Search PubMed⌕ Search

Biomedical subjects

M Rosen

Publications and source records attributed to M Rosen.

At least 37 records · Page 2Linked to original sources
PubMed2001

Psychosocial issues and coping strategies in families affected by urea cycle disorders.

A survey was sent to the American members of the National Urea Cycle Disorders Foundation to ascertain the types and extent of stress imposed on families who have a child with a urea cycle defect. Forty percent of the surveys were returned. The greatest sources of stress were financial, fear of death, and the restrictions imposed by the diet. Other than removal of the economic stress and uncertainty, the results did not suggest that any specific support systems required augmentation. Instructions to mitigate frustrations occurring in emergency situations would, however, be a great help to families.

Adaptation, Psychological↗
PubMed2001

The influence of trainee characteristics on the effectiveness of health and safety training for hazardous waste site operations work.

A 10-year retrospective analysis was done using training records for 869 trainees who had attended a 40-hour course for hazardous waste site work. The course is intended for professional site workers, but had been attended by a demographically diverse audience. Analysis of test, demographic, and course data revealed some spurious effects but also indicated that trainees were not disadvantaged in their learning gains based on their own background or that of the class overall. Moreover, a large class appears to present some advantages, and a diverse class appears to present advantages in training material applied across work duties (hands-on skills, decontamination, etc.). Logistics encountered in the study raise doubts that a definition of professional/nonprofessional can be achieved or applied. Overall, the routine practice of providing separate training to professionals and nonprofessionals requires revisiting.

Adult↗
PubMed2001

Laparoscopic hernia repair enhances early return of physical work capacity.

Several researchers have documented less postoperative pain and a quicker return to daily activities after laparoscopic herniorrhaphy. However, little objective data that validates this hypothesis exists. This study compares the rate of postoperative physical work capacity with return to preoperative levels, which is measured by a standard treadmill test in patients who underwent laparoscopic and conventional open hernia repair. Patients completed a 6-minute walking test preoperatively and 1 week postoperatively using a nonmotorized treadmill. The distance walked was recorded. If the distance that a patient achieved at 1 week was not within 0.02 miles of the preoperative values of the patient, the patient was asked to return at 1 month for repeat testing. Patients were enrolled prospectively in this study from October 1997 to February 1999. Sixty-six patients participated in the study (27 laparoscopic herniorrhaphies and 39 open herniorrhaphies were performed). There was no significant difference in age, body mass index, or preoperative distance achieved among the two groups. At 1 week, patients who underwent laparoscopic repair demonstrated a mean increase of 18 meters from preoperative distance (P = 0.07). In the open group, patients demonstrated a mean decrease of 90 meters at 1 week (P = 0.001). The change in distance at 1 week between the laparoscopic and the open groups was statistically significant (P = 0.001). However, at 1 month, there was no significant difference among the two groups. Measured using treadmill walking, laparoscopic hernia repair seems to offer an early advantage to open repair in return-to-physical-work capacity.

Exercise Test↗
PubMed2001

Surface roughness of aesthetic restorative materials: an in vitro comparison.

The purpose of this study was to compare the surface roughness of three types of aesthetic restorative material. Six standard samples of two brands of each type of material were prepared namely: hybrid composites (Prodigy, Z100), compomers (Compoglass F, Hytac Aplitip) and glass ionomer cements (Photac-Fil, Vitremer) in a perspex mould (N = 36). Upper and lower surfaces were covered with Mylar strips which, in turn, were covered with glass slides and compressed to express excess material. After light curing, specimens were stored in distilled water for 14 days. Thereafter, one side of each specimen was polished sequentially with medium, fine and super fine Soflex discs (treatment). Untreated surfaces served as controls. All surfaces were examined with Talysurf and the surface roughness (Ra) of each specimen was recorded. Three measurements were made of each specimen. A 4-way ANOVA and Tukey's Studentised range test were used to analyse the data. Statistically significant effects were found for both type of material (P = 0.0001) and for treatment process (P = 0.0065). Among unpolished specimens: Compoglass F is significantly rougher than Vitremer, Z100, Prodigy and Hytac Aplitip, and compomers are significantly rougher than hybrids. Among polished specimens: Photac-Fil is significantly rougher than Z100 but does not differ from Compoglass F, Vitremer, Prodigy and Hytac Aplitip, and glass ionomers are also significantly rougher than hybrids. The smoothest surface is obtained when curing materials against a Mylar strip.

Analysis of Variance↗
PubMed2001

Endoscopic therapy for gastroesophageal reflux disease.

