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Chemoprevention, or pharmacological intervention in healthy individuals at risk of developing cancer, is attracting attention as a potential tool in cancer prevention. Lung cancer, with its high incidence and poor prognosis, is a particularly interesting disease for these studies. The retinoids are a promising group of chemopreventive agents, since they are involved in growth control and are a necessary cofactor for proper activity of a protein receptor which we have shown to be a lung cancer suppressor. Nevertheless, the toxic side effects of retinoids at pharmacological dose present difficulties and current studies are aimed at determining the efficacy of various forms of retinoids and chemoprevention protocols in the target populations.

Illegitimate recombination is the most frequent mechanism for chromosomal rearrangements in mammalian cells, yet little is known about this process. Most of the studies to date have looked at the sequences present at illegitimate junctions. These revealed the presence of recurrent DNA motifs, none of which was consistently found. We have undertaken to determine if intrinsic DNA structures such as bent DNA elements could be a major determinant in chromosomal illegitimate recombination. Using a two dimensional electrophoretic assay we found that eight out of eight junctions, resulting from various types of chromosomal rearrangements, had migration behaviour characteristic of DNA containing intrinsically bent DNA elements. In all cases, these occurred within one kilobase of the junctions, and in most cases could be found in both participating DNA segments. We also found that these bent DNA elements were present before the recombination event. When we analysed the frequency of intrinsically bent DNA elements in random chromosomal fragments, we found it to be about one per 11 kilobases. Thus these results suggest that bent DNA is associated with chromosomal illegitimate recombination.

Early work with adenine phosphoribosyltransferase-deficient mutants of CHO cells suggested that a site existed in the third exon of this gene which was preferentially susceptible to mutation by ethyl methanesulphonate. To determine whether this was real we analysed a large collection of induced mutants, and generated a high-density mutational spectrum for this exon. In addition, 4 sites outside exon 3 were analysed by blot. 37 mutations were found in 19 available sites, six of which were at nucleotide 1365, 1 of 2 sites in the putative hotspot (P less than 0.02). One other site, 1308, also was mutated in 6 cell lines and may also be preferentially mutable.

We have previously shown that descendants of CHO-derived hprt or aprt mutants induced by ethyl methanesulphonate usually undergo a rapid loss of the mutant phenotype during the 10 generations or so of culture in non-selective medium immediately following mutagenesis (Bradley, 1980; Bradley and Laviolette, 1989). We now present an analysis of several mutants and their descendants which have lost the mutant phenotype, or 'reversed'. The drug-resistance properties of reversed cells were generally intermediate between W.T. and mutant, and message level and enzyme-specific activity were also intermediate, correlating with the phenotype. Although this was consistent with a model of inactivation-reactivation of the target gene to explain the reversal phenomenon, the model was ruled out by Northern blot analysis of several induced mutants, which showed no correlation between level of message and tendency of the mutant to lose its phenotype. Karyotype analysis showed that three out of four reversed lines were near-tetraploid and the fourth had a substantial proportion of near-tetraploid cells. This suggests cell fusion between a mutant and a W.T. cell may explain the phenomenon. A prediction of this model, namely that mutagen treatment increases cell hybrid formation, was tested and found to be true.

Different point mutations have been identified in the T3-binding domain of the c-erbA beta thyroid hormone receptor gene that are associated with variant phenotypes of generalized thyroid hormone resistance (GTHR). In most cases of GTHR, heterozygotes are affected; a single mutant allele results in the inhibition of the function of normal thyroid hormone receptors. We report here a novel genetic abnormality, a 3-basepair (bp) deletion in the T3-binding domain of the beta-receptor in a kindred, S, with GTHR. One patient, S1, was the product of a consanguineous union of two heterozygotes and was homozygous for this defect. Heterozygotes from kindred S harbored a CAC deletion at nucleotides 1295-1297, which resulted in the deduced loss of amino acid residue threonine at codon 332, and they displayed elevated free T4 levels and inappropriately normal TSH levels characteristic of other kindreds with GTHR. However, patient S1, who had two mutant alleles, had markedly elevated TSH and free T4 levels and displayed profound abnormalities in brain development and linear growth. A fibroblast c-erbA beta cDNA extending from codon 175 to stop codon 457 was cloned from patient S1, sequenced, and used to create a full-length mutant cDNA. The kindred S mutant receptor was synthesized in vitro and did not bind T3. This mutant receptor did bind with similar avidity as the wild-type human beta-receptor to thyroid hormone response elements of the human TSH beta (-12 to 43 bp) and rat GH (-188 to -160 bp) genes. Kindred S showed the effect in man of heterozygous and homozygous expression of a dominant negative form of c-erbA beta.

