Immunosuppressive function of hepatitis B antigens in vitro: role of endoribonuclease V as one potential trans inactivator for cytokines in macrophages and human hepatoma cells

The mRNAs of transiently expressed cytokine genes contain AUUUA-rich sequences in the 3' untranslated regions. In order to examine whether the AU-specific endoribonuclease V (EC 3.1.27.8) described previously by us transinactivates those mRNA species, we introduced a 51-nucleotide ATTTA sequence from tumor necrosis factor into the 3' untranslated region of beta-globin gene. Transcripts of that construct, synthesized in vitro, were prone to endoribonuclease V digestion at those AU-rich sequences. Stimulation of human macrophages with lipopolysaccharide resulted in a shift of the association state of the enzyme from the nuclear matrix-associated to the free form. This shift was strongly prevented by the hepatitis B surface antigen (HBsAg) and more weakly by hepatitis B nucleocapsid antigen and hepatitis B antigen of the X region. HBsAg and, to a lesser extent, hepatitis B nucleocapsid antigen and hepatitis B antigen of the X region inhibited the release of alpha interferon, tumor necrosis factor alpha, and granulocyte-macrophage colony stimulating factor, while it had no effect on interleukin-1 production from stimulated macrophages. Using the human hepatoma cell line PLC/PRF/5, we provide further experimental evidence that endoribonuclease V acts in trans as a posttranscriptional inactivator for nuclear matrix-associated cytokine transcripts. These results suggest that those cytokine transcripts which contain reiterated (overlapping) AUUUA sequences are degraded by nuclear matrix-associated endoribonuclease V. This degradation was comparably high in cells incubated with HBsAg or cells which produced this antigen.

[Age-related changes in the activity and post-translational modification of DNA topoisomerase II in the quail oviduct]

In the present work, we show that the activity of DNA topoisomerase II in quail oviduct nuclei significantly increases with age. Posttranslational modifications of the nuclear-matrix-associated enzyme by matrix-bound poly(ADP-ribose) synthetase and protein kinase, whose activities change with age, are demonstrated and offer possible mechanisms by which the age-dependent change in enzyme activity may be caused. It is assumed that the age-correlated enhancement of DNA-topoisomerase-II activity may cause changes in the topological state of DNA, with possible consequences for DNA replication, transcription, and repair with age.

[Magnetic resonance tomography in orthotopic liver transplantation]

14 patients with orthotopic liver transplantation were prospectively studied with MR imaging. MR imaging demonstrated a perivascular collar surrounding central portal venous branches in 14 patients. The perivascular collar had low signal intensity on T1-weighted and high signal intensity on T2-weighted images. In 10 of the 14 patients, a perivascular collar was also observed around peripheral portal venous branches. The perivascular collar is probably caused by intraoperative interruption of hepatic lymph vessels and resultant impaired lymph drainage. It is a normal postoperative phenomenon in hepatic transplants. MR imaging is particularly useful in the distinction of postoperative hematoma from other intra- and extrahepatic fluid collections and may provide a noninvasive assessment of liver transplant rejection.

Risks of hepatitis B for travellers

Retrospective and follow-up studies in travellers visiting developing countries suggest that 1 in 2500 develops symptomatic hepatitis B virus (HBV) infection after returning home. Vacationers are rarely affected. In contrast, persons working in developing countries frequently seroconvert. Hepatitis B vaccination is therefore indicated for all persons residing for a prolonged period of time in developing countries, particularly medical personnel, missionaries, or others having close contact with the autochthonous population. This immunization is usually unnecessary for vacationers, unless they intend to break basic rules of hygiene.

[Is epidural injection treatment with hypertonic saline solution in intervertebral disk displacement useful? (The effect of NaCl solution on intervertebral disk tissue)]

The effect of sodium chloride solution on disc tissue was investigated in vitro. Tissue material was obtained from 19 discectomies. The specimens were incubated in aqua ad injectionem and in different sodium chloride solutions and weighted regularly during a maximum of 24 hours. Following the incubation periods the specimens were examined histologically. After one hour the surgical specimens showed a weight increase of 290% for aqua bidest., 170% for 0.9% NaCl and 100% for 5.85% NaCl and 10% NaCl. Disc tissue obtained from six autopsies was also examined under the same conditions. The weight increase in nucleus pulposus and anulus fibrosus tissue was less than in the disc tissue obtained from surgery. The weight increase in anulus fibrosus tissue was less than in nucleus pulposus tissue. In vitro incubation of disc tissue in a hypermolar sodium chloride solution always resulted in a weight increase. Successful therapy could not be explained by shrinkage of disc tissue treated with hypermolar sodium chloride.

