Sodium and chloride transport by the intestine of the european flounderPlatichthys flesus adapted to fresh or sea water

1. Everted intestinal sacs prepared from Platichthys flesus adapted to sea water (SW) have higher rates of salt and water transport than did sacs prepared from fresh water adapted (FW) fish. 2. Intestines mounted in Ussing chambers gave stable open-circuit voltages and short-circuit currents after pre-incubation for 20--30 min of --1.91 +/- 0.14 (14) mV and --45.0 +/- 5.1 (14) muA/cm2, SW fish, and --1.24 +/- 0.14 (11) mV and --18.2 +/- 3.6 (11) muA/cm2, FW fish. 3. Isotope flux measurements indicated a net Na transport of 21.5 +/- 4.1 (11) neq/cm2-min in SW fish intestines, but no significant Na transport in FW fish (7.6 +/- 7.6 (9) new/cm2-min). Both preparations showed an active Cl transport, 26.6 +/- 6.1 (12) neq/cm2-min for SW and 18.5 +/- 9.7 (17) neq/cm2-min for FW fish. 4. No significant difference in the uptake of Na or Cl across the mucosa was observed between FW and SW fish. The uptake of both ions showed some saturation at high concentrations. 5. Interactions between Na and Cl uptake were small, although Cl uptake was significantly higher in Na-free solutions. 6. It is concluded that electrogenic Cl transport may be the dominant mechanism for water and salt transport in flounder intestine, and that adaptation to a saline environment involves regulation of pumping rather than Na or Cl entry across the mucosal membrane.     

Cellular renewal in the enamel organ and the odontoblast layer of the rat incisor as followed by radioautography using 3H-thymidine

Renewal of the cell populations of the incisor was studied in 100 gm male rats injected with a single dose of ³H-thymidine and sacrificed at various times from one hour to 32 days after injection. Radioautographs showed that a cohort of labeled cells within the enamel organ, odontoblast layer, and pulp was carried passively with the erupting incisor from the apical end toward the gingival margin where the life cycle of these cells was terminated. Labeled cells in the upper and lower incisor, although traversing different absolute lengths, were found in approximately the same functional stage of their life cycle at similar times after the injection. Thus, by one and one-half days labeled ameloblasts began inner enamel secretion. By 32 days labeled ameloblasts had traversed the entire maturation zone and were located at the gingival margin. Labeled odontoblasts followed closely the movement of labeled ameloblast. The mean rate of ameloblast migration was 567 μm/day on the upper incisor and 651 μm/day on the lower. For the odontoblasts this rate was 500 μm/day (upper) and 631 μm/day (lower). Finally, it was found that as the rat aged, the duration of the life cycle for epithelial and pulp cell populations of the incisor increased because of growth within the longitudinal axis of the tooth. It was concluded that the apical end of the incisor literally “grows backward” in the bony socket, and hence, the duration of the life cycle becomes greater simply because it takes cells longer to physically reach the gingival margin.     

Racial Disparities in Erectile Dysfunction among Participants in the California Men's Health Study

IntroductionThe burden of erectile dysfunction (ED) among different racial and ethnic groups is unclear, in part, because prior studies have not included all four major racial and ethnic groups in the same population‐based sample.AimTo determine the prevalence and odds of ED among all four major racial and ethnic groups after adjustment for demographic, medical, socioeconomic, and lifestyle characteristics.MethodsThis cross‐sectional study was conducted using data from men, aged 45–69 years, without a diagnosis of prostate cancer (N = 78,445), who completed questionnaires as part of the California Men's Health Study, a large multiethnic cohort study with detailed demographic, medical and, socioeconomic data.Main Outcome MeasureErectile dysfunction measured by a previously validated four‐level response question.ResultsThe overall prevalence of ED by age category was 13%, 24%, and 44% for men aged 45–49 years, 50 and 59 years, and 60–69 years, respectively. In a multivariable model, relative to white men, Hispanic (OR 1.05, 95% CI 0.99, 1.12), Asian (OR 1.1, 95% CI 1.02, 1.19), and other men (OR 1.13, 95% CI 1.06, 1.1.21) had increased odds of moderate‐severe ED, while black men were less likely to report moderate to severe ED (OR 0.86, 95% CI 0.81, 0.92). Black (OR 0.54, 95% CI 0.48, 0.61) and Asian men (OR 0.91, 95% CI 0.80, 1.04) were less likely to have severe ED after adjustment for age, socioeconomic status, medical co‐morbidities, and lifestyle characteristics.ConclusionThese data demonstrate that the prevalence of ED among different racial and ethnic groups is likely the result of complex phenomena and depends upon the interplay of socioeconomic, demographic, medical, cultural, and lifestyle characteristics. After accounting for these factors, these data suggest that Asian and black men are less likely to have severe ED relative to white men. Smith JF, Caan BJ, Sternfeld B, Haque R, Quesenberry CP, Jr, Quinn VP, Shan J, Walsh TJ, Lue TF, Jacobsen SJ, and Van Den Eeden SK. Racial disparities in erectile dysfunction among participants in the California men's health study.     

