Endoreplication in the ovary, testis, and intestine of strongyloides sterocalis

During development of the free-living adults of the human parasitic nematode Strongyloides stercoralis, cells in certain tissues grow by endoreplication in which rounds of DNA replication occur without cell or nuclear division. The DNA content of individual nuclei was measured by microdensitometry of Feulgenstained preparations. In females, some ovarian cells have up to 800 times the haploid DNA content (800C). In males, some cells of the testis have up to 100C. Intestinal cells in both sexes have up to 16C, whereas most other somatic cells have 2C (AU)

The development and validation of an age-structured model for the evaluation of disease control strategies for intestinal helminths

Epidemiological modelling can be a useful tool for the evaluation of parasite control strategies. An age-structured epidemiological model of intestinal helminth dynamics is developed. This model includes the explicit representation of changing worm distributions between hosts as a result of treatment, and estimates the morbidity due to heavy infections. The model is used to evaluate the effectiveness of different programmes of age-targeted community chemotherapy in reducing the amount of morbidity due to helminth infection. The magnitude of age-related heterogeneities is found to be very important in determining the results of age-targeted programmes. The model was verified using field data from control programmes for Ascaris lumbricoides and Trichuris trichiura, and was found to provide accurate predictions of prevalence and mean intensities of infection during and following different control regimes (AU)

The intestinal permeability test applied to the diagnosis of food allergy in paediatrics

Intestinal permeability was evaluated in 17 healthy children (control group), aged 4.3 ñ 1.9 years (mean ñ SD), weight 15.4 ñ 5.5 kg and in 11 infants with food allergy (allergic group, aged 2.3 ñ 1.6 years, weight 9.5 ñ 1.5 kg). In the two groups, the urinary excretion of two non-metabolized sugars (mannitol, lactulose) was measured by gas-chromatography after oral administration. Measurement of urinary content of these sugars 5 hours after administration in the control group showed a clearance of 20.2 ñ 8.6 percent for mannitol and 0.44 ñ 0.81 percent for lactulose. The lactulose/mannitol ratio in the same group presented a normal mannitol urinary excretion (16.5 ñ 13.4 percent, p = NS, Student's t-test) and an increase in the lactulose excretion (1.36 ñ 0.92 percent, p<0.001). Moreover, the allergic group showed a lactulose/mannitol ratio that was significantly different (0.105 ñ 0.071,p<0.001). The intestinal permeability test for the diagnosis of food allergies seems to be sensitive and non-invasive test that is well suited to the paediatric practice (AU)

Does Crohn's disease occur in Jamaica? - abstract

Crohn's disease is one of the most frequently encountered chronic digestive diseases in areas of North America and Europe with a marked rise in incidence over the past 20 years. However, there is considerable geographical variation in incidence of this disease. It seems to be relatively rare in Jamaica and the Caribbean. Twenty patients with Crohn's disease seen over the past 20 years at the University Hospital, Kingston, Jamaica are reported. There were 14 female and 6 males. The mean age at presentation was 37 years (range 8-67), and symptoms were present for a mean of 12 months (range 1 day-4 yrs). Fourteen patients presented with lower abdominal pain and diarrhoea was present in eleven. Lower gastrointestinal bleeding was the presenting feature in two. Ten patients had weight loss. Four patients had a tender mass in the right lower quadrant of the abdomen and in a fifth patient the mass was located in the lower umbilical region. Thirteen of the twenty patients were anaemic (Hb less than 11 grams/dl) and 9 had hypoalbuminaemia at presentation. The primary distribution of disease was ileal in six and eight had colonic involvement. Three patients had ileocolitis and one perianal disease. One patient had invlovement of the entire small intestine and ascending colon and another had skip lesions involving several areas of the small intestine. Surgical resection was performed in five patients. Three other patients required laparotomy for intestinal obstruction and another for drainage of an inflammatory mass. Three patients developed entero-enteric fistulas and two entero-cutaneous fistulas. Of the 15 patients medically treated 6 have remained well while 8 have had recurrent episodes of relapse. Except for two deaths, the other patients have remained well. Crohn's disease, although uncommon, has been seen in Jamaica for the past 20 years and should be considered in West Indian patients presenting with inflammatory bowel disease. In contrast to other series, most of our patients were black with a female preponderance, but the clinical features, anatomic involvement and course appear similar to those reported elsewhere (AU)

