Frequency of rpoB mutations inside and outside the cluster I region in rifampin-resistant clinical Mycobacterium tuberculosis isolates

The prevalence of recently described mutation V176F, located in the beginning of the rpoB gene and associated with rifampin resistance and the wild-type cluster I sequence, was determined by analyzing the distribution of rpoB mutations among 80 rifampin (RIF)-resistant Mycobacterium tuberculosis strains isolated in Germany during 1997. The most frequent rpoB mutations were changes in codon 456 (52 isolates, 65%), followed by changes in codon 441 (13 isolates, 16%) and codon 451 (11 isolates, 14%). The V176F mutation was detected in one isolate of the study population and in 5 of 18 RIF-resistant strains with no cluster I mutation from six previously published studies. In three isolates, a mixture of resistant and susceptible subpopulations (heteroresistance) prohibited the detection of rpoB mutations in the initial analysis; however, in these isolates, cluster I mutations could be verified after a passage on RIF-containing medium. IS6110 DNA fingerprinting of 76 strains revealed eight clusters comprising 27 strains with identical restriction fragment length polymorphism patterns that mainly also show identical rpoB mutations and identical or similar drug resistance patterns. In conclusion, our results indicate that the V176F mutation should be included in molecular tests for prediction of RIF resistance in M. tuberculosis. We further demonstrated that heteroresistance caused by a mixture of mycobacterial subpopulations with different susceptibilities to RIF may influence the sensitivity of molecular tests for detection of resistance.     

Frequent c-myc amplification in high-grade dysplasia and adenocarcinoma in Barrett esophagus

Barrett esophagus (BE) is a condition in which the normal squamous epithelium of the esophagus is replaced by a metaplastic columnar epithelium. BE is a premalignant lesion that represents the initial step in a metaplasia-dysplasia-carcinoma sequence. In the present study, amplification of the proto-oncogene c-myc was determined by means of differential polymerase chain reaction analysis of metaplastic specialized epithelium, low-grade dysplasia, high-grade dysplasia, and invasive adenocarcinoma obtained by microscopic dissection of 43 esophagectomy specimens. Amplification of c-myc was found in none of 29 specialized epithelial specimens, none of 23 low-grade dysplasia specimens, 6 of 24 high-grade dysplasia specimens, and 17 of 39 adenocarcinoma specimens. Our data indicate that amplification of c-myc is a late event in the metaplasia-dysplasia-carcinoma sequence in BE. Furthermore, determination of c-myc amplification may help identify high-risk patients who would benefit from intensified endoscopic surveillance or from immediate treatment.     

Percutaneous fetoscopic patch closure of human spina bifida aperta: advances in fetal surgical techniques may obviate the need for early postnatal neurosurgical intervention

Background  A percutaneous minimally invasive fetoscopic approach was attempted for closure of a spina bifida aperta in two fetuses with L5 lesions. The goal was to obviate the need for postnatal neurosurgery to manage this condition. Methods and Results  The percutaneous fetoscopic procedures were performed by a two-layer approach at respectively 22 ± 2 and 22 ± 4 weeks of gestation. The fetuses were delivered respectively at 32 ± 6 and 32 + 3 weeks of gestation. Their neural cords were completely covered although in small areas skin closure was incomplete. Postnatally, complete skin closure occurred beneath an occlusive draping within 2 to 3 weeks such that neurosurgical intervention was not required. Both neonates showed reversal of hindbrain herniation, near-normal leg function, and satisfactory bladder and bowel function. For one of the two fetuses, ventriculoperitoneal shunt insertion was not required. Conclusions  Percutaneous minimally invasive fetoscopic patch closure of spina bifida aperta offers a substantially less maternal trauma than open fetal surgical repair and currently may even obviate the need for postnatal neurosurgical repair. With a little further improvement in surgical techniques and a better understanding of incorporating surgical patches into the fetus, complete skin closure seems possible in the near future.     

