Critical reflections on the concept and impact of "scaling up" in Global Mental Health

The field of Global Mental Health (GMH) aims to address the global burden of mental illness by focusing on closing the "treatment gap" faced by many low- and middle-income countries (LMICs). To increase access to services, GMH prioritizes "scaling up" mental health services, primarily advocating for the export of Western centred and developed biomedical and psychosocial "evidence-based" approaches to the Global South. While this emphasis on scalability has resulted in the increased availability of mental health services in some LMICs, there have been few critical discussions of this strategy. This commentary critically appraises the scalability of GMH by questioning the validity and sustainability of its approach. We argue that the current approach emphasizes the development of mental health services and interventions in "silos," focusing on the treatment of mental illnesses at the exclusion of a holistic and contextualized approach to people's needs. We also question the opportunities that the current approach to GMH offers for the growth of mental health programmes of local NGOs and investigate the potential pitfalls that scalability may have on NGOs' impact and ability to innovate. This commentary argues that any "scaling up" of mental health services must place sustainability at the core of its mission by favouring the growth and development of local solutions and wider forms of support that prioritize social inclusion and long-lasting mental health recovery.

An unusual case of stridor: supraglottic inverted papilloma

Inverted papillomas are rare benign neoplasms that typically originate in the sinonasal area of middle-aged men. We report the first case of a supraglottic inverted papilloma presenting with stridor.

The long noncoding RNA MALAT1 suppresses miR-211 to confer protection from ultraviolet-mediated DNA damage in vitiligo epidermis by upregulating sirtuin 1

BACKGROUND

The absence of melanocytes poses a challenge for long-term tissue homeostasis in vitiligo. Surprisingly, while individuals with Fitzpatrick phototypes I-II (low melanin content) have a higher incidence of melanoma and nonmelanoma skin cancer, people with vitiligo are at a decreased risk for the same.

OBJECTIVES

To understand the molecular mechanisms that protect vitiligo skin from ultraviolet (UV)-induced DNA damage by (i) characterizing differentially expressed microRNAs in lesional vs. nonlesional epidermis and (ii) identifying their upstream regulators and downstream gene targets.

METHODS

Genome-wide microRNA profiling of nonlesional and lesional epidermis was performed on five individuals with stable nonsegmental vitiligo using next-generation RNA sequencing. The relevance of the upstream regulator and downstream target gene of the most differentially expressed microRNA was studied.

RESULTS

Our study found sirtuin1 (SIRT1), an NAD-dependent deacetylase, to be a direct target of miR-211 - the most significantly downregulated microRNA in lesional epidermis. Inhibition of SIRT1 with EX-527 downregulated keratin 10 and involucrin, suggesting that SIRT1 promotes keratinocyte differentiation. Overexpression of miR-211 mimic led to a significant increase in γ-H2AX positivity and cyclobutane pyrimidine dimer (CPD) formation, hallmarks of UVB-mediated DNA damage. These effects could be ameliorated by the addition of resveratrol, a SIRT1 activator. Furthermore, a long noncoding RNA, MALAT1, was identified as a negative upstream regulator of miR-211. Overexpression of MALAT1 resulted in increased expression of SIRT1 and a concomitant removal of UVB-induced CPDs in primary keratinocytes.

CONCLUSIONS

These findings establish a novel MALAT1-miR-211-SIRT1 signalling axis that potentially confers protection to the 'amelanotic' keratinocytes in vitiligo.

Radioiodinated Capsids Facilitate In Vivo Non-Invasive Tracking of Adeno-Associated Gene Transfer Vectors

Viral vector mediated gene therapy has become commonplace in clinical trials for a wide range of inherited disorders. Successful gene transfer depends on a number of factors, of which tissue tropism is among the most important. To date, definitive mapping of the spatial and temporal distribution of viral vectors in vivo has generally required postmortem examination of tissue. Here we present two methods for radiolabeling adeno-associated virus (AAV), one of the most commonly used viral vectors for gene therapy trials, and demonstrate their potential usefulness in the development of surrogate markers for vector delivery during the first week after administration. Specifically, we labeled adeno-associated virus serotype 10 expressing the coding sequences for the CLN2 gene implicated in late infantile neuronal ceroid lipofuscinosis with iodine-124. Using direct (Iodogen) and indirect (modified Bolton-Hunter) methods, we observed the vector in the murine brain for up to one week using positron emission tomography. Capsid radioiodination of viral vectors enables non-invasive, whole body, in vivo evaluation of spatial and temporal vector distribution that should inform methods for efficacious gene therapy over a broad range of applications.

