The value of a specialist lipid clinic

AIMS

To establish the value of the first 3 years of a cardiovascular risk factor clinic in tackling the major risk factors for cardiovascular disease (CVD).

METHODS

A database review of all 339 patients referred to the clinic.

RESULTS

Blood pressure levels in the hypertensive patients were significantly reduced and 9% of the smokers managed to quit for 12 months, half of them subsequently relapsing. Ninety-eight oral glucose tolerance tests were performed and 40% were abnormal yielding 10 patients with hitherto unsuspected diabetes and 29 with impaired glucose tolerance. Sixty-four of the 97 referrals of patients in the primary prevention group (no evidence of CVD) were found to have calculated Framingham coronary heart disease risk estimates of < 15% per decade, the lowest being 0.3%. Lipid levels were significantly reduced in both the hypercholesterolaemic (n = 290) and hypertriglyceridaemic (n = 49) patient groups through the use of more potent statins, extensive use of combination therapy and appropriate use of fibrates and omega-3 fish oil supplements. The annual drug cost per patient treated only increased from 310.72 pounds sterling to 398.08 pounds sterling, yet there was a 3.5-fold increase in the number of patients achieving the General Medical Services 2 target of a total cholesterol < 5 mmol/l and a 4.5-fold increase in patients achieving the Joint British Societies 2 target of a low-density lipoprotein (LDL) cholesterol < 2 mmol/l.

CONCLUSION

The need for a specialist clinic was demonstrated by the 66% of primary prevention referrals who did not meet the current NICE treatment threshold. Additionally, the clinic was able to diagnose and treat 39 patients with undiagnosed diabetes mellitus/impaired glucose tolerance and 12 with hypothyroidism. LDL cholesterol was reduced overall by 36% implying a greater than one-third reduction in future cardiovascular events before the improvements in blood pressure control and smoking cessation are included and this was achieved at marginal extra cost to the mean drug bill at referral.

Best practice in primary care pathology: review 8

This eighth best practice review examines four series of common primary care questions in laboratory medicine: (i) sodium abnormalities; (ii) faecal occult blood testing; (iii) warfarin management; and (iv) sputum cytology in diagnosis of bronchopulmonary malignancy. The review is presented in question-answer format, referenced for each question series. The recommendations represent a précis of guidance found using a standardised literature search of national and international guidance notes, consensus statements, health policy documents and evidence-based medicine reviews, supplemented by Medline Embase searches to identify relevant primary research documents. They are not standards but form a guide to be set in the clinical context. Most are consensus rather than evidence-based. They will be updated periodically to take account of new information.

Coping styles among families of children with HIV infection

The primary aim of this study was to examine coping strategies among families of HIV-infected children and how they relate to medical, central nervous system (CNS) and family environment factors. Caregivers of HIV-positive children (N=52) completed a family coping measure (F-COPES) and provided information regarding family environment. Data regarding medical and CNS status were obtained from patient records. Results indicated that families' passive coping and spiritual support were among the coping techniques used most often, and social support was used least often. Medical variables were unrelated to any coping styles. Families of children with CNS impairment endorsed more passive coping techniques than families of children with no apparent deficits. A trend was found for non-biological caregivers to seek out more community resources and support than biological caregivers. Findings suggest the need to target families least likely to utilize resources, and to teach them to effectively seek out and benefit from social and community supports.

Cardiovascular risk assessment in patients with retinal vein occlusion

AIM

Patients with retinal vein occlusions (RVO) are at increased risk of cardiovascular disease (CVD). The risk of future CVD was determined using the Framingham algorithm and this risk estimate was used to guide decisions about preventative treatment for CVD in RVO patients.

METHODS

107 unselected RVO patients were studied. After excluding 18 patients because of age, missing data, or pre-existing cardiovascular disease, the calculated coronary heart disease risks (cCHDR) and calculated cardiovascular disease risks (cCVDR) were calculated on the 89 remaining and compared with both the standardised risk and the published incidence of CHD in England by t test or chi(2) test.

RESULTS

The mean 10 year cCVDR was significantly higher than the Framingham standardised risk for all RVOs (20.6% (1.2%) v 15.7% (1.1%), p = 0.009) and female RVOs (17.8% (1.2%) v 12.7% (1.0%), p = 0.022) in particular. The 10 year cCHDR, compared to the actual incidence of CHD in England between the ages of 30 and 74 years, was > 15% in twice as many males than expected (62% v 28%, p <0.0001). This rose to almost six times when cCHDRs greater than 30% were compared (17% v 3%, p = 0.002). There was a fourfold increase in the proportion of female RVO patients with a cCHDR above 15% (40% v 9%, p <0.0001) and at a cCHDR of 30% and above (10% v 0%, p = 0.004). There were also significant differences in the cCHDR between central and branch RVO (both sexes). The branch form of RVO (BRVO) having higher cCHDRs because of systolic hypertension (164.1 (21.6) mm Hg v 149.5 (23.5) mm Hg, p = 0.003) and age (61.7 (8.3) years v 56.7 (10.6) years, p = 0.017).

CONCLUSIONS

RVO is the presenting complaint in a group of patients at increased risk of CVD and is in agreement with the long term follow up data demonstrating an increased mortality from CVD in patients with RVO. The Framingham algorithm can accurately determine the cCHDR (or cCVDR) to assist the clinician in deciding who to treat in accordance with the Joint British Societies' guidelines, with particular regard to hypertension, lipid lowering, and the use of aspirin therapy.

Serum homocysteine concentration is related to diabetes mellitus, but not to coronary heart disease, in Saudi Arabians

INTRODUCTION

Plasma homocysteine (HCYS) concentration is believed to be an independent risk factor for atherosclerosis.

