Zotepine for schizophrenia

BACKGROUND

Typical antipsychotic drugs are widely used as first line treatment for people with schizophrenia. The atypical class of antipsychotic drugs, however, is making important inroads into this approach and zotepine is one such compound. It is a dopamine antagonist and claimed to be to be particularly effective for negative symptoms

OBJECTIVES

To determine the effects of zotepine compared with placebo, typical and other atypical antipsychotic drugs for schizophrenia and related psychoses.

SEARCH STRATEGY

Electronic searches of Biological Abstracts (1980-1999), CINAHL (1982-1999), The Cochrane Library (Issue 1, 1999), The Cochrane Schizophrenia Group's Register (January 1999), EMBASE (1980-1999), Dialog Corporation Datastar service (1999), MEDLINE (1966-1999), and PsycLIT (1974-1999) were undertaken. References of all identified studies were searched for further trials. Knoll Pharmaceuticals and authors of trials were contacted.

SELECTION CRITERIA

All randomised clinical trials that compared zotepine to other treatments for people with schizophrenia or other psychoses were included.

DATA COLLECTION AND ANALYSIS

Citations and, where possible, abstracts were independently inspected by reviewers, papers ordered, re-inspected and quality assessed. Data were independently extracted. Data were excluded if loss to follow up was greater than 50%. For homogeneous dichotomous data the relative risk (RR), 95% confidence interval (CI) and, where appropriate, the number needed to treat (NNT) and numbers needed to harm (NNH), were calculated on an intention-to-treat basis. For continuous data, weighted mean differences were calculated (WMD). All data were inspected for heterogeneity.

MAIN RESULTS

All outcomes were short term (4-12 weeks). Limited data suggest that zotepine is an antipsychotic, at least as effective as typical drugs. Mental state measures of 'no clinically important improvement' favour zotepine when compared to other active drugs (n=356, RR 0.8 CI 0.7-0.9, NNT 7 CI 4-22). About one third of people in both zotepine and control groups left the studies before trial completion. Zotepine may result in less movement disorder adverse effects than typical antipsychotic drugs. Trials have not highlighted clear differences between zotepine and other atypical drugs.

REVIEWER'S CONCLUSIONS

Zotepine may be a valuable addition to the increasing ranks of atypical antipsychotic drugs. More data from already existing studies is urgently needed to increase the confidence in the findings of this review. New data from well planned, conducted and reported long term pragmatic randomised trials are necessary. Otherwise clinical use of zotepine will be based on speculation on the meaning of the findings of short explanatory trials for everyday practice.

Magnesium in drinking water supplies and mortality from acute myocardial infarction in north west England

OBJECTIVES

To examine whether higher concentrations of magnesium in drinking water supplies are associated with lower mortality from acute myocardial infarction at a small area geographical level; to examine if the association is modified by age, sex, and socioeconomic deprivation.

DESIGN

Small area geographical study using 13,794 census enumeration districts. Water constituent concentrations (magnesium, calcium, fluoride, lead) measured at water supply zone and assigned to enumeration districts.

SETTING

305 water supply zones in north west England.

SUBJECTS

Resident population of 1,124,623 men and 1,372,036 women (1991 census) aged 45 years or more.

MAIN OUTCOME MEASURE

Mortality from acute myocardial infarction, International Classification of Diseases, ninth revision (ICD-9) 410. Subsidiary analysis examined deaths from ischaemic heart disease, ICD 410-414.

RESULTS

There were 21,339 male and 17,883 female deaths from acute myocardial infarction in 1990-92. Drinking water magnesium concentrations in water zones ranged from 2 mg/l to 111 mg/l (mean (SD) 19 (20) mg/l, median 12 mg/l); 24% of variation in magnesium concentrations was within zone and 76% was between zone. The relative risk of mortality from acute myocardial infarction (standardised for age, sex, and Carstairs deprivation quintile) for a quadrupling of magnesium concentrations in drinking water (for example, 20 mg/l v 5 mg/l) was 1.01 (95% confidence interval (CI) 0.99 to 1.03). When adjusted for north-south and east-west trends in mortality from acute myocardial infarction and for drinking water calcium, fluoride, and lead concentrations, this relative risk was 1.01 (95% CI 0.96 to 1.06). There was no evidence of a protective effect for acute myocardial infarction even among age, sex, and deprivation groups that were likely to be relatively magnesium deficient. For ischaemic heart disease mortality there was an apparent protective effect of magnesium and calcium (with calcium predominating in the joint model), but these were no longer significant when the geographical trends were incorporated.