Success of cricopharyngeal myotomy for specific and non-specific cervical dysphagia

OBJECTIVE

The present study aimed to compare outcomes of cricopharyngeal myotomy (CPM) in patients with documented cricopharyngeal dysfunction (CPD) and those in whom the diagnosis is complex or in doubt.

MATERIALS AND METHODS

Retrospective comparative study of all patients undergoing CPM between 2001 and 2010 at a single UK centre. Patients were classified as having either CPD (n = 15) or non-specific cervical dysphagia (NSCD) (n = 12) based on contrast swallow results. They completed a 10-point visual analogue scale (VAS) questionnaire regarding their ability to swallow solids preoperatively and 6 months postoperatively. Scores were compared between groups, and symptom recurrence at 12 months postoperatively was also noted.

RESULTS

The median VAS for all patients in both groups preoperatively was 5.5 and improved postoperatively to 8.0 (p < 0.001), and median preoperative ratings between groups were similar (CPD = 6.0 vs. NSCD = 5.5; p > 0.05). The CPD group scored better postoperatively compared to their NSCD counterparts (CPD = 9.0 vs. NSCD = 7.5; p < 0.001). Recurrence rate at 12 months was lower in CPD (12.5%) compared to NSCD (60%) patients.

CONCLUSION

After CPM, patients with CPD showed significant improvement in swallowing solids, as did patients with NSCD, although to a lesser extent. CPD patients experienced better outcomes compared to their NSCD counterparts, including lower complication and recurrence rates. Larger studies are required before CPM can be advocated as the standard of care for NSCD patients.

Optical mapping of electrical heterogeneities in the heart during global ischemia

Real-time optical registration of electrical activity in the heart allows the study of arrhythmogenic mechanisms, in particular due to global ischemia. It is known that global ischemia increases electrical heterogeneity in the heart. However, inter-ventricular differences between the right (RV) and left ventricle (LV) during ischemia and their relationship to arrhythmogenesis remains poorly understood. We used high resolution optical mapping (di-4-ANEPPS, excitation at 532 nm, emission at 640+/-50 nm) of Langendorff-perfused rabbit hearts to quantify inter-ventricular heterogeneity in the heart during periodic pacing and ventricular fibrillation. Two fast CCD cameras were used to record electrical activity from the RV and LV during control, global ischemia (20 min), and reperfusion. Hearts were paced at progressively reduced (from 300 ms to 100 ms) basic cycle lengths and ventricular fibrillation was induced by burst pacing and recorded before the global ischemia, and after the reperfusion. The action potential durations (APD), maximum slopes of APD restitution curves (S(max)), and mean dominant frequency (DF) of ventricular fibrillation were measured for both LV and RV surfaces. No APD heterogeneity was observed in control hearts. Global ischemia induced inter-ventricular heterogeneity in APDs (RV: 109+/-21 ms, LV: 89+/-23 ms; p<0.01) that was abolished upon reperfusion. However, S(max) was uniformly decreased in both RV (control: 0.94+/-0.25, ischemia: 0.36+/-0.12; p<0.01) and LV (control: 0.99+/-0.24, ischemia: 0.43+/-0.21; p<0.01) and did not recover upon reperfusion. In addition, the DF of ventricular fibrillation during reperfusion decreased significantly in RV (from 8.6+/-1.3 Hz to 6.2+/-1.1 Hz; p<0.05) but remained the same in LV (9.0+/-0.8 Hz vs 8.5+/-1.0 Hz). Thus, our results demonstrate that global ischemia induces inter-ventricular heterogeneity in APD during periodic pacing. Although this effect was abolished upon reperfusion, S(max) did not recover, indicating the presence of residual changes in electrical properties of the heart. Therefore, reperfusion reveals the presence of inter-ventricular heterogeneities in the dynamics of ventricular fibrillation.

A multicentre audit of single-use surgical instruments (SUSI) for tonsillectomy and adenoidectomy

INTRODUCTION

Prions are resistant to conventional sterilisation procedures and, therefore, could be transmitted iatrogenically through re-usable adenoid and tonsil surgical instruments. Using disposable instruments would avoid the risk of transmission. We present the results of a complete audit loop using BBraun single-use surgical instruments (SUSI).