By continuous and simultaneous recording of nocturnal penile rigidity and circumferential expansion (tumescence), nocturnal penile rigidity and tumescence have been classified into 6 patterns: normal, dissociation, uncoupling, short episode, low amplitude and flat trace. The monitoring will be helpful to diagnose underlying disorders involving erectile impotence, if the pattern of nocturnal penile rigidity and tumescence are related with the disorders. This study analyzed the relationship between the pattern of nocturnal penile rigidity and tumescence and associated disorders in 105 patients with erectile impotence. Of 15 patients with central nervous system disorders, 9 (60%) had a pattern of short episode of rigidity. In 29 patients with cardiovascular disorders, the patterns of dissociation, low amplitude and flat trace were the main findings and observed in 41, 41, 35% of the group, respectively. No patients with diabetes mellitus showed normal pattern. Although the group of non insulin dependent diabetes mellitus (21 patients) had various patterns of rigidity and tumescence, the insulin dependent group (14 patients) mainly showed patterns of low amplitude (21%) and/or flat trace (71%). The continuous and simultaneous monitoring of penile rigidity and tumescence will be helpful, with an integral analysis of its pattern and other examinations, for accurate diagnosis of underlying disorders of organic impotence, besides for differentiation of organic impotence from psychogenic one.

The third report continues with recommendations on procedures related to the evaluation of micturition. It covers pressure-flow relationships and residual urine. These recommendations were subject to discussion during the Seventh Annual Meeting of the International Continence Society in Portoroz, Yugoslavia, September 1977.

Bladder function was studied in 44 patients with bladder outlet obstruction by gas cystometry, integrated sphincter electromyography and uroflowmetry. Of these 44 patients 18 demonstrated detrusor hyperreflexia on cystometry. To identify the prostate as a possible source for triggering sensory stimuli pharmacologic ablation with lidocaine was performed through a perineal approach in 11 patients with hyperreflexia. Prostatic block eliminated hyperreflexia in 10 of 11 patients and had no effect in 4 patients with a normal cystometrogram. We believe that this study lends support to the concept that sensory stimuli from an anatomically altered prostatic urethra induces detrusor hyperreflexia. This suggests that permanent ablation of sensory stimuli from the prostate in patients with outlet obstruction would be of benefit.

An electrophysiologic technique to evaluate the anatomic integrity of the peripheral pathways to the bladder and sphincters is described. Evoked electromyographic responses of the anal sphincter are produced by stimulating the bladder wall and urethra. Impulses travel via the pelvic nerves and cauda equina to the conus medullaris, activating the pudendal nerve nucleus and resulting in contraction of the external anal sphincter. Lesions along this pathway produce either prolonged latencies and depressed responses or complete loss of response. Correlation of the results of this technique in 110 patients with clinical myelographic and operative findings indicates that the technique is a useful clinical tool.

Autonomic and pudendal neuropathies are frequent and neglected diseases affecting the genitourinary system. In the initial stages they frequently are asymptomatic. Autonomic neuropathy is seen in association with peripheral neuropathy in a wide range of metabolic diseases, including diabetes mellitus. Diagnosis can only be made directly by electrophysiologic methods. Treatment is based upon an adequate laboratory study of genitourinary function.

