The heterochromatic Y chromosomes of several Drosophila species harbor a small number of male fertility genes (fertility factors) with several unusual features. Expression of their megabase-sized ...loci is restricted to primary spermatocytes and correlates with the unfolding of species-specific lampbrush loop-like structures resulting from huge transcripts mainly derived from clusters of loop-specific Y chromosomal satellites. Otherwise, there is evidence from genetic mapping and biochemical experiments that at least two of these loops, Threads in Drosophila hydei and kl-5 in D. melanogaster, colocalize with the genes for the axonemal dynein beta heavy chain proteins DhDhc7(Y) and Dhc-Yh3, respectively. Here, we make use of particular Threads mutants with megabase-sized deletions for direct mapping of DhDhc7(Y)-specific exons among the large clusters of satellite DNA within the 5.1-Mb Threads transcription unit. PCR experiments with exon-specific primer pairs, in combination with hybridization experiments with exon- and satellite-specific probes on filters with large PFGE-generated DNA fragments, offer a simple solution for the long-lasting paradox between megabase-sized loops and protein-encoding transcription units; the lampbrush loops Threads and the DhDhc7(Y) gene are one and the same transcription unit, and the giant size of the DhDhc7(Y) gene as well as its appearance as a giant lampbrush loop are merely the result of transcription of huge clusters of satellite DNA within some of its 20 introns.
Patients with small cell lung cancer (SCLC) and superior vena cava syndrome (SVCS) are widely believed to have a grave prognosis. The purpose of this study was to determine the prognosis of patients ...with SCLC and SVCS as compared to SCLC without SVCS.
A retrospective analysis of 408 cases of SCLC +/- SVCS was performed. Three- hundred and sixty showed no clinical signs of SVCS and 43 (11%) had SVCS; in 5 patients no adequate information was available about clinical signs of SVCS. All patients were classified as limited disease cases. About 98% received chemotherapy usually as the first treatment followed by radiotherapy. A median total dose of 46 Gy (range 30 to 70 Gy) was given at 2.0 Gy per fraction five times weekly. A prophylactic cranial irradiation was applied if a complete remission was achieved after chemotherapy or after 30 Gy of irradiation. Kaplan-Meier survival curves are shown and comparisons were made by the log-rank and the Gehan/Wilcoxon test. To adjust for prognostic factors, a proportional hazards analysis was done.
Patients without SVCS had 5-year survival rates ( +/- SE) and a median survival time (MST; 95% confidence intervals) of 11% +/- 2% and 13.7 months (12.7-14.5) in UICC Stage I to III; in Stage III the figures were 9% +/- 2% and 12.6 months (11.2-13.7). In comparison, SCLC with SVCS had 5-year survival rates of 15% +/- 7% and MST of 16.1 months (13.8-20.5). The difference was significant in univariate analysis (Stage II disease: p = 0.008 by the log-rank test). In a multivariate analysis of all patients, Stage (Stage I + II > III; p = 0.0003), SVCS (yes > no; p = 0.005), and Karnofsky performance status ( < or = 70 < 80-100%; p = 0.008) were of significant importance.
SVCS is a favorable prognostic sign in SCLC. The treatment should be curatively intended.
Fertility genes on the heterochromatic Y chromosome of various Drosophila species are unique for several reasons. Most of them are megabase-sized. Their expression is restricted to premeiotic ...spermatocytes and often associated with unfolding of huge species-specific lampbrush loops. Molecular analysis of the orthologous dynein genes Dhc-Yh3, DhDhc7(Y) and DeDhc7(Y) on the Y chromosome of the three species D. melanogaster, D. hydei and D. eohydei, respectively, revealed that the megabase gene size as well as the species-specific morphology of the corresponding lampbrush loops kl-5, Threads and diffuse loops result from huge introns and their specific sequence composition, whereas the majority of all 20 introns in each of the three genes is in a size of 45-72 bp. The loop-specifying introns are extreme exceptions due to extended assemblies of degenerated transposable elements and/or large clusters of satellite DNAs. Here we use sequence information from the complete intron sets of three orthologous Y chromosomal dynein genes to deduce a scenario for an evolutionary pathway leading to the megabase-sized genes on the heterochromatic Y chromosome of Drosophila. The obvious bias between very small and species-specific mega introns is explained as the result of an autocatalytic mode of intron growth. An initial coincidental hit by a single transposable element extends the size of a 50 bp intron for about two orders of magnitude and determines it for preferential extension by similar insertion events. This phase of continuous moderate growth is followed by rapid size enlargements by repeating amplifications generating extended clusters of satellite DNA. Size control by recombination, on the other hand, is suppressed in Drosophila males by achiasmatic meiosis.
