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Biomedical subjects

M Rosen

Publications and source records attributed to M Rosen.

At least 127 records · Page 7Linked to original sources
PubMed1991

Effect of impression technique and multiple pours on accuracy of stone models.

The number of accurate repour models obtainable from a single impression is of clinical importance. This study was designed to compare the accuracy of initial and repour models obtained from an impression recorded in a hydrophilic addition curing silicone and to determine whether or not this accuracy is affected by the impression technique employed and whether any interaction between impression techniques and levels of pour existed. The laminated and putty wash plus spacer techniques were employed. Six impressions were recorded of a brass master model with each technique. Improved stone models were poured after 2 hours and then repoured in the same impression at 3, 4, 5 and 6 hours. Thus, 30 models were poured with each impression technique. Using a reflex microscope, measurements between two fixed points on the brass model were taken and compared with similar measurements obtained from the stone models. The analysis of variance indicates that no significant difference exists between impression techniques (p greater than 0.05) and between the first pour and first repour model (p greater than 0.05). With the material tested, this study indicates that the laminated and putty wash plus spacer techniques both give accurate impressions and that only two accurate models can be poured.

Analysis of Variance↗
PubMed1991

The effect of the New York State restrictions on resident work hours.

New York state has recently restricted the hours that residents may work to an average of 80 hours per week. We have complied with these regulations through the addition of nonresident personnel, including attending physicians, a physician assistant, and nurse midwives. This study was designed to assess the effect of these changes on our residents. A questionnaire covering the effects of our new system was distributed to both attending and resident staff. Surgical case load and Council on Resident Education in Obstetrics and Gynecology (CREOG) scores since the change were compared with those of previous years. A marked improvement in resident life-style was noted. Although residents commented that they had increased time for reading, this was not reflected in an improvement in the CREOG scores. The quality of patient care was not felt to be improved, and the continuity of care was considered to be adversely affected. Resident surgical case load was unchanged. The assignment of emergency room coverage to attending physicians and gynecologic floor coverage to a physician assistant was seen as having a detrimental effect on resident experience. We conclude that the new restrictions on resident work hours in New York have improved resident quality of life. However, there does not appear to be an improvement in patient care, which was the original intent of the statute. Concerns are discussed about the effect of this decrease in hours worked on resident experience and education. Further research is needed to assess the long-term effects of reduced resident work hours on both patient care and resident education.

Attitude of Health Personnel↗
PubMed1990

Cognitive and functional competence after anaesthesia in patients aged over 60: controlled trial of general and regional anaesthesia for elective hip or knee replacement.

OBJECTIVE: To determine the influence of general or regional anaesthesia on long term mental function in elderly patients. DESIGN: Prospective study of patients randomly allocated to receive general or regional anaesthesia. SETTING: The patients' homes and a large teaching hospital in Cardiff. SUBJECTS: 146 Patients aged 60 and over scheduled for elective hip or knee replacement. MAIN OUTCOME MEASURES: Scores achieved in tests of cognitive function and functional competence. RESULTS: 72 Patients were allocated to receive general anaesthesia and 74 regional anaesthesia. Anaesthetic technique did not influence the duration of the operation, time to mobilisation postoperatively, requirements for analgesia after the operation, or duration of stay in hospital. Three months after the operation there was an improvement in the score for the recognition component (76 ms, 95% confidence interval 9 to 144) and the response component (82 ms, 5 to 158) of the choice reaction time in the group receiving general anaesthesia compared with the group receiving regional anaesthesia. This was the only significant difference between the two groups in the assessments of cognitive and functional competence. Eleven patients receiving regional anaesthesia and 12 receiving general anaesthesia reported that their memory and concentration were worse than before the operation, but this was not confirmed by testing. CONCLUSION: Cognitive and functional competence in elderly patients was not detectably impaired after either general or regional anaesthesia when attention was paid to the known perioperative influences on mental function.

Activities of Daily Living↗
PubMed1990

Recognition of an HLA public determinant (Bw4) by human allogeneic cytotoxic T lymphocytes.

The human class I HLA molecules are composed of both polymorphic, or private, and conserved, or public, regions. The private regions are recognized by alloreactive T cells and also serve as restriction elements for peptide presentation to autologous cells. Although the ability of public determinants to elicit antibody responses is well documented, little is known of their role in T cell function. In this study we examine the ability of one of these public HLA determinants, designated Bw4, to serve as a target Ag for CTL. We show that for some individuals the HLA-Bw4 epitope can function as a restriction element for CTL. This finding has important implications for organ transplantation.

Amino Acid Sequence↗
PubMed1990

Comparison of the respiratory effects of i.v. infusions of morphine and regional analgesia by extradural block.

