The role of OCT- angiography in predicting anatomical and functional recovery after endoscopic endonasal pituitary surgery: A 1-year longitudinal study.

PURPOSE: The purpose of this study was to investigate the changes in structural spectral-domain optical coherence tomography (SD-OCT), OCT Angiography (OCTA) parameters, and visual acuity, 1 year after endoscopic endonasal approach for the removal of an intra-suprasellar pituitary adenoma compressing optic chiasm and compare outcomes with 48 hours postoperative data. METHODS: Sixteen eyes of eight patients (4 males, 4 females, mean age 52 ± 11 years) were enrolled in this prospective study. The primary outcome was to evaluate the changes over time before and after surgery, analyzing the Best Corrected Visual Acuity (BCVA), Ganglion Cell Complex (GCC), Retinal Nerve Fiber Layer (RNFL) thicknesses, the retinal vessel density (VD) of Superficial Capillary Plexus (SCP), Deep Capillary Plexus (DCP), Radial Peripapillary Capillary (RPC) and the Foveal Avascular Zone (FAZ). The secondary outcome was to identify potential biomarkers that could predict visual acuity changes after 1-year follow-up. RESULTS: When comparing SD-OCT and OCTA measurements obtained after 1 year with those observed 48 hours after surgery, GCC and RNFL were significantly improved. After a significant reduction at 48 hours, GCC thickness showed a significant increase at 1 year after surgery (p = 0.007), while a significant restoration of RNFL thickness was found at 1 year (p = 0.005), as well as the VD of SCP, DCP, and RPC values. FAZ area did not change over time. BCVA significantly improved at each time after surgery (p = 0.037, p = 0.013). A statistically significant correlation was found between the preoperative BCVA, VD of SCP, DCP, RPC, and the postoperative BCVA at 1 year (p = 0.017, p = 0.029, p = 0.031, p = 0.023). CONCLUSION: SD-OCT and OCTA provide helpful information to identify the retinal structural and vascular improvements 1 year after surgery. OCTA parameters could serve as potential predictive markers for visual acuity recovery at long-term follow-up.

1,2,3-Triazole Bridge as Conformational Constrain in ß-Hairpin Peptides: Analysis of Hydrogen-Bonded Positions.

Conformational constrained ß-hairpin peptides are useful tool to modulate protein-protein interactions. A triazole bridge in hydrogen-bonded positions between two antiparallel strands induces a conformational stabilization of the ß-hairpin peptide. The entity of the stability of the ß-hairpin peptide depends on the length of the bridge.

Algorithm for the management of femoral shaft fractures in children.

PURPOSE: Pediatric closed femoral shaft fractures are commonly related to a good prognosis. There is no consensus on treatment. We aimed to evaluate the treatment, features, radiological findings and management strategies, creating an algorithm of treatment. MATERIALS AND METHODS: Fifty-two simple femoral shaft fractures in children were retrospectively evaluated for age and gender distribution, side of the fracture, etiology of injuries, limb length discrepancy, range of knee and hip motion and parents satisfaction with a mean clinical and radiographic follow-up of 3 years and 6 months. Twenty-eight patients were treated with reduction and early hip spica cast while 24 patients were treated with external fixation (EF). RESULTS: Nearly 58 % of the cases were caused by traffic accidents and were predominantly male (61.5 %). Most of the fractures were of the middle femoral shaft (57.6 %). Muscle strength was normal (MRC scale) in all patients with no pain (NIPS and PRS scale). Knee and Hip range of motion were similar in both types of treatment. Patients treated with EF had shorter limb length discrepancy compared with SC. There were no reports of re-fracture. We found a higher familiar satisfaction in patients treated with EF. CONCLUSIONS: An algorithm for the management of femoral shaft fractures in the pediatric population is proposed. Results on the study population gave raise to a satisfactory clinical and radiological results.

