The cost-effectiveness of transvaginal hydrolaparoscopy versus hysterosalpingography in the work-up for subfertility.

STUDY QUESTION: Is a strategy starting with transvaginal hydrolaparoscopy (THL) cost-effective compared to a strategy starting with hysterosalpingography (HSG) in the work-up for subfertility? SUMMARY ANSWER: A strategy starting with THL is cost-effective compared to a strategy starting with HSG in the work-up for subfertile women. WHAT IS KNOWN ALREADY: Tubal pathology is a common cause of subfertility and tubal patency testing is one of the cornerstones of the fertility work-up. Both THL and HSG are safe procedures and can be used as a first-line tubal patency test. STUDY DESIGN, SIZE, DURATION: This economic evaluation was performed alongside a randomized clinical trial comparing THL and HSG in 300 subfertile women, between May 2013 and October 2016. For comparisons of THL and HSG, the unit costs were split into three main categories: costs of the diagnostic procedure, costs of fertility treatments and the costs for pregnancy outcomes. PARTICIPANTS/MATERIALS, SETTING, METHODS: Subfertile women scheduled for tubal patency testing were eligible. Women were randomized to a strategy starting with THL or a strategy starting with HSG. The primary outcome of the study was conception leading to a live birth within 24 months after randomization. The mean costs and outcomes for each treatment group were compared. We used a non-parametric bootstrap resampling of 1000 re-samples to investigate the effect of uncertainty and we created a cost-effectiveness plane and cost-effectiveness acceptability curves. MAIN RESULTS AND THE ROLE OF CHANCE: We allocated 149 women to THL and 151 to HSG, and we were able to achieve complete follow-up of 142 versus 148 women, respectively. After the fertility work-up women were treated according to the Dutch guidelines and based on a previously published prognostic model. In the THL group, 83 women (58.4%) conceived a live born child within 24 months after randomization compared to 82 women (55.4%) in the HSG group (difference 3.0% (95% CI: -8.3 to 14.4)). The mean total costs per woman were lower in the THL group compared to the HSG group (THL group €4991 versus €5262 in the HSG group, mean cost difference = -€271 (95% CI -€273 to -€269)). Although the costs of only the diagnostic procedure were higher in the THL group, in the HSG group more women underwent diagnostic and therapeutic laparoscopies and also had higher costs for fertility treatments. LIMITATIONS, REASONS FOR CAUTION: Our trial was conducted in women with a low risk of tubal pathology; therefore, the results of our study are not generalizable to women with high risk of tubal pathology. Furthermore, this economic analysis was based on the Dutch healthcare system, and possibly our results are not generalizable to countries with different strategies or costs for fertility treatments. WIDER IMPLICATIONS OF THE FINDINGS: After 2 years of follow-up, we found a live birth rate of 58.4% in the THL group versus 55.4% in the HSG group and a lower mean cost per woman in the THL group, with a cost difference of -€271. The findings of our trial suggest that a strategy starting with THL is cost-effective compared to a strategy starting with HSG in the workup for subfertile women. However, the cost difference between the two diagnostic strategies is limited compared to the total cost per woman in our study and before implementing THL as a first-line strategy for tubal patency testing, more research in other fields, such as patient preference and acceptance, is necessary. STUDY FUNDING/COMPETING INTEREST(S): The authors received no external financial support for the research. B.W.J.M. is supported by an NHMRC Investigator Grant (GNT1176437). B.W.J.M. reports consultancy for ObsEva, Merck KGaA, Guerbet. B.W.J.M. reports receiving travel support from Merck KGaA. C.T.P. reports consultancy for Guerbet, outside of this manuscript. All other authors have no conflicts to declare. TRIAL REGISTRATION NUMBER: NTR3462.

Fertility-related quality of life in subfertile women undergoing tubal testing with transvaginal hydrolaparoscopy or hysterosalpingography.

