Pulmonary shunts in severe hepatosplenic schistosomiasis: Diagnosis by contrast echocardiography and their relationship with abdominal ultrasound findings

Background

Schistosomiasis is endemic to several parts of the world. Among the species that affect humans, Schistosoma mansoni is one of the most common causes of illness. In regions where schistosomiasis mansoni is endemic, reinfection is responsible for the emergence of hepatosplenic schistosomiasis (HSS) with portal hypertension in about 10% of infected individuals. Regardless of its etiology, portal hypertension may bring about the formation of arteriovenous fistulas and pulmonary vascular dilation, thus constituting a pulmonary shunt and its presence has been associated with the occurrence of neurological complications. The objective of this study was to identify pulmonary shunt using TTCE in patients with HSS and esophageal varices, and to compare the abdominal ultrasound and endoscopy findings among patients with and without pulmonary shunt.

Methodology/Principal findings

In this case series, a total of 461 patients with schistosomiasis mansoni were prospectively evaluated using abdominal ultrasound and endoscopy and 71 presented with HSS with esophageal varices. Fifty seven patients remained in the final analysis. The mean age of the patients was 55 ± 14 years, and 65% were female. Pulmonary shunts were observed in 19 (33.3%) patients. On comparing the groups with and without pulmonary shunt, no significant differences were observed in relation to the abdominal ultrasound and endoscopic findings. When comparing the two subgroups with pulmonary shunts (grade 1 vs grades 2 and 3), it was observed that the subgroup with shunt grades 2 and 3 presented with a significantly higher frequency of an enlarged splenic vein diameter (>0.9 cm), and an advanced pattern of periportal hepatic fibrosis (P = 0.041 and P = 0.005, respectively). None of the patients with pulmonary shunts had severe neurological complications.

Conclusions/Significance

Our findings suggest that in HSS with esophageal varices the pulmonary shunts may be present in higher grades and that in this condition it was associated with ultrasound findings compatible with advanced HSS.

Among the species of Schistosoma that infect humans Schistosoma mansoni is one of the most common causes of illness. In the areas where schistosomiasis mansoni is endemic, around 10% of infected individuals develop hepatosplenic schistosomiasis (HSS) with portal hypertension. Portal hypertension may promotes an imbalance in the hepatic production of vasoactive substances, which may act on the lungs promoting the formation of arteriovenous fistulas and pulmonary vascular dilation, a condition that is called a pulmonary shunt. When the pulmonary shunt is of higher grades, small thrombus or septic emboli that would normally be filtered through the pulmonary capillaries reach the left heart and the systemic circulation, which can lead to neurological complications. We found pulmonary shunts in patients with HSS and esophageal varices and we also found that patients with higher grades of pulmonary shunts presented with a significantly higher frequency of advanced periportal fibrosis and an enlarged splenic vein diameter. No neurological complications were observed. Our findings suggest that pulmonary shunts may be present in patients with HSS and esophageal varices. The abdominal ultrasound findings compatible with advanced HSS could be used as screening to investigate pulmonary shunt.

Remodeling of hepatic vascular changes after specific chemotherapy of schistosomal periportal fibrosis

Hepatosplenic schistosomiasis was the first human disease in which the possibility of extensive long standing hepatic fibrosis being degraded and removed has been demonstrated. When such changes occurred, the main signs of portal hypertension (splenomegaly, esophageal varices) progressively disappeared, implying that a profound vascular remodeling was concomitantly occurring. Hepatic vascular alterations associated with advanced schistosomiasis have already been investigated. Obstruction of the intrahepatic portal vein branches, plus marked angiogenesis and compensatory hyperplasia and hypertrophy of the arterial tree are the main changes present. However, there are no data revealing how these vascular changes behave during the process of fibrosis regression. Here the mouse model of pipestem fibrosis was used in an investigation about these vascular alterations during the course of the infection, and also after treatment and cure of the disease. Animals representing the two polar hepatic forms of the infection were included: (1) "isolated granulomas" characterized by isolated periovular granulomas sparsely distributed throughout the hepatica parenchyma; and (2) 'pipestem fibrosis' with periovular granulomas and fibrosis being concentrated within portal spaces, before and after treatment, were studied by means of histological and vascular injection-corrosion techniques. Instances of widespread portal vein obstruction of several types were commonly found in the livers of the untreated animals. These obstructive lesions were soon repaired, and completely disappeared four months following specific treatment of schistosomiasis. Treatment was accomplished by the simultaneous administration of praziquantel and oxamniquine. The most impressive results were revealed by the technique of injection of colored masses into the portal system, followed by corrosion in strong acid. The vascular lesions of non-treated pipestem fibrosis were represented in the plastic casts by considerable diminution of the fine peripheral portal vein radicles, plus dilatation of periportal collaterals. Four months after treatment, this last picture appeared replaced by tufts of newly interwoven vessels formed along the main portal vein branches, disclosing a strong angiomatoid reparative change. Understanding about the cellular elements at play during fibro-vascular repairing changes of hepatic schistosomiasis represents a matter of considerable scientific and conceptual importance. At present time one may only speculate about the participation of some type of natural stem-cell capable of restoring the diseased liver back to normal once the cause of the disorder has been eliminated.

Th2 cytokines are associated with persistent hepatic fibrosis in human Schistosoma japonicum infection

We conducted a prospective cohort study in Leyte, the Philippines, among 611 Schistosoma japonicum-infected participants 7-30 years old, all of whom were treated with praziquantel at baseline. To detect hepatic fibrosis, abdominal ultrasound was performed at baseline and 12 months after treatment. Stool for assessment of S. japonicum infection was collected at baseline and at 3, 6, 9, and 12 months after treatment. Cytokines (interleukin [IL]-4, IL-5, IL-10, IL-13, tumor necrosis factor- alpha , and interferon- gamma ) produced by peripheral-blood mononuclear cells in response to soluble worm antigen preparation (SWAP), soluble egg antigen (SEA), and control medium were measured once 4 weeks after treatment. IL-4 to SWAP and IL-10 to both SWAP and SEA were associated with the presence of baseline fibrosis after adjustment for potential confounding variables (P<.03, for all). In participants with fibrosis at baseline, IL-4 to SWAP and IL-5 and IL-13 to both SWAP and SEA were associated with persistent fibrosis at 12 months after treatment (P<.05, for all). Males showed consistently stronger T helper 2 (Th2) cytokine responses to both SWAP and SEA than did females (P<.02, for all). These results suggest an independent role for Th2-biased cytokine responses to S. japonicum antigens in persistent hepatic fibrosis and indicate that Th2 cytokines may contribute to the male-biased prevalence of fibrosis.

Assessment of portal hemodynamics by Doppler ultrasound and of liver morphology in the hepatosplenic and hepatointestinal forms of schistosomiasis mansoni

The aim of this study was to compare portal and splenic blood flows and the liver morphology in hepatosplenic (HS) and hepatointestinal (HI) schistosomiasis. Doppler ultrasound measurements were performed in 48 adult patients with schistosomiasis, according to the criteria of the World Health Organization, and compared with those performed in 20 healthy controls. Portal flow was significantly higher (P < 0.0001) in both HS and HI (2481 +/- 1467 and 2159 +/- 1446 ml/min, respectively) than in normal individuals (842 +/- 322 ml/min). There was no difference in splenic blood flow (822 +/- 685 and 458 +/- 292 ml/min, respectively) between HS and HI, but these values were significantly higher than those of normal controls (243 +/- 94 ml/min). Portal and splenic overflow are found in both the HS and the HI forms of schistosomiasis.

