Electrical stimulation methods and protocols for the treatment of traumatic brain injury: a critical review of preclinical research.

BACKGROUND: Traumatic brain injury (TBI) is a leading cause of disabilities resulting from cognitive and neurological deficits, as well as psychological disorders. Only recently, preclinical research on electrical stimulation methods as a potential treatment of TBI sequelae has gained more traction. However, the underlying mechanisms of the anticipated improvements induced by these methods are still not fully understood. It remains unclear in which stage after TBI they are best applied to optimize the therapeutic outcome, preferably with persisting effects. Studies with animal models address these questions and investigate beneficial long- and short-term changes mediated by these novel modalities. METHODS: In this review, we present the state-of-the-art in preclinical research on electrical stimulation methods used to treat TBI sequelae. We analyze publications on the most commonly used electrical stimulation methods, namely transcranial magnetic stimulation (TMS), transcranial direct current stimulation (tDCS), deep brain stimulation (DBS) and vagus nerve stimulation (VNS), that aim to treat disabilities caused by TBI. We discuss applied stimulation parameters, such as the amplitude, frequency, and length of stimulation, as well as stimulation time frames, specifically the onset of stimulation, how often stimulation sessions were repeated and the total length of the treatment. These parameters are then analyzed in the context of injury severity, the disability under investigation and the stimulated location, and the resulting therapeutic effects are compared. We provide a comprehensive and critical review and discuss directions for future research. RESULTS AND CONCLUSION: We find that the parameters used in studies on each of these stimulation methods vary widely, making it difficult to draw direct comparisons between stimulation protocols and therapeutic outcome. Persisting beneficial effects and adverse consequences of electrical simulation are rarely investigated, leaving many questions about their suitability for clinical applications. Nevertheless, we conclude that the stimulation methods discussed here show promising results that could be further supported by additional research in this field.

[Postmenopausal lichen planopilaris also known as fibrosing frontotemporal alopecia Kossard : An evidence-oriented practical guide to treatment from the University of the Saarland, Hair Research Center of the Dr. Rolf M. Schwiete Foundation]. / Postmenopausaler Lichen planopilaris alias fibrosierende frontotemporale Alopezie Kossard : Ein evidenzorientierter "practical guide to treatment" des Haarforschungszentrums der Dr. Rolf M. Schwiete Stiftung an der Universität des Saarlandes.

Postmenopausal lichen planopilaris (PLPP), also known as fibrosing frontotemporal alopecia Kossard (FFAK), is a not uncommon inflammatory scalp disease affecting approximately 5% of patients at specialized hair centers. The overall incidence of sporadic occurrence is believed to be just under 1% in the older, predominantly female, general population. Since the disease is often undiagnosed, it is statistically likely to be underrepresented. It especially occurs in postmenopausal women who are in the 6th and 7th decade of life (90%), but also in about 10% of premenopausal women, and in men it is documented only in isolated cases. The result is a permanent scarring hair loss accentuated at the front hairline with backward movement towards the neck mostly accompanied by a typical loss of the eyebrows. The disease therefore often leads to significant mental distress and social anxiety in those affected. This is the basis for a compelling need to develop evidence-based therapeutic concepts. While numerous retrospective case series have characterized the phenomenology of FFAK very well, to date there are no randomized controlled trials on evidence-based therapy. Here, we present the Homburger Evidence-Oriented Therapy Algorithm, which is oriented along the available case series evidence: It may (1) serve as a therapy guide for practice and (2) can be used as a basis for working out reliable data based on study evidence. The article contains detailed practical information on photo documentation, biopsy and histological processing up to the practical implementation of, for example, intralesional steroid therapy as well as information on selection criteria for suitable systemic therapies.

[Ethical case discussions in the intensive care unit : from testing to routine]. / Ethische Fallbesprechungen auf der Intensivstation : Vom Versuch zur Routine.

