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Biomedical subjects

M Riganti

Publications and source records attributed to M Riganti.

36 records · Page 2Linked to original sources
PubMed1989

Failure of interferon alfa and tribavirin in rabies encephalitis.

OBJECTIVE: To test the effect of interferon alfa and tribavirin (ribavirin) in patients with rabies encephalitis. DESIGN: An open trial of chemotherapy and intensive care in patients with early rabies. SETTING: The intensive care unit of a Bangkok hospital. PATIENTS: Four conscious men with clinical rabies encephalitis. INTERVENTIONS: Rapid virological diagnosis of rabies. Treatment with intravenous and intraventricular injections of high doses of lymphoblastoid interferon alfa in three patients and tribavirin in one patient. Intensive care was given throughout. MAIN OUTCOME MEASURES: Rabies infection confirmed by antigen detection and virus isolation. Rabies neutralising antibody and specific IgM sought in serum and cerebrospinal fluid. Interferon concentrations monitored before and during treatment in three patients. RESULTS: Interferon alfa treatment produced high concentrations in serum and cerebrospinal fluid. All four patients died after 5 1/2 to 12 1/2 days of treatment with no evidence of virostatic or clinically beneficial effects from either treatment. CONCLUSION: Interferon alfa treatment is not effective in rabies encephalitis. The use of tribavirin warrants further study, possibly combined with new therapeutic methods.

Adolescent↗
PubMed1989

Electron microscopic study of phagocytosis in human spleen in falciparum malaria.

The ultrastructure of the spleen of a patient who died of natural infection of Plasmodium falciparum was studied with emphasis on phagocytosis. Parasitized erythrocytes were shown to interact with the heterogenous populations of phagocytic cells. Phagocytosis occurred predominantly in macrophages than endothelial cells and immature forms of parasites were preferentially phagocytosed. Splenic trapping, pitting and destruction of both infected and noninfected erythrocytes were demonstrated. Other forms of interaction between phagocytic cells and parasitized erythrocytes observed include complex interdigitation, association of loose and tight phagosomes, and preferential sites of adherence, the significance of which need further investigation.

Adolescent↗
PubMed1989

Human pathology of Opisthorchis viverrini infection: a comparison of adults and children.

The pathology of human opisthorchiasis in 22 adults (20 to 68 years) and 7 children (7 to 15 years) at autopsy is described. The changes of the liver in adults and children are similar and are summarized as follows: Enlargement of the liver was a common finding. Pericholangitis was observed in most cases. The pathology was confined to the large and medium-sized bile ducts where the flukes inhabited. The small interlobular bile ducts had minimal or unremarkable changes. Dilatation of the bile ducts with hyperplasia, desquamation and proliferation of the bile duct epithelial cells, glandular formation and fibrous connective tissue infiltration of the walls were the most common features. The pathological changes were well established within 7 to 15 years. Dilatation of the gallbladder, chronic cholecystitis and carcinoma were found only in adults. Eight of ten cases were cholangiocarcinoma and two were hepatocellular carcinoma.

Adolescent↗
PubMed1988

Macrophages associated with murine tumours express plasminogen activator activity.

The fibrinolytic activity of cancer cells has been repeatedly implicated in mechanisms of local spread and tumour invasiveness. Mononuclear phagocytes associated with solid tumours might also contribute to fibrin dissolution at the tumour/host interface through the expression of plasminogen activator (PA) activity. We have investigated the PA activity of tumour-associated macrophages (TAM) from 4 transplanted murine tumours in syngeneic hosts; peritoneal macrophages (native and thioglycolate-elicited) from both tumour-bearing and control animals were studied as reference cells. TAM from 3 tumours (MSV, mFS6, MN/MCAI) had basal levels of PA activity (20% plasminogen-independent) comparable to or higher than those of thioglycolate-elicited peritoneal macrophages from the same tumour-bearing animals. TAM isolated from 1 tumour (MS2) had a PA which was very low (60% plasminogen-independent), but higher than the activity of unstimulated peritoneal macrophages. Molecular analysis of PA by SDS-PAGE electrophoresis and fibrin autography revealed in all macrophages a single species having an apparent MW of 48 kDA. It thus appears that, in some experimental neoplasms, tumour cell vicinity may represent an in vivo stimulus for macrophage PA expression.

