptor, globular actin, and DNA ploidy. There was general agreement between the presence of molecular abnormalities and histopathologic alterations; however, when disagreement occurred, the molecular abnormalities (e.g., Ki-67 and epidermal growth factor receptor) were more frequently altered (all P < or = .01). CONCLUSIONS: These findings suggest that smoking marijuana and/or cocaine, like tobacco smoking, exerts field cancerization effects on bronchial epithelium, which may place smokers of these substances at increased risk for the subsequent development of lung cancer.

Actins↗
PubMed1998

Airway inflammation in young marijuana and tobacco smokers.

Forty healthy young subjects, ages 20 to 49 yr, underwent videobronchoscopy, mucosal biopsy, and bronchial lavage to evaluate the airway inflammation produced by habitual smoking of marijuana and/or tobacco. Videotapes were graded in a blinded manner for central airway erythema, edema, and airway secretions using a modified visual bronchitis index. The bronchitis index scores were significantly higher in marijuana smokers (MS), tobacco smokers (TS), and in combined marijuana/tobacco smokers (MTS), than in nonsmokers (NS). As a pathologic correlate, mucosal biopsies were evaluated for the presence of vascular hyperplasia, submucosal edema, inflammatory cell infiltrates, and goblet cell hyperplasia. Biopsies were positive for two of these criteria in 97% of all smokers and for three criteria in 72%. By contrast, none of the biopsies from NS exhibited greater than one positive finding. Finally, as a measure of distal airway inflammation, neutrophil counts and interleukin-8 (IL-8) concentrations were determined in bronchial lavage fluid. The percentage of neutrophils correlated with IL-8 levels and exceeded 20% in 0 of 10 NS, 1 of 9 MS, 2 of 9 TS, and 5 of 10 MTS. We conclude that regular smoking of marijuana by young adults is associated with significant airway inflammation that is similar in frequency, type, and magnitude to that observed in the lungs of tobacco smokers.

Adult↗
PubMed1998

Evaluation of recombinant dengue viral envelope B domain protein antigens for the detection of dengue complex-specific antibodies.

To increase the specificity of dengue (DEN) diagnosis based on antibody detection, we have evaluated recombinant proteins as antigens that incorporate most of the B domain of the DEN virus envelope protein fused to the trpE protein of Escherichia coli (trpE-DEN). A pooled antigen consisting of trpE-DEN proteins representing all four serotypes of DEN virus was used in an indirect ELISA for the detection of IgG or IgM antibody. This assay was compared with a standard IgG indirect ELISA and an IgM-capture ELISA using DEN virus-infected cell culture pooled antigens. The results indicated that the trpE-DEN antigens and the cell culture antigens were equally sensitive for detecting IgM and IgG antibodies in convalescent sera from Peru and Indonesia representing virus isolation-confirmed primary and secondary DEN infections, respectively. Fourteen day postinfection IgG antibody-positive sera obtained from individuals infected with DEN-1 virus who had been vaccinated with other flaviviruses were more strongly reactive with the cell culture antigen than with the recombinant antigen, but by day 21 postinfection, a strong antibody response to the trpE-DEN antigens was present. These results suggested that the early antibody response was directed predominantly towards shared flavivirus group antigens that were not detected with the trpE-DEN antigens. Comparison of the trpE-DEN-1 recombinant antigen with a DEN-1 virus-infected cell lysate antigen for the detection of IgG antibody in sera from a cohort of 55 individuals from Peru who seroconverted over a one-year period indicated greater specificity for the recombinant antigens. Also, sera from individuals with no known DEN infections that had been sequentially vaccinated with yellow fever and Japanese encephalitis reacted with the DEN virus cell culture antigen in the IgG ELISA, but did not react with the trpE-DEN pooled antigens. Similarly, YF IgM antibody positive samples that showed cross-reactivity with the DEN virus cell culture antigens, did not react with the trpE-DEN pooled antigens. These results indicated that the trpE-DEN pooled antigen provided a more specific diagnosis of dengue infections than DEN virus-infected cell culture antigen and avoided the biohazards associated with handling live virus during the preparation of diagnostic reagents. The trpE-DEN pooled antigen should permit a better approach to distinguish between past DEN and other flavivirus infections in epidemiologic surveys, and also increase the specificity of serologic diagnosis of acute DEN infections.

