MYO1F as a candidate gene for nonsyndromic deafness, DFNB15

BACKGROUND

Earlier studies have mapped the autosomal recessive nonsyndromic deafness locus, DFNB15, to chromosomes 3q21.3-q25.2 and 19p13.3-13.1, identifying one of these chromosomal regions (or possibly both) as the site of a deafness-causing gene. Mutations in unconventional myosins cause deafness in mice and humans. One unconventional myosin, myosin 1F (MYO1F), is expressed in the cochlea and maps to chromosome 19p13.3-13.2.

OBJECTIVE

To evaluate MYO1F as a candidate gene for deafness at the DFNB15 locus by determining its genomic structure and screening each exon for deafness-causing mutations to identify possible allele variants of MYO1F segregating in the DFNB15 family.

METHODS

We used radiation hybrid mapping to localize MYO1F on chromosome arm 19p. We next determined its genomic structure using multiple long-range polymerase chain reaction experiments. Using these data, we completed mutation screening using single-stranded conformational polymorphism analysis and direct sequencing of affected and nonaffected persons in the original DFNB15 family.

RESULTS

Radiation hybrid mapping placed MYO1F in the DFNB15 interval, establishing it as a positional candidate gene. Its genomic structure consists of 24 coding exons. No mutations or genomic rearrangements were found in the original DFNB15 family, making it unlikely that MYO1F is the disease-causing gene in this kindred.

CONCLUSIONS

Although we did not find MYO1F allele variants in one family with autosomal recessive nonsyndromic hearing loss, the gene remains an excellent candidate for hereditary hearing impairment. Given its wide tissue expression, MYO1F might cause syndromic deafness.

Intermittent Pneumatic Compression Devices – Physiological Mechanisms of Action

There are many reports of how IPC is used effectively in the clinical setting; including the prevention of deep venous thrombosis, improvement of circulation in patients with lower extremity arterial diseases, reduction of lymphoedema, and the healing of venous ulcers. However, despite the widely accepted use of IPC, it is still unclear how IPC actually exerts its beneficial effects. The exact physiological mechanisms of action are unknown. The clinical utility of IPC and the putative mechanisms by which IPC could exert its therapeutic effect will be reviewed. The paper will examine the mechanical effects of IPC exerted on the lower extremity, and the subsequent biochemical changes in the circulation. In vitro studies of the effects of mechanical stress such as compressive strain and shear on cultured endothelial cells, and their clinical relevance to IPC will also be reviewed.

Free-space accommodative response and minus lens-induced accommodative response in pre-school children

PURPOSE

The purpose of this study was to investigate and compare the accommodative accuracy of pre-school children between free-space accommodative stimulus and minus lens-induced accommodative stimulus.

METHODS

The accommodative responses of 59 pre-school children, ages 2 to 5 years, were measured objectively with a Canon Autoref R-1 under two different conditions, giving an optical accommodative stimulus of 1 D; first, viewing a target placed 100 cm away (free-space stimulus), and second, viewing a distant target through a -1.00 D lens.

RESULTS

The mean lag of the accommodative response for the free-space accommodative stimulus is 0.24 D, while the mean lag of the accommodative response with the minus lens-induced accommodative stimulus is 0.69 D. The lag of accommodative response for free-space accommodative stimulus is significantly lower than the lag of accommodative response for minus lenses.

CONCLUSIONS

Pre-school children can accommodate more accurately toward a free-space accommodative stimulus, as compared with minus lens-induced accommodative stimulus.

2E4/Kaptin (KPTN)--a candidate gene for the hearing loss locus, DFNA4

Stereocilia of the inner ear play an integral role in the mechanotransduction of sound. Their structural support is derived from actin filaments and actin-binding proteins. We have identified a novel actin-binding protein, 2E4-kaptin (KPTN), which appears to be involved in this structural network. Using double label immunofluorescence, we now show that KPTN extends beyond the barbed ends of actin filaments at the tips of stereocilia, and using cloned human cDNA, we mapped KPTN to chromosome 19q13.4. A combination of FISH, radiation hybrid mapping and YAC screening localized KPTN between markers D19S412 and NIB1805, making this gene an excellent functional and positional candidate for DFNA4, a form of autosomal dominant non-syndromic hearing loss. We identified a second family with inherited deafness that also maps to the DFNA4 region. To screen KPTN for deafness-causing mutations, we first determined its genomic structure and then completed a mutational analysis by direct sequencing and SSCP in affected family members. Although no deafness-causing mutations were identified in the coding region, KPTN remains an excellent candidate gene for hearing loss; by synteny, its murine orthologue also remains a candidate gene for the Nijmegan waltzer (nv) mouse mutant, which has vestibular defects and a variable sensorineural hearing loss.

