"Threshold-crossing": A Useful Way to Establish the Counterfactual in Clinical Trials?

A central question in the assessment of benefit/harm of new treatments is: how does the average outcome on the new treatment (the factual) compare to the average outcome had patients received no treatment or a different treatment known to be effective (the counterfactual)? Randomized controlled trials (RCTs) are the standard for comparing the factual with the counterfactual. Recent developments necessitate and enable a new way of determining the counterfactual for some new medicines. For select situations, we propose a new framework for evidence generation, which we call "threshold-crossing." This framework leverages the wealth of information that is becoming available from completed RCTs and from real world data sources. Relying on formalized procedures, information gleaned from these data is used to estimate the counterfactual, enabling efficacy assessment of new drugs. We propose future (research) activities to enable "threshold-crossing" for carefully selected products and indications in which RCTs are not feasible.

Shift in prevalence of HPV types in cervical cytology specimens in the era of HPV vaccination

The aim of the present population-based cohort study was to analyze the association between the prevalence of 32 types of human papilloma virus (HPV) in 615 female patients with abnormal cervical cytopathology findings. In total, 32 HPV types were screened by DNA array technology. HPV infection was detected in 470 women (76.42%), 419 of whom (89.15%) were infected with ≥1 high-risk (HR)-HPV type. HPV16, which is recognized as the main HR-HPV type responsible for the development of cervical cancer, was observed in 32.98% of HPV⁺ participants, followed by HPV42 (18.09%), HPV31 (17.66%), HPV51 (13.83%), HPV56 (10.00%), HPV53 (8.72%) and HPV66 (8.72%). The prevalence of HR-HPV types, which may be suppressed directly (in the case of HPV16 and 18), or possibly via cross-protection (in the case of HPV31) following vaccination, was considerably lower in participants ≤22 years of age (HPV16, 28.57%; HPV18, 2.04%; HPV31, 6.12%), compared with participants 23-29 years of age (HPV16, 45.71%; HPV18, 7.86%; HPV31, 22.86%), who were less likely to be vaccinated. Consequently, the present study hypothesizes that there may be a continuous shift in the prevalence of HPV types as a result of vaccination. Furthermore, the percentage of non-vaccine HR-HPV types was higher than expected, considering that eight HPV types formerly classified as 'low-risk' or 'probably high-risk' are in fact HR-HPV types. Therefore, it may be important to monitor non-vaccine HPV types in future studies, and an investigation concerning several HR-HPV types as risk factors for the development of cervical cancer is required.

2012: A watershed year for Alzheimer's disease research

Despite negative topline phase 3 clinical trial results for bapineuzumab and solanezumab in mild to moderate AD, findings from these trials and recent advances suggest renewed optimism for anti-amyloid therapies. Aβ immunotherapy has now demonstrated its ability to engage CNS Aβ and modify downstream CNS biomarkers in bapineuzumab treated patients, and to show likely cognitive benefits in mild patients treated with solanezumab. The current availability of potent BACE inhibitors provides additional opportunities to test the value of reducing Aβ in the clinic. Trial enhancements, such as selecting and enriching for early stage AD, treating participants longer and using more sensitive composite endpoints may further improve our chances of demonstrating clinical efficacy and securing beneficial treatments for patients.

p16(INK4a) overexpression predicts translational active human papillomavirus infection in tonsillar cancer

The causal role of human papillomaviruses (HPV) in squamous cell carcinogenesis of tonsillar cancers (TSCC) depends on the activity of the viral oncoproteins E6 and E7, leading to inactivation of the cellular tumor suppressor p53 and the retinoblastoma gene product pRb. Because of the negative feedback mechanisms, the pRb inactivation causes an increase of the inhibitor of the cyclin-dependent kinases p16(INK4a). In 39 TSCC specimens, genotyping based on the amplification of HPV DNA was carried out using PCR by applying HPV type-specific oligonucleotides. Subsequently, amplicons were hybridised with fluorescence-labeled complementary probes using the Southern blot technology. For HPV E6/E7 mRNA expression, Northern hybridization and RT-PCR were performed, and for p16(INK4a) detection, immunohistochemistry was performed. With 21/39 (53%) HPV-positives, the detection rate is within the range that can be expected in TSCC. The E6/E7 oncogene mRNA was detectable in 11 cases, 10 of which showed positive signals after p16(INK4a) staining. Albeit the small study group was investigated, the correlation of the HPV DNA status with the p16(INK4a) expression was of statistical significance (p = 0.02). Kaplan-Meier estimations revealed better survival outcome for patients with HPV-positive tumors with detectable E6/E7 mRNA and p16(INK4a) overexpression (p = 0.02, median observation time 29 months). As mRNA expression tests are not routinely available in many clinical diagnostic laboratories, and based on the high correlation of p16(INK4a) staining with HPV E6/E7 mRNA expression, in conclusion we suggest for a deeper exploration for the use of p16(INK4a) as a surrogate marker with the potential to impact the standard of care of HPV DNA-positive head and neck carcinomas.

Pediatric follicular lymphoma--a clinico-pathological study of a population-based series of patients treated within the Non-Hodgkin's Lymphoma--Berlin-Frankfurt-Munster (NHL-BFM) multicenter trials

Background Pediatric follicular lymphoma has recently been recognized as a novel variant of follicular lymphoma in the World Health Organization classification of lymphomas. Given the rarity of the disease, histopathological and genetic data on this type of lymphoma are still scarce.

DESIGN AND METHODS

We analyzed 25 cases of pediatric follicular lymphoma (patients aged <or=18 years) by morphology, immunohistochemistry and interphase fluorescence in situ hybridization. All patients analyzed were treated within Non-Hodgkin's Lymphoma--Berlin-Frankfurt-Münster (NHL-BFM) multicenter trials, and the cohort was representative of the German population.

RESULTS

The genetic hallmark of adult follicular lymphoma, t(14;18)(q32;q21), was not detectable in any of the pediatric cases, although BCL2 protein was expressed in 55% of the latter cases. No correlation was found between BCL2 protein expression and outcome. Chromosomal breaks in the immunoglobulin heavy chain gene (IGH) and the BCL6 locus were detected in 5 of 17 and 1 of 18 cases, respectively. Patients with pediatric follicular lymphoma had long event-free survival and, in contrast to adult follicular lymphoma, the clinical course was not dominated by relapses. A simultaneous diffuse large B-cell lymphoma was frequently detected at initial diagnosis in children but did not indicate an aggressive clinical course. Conclusions Our data suggest that pediatric follicular lymphoma is a disease that differs from its adult counterpart both genetically and clinically.

