Cultural selection and genetic diversity in matrilineal whales.

Low diversities of mitochondrial DNA (mtDNA) have recently been found in four species of matrilineal whale. No satisfactory explanation for this apparent anomaly has been previously suggested. Culture seems to be an important part of the lives of matrilineal whales. The selection of matrilineally transmitted cultural traits, upon which neutral mtDNA alleles "hitchhike," has the potential to strongly reduce genetic variation. Thus, in contrast to other nonhuman mammals, culture may be an important evolutionary force for the matrilineal whales.

Uptake and continued metabolic activity of azotobacter within fungal protoplasts.

Uptake of vegetative cells of Azotobacter vinelandii into protoplasts of the mycorrhizal fungus Rhizopogon sp. can be induced by treatment with polyethylene glycol (molecular weight, 6000). An L-form of the bacteria has been selected for within the differentiated fungal mycelium which is capable of acetylene reduction and nitrogen fixation, as confirmed by nitrogen-15 assays; this allows the fungus to grow on media lacking any combined nitrogen. The fungus grows and reduces acetylene on concentrations of antibiotics that prevent the growth and activity of free-living Azotobacter. Electron microscopy has revealed modified mitochondrial forms or included bacterial L-forms surrounded by an extra fungal membrane within the hyphae of the modified strains. Poly-beta-hydroxybutyric acid, a storage product of Azotobacter cysts, has also been identified in the hyphae. This would appear to be the first report of the transgenosis for acetylene reduction activity and nitrogen fixation into a eukaryote cell.

A randomised control trial of oral health education provided by a health visitor to parents of pre-school children.

OBJECTIVES: To determine the effect of oral health education carried out by a specially trained health visitor on the dental health of young children. DESIGN AND SETTING: Children, who were recruited during their 8-month distraction-hearing test, were randomly allocated to intervention and control groups. A home visit by the health visitor was arranged to parents in the intervention group who were given dental health advice. A second home visit, when the child was about 20 months old, focused on a completed diet record sheet and discussions about what and when the child was eating and drinking. Children in the intervention group received a toothbrush and toothpaste containing 440 ppm fluoride at both visits while those in the control group received the level of care usually provided by health visitors in the area. The children's teeth were examined when they were three years old and two years later as part of a census survey of 5-year-old children in the area. MAIN OUTCOME MEASURES: The numbers of decayed, missing and filled tooth surfaces. RESULTS: 251 children were recruited to the control group and 250 to the intervention group. At age three, they were examined; the mean dmfs scores were 2.19 (95% Confidence Interval: 1.41-2.97) in the control group (n = 171) and 2.03 (CI: 1.39-2.67) in the intervention group (n = 181). During the census survey 276 of the children in the study were examined at school. At this age the mean dmfs scores were 4.84 (CI: 3.39-6.29) in the control group (n = 129) and 3.99 (CI: 2.54-5.04) in the intervention group (n = 147). However, the mean dmfs of the remaining 2,253 children who were examined was 5.94 (CI: 5.55-6.33). CONCLUSIONS: No statistically significant differences in mean dmfs scores were found between the control and intervention groups of children, although, as the children grew older, the gap between them widened. However, the mean dmfs score of other 5-year-olds in the area was significantly worse than that of children in the intervention group. Asking the control parents to take part in the study and examining their children at three years may have had an effect on their dental health status and have made it more difficult to detect any differences achieved by the programme.

Longitudinal Study of Caries Development from Childhood to Adolescence.

The World Health Organization (WHO) stated that globally, dental caries is the most important oral condition. To develop effective prevention strategies requires an understanding of how this condition develops and progresses over time, but there are few longitudinal studies of caries onset and progression in children. The aim of the study was to establish the pattern of caries development from childhood into adolescence and to explore the role of potential risk factors (age, sex, ethnicity, and social deprivation). Of particular interest was the disease trajectory of dentinal caries in the permanent teeth in groups defined by the presence or absence of dentinal caries in the primary teeth. Intraoral examinations to assess oral health were performed at 4 time points by trained and calibrated dentist examiners using a standardized, national diagnostic protocol. Clinical data were available from 6,651 children. Mean caries prevalence (% D3MFT > 0) was 16.7% at the first clinical examination (ages 7-9 y), increasing to 31.0%, 42.2%, and 45.7% at subsequent examinations. A population-averaged model (generalized estimating equations) was used to model the longitudinal data. Estimated mean values indicated a rising D3MFT count as pupils aged (consistent with new teeth emerging), which was significantly higher (4.49 times; 95% confidence interval, 3.90-5.16) in those pupils with caries in their primary dentition than in those without. This study is one of the few large longitudinal studies to report the development of dental caries from childhood into adolescence. Children who developed caries in their primary dentition had a very different caries trajectory in their permanent dentition compared to their caries-free contemporaries. In light of these results, caries-free and caries-active children should be considered as 2 separate populations, suggesting different prevention strategies are required to address their different risk profiles.

