Aquaculture: a rapidly growing and significant source of sustainable food? Status, transitions and potential.

The status and potential of aquaculture is considered as part of a broader food landscape of wild aquatic and terrestrial food sources. The rationale and resource base required for the development of aquaculture are considered in the context of broader societal development, cultural preferences and human needs. Attention is drawn to the uneven development and current importance of aquaculture globally as well as its considerable heterogeneity of form and function compared with established terrestrial livestock production. The recent drivers of growth in demand and production are examined and the persistent linkages between exploitation of wild stocks, full life cycle culture and the various intermediate forms explored. An emergent trend for sourcing aquaculture feeds from alternatives to marine ingredients is described and the implications for the sector with rapidly growing feed needs discussed. The rise of non-conventional and innovative feed ingredients, often shared with terrestrial livestock, are considered, including aquaculture itself becoming a major source of marine ingredients. The implications for the continued expected growth of aquaculture are set in the context of sustainable intensification, with the challenges that conventional intensification and emergent integration within, and between, value chains explored. The review concludes with a consideration of the implications for dependent livelihoods and projections for various futures based on limited resources but growing demand.

How have patients reacted to the implications of the DCCT?

OBJECTIVES: To assess the reactions of people with insulin-treated diabetes (ITD) to the results of the Diabetes Control and Complications Trial (DCCT). RESEARCH DESIGN AND METHODS: A leaflet documenting the purpose and results of the DCCT was circulated to all 771 patients ages 15-60 years with ITD attending our clinic. Patients were invited to complete and return a questionnaire on their responses. RESULTS: Of 550 respondents, 330 felt encouraged to improve glycemic control. Female respondents (P = 0.003) and younger age-groups (15-25 years, P = 0.001) were most likely to want to improve control. Patients with long duration of diabetes (> 20 years, P = 0.00001), hypoglycemia unawareness (P = 0.0001), or previous severe hypoglycemia (P = 0.001) were less likely to want to improve their control. Fear of hypoglycemia concerned all age-groups, whereas female respondents were most likely to be worried about the potential for weight gain (P = 0.00006). CONCLUSIONS: Knowledge of the results of the DCCT encourages significant numbers of patients to want to improve glycemic control. Fear of hypoglycemia and, in women, weight gain may prove significant impediments to the clinical implementation of the results of the DCCT.

Influence of puberty on endothelial dysfunction and oxidative stress in young patients with type 1 diabetes.

OBJECTIVE: To examine the influence of puberty on endothelial dysfunction and oxidative stress in children and young people with type 1 diabetes. RESEARCH DESIGN AND METHODS: There were 51 young patients with type 1 diabetes, including 12 prepubertal children, 16 adolescents, and 23 young adults who had no clinical diabetic angiopathy, studied; none had microalbuminuria. The three groups were matched for glycemic control, and systolic and diastolic blood pressures and cholesterol levels were not significantly different between the groups. Endothelium-dependent vasodilatation was assessed by laser Doppler flowmetry after iontophoresis of acetylcholine (ACh) to the skin of the dorsum of the right foot. Soluble E-selectin, intercellular cell adhesion molecule-1 (ICAM-1), von Willebrand factor (vWF), plasma thiol (PSH), red cell glutathione (GSH), and red cell superoxide dismutase (SOD) were measured in blood samples obtained in the early morning. RESULTS: Skin vascular responses to ACh were significantly reduced in the young adult group compared with the prepubertal group (P < 0.05, analysis of variance). The levels of soluble ICAM-1 and E-selectin were significantly higher in the adolescent group compared with the young adult group: 338 (267-415) and 89 (64-106) ng/ml (median [interquartile range]), respectively, versus 255 (222-284) and 58 (54-71) ng/ml (P < 0.01 and P < 0.005, Mann-Whitney U test). SOD levels were significantly higher in the prepubertal group at 250 (238-282) micro/ml, when compared with the adolescent, 217 (171-249) micro/ml (P < 0.04), and young adult, 217 (157-244) micro/ml (P < 0.02), groups. GSH tended to be lower in the adolescent group, 1,192 (1,047-1,367) micromol/l, when compared with the young adults, 1,286 (1,145-1,525) pmol/l, and levels of vWF tended to be higher in the adolescent group, but these failed to reach statistical significance (both P = 0.09). PSH was not different between the three groups. CONCLUSIONS: These results suggest that puberty modulates endothelial function and antioxidant mechanisms in childhood diabetes, which may have implications for therapy and intervention.

