PubMed Health⌕ Search

Biomedical subjects

R E Carter

Publications and source records attributed to R E Carter.

At least 19 recordsLinked to original sources
PubMed1992

Genetically epilepsy-prone rats have increased brain regional activity of an enzyme which liberates glutamate from N-acetyl-aspartyl-glutamate.

N-Acetylated-alpha-linked acidic dipeptidase (NAALADase) is a membrane-bound peptidase which hydrolyzes the endogenous neuropeptide N-acetylaspartylglutamate (NAAG) to N-acetylaspartate (NAA) and the excitatory amino acid, glutamate (Glu). Although there is evidence that NAAG might be a neurotransmitter, this dipeptide could also function as a precursor form of Glu, which is liberated by the dipeptidase. We found that the activity of this NAAG hydrolyzing enzyme in genetically epilepsy-prone rats was 11-26% greater than control in brain regions, including the amygdala, hippocampus and cerebellum, as well as the pyriform, entorhinal and frontal cortices. This is consistent with possible increased availability of Glu in certain CNS synapses in these rats, which are reported to have increased susceptibility to audiogenically, electrically and chemically induced convulsions.

Animals↗
PubMed1992

Clonal structure of the introduced freshwater snail Potamopyrgus antipodarum (Prosobranchia: Hydrobiidae), as revealed by DNA fingerprinting.

Multi-locus DNA fingerprints were obtained from individuals of the hydrobiid snail, Potamopyrgus antipodarum (= P. jenkinsi), by using an RNA derivative (pSPT 18.15) of Jeffrey's 33.15 minisatellite core sequence. Whole-body homogenization of snails yielded 3.21 +/- 0.09 micrograms DNA per individual, producing complex profiles comprising 12-22 fragments within the 1.0-20.0 kilobase (kb) size range. Fingerprints from natural and experimental populations identified three distinct clonal genotypes corresponding to morphological strains A, B and C, with only rare mutational variants. Mother-offspring comparisons of genetic fingerprints revealed genetic stability during apomictic parthenogenesis. Data support the notion that British populations of P. antipodarum comprise three widespread obligate parthenogenetic clones resulting from a mid-19th Century introduction from Australasia. The present-day low levels of genotypic diversity are discussed in relation to the typical occurrence of P. antipodarum in man-made or immature habitats.

Animals↗
PubMed1990

A comparison of the emphasis given to nine therapies in residency training and later practice of psychiatrists.

This study compared the emphasis given to various therapies in six psychiatry residencies and by psychiatrists in their later practice. Eighty-seven psychiatrists and 29 residents were surveyed in 1987. The two groups reported that almost the same amounts of time of their respective training programs had been devoted to the nine therapies surveyed. Patterns of practice were observed, including the finding that those who were highly trained in a therapy practiced it more than did those who had less training. Both those who were highly trained and those who were not extended their practices to the use of therapies in which their training was not extensive. Problems in the study design and variables affecting this type of research are identified as guidance for future investigations.

Adolescent↗
PubMed1988

Clonidine effect on spasticity: a clinical trial.

Clonidine was used as an adjunct to baclofen in 55 patients with spasticity due to spinal cord injury. Dosage was held at the minimum effect amount for those who responded. No effect was seen in 24 patients (44%), although 31 (56%) benefitted from the drug. Patients were grouped as quadriplegics or paraplegics, having complete or incomplete lesions. Of all quadriplegics, seven of 11 complete (64%) and 17 of 25 incomplete patients (68%) responded; among the paraplegics, six of 15 complete (40%) and one of four incomplete patients (25%) improved. Side effects were limited to postural hypotension necessitating reduction in dosage in three patients that were successfully treated; in the unsuccessfully treated group, one patient had insomnia, one had dizziness, and one had drowsiness.

Adolescent↗
PubMed1987

Structure-activity relationships for unsaturated dialdehydes. 1. The mutagenic activity of 18 compounds in the Salmonella/microsome assay.

A considerable number of terpenes that contain an "unsaturated dialdehyde" functionality, and possess various biological activities, such as antimicrobial activity, pungency, antifeedant activity, and/or mutagenicity, have been isolated from natural sources. However, large qualitative and quantitative activity differences have been observed for the natural unsaturated dialdehydes, and small structural changes (e.g., stereoisomerization) seem to dramatically affect the biological activity. As part of a general attempt to study structure-activity relationships for unsaturated dialdehydes, the activity of compounds 1-18 (Table 1) in the Salmonella/microsome assay (strains TA98, TA2637 and TA100) has been investigated. 10 of the compounds were found to possess direct-acting mutagenic activity, although the mutagenic potencies vary considerably in this group (from 430 to 0.32 revertants per nmole in the Salmonella strain TA2637). Some structural features that appear to moderate the activity are discussed. The necessity of an intact unsaturated dialdehyde functionality for the mutagenic activity of isovelleral (1) (see Scheme 1 for names, numbers, and chemical structures) in the Salmonella/microsome assay was demonstrated by chemical conversions: modification of either aldehyde group or reduction of the double bond led to loss of activity.

