Low-Mach-number turbulence in interstellar gas revealed by radio polarization gradients.

The interstellar medium of the Milky Way is multiphase, magnetized and turbulent. Turbulence in the interstellar medium produces a global cascade of random gas motions, spanning scales ranging from 100 parsecs to 1,000 kilometres (ref. 4). Fundamental parameters of interstellar turbulence such as the sonic Mach number (the speed of sound) have been difficult to determine, because observations have lacked the sensitivity and resolution to image the small-scale structure associated with turbulent motion. Observations of linear polarization and Faraday rotation in radio emission from the Milky Way have identified unusual polarized structures that often have no counterparts in the total radiation intensity or at other wavelengths, and whose physical significance has been unclear. Here we report that the gradient of the Stokes vector (Q, U), where Q and U are parameters describing the polarization state of radiation, provides an image of magnetized turbulence in diffuse, ionized gas, manifested as a complex filamentary web of discontinuities in gas density and magnetic field. Through comparison with simulations, we demonstrate that turbulence in the warm, ionized medium has a relatively low sonic Mach number, M(s) ≲ 2. The development of statistical tools for the analysis of polarization gradients will allow accurate determinations of the Mach number, Reynolds number and magnetic field strength in interstellar turbulence over a wide range of conditions.

The magnetic field of the Large Magellanic Cloud revealed through Faraday rotation.

We have measured the Faraday rotation toward a large sample of polarized radio sources behind the Large Magellanic Cloud (LMC) to determine the structure of this galaxy's magnetic field. The magnetic field of the LMC consists of a coherent axisymmetric spiral of field strength approximately 1 microgauss. Strong fluctuations in the magnetic field are also seen on small (<0.5 parsec) and large (approximately 100 parsecs) scales. The large bursts of recent star formation and supernova activity in the LMC argue against standard dynamo theory, adding to the growing evidence for rapid field amplification in galaxies.

Regression of endometrial thickness in combination with reduced withdrawal bleeding as a progestational effect of tibolone in postmenopausal women on oestrogen replacement therapy.

For 176 postmenopausal women on HRT with progestogen addition 'on demand' medroxyprogesterone acetate (MPA), noresthisterone and tibolone were used to protect the endometrium in 214 cases. Tibolone is a gonadomimetic steroid with combined progestogenic and estrogenic effects. In this study tibolone has been used as a progestogen. The results of these three progestogens were compared. The endometrial thickness before and after the use of progestogen was determined by vaginosonography. In 175 out of 214 cases progestogen addition during oestrogen therapy caused endometrial regression. Withdrawal bleeding was observed 166 times. If the endometrial thickness on the onset of progestogen addition was 5 mm or more, in nearly all cases withdrawal bleeding occurred when MPA or norethisterone was used. If tibolone was used, no withdrawal bleeding occurred in over half the cases studied. We report the first observation of induced endometrial regression without withdrawal bleeding.

[CRP versus BSE in pediatrics. How good is a diagnostic test?]. / CRP versus BSE in de kindergeneeskunde. Hoe goed is een diagnostische test?

In a prospective study CRP and BSE values were compared in 130 children who came to the first aid of our hospital with symptoms suspicious for an infection either viral or bacterial. Since the predictive value of both parameters dependents on the prevalence of diseases we discussed the likelihood ratio and the receiver operating characteristic as better parameters in the evaluation of a test i.e. BSE and CRP. It finally became clear that such characteristics are useful in clinical practice and therefore deserve more attention.

Prophylaxis of respiratory tract infection in patients on artificial respiration.

In a pilot study, a prophylactic regimen including ciprofloxacin and amphotericin B was applied in 102 consecutive patients on artificial respiration for greater than or equal to 5 days to prevent respiratory tract infection with aerobic Gram-negative bacilli. Ciprofloxacin was given twice a day, as 500 mg through a gastric tube or 200 mg intravenously, and both applications led to negative cultures for aerobic Gram-negative bacilli from faeces and throat, except for a few periods of carriage lasting only a few days. No patient acquired respiratory tract infection with one of the Enterobacteriaceae or Pseudomonadaceae after 4 days of artificial respiration. In contrast to other prophylactic regimens in intensive care patients, this regimen is relatively simple and effective. These preliminary data suggest that this regimen should be studied further with special emphasis on the induction of resistance in Intensive Care Units using prospective, double-blind study designs.

