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Biomedical subjects

C H Davis

Publications and source records attributed to C H Davis.

At least 55 records · Page 3Linked to original sources
PubMed1988

Low morbidity and mortality of carotid endarterectomy performed with regional anesthesia.

Various anesthetic and surgical techniques have been recommended with or without cerebral function monitoring in attempts to reduce the risk of carotid endarterectomy, but there is no consensus as to the ideal method for performing this procedure. General anesthesia is now the most common anesthetic technique used, but of 337 carotid endarterectomies performed by the author's service from 1981 through 1985, 305 (91%) were conducted with regional anesthesia. This paper presents the morbidity and mortality rates for those patients. There were two perioperative transient ischemic attacks (0.66%), two perioperative strokes (0.66%), and two perioperative deaths (0.66%). No patient in the series suffered a myocardial infarction within 30 days after endarterectomy. This series demonstrates that carotid endarterectomy can be performed with good results using regional anesthesia, which facilitates intraoperative cerebral function monitoring. Regional anesthesia is associated with a very low incidence of postoperative hypertension and perioperative myocardial infarction.

Adult↗
PubMed1988

Childcare responsibilities, peer relations, and sibling conflict: older siblings of mentally retarded children.

Household and childcare responsibilities, peer contacts, and out-of-home activities of older same-sex siblings of mentally retarded children as compared to a group of matched nonhandicapped children were examined. Older siblings of retarded children, particularly older sisters, assumed multiple caretaking responsibilities. For these siblings, increased childcare responsibilities were associated with sibling conflict and decreased opportunities for peer contacts and out-of-home activities. As a group, however, siblings of retarded children did not differ from their agemates in frequency of contact with friends or participation in out-of-home activities. Retarded younger siblings had less contact with friends than did their nonhandicapped agemates. Within-group differences appeared to be more important in understanding sibling risk status than whether the child had a younger retarded sibling.

Child↗
PubMed1988

Effects of a behavioral weight-loss program food purchases: instructions to shop with a list.

Effects of instructions to shop with a list on subsequent food purchases were evaluated in the context of a 12-week behavioral/nutritional weight loss program. In the fifth class, subjects were taught to prepare a weekly menu, convert the menu to a shopping list, adjust the list for foods already on hand and organize the list to be consistent with supermarket layout. Subjects were told to attempt to restrict their purchases to items and amounts on the list. Food purchases were reduced from 16,188 kcal per person per week prior to the shopping class to 9625 kcal during the remainder of the treatment period in five subjects losing greater than or equal to 4.5 kg during treatment and from 14,620 kcal to 12,305 kcal for five subjects losing less than 4.5 kg during the treatment. The decrease for subjects losing less than 4.5 kg did not reach significance, but a further decrease to 10,254 kcal during follow-up was significantly less than pre-intervention purchases. Reductions posted by the greater than or equal to 4.5 kg subjects were maintained over a 12-week post-treatment follow-up period. A non-equivalent control group of six shoppers who were not attempting to lose weight did not change over the same time period, (averaging 14,470, 14,939 and 12,636 kcal at pre-intervention, post-intervention and follow-up respectively), ruling out seasonal factors as an alternative explanation. Food purchases were also analyzed for qualitative changes.

Adult↗
PubMed1987

Nonoxidative antimicrobial effects of human polymorphonuclear leukocyte granule proteins on Chlamydia spp. in vitro.

Proteins from isolated granules of human polymorphonuclear leukocytes were assessed for their nonoxidative microbicidal effect on chlamydiae by two different methods: a radioisotope assay for elementary body integrity and a biological assay for inclusion development. Crude granule extract, which consisted of a mixture of all granule proteins, caused a 20 to 30% decrease in infectivity and a 52% decrease in infectivity when incubated with Chlamydia psittaci CAL-10 and Chlamydia trachomatis serovar E, respectively. To define more specifically the components that were damaging to chlamydiae, crude granule extract was subjected to Sephadex G-75 column chromatography and isolated granule fractions were obtained. Only fractions containing lysozyme as the major component consistently caused reductions in infectivity of C. trachomatis elementary bodies. In contrast, fractions collected after the lysozyme fraction, containing proteins with molecular masses of 13,000 daltons or less, had detrimental effects on C. psittaci infectivity. Additional experiments using highly purified human polymorphonuclear leukocyte lysozyme confirmed its infectivity-reducing action upon C. trachomatis but not upon C. psittaci.

Blood Bactericidal Activity↗
PubMed1987

Carotid plaque as a source of emboli in humans: a scanning electron microscopic study.