Expression of cyclin B1 in the metaplasia-dysplasia-carcinoma sequence of Barrett esophagus

BACKGROUND: It is known that proliferation is deregulated progressively during carcinogenesis in Barrett esophagus (BE). Cyclin B1 is a key protein for the regulation of G2-M-phase transition during the cell cycle and is essential for initiation of mitosis. METHODS: Using immunohistochemistry, samples of Barrett metaplastic specialized epithelium (SE; n = 36 samples), low-grade dysplasia (LGD; n = 25 samples), high-grade dysplasia (HGD; n = 25 samples), and invasive adenocarcinoma (CA; n = 46 samples) derived from 50 esophagectomy specimens were investigated for the expression of cyclin B1. The number of cyclin B1 positive cells was determined semiquantitatively. In addition, in SE, LGD, and HGD samples, the pattern of cyclin B1 expression was assessed by determination of the presence of positive cells in four mucosal compartments: the deep glandular zone, the lower crypt zone, the upper crypt zone, and the luminal surface. RESULTS: Cyclin B1 expression was found in all lesions under investigation. Regarding the percentage of positive cells, a marked increase of cyclin B1 positive cells was observed in SE samples compared with LGD samples and in HGD samples compared with CA samples (chi-square test; P < 0.0001), nevertheless showing a broad overlap between the different lesions. Concerning staining patterns, in the majority of SE samples (72.2%), cyclin B1 positive cells were restricted to the glandular zone and the lower crypt zone. In contrast, an expansion of cyclin B1 positive cells to superficially located zones of the mucosa (the upper crypt zone and/or the luminal surface) was observed in the majority of LGD samples (96.0%) and HGD samples (100%; P < 0.0001). CONCLUSIONS: Overexpression of cyclin B1 is a frequent and early finding in the metaplasia-dysplasia-carcinoma sequence in BE. It may contribute to the loss of growth control and, subsequently, to the development of tumors in this location.     

Psychomotor development in children with early diagnosed giant interhemispheric cysts

Systematic studies of cognitive development in individuals with congenital giant interhemispheric cysts (GIC) without neurosurgical intervention are rare. However, data from such studies are of great importance in deciding whether or not to perform cerebral shunting in otherwise asymptomatic patients. In this study, psychomotor function was examined in 13 children (three females, 10 males; mean age at follow-up: females 1 year 6 months, males 3 years 2 months; age range: females 13 months to 4.2 years, males 10 months to 10 years) all diagnosed with GIC during the neonatal period after indicative foetal ultrasound. Eight patients received neurosurgical treatment due to increased intracerebral pressure during the first year of life. Psychomotor development was evaluated using Griffith's Psychomotor Developmental Scales, the Sniders-Oomen Non-verbal Intelligence Scale for Young Children and the Kaufmann Assessment Battery for Children. The majority of patients showed normal intelligence, irrespective of the presence or absence of neurosurgical intervention. Evidence was found that the cognitive outcome might be related to an association of GIC with agenesis of the corpus callosum or additional congenital cerebral malformations, such as gyration anomalies. Main postoperative complications were chronic subdural effusions with spastic cerebral (hemi)-paresis; were present in three patients. In view of the risk of severe postoperative neurological complications and a comparable psychomotor development in patients without neurosurgical treatment, recommendations for early neurosurgical intervention in otherwise asymptomatic patients with a foetal or neonatal diagnosis of GIC should be viewed with caution.     

Penile metastasis secondary to follicular thyroid carcinoma

Penile metastases are rare and are considered to reflect end-stage malignant disease. The first case of a follicular thyroid carcinoma metastasizing to the penis is described. Local tumor control and probably enhanced survival was achieved by extended surgery of a previous pelvic recurrence and the penile metastasis and this procedure may be justified in selected cases.     

Zur operativen Behandlung der habituellen Schulterluxation

Ohne Zusammenfassung Mit 2 Textabbildungen.     

