bluuebunny/crossref_metadata_2025_split huggingface dataset:
Clinical manifestations and insulin resistance (IR) in polycystic ovary syndrome (PCOS) among South Asians and Caucasians: is there a difference?
Authors: Wijeyaratne Chandrika N. , Balen Adam H. , Barth Julian H. , Belchetz Paul E. 
Published: March 2003

Summaryobjective Polycystic ovary syndrome (PCOS) is more prevalent in South Asian women residing in the UK than in Caucasians. Insulin resistance (IR) is central to the pathogenesis of PCOS, while type 2 diabetes is commoner in South Asians. We aimed to determine a possible ethnic difference in the clinical and biochemical characteristics of South Asian vs. Caucasian women with PCOS.patients and design A case‐control cross‐sectional observational study of consecutive women with anovular PCOS (47 South Asians, 40 Caucasians) and their age‐matched controls (11 South Asians and 22 Caucasians).measurements Index subjects: a questionnaire‐based interview on clinical symptoms and family history; anthropometric measurements, clinical observations of the presence and degree of acne, hirsutism and acanthosis nigricans; transvaginal pelvic ultrasound; biochemical analyses of fasting blood sugar, fasting plasma insulin, fasting lipids, testosterone, and SHBG concentrations. Control group: age‐ and weight‐matched unrelated women from the same ethnic backgrounds without PCOS seeking treatment for male infertility were studied by similar methods to those used with the index subjects.results South Asians with PCOS presented at a younger age (age 26 ± 4 vs. 30·1 ± 5 years, P = 0·005). Body mass index (BMI) and waist : hip ratios were similar in the two affected cohorts. More South Asians had oligomenorrhoea commencing at a younger age. Hirsutism (Ferriman Gallwey score 18 vs. 7·5, P = 0·0001), acne, acanthosis nigricans and secondary infertility were significantly more prevalent in South Asians.The fasting glucose was similar (4·52 ± 0·08 vs. 4·62 ± 0·09 mmol/l, P = 0·25), the fasting insulin higher (89·4 ± 8·9 vs. 48·6 ± 4·8 pmol/l, P = 0·0001) and insulin sensitivity (IS) lower (0·335 ± 0·005 vs. 0·357 ± 0·002, P = 0·0001) among South Asians. Serum SHBG was significantly less in South Asians (35 ± 3·3 vs. 55 ± 9·4 nmol/l, P = 0·02), while serum testosterone was similar (2·69 ± 0·11 vs. 2·64 ± 0·13 nmol/l, P = 0·37).conclusions We conclude that South Asians with anovular PCOS seek treatment at a younger age, have more severe symptoms, and have higher fasting insulin concentrations and lower insulin sensitivity than Caucasians.
Effects of oestrogen‐only and oestrogen–progestogen replacement therapy upon circulating angiotensin I‐converting enzyme activity in postmenopausal women
Authors: Proudler Anthony J. , Cooper Alison , Whitehead Malcolm , Stevenson John C. 
Published: March 2003

Summaryobjective Levels of angiotensin I‐converting enzyme (ACE) in blood are associated with variation in cardiovascular disease risk. Serum ACE activity in women may be reduced by combined oestrogen–progestogen hormone replacement therapy (HRT). However, the relative contribution of each hormonal component to this observation is uncertain. We investigated ACE activity in two groups of healthy postmenopausal women receiving HRT regimens.design The first group received placebo or oestrogen‐only HRT randomly (oral conjugated equine oestrogens or transdermal 17β‐oestradiol). The second group was treated with oestrogen‐only HRT (oral 17β‐oestradiol) followed by sequential oestrogen‐progestogen HRT (17β‐oestradiol and dydrogesterone).measurements Assay of blood for soluble ACE activity before and whilst receiving HRT.results In the first group, oral conjugated equine oestrogens significantly reduced (P < 0·01) ACE activity by 18% on average relative to pretreatment whereas non‐significant changes of −9% and +7% were seen with transdermal 17β‐oestradiol or placebo treatment, respectively. In the second group oestrogen‐only HRT significantly reduced (P < 0·001) ACE activity by 15% on average. The reduction during both the oestrogen‐only and combined phases of sequential treatment was 12% and 19%, respectively, compared with pretreatment values (P < 0·01 and P < 0·001). ACE activity also differed significantly (P < 0·05) between the two phases of sequential treatment.conclusions Both oestrogen‐only and oestrogen‐progestogen HRT may reduce ACE activity in blood. Oestrogen and progestogen may exhibit additive effects on blood ACE activity.
The effect of growth hormone (GH) replacement therapy in adult patients with type 1 diabetes mellitus and GH deficiency
Authors: Christ E. R. , Simpson H. L. , Breen L. , P. H. Sönksen  , Russell‐Jones D. L. , Kohner E. M. 
Published: March 2003