OBJECTIVE: Both subfertility and its management can have significant impact on quality of life (QoL). Tubal patency testing as part of the fertility work-up, is considered to cause more physical complaints and stress than other tests. Pain scores for HSG are higher than for THL, but acceptability of the procedures was found to be comparable. Fertility-related QoL has not yet been studied in women undergoing tubal patency testing. STUDY DESIGN: We performed a standardized questionnaire study alongside a previously reported randomized controlled trial comparing THL and HSG in subfertile women, in which 24-month live birth rates occurred in 58.5% versus 55.4%, respectively. We randomly assigned 300 subfertile women to THL or HSG between May 2013 and October 2016. Women were eligible if they were undergoing a fertility work-up with an indication for evaluation of tubal patency. Fertility-related QoL was measured six weeks after the procedure with the validated FertiQoL questionnaire. The scores for the Core scale and subscales between THL and HSG were compared using Mann-Whitney-U test and multiple linear regression analysis. RESULTS: The questionnaire was completed by 84 women in the THL group (56%) and 96 women in the HSG group (64%). Core scores were 74.6 ± 12.8 for THL and 73.4 ± 12.4 for HSG (p = 0.39). Scores for the Emotional domain were 64.5 ± 19.0 for THL versus 66.0 ± 16.3 (p = 0.67) for HSG. Scores for the 'Mind-body' domain for THL were 76.9 ± 15.6 versus 74.1 ± 18.0 for HSG (p = 0.42), while scores for the Relational domain were 79.2 ± 12.9 for THL and 76.9 ± 15.6 for HSG (p = 0.21). Scores for the Social domain for THL were 77.9 ± 15.1 versus 76.7 ± 14.1, (p = 0.42). The multiple linear regression analysis showed only a statistical significant positive effect of older age on the score for the Emotional domain (p = 0.015). CONCLUSION: In a preselected group of women with low risk for tubal pathology we did not find differences in fertility-related QoL between tubal patency testing with THL versus HSG.

Domains and outcomes of the core outcome set of congenital melanocytic naevi for clinical practice and research (the OCOMEN project): part 2.

BACKGROUND: Congenital melanocytic naevi (CMN) can have a great impact on patients' lives owing to perceived stigmatization, and the risk of melanoma development and neurological complications. Development of a core outcome set (COS) for care and research in CMN will allow standard reporting of outcomes. This will enable comparison of outcomes, allowing professionals to offer advice about the best management options. In previous research, stakeholders (patients, parents and professionals) reached consensus on the core domains of the COS. To select the appropriate measurement instruments, the domains should be specified by outcomes. OBJECTIVES: To reach consensus on the specific core outcomes describing the core domains pertaining to clinical care and research in CMN. METHODS: A list of provisional outcomes (obtained earlier) was critically reviewed by the Outcomes for COngenital MElanocytic Naevi (OCOMEN) research team and by relevant stakeholders through an online questionnaire, to refine this list and provide clear definitions for every outcome. When needed, discussion with individual participants was undertaken over the telephone or by email. During an online consensus meeting, stakeholders discussed the inclusion of potential outcomes. After the meeting, participants voted in two rounds for the inclusion of outcomes. RESULTS: Forty-four stakeholders from 19 countries participated. Nine core outcomes were included in the COS relative to clinical care and 10 core outcomes for research. CONCLUSIONS: These core outcomes will enable standard reporting in future care and research of CMN. This study facilitates the next step of COS development: selecting the appropriate measurement instruments for every outcome.

Development of an international core domain set for medium, large and giant congenital melanocytic naevi as a first step towards a core outcome set for clinical practice and research.

