Genome size and chromosomes in marine sponges [Suberites Domuncula, Geodia Cydonium]

The genome size of the marine sponges Suberites domuncula and Geodia cydonium has been determined by flow cytofluorometric analysis using diamidino-phenylindole [DAPI]. Using human lymphocytes as reference the amount of DNA in cells from S. domuncula has been determined to be 3.7 pg and that of G. cydonium 3.3 pg. While no chromosomes could be identified in G. cydonium, the karyotype of the Suberites domuncula is 32 chromosomes in the diploid state. The size of the chromosomes was between 0.25 and 1.0 micron. No pronounced banding pattern was visible.

Risk of Cholera Among Western and Japanese Travelers

Background: There has been concern about an increased risk of cholera in travelers to Latin America since the spread of the pandemic to this part of the world. Additionally, before this study the continuous high incidence of imported cholera to Japan had so far not been analyzed. Methods: A retrospective analysis of cases notified in 1991 to national surveillance centers in industrialized countries and to the World Health Organization was carried out. Denominator data were obtained by the World Tourism Organization. Results: The reported rate of imported cholera in European and North American travelers visiting endemic areas remains in the range of 0,2 per 100,000, as was observed 10 years ago. This rate is, however, is manyfold higher in Japanese travelers, with a highest value of 13,0 per 100,000 reported in those returning from Indonesia, usually Bali. No secondary outbreaks were observed in those countries to which cholera was imported. Conclusions: It is assumed that the higher rates in Japanese travelers are mainly due to more intensive surveillance. On Bali and elsewhere, further studies are needed to determine both the role of V. cholerae as a cause of traveler's diarrhea in tourists and to re-evaluate the need for cholera vaccination at specific high-risk destinations.

Treatment of travellers' diarrhoea: zaldaride compared with loperamide and placebo

OBJECTIVE

To compare zaldaride maleate, a calmodulin inhibitor with gastrointestinal antisecretory properties, with loperamide and a placebo in the treatment of travellers' diarrhoea.

DESIGN

Randomized, double-blind, double-dummy study.

SETTING

Study clinic staffed by European residents on Nile cruise ships.

PATIENTS

Tourists (n = 436) who acquired travellers' diarrhoea during the Nile cruise.

INTERVENTIONS

(1) Zaldaride 20 mg four times daily, (2) zaldaride 2 x 20 mg as initial loading dose followed by three doses of 20 mg on the first day and four doses of 20 mg on the second day, (3) loperamide 2 x 2 mg loading dose following by a flexible dosage of 2 mg after each unformed stool (maximum of 16 mg daily), (4) placebo.

MAIN OUTCOME MEASURES

Number of unformed stools, rate of improvement of patients with diarrhoea, rate of relief from diarrhoea.

RESULTS

Among the 331 compliant and fully evaluated patients, the zaldaride with loading dose group showed no significant differences in cure rates from the loperamide group. For most parameters, zaldaride without a loading dose and the placebo resulted in significantly lower cure rates.

CONCLUSIONS

A zaldaride regimen including a loading dose was shown to be well tolerated and as effective as loperamide.

Efficacy and tolerance of insoluble carob fraction in the treatment of travellers' diarrhoea

The water-insoluble carob fraction (fraction insoluble caroube, FIC, Nestlé) has been successfully used in the treatment of infantile diarrhoea. To investigate the efficacy and toxicity of FIC (1970 mg to be taken every 2 hours over a 48-hour period except during sleeping time) in the treatment of travellers' diarrhoea in adults, a double-blind, computer randomized, placebo-controlled study was conducted. Of the 755 volunteers recruited at the Zurich University Vaccination Centre, 628 (83.5%) returned their questionnaires. Among them, 164 (27.7%) had diarrhoea, but only 69 (42%) used the trial medication correctly; the others were rated non-complaint. No significant difference in efficacy (p = 0.12) or adverse effects were observed in the two study groups. In conclusion, FIC, although showed a positive trend, was not efficacious.

Liver transplantation: significance of the periportal collar on MRI

OBJECTIVE

Liver transplantation is performed with increasing success and frequency all over the world. Experience with MRI of the liver allograft is, however, limited. This study was designed to correlate MRI to clinical-laboratory findings, CT, and biopsy and to evaluate the significance of the periportal collar on MRI.

