Reformulation of BMI and Percent Body Fat to Remove the Height Bias in 8‐year‐olds

BMI and percent body fat (%BF) are both related to height (Ht) in prepubertal children, so may misrepresent childhood adiposity, especially in tall or short children. We sought to construct replacement functions for BMI and %BF that are independent of Ht. Fat mass (FM) was measured using dual‐energy X‐ray absorptiometry, together with Ht and body mass (BM) in 746 healthy boys and girls aged 8 years (0.34 s.d.). Relationships between BM, FM, and Ht were measured and values of p and q derived such that the functions BM. Ht^?p and FM.BM^?q were unrelated to Ht. BM was not directly proportional to Ht², BMI being significantly related to Ht in both boys and girls (P < 0.001). BM was proportional to Ht³, BM. Ht^?3 being independent of Ht. Similarly, FM was not directly proportional to BM and %BF was significantly related to Ht (P < 0.001). While FM was proportional to BM², FM.BM^?1.5 was the function found to be independent of Ht. Using the 85th and 95th percentiles as the cutoffs for overweight and obesity respectively, 6.4% of the boys and 6.8% of the girls were classified differently by BMI and the Ht independent measure BM. Ht^?3. Similarly, 10.1% boys and 13.7% girls were classified differently by %BF and the Ht independent measure FM.BM^?1.5. We propose that improved diagnostic accuracy of body composition in 8‐year‐olds is provided by the BM function (BMF, BM. Ht^?3) and FM function (FMF, FM.BM^?1.5) replacing BMI and %BF, which both overestimate the adiposity of taller children and underestimate it in shorter children.     

The effect of Staphylococcus aureus carriage in late pregnancy on antibody levels to staphylococcal toxins in cord blood and breast milk

We investigated the effect of carriage of Staphylococcus aureus in the later stages of pregnancy on levels of antibody specific to the S. aureus toxins, staphylococcal enterotoxin B (SEB), staphylococcal enterotoxin C (SEC) and toxic shock syndrome toxin-1 (TSST-1), in cord blood and breast milk and also explored the relationship between levels of antibody in antenatal serum and cord blood. Nasopharyngeal swabs and stool samples were collected on two occasions, from 96 women, during the last 6 weeks of pregnancy. Samples were cultured and S. aureus isolates were identified. Antenatal and cord blood samples from the same women and their infants were analysed for IgG antibody to SEB, SEC and TSST-1 by enzyme-linked immunosorbent assay. Breast milk samples were analysed for IgA antibody to the same toxins. We found that S. aureus carriage in pregnancy is common and exposure to a toxin-producing isolate boosts immunity. Over 89% of women and infants have some protective antibody to the toxins, and antitoxin IgG levels are higher in cord blood samples compared with antenatal samples. Levels of cord blood IgG and breast milk IgA specific for the staphylococcal toxins vary. Some infants lack protection and could be at risk of toxin-induced disease.     

A species of Schellackia (Apicomplexa: Lankesterellidae) parasitising east and southeast Asian lizards

Schellackia orientalis n. sp. parasitises the Japanese lizard Takydromus tachydromoides on Honshu and Takydromus sexlineatus in Thailand. Merogony and gamogony occur in the epithelium of the small intestine, and octonucleate oöcysts form in the lamina propria. In infections induced by inoculation of infected blood, sporozoites appeared in blood cells 17–56 days post-inoculation, initially in any type of white blood cell but most commonly in macrophages and monocytes. Both erythroid and leucocytic cells were parasitised after five days. This haemococcidian is another component of the symbiotic complex found in Takydromus species of eastern and southeastern Asia.     

Two new trypanosome species from East African cordylid lizards

Two species ofTrypanosoma are described from East African cordylid lizards.Trypanosoma zonuri n. sp. was found in a disjunct population ofCordylus cordylus on the western slope of Ngorongoro Crater in Arusha Region, northern Tanzania. It has the appearance of a delicate and fragile trypanosome, slightly over half the size of the robust, leaf-likeT. cordyli n. sp. that parasitisesCordylus t. tropidosternum in the Rondo Forest, Lindi Region, southern Tanzania. These are the first trypanosome species recorded from the saurian family Cordylidae in East Africa.     