During the past decade the ability to assess urinary bladder function in diabetes mellitus has improved considerably because of changed concepts of urinary bladder function, imporved methods for evaluation, and increased capability for treatment. Evaluation of patients with urinary bladder dysfunction and diabetes mellitus has shown that peripheral visceral afferent pathways are first affected, followed by detrusor reflex decompensation.

Combined electromyographic and gas urethral pressure profilometry provide for rapid assessment of urethral function in neurological dysfunction of the detrusor muscle and urethra.

Urinary bladders and urethrae were collected from six adult and two juvenile female dogs. Five urethral regions and the neck and body of the bladder were sampled. Volume fractions for connective tissue including elastic fibers, smooth and striated muscle, and epithelium were obtained by projecting section images onto an array of points and computing the number of points overlying a tissue constituent per total points overlying the tissue section. Smooth muscle occupied approximately half the volume of the bladder wall, one-third the volume of the vesical neck, and one-fourth the volume of the proximal urethra. Striated muscle was present in the distal half of the urethra, where the total muscle coat occupied about one-third of the urethral wall volume. Smooth muscle was practically absent in the terminal urethra, where the striated urethralis muscle encircles urethra and vagina in common. Epithelial area and lumen perimeter were not significantly different along the length of the urethra except that urethral epithelium was significantly thicker adjacent to the vesical neck. In terms of histological proportions, the vesical neck was intermediate between the body of the bladder and the proximal urethra.

Histologic examination was used to determine the anatomic organization of the feline bulbospongiosus muscle (BSM). Bilaterally symmetrical cranial, middle, and caudal muscle fiber groups were identified. The caudal group was the largest of the 3 groups. Mean cross-sectional diameter of nonfixed BSM fibers was 79 micron. Muscle spindles were not observed in serial histologic sections. The innervation of the BSM was provided by the deep perineal nerve. Contractile properties of the BSM were determined in vitro, using direct muscle stimulation. Mean time-to-peak tension values were 71.4 ms and 62.7 ms at 30 C and 37 C, respectively, and were longer than that for the feline periurethral striated muscle and external anal sphincter muscle, but slightly shorter than that for the slow-twitch soleus muscle. Stimulation frequency at peak tetanic tension was 40 Hz, twitch-to-tetanus ratio was 0.30, and stimulus interval at peak tension for double response was 44 ms. Electrophysiologic properties examined were resting potentials and miniature end-plate potentials (MEPP). Mean resting potential was 68 mV. The MEPP had low mean amplitude (0.57 mV), fast mean rise time (0.99 ms), and low maximal frequency (0.06 Hz). Only focally recordable MEPP were observed. Pharmacologic properties were investigated by alternating direct and indirect stimulation. The latter was accomplished by electric field stimulation of intramuscular nerve fibers. A high sensitivity of the BSM to d-tubocurarine blockade was present. The results of this study support classification of the BSM as a slow-twitch muscle.

Bladder and urethral function was studied in 52 patients with multiple sclerosis using gas-cystometry combined with sphincter electromyography. 96% of the patients showed abnormalities of either detrusor or sphincter function. The abnormal patterns discovered indicated demyelinating lesions in the corticospinal as well as in the reticulospinal tract. Urgency and urge-incontinence were the predominant symptoms, whereas no signs of involvement of the upper urinary tract found. The use of gas-cystometry provides a fast and differentiated method for assessment of the detrusor function.

Changes in the concept of neural organization for micturition and the use of high flow gas cystometers have altered the performance of clinical cystometry and test interpretation. Detrusor reflex activation procedures in carbon dioxide cystometry include rapid bladder distension, change in postural states, use of bethanechol, urethral and anal distension, and sleep. Sleep cystometry requires the use of electroencephalography. These procedures have permitted specific delineation of the syndrome of detrusor reflex instability. Test interpretation is based upon detection of the presence of detrusor reflex instability or end organ denervation.