ACE inhibitor use is associated with hospitalization for severe hypoglycemia in patients with diabetes. DARTS/MEMO Collaboration. Diabetes Audit and Research in Tayside, Scotland. Medicines Monitoring Unit.

OBJECTIVE: To evaluate the association between the use of ACE inhibitors and hospital admission for severe hypoglycemia and to explore the effects of potential confounding variables on this relationship. RESEARCH DESIGN AND METHODS: The association between the use of ACE inhibitors and the incidence of hypoglycemia is controversial. A recent study reported that 14% of all hospital admissions for hypoglycemia might be attributable to ACE inhibitors. We performed a nested case-control study, using a cohort of 6,649 diabetic patients taking insulin or oral antidiabetic drugs, on the Diabetes Audit and Research in Tayside, Scotland (DARTS) database. From 1 January 1993 to 30 April 1994, we identified 64 patients who had been admitted to Tayside hospitals with hypoglycemia and selected 440 control patients from the same cohort. RESULTS: Hypoglycemia was associated with the use of ACE inhibitors (odds ratio [OR] 3.2, 95% CI 1.2-8.3, P = 0.023), whereas use of beta-blockers and calcium antagonists was not associated with an increased risk of hospitalization for hypoglycemia with ORs of 0.9 (95% CI 0.3-3.3) and 1.7 (95% CI 0.2-2.1), respectively. There were significant differences between case and control patients in type of diabetes treatment, diabetes duration, place of routine diabetes care, and congestive cardiac failure. These differences did not confound the relationship between ACE inhibitors and hypoglycemia (adjusted OR 4.3, 95% CI 1.2-16.0). CONCLUSIONS: The results show that the association between ACE inhibitor therapy and hospital admission for severe hypoglycemia is not explained by these confounding factors. Although ACE inhibitors have distinct advantages over other antihypertensive drugs in diabetes, the risk of hypoglycemia should be considered.

Diabetes and lower-limb amputations in the community. A retrospective cohort study. DARTS/MEMO Collaboration. Diabetes Audit and Research in Tayside Scotland/Medicines Monitoring Unit.

OBJECTIVE: There are few U.K. data on the incidence rates of amputation in diabetic subjects compared with the nondiabetic population. RESEARCH DESIGN AND METHODS: We performed a historical cohort study of first lower-extremity amputations based in Tayside, Scotland (population 364,880) from 1 January 1993 to 31 December 1994. The Diabetes Audit and Research in Tayside Scotland (DARTS) database was used to identify a prevalence cohort of 7,079 diabetic patients on 1 January 1993. We estimated age-specific and standardized incidence rates of lower-limb amputations in the diabetic and nondiabetic cohorts. Results were compared with a previous study that evaluated lower-extremity amputations in diabetic patients in Tayside in 1980-1982. RESULTS: There were 221 subjects who underwent a total of 258 nontraumatic amputations. Of the 221 subjects, 60 (27%) patients were diabetic (93% NIDDM), and 63% were first amputations. The median duration of diabetes was 6 years (range: newly diagnosed to 41 years). Nonhealing ulceration (31%) and gangrene (29%) were the two main indications for amputation in the diabetic subjects. Of the 161 nondiabetic subjects, 140 (80%) underwent first amputations. The adjusted incidences in the diabetic and nondiabetic groups were 248 and 20 per 100,000 person-years, respectively. Tayside patients with diabetes thus had a 12.3-fold risk of an amputation compared with nondiabetic residents (95% CI 8.6-17.5). The estimated proportion of diabetic patients in the population rose from 0.81% in 1980-1982 to 1.94% in 1993-1994, whereas the absolute rate of amputation in diabetic subjects was unchanged from that in 1980-1982. CONCLUSIONS: These population-based U.K. amputation data are similar to amputation rates in the U.S. Amputation rates appear to have decreased significantly since 1980-1982. The impact of diabetes education and prevention programs that target the processes leading to amputation can now be evaluated.