Laryngeal cancer cost analysis: association of case-mix and treatment characteristics with medical charges

OBJECTIVES

To examine the relationship of various pretreatment case-mix characteristics and treatment modalities with medical charges incurred during diagnosis, treatment, and 2-year follow-up for patients with laryngeal cancer.

DESIGN

Retrospective chart review and billing record analysis.

METHODS

The charts and billing records of patients diagnosed with laryngeal cancer at the University of Iowa Hospitals and Clinics (UIHC) between January 1, 1991 and December 31, 1994 were reviewed. The independent variables included various pretreatment patient-mix and tumor characteristics (age, AJCC TNM clinical stage, smoking history, ASA class, and comorbidity as defined by Kaplan-Feinstein grade) as well as type of treatment. The dependent variables included total physician, office, and university hospital-based charges incurred during the pretreatment evaluation and 0- to 3-, 3- to 12, and 12- to 24-month billing periods after the initiation of cancer-directed therapy. Total 1-year and 2-year charges were also evaluated. Univariate and multivariate analyses were used to investigate the relationships between dependent and independent variables and to develop models predictive of management charges during the individual and total billing periods.

RESULTS

Pretreatment charges showed no significant associations (P < .05) with any of the independent variables. Multiple regression analyses indicated that comorbidity, stage, and initial treatment modality were significant variables in one or more of the models predicting charges incurred during the 0- to 3-month, 3- to 12-month, total 1-year, and total 2-year billing periods. The models yielded R2 values for the total 1- and 2-year billing periods of 0.5246 and 0.5055, respectively.

CONCLUSIONS

This work supports continued study of measures that may result in earlier detection of laryngeal cancer as a potential means of reducing management charges. These results also indicate that a more accurate method of stratifying the disease severity of laryngeal cancer patients for reimbursement purposes would include measurements of the severity of the index disease as well as comorbid diseases.

Oral transmucosal fentanyl pretreatment for outpatient general anesthesia

The oral transmucosal formulation of fentanyl citrate (OTFC) has been reported to be an effective sedative, providing convenient and atraumatic sedation for children prior to general anesthesia or painful diagnostic procedures. Thirty-three young children (24-60 months of age) scheduled for outpatient general anesthesia for treatment of dental caries were enrolled in this randomized placebo-controlled clinical trial. To determine the effectiveness of the OTFC premedication, patient behavior was evaluated using three distinct outcome ratings. A sedation score rated behavior in the waiting room prior to OTFC as well as 10 minutes and 20 minutes after OTFC. A separation score rated the child's response to being separated from his/her parent or guardian for transport to the dental operatory. Finally, a cooperation score rated the child's acceptance of the mask induction. The OTFC formulation was well tolerated by most of the children in this study. Compared with the placebo oralet, the active OTFC improved behavior for separation from the parent (P < .05) and cooperation with the mask induction (P < .05). The duration of surgery and the time of recovery did not differ between placebo and active premedication. Side effects including respiratory and cardiovascular complications were reported more frequently in the active fentanyl group. Continuous monitoring of respiratory function is essential when using this unique and effective formulation of fentanyl for pediatric preanesthetic sedation.

Epithelial ovarian carcinoma in the reproductive age group

BACKGROUND

A retrospective review of women age < or = 40 years with epithelial ovarian carcinoma was undertaken to determine whether patient age and tumor grade are independent prognostic factors for survival, to investigate the survival rate for young women with ovarian carcinoma, and to characterize these young women in terms of reproductive capability.

METHODS

The tumor registry of the Massachusetts General Hospital was used to identify cases of ovarian carcinoma diagnosed between January 1980 and July 1996. Patient records and pathology were reviewed. Survival rates were calculated by the Kaplan-Meier method and Cox proportional hazards models were used to determine the independent effect of each variable on survival.

RESULTS

Ninety-two tumors epithelial tumors were identified with 46 (50%) classified as borderline. In the univariate analysis, stage (P < 0.001), grade (P < 0.001), residual disease (< or = 2 cm vs. > 2 cm, P < 0.001), and age (< 30 years vs. 31-40 years; P = 0.019) were found to be significant prognostic factors for survival. However, in the multivariate analysis only tumor grade (with borderline tumors assigned a grade of 0) and stage were significant predictors of survival (P < 0.01 for both). The 5-year survival rate for carcinoma patients with advanced disease was 22.9%. Patients with borderline tumors were more likely be diagnosed during an evaluation for infertility and were more likely to have successful live births after carcinoma treatment.

