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Biomedical subjects

R R Baker

Publications and source records attributed to R R Baker.

At least 109 records · Page 6Linked to original sources
PubMed1979

A comparison of modified radical mastectomy to radical mastectomy in the treatment of operable breast cancer.

This study compares the results of modified radical mastectomy (144 cases) to radical mastectomy (188 cases) in the treatment of operable breast cancer. Two hundred five patients had Stage I breast cancer, 60 had Stage II disease and 67 had Stage III disease (TNM System). There was no statistically significant difference in five year survival when the results of a radical mastectomy were compared to a modified radical mastectomy at any stage of disease. There was no statistically significant difference in the incidence of local recurrence in patients with Stage I and Stage II disease when the results of a radical mastectomy were compared to modified radical mastectomy. Those patients with Stage III disease who were treated by a modified radical mastectomy had a statistically significant higher incidence of local recurrence (chest wall and axilla) in comparison to patients treated by radical mastectomy. We have concluded that a modified radical mastectomy is the treatment of choice in patients with Stage I and Stage II diseases. In patients with Stage III disease, a radical mastectomy provides a better chance of local control of the disease but offers no increased chance of survival.

Breast Neoplasms↗
PubMed1979

The indications for transcervical mediastinoscopy in patients with small peripheral bronchial carcinoma.

A series of 80 patients with roentgenographic evidence of bronchial carcinomas 3 centimeters or less in size was analyzed as to the incidence of mediastinal lymph node metastases. Forty patients underwent transcervical mediastinoscopy prior to thoracotomy and 40 patients did not. Three patients with large cell undifferentiated carcinoma had mediastinal lymph node metastases which could be detected by transcervical mediastinoscopy. None of the 40 patients who did not undergo mediastinoscopy had palpable evidence of mediastinal lymph node metastases at thoracotomy. The survival rates for the two groups of patients were similar. On the basis of this study, we have concluded that mediastinal exploration is not routinely indicated in patients with peripheral T1, N1, M0 lesions.

Adenocarcinoma↗
PubMed1978

Preoperative assessment of the patient with breast cancer.

The clinical assessment of patients with Stages I and II breast cancer is outlined in Figure 1. A chest x-ray film and serum alkaline phosphatase are the only routine studies indicated. If the serum alkaline phosphatase is abnormal in the presence of otherwise normal liver function studies, a bone scan, liver scan, and CEA should be obtained. Areas of increased radioactivity on bone scan are always evaluated by additional radiographs and in some cases tomograms. The majority of focal areas of increased radioactivity will demonstrate radiographic evidence of benign bone lesions, predominantly degenerative joint disease. Only those focal areas of increased radioactivity that are normal on x-ray film or show radiographic evidence of metastases are considered to be positive for metastatic disease. The results of the liver scan are correlated with the level of CEA. Focal areas of decreased radioactivity associated with a CEA greater than 5 ng per ml are considered to be metastases. In the absence of elevation of the CEA, focal areas of increased radioactivity should be biopsied prior to any further considerations as to definitive therapy. The clinical assessment of patients with Stage III disease is outlined in Figure 2. Patients with this stage of disease have a much greater chance of having clinically occult metastases of sufficient size to be detected by chest x-ray film, serum alkaline phosphatase, and bone scan. If the serum alkaline phosphatase is abnormal, a liver scan and CEA are obtained in an effort to detect liver metastases. The same sequence of events is then followed as suggested for patients with Stages I and II disease. Several new techniques of detecting occult metastases are being evaluated. Biomarkers are the subject of another article in this volume. The use of computerized axial tomography is also being evaluated as a means of detecting lung, liver, and mediastinal metastases. The results of these initial clinical trials should be carefully followed.

Alkaline Phosphatase↗
PubMed1978

Therapeutic embolization for hemorrhage from locally recurrent cancer of the breast.

Embolization therapy is reported in three patients bleeding from metastatic carcinoma of the breast. Two had life threatening hemorrhage from sternal erosion; internal mammary arteriography indicated encasement, false aneurysm formation or tumor blush. The third patient had intermittent bleeding of extensive fungating axillary and anterior chest wall metastases. Autologous clot alone was used in the first case with immediate cessation of bleeding and transient neurological symptoms secondary to back flow of thrombus into the vertebral artery were noted. The second and third patients received Oxycel-Ivalon and Gel-foam respectively; bleeding ceased and no complications were noted.

Breast Diseases↗
PubMed1978

Pulmonary sequestration.

