Biomedical subjects
R J Morris
Publications and source records attributed to R J Morris.
Bimedial rectus recession using the anchored hang-back technique.
Hang-back recession of a rectus muscle offers several advantages over conventional techniques: a reduced risk of scleral perforation, easy intraoperative adjustment, and a convenient site for suturing to the sclera. There are also disadvantages: the muscle tends to collapse, thereby increasing the effective recession and making the result less predictable. In addition, the insertion cannot accurately be displaced upward or downward, as may be required to correct A- and V-patterns, or vertical deviations. The authors describe a modified technique, an anchored hang-back recession, and discuss the results in 60 consecutive cases of bimedial rectus recession.
Normal spatial learning despite regional inhibition of LTP in mice lacking Thy-1.
The process of learning involves stable changes in synaptic efficacy for which long-term potentiation (LTP) provides a widely adopted mammalian model. Synaptic modification induced by learning or LTP may involve the action of cell adhesion molecules. One such candidate is the ubiquitous neuronal glycoprotein Thy-1. In mice in which the gene encoding Thy-1 has been inactivated, we find a regionally selective impairment of LTP in vivo in the hippocampal formation: LTP is normal in area CA1 but strongly inhibited in the dentate gyrus. Spatial learning by Thy-1-deficient mice, as assessed in the watermaze, is unimpaired. Thus LTP in the cortical input to the dentate gyrus seems not to be required for spatial learning.
Mycobacterium fortuitum infection of the sternum. Review of the literature and case illustration.
Sternal wound infection with atypical mycobacteria following open heart surgery is a rare occurrence. Previous reports have described infection by Mycobacterium fortuitum, an acid-fast bacillus and member of a larger family of rapidly growing mycobacteria. The source and mode of transmission have not been identified. Surgical debridement and the combination of aminoglycosides and quinolones have been shown to be effective methods of treatment. More recently, clarithromycin has been shown to be the drug of choice against rapidly growing mycobacteria. We describe a 49-year-old woman who underwent infundibular stenosis repair and in whom M fortuitum sternal osteomyelitis developed. Total sternectomy, muscle flap reconstruction, and antibiotic treatment successfully eradicated the infection.
Internal thoracic artery for coronary artery grafting in octogenarians.
BACKGROUND: Use of the left internal thoracic artery as a bypass graft has been shown to result in better long-term patency and improved survival. In elderly patients, the internal thoracic artery has been used less often for coronary artery bypass grafts because of the belief that greater morbidity and mortality are associated with this procedure. This study was undertaken to test this premise in the octogenarian population. METHODS: Over an 8-year period, 474 consecutive patients 80 years of age and greater had coronary artery bypass grafting. The left internal thoracic artery was used in 188 patients (39.7%) (group 1) and saphenous vein grafts only (group 2), in 286 (60.3%). The mean age was 82.6 years (range, 80 to 95 years). There were 312 men (65.8%) and 162 women (34.2%). RESULTS: Use of the internal thoracic artery as a graft has risen steadily each year, as has the number of patients who are octogenarians. The hospital mortality rate was 7.8%. Patients in group 1 had a mortality rate of 9.0% and patients in group 2, a mortality rate of 7.0%. The mortality rate among survivors at 1 year was 6.7%. Long-term survival was significantly greater in group 1. CONCLUSIONS: On the basis of this study, we conclude that the internal thoracic artery is the bypass graft of choice, especially in regard to long-term mortality, and should not be denied to this high-risk group.
Comfortable effort level revisited.
The purpose of this study was to measure the variability of frequency and intensity of speech, using multiple voice samples obtained over a period of time at a speaker's "comfortable effort level." Variability in vocal output within and across several experimental sessions was assessed from measures of speaking fundamental frequency (SFF) and vocal intensity for utterances repeated three times a day over a 3-day period. Three distinct age groups of men and women-young, middle-aged and elderly-repeated the vowel /a/, read a standard passage, and spoke extemporaneously during each experimental session. Results indicated that variability in SFF and intensity were present across experimental sessions, age groups, gender, and speaking samples. Generally, group means indicated that approximately +/- 1 semitone of variability for SFF and approximately 2 db sound pressure level (SPL) variation in vocal intensity from any one experimental session to the next could be expected; individual variations within any group may reach two semitones and 6 db SPL.
Comparison of various automatic means for measuring mean fundamental frequency.
The purpose of this paper was to evaluate the reliability of, and agreement among, six speech analysis systems in the determination of fundamental frequency. Five male and five female speakers provided oral reading and sustained vowel samples for analysis. Each sample was analyzed five times by each system. The results indicated high reliability for all of the systems for both sexes and both utterance types. Agreement among the systems was high for the male sustained vowels and the female oral reading samples. In contrast, poor agreement occurred among the systems for the male oral reading samples and the female sustained vowels. The findings indicate that the output of these automatic methods tends to be consistent over repeated trials within the systems in their extraction of fundamental frequency; however, agreement among these systems varies.
Using UvrABC nuclease to detect 7,12-dimethylbenz[a]anthracene anti-diol epoxide-DNA binding specificity in the mouse H-ras gene.
