Sexually dimorphic roles for the type 2 diabetes-associated C2cd4b gene in murine glucose homeostasis

AIMS/HYPOTHESIS

Variants close to the VPS13C/C2CD4A/C2CD4B locus are associated with altered risk of type 2 diabetes in genome-wide association studies. While previous functional work has suggested roles for VPS13C and C2CD4A in disease development, none has explored the role of C2CD4B.

METHODS

CRISPR/Cas9-induced global C2cd4b-knockout mice and zebrafish larvae with c2cd4a deletion were used to study the role of this gene in glucose homeostasis. C2 calcium dependent domain containing protein (C2CD)4A and C2CD4B constructs tagged with FLAG or green fluorescent protein were generated to investigate subcellular dynamics using confocal or near-field microscopy and to identify interacting partners by mass spectrometry.

RESULTS

Systemic inactivation of C2cd4b in mice led to marked, but highly sexually dimorphic changes in body weight and glucose homeostasis. Female C2cd4b mice displayed unchanged body weight compared with control littermates, but abnormal glucose tolerance (AUC, p = 0.01) and defective in vivo, but not in vitro, insulin secretion (p = 0.02). This was associated with a marked decrease in follicle-stimulating hormone levels as compared with wild-type (WT) littermates (p = 0.003). In sharp contrast, male C2cd4b null mice displayed essentially normal glucose tolerance but an increase in body weight (p < 0.001) and fasting blood glucose (p = 0.003) after maintenance on a high-fat and -sucrose diet vs WT littermates. No metabolic disturbances were observed after global inactivation of C2cd4a in mice, or in pancreatic beta cell function at larval stages in C2cd4a null zebrafish. Fasting blood glucose levels were also unaltered in adult C2cd4a-null fish. C2CD4B and C2CD4A were partially localised to the plasma membrane, with the latter under the control of intracellular Ca2+. Binding partners for both included secretory-granule-localised PTPRN2/phogrin.

CONCLUSIONS/INTERPRETATION

Our studies suggest that C2cd4b may act centrally in the pituitary to influence sex-dependent circuits that control pancreatic beta cell function and glucose tolerance in rodents. However, the absence of sexual dimorphism in the impact of diabetes risk variants argues for additional roles for C2CD4A or VPS13C in the control of glucose homeostasis in humans.

DATA AVAILABILITY

The datasets generated and/or analysed during the current study are available in the Biorxiv repository ( www.biorxiv.org/content/10.1101/2020.05.18.099200v1 ). RNA-Seq (GSE152576) and proteomics (PXD021597) data have been deposited to GEO ( www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE152576 ) and ProteomeXchange ( www.ebi.ac.uk/pride/archive/projects/PXD021597 ) repositories, respectively.

Observational, longitudinal study of delirium in consecutive unselected acute medical admissions: age-specific rates and associated factors, mortality and re-admission

OBJECTIVES

We aimed to determine age-specific rates of delirium and associated factors in acute medicine, and the impact of delirium on mortality and re-admission on long-term follow-up.

DESIGN

Observational study. Consecutive patients over two 8-week periods (2010, 2012) were screened for delirium on admission, using the confusion assessment method (CAM), and reviewed daily thereafter. Delirium diagnosis was made using the Diagnostic and Statistical Manual Fourth Edition (DSM IV) criteria. For patients aged ≥65 years, potentially important covariables identified in previous studies were collected with follow-up for death and re-admission until January 2014.

PARTICIPANTS

503 consecutive patients (age median=72, range 16-99 years, 236 (48%) male).

SETTING

Acute general medicine.