PATIENTS AND METHODS

This was a prospective multicentre audit. Surgeons were asked to fill in a standardised questionnaire recording details including postoperative complications, and evaluation of each piece of equipment compared with their own experience of conventional re-usable instruments. In the first cycle, constructive criticisms of the instruments were noted and the manufacturers modified the instruments accordingly. A second cycle of audit was subsequently undertaken.

RESULTS

A total of 86 patients were audited in the first cycle and 97 in the second cycle. Postoperative haemorrhage rate for both cycles was well within acceptable range. In the first audit cycle, surgeons generally found the Draffin rods, Boyle-Davis gag and bipolar diathermy forceps of poor quality and difficult to use. These were redesigned and, on repeat evaluation during the second audit cycle, were found to be just as good, if not better, than the re-usable instruments.

CONCLUSIONS

This study suggests that SUSI may be just as good as re-usable instruments. Furthermore, they may be more cost effective.

Cherubism in siblings: A case report

Cherubism is a benign disease of bones affecting the jaws and giving a characteristic cherubic appearance to the patient. On radiography, the lesions exhibit bilateral multilocular radiolucent areas. Histopathology shows numerous multinucleated giant cells in the background of proliferating fibrous connective tissue. Cherubism can be a solitary case. The present report describe cherubism in two siblings and briefly review the literature on this subject.

How we do it: A novel approach to the skin?abutment interface of the bone-anchored hearing aid: use of local skin flaps

Various techniques involving skin grafts have been described to obtain thin hairless immobile skin at the abutment interface of the bone-anchored hearing aid (BAHA), but none are without significant complications such as necrosis and/or infection leading to total graft failure. A novel technique involving four local thin skin flaps was developed to prevent serious complications. The procedure essentially involves raising skin flaps at the intradermal level leaving the hair follicles in the subcutaneous tissue, which is subsequently excised. We have used the skin-flap approach around 21 BAHAs on 19 patients (two patients had bilateral devices) and the only complications were minor skin loss immediately adjacent to the implants in two patients and mild skin infections, which settled with topical antibiotics, in three patients. The innovative technique described is simple and straightforward, and does not require any special instrumentation. Furthermore, it may have specific advantages, in terms of morbidity, over contemporary skin grafting methods primarily because of the retained intrinsic blood supply of the skin flaps.

Functional rhinoplasty with batten and spreader grafts for correction of internal nasal valve incompetence

OBJECTIVE

We a describe technique for correction of internal nasal valve incompetence (INVI) using functional rhinoplasty (FRP) with combined cartilaginous batten and spreader grafts and report the functional and cosmetic outcomes.

DESIGN

Prospective series using subjective improvement in nasal airway and quality of life.

SETTING

Subregional ENT centre, one operating rhinologist.

PARTICIPANTS

Twenty-three consecutive adults presenting to ENT department at North Hertfordshire NHS Trust with symptomatic INVI.

MAIN OUTCOMES MEASURES

Pre and post-operative symptom scores for nasal obstruction and its impact on overall quality of life using visual analogue scales (1-100mm). Cosmetic outcome graded using subjective scores. Statistical analysis performed using the Wilcoxon signed rank test.

RESULTS

We found a median subjective improvement on the visual analogue scale of 55 mm for nasal patency (p<0.001) and of 49 mm for quality of life (p<0.001). Twenty-two patients felt that the appearance of their nose had not changed or had significantly improved post operatively.

CONCLUSION

Combined use of batten and spreader grafts for the correction of INVI in normal or narrow nasal vaults is effective without compromising cosmesis.

4 years' experience of head and neck tuberculosis in a south London hospital

In a south London department of otorhinolaryngology and head and neck surgery, 33 cases of tuberculosis were diagnosed in 4 years. The most common presentation was cervical adenitis (58%) and in some cases the initial investigations suggested malignant disease. Most of the patients were of non-British origin but none proved to be HIV seropositive. Fine-needle aspiration was positive for tuberculosis in 7 of 19 patients. 21 patients required a surgical procedure for diagnosis.

4 Years’ Experience of Head and Neck Tuberculosis in a South London Hospital

In a south London department of otorhinolaryngology and head and neck surgery, 33 cases of tuberculosis were diagnosed in 4 years. The most common presentation was cervical adenitis (58%) and in some cases the initial investigations suggested malignant disease. Most of the patients were of non-British origin but none proved to be HIV seropositive. Fine-needle aspiration was positive for tuberculosis in 7 of 19 patients. 21 patients required a surgical procedure for diagnosis.

