Cytoglobin-expressing cells in the splenic cords contribute to splenic fibrosis in cirrhotic patients

BACKGROUND AND AIM

Among several noninvasive evaluation methods of portal hypertension (PH), the measurement of spleen stiffness is a reliable method for predicting esophageal variceal bleeding; however, the underlying mechanisms for increased stiffness remain unclear. We attempted to elucidate the pathological changes to the spleen and the underlying mechanisms in patients with PH.

METHODS

Histological examination was performed using splenic tissues from 42 patients with PH who underwent laparoscopic splenectomy, and the results were compared with those from patients without PH.

RESULTS

In addition to splenic sinus congestion, diffuse fibrosis was detected in the splenic cords in the red pulp of patients with PH. The degree of the fibrosis was well correlated with severity in thrombocytopenia and splenomegaly. Cells expressing α-smooth muscle actin dramatically increased in the splenic cord. Cytoglobin (Cygb) expression was detected in human splenic cords as reported in animal reticular cells, and fluorescent double immunostaining revealed that these cells expressed α-smooth muscle actin in patients with PH, suggesting transformation of Cygb-expressing cells to myofibroblastic cells. Expression levels of nicotinamide adenine dinucleotide phosphate oxidase (NOX) 2, nitrotyrosine, and transforming growth factor-β were markedly upregulated in the red pulp of patients with PH, implying a significant role of oxidative stress in the mechanism for splenic fibrosis.

CONCLUSION

Splenic fibrosis progresses along with advancement of PH. Cygb-expressing cells in the splenic cord possibly participate in this process through mechanisms including oxidative stress.

Bronchobiliary fistula caused after hepatectomy for hepatocellular carcinoma: a case report

Background

A bronchobiliary fistula, an intercommunication between the biliary tract and bronchial trees, is an extremely rare complication after hepatectomy.

Case presentation

A 70-year-old male underwent partial resection of the liver for recurrent hepatocellular carcinoma under a thoracoabdominal approach. The immediate postoperative clinical course was uneventful, but the patient was febrile and laboratory examinations revealed leukocytosis on the 15th postoperative day. An intraabdominal abscess was suspected based on the computed tomography findings, and percutaneous drainage was performed. Bile was drained, and fluoroscopy using a contrast medium from the drainage tube revealed a communication between the cavity and the common hepatic duct. Two weeks after drainage, bilioptysis was seen. Fistulography demonstrated the presence of the bronchus in the right lower lobe of the lung via the subphrenic space. Therefore, the patient was diagnosed to have a bronchobiliary fistula. Fistulography revealed closure of the communication with the bronchus about a month after drainage. However, the bile leakage and bilioptysis did not stop even after endoscopic nasogastric biliary drainage, and ethanol injection therapy were performed. Eventually, residual right bisectionectomy without resection of the fistulous tract and involved lung was performed to remedy the intractable bile leakage. The clinical course after the reoperation was good without bile leakage, bilioptysis, or pulmonary disorders, and the patient was discharged 40 days after reoperation.

Conclusions

We experienced a rare case of bronchobiliary fistula that occurred after hepatectomy for hepatocellular carcinoma. Careful attention should be paid to prevent bile leakage during hepatectomy, since bile leakage has the potential to cause a bronchobiliary fistula.

Splenectomy attenuates murine liver fibrosis with hypersplenism stimulating hepatic accumulation of Ly-6C(lo) macrophages

BACKGROUND & AIMS

Splenectomy in cirrhotic patients has been reported to improve liver function; however the underlying mechanism remains obscure. In the present study, we investigated the mechanism using a murine model, which represents well the compensated liver cirrhosis.

METHODS

C57BL/6 male mice were allowed to drink water including thioacetamide (TAA: 300 mg/L) ad libitum for 32 weeks. After splenectomy at 32 weeks, mice were sacrificed on days one, seven, and 28, respectively, while TAA-administration was continued. Perioperative changes in peripheral blood and liver tissues were analyzed.