DNA fragments modified with chemically synthesized 7,12-dimethylbenz[a]anthracene anti-diol epoxide (anti-DMBADE) are sensitive to UvrABC nuclease incision. The incisions occur mainly 7 bases 5' and 4 bases 3' of an anti-DMBADE-modified adenine or guanine residue, and the kinetics of incision at different sequences in a DNA fragment are the same. These results indicate that UvrABC incision on anti-DMBADE-DNA adducts is independent of DNA sequences and is quantitative, the same as on syn-DMBADE-DNA adducts. This method was used to analyze the anti-DMBADE-DNA binding spectrum in the exon 2 region of the mouse H-ras gene, and it was found that anti-DMBADE binds to the two adenine residues at codon 61 of the H-ras gene with an average affinity. Previously, we have demonstrated that syn-DMBADE binds strongly to the adenines at codon 61 of H-ras; these results together suggest that the oncogenic mutation in H-ras may be induced by anti- and syn-DMBADE-DNA adducts.
Subcutaneous abdominal adipose tissue blood flow: variation within and between subjects and relationship to obesity.
1. We assessed the variation in subcutaneous abdominal adipose tissue blood flow within and between subjects and investigated whether it is correlated with body mass index. 2. We measured body mass index and subcutaneous abdominal adipose tissue blood flow in 38 fasting subjects on the same day and on different days and, in a subgroup of 16 subjects, after a mixed meal. 3. In 190 measurements in the fasted state, subcutaneous abdominal adipose tissue blood flow was significantly more variable between subjects than could be accounted for by the within-subject variation alone. Subcutaneous abdominal adipose tissue blood flow was also significantly more variable between days within subjects than could be accounted for by within-day variation alone. Fasting and post-prandial subcutaneous abdominal adipose tissue blood flow were negatively correlated with body mass index, as was the post-prandial rise in subcutaneous abdominal adipose tissue blood flow. Multiple regression analysis showed that fasting blood flow was not dependent on insulin concentration after allowing for body mass index. There was no correlation between post-prandial subcutaneous abdominal adipose tissue blood flow and insulin concentration. 4. Insulin does not appear to have a direct vasodilatory effect in subcutaneous adipose tissue. Obese subjects have lower fasting and post-prandial subcutaneous abdominal adipose tissue blood flow. This may be because of a blunted response to sympathetic stimulation, or it may be another aspect of the insulin-resistant state.
Further contrasts between self-reflectiveness and internal state awareness factors of private self-consciousness.
Although widely used as a unitary measure of self-focused attention, the Private Self-Consciousness subscale (Fenigstein, Scheier, & Buss, 1975) contains two factors. In the present study, this subscale and its self-reflectiveness (SR) factor predicted greater shame, guilt, other-directedness, and social anxiety; but the internal state awareness (ISA) factor displayed relationships that were in the opposite direction. Contrasts between SR and ISA often became more obvious in partial correlations, when one factor was examined while controlling for the other. In relationships with personal and social identity, SR appeared to reflect public as much as private self-consciousness. These data support recent suggestions that it may be necessary to construct more adequate measures of private self-consciousness.
Microphthalmos in association with Gorlin's syndrome.
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Asthma. Specific preventive strategies.
Asthma can be a destructive disease over time, resulting in partially irreversible obstruction. Early intervention is essential, and preventive strategies are preferred to treatment for flare-ups. These strategies include intensive patient education and constant monitoring of airflow as well as effective pharmacotherapy and management of concomitant disorders and side effects. Because allergy is a component in half or more of patients, consultation with an allergist is recommended. New agents for both oral use and inhalation are either in development or will soon be available.
Torticollis secondary to ocular pathology.
We report a series of 15 children, six male and nine female, of average age 20 months, seen at a paediatric orthopaedic clinic with torticollis. Orthopaedic examination revealed a normal range of neck movement in all cases but in seven there was palpable tightness in the absence of true shortening or contracture of the sternomastoid muscle. The patients were prospectively referred for ocular examination. In five of the 15 an ocular cause for the torticollis was detected with underaction of the superior oblique muscle in three, paresis of the lateral rectus muscle in one and nystagmus in one. Another two patients were found to have an abnormal ocular examination which was thought to be unrelated to their torticollis. Three of the patients with ocular torticollis required extra-ocular muscle surgery to abolish the head tilt and one of these had a tight sternomastoid muscle. Two of the non-ocular group had surgical release of the sternomastoid muscle; in the rest, the condition either resolved with physiotherapy or required no active treatment. We recommend that all patients with torticollis and no clear orthopaedic cause are referred for ocular assessment since it is not possible clinically to distinguish ocular from non-ocular causes.
NCAM requires a cytoplasmic domain to function as a neurite outgrowth-promoting neuronal receptor.
