The effects of ionizing radiation on the pulmonary vasculature of intact rats and isolated pulmonary endothelium

We studied the effects of ionizing radiation on the morphology of the pulmonary circulation using an in vivo rat model and an in vitro pulmonary artery endothelial cell model. Gamma radiation was given as either an acute (30 Gy) or fractionated (5 X 6 Gy) dose to one hemithorax of rats. An acute 30-Gy dose delivered resulted in a 70% decrease in pulmonary arterial perfusion, using technetium-99m microaggregated albumin (99mTc-MAA), in the irradiated lung by 2-3 weeks after irradiation. Pulmonary microradiographs, using a barium sulfate perfusion method, obtained 2-3 weeks after irradiation demonstrated widespread loss of capillary filling and segmentation of the vessels. Histologic examination demonstrated intact capillaries, suggesting that the alterations in pulmonary perfusion were at the precapillary level. Similar abnormalities in lung perfusion and morphology were found after delivery of fractionated doses of radiation, but the onset of the changes was delayed, occurring 4-6 weeks postirradiation. Using cultured pulmonary endothelial cell monolayers, cell sloughing and retraction from the surface substrate were observed within 24 h after in vitro delivery of 30 Gy. Similar findings occurred in monolayers given fractionated doses (5 X 6 Gy) of radiation 2-3 days after the final dose. The in vivo animal and in vitro endothelial cell models offer a useful means of examining the morphologic alterations involved in radiation lung vascular damage.

Anterior glossectomy: reconstruction with a posterior tongue rotation flap

With traditional techniques, reconstruction of the anterior tongue is often less than satisfactory. The difficulty lies mainly in providing the tongue with the appropriate amount of bulk essential for normal movement and function. We present an alternative method that involves raising a flap from the ipsilateral middle third of the tongue and rotating it into position for suturing to the anterior defect border. We have found this simple procedure to yield adequate tongue bulk for normal speech and deglutition.

The bilobed deltopectoral advancement flap

The bilobed deltopectoral advancement flap is a versatile reconstructive option for selected cervical defects. This modified version of Bakamjian's classic deltopectoral flap utilizes thin anterolateral neck skin to cover complex anterior neck defects. It offers the safety of a minimally rotated pedicle to reduce the chance of flap necrosis from kinking, and the convenience of a single-stage procedure. We have used this flap six times in our clinical experience. Typically, the defects were located in the anterior cervical region, and many of them were reconstructed following total laryngectomy and radical neck dissection. There was no incidence of flap necrosis in the patients, including those who had had preoperative irradiation.

Effect of sulfur amino acid supplementation of raw soy flour on the growth and pancreatic weights of rats

Rat feeding studies showed that L-cystine, L-cysteine, N-acetyl-L-cysteine and L-methionine enhance the nutritional quality of raw (unheated) soy flour as measured in rats by the protein efficiency ratio (PER). Pancreas weights of rats fed diets supplemented with sulfur amino acids were higher than those of rats fed unsupplemented diets. In some instances this increase resulting from nutritional improvement of the diet was relatively greater than that in total body weight. Explanations are offered for these effects in terms of the proposed biofeedback mechanism involving the gastrointestinal endocrine system and the hormone cholecystokinin. The observed stimulation of pancreatic growth by added sulfur amino acids may be closely associated with this pancreatic regulatory mechanism when activated in response to dietary trypsin inhibitors present in unheated soy protein. The extent to which pancreatic hypertrophy develops as a result of a given exposure to trypsin inhibitors may be limited when the total amount or quality of the protein in the diet is less than optimal.

Mesenteric venous thrombosis associated with pregnancy and oral contraception. A case report

Mesenteric vein thrombosis in a pregnant woman taking an oral contraceptive is reported. It is presumed that the hypercoagulable state of pregnancy combined with hormonal contraception led to the thrombosis.

Evaluating the Use of a Data Base System With Community Health Nursing Students

The Data Base Management System for community diagnosis was used during two academic semesters with 80 baccalaureate nursing students. At the end of the two semesters the DBMS was evaluated from feedback obtained through faculty discussions, final student papers and oral presentations. The DBMS met the goals established to evaluate the tool. The clarification of categories for essential data is an ongoing process.

Benign neoplasms of the oral cavity

A wide variety of benign tumors present in the oral cavity. These tumors are for the most part rare and are classified by the tissue of origin. Although benign oral cavity tumors are not life-threatening, they can result in extensive loss of soft tissue and/or bone. Furthermore, many patients are subject to the threat of recurrence, multiple surgical procedures, and the possibility of malignant degeneration. Because many tumors vary little clinically, an adequate biopsy specimen must be obtained for diagnosis. Radiographs are, in general, nondiagnostic. Collaboration with an experienced pathologist is necessary to determine the tumor's probable clinical behavior. Therapy, which is dictated by tumor type, is almost always surgical.