Increased granulocyte aggregation in vitro in diabetes mellitus.

Having previously shown an increase in white blood cell (WBC) aggregation in groups known to have a high incidence of cardiovascular events, we compared 28 patients with diabetes mellitus and no history or clinical evidence of macrovascular disease with 28 age- and sex-matched normal controls. Patients and controls had blood taken in the morning and analysed for WBC aggregation in vitro using a whole blood technique. WBC aggregation was significantly higher in the diabetic group compared with the normal controls (mean +/- SD 31.10 +/- 10.26% vs. 25.7 +/- 9.38%; p < 0.04, Student t-test). WBC aggregation predates the appearance of clinical symptoms of macrovascular disease in diabetes.

Predictors of epilepsy surgery outcome: a meta-analysis.

The potential efficacy of temporal and extratemporal resection in patients with partial epilepsy uncontrolled by anti-epileptic drugs is undisputed. However, there are still uncertainties about which patients will benefit most. A systematic review of the available literature has been undertaken by four pairs of reviewers to assess the overall outcome of epilepsy surgery and to identify factors better correlated to seizure outcome. A Medline search for studies on epilepsy surgery published since 1984 was performed. Studies were included if they had a well-defined population and design, a sample size of at least 30 patients, an MRI performed in least 90% of cases, an expected duration of follow-up of at least one year, and a post-operative outcome measured as seizure remission. A good outcome was considered as seizure control or seizure-free status for at least one year or Engel class I. Based on the review of 47 articles meeting all the eligibility criteria, febrile seizures (odds ratio, OR, 0.48; 95% confidence interval, CI, 0.27-0.83), mesial temporal sclerosis (OR 0.47; 95% CI 0.35-0.64), tumors (OR 0.58; 95% CI 0.42-0.80), abnormal MRI (OR 0.44; 95% CI 0.29-0.65), EEG/MRI concordance (OR 0.52; 95% CI 0.32-0.83), and extensive surgical resection (OR 0.24; 95% CI 0.16-0.36) were the strongest prognostic indicators of seizure remission (positive predictors); by contrast, post-operative discharges (OR 2.41; 95% CI 1.37-4.27) and intracranial monitoring (OR 2.72; 95% CI 1.60-4.60) predicted an unfavorable prognosis (negative predictors). Firm conclusions cannot be drawn for extent of resection, EEG/MRI concordance and post-operative discharges for the heterogeneity of study results. Neuromigrational defects, CNS infections, vascular lesions, interictal spikes, and side of resection did not affect the chance of seizure remission after surgery. Despite a number of limitations, the results of the review provide some insight into the selection of the best surgical candidates in clinical practice but raise concerns on the quality of published reports, and may serve as the basis for the identification of better standards to assess surgical outcome in observational studies.

Primary malignant melanoma of meninges: atypical presentation of subacute meningitis.

Primary malignant melanoma of the meninges is described in a 5-year-old boy who presented with a 3-month history suggestive of subacute meningitis. Clinically the diagnosis of tuberculous meningitis was made and antituberculous treatment was begun. Despite this treatment, the patient's condition continued to deteriorate. Through cytologic examination of the cerebrospinal fluid malignant melanoma cells were identified, emphasizing the importance of this investigation in children with atypical meningitis. The diagnosis of malignant melanoma of the meninges was confirmed on brain biopsy.

The sensitivity of the developing tooth germ to systemic disturbances.

