Cloning of HOXD1 from unfertilised human oocytes and expression analyses during murine oogenesis and embryogenesis.

We describe the cloning of HOXD1 in human unfertilised oocytes and detailed expression analyses during mouse oogenesis and embryogenesis. The cDNA of 1991bp has an open reading frame of 987bp encoding a protein of 329 amino acids. A comparison of the amino acid sequence with the mouse homologue revealed an overall homology of 85.5% with 99% identity within the homeodomain. Expression was detected in unfertilised human oocytes and 2-, 4-, 8-cell and blastocyst stage embryos. Expression analyses in mature mouse ovaries, early embryos and isolated gut revealed expression in the oocytes of the primary and secondary ovarian follicles, and in embryonal mesodermal derivatives such as dermatomes, urogenital tubercle, tail bud, kidney, ovaries, testes and enteric mesoderm adjacent to the caecum where expression was up-regulated in vitro in response to increasing doses of retinoic acid. Our observations indicate a possible role for HOXD1/Hoxd1 in the ovarian oocytes and the establishment of mesodermal derivatives during embryogenesis.

Manganese toxicity in children receiving long-term parenteral nutrition.

BACKGROUND: In patients receiving long-term parenteral nutrition (PN), cholestatic disease and nervous system disorders have been associated with high blood concentrations of manganese. In such patients, the normal homoeostatic mechanisms of the liver and gut are bypassed and the requirement for this trace element is not known; nor has it been certain whether hypermanganesaemia causes the cholestasis or vice versa. We explored the direction of effect by serial tests of liver function after withdrawal of manganese supplements from children receiving long-term PN. We also examined the relation between blood manganese concentrations and brain lesions, as indicated by clinical examination and magnetic resonance imaging (MRI). METHODS: From a combined group of 57 children receiving PN we identified 11 with the combination of hypermanganesaemia and cholestasis; one also had a movement disorder. Manganese supplements were reduced in the first three and withdrawn in the remainder. MRI was done in two of these children. We also looked at manganese concentrations and MRI scans in six children who had received PN for more than 2 years without developing liver disease. FINDINGS: In the hypermanganesaemia/cholestasis group, four of the 11 patients died. In the seven survivors baseline whole-blood manganese was 615-1840 nmol/L, and after 4 months it had declined by a median of 643 nmol/L (p < 0.01). Over the same interval total bilirubin declined by a median of 70 mumol/L (p < 0.05). Two of these children had movement disorders, one of whom survived to have an MRI scan; this showed, with T1 weighted images, bilateral symmetrically increased signal intensity in the globus pallidus and subthalamic nuclei. Such changes were also seen in five other children--one from the hypermanganesaemia/cholestasis group and four of six in the long-term PN group without liver disease (in all of whom blood manganese was above normal). INTERPRETATION: The cholestasis complicating PN is multifactorial, but these results add to the evidence that manganese contributes. In view of the additional hazard of basal ganglia damage from high manganese levels in children receiving long-term PN, we recommend a low dose regimen of not more than 0.018 mumol/kg per 24 h together with regular examination of the nervous system.

Ionic control of beta cell function in nesidioblastosis. A possible therapeutic role for calcium channel blockade.

A preterm female infant presented with intractable hypoglycaemia within 10 minutes of delivery. Normoglycaemia could be maintained only by the intravenous infusion of glucose at a rate of 20-22 mg/kg/min. Persistent hyperinsulinaemic hypoglycaemia of infancy was diagnosed from an inappropriately raised plasma insulin concentration (33 mU/l) at the time of hypoglycaemia (blood glucose < 0.5 mmol/l). Medical treatment with glucagon, somatostatin, and diazoxide led to only a modest reduction in the intravenous glucose requirement; a 95% pancreatectomy was performed and histological 'nesidioblastosis' confirmed. In vitro electrophysiological studies using patch clamp techniques on isolated pancreatic beta cells characterised the ionic basis for insulin secretion in nesidioblastosis. The beta cells were depolarised in low ambient glucose concentrations with persistently firing action potentials; these were blocked reversibly by the calcium channel blocking agent verapamil. Persistent postoperative hyperinsulinaemic hypoglycaemia was treated with oral nifedipine. This increased median blood glucose concentrations from 3.5 to 4.8 mmol/l and increased in duration the child's tolerance to fasting from 3 to 10.5 hours. These data allude to an abnormality in the ionic control of insulin release in nesidioblastosis and offer a new logical approach to treatment which requires further evaluation.

Serum zinc, selenium and copper concentration in children with allergic colitis.

Children with allergic colitis have low levels of zinc and selenium which is partly a reflection of their low albumin levels and/or increased utilization of zinc and selenium as antioxidants as a result of the inflammatory process.

Effects of chronic vitamin E deficiency and a high polyunsaturated fatty acid diet on rat mesenteric arterial function.