The neural cell adhesion molecule (NCAM) promotes axonal growth via a homophilic binding mechanism by acting both as a neuronal receptor and a substratum ligand. We have previously shown that the GPI-linked 120-kDa isoform of NCAM, which lacks a cytoplasmic domain, is effective at promoting neurite outgrowth as a cellular ligand. To test its ability to function as a neuronal receptor, we have transfected PC12 cells with a cDNA encoding human GPI-linked NCAM and tested clones displaying stable cell surface expression of this isoform for their ability to respond to NCAM in a cellular substratum. Although they continued to express endogenous transmembrane rat isoforms of NCAM (140 and 180 kDa), PC12 cells expressing the GPI-linked NCAM lost their ability to extend neurites in response to substratum associated NCAM. However, their outgrowth response to N-cadherin and other activators of axonal growth was undiminished. Removal of GPI-linked NCAM from the surface of these clones using phosphatidylinositol-specific phospholipase C (PIPLC) fully restored their responsiveness to NCAM, indicating that the inhibition was a direct consequence of cell surface expression of this "dominant negative" isoform of NCAM. We have previously shown that expression of transfected 140- and 180-kDa isoforms of human NCAM in PC12 cells does not result in a loss of the neurite outgrowth response to NCAM. However, we show that deletion of the cytoplasmic domain of the 140-kDa isoform has the same effect as expression of GPI-linked NCAM. We conclude that the cytoplasmic domain of NCAM is required for an appropriate neurite outgrowth response.
Uptake of organochlorines (chlorobiphenyls, dieldrin; total PCB & DDT) in bottlenose dolphins (Tursiops truncatus) from Cardigan Bay, west Wales.
High concentrations of organochlorine compounds (particularly PCB and chlorobiphenyls) have been found in three bottlenose dolphins from the vicinity of New Quay in West Wales. Although few in number, the animals ranged in age from 10 months to 23 years. The occurrence of high contaminant concentrations in all of these animals suggests that a high level of uptake of these compounds occurs in food after weaning as well as by transfer from mother to calf. In order to investigate this further we have tried to model the uptake using a bioenergetics-based approach. Using estimates of feeding rate we have calculated the concentrations of these contaminants in average prey items necessary to maintain the dolphin's body burden during the juvenile growth stage. The data available to date are too few for a rigorous test of this approach, however these preliminary studies suggest that the contaminant concentrations in local food items analysed to date are not sufficiently high to explain the high concentrations found in dolphin blubber. Further information is needed on the contaminant burdens of bottlenose dolphins in Cardigan Bay, and of their relationships and diet (including seasonal and migratory components), in order to validate this approach.
Patterns of fundamental frequency for three types of voice samples.
The purpose of this study was to determine the variability in speaking fundamental frequency (Fo) associated with sample type in two age groups of normal male and female speakers and a group with vocal-fold paralysis. Young and elderly normal control men and women produced a sustained vowel, read a passage, and spoke extemporaneously in the morning, early afternoon, and late afternoon on three different days. The vocal-fold-paralysis group produced two voice samples at different times on the same day. Two patterns of variability emerged in the normal groups. Young men produced sustained phonation at a significantly lower Fo than their reading or extemporaneous samples. Young and older women and older men produced sustained phonation with a higher Fo than their reading or extemporaneous samples. The eight subjects with unilateral vocal-fold paralysis (seven women, one man) produced samples with a pattern similar to that of the older normal groups but with greater differences between the sustained vowel and speech samples. The use of different sample types resulted in variations in mean speaking Fo in the normal subjects as well as in the vocal-fold-paralysis group. Within-day sampling of all normal subjects resulted in approximately the same variability as across-day sampling. In the vocal-fold-paralysis group, within-day sampling resulted in greater variability of mean Fo for vowels than for connected speech, following a pattern similar to the older normal control subjects and various speech materials for voice.(ABSTRACT TRUNCATED AT 250 WORDS)
Phonational profiles of male trained singers and nonsingers.
The purpose of this study was to compare the mean speaking fundamental frequency (SFF), speaking frequency range, and mean speaking intensity for a group of trained male singers and a group of age-matched non-singers in three age ranges: 20 to 35 years old; 40 to 55 years old; and older than 65 years. Each subject was recorded as he read "The Rainbow Passage" and produced the vowel /a/ to the limits of his phonational frequency range. The data indicated that the mean SFF of the nonsingers was significantly lower among the middle-aged speakers than with the young or elderly. In contrast, the tenors exhibited no age-related SFF trends, and the young bass/baritones exhibited lower SFF levels than the middle-aged or elderly. The elderly nonsingers produced frequency ranges that were smaller than any other group. Finally, the young nonsingers used greater speech intensity than did the other groups.
Narcissism, self-esteem, and parental nurturance.
Self-reported narcissism, self-esteem, and perceptions of parents as nurturing were examined in a sample of 459 undergraduates. In zero-order and partial correlations, dimensions from the Narcissistic Personality Inventory displayed inter-relationships and linkages with self-esteem and parental nurturance that conformed with the hypothesis that indices of narcissism fall along a continuum of mental health. Partial correlations controlling for self-esteem also indicated that at least some data for the more adaptive aspects of narcissism were mediated by healthier self-functioning. These results support recent suggestions that narcissism must be conceptualized within frameworks that include healthy self-esteem.