CONCLUSIONS

No evidence was found of an association between magnesium concentrations in drinking water supplies and mortality from acute myocardial infarction. These results do not support the hypothesis that magnesium is the key water factor in relation to mortality from heart disease.

Immunogenicity of DNA vaccines expressing tuberculosis proteins fused to tissue plasminogen activator signal sequences

Novel tuberculosis DNA vaccines encoding native ESAT-6, MPT-64, KatG, or HBHA mycobacterial proteins or the same proteins fused to tissue plasminogen activator (TPA) signal sequences were evaluated for their capacity to elicit humoral, cell-mediated, and protective immune responses in vaccinated mice. While all eight plasmids induced specific humoral responses, the constructs expressing the TPA fusions generally evoked higher antibody responses in vaccinated hosts. Although most of the DNA vaccines tested induced a substantial gamma interferon response in the spleen, the antigen-specific lung responses were 2- to 10-fold lower than the splenic responses at the time of challenge. DNA vaccines encoding the ESAT-6, MPT-64, and KatG antigens fused to TPA signal sequences evoked significant protective responses in mice aerogenically challenged with low doses of Mycobacterium tuberculosis Erdman 17 to 21 days after the final immunization. However, the protective response induced by live Mycobacterium bovis BCG vaccine was greater than the response induced by any of the DNA vaccines tested. These results suggest that the tuberculosis DNA vaccines were able to elicit substantial immune responses in suitably vaccinated mice, but further refinements to the constructs or the use of alternative immunization strategies will be needed to improve the efficacy of these vaccine candidates.

Choice of cost-effectiveness measure in the economic evaluation of cholesterol-modifying pharmacotherapy. An illustrative example focusing on the primary prevention of coronary heart disease in Canada

OBJECTIVE

To evaluate the effect of using different cost-effectiveness measures in the economic evaluation of cholesterol-modifying pharmacotherapy.

DESIGN AND SETTING

An economic model was used to examine the extent to which the relative cost effectiveness of cholesterol-modifying agents varies depending upon the cost-effectiveness measure used. The perspective taken was that of the Canadian public healthcare system.

PATIENTS

Individuals without coronary heart disease (CHD) with low-density lipoprotein cholesterol (LDL-C) levels in excess of 190 mg/dl.

INTERVENTIONS

Cholesterol-modifying pharmacotherapies available in Canada.

MAIN OUTCOME MEASURES AND RESULTS

Cost per 1% reduction in LDL-C level; incremental cost per life-year gained; least-cost agent achieving the LDL-C reduction required to meet the target level of 160 mg/dl; incremental cost per life-year gained of agents reaching the target LDL-C level of 160 mg/dl relative to no therapy; incremental cost per life-year gained of agents achieving the target LDL-C level of 160 mg/dl relative to the least-cost agent reaching the target. Each cost-effectiveness measure had a different informational content to decision-makers, both in terms of the usefulness of the information they provided, and in terms of the extent to which they showed one agent to be more cost effective than another. The most cost-effective treatment regimens were fluvastatin 20 mg per day, fluvastatin 40 mg per day, atorvastatin 10 mg per day and atorvastatin 20 mg per day, depending on the pretreatment LDL-C level and the cost-effectiveness measure used.

CONCLUSIONS

We recommend that the cost effectiveness of cholesterol-modifying pharmacotherapy be measured using incremental cost per life-year gained in reaching a predefined target LDL-C level.

Childhood secondary (symptomatic) epilepsy, seizure control, and intellectual handicap in a nontropical region of South Africa

PURPOSE

To determine the prevalence of secondary (symptomatic) epilepsy and to ascertain levels of seizure control and intellectual function in a clinic population of children drawn from a poor community in a temperate region of South Africa.

METHODS

Detailed review of the records of every child with recurrent seizures who attended a special epilepsy outpatient clinic during 1995.