Biolistic transformation of conidia of Botryotinia fuckeliana

Botryotinia fuckeliana, the causal agent of grey mould, was biolistically transformed to hygromycin B resistance using a plasmid (pOHT) containing a bacterial hygromycin phosphotransferase gene fused to regulatory sequences from Aspergillus nidulans. Multiple copies of the plasmid, precipitated onto tungsten particles, were delivered into the conidia by a helium-driven gene gun. Southern analysis showed that the plasmid was integrated into the fungal genome at one single locus. After five subsequent transfers on selective medium, all transformants were mitotically stable. When propagated on non-selective medium, four out of eight transformants retained their resistance to hygromycin B. Southern analysis of the fifth generation of transformants showed that no genetic rearrangements occurred during vegetative growth of stable transformants.     

Occipital meningocele and Mondini deformity of the cochlea

We present two cases of a previously unreported association between occipital meningocele and Mondini deformity of the cochlea. The probability of the association is supported by the intimate relationship between the development of these structures; the existence of dysembryoplastic factors that can cause both abnormalities; and the universal existence of cochlear abnormalities in anencephalic foetuses. The importance of considering the association is emphasized, in terms of early identification and referral of children with hearing loss, and avoidance of duplication of investigations.     

The silent sinus syndrome: a case series and literature review

PURPOSE: The purpose of this study is to describe the clinical and pathologic features of a form of chronic maxillary atelectasis referred to as the silent sinus syndrome, which is characterized by progressive enophthalmos secondary to maxillary collapse resulting from maxillary sinus hypoventilation. METHODS: A retrospective medical record analysis was carried out to identify patients with enophthalmos secondary to maxillary collapse. Clinical records, including ophthalmology and otolaryngology evaluations as well as computed tomography scans and operative reports, were carefully examined. A complete literature review for relevant studies was performed to examine possible pathophysiology and similar cases. RESULTS: Four patients with enophthalmos and asymptomatic maxillary sinus disease were identified. On computed tomography, all four of the patients had opacified, partially collapsed maxillary sinuses with osteopenia of the sinus walls and orbital floor displacement resulting in enophthalmos. All four underwent successful functional endoscopic sinus surgery and transconjunctival orbital floor repair. CONCLUSION: In some instances, chronic maxillary atelectasis can present with enophthalmos secondary to collapse of the maxillary sinus. For reasons that are unclear, the sinus component of the disease remains asymptomatic and is discovered only after thorough evaluation of the enophthalmos.     

Effect of nasal dilators on nasal structures, sniffing strategies, and olfactory ability

This paper describes the effects that nasal dilators have on olfactory ability. Experimental results demonstrate that nasal dilators increase odorant identification, lower odorant threshold, and increase perceptual odorant intensity. In other experiments, magnetic resonance imaging (MRI) data demonstrates that the size of the nasal cavity especially around the region of the nasal valve is increased when nasal dilators are worn. Additionally, pneumotachograph data demonstrates that during a sniff, the peak flow, maximum flow rate, volume, and duration are all increased when nasal dilators are worn. Taken together, the increase in olfactory ability can most easily be explained by an increase in both the amount and the proportion of inspired odorant molecules that are directed to the olfactory mucosa and are, therefore, available for odorant perception.     

Localization of the gene for familial laryngeal abductor paralysis to chromosome 6q16