Deciduous tooth germs were removed from 76 babies who were either stillborn or had died in infancy. Lines in enamel or dentine were identified histologically. A chronological association was found between these lines and systemic illness in the child or pregnant mother in half the cases studied. Enamel was more sensitive to environmental factors than dentine, but causes of disturbance appeared to be non-specific. Teeth are a sensitive but non-specific index of environmental disturbance.

Lower limb muscle dysfunction may contribute to foot ulceration in diabetic patients.

OBJECTIVES: To investigate the relationship between in-shoe plantar foot pressure and the co-ordinated activity of five lower limb muscles of diabetic patients, who are known to have a higher risk of foot morbidity. DESIGN: A portable six channel electromyographic system has been designed, developed and synchronised in real time with a 16 channel piezoelectric transducer in-shoe pressure measuring device, Gaitscan. BACKGROUND: So far, no one has tried to establish a relationship between in-shoe foot pressure distribution and muscle activity of the lower limb in diabetes. The measurement of phasic muscle activity has been related to foot pressure and compared to a control group of normal volunteers. METHODS: Twenty nine diabetic subjects and 22 healthy non-diabetic volunteers have been studied by recording electromyography of lower leg muscles and in-shoe foot pressure measurements simultaneously. RESULTS: In diabetic subjects, the period of contact pressure was greater than in normal control subjects (P<0.003). The initial forefoot time to contact with the ground was shorter in diabetics when compared to controls, indicating a faster forefoot contact. Of the dorsiflexor muscles, the Anterior Tibialis, normally contracting eccentrically at heel strike, was subject to a measurable delay in the initiation of contraction, of mean difference of 180 ms (P<0.001), in diabetic subjects when compared to the normal controls. CONCLUSIONS: The late firing of Tibialis Anterior means that its normal modulating role in lowering the foot to the ground after heel strike through eccentric contraction is disturbed. The result is that the foot reaches the foot flat stage in a less ordered manner, subjecting it to high plantar pressures. RELEVANCE: The results obtained may assist in planning realignment procedures of the foot and help prevent development of ulcers on the sole of the foot in high risk diabetic subjects.

Newer anti-epileptic drugs.

During the past few years, a number of drugs have been added to the anti-epileptic arsenal. This review focusses on five of these drugs which have undergone extensive trials: Vigabatrin, Lamotrigine, Gabapentin, Felbamate and Oxcarbazepine. Some of these antiepileptic drugs appear to be helpful for treatment of catastrophic childhood epilepsies. Vigabatrin appears promising in children with infantile spasms who do not respond to ACTH or Prednisolone. Children with Lennox-Gastaut syndrome may respond to treatment with Lamotrigine or Vigabatrin. Gabapentin and vigabatrin have proved to be effective in refractory partial seizures. Oxcarbazepine, a ketoderivative of carbamazepine, is as effective as Carbamazepine but has a better safety profile. Lesser neurotoxicity and fewer drug interactions is another advantage with these drugs. However monitoring is required to determine the long term safety with their usage. These drugs have a definite role in childhood epilepsies refractory to conventional antiepileptic drugs.

Senior house officers in medicine: postal survey of training and work experience.

OBJECTIVES: To describe working conditions for senior house officers in medicine in Scotland and to relate these to the quality of clinical training they receive. DESIGN: Postal questionnaire survey. SUBJECTS: All senior house officers in medicine and related specialties in post in Scotland in October 1995 (n = 437); 252 (58%) respondents. MAIN OUTCOME MEASURES: Questionnaires covered hours, working patterns, measures of workload, an attitudes to work scale, and experience of education and training. RESULTS: In the week before the questionnaire, doctors on rotas had worked a mean of 7.4 (95% confidence interval 5.8 to 9.0) hours in excess of their contracts, compared with 3.7 (2.0 to 5.5) hours for those on partial shifts. The most common reason for this was "the needs of the patients or the service." Those on partial shifts reported significantly less continuity of care with patients than those on rotas (Mann-Whitney U test, z = -4.2, P < 0.0001) or full shifts (z = -2.08, P = 0.03). Doctors in general medicine reported significantly higher measures of workload (number of acute admissions, number of times called out, and fewest hours' uninterrupted sleep) than those in subspecialties. Consultants' clinical teaching and style of conducting a ward round were significantly related to factors extracted from the attitudes to work scale. CONCLUSIONS: The quality of senior house officers' training is detrimentally affected by a variety of conditions, especially the need for closer support and supervision, the need for greater feedback, and the lack of time that consultants have to dedicate to clinical training. Efforts should be made to improve these conditions and to reinforce a close working relationship between trainee and supervising consultant.