RESULTS

Delirium occurred in 101/503 (20%) (71 on admission, 30 during admission, 17 both), with risk increasing from 3% (6/195) at <65 years to 14% (10/74) for 65-74 years and 36% (85/234) at ≥75 years (p<0.0001). Among 308 patients aged >65 years, after adjustment for age, delirium was associated with previous falls (OR=2.47, 95% CI 1.45 to 4.22, p=0.001), prior dementia (2.08, 1.10 to 3.93, p=0.024), dependency (2.58, 1.48 to 4.48, p=0.001), low cognitive score (5.00, 2.50 to 9.99, p<0.0001), dehydration (3.53, 1.91 to 6.53, p<0.0001), severe illness (1.98, 1.17 to 3.38, p=0.011), pressure sore risk (5.56, 2.60 to 11.88, p<0.0001) and infection (4.88, 2.85 to 8.36, p<0.0001). Patients with delirium were more likely to fall (OR=4.55, 1.47 to 14.05, p=0.008), be incontinent of urine (3.76, 2.15 to 6.58, p<0.0001) or faeces (3.49, 1.81-6.73, p=0.0002) and be catheterised (5.08, 2.44 to 10.54, p<0.0001); and delirium was associated with stay >7 days (2.82, 1.68 to 4.75, p<0.0001), death (4.56, 1.71 to 12.17, p=0.003) and an increase in dependency among survivors (2.56, 1.37 to 4.76, p=0.003) with excess mortality still evident at 2-year follow-up. Patients with delirium had fewer re-admissions within 30-days (OR=0.32, 95% CI 0.09 to 1.1, p=0.07) and in total (median, IQR total re-admissions=0, 0-1 vs 1, 0-2, p=0.01).

CONCLUSIONS

Delirium affected a fifth of acute medical admissions and a third of those aged ≥75 years, and was associated with increased mortality, institutionalisation and dependency, but not with increased risk of re-admission on follow-up.

Cerecyte coil trial: procedural safety and clinical outcomes in patients with ruptured and unruptured intracranial aneurysms

BACKGROUND AND PURPOSE

This study arose from a need to systematically evaluate the clinical and angiographic outcomes of intracranial aneurysms treated with modified coils. We report the procedural safety and clinical outcomes in a prospective randomized controlled trial of endovascular coiling for ruptured and unruptured intracranial aneurysms, comparing polymer-loaded Cerecyte coils with bare platinum coils in 23 centers worldwide.

MATERIALS AND METHODS

Five hundred patients between 18 and 70 years of age with a ruptured or unruptured target aneurysm planning to undergo endovascular coiling were randomized to receive Cerecyte or bare platinum coils. Analysis was by intention to treat.

RESULTS

Two hundred forty-nine patients were allocated to Cerecyte coils and 251 to bare platinum coils. Baseline characteristics were balanced. For ruptured aneurysms, in-hospital mortality was 2/114 (1.8%) with Cerecyte versus 0/119 (0%) bare platinum coils. There were 8 (3.4%) adverse procedural events resulting in neurological deterioration: 5/114 (4.4%) with Cerecyte versus 3/119 (2.5%) with bare platinum coils (P = .22). The 6-month mRS score of ≤2 was not significantly different in 103/109 (94.5%) patients with Cerecyte and 110/112 (98.2%) patients with bare platinum coils. Poor outcome (mRS score of ≥3 or death) was 6/109 (5.5%) with Cerecyte versus 2/112 (1.8%) with bare platinum coils (P = .070). For UIAs, there was no in-hospital mortality. There were 7 (2.7%) adverse procedural events with neurological deterioration, 5/133 (3.8%) with Cerecyte versus 2/131 (1.5%) with bare platinum coils (P = .13). There was a 6-month mRS score of ≤2 in 114/119 (95.8%) patients with Cerecyte versus 123/123 (100%) patients with bare platinum coils. There was poor outcome (mRS ≥3 and 1 death) in 5/119 (4.2%) patients with Cerecyte versus 0/123 (0%) patients with bare platinum coils (P = .011).

CONCLUSIONS

There was a statistical excess of poor outcomes in the Cerecyte arm at discharge in the ruptured aneurysm group and at 6-month follow-up in the unruptured group. Overall adverse clinical outcomes and in-hospital mortality were exceptionally low in both groups.

Population-based study of risk and predictors of stroke in the first few hours after a TIA

BACKGROUND

Several recent guidelines recommend assessment of patients with TIA within 24 hours, but it is uncertain how many recurrent strokes occur within 24 hours. It is also unclear whether the ABCD2 risk score reliably identifies recurrences in the first few hours.

METHODS

In a prospective, population-based incidence study of TIA and stroke with complete follow-up (Oxford Vascular Study), we determined the 6-, 12-, and 24-hour risks of recurrent stroke, defined as new neurologic symptoms of sudden onset after initial recovery.