There are many options regarding the treatment of gastroesophageal reflux disease (GERD). This report reviews the safety, efficacy, and early results of the various treatment options, with a focus on endoscopic therapy for GERD. This approach, which is still in its infancy, is viewed as cost-effective without the associated morbidity of surgery and the necessity of long-term compliance with medical therapy.

Catheter Ablation↗
PubMed2000

Improving cost efficiency on a vascular surgery service.

BACKGROUND: A vascular task force (VTF) consisting of two vascular surgeons and other key personnel was established to reduce costs and improve efficiency in the management of patients on a vascular surgery service. METHODS: The VTF met monthly beginning in 1994 to study and implement changes in the management of patients with (1) abdominal vascular, (2), carotid endarterectomy (3) distal bypass, and (4) other vascular procedures, including amputations. Length of stay, and fixed and variable costs were assessed for change over time using Pearson correlation coefficients. RESULTS: Improvements in efficiency (length of stay) and decreases in costs (fixed and variable costs) from fiscal year 1993 to fiscal year 1996 were significant for the total group of vascular patients (P </=0.001), with some intergroup differences. The major improvements were in the abdominal vascular and carotid endarterectomy groups, where length of stay and fixed and variable costs were reduced significantly (P </=0.01). Management of distal bypass and other vascular surgery patients showed less striking improvement. CONCLUSION: Vascular surgeons in collaboration with other dedicated personnel involved in the care of vascular patients can improve efficiency and reduce costs. Advances were greatest in patients who required operations for carotid and abdominal vascular disorders and least for patients who required distal bypasses and other vascular procedures.

Abdomen↗
PubMed2000

Farey sequences of spatiotemporal patterns in video feedback.

In this paper we present an experimental and theoretical description of the dynamic of spatial patterns obtained in a video feedback loop. A video camera monitors the screen to which it is connected and can turn around its optical axis at an angle alpha. Under certain conditions of brightness and magnification, this optoelectronic system produces spatiotemporal patterns in the form of spots located on a circle on the screen. These patterns are very similar to the spatial transverse modes obtained in other optical devices such as lasers or photorefractive media. It is possible to generate stationary patterns of n-fold symmetries for angles alpha=2pi/n. When the angle alpha varies around 2pi/n, the pattern rotates with a certain frequency proportional to the difference between 2pi/n and alpha. We discover more general patterns at angles 2pi/(p/k) with p-fold symmetry, following the hierarchy of the Farey algorithm which theoretically can produce stationary patterns at any angle alpha. Very accurate experiments were performed to observe these patterns up to the level k=6. This is the first time a Farey tree has been observed as a sequence of spatial patterns to our knowledge. Previous observations of this hierarchy were made only in the temporal domain.

Animals↗
PubMed1999

Membrane-protease interactions. III: A consideration of the difference in binding potential of pancreatic proteases to erythrocytes and erythrocyte ghosts.

Trypsin and chymotrypsin readily bind to human erythrocyte ghosts and to resealed right-side-out ghosts, but not to intact erythrocytes, as followed with [3H]trypsin and [3H]chymotrypsin and with cold proteases in a caseinolytic assay. The proteases freely reacted with casein in the presence of intact cells. Trypsin activated trypsinogen over an 8-hr time course at a faster rate in the presence of erythrocytes than in the absence thereof, after a slight initial delay. Trypsinogen did not bind to intact erythrocytes, thereby behaving comparably to trypsin. These results suggest that different microenvironments exist about the erythrocyte ghosts and the intact erythrocytes, thereby permitting the proteases to bind to the former but not to the latter. Hence, in the absence of considerable ghosts in circulating blood, which may mask the binding site of the proteases, the proteases may be more readily accessible for interaction with circulating serpins, leading to inactivation of the proteases and protection from their degradative potential. The presence of the serpins in circulating blood may assist in the control of the degradative power of the pancreatic proteases in pancreatitis and may negatively modulate such processes as thrombosis, activation of the complement system, and vascular remodeling.

Binding, Competitive↗
PubMed1999

The safety and effectiveness of remifentanil as an adjunct sedative for regional anesthesia.