To understand the contradiction between megabase-sized lampbrush loops and putative protein encoding genes both associated with the loci of Y chromosomal fertility genes of Drosophila on the ...molecular level, we used PCR-mediated cloning to identify and isolate the cDNA sequence of the Y chromosomal Drosophila hydei gene DhDhc7(Y). Alignment of the sequences of the putative protein DhDhc7(Y) and the outer arm dynein beta heavy chain protein DYH2 of Tripneustes gratilla shows homology over the entire length of the protein chains. Therefore the proteins can be assumed to fulfill orthologous functions within the sperm tail axonemes of both species. Functional dynein beta heavy chain molecules, however, are necessary for the assembly and attachment of outer dynein arms within the sperm tail axoneme. Localization of DhDhc7(Y) to the fertility factor Threads, comprising at least 5.1 Mb of transcriptionally active repetitive DNA, results from an infertile Threads- mutant where large clusters of Threads specifically transcribed satellites and parts of DhDhc7(Y) encoding sequences are missing simultaneously. Consequently, the complete lack of the outer dynein arms in Threads- males most probably causes sperm immotility and hence infertility of the fly. Moreover, preliminary sequence analysis and several other features support the hypothesis that DhDhc7(Y) on the lampbrush loops Threads in D. hydei and Dhc-Yh3 on the lampbrush loops kl-5 in Drosophila melanogaster on the heterochromatic Y chromosome of both species might indeed code for orthologous dynein beta heavy chain proteins.
To understand the effect of the megabase-sized, Y chromosomal fertility genes on different stages of spermatogenesis in Drosophila hydei, an immunoscreening was performed to search for ...testis-specific protein-encoding cDNAs. The array of isolated clones contained cDNA sequences derived from a gene on chromosome 5 at 101BC. The gene, Dhmst101(1), is a member of a small gene family and is specifically expressed in adult testis tissue. The mRNA encodes a protein of 344 amino acids with a deduced apparent molecular weight of 37,793 Da. The main portion of the protein sequence comprises repetitive, highly charged amino acid units and shows repeat number variations among several D. hydei laboratory stocks. Immunocytochemistry with antibodies raised against synthetic peptides localized the protein product in elongated spermatids. This pattern of expression and the evaluation of biophysical considerations on the protein sequence data suggest that the Dhmst101(1) gene product may have some importance for the structural integrity of the sperm tail. Moreover, Y chromosomal deletions affecting correct spermiogenesis lead to degradation of the Dhmst101(1) gene product.
Patients with malignant gliomas have a limited survival prognosis. We retrospectively analyzed data of malignant glioma patients with the aim of defining prognostic factors on which individualized ...treatment strategies might be built on.
Seventy-six patients with primary malignant glioma (51 glioblastoma multiforme, 20 anaplastic astrocytoma, 4 anaplastic oligo-astrocytoma, 1 anaplastic glioma) were postoperatively irradiated with 5 and 8 Me V photons, 2 Gy per fraction to a median total dose of 60 Gy (range 50 to 70 Gy).
The youngest quartile of patients (up to 45 years) had the highest 3-year survival rates (mean +/- SE: 15 +/- 8%) and median survival time (17.9 months, 95% confidence interval: 9.2, 24.2 months) as compared to the oldest quartile (> 61 years) with no 3-year survivor and a median survival time of 9.7 months (7.2, 12.3 months). The middle quartiles (46 to 61 years) showed intermediate results. The difference between the youngest and oldest quartile (p = 0.01) and the middle quartile versus the oldest quartile (p = 0.04) was significant. In univariate analysis, tumor size (p = 0.04 for -30 mm vs > 50 mm) was of importance. In multivariate analysis only age of the patient reached statistical significance (p = 0.03). As compared to the youngest quartile of patients, the oldest quartile had a relative risk of 2.1 (95% confidence interval: 0.9, 5.1) of dying from the disease; the age group of 46 to 61 years had a relative risk of 2.0 (0.9, 4.3).
Age of the patient is the most important factor for survival prognosis favouring younger age (< or = 45 years). The possible implications for radiation therapy are discussed.