RESULTS

Of 1,247 first TIA or strokes, 35 had recurrent strokes within 24 hours, all in the same arterial territory. The initial event had recovered prior to the recurrent stroke (i.e., was a TIA) in 25 cases. The 6-, 12-, and 24-hour stroke risks after 488 first TIAs were 1.2% (95% confidence interval [CI]: 0.2-2.2), 2.1% (0.8-3.2), and 5.1% (3.1-7.1), with 42% of all strokes during the 30 days after a first TIA occurring within the first 24 hours. The 12- and 24-hour risks were strongly related to ABCD2 score (p = 0.02 and p = 0.0003). Sixteen (64%) of the 25 cases sought urgent medical attention prior to the recurrent stroke, but none received antiplatelet treatment acutely.

CONCLUSION

That about half of all recurrent strokes during the 7 days after a TIA occur in the first 24 hours highlights the need for emergency assessment. That the ABCD2 score is reliable in the hyperacute phase shows that appropriately triaged emergency assessment and treatment are feasible.

Population-based study of event-rate, incidence, case fatality, and mortality for all acute vascular events in all arterial territories (Oxford Vascular Study)

BACKGROUND

Acute coronary, cerebrovascular, and peripheral vascular events have common underlying arterial pathology, risk factors, and preventive treatments, but they are rarely studied concurrently. In the Oxford Vascular Study, we determined the comparative epidemiology of different acute vascular syndromes, their current burdens, and the potential effect of the ageing population on future rates.

METHODS

We prospectively assessed all individuals presenting with an acute vascular event of any type in any arterial territory irrespective of age in a population of 91 106 in Oxfordshire, UK, in 2002-05.

FINDINGS

2024 acute vascular events occurred in 1657 individuals: 918 (45%) cerebrovascular (618 stroke, 300 transient ischaemic attacks [TIA]); 856 (42%) coronary vascular (159 ST-elevation myocardial infarction, 316 non-ST-elevation myocardial infarction, 218 unstable angina, 163 sudden cardiac death); 188 (9%) peripheral vascular (43 aortic, 53 embolic visceral or limb ischaemia, 92 critical limb ischaemia); and 62 unclassifiable deaths. Relative incidence of cerebrovascular events compared with coronary events was 1.19 (95% CI 1.06-1.33) overall; 1.40 (1.23-1.59) for non-fatal events; and 1.21 (1.04-1.41) if TIA and unstable angina were further excluded. Event and incidence rates rose steeply with age in all arterial territories, with 735 (80%) cerebrovascular, 623 (73%) coronary, and 147 (78%) peripheral vascular events in 12 886 (14%) individuals aged 65 years or older; and 503 (54%), 402 (47%), and 105 (56%), respectively, in the 5919 (6%) aged 75 years or older. Although case-fatality rates increased with age, 736 (47%) of 1561 non-fatal events occurred at age 75 years or older.

INTERPRETATION

The high rates of acute vascular events outside the coronary arterial territory and the steep rise in event rates with age in all territories have implications for prevention strategies, clinical trial design, and the targeting of funds for service provision and research.

Population-based study of delays in carotid imaging and surgery and the risk of recurrent stroke

BACKGROUND

Benefit from carotid endarterectomy is greatest when performed within 2 weeks of a presenting TIA or stroke and decreases rapidly thereafter.

OBJECTIVE

To determine the delays to carotid imaging and endarterectomy in Oxfordshire, UK, and the consequences for the effectiveness of stroke prevention.

METHODS

All patients undergoing carotid imaging for ischemic retinal or cerebral TIA or stroke were identified in two populations: the population of Oxfordshire, UK (n = 680,772), from April 1, 2002, to March 31, 2003, and the Oxford Vascular Study (OXVASC) subpopulation (n = 92,000) from April 1, 2002, to March 31, 2004. The times from presenting event to referral, scanning, and endarterectomy (Oxfordshire population) and the risk of stroke prior to endarterectomy in patients with > or = 50% symptomatic carotid stenosis (OXVASC population) were determined.

RESULTS

Among 853 patients who had carotid imaging in the Oxfordshire population, median (interquartile range) times from presenting event to referral, scanning, and endarterectomy were 9 (3 to 30), 33 (12 to 62), and 100 (59 to 137) days. Eighty-five patients were found to have 50 to 99% symptomatic stenosis, of whom 49 had endarterectomy. Only 3 (6%) had surgery within 2 weeks of their presenting event and only 21 (43%) within 12 weeks. The risk of stroke prior to endarterectomy in the OXVASC subpopulation with > or = 50% stenosis was 21% (8 to 34%) at 2 weeks and 32% (17 to 47%) at 12 weeks, in half of which strokes were disabling or fatal.