Loss of expression of LyGDI (ARHGDIB), a rho GDP-dissociation inhibitor, in Hodgkin lymphoma

The guanosine triphosphatase (GTPase) inhibitor LyGDI (ARHGDIB, Ly/D4-GDI, RhoGDIb or RhoGDI 2) is abundantly expressed in haematopoetic cells and possibly plays a role in the onset of apoptosis. Gene expression profiling of Hodgkin cell lines revealed that LyGDI expression was downregulated in these cell lines. The present study evaluated the expression of LyGDI in Hodgkin cells in vivo and studied the function of LyGDI in Hodgkin cell lines in vitro. Our results showed that virtually all Hodgkin and Reed-Sternberg cells in classical Hodgkin lymphoma lacked LyGDI protein expression. On the other hand, almost all non-Hodgkin lymphomas, except for anaplastic large cell lymphomas, expressed LyGDI protein. Transfection of the classical Hodgkin cell line L428 with a vector containing full-length LyGDI-induced apoptosis in a subset of cells. However, the majority of Hodgkin cells with transgenic expression of LyGDI escaped apoptosis. Our data show that lack of LyGDI expression is a frequent feature of cHL but that it is not of vital importance for the growth and survival of these cells.

The association of post-stroke neurological improvement with risk of subsequent deterioration due to stroke events

We sought to simultaneously confirm that substantial recovery at day 1 and day 7 after acute ischaemic stroke onset is associated with subsequent neurological deterioration in patients of the Acute Stroke Therapy by Inhibition of Neutrophils randomized clinical trial. Substantial recovery was assessed by improvement in the National Institutes of Health Stroke Score (NIHSS). Neurological deterioration was defined as any stroke event or NIHSS worsening from recovery assessment to day 90. After adjusting for age, t-PA and day 1 NIHSS, there was a non-significant tendency of substantial (pre-specified as 75%) recovery at day 1 to be associated with later deterioration [odds ratio (OR) 2.47; 95% CI, 0.95-6.50]. The corresponding OR for substantial (pre-defined as 65%) recovery at day 7 was 1.84 (0.85-3.96). Other thresholds for recovery were significantly associated with later deterioration: >50%, 80%, 90% and 100% for day 1 and >50%, 60%, 70%, 90% and 100% for day 7. The effect of recovery at day 1 was more important than that of later recovery. This study confirms the association between recovery and subsequent neurological deterioration and is the first to indicate the greater importance of acute recovery at day 1 in comparison with later recovery.

Solid pseudopapillary neoplasms of the pancreas are associated with FLI-1 expression, but not with EWS/FLI-1 translocation

Solid pseudopapillary neoplasms of the pancreas are rare pancreatic tumors with mostly benign behavior, affecting almost exclusively women. Their histogenetic origin is still unsolved, but a recently reported EWS/FLI-1 translocation t(11;22)(q24;q21) and the consistent expression of CD56 and the progesterone receptor, both genes located on the long arm of chromosome 11, point to chromosome 11q as a potential locus of gene aberration in solid pseudopapillary neoplasms. To further elucidate this issue, we studied 30 cases of solid pseudopapillary neoplasms by comparative genomic hybridization (CGH), fluorescent in situ hybridization (FISH) and immunohistochemistry. Immunohistochemically, 38% showed nuclear expression of FLI-1 and all cases revealed positivity for CD56 and the progesterone receptor, whereas no solid pseudopapillary neoplasm expressed CD34. No translocation of the EWS gene was found by FISH and no gross chromosomal gain or loss was detected by CGH. It is concluded that FLI-1 expression in solid pseudopapillary neoplasms is not associated with an EWS/FLI-1 translocation. In addition, there are no chromosomal gains or losses, especially on chromosome 11, where the FLI-1 gene is located adjacent to the gene for CD56 (NCAM). These data add another feature to the complex phenotypic appearance of solid pseudopapillary neoplasms.

Diffuse large B-cell lymphoma in pediatric patients belongs predominantly to the germinal-center type B-cell lymphomas: a clinicopathologic analysis of cases included in the German BFM (Berlin-Frankfurt-Münster) Multicenter Trial

Diffuse large B-cell lymphoma (DLBCL) in adults is a heterogeneous disease. Biologic subgroups of DLBCL with a favorable prognosis (germinal center B-cell–like, GCB) and with a poor prognosis (activated B-cell–like, ABC) have been defined by gene expression profiling and can be distinguished by immunohistochemistry. In contrast to their adult counterparts, children with DLBCL have an excellent prognosis. We analyzed 63 cases of DLBCL in pediatric patients by immunohistochemistry and fluorescence in situ hybridization (FISH) and found a striking predominance of a GCB subtype, which might explain the good clinical outcome in these lymphomas. Interestingly, FISH applied to 50 of these cases, as well as conventional cytogenetics available in 3 cases, revealed absence of the translocation t(14;18) involving the BCL2 gene, which is present in about 15% of adult GCB subtype DLBCL. Our data indicate that pediatric DLBCL differs from adult DLBCL and might comprise a biologically unique subgroup of DLBCL from which important insights into the pathogenesis and biology of this disease might be gained.

Intrapulmonary application of a 5-lipoxygenase inhibitor using surfactant as a carrier reduces lung edema in a piglet model of airway lavage

Leukotriene-generated effects on microvascular integrity and polymorphonuclear leukocytes (PMNL) play a key role in the inflammatory process of the alveolar-capillary unit in neonatal acute respiratory distress syndrome. We asked if intrapulmonary application of MK886, a 5-lipoxygenase inhibitor, and the use of a porcine surfactant preparation (Curosurftrade mark) as a carrier substance would improve lung function in a neonatal piglet model of airway lavage. Anesthetized, mechanically ventilated newborn piglets (n = 19) underwent repeated airway lavage to induce acute lung injury. Piglets then received either surfactant alone (S, n = 6), or MK886 admixed with surfactant (S + MK, n = 7), or an air-bolus injection as control (C, n = 6). Measurements of gas exchange, lung function, extravascular lung water (EVLW), cell counts, and leukotriene B(4) (LTB(4)) concentrations in bronchoalveolar lavage fluid (BAL) were performed during 6 hr of mechanical ventilation. Arterial oxygen partial pressure (PaO(2)) (S, 13.8 +/- 4.2 kPa, vs. S + MK, 20 +/- 6.6; P < 0.05), functional residual capacity (S, 15.1 +/- 6.8 ml/kg, vs. S + MK, 18.8 +/- 3.7 ml/kg; P < 0.05), and EVLW (S, 29 +/- 14 ml/kg, vs. S + MK 24 +/- 4 ml/kg; P < 0.05) were significantly improved in the MK886 group. This clinical effect was linked with a decrease in LTB(4) concentration in BAL (S, 3.5 (1.9-5.4) pg/ml, vs. S + MK, 1.6 (0.7-4.7) pg/ml; P < 0.05) and an increase in IL-8 (S, 2,103 (852-4,243) pg/ml, vs. S + MK, 3,815 (940-26,187) pg/ml; P < 0.05). PMNL counts in BAL were reduced (S, 570 +/- 42 cells/ml, vs. 275 +/- 35 cells/ml; P < 0.05). In conclusion, intrapulmonary application of the 5-lipoxygenase inhibitor MK886 with surfactant as a carrier improves lung function by decreasing EVLW as the main response to LTB(4) reduction.

Impact of latent Epstein-Barr virus infection on outcome in children and adolescents with Hodgkin's lymphoma

PURPOSE

The prognostic significance of latent Epstein-Barr virus (EBV) infection in Hodgkin's lymphoma (HL) is debated controversially. Especially in the pediatric age group, no conclusive data are available.