METHODS

HCYS was measured in a cohort of 584 Saudi Arabians participating in a national screening study of coronary heart disease (CHD) risk factors. A total of 173 subjects (114 men and 59 women) had clinical CHD, of whom 82 (47.4%) had type 2 diabetes mellitus (56 men and 26 women). A further 127 subjects (60 men and 67 women) also had type 2 diabetes mellitus but no CHD. A total of 284 individuals (120 men and 164 women) were recruited as healthy controls, and had no previous history of CHD or diabetes. Serum HCYS was measured by high-performance liquid chromatography (HPLC) with electrochemical detection.

RESULTS

Univariate analysis showed HCYS concentrations were significantly lower in those with diabetes mellitus (DM) than in controls, for both men [8.7 (4.2-18.6) vs. 10.5 (4.5-20.5) mmol/l, median (5th-95th percentiles, p = 0.009] and women [6.3 (3.3-24.0) vs. 8.1 (4.0-17.9) mmol/l, p = 0.049]. Stepwise multivariate regression analysis indicated a relationship between HCYS concentration and age, sex and the presence of DM, but not with CHD.

CONCLUSIONS

In the Saudi Arabian population, serum HCYS is not a risk factor for CHD, but is lower in patients with DM.

Human GABA(B)R genomic structure: evidence for splice variants in GABA(B)R1 but not GABA(B)R2

The type B gamma-aminobutryic acid receptor (GABA(B)R) is a G protein coupled receptor that mediates slow pre- and post-synaptic inhibition in the nervous system. We find that the human GABA(B)R2 gene spans greater than 350 kb and contains 2.8 kb of coding region in 19 exons. The overall similarity in genomic structure with regard to conservation of intron position and exon size between human or Drosophila GABA(B)R1 and GABA(B)R2 genes suggests a common ancestral origin. Multiple transcripts GABA(B)R1a-c and GABA(B)R2a-c have been described and alternative splicing has been proposed to result in GABA(B)R1c, GABA(B)R2b and GABA(B)R2c. The results described here provide support for the existence of GABA(B)R1c but not for GABA(B)R2b and GABA(B)R2c. Splice junctions present in the GABA(B)R1 gene sequence are consistent with the formation of GABA(B)R1c by exon skipping of one sushi domain module. The GABA(B)R2 gene lacks canonical splice junctions for the reported variants. Consistent with this, RNA analysis demonstrates the presence of GABA(B)R1c and GABA(B)R2 transcripts in fetal and adult human brain RNA but GABA(B)R2b and GABA(B)R2c transcripts are not detected. These results provide insight into the evolution and transcript diversity of the mammalian GABA(B)R genes.

A pilot study of homocyst(e)ine levels in essential hypertension: relationship to von Willebrand factor, an index of endothelial damage

An interaction between homocyst(e)ine and the endothelium in hypertensive patients may promote thrombogenesis and atherogenesis, leading to adverse cardiovascular events. We hypothesized that homocyst(e)ine levels are abnormal in patients with essential hypertension, and that this may be related to an adverse effect on the vascular endothelium. Accordingly, we compared plasma levels of homocyst(e)ine and von Willebrand factor (marking endothelial damage) in 83 patients (43 men; mean age 54 +/- standard deviation 15.9 years) with essential hypertension (> 160/90 mm Hg), with levels in 25 healthy normotensive controls (13 men; mean age 56+/-11.8 years). Baseline levels of the markers and other clinical indices were then related to adverse cardiovascular events at follow-up. Plasma homocyst(e)ine (P = .0001) and von Willebrand factor (P = .031) levels were significantly higher in hypertensives compared to controls. After a mean follow-up of 76 patients for 45 months (range, 1 to 66 months), 17 subjects experienced an end point of either cardiovascular death (n = 10) or adverse cardiovascular event (n = 7). Comparing these 17 with the 59 free of an end point, the former were older (P = .0002) and had a longer duration of known hypertension (P = .018). There was a nonsignificant trend toward higher median plasma homocyst(e)ine levels in the patients sustaining a vascular end point (P = .07). In this pilot study, we suggest that essential hypertension may be associated with increased plasma homocyst(e)ine levels, but that this amino acid is unrelated to endothelial damage (von Willebrand factor), clinical indices, or prognosis.

Degradation of lignin in wheat straw during growth of the oyster mushroom (Pleurotus ostreatus) using off-line thermochemolysis with tetramethylammonium hydroxide and solid-state (13)C NMR

The oyster mushroom (Pleurotus ostreatus) is widely cultivated on wheat straw (Triticum aestivum); however, there is a need to better understand the relationship between the chemical composition of the compost and mushroom growth. Wheat straw was degraded over a period of 63 days by P. ostreatus during which time it was sampled at weekly intervals. Off-line thermochemolysis with tetramethylammonium hydroxide and solid-state (13)C NMR were then used in the molecular characterization of the undegraded wheat straw and the degraded samples. The degraded wheat straw samples had a lower proportion of syringyl- to guaiacyl-derived moieties and cinnamyl- to guaiacyl-derived moieties than the undegraded control. There were increases in both guaiacyl and syringyl acid to aldehyde ratios with composting time, which showed that side-chain oxidation has been mediated by P. ostreatus. The (13)C NMR spectra confirmed the increase in carboxyl content but indicated that the overall lignin and methoxyl contents remained relatively constant, although some nonsystematic variations were observed. The spectra also showed a decrease in amorphous noncellulosic polysaccharides in relation to the crystalline cellulose upon degradation.

Plasma total homocysteine and retinal vascular disease

PURPOSE

Hyperhomocysteinaemia has been linked to macrovascular disease. Our aim was to investigate whether there is a relationship between fasting plasma total homocysteine levels and retinal vascular disease.

METHODS

We measured the homocysteine levels in 70 patients with arterial or venous retinal vessel occlusion and compared them with the levels in 85 controls without evidence of ischaemic heart disease. Homocysteine levels were determined by high-performance liquid chromatography with electrochemical detection and compared after logarithmic transformation.