1. Male rats were deprived as weanlings of dietary vitamin E and fed on a high polyunsaturated fatty acid (PUFA) diet for 6 months. Rats fed on a high PUFA or on an untreated diet served as controls. Mesenteric arterial beds were isolated and perfused at a constant flow rate (5 ml min-1) and the function of sympathetic nerves, smooth muscle and endothelium was assessed. 2. Electrical field stimulation (4-32 Hz, 90 V, 1 ms, for 30 s) elicited frequency-dependent vasoconstriction of the mesenteric arterial preparations. Response curves were similar between untreated control and PUFA-fed control groups. Maximum vasoconstrictor responses (at 24 and 32 Hz) were significantly attenuated in rats deprived of vitamin E and on a high PUFA diet compared to the PUFA-fed controls (P < 0.05). 3. Exogenous noradrenaline (NA; 0.15-500 nmol) elicited dose-dependent constriction of the mesenteric arterial beds. Preparations from rats fed on a high PUFA diet elicited significantly smaller responses compared to the control group. There was no significant difference in constrictor responses of PUFA rats deprived of vitamin E compared to the PUFA controls. Vasoconstrictor responses to doses of adenosine 5'-triphosphate (ATP) (5-5000 nmol) were significantly impaired in vitamin E-deficiency with a high PUFA diet compared to a high PUFA diet alone (P < < 0.001). Constrictor responses to potassium chloride (0.15 mmol) were significantly impaired in vitamin E-deficient PUFA rats compared to the PUFA-fed control group (P < 0.05). 4. Vasodilator responses were assessed in preparations in which tone was raised by continuous perfusion with methoxamine (4-25 microM). Mesenteric arterial beds from PUFA-fed rats deprived of vitamin E acquired significantly less tone, 59.8 +/- 4.6 mmHg (n = 7), than PUFA-fed controls 116.9 +/- 7.6 mmHg (n = 7) (P < 0.001) and were refractory to further increases in tone with further additions of methoxamine. Methoxamine-induced tone of PUFA-fed controls was greater than in P that in the untreated controls (83.9 +/- 7.4 mmHg; n = 5) (P < 0.05). Responses to the endothelium-dependent vasodilators acetylcholine (ACh) and ATP were significantly reduced in preparations from rats fed on the vitamin E-deficient high-PUFA diet compared to PUFA controls. Vasodilator responses to ACh were greater in PUFA controls than in untreated controls and this reached statistical significance at 5 nmol ACh. 5. Vasodilator responses to sodium nitroprusside, which acts directly on the vascular smooth muscle, were similar in untreated control and PUFA control groups. Responses were significantly attenuated in vitamin E-deficient PUFA rats compared to the PUFA control group (P < < 0.001). 6. These results indicate that a combination of a high PUFA diet and vitamin E deficiency impairs mesenteric arterial function at the level of the vascular smooth muscle. A high PUFA diet alone attenuates responses to NA and augments endothelium-dependent vasodilation. The detrimental effects of loss of antioxidant activity due to vitamin E-deficiency on vascular function may be exacerbated by a high PUFA diet.

Effects of dietary polyunsaturated fatty acids on small intestinal secretory and absorptive function: studies in rat jejunum in vitro.

1. Recent initiatives which advocate an increase in dietary polyunsaturated fat intake have led to the study of the effects of this upon gastrointestinal function. 2. Weanling rats were for 21 weeks fed diets containing 10% fat that were either high or low in polyunsaturated fats. Jejunal function was studied in vitro in an Ussing chamber. 3. Basal intestinal short-circuit was similar in both groups. 4. A decreased EC50 for the non-neural electrogenic secretory responses to acetylcholine, bethanecol and isobutylmethylxanthine was apparent in the jejuna of rats fed a diet high in polyunsaturated fatty acids. 5. Submaximal electrogenic galactose absorption was increased in the rats fed a diet high in polyunsaturated fatty acids. 6. Changing the composition of dietary lipid resulted in a change in the fatty composition of the apical enterocyte membrane. 7. Diets high in polyunsaturated fatty acids may be both prosecretory and proabsorptive in the small intestine.

Brown bowel syndrome: a late complication of intestinal atresia.

Two children, aged 11 years, who originally had jejunal atresia corrected in the neonatal period, developed massive dilatation of the proximal small intestine. This resulted in circular muscular hypertrophy with lipofuscin deposits giving the typical appearance of "brown bowel." The condition was associated with malnutrition and vitamin E deficiency. Because of relatively short bowel, the condition was treated by limited resection and extensive tapering of the dilated segment, end-to-end reanastomosis, vitamin E supplementation, and intensive nutritional support.

Self hypnotherapeutic treatment of habitual reflex vomiting.

A 9 year old boy with intractable postprandial reflex vomiting was taught a self hypnotherapy technique incorporating relaxation exercises, mental imagery, and suggestions of symptom relief. The sequence was recorded on a personal stereo cassette tape. Vomiting was completely eliminated within four weeks. At 12 month review vomiting had not recurred.

Loperamide in severe protracted diarrhoea.

Six infants with severe life-threatening protracted diarrhoea were treated with loperamide. Steady-state perfusion studies of the jejunum showed that in 2 of them the small intestine was in a net secretory state with respect to water, and in the others this was inferred from the fact that the diarrhoea persisted despite nothing by mouth. Loperamide resulted in a prompt and impressive improvement in the condition of each infant. We conclude that this drug has an important role in the management of protracted diarrhoeal states in some infants who are unresponsive to current treatments, and that its effect is related to its antisecretory action.