Summaryobjectives Specific problems in patients with insulin‐dependent diabetes mellitus (IDDM) and GH deficiency are hypoglycaemic attacks, increased insulin sensitivity and loss of energy. These problems may be related to GH deficiency.patients GH replacement was initiated in five patients with type 1 diabetes mellitus and GH deficiency for 6 months [four males and one female, mean age 41·6 ± 3·8 years, mean ± standard error of the mean (SEM); body mass index (BMI) 22·3 ± 1·2 kg/m2].methods Body composition (bioimpedance), metabolic control [haemoglobin A1C (HbA1C)], insulin requirement and frequency of hypoglycaemia were measured, and quality of life was assessed using validated questionnaires. Monthly eye photographs were taken.results IGF‐I concentrations were below the age‐adjusted range at baseline and increased significantly following GH replacement therapy [analysis of variance (anova), P < 0·05]. Diabetes control as assessed by HbA1C remained stable (8·2 ± 0·2 vs. 8·0 ± 0·4), but needed a 1·75‐fold increase in insulin dose/day. Lean body mass tended to increase (P = 0·07) and body fat mass decreased significantly (P > 0·01). Number of severe hypoglycaemic (< 3 mmol/l) attacks decreased significantly (P < 0·04) and quality of life assessed by validated questionnaires improved significantly in all patients [Psychological and General Well‐Being Schedule (PGWBS), P < 0·04; Nottingham Health Profile (NHP), P < 0·05]. Monthly eye photographs revealed no changes in the retina in any patients.conclusion GH replacement therapy has a beneficial effect at the dose used. It restores body composition and decreases frequency and severity of hypoglycaemic episodes, thus improving quality of life. Long‐term trials are needed to determine the safety of GH replacement therapy in these patients.
Ethnic factors in the pathology of the uterine cervix cervical screening: a population at variance with national targets
Authors: Ezra D. , Baithun S. I. , Dodd S. M. , Brown C. L. 
Published: March 2003

Ethnic factors in the pathology of the uterine cervix cervical screening: a population at variance with national targetsIn recent years, it has been noted that the rate of detection of high‐grade uterine cervical abnormalities by screening in the Newham and Tower Hamlets districts have been much lower than the national average. Whilst the national average for the detection rate of moderate and severe dyskaryosis has been around 1.6%, the detection rate in Newham and Tower Hamlets has consistently been substantially lower, at 0.6–1.0%. This discrepancy may be explained on demographic grounds. The ethnic make up of the two districts differs from the national average. Newham has a mixed ethnic structure: Moslem (11%), Asian non‐Moslem (12%) and other groups (77%). The population of Tower Hamlets is made up of Moslem (23%), Asian non‐Moslem (11%) and other groups (66%). In both districts, the rate of detection of moderate and severe dyskaryosis in these population subgroups between 1997 and 1999 was 0.57% for Moslem women, 0.52% for Asian non‐Moslem women and 1.18% for other women.
Personal view. Is it reality or an illusion that liquid‐based cytology is better than conventional cervical smears?
Authors: HERBERT AMANDA , JOHNSON JANE 
Published: March 2003

