Association of the therapeutic activity of praziquantel with the reversal of Symmers' fibrosis induced by Schistosoma mansoni

The impact of antischistosomal chemotherapy on the most important complication of intestinal schistosomiasis, Symmers' periportal fibrosis, has not been determined. Since abdominal ultrasonography has proven to be an effective tool in assessing the extent of Symmers' fibrosis in patients, we monitored the effect of chemotherapy, which involved the annual administration of praziquantel, on 48 Sudanese villagers having varying degrees of Symmers' fibrosis. Results indicate no significant differences in the fibrotic status of the 48 patients between 1986 and 1987, but test statistics (both the Wilcoxon signed rank test and Friedman's block/treatment test), indicated a significant decrease between the fibrotic status of the patients in 1986 and their fibrotic status in 1988 and 1989. Thus, after three years of therapy, 12 of the 48 patients no longer had detectable Symmers' fibrosis, while another 16 patients experienced a reduction in the amount of fibrosis in their livers. When coupled with our previous study, which demonstrated that annual treatment of children with praziquantel prevents the appearance of Symmers' fibrosis, it now appears that praziquantel may reverse this schistosomal-induced pathology.

Hypothyroidism: effect on warfarin anticoagulation

Although our observation is not the first case of reduced PT response to oral anticoagulants associated with hypothyroidism, it is the only such interaction reported since 1963, and the first case involving warfarin therapy in a human being. We submit this case as a reminder of a potentially forgotten interaction, and to stress the importance of close monitoring in patients receiving warfarin therapy who have concomitant changes in thyroid function.

Long term results of vein valve transplants placed in the popliteal vein for intractable post-phlebitic venous ulcers and pre-ulcer skin changes

Most patients with chronic venous ulceration or severe pre-ulcer damaged skin have incompetent popliteal valves and a high ambulant venous pressure (AVP). Competency can be restored by a vein valve transplant taken from the arm and placed in the popliteal fossa, with subjective and objective improvement. In this study 23 patients with post-phlebitic syndromes received 25 vein valve grafts as part of management. Seventeen patients had large recurrent ulcers after unsuccessful venous surgery: 6 patients had extensive pre-ulcer skin damage. Fifteen of 17 patients healed their ulcers, and all 6 patients with skin damage showed rapid improvement with relief of symptoms. Falls in the AVP, ranging from 10 to 40 mmHg occurred in 19 patients. All vein valve transplants were patent, after 18 months, but 5 grafted valves have evidence of venous reflux. These results suggest a functioning valve replacement in the popliteal fossa may lower the AVP sufficiently to heal intractable venous ulcers or severely damaged skin. Vein valve transplants function well long term, and the falls in the AVP are usually maintained. The popliteal fossa may be the ideal site since a component popliteal valve has been shown to limit adverse post-phlebitic changes.

Effect of antischistosomal chemotherapy on prevalence of Symmers' periportal fibrosis in Sudanese villages

Almost all mortality caused by Schistosoma mansoni is secondary to Symmers' periportal fibrosis of the liver which can now be diagnosed by ultrasonography. This study assessed the usefulness of ultrasonography in measuring the effect of chemotherapy on the prevalence of Symmers' periportal fibrosis in Sudanese villagers. The prevalence of Symmers' fibrosis in 318 randomly selected patients from two villages not receiving systemic antischistosomal chemotherapy was compared with that in 168 patients from a village where antischistosomal chemotherapy had been systematically applied since 1979. The prevalence of Symmers' fibrosis was two to three times lower among treated villagers, with an eight-fold difference for villagers aged 10-20 years.

Morbidity associated with Schistosoma mansoni infection as determined by ultrasound: a study in Gezira, Sudan

Previous studies demonstrated the usefulness of ultrasonography in diagnosing Symmers' periportal fibrosis. The prevalence and grade of Symmers' fibrosis was determined using ultrasonography in two villages in the Gezira region of Sudan and compared to standard clinical criteria. In El Dar 18% and Abu Jin 13% of the population had Symmers' fibrosis by ultrasonography. In contrast, only 6.3% in El Dar and 5.2% in Abu Jin with Symmers' fibrosis had splenomegaly, thus most of the population with Symmers' fibrosis would not have been diagnosed clinically. The degree of involvement was estimated by a set of previously defined criteria which ranged from mild (grade 1) to severe (grade 3). Involvement was greatest between 20-30 years and followed the age peak egg excretion rate by 5 years. The prevalence and degree of splenomegaly as well as the portal and splenic vein diameters increased with grade. The presence of hepatomegaly did not correlate with increasing grade. Ultrasonography is a much more sensitive technique than clinical evaluation in estimating the degree of Symmers' fibrosis in this population. A more accurate assessment of involvement will allow a more rational approach to the study of the pathophysiology of this complication and its eventual control.