The incidence of postoperative respiratory apnoea was compared between five patients receiving a continuous i.v. infusion of morphine (mean 73.6 mg) and five patients receiving a continuous extradural infusion of 0.25% bupivacaine (mean 192 mg) in the 24-h period following upper abdominal surgery. Monitoring consisted of airflow detection by a carbon dioxide analyser, chest wall movement detected by pneumatic capsules, and continuous electrocardiograph recorded with a Holter ambulatory monitor. Both obstructive (P less than 0.05) and central apnoea (P less than 0.05) occurred more frequently in patients who had a morphine infusion. There was also a higher incidence of tachyarrhythmias (P less than 0.05) and ventricular ectopic beats (P less than 0.05) in the morphine infusion group.

Abdomen↗
PubMed1990

Lower oesophageal contractility and detection of awareness during anaesthesia.

We have investigated the value of lower oesophageal contractility (LOC) in detecting awareness during anaesthesia in 20 human volunteer patients. LOC was measured either with subjects awake or after induction with propofol, during induction with propofol, and then as consciousness returned. Statistically significant changes were observed in the frequency of spontaneous contractions, peak and mean amplitude of spontaneous and provoked contractions, and the oesophageal contractility index as subjects lost consciousness and also as it was regained. The differences in LOC which occurred when subjects were conscious and unconscious support the view that LOC is related to the depth of anaesthesia, but its unreliability at the interface between consciousness and unconsciousness prevents selective detection of awareness, although the response in the presence of painful stimuli has not been tested.

Anesthesia, General↗
PubMed1990

Isoflurane with either 100% oxygen or 50% nitrous oxide in oxygen for caesarean section.

Two hundred mothers undergoing general anaesthesia for Caesarean section were allocated randomly to receive either 100% oxygen (group 100) or 50% nitrous oxide in oxygen (group 50), both supplemented with isoflurane. In each group the concentrations of isoflurane were chosen to deliver 1.5 MAC for the first 5 min after induction and 1.0 MAC thereafter. The mean umbilical venous PO2 was greater in group 100 for emergency sections (P = 0.001). Babies born to mothers in group 100 required less resuscitation than those in group 50 (P = 0.04) and there was a tendency to higher Apgar scores at 1 min in group 100, although this was not statistically significant. There were no instances of awareness, although two patients in group 100 and three in group 50 reported dreaming. This study confirms earlier findings that the use of 100% oxygen can significantly improve fetal oxygenation during Caesarean section, with particular benefit in emergency cases. This is associated with a lower incidence of neonatal resuscitation.

Anesthesia, General↗
PubMed1990

Effects of halothane, enflurane and isoflurane anaesthesia on renal plasma flow.

Effective renal plasma flow (ERPF) and linear cardiac output (aortic blood velocity) were measured in 15 patients who received halothane, enflurane or isoflurane in oxygen. All three agents caused a significant reduction in ERPF (P less than 0.05) and the effect was greater at 1.25 MAC than at 0.75 MAC. No significant difference was demonstrated between the agents. Linear cardiac output did not change significantly during the study, suggesting that the observed reduction in ERPF was not caused by cardiovascular depression.

Adult↗
PubMed1990

A jet nebuliser for delivery of topical anesthesia to the respiratory tract. A comparison with cricothyroid puncture and direct spraying for fibreoptic bronchoscopy.

Topical anesthesia of the respiratory tract for fibreoptic bronchoscopy was compared, in a single-blind study, inhaled from a simple and inexpensive jet nebuliser, administered by cricothyroid injection or by a 'spray-as-you-go technique'. Each technique was supplemented by spraying lignocaine through the fibrescope and intravenous fentanyl-droperidol sedation. Inhaled nebulisation was successfully used for 96% (46 of 48) of patients, was safe, effective and acceptable to the patient and bronchoscopist. The cricothyroid injection method produced better conditions than nebulisation in patients who had diagnostic bronchoscopy. The nebuliser technique is as satisfactory as the spraying technique in patients for diagnostic bronchial lavage in whom bleeding from a cricothyroid puncture is unacceptable. Patients who used the nebuliser were more satisfied. This technique may also be a useful method for 'awake' intubation.

Administration, Inhalation↗
PubMed1990

Blood contamination of anaesthetic and related staff.

The incidence of skin contamination of anaesthetic and related staff by patient's blood and saliva was studied during 270 anaesthetics in Cardiff hospitals over seven continuous days in October 1989. A survey was also made of current Hepatitis B immunisation status and glove-wearing habits of 75 anaesthetists. Blood from 35 (14%) patients caused skin contamination of 65 staff during 46 incidents. Twenty-eight (61%) of the contamination incidents occurred during vessel cannulation. Five (8%) of the 65 staff contaminated by blood already had cuts on their hands. There were nine incidents (4%) of skin contamination by saliva. Fifty-three (71%) anaesthetists were immunised against Hepatitis B. Only seven (9%) anaesthetists wear gloves for oral or nasal intubation, six (8%) for insertion of peripheral venous cannulae, 47 (63%) for insertion of arterial lines and 67 (89%) for insertion of central lines. All anaesthetic and associated staff should wear gloves on a routine basis.