A prospective double-blind randomized controlled trial comparing the suitability of KTP laser tonsillectomy with conventional dissection tonsillectomy for day case surgery

Tonsillectomy using a KTP laser has been performed increasingly but is not a routinely practised technique in the UK. In the USA, tonsillectomy is often performed as a day case procedure but, here in the UK, it is still standard practice to admit patients for overnight stay. We present the largest prospective double-blind randomized controlled trial to date (151 patients) comparing KTP laser with standard dissection tonsillectomy and assess the suitability of both procedures for day case surgery. We found that there was significantly less peroperative haemorrhage if tonsillectomy was performed using the KTP laser, but it did cause more postoperative pain, more depression in mood and a higher rate of both reactionary and secondary haemorrhage, which was not significant when compared with conventional dissection. There was no difference in operating time, and over 40% of patients in each group needed overnight admission. We conclude that KTP laser tonsillectomy offers no benefit apart from less intraoperative bleeding over standard dissection tonsillectomy. Discharge from hospital after tonsillectomy was found to be unpredictable. Tonsillectomy is therefore an unsuitable procedure for planned surgery through a day unit, but approximately 58% of patients could be discharged on the same day from an extended day surgery unit, and the rest have one night in hospital.

Diagrammatic recording of head and neck tumours

The increasing demands of clinical audit have resulted in the need for accurate data collection. The use of tumour maps allows standardization of the records of patients with head and neck cancer, which facilitates collation of data in multicentre studies and makes interdepartmental comparisons more meaningful. The aim of this study was to develop an improved standard set of tumour maps for recording the stage of head and neck tumours. A review of the existing tumour diagrams was performed to identify those anatomical areas that are not adequately represented or where ambiguity exists. The areas where improvements could be made were identified as: (1). the anterior commissure of the larynx; (2). axial and sagittal views of the larynx; (3). the pyriform fossa and cervical oesophagus; (4). the oropharynx and vallecula; (5). the nasal cavity and paranasal sinuses; and (6). cervical nodal involvement. A new set of tumour maps is presented in an attempt to correct some of the limitations of the existing diagrams.

Duodenal intubation and test for bile - a reliable method to rule out biliary atresia

Between January 1997 and December 1998, 30 consecutive children with suspected biliary atresia (BA) were selected to assess whether duodenal intubation (DI) and testing of aspirate for bile would help to rule out BA. Duodenal fluid was aspirated every 2 h for 24 h and tested for bile. A HIDA scan was also done in all cases. Every patient underwent a peroperative cholangiogram (POC) and liver biopsy; a Kasai portoenterostomy was done in indicated cases. In 22 cases all three investigations (DI, HIDA scan, POC) suggested BA. In 3 the HIDA scan ruled out BA, but DI and POC suggested BA. In 2 other cases, both the HIDA scan and DI suggested BA, but POC ruled it out and suggested biliary hypoplasia; in 3 others the HIDA scan suggested BA, but DI and POC both, ruled it out. There was no case where DI ruled out BA (i.e., showed bile in aspirate) and POC suggested BA. A liver biopsy confirmed BA in all proven cases. DI and testing the aspirate for bile is a very reliable means to rule out BA if the aspirate tests positive. It is an inexpensive, noninvasive, and quick bedside test that may be especially useful in developing countries where biliary scintigraphy is not available.

Intestinal atresia: an end-to-end linear anastomotic technique

In a series of 19 neonates with small-bowel atresia, 16 were treated by end-to-end linear anastomosis (ELA) without resection and 3 by resection anastomosis (RA). Seven atresias were jejunal, 11 were ileal, and 1 jejunoileal; 3 cases were type II, 12 type IIIa, 3 type IIIb, and 1 type IV. There were 4 deaths, 1 after ELA and 3 after RA. The overall mortality decreased from 68 to 20.80% and for linear anastomosis to 6.25% presumably, because the intestinal contents are propelled along the lumen in a linear fashion and not at an angle as in end-to-back anastomosis, avoiding shearing of the suture line. The additional plicating sutures reduce the radius and increase the propelling force. We recommend this technique because it is based on sound principles of physics and preserves the entire available length of intestine.

A solitary pulmonary cystic mass resulting from hydatid disease mimicking a pericardial cyst

A 28-year-old male, who was a non-smoker, presented to the accident and emergency department with right anterior sharp chest pain of 2 days' duration, which was worse on swallowing, lying on his right side and deep inspiration. He had had similar pains, but milder in intensity, for the previous 8 weeks. He gave a history of cough with sputum and a single episode of haemoptysis following a flu-like illness. He had no associated breathlessness, wheeze, indigestion or heartburn. There was no history of trauma to the chest. He was an office worker and lived in London all his life except for holidays on a farm in Ireland during childhood and a recent foreign trip to New Guinea.