BACKGROUND: The daily work of many healthcare professionals has become more complex and demanding in recent years. Apart from purely medical issues, ethical questions and problems arise quite often. Managing these problems requires ethical knowledge. Questions about the usefulness of a therapy and treatment occur especially at the end of life. So-called medical futility, a useless futile therapy, is often perceived by nurses and physicians in intensive care units who themselves often develop symptoms of depression or burnout. The clinical ethical model METAP (acronym from module, ethics, therapy decision, allocation and process) provides methods and criteria that allow the clinical team to treat and solve ethical issues according to a solution-oriented approach. The ethical decision-making of this model addresses these issues according to a series of sequential stages in the form of a so-called escalation model. When it is not possible to tackle and solve an ethical problem or dilemma in one stage, one moves to the next. The implementation of this approach in everyday practice requires the commitment of all team members in addition to certain basic conditions. MATERIAL AND METHODS: In a surgical intensive care unit a fixed date in the schedule is reserved for ethical case discussions (level 3 of the escalation model). At this level a team member who has been specified according to a quarterly plan is responsible for the organization and performance of the discussion. All protocols of the 44 ethical case discussions in 41 patients between January 2011 and July 2012 were collected and summarized. A short questionnaire to all participants recorded their assessment of the benefits for the patient and the team as well as their perception of personal stress reduction. Also queried was the impact of this method on the collaboration between nurses and physicians and the ethical competence. RESULTS: Ethical case discussions among the care team took place regularly (44 case discussions between January 2011 and June 2012). The duration of these discussions ranged from 30 to 60 min. On average 6.2 persons took part, including 2.7 nurses and 3.2 physicians. Of the 41 patients (16 female, 25 male) for whom a discussion was carried out, 23 died during the continued hospital stay. The respondents (response rate 52 %) assessed the benefit for patients and team as high (slightly higher benefit for physicians than nurses) and 55 % of physicians and 71 % of nurses perceived a reduction in the burden of decision-making in difficult cases due to the case discussions. All physicians and 66 % of the nurses reported an improvement in the cooperation between the professional groups and 80 % of the nurses and more than half of the physicians noticed an increase in their own ethical competence. CONCLUSION: A methodically structured ethical decision-making process can and should be integrated into the clinical routine. This process requires a fixed place in everyday practice and the defined responsibility for the actual organization and performance. Support by medical and nursing management personnel is also essential for the implementation. The regular occurrence of ethical case discussions among the care team relieves the participants and improves collaboration between nurses and physicians.

[Imaging in mitral valve interventions]. / Bildgebung bei interventionellen Mitralklappeneingriffen.

Percutaneous cardiac valve interventions have significantly extended the therapeutic options for patients with diseased cardiac valves. Technical miniaturization and major advancements in cardiac imaging techniques are the cornerstones of this successful development. Regarding mitral valve interventions periprocedural echocardiography in particular is of uttermost importance. This review describes the state of the art echocardiographic imaging techniques focusing on the clinically established mitral valve interventions: MitraClip® implantation, percutaneous closure of periprosthetic leaks and mitral balloon valvuloplasty.

Early results of a real-world series with two transapical transcatheter mitral valve replacement devices.

AIMS: Transcatheter mitral valve replacement (TMVR) with dedicated devices promises to fill the treatment gap between open-heart surgery and edge-to-edge repair for patients with severe mitral regurgitation (MR). We herein present a single-centre experience of a TMVR series with two transapical devices. METHODS AND RESULTS: A total of 11 patients were treated with the Tendyne™ (N = 7) or the Tiara™ TMVR systems (N = 4) from 2016 to 2020 either as compassionate-use procedures or as commercial implants. Clinical and echocardiographic data were collected at baseline, discharge and follow-up and are presented in accordance with the Mitral Valve Academic Research Consortium (MVARC) definitions. The study cohort [age 77 years (73, 84); 27.3% male] presented with primary (N = 4), secondary (N = 5) or mixed (N = 2) MR etiology. Patients were symptomatic (all NYHA III/IV) and at high surgical risk [logEuroSCORE II 8.1% (4.0, 17.4)]. Rates of impaired RV function (72.7%), severe pulmonary hypertension (27.3%), moderate or severe tricuspid regurgitation (63.6%) and prior aortic valve replacement (63.6%) were high. Severe mitral annulus calcification was present in two patients. Technical success was achieved in all patients. In 90.9% (N = 10) MR was completely eliminated (i.e. no or trace MR). Procedural and 30-day mortality were 0.0%. At follow-up NYHA class was I/II in the majority of patients. Overall mortality after 3 and 6 months was 10.0% and 22.2%. CONCLUSIONS: TMVR was performed successfully in these selected patients with complete elimination of MR in the majority of patients. Short-term mortality was low and most patients experienced persisting functional improvement.

Complementary and alternative medicine in lung cancer patients: a neglected phenomenon?

