Characterization and structure determination of ammonium bismuth oxalate hydrate, Bi(NH(4))(C(2)O(4))(2).xH(2)O.

From on-line coupled TGA-MS and TGA-FTIR measurements, in combination with a quantitative chemical analysis, it was deduced that the chemical formula for an unknown bismuth oxalate compound had to be Bi(NH(4))(C(2)O(4))(2).3.71(6)H(2)O. Solution of the crystallographic structure on the basis of X-ray powder data proved this formula to be correct. The diffraction pattern was indexed by a tetragonal unit cell [a and c respectively 11.6896(2) and 9.2357(3) A; M(20) = 195 and F(30) = 302; Z(calc) = 4], from which the space group I4(1)/amd (No. 141) was derived. Direct methods were applied to solve the structure. The initial structural model was subsequently refined by means of the Rietveld method (R(B) = 8.0%, R(wP) = 14.0%). Bi is 8-fold coordinated by oxygen from the oxalate anions. Since these BiO(8) polyhedrons do not share any edges or vertexes, an open framework is formed with water and ammonium molecules between. As a result, water can easily be removed, which is clearly indicated by the instant weight loss in the TGA upon heating. Moreover, as shown by HT-XRD, this process of water exchange is reversible as long as the heating temperature does not exceed 100 degrees C.

A new design of lead amalgam/lead sulphate electrode for potentiometric measurement of sulphate.

A new lead amalgam/lead sulphate electrode has been developed which is easy to handle and can be used in a simple measuring cell. Its electrochemical characteristics have been tested in two different cell systems. The potentials obtained were very stable, and reproducible within +/-0.04 mV. The electrode exhibited a Nernstian response to sulphate and its calculated standard potential (-350.68 +/- 0.13 mV) agreed very closely with that recorded in the literature.

Potentiometric investigation of the stability of silver(I) complexes of some N-methyl substituted 4-H-diethylenetriamines in aqueous solution.

By means of potentiometric pH and pAg measurements, the stability constants and the stoichiometric composition of the silver(I) complexes of some N-methyl-substituted 4-H-diethylenetriamines, in aqueous medium of ionic strength 1.3 and at a temperature of 25.00 degrees , have been determined. In addition to mononuclear and polynuclear complexes, together with their protonated forms, some hydroxo complexes are formed. The values of the stability constants are discussed in terms of possible structures.

Chronic pancreatitis: a 5-year experience.

Of 81 patients with chronic pancreatitis admitted to the Ottawa Civic Hospital over a 5-year period, 40 had conditions that were thought to be amenable to various operations. Good results were obtained in 70%. Of note were the 75% good results of pancreaticojejunostomy. Several patients needed further operations. The proportion of good results leaves no room for complacency, but it is difficult to envisage how a damaged gland can be expected to make a full recovery from either internal or external drainage procedures. Two patients died of carcinoma within 2 years of their initial operation and may have had carcinoma of the pancreas from the outset, although their mode of presentation and results of investigation were those of chronic pancreatitis. Alcohol abuse was thought to be responsible for the condition in 72% of these patients.

Cystadenoma and cystadenocarcinoma of the pancreas.

Cystic neoplasms of the pancreas are uncommon. The authors present one case each of a cystic carcinoma (possibly acinar, which is a rare variant of pancreatic carcinoma), cystadenocarcinoma arising in a mucinous cystadenoma and cystadenoma. These cases illustrate important features of the natural history and management of these lesions. The macrocystic cystadenoma is generally regarded as premalignant and merits aggressive treatment, while the microcystic type is considered benign. If the cystadenoma is removed completely, there should be no recurrence. The cystadenocarcinoma differs from duct carcinoma; usually, the tumour can be removed, and when this is possible the prognosis is excellent. Both the cystadenoma and the cystadenocarcinoma can be mistaken for a pancreatic pseudocyst. The distinction is important.

Antibodies to human T cell leukaemia virus-associated membrane antigens in haemophiliacs: evidence for infection before 1980.

Human T cell leukaemia virus (HTLV), HTLV proviral DNA, and antibodies to HTLV or a related agent have recently been detected in patients with acquired immunodeficiency syndrome (AIDS). Antibodies against HTLV-related antigens were assayed by means of indirect living cell immunofluorescence of HTLV-infected cells in sera recently collected from Georgia haemophiliacs and in sera collected between 1976 and 1981 from New York haemophiliacs. 5 of 45 Georgia haemophiliacs and 8 of 48 New York haemophiliacs had antibodies to HTLV-associated cell membrane antigen (HTLV-MA). None of the control Georgia patients on haemodialysis or with chronic hepatitis had detectable antibodies. The 5 haemophiliac patients from Georgia with HTLV-MA had significantly fewer T4 lymphocytes than similar HTLV-MA-negative patients. There were no other significant immunological differences between these groups. These data suggest that transfusions with blood products may expose haemophiliacs to a substantial risk of acquiring HTLV or a related virus.

Pancreatic abscess.

Pancreatic abscess, although an uncommon complication of pancreatitis, is a serious cause of morbidity and death. During the 5-year period beginning in March 1976, 19 patients with pancreatic abscess were seen at the Ottawa Civic Hospital. Abdominal pain, mass, fever and leukocytosis were common; the serum amylase value was usually normal. twelve patients underwent external drainage; in 6 the abscess was drained internally through the posterior wall of the stomach. The overall mortality was 16%. Morbidity was high; 7 (37%) of the 19 patients required reoperation for recurrent sepsis. Differentiation of pancreatic abscess from phlegmonous pancreatitis or pseudocyst can be difficult. Ultrasonography may be useful but computerized axial tomography is the the diagnostic method of choice. Prompt débridement and external drainage are the mainstays of surgical treatment but internal drainage may be appropriate in selected patients.

Traumatic intrapericardial rupture of the diaphragm.

A 60 year-old woman sustained an intrapericardial rupture of the diaphragm with herniation of a loop of transverse colon into the pericardium. There are ten previous reports of this condition. Reduction of the hernia and repair of the defect were readily accomplished through an upper midline abdominal incision.

Endoscopic retrograde cholangiopancreatography (ERCP) in the diagnosis of chronic pancreatitis.

In a personal series of 188 patients with pancreatic disease referred for endoscopic retrograde cholangiography (ERCP), one or more ducts were cannulated in 168 patients; of the 168 patients; of the 168 patients, 19 had carcinoma and 149 had chronic pancreatitis. Abnormalities were found in 71 of the 149 patients with pancreatitis, either in the pancreatic duct, the bile duct, or both ducts. The demonstration of these abnormalities was of critical importance in planning the management of these patients. Ducts were normal in 78 patients. No benefit could be expected from operating upon these patients. It is concluded that approximately one half of the patients with chronic pancreatitis will have demonstrable lesions amenable to operation, and one half will not. ERCP is essential in the investigation and management of patients suspected of having chronic pancreatitis.