RESULTS

Homocysteine levels were found by univariate analysis (unpaired two-tailed t-test) to be significantly higher in the group with retinal artery occlusion than the group with retinal vein occlusion (p = 0.045) and in both groups compared with controls (18.4 and 13.8 vs 9.5 mumol/l; p = 0.0002 and < 0.0001, respectively). The controls, however, were significantly younger than the subjects (51.5 +/- 15.4 vs 66.2 +/- 11.9 years; p < 0.0001), but analysis of the results by age revealed significant differences between the groups and controls for the seventh decade (vein occlusions, p = 0.05) and for the eighth decade (artery occlusions, p = 0.037). Subgroup analysis of the retinal vessel occlusion group revealed significant differences in mean blood pressure between those with branch retinal vein occlusions (175/100 mmHg) and both those with central retinal vein occlusions (155/88 mmHg) and those with retinal artery occlusions (157/86 mmHg). Both vein occlusion subgroups also differed significantly with regard to homocysteine levels, branch < central (12.2 +/- 1.3 vs 15.0 +/- 1.6 mumol/l, p = 0.03). Multiple linear regression analysis revealed significant relationships between homocysteine levels and the presence of retinal vessel occlusion (p = 0.0002), serum creatinine (p = 0.001) and age (p = 0.003), but not gender.

CONCLUSIONS

We conclude that homocysteine may be a risk factor for retinal vascular disease and could be simply and cheaply treated with folate and vitamins B6 and B12.

Predicting children's sunscreen use: application of the theories of reasoned action and planned behavior

BACKGROUND

Skin cancer remains the most common form of cancer in the United States despite the fact that most cases can be prevented by limiting sun exposure. Childhood and adolescence are periods of life during which prolonged sun exposure is particularly common. Accordingly, promoting sun-protective behaviors during these formative years can be of critical importance in preventing skin cancer. The present study applied the theories of reasoned action and planned behavior to the understanding of children's sunscreen use. Based on these theories, it was hypothesized that attitudes, subjective norms, and perceived behavioral control would be related to intentions to use sunscreen, which, in turn, would be related to actual sunscreen use.

METHODS

Questionnaires measuring sun-related attitudes, beliefs, perceived control, and intentions were administered to 199 fourth graders (ages 9 to 13, mean = 10.3) attending public schools in Florida. Self-report measures of sun-related behavior were administered to the same subjects 1 month later.

RESULTS

Results of correlational analyses were consistent with study hypotheses. Higher rates of sunscreen use at follow-up were predicted by stronger intentions to use sunscreen assessed 1 month previously. In addition, stronger intentions to use sunscreen were found to be related to more favorable attitudes toward sunscreen use, stronger beliefs that peers and parents favored sunscreen use, and greater perceptions of personal control in using sunscreen. Path and multiple regression analyses identified direct and indirect relationships among study variables that partially confirmed those predicted by the theories and provided support for the use of an expanded model that included perceived behavioral control.

CONCLUSIONS

The present study confirmed hypotheses derived from the theories of reasoned action and planned behavior regarding the relation of attitudes, subjective norms, and perceived behavioral control to sunscreen use among fourth graders. In addition to their theoretical significance, these findings suggest ways to intervene at the individual, classroom, and family levels to promote greater sunscreen use in this age group.

Treatment of root perforation by intentional reimplantation: a case report

Intentional reimplantation is defined as a procedure in which an intentional tooth extraction is performed followed by reinsertion of the extracted tooth into its own alveolus. In this paper, intentional reimplantation is described and discussed as a treatment approach to root canal instrument separation in conjunction with root perforation. An 8-year follow-up case report is presented. The reimplanted tooth is now a fixed bridge abutment. Although successful in this case, the intentional reimplantation procedure should be considered a treatment of last resort, that is, when another treatment option is not viable for the treatment of root perforation/instrument retrieval.

Molecular identification of the human GABABR2: cell surface expression and coupling to adenylyl cyclase in the absence of GABABR1

We have identified a gene encoding a GABAB receptor, the human GABABR2, located on chromosome 9q22.1, that is distinct from the recently reported rat GABABR1. GABABR2 structurally resembles GABABR1 (35% identity), having seven transmembrane domains and a large extracellular region, but differs in having a longer carboxy-terminal tail. GABABR2 is localized to the cell surface in transfected COS cells, and negatively couples to adenylyl cyclase in response to GABA, baclofen, and 3-aminopropyl(methyl)phosphinic acid in CHO cells lacking GABABR1. Baclofen action is inhibited by the GABABR antagonist, 2-hydroxysaclofen. The human GABABR2 and GABABR1 genes are differentially expressed in the nervous system, with the greatest difference being detected in the striatum in which GABABR1 but not GABABR2 mRNA transcripts are detected. GABABR2 and GABABR1 mRNAs are also coexpressed in various brain regions such as the Purkinje cell layer of the cerebellum. Identification of a functional homomeric GABABR2 coupled to adenylyl cyclase suggests that the complexity of GABAB pharmacological data is at least in part due to the presence of more than one receptor and opens avenues for future research leading to an understanding of metabotropic GABA receptor signal transduction mechanisms.

Plasma total homocysteine measurement by ion-paired reversed-phase HPLC with electrochemical detection

Homocysteine is thought to be a risk factor for vascular disease and this has led to an increase in demand for its assay in clinical laboratories. An HPLC method, incorporating electrochemical detection, for measurement of plasma total homocysteine is presented. The method is simple to perform, precise and suitable for clinical applications.