CONCLUSIONS

Young women with advanced epithelial carcinoma have a 5-year survival rate similar to that quoted in the literature, despite the use of more aggressive chemotherapeutic regimens. Patients with borderline tumors of any stage have an excellent prognosis for preserving fertility options.

Efficacy of media enriched with nonlactate-generating substrate for organ preservation: in vitro and clinical studies using the cornea model

BACKGROUND

Using a rabbit cornea model, our recent study demonstrated that Chen Medium (CM), an isotonic media enriched with nonlactate-generating high-energy substrates, is very effective for organ preservation. In the present study, the efficacy of CM is further evaluated with human corneas

METHODS

The effectiveness of CM and Optisol for preserving the endothelial integrity of human corneas in vitro was evaluated by scanning electron microscopy. Clinical efficacy was evaluated in a total of 83 patients: 10 patients with keratoconus grafted randomly with either CM- or Optisol-stored cornea of the same donor, and 73 patients with various conditions grafted with CM-stored corneas. After surgery, visual acuity and quality of the graft were monitored for up to 4.6 years.

RESULTS

The scanning electron microscopic study revealed that after 11-day storage at 4 degrees C, the CM-stored cornea had only marginal disruptive changes, 9.4+/-1.1%, in endothelial cells, as opposed to 42.4+/-4.6% of the Optisol-stored cornea. All 78 CM-stored corneas, including 67 with 12.2- to 17.7-hr death-to-storage time, 3-7.6 days of storage time, and initial marginal quality before storage, were successfully transplanted. These grafts were thin and clear, with an excellent epithelial integrity and without significant changes in endothelial cell density. Five Optisol-stored corneas were also successfully grafted; one of them, however, was edematous for about 4 weeks, and all the grafts were slightly thicker with substantial endothelial cell loss.

CONCLUSION

Using a cornea model, present and recent studies show that CM is very effective for preserving tissue viability and endothelial integrity. Previous study revealed that CM-stored tissues maintained high levels of ATP and metabolic function, with suppression of lactate formation and accumulation. Thus, these findings support the concept that preservation of tissue viability is closely associated with the ability of the tissues to retain metabolic activity, to generate ATP efficiently, and to prevent acidosis effectively during storage.

Toxicity and allergy to local anesthesia

Considering the amount of local anesthetic administered on a daily basis, dental professionals must be familiar with the factors that influence the dose and type of local anesthetic that induces a toxic or allergic reaction. In addition to the route and rate of administration, the patient's physical condition and health may also influence the dose of local anesthetic that could be safely administered. This article reviews the different causes of local anesthesia toxicity and allergy. With prevention and early recognition of the warning signs, poor prognosis can be avoided.

Active vs. passive methods of recruiting ethnic minority women to a health promotion program

Ethnic minority women have been underrepresented in health promotion research. There is a need to develop effective methods of recruiting ethnic minority women to health promotion programs and research studies. This article evaluates several methods for recruiting ethnic minority women to a study of a telephone and mail intervention encouraging participation in a home-based walking program. One hundred twenty-six sedentary ethnic minority women between the ages of 25 and 55 were recruited using two types of approaches. Number of participants screened, number enrolled, and recruitment efficiency (ratio of number recruited/number screened) were assessed. "Active" recruitment, contacting targeted individuals in person, by phone, or by mail, yielded 236 screened and 29 recruited with a recruitment efficiency of 11%. "Passive" recruitment, informing the community through public notices and waiting for volunteers to call, yielded 151 screened and 97 recruited with a recruitment efficiency of 64%. Those recruited by active or passive methods did not differ by demographic characteristics, baseline psychosocial variables, or dropout rates. Passive recruits walked significantly more at five-month follow-up than active recruits. Passive recruitment may be more economical at the cost of potentially biased samples.

Localization of a novel gene for nonsyndromic hearing loss (DFNB17) to chromosome region 7q31

Autosomal recessive nonsyndromic hearing loss (ARNSHL) is the most common form of hereditary hearing impairment (HHI). To date, 16 different loci have been reported, making ARNSHL an extremely heterogeneous disorder. One of these loci, DFNB4, was mapped to a 5-cM interval of 7q31 in a large Middle-Eastern Druze family. This interval also includes the gene for Pendred syndrome. We report on three new families with HHI from the Madras region of southern India that demonstrate linkage to 7q. Their pedigrees are compatible with autosomal recessive inheritance. Furthermore, the largest family identifies a novel locus (DFNB17) telomeric to the DFNB4 and Pendred intervals. A 3-cM region of homozygosity by descent between markers D7S486 and D7S2529 is present in all affected individuals in this family and generates a multipoint LOD score of 4.24. The two other families map to the previously reported DFNB4 region but have insufficient power to attain significant LOD scores. However, mutations in the Pendred syndrome gene are present in one of these families.

