STU1, a suppressor of a beta-tubulin mutation, encodes a novel and essential component of the yeast mitotic spindle

We have isolated a cold-sensitive allele of TUB2, the sole gene encoding beta-tubulin in S. cerevisiae, that confers a specific defect in spindle microtubule function. At 14 degrees C, tub2-406 cells lack a normal bipolar spindle but do assemble functional cytoplasmic microtubules. In an attempt to identify proteins that are important for spindle assembly, we screened for suppressors of the cold-sensitivity of tub2-406 and obtained four alleles of a novel gene, STU1. Genetic interactions between stu1 alleles and alleles of TUB1 and TUB2 suggest that Stu1p specifically interacts with microtubules. STU1 is essential for growth and disruption of STU1 causes defects in spindle assembly that are similar to those produced by the tub2-406 mutation. The nucleotide sequence of the STU1 gene predicts a protein product of 174 kD with no significant similarity to known proteins. An epitope-tagged Stulp colocalizes with microtubules in the mitotic spindle of yeast. These results demonstrate that Stulp is an essential component of the yeast mitotic spindle.     

Sex-Related Differences in Urethra Development in Human Embryos

Virtually no information on the chronology of prenatal development of the human urinary tract and the sex-related differences in the emergence of urinary tract topography during embryonic development is presently available. The aim of our work was to study sex-related differences in urethra development in human embryos and early fetuses. Forty-nine preparations of human embryos and early fetuses without external signs of anatomical abnormalities were studied in order to achieve the aim and fulfill the objectives of the study. Embryos and early fetuses were divided into six groups according to gestational age and parietococcygeal length. The complex of adequate methods of morphological research used in the study included preparation and microscopy of serial histological and anatomical sections of human embryos, including female and male urinary tracts, preparation of 3D-reconstruction models, and morphometry. The formation of prostatic urethra, a derivative of the urogenital sinus, was shown to occur at the beginning of the ninth week of embryogenesis, and the primordium of the internal sphincter of the urinary tract was formed at the end of the tenth week. Formation of the terminal part of spongy urethra took place during weeks 10–11 and involved funnel-like protrusion of the ectoderm from the top of the balanus towards the urethra lumen. The secondary ventral displacement of the urethral opening does not occur in female fetuses, and, therefore, only the prostatic urethra is a homolog of the female urinary tract. The pelvic part of the urogenital sinus was transformed into the prostatic urethra and the membranous urethra of the male at the end of the first stage of fetal development. Elongation of the genital tubercle (a penis primordium) and formation of the urethral ridge walls that involved the urogenital folds occurred at the same time.     

Ascending auditory interneurons in the cricketTeleogryllus commodus (Walker): comparative physiology and direct connections with afferents

Summary Ascending auditory interneurons of the cricket,Teleogryllus commodus (Walker), were investigated using simultaneous intracellular and extracellular recording in order to identify units which had previously been characterized only by extracellular recording. The morphology and physiology of the large adapting unit (LAU: Fig. 1) and of the small tonic unit (STU: Fig. 2) ofTeleogryllus correspond well to those of the ascending neuron 2 (AN2) and the ascending neuron 1 (AN1) ofGryllus (Figs. 1, 2), respectively.A summary of the ascending auditory interneurons described by various authors in 5 species of crickets is presented in order to establish common identities.Physiological evidence for direct connections between auditory afferents and the ascending auditory interneurons AN1 (STU) and AN2 (LAU) is presented. Simultaneous intracellular recordings from receptors and interneurons in response to sound as well as the activity of auditory interneurons upon electrical stimulation of the tympanal nerve reveal short and constant latencies of receptor-evoked synaptic activity in AN1 (STU) and AN2 (LAU).Abbreviations STU small tonic unit - LAU large adapting unit - AN ascending neuron - EPSP excitatory postsynaptic potential     

T-incision technique in distal hypospadias: a modification of meatal advancement and glanuloplasty

Hypospadias is among the most common of the congenital anomalies. Distal hypospadias refers to an orifice in the distal third of the penile shaft. Correction of distal hypospadias requires different techniques, depending on the location of the meatus. Simple advancement techniques can be used for most distal hypospadias, whereas hypospadias with chordee requires reconstruction of a urethra. The meatoplasty and glanuloplasty procedures developed by Duckett have become standard operations to correct these lesions. Complications such as meatal stenosis, meatal retraction, and fish mouth-like meatus can be seen after meatal advancement and glanuloplasty ("MAGPI"), though it usually yields good results. In an attempt to avoid the complications associated with the meatal advancement and glanuloplasty procedure, the authors added a modification to the procedure for those hypospadias cases located in the coronal sulcus or its distal part. As an addition to conventional meatal advancement and glanuloplasty, a transverse incision on top of the vertical incision was made so that the urethra was supported by lateral triangle flaps created on the glans. Lateral triangle flaps of the glans were sutured to the dorsal aspect of the urethra advanced from the previous position. Thus, stress on the urethra was lessened and meatal retraction was prevented. When closure was performed with a T incision, an M-shaped, zigzag incision line was placed instead of a circular incision line. Therefore, stenosis was prevented and a vertical meatus with good cosmetic appearance was obtained. Fifty-three boys aged 4 to 7 years were operated on with this technique and were followed for 2.4 years. Good functional and cosmetic results were achieved in most of the cases.     

