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Biomedical subjects

M Jansen

Publications and source records attributed to M Jansen.

At least 109 records · Page 6Linked to original sources
PubMed1998

Growth hormone therapy with three dosage regimens in children with idiopathic short stature. European Study Group Participating Investigators.

OBJECTIVE: In children with idiopathic short stature (ISS) we studied the growth-promoting effect at 4 years of recombinant human growth hormone (rhGH) therapy in three dose regimens and evaluated whether increasing the dosage after the first year could prevent a decline in height velocity (HV). DESIGN: Included were 223 patients who were treated with subcutaneous administrations of rhGH 6 days per week. They were randomized to three groups: 3 IU/m2 body surface/day, 4.5 IU/m2/day, and 3 IU/m2/day during the first year and 4.5 IU/m2/day thereafter, corresponding with dosages of 0.2 and 0.3 mg/kg body weight/week, respectively. Growth was compared with a standard of 229 untreated children with ISS [ISS standard]. RESULTS: During the first year of treatment HV almost doubled and was higher with 4.5 IU/m2 than with 3 IU/m2. In the second year HV no longer differed among the groups, but increasing the dosage slowed the rate of the fall of HV. During 4 years of therapy the height SD score for age increased by a mean (SD) of 2.5 (1.0) [ISS standards], or 1.2 (0.7) (British standards), bone age increased by 4.8 (1.3) years, and predicted adult height SD score increased by 1.5 (0.7). After 4 years the results of the group with 4.5 IU/m2 were slightly better than those of the other groups. When dropouts were included in the analysis (assuming a stable height SD score after discontinuation of rhGH therapy), height gain was still significant. CONCLUSIONS: During 4 years of rhGH therapy, growth and final height prognosis improved, slightly more with 4.5 IU/m2 than with 3 IU/m2 or 3 to 4.5 IU/m2. However, bone age advanced on average 4.8 years during this period; therefore, any effect on final height will probably be modest.

Body Height↗
PubMed1998

A comprehensive NMR study of cubic and hexagonal boron nitride.

A variety of techniques and measurements on all NMR accessible nuclei allow one to obtain a complete and precise set of chemical shift and quadrupole coupling parameters for both boron and nitrogen in cubic and hexagonal boron nitride. For hexagonal boron nitride, 11B to 15N cross polarization under magic angle sample spinning conditions is demonstrated at natural isotope abundance. The presented approach for NMR characterization of the crystalline boron nitrides should also be applicable to structurally related composite materials, nanotubes, and amorphous ceramics.

Boron Compounds↗
PubMed1998

Rectal hydrocortisone during stress in patients with adrenal insufficiency.

OBJECTIVE: Patients with glucocorticoid deficiency need lifelong glucocorticoid replacement treatment. During acute stressful events, steroid dosage must be increased several times, which is often problematical in children. This study investigated the reliability of rectal hydrocortisone administration as an alternative to the intramuscular route. STUDY DESIGN: Serum cortisol was assessed during stress in normal children to determine the concentration that should be achieved after rectal hydrocortisone. Subsequently, serum cortisol concentrations were measured three hours after administering a suppository containing hydrocortisone 100 mg/m2 to 57 patients with adrenocortical insufficiency. In eight patients, the time dependency of the cortisol rise after rectal administration was established. RESULTS: In 51 previously healthy children admitted to hospital with an acute stressful condition, the mean serum cortisol concentration was 1092 nmol/l. Rectal hydrocortisone in patients with adrenocortical insufficiency resulted in a mean serum cortisol concentration of 1212 nmol/l three hours after insertion of the suppository containing hydrocortisone. In 14 of 57 children, serum cortisol was < 1000 nmol/l and in eight children it was below 600 nmol/l. One hour after administration, the mean cortisol concentration had reached 1000 nmol/l. This was sustained for more than four hours. CONCLUSION: Rectal hydrocortisone is a safe alternative to parenteral administration in the self management of Addisonian prone conditions. However, because eight of 57 children did not achieve concentrations > 600 nmol/l, its use is recommended only after previously documenting an adequate serum cortisol concentration three hours after receiving a test dose.

Adolescent↗
PubMed1998

[Value of colonoscopy in tumor after-care after colorectal carcinoma].