RESULTS

TAA treatment of mice for 32 weeks reproducibly achieved advanced liver fibrosis with splenomegaly, thrombocytopenia, and leukocytopenia. After splenectomy, liver fibrosis was attenuated, and macrophages/monocytes were significantly increased in peripheral blood, as well as in the liver. Progenitor-like cells expressing CK-19, EpCAM, or CD-133 appeared in the liver after TAA treatment, and gradually disappeared after splenectomy. Macrophages/monocytes accumulated in the liver, most of which were negative for Ly-6C, were adjacent to the hepatic progenitor-like cells, and quantitative RT-PCR indicated increased canonical Wnt and decreased Notch signals. As a result, a significant amount of β-catenin accumulated in the progenitor-like cells. Moreover, relatively small Ki67-positive hepatic cells were significantly increased. Protein expression of MMP-9, to which Ly-6G-positive neutrophils contributed, was also increased in the liver after splenectomy.

CONCLUSIONS

The hepatic accumulation of macrophages/monocytes, most of which are Ly-6C(lo), the reduction of fibrosis, and the gradual disappearance of hepatic progenitor-like cells possibly play significant roles in the tissue remodeling process in cirrhotic livers after splenectomy.

Primary squamous cell carcinoma of the liver: an uncommon finding in contrast-enhanced ultrasonography imaging

Primary squamous cell carcinoma (SCC) of the liver is rare tumor with an unfavorable prognosis. We report a case of advanced primary SCC of the liver arising adjacent to a nonparasitic liver cyst, invading into the right diaphragm and the right lung tissue. Contrast-enhanced ultrasonography (CE-US) demonstrated unique enhancement in the late vascular phase, which was incompatible with those observed in hepatocellular carcinoma, cholangiocellular carcinoma, or metastatic adenocarcinoma. The patient underwent surgical resection of the tumor followed by systemic chemotherapy with 5-fluorouracil (5-FU) and cisplatin (CDDP), while radiation chemotherapy was not applied because of relatively poor performance status. Although postoperative image analysis revealed no recurrence 4 months later, the patient died 13 months after the operation from recurrence. Immunohistological analysis of the resected specimen revealed that this SCC contained many capillary endothelial vessels expressing CD31 or CD34, possibly reflecting the unique imaging pattern in the late vascular phase of CE-US, which has been reported in choangiolocellular carcinoma. In addition, we reviewed which kind of treatment would be suitable for advanced hepatic primary SCC in the literature. From the review, it could be proposed that a combination of radiation therapy, systemic chemotherapy (5-FU and CDDP) and surgical resection, if possible, is appropriate for advanced primary SCC of the liver.

[Multiple Ebola virus haemorrhagic fever outbreaks in Gabon, from October 2001 to April 2002]

Outbreaks of Ebola virus haemorrhagic fever have been reported from 1994 to 1996 in the province of Ogooué Ivindo, a forest zone situated in the Northeast of Gabon. Each time, the great primates had been identified as the initial source of human infection. End of November 2001 a new alert came from this province, rapidly confirmed as a EVHV outbreak. The response was given by the Ministry of Health with the help of an international team under the aegis of WHO. An active monitoring system was implemented in the three districts hit by the epidemic (Zadié, Ivindo and Mpassa) to organize the detection of cases and their follow-up. A case definition has been set up, the suspected cases were isolated at hospital, at home or in lazarets and serological tests were performed. These tests consisted of the detection of antigen or specific IgG and the RT-PCR. A classification of cases was made according to the results of biological tests, clinical and epidemiological data. The contact subjects were kept watch over for 21 days. 65 cases were recorded among which 53 deaths. The first human case, a hunter died on the 28th of October 2001. The epidemic spreads over through family transmission and nosocomial contamination. Four distinct primary foci have been identified together with an isolated case situated in the South East of Gabon, 580 km away from the epicenter. Deaths happened within a delay of 6 days. The last death has been recorded on the 22nd of March 2002 and the end of the outbreak was declared on the 6th of May 2002. The epidemic spreads over the Gabon just next. Unexplained deaths of animals had been mentionned in the nearby forests as soon as August 2001: great primates and cephalophus. Samples taken from their carcasses confirmed a concomitant animal epidemic.

[First major epidemic caused by Neisseria meningitidis serogroup W135 in Africa?]