Biosynthesis of constitutive nitric oxide synthase-derived nitric oxide attenuates coronary vasoconstriction and myocardial depression in a model of septic heart failure induced by Staphylococcus aureus alpha-toxin

OBJECTIVE: Myocardial depression, which frequently occurs in the course of septic shock, has been attributed to the cardiodepressant properties of nitric oxide (NO) generated by either the inducible NO synthase (iNOS) or the constitutive isoform (cNOS). We have previously demonstrated that alpha-toxin from Staphylococcus aureus induces thromboxane-mediated vasoconstriction accompanied by severe cardiodepression in isolated rat hearts. In the present study, we investigated the role of NO in the alpha-toxin-induced vascular and contractile abnormalities. DESIGN: Prospective, experimental study. SETTING: Research laboratory at a university hospital. SUBJECTS: Isolated hearts from male Wistar rats. INTERVENTIONS: Isolated hearts were perfused with purified staphylococcal alpha-toxin for 60 mins. MEASUREMENTS AND MAIN RESULTS: At a concentration of 0.25 and 0.5 microg/mL, alpha-toxin induced a rise in coronary perfusion pressure, depressed myocardial contractility, and caused edema formation. Simultaneously, a time- and dose-dependent rapid release of NO into the perfusate was noted as quantified by a chemiluminescence technique. L-NMMA, a nonselective inhibitor of NOS, but not PBITU, an iNOS-selective inhibitor, blocked NO synthesis, markedly increased the rise in coronary perfusion pressure and the loss in contractility, and enhanced edema formation in response to alpha-toxin. In contrast, zaprinast, a selective inhibitor of phosphodiesterase type V that is used for stabilization of cyclic guanosine monophosphate, attenuated the toxin-induced coronary vasoconstrictor response and the myocardial depression. L-arginine, the substrate of NOS, had similar, yet less potent, effects as zaprinast and slightly increased the release of NO caused by alpha-toxin. Immunohistochemical analysis of the myocardium at the end of the perfusion period demonstrated a positive staining for cNOS but not for iNOS. In addition, no up-regulation of iNOS mRNA was detected in the tissue of toxin-exposed hearts. CONCLUSIONS: Staphylococcal alpha-toxin provokes NO biosynthesis via activation of cNOS in rat hearts. NO partly antagonizes the deleterious effects of this pathogenicity factor on coronary vasoregulation and myocardial performance.     

Tartrate-resistant acid phosphatase 5b and C-terminal telopeptides of type I collagen as markers for diagnosis of aseptic loosening after total hip replacement

Introduction  

Plain radiography, bone scintigraphy, digital subtraction arthrography and various other techniques can be used to evaluate loosening of hip replacements. These methods are associated with radiation exposure and some of them have an increased morbidity. Furthermore, in some cases the results are not conclusive.     

Fetoscopic and ultrasound-guided decompression of the fetal trachea in a human fetus with Fraser syndrome and congenital high airway obstruction syndrome (CHAOS) from laryngeal atresia.

Congenital high airway obstruction syndrome (CHAOS) from laryngeal atresia bears a poor prognosis for hydropic fetuses owing to cardiac failure. We attempted percutaneous fetoscopic and ultrasound-guided tracheal decompression in a hydropic human fetus with CHAOS associated with Fraser syndrome.Percutaneous fetoscopic and ultrasound-guided tracheal decompression was performed using three trocars under general materno-fetal anesthesia at 19 + 5 weeks of gestation. Abnormal fetoplacental blood flow normalized within hours as a result of the intervention. Furthermore, a normalization of lung : heart size and lung echogenicity was observed within days. Resolution of hydrops was complete within 3 weeks. Premature rupture of membranes and premature contractions prompted emergency delivery of the fetus by ex-utero intrapartum treatment (EXIT) at 28 + 2 weeks of gestation. Following delivery, the lungs could be ventilated at low pressures and ambient oxygen concentration. Weaning from ventilation was achieved at 18 days of postnatal life.Our experience indicated that percutaneous fetoscopic and ultrasound-guided decompression of the fetal trachea is feasible and may permit normalization of hemodynamics in hydropic human fetuses with CHAOS from laryngeal atresia. The procedure may also result in normalization of heart : lung size and provide the time needed to regain the function of the overstretched diaphragm in this grave fetal condition.