Biomedical subjects
Publications and source records attributed to F Naso.
Poly(2,3,5,6-tetrafluoro-1,4-phenylenevinylene) (PTFPV) was prepared for the first time by the Stille cross-coupling reaction and the resulting material was characterized through MALDI-TOF mass spectrometry, employing a novel sample preparation protocol suitable for insoluble compounds; preliminary optical and electrooptical measurements were performed.
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A novel strategy for the synthesis of well-defined oligo(phenylenevinylene)s was developed. The procedure is entirely based upon two coupling processes, both involving vinyltrimethylsilanes. Bis(styryl)benzenes 2a-g bearing two octyloxy groups in the central aromatic ring and various substituents on the external aromatic rings were prepared in good yield by a regio- and stereoselective coupling reaction of 1 with different arenediazonium tetrafluoroborates. Oligomers with a more extended conjugated system, 4a-c, and with m-phenylene subunits 13a,b, were also readily obtained by conversion of the unsaturated trimethylsilyl derivatives 3a,c,d to the corresponding boron derivatives and a subsequent coupling reaction with compounds 2a and 2c.
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An analysis of genetic fitness was performed in Huntington's Disease (HD) and Spinocerebellar Ataxia 1 (SCA1) families. Two partially overlapping samples were used: clinically defined HD and SCA1 patients from families ascertained in definite geographical areas, and molecularly typed carriers of HD and SCA1 mutations (CAG trinucleotide expansions). In both cases, a control group of normal relatives was used. HD and SCA1 patients born before 1915-20 had more children than normal controls. Carriers of HD and SCA1 mutations, all in the low/medium expansion range (37-49 and 47-54 CAG repeats respectively), had a higher number of children than controls up to more recent times (1935-1950). The reproduction of heterozygotes for large expansions could be analysed only in subjects born after 1950 and provided indirect evidence of a lower than normal number of children. The above results fit a model based on a differential fitness according to the degree of expansion. Such a model predicts that 1) up to relatively recently the frequency of alleles in the low/medium range has been maintained or even increased by the increased fitness of their carriers, as well as by new mutations, and 2) the frequency of large expansions, part of which are lost at each generation, is maintained through further expansions of alleles in the low/medium expansion range. The implications of such a model on linkage disequilibrium and the possible spread of these diseases in future generations are discussed.
Huntington disease (HD) is a neurodegenerative disorder caused by an expanded trinucleotide repeat (CAG)n located at the 5' end of the novel IT15 gene. Discovery of this expansion allows the molecular diagnosis of HD by measuring repeat length. We applied a simple nonisotopic method to detect (CAG)n repeats, avoiding both radioactive and Southern transfer analysis. The assay is based on direct visualization of electrophoresed PCR products, after silver nitrate gel staining. Its accurate sizing of HD alleles allows presymptomatic diagnosis of at-risk persons. By avoiding isotopic manipulations, the method is safe and accurate, with no radioactive background bands. Furthermore, because it permits direct allele visualization after gel staining, the method is simple and rapid, allowing allele sizing within hours rather than days.
Six families with SCA1 were studied. The clinical data on 35 patients are reported. Cerebellar and pyramidal system involvement was invariably found in association with brainstem, spinal cord and/or peripheral nervous system disorders. In our patients the clinical features appeared concordant when the patients with the same disease duration were compared. Previous reports of SCA1 families had shown great variability in clinical phenotype both interfamilial and intrafamilial. We suggest that the phenotype might appear more homogeneous if disease duration is taken into account.
Endurance training in nursing home patients was evaluated by selecting 15 of 150 patients for a conditioning program eliminating those patients with dementia and/or significant cardiac disease. After a medical and laboratory screen, all had a symptom-limited exercise test (SLXT) using arm and leg ergometry. Only two patients were able to use the treadmill and many had difficulty with leg cycling. Exercise capacities averaged 2-3METs in most patients. The exercise (E) group included eight randomly selected subjects who participated in a three times weekly upper and lower conditioning program using target heart rates based on the SLXT. The control (C) group continued in the daily nursing home routine. The SLXT was repeated at the end of one year. Two patients in each group expired from unassociated medical problems. Three patients in group E were hospitalized for brief periods. In group E there was a small but significant training effect in the arms (p = 0.05) but not in the legs. It would appear that a small training effect can occur in elderly nursing home patients with a conditioning program. The magnitude is limited by the low intensity of the program as well as the detraining effect of intercurrent illness. Functional limitations of the legs may be responsible for the lack of a training effect in these muscle groups.
This report presents an unusual case of a lower extremity burn amputee with a marked degree of bone spur formation. A 17-year-old man suffered 56% body surface area mixed-depth electrical and flame burns, necessitating left below knee amputation. He was admitted to a rehabilitation center 3 months postinjury for pylon fitting and gait training. Difficulty was encountered with poor skin tolerance to weight bearing because of the prominent distal bony margins in the stump. X-rays of the stump revealed a marked degree of linear bone spur formation, extending longitudinally from the distal tibia and fibula with multiple cross-bridges. The spur formation was considered an extensive bony exostosis of unclear etiology. Surgical revision was elected to obtain a stump more suitable for prosthetic tolerance, and to avoid a bulky "bypass" prosthesis. This stump revision enabled the patient to attain independent functional prosthetic ambulation. Although there is evidence of some recurrence of bone spur formation, this remains limited and asymptomatic.
In protracted forms of dysphagia associated with neuromuscular dysfunction, myotomy of the upper esophageal sphincter has been suggested. The literature, however, is unclear about the indications and outcome of this procedure. In this article, 3 cases are presented of dysphagia associated with the failure of relaxation of the cricopharyngeus during swallowing. Two patients had brain stem infarctions and the 3rd had an inflammatory disease of the brain stem. In all patients, barium swallow revealed aspiration of contrast material into the trachea with failure of relaxation of the cricopharyngeal sphincter. Indirect laryngoscopy demonstrated partial paralysis of one or both vocal cords. In one, an emg of the laryngeal muscles showed normal results. A complete evaluation by the speech pathologist failed to reveal abnormality of the oral musculature in all patients. All patients required gastrostomies for their nutritional needs. Therapeutic modification and control of rate, quantity and consistency of food along with counseling for prevention of aspiration. Oral feeding, without aspiration, was achieved in the 3 patients within the treatment period, allowing removal of the gastrostomy. Cricopharyngeal myotomy, therefore, was not necessary in these patients, despite the long duration of the swallowing problem.
A program has been developed for training amputees with significant heart disease. In seven patients, a stress test was performed to evaluate cardiac functional capacity and heart rate response, utilizing both invasive and noninvasive techniques. Following this test, a conditioning program was instituted to improve cardiovascular function. At discharge and six week follow-up, all patients were able to ambulate at least 90 feet (27.4 meters) without excessive pulse rise or cardiac symptoms. This study demonstrates that by proper application of the principles of exercise physiology and cardiac pathophysiology, one should not necessarily deny a disabled patient wiith significant heart disease the opportunity to participate in a rehabilitation program.
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Thirty-two patients with heart disease in addition to another disability were monitored continuously with the ten-hour electrocardiographic (ECG) tape. Eighteen of the 32 patients manifested abnormalities of rate, rhythm or ST-segment depression. Patients with arrhythmia eventually did better than those with other ECG abnormalities because drug therapy was successful in abolishing the abnormal rhythm in most cases. Those patients with excessive tachycardia did poorly as a group in so far as their rehabilitation program was concerned. This technique of continuous ECG monitoring may be helpful in assessing myocardial performance in these patients and in defining the prescription for rehabilitation therapy.
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