BACKGROUND: Medium, large and giant congenital melanocytic naevi (CMN) can impose a psychosocial burden on patients and families, and are associated with increased risk of developing melanoma or neurological symptoms. Lack of consensus on what outcomes to measure makes it difficult to advise patients and families about treatment and to set up best practice for CMN. OBJECTIVES: Fostering consensus among patient representatives and professionals, we aim to develop a core outcome set, defined as the minimum set of outcomes to measure and report in care and all clinical trials of a specific health condition. We focused on the 'what to measure' aspect, the so-called core domain set (CDS), following the COMET and CS-COUSIN guidelines. METHODS: We conducted a systematic review to identify outcomes reported in the literature. Focus groups with patient representatives identified patient-reported outcomes. All these outcomes were classified into domains. Through e-Delphi surveys, 144 stakeholders from 27 countries iteratively rated the importance of domains and outcomes. An online consensus meeting attended by seven patient representatives and seven professionals finalized the CDS. RESULTS: We reached consensus on six domains, four of which were applied to both care and research: 'quality of life', 'neoplasms', 'nervous system' and 'anatomy of skin'. 'Adverse events' was specific to care and 'pathology' to research. CONCLUSIONS: We have developed a CDS for medium-to-giant CMN. Its application in reporting care and research of CMN will facilitate treatment comparisons. The next step will be to reach consensus on the specific outcomes for each of the domains and what instruments should be used to measure these domains and outcomes.

Protocol for the development of core set of domains of the core outcome set for patients with congenital melanocytic naevi (OCOMEN project).

BACKGROUND: Having large congenital melanocytic naevi (CMN) is associated with a psychosocial burden on patients and their parents because of its remarkable appearance and the extra care it may require. Large CMN also pose an increased risk of malignant melanoma or neurocutaneous melanosis. There is a lack of international consensus on what important outcome domains to measure in relation to treatment. This makes it difficult to compare options, to properly inform patients and their parents, and to set up treatment policy for CMN. Therefore, we aim to develop a core outcome set (COS), i.e. the minimum set of outcomes that are recommended to be measured and reported in all clinical trials of a specific health condition. This COS can be used in the follow-up of CMN patients with or without treatment, in clinical research and practice. METHODS: In the Outcomes for Congenital Melanocytic Nevi (OCOMEN) projects, we follow the recommendations from the Core Outcome Measures in Effectiveness Trials (COMET) initiative and the Cochrane Skin Core Outcomes Set Initiative (CS-COUSIN). This project entails the following: (i) a systematic review to identify the previous reported outcomes in literature; (ii) focus groups with national and international patients and parents to identify patient-important outcomes; (iii) classification of outcomes into outcome domains; (iv) e-Delphi surveys in which stakeholders (patients/parents and professionals) can rate the importance of domains and outcomes; and (v) an online consensus meeting to finalize the core outcome domains of the COS. RESULTS: The results will be disseminated by means of publication in a leading journal and presentations in international meetings or conferences. We engage international experts in CMN, both patients and professionals, to ensure the international utility and applicability of the COS.

The capacity of transvaginal hydrolaparoscopy versus hysterosalpingography to diagnose tubal pathology in the work-up of subfertile women, a randomised clinical trial.

OBJECTIVE: To assess the capacity of transvaginal hydrolaparoscopy (THL) versus hysterosalpingography (HSG) as a primary tool to diagnose tubal pathology. STUDY DESIGN: We performed a multicenter RCT (NTR3462) in 4 teaching hospitals in the Netherlands, comparing THL and HSG as first line tubal test in subfertile women. The primary outcome of the trial was cumulative live birth rate at 24 months. Here, we present the secondary outcomes, the diagnostic findings of both THL and HSG as well as performance defined as failures, complications and pain- and acceptability scores. RESULTS: Between May 2013 and October 2016, we allocated 149 women to THL and 151 to HSG, of which 17 women in the THL group (11.4%) and 12 in the HSG group (7.9%) conceived naturally before the scheduled procedure, while 13 HSGs and 5 THLs were not performed for other reasons (withdrawal of informed consent, not willing to undergo tubal testing and protocol violations). A total of 119 THLs and 134 HSGs were carried out. Failures were seen more in the THL group (n = 8, 5.6%) than in the HSG group (n = 1, 0.7%) (p = 0.014). Complications did not differ significantly between the groups (THL n = 4; 2.8% vs HSG n = 1; 0.7%) (p = 0.20). Bilateral tubal occlusion was detected in one versus three women (0.9% versus 2.2%) of the THL group and HSG group, while unilateral tubal occlusion was detected in seven (6.2%) versus eight (5.9%) women, respectively. Normal findings were seen in 96 (79.3%) women randomised to THL and in 119 (87.5%) in women randomised for HSG (RR 0.91 95%CI 0.81-1.01, p = 0.08). The pain score was significantly less for THL (VAS 4.7 (SD: 2.5)) than for HSG (VAS 5.4 (SD:2.5)) (p 0.038). The acceptability rate of THL and was high and comparable. CONCLUSION: THL and HSG have a comparable capacity in diagnosing tubal pathology with comparable performance in safety, pain and acceptability.