Cloning and functional characterization of PACAP-specific receptors in zebrafish

Two PACAP receptors were isolated from total zebrafish cDNA library prepared from 6-day old fish by a homology-based cloning strategy. The two zebrafish PACAP receptors have the same topology as the one found in other members of this class of seven membrane-spanning G-protein-coupled receptors. Each of the two zebrafish PACAP receptors shares about 70% sequence identity at the amino acid level with the human PACAP-type 1 receptor, and about 50% amino acid identity with PACAP/VIP R-1 and PACAP/VIP R-2 receptors. One of these zebrafish receptors contains the hop2 configuration found in the human and rat PACAP-type 1 receptors. On the basis of these structural characteristics the zebrafish PACAP receptors were classified as PACAP-type 1 and PACAP-type 2 receptors. In competitive binding experiments zebrafish PACAP-type 1 and PACAP-type 2 receptors showed similar binding specificity for zebrafish and human PACAP-38 and PACAP-27. Furthermore, the specificity of PACAP-type 1 and PACAP-type 2 receptors for zebrafish and human PACAPs is about 1,000-fold higher than for human VIP. These results demonstrate that zebrafish PACAP-type 1 receptor is a structural and pharmacological homolog of the mammalian PACAP-type 1 receptor. Additional pharmacological characterization is needed in order to classify the zebrafish PACAP-type 2 receptor.

Sequence and expression of glutamic acid decarboxylase isoforms in the developing zebrafish

We describe the isolation two glutamic acid decarboxylase (GAD) cDNAs from zebrafish with over 84% identity to human GAD65 and GAD67. In situ hybridization studies revealed that both GAD65 and GAD67 were expressed in the early zebrafish embryo during the period of axonogenesis, suggesting a role for GABA prior to synapse formation. Both GAD genes were detected in the telencephalon, in the nucleus of the medial longitudinal fasciculus in the midbrain, and at the border regions of the rhombomeres in the rostral hindbrain. In the caudal hindbrain, only GAD67 was detected (in neurons with large-caliber axons). In the spinal cord, both GAD genes were detected in dorsal longitudinal neurons, commissural secondary ascending neurons, ventral longitudinal neurons, and Kolmer-Agduhr neurons. Immunohistochemistry for gamma-aminobutyric acid (GABA) revealed that GABA is produced at all sites of GAD expression, including the novel cells in the caudal hindbrain. These results are discussed in the context of the hindbrain circuitry that supports the escape response. We conclude that fish, like mammals, have two GAD genes. The zebrafish GAD65 and GAD67 are present in identified neurons in the forebrain, midbrain, hindbrain, and spinal cord, and they catalyze the production of GABA in the developing embryo.

Measurement of fatigue in cancer patients: development and validation of the Fatigue Symptom Inventory

Although fatigue is one of the most common and debilitating symptoms experienced by cancer patients, it has received little systematic attention. This situation is due in large part to the lack of adequate instruments to measure fatigue. The primary aim of this study was to validate a newly developed measure of fatigue for use with cancer patients: the Fatigue Symptom Inventory (FSI). This 13 item self-report measure was designed to measure the intensity and duration of fatigue and its impact on quality of life. The psychometric properties of the FSI were assessed in women undergoing treatment for breast cancer, women who had completed treatment for breast cancer and women with no history of cancer. A seven-item interference subscale was found to have good internal consistency, with alpha coefficients above 0.90 in all three groups. The complete FSI was found to have rather weak to moderate test-retest reliability among patients in active treatment and healthy comparison subjects assessed on three separate occasions. Convergent validity was demonstrated using comparisons with existing measures of fatigue. Construct validity was demonstrated using comparisons between and within groups as well as comparisons with measures of anxiety and depression. Overall, the FSI was established as a valid and reliable measure of fatigue in cancer patients and healthy individuals. Suggestions are made for the potential application of the measure in clinical research.

A multidimensional measure of fatigue for use with cancer patients

PURPOSE

The purpose of this study was to develop and validate a multidimensional measure of fatigue for use with cancer patients.

DESCRIPTION OF STUDY

Items for the Multidimensional Fatigue Symptom Inventory (MFSI) were generated through literature review, discussion with healthcare providers, and a survey of currently available measures of fatigue. The 83-item MFSI was designed to assess global, somatic, affective, cognitive, and behavioral symptoms of fatigue. The instrument was administered on three occasions to 275 women who had received or were undergoing treatment for breast cancer and 70 women with no history of cancer. Reliability, validity, and factorial structure of the MFSI were analyzed.

RESULTS

The factor analysis produced five empirically derived scales that correspond generally to the five rationally derived scales. Reliability of the rationally and empirically derived scales was excellent (alpha coefficients .87 to .96). Estimates of test-retest reliability were also favorable. Other results support the validity of both the rationally and empirically derived scales. The MFSI appears to be sensitive to fatigue, accurately discriminating cancer patients from control subjects and between patients with varying levels of performance status.

CLINICAL IMPLICATIONS

The MFSI may be useful in identifying patterns of fatigue within individual patients and across treatment modalities. Such specificity may allow the clinician to develop, implement, and evaluate interventions that are targeted for differing patterns of fatigue. Because the measure is keyed to a 1-week time frame, it may be useful during the course of cancer treatment. The MFSI appears to be a valid and reliable tool to assess the full spectrum of symptoms that characterize the construct of fatigue.

Zebrafish TrkC1 and TrkC2 receptors define two different cell populations in the nervous system during the period of axonogenesis

We identified previously five distinct trk genes in the zebrafish. The structures of two of these, TrkC1 and TrkC2, are most similar to mammalian TrkC. Detailed sequence comparisons reported here indicate that although the similarities to TrkC are greatest in those regions of the extracellular domain implicated in ligand binding, the two sequences also differ significantly in these regions. Whole-mount in situ hybridization experiments in the early embryo revealed full-length trkC1 but no trkC2 transcripts in the cranial ganglia and in a subset of Rohon-Beard neurons. At the same time, full-length trkC2 but no trkC1 transcripts were detected laterally in the spinal cord, in the caudal hindbrain, in reticulospinal neurons of rhombomeres 4, 5, and 6, and in the midbrain. Both types of transcripts were expressed in clusters of cells in the dorsal telencephalon and the nucleus of the tract of the postoptic commissure. These results suggest distinct functions of trkC1 and trkC2 in nervous system development. The expression patterns define two different neuronal populations in the zebrafish.