BACKGROUND: Vocal fold paralysis is a common cause of neonatal stridor. Although it is usually classified as idiopathic or iatrogenic in origin, a small subset of patients have a family history of this disorder, indicating a possible genetic cause. OBJECTIVE: To identify the genetic locus of the gene that causes familial laryngeal abductor paralysis. DESIGN: A standard nonorganic protocol was used to extract DNA from whole-blood samples. The DNA samples were quantified by DNA fluorometry, and the concentration of all samples was standardized at 40 ng/microL. A pooled DNA strategy was used to facilitate rapid polymerase chain reaction screening of markers in the Weber v8.0 genome screening set. Polymerase chain reaction screening of individual DNA samples was performed using possible linked markers initially identified as having an allele that appeared with a higher incidence in the affected DNA pools. Statistical analysis of possible linkage was performed using the LINKAGE 5.1 set of linkage analysis computer programs. SUBJECTS: A family in which a form of familial laryngeal abductor paralysis segregates was ascertained. Whole blood samples were drawn from 40 participating individuals within this family after the subjects' fully informed consent was obtained. RESULTS: Initial screening of the pooled DNA specimens revealed a band pattern for D6S1021 on chromosome 6q16, indicating an allele with a higher incidence in the affected vs the nonaffected pool. Two-point analysis of individual allele patterns confirmed linkage to D6S1021 with an lod score of 3.86 (straight theta = 0.0) at a penetrance value of 0.8. Haplotype analysis with flanking markers defined a 5-centiray critical region between D6S283 and AFMA047YG1. CONCLUSION: An autosomal dominant form of familial laryngeal abductor paralysis is linked to a 5-centiray region on chromosome 6q16 surrounding D6S1021.     

Pediatric otolaryngologists' knowledge and understanding of genetic testing for deafness

OBJECTIVE: To assess the level of a cohort of pediatric otolaryngologists' knowledge and understanding of genetics and genetic testing for deafness and hard of hearing (D/HOH). METHODS: A questionnaire was designed to assess the level of knowledge and understanding of the genetic basis and genetic testing for deafness among a cohort of pediatric otolaryngologists. Three hundred questionnaires were made available to attendees of the 14th (1999) Annual Meeting of the American Society of Pediatric Otolaryngology, Palm Desert, Calif. A series of questions asked to gauge the respondent's level of knowledge of genetics and hearing impairment addressed estimating recurrence risks for deaf and normal-hearing parents and the likelihood of detecting a mutation in connexin 26 in specific clinical scenarios. RESULTS: A total of 28 questionnaires were completed and returned. All respondents reported that they regularly saw patients for D/HOH. Almost half commonly refer these patients for genetic testing and counseling. Seventeen (71%) of 24 otolaryngologists stated they offered genetic testing in all situations, while 6 offered counseling only at parental request or to address recurrence risk issues. One otolaryngologist offered genetic testing if there was a deaf sibling. Twelve (67%) of 18 offered pretest counseling, which was most frequently provided by a genetic counselor. Although 3 (19%) of 16 otolaryngologists provided the counseling themselves, 2 (13%) reported that they and a genetic counselor provided the counseling. While 24 (89%) of the 27 correctly stated that nonsyndromic D/HOH is usually autosomal recessive, recurrence risks were incorrectly estimated in several examples. CONCLUSIONS: While the surveyed pediatric otolaryngologists have a good knowledge of genetics and genetic testing for D/HOH, recurrence risks were often inaccurate. Since D/HOH testing is clinically available, it is imperative that physicians are educated about genetics and genetic testing and are able to communicate this to their patients and their patients' families.     

Therapeutic electrical stimulation of the hypoglossal nerve in obstructive sleep apnea

BACKGROUND: Hypoglossal nerve stimulation has been demonstrated to relieve upper airway obstruction acutely, but its effect on obstructive sleep apnea is not known. OBJECTIVE: To determine the response in obstructive sleep apnea to electrical stimulation of the hypoglossal nerve. METHODS: Eight patients with obstructive sleep apnea were implanted with a device that stimulated the hypoglossal nerve unilaterally during inspiration. Sleep and breathing patterns were examined at baseline before implantation and after implantation at 1, 3, and 6 months and last follow-up. RESULTS: Unilateral hypoglossal nerve stimulation decreased the severity of obstructive sleep apnea throughout the entire study period. Specifically, stimulation significantly reduced the mean apnea-hypopnea indices in non-rapid eye movement (mean +/- SD episodes per hour, 52.0 +/- 20.4 for baseline nights and 22.6 +/- 12.1 for stimulation nights; P<.001) and rapid eye movement (48.2 +/- 30.5 and 16.6 +/- 17.1, respectively; P<.001) sleep and reduced the severity of oxyhemoglobin desaturations. With improvement in sleep apnea, a trend toward deeper stages of non-rapid eye movement sleep was observed. Moreover, all patients tolerated long-term stimulation at night and did not experience any adverse effects from stimulation. Even after completing the study protocol, the 3 patients who remained free from stimulator malfunction continued to use this device as primary treatment. CONCLUSION: The findings demonstrate the feasibility and therapeutic potential for hypoglossal nerve stimulation in obstructive sleep apnea.