Interleukin-5 (IL-5) augments the progression of liver fibrosis by regulating IL-13 activity

Eosinophils are frequently found in increased numbers in a variety of chronic fibrotic diseases; however, their role in the development of hepatic fibrosis has not been dissected in vivo. Here, we used interleukin-5 (IL-5) knockout (KO) mice to determine whether eosinophils contribute to the progressive liver fibrosis that develops in response to chronic Schistosoma mansoni infection. Although infection intensities were similar in C57BL/6 and IL-5 KO mice, the average size of granulomas was significantly smaller in both acutely and chronically infected IL-5 KO mice. Their granulomas were also completely devoid of eosinophils. In addition, the knockout mice displayed over a 40% reduction in hepatic fibrosis by week 16 postinfection. The reduced fibrosis was associated with increased production of the antifibrotic cytokine gamma interferon. Moreover, although IL-13 production did not decrease consistently in the absence of IL-5, IL-13-triggered responses were substantially reduced in the granulomatous tissues. This was confirmed by analyzing the expression of several genes associated with alternative macrophage activation, including arginase 1, Fizz-1, and YM-1. Importantly, all of these IL-13-regulated genes have been linked with the mechanisms of wound healing and fibrosis. In addition to IL-5 polarizing the antigen-specific CD4+ Th2 cell response, we found that granuloma eosinophils were themselves a significant source of IL-13. Thus, by producing profibrotic mediators and polarizing the Th2 response, these findings illustrate both direct and indirect roles for eosinophils and IL-5 in the pathogenesis of schistosomiasis-induced liver fibrosis. Thus, inhibiting the activity of IL-5 or eosinophils may prove effective for a variety of chronic fibrotic diseases.

Experimental amebiasis: a selected review of some in vivo models

The use of in vivo animal models in amebiasis has contributed significantly to the knowledge of this common human parasitic disease. Although there is no animal model that mimics the whole cycle of the human disease, the use of different susceptible and resistant laboratory animals and the availability for many years of techniques for the axenic culture of trophozoites of Entamoeba histolytica have allowed a better understanding of the parasite and the host-parasite relationship. The recent introduction of frontier methodologies in biology has increased our comprehension of this parasite. New information on the cellular and molecular biology and genetics of this organism has been extensively reported, and much of this has clearly required the more frequent use of animal models to verify specific facts. Based on experimental animals characterized previously, the introduction of new animal models with genetic or surgical modifications, especially in mice, has allowed a more adequate analysis of the mechanisms of pathogenesis. Multiple factors have been considered in the promotion of the invasiveness and virulence of E. histolytica. Additionally, the immunological and physiological responses of the host, depending on the environmental conditions, lead to the establishment or the rejection of the parasite. The role of inflammatory reaction to amebic infection constitutes one of the controversies that has been studied by several authors. In susceptible animals (hamsters and gerbils), inflammatory cell damage seems to be related to target cell lysis, while in resistant animals (mice), inflammatory cells appear to protect the host by lysing the parasite. Presently, the involvement of various substances in the development of lesions including lectins, proteases, amebapores, promoters of apoptosis, cytokines, nitric oxide, etc., is being examined using different in vivo models.

Cytokine production associated with periportal fibrosis during chronic schistosomiasis mansoni in humans

Volunteers living in an area where schistosomiasis mansoni is endemic were subjected to ultrasound examination and classified into groups according to the levels of fibrosis diagnosed, namely, absence of indications of fibrosis (group 0), incipient fibrosis (group 1), and moderate/severe fibrosis (group 2). Peripheral blood mononuclear cells (PBMC) collected from the volunteers were stimulated with soluble antigens from adult schistosomes or from schistosome eggs, and the production of the cytokines gamma interferon, tumor necrosis factor alpha, transforming growth factor beta (TGF-beta), interleukin-4 (IL-4), IL-10, and IL-13 was determined. Potential associations of the level of fibrosis with age, sex, intensity of infection, and cytokine production were investigated between the three groups. Univariate analysis identified associations of age (>50), gender (male), and absence of eggs/g of feces with moderate/severe fibrosis and an association of intensity of infection (>100 eggs) with incipient fibrosis. When cytokine production in PBMC cultures stimulated by soluble egg antigens was categorized as low or high, significant differences in the distribution of IL-13 levels were established between groups 0 and 2. No significant differences were detected between the groups in the cytokines produced by PBMC cultures stimulated with soluble antigens from adult schistosomes. When all variables were tested in multivariate analyses, only IL-13 was strongly associated with fibrosis (odds ratio = 5.8; 95% confidence interval [CI] = 1.1 to 30.5). While high levels of TGF-beta appeared to be associated with protection against fibrosis, the strength of the association was low.

[Regression of hepatic fibrosis]

Extensive and persistent hepatic fibrosis has for a long time been considered irreversible. However, recent studies on the behavior of hepatic fibrosis, especially those related to evolution and involution of advanced schistosomiasis in man, have challenged this concept, and nowadays it is becoming clear that any type of fibrosis is reversible, including that associated with hepatic cirrhosis. The problem consists in identifying and eliminating its cause. Although fibrosis in the liver has little functional significance by itself, its severity derives from associated vascular changes. However, new data on fibrosis regression indicate that disappearance of fibrosis is usually accompanied by remodeling of vascular changes. But, there are peculiarities related to the anatomic type of fibrosis and to its functional significance, which suggest that sometimes fibrosis may indeed be irreversible. These aspects, some of which in need of further studies, are presented and discussed herein.

A spectral analysis of the myoelectric activity of the left colon in patients with schistosomiasis mansoni

The objective of the present study was to perform a spectral analysis of the electrical activity of the left colon of patients with hepatosplenic schistosomiasis. Thirty patients were studied, divided into 2 groups: group A was composed of 14 patients (9 males and 5 females) with hepatosplenic schistosomiasis and group B was composed of 16 female patients without schistosomiasis mansoni. Three pairs of electrodes were implanted in the left colon at the moment of the surgical treatment. The signals of the electric activity of the colon were captured after postoperative recovery from the ileus and fed into a computer by means of a DATAQ data collection system which identified and captured frequencies between 0.02 and 10 Hz. Data were recorded, stored and analyzed using the WINDAQ 200 software. For electrical analysis, the average voltage of the electrical wave in the three electrodes of all patients, expressed as millivolts (mV), was considered, together with the maximum and minimum values, the root mean square (RMS), the skewness, and the results of the fast Fourier transforms. The average RMS of the schistosomiasis mansoni patients was 284.007 mV. During a long period of contraction, the RMS increased in a statistically significant manner from 127.455 mV during a resting period to 748.959 mV in patients with schistosomiasis mansoni. We conclude that there were no statistically significant differences in RMS values between patients with schistosomiasis mansoni and patients without the disease during the rest period or during a long period of contraction.

[Experimental grounds of a new concept of Opisthorchis felineus infection formation in a definitive host]

In the course of experiments in was found out that golden hamsters having the bilious duct operationally blocked display receptivity to the infection with the non-excysted Opisthorchis felineus metacercariae passed to the stomach. Excysted metacercariae injected to the system of the portal vein settle down in the bilious pathways of the liver and develop there up to the adult stage. In vitro, the metacercariae survive in the blood serum of the intact golden hamsters during one day. Based on the experiments, it is hypothesized that the early stage of O. felineus infection in the bilious duct of definitive hosts is performed by means of hematogenic migration of metacercariae through the portal veins system from the mucous layer of the alimentary tract of the host.