Neisseria meningitidis serogroup W 135 (N.m. W 135) has caused sporadic infections and small epidemics such as those that occurred during religious pilgrimages in Saudi Arabia in 2000 and in 2001. It is routinely isolated from specimens coming from African countries. The first major epidemic involving N.m. W 135 occurred in Burkina Faso between January and May 1992. There were more than 1300 cases including 1500 deaths. Enhanced surveillance of circulating strains showed that N.m. W 135 accounted for 83% of the 203 positive cerebrospinal fluid specimen cultures. The offending organism was identical to the strain that caused the smaller epidemic in Saudi Arabia in 2000. Due to the shortage of tetravalent meningococcal vaccine against N.m. W 135, the Health Ministry based its response to the epidemic on treatment of symptomatic patients using chloramphenicol and ampicillian. These drugs were distributed free. The emergence of N.m. W135 has impacted public health in Africa. Repeated identification of this serogroup in Burkina Faso during 2002 raises the risk that similar outbreak will occur in the meningitis belt during the next epidemic season. The high cost of tetravalent meningococcal vaccine compounded with the only progressive increase in production capacity underline the need to reinforce surveillance of circulating strains and available treatment facilities. Control strategy for epidemic meningitis is currently the focus of close collaboration between the WHO and the health authorities and corresponding institutions in the countries involved.

[Detection of meningococcal meningitis epidemics in Africa: a new recommendation]

In sub-Saharan Africa, the control of meningococcal meningitis epidemics relies on early epidemic detection and mass vaccination. However, experience shows that interventions are often initiated too late to have a significant impact on the epidemic. A new recommendation drafted by participants of a consensus meeting proposes an alert threshold and an epidemic threshold based on the weekly number or incidence of meningitis cases, according to the population size and the epidemic risk, resulting in indicators with high sensitivity and specificity for the detection of an emerging epidemic. Meningitis outbreak investigations must include an assessment of the quality of epidemiologic surveillance. The new recommendation is published in English and French in the Weekly Epidemiologic Record [12]. The success of this consensus meeting shows the value of integrating results from surveillance, field experience and operational research for designing new health strategies.

Risk factors of malaria infection during pregnancy in Burkina Faso: suggestion of a genetic influence

A cohort of 570 untreated pregnant women from Burkina Faso was studied to assess the influence of epidemiologic factors on malaria infection, which was quantified as the mean of serial, season-adjusted parasitemia measurements (mean parasite density [MPD]) carried out during the last five months of gestation. A significant effect of the area of maternal residence on the MPD was found (P < 0.003) and was probably due to geographic differences in mosquito transmission conditions. The strong relationship observed between parity and malaria infection (P < 0.0001), with MPD levels decreasing as the number of gestations increased, confirms that primigravidae are a high-risk group whose protection should be a priority. After adjustment for two relevant epidemiologic factors (i.e., area of residence and parity), the residual MPD values fitted a mixture of two distributions. This result supports the view that a major gene is involved in the determination of malaria infection intensities and is consistent with the results of a recent familial study in Cameroon.

Detection of meningitis epidemics in Africa: a population-based analysis

Portions of sub-Saharan Africa are subject to major epidemics of meningococcal meningitis that require early detection and rapid control. We evaluated the usefulness of weekly meningitis rates derived from active surveillance data in Burkina Faso for detecting a meningitis epidemic. By analysing the rates of disease in 40 x 40km2 areas within a study region of Burkina Faso, we found that a threshold of 15 cases/100,000/week averaged over 2 weeks was 72-93% sensitive and 92-100% specific in detecting epidemics exceeding 100 cases/100,000/year. During epidemic periods, the positive predictive value of this threshold approached 100% for detecting local epidemics. Additionally, meningitis incidence was proportional to village size, with villages greater than 8000 having the highest disease rates during a major group A meningococcal epidemic in 1983-1984. Despite the rudimentary nature of surveillance data available in many developing countries, these data can be used to detect the early emergence of meningitis epidemics. Additional studies are needed to determine the relevance of this approach for detecting epidemics.