Performance of outpatient transvaginal hydrolaparoscopy.

STUDY QUESTION: What is the feasibility of performing transvaginal hydrolaparoscopy (THL) in an outpatient setting? SUMMARY ANSWER: It is feasible to perform THL in an outpatient setting, reflected by a low complication and failure rate and a high patients' satisfaction. WHAT IS KNOWN ALREADY: THL is a safe method to investigate tubal patency and exploring the pelvis in subfertile women. STUDY DESIGN, SIZE, DURATION: Retrospective cohort study of 1127 subfertile women who underwent THL as primary diagnostic method for testing tubal patency in an outpatient setting. PARTICIPANTS/MATERIALS, SETTING, METHODS: We studied all THL procedures performed as a primary diagnostic tubal patency test in an outpatient setting in subfertile women starting from the initial THL in four large hospitals. Baseline characteristics were obtained, as well as the outcome of the procedures in terms of success, complications and findings by examining medical records. We used a uniform visual analogue scale (VAS) score document to collect data on pain and acceptability prospectively and compared two methods of pain relief. MAIN RESULTS AND THE ROLE OF CHANCE: We studied a total of 1103 women who underwent THL. Successful access to the pouch of Douglas was achieved in 1028 women (93.2%), and 1017 women had a complete evaluation (92.2%). Double-sided tubal patency was found in 844 women (83%), unilateral tubal patency in 127 women (12.5%), while in 46 women (4.5%) bilateral occluded tubes were diagnosed. Endometriosis alone was seen in 64 women (6.3%), adhesions alone in 87 women (8.6%) and both endometriosis and adhesions in 42 women (4.1%).Complications occurred in 29 (2.6%) women, including 10 perforations of the rectum (0.9%), 8 perforations of the posterior uterine wall (0.7%) and 5 infections/pelvic inflammatory diseases (PIDs) (0.5%). Bleeding of the vaginal wall requiring intervention and hospital admissions due to pain was seen in 4 (0.4%) and 2 women, respectively (0.2%). The average pain score was rated 4.0 (±2.4 SD) on a VAS from 0 to 10 with 0 meaning no pain at all with no difference in different types of pain relief. Acceptability was rated 1.5 (±2.1 SD). LIMITATIONS, REASONS FOR CAUTION: The main limitation of the study is its retrospective character and the fact that only a fourth of the women were asked for pain and acceptability scores. WIDER IMPLICATIONS OF THE FINDINGS: THL can be used as a primary method for tubal assessment in an outpatient setting. Further randomized studies are needed to assess whether THL is superior to other methods and strategies for tubal assessment in terms of prognostic capacity and cost-effectiveness. STUDY FUNDING/COMPETING INTEREST: No external funding was either sought or obtained for this study. The authors have no competing interests to declare.

Prednisolone induces osteoporosis-like phenotype in regenerating zebrafish scales.