PATIENTS AND METHODS

Eight hundred forty-two children and adolescents (median age, 13.7 years) from pediatric multicenter treatment studies HD-90 and HD-95 were studied for latent EBV infection in Hodgkin's and Reed-Sternberg cells by immunostaining against latent membrane protein 1 (LMP-1). Results were compared with established risk factors.

RESULTS

Two hundred sixty-three patients (31%) were LMP positive. EBV infection correlated with sex (39% male v 23% female; P < .001), histologic subtype (69% mixed cellularity v 22% nodular sclerosis v 6% lymphocyte predominance; P < .001) and young age. With a median follow-up of 4.9 years, 820 patients (97%) are alive. Probability of overall survival at 10 years (+/- standard deviation) for EBV-negative and -positive patients was 98.1% +/- 0.6% and 95.1% +/- 1.4%, respectively (P = .017 by log-rank test). A negative effect of EBV infection became evident for patients with nodular sclerosis subtype Bennett II (P = .02), and those treated for advanced stages (P = .003). In multivariate analysis, LMP positivity was an independent factor for adverse outcome (RR = 3.08). Probability of failure-free survival (FFS) in LMP positive and negative patients was 89.1% +/- 2.3% and 84.1% +/- 3.9%, respectively (P = .86).

CONCLUSION

With effective combined treatment modalities in pediatric HL, latent EBV infection has no influence on FFS but is associated with an inferior overall survival in crucial subgroups.

Topical inhibition of nuclear factor-κB enhances reduction in lung edema by surfactant in a piglet model of airway lavage

OBJECTIVE

Acute respiratory distress syndrome is occasionally seen in newborn infants due to a severe inflammatory process in the lungs that affects capillary-alveolar permeability, epithelial integrity, and type I and II pneumocyte function. The aim of this study was to investigate the effect of a topically applied nuclear factor-kappaB inhibitor (IkappaB kinase-NF-kappaB essential modulator binding domain [IKK-NBD] peptide) on gas exchange, lung function, lung fluids, and inflammation in a piglet model of repeated airway lavage that is characterized by surfactant deficiency, lung edema, and an inflammatory response.

DESIGN

Prospective, randomized, controlled animal study.

SETTING

Research laboratory of a university children's hospital.

SUBJECTS

A total of 24 anesthetized, mechanically ventilated newborn piglets.

INTERVENTIONS

Repeated airway lavage was carried out until both the Pao2 decreased to approximately 40 mm Hg, while ventilating the piglets with an Fio2 of 0.6, and a peak inspiratory pressure of >/=18 cm H2O was needed to maintain tidal volume at 6 mL/kg. One group of piglets served as a control (n = 8), a second group (S, n = 8) received a porcine surfactant preparation (Curosurf), and a third group received IKK-NBD peptide admixed to surfactant (S+IN, n = 8).

MEASUREMENTS AND MAIN RESULTS

After 6 hrs of mechanical ventilation after intervention, S+IN group piglets showed decreased extravascular lung water (S+IN vs. S, 20 +/- 3 vs. 28 +/- 10 mL/kg; p < .05) and a lesser protein content in the epithelial lining fluid (S+IN vs. S, 38 +/- 5 vs. 50 +/- 5 mg/L; p < .05). Functional residual capacity (S+IN vs. S, 16.7 +/- 6.3 vs. 12.2 +/- 4.3 mL/kg; p < .05), alveolar volume (S+IN vs. S, 5.4 +/- 1.8 vs. 4.6 +/- 1.5 mL/kg; p < .05), and lung mechanics were improved. Bronchoalveolar lavage showed a lesser percentage of polymorphonuclear leukocytes (S+IN vs. S, 70% +/- 6% vs. 82% +/- 3%; p < .01) and a reduction in the chemokine leukotriene B4 (S+IN vs. S, 2.0 +/- 0.6 vs. 3.5 +/- 1.4 pg/mL; p < .01).

CONCLUSIONS

A topically applied nuclear factor-kappaB inhibitor improves lung edema and lung volumes and reduces inflammation in this newborn piglet model of airway lavage.

Minichromosome maintenance protein (MCM6) in low-grade chondrosarcoma: distinction from enchondroma and identification of progressive tumors

The distinction between chondrosarcoma and enchondroma is difficult, and no reliable immunohistochemical or molecular methods are available. Differentiation is important because the therapeutic consequences range from radiologic followup to radical operation. We studied 17 chondrosarcomas (12 grade 1) and compared them with 14 enchondromas immunohistochemically by using the monoclonal antibodies Ki-MCM6 (minichromosome maintenance protein 6), Ki-S5 (Ki-67), and Ki-S2 (repp86), in addition to the established clinical criteria. In comparison with the other markers, Ki-MCM6 proved more effective at identifying proliferative activity in grade 1 chondrosarcomas. The MCM6 labeling index correlated with tumor grade and was significantly increased in grade 1 chondrosarcomas compared with enchondromas. The 5 cases of progressive chondrosarcoma also had a significantly higher MCM6 labeling index than the nonprogressive cases. Furthermore, by means of the MCM6 labeling index, many cases of progressive disease were recognized among those of uncertain malignant potential, justifying their classification as low-grade chondrosarcomas.

[Proliferation and hTERT expression in neuroblastoma]

BACKGROUND

Transcription of the catalytic subunit of telomerase, human Telomerase Reverse Transcriptase (hTERT), and increased tumor cell proliferation are powerful prognostic factors in neuroblastoma. We therefore investigated their relationship in a large group of neuroblastomas.

METHODS

RT-PCR analysis was used to discriminate between the various hTERT transcripts. Tumor cell proliferation was assessed immunohistochemically using two different cell-cycle specific antibodies and the results were compared by statistical analysis.

RESULTS AND CONCLUSIONS

54 out of 115 neuroblastomas showed hTERT transcripts, 25 of which also possessed full-length transcripts. Full-length hTERT transcripts were correlated with MYCN-amplification, with a Ki67-proliferation index > or = 25% and a repp86-proliferation index > or = 10% (p<0,0001), but only a Ki67-proliferation index > or = 25% was associated with general hTERT transcription (p=0,001). Our data confirm the close relationship between hTERT transcription and tumor cell proliferation and further strengthen the exceptional prognostic power of the repp86-proliferation index.

The superior prognostic value of humoral factors compared with molecular proliferation markers in renal cell carcinoma

BACKGROUND

The American Joint Committee on Cancer and the Union Internationale Contre le Cancer have acknowledged routine laboratory parameters, such as serum calcium, alkaline phosphatase, hemoglobin, and the erythrocyte sedimentation rate (ESR), as predictors of survival in patients with renal cell carcinoma. The predictive value of these parameters compared with proliferation markers, such as Ki-67, proliferating cell nuclear antigen (PCNA), topoisomerase II-alpha, and p100, has not been determined.