Personal view. Is it reality or an illusion that liquid‐based cytology is better than conventional cervical smears? Liquid‐based cytology (LBC) has been heralded as the way forward for cervical screening, and as the answer to many of its problems. It is already used as a sole method of cell preparation in many private clinics in the UK. It is being used for colposcopy smears in many NHS clinics and is now being piloted for primary screening in three screening centres in England, as well as one in Scotland and one in Wales. LBC has been welcomed as a new technology because it deals with the problem of specimen adequacy at source, removing responsibility for slide preparation and fixation from the clinician or nurse. It provides uniformly well‐fixed preparations that are free of inflammatory exudate and blood, and seem easier to screen than conventional smears. There are many articles in the world literature suggesting that LBC is more accurate than conventional screening, and it is thought likely to reduce the number of false negative tests.1 The main reasons for piloting LBC in the NHS Cervical Screening Programme (NHSCSP) lie in its potential for reducing screening times and for reducing the numbers of repeats for inadequate tests. LBC is expensive in terms of equipment, capital costs, maintenance, consumables, training, technical preparation time, transportation and disposal of liquid media. Its costs could be justified if they were offset by the money saved from reduced screening time and repeat tests, but only if its accuracy in terms of sensitivity and specificity were proven to be equal to or better than conventional cytology.1 Although that is generally held to be true by the public and medical profession alike, there is very little hard evidence to support it.
Phenotypic variation in adult morphology and pupal colour within and among families of the speckled wood butterfly Pararge aegeria
Authors: Van Dyck Hans. , Matthysen Erik. , Wiklund Christer 
Published: March 2003

Abstract.1. Larvae from eggs of fifteen wild‐caught speckled wood females were reared individually under common conditions (LD 18:6 h and 17 °C) in the laboratory.2. Pupal colour (green or brown) and the following adult morphological variables that are known or assumed to be related to behavioural variation (thermoregulation, flight, crypsis) were studied: size, relative thorax mass, area of yellow patches on the dorsal forewing, size of submarginal eyespots on the dorsal hindwing, colour of the dorsal thorax, dorsal basal wing, and dorsal distal wing.3. The results of the breeding experiment indicate significant differences in adult morphological traits among families, sexes, and pupal colour types.4. All adult morphological variables (except spot size and thorax colouration) differed significantly among families, suggesting genetic variation underlying the phenotypic variation. Heritabilities for these features were intermediate (0.38) to high (> 1).5. Apart from known aspects (e.g. size), novel aspects of the sexual dimorphism were found: females had paler thoraxes than males, which relates to higher abundance of fur on the thorax and hence to thermoregulatory differences.6. Green pupae produced larger individuals with a larger relative thorax mass than brown pupae. Green pupae produced adults with a paler basal wing colour in females, but not in males. These relationships are novel and suggest a trade‐off between juvenile and adult investment.
When host choice is a problem for a generalist herbivore: experiments with the whitefly, Bemisia tabaci
Authors: Bernays E. A. 
Published: March 2003

Summary1. Experiments with adult females of the whitefly, Bemisia tabaci, demonstrated that when mixtures of host plants were present, performance was reduced relative to that on the best of the host plants when presented alone.2. Behavioural observations indicated that in the presence of a variety of plants, individuals moved more, switched between plants more frequently, and stayed feeding in one place for shorter periods of time, compared with the situation when single plant species were available.3. The data are interpreted as a constraint on attentiveness in the presence of complex, mixed‐sensory stimuli.
An experimental test of potential host range in the ant parasitoidApocephalus paraponerae
Authors: Morehead Shellee A. , Feener Donald H. 
Published: March 2003

Summary1. The work reported here tested experimentally whether specialisation inApocephalus paraponeraewas due to physiological interactions that limit the parasitoid to the host antParaponera clavata. The suitability of other ant species as hosts was tested, and behavioural traits that may promote a high degree of specificity within this host–parasitoid system are discussed.2. Data for development time, number of puparia, and adult eclosion success forA. paraponeraeovipositing in the regular hostP. clavataare provided. A new method for testing host suitability in parasitoids of ants is described. Eggs ofA. paraponeraewere transferred directly into potential ant hosts. The development time, number of puparia, and adults eclosed for the eggs transferred into other ant host species are compared with comparable data fromP. clavata.3. Seven ant species within the Ponerinae are suitable for the development ofA. paraponerae. The potential host range is greater than the actual host range ofA. paraponerae. Flies are not limited solely by host suitability of related ant species for the development of larvae. Host location and acceptance behaviours are proposed as the primary reasons for host specialisation. The large size of the primary hostP. clavata, and the ability of multiple females to raise many offspring successfully from those hosts may influence the specialisation ofA. paraponeraeonP. clavata.
Interactions between the egg and larval parasitoids of a gall‐forming midge and their impact on the host
Authors: Briggs Cheryl J. , Latto John 
Published: March 2003