Aldehydes↗
PubMed1987

Comparative study of electrophrenic nerve stimulation and mechanical ventilatory support in traumatic spinal cord injury.

Over the past two decades, the number of surviving apneic spinal cord injured patients has been increasing. Mechanical ventilation for home maintenance has been supplemented by electrophrenic respiration (EPR) since 1970. Nineteen patients who were totally mechanical ventilator dependent at discharge from rehabilitation in a spinal cord centre are compared with 18 patients discharged on EPR. There were more young males in the EPR group while the overall average ages were approximately the same. The mortality rates were approximately equal although the mechanical ventilator dependent patients expired earlier than the EPR group. Survivors on mechanical ventilation lived longer on an average and the vast majority of both groups were discharged to their home. There needs to be the establishment of a ventilatory dependent registry for spinal cord injury.

Adult↗
PubMed1987

The neurological and skeletal outcome in patients with closed cervical spinal cord injury.

Sixty-one patients with closed cervical spinal cord injury were cared for within a defined protocol and followed for at least 1 year. Neurological recovery and healing of spinal structures were evaluated at intervals. Forty-three patients were managed without surgical intervention at the site of spine trauma, and the incidence of spontaneous fusion ("autofusion") was noted. Surgical fusion was performed on 17 patients, mainly to restore spinal stability and alignment. One patient underwent laminectomy without fusion. In both the surgical fusion and the autofusion groups, there were significant numbers of patients who improved neurologically, including some designated as having a complete spinal cord lesion at the initial neurological examination. As expected, better spinal alignment was achieved in the surgical group, although alignment in the nonsurgically treated group was generally acceptable. The majority of patients developed radiographically apparent callus formation anterior to the injured vertebral bodies, regardless of the mechanism of injury or the method of treatment. After 3 months all patients who underwent surgical fusion achieved spinal stability, as did the majority of patients in the autofusion group. Only individuals with flexion-distraction injuries who did not undergo surgical fusion appeared to be at risk for progressive spinal column deformity. Neither retropulsion of bone fragments nor angulation at the fracture site appeared to correlate with a poor neurological outcome, since improvement in neurological function occurred similarly in patients with and without these deformities.

Adult↗
PubMed1987

Profile of denials of durable medical equipment for SCI patients by third party payers.

The difficulty in obtaining approval for payment of durable medical equipment by third party payers has impeded the rehabilitation program and discharge planning of many spinal cord patients throughout the country for many years. To gain some insight as to the number and level of patients affected, the kinds of equipment denied, the reasons given for the denial, which third party payers were mostly involved and how the patient and his/her family managed to cope or resolve this problem, a survey was undertaken. Letters were sent to 259 members of the American Spinal Injury Association (ASIA) asking them to list representative cases where requests for equipment deemed necessary were denied. Twenty-eight responses from different institutions were received from sixteen states describing 110 patients and 180 pieces of durable medical equipment denied in 1984 and 1985. Manual wheelchairs, motorized wheelchairs, shower/commode chairs, and environmental control units were the four most common equipment items denied by the third party payers. Government agencies ie., Medicaid, Medicare, Vocational Rehabilitation Departments and State Crippled Children's Services were the most frequent deniers, comprising 54% of the total sample. They were followed by private insurance (31%) and Workman's Compensation (3%). By far, the two most common reasons given for denials were: it was not covered by the insurance policy (38%) and it was not medically necessary (30%). Ninety (90) pieces of equipment (50%) were eventually obtained, most often by charity, or through the patient's family resources.

Data Collection↗
PubMed1987

Postdischarge outcomes for ventilator-dependent quadriplegics.

Based on data contributed to the National Spinal Cord Injury Data Base between the years 1975 and 1981, outcomes were assessed for 34 patients who had been injured approximately a year earlier and who were ventilator dependent when discharged from inpatient rehabilitation. Their outcomes were compared with those of 196 patients who required mechanical respiration some time during acute care or rehabilitation, but who were free of such assistance at discharge. Statistically significant differences were obtained between the groups in levels of spinal cord injury, duration of acute care hospitalization, duration of total hospitalization, extent of self-care capability, hours/week of hired attendant care, and hours of actual physical assistance/day. The groups did not differ significantly in terms of duration of inpatient rehabilitation, duration of rehospitalization, and vocational or prevocational status at follow-up.