Study on the use of complementary and alternative medicine (CAM) in lung cancer patients has been widely neglected. Therefore, we initiated a study on the use of CAM in lung cancer patients in addition to radiation treatment. Overall, 120 patients from 3 institutions were interviewed by a standardized questionnaire. Besides the tumor parameters and the use of CAM, the reason for the use, patient information of the medication, the information sources and the subjective condition of the patient. Altogether, 54% of the patients reported using CAM (66% of female patients, 52% of male patients). The most frequently used CAM measures were vitamin combinations (17%), mistletoe (15%), and selenium (12%). A total of 52% reported the wish to support the tumor treatment as a reason for using CAM and 27% had a 'better feeling' using CAM. 50% of CAM was bought by the patients themselves and 50% were prescribed by their family physicians. The use of CAM is frequent in lung cancer patients. Our results suggest that it is very important to obtain information on the CAM use of patients and, particularly in controlled clinical trials, to prospectively document it.

From sequence to chromosome: the tip of the X chromosome of D. melanogaster.

One of the rewards of having a Drosophila melanogaster whole-genome sequence will be the potential to understand the molecular bases for structural features of chromosomes that have been a long-standing puzzle. Analysis of 2.6 megabases of sequence from the tip of the X chromosome of Drosophila identifies 273 genes. Cloned DNAs from the characteristic bulbous structure at the tip of the X chromosome in the region of the broad complex display an unusual pattern of in situ hybridization. Sequence analysis revealed that this region comprises 154 kilobases of DNA flanked by 1.2-kilobases of inverted repeats, each composed of a 350-base pair satellite related element. Thus, some aspects of chromosome structure appear to be revealed directly within the DNA sequence itself.

Nortriptyline hydrochloride skin absorption: development of a transdermal patch.

The influence of propylen glycol (PG), ethanol, and oleic acid (OA) on nortriptyline hydrochloride (NTH) penetration through human epidermis was studied in vitro at two different pH values (5.5 and 7.4). The influence of lactic acid and polysorbate 80 was studied for a pH of 5.5. Permeation studies through Heat Separated Epidermis, as well as the enhancing effect of the different vehicles, showed a pH dependency. A pH value of 5.5 in the donor solution decreases significantly the permeability coefficient (Kp) with respect to a pH value of 7.4 (0.011+/-0.004 x 10(-6) versus 0.36+/-0.04 x 10(-6)cm/s). The vehicles showed an increasing enhancement effect in the order: polysorbate 80>ethanol/PG/OA>PG>ethanol>ethanol/lactic acid>lactic acid at pH 5.5 while they reduced the permeation of NTH at pH 7.4. Considering the results obtained at pH 5.5, the maximum enhancement ratios were found for polysorbate 80 and the combination ethanol/PG/OA (10.72 and 3.90). Both vehicles were selected for designing a NTH transdermal delivery system (NTH-TDS) using (hydroxypropyl)methyl-cellulose as polymer. The NTH-TDS based on the combination of ethanol/PG/OA showed an enhancement ratio with respect to control of 2.09 and the addition of polysorbate 80 to the matrix, of 5.82.

Acute and Long-Term Hemodynamic Effects of MitraClip Implantation on a Preexisting Secondary Right Heart Failure.

Positive results of MitraClip in terms of improvement in clinical and left ventricular parameters have been described in detail. However, long-term effects on secondary pulmonary hypertension were not investigated in a larger patient cohort to date. 70 patients with severe mitral regurgitation, additional pulmonary hypertension, and right heart failure as a result of left heart disease were treated in the heart centers Hamburg and Göttingen. Immediately after successful MitraClip implantation, a reduction of the RVOT diameter from 3.52 cm to 3.44 cm was observed reaching a statistically significant value of 3.39 cm after 12 months. In contrast, there was a significant reduction in the velocity of the tricuspid regurgitation (TR) from 4.17 m/s to 3.11 m/s, the gradient of the TR from 48.5 mmHg to 39.3 mmHg, and the systolic pulmonary artery pressure (PAPsyst) from 58.6 mmHg to 50.0 mmHg. This decline continued in the following months (Vmax TR 3.09 m/s, peak TR 38.6 mmHg, and PAPsyst 47.4 mmHg). The tricuspid annular plane systolic excursion (TAPSE) increased from 16.5 mm to 18.9 mm after 12 months. MitraClip implantation improves pulmonary artery pressure, tricuspid regurgitation, and TAPSE after 12 months. At the same time, there is a decrease in the RVOT diameter without significant changes in other right ventricular and right atrial dimensions.

