Biomedical subjects

R Hall

Publications and source records attributed to R Hall.

At least 91 records · Page 5Linked to original sources

PubMed1997

Evaluation and follow-up of patients with N1-3 M0 or NXM1 prostate cancer in phase III trials.

OBJECTIVES: The aim of this discussion is to review the design and conduct of phase III trials in metastatic prostate cancer, to seek ways of improving their study design, accuracy, relevance to clinical practice, acceptability to patients, and ease of participation by clinicians. We also aim to try to set uniform definitions for the evaluation of the different endpoints used in clinical trials on metastasized prostate cancer. METHODS: The work was started by correspondence between the participants in the group for the year before the consensus meeting. Two comprehensive questionnaires were circulated and the answers were distributed to all the members of the group. The statements were finalized during the consensus meeting. RESULTS: There were some differing opinions concerning the methods of evaluation of endpoints for follow-up, such as time to tumor progression and time to treatment failure. After the consensus conference, there were no major disagreements within the group. CONCLUSIONS: The aim of phase III trials is to influence clinical management. To obtain a credible result they require a sound statistical basis with appropriate power and encompassing patients from small urologic practices as well as large or academic institutions. However, deviation from routine practice may affect the accrual rate, and the trial procedure should therefore be as similar as possible to routine management. Trials inevitably involve extra work and cost. Both should be kept to a minimum to encourage participation and hasten a timely conclusion. It is mandatory to create uniform ways of designing and evaluating clinical trials in prostate cancer.

Clinical Trials, Phase III as Topic↗

PubMed1997

Baseline quality of life of patients with advanced prostate cancer. European Organization for Research and Treatment of Cancer (EORTC), Genito-Urinary Tract Cancer Cooperative Group (GUT-CCG)

Quality of life (QoL) is now commonly studied in prostate cancer. However, little is known about the appropriateness of the various QoL instruments in this group of patients. The purpose of this work was to study the baseline QoL assessment of patients with prostate cancer who were randomised into three EORTC phase III studies. The three trials included locoregional prostate cancer patients, poor prognosis metastatic patients and hormone resistance patients, respectively. In the three trials, patients were asked to complete a questionnaire assessing their physical and psychosocial functioning and their symptom levels. These questionnaires included questions from the EORTC QLQ-C30 (version 1): the physical functioning, role functioning, global health/QoL scales and a single pain item. The psychometric properties of the scales were assessed and an analysis was performed to investigate if differences existed in the scale scores between the three groups of patients, 638 baseline questionnaires were available for patients entered into the three trials. The Gutman coefficients of reproducibility and scalability were 0.94 and 0.71, respectively, for the physical functioning scale and 0.97 and 0.90, respectively, for the role functioning scale. The Cronbach's alpha reliability coefficients were 0.68, 0.48 and 0.90 for the physical functioning, role functioning and global health/QoL scales, respectively. The four scales were able to distinguish clearly between the patient populations under study. The physical functioning, role functioning, global health/QoL scales and the single pain item scale from the EORTC QLQ-C30 (version 1) are valid measures when used in the setting of prostate cancer.

Activities of Daily Living↗

PubMed1997

Headaches and neck pain in farmers.

The prevalence of headache and neck pain in farmers was determined by use of a questionnaire. Information about activities which increased the symptoms and about the treatments sought was also recorded. Results showed that 77.7% of farmers experienced neck pain and 79.2% experienced headache. Driving a tractor was the activity which was most frequently described as increasing symptoms in both conditions. While driving a tractor, farmers are exposed to whole-body vibration and assume a rotated neck posture. The contribution of these factors to the development of headache and neck pain is discussed.

Adult↗

PubMed1997

Aggregative adherence fimbria II, a second fimbrial antigen mediating aggregative adherence in enteroaggregative Escherichia coli.