METHODS

Forty-eight consecutive patients who underwent nephrectomy for nonmetastatic renal cell carcinoma between 1990 and 1994 were observed up to 120 months postoperatively. Ten of 48 patients developed tumor progression 6-69 months after surgery. Routine preoperative laboratory parameters as well as tumor-specific data were assessed. Findings were compared with tumor proliferation indices, which were obtained by immunohistochemical staining for nuclear antigens Ki-67, PCNA, topoisomerase II-alpha, and p100 in paraffin embedded tumor tissue.

RESULTS

Univariate and multivariate statistical analyses demonstrated superiority of routine laboratory values compared with tumor proliferation indices in predicting progression-free survival and disease-specific death. The best predictor after tumor size and symptomatic presentation was ESR (P < 0.0001), with ESR values > 70 mm at 2 hours indicating a significantly poorer prognosis. Only the proliferation marker Ki-67 reached univariate significance at a threshold of 7%.

CONCLUSIONS

Routine laboratory parameters, such as alkaline phosphatase, lactate dehydrogenase, thrombocyte count, and especially ESR, provided superior long-term prognostic information for patients with nonmetastatic renal cell carcinoma compared with the molecular tumor proliferation markers Ki-67, PCNA, topoisomerase II-alpha, and p100.

Up-regulation of cathepsin X in prostate cancer and prostatic intraepithelial neoplasia

BACKGROUND

Evidence is accumulating that several proteases are involved in prostate cancer progression. A locus which is often amplified in prostate cancer is the chromosomal region 20q13. Interestingly, one of the genes encoding the cysteine protease cathepsin X maps to this region. The aim of this study was to assess the expression pattern of cathepsin X in malignant and non-malignant prostatic tissue samples.

METHODS

Matched malignant and non-malignant tissue specimens were obtained from 56 men after radical prostatectomy. Cathepsin X was quantified at both protein and mRNA levels using several detection methods: Western blotting, immunohistochemistry, quantitative RT-PCR, and in situ hybridization. Furthermore, genomic DNA was analyzed by PCR for possible gene amplification.

RESULTS

Immunohistochemical analysis of formalin-fixed, paraffin-embedded sections of radical prostatectomy specimens was performed utilizing a polyclonal antibody against human procathepsin X and revealed staining of acinar basal cells in normal prostate glands. Prostatic intraepithelial neoplasias (PINs) and prostate carcinomas stained highly positive for cathepsin X, showing a significant difference to the staining of normal prostate glands. In contrast, relatively weak and heterogeneous staining was observed for cathepsins F, B, and L. Up-regulation of cathepsin X at the protein level was confirmed by Western blotting. No statistically significant difference was observed at the mRNA level. PCR of genomic DNA revealed that cathepsin X up-regulation most likely occurs in the absence of genomic amplification.

CONCLUSIONS

The high expression levels of cathepsin X both in PIN and invasive adenocarcinomas of the prostate suggest that cathepsin X may play a role in the early tumorigenesis of prostate cancer. Further studies are needed to define the utility of this cysteine protease as a diagnostic marker for the early detection of prostate cancer.

Expression of the c-kit receptor characterizes a subset of neuroblastomas with favorable prognosis

Expression of the c-kit proto-oncogene product in neuroblastomas has been reported, but its clinical relevance is unclear. We determined the expression of c-kit by immunohistochemistry in a series of 155 neuroblastomas with long-term follow-up. The specificity of the reaction was verified by Western blot analysis and quantitative RT-PCR, and exon 11 of the kit gene was screened for mutations by PCR and capillary electrophoresis. No mutations were detected, and transcription of the kit gene correlated with protein expression. c-kit expression was associated with lower tumor stages and a low rate of MYCN amplification. More importantly, it coincided with tumor differentiation (P<0.0001), and portended a favorable outcome with a relative risk of 0.18 (P<0.0001). In a multivariate analysis of event-free survival, loss of c-kit (relative risk 4.25, P<0.0001) was an independent prognostic factor next to INSS stage 4 and before MYCN amplification. It is concluded that c-kit is transcriptionally regulated in neuroblastomas. Its expression likely identifies a subset of neuroblastomas with conserved capacity for differentiation, which may represent the embryonal variety of the disease. Assessment of c-kit may improve prognostic models for neuroblastoma and provide a basis for new therapy concepts.

Telomerase activity in B-cell non-Hodgkin lymphomas is regulated by hTERT transcription and correlated with telomere-binding protein expression but uncoupled from proliferation

Telomere maintenance is a prerequisite for immortalisation, and in most malignant cells is carried out by telomerase, an enzyme that synthesis new telomeric repeats on the chromosome ends. In normal or reactive tissues with a high regenerative capacity, telomerase is regulated according to the telomere loss that occurs during proliferation. To evaluate the interaction of proliferation and telomerase activity in malignant lymphomas, we quantified telomerase expression in different non-Hodgkin lymphomas in comparison to normal or reactive lymph nodes. Surprisingly, the activity levels were the same in most of the lymphomas analysed as compared to reactive lymph nodes. Significantly higher activity was detected only in Burkitt's lymphoma. Telomerase activity correlated well with hTERT and c-myc expression, but was independent of proliferation. To evaluate interactions of telomere-binding protein expression on telomerase expression in non-Hodgkin lymphoma, the mRNA levels of TRF1, TRF2, tankyrase and hPif1 were assessed by real-time RT-PCR. We demonstrate here that the magnitude of telomerase upregulation does not necessarily reflect the requirement of telomere compensation caused by proliferation. Telomerase regulation in non-Hodgkin lymphomas is therefore uncoupled from proliferative stimuli found in reactive lymphoid tissue. We suggest that the upregulation of specific telomere-binding proteins like TRF2 may contribute to telomere maintenance in malignant lymphoma.

Repp86 expression and outcome in patients with neuroblastoma

PURPOSE

Given the well-known challenges of neuroblastoma prognosis, we investigated whether the expression of restrictedly expressed proliferation-associated protein of 86 kDa theoretical molecular mass (repp86), a proliferation-associated protein expressed in S, G2, and M phases of the cell cycle, correlates with the clinical outcome in patients with neuroblastoma.

PATIENTS AND METHODS

161 children with different stages of neuroblastoma were studied; the median follow-up time was 72.8 months. The patients were staged according to the International Neuroblastoma Staging System, and histologic grading of the tumors was performed according to the criteria of Hughes and those of the International Neuroblastoma Pathology Classification. The MYCN gene copy number was determined by Southern blot analysis or fluorescence in situ-hybridization, and repp86 expression was assessed immunohistochemically by means of monoclonal antibody Ki-S2 on paraffin sections from archival tumor samples.

RESULTS

A repp86 labeling index (RI) of more than 10% positive tumor cells significantly predicted a shortened disease-free interval and an increased tumor mortality (both P <.0001). Moreover, the RI allowed the identification of patients with favorable and adverse prognosis in subsets defined by stage, grade, age, and MYCN status. In a multivariate analysis, the RI emerged as the most important predictor of event-free and disease-specific survival with hazard ratios of 11.7 and 10.5, respectively (both P <.0001).

CONCLUSION

It seems that repp86 expression is closely associated with the biologic behavior of neuroblastoma. Assessment of the RI might, therefore, considerably refine prognostic models.