Iloprost for the attenuation of ischaemia/reperfusion injury in a distant organ

The objective of this study was to investigate antioxidant and cytoprotective properties of iloprost in a distant organ after ischaemia reperfusion injury. Male Wistar rats were divided into two groups. After application of anesthaesia both hindlimbs were occluded. A 2-h reperfusion procedure was carried out after 60 min of ischemia. Study group (STU) rats (n=10) received 10 microg kg(-1) iloprost in 1 ml of saline from the tail vein 10 min before reperfusion. Control (CON) group rats (n=10) received an equal amount of saline. The rats were sacrificed by injection of a high dose of thiopentone sodium. Blood and tissue samples (right kidneys) were taken for analysis. Differences in malondialdehyde (MDA), myeloperoxidase (MPO), Na+-K+ ATPase and total antioxidant capacity (TAC) between the groups were analysed. MPO, MDA and TAC levels in the sera of CON and STU groups were 1.60+/-0.26 U l(-1), 11.42+/-5.23 nmol ml(-1), 8.30 x 10(-2)+/- 3.93 x 10(-2) nmol ml(-1) h(-1) and 1.07+/-0.11 U l(-1), 7.60+/-1.81 nmol ml(-1) and 0.15+/-3.23 x 10(-2) nmol ml(-1) h(-1) (p=0.0001, p=0.043 and p=0.0001 respectively). MPO, ATPase and MDA levels in kidneys for CON and STU groups were 1.24+/-0.58 U g(-1), 85.70+/-52.05 nmol mg(-1), 17.90+/-7.40 nmol ml(-1) and 0.78+/-0.31 U g(-1), 195.90+/-56.13 nmol mg(-1) and 10.10+/-0.99 nmol ml(-1) (p=0.046, p=0.0001 and p=0.009 respectively). When given prior to reperfusion, the positive effect of iloprost in the attenuation of distant organ reperfusion injury has been demonstrated.     

Modulation of Formalin-Evoked Hyperalgesia by Intrathecal N-Type Ca Channel and Protein Kinase C Inhibitor in the Rat

1. -CgTx attenuated formalin-evoked biphasic flinches, while PKC inhibitor (STU) attenuated phase 2 and was reversed by PDBu.2. -CgTx and STU suppressed the increase in CSF-glutamate after formalin injection.3. Morphine completely suppressed both increased flinching and CSF glutamate release.4. Thus, -CgTx (N-type Ca channels) may regulate neurotransmitter release evoked by C fiber activation and the formalin-evoked hyperalgesia may possibly be provoked as a result of PKC activation elicited by both presynaptic neurotransmitter release and activation of NMDA receptors in the spinal neurons.     

Bim1p/Yeb1p mediates the Kar9p-dependent cortical attachment of cytoplasmic microtubules

In Saccharomyces cerevisiae, positioning of the mitotic spindle depends on the interaction of cytoplasmic microtubules with the cell cortex. In this process, cortical Kar9p in the bud acts as a link between the actin and microtubule cytoskeletons. To identify Kar9p-interacting proteins, a two-hybrid screen was conducted with the use of full-length Kar9p as bait, and three genes were identified: BIM1, STU2, and KAR9 itself. STU2 encodes a component of the spindle pole body. Bim1p is the yeast homologue of the human microtubule-binding protein EB1, which is a binding partner to the adenomatous polyposis coli protein involved in colon cancer. Eighty-nine amino acids within the third quarter of Bim1p was sufficient to confer interaction with Kar9p. The two-hybrid interactions were confirmed with the use of coimmunoprecipitation experiments. Genetic analysis placed Bim1p in the Kar9p pathway for nuclear migration. Bim1p was not required for Kar9p's cortical or spindle pole body localization. However, deletion of BIM1 eliminated Kar9p localization along cytoplasmic microtubules. Furthermore, in the bim1 mutants, the cytoplasmic microtubules no longer intersected the cortical dot of Green Fluorescent Protein-Kar9p. These experiments demonstrate that the interaction of cytoplasmic microtubules with the Kar9p cortical attachment site requires the microtubule-binding protein Bim1p.     