American visceral leishmaniasis: disease control strategies in Dracena microregion in Alta Paulista, SP, Brazil

Despite measures adopted to control American visceral leishmaniasis (AVL), the disease is spreading in a fast and worrying way throughout western São Paulo state. The aim of this work was to study the variables involved in the disease cycle as well as the effectiveness of controlling measures. The study was carried out in the microregion of Dracena, which is composed of twelve cities and belongs to Alta Paulista, a region of western São Paulo. The necessary data were provided by the Superintendence for Endemic Disease Control and Adolfo Lutz Institute, Regional Laboratory of Presidente Prudente. From August 2005 to January 2008, the following factors were observed: detection of phlebotomine sandflies in the cities and periods in which dogs or humans were diagnosed; number of human deaths; prevalence of suspected dogs tested by serology; percentage of euthanasia in suspected dogs; a possible correlation between positive dogs and cases of the disease in humans; and the disease prevalence among municipalities from the studied region. It was verified that, despite the strategies adopted in Dracena microregion to control AVL, the disease continues to rise. Thus, some procedures of the AVL Monitoring and Control Program should be reviewed, to grant the initiative more credibility and effectiveness.

Treatment of sleep-disordered breathing in children with myelomeningocele.

The prevalence of moderate to severe sleep-disordered breathing (SDB) in patients with myelomeningocele may be as high as 20%, but little information is available regarding treatment of these patients. To assess the efficacy and complications of treatments for these children, we collected data on 73 patients from seven pediatric sleep laboratories. Obstructive sleep apnea (OSA, n = 30) and central apnea (n = 25) occurred more frequently than central hypoventilation (n = 12). We also describe a sleep-exacerbated restrictive lung disease type of SDB in 6 patients who had hypoxemia during sleep without apnea or central hypoventilation. For each type of SDB, effective treatments were identified in a stepwise process, moving towards more complex and invasive therapies. For OSA, adenotonsillectomy was often ineffective (10/14), whereas nasal continuous positive airway pressure (CPAP) was usually successful (18/21). For central apnea, methylxanthines and/or supplemental oxygen proved sufficient in 2 of 9 and 3 of 6, respectively, but noninvasive positive pressure ventilation was required in 7 children. For central hypoventilation, supplemental oxygen (alone or with methylxanthines), noninvasive positive pressure ventilation, and tracheostomy with positive pressure ventilation were effective in 3, 2, and 2 patients, respectively. Sleep-exacerbated restrictive lung disease always required supplemental oxygen treatment, but in 2 cases also required noninvasive positive pressure ventilation; nutritional and orthopedic procedures also were helpful. Posterior fossa decompression was used for the first three types of SDB, but data were insufficient to delineate specific recommendations for or against its use. In summary, evaluation by an experienced, multidisciplinary team can establish an effective treatment regime for a child with myelomeningocele and SDB.

Do radiographic parameters correlate with clinical outcomes in adolescent idiopathic scoliosis?

STUDY DESIGN: A radiographic assessment has been developed to include coronal, sagittal, and axial parameters. OBJECTIVE: To determine the correlation of postoperative radiographic results and percentage postoperative radiographic improvement with patient clinical self-assessment. SUMMARY OF BACKGROUND DATA: With the increasing interest in outcome studies, the authors wanted to determine whether Scoliosis Research Society clinical questionnaire results would correlate with objective radiographic improvement. INCLUSION CRITERIA: adolescent idiopathic scoliosis treated with anterior or posterior instrumentation, a solid fusion, minimum 2-year follow-up, and a completed postoperative Scoliosis Research Society questionnaire. Seventy-eight patients met the criteria. Measurements included in the radiographic score: Cobb angles of the coronal curve, C7 to the center sacral vertical line, apical translation, apical vertebral rotation, T1 rib angle, end-instrumented vertebrae angulation, angulation of the disc below the end-instrumented vertebra, and curve type. Sagittal measurements included T2-T12, T5-T12, T2-T5, T12-L2, and L1-S1. RESULTS: The preoperative radiographic score of these 78 patients was mean 60.1 +/- 9.7 (range 41-88, maximum radiographic score, 100). The 2-year postoperative radiographic score was mean 83.8 +/- 8.8 (range, 65-100). The median Scoliosis Research Society questionnaire score was 98 +/- 12.3 (range, 58-116, maximum score, 125, showing that the patient is highly satisfied and asymptomatic). The postoperative radiographic score versus the questionnaire score showed a Spearman rank correlation of 0.04 (P = 0.68, little or no correlation throughout). Percentage improvement of the radiographic score versus the questionnaire score showed a Spearman rank correlation of 0.1 (P = 0.38, little or no correlation throughout). CONCLUSION: In this initial group of patients, the radiographic assessment shows a significant improvement between preoperative and 2-year postoperative scores. However, little correlation between the radiographic assessment and the questionnaire scores was found in this adolescent population, suggesting that separate analyses of radiographic and clinical outcome data are required when evaluating results of postoperative scoliosis surgery.