[Malaria prophylaxis of West German travelers to Africa]

From May 1985 to July 1988, 11,445 German residents who had travelled to Africa filled in a questionnaire during the return flight and a second questionnaire sent to them 3 months later. 92.6% of the travellers had been on holiday and 99.3% of these holiday-makers were aware of the risk of malaria. Before and during their stay in the tropics 10,955 travellers (95.7%) had taken the chemoprophylaxis correctly, though in some instances the drugs prescribed were not in accordance with the guidelines existing at the time. However, 3227 of them (35.5%) discontinued the drugs too early, i.e. less than four weeks after their return. Only 4.3% of the travellers had taken proper precautions against mosquito bites. In view of the ever increasing numbers of people travelling to countries where malaria is endemic, doctors and travelers should be provided with more information and should be given more consistent advice on malaria prophylaxis.

Malaria incidence and prevention among European and North American travellers to Kenya

A longitudinal survey was conducted among travellers departing from Nairobi airport to determine the use of malaria prevention measures and assess the risk for malaria while travelling in Kenya. Among 5489 European and North American travellers, 68 different drug regimens were used for prophylaxis, and 48% of travellers used both regular chemoprophylaxis and more than 1 antimosquito measure during travel; 52% of 3469 travellers who used chemoprophylaxis did so without interruption during their travel and for 4 weeks after departure. Compliance was lowest among travellers who visited friends and relatives, who were young, or who stayed more than 3 weeks. Sixty-seven (1%) travellers experienced symptoms of malaria, but the diagnosis could be verified for only 16 of these. Long-stay travellers appeared to be at higher risk for malaria than short-stay travellers, and health information needs to be targeted especially to the former. Similar investigations are needed among international travellers to other malaria-endemic countries. With comparable data available, consistent and effective malaria prevention guidelines can be developed.

[Ultrasound control of the repositioning of hip dislocation in a child in the unstable phase of splint retention (Hanausek position)]

In CDH ultrasound control of reduction in the unstable period of the first 3 months has to be performed by an inguinal access, as the splint can not be removed for the reason of high risks of redislocation. Controls are possible whenever required, according to anglo-american techniques. Thus treatment within the first year of life may be controlled by ultrasound imaging alone. Criteria for detection of posterior and cranial redislocation as well as for the anterior positioning of the femoral head are given.

Worldwide efficacy of bismuth subsalicylate in the treatment of travelers' diarrhea

So far four randomized studies, three of them double-blind and placebo-controlled, have investigated the role of bismuth subsalicylate (BSS) in the treatment of travelers' diarrhea. When compared with placebo BSS significantly reduced the number of unformed stools and increased the proportion of patients free of symptoms at the end of the trial. In the two studies that compared BSS with loperamide, the latter agent brought significantly faster relief. Diarrhea accompanied by dysenteric symptoms was influenced most favorably by administration of systemic antimicrobial agents. In all four studies only minor adverse effects were noted with BSS or the other active agents. One may include loperamide and a systemic antimicrobial agent in one's travel kit; however, loperamide should not be used for dysentery, and the antimicrobial agent should not be used in uncomplicated cases. As an alternative, although it is less effective, BSS has the unique advantage of being safe enough to use for all patients with travelers' diarrhea.

Malaria chemoprophylaxis among European tourists in tropical Africa: use, adverse reactions, and efficacy

In order to determine knowledge, attitudes and practices towards malaria prophylaxis, as well as its side-effects and efficacy, a self-administered questionnaire was distributed to European travellers on return flights from tropical Africa to Europe. Between 1985 and 1988 the questionnaire was completed by 44,472 passengers (80.1% of those on board) on 242 flights. A follow-up questionnaire was completed by 42,202 (94.9%) of the same travellers 3 months later. Almost all knew about the risk of malaria, but 10% relied solely on advice from nonmedical sources. While 55.6% had taken at least one measure against mosquito bites, only 4.5% adopted three such measures (used repellents and insecticides and wore long clothing after dusk). Compliance with chemoprophylaxis use was reported by 57.0% of travellers who spent less than 3 months in Africa, compared with 29.2% who stayed 3-12 months. Depending on the antimalaria regimen taken, 11-44% of the travellers experienced adverse effects, while four deaths were attributed to the chemoprophylaxis. The incidence of malaria per month of exposure for travellers who took no chemoprophylaxis was 15.2 per 1000 in East Africa and 24.2 per 1000 in West Africa. In East Africa, the prophylactic efficacy of the currently recommended antimalaria regimens (relative to that of no chemoprophylaxis) was zero for a chloroquine dosage of 300 mg base per week (4 malaria fatalities), 64.1% for a chloroquine dosage of 600 mg base per week (P = 0.03), and 94.0% for mefloquine (P = 0.003).

[Indications and current developments in liver transplantation]

Today, liver transplantation has become a routine treatment in many centres and will be increasingly applied in the future. Principal indications for liver transplantation are endstage chronic liver diseases, namely cirrhoses of various origin, fulminant hepatic failure, metabolic liver disease, and rarely non-resectable malignant tumors of the liver. Clinical and biochemical parameters indicative of the indication for liver transplantation can be stated with greater confidence. Advances in organ preservation with a new cold storage solution (University of Wisconsin solution) and further refinements in surgical technique and immunosuppression with application of multimodal protocols have led to a one-year-survival rate of 70%-80% in experienced centers. Since October 1988, 32 patients underwent liver transplantation in Berlin, currently, 31 patients are alive, while one patient died due to systemic fungal infection.

