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Biomedical subjects

B Holzer

Publications and source records attributed to B Holzer.

At least 19 recordsLinked to original sources

Unicoloniality, recognition and genetic differentiation in a native Formica ant.

Some ants have an extraordinary form of social organization, called unicoloniality, whereby individuals mix freely among physically separated nests. This mode of social organization has been primarily studied in introduced and invasive ant species, so that the recognition ability and genetic structure of ants forming unicolonial populations in their native range remain poorly known. We investigated the pattern of aggression and the genetic structure of six unicolonial populations of the ant Formica paralugubris at four hierarchical levels: within nests, among nests within the same population, among nests of populations within the Alps or Jura Mountains and among nests of the two mountain ranges. Ants within populations showed no aggressive behaviour, but recognized nonnestmates as shown by longer antennation bouts. Overall, the level of aggression increased with geographic and genetic distance but was always considerably lower than between species. No distinct behavioural supercolony boundaries were found. Our study provides evidence that unicoloniality can be maintained in noninvasive ants despite significant genetic differentiation and the ability to discriminate between nestmates and nonnestmates.

Aggression↗

Aetiology and surgical management of toxic megacolon.

OBJECTIVE: The purpose of this article is to review the surgical management and outcome of toxic megacolon and to update the aetiology of toxic megacolon. PATIENTS AND METHOD: A retrospective chart review of three academic colorectal surgery units was undertaken. Over a period of 20 years, 70 patients with surgically managed toxic megacolon were identified: 32 men and 38 women, median age 63 years (range, 23-87 years). RESULTS: In 33 (48%) patients the main cause of toxic megacolon was inflammatory bowel disease. Thirty-seven (52%) patients had toxic megacolon of different aetiology. Sixty-three patients underwent colonic resection: 49 (70%) subtotal colectomies and 14 (20%) total colectomies, including 4 (6%) proctocolectomies. Seven (10%) patients had decompression (n=3) or faecal diversion (n=4) only. Forty-four of the resected patients underwent a Hartmann's procedure and an ileostomy; 13 (19%) patients had primary anastomoses, 11 (16%) ileorectal anastomoses (IRA) and 2 (3%) patients had ileal pouch-anal anastomosis (IPAA). Twenty-six (37%) patients subsequently had continuity restored. Total surgical complication rate was 19% (n=13), 8% (n=4) in patients treated with subtotal colectomy, 21% (n=3) in patients treated with total proctocolectomy and 86% (n=6) in patients treated with either decompression or diversion. The total mortality rate was 16% (n=11). CONCLUSIONS: Toxic colitis complicated by toxic megacolon can occur after various diseases of the colon and remains a life-threatening disorder associated with a significant risk of postoperative complications. Subtotal colectomy with ileostomy remains the procedure of choice. Surgical colonic decompression with faecal diversion alone is associated with a high rate of complications.

Adult↗

Patients' expectations of colorectal surgery for cancer.

OBJECTIVE: The primary objectives of surgery for colorectal cancer are to achieve radical resection of the tumour and to ensure a satisfactory quality of life for the patient. But what is satisfactory quality of life for the patients? What do patients desire? The goal of our exploratory investigation was to evaluate prospectively the patient pre-operative expectations as objectively as possible and to analyse results in relation to age, gender and socio-economic status. METHODS: In the period from 1998 to 2001, 167 patients were given a questionnaire consisting of 15 questions prior to surgery. The questionnaire included various aspects that were thought to influence the patient's quality of life. Moreover the patients were given the opportunity to rate the questions they considered most important. RESULTS: The following five points were considered most important by the total group of patients: Complete cure of the disease was rated most important (95%); it was the prime expectation of the patients. This was followed by the avoidance of a stoma (81%), a reliable control of defaecation (52%), normal digestion (44%) and little pain (26%). CONCLUSION: Age, gender and education influence the pre-operative expectations of patients undergoing surgery for colorectal cancer. In addition to the surgical standard, the care of the individual patient must be given due consideration in the treatment strategy.

Adult↗

Improving the safety of laparoscopic cholecystectomy: the routine use of preoperative magnetic resonance cholangiography.