The effect of continued posterior spinal growth on sagittal contour in patients treated by anterior instrumentation for idiopathic scoliosis.

STUDY DESIGN: Retrospective analysis of radiographs on a prospective cohort of patients undergoing anterior instrumentation for thoracic idiopathic scoliosis. OBJECTIVES: To analyze the change in sagittal profile after growth. SUMMARY OF BACKGROUND DATA: The authors previously reported some advantages of anterior instrumentation for treatment of thoracic idiopathic scoliosis. However, postsurgery hyperkyphosis has resulted in some patients, especially those who were skeletally immature at the time of surgery. METHODS: Inclusion criteria required that participants have thoracic idiopathic scoliosis treated with anterior instrumentation and a confirmed solid fusion, no rod breakage, and a minimum follow-up period of 2 years. The 47 patients meeting the criteria were divided into a study group of 10 patients who were Risser 0 at the time of surgery and a control group of 37 patients who were Risser 1 to 5. Progressive sagittal kyphosis was defined as an increase of 10 degrees or more (T5-T12) after surgery. RESULTS: Sagittal progression greater than 10 degrees (average, 15 degrees ) occurred in 6 of 10 patients (60%) in the study group (Risser 0). Five patients progressed from 10 degrees to 19 degrees, and one patient from 20 degrees to 30 degrees. In contrast, sagittal progression occurred in only 10 of 37 patients (27%) in the control group (Risser 1 to 5). CONCLUSIONS: Some patients with thoracic adolescent idiopathic scoliosis treated with anterior instrumentation may be at risk for progressive sagittal kyphosis secondary to growth. Skeletal immaturity (Risser 0) appears to be a risk factor. In these immature patients, preserving the sagittal profile with intervertebral spacers, rigid rods, and bone graft (allowing for an average 15 degrees increase of kyphosis with growth) may be appropriate.

Neutrophil F-actin and myosin but not microtubules functionally regulate transepithelial migration induced by interleukin 8 across a cultured intestinal epithelial monolayer.

The role of the polymorphonuclear leukocyte (PMN) cytoskeleton during the transmigration across colonic epithelial cells is not very well understood. In order to study the role of different components of the PMN cytoskeleton during transepithelial migration across a colonic epithelial cell monolayer (T84), PMN were preincubated with drugs affecting either the actin cytoskeleton (cytochalasin B, iota toxin of Clostridium perfringens, and phalloidin) or the microtubules (colchicine and taxol). The role of PMN myosin during transepithelial migration was investigated using the inhibitor 2,3-butanedione monoxime (BDM) and DC3B toxin. PMN intracellular Ca2+, during neutrophil adhesion and translocation across the epithelium, was assessed by the Ca2+ chelator 1, 2bis-(2-aminophenoxy)-ethane-N,N,N', N'-tetra-acetic acid tetrakis (acetoxymethyl) ester (BAPTA-AM). Transmigration of PMN was initiated by applying either interleukin-8 or formyl-met-leu-phe (fMLP). While colchicine and taxol preexposure did not influence PMN transepithelial migration, treatment with cytochalasin B, iota toxin, phalloidin, BDM, DC3B toxin and BAPTA-AM greatly diminished migration of PMN across T84 monolayers. Similarly, cell-cell contacts established between PMN and epithelial cells during the transmigration were diminished after treatment of PMN with iota toxin or cytochalasin B. These data show that the neutrophil actin cytokeleton and myosin, but not the microtubules, evoke a Ca2+ -dependent motility that facilitates migration across the colonic epithelial barrier.

CD10 inhibitors increase f-Met-Leu-Phe-induced neutrophil transmigration.