Summary1. The gall‐forming midgeRhopalomyia californicawas exposed experimentally to parasitism and predation during only the egg stage, during only the larval stage, during neither stage, or during both stages.2. The combined action of natural enemies that attack during both the egg stage and the larval stage led to the lowest number of midges and total insects (midges + parasitoids) in the next generation, and the highest percentage parasitism.3. The larval parasitoid killed a large fraction of hosts without producing new parasitoid offspring, while there is some indication that the egg parasitoid on its own tended to produce the most parasitoid offspring. The contrasting implications of host mortality versus parasitoid production for biological control are discussed.4. Exposure to larval parasitoids resulted in a reduction in the number of egg parasitoid offspring produced, but exposure to the egg parasitoid did not affect the number of larval parasitoid offspring produced significantly.
Interactions of colonisation density and leaf environments on survival of Trioza eugeniae nymphs
Authors: Luft P. A. , Paine T. D. , Walker G. P. 
Published: March 2003

Summary1. Female eugenia psyllids Trioza eugeniae oviposit on the margins of expanding young Syzygium paniculatum leaves. The developing nymphs, feeding within pit‐shaped galls on the leaves, cause the leaves to become curled and deformed. The degree of leaf curling was correlated positively with densities of T. eugeniae nymphs.2. High relative humidity increased persistence of nymphs on leaves at low insect densities, but persistence did not differ between high or low relative humidity conditions when nymphal densities were high and leaves were greatly curled.3. Direct insolation increased nymphal mortality. Nymphs on the abaxial leaf surface in the direct sun had lower mortality than similarly exposed nymphs on the adaxial leaf surface.4. Field populations showed high preference for abaxial leaf surfaces and a stronger preference for shaded adaxial surfaces than for exposed adaxial surfaces.5. Adverse environmental conditions of direct insolation and low relative humidity may be mitigated by leaf curl associated with moderate populations, however competition at high nymphal density supersedes any potential benefit arising from leaf curling and has a negative effect on nymphal survival.
Do parasitoids diversify in response to host‐plant shifts by herbivorous insects?
Authors: Cronin James T. , Abrahamson Warren G. 
Published: March 2003

Summary1. For herbivorous insects, the incorporation of a novel host into the diet, and subsequent formation of distinct host associations (races), is thought to be a significant early step in the speciation process. While many studies have addressed this issue, virtually nothing is known about the evolutionary response of natural enemies to herbivore host‐race formation.2. The hypothesis that the parasitoid wasp Eurytoma gigantea (Hymenoptera: Eurytomidae) has formed host races in direct response to the host shift and subsequent host‐race formation by its host, the gallmaker Eurosta solidaginis (Diptera: Tephritidae) was tested. Emergence time, mating preference, and female oviposition preference were determined for parasitoids derived from galls of each Eurosta host race.3. Male and female E. gigantea overlap broadly in their emergence times from each Eurosta host race, suggesting that there is no phenological barrier to gene flow.4. In choice experiments, female parasitoids did not mate assortatively: females that emerged from one Eurosta host race were equally likely to mate with males from either Eurosta host race.5. Oviposition behaviour experiments revealed that female parasitoids do not prefer to oviposit on their host race of origin and that there is no overall preference for one host race, even though fitness is higher when parasitoids are reared from Eurosta galls of the Solidago gigantea host race than when reared from Eurosta galls of the Solidago altissima host race.6. These results suggest that E. gigantea has not diverged in parallel with its host in response to the herbivore host‐plant shift. Further studies are needed before the ubiquity of this diversification mechanism can be evaluated fully.
Nourishment affects colony demographics in the paper waspPolistes metricus
Authors: Hunt J. H. , Dove M. A. 
Published: March 2003