The significance of colonoscopic follow up is discussed controversially. Colonoscopy after resection of colorectal cancer offers the possibility of direct inspection and to take biopsies for the early detection of local recurrence or additional neoplasms. In a retrospective study we examined the benefit of regular colonoscopies. Between 1/1995 and 4/1996 237 colonoscopies were performed on 164 patients after resection of colorectal cancer. The evaluation was done due to the stage of the primary tumor, the age of the patients, the time after operation and the number of previous colonoscopies. 54 adenomas were found in 35 of 164 patients. 32% of the adenomas were diagnosed in the ascending colon or colon transversum. Additionally three carcinomas were found. There were two local recurrences and one metachronous neoplasm. Two patients were diagnosed without clinical symptoms and were able to undergo potential curative resection again. Because of the number and the localisation of diagnosed neoplasms colonoscopic surveillance should be performed every six months in the first two years after resection of colorectal cancer.

Adenomatous Polyposis Coli↗
PubMed1998

[Colon carcinoma after ureterosigmoidostomy--a case report].

Ureterosigmoidostomy was the method of choice for continent urinary diversion in cases of bladder exstrophy. The development of colonic cancer at the ureterocolic junction is one of the major complications in the late course of this procedure. The risk of large bowel carcinoma is increased 150-500-fold compared to the general population. Therefore regular examinations are mandatory. Based on a case report the problems associated with ureterosigmoidostomy are presented.

Adenocarcinoma↗
PubMed1998

[Results of intraperitoneal active charcoal-mitomycin C therapy of stomach carcinoma with serosa invasion].

Patients with gastric carcinoma and serosal invasion were randomized into a "treatment" or "control" protocol after R0 resection ("prophylactic group", n = 45) or palliative resection without cytoreductive surgery in cases with localized peritoneal seeding ("therapy group", n = 19). The results of a planned interim analysis after 5 years indicate that MMC-CH therapy causes little systemic toxicity but enhances the rate of intraabdominal infections (9/33 vs. 2/31, p < 0.01) and reoperations (5/33 vs 0/31, p < 0.05). The preliminary survival analysis shows a possible prognostic effect following R0 resection after 24 months (p < 0.05) and 36 months (p < 0.07), but no benefit for the palliative procedures, which caused the withdrawal of the "therapy" study arm.

Adenocarcinoma↗
PubMed1997

[HIV infection and risky sexual behavior in a new cohort of young homosexual men in Amsterdam, 1995-1996].

OBJECTIVE: The surveillance of HIV prevalence and incidence and of sexual risk behaviour among young homosexual men. DESIGN: Cohort study, cross-sectional data presentation. SETTING: Municipal Health Service of the City of Amsterdam, the Netherlands. METHODS: At entry into the study participants were questioned about their sexual behaviour and blood or saliva samples were collected for laboratory determination of antibodies against HIV, hepatitis B and syphilis. RESULTS: In June 1995-October 1996, 429 men with a mean age of 25 years were enrolled in the cohort study. Of these 22 (5%) were positive for antibodies against HIV. Based on the duration of homosexual activity of the participants the HIV incidence in this group was estimated at 1% per year. Furthermore, 10% of the participants had experienced hepatitis B infection and 1% had serological evidence of syphilis. Of those under investigation 38% had practised unprotected anogenital intercourse with steady or non-steady partners in the last six months. CONCLUSIONS: The data suggest that HIV is spreading among young homosexual men. Given the high levels of risk behaviour continued prevention activities in this group are necessary.

AIDS Serodiagnosis↗
PubMed1997

Pharmacological characterization and selectivity of the NPY antagonist GR231118 (1229U91) for different NPY receptors.

Neuropeptide Y (NPY) is widely distributed throughout the central and peripheral nervous system and exerts a wide range of physiological responses by activating specific receptors. In this study we have characterized the potency of the high affinity peptide dimer antagonist, GR231118, to displace radiolabeled NPY/PYY from different tissues and cell lines expressing Y1 or Y2 receptors and from CHO cells stably transfected with human cDNA encoding for Y1, Y2 and Y4 receptors. GR231118 displays high affinity for Y1 and Y4 receptors, equal or better than that of NPY itself, while its activity is several fold weaker for Y2 receptors. Displacement of radiolabeled PYY from rat hypothalamic membranes by GR231118, reveals the existence of high and low affinity binding sites which may be equated to Y1 and Y2 receptors respectively suggesting that the compound maybe used as a tool to dissect central NPY receptors.

Animals↗
PubMed1997

[Endosonography control of percutaneous paracoccygeal drainage of deep pelvic abscesses after rectum resection].