Anesthesiology↗
PubMed1990

Changes in a light-cured composite resin material used to restore primary anterior teeth: an eighteen month in vivo study.

A simple method for treating grossly decayed primary anterior teeth (GDPAT) is of clinical importance since the age of the patient precludes lengthy and difficult procedures. This study assessed the suitability of a light-cured microfilled composite resin material for the repair of GDPAT. The material Durafill was used to restore 81 primary teeth in 24 children (mean age 3.5 y). The restorations were assessed according to predetermined criteria at 6, 12, and 18 months. Results showed a significant deterioration in cavomarginal discoloration and anatomic form (p less than 0.05). Changes in anatomic form were significantly related to marginal adaptation, secondary caries, gingivitis and pain (p less than 0.05). Despite the observed changes, Durafill performed adequately and offers the dentist a simple method for restoring GDPAT.

Child↗
PubMed1990

Dental treatment: utilization, motivation and prevention. A behavioural study of why people seek dental care.

Fears of over-production of dentists in South Africa may be unfounded as less than 30 per cent of the population attend for preventive dental treatment (PDT). This study was undertaken to ascertain what motivates a person to seek PDT. The sample population consisted of 107 members of the Vanderbijlpark Medical Benefit Fund. Data gathered from questionnaires led to the following results. A belief in the benefits to be derived from dental treatment when combined with a belief in the seriousness of the consequences of dental disease, as well as when these two variables are combined with a belief in one's own susceptibility to dental disease, all significantly influence making a preventive dental visit (PDV). To promote acceptance of PDT efforts should be directed towards three areas: firstly information must be propagated to show people that they will be severely handicapped by the loss of their natural teeth and that dentures are a poor substitute. Secondly, the benefit of dental treatment should be pointed out, with the emphasis that fillings do last and, therefore, are not a waste of money. Thirdly, the fatalistic attitude which exists towards dental decay and tooth loss should be changed so that people realize that they can keep their teeth all their life. Due to the heterogeneity of the population the needs, demands and attitudes of each socio-economic and ethnic group should be ascertained before promoting any preventive programme.

Dental Health Services↗
PubMed1990

Health maintenance strategies for women of different ages. An overview.

Preventive health strategies for screening for specific illnesses, counseling, and immunization are discussed. Emphasis is given to cardiovascular screening and risk reduction, screening for malignancies, and immunization practices. A framework for designing periodic health examinations for patients is detailed.

Adult↗
PubMed1989

NMR studies of DNA (R+)n.(Y-)n.(Y+)n triple helices in solution: imino and amino proton markers of T.A.T and C.G.C+ base-triple formation.

High-resolution exchangeable proton two-dimensional NMR spectra have been recorded on 11-mer DNA triple helices containing one oligopurine (R)n and two oligopyrimidine (Y)n strands at acidic pH and elevated temperatures. Our two-dimensional nuclear Overhauser effect studies have focused on an 11-mer triplex where the third oligopyrimidine strand is parallel to the oligopurine strand. The observed distance connectivities establish that the third oligopyrimidine strand resides in the major groove with the triplex stabilized through formation of T.A.T and C.G.C+ base triples. The T.A.T base triple can be monitored by imino protons of the thymidines involved in Watson-Crick (13.65-14.25 ppm) and Hoogsteen (12.9-13.55 ppm) pairing, as well as the amino protons of adenosine (7.4-7.7 ppm). The amino protons of the protonated (8.5-10.0 ppm) and unprotonated (6.5-8.3 ppm) cytidines in the C.G.C+ base triple provide distinct markers as do the imino protons of the guanosine (12.6-13.3 ppm) and the protonated cytidine (14.5-16.0 ppm). The upfield chemical shift of the adenosine H8 protons (7.1-7.3 ppm) establishes that the oligopurine strand adopts an A-helical base stacking conformation in the 11-mer triplex. These results demonstrate that oligonucleotide triple helices can be readily monitored by NMR at the individual base-triple level with distinct markers differentiating between Watson-Crick and Hoogsteen pairing. Excellent exchangeable proton spectra have also been recorded for (R+)n.(Y-)n.(Y+)n 7-mer triple helices with the shorter length permitting spectra to be recorded at ambient temperature.(ABSTRACT TRUNCATED AT 250 WORDS)

Base Composition↗