Polysplenia and reversed rotation of the midgut

A 3-week-old female infant with polysplenia syndrome and partial situs inversus with reversed rotation of the intestinal tract who presented with subacute bowel obstruction at the University Hospital of the West Indies is reported. The absence of associated cardiovascular anomalies is notable. A modified Ladd's procedure was successful in relieving the obstruction. The clinical and diagnostic features of polysplenia syndrome are discussed. When complex cardiovascular anomalies, which usually account for the high mortality rate, are absent, normal growth and development can be expected. (AU)

A method for the isolation of the amide nitrogen of glutamine from biological samples for mass spectrometry

The amide nitrogen from L-glutamine has been isolated from an artificial plasma, in a form suitable for mass spectrometry, by a macromodification of the glutaminase reaction. The prior removal of free ammonia was carried out by alkaline aeration. When this was performed at 0§C for 3 h, spontaneous hydrolysis of glutamine was 1.4 percent. Cross-contamination with nitrogen liberated from the amide group of asparagine can be avoided by preincubation with asparaginase for 2h and removal of the freed ammonia prior to reacting with glutaminase. Hydrolysis of glutamine during this step is 12 percent. Measurements of enrichment can be made on samples yielding more than 1 æmol of glutamine amide-derived ammonia.(AU)

Glutamine production rate and its contribution to urinary ammonia in normal man

Glutamine [15N]amide was infused at a steady rate of 33.34 micromoles/h into seven male adult volunteers who were in the fed state and normal acid-base status. Plasma glutamine amide N enrichment and urinary ammonia N enrichment rose to a constant value within 3h. The glutamine production rate was 51.8 ñ 7.9 millimoles/h. The total ammonia execretion rate was 0.87 millimoles/h. Of this excreted ammonia 62.6 ñ 9 percent was derived from the amide N atom of glutamine. The excreted glutamine amide N (0.53 millimoles/h) was only 1 percent of the glutamine production. If half the ammonia formed by the kidney is excreted in urine and half liberated into the renal vein in subjects with normal acid-base status [E. E. Owen & R. R. Robinson (1963) Journal of Clinical Investigation, 42, 263-276], then the kidney accounts for only 2 percent of glutamine disposal. Whole body protein turnover, measured from the urinary [15N]ammonia enrichment, was 30.3 ñ 7.7 g of N/day (2.8 g of protein/day/kg). (AU)

Glutamine metabolism in metabolic acidosis

In chronic metabolic acidosis in the rat, there is increased ammoniagenesis, gluconeogenesis and renal extraction of gluatmine with induction of renal phosphate-dependent glutaninase (PDG). Because the stimulus for these changes is not yet clear and also because acute acidosis is the more common clinical problem, the present study deals mainly with the metabolism of glutamine in acute metabolic acidosis. When acute metabolic acidosis is produced in rats by administration of mineral acid or by causing them to swim, thus inducing a severe lactic acidosis, a factor is found in the plasma which stimulates renal glutamine uptake and ammoniagenesis in vivo as well as in vitro. Acute acidosis dose not induce synthesis of PDG in the kidney but causes a change in enzyme kinetics. The plasma factor not only enhances glutamine entry into cells, but apparently causes a conformational change in PDG, as shown by an increase in V1.0mM/Vmax. Intestinal metabolism of glutamine is also stimulated in vivo and in vitro by the plasma factor of acute acidosis. (AU)

Malabsorption and protein-losing enteropathy following small gut ischemia

This is a case reported of a 41-year-old male who was first seen at the University College Hospital with an incarcerated inguinal hernia. At herniorraphy, the suspiciously gangrenous segment of gut was not resected. Six weeks later the patient returned to hospital with severe weight loss, and symptoms and signs of intestinal obstruction. There was radiological, biochemical and haematological evidence of malabsorption and severe protein losing enteropathy. The patient made a complete recovery after surgical resection of the affected segment of gut (AU)

The acute abdomen during pregnancy: report of three unusual cases

The details of three cases are presented in which surgical emergencies arose during the course of pregnancy. These consisted of torsion of the spleen, traumatic rupture of the spleen and a volvulus with internal hernia involving large and small bowel. Details of management are discussed as well as the implications of such conditions during pregnancy. (AU)