Stu2p: A Microtubule-Binding Protein that Is an Essential Component of the Yeast Spindle Pole Body

Previously we isolated tub2-423, a cold-sensitive allele of the Saccharomyces cerevisiae gene encoding β-tubulin that confers a defect in mitotic spindle function. In an attempt to identify additional proteins that are important for spindle function, we screened for suppressors of the cold sensitivity of tub2-423 and obtained two alleles of a novel gene, STU2. STU2 is an essential gene and encodes a protein whose sequence is similar to proteins identified in a variety of organisms. Stu2p localizes primarily to the spindle pole body (SPB) and to a lesser extent along spindle microtubules. Localization to the SPB is not dependent on the presence of microtubules, indicating that Stu2p is an integral component of the SPB. Stu2p also binds microtubules in vitro. We have localized the microtubule-binding domain of Stu2p to a highly basic 100-amino acid region. This region contains two imperfect repeats; both repeats appear to contribute to microtubule binding to similar extents. These results suggest that Stu2p may play a role in the attachment, organization, and/or dynamics of microtubule ends at the SPB.     

Ultrasound and X-ray urethrography and urethroscopy during endoscopic operations on the urethra

In 41 patients are made x-ray ascending and descending and transrectal US (TRUS) of an urethrography and endoscopy before and after transurethral (TUR) of operations on a urethra. For 35 patients there were posttraumatic strictures and obliterations of a urethra, for 3--postinflammatory strictures, for 2--iatrogenic false courses of a urethra and for 1--congenital diverticulum of a urethra. The comparative estimation ultrasonic and x-ray urethrography and urethroscopy has shown, that they are not competitive, but complementary techniques. Thus TRUS of a urethra, as the technique irrelevant with radial load on the patient, can and should more widely be used born for primary diagnostic, and for monitoring outcomes TUR on a urethra.     

Mathematical model of the male urinary tract

The paper presents a simplified (but not trivial) mathematical model of the interaction between the urine flow and the male urethra and bladder, respectively. Urine is assumed to be a Newtonian fluid. The flow is considered to be non-stationary, isothermal and turbulent. The urethra and bladder wall, featuring elastic properties, experience large displacements and strains. The dynamic forces are included in the urethra wall motion. When fully extended the urethra attains the shape of an axisymetric tube. An iterative method based on the uncoupled approach is developed.     

Normal development of the male anterior urethra

A histological study was performed on serially sectioned human and mouse embryos to study the influences of programmed cell death (PCD) during morphogenesis for clarifying the existing controversies on the morphology and basic processes involved in the embryonic development of the male anterior urethra. The following new insights into the development of the anterior urethra could be established. The formation of the urethra starts with the early adhesion of the arms of the genital tubercle. In this way an epithelial plate is formed, located in the ventral midline, that is in continuity with the cloacal membrane. Male sex differentiation takes place following rupture of this cloacal membrane through programmed cell death. Fusion of the urogenital swellings with primary luminization gives rise to the penile urethra, whereas the glandular part of the urethra is formed through secondary luminization of the epithelial cord that is formed during fusion of the arms of the genital tubercle, i.e., the glans. In both fusion processes, apoptosis plays a key role. The consequence of fusion of the urogenital swellings is that their mesodermal cores unite on the ventral aspect of the penile urethra, where they differentiate into the integumental structures. The prepuce starts to develop as a fold of ectoderm with a mesodermal core after complete fusion of the entire urethra. Finally, the scrotum was found to develop through merging of the labioscrotal swellings and not by fusion.     

Alpha- and beta-adrenergic and muscarinic cholinergic binding sites in the bladder and urethra of the rabbit

The affinities of a number of alpha- and beta-adrenergic binding sites and muscarinic cholinergic binding sites in rabbit urethra and bladder have been determined, using specific radioligand receptor binding assays. There was a greater density of beta-binding sites than alpha-binding sites in the bladder, while, in the urethra, there was a greater density of alpha-binding sites than beta-binding sites. The number of alpha-binding sites was fourfold greater in the urethra, whereas there were fewer beta-binding sites in the urethra. There were fewer muscarinic binding sites in the urethra than in the bladder. The dissociation constant for [3H]dihydroalprenolol at the beta-binding site was 6.4 nM, for [3H]dihydroergocryptine at the alpha-binding site was 2.11 nM, and for 3H-labelled l-quinuclidinyl benzilate at the muscarinic binding site was 0.22 nM.     