Successful ivermectin treatment of hepatic strongyloidiasis presenting with severe eosinophilia

A 49-year-old, previously healthy nurse presented with hepatic lesions and severe peripheral eosinophilia due to strongyloidiasis. Imaging studies of the abdomen showed predominantly peripheral, confluent hepatic lesions. The hepatic lesions and eosinophilia did not show any improvement with albendazole, but completely resolved with ivermectin treatment. Our findings suggest that Strongyloides stercoralis can present with isolated focal hepatic lesions and severe eosinophilia, and resolves with ivermectin treatment.

Association of type 2 cytokines with hepatic fibrosis in human Schistosoma mansoni infection

The objective of this study was to evaluate the role of cytokines in hepatic fibrosis in the prehepatosplenic and early hepatosplenic stages of schistosomiasis mansoni. Hepatic fibrosis was classified by ultrasonography of 94 patients. Immunological evaluation was performed by the measurement of secreted cytokines (interleukin-5 [IL-5], IL-10, IL-13, gamma interferon, tumor necrosis factor alpha, and transforming growth factor beta) in peripheral blood mononuclear cells (PBMC) stimulated by Schistosoma mansoni antigens. Significantly, higher levels of IL-5, IL-10, and IL-13 were found in supernatants of soluble egg antigen-stimulated PBMC from subjects with degree III hepatic fibrosis compared to patients with degree I or II fibrosis. Significant increases in IL-5 and IL-13 levels were also observed in some of the subjects who remained untreated for 1 year following initial assessment and developed more serious fibrosis during this period. The data suggest a role for type 2 cytokines in hepatic fibrosis in human schistosomiasis mansoni.

Portal hyperflow in patients with hepatosplenic mansonic schistosomiasis

PURPOSE

The purpose of this study was to assess portal hemodynamics in patients with portal hypertension due to hepatosplenic schistosomiasis as well as to assess the contribution of splanchnic hyperflow to the pathophysiology of the portal hypertension.

METHODS

Sixteen patients with schistosomal portal hypertension and previous history of upper digestive bleeding due to esophageal varices rupture underwent elective esophagogastric devascularization and splenectomy and were prospectively studied. All patients underwent intraoperative invasive hemodynamic portal monitoring with a 4F-thermodilution catheter. The intraoperative portal hemodynamic assessment was conducted after laparotomy (initial) and after esophagogastric devascularization (final).

RESULTS

The initial portal pressure was elevated (mean 28.5 +/- 4.5 mm Hg), and a significant drop of 25% was observed at the end of the surgery (21.9 +/- 4.9 mm Hg). The initial portal flow was elevated (mean 1766.9 +/- 686.6 mL/min). A significant fall (42%) occurred at the end of the surgical procedure (1025.62 +/- 338.7 mL/min). Fourteen patients (87.5%) presented a portal flow of more than 1200 mL/min, and in 5 cases, values greater than 2000 mL/min were observed.

CONCLUSIONS

Esophagogastric devascularization and splenectomy promote a significant reduction of the elevated portal pressure and flow in schistosomal portal hypertension. These data favor the hypothesis of portal hyperflow in the physiopathology of portal hypertension of schistosomiasis.

Prevalence of pulmonary hypertension in patients with hepatosplenic Mansonic schistosomiasis--prospective study

BACKGROUND/AIMS

Thirty-four patients with portal hypertension and previous history of esophageal varices hemorrhage due to hepatosplenic Mansonic schistosomiasis were prospectively studied.

METHODOLOGY

All patients underwent invasive hemodynamic monitoring with introduction of a pulmonary artery catheter. Hemodynamic evaluation was characterized by an increased cardiac index (4.90 +/- 1.27 L/min/m2) associated to a decrease in systemic vascular resistance index (1461 +/- 443.04 dynes.sec/cm5.m2).

RESULTS

Mean pulmonary artery pressure (17.97 +/- 6.97 mmHg) and right atrial pressure (7.65 +/- 3.67 mmHg) were increased while pulmonary vascular resistance index was decreased (147.95 +/- 126.21 dynes.sec/cm5.m2). Twenty-four patients (70.5%) presented pulmonary hypertension (mean pulmonary artery pressure > 15 mmHg); in fifteen (44.1%) pulmonary pressure was between 15 and 20 mmHg, in three between 20 and 25 mmHg and, in four patients, pulmonary pressure was higher than 25 mmHg.

CONCLUSIONS

In conclusion, pulmonary hypertension is a frequent complication in patients with portal hypertension due to hepatosplenic Mansonic schistosomiasis and, in 20.6% of the cases, it can be considered as moderate or severe. Our results suggest that shunt surgeries, which can aggravate pulmonary hypertension, should be employed very cautiously in the treatment of schistosomal portal hypertension.

Retinal fluorescein contrast arrival time of young patients with the hepatosplenic form of the Schistosomiasis mansoni

Schistosoma mansoni is responsible for lesions that can alter the hemodinamic of the portal venous circulation, lung arterial and venous sistemic systems. Therefore, hemodinamic changes in the ocular circulation of mansonic schistosomotic patients with portal hypertension and hepatofugal venous blood flow is also probable. The purpose of this study was to determine the fluorescein contrast arrival time at the retina of young patients with the hepatosplenic form of schistosomiasis, clinically and surgically treated. The control group included 36 non schistosomotic patients, mean age of 17.3 years, and the case group was represented by 25 schistosomotic patients, mean age of 18.2 years, who were cared for at The University Hospital (Federal University of Pernambuco, Brazil), from 1990 to 2001. They underwent digital angiofluoresceinography and were evaluated for the contrast arrival time at the early retinal venous phase of the exam. Both groups were ophthalmologically examined at the same hospital (Altino Ventura Foundation, Recife, Brazil), using the same technique. There was retardation of the retinal contrast arrival time equal or more than 70 sec in the eyes of three schistosomotic patients (12%) and in none of the control group, however, the mean contrast arrival time between the two groups were not statistically different. These findings lend support to the hypothesis that there could be a delay of the eye venous blood flow drainage.

Duplex Doppler ultrasound of hepatic Schistosomiasis japonica: a study of 47 patients

This study describes the ultrasound (US) appearances of the liver with hepatic schistosomiasis japonica (HSJ), and studies the portal hemodynamics in 47 patients with HSJ using duplex Doppler US over a period of 15 years. All patients but two were Chinese war veterans seen in Taiwan about 35-55 years after their presumed infection in Mainland China. The US presentations were reviewed. The data from Doppler portal flow studies were available for 39 patients with HSJ, and compared to data from Doppler portal flow studies in 40 normal healthy volunteers and to this data in 40 patients with postnecrotic cirrhosis. A typical "coarse reticular pattern" due to fibrosis in the whole liver was noted in 40 patients (85%). Other findings included periportal fibrosis (15%), septum-like fibrous bands extending to the liver capsule (32%), and an apparent nodular liver surface (19%). Splenomegaly was noted in seven patients. While coexisting hepatocellular carcinomas (HCC) were evident in three patients, and esophageal varices were found in three others, yet both conditions were found only in patients with positive hepatitis-B-surface antigen (HBsAg). Doppler flowmetry of the portal veins in HSJ patients showed a mean flow rate of 15.34 +/- 6.82 cm/sec, and a mean flow volume of 993.21 +/- 290.63 ml/min, both showed no significant difference from those in normal adults (p > 0.5). HSJ can be confidently diagnosed in patients with hepatic fibrosis when the hepatic pathology is presented as a coarse reticular pattern. The portal hemodynamics in HSJ patients who have been isolated from the infection site (for more than 35 years) are significantly different from portal hemodynamics in cirrhotic patients and are similar to those in healthy volunteers.