Effect of chloroquine chemoprophylaxis during pregnancy on birth weight: results of a randomized trial

To determine the effect of chloroquine chemoprophylaxis during pregnancy on birth weights, a randomized trial was carried out in 1987 and 1988 in Banfora, Burkina Faso (West Africa). Seven hundred forty-five randomly selected women treated with chloroquine sulfate were compared to with 719 controls who received no treatment. In spite of an unquestionable effect of chloroquine in preventing placental infection (4.1% infected placentas in the treated group versus 19.0% in the controls), the mean difference in birth weights between the two groups (6 g) was not significant. The difference in the proportion of low birth weight (LBW) newborn babies in two groups (16.3% versus 16.4%) was also not significant. However, there was a strong relationship between placental infection and birth weight (the mean birth weight difference between infected and uninfected placentas was 113 g, and the proportion of LBW babies was 26.0% in infected placentas versus 14.8% in uninfected placentas). The small difference in birth weights observed between the two groups may be due to the fact that the prevalence rate of placental infection is low and that prophylaxis is effective only on a portion of the subjects in the treated group. It may also indicate that malaria is only one of several risk factors responsible for LBW. The relatively small increase in birth weight, the expected poor acceptance of mass prophylaxis, and the spreading of chloroquine-resistant Plasmodium strains should be considered before extending malaria chemoprophylaxis to all pregnant women. It might be worth considering to limit prophylaxis to primigravidae.

[Comparison of 2 field methods for urinary assay of chloroquine]

Two methods of urinary chloroquine assay were tested in pregnant women in the town of Banfora (Burkina Faso): the method with bromothymol blue (Bergqvist) and the method with methyl-orange (Haskins and Mount or HMM II). Urinary assay of chloroquine was performed with both methods in 45 women chosen at random whether or not under chemoprophylactic treatment (21 taking a weekly prophylaxis of 300 mg of chloroquine, and 24 controls). The HMM II method proved to be more sensitive (100%) and more specific (91.7%) than the Bergqvist method (80.9% and 83.3% respectively); it was also more reliable with regard to positive (91.3% versus 80.9%) and negative (100% versus 91.3%) predictive values. Moreover, the quantitative appreciation of the levels of chloroquine excretion proved to be superior with the HMM II method. Finally, this method is faster to perform, easier to use and cheaper, making it the method of choice for field assay of chloroquine in urine.

Age-specific differences in duration of clinical protection after vaccination with meningococcal polysaccharide A vaccine

Sequential case-control studies were used to monitor changes in the clinical protection induced by group A meningococcal polysaccharide vaccine over a 3-year period. Overall, vaccine efficacy declined from 87% 1 year after vaccination to 70% and 54% at 2 and 3 years, respectively. When stratified by age at time of vaccination the data showed that, although vaccine efficacy remained high in children greater than or equal to 4 years of age (vaccine efficacy 85%, 74%, and 67% at 1, 2, and 3 years after vaccination, respectively), it declined dramatically in those less than 4 years of age at time of vaccination (vaccine efficacy 100%, 52%, and 8%, respectively, at 1, 2, and 3 years after vaccination). Thus, a single dose of group A meningococcal vaccine does not yield lasting clinical protection in children less than 4 years of age.

[Extent of endemic yaws in Upper Volta in 1981]

This yaws investigation has been realized in the South West of Upper-Volta, in 1981, in areas around Gaoua, Niangoloko, N'Dorola; this investigation concerns 15 villages, chosen at random, and a sample of 1540 persons older than 4 years. The clinical prevalence (infectious cases) is 0.6%; the higher prevalence is observed around Gaoua (1.5%). Infectious contagious lesions are found especially in the 5-14 years old group. This investigation shows a low prevalence (under 5%) of active yaws. The serological prevalence (Kline-test) is 5.8% and we observe also around Gaoua the highest prevalence (8%). Periodical screening surveys of the population, during years 1952-1957, had shown a low prevalence of yaws, with a medium prevalence of yaws around Gaoua. Yaws treatment campaigns had been realized from 1957 to 1960 in South-West of Upper-Volta with very good results (prevalence: 0.06% - 1960). Now, in 1981, we note a resurgence of endemic foci, especially around Gaoua, from where the infection is spreading again, this, threatening the gains made by previous mass treatment campaigns. Taking in account the present result, it is necessary to treat contagious cases and contact sick persons (selective mass treatment or S.M.T., recommended in areas of low prevalence, by the WHO scientific group on treponemal infections).