A home-based behavioral intervention to promote walking in sedentary ethnic minority women: project WALK

A home-based telephone and mail intervention was evaluated for its effectiveness in promoting walking in a sample of sedentary, ethnic minority women. One hundred twenty-five women (ages 23-54) were randomly assigned to behavioral or brief educational interventions. Women in the 8-week behavioral condition received behavior change materials through the mail and 6 structured telephone counseling sessions. Educational condition participants received a single 5-min telephone call and educational information. Both groups reported significantly increased walking at a 2-month posttest (M change = 86 and 81 min per week for behavioral and educational groups, respectively) and 5-month follow-up (M change = 40 and 52 min per week). A 30-month follow-up of 50 participants indicated both groups continued to report more walking than at baseline. The behavioral intervention was not superior to the educational condition at any assessment point. The findings may be explained as (a) both interventions were equally effective, so extensive telephone counseling is unnecessary; (b) changes over time reflected secular trends; or (c) increases in self-reported walking may be due to socially desirable reporting. Other strategies need to be evaluated for promoting walking that are tailored to the needs of ethnic minority women.

Presymptomatic diagnosis of nonsyndromic hearing loss by genotyping

BACKGROUND

Nonsyndromic hearing loss (NSHL) is the most common type of hereditary hearing impairment (HHI). It is genetically heterogeneous, and although the exact number of genes is not known, 38 loci have been identified. By cloning the relevant genes and studying the function of the encoded proteins at the molecular level, it may be possible to impact the habitation of persons at risk for HHI. Currently, for select families, presymptomatic diagnosis of NSHL by genotyping is possible.

OBJECTIVE

To provide presymptomatic diagnosis of HHI to individuals in select families who have participated in linkage studies.

DESIGN

In 2 large families with autosomal dominant HHI, genes for NSHL were mapped to chromosomes 6 (DFNA10) and 19 (DFNA4). In each family, the phenotype is one of progressive sensorineural hearing loss that begins in the individual's mid-30s and progresses to a severe-to-profound loss requiring amplification. Presymptomatic diagnosis was requested by, and provided to, 19 at-risk persons in these kindreds.

RESULTS

By reconstructing haplotypes through the use of short tandem repeat polymorphisms tightly linked to the disease gene, risk calculations and genetic counseling were provided to these persons.

CONCLUSIONS

By simple Mendelian genetics, the risk of inheriting a fully penetrant autosomal dominant NSHL gene from a single affected parent is 50% for each offspring. However, by reconstructing haplotypes in families in which an HHI gene has been localized, this risk can be changed substantially.

Labor induction with intravaginal misoprostol in term premature rupture of membranes: a randomized study

OBJECTIVE

To evaluate the safety and clinical effectiveness of intravaginal misoprostol, a synthetic prostaglandin E1 analogue, for labor induction in gravidas with premature rupture of membranes (PROM) at term.

METHODS

One hundred forty-one pregnant women with term PROM were assigned randomly to one of two induction groups: 1) intravaginal misoprostol or 2) intravenous oxytocin by continuous infusion.

RESULTS

Seventy subjects were allocated to the misoprostol group and 71 to the oxytocin group. The mean (+/- standard deviation) interval from induction to delivery was significantly shorter in the misoprostol group (416 +/- 276 compared with 539 +/- 372 minutes; P = .04). In 85.7% of patients in the misoprostol group, only one dose was required. Intrapartum complication rates, mode of delivery, and neonatal or maternal adverse event rates were similar in the two treatment groups. Uterine tachysystole occurred more frequently with misoprostol than with oxytocin (28.6% compared with 14.0%; P < .04).

CONCLUSION

Intravaginal administration of misoprostol induces labor safely and effectively in patients with PROM at term.

Changes in the interpupillary distance with age and its effect on the near fusion free position

PURPOSE

The effect of the rate of the interpupillary distance (IPD) change with age on the near fusion free position was investigated in the present study.

METHODS

Three hundred and fifty-two children aged from 2 to 16 years of age were tested. Interpupillary distance was estimated with a modified Viktorin's method and the near fusion free position was measured with a modified Maddox Wing.

RESULTS

The results reveal a significant difference in IPD growth rate between females and males and between children aged below and above 5 years. Most children below 5 years of age were orthophoric, but heterophoria became more common above 5 years of age.

CONCLUSION

The present study suggests that the oculomotor control system for convergence can compensate for age changes in IPD.