Vocal clans in sperm whales (Physeter macrocephalus).

Cultural transmission may be a significant source of variation in the behaviour of whales and dolphins, especially as regards their vocal signals. We studied variation in the vocal output of 'codas' by sperm whale social groups. Codas are patterns of clicks used by female sperm whales in social circumstances. The coda repertoires of all known social units (n = 18, each consisting of about 11 females and immatures with long-term relationships) and 61 out of 64 groups (about two social units moving together for periods of days) that were recorded in the South Pacific and Caribbean between 1985 and 2000 can be reliably allocated into six acoustic 'clans', five in the Pacific and one in the Caribbean. Clans have ranges that span thousands of kilometres, are sympatric, contain many thousands of whales and most probably result from cultural transmission of vocal patterns. Units seem to form groups preferentially with other units of their own clan. We suggest that this is a rare example of sympatric cultural variation on an oceanic scale. Culture may thus be a more important determinant of sperm whale population structure than genes or geography, a finding that has major implications for our understanding of the species' behavioural and population biology.

The presentation of newly-diagnosed diabetic patients in Uganda.

We assessed the clinical characteristics of newly-diagnosed diabetic patients presenting to the Mulago Hospital Diabetic Clinic for the first time between 1 January 1993 and 10 August 1994. There were 252 patients: 117 men and 135 women. Mean age at onset of diabetes was 45 years (range 2-87 years) and peak incidence was at 40-49 years. Body mass index (BMI) was available in only 71 patients, of whom 53.5% (33.8% female, 19.7% male) were overweight (BMI > 25 in women, in > 27 men) and 11.3% (8.5% men, 2.8% women) were underweight (BMI < 20). Obesity was more marked in young women. Almost all patients presented with the classical symptoms of diabetes, and the majority were severely hyperglycaemic. A family history of diabetes was identified in 16%. Concurrent illnesses at diagnosis of diabetes were unusual. Sepsis was commonest (11.9%), followed by malaria (7.8%), tuberculosis (1.2%), AIDS (1.2%) and pancreatitis (0.8%). Peripheral neuropathy was present in 46.4% of patients, hypertension (BP > 150/100) in 27.3%, impotence in 22.2% of the men, proteinuria in 17.1%, ischaemic heart disease in 4.8%, foot ulcers in 4.0% and cataracts in 3.2%. Insulin was the most commonly prescribed treatment (52.8%); 31% of patients received oral hypoglycaemic agents, only 15.1% were managed on diet only, and 1.2% opted for herbal medicine.

Blood pressure responses to phenylephrine infusions in subjects with Cushing's syndrome.

The pathogenesis of the hypertension associated with Cushing's syndrome is not completely understood. Sensitivity to pressor agents may play a role. We have investigated this possibility by measuring blood pressure (BP) during incrementally increasing infusions of the alpha-adrenergic agonist phenylephrine. Ten subjects (8 women: 2 men), aged 40 +/- 5 years (mean +/- s.e.m.) with Cushing's syndrome were studied. All had raised BP but none had received any anti-hypertensive treatment for at least 16 days before study. Ten age- (40 +/- 5 years) and sex-matched control subjects were also studied. At 13.30, 30 min after a light meal, subjects had an intravenous cannula inserted, ECG leads and a sphygomanometer cuff attached, and then rested supine in a quiet room for 30 min. Phenylephrine was then infused incrementally at intervals of 5 min. The doses used were 0.3, 0.6, 0.9, 1.35 and 2 micrograms/kg/min. Basal mean blood pressure (MAP) was 108 +/- 2 mm Hg (mean +/- s.e.m.) in patients and 74 +/- 3 mm Hg in controls (P < 0.05) and pulse rate was 75 +/- 5 and 68 +/- 3 beats/min (NS), respectively). MAP increased and pulse rate decreased linearly with time. The rate of rise of MAP was 1.7 +/- 0.4 mm Hg/min in subjects and 1.1 +/- 0.2 mm Hg/min in controls (NS). The rate of decrease of pulse was significantly more rapid in Cushing's subjects than in controls (1.4 +/- 0.2; 0.6 +/- 0.1 beats/min2; P < 0.05). The lack of any increased BP response to alpha-adrenergic stimulation suggests that altered sensitivity is not a major cause of the increased BP seen in patients with Cushing's syndrome.