UNLABELLED: We assessed the sedative potential of continuous infusions of remifentanil with a validated composite alertness scale in 160 patients (ASA physical status I or II) undergoing hip replacement surgery with spinal block (n = 61) or hand surgery using brachial plexus block (n = 93). They were randomized to receive one of the following initial dose regimens in double-blinded fashion: placebo or 0.04, 0.07, or 0.1 microg x kg(-1) x min(-1) remifentanil subsequently titrated to effect. Additional midazolam IV was allowed for adequate sedation as required. The combined analysis of both surgery groups revealed a dose-related increase in achievement of sedation level > or =2 within 15 min of the start of the study drug infusion; all remifentanil dose comparisons with placebo reached significance (P < 0.001). The remifentanil 50% effective dose for a composite sedation level > or =2 within 15 min of the start of drug infusion was estimated as 0.043 microg x kg(-1) x min(-1) (95% confidence interval 0.01, 0.059). The requirement for midazolam decreased with increasing remifentanil dose compared with placebo (P < 0.001). The median time to return to alertness after the end of infusion was 10-12 min in the remifentanil groups and 5 min in the placebo group. Significant incidences of nausea, pruritus, sweating, and respiratory depression were reported during remifentanil infusions compared with placebo. The data suggest that remifentanil may be useful for supplementation of regional anesthesia, provided that ventilation is carefully monitored. IMPLICATIONS: In this dose-finding, placebo-controlled study, remifentanil infusions were used to provide sedation during spinal and brachial plexus regional anesthesia. The 50% effective dose for achievement of sedation was 0.043 microg x kg(-1) x min(-1). Return to alertness occurred after 10-12 min (median time). Remifentanil infusions can be used to supplement regional anesthesia, but this requires careful monitoring of ventilation.

Adjuvants, Anesthesia↗
PubMed1999

Performance of an algorithm to detect Pneumocystis carinii pneumonia in symptomatic HIV-infected persons. Pulmonary Complications of HIV Infection Study Group.

STUDY OBJECTIVES: To determine whether an algorithm consisting of a chest radiograph and the diffusing capacity of the lung for carbon monoxide (D(LCO)) is effective in detecting Pneumocystis carinii pneumonia (PCP) in symptomatic HIV-infected persons; and to establish a benchmark for future comparisons of alternative algorithms. DESIGN: Prospective, 64-month study. SETTING: Multicenter, ambulatory care. PATIENTS: 306 HIV-infected subjects enrolled in the Pulmonary Complications of HIV Infection Study who developed 467 episodes of new or worsening respiratory symptoms. MEASUREMENTS: Chest radiography followed by D(LCO) measurement, if the radiograph was normal or unchanged. RESULTS: An algorithm combining a chest radiograph followed by a D(LCO) measurement, if the radiograph was normal or unchanged, was effective and detected abnormalities that led to a diagnosis of PCP in 78 of 80 evaluable episodes (97.5%). The radiograph (specific parenchymal abnormality, number of lung zones involved) and the D(LCO) (degree of decrease, degree of decrease from baseline) also provided additional information on the probability of PCP. CONCLUSIONS: In symptomatic HIV-infected patients suspected of having PCP, the diagnostic evaluation should begin with a chest radiograph, followed by a D(LCO) measurement, if the radiograph is normal or unchanged. If both of these tests are normal, it may be reasonable to conclude the evaluation rather than to proceed on to additional testing. This algorithm can serve as a benchmark for future comparisons.

AIDS-Related Opportunistic Infections↗
PubMed1998

Follow-up of colorectal cancer: a meta-analysis.

PURPOSE: The value of intensive follow-up for patients after resection of colorectal cancer remains controversial. This study reviews all randomized and prospective cohort studies to assess the value of aggressive follow-up. METHODS: The literature was searched from the years 1972 to 1996 for studies reporting on the follow-up of patients with colorectal cancer. Randomized and comparative-cohort studies that included history, physical examination, and carcinoembrionic antigen values at least three times a year for at least two years were included in a meta-analysis. Single-cohort studies with intensive follow-up and traditional follow-up were also included in a two-group comparative analysis for each outcome indicator. Outcome indicators were 1) curative resection rates after recurrent cancer, 2) survival rates of curative re-resections, 3) length of survival after recurrence, and 4) cumulative five-year survival. RESULTS: Two randomized and three comparative-cohort studies met these criteria and included 2,005 patients, which were evaluated in the meta-analysis. The cumulative five-year survival was 1.16 times higher in the intensively followed group (P = 0.003). Two and one-half times more curative re-resections were performed for recurrent cancer in those patients undergoing intensive follow-up (P = 0.0001). Those patients in the intensive follow-up group with a recurrence had a 3.62-times higher survival rate than the control (P = 0.0004). Fourteen single-cohort studies were also included in the comparative analysis of 6,641 patients. The findings from these aggregated studies support the results of the meta-analysis. CONCLUSION: Our study concludes that intensive follow-up detects more recurrent cancers at a stage amenable to curative resection, resulting in an improvement in survival of recurrences and an increased overall five-year cumulative rate of survival.

Adult↗