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Biomedical subjects

R Sawyer

Publications and source records attributed to R Sawyer.

At least 19 recordsLinked to original sources
PubMed1998

Evidence for a neurotensin receptor in rat serosal mast cells.

OBJECTIVE AND DESIGN: The ability of neurotensin (NT) at nmolar levels to stimulate exocytosis of the mast cell suggested that it could play a role in neuro-immune-endocrine interactions. The inhibition by a specific receptor antagonist of NT's mast cell stimulation suggested the presence of a specific mast cell NT receptor. We have here employed several probes to determine if a specific neurotensin receptor was present on rat serosal mast cells. MATERIAL: Serosal mast cells were isolated from the peritoneal and pleural cavities of male Sprague-Dawley rats. METHODS: Immunocytochemistry with an antibody raised against the C-terminal peptide of the neurotensin receptor was utilized. The same antibody was employed in immunoblotting following SDS gel electrophoresis of mast cell extracts. An RNA probe for ribonuclease protection assays (RPA) was prepared using the rat brain neurotensin receptor cDNA and polymerase chain reaction was carried out using primers based on the rat brain neurotensin receptor sequence. RESULTS: Mast cells showed specific staining with the anti-neurotensin receptor antibody and this same antibody revealed a protein on SDS gels migrating as a 70 kDa species. Ribonuclease protection assays revealed the predicted protected fragment at approximately 450 bp while PCR amplification gave a major product at 843 bp. CONCLUSIONS: These results indicate that a specific neurotensin receptor is present on the rat mast cell.

Animals↗
PubMed1998

Idiopathic pulmonary fibrosis and cyclosporine: a lesson from single-lung transplantation.

Idiopathic pulmonary fibrosis (IPF) has a poor prognosis and therapeutic options are limited with a 5-year survival of less than 50%. This report includes a case of histologically confirmed IPF in a patient whose native lung showed objective improvement as measured by high-resolution CT while he was receiving cyclosporine-based immunosuppressive therapy after single-lung transplantation.

Cyclosporine↗
PubMed1997

The impact of routine CT of the chest on the diagnosis and management of newly diagnosed squamous cell carcinoma of the head and neck.

OBJECTIVE: The purpose of the study was to ascertain how often additional malignant neoplasms are detected on CT scans of the thorax in patients with newly diagnosed squamous cell carcinoma of the head and neck and to determine how often these findings are evident on conventional radiographs of the chest. SUBJECTS AND METHODS: One hundred eighty-nine patients with newly diagnosed squamous cell carcinoma of the head and neck were prospectively examined in a 5-year period. At the time of the initial diagnosis, each patient underwent both chest radiography (posteroanterior and lateral radiographs in 95%, anteroposterior in 5%) and thoracic CT to assess the prevalence of additional primary or metastatic malignant neoplasms of the thorax and upper abdomen. RESULTS: Of the 189 patients studied, 66 showed a total of 73 significant abnormalities on thoracic CT scans of which only 17 abnormalities (23%) were detected on chest radiographs alone. Of these 66 patients, 36 (55%) were found to have one or more primary or metastatic neoplasms. These 36 patients manifested a total of 41 additional primary or secondary malignant neoplasms including 24 cases in which one or more pulmonary nodules were detected, six cases of lymphadenopathy, three hepatic lesions, three bone lesions, two pleural masses, two esophageal masses and one adrenal mass. Of these 41 malignant tumors, 13 (32%) were synchronous primary tumors and 28 were metastases. Only 12 (29%) of the 41 malignant tumors detected by thoracic CT were seen on the chest radiographs. In all patients in which an additional malignant tumor was diagnosed, clinical management was significantly affected, resulting in a modification of the planned surgery or the addition of chemotherapy, radiation therapy, or both. CONCLUSION: A relatively large percentage of patients (19%) with newly diagnosed squamous cell cancer of the head and neck was found to have additional malignant tumors, 32% of which were synchronous primary tumors. The discovery of these additional neoplasms had a major effect on both the therapy and the prognosis of these patients. The combination of a relatively poor detection rate for conventional chest radiography, with only 29% of the malignant tumors detected on CT scans of the chest being seen on chest radiographs, and the high prevalence of disease in this population support the routine inclusion of thoracic CT in these patients.

Carcinoma, Squamous Cell↗
PubMed1996

T cell responses to the paramyxovirus simian virus 5: studies in multiple sclerosis and normal populations.

A recent study suggested that a significant portion of the oligoclonal IgG found in multiple sclerosis (MS) cerebrospinal fluid may be removed by absorption with simian virus 5 (SV5). We have now evaluated the proliferative responses to SV5 generated by peripheral blood mononuclear cells from normal adult subjects and from patients with MS. Positive responses were detected in 16 of 16 subjects in each group. The magnitude of the response was not significantly different in the two groups. There was no correlation between the level of response and the presence or absence of HLA-DR2. No cross-reactivity with SV5 was demonstrated by panels of human T cell clones directed against myelin basic protein or measles virus. More than 60% of normal individuals between 10 and 16 years of age also generated positive T cell proliferative responses to SV5, while fewer than 25% of subjects below the age of 6 generated positive responses. Intermediate percentages of positive responders were detected in subjects 6-9 years of age. We conclude that the adult human population has been widely exposed to this organism and that initial exposure generally occurs in the early to middle school-age years.

