Search PubMed⌕ Search

Biomedical subjects

R Sim

Publications and source records attributed to R Sim.

45 records · Page 3Linked to original sources
PubMed1992

Neuroendocrine changes in rat stomach during experimental diabetes mellitus.

The effects of 48 days of streptozotocin-induced diabetes mellitus in rats on plasma concentrations of gastrin, somatostatin, pancreatic glucagon, and enteroglucagon have been assessed. In addition, neuroendocrine changes in sections of gastric mucosa were quantified using a computer-assisted morphometric system following immunohistochemical staining with polyclonal antibodies directed against gastrin, PGP 9.5 (a neural protein), and somatostatin. Diabetes resulted in significantly increased fasting plasma concentrations of somatostatin, and entero- and pancreatic glucagon. In contrast, lower plasma gastrin concentrations and decreased antral G-cell density were noted in diabetic rats. Gastric somatostatin and neuronal PGP 9.5 stain densities were unaltered by diabetes. Stomachs of diabetic rats weighed less, but both the jejunum and ileum showed evidence of mucosal hyperplasia. The gastric neuroendocrine atrophy observed in diabetes may be a consequence of elevated plasma somatostatin derived from nongastric sources. The enhanced growth of the intestinal mucosa may be related, directly or indirectly, to raised intraluminal glucose concentration in diabetes.

Animals↗
PubMed1992

A ferret model of acute multifocal gastrointestinal infarction.

Based on the demonstration of mural granulomatous vasculitis in Crohn's disease, it was hypothesized that this vasculitis may account for the discontinuous pattern of lesions in this condition. Accordingly, the present study investigated the histological changes produced by interruption of the submucosal and mucosal microcirculation in the ferret midgut. Two techniques were used. First, up to 30 adjacent vasa recta were ligated using microsurgical techniques; this produced no evidence of ischemic damage. Second, interruption of the submucosal collateral plexus by the intra-arterial injection of styrene microspheres (27-, 50-, or 90-microns diameter) produced acute intestinal mucosal damage. A combination of 27- and 90-microns spheres resulted in focal mucosal inflammation, necrosis, and ulceration. "Summit" lesions with normal adjacent mucosa were observed 48 hours after embolization, with evidence of regeneration of the mucosa overlying the occluded vessels at 72 hours. This model shows that focal gastrointestinal infarction with normal adjacent mucosa can be produced by acute occlusion of submucosal and mucosal arteries.

Acute Disease↗
PubMed1992

Mucosal capillary thrombi in rectal biopsies.

We studied the initial rectal biopsy from 46 patients in whom subsequent follow-up established the diagnosis of either self-limited colitis or inflammatory bowel disease. An additional 12 non-inflamed rectal biopsies were also studied. There was between 2 and 8 years of follow-up in each of these cases. Staining for fibrin (MSB, fibrinogen), platelets (factor XIIIA, Y2/51), and capillary basement membrane (reticulin, collagen 4) was performed to identify thrombotic material within capillaries. Mucosal capillary thrombi were best identified by staining for factor XIIIA; thrombi were observed in 8/13 cases of ulcerative colitis, 4/10 cases of Crohn's disease, 1/3 cases of unspecified inflammatory bowel disease and 5/20 cases of self-limited colitis. The presence of capillary thrombi was not related to the severity of inflammation, but none of the control biopsies showed capillary thrombi. Their presence seems of little diagnostic value in distinguishing inflammatory bowel disease from self-limited colitis. The pathogenetic significance of these mucosal capillary thrombi is uncertain.

Adult↗
PubMed1992

Kielland's forceps delivery: is it a dying art?

A retrospective study in the use of Kielland's Forceps for rotation of the foetal head and mid-cavity delivery in Kandang Kerbau Hospital, Singapore from 1987-1990 is presented. Out of a total of 53,889 singleton births during this period, Kielland's Forceps was used for delivery in 137 (0.25%) patients with an incidence of 0.65% in the primiparae and 0.07% in the multiparae. Primiparity, induction of labour and epidural analgesia were associated with a significantly higher incidence of rotational delivery by Kielland's forceps. The success rate of Kielland's forceps delivery was 93.4% (128 of 137). There was no maternal or perinatal mortality. About one-third of the mothers experienced postpartum morbidity, commonest being retention of urine, postpartum haemorrhage and vaginal lacerations. Traumatic injuries were present in about one-quarter of the babies and were minor. Out of a total of 306 mid-cavity deliveries for occipito-transverse malposition, Kielland's forceps accounted for 38.2% (117), vacuum extraction 30.7% (94), manual rotation followed by Neville-Barnes forceps 11.1% (34) and Caesarean section 20.0% (61). The junior specialists tended to use vacuum extraction for rotational delivery more than the senior specialists.

Birth Injuries↗
PubMed1991

Granulomatous vasculitis in Crohn's disease.

This study investigated a possible vascular origin for granulomas in Crohn's disease. Twenty-four consecutive resected specimens of small and large intestinal Crohn's disease were preserved by arterial perfusion-fixation with 10% formol saline, at mean arterial pressure (100 mm Hg). Fifteen specimens contained granulomas on routine examination of H&E-stained sections. These 15 specimens were examined in detail using a range of immunohistochemical staining techniques to identify vascular structures and granulomas. A total of 485 granulomas were found, 85% of which were identified as being directly involved in vascular injury. The majority (77%) of granulomas were deep to the mucosa; they were found most frequently in the submucosa (42%). The techniques used in this study enhanced the recognition of granulomatous vasculitis. The results suggest that the majority of granulomas in Crohn's disease form within walls of blood vessels. Vascular localization of granulomatous inflammation suggests that the intestinal microvasculature contains an early element in the pathogenesis of Crohn's disease.

Crohn Disease↗
PubMed1986

Exfoliative cheilitis--a factitious disorder?

Exfoliative cheilitis is an uncommon lip lesion usually of great concern to the patient and quite refractory to treatment. The available literature was surveyed, and 3 cases have been described to illustrate various aspects of the condition. The difficulty of treating such lesions has been discussed, and a proposition put forward that the lesions are of a factitious nature.

Adult↗
PubMedDate not supplied

Prevalence of caries in urban Australian aborigines aged 1-3.5 years.

PURPOSE: This study investigated the prevalence and etiological factors associated with caries in a group of young Australian aboriginal children from 1 to 3.5 years of age. METHODS: One hundred and forty-seven healthy infants, aged from 1 to 3.5 years, attending a community health center in Brisbane, a nonfluoridated state capital city, were randomly selected for the study. RESULTS: The caries prevalence was 39% by subjects and 32% by the total number of teeth present. The mean number of decayed, filled teeth (dtf) was 2.5 +/- 0.4, which is more than twice the figure for 3-year-old children in Australia. Furthermore, the filled (f) component represented only 1% of the total dft, suggesting very low treatment levels. Increased caries experience of the infants was strongly associated with high dental plaque scores, high levels of Streptococcus mutans infection, and sleep-time consumption of milk containing added sugar. CONCLUSION: The results suggest that urban Australian aboriginal infants are at high risk for caries, and that preventive strategies are urgently required.

Chi-Square Distribution↗