PubMed Health⌕ Search

Biomedical subjects

R C Edwards

Publications and source records attributed to R C Edwards.

At least 19 recordsLinked to original sources
PubMed1995

Parathyroid hormone-related protein (PTHrP) in breast cancer and benign breast tissue.

Parathyroid hormone-related protein (PTHrP) 1-86 was quantified by immunoassay in extracts of 132 breast cancers, 27 samples of normal breast tissue and four fibroadenomas. PTHrP 1-86, was detected in 68% of primary tumours (range 40-302,000 fmol/g), 33% of normal breast tissues (range 100-1800 fmol/g), and all four fibroadenomas (range 110-11,600 fmol/g). PTHrP displayed molecular heterogeneity on gel filtration chromatography, and 1-86, 1-34 and 37-67 immunoreactivity eluted as 25-27 kDa together with a peak of 19-21 kDA containing only 37-67 activity. Tumour PTHrP 1-86 levels correlated inversely with age (P < 0.05) and were higher in premenopausal women (P = 0.05). The proportion of tumours containing PTHrP was higher in axillary node positive premenopausal women (P < 0.05). These data suggest that oestrogen may regulate expression of PTHrP in breast cancer and that production of PTHrP may be linked to development of axillary node metastases.

Adult↗
PubMed1994

Patient-controlled analgesia: a comparison of dosing regimens for acute postsurgical pain.

This study compares several dosing regimens for patient-controlled analgesia (PCA) in the management of acute maxillofacial surgical pain. The dosing methods differed by presence or absence of an active drug (morphine [MS] vs saline), presence of a baseline infusion, and dose of drug delivered. Sixty-eight patients were enrolled in this prospective, randomized, double-blind, placebo-controlled trial that lasted 24 hours. The study was completed in two separate parts, each of which involved randomization of patients into four groups (part I) or three groups (part II). No significant differences were noted in pain scores in the preoperative, immediate postoperative, or 4-, 8-, 12-, or 24-hour periods among any of the groups, including the saline-only control groups; in either part I or part II of the study. Significant differences (P < .01), however, were noted in nausea and vomiting scores. Fifty percent (50%) of patients receiving MS vomited, while no patients in the saline groups vomited. This study calls into question the usefulness of PCA with MS in maxillofacial surgery patients. Pain control was questionable at best, and the rate of emesis was unacceptably high in patients with potentially compromised airways. Further research is required to determine if other analgesics provide better pain control with less nausea in the PCA system or if antiemetics can effectively be used to lower the incidence of nausea and vomiting.

Adolescent↗
PubMed1993

Expanding the specialty: a survey of oral and maxillofacial surgery residencies in the United States.

This article reports the results of a survey of oral and maxillofacial surgery (OMS) residency program directors regarding teaching of expanded scope surgical procedures during the academic year 1990 to 1991. Data is provided for the nation as a whole, as well as grouped by geographic regions and type of residency program. Significant differences were found for some procedures based on both geographic region and program type. The majority of program directors responding to this survey disagreed with the trend toward expanding the scope of OMS into cosmetic procedures. Directors of integrated dual degree programs believed that the trend toward expanding the scope of OMS was positive; 2:1 over directors of MD optional or traditional OMS programs.

Curriculum↗
PubMed1992

Autogenous conchal cartilage as a replacement after a diskectomy.

A surgical procedure to place autogenous conchal cartilage as an interpositional graft after a diskectomy is described. The apparent advantages of this procedure are as follows: (1) the form of the external ear corresponds to joint morphology; (2) a graft of adequate size can be harvested; (3) the form of the external ear remains unchanged after surgery; (4) the graft can be obtained adjacent to the surgical site; (5) biologically acceptable material is used; (6) the additional expense of allogeneic grafts is avoided; and (7) excellent results have been reported.

Cartilage, Articular↗
PubMed1991

Survey of antibiotic prophylaxis for intraoral orthognathic surgery.

A survey was sent to 114 oral and maxillofacial surgery residency programs to determine the prophylactic use of antibiotics with intraoral orthognathic procedures. Seventy-four percent of the programs responded. Review of the data showed that all programs used antibiotic prophylaxis for intraoral orthognathic procedures, and that penicillin or a cephalosporin were the drugs most often used. However, there was no consistent protocol for the method or duration of drug administration. A discussion of rationale for antibiotic usage, concentration, and duration is presented.

Anti-Bacterial Agents↗
PubMed1991

Prolonged sedation associated with secobarbital in newborn infants receiving ventilatory support.

Newborn infants receiving ventilatory support often require sedation. Secobarbital is commonly used in these patients, but dosage guidelines to avoid prolonged sedation are not available. Seventeen infants (gestational age, 30 to 40 weeks; postnatal age, 0 to 3 days) with hyaline membrane disease or persistent pulmonary hypertension on mechanical ventilation were studied. These patients received secobarbital, 4 to 14 mg/kg/day intravenously for 1 to 10 days to produce sedation. Sedation was considered prolonged if it lasted more than 24 hours after the last dose. Nine of 17 infants experienced prolonged sedation. The mean daily secobarbital dose was 11.2 mg/kg/day in patients with prolonged sedation and 6.9 mg/kg/day in those patients without (p less than 0.05); the cumulative mean dose in the respective groups was 33.3 and 21.3 mg/kg (p less than 0.05). Four infants were sedated for 3 to 4 days after stopping secobarbital; the mean daily and cumulative dose was 13 mg/kg/day and 53 mg/kg in these patients. Duration of sedation was related to both daily and cumulative doses of secobarbital. Based on our results, the daily dose of secobarbital should not exceed 7 mg/kg/day to avoid prolonged sedation in infants. Frequent monitoring appears necessary to ensure efficacy with the lowest cumulative dose of secobarbital in newborn infants.