[Late morphologic and hemodynamic changes in the splenic territory of patients with mansoni's hepatosplenic schistosomiasis after distal splenorenal shunt. (Ultrasonography-Doppler study)]

BACKGROUND

The distal splenorenal anastomosis (Warren's operation) has been indicated for the treatment of high digestive bleeding caused by esophagic varices because it would ideally reduce the venous pressure in the cardiotuberositary territory without changing the mesenteric-portal venous flow. However, the changes it produce in the splenic territory have not been fully understood.

AIM

To appraise the late morphologic and hemodynamic changes in the splenic territory produced by the distal splenorenal anastomosis in patients with portal hypertension due to mansoni's hepatosplenic schistosomiasis complicated by esophagic bleeding.

METHOD

Ultrasonography-Doppler study of the splenic region of 52 patients with portal hypertension due to mansoni's schistosomiasis and previous bleeding by esophagic varices. They were divided in two groups: 40 non operated upon and 12 with a distal splenorerenal anastomosis. The following parameters and indices were compared between the two groups: a) morphometric parameters (splenic artery and vein's diameter, splenic diameters (longitudinal, transversal and antero-posterior); b) velocimetric parameters of the splenic vessels (systolic peak velocity in the splenic artery, mean flow velocity in the splenic vein; c) biometric index of the spleen (longitudinal x transversal); volumetric index of the spleen (longitudinal x transversal x antero-posterior x 0,523); hemodynamic indices of the splenic artery's impedance: pulsatility and resistivity.

RESULTS

The patients with distal splenorenal anastomosis showed: a) reduction in splenic indices: volumetric (non operated 903,83 +/- 452, 77 cm / distal splenorenal anastomosis 482,32 +/- 208,02 cm (46,64%)) and biometric (non operated 138,14 +/- 51,89 cm /distal splenorenal anastomosis 94,83 +/- 39,83 cm (33,35%)); b) no change: splenic artery's diameter (non operated 0,57 +/- 0,16 cm/distal splenorenal anastomosis 0,57 +/- 0,23 cm); velocity in the splenic artery non operated 107 +/- 42,02 cm/seg/distal splenorenal anastomosis 89,81 +/- 41,20 cm/seg), resistivity (non operated 0,58 +/- 0,008/distal splenorenal anastomosis 0,56 +/- 0,06) and pulsatility (non operated 0,91 +/- 0,19/distal splenorenal anastomosis 0,86 +/- 0,15, splenic vein (non operated 1,10 +/- 0,30 cm/distal splenorenal anastomosis 1,19 +/- 0,29 cm); c) increase: mean flow velocity in the splenic vein (non operated 20,54 +/- 8,45 cm/seg/distal splenorenal anastomosis 27,83 +/- 9,29 cm/seg).

CONCLUSIONS

The comparison of the ultrasonography Doppler results of the two groups of patient (non operated and distal splenorenal anastomosis) showed that in patients with distal splenorenal anastomosis there was a decrease of the volume of spleen; increase in the mean flow velocity in the splenic vein; no changes in the morphologic and hemodinamyc parameters of the splenic artery neither in its velocimetric indices.

[Patent paraumbilical vein: hemodynamic importance in Mansoni's hepatosplenic portal hypertension (Study with ultrasonography Doppler]

BACKGROUND

The hemodynamical effect of the collateral portosystemic circulation upon the portal system has not yet been fully understood. The US-Doppler made possible the non-invasive study of the portal system by evaluating the parameters: flow direction, diameter and flow velocity in it's vessels.

AIMS

To study the paraumbilical vein as a collateral portosystemic pathway and identify patterns for appraising its hemodynamic importance to the portal system.

METHOD

US-Doppler study of the portal system of 24 patients with Mansoni's hepatosplenic schistosomic portal hypertension, previous esophagic variceal bleeding and patent paraumbilical vein with hepatofugal flow. The diameter and the mean flow velocity were measured in the paraumbilical vein and so were the mean flow velocity in the portal vein, right and left portal branches. The Pearson test (linear correlation) was applied to the portal vein's mean flow velocity and the paraumbilical vein's diameter and mean flow velocity. The patients were divided in four groups: D1-paraumbilical vein with diameter < 0.68 cm (n = 14), D2-paraumbilical vein with diameter > or = 0.68 cm (n = 10), V1-paraumbilical vein with mean flow velocity < 18.41 cm/seg (n = 13) and V2-paraumbilical vein with mean flow velocity > or = 18.41 cm/seg (n = 11). The mean flow velocity in the portal vein, right and left portal branches of the four groups were compared.

RESULTS

The paraumbilical vein diameter was 0.68 +/- 0.33 cm (range: 0.15-1.30 cm) and the mean flow velocity was 18.41 +/- 11.51 cm/seg (range: 5.73-38.20 cm/seg). The linear correlation between the portal vein's mean flow velocity/paraumbilical vein diameter and the paraumbilical vein's mean flow velocity showed r = 0.504 and r = 0.735, respectively. In the group D2 there was an increase in the mean flow velocity in the portal vein (17.80 +/- 3.42/22.30 +/- 7.67 cm/seg) and in the left portal branch (16.00 +/- 4.73/22.40 +/- 7.90 cm/seg). In the group V2 there was an increase in the mean flow velocity in the portal vein (16.31 +/- 3.49/21.96 +/- 5.89 cm/seg) and in the left portal branch (14.22 +/- 4.41/21.94 +/- 7.20 cm/seg). There was no change in the right portal branch (13.67 +/- 5.74/15.43 +/- 3.43 cm/seg).

CONCLUSIONS

In portal hypertension due to hepatosplenic schistosomiasis, the patent paraumbilical vein, with hepatofugal flow, diameter > or = 0.68 cm and mean flow velocity > or = 18.41 cm/seg causes an increase of the mean flow velocity in the portal vein and left portal branch. The best US-Doppler parameter to appraise the paraumbilical vein influence upon the portal system is the mean flow velocity. The correlation between the increase in portal vein's mean flow velocity is stronger with the paraumbilical vein's mean flow velocity than with its diameter. The increase in the portal vein's and left portal branch's mean flow velocity may be understood as the paraumbilical vein's hemodynamic influence upon the portal system. An active portosystemic collateral pathway increases the mean flow velocity in the vein's segment proximal to its point of origin.

Schistosoma mansoni egg-induced hepatic granulomas in mice deficient for the interferon-gamma receptor have altered populations of macrophages, lymphocytes and connective tissue cells

Systemic production and mobilization of inflammatory cells and formation of hepatic periovular granulomas were studied in Schistosoma mansoni-infected mice with deficient interferon gamma (IFN-gamma) receptor (IFN-gammaR(o/o)). The impaired IFN-gamma signaling did not cause a significant modification of the overall kinetics of inflammatory cells, but mutant mice developed smaller hepatic periovular granulomas with a two-fold reduction in all the cell lineages. In granulomas of normal mice, the fully differentiated macrophages were progressively predominant, whilst in IFN-gammaR(o/o) mice, the granulomas contained a higher percentage of immature and proliferating monocytes. Granulomas of IFN-gammaR(o/o) mice had an enhanced and accelerated fibrotic reaction, corresponding to an increased content of proliferative and activated connective tissue cells. Simultaneously, their granulomas had an increased ratio of T over B cells, with an increase in CD8(+) and a reduction in CD4(+) T cells. The functional IFN-gamma receptor was not required for initial recruitment of monocytes and lymphocytes into granulomas, but it was necessary for the maturation of macrophages, upregulation of major histocompatibility class 2 (MHC-II) expression and consequent stimulation of lymphocyte subpopulations depending upon the MHC-II-mediated antigen presentation.

