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Biomedical subjects

D Parekh

Publications and source records attributed to D Parekh.

52 records · Page 3Linked to original sources
PubMed1990

Effects of aging on duodenal bicarbonate secretion.

The incidence of duodenal ulcer increases with age, but acid secretion does not. We have investigated the effects of aging on a mechanism of duodenal mucosal defense. Basal and acid-stimulated bicarbonate secretions were measured in the proximal duodenum in anesthetized rats of three different age groups (3 months, 1 year, and 2 years). The proximal duodenum was cannulated in situ between two plastic tubes that extend downward from a titrating chamber, and bicarbonate secretion was measured by the method of Flemström et al. Although there was no significant difference in basal secretion among three groups, bicarbonate secretion in response to luminal acid (100 mmol/L [millimolar] HCl) was diminished in 1-year-old and 2-year-old rats (1-hour integrated bicarbonate secretions; 3 months = 5.8 +/- 0.7; 1 year = 3.1 +/- 1.0*; 2 years = 2.0 +/- 0.7*). We also studied the effects of two mediators for acid-stimulated duodenal bicarbonate secretion, vasoactive intestinal polypeptide (VIP), and prostaglandin E2 (PGE2). Intravenous infusion of VIP (0.4, 4, 40 nmol/kg/hr) and intraluminal administration of PGE2 (10(-5) mol/L [molar] and 10(-4) mol/L) induced duodenal bicarbonate secretion in a dose-dependent manner in all three groups, without significant difference between groups. These findings suggest that the release of mediator(s) in response to acid is decreased in the duodenum of the aging rats. The progressive breakdown in mucosal defense mechanisms with increasing age may explain, at least in part, the age-related increase of incidence of duodenal ulcer disease.

Acid-Base Equilibrium↗
PubMed1989

Post-traumatic parotid fistulae and sialoceles. A prospective study of conservative management in 51 cases.

The management of parotid sialoceles and fistulae have been unsatisfactory in the past, and numerous methods of treatment with varying success and morbidity have been described. The present prospective study reports results of conservative therapy in 51 patients over a 3-year period. In 50 patients, the injury healed upon conservative management. During the early phase of the study, a limited conservative regimen through which the patients received nothing orally for 5 days only was used. During the latter part of the study, patients were administered nothing orally until complete healing of the injury. In terms of the time it took for healing of the injury, the differences of the two regimens (24 +/- 4 vs. 9.4 +/- 0.9 days) was highly significant (p less than 0.001). The response to conservative management depended on the severity of injury as demonstrated by sialography. Injury to minor intraparotid ducts (G1) healed in significantly less time compared with that to a major intraparotid duct (G2) or ductal injuries (p less than 0.001). There was no difference between the healing of G2 injury (10.3 +/- 1.8 days) and partial ductal transections (10.5 +/- 2.2 days) (p greater than 0.05). There was a significantly greater delay in healing with complete duct transections (21.5 +/- 3.7 days) compared with partial duct transections and G2 injuries (10.2 +/- 2.1 days) (p less than 0.01). There was no difference in the mean period for healing between salivary fistulae and sialoceles (p greater than 0.05). It is concluded that a new classification of parotid fistulae based on sialographic findings has prognostic and therapeutic value. Furthermore, the excellent results achieved with conservative therapy in this study suggest that it may be the initial treatment of choice for parotid fistulae.

Acute Disease↗
PubMed1989

Technetium-pertechnetate uptake by ectopic antral mucosa. An experimental study.

The ability of ectopically placed fundic mucosa and retained antral mucosa to concentrate technetium has previously been demonstrated. The ability of ectopically placed antral mucosa to concentrate technetium was investigated. The denervated antrum implanted into the colon concentrated technetium in 5 dogs. However, this response was significantly less than that of parietal cell-containing mucosa (P less than 0.005) of the stomach. Technetium scanning may be useful in detecting ectopic and retained antral mucosa.

Animals↗
PubMed1989

Canine duodenal mucosal protection.

In an experimental study on dogs the absence of bile or both bile and pancreatic juice from the duodenum did not result in ulceration. It is suggested that the inhibitory control of the duodenum on acid secretion is the explanation for this observation.

Animals↗
PubMed1988

Lesser-curve ischaemic necrosis mimicking a gastric ulcer--a complication of highly selective vagotomy. A case report.