Chronic interstitial lung disease with lung fibrosis in a girl: uncommon sequelae of Epstein-Barr virus infection

A 12-month-old immunocompetent girl presented with tachypnea, inspiratory crackles, mild hypoxemia, and failure to thrive after an acute Epstein-Barr virus (EBV) infection. The course of acute EBV infection was demonstrated by viral load measurement in plasma and peripheral blood mononuclear cells (PBMC) by using real-time polymerase chain reaction (PCR). EBV DNA was further detected by PCR in bronchoalveolar lavage (BAL) fluid and from a lung-tissue specimen obtained by open-lung biopsy, which indicates the pulmonary involvement of active EBV infection. Histology revealed an uncharacteristic interstitial infiltration and fibrosis. Following topic and systemic treatment with corticosteroids, the child became asymptomatic and showed normal weight gain as well as mental and physical development. Pulmonary parenchymal involvement during the course of primary EBV infection may result in interstitial lung disease and fibrosis not only in immunodeficient, but in immunocompetent children as well. Treatment with combined inhaled and oral steroids seems to be a treatment option in these patients.

Full-length telomerase reverse transcriptase messenger RNA is an independent prognostic factor in neuroblastoma

Telomerase activity (TA) is the most recently recognized prognostic factor in neuroblastoma, and its outstanding predictive power was documented by several studies. However, TA measurements require fresh tumor tissue that is not always available in daily clinical practice. We previously described a reverse transcriptase-polymerase chain reaction assay that we used to investigate the possible prognostic relevance of the telomerase catalytic subunit, hTERT, at the mRNA level. Because hTERT mRNA undergoes alternative splicing as a regulatory mechanism of TA, we discriminated between truncated and full-length hTERT transcripts. In a retrospective study on 124 neuroblastomas, 56 (45.2%) tumors showed spliced hTERT transcripts, whereas 30 (24.2%) contained full-length hTERT transcripts. The presence of both spliced and full-length hTERT transcripts was significantly associated with MYCN amplification. hTERT in general showed no correlation to other prognostic factors, ie, International Neuroblastoma Staging System stage, International Neuroblastoma Pathology classification grade, or age at diagnosis, whereas the presence of full-length transcripts was significantly associated with higher stages. The presence of any hTERT transcripts carried no significant prognostic information, yet full-length hTERT transcripts were highly predictive of poor outcome (P < 0.0001). In a multivariate analysis, full-length hTERT transcripts and International Neuroblastoma Pathology classification grade emerged as the sole independent predictors of event-free survival, with relative risks of 10.0 and 3.9, respectively. The strong statistical correlation of full-length hTERT transcripts with clinical outcome in neuroblastoma suggests that the reverse transcriptase-polymerase chain reaction analysis of hTERT transcripts may be equatable to TA measurements. Because this assay is well suited for archival material, it could become a useful adjunct in evaluating the prognosis of individual neuroblastoma cases.

Expression of human beta-defensins 1 and 2 in kidneys with chronic bacterial infection

BACKGROUND

Constitutive expression and localization of antimicrobial human beta-defensin-1 (HBD-1) in human kidneys as a potential mechanism of antimicrobial defense has been previously reported. Inducible expression of human beta-defensin-2 (HBD-2) has been described in various epithelial organs but not for the urogenital tract.

METHODS

We investigated the gene- and protein expression of HBD-1 and HBD-2 by reverse transcriptase-polymerase chain reaction, and immunohistochemistry in 15 normal human kidney samples and 15 renal tissues with chronic bacterial infection. Additionally, cell culture experiments were performed to study HBD gene expression by real-time RT-PCR in response to inflammatory cytokines TNFalpha and IL-1beta as well as lipopolysaccharide from Gram-negative bacteria.

RESULTS

Constitutive HBD-1 gene- and protein expression was detected in normal renal tissue and kidneys with chronic infection. As a novel finding, inducible HBD-2 gene- and protein expression was demonstrated in tubulus epithelia with chronic infection but not in normal renal tissue. In pyelonephritic kidneys HBD-1 and HBD-2 expression showed a similar pattern of localization in distal tubules, loops of Henle and in collecting ducts of the kidney. Furthermore, real-time RT-PCR of kidney derived cell lines stimulated with inflammatory agents TNF-alpha, IL-1beta and LPS revealed a strong increase in relative HBD-2 transcription level and also a slight increase in relative HBD-1 transcription level.

CONCLUSIONS

Upregulated HBD-2 expression in renal tubulus epithelium indicates a role of a wider range of human defensins for antimicrobial host defense in the urogenital tract than previously recognized.

Proliferation marker KI-S5 discriminates between favorable and adverse prognosis in advanced stages of neuroblastoma with and without MYCN amplification

BACKGROUND

The biologic behavior of neuroblastoma is notoriously variable, and even carefully elaborated prognostic models fail to predict the clinical course in a portion of cases. Because the proliferative activity is determined by the sum of all molecular imbalances that influence cell cycling, the authors investigated the potential prognostic relevance of the tumor growth fraction in neuroblastoma.

METHODS

A retrospective analysis was conducted on a cohort of 161 neuroblastoma patients with a median follow-up period of 72.8 months. Tumors were classified according to Hughes typing and grading criteria. The proliferative index (PI) was assessed immunohistochemically on archival biopsy specimens using monoclonal antibody Ki-S5 (Ki-67), and the MYCN status was determined by means of Southern blot analysis.

RESULTS

The PI, MYCN status, International Neuroblastoma Staging System (INSS) stage, International Neuroblastoma Pathology Classification grade, Hughes grade, and the patients' age at diagnosis were all found to be significant predictors of event free survival by univariate Kaplan-Meier analysis. However, the PI identified prognostically distinct subsets in higher tumor stages and Grade 2 and 3 neuroblastomas as well as tumors with unfavorable histology, and enabled risk stratification in tumors with and without MYCN amplification (P = 0.034 and 0.002, respectively). Multivariate Cox regression analysis selected INSS stage (relative risk [RR], 4.05; P < 0.0001) and the PI (RR, 2.49; P = 0.007) as the sole independent prognostic indicators, whereas MYCN entered the selection only after exclusion of the PI.

CONCLUSIONS

It emerges that the PI as a single factor has greater predictive power than the MYCN status. Proliferation measurements therefore might significantly improve the accuracy of current prognostic models for neuroblastoma.