CONCLUSION

Delays to carotid imaging and endarterectomy after TIA or stroke in the United Kingdom are similar to those reported in several other countries and are associated with very high risks of otherwise preventable early recurrent stroke.

A simple score (ABCD) to identify individuals at high early risk of stroke after transient ischaemic attack

BACKGROUND

Effective early management of patients with transient ischaemic attacks (TIA) is undermined by an inability to predict who is at highest early risk of stroke.

METHODS

We derived a score for 7-day risk of stroke in a population-based cohort of patients (n=209) with a probable or definite TIA (Oxfordshire Community Stroke Project; OCSP), and validated the score in a similar population-based cohort (Oxford Vascular Study; OXVASC, n=190). We assessed likely clinical usefulness to front-line health services by using the score to stratify all patients with suspected TIA referred to OXVASC (n=378, outcome: 7-day risk of stroke) and to a hospital-based weekly TIA clinic (n=210; outcome: risk of stroke before appointment).

RESULTS

A six-point score derived in the OCSP (age [> or =60 years=1], blood pressure [systolic >140 mm Hg and/or diastolic > or =90 mm Hg=1], clinical features [unilateral weakness=2, speech disturbance without weakness=1, other=0], and duration of symptoms in min [> or =60=2, 10-59=1, <10=0]; ABCD) was highly predictive of 7-day risk of stroke in OXVASC patients with probable or definite TIA (p<0.0001), in the OXVASC population-based cohort of all referrals with suspected TIA (p<0.0001), and in the hospital-based weekly TIA clinic-referred cohort (p=0.006). In the OXVASC suspected TIA cohort, 19 of 20 (95%) strokes occurred in 101 (27%) patients with a score of 5 or greater: 7-day risk was 0.4% (95% CI 0-1.1) in 274 (73%) patients with a score less than 5, 12.1% (4.2-20.0) in 66 (18%) with a score of 5, and 31.4% (16.0-46.8) in 35 (9%) with a score of 6. In the hospital-referred clinic cohort, 14 (7.5%) patients had a stroke before their scheduled appointment, all with a score of 4 or greater.

CONCLUSIONS

Risk of stroke during the 7 days after TIA seems to be highly predictable. Although further validations and refinements are needed, the ABCD score can be used in routine clinical practice to identify high-risk individuals who need emergency investigation and treatment.

Effect of body size on operative risk of carotid endarterectomy

Many studies have found that women have a higher risk of perioperative stroke or death from carotid endarterectomy. Other vascular surgical procedures have demonstrated that body size and morphology impact on operative risk. We correlated the 30 day operative risk of stroke and death in the European Carotid Surgery Trial (ECST) with height, weight, body surface area (BSA), and body mass index using single variable analyses and multivariable logistic regression. Women were at significantly higher risk of perioperative stroke and death in the ECST. Both height and BSA confounded the effect of sex, implying that the generally smaller size of women may contribute to their increased risk. This finding should be validated in other large datasets.

Autoantibodies to the islet cell antigen SOX-13 are associated with duration but not type of diabetes

AIMS

The autoantigen SOX-13 of the SRY-related high mobility group box is a low-frequency reactant in sera from patients with Type 1 diabetes. We further investigated the potential diagnostic role of anti-SOX-13, and in particular its ability to distinguish Type 1 from Type 2 diabetes, in two large, well-characterized cohorts.

METHODS

SOX-13 autoantibody status was ascertained using a radioimmunoprecipitation assay in (i) a random sample of 546 participants in an Australian community-based study (the Fremantle Diabetes Study; FDS) of whom 119 had Type 1 and 427 Type 2 diabetes, and (ii) a sample of 333 subjects with Type 2 diabetes from the United Kingdom Prospective Diabetes Study (UKPDS) stratified by age, anti-glutamic acid decarboxylase (GAD) and islet cell antibody (ICA) status, and requirement for insulin therapy within 6 years of diagnosis.