MATERIALS AND METHODS

Fourteen patients who had undergone orthotopic liver transplantation were studied by CT and MRI [T1-weighted imaging: gradient-echo, repetition time/echo time (TR/TE) 306/14 ms, theta 90 degrees; proton density and T2-weighted imaging: spin-echo, TR/TE 1,600/30-120 ms]. Three patients also had follow-up MR examinations 43 days, 89 days, and 5 months after transplantation.

RESULTS

Magnetic resonance imaging demonstrated a perivascular collar around central portal venous branches in all 14 patients and around peripheral portal branches in 10 of the 14 patients on the initial MRI study. The perivascular collar showed low signal intensity on T1-weighted imaging and an increase in signal intensity on T2-weighted multiecho imaging. The distribution and prevalence of central and peripheral periportal collars were identical on MR and CT. Peripheral periportal collars were seen in 9 patients who had no clinical-laboratory signs of rejection. In 3 patients with biopsy-proved rejection, the periportal collar was less prominent on MR at the time of rejection when compared with MR performed when the patient had no signs of transplant rejection.

CONCLUSION

A perivascular collar in a patient with liver transplantation is likely to be related to impaired lymph drainage after surgical interruption of the draining lymph vessels and lymphedema. In contrast to previous CT reports, however, a perivascular collar around peripheral portal branches does not appear to correlate to rejection, since it is frequently observed in the normal liver allograft.

Formation of spicules by sclerocytes from the freshwater sponge Ephydatia muelleri in short-term cultures in vitro

Cells from the freshwater sponge Ephydatia muelleri were isolated by dissociating hatching gemmules. During the first 24 h the cells reaggregated, but the aggregates progressively disintegrated again to single cells, among which the spicule-forming sclerocytes were recognized. Such cultures were used to study spicule (megascleres) formation in vitro. The isolated sclerocytes formed the organic central axial filament onto which they deposited inorganic silicon. The size of the spicules (200 to 350 microns in length) as well as the rate of spicule formation (1 to 10 microns/h) under in vitro conditions were similar to the values measured in vivo. Immediately after completion of spicule formation, or even before, the sclerocyte could start formation of a new spicule; 5% of the cells were in the process of forming two spicules simultaneously. Cultivation of sclerocytes in the absence of silicon resulted in the formation of the axial filament only. We succeeded in maintaining the sclerocytes in a proliferating and spicule-forming state for up to 3 mo. These results demonstrate that the establishment of short-term cell cultures from E. muelleri is possible; however, future studies must be undertaken to identify the growth factors required for a permanent culture of sponge cells.

Benefit/risk considerations with respect to OTC-descheduling of loperamide

The main criteria to be considered for releasing an antidiarrhoeal from a prescription to an OTC-drug are guaranteed quality control, established efficacy and safety and the evaluation of the drug experience on major markets. Besides the considerable benefits from a socio-economic point of view, the risk for potential inappropriate use of loperamide (CAS 53179-11-6) as self-medication can be minimized by its use being avoided in children of 5 years of age or less (e.g. by making available a solid formulation only), by limiting the treatment duration to 48 h, and by contraindicating the use of the drug in cases of fever (> 38 degrees C) and/or blood in the stools. On the basis of a broad review loperamide can be considered to be efficacious in acute non-specific, acute functional and traveller's diarrhoea. The agent has a good safety profile if the mentioned restrictions are born in mind. Loperamide thus satisfies the OTC criteria.

[Biomechanical considerations concerning the use of internal fixator systems in spinal interventions]

Three different internal fixateurs ("Dick", "Kluger", "SOCON") were investigated in an in-vitro setting. The systems showed nearly identical deformation under physiological loads. A new definition for the stabilizing capacity indicated a distinct weakness under compressive and torsional loading. In order to avoid early failure of the implant and/or the vertebra-implant interface bracing and a restricted mobilisation is recommended until healing of the fracture/fusion has taken place.

Hepatitis A in travelers: the European experience

Each year approximately 14 million Europeans travel to developing countries in Africa, Asia, and Latin American as well as to infrequently visited countries in eastern Europe. Without protection, travelers develop symptomatic hepatitis A at the rate of 3 cases per 1000 people per month of stay. Those who eat and drink under poor hygienic conditions have an even higher risk, 20/1000/month. Studies show that hepatitis A is the most frequent vaccine-preventable disease in travelers to developing countries. Immunity to hepatitis A virus is infrequent among northern European travelers, except for those born before 1945, with a history of jaundice, or who lived for > 1 year in a developing country.

