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Biomedical subjects

A G Little

Publications and source records attributed to A G Little.

At least 37 records · Page 2Linked to original sources
PubMed1993

Calcium effects on human esophageal smooth and striated muscle.

Because of conflicting results in earlier investigations, our study was carried out to determine the effects of acute hypercalcemia on esophageal muscle function at the lower esophageal sphincter and on the smooth and striated muscle of the esophageal body. Variables measured included lower esophageal sphincter pressure and length and esophageal body contraction pressure, duration, and velocity in the middle, distal, and proximal esophagus. Despite 3 hr of induced acute hypercalcemia, there were no statistically significant changes in any of the variables. Although esophageal muscle contraction requires calcium, our results, in contrast to some earlier studies, suggest that the availability of excess calcium does not effect esophageal function.

Adult↗
PubMed1993

Erythromycin, motilin, and the esophagus.

BACKGROUND: Motilin induces phase III activity of the gastroesophageal tract. Erythromycin has a motilin-like effect on the stomach, but possible esophageal effects have not been evaluated and are the focus of our investigation. METHODS: Esophageal manometry was performed in 11 healthy volunteers before and after intravenous infusion of 500 mg erythromycin. Values are expressed as means +/- SEM. RESULTS: Lower esophageal sphincter (LES) pressure increased from 21.1 +/- 2.6 mm Hg at baseline to 37.5 +/- 3.8 mm Hg after erythromycin infusion (p < 0.0001). Erythromycin did not affect LES length, esophageal body contraction amplitude, duration or velocity, or the upper esophageal sphincter. Serum motilin levels decreased from 96.4 +/- 10.9 pmol/L to 81.8 +/- 10.9 pmol/L (p < 0.01) after erythromycin administration. CONCLUSIONS: Erythromycin profoundly stimulates the normal human LES. This is a direct motilin agonist-like effect and is not mediated by release of endogenous motilin. Erythromycin has no important effect on the esophageal body or the upper esophageal sphincter.

Adult↗
PubMed1992

Somatostatin stimulation of the normal esophagus.

The inhibitory effects of somatostatin on gastric and small bowel motor function are well documented. However, the effects of somatostatin on esophageal body motility and lower esophageal sphincter tone are not completely defined. We investigated the effects of octreotide, a long-acting somatostatin analogue, on the esophageal body and the lower esophageal sphincter in 15 healthy volunteers. Lower esophageal sphincter tone was increased by octreotide infusion. Esophageal body contraction amplitude and velocity were also increased by octreotide infusion. Our data show that somatostatin stimulates the normal human esophagus, an action mediated either by a direct effect, a central nervous system action, or the inhibition of the secretion of gastrointestinal hormones that influence esophageal motor activity.

Adult↗
PubMed1991

High-grade dysplasia in the columnar-lined esophagus.

Abnormal columnar lining of the esophagus is a well-recognized premalignant condition. The management of patients with high-grade dysplasia without evidence of carcinoma remains controversial. Esophagectomy is proposed by some investigators, whereas others favor follow-up endoscopy and biopsy until microinvasive malignancy is documented. We reviewed our experience with nine patients referred with high-grade dysplasia on endoscopic biopsies without evidence of carcinoma. Eight patients had the columnar lining extending orad from the cardia, and one patient had heterotopic columnar epithelium in the cervical esophagus. All were white men ranging in age from 19 to 76 years (median: 47 years). Eight patients underwent esophagectomy with colon interposition. A sleeve resection of the cervical esophagus was done in one patient. Multifocal carcinoma was found in three patients, all of whom had severe dysplastic changes throughout the columnar lining. The patient with heterotopic columnar epithelium had microinvasive carcinoma. All four patients with carcinoma had negative nodes and are long-term survivors. No carcinoma was found in the resected specimens of the remaining five patients. High-grade dysplasia is an important marker of malignancy in patients with a columnar-lined esophagus. Esophagectomy is indicated in suitable candidates since carcinoma was found in 45% of our patients.