A protein related to p21-activated kinase (PAK) that is involved in neurogenesis in the Drosophila adult central nervous system.

Brains are organized by the developmental processes generating them. The embryonic neurogenic phase of Drosophila melanogaster has been studied in detail at the genetic, cellular and molecular level. In contrast, much of what is known of postembryonic brain development has been gathered by neuroanatomical and gene expression studies. The molecular mechanisms underlying cellular diversity and structural organisation in the adult brain, such as the establishment of the correct neuroblast number, the spatial and temporal control of neuroblast proliferation, cell fate determination, and the generation of the precise pattern of neuronal connectivity, are largely unknown. In a screen for viable mutations affecting adult central brain structures, we isolated the mushroom bodies tiny (mbt) gene of Drosophila, which encodes a protein related to p21-activated kinase (PAK). We show that mutations in mbt primarily interfere with the generation or survival of the intrinsic cells (Kenyon cells) of the mushroom body, a paired neuropil structure in the adult brain involved in learning and memory.

Expression of a gene duplication encoding conserved sperm tail proteins is translationally regulated in Drosophila melanogaster.

We have analyzed a locus of Drosophila melanogaster located at 98C on chromosome 3, which contains two tandemly arranged genes, named Mst98Ca and Mst98Cb. They are two additional members of the Mst(3)CGP gene family by three criteria. (i) Both genes are exclusively transcribed in the male germ line. (ii) Both transcripts encode a protein with a high proportion of the repetitive motif Cys-Gly-Pro. (iii) Their expression is translationally controlled; while transcripts can be detected in diploid stages of spermatogenesis, association with polysomes can be shown only in haploid stages of sperm development. The genes differ markedly from the other members of the gene family in structure; they do not contain introns, they are of much larger size, and they have the Cys-Gly-Pro motifs clustered at the carboxy-terminal end of the encoded proteins. An antibody generated against the Mst98Ca protein recognizes both Mst98C proteins in D. melanogaster. In a male-sterile mutation in which spermiogenesis is blocked before individualization of sperm, both of these proteins are no longer synthesized. This finding provides proof of late translation for the Mst98C proteins and thereby independent proof of translational control of expression. Northern (RNA) and Western immunoblot analyses indicate the presence of homologous gene families in many other Drosophila species. The Mst98C proteins share sequence homology with proteins of the outer dense fibers in mammalian spermatozoa and can be localized to the sperm tail by immunofluorescence with an anti-Mst98Ca antibody.

The biological and toxicological importance of molybdenum in the environment and in the nutrition of plants, animals and man. Part 2: Molybdenum in animals and man.

Molluscs and insects accumulate between 200 and 1050 microg Mo/kg of dry matter. Mice and vole species incorporate 350-650 microg Mo/kg, whereas shrews store 1500-2500 microg Mo/kg, i.e. insectivores have significantly higher molybdenum contents than rodents. The amounts of molybdenum accumulated by wild and domestic mammals are highest in the liver and kidneys, and lowest in muscle tissue and hair. The molybdenum status of mammals is reflected by all tissues tested except the heart. The best indicators of molybdenum deficiency and intoxication are liver, kidneys, blood and milk. The intrauterine storage of molybdenum in mammals is low. The milk delivers sufficient molybdenum amounts to the newborns. In man, the transfer of molybdenum follows the same rules as those found in mammals.

Safety and efficacy of the percutaneous transaxillary access for transcatheter aortic valve implantation using various transcatheter heart valves in 100 consecutive patients.