Susceptibility to periportal (Symmers) fibrosis in human schistosoma mansoni infections: evidence that intensity and duration of infection, gender, and inherited factors are critical in disease progression

Lethal disease in Schistosoma mansoni infections is mostly due to portal hypertension caused by hepatic periportal fibrosis. To evaluate the factors that may determine severe disease, livers and spleens were examined by ultrasound in a Sudanese population living in a village where S. mansoni is endemic. Early (FI), moderate (FII), or advanced (FIII) fibrosis was observed in 58%, 9%, and 3% of the population, respectively. Although FI affected 50%-70% of the children and adolescents, FII prevalence was low in subjects </=20 years old but increased sharply (45%-58%) in men 21-30 years old and was associated with the highest infections. Portal and splenic vein diameters were increased in one-third of persons with FII and in almost all with FIII disease. Severe disease, FII or FIII with portal hypertension, affected 6% of the population, was associated with splenomegaly, occurred mostly in adult men, and was clustered in a few pedigrees. These observations suggest that infection intensity and duration, gender-related factors, and inherited factors are important in fibrosis development.

Role of cytokines in the formation and downregulation of hepatic circumoval granulomas and hepatic fibrosis in Schistosoma mansoni-infected mice

Schistosoma mansoni infections are associated with a strong Th2 cytokine response. Treatment of mice with IL-12 or anti-IL-2 or anti-IL-4 before i.v. injection of eggs increased IFN-gamma production and downregulated Th2 responses and pulmonary granuloma size. Conversely, anti-IFN-gamma antibody treatment increased Th2 responses and granuloma size. Similar manipulation produced less dramatic results in infected mice. However, sensitization of mice with eggs + IL-12 before infection augmented the Th1 response and decreased Th2 cytokines, granuloma size and fibrosis. Antisera to IFN-gamma, TNF-alpha or IL-12 during IL-12-egg immunization partly restored granuloma size and fibrosis following infection. Variations in the size of granulomas in acute (8 week) infections may be influenced primarily by the number and state of activation of T cells. In chronic (12-16 week) infections immunologic downmodulation proceeded normally in mice without functional CD8+ cells and in IFN-gamma KO mice but not in B cell KO (microMT) mice or in mice deficient in FcR expression in spite of the fact that these mice downregulated their T cell and cytokine responses. It is evident that the participation of cytokines in granuloma formation and regulation is complicated and that the mechanisms controlling both these phenomena are likely to involve both T cells and antibody/FcR interactions.

Impact of hepatitis C virus infection on schistosomal liver disease

BACKGROUND/AIMS

This study was conducted to determine whether Hepatitis C virus infection has a role in patients with schistosomal liver disease.

METHODOLOGY

Sixty patients with hepatosplenic schistosomiasis and evidence of portal hypertension were seen at the Armed Forces Hospital Riyadh, Saudi Arabia over 5 years. The impact of Hepatitis C virus infection on chronic schistosomal liver disease was studied in 30 of these patients (group one) who were Hepatitis C virus positive and compared with the other 30 patients (group two) who were Hepatitis C virus negative (control group).

RESULTS

Hepatitis C virus may be an important factor contributing to deterioration of liver function for patients with hepatosplenic schistosomiasis. Liver functions showed elevated ALT in 83.3% in group one compared to 23.4% in group two. Liver biopsy in 19 patients (group one) and 16 patients (group two) showed evidence of schistosomiasis and in patients of group one, liver biopsy also showed chronic active hepatitis together with Schistosoma in 57.9%, and cirrhosis in 31.6%. None of group two patients had cirrhosis. Alpha-fetoprotein levels were elevated in 16 patients (group one) and 3 of these patients had hepatocellular carcinoma. None of the control group had radiological or histological evidence of hepatocellular carcinoma.

CONCLUSION

The mean age of HCV positive patients was less than the HCV negative patients, which may indicate that Hepatitis C virus infection leads to decompensation of liver function earlier in patients with Schistosoma and severe liver disease may be promoted at a younger age in Schistosoma patients with hepatitis C.

[Angiographic aspects of the hepatic veins in portal hypertension in schistosomiasis. The importance in assessing the hepatic vein pressure]

The authors comment upon the importance of the hepatic wedged venous pressure for the appraisal of the circulatory conditions of the portal system, mainly in cirrhotic patients. Wondering about the irregular results obtained in the study of schistosomotic portal hypertensive patients by occlusive catheterization and with the use of an occlusive balloon catheter, noted the scarcity of angiographic studies on the subject in this pathology. Present the angiographic aspects that were obtained from patients with schistosomotic portal hypertension complicated by digestive bleeding, by means of injecting the contrast material into a hepatic vein of the right hepatic lobe via a loosely introduced catheter. Those radiological aspects were distributed in two categories: 1) type I-presenting variable sinusoidal filling. Presence of anastomotic intraparenquimatous communications with or without calibrous anastomotic veins between the hepatic veins, 2) type II-presenting no sinusoidal filling. Presence of multiple anastomotic communications of varied calibers between the hepatic veins. Commenting the difficulty of assessing the wedged pressure in patients with schistosomotic portal hypertension because of the easy communication between the hepatic veins, the authors point out that the measured pressure, in all the cases, will be that of the opposite hepatic vein. That pressure, in this pathology, might represent the sinusoidal resistance (when present) between hepatic veins, instead of relating to the portal vein. Suggestion is made that the measure of the wedged hepatic pressure, in patients with schistosomotic portal hypertension, be appraised considering the angiographic aspects of the hepatic veins.

[Hyperdynamic circulation in Manson's hepatosplenic schistosomiasis]

Twenty two patients having indication for surgical treatment of portal hypertension due to hepatoesplenic schistosomiasis were prospectively studied. Each patient was submitted to preoperative monitoring with pulmonary artery catheterization. The results showed hemodynamic alterations characterized by an increase of cardiac index (4.50 +/- 0.96 l/min/m2) associated to a decrease of systemic vascular resistance index (1638.60 +/- 441.86 dyn.s/cm5.m2). The stroke index and all right and left cardiac work indeces were increased. The pulmonary artery mean pressure was increased (17.23 +/- 8.63 mmHg) and the pulmonary vascular resistance index was decreased (147.95 +/- 126.21 dinas.seg/cm5.m2). We concluded that hepatoesplenic schistosomiasis determines hyperdynamic systemic circulation, probably correlated with portosystemic shunt, and pulmonary hypertension.

Systemic and hepatic hemodynamics in hepatosplenic Manson's schistosomiasis with and without propranolol

Systemic and hepatic hemodynamics were prospectively studied in 11 patients with Manson's schistosomiasis and portal hypertension, as well as alterations resulting from the use of propranolol. It was decided that patients whose portal pressure was reduced by 30% with the use of the drug would not undergo surgery and that treatment would consist of the chronic use of propranolol, associated with sclerosis of esophageal varices. This objective was not met by any of the patients whose portal pressure was measured and the study was interrupted. Results show that patients with Manson's schistosomiasis and portal hypertension have hyperdynamic circulation, mild pulmonary hypertension, greatly increased splenic blood flow, and preservation of total hepatic blood flow. Administration of propranolol corrects hyperdynamic circulation, aggravates pulmonary hypertension, does not alter portal pressure and reduces the sectorial portal blood flows, especially of the azygos vein, with maintenance of total hepatic blood flow. These data favor the hypothesis of portal overflow in the physiopathology of portal hypertension of schistosomiasis.