RESULTS

A total of 1,017 children was studied. In 432 (43%), there was historic, clinical, and radiologic evidence to suggest that epilepsy was symptomatic of underlying brain damage or defect. Acceptable seizure control was maintained with a single standard anticonvulsant drug (AED) in 65% of cases. In the 6 months preceding the study, 37% of the subjects had remained seizure free. Forty-seven percent of the study population were considered to be of subnormal intelligence.

CONCLUSIONS

In a children's hospital outpatient population in the Western Cape region of South Africa, the prevalence of secondary epilepsy is higher than is found in developed countries. There is need within the community for preventive measures aimed at reducing the prevalence of perinatal insults, meningitis, tuberculosis, neurocysticercosis, and cerebral trauma.

Changes in Rous sarcoma virus RNA secondary structure near the primer binding site upon tRNATrp primer annealing

Predicted secondary-structure elements encompassing the primer binding site in the 5' untranslated region of Rous sarcoma virus (RSV) RNA play an integral role in multiple viral replications steps including reverse transcription, DNA integration, and RNA packaging (A. Aiyar, D. Cobrinik, Z. Ge, H. J. Kung, and J. Leis, J. Virol. 66:2464-2472, 1992; D. Cobrinik, A. Aiyar, Z. Ge, M. Katzman, H. Huang, and J. Leis, J. Virol. 65:3864-3872, 1991; J. T. Miller, Z. Ge, S. Morris, K. Das, and J. Leis, J. Virol. 71:7648-7656, 1997). These elements include the U5-Leader stem, U5-IR stem-loop, and U5-TPsiC interaction region. Limited digestion of the 5' untranslated region of wild-type and mutant RSV RNAs with structure- and/or sequence-specific RNases detects the presence of the U5-Leader stem and the U5-IR stem-loop. When a tRNATrp primer is annealed to wild-type RNAs in vitro, limited nuclease mapping indicates that the U5-IR stem becomes partially unwound. This is not observed when mutant RNAs with altered U5-IR stem-loop structures are substituted for wild-type RNAs. The U5-Leader stem also becomes destabilized when the tRNA primer is annealed to either wild-type or mutant RNA fragments. Nuclease mapping studies of tRNATrp, as well as the viral RNA, indicate that the U5-TPsiC helix does form in vitro upon primer annealing. Collectively, these data suggest that the various structural elements near the RSV primer binding site undergo significant changes during the process of primer annealing.

Type 1 diabetes in Thai children aged 0-14 years

Fifty-nine patients were diagnosed with diabetes in the ten years from 1987 to 1996 in the Division of Endocrinology and Metabolism, Department of Pediatrics, Faculty of Medicine Siriraj Hospital, Bangkok, Thailand. All patients were less than fifteen years old. Fifty-five patients (93.3%) were type 1 diabetes, three (5%) were type 2 diabetes and MODY, and one (1.7%) was diabetes secondary to beta thalassemia major. Patients with type 2 diabetes, MODY, and secondary diabetes were excluded from this study, and fifty-five patients with type 1 diabetes were analysed. The aims of this study were to determine some of the general characteristics of Thai childhood type 1 diabetes and to see whether a seasonal variation is present. The results showed a female to male ratio of 1.39:1. The peak age at diagnosis was from 9 to 12 years. Seventy-seven per cent had diabetic ketoacidosis at the time of diagnosis. The majority of patients (93.9%) had a BMI of less than 20 kg/m2. A family history of diabetes was reported in 38 per cent but only 2 per cent were type 1 diabetes. We found a high prevalence of patients in the summer and winter seasons (35-48% and 37-50% respectively) and a lower prevalence in the rainy season (14.8-15%). These results are different from a previously reported study in 1984-1985 which found no differences in summer, winter, and rainy seasons. Further research study into Thai childhood type 1 diabetes is needed, especially the influence of seasonal factors, the incidence of the disease, and the significance of family history.