Quality of life following bone marrow transplantation for breast cancer: a comparative study

As more women are treated with bone marrow transplantation (BMT) for breast cancer, there is growing interest in quality of life (QOL) following treatment. Although there have been some clinical studies of QOL following BMT, this area has received little systematic attention. In particular, it is unclear how QOL for women treated with BMT for breast cancer differs from that which might be expected for 'healthy' women of about the same age. To address this issue, we compared QOL reported by women treated with autologous BMT for breast cancer with that of a group of women of similar age with no history of cancer. In addition, we examined the relationship of demographic factors, medical factors, and self-reported symptom prevalence, severity, and distress to QOL in post-BMT patients. All participants completed the SF-36 Health Survey developed from the Medical Outcomes Study (SF-36). Post-BMT patients also completed the ECOG Performance Status Rating Scale (PSR) and the Memorial Symptom Assessment Scale (MSAS). Results indicated that, compared to the women with no cancer history, post-BMT patients reported significantly impaired physical functioning, physical role functioning, general health, vitality, social functioning, and emotional role functioning. Impaired QOL following BMT was significantly associated with lower income, a longer time to engraftment, longer hospital stay, poor performance status, and greater symptom prevalence, severity, and distress. The problems identified in this study may be important targets for intervention when trying to improve QOL following BMT.

Fatigue in women treated with bone marrow transplantation for breast cancer: a comparison with women with no history of cancer

As more individuals undergo autologous bone marrow transplantation (BMT), there is growing interest in the impact of treatment side effects on quality of life. Fatigue is a potentially disruptive treatment side effect that has not been systematically assessed following BMT. The primary aim of this study was to determine whether the severity of fatigue and its impact on quality of life is significantly greater in women who had undergone BMT for breast cancer than in women of similar age with no history of cancer. Another aim was to identify the medical and psychosocial correlates of fatigue in women who had completed BMT. A group of women treated with autologous BMT for breast cancer (n = 43; mean age = 44; mean time since BMT = 20 months) and a group of women of similar age with no history of cancer (n = 43; mean age = 46) participated in this study. Subjects completed measures of fatigue, anxiety, depression, and sleep habits. Medical data were obtained from computerized patient records. Women who had completed BMT for breast cancer reported significantly more frequent and severe fatigue than women with no cancer history. In addition, fatigue had a significantly greater impact on daily functioning and quality of life in BMT recipients than in women with no cancer history. Fatigue following BMT for breast cancer was related to both medical factors (i.e., time since BMT) and psychosocial factors (i.e., anxiety, depressive symptoms and sleep difficulties). Following BMT for breast cancer, women may experience fatigue that is worse than might "normally" be expected and can interfere with daily functioning and quality of life. Future research should focus on identifying the biological correlates of fatigue, psychological and physiological mechanisms by which fatigue is produced, and interventions to alleviate fatigue.

Creating university hospitals: rationales and realities

This article analyzes the reasons given for the founding of three early university hospitals: those at the University of Michigan, the University of Pennsylvania, and Johns Hopkins University. The hospital at the University of Michigan was founded to ensure medical students' access to clinical instruction. The University of Pennsylvania's desire to have not only access to but control over hospital affairs provided the impetus to build a university hospital. Johns Hopkins University, building upon the examples of Michigan and Pennsylvania, firmly joined the hospital and medical school and introduced research as a link between these institutions. The early histories of these three institutions demonstrate how each created a different mission for its university hospital. Today, as in the past, university hospitals must choose which of their multiple roles to emphasize. The meaning of "university hospital" has always been ambiguous, and this ambiguity can provide useful flexibility to institutions responding to a changing environment.

Five Trk receptors in the zebrafish

Using a homology-based cloning strategy we have identified five members of the Trk family in the zebrafish Danio rerio. They are homologous to the three mammalian Trk receptors in their conserved intracellular kinase regions and the organization of their extracellular regions. The five trk genes are differentially expressed in the developing brain, spinal cord, cranial ganglia, and retina. Full-length forms of three of the trk genes are expressed when neurons pioneer the major axon tracts, whereas the two other trk genes have a later onset of expression. Truncated transcripts and forms containing an extracellular juxtamembrane region insert were found. The degree of sequence variation and expression differences within the family suggest that each of the five zebrafish Trk receptors have a functionally distinct role. These findings demonstrate that the vertebrate Trk family is larger than previously appreciated.

Activation by ATP of a P2U 'nucleotide' receptor in an exocrine cell

1. We employed the perforated patch whole-cell technique to investigate the effects of ATP and other related nucleotides on membrane conductances in avian exocrine salt gland cells. 2. ATP (10 microM-1 mM) evoked an increase in maxi-K+ and Cl- conductances with a reversal potential of -35 mV. At lower concentrations of ATP (< or = 100 microM) responses were generally oscillatory with a sustained response observed at higher concentrations (> or = 200 microM). 3. Both oscillatory and sustained responses were abolished by the removal of bath Ca2+. In cells preincubated in extracellular saline containing reduced Ca2+, the application of ATP resulted in a transient increase in current. 4. As increasing concentrations of ATP (and related nucleotides) evoked a graded sequence of events with little run-down we were able to establish a rank order of potency in single cells. The order of potency of ATP analogues and agonists of the various P2-receptor subtypes was UTP > ATP = 2-methylthio-ATP > ADP. Adenosine (1 microM-1 mM), AMP (1 microM-1 mM), alpha,beta-methylene-ATP (1 microM-1 mM) and beta,gamma-methylene-ATP (1 microM-1 mM) were without effect. 5. In conclusion, although unable to preclude a role for a P2Y-receptor, our results suggest that ATP binds to a P2U-receptor increasing [Ca2+]i and subsequently activating Ca(2+)-sensitive K+ and Cl- currents.

