Conservative and surgical semen retrieval in patients with spinal cord injury

Assisted semen retrieval was applied in 219 men with spinal cord injury (212 supranuclear, seven infranuclear lesions). Vibrostimulation in supranuclear lesions was successful in 133, and in five more after physostigmine injection. Electroejaculation was successful in all seven infranuclear lesions and in four supranuclear patients failing with vibrostimulation. Eight more supranuclear patients responded to electroejaculation and physostigmine. Surgical retrieval was applied in 27 patients. Nine Wagenknecht spermatoceles showed only one success, from all 18 implanted Brindley reservoirs semen could be collected. Three patients, in whom no pregnancy could be induced after Brindley reservoir implantation, had testicular sperm aspirated. In 109 patients who wanted to have offspring, 73 pregnancies could be induced in 46 couples, leading to 54 births (four twins), 16 abortions and three pregnancies. Conservative semen retrieval was possible in 82 of these men (63 pregnancies in 37 couples) and surgical methods were used in 27 (10 pregnancies in nine couples).

Bladder autoaugmentation in adult patients with neurogenic voiding dysfunction

Bladder autoaugmentation offers an alternative to enterocystoplasties for patients with low capacity high pressure bladders caused by non-malignant pathology. In particular for patients with neuropathic hyperreflexive bladders, refractory to less invasive therapy, bladder autoaugmentation will attain comparable results with less impact on life quality compared to other bladder augmentation procedures. The procedure does not preclude later enterocystoplasty or deafferentations. Over the last 7 years, 50 patients were treated by this method, some of them for other than neurogenic voiding dysfunction. Substantial increase of bladder capacity and compliance resulted, at the cost of increased residual urine and the need for intermittent catheterisation in most patients. Some patients are able to perform complete voiding at will. The time lapse between surgery and functional rehabilitation of the bladder (substantial increase of capacity and detrusor compliance) cannot be predicted yet. In most patients this amelioration was observed 1-6 months after surgery, but in some the effect was equivocal for a year or longer. Low-dose anticholinergics appear to speed up the therapeutic effect. One patient had enterocystoplasty and one deafferentation later, one had rupture of the bladder, probably from the use of an artificial sphincter, and two are rated as failures because of psychogenic bladder-centred problems. Bladder autoaugmentation is a favourable treatment for patients who are motivated to wait possibly longer for functional changes to occur and are willing to perform intermittent catheterisation afterwards.

Ribosomes and ribosomal RNA as chaperones for folding of proteins

BACKGROUND

Provocative recent reports indicate that the large subunits of either prokaryotic or eukaryotic ribosomes have the capacity to promote refolding of denatured enzymes.

RESULTS

Salt-washed Escherichia coli ribosomes are shown to promote refolding of denatured rhodanese. The ability of the ribosomes to carry out renaturation is a property of the 50S ribosomal subunit, specifically the 23S rRNA. Refolding and release of enzymatically active rhodanese leaves the ribosomes in an inactive state or conformation for subsequent rounds refolding. Inactive ribosomes can be activated by elongation factor G (EF-G) plus GTP or by cleavage of their 23S rRNA by alpha-sarcin. Activation by either mechanism is strongly inhibited by the EF-G.GDP.fusidic acid complex.

CONCLUSIONS

Large subunits of E. coli ribosomes, specifically 23S rRNA, have the capacity to mediate refolding of denatured rhodanese. Refolding activity is related to the state or conformation of ribosomes that is promoted by EF-G. Activation by either mechanism is strongly inhibited by the EF-G.GDP.fusidic acid complex.

Binding of an N-terminal rhodanese peptide to DnaJ and to ribosomes

A peptide corresponding to the N-terminal 17 amino acids of bovine rhodanese was fluorescently labeled with a coumarin derivative at its primary amino group(s) and then purified by high performance liquid chromatography. This peptide interacted with the molecular chaperone DnaJ in the absence of other chaperones and ATP. In the presence of ATP, the molecular chaperone DnaK bound to the DnaJ-peptide complex, but not to the peptide alone. The chaperone GrpE appeared to cause the release of the peptide bound to the ternary complex in the presence of ATP but not in the presence of ADP. This nucleotide apparently stabilized the complex. The peptide also bound to salt-washed Escherichia coli 70 S ribosomes, specifically to 50 S ribosomal subunits, not to 30 S subunits. DnaJ plus DnaK interacted with the peptide on the ribosome. GrpE caused dissociation of the peptide from the ribosome; ATP was required for this reaction. It was inhibited by ADP. A comparable series of chaperone-mediated reactions is assumed to occur with the N-terminal segment of the nascent polypeptide to facilitate its folding on ribosomes.