Ischaemic necrosis of the lesser curve of the stomach is thought to be a specific but rare complication of highly selective vagotomy. While it commonly presents as a free perforation, it may also present as sloughing of the mucosa only, a gastric fistula or a sealed perforation of the lesser curve mimicking a chronic gastric ulcer. We describe a case in which ischaemic necrosis of the lesser curve presented as a chronic gastric ulcer from a sealed perforation.

Adult↗
PubMed1988

Penetrating injuries of the diaphragm.

This study involved 163 patients with penetrating injuries of the diaphragm (knife, 139; bullet, 24). Intra-abdominal injuries were present in 122 patients (75 per cent) and this resulted in early diagnosis and treatment of the associated diaphragmatic injury (mortality 3.2 per cent). In the remaining 41 patients (25 per cent) the injury was confined to the diaphragm, and the diagnosis was missed during the initial admission in 10 patients who returned at a later stage with diaphragmatic hernia. A diaphragmatic hernia was found in 24 cases (14.7 per cent). Fourteen of these were diagnosed during the initial admission (mortality 7.1 per cent) and the remaining ten were diagnosed during a subsequent admission (mortality 30 per cent). The initial chest radiograph was diagnostic of diaphragmatic injury in 13 per cent, abnormal but not diagnostic in 76 per cent, and completely normal in 11 per cent. The importance of early diagnosis in reducing mortality, morbidity and hospital stay is emphasized. A high index of suspicion, careful clinical examination, and serial chest radiographs remain the best way of making the diagnosis.

Abdominal Injuries↗
PubMed1988

Factors influencing the morbidity of colostomy closure.

A series consisting of 110 patients who had colostomy closure was studied in an attempt to define the role of various factors in causing colon-related morbidity. The overall complication rate was 14.5 percent (wound sepsis 11.8 percent and anastomotic leak 2.7 percent). Patient age, the underlying pathologic abnormality (trauma versus nontrauma), the type of colostomy (loop versus end colostomy), the site of the stoma (right side, left side, or transverse), whether a drain was inserted or not, and the timing of the operation did not influence morbidity. Oral preoperative antibiotics appeared to be associated with less morbidity than parenteral antibiotics (p less than 0.01), and experienced surgeons had less complications than junior surgeons (p less than 0.05).

Adolescent↗
PubMed1988

The effect of chronic acidification of the canine duodenum on gastrin release from the antrum transplanted into the colon.

Exogenous infusion of acid into the canine duodenum inhibits acid secretion stimulated by endogenously released and exogenously administered gastrin. The importance of this mechanism in normal acid homeostasis and in the inhibition of chronic endogenous acid hypersecretion is not established. In this study the classic Dragstedt model antral colonic transplant (ACT) was used to produce endogenous hypergastrinemia and acid hypersecretion. The effects of the ACT when the duodenum was retained in continuity with the stomach (gastroduodenostomy) were compared with those obtained when the duodenum was no longer in continuity with the stomach (gastrojejunostomy). The duodenum markedly suppressed gastrin release (p = 0.003) and gastric acid secretion (p = 0.005) in each of the four dogs. The dogs remained free of ulcers for 8 months after gastroduodenostomy and ACT. However, after conversion to gastrojejunostomy, large, chronic peptic ulcers developed after a mean of 3.5 months. The inhibitory effect of the duodenum on gastric release and gastric acid secretion protected the dog against ulceration for an extended period. The duodenum may be the major site of inhibitory control of acid secretion and endogenous gastrin release in dogs.

Anastomosis, Surgical↗
PubMed1987

Benign chylous ascites. A case report.

Although most cases of benign chylous ascites are a result of surgical trauma, inflammatory conditions and unknown causes still account for a significant proportion. A case of idiopathic chylous ascites is discussed to highlight the difficulties in diagnosis and management.

Adult↗
PubMed1987

Gallstone disease among black South Africans. A review of the Baragwanath Hospital experience.

