Colonic atresia: a rare entity in the newborn. A six-case report and a bibliographic review

INTRODUCTION

Colonic atresia is a rare malformation accounting for 1.8-15% of all intestinal atresias. We present a 6-case series along with a bibliographic review.

CLINICAL CASE

This 6-case series consists of three female cases and three male cases diagnosed 24-84 hours following birth. They were all located in the right hemicolon. The most relevant clinical signs included abdominal distension, absence of defecation, and bilious to fecal vomit. Repairs included primary or step-by-step anastomoses for bowel transit reconstruction. One patient diagnosed at > 72 hours of life died.

CONCLUSION

In our experience with colonic atresia, when primary or step-by-step intestinal recanalization (diversion for future repair) is achieved, the expected prognosis is excellent, provided that colonic atresia has been diagnosed at 24-48 hours of life.

Design of Metabolic Engineering Strategies for Maximizing l-(-)-Carnitine Production by Escherichia coli. Integration of the Metabolic and Bioreactor Levels

In this work metabolic engineering strategies for maximizing L-(-)-carnitine production by Escherichia coli based on the Biochemical System Theory and the Indirect Optimization Method are presented. The model integrates the metabolic and the bioreactor levels using power-law formalism. Based on the S-system model, the Indirect Optimization Method was applied, leading to profiles of parameter values that are compatible with both the physiology of the cells and the bioreactor system operating conditions. This guarantees their viability and fitness and yields higher rates of L-(-)-carnitine production. Experimental results using a high cell density reactor were compared with optimized predictions from the Indirect Optimization Method. When two parameters (the dilution rate and the initial crotonobetaine concentration) were directly changed in the real experimental system to the prescribed optimum values, the system showed better performance in L-(-)-carnitine production (74% increase in production rate), in close agreement with the model's predictions. The model shows control points at macroscopic (reactor operation) and microscopic (molecular) levels where conversion and productivity can be increased. In accordance with the optimized solution, the next logical step to improve the L-(-)-carnitine production rate will involve metabolic engineering of the E. coli strain by overexpressing the carnitine transferase, CaiB, activity and the protein carrier, CaiT, responsible for substrate and product transport in and out of the cell. By this means it is predicted production may be enhanced by up to three times the original value.

Low levels of urinary iodine excretion in schoolchildren of rural areas in Cuba

OBJECTIVE

We set up a baseline data on urinary iodine excretion from a nationwide representative sample of rural schoolchildren before instituting iodine supplementation.

DESIGN

Stratified multistage cluster sampling in three different strata: lowlands, foothills and mountainous areas. Early morning urine samples were collected for evaluation of iodine status.

SETTING

Field study in 25 municipalities in 11 out of 14 provinces. The study was carried out from October to December 1995.

SUBJECTS

Three thousand and twenty-seven schoolchildren of either sex, 6 to < 12 y from 87 primary schools.

RESULTS

The median urinary iodine excretion was 95 microg/L for the whole sample. The situation in a few foothills and all mountainous areas showed a moderate to severe deficiency. In the mountainous stratum, the median urinary iodine excretion values was less than 20 microg/L.

CONCLUSIONS

Cuba has a mild iodine deficiency public health problem with respect to WHO criteria, which in the mountainous areas is severe. The Government of Cuba has started a national Plan of Action and funds are being mobilized to introduce nationwide iodized salt.

Centrally infused galanin-(1-15) but not galanin-(1-29) reduces the baroreceptor reflex sensitivity in the rat

It has been demonstrated previously that central administration of the N-terminal galanin fragment (1-15) elicits hypertension and tachycardia and antagonizes the hypotensive effect of the parent molecule galanin-(1-29). In order to further clarify the role of galanin in central cardiovascular control, the possible modulation of the baroreceptor reflex by both galanin molecules has been studied. Different groups of rats were injected in the lateral ventricle with subthreshold doses of galanin-(1-15) (0.1 nmol/rat, or 0.3 nmol/rat), with subthreshold doses of galanin-(1-29) (0.1 nmol/rat, and 0.3 nmol/rat) or with an effective dose of galanin-(1-29) (3.0 nmol/rat). The baroreceptor reflex was elicited by intravenous injections of different doses of L-phenylephrine before and after the intraventricular administration of galanin peptides. The changes of the bradycardic responses after galanin peptide injections as well as the modifications of the baroreceptor reflex sensitivity were evaluated. Intraventricular injections of galanin-(1-15) significantly inhibited the reflex bradycardia elicited by intravenous L-phenylephrine and thus decreased the baroreceptor sensitivity. However, neither subthreshold doses of galanin-(1-29) nor its effective dose were able to modulate these cardiovascular responses. From these data it may be suggested that the galanin fragment (1-15) plays a more important role in central cardiovascular regulation than galanin-(1-29), possibly acting on a specific receptor subtype which exclusively recognizes N-terminal fragments of galanin, and exists on cardiovascular areas of the central nervous system.