Stable expression in HEK-293 cells of the rat alpha3/beta4 subtype of neuronal nicotinic acetylcholine receptor

The alpha3/beta4 subtype of neuronal nicotinic acetylcholine receptor (nAChR) was stably expressed in human embryonic kidney (HEK) 293 cells that co-expressed a voltage-gated Ca2+ channel. alpha3/beta4-nAChR-expressing clones were identified using the fura-2 Ca2+ imaging technique, and were further characterised by single-cell and whole-cell patch-clamp studies. Acetylcholine (ACh) induced fast activating currents which showed desensitisation and inward rectification. The conductance of the ACh-activated channel was 29 pS. The order of potency of the nicotinic agonists tested was cytisine approximately = nicotine > acetylcholine. The EC50 value for ACh was 145 microM; the Hill coefficient was close to 2. The currents elicited by ACh were effectively blocked by nicotinic antagonists, but not by the muscarinic antagonist atropine. These properties are comparable to the pharmacological and physiological profile of ganglionic nicotinic receptors and type III currents of cultured hippocampal neurons.

Are T cells from healthy heart really only passengers? Characterization of cardiac tissue T cells

Numerous studies have dealt with occurrence of dendritic cells in various nonlymphoid organs such as kidney, liver or heart, whereas lymphocyte patterns in these organs have not been analyzed in detail. In the present study, leukocytes were quantified as cells/mm2 in the perivascular, interstitial and parenchymal tissue sections of normal heart. We measured an overall mean leukocyte count in normal heart tissue of 17.0 +/- 2.7 CD45+ leukocytes/mm2, 9.1 +/- 1.8 thereof being CD4+ T-helper cells (Th). By comparison, CD8+ T-cytotoxic/suppressor cells (Ts) and CD14+ macrophages each accounted for only approximately 2.5 cells/mm2, and CD20+ B cells for only 1.3 cells/mm2. These T cells were further characterized as either CD45RA+ naive T cells or as CD45RO+ memory T cells. Segmentation of the tissue as defined in Section 2 yielded an ascending number of CD45RO+ memory T cells from perivascular (0.4 +/- 0.2 cells/mm2) through parenchymal (12.8 +/- 3.0 cells/mm2) to interstitial (21.0 +/- 5.3/mm2). By contrast, the number of CD45RA+ and Leu-8+ cells decreased from perivascular to parenchymal. Peripheral T cells showed a reverse pattern of CD45RA/CD45RO antigen expression. Only approximately 3% of T cells expressed activation markers IL-2R and IL7R. Our data demonstrate that the majority of T cells in normal heart tissue are resting memory tissue T cells and are not contaminating T cells from the peripheral blood. The increase in CD45RO+ cells from perivascular to parenchymal with a corresponding decrease in CD45RO+ and Leu-8+ heart-tissue T cells argues in favor of T-cell traffic in normal heart tissue.

Effect of multimerization of human and recombinant von Willebrand factor on platelet aggregation, binding to collagen and binding of coagulation factor VIII

The smallest circulating von Willebrand factor (vWF) molecule is a dimer composed of two identical subunits containing binding sites for heparin, collagen, platelet glycoproteins and coagulation factor VIII (FVIII). Interdimeric disulfide linking leads to multimers composed of up to 40 dimers. vWF serves as a carrier of FVIII and is required for normal interactions of platelets with the subendothelium of the injured vessel wall. Von Willebrand factor was purified from human plasma cryoprecipitate and fermentation supernatant of recombinant CHO cells by anion exchange chromatography. Heparin affinity chromatography was used to isolate vWF polymers of different degree of multimerization. Analysis of collagen binding and platelet aggregation revealed that these activities increase with increasing degree of multimerization of vWF. Binding of FVIII to vWF was studied by real-time biospecific interaction analysis and surface plasmon technology. The binding data showed that the binding of FVIII is independent of vWF multimerization. Using recombinant FVIII and recombinant vWF, real-time biospecific interaction analysis resulted in a potential stoichiometry of 2 to 2.5 vWF-subunits per bound FVIII molecule. The kinetic analysis of the vWF-FVIII interaction resulted in a binding rate constant of about 3 x 10(6) M-1 s-1 and an equilibrium dissociation constant of about 0.4 x 10(-9) M.

An unusual presentation of Zenker's diverticulum

Zenker's diverticula are esophageal outpouchings in the region of the cricopharyngeus which typically grow in a posterolateral and inferior direction and can cause esophageal compression if the diverticulum is large enough. We describe a patient in whom a Zenker's diverticulum expanded posteriorly and superiorly so that it was positioned in the posterior pharyngeal space, causing both esophageal and tracheal narrowing.