Enteroaggregative Escherichia coli (EAEC) has been implicated as an agent of pediatric diarrhea in the developing world. We have shown previously that EAEC adheres to HEp-2 cells by virtue of a plasmid-encoded fimbrial adhesin designated aggregative adherence fimbria I (AAF/I), the genes for which have been cloned and sequenced. However, not all EAEC strains express AAF/I. Using TnphoA mutagenesis, we have characterized a novel fimbria (designated AAF/II) which mediates HEp-2 adherence of the human-pathogenic strain 042. AAF/II is 5 nm in diameter and does not bind AAF/I antiserum, as determined by immunogold transmission electron microscopy. TnphoA identified a gene (designated aafA) which bears significant homology to aggA, the fimbrial subunit of AAF/I (25% identity and 47% similarity at the amino acid level). When hyperexpressed and purified by polyhistidine tagging, the AafA protein assembled into 5-nm-diameter filaments which bound anti-AAF/II antiserum. The cloned aafA gene complemented a mutation in the aggA gene to confer fimbrial expression from the AAF/I gene cluster, manifesting phenotypes characteristic of AAF/II but not AAF/I. The aafA mutant did not adhere to human intestinal tissue in culture, suggesting a role for AAF/II in intestinal colonization. By using DNA probes for AAF/I and AAF/II derived from fimbrial biosynthesis genes, we show that AAF/I and AAF/II are each found in only a minority of EAEC strains, suggesting that still more EAEC adhesins exist. Our data suggest that AAF adhesins represent a new family of fimbrial adhesins which mediate aggregative adherence in EAEC.

Adhesins, Escherichia coli↗

PubMed1997

Stress fracture of the tibia after arthrodesis of the ankle or the hindfoot.

We studied twelve patients who had a stress fracture of the tibia and one patient who had a stress fracture of the fibula after arthrodesis of the ankle or the foot. A second stress fracture subsequently developed in two patients. All but two patients were managed non-operatively, and the fractures healed uneventfully. One patient who was managed operatively had a below-the-knee amputation to treat a painful non-union of a tibial fracture, and the other had interlocking intramedullary nailing for a displaced fracture. All but one of the arthrodesis sites had fused before the stress fracture occurred. All of the stress fractures that occurred after arthrodesis of the ankle were in the middle and distal aspects or the distal aspect of the tibia, while those that occurred after triple arthrodesis were in the distal aspect of the fibula or the medial malleolus. Although six of the thirteen patients still had uncorrected alignment and deformity after the arthrodesis, optimum alignment after the arthrodesis did not preclude the occurrence of a stress fracture. We conclude that stress fracture must be considered in the differential diagnosis of pain months or even years after solid fusion at the site of an ankle or triple arthrodesis.

Adult↗

PubMed1996

As mammography use increases, are some providers omitting clinical breast examination?

OBJECTIVE: To explore use of clinical breast examination (CBE) among women receiving mammography. METHODS: A retrospective cohort analysis of 100 women aged 50 years or older with at least one bilateral mammogram. Chart review documented demographic information, severity of illness, and performance of CBE (from 1 year prior to 18 months after the mammogram). RESULTS: The mean age of the 100 women was 63 years. They were predominantly unmarried (60%), nonwhite (58%), and not currently employed (57%). Three quarters (76%) had mammography and CBE (comprehensive screening), while the remaining 24% had mammography only. Sociodemographic factors did not differ for women with and without comprehensive screening (P>.1). However, patients of female providers were more likely to receive comprehensive screening than patients of male providers. Specifically, 95% of women seen by female attending physicians or fellows had comprehensive screening vs 67% for male attending physicians or fellows and 61% for residents (P=.008). CONCLUSIONS: Mammography may be replacing CBE especially among patients of male providers. Interventions targeted to these providers could help improve the use of CBE and mammography.

Aged↗

PubMed1996

Conservation of neutralizing determinants between the sporozoite surface antigens of Theileria annulata and Theileria parva.

The sporozoite surface antigens SPAG-1 of Theileria annulata and p67 of Theileria parva are postulated to contain determinants necessary for host cell invasion and/or recognition and are both being considered as candidates for inclusion in subunit vaccines. Preliminary data suggest that these are related molecules. In this paper we describe the investigation of the relationship between these sporozoite antigens further by analysis of the immunological cross-reactivity using Mabs and sera raised against each antigen. The cross-reactions were examined by carrying out Western blots, IFA tests, and in vitro sporozoite neutralization assays. In addition, sequence comparison data which clearly establish that these surface antigens are encoded by related genes are presented. The regions of SPAG-1 identified as containing cross-reactive epitopes recognized by p67 antiserum correlated to regions of high predicted homology between p67 and SPAG-1, which are located at their respective N- and C-termini. Furthermore, p67 and SPAG-1 were found to contain cross-reactive determinants responsible for neutralization of sporozoite infectivity in vitro, and at least some of these were located in the C-termini of both molecules. The relevance of these findings to the possible roles for these molecules in host cell invasion is discussed.