Humans↗
PubMed1991

Effects of hypoxia and ischemia on autoregulation in postnatal intestine.

Pressure-flow autoregulation was quantified within in vitro intestine from 3- and 35-day-old swine before and after lowering arterial PO2 (hypoxia) or lowering baseline blood flow by means of norepinephrine infusion (ischemia). Autoregulation was elicited by reducing arterial pressure approximately 33% from an age-appropriate baseline pressure. In 3-day-old intestine, autoregulation was unaffected by hypoxia or ischemia: vascular resistance was unchanged after pressure reduction, while Gf averaged -0.33 +/- 0.15 vs. -0.26 +/- 0.05 under control vs. hypoxic conditions, and -0.48 +/- 0.15 vs. -0.46 +/- 0.11 under control vs. ischemic conditions, respectively. In 35-day-old intestine, autoregulation was enhanced by hypoxia and ischemia. Under both experimental conditions, vasodilation was noted in response to pressure reduction: Gf averaged -0.04 +/- 0.14 vs. 0.38 +/- 0.08 under control vs. hypoxic conditions, and -0.12 +/- 0.10 vs. 0.28 +/- 0.08 under control vs. ischemic conditions, respectively. Regression analysis revealed a significant inverse linear correlation between Gf and venous PO2 in older, but not younger, subjects. Significant relationships between Gf and blood flow were not demonstrated in either group under any experimental condition. We conclude that autoregulation is enhanced within in vitro intestine from 35-, but not 3-day-old, swine during hypoxia or ischemia, and that reduction of venous PO2 is the principal factor responsible for the effect noted in older subjects.

Analysis of Variance↗
PubMed1988

Developmental aspects of phenobarbital dosage requirements in newborn infants with seizures.

Although phenobarbital is the most widely used drug to control seizures, dosage guidelines are not available for infants of varying gestational ages. The primary objective of this study was to develop age specific dosage guidelines for phenobarbital in newborn infants with seizures. Fifty-one patients (27 premature infants, gestational ages 27 to 38 weeks; 24 term infants) receiving phenobarbital, 3 to 6 mg/kg/d were studied during the first month of life. Multiple serum concentrations were determined in each patient during extended therapy. Trough serum concentration of phenobarbital ranged from 12.5 to 50.2 mcg/mL. Phenobarbital serum concentrations were within therapeutic range (15 to 40 mcg/mL) in 99 of 114 measurements at a maintenance dose of 3.5 to 4.5 mg/kg/d. The remaining 15 measurements were made in infants, greater than 35 weeks' gestation and required phenobarbital doses of 4.0 to 5.0 mg/kg/d to achieve therapeutic serum concentration. These data suggest that the initial maintenance dose of phenobarbital during the first month of life should be 3.5 to 4.5 mg/kg/d in infants less than or equal to 35 weeks and 4.0 to 5.0 mg/kg/d in those greater than 35 weeks' gestation. Term infants with asphyxia had higher trough serum concentration than those without asphyxia (P less than 0.005). In nine infants, trough serum concentration normalized for dose decreased substantially during a 3-weeks period (P less than 0.0005). This suggests that phenobarbital serum concentration should be monitored frequently during the first month of life.

Drug Administration Schedule↗
PubMed1985

Analysis of adenocarcinoma in Barrett's esophagus utilizing a staging system.

Based on a retrospective review of nine patients with adenocarcinoma in a Barrett's esophagus and the reports of similar cases in the literature, a staging system for this malignancy was devised. A progression of changes could be identified that corresponded to the stages. These changes consisted of dysplasia progressing to carcinoma in situ and invasive malignancy with metastases. Stage III disease carried the same grim prognosis as a similar stage of squamous cell carcinoma of the esophagus. Earlier stages of adenocarcinoma of the esophagus appeared to have a better prognosis. White men with symptoms of reflux esophagitis, esophageal strictures, and/or hiatal hernias who have Barrett's esophagus extending proximal to the distal 10 cm of the esophagus appear to have a propensity to develop adenocarcinoma of the esophagus. Consideration should be given to antireflux surgery and close follow-up by periodic esophagoscopy and biopsy of the esophagus in these patients. If neoplasia is found, the thoracic esophagus should be totally removed with the stomach or left colon anastomosed to the cervical esophagus. Because of the poor prognosis of Stage III disease, postoperative chemotherapy should be considered.

Adenocarcinoma↗
PubMed1982

Reimplantation of freeze-treated bone in immediate reconstruction of the mandible.

Surgical defects encountered with corrective surgery of the mandibular complex have been repaired most successfully with autogenous composite bone grafts. Their use belies inherent consequences associated with distant donor sites. Presented here are the experiences and results in two patients whose reconstructions consisted of immediate replacement of the resected mandibular segment after its devitalization with cryogenic freezing treatments. Such treated, autologous bone provides an ideal anatomic graft, nondistinct antigenicity, and immediate restoration of form and function. Monitoring of neoosteogenesis was performed with sequential panographic, nuclear, and histologic studies that documented clinical and histologic repair.

Aged↗