Frequency of blood glucose monitoring in relation to glycaemic control: observational study with diabetes database.

OBJECTIVES: To investigate patterns of self monitoring of blood glucose concentration in diabetic patients who use insulin and to determine whether frequency of self monitoring is related to glycaemic control. SETTING: Diabetes database, Tayside, Scotland. SUBJECTS: Patients resident in Tayside in 1993-5 who were using insulin and were registered on the database and diagnosed with insulin dependent (type 1) or non-insulin dependent (type 2) diabetes before 1993. MAIN OUTCOME MEASURES: Number of glucose monitoring reagent strips dispensed (reagent strip uptake) derived from records of prescriptions. First recorded haemoglobin A1c concentration in the study period, and reagent strips dispensed in the previous 6 months. RESULTS: Among 807 patients with type 1 diabetes, 128 (16%) did not redeem any prescriptions for glucose monitoring reagent strips in the 3 year study period. Only 161 (20%) redeemed prescriptions for enough reagent strips to test glucose daily. The corresponding figures for the 790 patients with type 2 diabetes who used insulin were 162 (21%; no strips) and 131 (17%; daily tests). Reagent strip uptake was influenced both by age and by deprivation category. There was a direct relation between uptake and glycaemic control for 258 patients (with recorded haemoglobin A1c concentrations) with type 1 diabetes. In a linear regression model the decrease in haemoglobin A1c concentration for every extra 180 reagent strips dispensed was 0.7%. For the 290 patients with type 2 diabetes who used insulin there was no such relation. CONCLUSIONS: Self monitoring of blood glucose concentration is associated with improved glycaemic control in patients with type 1 diabetes. Regular self monitoring in patients with type 1 and type 2 diabetes is uncommon.

Use of mobile screening unit for diabetic retinopathy in rural and urban areas.

OBJECTIVES: To compare the effectiveness of a mobile screening unit with a non-mydriatic polaroid camera in detecting diabetic retinopathy in rural and urban areas. To estimate the cost of the service. DESIGN: Prospective data collection over two years of screening for diabetic retinopathy throughout Tayside. SETTING: Tayside region, population 390,000, area 7770 km2. SUBJECTS: 961 patients in rural areas and 1225 in urban areas who presented for screening. MAIN OUTCOME MEASURES: Presence of diabetic retinopathy, need for laser photocoagulation, age, duration of diabetes, and diabetic treatment. RESULTS: Compared with diabetic patients in urban areas, those in rural areas were less likely to attend a hospital based diabetic clinic (46% (442) v 86% (1054), p < 0.001); less likely to be receiving insulin (260 (27%) v 416 (34%), p < 0.001 and also after correction for differences in age distribution); more likely to have advanced (maculopathy or proliferative retinopathy) diabetic retinopathy (13% (122) v 7% (89), p < 0.001); and more likely to require urgent laser photocoagulation for previously unrecognised retinopathy (1.4% (13) v 0.5% (6), p < 0.02). The screening programme cost 10 pounds per patient screened and 1000 pounds per patient requiring laser treatment. CONCLUSION: The mobile diabetic eye screening programme detected a greater prevalence of advanced retinopathy in diabetic patients living in rural areas. Patients in rural areas were also more likely to need urgent laser photocoagulation. Present screening procedures seem to be less effective in rural areas and rural patients may benefit more from mobile screening units than urban patients.

The diabetes audit and research in Tayside Scotland (DARTS) study: electronic record linkage to create a diabetes register. DARTS/MEMO Collaboration.