Influence of occupation and living habits on semen quality in men (scrotal insulation and semen quality).

Fifty-six males from infertile couples were categorised into two different groups and their semen quality examined. Patients in which there was no evidence of interference with normal testicular thermoregulation either during the day or the night were classified as 'cool workers' and 'cool sleepers' (Group I, n = 26). In the other group (II), 'warm workers'/'warm sleepers' (n = 30), there was evidence for scrotal insulation. The number of good moving spermatozoa per ejaculate as well as this number per ml was greater in 'cool workers'/'cool sleepers' than in 'warm workers'/'warm sleepers' (p less than 0.001). These results emphasize the need for comprehensive patient history when evaluating infertility problems. Similarly, living habits may play a role in human male infertility and treatment.

Ciprofloxacin therapy of respiratory tract infection with Pseudomonas aeruginosa.

Forty-two patients with respiratory tract infection caused by Pseudomonas aeruginosa were treated with 500 mg ciprofloxacin administered orally twice daily. Pseudomonas aeruginosa was eradicated in 22 patients but recurred in eight patients. Clinical improvement or resolution was noted in 37 patients (88%). Eradication and cure rates were highest in patients without permanent risk factors, and in patients with hospital-acquired infection. New colonization during treatment was noted in 14 patients (33%), but no superinfection occurred. In persisting strains of Pseudomonas aeruginosa the in vitro sensitivity to ciprofloxacin decreased significantly during therapy.

Ciprofloxacin for respiratory tract infection with Pseudomonas aeruginosa.

Thirty one patients were treated with oral ciprofloxacin for bronchitis with Pseudomonas aeruginosa. Twenty eight patients had permanent and 14 transient risk factors. Nine patients had a hospital infection with Pseudomonas aeruginosa. Sixteen patients were cured, complete or partial, but Pseudomonas aeruginosa persisted or recurred in 19 patients. Patients with hospital infection did better than other patients. There was a significant decrease in in vitro susceptibility of persisting strains of Pseudomonas aeruginosa to ciprofloxacin and a tendency of recovery of susceptibility for the drug after treatment.

An estimate for the source of coagulase-negative staphylococci in blood cultures.

An estimate for the source of coagulase-negative staphylococci in blood cultures is presented and its use illustrated in two populations. The method estimates the probability that a positive blood culture is positive due to contamination and the probability of it being positive due to bacteraemia. The effect of changes in efficiency of the blood culture technique on these estimates is demonstrated. One of the illustrative populations consists of 537 sample pairs from 273 patients, taken after open-heart surgery in 1978-80. The other consists of 500 consecutive sample pairs taken in one of two hospitals in 1983-4.

A comparison of single-dose and multi-dose metronidazole prophylaxis for hysterectomy.

A multi-centre double-blind, placebo-controlled clinical trial was performed to determine the minimum number of doses of metronidazole required for effective prophylaxis of vaginal cuff abscess following hysterectomy. Four hundred and seventy-five patients received zero, one, two, three, six or twenty-one 500 mg doses of metronidazole. Data from 440 patients were analysed and showed that one dose of metronidazole markedly reduced the risk of vaginal cuff abscess in patients undergoing vaginal hysterectomy. The effect on vaginal cuff cellulitis was not evident. It is concluded that one preoperative dose of 500 mg metronidazole is an effective, convenient and cheap prophylaxis for patients undergoing vaginal hysterectomy.

Peroperative systemic prophylaxis in colorectal surgery.

In an effort to reduce infection rates in elective colorectal surgery to acceptable levels without oral non-absorbable antimicrobials, using only a short course of systemic antimicrobials, 50 patients were studied in a multicentre trial. Each patient received metronidazole for anti-anaerobic coverage. The anti-aerobic coverage consisted of netilmicin, cefuroxime or placebo, administered in a double-blind manner. Five out of 36 evaluable patients had an infection at the operation site. Two patients had peritonitis (one metronidazole-netilmicin and one metronidazole-placebo) and three had a wound abscess in the abdominal wall (all metronidazole-placebo). It is concluded that a short course of peroperative systemic prophylaxis with metronidazole and netilmicin or cefuroxime--without the use of oral non-absorbable antimicrobials--gave acceptable results in the centres studied.

Prophylactic trimethoprim for prostatectomy.