Adult↗
PubMed1991

Disorders of esophageal motility.

Patients with esophageal motility disorders usually have dysphagia and many also have chest pain similar to angina. The diagnosis is suggested by the clinical presentation, and supporting evidence is often provided by contrast roentgenography. Esophageal manometry is usually necessary to confirm the diagnosis. Conservative therapy using pharmacologic agents is often useful as an initial trial, although many patients who continue to be symptomatic ultimately require surgical intervention.

Esophageal Motility Disorders↗
PubMed1990

Flow cytometric DNA analysis of squamous cell carcinoma of the esophagus.

Although an abnormal amount of cellular DNA content is known to occur in squamous cell carcinoma of the esophagus, the significance and clinical relevance of this finding have yet to be elucidated. Paraffin-embedded blocks from 77 patients with squamous cell carcinoma of the esophagus were dewaxed and made into a suspension by mechanical mincing and enzymatic digestion. The nuclei were stained with propidium iodide, and the DNA content evaluated with flow cytometric study. The DNA index (DI) and the coefficient of variation were determined and the results were compared with other pathologic prognostic features. DNA aneuploidy was identified in 70.1% of the specimens and found to correlate significantly with both histologic grading (P less than 0.025) and the incidence of postoperative recurrence (P less than 0.05). Although the 5-year survival was slightly better in the euploid group than in the aneuploid group (28.8% and 19.1%, respectively), this difference was not statistically significant (P greater than 0.1). There was no correlation of the DI with the extent of wall penetration by the tumor, the incidence of lymph node metastases, or the surgical staging, features previously shown to correlate with prognosis in patients with esophageal carcinoma.

Carcinoma, Squamous Cell↗
PubMed1990

Expression of ras oncogene p21 protein in esophageal squamous cell carcinoma.

In order to investigate the value of ras oncogene expression as a prognostic indicator in esophageal squamous cell carcinoma, we evaluated the level of ras oncogene protein product (p21) in 52 specimens resected between 1977 and 1986. All patients were followed until death or for at least 2 years. Pathology slides and archival paraffin blocks were retrieved for confirmation of the original diagnosis, study of histopathologic features, and measurement of p21 content. P21 titers were obtained using the RAP-5 monoclonal antibody in a semiquantitative immunohistochemical assay. Titer was expressed as the highest dilution of antibody giving definitive staining using the avidin-biotin peroxidase method. Ras oncogene was expressed in 88.5% of the specimens. We did not find a significant correlation between ras expression and any of a variety of clinical and histopathologic prognostic parameters. Although patients' median survival after resection of specimens with ras oncogene expression was less than half the median survival after removal of tumors without such expression, this difference was not statistically significant. Further prospective investigations are needed to assess the role of ras oncogene evaluation in clinical practice.

Adult↗
PubMed1990

Indications for esophagectomy in nonmalignant Barrett's esophagus: a 10-year experience.

Between 1978 and 1988, 88 patients were referred for the surgical treatment of nonmalignant Barrett's esophagus. Nineteen patients required esophageal resection. Male/female ratio was 13:6; age range was 13 to 84 years (mean age, 49.8 years; median age, 40 years). Preoperative studies demonstrated strictures in 11 patients and ulcers in 7. Penetrating Barrett's ulcer resistant to treatment was the indication for resection in 5 patients. Ulcers penetrated to the pericardium (1 patient), pulmonary vein (1), lung (1), and mediastinum (2). Other indications for resection included undilatable strictures (2), previous operations (4), high-grade dysplasia (3), parietal cells lining the esophagus (1), patient's refusal of long-term surveillance (2), and the inability to exclude adenocarcinoma preoperatively (2). Reconstruction was achieved by colon interposition (15) or esophagogastrostomy (4), with one postoperative death. Mean follow-up was 41 months and was 100% complete. Of the 18 patients, 3 have occasional regurgitation but none have any dysphagia or weight loss. Esophageal resection is indicated in a select group of patients with Barrett's esophagus. Absolute indications include a deep penetrating ulcer confirmed intraoperatively, high-grade dysplasia, strong suspicion of cancer, and multiple previous operations. Relative indications include strictures not responding to dilation and young patients refusing long-term surveillance.