Behavioural aspects of travellers in their use of malaria presumptive treatment

The use of stand-by treatment for malaria by travellers depends on their knowledge, attitudes and behaviour. We examined the behavioural aspects of a cohort of travellers from Switzerland to low-risk malarial areas who, on recruitment, were provided with a kit containing medication for stand-by treatment, guidelines on the diagnosis of malaria, and materials for collection of blood samples for later confirmation of malaria. All subjects were urged to seek medical advice at the first signs of possible malarial symptoms. Illness (fever as the main indicator) was reported by 123 of the 1187 participants, often accompanied by shivering/chills (36.6%), headache (35.0%), gastrointestinal symptoms (69.9%), and myalgia and/or arthralgia (41.5%). Two-thirds of those ill failed to seek medical attention despite their symptoms and pretravel advice. Only 9 (7.3%) were actually beyond the reach of medical attention. The stand-by treatment was self-administered by 6 travellers, only one of whom had confirmed malaria. Two non-serious adverse events were reported. All users consulted a physician after administering the presumptive treatment. This stand-by approach is limited by inappropriate behaviour and poor malaria awareness among travellers. These negative factors can be mitigated by development of an improved kit containing a simple test for self-diagnosis.

Advances in hepatitis A prevention in travellers

The introduction of an active vaccine against hepatitis A, the most frequent of the vaccine-preventable infections in travellers, is an important contribution to travellers' health. Although theoretically the risk of exposure may be minimised by taking hygienic precautions, most travellers in practice remain at considerable risk. As compared to immunoglobulin, vaccine has the advantages of better and long-lasting protection. A double-strength vaccine has been introduced (HAVRIX, 1440 enzyme-linked immunosorbent [ELISA] units [EL.U]) and a single injection will protect from day 14 for 1 year. No significant adverse events have been reported. Questions that remain unanswered are whether travellers leaving before day 14 should receive immune globulin plus vaccine and whether very young travellers should all be immunised.

Comparison of Seven Commonly Used Agents for Prophylaxis of Seasickness

The objective of the study was to compare the efficacy and tolerability of seven drugs frequently used for the prevention of seasickness: the drugs were namely cinnarizine, cinnarizine with domperidone, cyclizine, dimenhydrinate with caffeine, ginger root, meclozine with caffeine, and scopolamine. The design was a randomized, double-blind study with two arms. On ethical grounds, a placebo group was not included as in a previous study, in the same setting, 80% of the passengers not receiving prophylactic drugs were seasick. The setting was in Andenes (Norway) during a time period from July to September 1992. Subjects were 1741 tourist volunteers who were joining a whale safari. The main outcome measures were vomiting, malaise (modified Graybiel criteria), and subjective reports of adverse events. Follow up was possible in 1489 volunteers (85.5%). In each active treatment group, 4.1-10.2% experienced vomiting and 16.4-23.5% experienced malaise (not significant). Equally, there was no significant difference in the incidence and characteristics of adverse events reported in the various medication groups. Scopolamine Transdermal Therapeutic System (TTS) users exhibited slightly more visual problems and the agent tended to be less effective. Six of the seven medications may be recommended for prevention of seasickness; scopolamine TTS seems the least attractive.

[Prevention for travel to the tropics]

The Swiss Working Group for Health Advice to Travellers regularly publishes its recommendations for malaria prophylaxis and vaccination as supplement to the 'Bulletin' of the Federal Office of Public Health. In this review the strategy with respect to information, to clever behavior abroad, to chemoprophylaxis and immunization prophylaxis is analyzed. A critical evaluation of emergency self-therapy describes remaining questions in particular.

Epidemiology and prevention of hepatitis A in travelers

OBJECTIVE

To assess the risk of hepatitis A in international travelers and to recommend preventive measures.

DATA SOURCES

Index Medicus, 1974 through 1983; MEDLINE, 1984 through 1993; and unpublished data of the Centers for Disease Control and Prevention.

STUDY SELECTION

Review of all retrospective and cohort studies on hepatitis A and other vaccine-preventable diseases in travelers, of seroepidemiologic surveys of hepatitis A virus (HAV) antibodies in travelers, of data on the various hepatitis A vaccines, of economic analyses, and of recommendations of recognized organizations.