OBJECTIVES: Transcatheter Aortic Valve Implantation (TAVI) can be performed via the transaxillary approach, but data about complications and procedural outcome is limited. INTRODUCTION: TAVI is an established treatment option for patients at high risk for conventional aortic valve replacement. Nowadays, the transfemoral approach is the most commonly used access for TAVI. Nevertheless, the transfemoral access is not suitable in many patients necessitating alternative approaches. METHODS: We analyzed the outcome of 100 consecutive cases receiving percutaneous transaxillary TAVI at two different hospitals. Data were retrospectively analyzed by means of procedural, hemodynamic and clinical outcome. In addition, 1st versus 2nd generation devices were analyzed. RESULTS: Mean age was 78.2±2.1years and the logEuroSCORE I was 24.6±13.9%. Transaxillary TAVI was performed in 85% via the left and in 15% via the right axillary artery. Device success was achieved in 95%. In general, there was a clear learning curve with this approach. No patient experienced a major and 11% a minor access site complication. There was one procedural death (annular rupture) and one peri-procedural TIA. 23% of the patients received a new pacemaker. At discharge, effective orifice area was 1.94±0.16cm2 and the mean aortic gradient was 6.8±2.1mmHg. Moderate aortic regurgitation/paravalvular leakage was documented in two patients. Mortality rates at 30days and one year were 6% and 14.8%. Last but not least, 2nd generation devices showed improved procedural outcomes. CONCLUSIONS: The percutaneous transaxillary access for TAVI is technically feasible and safe thereby yielding excellent clinical results. CONDENSED ABSTRACT: We investigated In 100 consecutive patients undergoing percutaneous transaxillary transcatheter aortic valve implantation thereby demonstrating that this approach is technically feasible and safe with acceptable numbers of minor vascular complications.

Radiation-induced capsule tissue reactions around textured breast implants in a rat model.

Capsule fibrosis and other complications around various filled breast implants were evaluated in a rat radiation model after 12 months of implantation. Model implants, one per rat, were implanted subcutaneously. One month after subcutaneous implantation, high voltage radiation followed one half each group. A higher rate of capsule fibrosis occurred in radiated animals. Malignant tumors at the implantation site developed in 40% of radiated and 24% of non-radiated animals, with a much higher rate of mitosis in the radiated group (Mann-Whitney, P=0.008). The presence of an implant is a cofactor for tumor development in rats (chi2-test, chi2=6.927; P=0.008) as well as radiation, since none of the control animals developed tumors. Applied to humans, capsule contracture (fibrosis) is a common complication of radiation, while development of radiation-induced sarcoma is a rare complication after postoperative radiotherapy by all account. Still further long-term follow-up human studies are necessary.

Protein traffic in bacteria: multiple routes from the ribosome to and across the membrane.

Bacteria use several routes to target their exported proteins to the plasma membrane. The majority are exported through pores formed by SecY and SecE. Two different molecular machineries are used to target proteins to the SecYE translocon. Translocated proteins, synthesized as precursors with cleavable signal sequences, require cytoplasmic chaperones, such as SecB, to remain competent for posttranslational transport. In concert with SecB, SecA targets the precursors to SecY and energizes their translocation by its ATPase activity. The latter function involves a partial insertion of SecA itself into the SecYE translocon, a process that is strongly assisted by a couple of membrane proteins, SecG, SecD, SecF, YajC, and the proton gradient across the membrane. Integral membrane proteins, however, are specifically recognized by a direct interaction between their noncleaved signal anchor sequences and the bacterial signal recognition particle (SRP) consisting of Ffh and 4.5S RNA. Recognition occurs during synthesis at the ribosome and leads to a cotranslational targeting to SecYE that is mediated by FtsY and the hydrolysis of GTP. No other Sec protein is required for integration unless the membrane protein also contains long translocated domains that engage the SecA machinery. Discrimination between SecA/SecB- and SRP-dependent targeting involves the specificity of SRP for hydrophobic signal anchor sequences and the exclusion of SRP from nascent chains of translocated proteins by trigger factor, a ribosome-associated chaperone. The SecYE pore accepts only unfolded proteins. In contrast, a class of redox factor-containing proteins leaves the cell only as completely folded proteins. They are distinguished by a twin arginine motif of their signal sequences that by an unknown mechanism targets them to specific pores. A few membrane proteins insert spontaneously into the bacterial plasma membrane without the need for targeting factors and SecYE. Insertion depends only on hydrophobic interactions between their transmembrane segments and the lipid bilayer and on the transmembrane potential. Finally, outer membrane proteins of Gram-negative bacteria after having crossed the plasma membrane are released into the periplasm, where they undergo distinct folding events until they insert as trimers into the outer membrane. These folding processes require distinct molecular chaperones of the periplasm, such as Skp, SurA, and PpiD.

Identification of a nitric oxide-regulated zinc finger containing transcription factor using motif-directed differential display.