Medium and long-term complications of endoscopic sphincterotomy for choledocholithiasis.

The medium and long-term complications of endoscopic sphincterotomy for choledocholithiasis were examined in patients referred to an endoscopy centre in an area general hospital. One hundred and thirty-eight patients were reviewed between 6 months and 7 years after successful endoscopic sphincterotomy for choledocholithiasis. The procedure was carried out post-cholecystectomy in 69 (50%) and with the gallbladder in situ in 69 patients. Four post-cholecystectomy patients and 10 with intact gallbladders had died by the time of review. A postal questionnaire was completed by the remaining 124 patients. Sixty-two post-cholecystectomy and 49 with gallbladders still intact remained symptom-free at follow-up. Eight patients had had the sphincterotomy as a preliminary to cholecystectomy. There were persistent symptoms in three post-cholecystectomy and two with intact gallbladders. Medium to long-term complications are uncommon after endoscopic sphincterotomy for choledocholithiasis.

The Northern Ireland experience of growth hormone therapy for short stature.

In 1967 the first patient in Northern Ireland commenced growth hormone treatment for short stature. By the end of December 1988 a total of 89 patients had been treated. Thirty-two had idiopathic isolated growth hormone deficiency, an incidence of 1.5 new cases per year (in a population of 1.5 million with approximately 30,000 births per year). Since 1967 the mean age at starting treatment has fallen from 18 years to 10 years and the height standard deviation score has fallen from -4.7 +/- 0.6 to -3.4 +/- 0.3. The group with classical growth hormone deficiency (maximum GH less than 7 mU/l during insulin-induced hypoglycaemia) had a greater increase in height velocity over the first year of treatment, 3.8 +/- 0.4 cm, than those with a partial deficiency (maximum growth hormone 7.1 - 20 mU/l), 1.9 +/- 0.4 cm. All pre-pubertal children responded with a rise in the height velocity standard deviation score from -1.8 +/- 0.3 before treatment to +3.5 +/- 0.4 over the first year of treatment. 58% of the adult males and 25% of adult females have attained an adult height within the normal range (3rd centile or above). There have been three deaths, one each from Fanconi's aplastic anaemia which predated growth hormone treatment, an accidental fire injury and a relapsing craniopharyngioma. There have been no deaths from Creutzfeldt-Jakob disease. Growth hormone therapy is safe and effective, but continues to be commenced late in terms both of age and height standard deviation score.

A cluster-randomized controlled trial: fluoride varnish in school children.

We conducted a school-based parallel cluster randomized controlled trial with 36-month follow-up of children aged 7 to 8 years. Primary schools were randomly assigned to 2 groups: 3 applications of fluoride varnish (22,600 ppm) each year or no intervention. The primary outcome was DFS increment in the first permanent molars, with the hypothesis that 9 applications of varnish over 3 years would result in a lower increment in the test group. Follow-up measurements were recorded by examiners blind to the allocation. Ninety-five schools were randomized to the test and 95 to the reference groups; 1473 (test) and 1494 (reference) children participated in the trial. An intention-to-treat analysis was carried out with random effects models. The DFS increment was 0.65 (SD 2.15) in the test and 0.67 (SD 2.10) in the reference groups, respectively. There was no statistically significant difference between the groups. We were unable to demonstrate an effect for fluoride varnish when it was used as a public health intervention to prevent caries in the first permanent molar teeth (Inter-national Standard Randomized Controlled Trial Registration: ISRCTN: #72589426).

Culture in whales and dolphins.

Studies of animal culture have not normally included a consideration of cetaceans. However, with several long-term field studies now maturing, this situation should change. Animal culture is generally studied by either investigating transmission mechanisms experimentally, or observing patterns of behavioural variation in wild populations that cannot be explained by either genetic or environmental factors. Taking this second, ethnographic, approach, there is good evidence for cultural transmission in several cetacean species. However, only the bottlenose dolphin (Tursiops) has been shown experimentally to possess sophisticated social learning abilities, including vocal and motor imitation; other species have not been studied. There is observational evidence for imitation and teaching in killer whales. For cetaceans and other large, wide-ranging animals, excessive reliance on experimental data for evidence of culture is not productive; we favour the ethnographic approach. The complex and stable vocal and behavioural cultures of sympatric groups of killer whales (Orcinus orca) appear to have no parallel outside humans, and represent an independent evolution of cultural faculties. The wide movements of cetaceans, the greater variability of the marine environment over large temporal scales relative to that on land, and the stable matrilineal social groups of some species are potentially important factors in the evolution of cetacean culture. There have been suggestions of gene-culture coevolution in cetaceans, and culture may be implicated in some unusual behavioural and life-history traits of whales and dolphins. We hope to stimulate discussion and research on culture in these animals.