Expression and characterization of elastase inhibitors from the ascarid nematodes Anisakis simplex and Ascaris suum

Two elastase inhibitors, ASPI-1 and ASPI-2, from the parasitic nematode Anisakis simplex, have been isolated and characterized. Because these inhibitors are similar in size (60 amino acids in length) and primary sequence (52 and 47% identical) to the Ascaris suum chymotrypsin/elastase inhibitor-1 (AsC/E-1), we suggest that these Anisakis elastase inhibitors belong to the same unique class of canonical inhibitors formed by the family of Ascaris inhibitors (Huang K, Strynadka NCJ, Bernard VD, Peanasky RJ, James MG. Structure 1994;2:679-689). To compare ASPI-1 with AsC/E-1, we expressed both inhibitors in Pichia pastoris and found that: (1) the association constant of rASPI-1 with porcine pancreatic elastase (PPE) is similar to native inhibitor (Ka = 4.5 x 10(9) and 6.4 x 10(9) M(-1), respectively); (2) rASPI-1 is a potent inhibitor of PPE and human leukocyte elastase (Ka = 1.6 x 10(9) M(-1)); and (3) it is only a very weak inhibitor of chymotrypsin (CHYM) (Ka = 1.2 x 10(6) M(-1)). In contrast to the Anisakis inhibitor, however, rAsC/E inhibitor-1 is a very strong inhibitor of both PPE (Ka = 3.5 x 10(10) M(-1)) and CHYM (Ka = 3.6 x 10(12) M(-1)). We also found that the determined reactive sites (P1-P'1) of rASPI-1 and rAsC/E-1, as recognized by PPE, are Ala 28-Met 29 and Leu 31-Met 32, respectively. These P1-P'1 residues of AsC/E-1 constitute the same reactive site as that also recognized by CHYM (Peanasky RJ, Bentz Y, Homandberg GA, Minor ST, Babin DR. Arch Biochem Biophys 1994;232:135-142). The difference in specificities of ASPI-1 and AsC/E-1 toward their cognate serine proteases may be attributed to the P1 and P'3 residues in the inhibitors. Elastase, which recognizes both alanine and leucine, canaccommodate both ascarid inhibitors, whereas chymotrypsin, which prefers bulky, hydrophobic residues, only recognizes the Ascaris C/E inhibitor-1.

Case-control isotonic regression for investigation of elevation in risk around a point source

Stone's isotonic regression method for analysing count data to estimate disease risk in relation to a point source of environmental pollution is now routinely used. This paper develops the corresponding procedure for case-control data consisting of the locations of individual cases with controls with associated covariate information. In this setting, the generalized likelihood ratio statistic to test the null hypothesis of constant risk against the alternative that risk is a monotone non-increasing function of distance from the point source is intractable. An approximate Monte Carlo test is described, extending an exact test proposed by Bithell for the situation in which there are no covariates. Interval estimates of risk as a function of distance from the point source are constructed by simulation of the sampling distribution of the isotonic regression estimator. The methodology is illustrated by two applications: one to the relative risk of larynx cancers and lung cancers near a now-disused industrial incinerator; the other to the risk of asthma in children in relation to distance of residence from the nearest main road.

The association between tender points, psychological distress, and adverse childhood experiences: a community-based study

OBJECTIVE

To examine the hypothesis that characteristics of somatization and illness behavior, and their childhood antecedents, are associated with the presence of multiple tender points.

METHODS

Two hundred eighty-nine subjects who had demonstrated psychological distress (General Health Questionnaire score > or =2) had a tender point examination and in-depth psychological evaluation. In addition, subjects were interviewed about a number of adverse childhood experiences. The 99 subjects with 5 or more tender points were compared with the remaining 190 subjects.

RESULTS

A high tender point count (> or =5) was associated with low levels of self-care (odds ratio [OR] 2.4, 95% confidence interval [95% CI] 1.1-5.0), reports of a greater number of somatic symptoms (OR 2.2, 95% CI 1.0-4.9), high levels of fatigue (OR 3.3, 95% CI 1.7-6.3), and a pattern of illness behavior characterized by increased medical care usage (OR 4.2, 95% CI 2.1-8.4). Those with high tender point counts were substantially more likely to report adverse childhood experiences, including loss of parents (OR 2.1, 95% CI 1.1-3.9) and abuse (OR 6.9, 95% CI 2.0-24.6). These results were not explained by the presence of chronic pain.

CONCLUSION

These data add further weight to the hypothesis that tender points, as part of the fibromyalgia syndrome, are strongly associated with specific components of psychological distress as well as characteristics of somatization and its antecedents. It is possible that these features contribute to the development of the syndrome of fibromyalgia.