RESULTS

The frequencies of anti-SOX-13 in the FDS subjects were 16.0% and 14.8% for Type 1 and Type 2 patients, respectively, and levels were similar. In the UKPDS subjects, the frequency was 4.5%. In a logistic regression model involving demographic, anthropometric and metabolic variables, only diabetes duration was significantly associated with anti-SOX-13 positivity, especially for duration > 5 years (P < 0.002). When the coexistence of autoantibodies was assessed in the two study samples, there were no significant associations between anti-SOX-13 and ICA, anti-GAD or ICA512/IA-2.

CONCLUSIONS

Whilst the frequency of anti-SOX-13 may be increased in some populations of diabetic patients, this reactivity does not usefully distinguish Type 1 from Type 2 diabetes. However, the association with diabetes duration suggests that anti-SOX-13 may be a non-specific marker of tissue damage associated with chronic hyperglycaemia.

Long-term durability of carotid endarterectomy for symptomatic stenosis and risk factors for late postoperative stroke

BACKGROUND AND PURPOSE

Carotid endarterectomy (CEA) reduces the risk of stroke ipsilateral to recently symptomatic severe carotid stenosis. Other techniques such as percutaneous transluminal angioplasty with stenting are currently being compared with CEA. Thus far, case series and several small, randomized, controlled trials of CEA versus percutaneous transluminal angioplasty (with and without stenting) have focused primarily on the 30-day procedural risks of stroke and death. However, long-term durability is also important. To determine the long-term risk of stroke after CEA and to identify risk factors, we studied patients in the European Carotid Study Trial (ECST), the largest published cohort with long-term follow-up by physicians after CEA.

METHODS

Risks of ipsilateral carotid territory ischemic stroke were calculated by Kaplan-Meier analysis starting on the 30th day after CEA in 1728 patients who underwent trial surgery. Risk factors were determined by Cox regression. For comparison, we also determined the "background" risk of stroke on medical treatment in the ECST in the territory of 558 previously asymptomatic contralateral carotid arteries with <30% angiographic stenosis (ECST method) at randomization.

RESULTS

The risks of disabling ipsilateral ischemic stroke and any ipsilateral ischemic stroke were constant after CEA, reaching 4.4% [95% confidence interval (CI), 3.0 to 5.8] and 9.7% (95% CI, 7.6 to 11.7), respectively, by 10 years. The equivalent ischemic stroke risks distal to contralateral <30% asymptomatic carotid stenoses were 1.9% (95% CI, 0.8 to 3.2) and 4.5% (95% CI, 1.5 to 7.4). Presentation with cerebral symptoms, diabetes, elevated systolic blood pressure, smoking, male sex, increasing age, and a lesser severity of preoperative stenosis were associated with an increased risk of late stroke after CEA, but plaque morphology and patch grafting were not.

CONCLUSIONS

Although the risk of late ipsilateral ischemic stroke after CEA for symptomatic stenosis is approximately double the background risk in the territory of <30% asymptomatic stenosis, it is still only approximately 1% per year and remains low for at least 10 years after CEA. This is the standard against which alternative treatments should be judged. Several risk factors may be useful in identifying patients at particularly high risk of late postoperative stroke.

Carotid artery disease and stroke during coronary artery bypass: a critical review of the literature

OBJECTIVES

to determine the role of carotid artery disease in the pathophysiology of stroke after coronary artery bypass (CABG).

DESIGN

systematic review of the literature.

RESULTS

the risk of stroke after CABG was 2% and remained unchanged between 1970-2000. Two-thirds occurred after day 1 and 23% died. 91% of screened CABG patients had no significant carotid disease and had a <2% risk of peri-operative stroke. Stroke risk increased to 3% in predominantly asymptomatic patients with a unilateral 50-99% stenosis, 5% in those with bilateral 50-99% stenoses and 7-11% in patients with carotid occlusion. Significant predictive factors for post-CABG stroke included; (i) carotid bruit (OR 3.6, 95% CI 2.8-4.6), (ii) prior stroke/TIA (OR 3.6, 95% CI 2.7-4.9) and (iii) severe carotid stenosis/occlusion (OR 4.3, 95% CI 3.2-5.7). However, the systematic review indicated that 50% of stroke sufferers did not have significant carotid disease and 60% of territorial infarctions on CT scan/autopsy could not be attributed to carotid disease alone.

CONCLUSIONS

carotid disease is an important aetiological factor in the pathophysiology of post-CABG stroke. However, even assuming that prophylactic carotid endarterectomy carried no additional risk, it could only ever prevent about 40-50% of procedural strokes.