Adult↗
PubMed1985

Evaluation of upper extremity vasculature with high-resolution ultrasound.

Twenty-eight vascular and perivascular lesions of the upper extremity in 21 patients were studied from August 1982 to December 1982 by means of a 10 MHz real-time B-mode ultrasound unit. They included eight perivascular masses, 16 arterial repairs, and five thrombosed or occluded arteries. Imaging of arteries that ranged in size from a brachial to a digital artery was reliable. Vessels were tracked proximally and distally while changes in wall compliance, luminal diameter, wall diameter, intimal integrity, and luminal compression were observed dynamically. Size, location, acoustic characteristics, and extent of vascular involvement could be determined in cases of perivascular masses. Sonographic findings were confirmed by arteriography, dynamic radionuclide imaging, computerized tomography, or surgical exploration. Ultrasonography eliminated the need for preoperative arteriography in some cases. In no instances were our ultrasonographic impressions in error when correlated with results of more invasive techniques. No adverse effects were encountered. We concluded that real-time 10 MHz ultrasonography is a safe, noninvasive, reproducible, and accurate technique that can be used quantitatively and qualitatively on the upper extremity after surgery to assess patency, pulse dynamics, and anastomotic characteristics of arterial repairs and before surgery to evaluate perivascular masses for acoustic characteristics, location, and influence on adjacent vascular structures.

Adolescent↗
PubMed1984

Incidence of medical complications in spinal cord injury: patients in specialised, compared with non-specialised centres.

Facilities providing a co-ordinated 'system' of care to the spinal cord injured are now more accepted as being preferable to fragmented 'non-system' facilities. Data reflecting the incidence of selected complications common to spinal cord injury were collected over a 2-year period from a system located outside the United States and from 'non-systems' within the United States. The latter was defined as care provided in community facilities prior to entry into one of 14 model United States spinal cord injury centres. All complications occurred more frequently in the American group, particularly decubitus ulcers and urinary tract infections. The data suggest that system care is preferable to non-system care in its capacity to prevent costly complications and the sooner the spinal cord injured patient is referred to a spinal cord centre capable of meeting all his needs, the less likely will he be exposed to complications that could slow the rehabilitation effort.

Delivery of Health Care↗
PubMed1983

Home positive-pressure ventilation. Twenty years' experience.

We studied retrospectively 26 adults and 21 children with chronic respiratory failure whose condition was managed at home using positive-pressure ventilators in order to ascertain the outcome, benefits, and complications of this form of management. Twenty-six (55 percent) of the patients had injuries to the spinal cord. Among the 47 patients, nine were eventually weaned from the ventilator, and two died at home because of disconnection from their ventilators. Using life-table analysis, projected three-year survival was 74 percent for patients without spinal injury and 63 percent for patients with spinal injury. Mortality was greater for children than for adults. For a majority of patients, the cost of management at home was significantly less than management in the hospital, depending largely on the level of nursing care required. We suggest that mechanical ventilation at home may be a reasonable alternative to prolonged hospitalization for medically stable ventilator-dependent adults and children.

Adolescent↗
PubMed1982

Developing a system of comprehensive care for the spinal cord injured patient in Houston, Texas, U.S.A.

The authors agree with the principle, widely accepted, that spinal cord injured (SCI) individuals should receive all their acute, rehabilitative and follow-up care in a spinal cord injury centre. The evolution of rehabilitation medicine and services in the United States, however, has favoured the separation of acute and rehabilitation care for spinal cord injured patients, as well as other disabilities. This has resulted partly from specialisation of medical and allied health personnel, physical separation of acute and rehabilitation facilities, and reluctance of some funders of health care to see rehabilitation as a natural extension of medical care in these patients. In Houston the proximity of a rehabilitation facility to three acute care university hospitals, representing three medical schools, provided an opportunity to improve communication among the medical personnel. These individuals have recognised the value of early rehabilitation even while the patient is acutely ill; they agreed to institute a system of care wherein the rehabilitation physician partakes in the early management in a designated area of the acute hospitals for spinal cord injured patients and works toward early transfer to the rehabilitation hospital in as ideal a condition as possible. Surgeons, who have initial primary responsibility, also visit the rehabilitation hospital, following their patient's progress at selected conferences and at the bedside. This paper describes how, a spinal cord injury service was established, how the major barriers to early transfer were confronted, and the results of the first 6 months of operation.

Comprehensive Health Care↗