The influence of solution viscosity on the dissolution rate of soluble salts, and the measurement of an "effective" viscosity

The rate of solution of KCl and NaCl from compressed discs has been determined under controlled conditions, in water at 25° and in solutions of varying concentrations of polyvinylpyrrolidone (molecular weight 360 000), polyoxyethylene glycol 6000 and cetomacrogol 1000. Dissolution rate constants decrease with increasing bulk solution viscosity, as expected, but no one equation relating rate constant and bulk viscosity fits the results for the systems studied. Calculation of an effective viscosity from the diffusion coefficients of the salts in water and the diffusion coefficients of the salt in the polymer solutions enables an empirical correlation of the results to be made. The relation of the effective viscosity to the microscopic viscosity is discussed in an Appendix.

Studies on double acylation of aromatic hydrocarbons. XI. A total synthesis of 5,6-Dihydro-4H-benz[de]anthracene

Starting from ethyl 3-(1-naphthyl)propionate (1), the dibasic acid 4-(4-carboxy-ethyl-I-naphthyl)butyric acid (3) was prepared, which served as a key compound for the synthesis of 5,6-dihydro-4H-benz[de]anthraoene (6) by a double intramolecular cyclization. The monocyolization of the dibasic acid (3) gave rise by a preferential six-membered ring closure, to 3-(1-oxo-1,2,3,4-tetrahydro-9-phenanthryl)propionic acid (7). A partial synthesis of 5,6-dihydro-4H-benz[de]anthracene (6), by succinoylation of perinaphthane followed by usual synthetic steps, is reported as confirmatory evidence of the identity of (6) obtained by double cyclization of the diacid. Some aspects of the orientation of intramolecular acylation are discussed.

Uncommon cause (fecolith or enterolith) of small intestinal obstruction in the adult

Intestinal obstruction due to fecolith is a rare cause of small bowel obstruction. A 40 years old lady presented with the features of intestinal obstruction of 6 days duration. She had H/O laparatomy for DU perforation and hysterectomy. Clinical examination and investigations pointed to intestinal obstruction because of intestinal adhesions from previous surgeries. Conservative treatment did not give relief to the patient. Diagnostic laparoscopy revealed ascites and moderate adhesion A lump with hard consistency was detected in the terminal ileum. A diagnosis of lymphoma was made and hemicolectomy was planned. After mobilizing the caecum and part of ascending colon laparoscopically, small transverse incision was made in RIF. Whole mass and caecum was delivered through the wound. The mass in the ileum was felt moving proximally on traction. The mass was pushed proximally and enterotomy was made to take out the lump. It was a 6 x 4 x 2 cm fecolith (fig-3). There was no other abnormality or cause of intestinal obstruction except mild adhesion at the terminal ileum.DOI: 10.3329/pulse.v3i1.6555Pulse Vol.3(1) July 2009 p35-37

Textiloma: a case of foreign body mimicking a dermoid/mesenteric cyst

Items such as cotton or gauze pads can be mistakenly left behind during operations. Such foreign materials (called textiloma) cause foreign body reaction in the surrounding tissue. The complications caused by these foreign bodies are well known, but cases are rarely published because of medico-legal implications. Some textilomas cause infection or abscess formation in the early stage, whereas others remain clinically silent for many years. Here, we describe a case of textiloma in which the patient presented with huge abdominal lump 6 years after caesarean section operation abroad. Imaging revealed a dermoid / mesenteric cyst in pelvis and left lower abdomen. The case was treated successfully in Apollo Hospitals Dhaka and discussed here in the light of published literature.DOI: 10.3329/pulse.v3i1.6548Pulse Vol.3(1) July 2009 p20-22

Carcinoma transvers colon with caecal perforation mimicking appendicular lump

A 43 year-old female with caecal perforation and localized peritonitis as a result of transverse colon malignant stricture was presented. Initially she was evaluated in two different clinics and treated conservatively as appendicular lump. She was brought to Apollo Hospitals Dhaka as her condition deteriorated. CECT abdomen disclosed an annular soft tissue mass at mid part of transverse colon that completely obstructed the lumen. The colon proximal to the lesion and small bowel were grossly dilated and filled up with fecal matter. On laparotomy, a lump was noted in right iliac fossa which was made of omentum, small bowel and lateral abdominal wall. A perforation was noted in the lateral wall of caecum after dismantling the lump. The colon and the small bowel were decompressed through caecal perforation site peroperatively. Right hemicolectomy and primary anastomosis was performed. Patient survived the operation and she was discharged from hospital on the 10th postoperative day with an advice of regular follow up in surgical OPD. She was referred to Oncology centre for chemotherapy.In conclusion, any patient around the age of forty or above with features of appendicular lump deserves full work-up including CECT to exclude colonic malignancy. Resection and primary anastomosis may be a preferred procedure for right colonic carcinoma perforation.DOI: 10.3329/pulse.v3i1.6552Pulse Vol.3(1) July 2009 p29-30