Regulation of telomerase activity by alternate splicing of human telomerase reverse transcriptase mRNA in a subset of neuroblastomas

It has been proposed that the regulation of telomerase takes place at the transcriptional level, the expression of the catalytic subunit human telomerase reverse transcriptase (hTERT) being crucial for telomerase activity (TA). Recently, differential splicing of hTERT mRNA has been demonstrated in various tissues during embryonal development, and it has been suggested that only full-length transcripts translate into functionally active telomerase. With this in view, we analyzed the different hTERT transcripts by reverse transcriptase-polymerase chain reaction in neuroblastic tumors and compared the results with the TA, the tumor growth fraction, and the MYCN status. In a series of 38 neuroblastic tumors, high TA and full-length hTERT transcripts were found in nine samples, whereas nine samples showed absence of both enzymatic activity and hTERT transcripts. Interestingly, in another eight samples, low or absent TA coincided with a lack of full-length hTERT transcripts. Eleven samples contained hTERT transcripts with low or undetectable TA and one sample had low TA but no hTERT transcripts. TA correlated with MYCN amplification and was weakly associated with the proliferative activity. Moreover, a significant correlation with tumor progression was observed. Our findings point at a posttranscriptional regulation of TA in a subset of neuroblastic tumors. Because high TA was detected only in tumors with full-length hTERT transcripts, reverse transcriptase-polymerase chain reaction analysis of archival neuroblastic tumor samples might help to appraise the malignant potential in individual cases.

The attentional role of the left parietal cortex: the distinct lateralization and localization of motor attention in the human brain

It is widely agreed that visuospatial orienting attention depends on a network of frontal and parietal areas in the right hemisphere. It is thought that the visuospatial orienting role of the right parietal lobe is related to its role in the production of overt eye movements. The experiments reported here test the possibility that other parietal regions may be important for directing attention in relation to response modalities other than eye movement. Specifically, we used positron emission tomography (PET) to test the hypothesis that a 'left' parietal area, the supramarginal gyrus, is important for attention in relation to limb movements (Rushworth et al., 1997; Rushworth, Ellison, & Walsh, in press). We have referred to this process as 'motor attention' to distinguish it from orienting attention. In one condition subjects spent most of the scanning period covertly attending to 'left' hand movements that they were about to make. Activity in this first condition was compared with a second condition with identical stimuli and movement responses but lacking motor attention periods. Comparison of the conditions revealed that motor attention-related activity was almost exclusively restricted to the 'left' hemisphere despite the fact that subjects only ever made ipsilateral, left-hand responses. Left parietal activity was prominent in this comparison, within the parietal lobe the critical region for motor attention was the supramarginal gyrus and the adjacent anterior intraparietal sulcus (AIP), a region anterior to the posterior parietal cortex identified with orienting attention. In a second part of the experiment we compared a condition in which subjects covertly rehearsed verbal responses with a condition in which they made verbal responses immediately without rehearsal. A comparison of the two conditions revealed verbal rehearsal-related activity in several anterior left hemisphere areas including Broca's area. The lack of verbal rehearsal-related activity in the left supra-marginal gyrus confirms that this area plays a direct role in motor attention that cannot be attributed to any strategy of verbal mediation. The results also provide evidence concerning the importance of ventral premotor (PMv) and Broca's area in motor attention and language processes.

Cerebral dominance for action in the human brain: the selection of actions

PET was used to study cerebral dominance for the selection of action. In one condition the subjects moved one of two fingers depending on the cue presented (choice reaction time), and in another they moved the same finger whatever the cue (simple reaction time). There was also a baseline condition in which cues were shown but no movements were made. A conjunction analysis was performed to reveal those areas which were more activated for the choice versus simple reaction time, irrespective of whether the right or left hand was used. The activations were in prefrontal, premotor and intraparietal areas, and they were all in the left hemisphere. Thus, while there were activations in the right hemisphere for the choice versus simple reaction time task when the subjects used their left (contralateral) hand, there were activations in left prefrontal, premotor and parietal areas whether the right (contralateral) or left (ipsilateral) hands were used. It is argued that the results suggest that the left hemisphere is dominant not only for speech but also for action in general.

Absence of 9q22-9qter in trisomy 9 does not prevent a Dandy-Walker phenotype

We report on a female fetus with partial trisomy 9 due to a reciprocal translocation in the mother. Routine ultrasound examination at 23 weeks showed hypoplasia of the cerebellar vermis, dilated foramen Magendii, and dilatation of the cisterna magna. Due to the poor prognosis, the parents opted for termination of pregnancy. A postmortem examination confirmed caudal hypoplasia and dysplasia of the cerebellar vermis, resulting in a massively dilated foramen Magendii through which the enlarged cisterna magna communicated with the fourth ventricle. There was also micropolygyria indicating migration disorder. Cytogenetic studies showed a 47,XX,+der(9)t(7;9) (q35;q22.2)mat karyotype. Investigation of the parents revealed a translocation (7;9) (q35;q22.2) in the mother and a normal male karyotype in the father. We systematically searched the chromosome 9 gene map for genes that were trisomic in our fetus and genes that were located on the regions that had the normal two copies of genes. Genes that could potentially be involved in the formation of the Dandy-Walker phenotype are transcription factors or genes responsible for the regulation of normal in particular cerebral development but also adhesion molecules. We conclude that one cause for Dandy-Walker malformation could be a gene dosage effect of genes located on 9pter-9q22. In addition, it seems that absence of trisomy 9 in q22-pter does not prevent abnormal cerebellar development.

In situ reverse-transcriptase polymerase chain reaction demonstration of the EWS/FLI-1 fusion transcript in Ewing's sarcomas and peripheral primitive neuroectodermal tumors

It is now widely accepted that the EWS/FLI-1 fusion transcript is associated with tumors of the Ewing family. To test whether it is possible to detect the fusion transcript by means of combining polymerase chain reaction (PCR) methodology and immunohistochemistry, we investigated tumors of the Ewing family using in situ reverse transcriptase (RT)-PCR. We were able to demonstrate the t(11;22) fusion transcript in five of six cases of Ewing's sarcoma and four of four peripheral primitive neuroectodermal tumors. These results were confirmed using fluorescence in situ hybridization in seven tumor samples. In situ RT-PCR-labeled fusion transcripts were found in virtually all tumor cells within a given sample, indicating that each cell possessed the t(11;22) transcript. We conclude from these results that in situ RT-PCR can be used for the rapid detection of EWS/FLI-1 fusion transcripts in biopsy material. The findings also suggest that all cells of the tumors of the Ewing family carry the EWS/FLI-1 fusion transcript.

The neuroanatomy of autism: a voxel-based whole brain analysis of structural scans

Autism is a biological disorder which affects social cognition, and understanding brain abnormalities of the former will elucidate the brain basis of the latter. We report structural MRI data on 15 high-functioning individuals with autistic disorder. A voxel-based whole brain analysis identified grey matter differences in an amygdala centered system relative to 15 age- and IQ-matched controls. Decreases of grey matter were found in anterior parts of this system (right paracingulate sulcus, left inferior frontal gyrus). Increases were found in posterior parts (amygdala/peri-amygdaloid cortex, middle temporal gyrus, inferior temporal gyrus), and in regions of the cerebellum. These structures are implicated in social cognition by animal, imaging and histopathological studies. This study therefore provides converging evidence of the physiological basis of social cognition.