Reduced oxygen tension induces pulmonary endothelium to release a pulmonary smooth muscle cell mitogen(s)

Bovine pulmonary endothelial cells grown in vitro were shown to release a factor that was mitogenic for pulmonary smooth muscle cells during exposure to a reduced oxygen tension atmosphere. The addition of hypoxic endothelium-derived medium resulted in a 60% increase in smooth muscle cell number after 24 h of exposure. Addition of medium from pulmonary endothelium exposed to normoxic conditions or medium derived from either hypoxic or normoxic aortic endothelium did not result in significant increases in smooth muscle cell number. Physicochemical characterization of the hypoxic pulmonary endothelial cell-derived factor(s) showed that it was resistant to heat and reducing agent treatment and stable between pH 3 and 10. The mitogenic activity decreased by 71% at pH 2 and by 68% after treatment with trypsin. The activity adhered to DEAE Sephadex. Gel filtration chromatography of the hypoxic-conditioned medium demonstrated 2 major peaks of smooth muscle cell growth factor activity corresponding to molecular weights between 6,000 and 14,000 and 20,000 and 65,000 daltons, respectively. These data suggest that this pulmonary endothelial cell-derived smooth muscle cell peptide mitogen(s) may be involved in the smooth muscle cell proliferative response seen with chronic alveolar hypoxia.

Nutritional value and safety in mice of proteins and their admixtures with carbohydrates and vitamin C after heating

When a nutritionally complete basal diet containing 10% protein from casein was supplemented with 20% protein from unheated casein, wheat gluten or soy protein isolate, weanling mice exhibited significantly increased weight gains. In contrast, weight gains were markedly reduced compared to those with the basal diet; that is, growth was inhibited, when the supplement was soy protein or gluten that had been heated at 200 or 215 degrees C for 72 min in the dry state to stimulate crust baking. Addition of various carbohydrates to the gluten during heating prevented such growth inhibition. After heating with sodium ascorbate (but not L-ascorbic acid), soy protein (at 200 degrees C) and gluten (at 215 degrees C) completely prevented growth when added to the basal diet. Growth inhibition also occurred with a heated casein-ascorbate mixture, but was less than with the other proteins. The extent of growth inhibition increased sharply with temperature of heating in the range 180-215 degrees C and with sodium ascorbate concentration in the range 1-20%. Possible physical and chemical changes during heating of protein-ascorbate mixtures are discussed, as are possible mechanisms for the growth inhibition.

Sternomastoid myoperiosteal flap for reconstruction of the subglottic larynx

Reconstruction of the subglottis is usually required after resection of cricoid cartilage or tracheal tissue in cases of trauma, subglottic stenosis, or invasive thyroid carcinoma. There are multiple techniques available for reconstruction of the subglottic larynx, but most of them have a high rate of complications or graft failure. We have found the sternocleidomastoid myoperiosteal flap to be an ideal means of reconstruction. In an experimental study, we performed subglottic reconstruction using the sternomastoid myoperiosteal flap on 15 mongrel dogs to determine the presence of bone formation versus calcified fibrous scar. Radiologic studies suggested apparent metaplastic bone formation at the graft site, and histologic studies confirmed this. Functionally, 12 dogs had stable airways without stridor or subglottic narrowing. Three dogs died of complications. With successful reconstruction of large defects in the canine subglottis, attempts to repair large subglottic and tracheal defects in the human are feasible.

Acute cardiovascular and pulmonary effects of intravenous and aerosolized amiloride in the dog

Active Na+ absorption by the epithelia that line the airways can drive volume from the airway surface. Exposure of the lumen-facing surface of airway epithelia to amiloride inhibits Na+ transport. Consequently, aerosolized amiloride may help hydrate the desiccated surface liquid that characterizes lung diseases such as cystic fibrosis. We studied the acute cardiovascular and pulmonary effects of amiloride in anesthetized dogs. Intravenous amiloride reduced blood pressure and increased ventilation frequency and airways resistance of the dog. The effects were dose-related (ED50 = 1.3 X 10(-6) mol/kg), resembled those of injected histamine, and were antagonized by methapyrilene. These results were compatible with the release of endogenous histamine by amiloride, but the graded dose-effect relationship for amiloride differed from the quantal relationship induced by the prototypical releaser, 48/80. Aerosolization of a Ringer's solution that was nearly saturated with amiloride deposited, in upper airway surface liquid, drug concentrations which in previous studies, were sufficient to inhibit Na+ transport by canine airways (ED50 approximately 10(-6) M). Cardiovascular function, airways resistance, and indices of pulmonary tissue water, gas exchange, and perfusion were not affected. Since circulating amiloride after aerosolization was estimated to fall below the concentration that induced vasodepression and correct circled bronchoconstriction after intravenous injection, we conclude that the potency of aerosolized amiloride to induce acute effects in tissues other than airway epithelia is no greater than that of intravenous drug.

