PubMed Health⌕ Search

Biomedical subjects

M H Clark

Publications and source records attributed to M H Clark.

13 recordsLinked to original sources
PubMed2001

Monitoring pudendal nerve function during labor.

BACKGROUND: To determine methodology and feasibility of pudendal nerve monitoring during labor and delivery. METHODS: With Institutional Review Board approval, 13 low-risk, singleton pregnant women were recruited. The latency and amplitude of the perineal branch of the pudendal nerve compound muscle action potential were recorded during the second stage of labor and after delivery. With the first two patients, a wire electrode was used to stimulate the pudendal nerve continuously at the ischial spine. For the remaining 11 patients, a St. Mark's electrode was used to stimulate transvaginally. Aurethral ring electrode on a 14 French foley catheter monitored the response from the urethral sphincter. All patients received prophylactic antibiotics. EXPERIENCE: Twelve patients delivered vaginally, and one by cesarean. In two patients, continuous wire stimulation showed a gradual decrease in amplitude. Changes were minimal over 15-minute intervals. Wire electrode placement was technically difficult and dislodged easily. With the remaining 11 patients, all had data available for interpretation, and of the 85 potential perineal branch of the pudendal nerve compound muscle action potentials, 53 were obtained. No patients developed cystitis. CONCLUSION: Intrapartum assessment of pudendal nerve function is feasible. Continuous wire stimulation is technically more difficult and does not provide additional information beyond that available from intermittent stimulation.

Action Potentials↗
PubMed2000

Correlation of intraurethral ultrasonography and needle electromyography of the urethra.

OBJECTIVE: To correlate structural intraurethral ultrasound findings with needle electromyography of striated urethral sphincters in young continent nulliparas. METHODS: Twenty-three nulliparas, each less than 35 years old and without pelvic floor disorders, were recruited at Methodist Hospital in Indianapolis, Indiana, and the University of Louisville in Louisville, Kentucky. Each had concentric needle electromyography of their urethra to localize their striated urethral sphincter. Intraurethral ultrasound was used to identify the needle tip and layer in which it was found, examine the sonographic appearance of periurethral anatomy, and measure the thickness of hypoechoic and outer hyperechoic layers. RESULTS: Three layers were seen on intraurethral ultrasound: a mildly hyperechoic inner layer, a hypoechoic middle layer, and a hyperechoic outer layer. The concentric needle tip was seen in all subjects and showed motor unit action potentials when located in the outer hyperechoic layer. The mean thickness of the hypoechoic layer was 2.5 mm, and the mean thickness of the outer hyperechoic layer was 2.6 mm. CONCLUSION: Motor unit action potentials showed that striated muscle was present in the outer hyperechoic layer on intraurethral ultrasound, implying that it contains the striated urethral sphincter.

Action Potentials↗
PubMed2000

Intraclass correlations from a community-based alcohol prevention study: the effect of repeat observations on the same communities.

OBJECTIVE: School- and community-based alcohol prevention programs are often evaluated using a group-randomized trial (GRT) design with a single pretest and a single posttest survey. To size such studies properly, investigators need accurate estimates of the variance and intraclass correlation that will be operative in their analyses. Until recently, the only available estimates were based on cross-sectional analyses. A recent report suggests that values from cross-sectional analyses may overestimate the intraclass correlation operative in pretest-posttest analyses. The purpose of this article is to review these issues, present estimates of intraclass correlation for a variety of alcohol-related endpoints based on cross-sectional analyses and to compare those estimates to estimates based on pretest-posttest analyses. We will also show how these estimates can be used to establish optimal sample sizes for GRTs to evaluate school- and community-based alcohol prevention programs. METHOD: Data were collected from 18 to 20 year olds and high-school seniors as part of an alcohol prevention effort employing a group-randomized trial design with a single pretest and a single posttest survey. Data were analyzed via mixed-model regression methods to estimate components of variance. Those components were then used to compute the intraclass correlations operative in both cross-sectional analyses and in pretest-posttest analyses. RESULTS: Results indicate that intraclass correlations operative in pretest-posttest analyses are much smaller than are those operative in cross-sectional analyses. CONCLUSIONS: Our findings indicate that future alcohol-prevention studies employing a group-randomized trial design with a single pretest and single posttest survey may not need to be as large as previously suggested by intraclass correlation estimates based on cross-sectional data. This holds true even if they are analyzed to reflect the extra variation typical of group-randomized trials.

Adolescent↗
PubMed1999

Fecal incontinence and the menstrual cycle: a case report.

Urinary tract dysfunction influenced by the menstrual cycle has been described. This case demonstrates mensturation-influenced fecal incontinence. The patient had difficulty with stool control and rectal hygiene only during the week prior to her period. These symptoms had been present since she had discontinued oral birth control. Progestin levels and anal manometry were obtained during the secretory and luteal phases of her cycle and demonstrated a difference in resting anal tone between phases. Progestin smooth muscle relaxation is presumed to have uncovered an already weakened anal continence mechanism. With reinstitution of oral contraceptive pills the patient's cyclic fecal incontinence resolved.

Adult↗
PubMed1989

Nevra in a Greek village: idiom, metaphor, symptom, or disorder?

The folk model for nevra (nerves) in Methana, Greece, is discussed in terms of the contradiction between the ideal of solidarity, central to the local family ideology, and the reality of interpersonal conflict in daily life. Contradictions in values resulting from rapid socioeconomic change are also considered. Nevra, a broad, ambiguous, negotiated concept, expresses a wide range of symptoms and serves as a culturally condoned medium for expression of otherwise unacceptable emotions. The notion of nevra provides a metaphor for social disorder such as interpersonal conflict between close kinfolk and value conflicts between generations. Case studies of social interaction demonstrate the relationship of nevra to various kinds of social disorder as well as to what Western psychiatry labels emotional disorders. Nevra is also related to other idioms of distress: the evil eye, possession by the devil, excessive drinking, and pilgrimages to religious shrines.

Adult↗
PubMed1989

A pedigree primer.

Pedigree-taking skills can promote an understanding of how genetic information relates to a comprehensive family health assessment. The format of the pedigree is used to structure and organize data gathered in the assessment process. The pedigree can assist the nurse and genetics specialist to identify possible patterns of inheritance. This article outlines for the staff nurse the pertinent areas that need to be explored during the assessment process. It discusses common terms and symbols used in the pedigree. Information gathered from the health assessment of an adolescent with Usher's syndrome is used for an example of how the pedigree is constructed.

Adolescent↗
PubMed1984

Is schizophrenia rare if grain is rare?

If, as hypothesized, neuroactive peptides from grain glutens are the major agents evoking schizophrenia in those with the genotype(s), it should be rare if grain is rare. To test this, we analyzed the results of our clinical examinations (e.g., kuru) and observations of anthropologists on peoples consuming little or no grain. Only two overtly insane chronic schizophrenics were found among over 65,000 examined or closely observed adults in remote regions of Papua New Guinea (PNG, 1950-1967) and Malaita , Solomon Islands (1980-1981), and on Yap , Micronesia (1947-1948). In preneuroleptic Europe over 130 would have been expected. When these peoples became partially westernized and consumed wheat, barley beer, and rice, the prevalence reached European levels. Our findings agree with previous epidemiologic and experimental results indicating that grain glutens are harmful to schizophrenics.

Adolescent↗