Antiherpetic efficacy of aqueous extracts of the cyanobacterium Arthrospira fusiformis from Chad

Natural substances offer interesting pharmacological perspectives for antiviral drug development with regard to broad spectrum antiviral properties and novel modes of action. Drugs currently used to treat cutaneous or genital herpetic infections are effective in limiting disease, but the emergence of drug-resistant viruses in immunocompromised individuals can be problematic. A nontoxic cyanobacterium Arthrospira strain from Chad has been characterized by sequence analysis of the intergenic spacer region of the phycocyanin gene. This cyanobacterium was identified as Arthrospira fusiformis by phylogenetic tree analysis. The antiherpetic activity of crude aqueous extracts from the Chad A. fusiformis isolate was determined. Antiviral efficacy against herpes simplex virus of cold water extract, hot water extract and phosphate buffer extract was assessed in plaque reduction assays and their mode of antiherpetic action was analysed. In virus suspension assays, cold water extract, hot water extract and phosphate buffer extract inhibited virus infectivity by 54.9%, 64.6%, and 99.8%, respectively, in a dose-dependent manner. The mode of antiviral action was determined by addition of cyanobacterial extracts separately at different time periods during the viral infection cycle. Extracts of A. fusiformis strain clearly inhibited herpesvirus multiplication before and during virus infection of host cells. The phosphate buffer extract of the A. fusiformis strain affected free herpes simplex virus prior to infection of host cells and inhibited intracellular viral replication. It is concluded, that Arthrospira compounds warrant further investigation to examine their potential role in the treatment of herpetic infections.

Molecular authentication and characterization of the antiherpetic activity of the cyanobacterium Arthrospira fusiformis

In recent years there has been an increasing interest for application of natural products as antiinfectives and concerns about the safety of synthetic compounds have encouraged more detailed studies of natural resources. Two different strains of the nontoxic cyanobacterium Arthrospira from the United States and Egypt have been characterized by sequence analysis of the intergenic spacer region of the phycocyanin gene. Both cyanobacteria were identified as Arthrospira fusiformis by phylogenetic tree analysis. The antiherpetic activity of crude aqueous extracts from the US and the Egyptian A. fusiformis isolates was determined. Antiviral activity against herpes simplex virus of cold water extracts, hot water extracts and phosphate buffer extracts from the American and the Egyptian strains was assessed in plaque reduction assays and their mode of antiherpetic action was analysed. In virus suspension assays, all extracts of the American cyanobacterium and the phosphate buffer extract of the Egyptian cyanobacterium inhibited virus infectivity by > 90% in a dose-dependent manner. Phosphate buffer extract and hot water extract of the US cyanobacterium demonstrated the highest antiviral activity at low extract concentrations with high selectivity indices of 7464 and 542, respectively. The mode of antiviral action has been determined by addition of cyanobacterial extracts separately at different time periods during the viral infection cycle. Two extracts of the US A. fusiformis strain clearly inhibited herpesvirus multiplication before and after virus infection of host cells. In contrast, extracts of the Egyptian A. fusiformis strain affected only free herpes simplex virus prior to infection of host cells by direct inactivation of virus particles. In this study different Arthrospira crude extracts showed a significant antiviral effect and might be applied in recurrent herpetic infections.

Pathogenesis of varices in schistosomal portal hypertension

Patients with schistosomiasis and portal hypertension have significantly lower levels of hydroxyproline in their saphenous veins and anterior rectus sheaths than do individuals without schistosomal hepatic fibrosis. The stomach of patients with schistosomal portal hypertension demonstrates an increased number of lymphatics by lymphangiography. The disrupted lymph node architecture in these patients could be partially responsible for dilation, tortuosity, and retrograde lymph flow in the gastric lymphatics. These histological and lymphangiographic findings could be attributed to the effect of venous and patients with decompensated schistosomal portal hypertension revealed edema of the entire esophageal wall with lymphatic dilation and tortuosity. Based upon these data, we suggest that the varices that develop in patients with schistosomal portal hypertension occur as a consequence of an increased portal venous pressure together with acquired lymphangiectasia as well as an intrinsic weakness of the walls of the portosystemic venous channels.

Oesophageal varices in schistosomiasis: treatment with a modified Warren's distal splenorenal shunt

Thirty-five patients of bleeding oesophageal varices were treated by modified Warren's distal splenorenal procedure. In this procedure the spleen was removed. The value of the technique in maintaining liver perfusion, and relieving hypersplenism is discussed.

The role of lymphovenous communication in the development of postmastectomy lymphedema

Forty women were investigated 6 to 24 months after radical mastectomy for the presence of functioning lymphovenous communications in the arm; 20 cases were edematous and the rest were not. Ten normal volunteer women were also investigated and served as controls. Iodinated (I125) human serum albumin was injected intralymphatically in the arm, and samples of blood were taken from both basilic veins simultaneously at 5, 10, 15, 30, 45, and 60 minutes. The radioactivity of each sample was determined with a scintillation counter. Lymphangiography was performed in all cases 1 month after the isotopic studies and lymphangiograms were evaluated for the presence of lymphovenous shunts. In the volunteers and the edematous postmastectomy group, there was negligible lymphovenous shunting of labeled albumin. In the nonedematous postmastectomy group, there was an increased quantity of local lymphovenous transfer of iodinated albumin. Lymphovenous shunts were detected radiologically in two patients who did not have edema. On the basis of our observations, the incidence of postmastectomy lymphedema is predetermined and is a consequence of the lack of existence of lymphovenous communications that can allow adequate lymph flow drainage from the arm after radical dissection of axillary lymph nodes.

Thoracic duct decompression by side to end anastomosis to external jugular vein

A new technique for internal decompression of thoracic duct in protal hypertension by anastomosis of the external jugular vein to the side wall of the thoracic duct is described.

Prolapse of the rectum in young men: treatment with a modified Roscoe Graham operation

Twenty-two cases of massive rectal prolapse were treated by the modified Roscoe Graham procedure. In this series, the disease was more common in young men. Intestinal schistosomiasis was present in most cases. The value of the technique in maintaining normal ejaculatory function is discussed.

The role of lymphatics in the formation of ascites complicating schistosomal hepatic fibrosis

The total protein content in plasma, ascitic fluid, thoracic duct lymph, hepatic and intestinal lymph was studied in a series of 15 patients suffering from schistosomal hepatic fibrosis and intractable ascites. Pure schistosomal cases with presinusoidal resistance to portal blood flow have excessive thoracic duct lymph low in protein. The main source of such excess lymph is the extra-hepatic portal bed. Ascitic fluid in such patients has a low protein content and has the character of a transudate. The bulk of such peritoneal fluid seems to originate largely from the excess extrahepatic portal lymph.

Thoracic duct changes in schistosomal hepatic fibrosis

The changes in the thoracic duct were studied in schistosomatic hepatic fibrosis, particularly in cases with ascites. The postmortem findings, lymphangiography, and clinical thoracic duct cannulation showed that, particularly in cases with ascites, the thoracic duct is dilated, pressure within is raised, and the lymph flow is increased. The significance of these findings is discussed in relation to the site and the treatment of ascites.

Histopathological study of lymphocyte transfer in man

The normal lymphocyte reaction was studied in 24 subjects by skin window technique and skin biopsies.

The skin window technique revealed eosinophilia and basophilia in response to homologous lymphocyte injection. Within 36 hr. accumulation of pyroninophilic cells started to appear in the exudates.

Biopsies showed that the reaction is accompanied by mononuclear cellular infiltration typical of that seen in the delayed hypersensitivity reaction. Vacuolation of the epidermal cells was also seen.