BACKGROUND: The aim of this study was to determine the value of routinely performed preoperative magnetic resonance cholangiography (MRC) in detecting common bile duct (CBD) stones in patients stated to undergo elective laparoscopic cholecystectomy. In addition, we used MRC to investigate possible variants of the cystic duct. METHODS: Magnetic resonance cholangiography was performed preoperatively in 773 patients (311 male and 462 female; median age 55 years, range 16-91) who had no clinical signs of cholestasis prior to undergoing elective laparoscopic cholecystectomy. In cases where the MRC was positive for CBD stones, endoscopic retrograde cholangiopancreatiography (ERCP) was then performed. A total of 532 patients were available for continuous postoperatively follow-up (median 54 months, range 36-85). In 462 patients (247 female, and 215 male), MR images were also reviewed for variants of the cystic duct. RESULTS: In 705 patients (91%), MRC was negative for CBD stones. In 64 patients (9%) MRC was positive. Of these patients, 47 (6%) had CBD stones on ERCP. In 12 patients (2%), MRC was false positive. In five cases (0.6%), ERCP had an inconclusive result postoperative follow-up (532 patients, or 69%) revealed evidence of CBD stones in three patients (10.4%) despite a preoperative negative MRC result. Anatomical variants in the course of the cystic duct and its confluence with the common bile duct were found in 27 of 462 patients (6%). CONCLUSIONS: Magnetic resonance cholangiography proved to be a reliable screening technique in the preoperative evaluation of patients with silent CBD stones. Imaging of the course of the cystic duct is possible in a high percentage of cases. Therefore, MRC can be recommended as a screening technique before laparoscopic cholecystectomy.

Adolescent↗

Inhibition of polyprotein processing and RNA replication of human rhinovirus by pyrrolidine dithiocarbamate involves metal ions.

Pyrrolidine dithiocarbamate (PDTC) is an antiviral compound that was shown to inhibit the replication of human rhinoviruses (HRVs), poliovirus, and influenza virus. To elucidate the mechanism of PDTC, the effects on the individual steps of the infection cycle of HRV were investigated. PDTC did not interfere with receptor binding or internalization by receptor mediated endocytosis of HRV2 particles into HeLa cells. But we demonstrate that the processing of the viral polyprotein was prevented by PDTC treatment in HeLa cells infected with HRV2. Furthermore, PDTC inhibited the replication of the viral RNA, even when added four hours post infection. As PDTC is described as a metal ion binding agent, we investigated the effect of other metal chelators on the multiplication of HRV2. We show that EDTA, omicron-phenanthroline, and bathocuproine disulfonic acid do not exhibit any antiviral properties. Surprisingly, these substances, coadministered with PDTC, abolished the antiviral effect of PDTC, suggesting that metal ions play a pivotal role in the inhibition of virus multiplication. These results suggest that PDTC inhibits the activity of the viral proteases in a metal ion dependent way.

Antioxidants↗

Efficacy and tolerance of a new gentamicin collagen fleece (Septocoll) after surgical treatment of a pilonidal sinus.

OBJECTIVE: Pilonidal sinus is common. It causes substantial loss of working hours. The major disadvantage of open wound treatment is the long time required for healing. Primary wound closure is on the other hand often followed by infection. A controlled, multicentre trial was carried out to evaluate the efficacy of a new gentamicin collagen fleece (Septocoll) combined with primary closure. PATIENTS AND METHODS: One hundred and three patients (88 men, 15 women, median age 30 years) were included. Fifty-one were randomised to gentamicin fleece plus primary closure (Genta Group), and 52 patients to open treatment alone (Open Group). RESULTS: The median interval to wound healing was 17 days in the Genta group and 68 days in the Open group (P = 0.0001, log-rank test). Two patients in Group 1 developed infection within the first two weeks, requiring reopening of the wound, with primary wound healing occurring in 73%. Failure of primary healing (27%) was usually due to seroma or spontaneous dehiscence which subsequently healed. CONCLUSION: The combination of gentamicin collagen fleece (Septocoll) with primary closure resulted in a shorter period to healing than the open technique without unwanted effects.

Adolescent↗

[Single and multiple interventions in ileus of the large intestine due to carcioma].