Sequence variants of the sarco(endo)plasmic reticulum Ca(2+)-transport ATPase 3 gene (SERCA3) in Caucasian type II diabetic patients (UK Prospective Diabetes Study 48)

AIMS/HYPOTHESIS

Type II (non-insulin-dependent) diabetes mellitus is a common heterogeneous metabolic disorder of largely unknown genetic aetiology. The sarco(endo)plasmic reticulum Ca(2+)-transport ATPase (SERCA) plays an important part in the glucose-activated beta-cell Ca(2+) signalling that regulates insulin secretion. Impaired function and expression of SERCA have been shown in islets of Langerhans from diabetic animal models and have also been associated with beta-cell apoptosis. Thus, the SERCA3 encoding gene is a plausible candidate for a primary pancreatic beta-cell defect.

METHODS

In this study, the entire coding and the promoter regions of SERCA3 gene were screened by single-strand conformation polymorphism analysis in white Caucasian Type II diabetic patients.

RESULTS

We found four rare missense mutations [Exon 4: Gln(108)-->His (CAG-->CAT), Exon 14: Val(648) -->Met (GTG-->ATG) and Arg(674)-->Cys (CGC--> TGC), and Exon 15: Ile(753)-->Leu (ATC-->CTC)]. The patients with Gln(108)-->His, Val(648)-->Met and Arg(674)-->Cys mutations, which may affect the E1P-E2P transition of SERCA3 during its enzyme cycle, had normal body weight with marked hyperglycaemia and beta-cell dysfunction. That is an unusual phenotype only found in 6 % of the Type II diabetic patients recruited for the UK Prospective Diabetes Study. In addition, five silent polymorphisms, six intron variants and two polymorphisms in the 3' untranslated region of exon 22 were found with similar frequency in diabetic and control subjects.

CONCLUSION/INTERPRETATION

Our result suggests that in white Caucasians, the SERCA3 locus possibly contributes to the genetic susceptibility to Type II diabetes [Diabetologia (1999) 42: 1240-1243].

Dissociable contributions of the two cerebral hemispheres to judgments of line orientation

A previous study of the performance of men with chronic unilateral focal brain lesions (due to wartime missile injury) on a standard test of line orientation suggested a left hemisphere (LH) as well as a right hemisphere (RH) contribution to visuospatial processing. The present study was designed to fractionate the variables that could underlie this unexpected finding and thereby to tease out the mechanisms involved in LH as compared with RH processing. A simpler ("purer") version of the standard line orientation task was used, as were two other versions in which matching in an array and matching with distractors were measured. The findings confirmed the hypothesis of RH involvement in the purer task of metric measurement and suggested that the LH has an important role in keeping track decisions and updating decisions in more complex aspects of line orientation judgment.

Selective loss of verbal imagery

This single case study of the ability to generate verbal and non-verbal imagery in a woman who sustained a gunshot wound to the brain reports a significant difficulty in generating images of word shapes but not a significant problem in generating object images. Further dissociation, however, was observed in her ability to generate images of living vs non-living material. She made more errors in imagery and factual information tasks for non-living items than for living items. This pattern contrasts with our previous report of the agnosic patient, M.S., who had severe difficulty in generating images of living material, whereas his ability to image the shape of words was comparable to that of normal control subjects. Furthermore, with regard to the generation of images of living compared with non-living material, M.S. shows more errors with living than nonliving items. In contrast, the present patient, S.M., made significantly more errors with non-living relative to living items. There appear to be two types of double dissociation which reinforce the growing evidence of dissociable impairments in the ability to generate images for different types of verbal and non-verbal material. Such dissociations, presumably related to sensory and cognitive processing demands, address the problem of the neural basis of imagery.