Animals↗
PubMed1988

Opisthorchis viverrini eggs and adult flukes as nidus and composition of gallstones.

Three cases of opisthorchiasis with calculous cholecystitis was presented. The diagnosis of gallstones was made before praziquantel therapy in 2 cases, and 4 years after treatment in one case. The patients underwent cholecystectomy. Numerous O. viverrini eggs and one dead fluke were found in the bile in one case. A single stone was recovered from each gallbladder. All stones contained O. viverrini eggs. Fragments of flukes were also present in two cases. The stones consisted of a mixture of bilirubin pigment and calcium salts.

Adult↗
PubMed1987

Spleen in falciparum malaria: ultrastructural study.

An ultrastructural study was undertaken of the spleen of 13 year-old-boy who died of falciparum malaria. The spleen revealed the following: both parasitized and non-parasitized erythrocytes are phagocytosed in large numbers by macrophages, littoral and reticular cells. Blood congestion and trapping of parasitized erythrocytes are commonly seen in splenic sinusoids and cords. Erythrocytes forming rosette structure around immuno-presenting cells is observed. The results of this study provide evidence that the mechanisms underlying splenic host defence in malaria include both immunological and non-immunological interaction with erythrocytes. Splenic trapping of parasitized erythrocytes is an important defence mechanism and the phagocytosis of erythrocytes probably accounts for anaemia.

Adolescent↗
PubMed1987

Subcutaneous phycomycosis mimics elephantiasis.

A case of subcutaneous phycomycosis involving the right thigh for 1 year duration which mimic elephantiasis was reported in a 21-year-old military man. An initial diagnosis was that of a subcutaneous tissue lesion attributed to parasitic manifestation but turned out to be that of subcutaneous fungal infection both clinically and histologically. The lesion was successfully treated with cotrimoxazole for a period of one month, and followed up for 4 1/2 months with complete cure.

Adult↗
PubMed1985

Electron microscopy of the human brain in cerebral malaria.

Ultrastructure of erythrocytes infected with Plasmodium falciparum in human brain, obtained 3 hours post mortem revealed gross distortion of host red cells with abnormality of the red cell surface. The superficial alterations of the parasitized cells as knob-like protrusion appear to be the sites of attachment to vascular endothelium. There was evidence of platelets sticking to the injured endothelium. The endothelial vesicular membrane is in close adhesion to the parasitized red cell, and also to the platelets involved in this mechanism. Thus, explaining the sequestration of parasitized red cell and obstruction in cerebral microcirculation, cerebral oedema and low peripheral platelet count. The was no evidence of inflammation, fibrin or thrombus formation observed in our studies.

Adolescent↗
PubMed1985

Clinical features in severe opisthorchiasis viverrini.

Clinical features of severe opisthorchiasis were studied in 88 patients. The ratio of males to females was 6.3 : 1; 75% were over 40 years old. The presenting symptoms were obstructive jaundice, 25% associated with secondary infection of biliary system; cholangitis and cholecystitis; intraabdominal mass, which was enlarged liver; 18% had palpable gallbladder; 18% had adenocarcinoma of the bile duct. High bilirubin was found in 46% of cases, high alkaline phosphatase in 80%; elevation of serum transaminase in 78% and low serum albumin in 62% of patients. There was no correlation between severity of the disease and the faecal egg output. The obstructive jaundice patients had low or no egg output. Two patients had no eggs in stool, but numerous Opisthorchis viverrini eggs and flukes were found in the gallbladder and bile ducts at operation.

Adult↗
PubMed1984

Opisthorchis viverrini infection: pathogenesis and clinical features.