Ca2+ influx drives agonist-activated [Ca2+]i oscillations in an exocrine cell

In current models describing agonist-induced oscillations in [Ca2+]i, Ca2+ entry is generally assumed to have a simple sustaining role, replenishing Ca2+ lost from the cell and recharging intracellular Ca2+ stores. In cells from the avian nasal gland, a model exocrine cell, we show that inhibition of Ca2+ entry by La3+, SK&F 96365, or by membrane depolarization, rapidly blocks [Ca2+]i oscillations but does so without detectable depletion of agonist-sensitive Ca2+ stores. As the rate of Mn2+ quenching during [Ca2+]i oscillations is constant, Ca2+ entry is not directly contributing to the [Ca2+]i changes and, instead, appears to be involved in inducing the repetitive release of Ca2+ from internal stores. Together, these data contradict current models in that (i) at the low agonist concentrations where [Ca2+]i oscillations are seen, generated levels of Ins(1,4,5)P3 are themselves inadequate to result in a regenerative [Ca2+]i signal, and (ii) Ca2+ entry is necessary to actually drive the intrinsic oscillatory mechanism.

The development of neurotrophin receptor Trk immunoreactivity in the retina of the zebrafish (Brachydanio rerio)

The purpose of this study was to examine the cellular distribution of the Trk family of neurotrophin receptors in the retina and optic nerve of the zebrafish (Brachydanio rerio) during embryonic development. Semithin sections from zebrafish retinae were examined immunohistochemically for the presence of Trk polypeptides using commercially available antisera that cross-react with the fish. Cross-reactivity was confirmed by Western blot. Trk polypeptides were detected at about 1 day of age on the surfaces of retinal neuroblasts and faint Trk immunoreactivity was observed in the primordial optic nerve at 1.5 days. By 2 days the optic nerve was clearly positive for Trk and at 2.5 days Trk immunoreactivity was found in the outer plexiform, inner nuclear, inner plexiform and ganglion cell layers, as well as in the optic nerve. At 3 days and 4 days the location of Trk immunoreactivity was unchanged but by 4 days it had diminished in intensity. In the adult zebrafish retina Trk immunoreactivity was found in the same locations as in the embryonic fish, as well as in a population of cells in the middle of the inner nuclear layer and in photoreceptors. We conclude that Trk neurotrophin receptors are present in the zebrafish eye during development and that their persistence in the adult may support the continuous neural reorganization that accompanies the growth of the eye in the fish.

Vasoactive intestinal peptide stimulates a cAMP-mediated Cl- current in avian salt gland cells

VIP plays an integral role in both protein and fluid secretion in many exocrine glands. By employing the perforated patch-clamp whole-cell recording technique we investigated the effects of VIP on membrane potential and transmembrane currents in avian exocrine salt gland cells. Prior to application of VIP, salt gland cells had a resting membrane potential close to -45 mV. When challenged with VIP (1-100 nM) a sustained depolarization to ECl- was induced which was mimicked by the application of cell-permeable cAMP analogues or forskolin (1 microM). By employing the voltage-clamp recording configuration a sustained increase in current was observed with a reversal potential which approximated ECl-. Ionic substitution experiments confirmed that the current was a Cl- conductance which was inhibited by the Cl- channel blockers flufenamic acid and niflumic acid and by the inhibitory cAMP isomer, adenosine-3',5'-cyclic monophosphothioate, Rp-isomer. Based on this, and the fact that the kinetic properties of the Cl- current activated by VIP are similar to those activated by cAMP, we propose that VIP-receptor interaction results in the activation of a cAMP-dependent Cl- current.

The development of GABA immunoreactivity in the retina of the zebrafish (Brachydanio rerio)

The goal of this study was to determine the pattern of gamma-aminobutyric acid (GABA) expression in the retina and optic nerve of the zebrafish (Brachydanio rerio) during embryonic development. Zebrafish embryos were fixed at intervals between 1 and 4 days postfertilization, and semithin plastic sections were prepared for postembedding immunocytochemistry with antisera against GABA. Sections were also prepared from several adult zebrafish eyes for comparison. GABA immunoreactivity first appeared in the optic nerve at 2 days postfertilization, and by 2.5 days the inner nuclear layer (INL), inner plexiform layer (IPL), retinal ganglion cell layer, and optic nerve were all positive for GABA. The GABA expression in the retinal ganglion cell layer and optic nerve was transient, however, and these structures were largely unlabeled by 4 days postfertilization. The pattern of GABA immunoreactivity at 4 days resembled that seen in the adult zebrafish: A large population of presumptive amacrine cells was labeled at the base of the INL, and the IPL was positive for GABA, as were occasional cells in the ganglion cell layer. Horizontal cells, particularly at the retinal margins, were also GABA positive beginning at about 3 days postfertilization. The transient expression of GABA in retinal ganglion cells and their axons during the period when synaptic contacts are being established both within the retina and between the retina and central targets suggests that GABA may have a role in the development of this system, in addition to serving as a classical neurotransmitter.

Potentiation of Ca(2+)-activated secretory activity by a cAMP-mediated mechanism in avian salt gland cells

In the avian salt gland carbachol (CCh) evokes oscillations in K+ and Cl- current that are sufficient to fully activate secretory activity. Employing the perforated patch-clamp technique, we demonstrate that beta-adrenergic receptor activation stimulates a sustained adenosine 3',5'-cyclic monophosphate (cAMP)-dependent Cl- current with no increase in K+ current. This evokes only a modest increase in secretory activity. However, application of isoproterenol in the presence of a threshold dose of CCh results in maximal secretory activity. Membrane potential measurements demonstrate that isoproterenol stimulates a sustained membrane depolarization from approximately -45 mV to the Cl- equilibrium potential (ECl), whereas CCh evokes oscillations in membrane potential to levels more negative than ECl, representing a mixture of K+ and Cl- conductances. We conclude that, in agreement with current models of fluid secretion, maximal stimulation can only be achieved with simultaneous activation of both K+ and Cl- currents. Because isoproterenol fails to stimulate a K+ current, Cl- secretion is reduced as the driving force for Cl- secretion is dissipated. However, if a driving force is imposed by increasing K+ channel activity (by coadministering CCh), Cl- efflux is sustained. These results could provide a basis for the marked potentiation of Ca(2+)-mediated secretion by agonists that increase cAMP seen in in vivo studies of salivary glands and other exocrine tissues.