UNLABELLED: We demonstrate that glucocorticoids induce an osteoporotic phenotype in regenerating scales of zebrafish. Exposure to prednisolone results in altered mineral content, enhanced matrix breakdown, and an osteoporotic gene-expression profile in osteoblasts and osteoclasts. This highlights that the zebrafish scale provides a powerful tool for preclinical osteoporosis research. INTRODUCTION: This study aims to evaluate whether glucocorticoid (prednisolone) treatment of zebrafish induces an osteoporotic phenotype in regenerating scales. Scales, a readily accessible dermal bone tissue, may provide a tool to study direct osteogenesis and its disturbance by glucocorticoids. METHODS: In adult zebrafish, treated with 25 µM prednisolone phosphate via the water, scales were removed and allowed to regenerate. During regeneration scale morphology and the molar calcium/phosphorus ratio in scales were assessed and osteoblast and osteoclast activities were monitored by time profiling of cell-specific genes; mineralization was visualized by Von Kossa staining, osteoclast activity by tartrate-resistant acid phosphatase histochemistry. RESULTS: Prednisolone (compared to controls) enhances osteoclast activity and matrix resorption and slows down the build up of the calcium/phosphorus molar ratio indicative of altered crystal maturation. Prednisolone treatment further impedes regeneration through a shift in the time profiles of osteoblast and osteoclast genes that commensurates with an osteoporosis-like imbalance in bone formation. CONCLUSIONS: A glucocorticoid-induced osteoporosis phenotype as seen in mammals was induced in regenerating scalar bone of zebrafish treated with prednisolone. An unsurpassed convenience and low cost then make the zebrafish scale a superior model for preclinical studies in osteoporosis research.

Visual Scanning Training for Neglect after Stroke with and without a Computerized Lane Tracking Dual Task.

Neglect patients typically fail to explore the contralesional half-space. During visual scanning training, these patients learn to consciously pay attention to contralesional target stimuli. It has been suggested that combining scanning training with methods addressing non-spatial attention might enhance training results. In the present study, a dual task training component was added to a visual scanning training (i.e., Training di Scanning Visuospaziale - TSVS; Pizzamiglio et al., 1990). Twenty-nine subacute right hemisphere stroke patients were semi-randomly assigned to an experimental (N = 14) or a control group (N = 15). Patients received 30 training sessions during 6 weeks. TSVS consisted of four standardized tasks (digit detection, reading/copying, copying drawings, and figure description). Moreover, a driving simulator task was integrated in the training procedure. Control patients practiced a single lane tracking task for 2 days a week during 6 weeks. The experimental group was administered the same training schedule, but in weeks 4-6 of the training, the TSVS digit detection task was combined with lane tracking on the same projection screen, so as to create a dual task (computerized visual reaction time task designed for training). Various neglect tests and driving simulator tasks were administered before and after training. No significant group and interaction effects were found that might reflect additional positive effects of dual task training. Significant improvements after training were observed in both groups taken together on most assessment tasks. Ameliorations were generally not correlated to post-onset time, but spontaneous recovery, test-retest variability, and learning effects could not be ruled out completely, since these were not controlled for. Future research might focus on increasing the amount of dual task training, the implementation of progressive difficulty levels in driving simulator tasks, and further exploration of relationships between dual task training and daily functioning.

Methotrexate or expectant management in women with an ectopic pregnancy or pregnancy of unknown location and low serum hCG concentrations? A randomized comparison.