A functional anatomy of anticipatory anxiety

Anticipatory anxiety is a complex combination of a future-oriented cognitive state, negative affect, and autonomic arousal. A dual-task paradigm of anticipation of electric shocks and a motor-learning task was used to examine the changes in neural patterns of activation associated with modulation of the cognitive state in anxiety by a distracting motor task. We used positron emission tomography (PET) and 15O-water to measure regional cerebral blood flow (rcbf) in 10 healthy male volunteers. A 2x2 factorial design-(shock vs no shock) x (low vs high distraction) was used with three scans per condition. Twelve PET scans were performed on each subject. In six of these scans, subjects were given electric shocks. In all scans, subjects also simultaneously performed a motor repetition (low distraction) or learning (high distraction) task. Galvanic skin conductance (GSR), Spielberger State and Trait Anxiety Inventory (STAI), and self-report data were also collected. In comparisons between the shock and no-shock conditions, the main finding was of increased rcbf in the left insula (-38,8,8) (z = 4.85, P<0.05 corrected) and a homologous area in the right insula at a lower threshold (z =3.20, P = 0.001 uncorrected). Other areas activated were the right superior temporal sulcus, left fusiform, and left anterior cingulate. Using the STAI-state scores as a covariate of interest, significant correlations with rCBF were seen in the left orbitofrontal cortex, left insula, and left anterior cingulate cortex. There was no significant distraction effect as measured by the STAI, self-report, GSR response or interactional analysis of the PET data. These findings support the role of paralimbic structures as neural substrates of anticipatory anxiety. The failure to demonstrate behavioral and neurophysiological changes with the distractor task may reflect the modest increases in anxiety with the shock, the relatively simple distractor task, and small sample size.

[Rhabdomyosarcoma and extraosseous Ewing's sarcoma]

Rhabdomyosarcomas (RMS) and extraosseous Ewing's sarcomas (EOE) including malignant peripheral neuroectodermal tumors (MPNT) are the most frequent soft tissue malignancies of childhood. They account for 60.2% of 2.350 cases collected in the files of the Kiel Pediatric Tumor Registry. RMS: It is absolutely necessary to distinguish between embryonal (e) and alveolar (a) RMS, since these are two distinct tumor entities with significant differences in clinical presentation, morphology, molecular biology, cytogenetics and prognosis (Botryoid and spindle cell RMS are special variants of eRMS). The overall proportion of eRMS: aRMS is 2.4:1. Most cases of eRMS develop in the first 10 years of life (77.3%) while the age distribution of aRMS is almost constant in childhood and adolescence. Embryonal RMS exhibit a significantly higher proportion of male patients than aRMS (m:f = 1.72:1 vs. 1.06:1). A higher percentage of aRMS cases (25%) shows metastatic disease at the time of diagnosis than eRMS (8%), and the overall survival rates of aRMS are significantly lower even in localised disease (stage I-III) than in eRMS (59% vs. 76%; p < 0.002) (Data from the Cooperative Soft Tissue Sarcoma Study CWS). EOE: Despite proven histogenetic relationship (identical chromosomal rearrangements and fusion genes) the members of the Ewing's sarcoma (ES) family, classic ES and MPNT, whether osseous or extraosseous display significant differences in location, morphology and prognosis. Morphologically, MPNT and classic ES can be considered to be the extremes of a spectrum with overt neurodifferentiation in the former and lack of neural differentiation in the latter. Matched-pairs analysis of CWS EOE and MPNT cases show dramatically more unfavorable overall survival rates in MPNT than in EOE (45% vs. 67%).

Kallmann's syndrome: mirror movements associated with bilateral corticospinal tract hypertrophy

OBJECTIVE

To investigate the etiology of mirror movements in patients with X-linked Kallmann's syndrome (xKS) through statistical analysis of pooled white matter data from structural MR images.

BACKGROUND

Mirror movements occur in 85% of xKS patients. Previous electrophysiologic studies have suggested an abnormal ipsilateral corticospinal tract projection in xKS patients exhibiting mirror movements. However, an alternative hypothesis has proposed a functional lack of transcallosal inhibitory fibers.

METHODS

T1-weighted brain scans were normalized into stereotaxic space with segregation of gray and white matter to allow comparison of pooled white matter data on a voxel-by-voxel basis using SPM-96 software. Nine xKS patients were compared with two age-matched groups of nonmirroring individuals: nine patients with autosomal Kallmann's syndrome (aKS) and nine age-matched normal (healthy) men.

RESULTS

Hypertrophy of the corpus callosum was found in both Kallmann's syndrome groups: the anterior and midsection in xKS, and the genu and posterior section in aKS. Bilateral hypertrophy of the corticospinal tract was found only in the group of xKS patients exhibiting mirror movements. SPM analysis was validated by an independent region of interest analysis of corpus callosum size.

CONCLUSION

Although morphometry on its own cannot determine the cause of mirror movements, the specific finding of a hypertrophied corticospinal tract in xKS is consistent with electrophysiologic evidence suggesting that mirror movements in xKS result from abnormal development of the ipsilateral corticospinal tract fibers.

The time course of changes during motor sequence learning: a whole-brain fMRI study

There is a discrepancy between the results of imaging studies in which subjects learn motor sequences. Some experiments have shown decreases in the activation of some areas as learning increased, whereas others have reported learning-related increases as learning progressed. We have exploited fMRI to measure changes in blood oxygen leve-dependent (BOLD) signal throughout the course of learning. T2*-weighted echo-planar images were acquired over the whole brain for 40 min while the subjects learned a sequence eight moves long by trial and error. The movements were visually paced every 3.2 s and visual feedback was provided to the subjects. A baseline period followed each activation period. The effect due to the experimental conditions was modeled using a square-wave function, time locked to their occurrence. Changes over time in the difference between activation and baseline signal were modeled using a set of polynomial basis functions. This allowed us to take into account linear as well as nonlinear changes over time. Low-frequency changes over time common to both activation and baseline conditions (and thus not learning related) were modeled and removed. Linear and nonlinear changes of BOLD signal over time were found in prefrontal, premotor, and parietal cortex and in neostriatal and cerebellar areas. Single-unit recordings in nonhuman primates during the learning of motor tasks have clearly shown increased activity early in learning, followed by a decrease as learning progressed. Both phenomena can be observed at the population level in the present study.

The preparation, execution and suppression of copied movements in the human brain

We used positron emission tomography (PET) to measure movement set-related changes in regional cerebral blood flow (rCBF) when human subjects were asked to copy hand movements. Movement set-related activity in the brain is thought to reflect the processes of movement selection, preparation and inhibition. Four conditions were used. In the first condition, prepare and execute (PE), the hand stimulus to be copied was shown to subjects 3 s before an auditory "go"-cue instructed subjects to execute the movement; a large part of the scanning time was therefore spent in preparing to move. In the immediate execution condition (E), the hand stimulus and the go cue were presented simultaneously. The prepare-only condition (P) was similar to PE, except subjects only prepared to make the movement and did not actually execute any movement when they heard the auditory go-cue. The same stimuli were presented in a baseline condition (B), but the subjects were instructed to neither prepare nor execute movements. There were 5 principle findings: (1) In contrast to a previous study of human set-related activity in which movements were instructed by an arbitrary pattern of LEDs, preparing to make a copied movement causes rCBF changes in area 44 in posterior Broca's area; (2) set-related activity can be recorded in the cerebellar hemispheres and midline; (3) we confirmed that the supramarginal gyrus has a general role in preparing movements - there was more rCBF in the P than the E condition; (4) the cerebellar nuclei and the basal ganglia may be particularly involved in the initiation and execution of a planned movement; these regions were more active in the PE condition than the P condition; (5) the ventrolateral prefrontal cortex and a left anterior cingulate area are part of a distributed system involved in the suppression of a motor response; these areas were significantly more active in the P than the PE condition.