Lumbar and sacral afferent axons in the submucosa of the urinary bladder were recognized by degeneration in seven cats subjected to spinal ganglionectomies. Of 2,935 observed terminating axon profiles, 145 were found degenerating. Lumber afferent axons were 3.7 times more numerous than sacral afferent axons in the submucosa, a reversal of the ratio reported for the muscle coat of the bladder. Sacral afferent axons were evenly distributed to different regions of the bladder, but lumbar afferents were concentrated in the bladder neck. Apparent afferent endings in the submucosa of the urinary bladder were principally free nerve endings. Synaptic vesicles were found in 57% of observed terminating axon profiles. The bladder neck had more terminating axon profiles of all kinds than other regions of the urinary bladder.

A new technique for recording of the urethral closure pressure profile using gas-inflation and simultaneous EMG-recording from the urethra is described. With the present technique, the parameters of the urethral closure pressure profile in healthy volunteers were in accordance with previous reports using water-infusion. The effect of alpha-adrenergic blockade on the pressure profile was studied in a series of patients. Half of the patients showed a marked reduction of the intraurethral pressure in the presphincteric part of the profile after alpha-adrenergic blockade. This indicated that sympathetic innervated smooth musculature gives a significant contribution to the total intraurethral pressure.

Stimulating electrodes were placed on the terminal branches of the pelvic nerves to the urinary bladder and the pudendal nerve to the sphincters in seven Rhesus monkeys and two chimpanzees. The proximity of the electrodes to these structures assured organ specificity. Evoked responses produced by stimulation of these terminal nerve branches were recorded in the fascicles and rootlets of the lower thoracic, lumbar, and sacral nerve roots. During identical stimulating and recording conditions, the amplitude as well as presence or absence of the evoked responses recorded was variable within the various roots. The amplitude of the evoked responses or their absence depended on the number of fibers within a particular fascicle which conducted impulses to the urinary bladder or the urethral and anal sphincters. By this method, it was determined that there was segregation or compartmentalization of the nervous innervation to the urinary bladder and sphincters within the spinal roots. In addition, the segmental spinal cord origin of the innervation of the urinary bladder was determined for the Rhesus monkey and chimpanzee. In the Rhesus monkey, the pelvic nerves to the urinary bladder arose from the first and second sacral segments and to a much lesser extent from the seventh lumbar segment. In the chimpanzee, the sacral segments one to four gave rise to innervation of the urinary bladder.

Bowel, bladder and sexual dysfunction are common in multiple sclerosis and are generally attributed to the widespread nature of the involvement of the neuroaxis by the demyelinating plaques. Recently we encountered a specific subset of patients within this group who had characteristic clinical complaints of hesitancy, straining and incomplete voiding, perineal hypesthesia on examination, areflexia by cystometry and colonometry and electrophysiological parameters suggesting involvement of the conus medullaris. This heretofore postulated but undocumented mechanism of neurovisceral dysfunction in multiple sclerosis is detailed and discussed in 2 patients in this report.

The authors describe long-term follow-up results (4 to 6 years) in 13 patients who underwent differential sacral rhizotomy for urgency incontinence. Six patients were originally presented in a preliminary report in 1973. In the last seven patients, a highly selective rhizotomy of sacral fascicles innervating only the urinary bladder was performed. Results in the original six patients appear to be superior to those in patients who underwent a more refined rhizotomy. Possible explanations for this as well as alternative approaches to the treatment of urgency incontinence are briefly discussed.

Postural changes in bladder function have been documented previously only in female incontinent patients without evidence of neurologic or urologic disease. In our study the syndrome of postural hyperreflexia is described in patients of both sexes having a variety of neurological disorders. The investigations showed impaired function of supraspinal control of the sacral micturition center.

Two mechanisms are implicated in generating recessive drug resistance mutants at the adenine phosphoribosyltransferase (aprt) locus of Chinese hamster ovary (CHO) cells, one of which is a spontaneous high-frequency deletion of the entire gene. We have isolated and mapped a 19-kb fragment carrying aprt and its flanking sequences. A Southern blot study of 198 independent deletion mutants revealed that two different mutants have one of their breakpoints within the 19-kb region analyzed. One of these has an upstream breakpoint which could be narrowed down to a 4-kb fragment containing repetitive sequences. The other mutant has a breakpoint within a 410-bp sequence located 8.5 kb downstream of the aprt gene and which carries several elements similar to those signaling V-(D)-J joining in immunoglobulin and T-cell receptor gene rearrangements. In each case the other breakpoint lay outside of the analyzed region. These results support the previous indications that the deletions created by this spontaneous event are large.