A variety of bacterial enterocolitis in their active stages are characterized by the migration of polymorphonuclear leukocytes (PMNs) across epithelial surfaces. These mechanisms could explain some effects of enterotoxins observed in the intestinal mucosae. Here, using specific inhibitors, we investigated the potential role of CD10 (E.C. 3.4.24.11), present at the surface of human neutrophils, on formyl-Met-Leu-Phe (fMLP)-induced PMN migration across cultured monolayers of the human intestinal cell line T84. Transmigration of human neutrophils across T84 epithelial cells was observed for concentrations of fMLP as low as 10(-9) M, whereas maximal effect was achieved at 10(-7) M as determined by transepithelial resistances and PMN myeloperoxidase assays. RB25, a CD10 inhibitor, reduced by two orders of magnitude the concentration of fMLP required to obtain full neutrophil transmigration across T84 epithelial cell line. RB25 response was concentration dependent with half-maximal and maximal effect occurring at 10(-9) and 10(-7) M, respectively. These concentrations of RB25 corresponded exactly to the half-maximal and maximal inhibition of endopeptidase 24.11 at the neutrophil cell surface. However, the effect of CD10 inhibitors on PMN transmigration cannot be accounted for by a direct action on T84 epithelial cells, since these cells fail to express any detectable endopeptidase 24.11 activity. Moreover, blocking of CD10 enzymatic activity by various and selective inhibitors potentiated the effect of low concentrations of fMLP on PMN transmigration. Finally, RB25 failed to affect interleukin-8 (IL-8)-induced PMN transmigration across T84 epithelial cells, in agreement with the preference of CD10 for small peptidic substrates. Taken together, these results demonstrate that inhibition of CD10 significantly reduced the concentration of fMLP needed for eliciting transmigration of PMN across intestinal epithelia.

Unmasking of intestinal epithelial lateral membrane beta1 integrin consequent to transepithelial neutrophil migration in vitro facilitates inv-mediated invasion by Yersinia pseudotuberculosis.

Idiopathic intestinal disease states characterized by active inflammation associated with transepithelial migration of neutrophils may, paradoxically, be associated with an increased risk of infection by enteric pathogens. Although the specific ligands with which various intestinal pathogens associate remain largely unknown, it is thought that many reside on the basolateral membrane. For example, beta1 integrin, a basolateral membrane protein, mediates the specific interaction between epithelial cells and the inv gene product (invasin) on the surface of Yersinia pseudotuberculosis. Our observations indicate that neutrophil migration across model T84 cell intestinal epithelia produced transient separation of epithelial cells at sites of neutrophil migration, resulting in microdiscontinuities that remained unsealed for several hours. We hypothesized that such sites of microdiscontinuities would yield a potential route for luminal pathogens to gain access to basolateral ligands and, thus, provide a window of risk for enteric infection. The surface biotinylation and fluorescence localization studies reported here revealed that, as in natural intestinal epithelia, beta1 integrin was strictly polarized to the basolateral membrane in confluent T84 monolayers. However, the transient microdiscontinuities resulting from neutrophil migration permitted access to beta1 integrin from the apical reservoir. Coincident with such basolateral exposure of beta1 integrin, monolayers became susceptible to invasion by Y. pseudotuberculosis. Fluorescence localization indicated that Y. pseudotuberculosis selectively associated with monolayers at sites where small discontinuities resulting from neutrophil transmigration were found. An increased risk for Y. pseudotuberculosis infection was specifically related to exposure of beta1 integrin (normally concealed by tight junctions) to the apical compartment, as Y. pseudotuberculosis cells lacking the inv gene were unable to invade following neutrophil transepithelial migration. Following closure of the microdiscontinuities associated with neutrophil migration, a small pool of beta1 integrin remained apically localized, presumably due to incomplete repolarization. However, this small apical pool of beta1 integrin was insufficient to support a detectable increased risk of Yersinia infection. Together, these observations indicate that by transiently perturbing monolayer continuity, neutrophil transepithelial migration is associated with a window of risk in which luminal pathogens can access basolateral ligands such as beta1 integrin.

Na:K:2Cl cotransporter (NKCC) of intestinal epithelial cells. Surface expression in response to cAMP.

During intestinal chloride secretion, epithelial uptake of salts is accomplished largely by a bumetanide-sensitive Na:K:2Cl cotransporter designated here as NKCC. Using monoclonal antibodies directed against NKCC from the human crypt epithelial cell line, T84, we define its surface localization as a function of cotransporter activation. Immunoelectron microscopy, confocal localization, and selective surface biotinylation studies revealed that the 195-kDa NKCC protein is polarized to the basolateral domain. Following immunoprecipitation, several polypeptides coprecipitated with the 195-kDa cotransporter including two prominent proteins of molecular mass 160 and 130 kDa. Immunoblotting with three distinct anti-NKCC monoclonal antibodies in conjunction with deglycosylation experiments suggested that the 160- and 130-kDa bands represented novel proteins unrelated to the cotransporter. Stimulation of T84 monolayers with cAMP agonists, a condition which elicits chloride secretion and leads to microfilament-dependent NKCC activation, did not significantly increase the number of bumetanide-binding sites and only marginally increased surface expression of the 195-kDa cotransporter available for surface biotinylation. In contrast, cAMP agonist stimulation increased the surface expression of the coprecipitating 160- and 130-kDa proteins approximately 6-fold. The increase in surface 160- and 130-kDa proteins was attenuated by phalloidin preloading the cells, a condition which also prevents activation of NKCC without influencing the activity of other membrane transporters participating in chloride secretion. These studies define the polarized distribution of the NKCC protein on intestinal epithelia, indicate that NKCC may be associated with two other previously unidentified membrane proteins and such association is influenced by the F-actin cytoskeleton.