Airway reactivity in welders: a controlled prospective cohort study

In a 3-year survey, respiratory symptoms, spirometry, and methacholine reactivity were measured annually in welders (n = 51) and non-welder controls subjects (n = 54) to determine whether welding-related symptoms are associated with accelerated decline in lung function or changes in airway reactivity. In the cross-workshift study, maximal midexpiratory flow rate declined reversibly during a welding day, whereas 1-second forced expiratory volume and forced-vital capacity were unchanged. In the longitudinal study, the welders had significantly more reversible work-related symptoms of cough, phlegm, wheeze, and chest tightness than the non-welder shipyard control subjects. In this group of actively working welders, across-workshift changes in midflow and reversible symptoms were related to the welding occupation, but evidence for chronic irreversible effects on spirometry or airway reactivity was not seen over the 3 years of observation. The short period of observation was not optimal for detecting a chronic effect on lung function. Work practices and engineering controls may be successfully preventing irreversible respiratory effects, but not mild reversible effects, in this group of welders.

Early postoperative angiographic assessment of radial grafts used for coronary artery bypass grafting

Despite a revival of interest in using the radial artery as an alternative conduit for myocardial revascularization, little angiographic documentation of early postoperative results has been presented, particularly in North America. Accordingly, 60 of 150 patients who underwent coronary artery bypass with radial arteries from November 1993 to July 1995 have had postoperative cardiac catheterization at our institution. The patency rate of the radial artery grafts was 95.7% (90 of 94 grafts patent) with an average internal diameter of 2.51 mm. Four radial artery grafts showed diffuse narrowing. The patency rate of the internal thoracic artery grafts was 100% with an average internal diameter of 2.25 mm. Three of 62 grafts demonstrated diffuse narrowing. Two of 24 (7.7%) saphenous vein grafts were occluded; the average internal diameter was 3.23 mm. The internal thoracic artery, the radial artery, and saphenous vein grafts were, respectively, 7.5%, 19.5%, and 53.3% larger than the anastomosed native coronary arteries. Graft-dependent flow was found in 81.1% of the radial artery grafts.

CONCLUSION

The results of this study demonstrate that the short-term patency rate of radial artery grafts is excellent.

Incidence of vocal fold paralysis in infants undergoing ligation of patent ductus arteriosus

BACKGROUND

Left-sided, iatrogenic vocal fold paralysis (IVFP) secondary to recurrent laryngeal nerve injury is a potential complication of ligation of patent ductus arteriosus (PDA). This study investigates specific risk factors associated with IVFP.

METHODS

A retrospective chart review was performed for all infants 12 months of age or younger who underwent operative PDA closure at the University of Iowa from January 1, 1991, to January 1, 1994.

RESULTS

Six cases of IVFP were diagnosed in 68 infants who underwent PDA ligation using clips (52.9%), suture ligatures (41.2%) or both (5.9%). Compared with infants without postoperative IVFP, infants with IVFP were smaller at birth (0.9 versus 2.3 kg; p < 0.001) and more premature (gestational age, 26.3 versus 33.8 weeks; p < 0.001), and were smaller (1.1 versus 3.4 kg; p < 0.001) and younger (31.9 versus 88.4 days; p < 0.001) at operation. Weight gain from birth to operation was significant only in infants without postoperative IVFP (p < 0.05). Although the overall incidence of IVFP in all infants undergoing PDA closure was 8.8%, five of the six cases (83.3%) of IVFP occurred in extremely low birth weight infants, ie, those weighing 1 kg or less at birth. Among the cohort of extremely low birth weight babies undergoing operation, the incidence of IVFP was 22.7%. Iatrogenic vocal fold paralysis was associated only with the use of surgical clips; however, because clips were used in 90.9% of the premature infants requiring PDA ligation, it was not possible to establish whether suture ligature is a safer technique.

CONCLUSIONS

This study demonstrates that the single major risk factor for IVFP after ligation of PDA is birth weight less than 1 kg.

Chondroid syringoma of the head and neck: clinical management and literature review

This report describes the case of a chondroid syringoma occurring in the nasofacial groove of a 60-year-old woman. This benign, mixed epithelial tumor is infrequently seen by the otolaryngologist-head and neck surgeon, and therefore may not be included in the differential diagnosis of a nodular lesion on the skin of the head and neck. However, the most frequent site of occurrence for these relatively rare cutaneous lesions is the head and neck region. Histologically, these tumors are quite similar to pleomorphic adenomas of salivary gland origin, and optimal surgical management similarly requires removal of a cuff of normal tissue, rather than a simple shelling out of the lesion. The clinical presentation, pathology and recommended management of this rare tumor are discussed.