Bladder sensation is an important variable in cystometry. Sensory complaints are a valuable portion of the history which may be further defined and documented by the cystometric examination.

The innervation of the male detrusor muscle and urethra is a complex network of synaptic interactions between nuclear collections in the cerebral cortex, the brain stem, and the gray matter of the sacral spinal cord. The multiplicity of influences in this reflex emphasizes its vulnerability to disease processes.

Median nerve compression at the wrist (Carpal Tunnel Syndrome) is commonly associated with local trauma around the flexor retinaculum. Repeated manual activity also exacerbates the disease severity. We undertook a prospective study of the incidence of Carpal Tunnel Syndrome (CTS) in 47 paraplegic patients who have used their hands extensively for daily activity. Since surgical decompression generally provides excellent relief of symptoms, early detection of CTS will be particularly important in these patients. Of the 47 patients studied, 19 had clinical CTS (40%). A total of 91 hands (nerves) were tested with motor and sensory nerve conduction of the median and ulnar nerves. Electrophysiological evidence of CTS was noted in 57 hands (63%). The incidence of CTS appears to be related to the duration of Spinal Cord Injury. Concurrent ulnar neuropathy at the elbow was noted in 19 patients (40%). There was no predisposing factor such as diabetes mellitus in any of these patients, and the compressive neuropathy appears to be purely mechanical.

We describe the use of sacral nerve blocks in conjunction with air cystometry and sphincter electromyography to determine the functional innervation of the bladder and sphincters. This technique has aided in the selection of patients for sacral rhizotomy. Phenol sacral nerve blocks have been used successfully in treating hyperactive bladder disease and intractable perineal pain.

Urinary flow in the male subject is associated with turbulence at the bladder neck. This turbulence is associated with the production of a sound in the healthy male subject, transmitted to the perineum.

Averaged evoked potentials were recorded from the scalp of 22 dogs after repetitive stimulation of the pudendal nerve. Four experimental procedures were used: (1) percutaneous needle-stimulating electrodes with dogs tranquilized with xylazine; (2) percutaneous needle-stimulating electrodes with dogs tranquilized with acepromazine; (3) percutaneous needle-stimulating electrodes with dogs anesthetized with alpha-chloralose; and (4) Sherrington type stimulating electrodes applied directly to nerves with dogs anesthetized with alpha-chloralose. The average evoked potentials were similar with all treatments. Three peaks (N1, P1, and N2) with consistent latency and amplitude were generally present, followed by additional peaks with variable latencies and amplitudes. The mean latency for N1 after direct stimulation was significantly longer than the mean latency for N1 in the 3 other groups (95% confidence intervals). There were no other significant differences in mean latencies among groups for any of the peaks.

The terminology of lower urinary tract function will be standardized by the ICS. This report contains the recommendations dealing with urinary incontinence, procedures related to the evaluation of urine storage (cystometry, urethral closure pressure profile) and units of measurement.

Evidence for differences between the periurethral striated muscle and external anal sphincter of the cat is provided by measurement of the contractile properties in situ and in vitro and the electrophysiologic properties in vitro. In the periurethral striated muscle, the contractile pressure response was faster, d-tubocurarine sensitivity was greater, d-tubocurarine blockade had a shorter duration, and fatigue was faster but not uniquely fast as compared with results for the external anal sphincter. These results suggest that the periurethral striated muscle has similar characteristics to certain fast twitch muscles. Effect of succinylcholine on the periurethral striated muscle and external anal sphincter was similar. Miniature end-plate potentials had large amplitudes which appeared to be correlated to the small diameter of the periurethral striated muscle fibers. Since only focally distributed miniature end-plate potentials could be found, true physiologically slow muscle fibers were absent.