Adolescent↗
PubMed1996

Elevated prostate-specific antigen levels in black men and white men.

The usual ranges for prostate-specific antigen (PSA) are derived from a community-based population of White men but are used for screening on all men on the assumption that the differences between the PSA levels of different racial groups are small or have no clinical significance. Recently published reports, however, suggest that PSA levels in a specific racial population may vary directly with the relative risk of prostatic cancer within that population. PSA ranges were determined in Black and White men registered with the Veterans Affairs Maryland Health Care System, Baltimore, Maryland. The total patient census of 122,602 has near-equal numbers of Black and White men and maintains records of race designation for inpatients. Among the male patients with no known prostatic cancer, there were 10,808 men 40 years of age or older and 19,482 PSA test results. In this group, there were 3274 men identified as Black; 2993 identified as White, Not of Hispanic Origin, and 4541 identified as Other Race or Race Unknown. The 95th percentile PSA values in Black men and White men 40 through 49 years of age were 2.80 ng/mL and 2.01 ng/mL, respectively; 50 through 59 years old, 5.40 ng/mL and 4.19 ng/mL, respectively; 60 through 69 years old, 9.59 ng/mL and 7.00 ng/mL, respectively; 70 through 79 years old, 15.45 ng/mL and 9.40 ng/mL, respectively; and for men older than 80 years of age, the 95th PSA values were 21.05 ng/mL in Black men and 18.25 ng/mL in White men. In every age group, Black men had a higher range (for the 95th percentile) than did White men. The largest difference was found in men 70 through 79 years old; in this age group, the ratio of the upper limit of PSA for Black men compared with White men was 1.6 ng/mL.

Adult↗
PubMed1995

Short- and long-term outcome of esophageal perforation.

Esophageal perforation is an important complication of endoscopy and dilation, but few data are available regarding long-term outcome in these patients. Thirty-one consecutive patients with esophageal perforation were studied. Long-term outcome was determined by office follow-up and questionnaires via mail or telephone. The study group included 16 men and 15 women with a mean age of 61 +/- 4 years. Instrumentation was the principal cause of perforation (77%), and pain was the principal symptom in the majority of cases. However, some patients reported no pain, their only symptom being shortness of breast or dysphagia on swallowing saliva. Contrast examinations were used to establish the diagnosis, but results were initially negative in 3 of 27 patients (11%). Seven patients were treated nonsurgically (nasogastric drainage, antibiotics, and intravenous alimentation). Fourteen patients underwent primary closure of the esophageal rent. Six patients underwent surgical drainage, 3 underwent total esophagectomy, and 1 died during surgery before the esophagus was exposed. Thirty-day mortality was 6.4%. Mean hospital stay was 26 +/- 5 days. Postdischarge follow-up was available in 28 of the 29 patients (97%) surviving initial hospitalization, and the mean follow-up was 47 +/- 9 months. Nineteen patients had persistent dysphagia, and 6 underwent dilation again. One of these patients had a second perforation. Contrary to results of some earlier studies, the mortality from esophageal perforation was low in our study because of early intervention in suspected cases. Results of contrast studies are sometimes negative in the early stages after perforation, and studies may need to be repeated.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Sexual knowledge, behavior and sources of information among deaf and hard of hearing college students.

A sexual health knowledge, behavior and sources of sexual health information survey was administered to 134 deaf and hard of hearing college students. Results indicated the students in this sample were not particularly well informed about sexual health and sexuality issues, were engaging in high risk sexual behaviors and relied primarily on peers for sexual health information. The need for the development of psychometrically sound measurement instruments for use with deaf populations as well as areas for future sexual health research are discussed.

Adult↗
PubMed1994

Is there still a role for distal pancreatectomy in surgery for chronic pancreatitis?

The medical records of patients subjected to distal pancreatectomy for chronic pancreatitis from 1982 to 1992 were reviewed to ascertain if pain relief could be predicted based on computed axial tomography (CAT) and endoscopic retrograde cholangiopancreatography (ERCP) findings. Of 10 patients who had severe pain preoperatively and disease limited to the body or tail of the pancreas, 9 had no pain or only mild pain postoperatively. Of 7 patients with severe pain preoperatively and diffuse disease or disease localized to the head of the pancreas, 6 required further hospitalization and resection or drainage procedures for severe, recurrent pain. We believe 50% to 60% of distal pancreatectomy procedures meet most criteria for the best operation for a select group of patients with chronic pancreatitis: those patients with severe pain, small ducts (< 5 mm), and whose disease is limited to the body or tail of the gland.