[VLA and alpha6, beta4 integrins. Expression in normal and neoplastic human tissues]. / Les integrines VLA et alpha6beta4 expression sur les tissus humains normaux et neoplasiques.

Among the cellular adhesion molecules, the integrin family, more particularly the VLA (Very late antigen) integrins, is currently the subject of numerous investigations in pathology. These integrins are involved in cell-cell contact or cell-matrix adhesions. During neoplastic diseases, cellular expression of integrins changes and a study of the modifications could allow a new etiopathogenic approach carcinogenesis and metastatic phenomena. New prognostic factors may be defined in tumor pathology. We describe the general structure of integrins and the mechanisms of their binding with matricial ligands and with cytoskeleton. The expression of VLA integrins and the alpha6beta4 heterodimer on normal and neoplastic human tissues is then described. Finally, we describe the involvement of these proteins in tumor progression and tissue invasion.

Non-typhoid Salmonella subdural empyema in a patient with AIDS.

In AIDS patients, non-typhoid salmonella metastatic abscesses in lung and brain due to bacteremia have been described previously. Here we present a case in which a group B Salmonella, serotype Copenhagen, caused right parietal subdural empyema. The etiologic diagnosis was based on culture of pus obtained from the lesion. The patient was treated for bacterial meningitis and made a good recovery. He is at present reasonably well and is taking ciprofloxacin as prophylaxis against salmonella relapse.

Interferon-gamma induces a cell surface phenotype switch on T84 intestinal epithelial cells.

Intestinal epithelia are in intimate contact with submucosal and intraepithelial lymphocytes. The concentration of intraepithelial lymphocytes increases during inflammatory processes, and, when stimulated, these cells generate cytokines such as interferon-gamma (IFN-gamma). In this study, we examined the effect of recombinant human IFN-gamma on ion transport events in T84 cells, a crypt epithelial cell line widely used to study electrogenic Cl- secretion, the transport event responsible for mucosal hydration. Epithelial exposure to IFN-gamma brought about a marked attenuation in stimulated Cl- secretion, as measured by generation of short-circuit current (ISC). This IFN-gamma-elicited decrease in the Cl- secretory response was present for a variety of specific agonists, appeared largely due to IFN-gamma interactions with the basolateral surface, and did not result from a defect in second messenger generation. Efflux and uptake studies were utilized to functionally define the individual cell surface transport proteins that participate in Cl- secretion and revealed that, in response to epithelial exposure to IFN-gamma, apical Cl- channels and basolateral Na(+)-K(+)-2Cl- cotransporters, K+ channels, and Na-K-adenosinetriphosphatase were all functionally downregulated. [3H]bumetanide binding assays suggested that surface expression of the cotransporter was diminished by > 70% after IFN-gamma preexposure. Concurrently, surface immunofluorescence studies revealed that epithelial exposure to IFN-gamma brought about the induction of major histocompatibility complex (MHC) class II molecule expression on T84 epithelial monolayers and markedly increased MHC class I surface expression. Finally, neutrophil-epithelial adhesion studies revealed that preexposure of epithelial monolayers to IFN-gamma elicited a beta 2-integrin-dependent induction of neutrophil adhesion.(ABSTRACT TRUNCATED AT 250 WORDS)

Identification of coelomocyte unconventional myosin and its association with in vivo particle/vesicle motility.