Ileus due to a colorectal carcinoma is still an illness with high mortality currently between 15 and 20%. Advanced tumor stages are found in the majority of the patients. Today one-staged procedures are preferred, although a clear advantage in postoperative mortality was not proven so far. We recommend a concept, depending on localization, general condition and tumor stage. For patients in very bad general condition a primary colostomy is still a good option today. In case of a damaged intestine we recommend either a two-staged procedure with primary resection and colostomy and secondary closure of the stoma or a subtotal colectomy in patients who are in a good general condition. For patients in very good condition an one-staged procedure should be performed, whereby we prefer the resection with on table lavage.

Anastomosis, Surgical↗

[Malaria--chemoprophylaxis 2001].

An estimated 20,000 to 30,000 cases of imported malaria are annually diagnosed in industrialised countries. Some 700 of them concern Swiss travellers and foreign guests. Exposure prophylaxis and chemoprophylaxis for high risk destinations lower the risk of malarial disease. The latter is defined as regular intake of antimalarial drugs in subtherapeutic dosage in order to suppress the development of clinical disease. Drugs are usually taken from one week before travel until four weeks after return from an endemic area. Mefloquine, doxycycline, chloroquine plus proguanil, and presumably soon also atovaquone plus proguanil are available in Switzerland for chemoprophylaxis.

Africa↗

Sacral nerve stimulation as a treatment for fecal incontinence.

BACKGROUND & AIMS: Sacral nerve stimulation is a proven therapeutic option for the treatment of some forms of urinary incontinence. Very recently, preliminary reports have given evidence for its efficacy in fecal incontinence (FI) too. METHODS: Since November 1998, 20 patients have been treated for severe FI. The cause of FI was mainly neurologic (n = 15), and was idiopathic in 5 patients. After temporary (subchronic) external stimulation over a period of 10-14 days, patients whose continence status improved underwent implantation of a permanent quadripolar lead and a subcutaneously implanted pulse generator. RESULTS: Acute (needle) testing revealed a positive pelvic floor response in 16 patients who underwent subsequent permanent implantation. The median number of incontinence episodes decreased from 6 episodes (3-15/21 days) to 2 (0-5/21 days). The time period of retention of a volume of saline causing an urge until definitive defecation was 2 minutes (range, 0-5 minutes) preoperatively and increased to 7.5 minutes (2-15 minutes) postoperatively. Results of preoperative and postoperative (3 months) anal manometry showed a statistically significant increase in maximal resting and squeeze pressures. CONCLUSIONS: Sacral nerve stimulation seems to be a new and promising modality for patients with certain types of FI in whom conventional treatment options have failed to achieve an improvement.

Adolescent↗

[Acute and perforated sigmoid diverticulitis. Surgical indication: single stage versus multiple-stage operation].

The indication and the optimal surgical procedure of complicated diverticulitis are still under discussion. The choice of the surgical therapy has its highest priority in the cure of the infection by sigmoid resection. Resection with primary anastomosis can be done in cases of covered perforation (Hinchey 1 + 2) with a low mortality. Diffuse peritonitis should be treated depending on the individual local situation.

Adult↗

Needle perforation of the appendix.

BACKGROUND/AIMS: Needles are among the most frequently swallowed foreign bodies. In most cases they are excreted per vias naturales, but in some cases needles can lead to perforation of the stomach or duodenum in adults. METHODS: We report a case of acute appendicitis after perforation of the appendix by a swallowed needle. An appendectomy was performed without any knowledge of the reason for perforation. RESULTS: Inspection of the resected appendix demonstrated a needle of 1.5 cm length inside the lumen of the appendix, which had caused a perforation of the distal end of the appendix. CONCLUSION: As seen in this case a longer-lasting nondiagnosed perforation can lead to extensive local inflammation which could have been avoided by early surgical treatment which should also be considered if the patient has very few symptoms, as in this case.

Adult↗

[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.

Antimalarials↗

Double-blind randomised clinical trial of pentoxiphyllin in vaso-occlusive sickle cell crisis.

Frequent painful sickle cell crisis leads to a high number of active days lost due to morbidity or mortality. Only one of the specific drugs has been shown to be efficacious in a controlled clinical trial in the USA. The efficacy and the appropriateness of a drug acting on the erythrocytic membrane, pentoxiphyllin, was investigated in a randomised, double blinded clinical trial in the treatment of acute incapacitating crisis. In the 36 patients studied in a rural hospital in Togo (West Africa) where sickle cell disease is frequent (0.51% of all births), the mean (standard deviation = SD) duration of inpatient treatment was significantly shorter in the actively treated group active drug: 77.6 (40.19) hours, placebo: 102.4 (25.31) hours, difference between means: 24.8 (95% confidence intervals (= 95% CI) 2.02-47.5) hours); p = 0.03. This marked effect of active treatment was evident during the first 48 hours only. The suitability of this therapeutic regime within the studied area is discussed.