Patient history as a simple predictor of pelvic pathology in subfertile women

The objective of this study is to determine in a group of subfertile women whether patient history can differentiate women with a healthy pelvis from those with endometriosis or adnexal adhesions. In this prospective study, consecutive subfertile women undergoing laparoscopy and tubal hydrotubation for the sole indication of subfertility were evaluated at the teaching hospital fertility unit. They had a minimum of 2 years subfertility. The main outcome measures were: patients' response to a 7-point physical symptom and medical history questionnaire, laparoscopic findings of endometriosis and adnexal adhesions quantified according to the American Fertility Society classification. Of 104 patients, 99 patients were retained in the analysis. Forty per-cent had endometriosis, 19% pelvic adhesions and 40% a normal pelvis. Severe dysmenorrhoea was the only symptom predictive for endometriosis (relative risk 1.7). Severe dysmenorrhoea, a vaginal discharge, past use of a coil and previous laparotomies were all predictive for pelvic adhesions (relative risks 2.1, 3.3, 2.1, 1.9, respectively). The relative risk increased with severity of the disease. Patients with moderate and severe adhesions were 4.2 and 5.3 times more likely to have severe dysmenorrhoea and a vaginal discharge than patients with a normal pelvis. Subfertile women giving a positive response to selected questions about their medical history are at increased risk of endometriosis and pelvic adhesions. Where resources are limited, such a system could be used to plan effective use of available diagnostic facilities.

Selective loss of imagery in a case of visual agnosia

Experiments were designed to examine the imagery abilities of an agnosic patient, M.S., who has consistently shown more severe deficits in recognizing visually, and in retrieving knowledge of living as compared with non-living items. Judgements of visual similarity were required for named objects and for object-pictures, as well as for the factual properties of these stimuli. The same disproportionate difficulty in processing living ('natural') objects was found in these tasks as well as in forced-choice recognition. In contrast, no deficit was found on analogous tasks concerned with word-shape similarities. These findings have a bearing on concepts of semantic memory.

A role for the left hemisphere in spatial processing

This study extended our recently reported evidence of a left hemisphere (LH) contribution to spatial processing on standard visuospatial tasks. The present investigation compared performance on these standard tasks with that on 'purer' experimental tasks. Two tasks of line orientation, two of shape rotation and a shape matching task were administered to 50 men with stable unilateral post-Rolandic missile injuries and 32 control subjects. A LH deficit was found on the standard task of line orientation but not the 'purer' task, suggesting that the LH plays a role in eliminating extraneous information, presented only in the standard test. As for shape rotation, the LH group was impaired on both tasks. On the shape matching task, both experimental groups were significantly slower than control subjects. It is proposed the LH makes an important contribution to mental rotation and the understanding of Euclidean geometrical shapes.

Brown-Séquard syndrome associated with posttraumatic cervical epidural hematoma: case report and review of the literature

Post-traumatic cervical epidural hematoma is an uncommon entity. A case is presented in which such a lesion developed after chiropractic manipulation of the neck. The patient presented with a Brown-Séquard syndrome, which has only rarely been reported in association with cervical epidural hematoma. The correct diagnosis was obtained by computed tomographic scanning. Surgical evacuation of the hematoma was followed by full recovery.

Category-specificity and modality-specificity in semantic memory

Studies of agnosia have revealed two apparently orthogonal dimensions along which knowledge may break down. In some cases, knowledge of specific categories (such as living things) seems lost, regardless of the modality being tested. In other cases, knowledge in specific modalities (such as vision) seems lost, regardless of the category of stimuli being tested. These different sets of phenomena suggest different organizations for knowledge in the brain, the first by category and the second by modality. Unfortunately, possible confoundings between category, modality, and difficulty level in the previous studies prevent us from drawing strong conclusions from these data. The present study was aimed at assessing the nature of the breakdown in the semantic memory of a prosopagnosic patient, by orthogonally varying category and modality, while assessing difficulty level. The findings do not implicate a simple categorical or modality-dependent organization of his knowledge, but rather an organization in which both category and modality play a role.

A left hemisphere contribution to visuospatial processing

Men with chronic, focal, unilateral missile injures of the brain--twenty-five with left hemisphere lesions (LH group) and twenty with right hemisphere lesions (RH groups)--and twenty-two control subjects were given two visuoperceptual and two visuospatial tests. The LH group was significantly impaired in relation to the control group on both the spatial tasks. A different pattern of dissociable perceptual and spatial deficits was found in the experimental groups: better preserved perceptual than spatial performance was observed more frequently in the LH group whereas the converse--relatively better spatial than perceptual performance--was more evident in the RH group. Double dissociations in performance on the two spatial tasks were found predominantly in the LH group. These findings suggest an important left hemisphere contribution to visuospatial processing and the possibility of a more focal representation of spatial abilities in the left hemisphere than in the right.