Abstract 1. Colony survivorship and numbers of nest cells, pupae, and adult females were monitored throughout the nesting season for a cohort of 78 colonies of the paper waspPolistes metricusSay. Thirty‐nine colonies received a twice‐weekly nourishment supplement of honey during pre‐emergence and early emergence phases of the colony cycle; 39 colonies were unsupplemented controls.2. Colony survivorship was unaffected by the supplemental nourishment. Loss of colonies to predation differed among three sites but was unaffected by supplementation.3. Honey‐supplemented colonies constructed more nest cells than did control colonies but this effect was not expressed until after supplementation had ceased.4. Honey‐supplemented colonies produced more pupae than did control colonies but the number of adult females at nests did not differ between supplemented and control colonies. Because honey‐supplemented colonies had more offspring but fewer of them remained as workers at the nest, honey supplementation led to a lower frequency of workers and corresponding higher frequency of reproductives than in control colonies.5. In a second year of study, colony survivorship and numbers of nest cells, pupae, and adult females were monitored from late pre‐emergence until the end of the nesting season for a cohort of 32 colonies ofPolistes metricus. In 16 colonies, trophallactic saliva was taken from final‐instar larvae on nine dates in the late pre‐emergence and early emergence periods; 16 colonies served as controls.6. Saliva‐diminished colonies had lower survivorship, fewer nest cells, fewer pupae, and fewer adult females at the nest than did control colonies.7. These results show that variation in nourishment in the early to mid phases of the colony cycle can have significant effects on the subsequent colony demographics ofPolistes metricuspaper wasps.
Facultative bacterial endosymbionts benefit pea aphids Acyrthosiphon pisum under heat stress
Authors: Montllor Clytia B. , Maxmen Amy , Purcell Alexander H. 
Published: March 2003

Abstract 1. Natural populations of pea aphids in California contain at least two facultative bacterial secondary symbionts (pea aphid secondary symbiont, PASS, or pea aphid rickettsia, PAR) in a range of frequencies throughout the state.2. Two pea aphid clones without either of these facultative associates failed to reproduce in the first 8 days after the final moult if they had been heat‐stressed for a period of about 4 h at 39 °C as 1‐day‐old larvae in the laboratory.3. Aphids infected artificially with PASS, however, were able to produce up to 48% of the normal complement of offspring produced by PASS‐positive aphids that had not been heat‐stressed. Clones infected artificially with PAR did not have the same advantage as those with PASS after heat stress.4. In aphids without PASS or PAR, heat stress reduced the number of bacteriocytes (in which the obligate primary symbiont, Buchnera, resides) to 7% of non‐heat‐stressed aphids, while aphids with only PASS retained 70% of their bacteriocytes. Bacteriocytes in aphids with PAR but not PASS were reduced to 42% of controls.5. When larvae were heat‐stressed as older instars (5 days old), a similar pattern emerged, though the effect of heat stress was less extreme. Clones containing PASS produced the most offspring, three to 14 times as many as aphids without PASS or PAR. Aphids with PAR only, or PASS and PAR together, had reduced or no advantage over aphids without facultative symbionts.6. Aphids of all clones that had been heat‐stressed as later instars gave birth to a variable number of stillborn offspring. Aphids without facultative symbionts produced the most stillborn larvae.7. Field studies showed a higher incidence of PASS in aphids collected in California in summer compared with aphids from the same sites collected 2–4 months earlier. The difference was significant in two of three widely dispersed locations.
Caste‐specific N and C isotope ratios in fungus‐growing termites with special reference to uric acid preservation and their nutritional interpretation
Authors: Tayasu I. , Hyodo F. , Abe T. 
Published: March 2003

Abstract 1. Nitrogen and carbon isotope ratios and uric acid concentrations in fungus‐growing termites (Isoptera: Termitidae: Macrotermitinae), sampled in Cameroon and Thailand, were determined in order to compare castes that are known to differ in behaviour and feeding habits.2. Nitrogen isotope ratios (δ15N) were either not significantly changed or lower in workers compared with the diet (the fungus combs), whereas carbon isotope ratios (δ13C) were higher in worker termites than in the fungus combs.3. In old workers, δ15N values were unexpectedly low and correlated negatively with whole‐body uric acid concentrations. This indicates that older workers retain uric acid, which has a low δ15N value, to conserve nitrogen within the colony and, furthermore, that older colony members may ultimately be consumed by younger conspecifics.