Rapid radiation of ant parasitic butterflies during the Miocene aridification of Africa

Africa has undergone a progressive aridification during the last 20 My that presumably impacted organisms and fostered the evolution of life history adaptations. We test the hypothesis that shift to living in ant nests and feeding on ant brood by larvae of phyto-predaceous Lepidochrysops butterflies was an adaptive response to the aridification of Africa that facilitated the subsequent radiation of butterflies in this genus. Using anchored hybrid enrichment we constructed a time-calibrated phylogeny for Lepidochrysops and its closest, non-parasitic relatives in the Euchrysops section (Poloyommatini). We estimated ancestral areas across the phylogeny with process-based biogeographical models and diversification rates relying on time-variable and clade-heterogeneous birth-death models. The Euchrysops section originated with the emerging Miombo woodlands about 22 million years ago (Mya) and spread to drier biomes as they became available in the late Miocene. The diversification of the non-parasitic lineages decreased as aridification intensified around 10 Mya, culminating in diversity decline. In contrast, the diversification of the phyto-predaceous Lepidochrysops lineage proceeded rapidly from about 6.5 Mya when this unusual life history likely first evolved. The Miombo woodlands were the cradle for diversification of the Euchrysops section, and our findings are consistent with the hypothesis that aridification during the Miocene selected for a phyto-predaceous life history in species of Lepidochrysops, with ant nests likely providing caterpillars a safe refuge from fire and a source of food when vegetation was scarce.

Avian exposure and bronchogenic carcinoma

OBJECTIVE

To investigate the association between bird keeping and risk of lung cancer.

DESIGN

Case-control study asking detailed questions on exposure to domestic birds and other pets, smoking, and various demographic and potentially confounding variables.

SETTING

District general hospital; current admissions interviewed in hospital or recent admissions interviewed at home.

PATIENTS

143 patients with lung cancer, 143 controls with heart disease, and 143 controls with orthopaedic conditions individually matched for age, sex, date of admission, and current or past admission.

MAIN OUTCOME MEASURES

Odds ratios for lung cancer in relation to various aspects of bird keeping, after adjustment for smoking and other relevant confounding variables.

RESULTS

Risk of lung cancer was not significantly associated with household exposure to pet birds at any time or at various specific periods in life, or to keeping large numbers of birds. For specific types of birds no association was seen for living in households with budgerigars or canaries but risk was significantly associated with keeping pigeons (odds ratio 3.53, 95% confidence interval 1.56 to 7.98). This remained significant after regression analysis to account for confounding variables (3.9, 1.2 to 12.62) in both sexes and all age groups.

CONCLUSION

Bird keeping may confer some risk of lung cancer but the relation is not as strong as previously reported.

Coxsackie B infection in a general medical unit

From January 1979 until December 1980, neutralizing antibody titres to Coxsackie B1-6 viruses were measured in sera from 220 patients presenting to a general medical unit, the majority of whom had chest pain. No four-fold or greater rises in antibody titre were detected in these hospital patients. However, 49 per cent had titres of greater than or equal to 256 to one or more Coxsackie B virus types compared with 10 per cent of the 950 persons studied during a 'normal population' survey in the West of Scotland. When a more rigorous threshold was adopted, titres greater than or equal to 512 were found in 33 per cent and 4 per cent respectively. We conclude that Coxsackie B infections are not uncommon in the practice of a general medical unit and that they may account for more cases of both acute and subacute left chest pain than is usually realised.

Failure of the hydrogen breath test to detect pulmonary sugar malabsorption

Five patients with sucrase-isomaltase deficiency, and one patient with primary glucose-galactose malabsorption had no increases in breath hydrogen excretion after oral sucrose or glucose. Anaerobic incubation with sugars of stool suspensions from 5 patients with primary sugar malabsorption produced by trace of hydrogen (17 microliter) in only one, while those from 13 or 14 controls produced a mean hydrogen volume of 640 microliter under similar conditions. Altered bacterial metabolism is a probable explanation. Breath hydrogen excretion did increase appreciably in 2 of these patients after oral lactulose showing that hydrogen excretion may vary according to the substrate. Therefore, observation of breath hydrogen excretion after lactulose is not recommended as a means of predicting false-negative breath tests with other sugars. The hydrogen breath test is not a reliable mean of diagnosing primary sugar malabsorption in children.