Physiological growth hormone secretion in adult growth hormone deficiency: comparison with normal controls.

A comparison was made between the pulsatile pattern of growth hormone secretion in 14 growth hormone deficient adults (serum growth hormone less than 7 mU/I following insulin-stimulated hypoglycaemia) and 14 age and sex matched controls. The 24-h secretory profile was generated by 2-hourly sampling from 0800 to 2200 h, and 30-min sampling from 2200 to 0600 h. Plasma GH in each sample was measured using a double antibody radioimmunoassay. The profiles were analysed using a computer program (Pulsar). Sleep-electroencephalography was recorded in all subjects. The total amount of GH secreted in a 24-h period (area under the curve over baseline) was significantly less in the growth hormone deficient group (P less than 0.002). The pulse frequency, amplitude, height and percentage GH secreted in peaks were also significantly less in the growth hormone deficient group (P less than 0.002 respectively). We conclude that adults deficient in GH, as defined by conventional pharmacological stimuli, are in addition physiologically deficient of pulsatile GH secretion.

Social evolution in toothed whales.

Two contrasting results emerge from comparisons of the social systems of several odontocetes with terrestrial mammals. Researchers have identified remarkable convergence in prominent features of the social systems of odontocetes such as the sperm whale and bottlenose dolphin with a few well-known terrestrial mammals such as the elephant and chimpanzee. In contrast, studies on killer whales and Baird's beaked whale reveal novel social solutions to aquatic living. The combination of convergent and novel features in odontocete social systems promise a more general understanding of the ecological determinants of social systems in both terrestrial and aquatic habitats, as well as the relationship between relative brain size and social evolution.

Patterns of kinship in groups of free-living sperm whales (Physeter macrocephalus) revealed by multiple molecular genetic analyses.

Mature female sperm whales (Physeter macrocephalus) live in socially cohesive groups of 10-30, which include immature animals of both sexes, and within which there is communal care of the young. We examined kinship in such groups using analyses of microsatellite DNA, mitochondrial DNA sequence, and sex-linked markers on samples of sloughed skin collected noninvasively from animals in three groups off the coast of Ecuador. Social groups were defined through photographic identification of individuals. Each group contained about 26 members, mostly female (79%). Relatedness was greater within groups, as compared to between groups. Particular mitochondrial haplotypes were characteristic of groups, but all groups contained more than one haplotype. The data are generally consistent with each group being comprised of several matrillines from which males disperse at about the age of 6 years. There are indications of paternal relatedness among grouped individuals with different mitochondrial haplotypes, suggesting long-term associations between different matrilines.

Growth hormone treatment in adults with growth hormone deficiency: effect on muscle fibre size and proportions.

The effect of a 6-month period of substitution therapy with recombinant human growth hormone (rhGH) on muscle fibre size and muscle fibre type proportions has been investigated in a group of 13 adults with growth hormone deficiency. All had a peak growth hormone (GH) response to insulin-induced hypoglycaemia of less than 7 mU/l. There was no statistically significant change in the lesser fibre diameter or fibre proportions of either type 1 or type 2 muscle fibres in the rhGH group, as compared with placebo.

The effect of cyproheptadine and/or bromocriptine on plasma ACTH levels in patients cured of Cushing's disease by bilateral adrenalectomy.

Cyproheptadine and bromocriptine have been reported to be therapeutic in suppressing ACTH levels in Cushing's disease and Nelson's syndrome. However, there have been only scattered reports of their effect in suppressing raised ACTH levels found in patients cured of Cushing's disease by bilateral adrenalectomy. In order to assess whether these agents could prove beneficial in such patients we studied 12 patients previously treated with bilateral adrenalectomy alone for Cushing's disease before and after 3 weeks of cyproheptadine and/or bromocroptine therapy. All had raised plasma ACTH values but no patient had evidence of a pituitary macroadenoma. Plasma ACTH and cortisol were sampled 2-hourly for 24 h. Neither drug regime led to any change in plasma levels of cortisol for 24 h after a 20 mg dose of oral hydrocortisone. Plasma ACTH (mean +/- SEM) showed a small but significant overall reduction (523 +/- 45 vs 392 +/- 34 ng/l; P less than 0.05) while on bromocriptine alone (5 mg given at 0800 and 1800 h, n = 5). When each time point was analysed individually this reduction was significant at only five out of 13 time points. At 0400 h plasma ACTH (mean +/- SEM) was 758.4 +/- 298.1 vs 380.2 +/- 166.6; 0600 h, 795 +/- 288.7 vs 477.8 +/- 191.7; 1200 h, 266.8 +/- 106.2 vs 187.0 +/- 80.3; 1400 h, 470.0 +/- 239.0 vs 302.0 +/- 135.9; 1600 h, 548.6 +/- 262.5 vs 394.2 +/- 178.5 ng/l (P less than 0.05). There was no significant change in plasma ACTH during treatment with the combination of bromocriptine and cyproheptadine.(ABSTRACT TRUNCATED AT 250 WORDS)