Antibodies, Viral↗
PubMed1998

Evaluation of the protective efficacy of a recombinant dengue envelope B domain fusion protein against dengue 2 virus infection in mice.

A recombinant protein containing part of the dengue (DEN) 2 envelope protein was evaluated as a subunit immunogen for vaccination against DEN virus infection. A gene fragment encoding amino acids 298-400 (B domain) of the DEN-2 virus envelope was expressed as a fusion protein with the maltose binding protein (MBP) of Escherichia coli. This recombinant, DEN-2(B)/MBP, was purified and analyzed for its antigenicity, immunogenicity, and ability to protect mice against lethal challenge. The recombinant antigen reacted with a DEN-2 type-specific neutralizing monoclonal antibody (3H5), DEN-2 hyperimmune mouse ascitic fluid, and DEN-2 immune human sera. When administered to mice, DEN-2(B)/MBP elicited a DEN-2 virus neutralizing antibody response that conferred partial protection against challenge infection with a lethal dose of DEN-2 virus administered by intracranial inoculation. In addition, no replication of DEN-2 virus was detectable in the brains of the immunized mice as compared with control mice that were killed six days after challenge. Sera from immunized mice revealed no cross-neutralizing antibody to any of the other DEN serotypes in the plaque-reduction neutralization test. These findings warrant further studies with the DEN-2(B)/MBP antigen as a potential human vaccine candidate. An effective vaccine could prevent thousands of cases of illness and many deaths each year resulting from DEN virus infections.

ATP-Binding Cassette Transporters↗
PubMed1997

The validity and utility of disease detection methods and of occlusal therapy for temporomandibular disorders.

Our evaluation of the clinical usefulness or devices for the diagnosis or treatment of temporomandibular disorders (TMD) led to the conclusion that the only current gold standard for TMD is a global clinical examination, because none of the instruments can be said to provide more than ancillary documentation and none have proven diagnostic validity or utility. Regarding the therapeutic efficacy of occlusal adjustment, we could find no comparative studies that test the efficacy of occlusal adjustment in preventing TMD. The studies we reviewed on the relationship of occlusion to TMD are not convincing, powerful, or practical enough to make any recommendations about a causal association.

Centric Relation↗
PubMed1996

Recombinant, octavalent group A streptococcal M protein vaccine.

One of the major obstacles to the development of group A streptococcal M protein vaccines is the multiplicity of M serotypes expressed by these organisms. In this study, we have constructed a recombinant, hybrid M protein that contains type-specific aminoterminal fragments of eight different M proteins. We show that the purified hybrid recombinant protein is immunogenic in rabbits and evokes antibodies that react with native M proteins from the respective streptococcal serotypes. In addition, the immune sera evoked by the octavalent protein opsonized six of the eight serotypes of streptococci, indicating that the majority of the M protein fragments contained protective epitopes that retained their native conformations in the hybrid protein. None of the antisera raised against the octavalent protein crossreacted with human heart tissue. These studies indicate that multivalent, hybrid M proteins may be used to elicit broadly protective immune responses against multiple serotypes of group A streptococci.

Animals↗
PubMed1996

The effect of gestational age at birth on morbidity in patients with gastroschisis.

Infants born with gastroschisis frequently present with an eviscerated intestinal segment that is inflamed and thickened. The damaged segment of intestine displays absorption and motility disturbances for a variable period of time after gastroschisis repair. Clinical and animal research suggests that the damage to the eviscerated intestine is caused by prolonged exposure to amniotic fluid and/or progressive constriction on the intestine and its blood supply by the umbilical ring. Some obstetricians and pediatric surgeons have advocated early elective delivery to decrease the exposure of the bowel to these potentially damaging influences. Fifty-five patients underwent gastroschisis repair at the authors' institution during the last 6 years. Many of these patients had early elective delivery after their pulmonary maturity was judged adequate based on their amniotic lecithin/sphingomyelin ratios. The patients were divided into three groups according to gestational age at the time of delivery. Elective early delivery did not lessen the need for silo closure or hasten the time until enteral feeding could be tolerated. The hospital stay was not shortened for the early delivery group. This retrospective review supports the concept that patients with sonographically identified antenatal gastroschisis are best managed by delivery at full term.

