Measurement precision and normal range of endometrial thickness in a postmenopausal population by transvaginal ultrasound.

OBJECTIVES: The aim of this study was to examine the endometrial thickness (ET) in an asymptomatic postmenopausal population, and to assess the long-term variability. DESIGN: A total of 1182 asymptomatic generally healthy postmenopausal women were enrolled into this cross-sectional evaluation of the ET. Measurements were performed by transvaginal ultrasound. A subset of the women (n = 178) was examined twice 3 months to 2 years apart to assess the long-term variability. RESULTS: Cross-sectionally, ET varied with length of menopause. During the first 5 years after menopause (YSM) the mean ET was 2.3 mm but it decreased by 0.03 mm/year (P < 0.01). From 5 to 13 YSM the ET remained stable at a mean of 1.8 mm with no significant changes (P = 0.13). Thereafter there was a minimal increase of 0.01 mm/year (P < 0.05). In order to minimize the influence of natural changes on ET, only women who had reached the menopause more than 5 years earlier were entered into the subsequent long-term study. The mean ET was 2.0 mm +/- 1.0 mm with no significant differences within or between the observers' measurements. The precision errors were less than 1 mm. CONCLUSIONS: The normal range of the thickness of the postmenopausal endometrium in asymptomatic women varies with YSM. There is a high long-term agreement within and between observers in measuring the ET.     

A Recirculatory Model of the Pulmonary Uptake and Pharmacokinetics of Lidocaine Based on Analysis of Arterial and Mixed Venous Data from Dogs

Pulmonary uptake of basic amine xenobiotics such as lidocaine may influence the onset of drug effect and ameliorate toxicity. To date, pharmacokinetic analysis of pulmonary drug uptake has been only semiquantitative and ill-suited for relating pharmacodynamics to pharmacokinetics or jar estimating the time course of the fraction of drug dose residing in the lung during a single pass. We have developed recirculatory models in an experiment in which lidocaine was injected into the right atrium simultaneously with markers of intravascular space (indocyanine green) and total body water (antipyrine): this was followed by rapid arterial and mixed venous blood sampling. Such models are interpretable physiologically and are capable of characterizing the kinetics of the pulmonary uptake of lidocaine in addition to peripheral tissue distribution and elimination. The apparent pulmonary tissue volume of lidocaine (39 ml/kg) was nearly ninefold greater than that of antipyrine (4.5 ml/kg). The recirculatory model characterized both arterial and mixed venous data, but the latter data were not essential for estimating lidocaine's pulmonary disposition either before or after recirculation of drug was evident.     

Predictive value of parathyroid scintigraphy in the preoperative evaluation of patients with primary hyperparathyroidism.

BACKGROUND AND AIMS: The surgical gold standard in primary hyperparathyroidism was until recently exploration of all four parathyroid glands. Today more patients undergo minimal invasive procedures demanding more accurate preoperative localization studies. The aim of the study was to determine the positive predictive value (PPV) of parathyroid scintigraphy (PS) and to some extent ultrasonography (US), defined as the probability of finding one single adenoma on the affected side at surgery when the scans had shown one single focus. MATERIAL AND METHODS: Eighty-eight surgically treated patients (76 women and 12 men, 8 with multiglandular disease) were included. The PS consisted of 99mTc-sestamibi scan with dual-phase technique, both planar and SPECT imaging, followed by 99mTc-pertechnetate scan. A positive scan was defined as a single focus accumulating sestamibi. Focal lesions on US were defined as hypoechoic nodules. RESULTS: PS was positive in 80 patients. Seventy-nine had only one focus, of which 64 were correctly localized adenomas (PPV 81%). Forty-seven of 77 US examinations were positive. In 44 there was only one focus of which 38 were correctly localized (PPV 86%). PPV was 97% when both examinations were positive. CONCLUSIONS: Both PS and US have acceptably high PPVs defined as the ability to predict whether or not one single focus represents a parathyroid adenoma. Concordant positive results were accompanied by a PPV close to 100%.     