Pelvic abscesses are severe complications after rectal surgery. In recent years, surgical drainage has been edged out by percutaneous drainage techniques. We report our experience with the drainage of postoperative pelvic abscesses via the paracoccygeal route controlled by endosonography. In eight patients the diagnosis of a retrorectal pelvic abscess was established by endosonography and confirmed by endosonographically controlled exploratory puncture. Drainage of the abscesses was performed via the paracoccygeal access route by trocar or Seldinger technique under permanent visual control by endoluminal sonography. Irrigation of the abscess cavity was than performed daily. In all cases drainage was successful without complications. Duration of drainage was 9-14 days with a mean of 10.8 days. In one patient there was a recurrence of the abscess because of early removal of the drainage catheter. Because of its overall availability and its good results, paracoccygeal percutaneous endosonographically controlled drainage seems to be a suitable uncomplicated method for drainage of postoperative pelvic abscesses.

Abdominal Abscess↗
PubMed1997

[6 years experience with reversible and surgical upper eyelid weighting in lagophthamos].

BACKGROUND: The procedures for prophylaxis and treatment of keratopathy following facial palsy with lagophthalmos are unsatisfying from the functional point of view. PATIENTS AND METHODS: Three years ago we created a "lid-dynamic" procedure and applied it to 46 patients with Bell's palsy or before implantation of a gold lid weight. Fixation of lead weights of 0.8-2.0 g to the upper lid by a foil adhesive on both sides (Tesafix), can lead to restoration of lid closure. Within 6 years we implanted 24-carat gold weights into the upper lid in 72 patients. RESULTS: In all cases lid function was markedly improved; all patients appreciated the procedure. The lead weights were well tolerated. In 27% of the operative cases we observed a slight underdosage, in 10% a slight overdosage. CONCLUSION: Lid loading is a simple and effective method for functional and cosmetical rehabilitation of patients with lagophthalmos. Despite the dependence upon gravity, the procedure can be recommended for all cases of facial palsy.

Adult↗
PubMed1997

Growth response and levels of growth factors after two years growth hormone treatment are similar for a once and twice daily injection regimen in girls with Turner syndrome. (Dutch Working Group on Growth Hormone).

UNLABELLED: GH is known to improve height velocity in girls with Turner syndrome (TS) but the optimal dosage regimen has yet to be defined. OBJECTIVE: We attempted to improve the growth response by trying to mimic normal pulsatile GH secretion more closely. DESIGN: In a 2-year study the effect of fractionated twice daily (BID) was compared with once daily (OD) s.c. injections of a total GH dose of 6 IU/m2/day. BID injections were administered as two-thirds at bedtime and one-third in the morning. The subjects concurrently received low dose ethinyl oestradiol (0.05 mg/kg/day, orally). SUBJECTS: Nineteen girls with TS aged 11 years or over, who were previously involved in a 10-week GH cross-over study. MEASUREMENTS: Height and bone age were evaluated in relation to untreated Turner reference data. Final height (FH) was predicted using the Bayley and Pinneau (BP) method, the modified index of Potential Height (mIPHRUS), and a recently developed Turner-specific method (PTSRUS) based on regression coefficients for height (H), chronological age (CA) and bone age (BA). Plasma levels of GH, GHBP, IGF-1, and IGFBP-3 were determined by RIA. RESULTS: After 2 years treatment the growth response expressed as HV, HVSDS, the change in HSDSCA, the gain in height over estimated untreated values and in FH prediction all showed significant improvements. Although mean values tended to be higher with OD injections, significant differences between groups were not found. Bone maturation was similar between groups and compared with untreated estimated values. Independent of treatment group, the change in HSDSCA after 2 years of GH treatment was related negatively to the baseline CA and HSDSCA, and positively to BA delay at baseline. After 18 months of GH treatment the significant decrease in GHBP plasma levels observed after 6 months was no longer significant. In contrast, IGF-1 and IGFBP-3 plasma levels and the IGF-1 to IGFBP-3 ratio increased significantly during 18 months GH therapy. None of these growth related factors showed a difference between groups in their 18 months change. Relevant side-effects were not observed during the first 2 years of GH treatment. CONCLUSIONS: The present growth data are in conformity with the data of the earlier 24-hour GH profiles. The growth response and plasma levels of growth related factors after 2 years GH on a total dose of 6 IU/m2/day in combination with low-dose oestrogens were not significantly different between the once daily and the twice daily GH injection regimen.

Adolescent↗
PubMed1997

LDL-apheresis significantly reduces urinary apo(a) excretion.