Lactose malabsorption during gastroenteritis, assessed by the hydrogen breath test

Thirty-eight infants and young children with gastroenteritis were investigated for lactose malabsorption. Each of them was given an oral lactose load of either 0.5 g/kg or 2 g/kg after which breath hydrogen excretion was measured, and each was observed to see if he had clinical symptoms of lactose intolerance. Only one patient, given 2 g/kg lactose, had clinical intolerance. His breath hydrogen excretion however was negative. Three of 18 patients given 0.5 g/kg lactose had positive breath hydrogen tests. None of these was symptomatic. Lactose intolerance in gastroenteritis was rare in our study, and the hydrogen breath test was not an appropriate technique for detecting it.

Collection of breath for hydrogen estimation

The breath hydrogen test is used in gastroenterological investigation, particularly for sugar malabsorption, transit time, and the investigation of small-bowel bacterial overgrowth. Several methods of collecting breath from infants and children for hydrogen assay have been described. Four such techniques (postnasal catheter, nasal prong, Rahn-Otis end-tidal sampler, and modification of a party toy--the 'Wiggins's blowout') were compared with breath collection using the Haldane-Priestley tube. Multiple sampling of breath from 3 adults was performed after initial lactulose loads to increase breath hydrogen excretion. The variability between the different assay techniques was less than the inherent variability of repeated breath hydrogen assays using the same technique. Each technique is therefore adequate for breath hydrogen collection; we recommend the Rahn-Otis end-tidal sampler in young infants and children, and the Haldane-Priestley tube in older children, since these were most acceptable to the children and their parents.

Gastroenteritis in Alice Springs

One hundred and thirty admissions to Alice Springs Hospital of full-blood Aboriginal children with acute gastroenteritis during a six-months period in 1975-1976 were examined retrospectively. Sixty-two (48%) of the children were malnourished, including seven (5.4%) who were marasmic. An accelerated weight gain was demonstrated during the recovery phase, averaging 418% of that expected for age. Hypokalaemia occurred in 77 of 117 children (66%); it was severe (serum potassium levels being less than or equal to 2.5 mmol/l.) in 15 (13%), and did not correlate with dehydration as assessed by initial weight gain, or with nutritional status. Hyponatraemia occurred in 32 of 123 children (26%) and was severe (serum sodium levels being less than or equal to 130 mmol/l.) in 11 (9%). Hypoalbuminaemia (serum albumin levels below 35 g/l.) and anaemia (haemoglobin values below 10 g/100 ml) occurred in 15% and 22% respectively. Potential faecal pathogens were isolated during 80 of the 130 admissions (62%). Multiple pathogens were common. Interrelationships of nutrition, infection and immune response are discussed, and measures for reducing morbidity and mortality are outlined.

Cytogenetic survey of a hospital for the mentally retarded

A cytogenetic survey of all 588 patients in Strathmont Training Centre, an Australian hospital for the mentally retarded, was carried out. Abnormal karyotypes were found in 90 (15.3%) patients, of whom 73 (12.4%) had clinical Down syndrome, 12 (2.04%) other autosomal abnormalities, and 5 (0.85%) sex chromosome abnormalities.

Familial pericentric inversion of chromosome 19, inv(19) (p13q13) with a note on genetic counseling of pericentric inversion carriers

An inmate of a hospital for the mentally retarded was found during a cytogenetic screening programme to have karyotype 46,XY,inv(19)(p13q13)mat. Clinical, cytogenetic and family findings are presented and it is concluded that the chromosomes abnormality was probably not the cause of the patient's retardation. The problem of genetic counseling of inversion carriers is examined in some detail and estimates of risk are given.

Pulmonary oedema in paraguat poisoning

This is the case report of a 47-year-old man who swallowed a powerful commercial herbicide containing paraquat. He developed oral, oesophageal, renal, and hepatic damage and, at an earlier stage than is usual, severe pulmonary changes from which he made a satisfactory recovery. The disordered pulmonary function and production of pulmonary oedema fluid in this patient are attributed to interference with surfactant activity in the lung.