Personal and Social Factors Influencing Age at First Sexual Intercourse

Early initiation of sexual activity is aconcern, in part because of increased risk of sexuallytransmitted diseases, including HIV, and unwantedpregnancies among young people. In this study, 241 high schoolers were administered a questionnaire toestablish the relationships between age at first sexualintercourse and personal qualities (sexual style,attractiveness, physical maturity, restraint, autonomy expectations, and attitudes to gender roles),smoking and drug use, and aspects of the social context(social activities, media impact, peer norms). Therewere few effects of sex of respondent and none in which respondents' sex impacted on age ofinitiation. Overall (and among the male sample),perceptions of greater physical maturity, greater use ofuncommon (mostly illicit) drugs, and expectations of earlier autonomy significantly differentiatedbetween early and later initiators. This group offactors tends to confirm the view that early experienceof sexual intercourse is correlated with problembehaviors and a press toward adultbehaviors. For girls, this pattern was even clearer,with use of uncommon drugs being replaced as asignificant contributor to early sexual experience byrelative lack of restraint. We conclude that the desire to achieve thetransition to adulthood at an earlier age than theirpeers constitutes a powerful incentive for young peopleto become sexually active.     

Intravenous high-dose methylprednisolone efficacy for treatment of idiopathic thrombocytopenic purpura in adults

OBJECTIVE: To determine the efficacy of a short intravenous course of high-dose methylprednisolone compared with the standard treatment with prednisone for adult patients with idiopathic thrombocytopenic purpura (ITP). DESIGN: Retrospective. METHODS: For all patients diagnosed with ITP between January 1st 1988 and January 1st 1998 in the University Hospital Vrije Universiteit, Amsterdam, the Netherlands, data were obtained until June 1st 1998. These patients had received a brief course of treatment with methylprednisolone i.v. (1 g per day on three successive days in the outpatient department) or the standard treatment (protracted oral treatment with prednisone). A response was defined as a rise in platelet count of > 50 x 10(9)/l. When a remission lasted more than a year a patient was defined as longterm responder. RESULTS: The results concerned 41 patients. The prednisone group comprised 7 males and 20 females, mean age 39 years, the methylprednisolone group comprised 2 males and 12 females, mean age 43 years. Initial treatment with prednisone or methylprednisolone resulted in equal response rates of, respectively, 63% (17/27 patients) and 64% (9/14 patients). The number of longterm responders was 8 of 27 patients in the prednisone group and 2 of 14 patients in the methylprednisolone group. At time of relapse 22 patients were treated with the other treatment modality. The response rate in the group of patients treated with prednisone after first-line treatment with methylprednisolone, was 67% (6/9), for methylprednisolone after first-line treatment with prednisone the response rate was 23% (3/13). CONCLUSION: A short intravenous course of high-dose methylprednisolone is effective as initial treatment of adults with ITP. Toxicity of longterm treatment with prednisone can be avoided in a number of patients with ITP. In patients refractory to treatment with methylprednisolone, the response rate to second-line treatment with prednisone was not negatively influenced, since two thirds of these relapsing patients subsequently responded to prednisone.     

Intra-osseus gas formation in osteomyelitis of vertebrae and pelvis by Klebsiella pneumoniae]

A 59-year-old woman had persistent sepsis after abdominal operations because of a volvulus and subsequently a retroperitoneal abscess, in spite of antibiotic treatment against Klebsiella pneumoniae, which grew in blood cultures. During abscess drainage, a haemorrhage from the infrarenal part of the aorta had occurred; in view of a presumed aortitis this part had been replaced by a bifemoral bypass. Computer tomography revealed intraosseous formation of gas in vertebrae and pelvis. At operation, abscesses were drained and necrotomy and sequestrotomy of the bone were performed. Cultures of the pus from the iliac crests showed K. pneumoniae. The antibiotic management was changed; the wounds were flushed regularly. After exposure of the wounds still draining after 6 months and vascular surgery because of occlusion of the bypass after 7 months, the patient recovered well. She died 2 years later from a cerebral haemorrhage.     

Dosimetric verification of intensity modulated beams produced with dynamic multileaf collimation using an electronic portal imaging device

Dose distributions can often be significantly improved by modulating the two-dimensional intensity profile of the individual x-ray beams. One technique for delivering intensity modulated beams is dynamic multileaf collimation (DMLC). However, DMLC is complex and requires extensive quality assurance. In this paper a new method is presented for a pretreatment dosimetric verification of these intensity modulated beams utilizing a charge-coupled device camera based fluoroscopic electronic portal imaging device (EPID). In the absence of the patient, EPID images are acquired for all beams produced with DMLC. These images are then converted into two-dimensional dose distributions and compared with the calculated dose distributions. The calculations are performed with a pencil beam algorithm as implemented in a commercially available treatment planning system using the same absolute beam fluence profiles as used for calculation of the patient dose distribution. The method allows an overall verification of (i) the leaf trajectory calculation (including the models to incorporate collimator scatter and leaf transmission), (ii) the correct transfer of the leaf sequencing file to the treatment machine, and (iii) the mechanical and dosimetrical performance of the treatment unit. The method was tested for intensity modulated 10 and 25 MV photon beams; both model cases and real clinical cases were studied. Dose profiles measured with the EPID were also compared with ionization chamber measurements. In all cases both predictions and EPID measurements and EPID and ionization chamber measurements agreed within 2% (1 sigma). The study has demonstrated that the proposed method allows fast and accurate pretreatment verification of DMLC.     