Detrusor and urethral function was studied in 10 patients before and 3 months after transurethral resection of the prostate by means of flowmetry, and simultaneous gas cystometry and integrated sphincter electromyography. THE PATIENTas cystometry and integrated sphincter electromyography. The patient had no clinical signs of neurological disease. Six had neurogenic exaggeration of the detrusor reflex in the preoperative studies. In 3 patients changes in the detrusor reflex were found postoperatively. Postural changes in detrusor reflex excitability were encountered preoperatively and postoperatively. The preoperative finding of detrusor hyperreflexia in the majority of the patients is ascribed to lesions in the detrusor reflex organization at 2 anatomical sites: 1) a subclinical lesion of the cerebral circuits of the detrusor reflex control owing to arteriosclerosis and 2) an increase of sensory detrusor-reflex triggering stimuli from the morphologically changed prostatic urethra. The study calls for diagnostic techniques for delineation of minimal cerebrospinal impairment and objective assessment of the sensory innervation of the urethra.

The dorsal nerve of the penis has been linked closely to penile erection and response. We measured the nerve conduction velocity of the dorsal nerve of the penis, latency of the bulbocavernosus reflex and pudendal evoked potential in 23 normal men and 20 insulin-dependent diabetics with impotence. The conduction velocity of the dorsal nerve of the penis was significantly slower in diabetic than in normal men and passive gentle elongation of the penis by weight stretching enhanced the slowing. In contrast, the bulbocavernosus reflex and pudendal evoked potential showed no significant differences between the 2 groups. We demonstrate the potential usefulness of measurement of the conduction velocity of the dorsal nerve of the penis in the detection of penile neuropathy.

A series of stable mutants bearing nuclear genetic markers were developed from the established chicken cell line DU24. The mutants were obtained after mutagenesis of DU24 cells with ethyl methanesulfonate (EMS) or arose spontaneously when plated in the appropriate selective medium. Clones resistant to 5-bromodeoxyuridine (BrdU) were obtained following a two-step selection procedure and analyzed. The BrdUr cells were found to be deficient in thymidine kinase activity and were HAT sensitive. Molecular characterization of these mutants revealed no deletions or other rearrangements, but methylation of some cytosine residues was decreased in the mutants. A similar restriction profile was seen in a series of mutants made resistant to BrdU after cultivation of DU24 cells in increasing concentrations of the drug over a period of six months. Selection of EMS-treated BrdUr cells in 10 microM ouabain gave rise to a clone resistant to both drugs and which was still HAT sensitive. Clones resistant to 6-thioguanine were also isolated, but showed wild-type hypoxanthine phosphoribosyltransferase activity and were HAT resistant. A number of the cell lines isolated were found to be suitable for fusion experiments with both chicken cells and cells from other vertebrate species.

Two new methods of evaluating erectile function were compared and contrasted in a series of 41 patients complaining of impotence. The first method consisted of a single measurement of maximum rigidity at penile base and along the penile shaft utilizing Snap-Gauges. The second method consisted of simultaneous continuous monitoring of penile tumescence and rigidity of the penile base and shaft. The results demonstrated concurrence of interpretation of both techniques. However, whereas the results of Snap-Gauge testing clearly distinguished between organic and psychogenic impotence, continuous penile rigidity monitoring usually delineated the nature of the penile erectile abnormality.

Many electrophysiologic tests have been performed and have proved useful for diagnosing sexual function. However, there have been limitations to the interpretation of the tests because of paucity of details concerning penile innervation. Therefore, electrophysiologic studies were performed in 3 patients with psychogenic impotence and in 15 patients with organic impotence to assess accurately the peripheral somatic innervation of the penis. The glans penis was innervated by the dorsal nerve of the penis. In some patients dual innervation was present at the ventral aspect of the glans penis by the dorsal nerve of the penis and the perineal nerve. The predominant innervation and fiber spectra of the glans by the dorsal nerve of the penis and the crucial role of the glans in sexual arousal and erectile function provide adequate rationale for the measurement of nerve conduction velocity of the dorsal nerve of the penis in sexual dysfunction.