STUDY QUESTION: What is the treatment success rate of systemic methotrexate (MTX) compared with expectant management in women with an ectopic pregnancy or a pregnancy of unknown location (PUL) with low and plateauing serum hCG concentrations? SUMMARY ANSWER: In women with an ectopic pregnancy or a PUL and low and plateauing serum hCG concentrations, expectant management is an alternative to medical treatment with single-dose systemic MTX. WHAT IS KNOWN AND WHAT THIS PAPER ADDS: MTX is often used in asymptomatic women with an ectopic pregnancy or a PUL with low and plateauing serum hCG concentrations. These pregnancies may be self-limiting and watchful waiting is suggested as an alternative, but evidence from RCTs is lacking. The results of this RCT show that expectant management is an alternative to treatment with systemic MTX in a single-dose regimen in these women. STUDY DESIGN, SIZE, DURATION: A multicentre RCT women were assigned to systemic MTX (single dose) treatment or expectant management, using a web-based randomization program, block randomization with stratification for hospital and serum hCG concentration (<1000 versus 1000-2000 IU/l). The primary outcome measure was an uneventful decline of serum hCG to an undetectable level (<2 IU/l) by the initial intervention strategy. Secondary outcome measures included additional treatment, side effects and serum hCG clearance time. PARTICIPANTS, SETTING, METHODS: From April 2007 to January 2012, we performed a multicentre study in The Netherlands. All haemodynamically stable women >18 years old with both an ectopic pregnancy visible on transvaginal sonography and a plateauing serum hCG concentration <1500 IU/l or with a PUL and a plateauing serum hCG concentration <2000 IU/l were eligible for the trial. MAIN RESULTS: We included 73 women of whom 41 were allocated to single-dose MTX and 32 to expectant management. There was no difference in primary treatment success rate of single-dose MTX versus expectant management, 31/41 (76%) and 19/32 (59%), respectively [relative risk (RR) 1.3 95% confidence interval (CI) 0.9-1.8]. In nine women (22%), additional MTX injections were needed, compared with nine women (28%) in whom systemic MTX was administered after initial expectant management (RR 0.8; 95% CI 0.4-1.7). One woman (2%) from the MTX group underwent surgery compared with four women (13%) in the expectant management group (RR 0.2; 95% CI 0.02-1.7), all after experiencing abdominal pain within the first week of follow-up. In the MTX group, nine women reported side effects versus none in the expectant management group. No serious adverse events were reported. Single-dose systemic MTX does not have a larger treatment effect compared with expectant management in women with an ectopic pregnancy or a PUL and low and plateauing serum hCG concentrations. WIDER IMPLICATIONS OF THE FINDINGS: Sixty percent of women after expectant management had an uneventful clinical course with steadily declining serum hCG levels without any intervention, which means that MTX, a potentially harmful drug, can be withheld in these women. BIAS, LIMITATION AND GENERALISABILITY: A limitation of this RCT is that it was an open (not placebo controlled) trial. Nevertheless, introduction of bias was probably limited by the strict criteria to be fulfilled for treatment with MTX. STUDY FUNDING: This trial is supported by a grant of the Netherlands Organization for Health Research and Development (ZonMw Clinical fellow grant 90700154). TRIAL REGISTRATION: ISRCTN 48210491.

Metamemory and memory test performance in stroke patients.

Memory Self-Efficacy (MSE) has been shown to be related to memory performance and social participation in a healthy elderly population. This relation is unclear in stroke. As about 30% of all stroke survivors report memory complaints, there is an urgent need for effective treatment strategies. Before implementing MSE as a potential target in memory training, it should be examined whether the association between MSE and memory performance demonstrated in healthy elderly people also applies in stroke patients. This study therefore explored the predictive value of MSE on two kinds of memory tests in stroke patients; adjusted and unadjusted for age, gender, education and location of stroke. In 57 stroke patients, the Metamemory in Adulthood Questionnaire (MIA), an everyday memory test (RBMT) and a more traditional memory test (AVLT) were completed. The results show that MSE significantly predicts memory test performance on both memory tests (RBMT: beta = .34; p = .01 AVLT: beta = .28; p = .04). When adjusted for gender, age, education and location of stroke, the predictive value of MSE remained significant for the AVLT (RBMT: beta = .23; p = .07; AVLT: beta = .23; p = .05). The results support the hypothesis that MSE predicts test performance in stroke patients and, by consequence, enables improving memory performance in post-acute memory rehabilitation after stroke.

[Surgery for respiratory tuberculosis at the Research Institute of Phthisiopulmonology, I. M. Sechenov Moscow Medical Academy: history and current trends].