Die zeitliche Integration von Operation, Chemotherapie und Strahlentherapie bei der brusterhaltenden Behandlung des Mammakarzinoms ist in den letzten Jahren zunehmend in den Blickpunkt des Interesses ...gerückt. Die Grundlage dieser Studie bilden 74 Patientinnen, die im Zeitraum 1985 bis 1992 an unserem Institut eine postoperative Strahlentherapie erhielten. Die mediane Nachbeobachtungszeit betrug fünf Jahre. In 73% der Fälle waren die Patientinnen prä- oder perimenopausal. Fast alle Patientinnen (91%) befanden sich im UICC-Stadium II. Axilläre Lymphknoten waren dabei in 95% befallen. Eine makroskopisch vollständige Tumorresektion wurde bei allen Patientinnen erreicht, und in 65% der Fälle waren die Resektionsränder frei von invasivem oder intraduktalem Karzinom. Postoperativ wurden in 70% der Fälle sechs Zyklen Polychemotherapie (hauptsächlich CMF) vor Bestrahlungsbeginn appliziert. Die Strahlendosis betrug fast ausschließlich 60 Gy inklusive 10 Gy Boost. Fünf Jahre nach Behandlungsbeginn betrug die Überlebensrate 86% (95%-Vertrauensbereich 76 bis 93%), die krankheitsfreie Überlebensrate 73% (61 bis 83%) und die Lokalrezidivrate 8% (3 bis 16%). Der einzige signifikante prognostische Faktor für das krankheitsfreie Überleben war die Anzahl befallener Lymphknoten: 0 bis 3=86%, ≥4=40% (p<0,0001). Das Intervall zwischen Operation und Bestrahlungsbeginn (≤ oder >20 Wochen) hatte keinen signifikanten Einfluß auf das krankheitsfreie Überleben oder die lokale Tumorkontrolle. Dagegen fand sich ein Hinweis auf eine vermehrte lymphogene und hämatogene Metastasierung bei Verkürzung des Intervalls, bedingt durch die Applizierung von weniger als sechs Zyklen Chemotherapie vor Beginn der Strahlentherapie. In unserer Erfahrung hat die Verzögerung der Strahlentherapie, um die volle Anzahl von Chemotherapiezyklen vor Bestrahlungsbeginn applizieren zu können, keinen negativen Einfluß auf die lokale Tumorkontrolle. Dabei muß allerdings die niedrige statistische Power dieser Auswertung aufgrund der kleinen Patientenzahl beachtet werden. Es erscheint möglich, daß eine weniger intensive Chemotherapie vor Beginn der Bestrahlung mit einer Erhöhung der Fernmetastasierungsrate und einer entsprechenden Verschlechterung der krankheitsfreien Überlebensrate korreliert. Für Patientinnen mit erhöhtem Metastasierungsrisiko befürworten wir daher sechs Zyklen Polychemotherapie vor der Strahlenbehandlung. The timing of breast conserving surgery, chemotherapy, and radiotherapy in breast cancer treatment has become the subject of increasing interest over the last years. Seventy-four patients who underwent postoperative radiotherapy at our institution between 1985 and 1992 form the basis of this study. Median follow-up time was 5 years. Seventy-three percent of patients were pre- or perimenopausal. Almost all patients (91%) were UICC-stage II. Axillary lymph nodes were positive in 95% of cases. Complete gross tumor resection was achieved in all patients, and in 65% final pathological margins were free of invasive or intraductal carcinoma. Postoperatively, 70% of patients received 6 cycles of polychemotherapy (predominantly CMF) before onset of irradiation. The radiation dose was in almost all cases 60 Gy including 10 Gy boost. Five years after start of treatment overall survival, disease-free survival, and local recurrence rates were 86% (95%-confidence limits, 76 to 93%), 73% (61 to 83%), and 8% (3 to 16%), respectively. For disease-free survival, the only significant prognostic factor was the number of involved lymph nodes: 0 to 3=86%, ≥4=40% (p<0,0001). The interval between surgery and radiation (≤versus >20 weeks) had no significant influence on disease-free survival or local tumor control. In contrast, there was a trend of increased regional and distant failure with shortening of the interval due to the delivery of less than 6 cycles chemotherapy before the onset of radiotherapy. In our experience, there was no negative impact of a delay of radiotherapy in order to deliver full course chemotherapy before initiation of radiotherapy. However, the low statistical power of this analysis due to the small number of patients must be considered. It appears possible that a less intense chemotherapy before starting radiation treatment correlates with enhanced distant failure and subsequently decreased disease-free survival rates. Therefore, for patients at increased risk for distant metastasis, we prefer to give 6 cycles polychemotherapy before irradiation.PUBLICATION ABSTRACT
Fruit fly species of the genus Drosophila show a remarkable variation in sperm length. Some of them produce gigantic sperm several times the total male body length. Sperm of Drosophila hydei, for ...example, are more than 20 mm long. Little is known about the advantage of such elongated sperm or about the proteins that stabilize their thin flagellar tails. Recently, two members of a novel gene family Dhmst101(1) and Dhmst101(2), whose gene products are associated with the sperm tail, were isolated and characterized. Here a third member of this gene family, Dhmst101(3), is described. It was previously demonstrated that all three genes are located in a single small cluster on chromosome 5 of D. hydei. They are located within 15 kb of genomic DNA, oriented in the same direction and transcribed testis‐specifically. The encoded sperm tail‐specific proteins are mainly composed of tandemly arranged repeats of a highly charged, cysteine‐containing motif of 16 amino acids with the consensus sequence KKKCA/EEAAKKEKEAAE. Experiments with synthetic repeat monomers and dimers have demonstrated a tendency for α‐helical rod formation, which increased strongly with an increase in repeat number. Therefore, Dhmst101 proteins with 7–60 repeats with regularly spaced cystein‐residues are thus expected to form long α‐helical rods cross‐linked by numerous Cys‐Cys bridges. Here we apply immuno‐ electron microscopy and monospecific antibodies, α‐mst101, raised against the KKKCAEAAKKEKEAAE‐motif to investigate the distribution of Dhmst101 proteins within the sperm tail of D. hydei. We show that Dhmst101 proteins are part of the outer sheath of the sperm tail where they presumably help to provide a tight but elastic envelope for the extremely extended spermatozoa of D. hydei.
PDF