He was in pain but had no pallor, clubbing, cyanosis or enlargement of neck lymph nodes. His pulse was regular with a rate of 90/minute, his blood pressure was 130/70 mmHg and his jugular venous pressure was not raised. Cardiac, respiratory and abdomen examination revealed no abnormality. Haemoglobin, white cell count, differential count, platelets, erythrocyte sedimentation rate, urea and electrolytes, and liver function tests were normal. An electrocardiogram showed normal sinus rhythm. A chest radiograph showed a large, round, smooth mass of 7 cm in diameter in the right mid and lower zone adjacent to the right cardiac border (Figure 1). On a computed tomography (CT) scan of the chest, this was seen to be a smooth-walled cyst, containing fluid of water density attenuation (Figure 2). It extended from the right hilum to the anterior chest wall, causing compression of the right middle lobe bronchus and partial collapse of the right middle lobe. A CT and ultrasound scan of the liver showed no similar cysts. The appearance of the cyst was thought to be characteristic of a pericardial cyst. The possibility of hydatid disease was considered. However, hydatid serology (Echinococcus antibodies) was negative (titre 1<16).

In view of the symptomatic nature of the cyst causing chest pain and partial collapse of the right middle lobe, the patient was referred for surgical removal of the cyst. During the operation, a large cystic mass was seen in the right chest, outside the pericardium, displacing and compressing the right middle lobe. The cyst was excised intact with its capsule together with the right middle lobe. The gross appearance of the cyst was thought be consistent with that of a pericardial cyst (Figure 3). However, histological examination of the cyst showed active hydatid with viable germinal membrane and scolices. The patient was given praziquantel 50 mg/kg/day plus albendazole 400 mg twice daily for 7 days to treat any remaining fragments of the hydatid cyst postoperatively. He received further treatment with albendazole 400 mg twice daily for a total of 12 weeks (three 4-week courses with two 2-week breaks) to maximize the chances of eradication.

Application of cocaine to the nasal mucosa: a novel method

Topical vasoconstriction using four to 10 per cent cocaine is widely used for nasal surgery. A number of techniques are being used with equally satisfactory results. Here we describe a novel method of topical application of cocaine for nasal surgery. The method is simple, cheap and effective.

Pseudoexstrophy of the bladder: a rare variant

A 15-day-old female presented with a healed omphalocele and a triangular musculoskeletal defect in the hypogastric area similar to the defect seen in classic bladder exstrophy. The bladder was normal on exploration. The defect was successfully closed using a bilateral anterior pubic ramotomy. Only ten cases of pseudoexstrophy have been reported in the world literature.

Injury to the spinal cord without radiological abnormality (SCIWORA) in adults

Injury to the spinal cord without radiological abnormality often occurs in the skeletally immature cervical and thoracic spine. We describe four adult patients with this diagnosis involving the cervical spine with resultant quadriparesis. The relevant literature is reviewed. The implications for initial management of the injury, the role of MRI and the need for a high index of suspicion are highlighted.

Injury to the spinal cord without radiological abnormality (SCIWORA) in adults

Injury to the spinal cord without radiological abnormality often occurs in the skeletally immature cervical and thoracic spine. We describe four adult patients with this diagnosis involving the cervical spine with resultant quadriparesis. The relevant literature is reviewed. The implications for initial management of the injury, the role of MRI and the need for a high index of suspicion are highlighted.

Impact of new developments in antiretroviral treatment on AIDS prevention and care in resource-poor countries

Combination antiretroviral treatment (ARV) including protease inhibitors, decreased the morbidity and mortality due to AIDS in the industrialized world. Many obstacles remain before ARVs can be introduced in resource-poor countries: high treatment costs, lack of laboratories to monitor the treatment, weak healthcare systems, and many other competing healthcare needs. The introduction of ARVs in resource-poor countries should be closely monitored. The first priority for the use of ARVs in resource-poor countries is the prevention of mother-to-child transmission of HIV. News about the success of ARV treatment may lead to an increase in unsafe behaviors including a decreased use of condoms. Therefore, prevention efforts should be strengthened; especially the development of an HIV vaccine needs to become a top priority. Funds for ARV treatment cannot come from the already strained healthcare budgets of resource-poor countries. The pressure on politicians and international donor agencies to provide ARVs to resource-poor countries should be used to increase overall healthcare budgets and to improve healthcare services in general.