DATA EXTRACTION

Independent analysis by multiple observers.

DATA SYNTHESIS

The incidence rate for unprotected travelers, including those staying in luxury hotels, is estimated to be three per 1000 travelers per month of stay in a developing country. Persons eating and drinking under poor hygienic conditions have a rate of 20/1000 per month. This makes hepatitis A the most frequent infection in travelers that may be prevented by immunization. In many industrialized countries persons born after 1945 have an HAV antibody seroprevalence (immunity) of less than 20%. New inactivated HAV vaccines induce protective antibodies in more than 95% of recipients and offer protection estimated to last for 10 years or more, whereas protection by immune globulin lasts only 3 to 5 months.

CONCLUSIONS

Hepatitis A vaccine, or immune globulin where HAV vaccine is not available, is recommended for all nonimmune travelers visiting developing countries. Prescreening for antibodies to HAV in travelers living in countries with low prevalence is usually not necessary in persons born after 1945.

[Importance of the back muscles in rehabilitation of postoperative segmental lumbar instability--a biomechanical analysis]

In the present study, a biomechanical in-vitro experimental design for assessing lumbar instability following discectomy had been complemented by computer simulation of the muscular influence. The most impressive changes of the instability parameters chosen, i.e., mobility (flexibility) and neutral zone, occurred in respect of the study movement directions Ty, Tz and Mx (lumbar disc height, anterior/posterior dislocation, and flexion/extension). The influence of the multifidus muscle had enabled the flexion/extension neutral zone changes to be offset. Flexibility (+/- Rx) was found to have been influenced to a minor degree.

Bacterial and fungal colonization and infections using oral selective bowel decontamination in orthotopic liver transplantations

Bacterial and fungal infections are a major cause of morbidity and mortality after orthotopic liver transplantation. In the immunocompromised host, infections are thought to arise from the gut, which is almost always colonized with potential pathogens. Using oral selective bowel decontamination (SBD), potential pathogens can be eradicated from the gut and infections prevented. In this catamnestic study we have reviewed gastrointestinal colonization, bacterial and fungal infections, and bacterial resistance to standard antibiotics in our first 206 liver transplant patients while under SBD. With few exceptions, gram-negatives were eradicated from the gastrointestinal tract and secondary colonization was inhibited. In spite of unsatisfactory elimination of Candida, probably because nystatin doses were too low, Candida infections were rare (n = 4) and none was fatal. One and two-year survival rates were 93% and 92%, respectively. The bacterial and fungal infection rate was 27.8% with an infection-related mortality of 1.95%. Infections with aerobic gram-positive bacteria prevailed and only 11 gram-negative and 11 fungal infections occurred; among the latter, Aspergillus and Mucor were the most serious and responsible for three of the six deaths in this series. With regard to the development of resistance, we found an increasing number of enterococci and coagulase-negative staphylococci resistant to ciprofloxacin and imipenem, respectively, but unlikely as a consequence of SBD.

[Do's and don'ts in travel medicine advice]

The cornerstones of a travel health consultation are: information, advice on anti-mosquito measures, vaccinations, malaria chemoprophylaxis and guidelines for presumptive treatment. The art of travel medicine is the ability to focus on the realistic health needs of the traveller whilst leaving aside superfluous information. In this way, unnecessary adverse events, expenses and patient anxiety can be avoided.

Stand-by treatment of malaria in travellers: a review

Stand-by treatment is the use of anti-malaria drugs carried for self-administration when fever and flu-like symptoms occur and prompt medical attention is not available. This paper aims to review the rationale for the stand-by therapy concept, the range of options available, the factors influencing the choice of therapy and the efficacy and toxicity of the various agents available in the light of ever increasing resistance to conventional drugs. The use of chloroquine as a possible stand-by treatment is limited because of widespread chloroquine resistance and the problem is further compounded by the increasing prevalence of parasites resistant to antifolate/sulpha drug combinations, particularly in South-East Asia and South America. Mefloquine is a promising agent for presumptive malarial treatment with limited foci of drug resistance, notably in Thailand. Mefloquine therapy has been associated with adverse events, mostly minor but with occasional neuropsychiatric events. The use of halofantrine, hitherto often recommended as a stand-by treatment, has been curtailed after recent research reports demonstrated that the drug may cause prolongation of the QTc interval. Current experience with stand-by therapy is limited and studies are in progress to elucidate the exact circumstances under which travellers actually use their emergency medication. Stand-by treatment is an option for clearly defined situations while prophylaxis remains the safest choice for travellers to areas of high transmission.