Pulmonary sequestration is an uncommon congenital abnormality in which nonfunctioning lung tissue is supplied by an anomalous systemic artery. Both the extralobar and intralobar forms probably develop from an accessory lung bud from the primitive foregut. Both forms are situated on the left side in about two-thirds of patients. The anomalous arterial supply usually originates from the descending thoracic aorta, and there may be a large left-to-left or left-to-right shunt through the sequestration. The sequestration may have a fistulous communication with the upper gastrointestinal tract. Congenital anomalies, particularly diaphragmatic hernia, are frequently associated with the extralobar form. Intralobar sequestration occasionally is an incidental finding on roentgenograms of the chest in an asymptomatic patient; however, the disorder is usually symptomatic and the most common presentation is recurrent pulmonary infection. Presentation may be characterized by gastrointestinal symptoms, congestive heart failure, hemoptysis or hemothorax. Extralobar sequestration is usually an incidental finding on routine roentgenograms of the chest or during the management of some other congenital anomaly. Infrequently, extralobar sequestration presents with symptoms similar to those seen with the intralobar form. Roentgenograms of the chest, upper gastrointestinal series and arteriography are the most helpful diagnostic aids. The usual treatment is resection of the sequestration by removal of only the sequestration in patients with the extralobar form and by lobectomy or segmental resection in patients with the intralobar form. The reported results of operation have generally been excellent.

Abnormalities, Multiple↗
PubMed1977

Identification of retinoyl complexes as the autofluorescent component of the neuronal storage material in Batten disease.

Cytosomes filled with intensely fluorescent material in the form of curvilinear bodies were isolated by density gradient centrifugation followed by pronase digestion from the cerebral cortex of a child who had died at age 7 from the late infantile form of Batten disease. Forty-three percent of the dry weight of the storage material was extracted by a mixture of chloroform and methanol, leaving a waterinsoluble amorphous fluorescent residue. Infrared spectroscopy, proton magnetic resonance spectrscopy, and mass spectrometry of this residue strongly suggested the presence of retinoyl polyenes linked to a small peptide. Base hydrolysis and methanolysis yielded retinoic acid and methyl retinoate, respectively. Ozonolysis yielded a product derived from the substituted cyclohexenyl ring of vitamin A. The results indicate that the fluorescent component of the neuronal storage material is a retinoyl complex and is not derived from peroxidized polyunsatured fatty acids as previously thought.

Brain↗
PubMed1977

Out-patient breast biopsies.

Because an increasing number of women do not wish to be anesthetized not knowing the specific diagnosis and not knowing if they will awaken with or without their breast, the traditional approach of biopsy under general anesthesia, frozen section and simultaneous mastectomy has been abandoned in most instances. One-hundred and fifty-three consecutive biopsies have been performed under local anesthesia. Nineteen patients proved to have a carcinoma, 23 patients had non-obligate precursors of carcinoma, five patients had a lymphoma and the remaining patients had benign disease. No significant complications occurred. Breast biopsies under local anesthesia avoid a good deal of psychologic trauma to the patient and allow the surgeon to plan therapy based on a precise histologic diagnosis. There are also substantial savings on both the direct and indirect cost of a breast biopsy under local anesthesia compared to a similar procedure under general anesthesia.

Adolescent↗
PubMed1977

An evaluation of bone scans as screening procedures for occult metastases in primary breast cancer.

Preoperative bone scans were obtained in 104 patients with operable breast cancer. Areas of increased radioactivity detected by the bone scan were correlated with appropriate radiographs. One of 64 patients (1.5%) with clinical Stage I and Stage II breast cancer had a metastatic lesion detected by the preoperative bone scan. In contrast, 10 of 41 patients (24%) with Stage III breast cancer had occult metastatic lesions detected by the preoperative bone scan. The majority of patients with abnormal bone scans and no radiographic evidence of a benign lesion to explain the cause of the increased radioactivity proved to have metastatic breast cancer on follow-examination. Even though 20% of patients with operable breast cancer will eventually develop bone metastases, our results indicate that preoperative bone scans are not an effective means of predicting which patients with Stage I and Stage II disease will develop metastatic breast cancer. Because of the considerably increased frequency of detection of occult metastases in patients with Stage III breast cancer, bone scans should be obtained routinely in the preoperative assessment of these patients.

Adult↗
PubMed1976

The preparation and characterization of synaptic vesicles of high purity.

Very pure preparations of synaptic vesicles have been obtained from guinea pig cerebral cortex and from the electromotor synapses of Torpedo marmorata by density gradient centrifugation in a zonal rotor followed by chromatography on columns of glass beads of controlled pore size. Markers for soluble cytoplasm (lactate dehydrogenase), plasma and endoplasmic membranes membranes (Na-K-ATPase; acetylcholinesterase, NADPH-cytochrome c reductase], mitochondrial membranes [cytochrome oxidase] and lysosomes [acid phosphatase] were used to assess contamination and were undetectable. The only enzymes detected in the highly purified preparations from guinea pig cerebral cortex were Mg- and Ca-activated ATPases, but their content relative to acetylcholine fell on chromatography suggesting that they may be constituents of non-cholinergic vesicles. Lipids analyses of the highly purified vesicles confirmed earlier results and showed that glycolipids and lysolecithin are present in negligible amounts; this suggests that lysolecithin is not required for exocytosis of synaptic vesicles. A discussion of the probable limiting concentration of acetycholine in cerebral cortical vesicles derived solely from cholinergic terminals suggests that from 13 to 56% of the vesicles isolated are cholinergic, depending on the assumptions made.