OBJECTIVES: To identify all patients with diabetes in a community using electronic record linkage of multiple data sources and to compare this method of case ascertainment with registers of diabetic patients derived from primary care. DESIGN: Electronic capture-recapture linkage of records included data on all patients attending hospital diabetes clinics, all encashed prescriptions for diabetes related drugs and monitoring equipment, all patients discharged from hospital, patients attending a mobile unit for eye screening, and results for glycated haemoglobin and plasma glucose concentrations from the regional biochemistry database. Diabetes registers from primary care were from a random sample of eight Tayside general practices. A detailed manual study of relevant records for the 35,144 patients registered with these eight general practices allowed for validation of the case ascertainment. SETTING: Tayside region of Scotland, population 391,274 on 1 January 1996. MAIN OUTCOME MEASURES: Prevalence of diabetes; population of patients identified by different data sources; sensitivity and positive predictive value of ascertainment methods. RESULTS: Electronic record linkage identified 7596 diabetic patients, giving a prevalence of known diabetes of 1.94% (0.21% insulin dependent diabetes, 1.73% non-insulin dependent): 63% of patients had attended hospital diabetes clinics, 68% had encashed diabetes related prescriptions, 72% had attended the mobile eye screening unit, and 48% had biochemical results diagnostic of diabetes. A further 701 patients had isolated hyperglycaemia (plasma glucose > 11.1 mmol/l) but were not considered diabetic by general practitioners. Validation against the eight general practices (636 diabetic patients) showed electronic linkage to have a sensitivity of 0.96 and a positive predictive value of 0.95 for ascertainment of known diabetes. General practice lists had a sensitivity of 0.91 and a positive predictive value of 0.98. CONCLUSIONS: Electronic record linkage was more sensitive than general practice registers in identifying diabetic subjects and identified an additional 0.18% of the population with a history of hyperglycaemia who might warrant screening for undiagnosed diabetes.

Hypopituitarism following coronary artery bypass surgery.

Coronary artery bypass surgery (CABS) is a common operation, which is often complicated by neurological sequelae. Disturbances of cerebral blood flow have been reported up to eight days after surgery and pituitary apoplexy has previously been reported. We report a case of hypopituitarism without pituitary apoplexy, which developed after a period of sustained arterial hypotension, during coronary artery bypass surgery.

Anaplastic carcinoma of the thyroid in a patient receiving radio-iodine therapy for amiodarone-induced thyrotoxicosis.

We describe a case of amiodarone-induced thyrotoxicosis following heart valve replacement in a patient with a multinodular goitre. He responded to medical therapy with carbimazole and potassium perchlorate. Subsequent therapy with radio-iodine was followed 30 weeks later by the development of anaplastic thyroid carcinoma. It is possible that amiodarone caused a low uptake of radio-iodine by the thyroid. It is not known whether this possible low dose exposure to ionising radiation played a part in the development of the anaplastic carcinoma.

Metabolic control in diabetic subjects following myocardial infarction: difficulties in improving blood glucose levels by intravenous insulin infusion.

Optimal metabolic control during the first twelve hours after myocardial infarction may be associated with improved survival in diabetic subjects. A comparison of an intravenous insulin infusion regimen aimed at improving blood glucose levels (n = 35), with 'routine control' (n = 34) in the post infarction period has been carried out in diabetic subjects admitted to four Coronary Care Units over a two year period. However, glycaemic control was similar in both groups (intravenous infusion regimen, mean +/- SD capillary blood glucose 10.3 +/- 2.1 mmol/l, 'routine control' glucose 10.7 +/- 3.6 mmol/l). There were no differences in the rates of arrhythmias (31% v 32%), heart failure (46% v 47%) or mortality (17% v 18%). Mortality in diabetic subjects was lower than that quoted in previous studies but was higher than in non-diabetic subjects admitted to the Coronary Care Unit during the same period. Attempts to improve glycaemic control by means of intravenous insulin infusion were unsuccessful.