Increased plasma Lp(a) is an established risk factor for atherosclerosis. We recently described the presence of apo(a) fragments in urine and the significant correlation between urinary apo(a) concentrations and plasma Lp(a). Here we investigated urinary apo(a) in patients suffering from familial hypercholesterolaemia (FH), treated with LDL apheresis. Before treatment, plasma Lp(a) levels and urinary apo(a) normalized to creatinine were > 2-fold increased in FH patients (P < 0.0001) as compared to controls. LDL-apheresis led to a reduction of plasma Lp(a) by 75% and a concomitant immediate reduction of urinary apo(a) by 45%. We conclude that a steady state condition for urinary apo(a) is rapidly achieved via LDL-apheresis.

Adult↗
PubMed1997

Lipoprotein pattern in end-stage renal disease and following successful renal transplantation.

Lipoprotein abnormalities are common in uremia and frequently persist after successful renal transplantation (RT). Based on the influence of immunosuppression on lipoprotein metabolism, this prospective study in 76 patients has been focused on lipoprotein pattern in end-stage renal disease and after successful RT during a follow-up period of 18 months. Additionally, the influence of different immunosuppressive regimes has been evaluated. Hyperlipidemia was present in 32% of the patients before and in 59% after grafting. Total cholesterol was 5.42 +/- 1.57 mmol/l (mean S D) before RT and continuously and significantly increased during the entire observation period, being highest 18 months after RT (6.8 +/- 1.63 mmol/l; p < 0.01). This was mainly due to an increase in LDL-cholesterol (before RT: 3.68 (1.41 mmol/l; 18 months after RT: 4.69 +/- 1.88 mmol/l; p < 0.05) while HDL-cholesterol values only slightly increased (before RT: 0.99 +/- 0.36 mmol/l; 18 months after RT: 1.13 +/- 0.3 mmol/l; p < 0.05). Changes in total HDL-cholesterol were mainly due to an increase in HDL 3, while HDL 2 moderately increasing remained at low concentrations. As corticosteroid dosage was substantially reduced during the entire observation period, other factors such as cyclosporin A have to be considered for hyperlipidemia in renal transplant recipients. The observation on LDL-cholesterol being highest 18 months after transplantation suggests lipid lowering interventions to be indicated and might improve long-term outcome in renal transplant recipients.

Adult↗
PubMed1997

[Preoperative diagnosis of laparoscopic cholecystectomy. Is there an indication for routine intravenous cholangiography?].

In a retrospective study including 163 patients we investigated the necessity of i.v. cholangiography in preoperative routine diagnostic workup prior to laparoscopic cholecystectomy. We evaluated the evidence of i.v. cholangiography concerning the anatomy of the biliary system, the evidence of common bile duct or cystic duct stones and the influence on the further therapeutic procedure. While the common bile duct could be demonstrated in 96.3%, the cystic duct could be visualized in only 54.6%. One out of two patients with a short cystic duct was identified. Stones in the gallbladder were recognized in 72.4% of cases, while only two out of three patients with common bile duct stones were diagnosed. In nine cases a deep junction of the cystic duct was found, but there was no influence on further operative procedure. Thus we found no improvement after routine use of i.v. cholangiography concerning the evidence of common bile duct stones or avoidance of intraoperative lesions of the common bile duct. The routine use of i.v. cholangiography prior to laparoscopic cholecystectomy is therefore not justified.

Adolescent↗
PubMed1997

[Quality of life parameters in after-care of esophageal carcinoma].

Thirty-three patients with a radically resected esophageal carcinoma were included in a prospective follow-up study measuring quality of life parameters under the condition of continuous postoperative out-patient care. None of the perioperatively suspected risk factors, like postoperative complications, preoperative risk and weight course or a performed thoracotomy had a predictive value for the long-term quality of life parameters. Yet endoscopic interventions and conservative treatment of dysphagia and eating restrictions improved the quality of life in 12 out of 16 patients with severe symptoms, making the postoperative follow-up an important factor for the quality of life for resected esophageal cancer patients.

Adenocarcinoma↗
PubMed1997

[Ultrasound-controlled, percutaneous drainage: a safe and simple method for treatment of intra-abdominal abscesses].

Ultrasound-guided percutaneous catheter drainage is useful in the diagnosis and treatment of intra-abdominal abscesses. The indication depends on the localisation and cause of the abscess. Keeping the indications, we treated 62 patients with ultrasound-guided percutaneous catheter drainage and recorded a primary success of 90% and no severe complications such as bleeding or bowel perforation.

Abdominal Abscess↗