SALMFamide2 and serotonin immunoreactivity in the nervous system of some acoels (Xenacoelomorpha)

Acoel worms are simple, often microscopic animals with direct development, a multiciliated epidermis, a statocyst, and a digestive parenchyma instead of a gut epithelium. Morphological characters of acoels have been notoriously difficult to interpret due to their relative scarcity. The nervous system is one of the most accessible and widely used comparative features in acoels, which have a so‐called commissural brain without capsule and several major longitudinal neurite bundles. Here, we use the selective binding properties of a neuropeptide antibody raised in echinoderms (SALMFamide2, or S2), and a commercial antibody against serotonin (5‐HT) to provide additional characters of the acoel nervous system. We have prepared whole‐mount immunofluorescent stainings of three acoel species: Symsagittifera psammophila (Convolutidae), Aphanostoma pisae, and the model acoel Isodiametra pulchra (both Isodiametridae). The commissural brain of all three acoels is delimited anteriorly by the ventral anterior commissure, and posteriorly by the dorsal posterior commissure. The dorsal anterior commissure is situated between the ventral anterior commissure and the dorsal posterior commissure, while the statocyst lies between dorsal anterior and dorsal posterior commissure. S2 and serotonin do not co‐localise, and they follow similar patterns to each other within an animal. In particular, S2, but not 5‐HT, stains a prominent commissure posterior to the main (dorsal) posterior commissure. We have for the first time observed a closed posterior loop of the main neurite bundles in S. psammophila for both the amidergic and the serotonergic nervous system. In I. pulchra, the lateral neurite bundles also form a posterior loop in our serotonergic nervous system stainings.     

Mechanisms and evolution of inter-male spacing in the painted reedfrog (Hyperolius marmoratus)

Inter-male spacing in Hyperolius marmoratus choruses was studied at a natural breeding site. Calling males maintain minimum inter-individual distances of 50 cm. Agonistic behaviour and encounter calling appear to help maintain spacing. Males wrestle with one another by grappsling with their forelimbs and attempt to displace each other with powerful kicks from the hindlimbs. Acoustic playback experiments demonstrated that inter-male spacing was vocally mediated and that signal intensity provides cues regarding the proximity of near neighbours. When given a choice of three identical calls, differing only in their spatial separation, females displayed selective phonotaxis to the most widely spaced call. Such discrimination by females must generate strong selective pressure for males to maintain adquate spacing if they are to attract mates successfully.     

Effect of time post mortem on the concentration of endotoxin in rat organs: implications for sudden infant death syndrome (SIDS)

The aim of the study was to test the following hypotheses: (i) that endotoxin injected 40 min prior to death can be detected in rat organs post mortem and (ii) that endotoxin levels do not change with increasing time post mortem. Rats were injected with or without endotoxin in buffered saline, 40 min prior to being killed. Endotoxin levels in rat organs were assessed using a Limulus amoebocyte assay. The effect of storage time post mortem was assessed by following various storage regimes at 25 degrees C and 8 degrees C. Significant differences (P = < 0.001) in endotoxin levels of all samples tested were found between rats injected with and without endotoxin. A significant increase in detectable endotoxin was observed between 0 h and 6 h post mortem in rats injected with or without endotoxin. No difference in detectable endotoxin levels in the kidney, liver and spleen was observed from 30 h to 102 h post mortem in rats injected with or without endotoxin. In rats injected with endotoxin, detectable endotoxin levels in the heart were raised between 0 h and 6 h, 6 h and 54 h, and 30 h and 78 h. Endotoxin injected into rats 40 min prior to death can be detected post mortem. For rats injected with saline or endotoxin prior to death levels in the kidney, liver and spleen were not affected by storage at 8 degrees C for 30-102 h, after initial storage at room temperature for 6 h. Levels of endotoxin detected in the hearts of rats injected with saline were not affected by storage up to 102 h. In rats injected with endotoxin prior to death, detectable levels in the heart were significantly affected by increasing time in storage.     

Sleeping position in infants over 6 months of age: implications for theories of sudden infant death syndrome

The aim of this study was to determine the prevalence of prone and supine sleeping in infants aged 0-12 months and relate this to changes in the number of cases of sudden infant death syndrome (SIDS) since 1985. Seventy-two babies, 38 male and 34 female, were followed for the first 18 months of life with regular home visits and sleeping position was recorded. In addition, data on the number of cases of SIDS in England and Wales between 1985 and 1995 were analysed. All babies slept supine for the first 5 months of life, but once they could turn over in their cots (mean age 7.34 months, range 5-11 months) the majority slept prone. By 11 months of age, 53 regularly slept prone (73%), 95% CI +/- 19.8%), while 11 slept supine, three adopted the side position and five varied from night to night. The number of cases of SIDS in infants aged 7-11 months has fallen significantly (P<0.0001) in a period in which the prevalence of prone sleeping, in that age group, has not changed. The most plausible explanation for this paradoxical result is that supine sleeping in the first 5 months of life reduces the absolute risk of SIDS in the second 6 months of life even though most babies are then sleeping prone. It is suggested that reduced exposure to nasopharyngeal bacterial superantigens in babies sleeping prone might explain this effect.