Muscarinic-receptor activation stimulates oscillations in K+ and Cl- currents which are acutely dependent on extracellular Ca2+ in avian salt gland cells

By utilizing the perforated-patch variant of the whole-cell patch-clamp recording technique, in order to maintain the integrity of the normal cellular buffering systems, we demonstrate that carbachol (CCh) stimulates simultaneous oscillations in a Ca(2+)- and voltage-activated K+ current and a linear Ca(2+)-activated Cl- current in an exocrine avian salt gland cell preparation. Similar conductance changes, although sustained rather than oscillatory, are stimulated by the Ca2+ ionophore A23187. The outward K+ current can be inhibited by tetraethylammonium chloride (TEA) whereas the Cl- current is inhibited by the Cl- channel blockers 5-nitro-2-(3-phenylpropylamino) (NPPB) and N-phenylanthranilic acid (DPC). The oscillations in current stimulated by CCh are acutely dependent on extracellular Ca2+ and are not affected by the application of low doses of caffeine. In addition, the application of caffeine at all doses fails to mimic the current transients stimulated by CCh. As both caffeine and A23187 are unable to stimulate oscillations under the perforated-patch conditions we suggest that in avian salt gland cells the primary oscillatory mechanism probably involves a one-pool mechanism of Ca2+ release which is intimately related to the activation of a Ca2+ influx pathway.

The resurgence of tuberculosis in the United States: societal origins and societal responses

Planning of effective responses to the recent resurgence of tuberculosis in the United States, and particularly in New York City, requires review of our knowledge of (1) the factors that led to the decline of tuberculosis in the U.S. and other countries during the nineteenth and the first three-quarters of the twentieth century, and (2) the recent changes in these same factors and the rise of new factors that have contributed to its resurgence. Because the analysis of the impact of all of these factors in both the remote and the recent past is controversial, it is important to use a well-defined framework to organize the analysis. The framework we will use is shown in Table 1. To the classic epidemiologic triad of Agent, Host and Environment it adds the category of Health Services. In this paper we redefine both the classic and new categories using current disciplines and concepts applicable to tuberculosis.

Increased phosphate content of fibrinogen in vivo correlates with alteration in fibrinogen behaviour

Fibrinogen was purified from five patients admitted for hip-replacement surgery the day before (day 0), the day after (day 2) and and one week after the operation (day 8). The behaviour of each patient's three fibrinogens was compared in thrombin gelation assays and plasmin degradation experiments to investigate whether the reported increase in protein-bound phosphate at day 2 and day 8 had any effect on the functional behaviour of fibrinogen as has been demonstrated in vitro. It was found that the thickness of the fibrin fibres produced by thrombin increased markedly at day 2 and declined thereafter. Susceptibility to plasmin appeared to decrease post-operatively by 50% and remained at that level on day 8 despite the phosphate content returning to normal. This has also been shown for fibrinogen phosphorylated in vitro. We conclude, after testing the fibrinogens with and without alkaline phosphatase pretreatment, that our data most resemble the published findings for in vitro phosphorylation of fibrinogen by casein kinase II.

Differential regulation of the nerve growth factor and brain-derived neurotrophic factor genes in L929 mouse fibroblasts

Nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) are structurally related survival and differentiation factors for distinct sets of peripheral and central neurons. The regulation of NGF gene expression has been extensively studied in L929 mouse fibroblasts. L929 cells also express the BDNF gene. Northern blot hybridization analysis revealed 4 discrete BDNF mRNA species in L929 cells and rat hippocampus after induction of seizures with kainic acid. Serum as well as 12-O-tetradecanoyl phorbol-13-acetate (TPA) stimulated NGF and all 4 BDNF mRNAs in L929 cells. Treatment with both agents induced NGF mRNA to a much larger extent than the BDNF mRNAs. The induction of the BDNF mRNAs was rapid, with nearly maximal levels by 1 hr. In contrast, NGF mRNA induction occurred later and peaked at 4-6 hr. Both NGF and BDNF mRNA induction were inhibited by actinomycin D. Cycloheximide, on the other hand, inhibited only NGF but not BDNF mRNA induction. Corticosterone rapidly decreased NGF mRNA but not the BDNF mRNAs, and had no effect on seizure-induced NGF or BDNF mRNAs. Forskolin did not stimulate NGF or BDNF mRNAs. In contrast to NGF mRNA, forskolin did not interfere with the serum induction of BDNF mRNAs. These results demonstrate that 2 genes which encode closely related neurotrophic factors are differentially regulated in L929 cells. The molecular mechanisms which bring about this differential regulation remain to be elucidated.

ATP activates a Ca(2+)-dependent Cl- current in the rat thyroid cell line, FRTL-5

The effect of external ATP on both the membrane potential and the transmembrane current of the thyroid cell line FRTL-5 has been investigated in the patch-clamp whole-cell recording configuration. In the resting situation the membrane potential is around -70 mV and the membrane acts like a K(+)-sensitive electrode. Application of ATP at concentrations higher than 1 microM elicited an increase in Cl- conductance, responsible for a membrane depolarization which could be blocked by preincubation with the P2-antagonist quinidine. Chelation of intracellular Ca2+ also blocked the ATP induced changes in membrane potential and Cl- current. Intracellular perfusion with inositol trisphosphate (IP3) (50 microM) also stimulated a Cl- current which mimicked the response induced by ATP. ATP is able to initiate a response in the absence of extracellular Ca2+, but also opens a Ca(2+)-influx pathway, as demonstrated by a secondary response upon Ca2+ readmission in the external medium, in the continued presence of ATP. ADP and ATP gamma S were able to mimic the ATP response, whereas AMP and adenosine were unable to elicit a Cl- current. The P2X receptor agonist alpha,beta-methyleneATP was without effect as was the P2Y receptor agonist 2-methylthio ATP. We conclude that ATP is able to elicit a large IP3-mediated Ca(2+)-dependent Cl- current and membrane depolarization via a novel P2-type purinergic receptor.