The authors present concise data on the history of surgical treatment for pulmonary tuberculosis at the Research Institute of Phthisiopulmonology, I. M. Sechenov Moscow Medical Academy (1918-2008). They analyze the results of surgical treatment in 1007 patients with different forms of pulmonary tuberculosis in the past 10 years. The most common indications for surgical treatment are tuberculoma (44.2%), fibrocavernous and cirrhotic tuberculosis (37.8%), chronic pleuritis and pleural empyema (7.3%). There are prevalent resection-type operations (77.7%), with fatal cases after pneumonectomy (3.9%), lobectomy (0.6), and minor resections (0%). The proportion of thorocoplastic operations was 4.1% without fatal cases. Mini-invasive surgery using video-assisted technologies have received wide recognition in the diagnosis and surgical treatment of pulmonary tuberculosis. The results of treatment depend on the extent and presence of complications of a tuberculous process, comorbidity, suppressed immunity, and the scope of a surgical intervention. Overall, the efficiency of surgical treatment of patients with pulmonary tuberculosis is 90% or more.

[Tuberculosis of intrathoracic lymph nodes in children and adolescents: diagnosis and surgical treatment].

A hundred and seven children and adolescents with intrathoracic lymph node (LTLN) tuberculosis were operated on. Late diagnosis and long-term ineffective antituberculous therapy lead to the development of complicated forms of ITLN tuberculosis in 44% of children. Computed tomography significantly determines extent, localization, the state of the adjacent tissue, and the phase of a tuberculous process, evaluates the efficiency of antituberculosis therapy, and ascertains the optimum time of a surgical intervention. Surgical removal of the involved ITLN is a highly effective operation causing the minimum number of complications. Bilateral successive one-stage removal of the involved lymph nodes is possible in children with bilateral ITLN tuberculosis.

[Surgical treatment for tuberculosis of intrathoracic lymph nodes in children and adolescents].

Ninety-four children and adolescents with tuberculosis of intrathoracic lymph nodes (TITLN) were operated on. Late diagnosis and long-term ineffective antituberculous therapy (chemotherapy lasted 2-3 years in 29.8% and 4-5 years in 19.1%) lead to the occurrence of complicated forms of TITLN in 34% of children. Computed tomography (CT) reliably determines the extent, site, and phase of a tuberculous process, assesses the time course of changes in the efficiency of antituberculous therapy. CT aids in defining the optimal time of surgical interventions. Bilateral consecutive one-stage removal of affected lymph nodes is possible in children with bilateral TITLN.

The regulation of embryonic patterning and DNA replication by geminin.

Geminin is a multifunctional protein. After DNA replication is initiated during a cell cycle, geminin binds to Cdt1, one of the key DNA replication licensing factors. This highly regulated interaction sequestrates Cdt1, thus preventing DNA rereplication in the same cell cycle. In addition, geminin directly interacts with Six3 and Hox homeodomain proteins during embryogenesis and inhibits their functions. The regulation of Hox function by geminin also involves a transient association with the Hox repressive Polycomb complex. The functions of geminin to obstruct key molecules of both cell proliferation and embryonic development suggest a competitive coordination of these two processes.

Direct visualization of receptor arrays in frozen-hydrated sections and plunge-frozen specimens of E. coli engineered to overproduce the chemotaxis receptor Tsr.

We have recently reported electron tomographic studies of sections obtained from chemically fixed E. coli cells overproducing the 60-kDa chemotaxis receptor Tsr. Membrane extracts from these cells prepared in the presence of Tween-80 display hexagonally close-packed microcrystalline assemblies of Tsr, with a repeating unit large enough to accommodate six Tsr molecules arranged as trimers of receptor dimers. Here, we report the direct visualization of the Tsr receptor clusters in (i) vitrified cell suspensions of cells overproducing Tsr, prepared by rapid plunge-freezing, and (ii) frozen-hydrated sections obtained from cells frozen under high pressure. The frozen-hydrated sections were generated by sectioning at -150 degrees C using a diamond knife with a 25 degrees knife angle, with nominal thicknesses ranging from 20 to 60 nm. There is excellent correspondence between the spatial arrangement of receptors in thin frozen-hydrated sections and the arrangements found in negatively stained membrane extracts and plunge-frozen cells, highlighting the potential of using frozen-hydrated sections for the study of macromolecular assemblies within cells under near-native conditions.