We report here the isolation of human zinc finger 2 (HZF2), a putative zinc-finger transcription factor, by motif-directed differential display of mRNA extracted from histamine-stimulated human vein endothelial cells. The expression of HZF2 mRNA in venous endothelial cells was verified by Northern blot analysis, which also revealed an enrichment of HZF2 mRNA in lymphocytes and monocytes. Histamine induced a time- and concentration-dependent upregulation of HZF2 level with a 6-fold peak increase of mRNA at 30 min. HZF2 upregulation was abolished by different NOS isozyme inhibitors. Guanylate cyclase inhibition resulted in a significant decrease of HZF2 expression. These observations indicate HZF2 as a potentially interesting new target for studies concerning rapid NO-mediated gene regulation.

Genetic and molecular characterization of sting, a gene involved in crystal formation and meiotic drive in the male germ line of Drosophila melanogaster.

The sting mutation, caused by a P element inserted into polytene region 32D, was isolated by a screen for male sterile insertions in Drosophila melanogaster. This sterility is correlated with the presence of crystals in spermatocytes and spermatids that are structurally indistinguishable from those produced in males carrying a deficiency of the Y-linked crystal (cry) locus. In addition, their morphology is needle-like in Ste+ flies and star-shaped in Ste flies, once again as observed in cry- males. The sti mutation leads to meiotic drive of the sex chromosomes, and the strength of the phenomenon is correlated with the copy number of the repetitive Ste locus. The same correlation is also true for the penetrance of the male sterile mutation. A presumptive sti null allele results in male sterility and lethal maternal effect. The gene was cloned and shown to code for a putative protein that is 866 amino acids long. A C-terminal domain of 82 amino acids is identified that is well conserved in proteins from different organisms. The gene is expressed only in the germline of both sexes. The interaction of sting with the Ste locus can also be demonstrated at the molecular level. While an unprocessed 8-kb Ste primary transcript is expressed in wild-type males, in X/Y homozygous sti males, as in X/Y cry- males, a 0.7-kb mRNA is produced.

The egghead gene product influences oocyte differentiation by follicle cell-germ cell interactions in Drosophila melanogaster.

Oogenesis in Drosophila is a useful model for studying cell differentiation. We have analyzed the role of the egh gene in these processes with the aid of a newly isolated viable but female sterile allele. This mutation results in diverse variable defects in oogenesis. The most frequent defect being follicles that have either more or less than the normal number of 16 germ cells. This is caused by erroneous splitting and/or fusion of correct clusters of 16 cystocytes. The entire follicle has a rather flexible structure in this allele, most obvious by a highly variable position of the oocyte within the follicle. Moreover, a second oocyte can also develop in egh clusters. This is exclusively observed in aberrant follicles that are generated by the aforementioned splitting/fusion process. Surprisingly, even a germ cell which is distinct from the two pro-oocytes can differentiate into an oocyte under these circumstances. Hence, determination of the oocyte is definitely not fixed when germ cell clusters are enveloped by prefollicular cells, and interactions between follicle cells and germ cells must play an important role in oocyte specification. Molecular analysis proves that the oocyte-specific transcript of the egh gene is drastically reduced in this viable allele.

A cluster of four genes selectively expressed in the male germ line of Drosophila melanogaster.

The gene Mst87F is exclusively expressed in the male germ line and is subject to translational regulation. The Mst87F mRNA is transcribed in the primary spermatocytes, stored for three days and then subsequently translated in the post-elongation period of spermiogenesis. Here we report on the isolation of a cluster of four small genes closely related in structure and function to Mst87F. These genes are located at polytene band 84D on the right arm of chromosome three and are named Mst84Da, Mst84Db, Mst84Dc and Mst84Dd. All four genes encode putative proteins composed primarily of a repetitive motif of cysteine-glycine-proline. The genes are exclusively expressed in the male germ line. The poly(A) tail of the Mst84D mRNAs increases in length at day three of pupal development, the time at which a similar change in Mst87F mRNA and translation has been shown to begin. In addition we have identified a conserved 12 base pair element within the 5' untranslated region (UTR) of each gene which is also found at an identical position in Mst87F and which has been demonstrated to be the structural element for translational control of Mst87F expression (Schäfer et al., 1990 EMBO J. 9, 4519-4525). We have mapped the gene cluster to a small deletion associated with a rotund mutation at 84D. Although flies with a homozygous deletion of the cluster still produce motile sperm, electron microscopic examination revealed numerous malformations in the ultrastructure of the axoneme resulting in a drastic reduction of motile sperm.