Amino Acid Sequence↗

PubMed1996

Effectiveness of a consultation intervention to promote tobacco control policies in Northwest Indian tribes: integrating experimental evaluation and service delivery.

A quasi-experimental replication of an intervention for promoting tobacco control policies in Northwest Indian tribes is described and the process of intervention including issues of collaboration among research institutions and Indian organizations is discussed. The policy intervention was evaluated using a pretest-posttest design wherein 20 tribes that had served as wait-list controls now received the intervention. The intervention comprised a tribal representative attending a kickoff orientation; follow-up visits to the tribes; distribution of tobacco policy workbooks; and phone call consultations. Policy status and stringency were assessed by means of telephone interviews with two key contacts per tribe, and by a count of enacted policies. There were significant pre-post changes in the primary outcome measure, a composite summary score of tobacco policy stringency, and changes were also reflected in enacted policies. The intervention effects observed were similar to those found in the prior randomized trial and suggest a robust, disseminable intervention. Much of the success achieved was attributed to the role of an Indian organization in planning the project and implementing the intervention and evaluation protocols.

Follow-Up Studies↗

PubMed1996

Underdetection of clinical benign prostatic hyperplasia in a general medical practice.

OBJECTIVE: To measure detection of clinical benign prostatic hyperplasia (BPH) in a general medicine practice. DESIGN: Self-administered questionnaire and retrospective ambulatory medical record review. SETTING: Hospital-based general medicine practice. PATIENTS: Two hundred and four men aged 50 years and older. MEASUREMENTS AND MAIN RESULTS: Clinical information was obtained from a self-administered questionnaire containing the American Urological Association symptom index and the BPH Impact Index bother scale, and from retrospective review of ambulatory medical records for the previous 24 months. Thirty percent of patients had moderate to severe urinary tract symptoms, and 67% of these individuals were bothered by the symptoms. Only 52% with moderate to severe symptoms recalled any discussion with their primary care physician about their symptoms. There was medical record documentation of a review of urinary tract symptoms in only 18% and a prostate examination in only 64%. Patients with more symptoms and bother tended to recall a discussion of urinary tract symptoms with their physician. However, moderate to severe symptoms and bother were not associated with increased documentation of a history of urinary tract symptoms or prostate examination. CONCLUSIONS: Clinical BPH was underdetected in a general medicine practice. Because many men do not complain to their physicians about urinary tract symptoms and reduced quality of life, perhaps primary care physicians should pay more attention to recognizing this common condition of older men.

Family Practice↗

PubMed1996

Immunization levels for preventing epidemics in a community of households made up of individuals of various types.

A method is proposed for computing an epidemic threshold parameter for the spread of a communicable disease in a community of households in which individuals are of p different types. The threshold parameter is the largest eigenvalue of a p x p matrix whose elements depend on the rates of disease transmission between types and the distribution of the household size. More explicit expressions are given for diseases that are highly infectious within households, to the point that the infection of any member of a household results in the infection of all susceptible members of that household. For a variety of vaccination strategies it is described how this approach can be used to determine the level of immunity required to prevent epidemics. A numerical example illustrates the results.

Communicable Disease Control↗

PubMed1996

Finger duplication in Apert's syndrome.

Three cases of unilateral duplication of the little finger in children with Apert's syndrome are presented. They provide additional evidence that the hands in Apert's syndrome are not always symmetrically affected.

Acrocephalosyndactylia↗

PubMed1996

Randomized trial comparing intermittent antegrade warm blood cardioplegia with multidose cold blood cardioplegia for coronary artery bypass.

Forty patients were randomized to receive antegrade multidose warm (WBC) or cold blood cardioplegia (CBC) during coronary artery bypass. Cardioplegia was infused at a predetermined dose every 10 min during cardioplegia arrest and core temperature was maintained at 37 degrees C in both groups during extracorporeal circulation. Patient profiles were similar in the two groups. Cardiac index, left ventricular stroke work index, and myocardial oxygen consumption were measured before bypass and during the first 7 h of reperfusion. There was no significant difference in myocardial metabolic and function recovery, the incidence of myocardial infarction, low cardiac output or death. Our data suggests that similar protection is provided with the two techniques of myocardial protection.

Coronary Artery Bypass↗

PubMed1996

Acute hydrocephalus following aneurysmal subarachnoid hemorrhage.