The growth hormone response to growth hormone releasing hormone in patients previously treated with bilateral adrenalectomy alone for Cushing's disease.

Human growth hormone releasing hormone (GHRH) fails to stimulate human growth hormone (GH) in hypercortisolism. In order to study whether the responsiveness to GHRH stimulation returns after cure of the hypercortisolism, the GH response to GHRH was examined in 8 patients at least 5 yr after they had undergone bilateral adrenalectomy as their sole treatment for Cushing's disease. None had current evidence of a pituitary macroadenoma. A group of 8 healthy subjects matched for age and sex formed the control group. All patients and subjects received an iv injection of GHRH 1 microgram/kg, after an overnight fast, blood samples were taken before and at 15, 30, 45, 60, 90 and 120 min. There was no statistical difference between the peak GH or area under curve (AUC) response (median, range) in the two groups studied (adrenalectomized peak GH 9.2 (4.6-32.0) vs 16.5 (7.5-63) mU/l, adrenalectomized AUC response 647.5 (344.2-1489.5) vs 1103.5 (339.7-5188.5) mU/l. Patients with Cushing's disease once cured of hypercortisolism, have a GH response to GHRH.

Growth hormone treatment of adults with growth hormone deficiency: results of a 13-month placebo controlled cross-over study.

OBJECTIVE: We aimed to study the effect of biosynthetic growth hormone (GH) replacement in growth hormone deficient adults. DESIGN: We performed a double-blind placebo-controlled cross-over study of 6 months biosynthetic GH, replacement and 6 months placebo separated by a 1-month's washout period. PATIENTS: Fourteen growth hormone deficient adults were studied. MEASUREMENTS: We measured total body weight, percentage fat mass, lean body mass, muscle volume, exercise capacity, maximum oxygen consumption, muscle strength, bone mineral content, a number of biochemical parameters, IGF-I, GH antibodies and psychological well-being. RESULTS: Total body weight remained unchanged, but lean body mass increased (before GH mean +/- SEM 49.8 +/- 5.5, after 53.4 +/- 5.6 kg; placebo before 51.2 +/- 5.4, after 50.4 +/- 5.1 kg; P less than 0.05 and fat mass decreased (before GH 21.5 +/- 4.1, after 19.3 +/- 4.3; placebo before 19.3 +/- 4.0, after 22.5 +/- 4.5 kg; P less than 0.05). Thigh muscle volume increased: (before GH 94.1 +/- 7.7, after 99.5 +/- 8.4 ml; placebo before 99.3 +/- 8.6, after 95.4 +/- 7.8 ml/0.8 mm computerized tomographic slice; P less than 0.05). Exercise capacity increased (before GH 174 +/- 15, after 199 +/- 18.9 watts; placebo before 162.5 +/- 2.3, after 154 +/- 19.8 watts; P less than 0.05), as did maximum oxygen consumption (before GH 1.93 +/- 0.2, after 2.17 +/- 0.2 l/m; placebo before 1.92 +/- 0.3, after 1.98 +/- 0.2 l/m; P less than 0.05). There was no change in quadriceps muscle strength. Alkaline phosphatase increased (before GH 87.5 (32-158), after 106.0 (49-179) U/I, placebo 99.5 (50-145), after 72.0 (40-111) U/I; P less than 0.05) without a change in the spinal bone density. IGF-I increased (before GH 62 (36-97), after 216 (62-362) micrograms/l; placebo before 59 (52-112), after 60.5 (38-94) micrograms/l; P less than 0.05). Carbohydrate tolerance remained unchanged as did fasting lipids, serum sodium, potassium, urea, calcium, phosphate and liver transaminases. Psychological well-being remained unchanged. No growth hormone antibodies were detected before or after GH treatment. CONCLUSIONS: GH alters the body composition of growth hormone deficient adults and leads to improved exercise capacity; alkaline phosphatase activity increases but without a change in spinal bone density, and carbohydrate tolerance remains unaltered.