It has been suggested that gallstone disease is rare in Africa. The 118 cholecystectomies for this condition performed at Baragwanath Hospital over the 3-year period 1983-1985 were reviewed; 100 records were available. The male: female ratio was 1:4, the mean age 51 years. Fifty-one per cent of patients presented with acute cholecystitis, 18% with obstructive jaundice, 9% with pancreatitis and only 22% with biliary colic. The incidence of complicated presentation was higher in the over 60-year-old age group (P less than 0.05). The correct diagnosis was made on admission in only 41% of cases. The mean delay in diagnosis was 5 days; however, the delay was 8 days for patients admitted to the medical wards compared with 2 days in the surgical wards (P less than 0.001). Elective operations were performed on 82% of patients and 18% had urgent surgery. The incidence of common bile duct stones was 22%. The overall mortality rate was 10%; however, the mortality rate was 3.2% for the under-60-year-old group compared with 21% for patients 60 years and older (P = 0.006). This series, which is probably the largest reported in black patients, suggests that greater awareness of acute cholecystitis is necessary in the black patient since there is a rising in-hospital incidence.

Adult↗
PubMed1987

Salivary immunoglobulins in healthy white and black adults compared with oesophageal cancer patients.

Saliva is a readily accessible mucosal secretion and salivary antibodies reflect the repertoire of gut-associated antigens; it therefore appears to be ideal for the study of gastro-intestinal disease. A study of salivary immunoglobulins in healthy white and black adults and patients with oesophageal cancer showed that salivary immunoglobulin A levels were higher (but not significantly) in whites than blacks. The levels, however, were similar in healthy blacks and oesophageal cancer patients. There is a wide variation in normal levels of salivary immunoglobulins. Also, immunoglobulins are readily influenced by physiological factors and so at present are unreliable indices of gastro-intestinal disease.

Adult↗
PubMed1987

Plunging ranula: a report of three cases and review of the literature.

Three cases of plunging ranula are reported and the literature reviewed. Extravasation of saliva from the sublingual gland due to trauma or obstruction of its ducts appears to be the most likely cause of plunging ranula. Available data suggest that the submandibular gland is usually not involved, although at the time of surgery it may be extremely difficult to exclude a submandibular origin of the cyst in the neck. Communication between the oral and cervical components of the plunging ranula probably occur via a hiatus in the mylohyoid muscle. Such communication passing directly into the submandibular compartment may simulate submandibular gland involvement. Since 1910, 139 procedures in 89 patients with plunging ranula have been reported in the English literature. The recurrence rate was 70 per cent after incision and drainage of the cyst, 53 per cent after marsupialization, 85 per cent after excision of the cyst in the neck and 2 per cent after excision of the sublingual gland via the cervical or intra-oral route. This review suggests that excision of the sublingual gland with intra-oral drainage of the cervical swelling appears to be the treatment of choice for the plunging ranula.

Adolescent↗
PubMedDate not supplied

Development of systemic immunologic responses against hepatic metastases during gene therapy for peritoneal carcinomatosis with retroviral HS-tk and ganciclovir.

Gene therapy with retroviral mediated gene transfer of the herpes simplex thymidine kinase (HS-tk) gene into a tumor mass confers sensitivity of the tumor cells to ganciclovir (GCV). Tumor-specific immunologic responses may develop following treatment of the primary tumor with retroviral HS-tk and GCV. In the present study we assessed whether GCV treatment of HS-tk transduced colon cancer (TK+) implanted in the peritoneal cavity induced a systemic antitumor response that would inhibit growth of a second wild-type (TK-) tumor implanted in the liver. DHDK12 rat colon cancer cells were transduced in vitro with the retroviral HS-tk vector and established as a permanent cell line (TK+ cells). TK+ or TK- DHDK12 cells (6x10(6) cells) were injected intraperitoneally on day 0 into BD-IX rats. On day 10, TK- cells (3x10(6) cells) were injected into the liver in all the groups. The animals were then treated with GCV (150 mg/kg) for 13 days. TK+ peritoneal tumors underwent significant regression during therapy with GCV (0.05+/-0.004 g; n=7) compared to wild-type (TK-) tumors (2.2+/-0.7g; n=6) (P<0.05). The volume of TK- tumors in the liver was significantly lower in GCV-treated rats with TK+ peritoneal tumors (12.5+/-8.3 mm3) compared to rats with TK- peritoneal tumors (96.7+/-18.1 mm3) (P<0.05). Histology of the liver tumors in the TK+ groups showed a dense monocytic infiltrate with fibrosis and only occasional viable tumor cells. Gene therapy with retroviral HS-tk vectors may provide a novel approach to treatment of gastrointestinal cancer by both direct cytotoxicity and an indirect mechanism that may include enhanced immuno logic responses against disseminated disease.

Animals↗