Case report. Bilateral simultaneous patellar tendon ruptures associated with osteogenesis imperfecta

Images

Tuberculosis of the mandible in a child

The incidence of notification of tuberculosis is increasing in the developed world. The disease has a variable mode of presentation and therefore diagnosis is not easy. We present an unusual case of tuberculosis involving the ramus of the mandible in a six-year-old boy and outline its management.

Bilateral mandibular nerve damage following root canal therapy

A case of bilateral inferior dental nerve paraesthesia following accidental introduction of root canal filling material into the canal is described. The significance of early recognition of the complication and prompt surgical intervention is highlighted.

Imaging of brain tumor proliferative activity with iodine-131-iododeoxyuridine

METHODS

Iodine-131-iododeoxyuridine (IUdR) uptake and retention was imaged with SPECT at 2 and 24 hr after administering a 10-mCi dose to six patients with primary brain tumors. The SPECT images were directly compared to gadolinium contrast-enhanced MR images as well as to [18F]fluorodeoxyglucose (FDG) PET scans and 201Tl SPECT scans.

RESULTS

Localized uptake and retention of IUdR-derived radioactivity was observed in five of six patients. The plasma half-life of [131I]IUdR was short (1.6 min) in comparison to the half-life of total plasma radioactivity (6.4 hr). The pattern of [131I]IUdR-derived radioactivity was markedly different in the 2-hr compared to 24-hr images. Radioactivity was localized along the periphery of the tumor and extended beyond the margin of tumor identified by contrast enhancement on MRI. The estimated levels of tumor radioactivity at 24 hr, based on semiquantitative phantom studies, ranged between < 0.1 and 0.2 microCi/cc (< 0.001% and 0.002% dose/cc); brain levels were not measurable.

CONCLUSIONS

Iodine-131-IUdR SPECT imaging of brain tumor proliferation has low (marginal) sensitivity due to low count rates and can detect only the most active regions of tumor growth. Imaging at 24 hr represents a washout strategy to reduce 131I-labeled metabolites contributing to background activity in the tumors, and is more likely to show the pattern of [131I]IUdR-DNA incorporation and thereby increase image specificity. Iodine-123-IUdR SPECT imaging at 12 hr and the use of [124I]IUdR and PET will improve count acquisition and image quality.

Horizontal root fracture--an unusual complication

Cystic change at the site of a root fracture is an unusual sequelae. A case report of such an occurrence in a horizontal root fracture involving the apical third of a permanent central incisor in a 22-year-old man is presented and management of these injuries is discussed in brief.

Responses of glomerular filtration, renal blood flow and salt-water handling to acute cardioselective and non-selective beta-adrenoceptor blockade in essential hypertension

The effects on renal hemodynamics and salt-water handling of equipotent doses of the cardioselective beta-blocker metoprolol (M, 100 mg) and of the non-selective (intrinsic sympathetic activity) beta-antagonist pindolol (P, 10 mg) were compared in 30 WHO Grade 1-2 hypertensive men. M lowered pulse rate more than P. Systolic pressure was equally reduced by both agents, and diastolic and mean pressures were decreased only after P. Glomerular filtration rate was not significantly altered by either antagonist, and renal blood flow decreased by approximately 11% both after M and P. Renal vascular resistance was unchanged after P, and was increased by 10% after M. It is concluded that, like the effects on central haemodynamics, ISA is more important in the renal response to beta-adrenoceptor blockade than is beta-receptor selectivity.

Predominant left hemisphere metabolic dysfunction in dementia

Thirty-one patients with probable Alzheimer's disease and 11 patients with memory disorders, attributable to multiple cerebral infarctions, were studied using 18-F-fluorodeoxyglucose-positron emission tomography scans. Asymmetry in cerebral glucose metabolism within these diagnostic groups was assessed by comparison with the metabolic rates obtained in age-equivalent healthy control subjects. A significantly greater number of individuals in both patient groups exhibited predominant left rather than right hemisphere hypometabolism. In addition, for patients with Alzheimer's disease, the degree of asymmetry was not related to either the severity or duration of dementia. These findings could be explained by greater susceptibility of the left hemisphere to degenerative or ischemic brain disease, by a specific sampling effect, or most likely, by greater metabolic deficits resulting from left rather than right hemisphere impairment.