Sea urchin coelomocytes undergo an inducible structural transformation from petalloid to filopodial form during the 'clotting' response in sea urchins. Using a petalloid coelomocyte model, stimulated coelomocytes exhibited bidirectional particle/vesicle motility with a broad distribution of velocities, ranging from 0.02 to 0.12 microns s-1 in the outward bound direction. Coelomocytes treated with the microtubule-disrupting drug, nocodazole, continued to exhibit outward particle/vesicle movements along linear paths with an average velocity of 0.028 +/- 0.006 microns s-1. We partially purified a 110 kDa polypeptide possessing K+EDTA-, Ca2(+)-, Mg2(+)- and F-actin-activated Mg(2+)-ATPase activities characteristic of myosin-like motor proteins. The 110 kDa protein immuno-crossreacted with both affinity-purified, anti-brush border unconventional myosin-I polyclonal antibodies and anti-Acanthamoeba myosin head monoclonal antibodies. By indirect immunofluorescence, the 110 kDa unconventional myosin was localized to clusters of particles/vesicles within the perinuclear region of unstimulated coelomocytes, an area containing numerous mitochondria, acidic, lysosomal and Golgi organelles. Indirect immunofluorescence of partially transformed and filopodial coelomocytes detected a diminution of perinuclear staining with a concomitant appearance of stained linear arrays of particles/vesicles, enhanced staining of peripheral lamellae, and staining of the entire length of the filopodia. Subfractionation of unstimulated coelomocyte homogenates on linear sucrose gradients identified distinct peaks of ATPase activity associated with fractions containing conventional and 110 kDa unconventional myosin. Unconventional myosin-containing fractions were found to have numerous particles that stained with anti-brush border unconventional myosin-I antibodies and the lipophilic dye, DiOC6. Thus, coelomocytes demonstrate activatable movements of particles/vesicles in cells devoid of microtubules and possess an unconventional myosin, which may be the motor protein driving particle/vesicle translocation.

Could migraine be a "protective factor" against tumors?

Patients with migraine headaches show significantly lower prevalence of malignant neoplasms when compared with the general control group or the age-matched control group. Conversely, no significant difference concerning the family history for neoplasms has been found between the two groups. Nevertheless, headache and cancer in a family member in migraneous are not coexistent. Although more extensive, epidemiological studies are necessary to confirm our data, it is suggested that some particular biochemical or psychologic aspects involved in the pathogenesis of migraine might represent the presence of a protective factor against neoplasm development.

Quantitative and qualitative modifications of lymphocyte subsets after sublingual administration of isosorbide dinitrate in migraineurs. Preliminary report.

In 22 migraine patients and 5 healthy controls an investigation has been performed on lymphocyte subsets in basal conditions and 90 minutes after sublingual isosorbide dinitrate (IDN) administration. In all patients the drug assumption induced a typical migraine attack with increase in all examined lymphocyte subsets with except of NK cells. A statistically significant increase (p < 0.05) in T lymphocyte subsets we found during the crisis, whereas in healthy controls neither a migraine attack nor any modification in lymphocyte subsets could be observed. These results seem to confirm the immune alteration we have previously found in migraineous patients and suggest the possible role of IDN-stimulated endothelium not only in vasodilatation but also in production of substances responsible of the observed immune modifications.

Isolation and localization of a spectrin-like protein from echinoderm sperm.

Thyone sperm undergo an explosive acrosome reaction resulting in the extension of a 90 microns long acrosomal process. In unreacted sperm, profilamentous actin is sequestered within the profilactin cup (Tilney: Journal of Cell Biology 69:73-89 1976), which consists of four major polypeptides: actin, profilin, and a 250/235 kDa equimolar doublet (TS 250/235). Dialysis of profilactin preparations into an actin assembly buffer resulted in the formation of acrosomal-like macromolecular aggregates containing actin, TS 250/235, and several other polypeptides as detected by SDS-PAGE. TS 250/235 was purified by subjecting extracts of pH solubilized profilactin cups to DEAE and phosphocellulose ion exchange chromatography. TS 250/235 demonstrated immunocrossreactivity with affinity purified polyclonal antibodies raised against S. purpuratus egg spectrin. As determined by biotinylated-calmodulin overlays, both subunits of TS 250/235 bound calmodulin in a Ca(++)-sensitive manner. Electron microscopy of low angle, rotary shadowed replicas of TS 250/235 revealed an elongate rod-shaped molecule with an average contour length of 203 nm. By indirect immunofluorescence, TS 250/235 was found to be uniformly distributed throughout the profilactin cup of the unreacted sperm. This distribution of TS 250/235 correlated with the location of monomeric actin as determined by localization studies utilizing fluorescent-DNase-1. Upon sperm activation, the cellular distribution of TS 250/235 dramatically changed and was observed both along the length and at the base of the extended acrosomal process.