Age Factors↗
PubMed1996

Health practices among Russian and Ukrainian immigrants.

Since 1990, due to political and legislative changes, immigration from the former Soviet Union to the United States has increased significantly. Population reports from 1988 indicate that there were approximately 406,000 Soviet immigrants in the United States at that time. This number is expected to increase due to the Immigration Reform Act of 1990, which raised the Soviet refugee ceiling to 50,000 per year. Currently, very little is known about the health status and health practices of this population, although some published data indicate that life expectancy and infant mortality rates compare poorly with those of the general population in the United States. Although the former Soviet republics experienced universal health care coverage, there was little emphasis on promoting a healthy lifestyle. Heavy cigarette use, high alcohol intake, poor dietary intake, little attention to physical fitness, and crowded living conditions have been described. Environmental pollution and poor occupational safety are common and have contributed to the health problems of the population. As the influx of immigrants continues, the consequences of these health conditions will impose a burden on health care services in this country. As with any immigrant group, an understanding of the potential health conditions and cultural values can facilitate appropriate medical care. This research was conducted to explore these issues. Interviews and a physical assessment were conducted with 30 adults from the former Soviet Union. The major health problems identified included various dental conditions requiring treatment, obesity, and the absence of basic health screening measures such as cholesterol testing, high blood pressure screening, Pap smears, and mammograms. The authors also identified a need for translators and for education regarding preventative self-care, such as breast self-examinations.

Adult↗
PubMed1995

Bench evaluation: three face-shield CPR barrier devices.

UNLABELLED: Due to the fear of disease transmission, the practice of mouth-to-mouth (M-M) rescue breathing is rarely performed; to address this concern, many types of CPR barrier devices have been developed. These include bag-valve-mask devices, mouth-to-mask devices, and face shields (FS). The purpose of this study was to measure the volumes delivered during mouth-to-face shield (M-FS) breathing, to measure the back pressure and calculate the resistance to flow through their 1-way valves, and to test for backward leak of gas through the valves. METHODS: Three FS brands were evaluated: Kiss of Life (KOL), MicroSHIELD (Micro) and Res-Cue Key (RCK). Volume delivered during M-M and M-FS breathing was evaluated by 10 rescuers who used the devices while performing rescue breathing on a CPR mannequin. Back pressure was measured and resistance calculated by directing airflow through the 1-way valves. Backward leak was evaluated by measuring the O2 concentration at the rescuer side of the valve while 100% O2 was directed toward the patient side of the valve. Differences among the brands were evaluated using analysis of variance. RESULTS: The mean (SD) values for volumes in L were: M-M 1.00 (0.25), Micro 0.77 (0.20), RCK 0.64 (0.10), and KOL 0.24 (0.11). Mean values for back pressure in cm H2O at 50 L/min were Micro 16.7 (1.29), KOL 7.22 (0.13), and RCK 2.15 (0.16). Significant backward leak only occurred with RCK. CONCLUSION: Not one of the FSs tested met all of the requirements suggested by the American Heart Association and by the International Standards Organization.

Analysis of Variance↗
PubMed1994

The UCLA population studies of chronic obstructive respiratory disease: XI. Impact of air pollution and smoking on annual change in forced expiratory volume in one second.

We assessed the relative impact of residential exposure to community air pollution and habitual cigarette smoking on lung function by comparing the annualized rate of change in forced expiratory volume in 1 s (FEV1) in current, former, and never-smokers 25 to 59 yr of age residing in three demographically similar areas of the Southern California air basin who had been chronically exposed to (1) moderate levels of photochemical oxidants and very low levels of other pollutants (Lancaster); (2) very high levels of photochemical oxidants, sulfates, and particulate matter (Glendora); and (3) high levels of sulfates, oxides of nitrogen, and probably hydrocarbons (Long Beach), together with moderate levels of sulfur dioxide. Of the 621 to 763 nonsmokers, 317 to 479 former smokers and 472 to 691 continuing smokers residing in the three areas who were studied initially, 53 to 64, 49 to 59, and 43 to 54%, respectively, were retested. For male residents, area of residence and smoking category each had highly significant effects on FEV1 decline (two-way ANCOVA; p < 0.001) without significant interaction (p > 0.4). After adjustment for baseline FEV1, age, height, and a history of allergy, the mean decline in FEV1 attributable to living in Long Beach compared with living in Lancaster was 23.6 ml/yr, which was 71% of the rate of decline in FEV1 (33.3 ml/yr), attributable to smoking > 1 pack of cigarettes per day. For female residents, a significant interaction was noted between area and smoking (p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Resistance to flow through the valves of mouth-to-mask ventilation devices.