The association between tender points, psychological distress, and adverse childhood experiences: a community-based study

OBJECTIVE

To examine the hypothesis that characteristics of somatization and illness behavior, and their childhood antecedents, are associated with the presence of multiple tender points.

METHODS

Two hundred eighty-nine subjects who had demonstrated psychological distress (General Health Questionnaire score > or =2) had a tender point examination and in-depth psychological evaluation. In addition, subjects were interviewed about a number of adverse childhood experiences. The 99 subjects with 5 or more tender points were compared with the remaining 190 subjects.

RESULTS

A high tender point count (> or =5) was associated with low levels of self-care (odds ratio [OR] 2.4, 95% confidence interval [95% CI] 1.1-5.0), reports of a greater number of somatic symptoms (OR 2.2, 95% CI 1.0-4.9), high levels of fatigue (OR 3.3, 95% CI 1.7-6.3), and a pattern of illness behavior characterized by increased medical care usage (OR 4.2, 95% CI 2.1-8.4). Those with high tender point counts were substantially more likely to report adverse childhood experiences, including loss of parents (OR 2.1, 95% CI 1.1-3.9) and abuse (OR 6.9, 95% CI 2.0-24.6). These results were not explained by the presence of chronic pain.

CONCLUSION

These data add further weight to the hypothesis that tender points, as part of the fibromyalgia syndrome, are strongly associated with specific components of psychological distress as well as characteristics of somatization and its antecedents. It is possible that these features contribute to the development of the syndrome of fibromyalgia.

Chronic widespread pain in the community: the influence of psychological symptoms and mental disorder on healthcare seeking behavior

OBJECTIVE

To determine whether psychological symptoms and mental disorder are an intrinsic part of the chronic widespread pain syndrome or whether they have been observed in clinic attenders primarily because of their influence on the decision to seek a medical consultation.

METHODS

A population survey of 1953 subjects was conducted in the Greater Manchester area of the United Kingdom. The survey included a postal questionnaire, and in a subgroup of respondents with high levels of distress, the presence of mental disorder was assessed by a semistructured standardized interview. Subjects with chronic widespread pain were classified according to whether they had sought a medical consultation for the reported pain ("consulters") or not ("nonconsulters").

RESULTS

In all, 252 subjects (13%) satisfied American College of Rheumatology criteria for chronic widespread pain, and of these 72% reported having consulted a general practitioner about this pain. There was a clear difference in levels of psychological distress, measured by the General Health Questionnaire (GHQ), between consulters, nonconsulters, and those with no pain. Consulters did not differ from nonconsulters in terms of levels of fatigue, social dysfunction, or number of somatic symptoms reported. Although consulters (among whom one in 4 had a mental disorder) were more likely to have a mental disorder than subjects without pain [OR = 4.9, 95% CI (2.6, 9.5)] the increase in risk comparing consulters to nonconsulters [OR = 2.1, 95% CI (0.7, 5.9)] and nonconsulters to subjects without pain [OR = 1.4, 95% CI (0.7, 2.6)] was not significant.

CONCLUSION

The results suggest that psychological distress is associated with chronic widespread pain in addition to any effect on whether consultation is sought for symptoms. The finding that one-quarter of consulters to primary care with chronic widespread pain have a mental disorder should alert primary care physicians and rheumatologists to screen for mental disorder in this group.

Serum cytosolic beta-glucosidase elevation and early ischemic injury to guinea pig small intestine

BACKGROUND

The lack of an early, sensitive marker for intestinal ischemia has led to delay in diagnosis and worsended outcome for patients with acute onset of this condition. Our preliminary studies revealed that guinea pig cytosolic beta-glucosidase (CBG) is expressed predominantly in the small intestine, with lower levels in the liver and pancreas and undetectable levels in other organs. Cytosolic beta-glucosidase was investigated as a serum marker of small intestinal ischemia in a guinea pig model.

METHODS

Guinea pigs underwent anesthesia, sham laparotomy, 30 minutes of mesenteric ischemia followed by 6 hours of reperfusion 6 hours of sustained mesenteric ischemia, or closed-loop small bowel obstruction. Serum samples were assayed for CBG activity. At the conclusion of the ischemia/reperfusion experiments, small bowel samples were assayed for residual enzyme activity, and paraffin sections were graded for the severity of histologic injury.