Clinicopathological features and histopathology of experimental hepatic capillariasis in muskrats (Ondatra zibethicus)

Ten muskrats (Ondatra zibethicus) each were infected with 17,000 eggs (long-term study) and eight muskrats each were infected with 8,000 eggs (short-term study) of Capillaria hepatica (Nematoda). Food intake, body weight, and selected clinicopathological parameters were measured every 2 days for 28 days in the short-term study and every 14 days for 184 days in the long-term study. Muskrats in the short-term study had moderate to severe necrotizing granulomatous hepatitis associated with mild anorexia and weight loss, varying degrees of leukocytosis with eosinophilia and elevation of serum alanine and aspartate aminotransferases. No significant changes in packed cell volume, hemoglobin, total plasma protein, albumin, blood urea nitrogen, bilirubin, lactate dehydrogenase or alkaline phosphatase were found among animals from the short-term study. Muskrats in the long-term study had severe necrotizing granulomatous hepatitis associated with marked anorexia, weight loss and 60% mortality over 39 days post-inoculation (PI); animals that survived for 184 days did not return to pre-inoculation body weights despite returning to normal food intake. Hepatic lesions at 184 days PI consisted of minimal to severe liver replacement by C. hepatica eggs. No statistically significant differences in values of clinical parameters between inoculated animals and a non-inoculated control group from the long term study were found.

Hyperfibrinolysis in hepatosplenic schistosomiasis

AIM

To evaluate the nature of accelerated fibrinolysis in hepatosplenic schistosomiasis.

METHODS

The biological activity of plasminogen (Plg), plasminogen activators (PA), alpha 2-antiplasmin (alpha 2-AP) and plasminogen activator inhibitor-1 (PAI-1) was determined by photometric analysis in 15 compensated and 35 decompensated patients with endemic Egyptian hepatosplenomegaly. Quantitative measurement of plasma concentrations of tissue t-PA, t-PA-PAI-1 complex, alpha 2-antiplasmin-plasmin complex (alpha 2-APP), fibrinogen degradation products (FbDP), D-dimers (D-D), thrombin-antithrombin complex (TAT) and prothrombin fragment (F 1 + 2) complexes, using double antibody sandwich enzyme linked immunosorbent assays and grading of the degree of hepatic insufficiency according to the Child-Pugh classification, were also carried out.

RESULTS

The progressive deterioration of liver function in schistosomal patients, which matched the severity of the disease, led to simultaneous defects in profibrinolytic (decreased Plg and increased PA and t-PA) and antifibrinolytic (decreased alpha 2-AP and PAI-1) factors-the latter defects being the most prominent-resulting in significant generation of plasmin (increased APP complexes) and therefore enhanced fibrinolysis (increased FbDP and D-dimer). The raised concentrations of FbDP, D-D, TAT and F 1 + 2 established its secondary nature.

CONCLUSION

These findings suggest that the amount of PAI-1 available to bind and neutralise circulating t-PA may be a critical factor in the progress of hyperfibrinolysis observed in hepatosplenic schistosomiasis, and that the pronounced reduction in its plasma concentration may be regarded as a potential warning indicator of haemostatic imbalance in decompensated schistosomal patients at high risk of variceal bleeding.

Systemic and splanchnic hemodynamic changes in patients with hepatic schistosomiasis

Although hepatic schistosomiasis is a common cause of portal hypertension, only a few hemodynamic studies, in humans, have been published on this subject. The aim of this study was to determine the systemic and splanchnic hemodynamic changes in hepatic schistosomiasis and to evaluate the influence of liver fibrosis on these changes. A retrospective analysis of a series of 13 patients with hepatic schistosomiasis who had undergone hemodynamic studies was performed. Portal or perisinusoidal fibrosis was present at liver biopsy in 8 patients. The control group included 22 patients with chronic hepatitis and normal hepatic venous pressure gradients. Patients with schistosomiasis exhibited high cardiac index (4.11 +/- 1.15 l.min-1.m-2 vs 2.99 +/- 0.85 l.min-1.m-2; p < 0.05) and low systemic vascular resistance (1039 +/- 316 dyn.s.cm-5 vs 1334 +/- 336 dyn.s.cm-5; p < 0.05). The hepatic venous pressure gradient and hepatic blood flow were normal. Azygos blood flow was markedly increased (0.90 +/- 0.66 l.min-1 vs 0.13 +/- 0.04 l.min-1; p < 0.05). Hemodynamic values were not significantly different between patients with liver fibrosis and those without fibrosis at liver biopsy. In conclusion, patients with hepatic schistosomiasis had a hyperkinetic systemic and splanchnic circulation. In patients with esophageal varices, a normal hepatic venous pressure gradient confirmed presinusoidal portal hypertension. The presence of portal or perisinuoidal fibrosis did not influence hyperdynamic splanchnic state.

Schistosoma mansoni: influence of infection on mouse behavior

Schistosoma mansoni infection in humans and animals induces abnormal neurobehavioral responses following granuloma formation. In mice, granulomas in the liver are observed 8 weeks after infection, while after 15-20 weeks, the presence of eggs and granulomas in the brain has been reported. In this study, outbred CD-1 female mice were infected with S. mansoni and examined in several behavioral tests (open field, novel object investigation, black/white box, and hot plate) 8 and 15 weeks after infection. The detected effects of schistosome infection were a reduction of body weight in 8-week infected mice, marked changes in exploration/activity, rearing, and wall-rearing in 8- and 15-week infected mice, an enhancement of sniffing and grooming in 8-week infected mice, and finally an increase in the threshold of pain response to the hot plate in 15-week infected mice. The results of the present study indicate that S. mansoni infection markedly alters exploratory behavior of mice, affecting particularly the vertical movements of the animals, and suggests that the differences in behavioral abnormalities between 8- and 15-week infected mice might be associated with modifications in the levels of nerve growth factor and cytokines induced by granulomas.

Evaluation of colchicine with or without praziquantel therapy in the control of hepatic fibrosis in murine schistosomiasis

Colchicine alone or following praziquantel was given to mice infected with Schistosoma mansoni either 6 or 10 weeks post infection. Praziquantel increased body weight gain, histologically reduced number, diameter and cellularity of granuloma and improved liver function parameters. Early praziquantel therapy decreased hepatic collagen content as detected by the colorimetric method and the serum procollagen propeptide (PIIIP), while later treatment at the 10th week of infection increased hepatic collagen content and serum PIIIP. Colchicine therapy significantly decreased body weight gain with significant weight loss after early treatment. Colchicine did not change the histologic picture of schistosomal liver fibrosis; it induced a detectable hepatocytic injury recorded ultrastructurally and histologically with excitation of the inflammatory reaction in the granuloma and in portal tracts after early treatment. Excess pigmentation in macrophages and Kupffer cells, binucleation and large sized hepatocytic nuclei were evident after colchicine therapy. Colchicine increased hepatic collagen content microgram/mg protein, raised globulin and total serum protein and normalized the raised serum PIIIP of infected mice, but had no effect on PIIIP of normal mice. Early cessation of schistosomal infection evidently minimized the adverse effects of colchicine.