Beta-helix model for the filamentous haemagglutinin adhesin of Bordetella pertussis and related bacterial secretory proteins.

Bordetella pertussis establishes infection by attaching to epithelial cells of the respiratory tract. One of its adhesins is filamentous haemagglutinin (FHA), a 500-A-long secreted protein that is rich in beta-structure and contains two regions, R1 and R2, of tandem 19-residue repeats. Two models have been proposed in which the central shaft is (i) a hairpin made up of a pairing of two long antiparallel beta-sheets; or (ii) a beta-helix in which the polypeptide chain is coiled to form three long parallel beta-sheets. We have analysed a truncated variant of FHA by electron microscopy (negative staining, shadowing and scanning transmission electron microscopy of unstained specimens): these observations support the latter model. Further support comes from detailed sequence analysis and molecular modelling studies. We applied a profile search method to the sequences adjacent to and between R1 and R2 and found additional "covert" copies of the same motifs that may be recognized in overt form in the R1 and R2 sequence repeats. Their total number is sufficient to support the tenet of the beta-helix model that the shaft domain--a 350 A rod--should consist of a continuous run of these motifs, apart from loop inserts. The N-terminus, which does not contain such repeats, was found to be weakly homologous to cyclodextrin transferase, a protein of known immunoglobulin-like structure. Drawing on crystal structures of known beta-helical proteins, we developed structural models of the coil motifs putatively formed by the R1 and R2 repeats. Finally, we applied the same profile search method to the sequence database and found several other proteins--all large secreted proteins of bacterial provenance--that have similar repeats and probably also similar structures.

Translocation pathway of protein substrates in ClpAP protease.

Intracellular protein degradation, which must be tightly controlled to protect normal proteins, is carried out by ATP-dependent proteases. These multicomponent enzymes have chaperone-like ATPases that recognize and unfold protein substrates and deliver them to the proteinase components for digestion. In ClpAP, hexameric rings of the ClpA ATPase stack axially on either face of the ClpP proteinase, which consists of two apposed heptameric rings. We have used cryoelectron microscopy to characterize interactions of ClpAP with the model substrate, bacteriophage P1 protein, RepA. In complexes stabilized by ATPgammaS, which bind but do not process substrate, RepA dimers are seen at near-axial sites on the distal surface of ClpA. On ATP addition, RepA is translocated through approximately 150 A into the digestion chamber inside ClpP. Little change is observed in ClpAP, implying that translocation proceeds without major reorganization of the ClpA hexamer. When translocation is observed in complexes containing a ClpP mutant whose digestion chamber is already occupied by unprocessed propeptides, a small increase in density is observed within ClpP, and RepA-associated density is also seen at other axial sites. These sites appear to represent intermediate points on the translocation pathway, at which segments of unfolded RepA subunits transiently accumulate en route to the digestion chamber.

The avian organizer.

The development of avian embryos is characterized by the large amount of yolk present from the one-cell stage until late phases of organogenesis. In the chick, an axis of bilateral symmetry is established already before egg laying, when the egg rotates in the uterus. There is evidence for an active Wnt-catenin pathway in the vegetal cells in the periphery of the multi-cellular embryo. It overlaps with the posteriorly restricted expression of genes characterizing the vegetal hemisphere in amphibia. The zone of overlap bears several functional characteristics of a Nieuwkoop center, which is first apparent in the posterior marginal zone, but continues into the early primitive streak. Only the anterior part of the late streak is capable of direct neural induction, and only its tip, Hensen's node, can induce an anterior neural identity. This latter activity leaves the node together with the cells representing the anterior mesendoderm. Thus, although the constraints and dynamics of avian development make comparisons with the amphibian situation a complex undertaking, Hensen's node comes as close as possible to an organizer in Spemann and H. Mangold's definition.