Indices of brain beta-adrenergic receptor signal transduction in the learned helplessness animal model of depression

Both stress response and antidepressant drug action may be mediated by beta-adrenergic receptors (beta AR). Since learned helplessness is a stress-induced animal model of depression, beta AR are relevant to investigate in this model. To date, studies have measured changes in total receptor density (RT), but have not examined more detailed aspects of signal transduction mechanisms such as coupling of the receptor to GS protein. We have investigated brain beta AR coupling in the frontal cortex, hippocampus and hypothalamus of rats exposed to inescapable shock and then tested for learned helplessness, and in both tested and naive controls using [125I]-iodocyanopindolol (ICYP) as the ligand. Both antagonist-saturation and agonist-displacement experiments were conducted, and the specificity for the beta AR was optimized by excluding ICYP binding to 5HT1B receptors. The percentage receptor density in the high-conformational state (%RH) and the ratio of agonist (isoproterenol) dissociation constant from the receptor in the low-/high-conformational states (KL/KH) were used as indices of coupling to GS protein. No significant differences were found between rats developing learned helplessness and non-helpless rats after inescapable stress in any parameter measured in any brain region. In the frontal cortex, exposure to inescapable shock induced beta AR uncoupling from GS protein as suggested by a low KL/KH ratio both in helpless and non-helpless rats but not in either control group. In the hypothalamus, there were trends for higher RL, RT and KL/KH ratio in helpless rats and stressed controls compared to naive controls. These findings suggest that beta AR binding parameters in frontal cortex, hippocampus or hypothalamus did not differentiate between helpless and non-helpless rats. Changes in beta AR coupling observed in these brain regions may reflect effects of stress, which appeared to be region-specific, rather than stress-induced behavioral depression.

Maximal external electrical stimulation for treatment of neurogenic or non-neurogenic urgency and/or urge incontinence

Maximal electrical stimulation by intravaginal or intra-anal electrodes was used for treatment of 75 patients with complaints of urgency and/or urge incontinence. The patient group consisted of 51 women and 24 men. A neurogenic background was present in 30 of the women who had a diagnosis of multiple sclerosis, in the other 45 patients the pathology was idiopathic in nature. After 3 weeks of maximal electrical stimulation treatment, composed of 15 sessions of 20 minutes duration, 59% of the patients had urodynamic and subjective improvement and an additional 40% only subjective improvement. One patient found no benefit after this treatment. The effect lasted for at least 2 years in 64% of the idiopathic group. In the multiple sclerosis group relapse occurred within about 2 months. Re-treatment of the failures was successful again immediately; the multiple sclerosis patients do need daily home stimulation treatments.

Restoration of micturition in patients with acontractile and hypocontractile detrusor by transurethral electrical bladder stimulation

The aim of transurethral electrical bladder stimulation (TEBS) treatment in patients with diminished detrusor contractility is to attain complete voiding, i.e., micturition without residual urine, which is under volitional control. In contrast to other types of electrical bladder stimulation, the physiological basis for this kind of treatment is sensitizing of the bladder mechanoreceptor afferents. The latency of afferent stimuli in normal conditions indicates that myelinated A-delta-fibers are used for neurotransmission from these mechanoreceptors. Forty-eight patients with hypocontractile or acontractile detrusor underwent intravesical electrical stimulation. All patients had a history pointing to neurogenic pathology. Forty patients had an acontractile and 8 a hypocontractile bladder. Prior to therapy, the mean residual urine volume was 461 ml. After stimulation, 32 of 48 patients were able to void with a mean residual of 57 ml. Detrusor contraction was achieved in 39% and bladder sensation was perceived by 75% of patients who failed these conditions before treatment. Following therapy, 19 of 35 patients were able to empty their bladder without the previously needed catheterization. Side effects were epididymitis in 1 and cystitis in 7 patients.

Tissue polypeptide-specific antigen in renal cell carcinoma

OBJECTIVES

The usefulness of serum tissue polypeptide-specific antigen (TPS), a cytokeratin 18-associated marker, in renal cell carcinoma (RCC) was assessed in vitro and in vivo.

METHODS

Indirect immunoperoxidase staining for TPS expression was performed on frozen sections of normal renal tissue and RCC specimens. By using a monoclonal TPS immunoradiometric assay, serum TPS concentrations were analyzed in 82 healthy controls, in 20 patients with locoregional RCC before and after surgery and in 18 patients with advanced disease following surgery receiving immunotherapy with interferon-gamma.