UNLABELLED: We conducted this study to determine the inspiratory and expiratory flow resistance of the valves of eight commercially available mouth-to-mask ventilation devices. METHODS & MATERIALS: We evaluated the valves of Intertech, Laerdal, Life Design Systems (LDS), Res-Q, Respironics, Rondex, Vital Signs, and White. The devices were supplied by the manufacturers and included the valve and any filter or extension tube supplied with the valve. Expiratory resistance was evaluated by directing air through the valve in the direction of flow when the patient exhales. Inspiratory resistance was evaluated by directing air through the valve in the direction of flow when a breath is delivered to the patient. Flow was controlled by a Timeter 0-75 flowmeter and measured using a calibrated Timeter RT-200. Flows of 10, 20, 30, 40, 50, 60, 70, 80, and 90 L/min were used. 'Back' pressure due to the resistance of the valves was measured using a calibrated Timeter RT-200. Resistance was calculated by dividing back pressure by flow. Five measurements were made at each flow setting for each valve. RESULTS: We observed significant differences in back pressures and resistances between the flows evaluated (p < 0.001 for both inspiratory and expiratory flows), and between the commercially available devices (p < 0.001 for both inspiratory and expiratory flows). At a flow of 50 L/min, the inspiratory back pressures produced by the devices were [mean (SD) in cm H2O] Intertech 5.2 (0.06), Laerdal 4.6 (0.09), LDS 4.7 (0.03), Res-Q 3.1 (0.04), Respironics 3.3 (0.04), Rondex 1.1 (0.02), Vital Signs 4.0 (0.06), and White 4.3 (0.10). At this same flow, the expiratory back pressures were Intertech 4.8 (0.30), Laerdal 9.1 (0.10), LDS 3.3 (0.02), Res-Q 3.7 (0.35), Respironics 0.5 (0.01), Rondex 1.4 (0.01), Vital Signs 3.6 (0.05), and White 13.7 (0.48). CONCLUSIONS: In some cases, the resistance through these devices might be considered excessive; however, most of the devices meet the International Standards Organization (ISO) standard (back pressure < 5 cm H2O at 50 L/min).

Data Collection↗
PubMed1993

A rapid membrane based immunobinding assay for the detection of dengue virus in tissue culture.

A rapid, simple dot immunoassay (DOTIA) was developed and evaluated for the detection of dengue-1 viral antigen in infected Aedes albopictus C6/36 cells. Dengue virus infected cells were solubilize in sodium dodecyl sulfate (SDS) and the lysate was pressure filtered through a hydrophobic polyvinylidene difluoride (PVDF) membrane. Viral antigen retained in the membrane was detected by a dengue-1 type specific monoclonal antibody and a peroxidase-labeled second antibody. Addition of tetramethylbenzidene (TMB) substrate produced a blue-colored precipitate which allowed for quantitation of viral antigen using a portable white light reflectance densitometer. Estimate of viral infectivity in the cell lysates tested by the DOTIA was determined by standard plaque assays and the results indicated an excellent correlation between these two methods. The dot immunoassay detected dengue viral antigen in infected C6/36 cells between days three and eight post-inoculation, depending on the titer of the inoculum. An infectivity titer of at least 10(3) plaque forming units (PFU) per ml was required to detect antigen by the DOTIA. The DOTIA also detected viral antigen in cells inoculated with twelve acute sera from known dengue-1 virus infected patients, thus demonstrating that this technique is useful for the detection and identification of dengue-1 virus from clinical specimens.

Aedes↗