Adolescent↗
PubMed1990

Pericardial window: mechanisms of efficacy.

Although the term implies a persistent communication through which fluid might drain, how a pericardial window works is not clear. We believe that the mechanism of success is not window but rather fusion of the epicardium to the pericardium with obliteration of the potential space. To evaluate this, we studied 28 patients, all of whom underwent a subxiphoid pericardial window procedure with tube drainage maintained until output was minimal. There were no operative deaths, and 26 patients (92.9%) obtained permanent relief. Postoperative echocardiograms demonstrated thickening of the pericardium/epicardium and obliteration of the pericardial space. Autopsy performed on 4 patients who died of their underlying malignancy confirmed this fusion, which begins as an inflammatory process. A subxiphoid pericardial window relieves effusions with a low operative mortality and good long-term success (92.9%, 26 of 28). This success is dependent on the inflammatory fusion of the epicardium to pericardium and not maintenance of a window. Tube decompression should be maintained until fluid output is minimal to allow apposition and fusion of the two surfaces.

Adult↗
PubMed1990

Perioperative blood transfusion adversely affects prognosis of patients with stage I non-small-cell lung cancer.

It has been speculated that blood transfusion might adversely affect prognosis in cancer patients by immunosuppression. To avoid the confounding affect of advanced disease, we tested this hypothesis in 117 patients with stage I non-small-cell lung cancer. Mean and median follow-up were 49.7 months and 47 months, respectively. Patients who died during the postoperative period were not included. Perioperative transfusion was defined as administration of whole blood or packed cells within 30 days of operation. The overall cumulative 5-year disease-free survival rate was 67%. In patients with transfusion, it was 53% and in patients without transfusion it was 81% (p = 0.0055). A multivariate analysis was performed that included patient age, race, sex, cell type, extent of operation (pneumonectomy versus lobectomy/segmentectomy), operative blood loss, admission hematocrit, discharge hematocrit, and the presence or absence of perioperative transfusion. The only variable that significantly correlated with 5-year disease-free survival was the presence or absence of perioperative transfusion (p = 0.0278), and this effect was not related to the number of transfusions. Retrospective analysis of long-term results of patients surviving curative operation for stage I lung cancer shows that any perioperative transfusion significantly worsens the patient's prognosis and suggests very strongly that this association is due to an adverse effect of the transfusion rather than the transfusion serving as a marker for another risk factor.

Carcinoma, Non-Small-Cell Lung↗
PubMed1990

Yellow nails, lymphedema and pleural effusion. Treatment of chronic pleural effusion with pleuroperitoneal shunting.

Pleural effusion secondary to lymphedema may be chronic, symptomatic and refractory to treatment, occasionally requiring invasive and painful procedures such as chemical pleurodesis, open pleural abrasion or pleurectomy to achieve control of the effusion and gain symptomatic relief. We report a patient with yellow nail syndrome and chronic pleural effusion successfully treated with pleuroperitoneal shunting.

Aged↗
PubMed1990

Clinical staging of patients with non-small cell lung cancer.

This article is the first in a planned series from the Section on Lung Cancer of the ACCP addressing the important and clinically relevant aspects of what is now the most common malignancy in the world, lung cancer. This initial report addresses the problem of staging of lung cancer. Staging, or identifying the anatomic extent of disease according to the AJCC TNM classification scheme, is the first clinical activity in caring for a patient with known or presumed lung cancer because the results determine appropriate types of therapy. This is, therefore, a critically important aspect of the patient's care which forms the foundation for subsequent treatment. In addition, consistent use of this system, based on appropriate clinical and pathologic staging, in stratifying patients in clinical reports is mandatory; otherwise, meaningful comparisons and conclusions are impossible.

Biopsy↗
PubMed1989

Efficacy of computed tomography of the thorax and upper abdomen and whole-body gallium scintigraphy for staging of lung cancer.

