An evaluation of duckweed-based pond systems as an alternative option for decentralised treatment and reuse of wastewater in Zimbabwe.

A study was carried out in Zimbabwe to evaluate the performance of duckweed ponds as an option for treating and reusing wastewater in small, decentralised communities. The study focused on nitrogen and phosphorus removal, operational problems, and duckweed application. Two full-scale trial plants at Nemanwa and Gutu-Mupandawana growth points were used. Sewage samples were collected and analysed monthly from September 2000 to August 2001 for NO3, NH4(-)1 TKN, TP, COD, and other field measurements. The duckweed was harvested daily and fed to chickens. The Nemanwa plant had high nutrient levels due to nil outflows caused by water rationing in the area. The Gutu effluent had averages of 38.7 +/- 23.1 mg/l TN and 7.5 +/- 2.4 mg/l TP which are above the respective Zimbabwean standards of 10 mg/l TN and 1 mg/l TP. COD removal efficiency at Gutu was poor at 45%. The performance of Gutu and Nemanwa plants suffered from inappropriate design especially pond depth and short-circuiting. The duckweed died off in the November-January period, this being attributed to excessive levels of ammonia. It was concluded that the duckweed pond systems would offer a good alternative for managing and reusing wastewater at community level provided due regard is paid to appropriate design criteria.

Thrombosis of abdominal aortic aneurysms.

The usual complication of abdominal aortic aneurysms is rupture. Although thrombosis of peripheral aneurysms is common, thrombosis of abdominal aortic aneurysms is rare. Sudden thrombosis of abdominal aortic aneurysms constitutes a surgical emergency, with a mortality of 50 percent. The patient often presents with cool and mottled skin, and with severe pain from the umbilicus to the lower extremities. Femoral pulses are rarely present, and neurologic deficits below the level of occlusion are common. We reviewed four recent patients with thrombosed abdominal aortic aneurysms. They presented with a range of symptoms that included impotence, abdominal pain, lower extremity pain, coolness, and weakness. Angiography in three of the patients revealed complete occlusion of the aorta. The fourth patient did not undergo angiography because of hemodynamic instability. Three of the four patients underwent thrombectomy, aneurysmectomy, and bypass grafting. The other patient underwent axillofemoral bypass grafting in lieu of aneurysmectomy because of severe coronary arteriosclerotic heart disease. All patients did well postoperatively. Our limited experience suggests that prompt diagnosis and surgical management of patients with thrombosed aortic aneurysms can lead to a successful outcome.

Ruptured mycotic salmonella aortic aneurysm treated with combined cefotaxime antibiotic and staged surgical management.

A case of salmonella infrarenal aortic aneurysm that ruptured and was treated with staged operative procedures and a highly effective antibiotic is reported and analyzed. An emergency situation with a ruptured abdominal aortic aneurysm required prompt surgical intervention with an aortobifemoral graft insertion. In the immediate postoperative period it was realized that a prosthetic graft was placed in the bed of a mycotic aneurysm. The patient had significant arteriosclerotic occlusive disease limiting the distal anastomotic site to the common femorals. Interoperatively the superficial femorals were noted to be occluded chronically. Consequently, revascularization via an extra-anatomical bypass after aortobifemoral graft removal was more complex. This was managed in a staged delayed fashion, while suppressing the infecting organism with Cefotaxime. The details of this complex situation are described within.

Fibromuscular annular pancreas. A variant of pancreatic malformation?

All reported cases of annular pancreas consist of histologically normal pancreatic tissue. The most widely accepted theory of the pathogenesis of the pancreatic annulus agrees with, and is partially based on this fact. The pancreatic annulus encircling the stenotic second part of the duodenum in our patient was composed of fibromuscular tissue with lymph glands and a few pancreatic acini scattered among the smooth muscle fibers. This unique histologic variant of annular pancreas possible arose from a double fault in the ventrial anlage of the embryonal pancreas: faulty rotation (giving rise to the annular malformation) and abnormal histologic structure.

[Appendiceal carcinoma]. / Appendixkarzinome

Three cases of carcinoma of the vermiform appendix are reported. The rarity of the disease has been emphasized as well as the resulting lack of clinical experience. Medical literature on the subject has been reviewed.