Ten fresh carotid plaques obtained from patients undergoing carotid endarterectomy were fixed, and their luminal surfaces were examined with a scanning electron microscope. Luminal surface defects, characterized in scanning electron microscopy as endothelial discontinuities having diameters of 50 to 1500 microns, were a frequent finding, but their presence did not correlate well with the location of ulcers seen on angiography. Potential sources of emboli found were peels of subendothelial matrix, fibrin-platelet aggregates, fibrin-red blood cell clusters, and, possibly, damaged endothelial cells. Areas of endothelial cell injury consisting of small denuded patches, sheets of endothelial cytoplasm, and distorted endothelial cell profiles were observed. These areas resembled the type of damage seen in experimental ischemic vessel lesions and were believed to be the result of carotid cross clamping. Their presence suggests that a similar mechanism may result in loss of endothelial cells and exposure of the "raw" plaque surface in vivo.

Brain Ischemia↗
PubMed1987

Symptomatic subependymoma of the cervical spinal cord. Report of two cases.

Subependymomas are relatively unusual tumors with a distinctive histological appearance. They are generally considered to be benign, and they are often found incidentally at autopsy. Most are located intracranially, and the most common site of origin is the fourth ventricle. Only two cases of subependymoma of the spinal cord have been reported previously. The authors present two additional cases of subependymoma of the cervical cord; both were symptomatic, and both were treated by microsurgical removal.

Adult↗
PubMed1987

Mentally retarded children and their older same-sex siblings: naturalistic in-home observations.

In-home interactions of mentally retarded children and their older nonhandicapped siblings were observed, as were interactions between target children and their mothers and fathers. Thirty-two same-sex sibling pairs participated; 16 with a mentally retarded child. Comparison siblings were matched on age, sex, race, parent marital status, education, and family income. High rates of interaction occurred between siblings. Older siblings accommodated the presence of a retarded child through their selection of activities. Interactions between retarded children and siblings were characterized by accentuated role asymmetries and less joint object play; no differences in affect were found. Gender differences in roles occurred as did relationships between competency of the retarded child and sibling interaction. Indirect effects on the parent-child relationship were also detected.

Child↗
PubMed1986

Giant cell tumors of synovium (Pigmented villonodular synovitis) involving the vertebral column.

Giant cell tumors of synovium (pigmented villonodular synovitis) involving the vertebral column recently have been seen in two women: the third and fourth cases to be reported in the English-language literature. Unlike the previously reported cases, both these tumors grew outside the dura and produced symptoms of spinal cord compression. The first case involved lumbar vertebrae 5 and 6; the second, lumbar vertebrae 2 and 3. Even though initial resection of both tumors was incomplete, the patients improved postoperatively. One tumor was known to be unresectable at the time of surgery. In the other patient, a recurrence of symptoms required second and third resections 4 and 8 months after the first, respectively. Although synovial giant cell tumors rarely metastasize, the rate of local recurrence is high, especially if excision is incomplete. For this reason, close follow-up of patients with lesions in the spinal column is indicated. Increased physician awareness that synovial giant cell tumors can occur in the spine will help to ensure that these tumors are not misdiagnosed in this location.

Adult↗
PubMed1986

False aneurysm complicating carotid endarterectomy.

We present two cases of false aneurysm after carotid endarterectomy with primary arteriotomy closure. In both cases, infection appeared to be the precipitating cause. Both lesions were repaired with a saphenous vein patch graft, but infection in one patient persisted, and recurrence of a false aneurysm required ligation of the common carotid artery. There were no neurological sequelae in either patient. A review of the English language literature, our experience, and personal communications yielded 57 cases of false aneurysm. The overall incidence of false aneurysm after carotid endarterectomy was 0.30%. There was no significant difference in the incidence after endarterectomy alone and that after endarterectomy and patch grafting. A significant increase in neurological deficit occurred only when carotid ligation was used, with a morbidity/mortality of 50% in eight reported cases. Infection was the major cause of false aneurysm after endarterectomy; it occurred in 50% of cases closed primarily without patch grafting. Repair with a saphenous vein patch graft and monofilament synthetic suture, plus liberal use of antibiotics, should be considered in the treatment of this condition.

Aged↗
PubMed1985

Oculomotor palsy with pupillary sparing in a patient with chronic subdural hematoma.

A patient with adult-onset diabetes mellitus developed an oculomotor palsy with pupillary sparing. Five days after her initial evaluation, she presented in a confused state with a complete oculomotor palsy. Computed cranial tomography revealed a chronic subdural hematoma. We recommend that noninvasive radiographic intracranial investigation be considered in elderly patients with adult-onset diabetes mellitus who present with headache and pupil-sparing oculomotor palsy.