To assess the efficacy of performing both computed tomography (CT) of the thorax and upper abdomen and whole-body gallium scintigraphy for staging lung cancer, the results of each test were compared with those obtained by chest radiography and clinical examination in 100 patients. Clinical efficacy was defined in terms of accuracy in staging the tumor based either on surgery, biopsy, or clinical and radiologic follow-up. The CT provided significantly superior accuracy in 27 patients and minor additional staging information in 17 patients compared with the gallium scan. Whole-body gallium scintigraphy provided important additional information in nine patients and minor additional information in a further eight. The diagnostic yield of CT and gallium scanning was considered equivalent in 39 cases. Of the nine cases in which gallium was significantly superior to CT, clinical findings which suggested the presence of metastases had been noted before the scan in four cases. The authors' results confirm the utility of CT for staging lung cancer and indicate that the additional yield from gallium scintigraphy is relatively low provided a thorough history and physical examination have been performed.

Adult↗
PubMed1989

Correlation between automated karyometric measurements of squamous cell carcinoma of the esophagus and histopathologic and clinical features.

The clinical staging of esophageal carcinoma is unreliable currently, making it difficult to select patients for aggressive therapy. To further refine staging criteria, the nuclear characteristics of a series of 31 patients with squamous cell carcinoma of the esophagus were studied using a computerized image analysis system (MicroTICAS). Karyometric measurements, including total nuclear DNA content, nuclear area, and nuclear roundness were compared with various clinical and histologic variables. Nearly all tumors (30 of 31) were aneuploid. Tumors with nuclear areas greater than 70 microns2 were associated with transmural esophageal penetration (P less than 0.05) and to a lesser extent with poor survival (less than 6 months; P = 0.06). Surprisingly, nuclear ploidy did not correlate with either variable. These data support a role for nuclear analysis on preoperative biopsy specimens as an adjunct in clinical staging.

Aneuploidy↗
PubMed1989

Early evaluation and therapy for caustic esophageal injury.

Forty-one patients with caustic ingestion were reviewed. Eighty-three percent were children, all of whom suffered accidental injury. Liquid drain cleaner was the agent in 57 percent and was responsible for all esophageal burns. Symptoms and physical findings were unreliable in predicting the extent of injury. Endoscopy was performed in most patients within 36 hours of ingestion and accurately estimated the risk of subsequent esophageal stricture formation. Steroid administration had no influence on the development of strictures. Esophageal strictures developed in 22 percent of the patients. One-third were successfully managed by periodic dilation, whereas the remaining two-thirds required esophagectomy and reconstruction. Early endoscopic evaluation was the best means of assessing the degree of injury after caustic ingestion. Routine steroid administration had no apparent clinical benefit.

Adult↗
PubMed1989

Surgical and endoscopic palliation of esophageal carcinoma.

We reviewed the records of 732 patients with advanced esophageal carcinoma to determine the efficacy of palliative therapy. Palliative resection was performed in 156 patients. Hospital mortality was 9.6%, 1-year survival was 29.1%, and median survival was 7.8 months. Excellent or good palliative results were obtained in 78% of operative survivors. Bypass procedures were performed in 49 patients: hospital mortality was 20.4%, with a median survival of 6.2 months. Excellent or good palliative results were obtained in 71% of operative survivors. Intubation of the tumor was performed in 254 patients. Thirty-day mortality was 10.2%, and median survival was 4.0 months. No patient received excellent palliation. Neodymium:yttrium-aluminum-garnet laser therapy or photodynamic therapy was performed in 50 patients. No procedure-related deaths were recorded, and median survival was 4.1 months. Excellent or good results were obtained in 83% of patients. Lesser procedures were performed in 106 patients, and 117 had only staging examinations. Although surgical palliation of esophageal cancer with resection or bypass provides good results, the cost is high. Improvements in palliative results require reduction in operative mortality, increased accuracy of preoperative staging, continuing use of laser therapy, and increased use of chemotherapy alone or in combination with radiotherapy and operation.

Adult↗