Mirror movements in X-linked Kallmann's syndrome. II. A PET study

To investigate the mechanism of mirror movements seen in X-linked Kallmann's syndrome, we measured changes of regional cerebral blood flow with H2 15O-PET. We studied six right-handed Kallmann male subjects and six matched, right-handed control subjects during an externally paced finger opposition task. The analyses were done both on a single subject and a group basis. The Kallmann group showed a strong primary motor cortex (M1) activation contralateral to the voluntarily moved hand, but there was also a significant degree of M1 activation ipsilateral to the voluntarily moved hand, i.e. contralateral to the mirroring hand. However, when comparing contralateral to ipsilateral M1 activation, the M1 activation contralateral to the voluntarily moved hand was significantly stronger. In the controls, significant increases in rCBF were seen in the contralateral M1 during voluntary movement of either hand; a small ipsilateral M1 activation was found in two out of six normal subjects when they moved their left hand. In a second experiment it was shown that, in two out of two Kallmann subjects, passive movements of the right hand resulted in left M1 activation that was similar to the activation in the left M1 when subjects made mirror movements with their right hand. This suggests, but does not prove, that the small but significant activation of the ipsilateral M1 in Kallmann's subjects may be due to sensory feedback from the involuntarily mirroring hand.

Mirror movements in X-linked Kallmann's syndrome. I. A neurophysiological study

Possible mechanisms underlying the pathological mirror movements that are seen in the majority of patients with X-linked Kallmann's syndrome have been investigated using neurophysiological techniques. An EMG was recorded from the first dorsal interosseous muscle (1DI) during voluntary self-paced abduction of one indexed finger; EMG activity could also be recorded simultaneously from the contralateral 1DI. There was no significant difference between the time of onset of the bursts of voluntary and involuntary mirroring EMG. Focal magnetic stimulation of the hand area of the motor cortex revealed the presence of fast conducting bilateral corticospinal projections from each motor cortex in all subjects. However, both inter- and intra-subject differences exist when considering the ratio of ipsilaterally to contralaterally projecting axons. Cross-correlation analysis of multi-unit EMGs recorded during simultaneous voluntary sustained activation of homologous left and right pairs of distal upper limb muscles was performed. A short duration central peak was seen in the cross-correlograms indicating the presence of a common drive to left and right homologous motor neuron pools. This common drive may result from the synchronous activation of intermingled ipsilaterally and contralaterally projecting corticospinal neurons in the motor cortex. Cutaneomuscular reflexes were recorded from the 1DI following stimulation of the digital nerves of the index finger. Typically each reflex comprises spinal and longer latency trans-cortical components. In these subjects, the long latency components of the reflex response could, in addition, be recorded from the 1DI of the non-stimulated side. We conclude that these subject have a novel ipsilateral at least in part, for the pathological mirroring.

Detection of rare RNA sequences by single-enzyme in situ reverse transcription-polymerase chain reaction. High-resolution analyses of interleukin-6 mRNA in paraffin sections of lymph nodes

To study the distribution pattern of interleukin-6 (IL-6)-producing cells in normal human lymph nodes, we applied the in situ reverse transcription-polymerase chain reaction technique. We describe a new modification of this technique for monitoring small amounts of specific nucleotide sequences in conventional paraffin sections. This technique differs in at least two respects from those described earlier. The two decisive steps are: 1) the reverse transcription of mRNA and the subsequent amplification of cDNA by polymerase chain reaction are performed by a new single enzyme capable of both reaction types in one and the same medium without buffer exchange; and 2) for the specific detection of the amplified cDNA, a modified version of the primed in situ labeling technique was used. The technique, carried out on normal human lymph nodes, traces a low load of IL-6 mRNA in fibroblasts, endothelial cells, and a minor population of T lymphocytes in the pulp region. High levels of expression were encountered in about 20% of perisinusoidal pulp macrophages. In addition, moderate activity was detectable in sinus lining cells. Because no major activity was found in the germinal centers of the lymphoid B follicles and in the T zone, it is suggested that the plasma cell differentiation ensuing from primary and secondary B-cell immunization is mainly effected by the sinus lining cells as well as perifollicular and perisinusoidal pulp macrophages capable of producing high amounts of IL-6.

Elevation of intracranial pressure in acute AIDS-related cryptococcal meningitis

Prior to the AIDS-era, elevation of intracranial pressure was known to be a typical complication of cryptococcal meningitis associated with an increased risk of early death. In AIDS-patients, however, the prevalence and clinical significance of this complication are as yet unclear. We analysed clinical features and courses, CSF findings, serological results and neuroimaging scans in acute cryptococcal meningitis in eight patients with AIDS. Five showed symptoms and signs compatible with raised intracranial pressure, which was life-threatening in one and the most probable cause of death in another. Serial monitoring of intracranial pressure together with repeated CSF analysis revealed that severe intracranial pressure elevation in AIDS related cryptococcal meningitis can occur in spite of effective antimycotic treatment, does not depend on an increased CSF/serum osmolality ratio or CSF overproduction and can be associated with normal cranial computed tomography and magnetic resonance imaging findings. Our data support the hypothesis that CSF reabsorption failure plays the crucial role in the pathophysiological mechanism. External lumbar drainage may be of benefit in selected cases of acute AIDS related cryptococcal meningitis with persisting life threatening elevation in intracranial pressure and normal computed tomogram.

[Treatment of advanced breast cancer in postmenopausal women with droloxifene: results of a double-blind phase II trial for dose determination]

To determine the optimal daily dose of a new antiestrogen, droloxifene, for the treatment of advanced breast cancer, we have conducted a multicenter, randomized, double blind trial. Postmenopausal women with advanced breast cancer, who could not benefit from loco regional therapy, with positive or unknown estrogen or progesterone receptors were entered in this study. Droloxifene was administered in a double blind randomized design, with daily dose of either 20 (group I), 40 (group II) or 100 mg (group III). None of the patients had received previous systemic antitumor therapy, with the exception of adjuvant chemotherapy terminated at least one year before the patient's recruitment. Patients with at least one measurable tumoral lesion were entered into the trial. Three hundred and sixty nine patients have been enrolled, 234 are fully evaluable for efficacy. Objective response rate (CR + PR) is 31.1, 44.6 and 41.9% for the groups I, II and III respectively (P = NS). Time to response has been short: in the three groups, 50% of the responses have been observed within the 2 first months of treatment. Time to disease progression is 6, 8.3 and 6 months respectively for the 20, 40 and 100 mg/day treatment group. Side effects have been moderate and not dose related. Hot flushes and gastro intestinal disorders have been observed most often. This promising new drug deserves further study and randomized comparison versus tamoxifen.