Liver function in Clonorchis sinensis-infected rabbits

Nine rabbits were fed with Clonorchis sinensis metacercariae (MC) and the blood samples chronologically obtained were analyzed biochemically. Rabbits infected by less than 100 flukes were grouped into Group I, and by 100-250 flukes into Group II. The serum level of alanine aminotransferase (ALT) was increased from 3 weeks after the infection of the metacercariae (AIM) and showed a peak at 8 weeks, and decreased from 12 weeks AIM. The serum level of aspartate aminotransferase (AST) was raised to 92.3 +/- 65.4 U/L at 3 weeks AIM and stayed high until 8 weeks, then lowered thereafter. The serum level of gamma-glutamyl transpeptidase (gamma-GT) was increased rapidly to the highest value (18.9 +/- 14.6 U/L) at 16 weeks AIM, and decreased to the control level after 20 weeks. The serum level of alkaline phosphatase (ALP) was headed down from the early infection to 52 weeks AIM. The serum cholesterol level was increased from 8 weeks and reached at a peak 16 weeks AIM, and decreased thereafter to the control level. It is suggested that serum ALT, AST, ALP and gamma-GT tests be useful to diagnose the early infection of C. sinensis.

Liver morphology and function in visceral leishmaniasis (Kala-azar)

AIM

To study the morphology and function of the liver in visceral leishmaniasis (Kala-azar).

METHODS

Percutaneous liver biopsy specimens from 18 patients with confirmed visceral leishmaniasis were examined under light and electron microscopy before and after treatment with pentovalent antimony. The tissue was also examined for hepatitis B surface and core antigens using immunoperoxidase staining. Liver function was investigated in nine patients before and after treatment.

RESULTS

Specimens before treatment showed Kupffer cells and macrophages colonised by leishmania parasites in 40% of cases. A chronic mononuclear cell infiltrate had affected the portal tracts and lobules. Ballooning degeneration of the hepatocytes, fibrosis of the terminal hepatic venules, and pericellular fibrosis were common findings. The fibrosis was related to Ito cells transforming to fibroblast-like cells. None of the patients had hepatitis B infection. All patients had biochemical evidence of liver dysfunction before treatment. Liver function improved after treatment.

CONCLUSION

Visceral leishmaniasis causes morphological and functional disturbance in the liver. Focal fibrosis rather than cirrhosis occurs. The exact aetiology of hepatic damage is unclear but may have an immunological basis.

[Hepatosplenic schistosomiasis: case report and clinical review]

Although seen rarely in Switzerland, schistosomiasis is a parasitosis affecting 200 to 250 million people round the world, mainly in tropical and subtropical regions of Africa, Asia, Central and South America. Depending on the parasitic species, the ureters and the bladder (S. haematobium) or the intestine and the liver (S. mansoni, S. japonicum, S. mekongi) are primarily involved. Other organs may be affected (lung, kidneys and central nervous system). Hepatosplenic schistosomiasis represents a special form of chronic infection by S. mansoni, S. japonicum or S. mekongi predominantly occurring in adolescents heavily and repeatedly infected during childhood, together with an additional genetic predisposition for the disease. Hepatosplenic schistosomiasis on a worldwide scale is one of the most prevalent causes of portal hypertension in man. We describe a 33-year-old Portuguese female with mansonian hepatosplenic schistosomiasis 12 years after leaving Africa, who had hepatosplenomegaly, portal hypertension, esophageal varices and hypersplenism. Splenomegaly and slight anemia had been known for years without prompting further work-up. Two months before diagnosis she had been delivered of a normal child after pregnancy without portal-hypertensive complications, namely esophageal hemorrhage. Because of placenta accreta, however, erythrocyte transfusion had been performed after delivery and was possibly responsible for hepatitis C found later on. Pathophysiology, clinical findings and therapy of the disease are discussed.

Theophylline metabolism in patients with hepatosplenic mansoniasis and cirrhosis

The pharmacokinetics of theophylline were studied in 12 patients with hepatosplenic mansoniasis, 14 patients with cirrhosis and 16 normal controls. Following a single intravenous dose of aminophylline volumes of distribution, serum half-lives and body clearances were determined. Volumes of distribution of theophylline in patients with schistosomiasis (mean 0.624 l/kg) did not differ from cirrhotic patients (mean 0.616 l/kg) or normal controls (mean 0.593 l/kg). Cirrhotic patients had a prolonged half-life compared to normal subjects (mean 22.1 vs. 9.9 h), while patients with schistosomiasis did not substantially differ from normal controls (15.8 vs. 9.9 h). Body clearance in patients with schistosomiasis was similar to controls (34.02 vs. 49.20 ml/h per kg) but decreased (29.24 ml/h per kg) in patients with cirrhosis. Individual analysis of the group with schistosomiasis disclosed three patients with reduced theophylline elimination. No relationship was found between laboratory tests of liver function and the pharmacokinetics of theophylline in any group. The administration of theophylline to patients with hepatosplenic schistosomiasis, although less dangerous than in cirrhosis, must be closely followed.

Hepatosplenic schistosomiasis. Pathophysiology and treatment

HSS represents a special model of intrahepatic portal hypertension characterized by a presinusoidal portal block and a well-preserved liver parenchyma. Symmers' fibrosis appears in a small but significant proportion of patients with a high worm load. Its pathogenesis is not well established, although experimental and clinical studies point to egg granulomata as the main pathogenetic factor. The eggs carried continuously through the portal circulation produce inflammation and gross amputation of the intrahepatic veins, portal and periportal granulomas, and, eventually, a coarse perilobular fibrosis ("pipe-stem"). Portal hypertension, esophageal varices, and hepatosplenomegaly are the main consequences of these morphologic changes. Gastrointestinal bleeding is the most frequent cause of death. Unlike in cirrhosis, advanced liver failure is not seen except when HSS is associated with liver lesions from other causes such as virus and alcoholism. Helminthiasis treatment is based on chemotherapy with praziquantel or oxamniquine. Bleeding esophageal varices are managed by sclerotherapy or surgical procedures. Splenectomy with gastroesophageal devascularization seems to be the best choice.

Duplex Hemodinamic evaluation of hepatosplenic mansoni schistosomiasis

Conventional ultrasonography highly contributes to a non invasive diagnosis of HS schistosomiasis (Cerri et al., 1984). The introduction of Doppler allowed new advances in the knowledge of the portal dynamics of this disease (Taylor et al. 1985; Moriyasu et al., 1986). The aim of this paper was to analyze the hemodynamic behavior of the portal vessels, considering caliper, maximum flow speed, direction of flow and preferential disposition of the collateral vessels. Thirty two patients with schistosomiasis mansoni with confirmed hepatosplenic form (HSSM), were analyzed. Fourteen patients with the intestinal form, have been analyzed as a control group. The results demonstrated that the maximum speed of the portal vein in the two groups has not been significantly different. Nevertheless, the diameter of the PV in the hepatosplenic group has been larger. The splenic vein presented speed and caliper larger than the superior mesenteric vein. The hepatic artery has been detected in only 40% of the cases. The hepatic veins presented normal caliper and spectral pattern. The duplex proved to be an useful technic complementary and non-invasive, in the study of HSSM.

Hepatic regeneration after hepatectomy in schistosomatic fibrosis

After partial hepatectomy (approximately 30%), the labelled hepatocyte index (LHI) of the normal mouse is increased and reaches its highest value 48 h after surgery. In mice with schistosomatic fibrosis (SF), the LHI was lower than in the controls at 24, 48 and 72 h after hepatectomy.

[The effect of cholagogic preparations and Essentiale on the natriuretic hormone content of the blood plasma and on kidney function in patients with liver pathology]

The effect of cholagogic drugs on blood plasma content of natriuretic hormone (NH) in 41 patients with chronic opisthorchiasis was studied. The drugs were found to exert no effect on NH content and the kidney function in this pathology. The use of essentiale in patients with persistent hepatitis and cirrhosis of the liver was shown to increase sodium excretion due to an increase of NH content.