Diffuse and localized pigmented villonodular synovitis: evaluation of treatment of 38 patients

We performed a retrospective study of 38 patients with pigmented villonodular synovitis (PVNS) to evaluate the treatment and functional results. The mean age of the patients was 32 (range 12-72) years at the time of treatment. Three types of PVNS have been identified: localized nodules in 9 patients, diffuse PVNS of the entire synovial membrane in 26, a combination of a diffuse involvement of the synovial membrane and an extra-articular presentation in 1, and extra-articular lesions in 2. The location of the lesions was knee (n = 31), hip (n = 3), ankle (n = 2), femoral triangle (n = 1), and gluteal region (n = 1). The procedures performed were surgery alone, surgery combined with radiosynovectomy and radiosynovectomy only. A follow-up was done after a mean of 4 (range 1-19) years in 34 patients. A functional evaluation according to the Musculoskeletal Tumor Society was performed in 31 patients. The mean functional evaluation score of 34 patients was 24 (range 15-30). Most of the ratings were excellent or good, in 6 cases fair, and in 2 cases poor. This study demonstrates that the functional results are good despite residual or recurrent disease; in addition, we showed that functional evaluation after treatment gives an optimal view of the impact and results of the operation.     

Cell type-specific acquired protection from crystal adherence by renal tubule cells in culture

BACKGROUND: Adherence of crystals to the surface of renal tubule epithelial cells is considered an important step in the development of nephrolithiasis. Previously, we demonstrated that functional monolayers formed by the renal tubule cell line, Madin-Darby canine kidney (MDCK), acquire protection against the adherence of calcium oxalate monohydrate crystals. We now examined whether this property is cell type specific. The susceptibility of the cells to crystal binding was further studied under different culture conditions. METHODS: Cell-type specificity and the influence of the growth substrate was tested by comparing calcium oxalate monohydrate crystal binding to LLC-PK1 cells and to two MDCK strains cultured on either permeable or impermeable supports. These cell lines are representative for the renal proximal tubule (LLC-PK1) and distal tubule/collecting duct (MDCK) segments of the nephron, in which crystals are expected to be absent and present, respectively. RESULTS: Whereas relatively large amounts of crystals adhered to subconfluent MDCK cultures, the level of crystal binding to confluent monolayers was reduced for both MDCK strains. On permeable supports, MDCK cells not only obtained a higher level of morphological differentiation, but also acquired a higher degree of protection than on impermeable surfaces. Crystals avidly adhered to LLC-PK1 cells, irrespective of their developmental stage or growth substrate used. CONCLUSIONS: These results show that the prevention of crystal binding is cell type specific and expressed only by differentiated MDCK cells. The anti-adherence properties acquired by MDCK cells may mirror a specific functional characteristic of its in situ equivalent, the renal distal tubule/collecting ducts.     

Effects of an information booklet on well-being of hospital patients

Although informational booklets are being used increasingly in Dutch hospitals, little is known of their effects and the conditions for optimal use. Various aspects of the use and effects of a specially developed information booklet were investigated in two surgical wards of a general hospital. The booklet gave information about ward procedures, operative routines, narcosis, and psychosocial care possibilities. Both before and after introduction of the booklet we gathered data on the satisfaction, knowledge, and emotional state of patients on the two wards and their perception of the care climate. Patients on the control ward received just the booklet. On the experimental ward staff nurses were trained in nondirective therapeutic skills, and measurements were repeated on both wards after this intervention. In a third manipulation on the experimental ward, some of the patients had a supportive and informative talk with a trained nurse. Although patients appreciated and read the booklet better than a general hospital leaflet, the results show that the booklet and other supporting measures had no effect on the patients' perception of their well-being.     

Nucleic acid analysis of antibiotic resistance

The past 15 years the field of molecular biology and especially DNA technology has developed rapidly. This did not leave microbiology unaffected. DNA sequencing and the use of DNA probes led to new insights in the evolution and spread of antibiotic resistance genes. It became clear that resistance determinants often show partial homology even when species are not closely related. DNA probes have established their value as epidemiological tools and currently efforts are being made to introduce them into routine diagnostics.