Cathepsin D displays in vitro β-secretase-like specificity

The formation of Aβ and Aβ-containing fragments is likely a key event in the process of neural degeneration in Alzheimer's disease. The N-terminal residue (Asp-1) of Aβ and its C-terminally extended sequences is liberated from the β-amyloid precursor protein (βAPP) by β-secretase(s). This activity appears highly increased by the presence (N-terminally to Asp-1) of a double-mutation (KM→NL) found in several Swedish families affected by early onset Alzheimer's disease. By means of synthetic peptides encompassing the ‘normal' (N peptide) and mutated (ΔNL peptide) sequences targeted by β-secretase(s), we have detected a human brain protease displaying preferred efficiency for the ΔNL peptide than for the non-mutated analog. This activity is sensitive to pepstatin, maximally active at acidic pH and hydrolyses the two peptides at the expected M/D or L/D cleavage sites. Such acidic activity is also detected in rat brain, PC12 cells and primary cultured astrocytes. The pepstatin sensitivity and pH maximum of the brain activity that appeared reminiscent of those displayed by the acidic protease cathepsin D led us to examine this enzyme as a putative β-secretase-like candidate. Purified cathepsin D displays higher catalytic parameters for the ΔNL peptide than for the non-mutated peptide, cleaves these two substrates at the expected M/D or L/D sites, and is maximally active at acidic pH. However, cathepsin D does not cleave peptides bearing mutations that were previously shown to drastically lower or fully block Aβ secretion by transfected cells. Furthermore, cathepsin D hydrolyses recombinant baculoviral ΔNLβAPP₇₅₁ at a 6-fold higher rate than βAPP₇₅₁ and gives rise to a 12-kDa C-terminal product that is recognized by antibodies fully specific of the N-terminus of Aβ. Altogether, our study indicates that cathepsin D displays several in vitro β-secretase-like properties that suggests that this protease could fulfill such a role, at least in the Swedish genetic form of Alzheimer's disease. © 1997 Elsevier Science B.V. All rigths reserved.     

Anal endosonographic findings in the follow-up of primarily sutured sphincteric ruptures.

Twenty-four women with primary suture of an obstetric tear of the anal sphincter were examined with anal endosonography a median of 12 (range 3-18) months after delivery. Endosonography was normal in ten patients, of whom one was incontinent. The examination showed a defect in the external anal sphincter in 13 patients; six of these were incontinent, two of whom had normal findings on palpation. An isolated internal sphincter defect was found in a continent patient. Since anal endosonography causes no more discomfort than digital examination, it may be useful to identify patients who would benefit from surgical reconstruction of the anal sphincter.     

Structure of the hard segments in non hydrogen bond forming polyurethane elastomers as derived from oligomeric model compounds

Several molecularly uniform oligourethane model compounds for the hard segment of segmented polyurethane elastomers with piperazine (PIP) and tetramethylene bischloroformate based hard segments have been synthesized. X-ray structure analysis was performed on single crystals with both compounds representing different parts of the piperazine-1,4-diylcarbonyloxy-tetramethyleneoxycarbonyl repeating unit or containing at least one complete repeating unit and methylurethane end groups. A common feature of the model compounds investigated was that the PIP rings are in the chair conformation; the oxytetramethyleneoxy unit is in the g⁺ tg^? conformation, which is also the conformation of the higher melting modification of the two hard segment model polymorphs. The conformation and packing model of the hard segment was derived from the crystal structure of the model compound containing one repeating unit by connecting the two methyl end groups of successive molecules by a CH₂CH₂ unit without shifting the molecules, i. e., by replacement of two opposing OCH₃ groups by an oxytetramethyleneoxy chain in the g⁺ tg^? conformation. The resulting cell for the polyurethane model structure is triclinic and contains two units of half a polymer repeat, and is in excellent agreement with the experimental X-ray powder diffraction pattern of the hard segment polymer.     

Duodenal diverticula demonstrated by barium examination

An investigation for biliary tract calculi and food-stimulated gastro-oesophageal reflux was carried out in 37 patients with duodenal diverticula demonstrated by barium examination. Sixty per cent of the diverticula were located in the descending part of the duodenum. Biliary tract calculi were demonstrated in 38 per cent and food-stimulated gastro-oesophageal reflux in 81 per cent of the patients. The detection of a duodenal diverticulum should result in a supplementary investigation for gallstones and gastro-oesophageal reflux and its sequelae.