RESULTS

Serum CBG activity rose rapidly after intestinal ischemia with and without reperfusion. Peak enzyme activities were elevated 23-fold for reperfused animals (P < .001) by 4 hours. For nonreperfused animals, peak serum CBG activities reached 29-fold above baseline and were significantly higher than the CBG activities of reperfused animals at 4 hours (P < .01) and at 6 hours (P < .05). Mucosal injury ranged from undetectable to moderate and corresponded in severity with both peak serum enzyme activity and decreased residual activity in the small bowel. In animals subjected to closed-loop obstruction, there was a mean increase of serum CBG of 9.2-fold from 4 to 6 hours after establishment of obstruction (P < .05).

CONCLUSIONS

In the guinea pig model, CBG is a sensitive marker of ischemic injury caused by arterial occlusion or closed-loop obstruction of the small bowel.

Strategies for migration in the terrestrial christmas island red crab gecarcoidea natalis: intermittent versus continuous locomotion

The terrestrial red crab Gecarcoidea natalis undertakes an annual breeding migration and must sustain locomotion for prolonged periods. The migrating crabs must travel a specific distance in a fixed time and can either walk at a constant speed or walk faster for short periods and then pause to feed or rest. To simulate the potential differences between continuous and intermittent locomotion during the migration, red crabs were sampled after walking at a voluntary speed for 5 or 20 min without pausing or after 20 min of enforced walking intermittently at approximately twice that speed. The respiratory and metabolic status of the crabs was investigated during the different exercise regimes to assess which strategy might be more advantageous during the migration. The gills and lungs appeared to function similarly in gas exchange, and the PO2 in the haemolymph was 8.2 kPa which fully saturated the haemocyanin with O2. The uptake of O2 by red crabs was diffusion-limited and the diffusion coefficient (Ldiff) varied from 0.53 in resting crabs to 0. 8 post-exercise. Post-exercise, red crabs experienced a mixed respiratory/metabolic acidosis which was greatest (0.2 pH units) in crabs walking intermittently, i.e. at a higher speed. Haemolymph l-lactate concentrations peaked at 5 mmol l-1 immediately post-exercise in the intermittent exercise group, whereas after 20 min of continuous exercise haemolymph l-lactate continued to increase, reaching a maximum of 2.5 mmol l-1 at 1 h post-exercise. l-Lactate recovered slowly to basal levels within 5 h. The maximum rate of l-lactate clearance from the haemolymph was only 1.75 mmol l-1 h-1, and short pauses in exercise were insufficient for substantial l-lactate reoxidation. Exercise regimes in the laboratory were within the locomotor speeds determined for migrating red crabs, which overall have a mean walking speed close to their aerobic limit but periodically pause and also exceed this limit by three- to fourfold.

Pupillary responses evoked during verbal fluency tasks indicate semantic network dysfunction in schizophrenia

Pupillary responses, which index task controlled processing load, were recorded during semantic and phonemic fluency tasks to examine controlled search and automatic semantic network deficits in patients with schizophrenia. Word retrieval was more impaired on semantic than on phonemic fluency, but only during the first 15 seconds of trials. Pupillary dilation was greater on phonemic than on semantic fluency in nonpsychiatric participants but was greater on semantic than on phonemic fluency in the patients, during the first 15 seconds of trials. Thus, early in semantic fluency trials, patients with schizophrenia showed poorer word retrieval and abnormally high demand for frontal lobe controlled search processes, suggesting impairments in the temporal lobe automatic semantic memory processes that normally facilitate word retrieval.