Acetylcholine↗
PubMed1976

Spontaneous regression of bronchogenic carcinoma.

Two cases of spontaneous regression of bronchogenic carcinoma were discovered in the literature, and the pertinent findings are described. Six equivocal cases of spontaneous regression are also presented. The reasons for the scarcity of spontaneous regression of bronchogenic carcinoma are discussed; no apparent reasons for spontaneous regression in these two cases could be determined.

Adenocarcinoma↗
PubMed1975

The involvement of lysophosphoglycerides in neurotransmitter release; the composition and turnover of phospholipids of synaptic vesicles of guinea-pig cerebral cortex and Torpedo electric organ and the effect of stimulation.

(1) Crude synaptosomal fractions (P2) derived from guinea-pig cerebral cortex were incubated in the presence of 50 mM KCl in a Krebs-glucose medium. Torpedo marmorata electric organs were stimulated electrically in vivo at 5 pulses/sec for 30 min by electrodes placed on the electric lobe. Synaptic vesicles were isolated from each source and the phospholipid compositions analysed and compared with vesicles from unstimulated controls. (2) Lysophosphatidylcholine was the only lysophosphoglyceride demonstrable in the synaptic vesicles from either source and its low levels did not increase as a result of chemical or electircal stimulation. In each case there was a close similarity of the phospholipid distributions in the vesicles taken from control and stimulated samples. (3) Control experiments indicated extensive decreases in the acetylcholine content of the vesicles from the stimulated electric organ and smaller decreases in the acetylcholine content of the synaptic vesicles from stimulated crude synaptosomal fractions. These fractions were found to respire linearly in the presence of 10 mM glucose and the vesicle fractions were shown to have low levels of contaiminating membranes as judged by marker enzyme analyses. (4) Crude synaptosomal fractions from guinea-pig cerebral cortex were incubated in a Krebs-glucose medium with labelled fatty acids and [3H]glucose in the presence or absence of 50 mM KCl. Subsynaptosomal fractionation was carried out and specific radioactivities of phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine and phosphatidylinositol were determined in fractions D (synaptic vesicles), E (microsomes) and H (disrupted synaptosomes). The release of neurotransmitter did not significantly enhance the labelling of phospholipids in any of the fractions studied as compared with phospholipids from unstimulated fractions. This was found after two incubation times and using [14C]oleate, [14C]arachidonate, [3H]palmitate and [3H]glucose.

Acetylcholine↗
PubMed1975

The clinical assessment of selected patients with bronchogenic carcinoma.

This paper describes the clinical management of patients with malignant cells in their sputum and a normal chest roentgenogram and those with asymptomatic peripheral pulmonary masses. The source of malignant cells in the sputum of patients with no roentgenographic abnormalities can be localized by tantalum bronchography and fiberoptic bronchoscopy. Peripheral pulmonary masses can be diagnosed preoperatively by needle biopsy or transbronchial fiberoptic bronchoscopy with little morbidity and no mortality. These procedures are not necessary, however, if there is firm clinical and roentgenographic evidence of malignancy. Bronchogenic carcinomas presenting as asymptomatic circumscribed peripheral pulmonary masses have a 25% incidence of occult mediastinal lymph node metastases. In view of this relatively high incidence of metastasis, we think mediastinoscopy should routinely be performed prior to thoracotomy is asymptomatic patients with a peripheral pulmonary mass and no roentgenographic evidence of mediastinal widening.

Biopsy, Needle↗
PubMed1975

Local ablative procedures designed to destroy squamous-cell carcinoma.

In a series of experiments in dogs, the bronchial mucosa was either excised or destroyed prior to closure of a bronchial stump following a lobectomy or the reanastomosis of a divided bronchus. The experiments were designed to simulate the clinical situation in which focal areas of squamous-cell carcinoma in situ in the bronchial margin would be managed by local ablation of the mucosa rather than by excision of additional bronchus. The experiments demonstrated that the bronchial mucosa is not necessary for bronchial healing. They also demonstrated that functionally and morphologically normal bronchial epithelium regenerates across the denuded bronchus. The source of this regenerated epithelium appears to be the submucosal glands which remain in the bronchial wall after a variety of local ablative procedures. Since our clinical experience has demonstrated that these submucosal glands frequently contain small foci of squamous-cell carcinoma in situ, we have concluded that either excision or thermal destruction of the bronchial mucosa has very limited clinical application and should be considered only in patients who cannot tolerate excision of more than one lobe of the lung.

Animals↗