RESULTS

Using immunohistochemistry, TPS was found to be expressed by both normal and cancerous renal epithelial cells. The mean TPS concentrations in 82 healthy controls was 56 +/- 49 U/1 with a 95% percentile of 78.5 U/1. Out of 20 patients with locoregional RCC, 8 presented with elevated values (mean 168 +/- 82 U/1) above the cut-off level (78.5 U/1, sensitivity 40%) which dropped to normal within 2 weeks after surgery. During a follow-up period of 1 year, none of the patients presented with tumor recurrence and TPS concentrations remained low (mean 52 +/- 36 U/1). In 18 patients receiving interferon-gamma therapy, serum TPS concentrations were monitored over a period of 12 months. In 5/18 patients, baseline levels were within the normal range (mean 37 +/- 21 U/1); interestingly, these at the same time were the only responders to immunotherapy (n = 2) or at least showed stable disease (n = 3). Response to therapy was reflected by low serum TPS levels (mean 28 +/- 23 U/1) over the entire observation period. Thirteen patients suffered progressive disease during therapy, all of them exhibiting significantly elevated (p < 0.005) pretherapeutic TPS concentrations (mean 186 +/- 124 U/1) that remained equally elevated throughout therapy (mean 192 +/- 102 U/1), reflecting tumor progression.

CONCLUSIONS

TPS might have some clinical value as prognostic marker in RCC, possibly by reflecting the proliferative tendency of the tumor.

Low plasma homovanillic acid levels in recently abstinent alcoholic men

OBJECTIVE

To explore dopaminergic mechanisms in alcohol dependence, the authors measured plasma homovanillic acid (HVA) in recently detoxified alcohol-dependent men.

METHOD

Plasma HVA was measured in 83 male patients with a diagnosis of alcohol dependence who had maintained documented abstinence for at least 3 weeks and in 69 healthy male comparison subjects.

RESULTS

The alcoholic patients as a group had significantly lower levels of plasma HVA than the comparison subjects. This difference was not influenced by any other measured covariate, including a family history of alcohol dependence.

CONCLUSIONS

These results imply that factors such as alcohol dependence should be taken into account in future studies of plasma HVA.

Phenotypic patterns of mononuclear cells in dilated cardiomyopathy

BACKGROUND

Immunological factors in the pathogenesis of idiopathic dilated cardiomyopathy (IDC) were suggested previously on the basis of the demonstration of mononuclear cell infiltrates and autoantibodies against the myocardium. The present study investigated whether tissue leukocyte subpopulations isolated from hearts with IDC (n = 6) differ in phenotype from those of tissues without IDC (n = 7).

METHODS AND RESULTS

Leukocytes were quantified as reactive cells per square millimeter in perivascular, interstitial, and parenchymal tissue sections. Freshly isolated heart-tissue T cells and peripheral-blood T cells from the same patients were analyzed by triple staining and flow cytometry to identify T-cell subpopulations as well as their states of differentiation (expression of CD45RA and Leu-8 versus CD45RO) and activation (IL-2R, IL-7R, very late antigen-1, HLA-DR). All types of infiltrating cells (T cells, B cells, macrophages, granulocytes) are increased in hearts with IDC compared with normal hearts, but only CD8+ T cells and macrophages are increased relative to the other leukocyte subpopulations. CD45RO+/CD45RA-/Leu-8- cells constitute the majority of heart-tissue T cells in both normal hearts and hearts with IDC. Strikingly, hearts with IDC are infiltrated by eightfold greater numbers of perivascularly located IL-2R(+)- (26% of all T cells) and CD45RO(+)-activated memory T cells; moreover, in contrast to normal heart, approximately 40% of both CD4+ and CD8+ heart-tissue T cells express activation markers.

CONCLUSIONS

Both normal hearts and hearts with IDC are populated by leukocytes. The quantitative increase in IDC, associated with a dramatically altered activation status of heart-tissue T cells, suggests a direct role of infiltrating leukocytes in the pathogenesis of IDC.

Folding of an enzyme into an active conformation while bound as peptidyl-tRNA to the ribosome

Rhodanese bound to bacterial ribosomes as peptidyl-tRNA can be folded into an enzymatically active conformation by generating C-terminal extensions of the wild-type enzyme. Rhodanese was synthesized by coupled transcription/translation in a cell-free Escherichia coli system from plasmids containing the coding sequences for the wild-type enzyme or its C-terminally extended mutants. Two proteins with extensions of 23 amino acids or longer were enzymatically active while bound to the ribosomes whereas wild-type protein and a 13-amino acid extension were not. All forms of the enzyme were active after termination and release of the full-length protein from the ribosomes. All five of the bacterial chaperones were required to substantially increase the specific enzymatic activity of the extended rhodanese while the nascent protein was bound to ribosomes. The results provide direct support for the hypothesis that proteins acquire tertiary structure as they are formed in ribosomes.