Acute Disease↗

[Medical problems in refugees from Sri Lanka (Tamil)].

Recently many refugees from Sri Lanka have arrived in Europe. The purpose of the present investigation was to analyze the subjective complaints and diagnoses in these refugees. One hundred refugees (97 males, 3 females, age 19 to 42 years) were investigated. The most common reasons for consulting a general internist were cough (23%), general pain in soft tissue and joints (21%), disorders of the gastrointestinal tract (19%) and ear or throat complaints (15%). In 43% of the patients no diagnosis could be established. 58 patients were investigated for parasites in stool: 57% of these patients had hookworms, 12% non-pathogenic protozoon, 9% Entamoeba histolytica cysts, and 2% Giardia lamblia. In 12% of the patients the diagnosis was tonsillitis or pharyngitis, in 7% bronchitis, pneumonia or asthma and in 5% arterial hypertension. Various other diagnoses were established in 48 patients. With the exception of the high frequency of intestinal parasites, complaints and diagnoses in these refugees were the same as in a comparable European population.

Adult↗

Parental influences on children's eating behavior and relative weight.

We investigated the relationship between selected parent behaviors, child mealtime behavior, and infant relative weight. Subjects were 7 male and 7 female children varying in age from 12 to 30 months (mean = 23.9 months). Each subject and parents were observed during the dinnertime meal on two occasions using the BATMAN (Bob and Tom's Method of Assessing Nutrition). The children spent 58% of the mealtime eating. They spent very little time making active decisions about what and how much they ate (food requests = 2% of the time; food refusals = 1% of the time). We found significant correlations between child relative weight and (a) parental prompts to eat (r = .81, p less than .001), (b) parental food offers (r = .51, p less than .05), and (c) parental encouragement to eat (r = .82, p less than .001). Thus, the present study suggests a relationship between certain parental variables and the relative weight of their children.

Body Weight↗

Studies on the epidemiology of schistosomiasis in Liberia: the prevalence and intensity of schistosomal infections in Bong County and the bionomics of the snail intermediate hosts.

Urine samples from 3548 individuals residing in six of the eight districts which comprise Bong County, Liberia, the project area of the Bong County Agricultural Development Project (BCADP), and fecal specimens from 3408 of these individuals were examined for schistosome ova. A total of 164 water sites, including rice paddies, were surveyed for schistosome vector snails and monthly changes in snail population density and infection rate were determined in selected water sites. Bulinus globosus was more widely distributed than Biomphalaria pfeifferi but the latter species showed a higher infection prevalence (12.3%) than the former one (10.3%). Snail population density and infection rate fluctuated with season, being higher in the dry season and lower during periods of heavy rainfall. Dessication and/or heat stress may have contributed to the contraction of snail population size at the end of the dry season. More water sites contained infected snails during December through February than at any other time of the year. In selected water sites examined at monthly intervals, mean snail density was higher in rice paddies than in other water contact sites but the latter showed a higher prevalence of infected snails than the former. The overall prevalence of Schistosoma mansoni (24.8%) was significantly higher than that of S. haematobium (22.7%) but the difference in prevalence rates of two species in school children was not statistically significant. The intensity of S. haematobium infection (13.2 means G) was significantly higher than that of S. mansoni (6.3 means G). Mixed infections in school children did not have a significant effect on egg output. The prevalence and intensity of S. haematobium showed a dramatic decline between the age groups 0-15 and 20-50 + years old; the differences between these age groups in S. mansoni infection were unremarkable. In Zota, Jorquelle and Kokoya Districts, prevalence rates of S. haematobium were higher than those of S. mansoni; the reverse was observed in Suakoko and Panta-Kpai Districts but relative prevalence rates varied according to specific locality in each district. A south to north stratification of schistosomal infection prevalence was observed similar to the west to east gradient reported by Saladin et al. (1980). New rice paddies developed during the three year operational period of the BCADP contained little or no vector snails and schistosomal infections in farm families of these paddies reflected the characteristic of the disease in corresponding localities.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