BACKGROUND: Acute hydrocephalus is a potentially treatable cause of early neurological deterioration after aneurysmal subarachnoid hemorrhage (SAH). METHODS: A retrospective study of 105 consecutive cases of aneurysmal SAH was undertaken to determine those factors significantly related to the development of acute hydrocephalus. Acute hydrocephalus was diagnosed when the bicaudate index was greater than the 95th percentile for age on a CT scan within 72 hours of the ictus. RESULTS: Thirty-one percent of the patients developed acute hydrocephalus. Grade of SAH was a significant factor for the development of acute hydrocephalus on univariate analysis as 87% of patients with acute hydrocephalus (29/32) presented with at least grade 3 (Hunt-Hess) SAH (P < 0.05). In addition, posterior circulation aneurysms on univariate analysis were associated with acute hydrocephalus (p < 0.05). Both premorbid hypertension and intraventricular blood (p < 0.05) were predictors for acute hydrocephalus, whereas intracisternal blood, age and sex were not. On multivariate linear regression analysis, factors found to be significantly associated with acute hydrocephalus were premorbid hypertension, intraventricular blood, CSF diversion and definitive shunt procedures. External ventricular drainage was not associated with any instances of rebleeding. Thirty-seven percent (10/27) of patients with acute hydrocephalus who survived were improved by pre-operative external ventricular drainage. CONCLUSIONS: Patients with acute hydrocephalus following SAH can be safely treated with external ventricular drainage. Multiple factors can be identified to predict those patients who will develop acute hydrocephalus post aneurysmal rupture. Approximately 30% of those patients with acute hydrocephalus will require definitive shunt placement. Acute hydrocephalus occurred in 31% of aneurysmal SAH patients in this series.

Acute Disease↗

PubMed1996

Preventing epidemics in a community of households.

The occurrence of epidemics of vaccine-preventable diseases, and the immunization coverage required to prevent them, is affected by the presence of households and heterogeneity in the community. We consider a community where individuals live in households and are of different types, according to infectivity and/or susceptibility to infection. We describe a method for computing the critical immunization coverage to prevent epidemics in such communities and discuss the effectiveness of immunization strategies. In a heterogeneous community where individuals live in households several immunization strategies are possible and we examine strategies targeting households, randomly selected individuals, or groups with highly intense transmission, such as school children. We compare estimates of the critical immunization coverage if we assume that disease is spread solely by random mixing with estimates which result if we assume the effects of the household structure. Estimates made under these two sets of assumptions differ. The results provide insights into the community effects of vaccination, and the household structure of the community should be taken into account when designing immunization policies.

Child↗

PubMed1996

The role of complement in the pathogenesis of postpartum thyroiditis: ultrasound echogenicity and the degree of complement-induced thyroid damage.

Postpartum thyroiditis (PPT) is a transient autoimmune thyroiditis occurring during the postpartum year that is characterized by circulating antithyroid antibodies, abnormal thyroid ultrasound echotexture, and episodes of hyperthyroidism, hypothyroidism, or both. In this study we examined the relationship between lymphocytic thyroiditis, as indicated by echotexture changes, and complement-activating thyroid autoantibodies. Thyroid ultrasound echotexture, thyroid function, and bioactive (complement-activating) thyroid peroxidase (TPO) antibodies have been measured in a group of 63 TPO antibody-positive women during the postpartum year. When the maximum bioactive TPO antibody activity recorded was compared with echogenicity and thyroid status, there was a correlation between hypoechogenicity, elevated antibody activity, and abnormal thyroid status (r = 0.72, p < 0.001). However, 7 cases showed severe ultrasound changes in the absence of any thyroid dysfunction (3 of these cases showed normal bioactive antibody activity), while 4 (all hyperthyroid PPT) showed thyroid dysfunction in the absence of any ultrasound changes. Within the euthyroid ultrasound normal group, bioactive TPO antibody activity remained low throughout the postpartum year. Antibody activity in the hypoechogenic euthyroid women was significantly elevated (p < 0.001) compared with the echo normal group, but was indistinguishable from the activity curve obtained in women whose PPT included a hypothyroid phase. The determination of echotexture by thyroid ultrasonography gives a useful, noninvasive measure of the degree of thyroiditis in these women. However, as a significant number of cases with severe changes in echotexture remained euthyroid, we conclude that the development of thyroid dysfunction is not an inevitable consequence of lymphocytic thyroiditis during the postpartum and suggests that other factors must also be involved in progression to overt thyroid dysfunction.