Praziquantel in the treatment of hepatosplenic schistosomiasis: biochemical disease markers indicate deceleration of fibrogenesis and diminution of portal flow obstruction

Serological indicators for disease activity and portal vein obstruction and/or deviation were assessed in 23 patients with hepatosplenic schistosomiasis before, and up to 18 months after, praziquantel treatment, as well as in 25 matched local controls. Cessation of egg-induced immunopathology was reflected by the return to normal of serum procollagen-III-propeptide and neopterin concentrations. Reversibility of portal vein pathology was indicated by normal clearance of cholylglycine in cases without signs of decompensating portal hypertension. In most patients with a history of ascites and/or haemorrhage, serum cholylglycine concentration remained pathological. The results provide evidence that the fibrogenic process ceases after specific chemotherapy, and that portal vein pathology regresses in a substantial proportion of hepatosplenic schistosomiasis cases.

Liver function and plasma protein metabolism in rodent model of filariasis

Rodent model of filariasis was developed by infecting Wistar rats with Litomosoides carinii. Liver function tests, plasma protein concentrations, and synthesis rates of liver-formed proteins were estimated in these rats at 63 and 90 days post-infection. At 63 days post-infection, aspartate aminotransferase and alkaline phosphatase were significantly increased. Alanine aminotransferase, plasma total proteins and plasma albumin were in the normal range. However, at 90 days post-infection all these parameters were affected, reflecting progressive liver involvement. Hypoalbuminemia at 90 days post-infection did not appear to be due to decreased synthesis rate, indicating higher catabolism and/or altered distribution in pools.

Effects of induction of anti-embryonation immunity on liver granulomas, spleen weight and portal pressure in mice infected with Schistosoma japonicum

BALB/c mice sensitized with injections of viable immature Schistosoma japonicum eggs had significantly fewer and smaller granulomas in the liver, lower portal pressure and smaller spleens at D + 75 of infection compared to similarly infected unsensitized controls. The portal pressure and spleen weights of the mice sensitized with immature eggs were not different from uninfected unsensitized mice of similar ages at D + 75 of infection. The results strongly support our hypothesis that it should be possible to prevent serious hepatosplenic disease in schistosomiasis japonica by vaccination to induce anti-embryonation immunity.

Lack of correlation between jejunal mucosal morphology and intestinal absorption in the hepatosplenic form of schistosomiasis mansoni

Eleven patients with the hepatosplenic form of schistosomiasis mansoni were studied. Intestinal absorption of fat and xylose was normal in all patients. Despite these normal absorption parameters, the mucosa showed variable degrees of villus atrophy and an increase of the number of inflammatory cells in the lamina propria. Through morphometric analysis it was seen that the villi were shorter and the ratio villus height/crypt depth was increased in schistosomiasis patients as compared to normal control children. Five of the 11 biopsies contained granulomata with ova in the mucosa or submucosa.

Aging of the murine immune system is reflected by declining ability to generate antibodies that promote elimination of Trypanosoma musculi

Trypanosoma musculi established extracellular infections in aged BC3F1 and C57BL/6 mice that were approximately 10 times greater and twice as long in duration as those in young adult mice. Elimination of T. musculi infections was found to be an antibody-dependent, cell-mediated process involving effector (presumably phagocytic) cells in the liver and, to a lesser extent, the spleen. A major difference between young and aged mice of the C57BL/6 strain was the deficiency in the ability of aged animals to generate antibodies of appropriate specificity and/or isotype in sufficient amount to promote trypanosome elimination. Indeed, at the time when infected young-adult mice began to produce antibodies that facilitated rapid trypanosome clearance (in young adult, but not in aged animals), the serum of aged mice was found to contain substances that inhibited parasite clearance. Overall, however, the development of antibodies of different isotypes, capable of reacting with intact trypanosomes, was about the same in young and aged animals. Hepatic and splenic effector cells of old mice were at least as efficient as those of young adults. The immunoblotting procedure was used to try to detect trypanosome Ag against which aged animals failed to generate antibodies of one or more isotypes. The complexity of the reactions of infected mouse serum antibodies with the spectrum of trypanosome Ag precluded a precise analysis. However, it was apparent that a delay in the appearance of antibodies of IgG2a and IgG2b isotypes, against Ag of relatively high m.w., was typical of aged, in comparison to young, mice. More exacting analyses, involving fractionated trypanosome extracts and mAb of varying isotypes, are underway to identify key trypanosome Ag that elicit antibodies of isotypes that can facilitate hepatic and splenic clearance of the parasites. This line of investigation will provide information that, in addition to its intrinsic interest, may be vital in judging the future impact of endemic parasitic infections on the emerging cohort of elderly persons in developing tropical nations.

[Biometric data on adult patients with schistosomiasis, Bahia (Brazil)]

De dezessete indivíduos esquistossomóticos, hepatosplênicos, pareados com outros dezessete controles, hepatointestinais, da mesma região, foram aferidas 17 medidas antropométricas. Todas as pessoas tinham de 21 a 50 anos de idade. Esta e outros critérios foram previamente estabelecidos como fatores de pareamente, de inclusão e exclusão no estudo. Porém, não se observou diferenças estatísticas entre as médias dos dois grupos de pacientes.

Pathophysiology of severe falciparum malaria in man

The term severe falciparum malaria implies an infection with manifestations and complications which are potentially fatal in man, the natural host for this parasite. Much that has been written on the pathophysiology of animal malarias is of doubtful relevance to the understanding of the mechanism ofPlasmodium falciparuminfection in man. The clinical picture of severeP. falciparuminfection differs in several respects from severe animal malarias, even those of non-human primates. Cerebral dysfunction is the most common severe manifestation of falciparum malaria in man. Coma develops suddenly after a generalized convulsion or gradually towards the end of the first week of illness. There are signs of a symmetrical upper motor neurone lesion and brain-stem dysfunction, but only about 5% of survivors show persisting neurological deficit after 2 or 3 days of unconsciousness. The mortality of cerebral malaria depends on how it is defined and on the predominant age group and other factors. In patients with proved acuteP. falciparuminfection with unrousable coma, in whom other causes of encephalopathy have been excluded, the mortality is between 15 and 50% despite treatment with antimalarial drugs (Warrell, Looareesuwan, Warrell, Kasemsarn, Intaraprasert, Bunnag & Harinasuta, 1982).

Effect of oral contraceptive on liver function tests of women with schistosomiasis in the Philippines

A prospective study was undertaken to determine the effect on liver function tests of a combined oral contraceptive containing norethisterone 1 mg and mestranol 0.05 mg, in women with schistosomiasis japonica in Leyte, Philippines. Women who volunteered and met the standard criteria for oral contraception, with and without infection, were followed for six months of pill intake. Concurrently, non-pill users, both infected and uninfected, were similarly followed. Baseline and six-month liver function tests were compared. Of the 466 subjects admitted in the study, 383 completed six months, and 83 discontinued. At the start of the study, there were no significant differences among the four groups in liver function tests except that the infected women had a higher total protein and alkaline phosphatase, and lower alanine aminotransferase levels. After six months, the only statistically significant finding was a lesser decrease in total protein among the infected pill users compared to the uninfected pill users. This finding was not clinically significant since there was no associated clinical complications; there were fewer number of subjects with abnormal values at the sixth month; and the mean values of this variable remained within normal limits. Our findings show that the use of low dose progestin and estrogen oral contraceptive in the presence of mild schistosomiasis japonica infection does not appear to have adverse effect on liver function tests of young women after six months of contraceptive use.