A new method to correlate histology with biomechanical properties in urethral tissue. An in-vitro study using light microscopy and scanning acoustic microscopy

When surveying the classical biomechanical theory of flow and resistance, the passive elastic properties of the urethra seems to be important for the transport of urine though the urethra. The aim of this study was to show that scanning acoustic microscopy (SAM) is a suitable methodology for investigating elastic properties of the urethra, and that it can be used to correlate elastic properties to histological areas. One 40 kg female pig and one 2 kg male rabbit comprised the material. A SAM2000 was used at a working frequency of 1000 MHz. Sections of nominal 3 micrometer thickness fixed urethral tissue were prepared for SAM and stained for light microscopy. The histological layers of the urethra were evident in the SAM image, and showed highly variable values of elastic properties. The layers seen with SAM correlated well with those seen with light microscopy. In conclusion, we have provided the first images of the microelastic properties of the urethra and correlated them to histology.     

Carcinome urothélial de l’urètre: une nouvelle observation et revue de la littérature

Urothelial carcinoma of the male urethra is a rare tumour. We report a new case of urothelial carcinoma of the urethra in a 64-year old man who was examined due to a dysuria. Retrograde and voiding urethrocystography carried out had shown images of bulbopenile urethral stricture treated by urethroplasty. Histological examination of the urethrectomy part revealed a urothelial carcinoma of the urethra. The patient refused any additional treatment and survived 14 months after diagnosis.     

Muscular tubes of urethra engineered from adipose-derived stem cells and polyglycolic acid mesh in a bioreactor

We have explored the feasibility of using adipose-derived stem cells (ADSCs) and polyglycolic acid (PGA) for constructing muscular tubes of urethra in a bioreactor. With the induction of by 5-azacytidine, ADSCs were found to acquire a myoblast phenotype. Here we seeded ADSCs in a PGA mesh to construct the cell–PGA complex that was cultured statically for 1 week. Afterwards, the cell–PGA complex was subjected to extension stimulation in a bioreactor for 5 weeks. A muscular tube of urethra was formed after 6 weeks. Histological examination showed differentiated ADSCs and collagenous fibers had orientated well. This study demonstrates that tissue engineering of urethra tissues in vitro by using a bioreactor leads to tissue maturation and the differentiation of ADSCs. This novel technique could provide an effective approach for urethra tissue engineering.     

HIV-1 integrase interacts with yeast microtubule-associated proteins

The human immunodeficiency virus type 1 (HIV-1) integrase (IN) mediates the insertion of viral DNA into the human genome. In addition to IN, cellular and viral proteins are associated to proviral DNA in the so-called preintegration complex (PIC). We previously reported that the expression of HIV-1 IN in yeast leads to the emergence of a lethal phenotype. This effect may be linked to the IN activity on infected human cells where integration requires the cleavage of genomic DNA. To isolate and characterize potential cellular partners of HIV-1 IN, we used it as a bait in a two-hybrid system with a yeast genomic library. IN interacted with proteins belonging to the microtubule network, or involved in the protein synthesis apparatus. We focused our interest on one of the selected inserts, L2, which corresponds to the C-end half of the yeast STU2p, a microtubule-associated protein (MAP). STU2p is an essential component of the yeast spindle pole body (SPB), which is able to bind microtubules in vitro. After expressing and purifying L2 as a recombinant protein, we showed its binding to IN by ELISA immunodetection. L2 was also able to inhibit IN activity in vitro. In addition, the effect of L2 was tested using the "lethal yeast phenotype". The coexpression of IN and the L2 peptide abolished the lethal phenotype, thus showing important in vivo interactions between IN and L2. The identification of components of the microtubule network associated with IN suggest a role of this complex in the transport of HIV-1 IN present in the PIC to the nucleus, as already described for other human viruses.     

A method of obtaining material for the bacteriological diagnosis of urethral diseases

An installation is developed for sampling the contents of urethra (A. c. USSR 980726). The installation promotes acceleration of the correct diagnosis under the torpid and chronic inflammatory processes in the urethra. The above installation permits obtaining data on distribution of the microbic flora at a different depth of mucosa of the anterior area of the male urethra. In this case the mixing of samples taken for investigation from different sites is impossible.     

Differential perturbation of the interstitial cystitis-associated genes of bladder and urethra in rat model

Interstitial cystitis (IC) is a chronic bladder dysfunction characterized as urinary frequency, urgency, nocturia, and pelvic pain. The changes in urethra may wind up with the bladder changes in structure and functions, however, the functions of the urethra in IC remains elusive. The aim of this study was to understand the perturbed gene expression in urethra, compared with urinary bladder, associated with the defected urodynamics. Using female IC mimic rats, a comprehensive RNA-sequencing combined with a bioinformatics analysis was performed and revealed that IC-specific genes in bladder or urethra. Gene ontology analysis suggested that the cell adhesion or extracellular matrix regulation, intracellular signaling cascade, cardiac muscle tissue development, and second messenger-mediated signaling might be the most enriched cellular processes in IC context. Further study of the effects of these bladder- or urethra-specific genes may suggest underlying mechanism of lower urinary tract function and novel therapeutic strategies against IC.