Segmental intestinal muscular thinning: a possible cause of intestinal obstruction in the newborn

Intestinal obstruction proximal to a transition zone without an interposed physical barrier usually indicates Hirschsprung disease. The authors report one case of focal small bowel muscular thinning just distal to a transition zone that produced clinical and radiographic findings that simulated long-segment Hirschsprung disease in a 2-day-old infant.     

Comparative metabolism of BHA, BHT and other phenolic antioxidants and its toxicological relevance

Following oral administration, butylated hydroxyanisole (BHA) is absorbed and rapidly excreted by the rat, rabbit and man, with little evidence of long-term tissue storage. The major metabolic pathways for BHA are conjugation (phase 2) reactions, oxidative metabolism (O-demethylation) being relatively unimportant. In the dog, the extent of absorption and urinary excretion is less, and oxidative metabolism is more important than in other species. In contrast, butylated hydroxytoluene (BHT) is cleared less rapidly from most species, enterohepatic circulation being partly responsible for the delay. Tissue accumulation is also greater for BHT than for BHA. Oxidative metabolism (phase 1 reactions) mediated by the microsomal monooxygenase system is the major route for BHT degradation; oxidation of the ring methyl group predominates in the rat, rabbit and monkey, and oxidation of the tert-butyl groups in man. Gallates and 2-tert-butylhydroquinone are mainly metabolized by non-oxidative pathways (methylation or conjugation with sulphate and glucuronic acid). The different biological properties of these compounds may be related to the differences in their absorption and metabolic disposition. Thus, whereas BHT, which is metabolized by oxidation reactions, is an inducer of the microsomal mono-oxygenase system, the other phenolic antioxidants, including BHA, are only weak inducers.     

Effects of Increasing Gestation,Cortisol and Maternal Undernutrition on Hypothalamic Neuropeptide Y Expression in the Sheep Fetus

We have characterized the localization and the ontogenetic changes in Neuropeptide tyrosine (NPY) before birth and investigated the regulation of NPY expression by cortisol and undernutrition in the fetal sheep hypothalamus during late gestation. Using immunohistochemistry, we have identified NPY-containing neurons in the infundibular nucleus and the internal layer of the median eminence in fetal hypothalami collected between 110 and 147 days gestation. NPY projections were also present in the paraventricular nucleus (PVN) of fetal hypothalami at all ages between 110 days gestation and term. There was a significant increase in the amount of immunoreactive NPY/g hypothalamus between 87 and 113 days and 131–140 days gestation and a further significant increase after 141 days gestation. The total hypothalamic content of immunoreactive NPY increased significantly between 87 and 113 days and 141–145 days gestation. The levels of NPY mRNA: 18S rRNA in the mediobasal region of the fetal hypothalamus were significantly higher at 145–146 days gestation than at any earlier gestational age between 116 and 141 days gestation. Cortisol (2.5–3.0 mg/24 h) was infused intrafetally between 109 and 116 days gestation. The ratio of NPY mRNA: 18s rRNA in the mediobasal region of the fetal hypothalamus was significantly higher in the cortisol-infused group when compared with the saline-infused control group at 116 days gestation. Maternal, and hence fetal undernutrition, was induced between 110 and 146 days gestation. At 145–146 days gestation the ratio of NPY mRNA: 18S rRNA in the mediobasal region of the fetal hypothalamus was significantly higher in the undernutrition group when compared with control animals. We have therefore demonstrated that NPY is present in the hypothalamus of the sheep fetus before birth and that hypothalamic NPY content and NPY mRNA increase before delivery. We have also found that glucocorticoids and undernutrition stimulate increases in NPY mRNA levels in the hypothalamus before birth.     

Synthesis and Antitumour Activity of New Derivatives of Flavone-8-acetic Acid (FAA). Part 1: 6-Methyl Derivatives

A range of 17 derivatives of flavone-8-acetic acid (FAA) with a 6-methyl substituent have been prepared and their anti-tumour activity evaluated in vitro against a panel of human and murine tumour cell lines and in vivo against MAC 15A. While many of the compounds show activity comparable to FAA in vitro, this essentially disappears in vivo, possibly due to degradation before the compounds can reach the tumour site.     

Magnetic resonance imaging reveals no ventriculomegaly in polydrug abusers

Previous studies of cerebral structure in substance abusers yielded controversial results, largely due to issues of subject selection and/or limitations of experimental techniques. The purpose of the present study was to assess whether the ventricle-to-brain ratio (VBR), determined volumetrically by magnetic resonance imaging (MRI), differed in polysubstance abusers (n = 10), as compared with age-matched controls (n = 10). Subjects were male volunteers 21–39 years of age. The values of VBR in the polydrug abuse group were not larger than those in control group, nor was there any tendency toward relative ventriculomegaly in the substance abusers. Therefore, the present findings provide no evidence that polysubstance abuse produces abnormalities of gross brain structure in relatively young and physically healthy men.     

Excision of a Clival and Upper Cervical Pheochromocytoma by an Extended Maxillotomy Approach: A Case Report

By use of an extended maxillotomy approach, greater surgical access is provided to the midline skull base in comparison with lateral approaches. We describe this technique used to debulk a tumor extending from the sphenoid sinus across the craniocervical junction to the second cervical vertebrae.     

Pulmonary aspiration complicating intraoperative small-bowel decompression: a case report and literature review

When conservative management of intestinal obstruction fails, the surgeon has two operative choices for decompression: the open procedure with enterotomies and suction and the closed procedure consisting of retrograde stripping and nasogastric suction. A previously undocumented complication of the latter procedure — pulmonary aspiration — is reported in a 20-year-old man with small-bowel obstruction. Practical modifications to the technique of small-bowel decompression are suggested. They include feeding the nasogastric tube into the distal duodenum, using a wider bore tube, inserting an esophageal balloon before extubation, using a nasogastric tube with suction throughout extubation and, immediately postoperatively, making a more conscious effort to remove all gastric contents before extubation, and milking the contents distally through the ileocecal valve.     

Detection of haematoporphyrin derivative and haematoporphyrin excited states in cell environments

The photosensitiser currently used in the photodynamic therapy of cancer is haematoporphyrin derivative. Pulsed laser studies of this material and also of the "parent" molecule haematoporphyrin in polyoma-transformed fibroblast cells have now been studied. We report, for the first time, the observation of the triplet absorption of these sensitisers in cells. The corresponding triplet-triplet spectra are red shifted compared to aqueous buffer, lambda(max) 420 nm shifts to 460 nm. We also report our failure to observe singlet oxygen from the cells even though the triplet state can be seen to interact with the oxygen and even though singlet oxygen can be readily detected with the same sensitisers bound to serum albumin.