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M L Nance

Publications and source records attributed to M L Nance.

26 records · Page 2Linked to original sources

Awareness of memory loss after severe closed-head injury.

This study investigated unawareness of memory loss in 48 severe closed-head injury patients. Awareness was measured as the correlation of patients' memory test scores with their self-ratings on the Everyday Memory Questionnaire (EMQ). Patients who endorsed atypical memory failures on the EMQ were classified as invalid responders. Invalid responders had poorer memory test performances and a higher rate of focal left hemispheric lesions, but did not report greater emotional symptoms. Correlations between memory test scores and memory self-ratings were weaker among invalid responders or those classified as depressed, and stronger among valid responders, especially those classified as non-depressed. The results indicate that the validity of memory self-reports is influenced by both neurogenic and psychogenic factors, and suggest that invalid responding is an important problem with self-reports by brain-injured patients.

Adolescent↗

Large animal model of ischemic mitral regurgitation.

A large animal model of ischemic mitral regurgitation (MR) that resembles the multiple presentations of the human disease was developed in sheep. In 76 sheep hearts, the anatomy of the coronary arterial circulation was determined by observation and polymer casts. Two variations, types A and B, which differed by the vessel that supplied the left ventricular apex, were found. In all hearts, the circumflex coronary artery has three marginal branches and terminates in the posterior descending coronary artery. The amount and location of left ventricular (LV) mass supplied by each marginal circumflex branch was determined by dye injection and planimetry. In type A hearts, ligation of the first and second marginal branches infarcts 23% +/- 3.0% of the LV mass, does not infarct either papillary muscle, significantly (p < 0.001) increases LV cavity size 48% at the high papillary muscle level by 8 weeks, and does not cause MR. Ligation of the second and third marginal branches infarcts 21.4% +/- 4.0% of the LV mass, includes the posterior papillary muscle, significantly increases (p < 0.001) LV cavity size 75%, and causes severe MR by 8 weeks. Ligation of the second and third marginal branches and the posterior descending coronary artery infarcts 35% to 40% of the LV mass, increases LV cavity size 39% within 1 hour, and causes massive MR. After moderate (21% to 23%) LV infarction, development of ischemic MR requires both LV dilatation and posterior papillary muscle infarction; neither condition alone produces MR. Large posterior wall infarctions (35% to 40%) that include the posterior papillary muscle produce immediate, severe MR.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Socioeconomic impact of gunshot wounds in an urban pediatric population.

Trauma continues to be a leading cause of death and disability in the pediatric population. We retrospectively reviewed 139 cases of gunshot wounds (GSW) in patients under 17 years of age, who were admitted to Children's Hospital of Philadelphia from January 1, 1986 to June 30, 1992. There were 4,587 trauma admissions during this period, and the proportion of GSW victims increased from 1.02% in the first 12 months to 5.6% in the final 12 months of the study (P < .001). The average age of patients treated for GSW was 11.5 +/- 4.4 years. Eighty percent were male, 88.5% were black, and the average hospital stay was 5.6 +/- 8.5 days. In this group, the mean trauma score was 14.5 (range, 1 to 16), and the mean injury severity score was 9.8 (range, 1 to 75). There were 11 deaths (7.9%), with head injuries the most common cause (20.6%). The predicted probability of survival for the patients who died was 0.31, compared with 0.97 for those who survived. The extremities were the most commonly injured area, (41%) but GSW to the abdomen were the most likely to require operative intervention (85.7%). The shootings were considered intentional in only 26.6%), and the assailant was known in 32.4% of instances. Of the teenage patients tested for substance abuse, results were positive for 36%. The majority of GSW victims (68%) had public or no insurance. In contrast, of the overall hospital population, only 40% had public or no insurance. Over the period of study, the hospital lost an estimated $1.63 million in the care of these patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Home parenteral nutrition after near total enterectomy.

Six patients with extreme short bowel syndrome (4.2 +/- 4.9 cm of residual small bowel) were provided home parenteral nutrition (HPN) for 14,397 days. The average age at onset of HPN was 38 years (18-64 years). Patients maintained body weight at 97% of ideal (86-112%) with mean serum albumin of 3.7 +/- 0.6 g/dL (normal 3.5-5.8 g/dL), serum transferrin of 341 +/- 104 mg/dL (normal 200-400 mg/dL), and mean serum pre-albumin of 27.5 +/- 12.6 mg/dL (normal 16.6-43 mg/dL). Hospital admission for HPN-related complications was required 10.3 times/patient for a total of 864 hospital days and was catheter related in 71% of episodes. Catheter sepsis occurred once per 436 catheter days and required catheter removal in only 33% of instances. Five patients were able to resume an oral diet, five had returned to work or school, and three were married with family. HPN allowed return to a quality productive life with acceptable morbidity following catastrophic massive bowel resection.

Adolescent↗

Pathogenesis of ischemic mitral insufficiency.

We developed a new animal model of ischemic mitral insufficiency in sheep and used it to test the hypothesis that the combination of posterior papillary muscle infarction and left ventricular dilatation was required to produce mitral regurgitation after acute inferior myocardial infarction of moderate size. In 12 sheep, ligation of the first two circumflex marginal coronary arteries infarcted 23% of the left ventricular mass, increased left ventricular cavitary area from 13.2 +/- 1.2 cm2 to 20.0 +/- 2.7 cm2 by 8 weeks and did not produce ischemic mitral regurgitation. In 13 sheep, ligation of the second and third circumflex marginal arteries infarcted 21% of the left ventricular mass and, in 11 of these sheep, the posterior papillary muscular mass as well. When the papillary muscle was included, this infarction produced progressively severe mitral regurgitation over 8 weeks, as left ventricular cavitary area increased from 12.5 +/- 2.6 cm2 to 22.8 +/- 3.8 cm2. We conclude that neither posterior papillary muscle infarction nor left ventricular dilatation alone produces ischemic mitral regurgitation after moderate-sized inferior wall infarction, but that the combination does.

Animals↗