Use of sentinel lambs for early monitoring of the South Powys Hydatidosis Control Scheme: prevalence of Echinococcus granulosus and some other helminths

Sentinel lambs were used to identify young Echinococcus granulosus infections in sheep, to provide an early indication of the progress of the South Powys Hydatidosis Control Scheme. Four sentinel lambs were purchased on each of 60 farms, from inside and outside the control area; they were examined when approximately six, 10 and 15 months of age. Gross examination, thin slicing of organs and histological examination of the lesions in the viscera revealed no E granulosus hydatid cysts in lambs born within the control area, whereas 25 per cent of the 15-month-old lambs from outside the area harboured E granulosus cysts (less than 1 to 2 mm in diameter). Lambs from E granulosus infected farms had significantly higher anti-E granulosus ELISA antibody titres than lambs from uninfected farms. It was concluded that within one year of beginning to treat dogs with praziquantel every six weeks the transmission of E granulosus to sheep had ceased. In contrast, this treatment did not prevent infections with Taenia hydatigena or T ovis; an examination of the 240 lambs revealed T hydatigena in 33.3 per cent of them, Tovis in 4.2 per cent, Dictyocaulus filaria in 12.1 per cent and Meullerius capillaris in 49.2 per cent.

The effects of in vitro phosphorylation and dephosphorylation on the thrombin-induced gelation and plasmin degradation of fibrinogen

The alpha-chain of human fibrinogen was found to be phosphorylated in EDTA-anticoagulated whole blood when trace amounts of (gamma-32P)ATP and 7.5 mM Mg2+ ions were added. Fibrinogen was not phosphorylated if only the ATP was added. The thrombin-induced gelation of fibrinogen phosphorylated by protein kinase A, casein kinase I or II was studied spectrophotomerically. It was found that phosphorylation by protein kinase A caused the formation of thinner fibrin fibres, whereas phosphorylation by casein kinase II resulted in fibres slightly thicker than those of the control fibrinogen (equivalent to a 20% increase in the control fibrinogen concentration). Phosphorylation with casein kinase I did not significantly affect the fibrin fibre thickness. Dephosphorylation by alkaline phosphatase removed 50% of the 32P-labelled phosphate from protein kinase A-phosphorylated fibrinogen and over 90% from the casein kinase I or II-phosphorylated fibrinogens. This dephosphorylation resulted in a general increase in fibre thickness in the gelation assay in all samples, although the fibres of the phosphorylated fibrinogens remained substantially thinner than the dephosphorylated control fibrinogen. Plasmin digestion of the phosphorylated fibrinogens showed that they were more resistant to cleavage, being cleaved at only 30% to 70% of the rate of control fibrinogen and that this resistance was unaltered by dephosphorylation, in contrast to the thrombin gelation experiments.

Conformational changes in human fibrinogen after in vitro phosphorylation and their relation to fibrinogen behaviour

The far-ultraviolet circular dichroism spectra of fibrinogens phosphorylated by protein kinase C or casein kinase II indicated a conformational change corresponding to an increase in ordered secondary structure. The spectra of protein kinase A- or casein kinase I-phosphorylated fibrinogens did not differ substantially from the control. Fluorescence studies indicated changes in the tertiary structure around tryptophan residues for protein kinase A- or C-phosphorylated fibrinogens, but failed to show any such change for fibrinogen phosphorylated by either of the casein kinases. This latter result was also confirmed by circular dichroism measurements in the near-ultraviolet region. The apparent increase in ordered structure was proposed as an explanation for the slower rate of plasmin degradation seen in fibrinogens after phosphorylation by protein kinase C [6], and casein kinase II, especially as both spectral changes and plasmin degradation rate were unaffected by alkaline phosphatase.

A survey of exposures, practices and recommendations of surgeons in the care of patients with human immunodeficiency virus

Policy makers face a conflict between satisfying concerns of health care workers (HCW) about the occupational risk of human immunodeficiency virus (HIV) infection and ensuring adequate care for patients. This conflict is particularly severe in the field of surgery. We mailed a questionnaire on the surgical care of patients infected with HIV to 1,461 surgeons in New York City and Philadelphia, and 551 (37.7 per cent) responded. Although 1.9 per cent currently were testing all patients for HIV, 42.6 per cent of surgeons believed that all patients in their hospital should be tested. Of the surgeons who responded, 6.3 per cent refused to treat any patient infected with HIV. Less than 50 per cent recommended the use of barrier precautions on all patients in their hospital. Surgeons in New York City were significantly more likely than those in Philadelphia to favor separate facilities for HIV-infected patients. Surgeons considering themselves at higher occupational risk were more likely than those at lower risk to favor widespread testing, separate facilities and use of precautions. Surgeons reported a wide range of opinions. Their approach to the use of barrier precautions differs from the Centers for Disease Control recommendations. The patterns observed suggest that distinct policies may be appropriate for different hospitals.

Plasmin digestion of human fibrinogen previously phosphorylated by protein kinase C or dephosphorylated by alkaline phosphatase in vitro

Human fibrinogen, either untreated or previously phosphorylated by protein kinase C, was incubated with plasmin generated by streptokinase, urokinase or tissue plasminogen activator and the resulting fragments were separated by gel electrophoresis. Plasmin degradation resulted in the expected X, Y and D fragments, but the degradation rates differed. In vitro phosphorylation of fibrinogen was seen to inhibit the plasmin digestion. Treatment with alkaline phosphatase did not reverse the inhibition.