Age-dependent increase of DNA topoisomerase II activity in quail oviduct; modulation of the nuclear matrix-associated enzyme activity by protein phosphorylation and poly(ADP-ribosyl)ation

Nuclear DNA topoisomerase II activity in quail oviduct tissue was found to increase by about 70% with age. This age-dependent increase was observed with both the enzyme in whole nuclear extract and nuclear matrix-associated topoisomerase II. Both purified topoisomerase II and the nuclear matrix-bound enzyme were found to be modifiable by phosphorylation and poly(ADP-ribosyl)ation. Phosphorylation of the purified enzyme by isolated nuclear protein kinase NII or protein kinase C resulted in a 2- to 3-fold increase in specific activity, while poly(ADP-ribosyl)ation by soluble poly(ADP-ribose) synthetase caused a 50% inhibition of the enzyme. Using immunoprecipitation and immunoblotting procedures, phosphorylation and poly(ADP-ribosyl)ation could also be demonstrated to occur with the nuclear matrix-associated enzyme. The nuclear matrix-associated NII-like protein kinase activity, assumed to be involved in post-translational modification of topoisomerase II, displayed a 1.4- to 1.6-fold increase in old animals compared to mature ones, while the matrix-bound poly(ADP-ribose) synthetase activity decreased by about 50%. It is suggested that age-correlated enhancement of DNA topoisomerase II activity, possibly due to age-dependent changes in activities of nuclear protein kinases and poly(ADP-ribose) synthetase, may result in alterations in the topological state of DNA, possibly affecting DNA replication, transcription and repair with age.

Beyond 1 year after liver transplantation

We retrospectively reviewed the long-term results in 46 patients who survived at least 1 year after liver transplantation. Only one death has occurred, and one patient has required retransplantation. Biochemical liver function tests showed median values in the normal range, except for mild elevation of serum gamma-glutamyltransferase. In patients with primary biliary cirrhosis, these test results were completely normal. A liver biopsy 1 year after transplantation disclosed normal histologic findings in 31 patients (67%). The other patients had either transient (acute rejection) or stable (chronic rejection) abnormalities, except for two patients with progressive graft dysfunction attributable to chronic rejection. A clinically significant vascular anastomotic abnormality was noted in one patient who had hepatic artery thrombosis. Late bile duct complications occurred in 15% of patients, all of whom had a satisfactory outcome after surgical or radiologic intervention. Cyclosporine-related nephrotoxicity and hypertension each occurred in 67% of patients; however, conversion to a low-dose cyclosporine-azathioprine regimen yielded stabilization of renal function after the first postoperative year, and hypertension has been easily controlled medically. Diabetes necessitating insulin treatment developed in three patients. The body weight of the study patients had increased by a median of 6.5 kg at 1 year but stabilized thereafter. Subjective well-being and satisfaction with life were reported by 91% of the patients. Of the 46 patients, 26 were employed, 16 were homemakers, and only 4 did not work, 2 because of transplant-related medical problems. Thus, we conclude that liver transplantation rehabilitates patients with end-stage liver disease and enhances their quality of life.

Measurement of human lumbar spine ligaments during loaded and unloaded motion

Length changes in the ligaments of human lumbar spine motion segments were investigated in order to find conditions under which unusual stress or stress reduction is found in the longitudinal ligaments and facet joint capsules. Flexibility measurements were performed under load. Increasing load and height reduction in the motion segment increases the flexibility. The anterior and posterior longitudinal ligament normally operate in the elastic part of their stress-strain curve. Destruction of the intervertebral disc leads to a dislocation of the centers of rotation in the motion segment. Two types of facet joint capsules were observed. Height reduction in the motion segment leads to abnormal strains in one type sooner than in the other, which can be normalized by slight flexion. Injection of a silicone compound into the disc normalizes many of the changes in the motion segment due to height reduction.

Travelers' diarrhea in West Africa and Mexico: fecal transport systems and liquid bismuth subsalicylate for self-therapy

The goals of this study were threefold: to compare the etiology of travelers' diarrhea in West Africa and Mexico, to evaluate two fecal transport systems for the recovery of enteropathogens, and to verify the efficacy of liquid bismuth subsalicylate (BSS) in different locations and under different entrance criteria for disease severity. The study populations consisted of 133 European tourists in West Africa and 112 American students in Mexico who had suffered from travelers' diarrhea. In 60% and 38% of the stool samples at the two study sites, similar proportions of enteropathogens were detected. A two-vial system consisting of Enteric Plus medium and polyvinyl alcohol fixative was slightly superior for identifying enteric pathogens than was a three-vial system with buffered glycerol saline, Cary-Blair medium with campylobacter antibodies, and polyvinyl alcohol fixative. In a parallel, double-blind, randomized trial, BSS significantly shortened disease duration at both study sites.