Cause of Death↗
PubMed1993

Uridine allows dose escalation of 5-fluorouracil when given with N-phosphonacetyl-L-aspartate, methotrexate, and leucovorin.

BACKGROUND: In a previous trial in which methotrexate and N-phosphonacetyl-L-aspartate (PALA) were used to modulate 5-fluorouracil (5-FU), four of six patients could not tolerate treatment at the 600 mg/m2 5-FU dose level because of mucositis, diarrhea, and a decrease in performance status. The current study examines the ability of uridine rescue to prevent such toxic effects in the same regimen and, thereby, allow additional dose escalation of 5-FU. METHODS: Twenty-nine patients with advanced malignant neoplasms received PALA and MTX, each at 250 mg/m2, followed 24 hours later by increasing bolus doses of 5-FU (600-750 mg/m2) with a leucovorin rescue (10 mg orally every 6 hours for eight doses) and uridine rescue (3 g/m2/hour, for a 72-hour infusion, 3 hours on, 3 hours off). Treatment was repeated weekly with either 2 weeks on, 2 weeks off, or 3 weeks on, 1 week off. RESULTS: Mucositis, which occurred in 4 of 12 patients treated at the 750 mg/m2 5-FU dose level, was the only significant chemotherapy-induced toxic effect. However, uridine-related central venous catheter complications (cellulitis in six patients and superior vena cava syndrome in one patient) precluded additional treatment on this protocol. CONCLUSIONS: In the current regimen, uridine allowed dose escalation of 5-FU to 750 mg/m2, which some patients tolerated on a 3-week on, 1-week off schedule. Because of the vascular toxic effects associated with intravenous uridine, the authors recommend additional studies with oral uridine to determine whether the increase in 5-FU dose that uridine allows is associated with improved response rates.

Adult↗
PubMed1993

Head and neck malignant fibrous histiocytomas.

Malignant fibrous histiocytoma of the head and neck is a rare tumor with less than 50 total cases reported in the literature. Its rarity and complex histopathology combine to make it a difficult diagnosis. Two cases are described. Pathology characteristics are discussed. The traditional treatment of choice is wide surgical excision. Radiation therapy is usually reserved for recurrent, unresectable, or extremely aggressive tumors.

Adult↗
PubMed1993

Myxomas of the mandible and maxilla.

Myxomas of the mandible and maxillary sinus are rare but well described neoplasms. They appear to be odontogenic in origin related to malformations or missing teeth. Their local aggressiveness and ability to erode bone should not be underestimated. Based on our experience we feel that conservative surgical management including total excision and sparing of uninvolved structures allows for preservation of function. Long-term follow-up is necessary and in case of recurrence, a more radical procedure may have to be performed for this benign disease.

Adult↗
PubMed1992

A phase II trial of biochemical modulation using N-phosphonacetyl-L-aspartate, high-dose methotrexate, high-dose 5-fluorouracil, and leucovorin in patients with adenocarcinoma of unknown primary site.

BACKGROUND: 5-Fluorouracil (5-FU) has modest activity as a single agent in a number of human adenocarcinomas. The technique of biochemical modulation has been used preclinically to increase the activity of 5-FU. METHODS: With doses based on a Phase I study, the authors performed a Phase II trial in patients with advanced metastatic adenocarcinoma of an unknown primary site using N-phosphonacetyl-l-aspartate (PALA), methotrexate (MTX), 5-FU, and leucovorin. In some patients, 5-phosphoriosyl-l-pyrophosphate (PRPP) and uridine triphosphate (UTP) metabolite pools were assayed before and after PALA and MTX to assess metabolite pool shifts. RESULTS: Twenty-one patients were treated in this Phase II trial. Toxicity was tolerable. Biopsy specimens of tumor tissue showed increases in PRPP and decreases in UTP levels in two of three and three of four patients, respectively. However, only one objective response was seen, which is not different from that expected with 5-FU alone. CONCLUSIONS: Expected PRPP and UTP metabolite pool shifts were seen when biochemical modulation was performed with these drugs according to this schedule. Because toxicity was mild, more intense dose schedules of 5-FU are planned for future studies.

Adenocarcinoma↗
PubMed1990

Metronidazole in head and neck surgery--the effect of lengthened prophylaxis.

Previous studies of antibiotic prophylaxis have shown that treatment for 24 hours has been beneficial for head and neck surgery and that longer periods of antibiotic therapy have not improved results. Metronidazole (Flagyl), unlike other antibiotics tested, has been shown to be effective in an experimental abscess, even if treatment is begun up to 120 hours after administration of inoculum. This article presents a prospective, randomized, multifactorial study comparing a brief vs. a prolonged duration of metronidazole and cefazolin prophylaxis in 50 consecutive patients with a head and neck cancer undergoing operation. Patients receiving 2 days vs. 7 or more days of antibiotic prophylaxis were compared. Statistical analysis of data demonstrated a striking reduction in severity of wound complications and a reduced incidence of wound infections in the group treated with 7 or more days of antibiotic prophylaxis.

Adult↗