The pathological changes are more or less related to the intensity and the duration of the infection, and are commonly seen in older patients with a large number of flukes. The pathogenesis is due to the mechanical irritation by the flukes and some toxic substances produced by them. Lesions are mainly confined to the biliary system. There is hyperplasia of the epithelial cells lining the bile ducts. In heavy and severe infections there are obstruction of the biliary tract, bile retention, extensive hyperplasia of the biliary system, with glandular proliferation of papillomatous and adenomatous type, cholangitis, periductal infiltration with eosinophils, round cells and fibrosis in the portal areas, necrosis and atrophy of hepatic cells. The bile ducts are dilated and in late cases saccular or cystic formations may develop into large cysts. The gallbladder may enlarge and contain white bile. The liver profile is generally normal. The majority of cases are symptomless. Clinical features vary from mild to severe. The symptoms and signs are vague gastro-intestinal symptoms, flatulence, anorexia, lassitude, weight loss, dull pain at the right hypochondrium, hot cutaneous sensation of the abdomen, and enlargement of the liver with some tenderness. In few cases the manifestations are severe. There is relapsing cholangitis, the patient is seriously ill and may succumb to septic shock. Cholangiocarcinoma, gallstones and obstructive jaundice are not unusual associations.

Bile Ducts↗
PubMed1984

Opisthorchis viverrini: clinical experience with praziquantel in Hospital for Tropical Diseases.

Praziquantel (2-cyclohexylcarbonyl-1,2,3,6,7,11b-hexahydro-4H-pyrazino[2,1-a]++ +isoquinolin- 4-one, EMBAY 8440, Biltricide) has been used in 4853 patients with Opisthorchis viverrini infection. 786 patients were treated as inpatients with extensive clinical evaluation and the rest were out-patients. A cure rate (evaluated with 5 faecal samples) of 100% was obtained in groups given 6 X 25 mg/kg on 2 days and 3 X 25 mg/kg on 1 day, while in groups given 2 X 25 mg/kg, 1 X 25 mg/kg and 1 X 40 mg/kg all on 1 day the cure rates were 88, 44 and 91%, respectively. With one sample evaluation the parasitological cure rate was 96% in further 96 patients excreting the geometric mean (GM) of 5394 eggs per gram (EPG) and receiving 1 X 40 mg/kg. Another 68 patients with an egg output of 26044 (GM/EPG) and treated with 1 X 50 mg/kg showed a cure rate of 97% by similar evaluation. Side effects were mild and transient and were more frequent in higher dosage groups. They included anorexia, nausea, vomiting, abdominal pain, epigastric pain, rumbling in the abdomen, diarrhoea, lassitude, myalgia, headache, dizziness, sleeplessness, sleepiness, "hot sensation", shortness of breath, and skin rash in a few cases. Headache (30.7%) was most common in the 6 X 25 mg/kg group. In 53 patients with severe jaundice the side effects were similar. There was no evidence of toxicity. Remarkable was one patient treated with 1 X 50 mg/kg who expelled 5636 O. viverrini worms, most of which were elongated and damaged. When a single dose is prescribed it should be given at bed time to reduce the side effect of sedation.

Adult↗
PubMed1980

Effects of antibody to Vibrio cholerae El Tor hemolysin on pathological changes of the intestines in cholera.

Pathological abnormalities of the infant mouse small intestines were evident after V.cholerae El Tor, Ogawa, infection. These were revealed by an enteritis manifested by mononuclear cells containing inflammatory exudate, intervillous blood capillary congestion, marked increase in goblet cells, desquamation of epithelium and diapedesis of cells. Mice received V.cholerae pretreated with high concentration of antihemolysin, though developed diarrhea, had marked decrease in pathological severity. The less amount of the antibodies the more pathological changes were found.

Animals↗
PubMedDate not supplied

DMSO-induced changes in the procoagulant and fibrinolytic activity of B16 melanoma cells: influence on lung colony formation.

In this study DMSO (dimethylsulphoxide) was used as a tool to test the significance of in vitro modifications of procoagulant and fibrinolytic activity of tumor cells for their in vivo metastatic ability. B16 melanoma cells were chosen as the experimental model. After four days' treatment DMSO increased both the procoagulant and fibrinolytic (plasminogen activator) activity of B16 melanoma cells in a dose-related manner. DMSO treated cells showed significantly greater lung colonizing ability than untreated cells. Our results indicate that DMSO treatment in vitro can modulate procoagulant and fibrinolytic activity and the metastatic ability of B16 melanoma cells; however a direct causal relationship between these in vitro and in vivo effects remains to be established.

Animals↗