The efficacy of prophylaxis for control of infection in prostatectomy was studied in 260 patients in a double-blind clinical trial using a single dose of 300 mg trimethoprim and a placebo. Results in 141 transurethral and 119 patients operated on abdominally were analyzed separately. Neither group showed significant heterogeneity of risk factors. Trimethoprim did not prevent bacteremia during operation. No significant difference in infection between trimethoprim and placebo groups was found in either group. After several studies the efficacy of antimicrobial prophylaxis in prostatectomy still remains to be proved; it may be too low to warrant such a prophylaxis in general.

Netilmicin 150 mg every 12 hours in systemic infections.

Most (76%) of the 284 gentamicin-resistant Enterobacteriaceae isolated from patients hospitalised in Eindhoven or its vicinity proved to be sensitive to netilmicin. The sensitivity rate was 96% for amikacin and 97% for cefotaxime. Thirty-four patients with systemic infections and isolation of netilmicin-sensitive Enterobacteriaceae were treated with 150 mg netilmicin intravenously every 12 h. All except one patient reacted favourably. The patient who did not had a netilmicin-sensitive Escherichia coli septicaemia which recurred during treatment. The treatment was well tolerated. No ototoxicity or permanent nephrotoxicity were noted. Although the variation of serum levels was as great for netilmicin as has been reported for other aminoglycosides, they were in general within acceptable limits. In patients with reduced renal function peak levels above 16 mg/l were found five times more frequently than in patients with normal renal function. However, serum levels should also be monitored in patients with normal renal function.

[Campylobacter enteritis in 0-5-year-old children in the Eindhoven area - and epidemiological study]. / Campylobacter-enteritis bij kinderen (o-15-jr) in de regio Endhoven - een epidemiologisch onderzoek.

In the region Eindhoven 36 children with Campylobacter-enteritis were examined from I January 1980 to 31 December 1980. Symptoms were studied and stools were cultured over a four-month period. Abdominal pain and/or diarrhea occurred in more than 90% of patients and were not infrequently of longer duration. Bloody stools were found in 58% of patients and disappeared relatively early during the time of illness, as well as fever and vomiting. After one month Campylobacter could only be cultured in 5% of children; 14 household contacts, who proved to have Campylobacter-enteritis, had also negative stool cultures after one month. Asymptomatic carriership was found in four cases among these household contracts. Campylobacter fetus subspecies jejuni could not be isolated in stools of a number of asymptomatic individuals, working in the meat industry, who were considered to have a higher risk of infection. This group could therefore not be determined as an endogenous human reservoir. On the other hand Campylobacter was isolated in a few domestic animals without symptoms of illness, as well as in some cattle stables and sites. In these places, where several contaminated animals are together, significant reservoirs for human infection may be present.

Nosocomial klebsiellas. I. Colonization of hospitalized patients.

The colonization of patients by Klebsiella and several other gram-negative bacteria was studied in a hospital urological ward over a period of six months. Before and during the survey there was no evidence of an outbreak of nosocomial infection and multi-drug resistant strains of Klebsiella were not isolated. Klebsiella were biotyped by nine biochemical tests, which led to the detection of 66 biotypes spread uniformly throughout the survey period. This method of biotyping proved a useful epidemiological tool. The colonization rate of throats, hands, and faeces of patients increased after admission to the ward, especially when antibiotics were used. The effect of systemic antibiotics was greater than that of urinary antibiotics especially on throat and faeces carrier rates. Carrier rates for Klebsiella increased also after catheterization and operation--relationships which could well be multifactorial. During the first two weeks after admission the proportion of antibiotic resistant strains of Klebsiella in carriers increased. The proportion of resistant strains amongst isolations from clinical infections was always greater than among strains isolated routinely from sites of carriage.

Nosocomial klebsiellas. II. Transfer in a hospital ward.

During a 6-month period an epidemiological survey of the carriage of Klebsiella was conducted in a hospital ward where no outbreak of nosocomial infection occurred. In this endemic situation the regular sampling of several sites of patients, members of the nursing staff, and the environment, and the biotyping of Klebsiella made it possible to analyse the patterns of transmission between sites. There was abundant evidence for striking transmission of Klebsiella between the throat, hands, and faeces of patients. Transmission between patients seemed to be mainly through hands. The role of nurses' hands in transmission was not evident from this survey, probably due to the relatively long interval (a week) between samplings. Through the hands of patients, wash stands and the surrounding floor were contaminated with Klebsiella. The biotyping of Klebsiella facilitated the epidemiological analysis of the results.