Autoantibodies↗

PubMed1996

The clinical spectrum of postpartum thyroid disease.

The clinical and biochemical features of postpartum thyroid disease were analysed in 152 antithyroid peroxidase antibody-positive (anti-TPO+ve) women and compared with 239 anti-TPO-ve age-matched control postpartum women. All were assessed monthly for up to 12 months postpartum. Seventy three anti-TPO+ve women developed postpartum thyroiditis (PPT): 19.2% hyperthyroid alone, 49.3% hypothyroid alone, and 31.5% characterized by hyper- followed by hypothyroidism. None of the antibody-negative women developed any thyroid dysfunction. A significant increase in many of eleven symptoms of hypothyroidism and some of eight symptoms of hyperthyroidism compared to control women was observed in all anti-TPO+ve women, independent of thyroid status. This was particularly seen in women who later developed PPT when they were euthyroid, but was also observed in euthyroid anti-TPO+ve women who showed no decline of thyroid function during the postpartum period. Although PPT is usually transient, this condition, and the euthyroid antibody-positive state, may be associated with significant symptomatology, including an increased incidence of minor to moderate depression. Early recognition of this syndrome by antenatal screening of thyroid antibodies may contribute to improved management of women during the postpartum period.

Adult↗

PubMed1996

The comparative effects of sevoflurane versus propofol in the induction and maintenance of anesthesia in adult patients.

A randomized, prospective study was performed at four institutions to compare anesthetic induction, maintenance, and recovery characteristics between sevoflurane- and propofol-based anesthesia in 186 ASA physical status I and 11 patients undergoing elective surgical procedures of 1-3 h. Group 1 (n = 93) patients received sevoflurane-nitrous oxide for both induction and maintenance of anesthesia while Group 2 (n = 93) received propofol-nitrous oxide anesthesia. Induction of anesthesia and tracheal intubation times were significantly shorter with propofol (2.21 +/- 0.2 min, 5.11 +/- 0.3 min, respectively) than with sevoflurane (3.11 +/- 0.2 min, 7.21 +/- 0.3 min, respectively). Emergence times after sevoflurane (8.81 +/- 1.2 min) were significantly shorter than with propofol (13.21 +/- 1.2 min). Overall frequency of complication-free induction, maintenance, and emergence did not differ between the two anesthetic groups. However, side effects involving airway excitement were more prevalent during mask induction with sevoflurane as compared to propofol. Patients in the sevoflurane group were oriented and required postoperative analgesia much earlier than those who received propofol. Both groups were hemodynamically stable throughout the study period. The incidence of postoperative nausea, vomiting, and pain-discomfort scores were similar between the two groups. Urinary specific gravity decreased in the sevoflurane-treated group while serum creatinine and urinary pH were unchanged from preoperative values in both groups. Sevoflurane compared favorably with propofol when used for anesthesia for elective procedures of 1-3 h duration.

Adult↗

PubMed1996

Major histocompatibility complex class II and complement polymorphisms in postpartum thyroiditis.

The objective was to re-evaluate the association between class II HLA-DR and DQ MIIC antigens and postpartum thyroiditis (PPT) and to determine the prevalence of the class III complement allotypes of Properdin factor B (Bf), C4A and C4B in this condition. Two hundred and sixty-five (of 2897) pregnant women screened positive for thyroid autoantibody activity took part. Further blood samples were obtained for HLA class II (185) and complement (193) typing. The severity of the ensuing PPT was assessed by measuring thyroid function during the postpartum year. The HLA-DR and DQ phenotypes were assigned from restriction fragment length polymorphism analysis, and Bf, C4A and C4B allotypes were determined by immunofixation with anti-Bf or anti-C4 antibodies after electrophoresis. A weak association between the HLA class II antigens and PPT, as indicated by a reduced frequency of DR15 and DQ6 together with an increased frequency of-DR5 and DQ7, was confirmed. However, only the change in DR5 frequency remained significant after correction (corrected p < 0.05). Postpartum thyroiditis was also associated with frequency disturbances in BI and C4A allotypes but not C4B allotypes. Whilst this study has not provided evidence of a strong marker gene for PPT, it does not preclude the involvement of the MIIC in this condition. These data show disturbances in complement allotype frequencies, suggesting that the class III region may provide a useful focus for further study of this pathology.

Complement C4a↗