The results of strictureplasty in pediatric patients with multifocal Crohn's disease

This study is a retrospective review of eight pediatric patients with multifocal intestinal Crohn's disease who underwent strictureplasty with or without concomitant bowel resection between January 1978 and April 1992. The patients ranged in age from 9.9 years to 18.5 years. Indications for surgery were partial intestinal obstruction (n = 6), failure of medial therapy or steroid dependence (n = 4), growth failure (n = 2), and enterocutaneous fistula (n = 2). Thirty-six strictureplasties were performed in the eight patients (median, 4.5 strictureplasties per patient; range, 1-12). Bowel resection was performed in six of the eight patients in areas where strictureplasty was not feasible. The mean length of resection was 40 cm (range, 15-82 cm). The only complication was intestinal hemorrhage, which was conservatively managed in two patients. The patients were followed for a mean of 19 months (range, 3-55 months). Five patients had a weight below the fifth percentile prior to surgery. Postoperatively, there was a weight gain in seven patients, including all five patients who were originally below the fifth percentile. A statistically significant weight gain was found when a paired t test analysis was applied to the entire group (p = 0.04). Five of six patients who were on steroid medication at the time of surgery were successfully weaned within 1.5-3 months (mean, 2.3 months) from the time of surgery. Seven of eight patients had relief of their intestinal symptoms. Strictureplasty with small-bowel resection, or perhaps strictureplasty alone, in pediatric patients with multifocal intestinal Crohn's disease can improve gastrointestinal symptoms, promote weight gain, and allow discontinuation of steroid medications.(ABSTRACT TRUNCATED AT 250 WORDS)

Technique and results of biliary reconstruction using side-to-side choledochocholedochostomy in 300 orthotopic liver transplants

OBJECTIVE

The authors evaluated the complication rate and outcome of side-to-side common bile duct anastomosis after human orthotopic liver transplantation.

SUMMARY BACKGROUND DATA

Early and late biliary tract complications after orthotopic liver transplantation remain a serious problem, leading to increased morbidity and mortality. Commonly performed techniques are the end-to-end choledochocholedochostomy and the choledochojejunostomy. Both techniques are known to coincide with a high incidence of leakage and stenosis of the bile duct anastomosis. The side-to-side bile duct anastomosis has been shown experimentally to be superior to the end-to-end anastomosis. The authors present the results of 316 human liver transplants, in which a side-to-side choledochocholedochostomy was performed.

METHODS

Biliary tract complications of 370 transplants in 340 patients were evaluated. Three hundred patients received primary liver transplants with side-to-side anastomosis of donor and recipient common bile duct. Thirty-two patients with biliary tract pathology received a bilioenteric anastomosis, and in eight patients, side-to-side anastomosis was not performed for various reasons. Clinical and laboratory investigations were carried out at prospectively fixed time points. X-ray cholangiography was performed routinely in all patients on postoperative days (PODs) 5 and 42. In patients with suspected papillary stenosis, endoscopic retrograde cholangioscopy and papillotomy were performed.

RESULTS

One biliary leakage (0.3%) was observed within the early postoperative period (PODs 0 through 30) after liver transplantation. No stenosis of the common bile duct anastomosis was observed during this time. Late biliary stenosis occurred in two patients (0.6%). T tube-related complications were observed in 4 of 300 primary transplants (1.3%). Complications unrelated to the surgical technique, including papillary stenosis (5.7%) and ischemic-type biliary lesion (3.0%), which must be considered more serious in nature than complications of the anastomosis or T tube-related complications, were observed. Papillary stenosis led to frequent endoscopic interventions and retransplantations in 1.3%.

CONCLUSIONS

Side-to-side common bile duct anastomosis represents a safe technique of bile duct reconstruction and leads to a low technical complication rate after human orthotopic liver transplantation. Ischemic-type biliary lesion evoked by preservation injury, arterial ischemia, cholestasis, and cholangitis may represent a new entity of biliary complication, which markedly increases the morbidity after human liver transplantation. Therefore, this complication should be the subject of further research.