Aged↗
PubMed1985

Home ventilator dependence after high cervical cord injury.

Home ventilator support, though somewhat unorthodox, is economically desirable and is now technically feasible. Close cooperation between public health providers, ventilator suppliers, and the family physician, as well as strong patient and family compliance, is essential for success in maintaining a ventilator-dependent patient at home.

Aged↗
PubMed1985

Intact arch spondylolisthesis. A review of 50 cases and description of surgical treatment.

Over the past 11 years, the authors have treated 50 cases of intact arch spondylolisthesis. There were 38 female and 12 male patients, and all but 11 were older than 60 years of age. Almost all had severe low-back pain made worse by standing or walking. Other common manifestations were unilateral leg pain, numbness or weakness of the leg, and evidence of mild cauda equina compression. Severe cauda equina compression was rare. Myelography invariably showed an extradural dorsal compression. A waist deformity was characteristic in many patients, but 12 had a complete block. In 15 patients (30%) the myelographic impression was that of a herniated intervertebral disc. Most subluxations were of L-4 on L-5. At operation, the facets were found to be thickened, distorted, and irregular. All patients were treated with a wide decompression and laminectomy, which included a medial facetectomy of the inferior and superior facets. An intervertebral disc was removed in 10 patients. Follow-up monitoring of 41 patients (for an average period of 36 months) showed that 26 (63%) were pain-free, 11 had less pain, and four were unimproved. Five other patients with short follow-up periods (average 5 months) were all improved.

Aged↗
PubMed1985

Relationship of hunger, use of a shopping list and obesity to food purchases.

Shopping with a list and shopping after a meal are two commonly employed behavioral weight loss guidelines designed to reduce food purchases and therefore food consumption. A survey of 596 female shoppers, which analyzed purchases on the basis of caloric value, failed to support either of these guidelines. Analysis of kilocalories (kcal) purchased indicated that overweight shoppers purchased more total kcal, with a greater percentage of their kcal coming from fat and correspondingly lower percentage of kcal coming from carbohydrates.

Adult↗
PubMed1984

Myocardial infarction following regional anaesthesia for carotid endarterectomy.

From 1969 through 1982, 185 carotid endarterectomies were performed under regional anaesthesia on 153 patients. Of these patients, 38 (25 per cent) had suffered a previous myocardial infarction, 63 (41 per cent) had documented coronary artery disease, and 115 (75 per cent) had hypertension. Anaesthesia was provided by a superficial cervical plexus block. Monitoring consisted of measurement of direct arterial pressure and continuous display of the electrocardiogram. Oxygen was administered by nasal cannula throughout the procedure. Mean arterial pressure was elevated when necessary by infusion of phenylephrine. No patient in this study suffered an acute myocardial infarction. The only cardiac complications consisted of eight episodes of non-life-threatening dysrhythmias. We conclude that regional anaesthesia for carotid endarterectomy is associated with a low risk of perioperative myocardial infarction.

Anesthesia, Conduction↗
PubMed1984

ACTH-producing pituitary adenoma in an infant with cysts of the kidneys and lungs.

The light microscopical, electron microscopical and immunohistological features of a rare ACTH-producing chromophobe adenoma of the pituitary gland in an 11-month-old infant are presented. An unusual histological feature was the presence of numerous follicles. These follicles may develop secondary to necrosis of individual tumour cells. There is only one previous report in the literature of a pituitary adenoma occurring in infancy and that tumour also produced ACTH and showed a follicular histological pattern. It is of interest that our patient also had a combination of medullary cysts of the kidneys and congenital peripheral cysts of the lungs. The association of cysts in lungs with cysts in kidneys also has been reported only once previously. We conclude that the occurrence of cysts in kidneys and lungs and a pituitary tumour in infancy represents a bizarre coincidence although an unknown common embryonic insult to these organs cannot be ruled out.

Adenoma↗
PubMed1984

Metabolism of dihydrouracil in Rhodosporidium toruloides.

Previous studies, including those done with a similar species, have indicated that dihydrouracil is formed by the breakdown of uracil and is degraded into N-carbamyl-beta-alanine. (Fink et al., J. Biol. Chem. 201:349-355, 1953; S. R. Vilks and M. Y. Vitols, Mikrobiologiya 42:567-583, 1973; O. A. Milstein and M. L. Bekker, J. Bacteriol. 127:1-6, 1976). In the present work the conversion of dihydrouracil to uracil is studied in Rhodosporidium toruloides, and the growth characteristics of mutants that have lost the ability to use dihydrouracil as a source of nitrogen are examined. It is concluded that dihydrouracil must be converted to uracil before catabolism of the pyrimidine ring can take place.

Basidiomycota↗