The functioning of the haemocyanin of the terrestrial christmas island red crab gecarcoidea natalis and roles for organic modulators

Gecarcoidea natalis is a land crab that migrates annually several kilometres to breed. The O2-binding properties of haemocyanin in G. natalis were investigated in vitro to test the idea that the O2-binding properties of the haemocyanin of land crabs are not dependent on circulating modulators and to provide a model of haemocyanin functioning during exercise. The affinity of the haemocyanin for O2 decreased with increasing temperature (change in the heat of oxygenation; capdelta H=-59 kJ mol-1). The haemocyanin of G. natalis apparently differs from that of other terrestrial crabs in showing haemocyanin O2 modulation by both organic and inorganic molecules. Haemocyanin O2-affinity was not affected by Mg2+ but was sensitive to changes in Ca2+ concentration ( capdelta logP50/ capdelta log[Ca]=-0.61, where P50 is the partial pressure of O2 required for half-maximal O2 binding). The Bohr factor was modest ( &phgr;=-0.26+/-0.03, N=4, in whole haemolymph at 25 degreesC) and there was no specific effect of CO2 on the O2-binding properties of the haemocyanin. An increase in urate concentration increased haemocyanin O2-affinity, but the effect was linear ( capdelta logP50/ capdelta [urate]=-0.06) and not logarithmic as is the case in other species. The effect of l-lactate on the haemocyanin O2-affinity in G. natalis was unique among the crustaceans,because an increase in l-lactate concentration decreased the haemocyanin O2-affinity. The effect of l-lactate on haemocyanin O2-affinity ( capdelta logP50/ capdelta log[lactate]) was time-dependent and decreased from a maximum of 0.044 on day 1 to 0.001 after 4 days of storage at 4 degreesC. The presence of an unknown dialysable and unstable factor in the haemolymph is postulated to explain the time-dependent effect of l-lactate on haemocyanin O2-binding properties. Model oxygen equilibrium curves constructed for in vivo conditions showed that the reverse effect of l-lactate was advantageous by decreasing the O2-affinity of the haemocyanin beyond that predicted by the Bohr shift alone and assisted in O2 off-loading at the tissues. This effect of lactate can only provide an advantage if the gas-exchange organs maintain arterial O2 loading and thus is dependent on lung function in land crabs and must have occurred coincident with the evolution of these other features.

The natural history of CIN I lesions

The published literature indicates 11% of CIN I lesions on average progress to a higher grade dysplasia and the remainder either regress or persist. Reliable markers of disease outcome are yet to be identified. A longitudinal study of 342 women referred for colposcopic examination of a CIN I detected by a screening Pap test, and classified by the colposcopic impression and Pap test at that exam as </= CIN 1 was designed to identify predictors of disease outcome. The cohort was comprised of 220 women who satisfactorily completed the study and whose disease was neither biopsied or treated at the initial examination. All had HPV DNA testing by PCR, and were followed with interval colposcopic examinations and repeat Pap tests for a limited time period. The initial HPV DNA status and a number of measured clinico-pathological and risk factor variables were analyzed to identify outcome predictors. All underwent a biopsy either at the conclusion of the study or because their disease was considered to have progressed during the follow up period. Biopsy confirmed progression to CIN II/III occurred in 41 (18.6%), persistence of CIN I/Condyloma in 41 (18.6%), and regression to <CIN I/Condyloma in 138 (62.7%). HPV DNA positivity and current, oral contraceptive use were the only independent predictors of progression when age at diagnosis, the number of follow up visits, and time to progression were controlled. Predictors of persistent and regressed disease were not identified. The study highlights a clinical role for HPV testing in the colposcopic management of CIN I lesions. Oral contraceptives may promote progression by regulating the oncogenic sequences of the HPV.

All change: cancer services in transition

The policy and health service background to this discussion are the radical changes in cancer services currently underway in the wake of the Calman-Hine Report and the wider changes ushered in by the NHS and Community Care Act 1990 (UK). Using the changing face of hospice care as the focus, the authors explore some of the potential issues and dilemmas involved in providing supportive care for cancer patients and their families. Three 'themes', or areas of concern, are highlighted: links between services, changing organizational factors, and increasing 'medical imperialism'. Potential benefits and drawbacks of the changing ethos and organizational structures are discussed. Interview data are used as 'triggers' for the presentation of the authors' own reflections on developments in the hospice and cancer services' arenas. The paper draws on interview data collected in the pilot phase of a 3-year study on the psycho-social needs of cancer patients and their informal carers in north-west England. Twenty-nine interviews were conducted with a range of professionals involved in the provision of cancer services in Lancaster and Kendal. In the spirit of 'gathering thoughts' and facilitating debate, a commentary on developments in the hospice sector is offered rather than any firm conclusion.