Difficult decisions in parotid surgery

Six atypical case presentations of parotid tumors are presented along with solutions proposed by two experts on the topic. The differences and similarities of the opinions expressed are summarized and discussed by the editor.

Surgical treatment of hyperparathyroidism

During the past decade, major advances have been made in many crucial areas of the surgical management of hyperparathyroidism. An up-to-date protocol is presented and stresses preoperative localization, operative technique, intraoperative diagnosis, cryopreservation, and autotransplantation designed for practical application.

Reversible alterations in cultured pulmonary artery endothelial cell monolayer morphology and albumin permeability induced by ionizing radiation

The effects of ionizing irradiation (0, 600, 1,500, or 3,000 rads) on the permeability of pulmonary endothelial monolayers to albumin were studied. Pulmonary endothelial cells were grown to confluence on gelatin-coated polycarbonate filters, placed in serum-free medium, and exposed to a 60Co source. The monolayers were placed in modified flux chambers 24 hours after irradiation; 125I-albumin was added to the upper well, and both the upper and lower wells were serially sampled over 4 hours. The amount of albumin transferred from the upper well/hour over the period of steady-state clearance (90-240 min after addition of 125I-albumin) was 2.8 +/- 0.2% in control monolayers and was increased in monolayers exposed to 1,500 or 3,000 rads (increase of 63 +/- 10% and 61 +/- 10%, respectively, P less than 0.01). No increase was found in monolayers exposed to 600 rads. The increases in endothelial albumin transfer rates were associated with morphologic evidence of monolayer disruption and endothelial injury which paralleled the changes in albumin permeability. Dose-dependent alterations in endothelial actin filament organization were also found. Incubation of the monolayers exposed to 3,000 rads with medium supplemented with 10% fetal calf serum for 24 hours resulted in normalization of albumin permeability, improvement in morphologic appearance of the monolayers, and reorganization of the actin filament structure. These studies demonstrate that ionizing radiation is an active principle in the reversible disorganization of cultured pulmonary endothelial cell monolayers without the need of other cell types or serum components.

Deposition, clearance, and effects of aerosolized amiloride in sheep airways

Persistent Na+ absorption across a relatively Cl- impermeable epithelial barrier may contribute to the smaller water content of airway surface liquid (ASL) in cystic fibrosis. In this study, the feasibility and effectiveness of delivering an inhibitor of Na+ absorption, amiloride, by aerosol to the ASL of awake sheep was evaluated. Aerosolization of 6 X 10(-3) M amiloride, with [14C]amiloride, resulted in an estimated concentration of 7 X 10(-4) M in ASL. The transtracheal electric potential difference (PD), an index of the rate of Na+ absorption, was significantly inhibited (-29%) immediately after aerosolization of amiloride. The inhibition was short-lived and was correlated with rapid disappearance of the drug from ASL (half-time, 10.5 min between 0 and 30 min after aerosolization). Amiloride but not aerosol vehicle increased ASL volume significantly. The unidirectional flow of [14C]amiloride from the lumen to the submucosa across excised, short-circuited sheep airways exceeded flow from submucosa to lumen by a factor of at least 6. This finding suggests that amiloride is actively absorbed and is consistent with the rapid clearance from the airway surface and the short-lived effects of aerosolized amiloride in vivo. We conclude that sufficient concentrations of amiloride can be delivered to sheep airways by aerosol to inhibit PD and Na+ absorption for short periods.

Juvenile nasopharyngeal angiofibroma

JNA is a highly vascular, benign, yet locally invasive tumor that occurs in preadolescent males. Diagnosis is based on history, physical examination, and radiographic findings. CT scanning is invaluable for evaluating tumor extent. Angiography combined with embolization aids surgeons in identifying the main feeding vessels and decreasing intraoperative blood loss. Surgery is the mainstay of therapy with radiation therapy reserved for inoperable masses. For highly aggressive, recurrent angiofibroma, chemotherapy has shown some promise.

Malignant tumors of the major salivary glands

A total of 512 patients with major salivary gland tumors were treated at our institution between the years 1960 to 1975. The 147 cases of malignant salivary gland tumors were reviewed according to presenting characteristics and stage, histology, and outcome. Treatment for each type is summarized. The battery of diagnostic aids and prognostic indicators available to the physician are also reviewed. The newer and more controversial procedures of CT scanning, nuclear magnetic resonance scanning, and fine-needle aspiration are discussed in detail. In the past, salivary gland tumors have been classified by histology alone. Current trends employ the TNM staging system in planning treatment and predicting end results. We have found a far better survival rate in patients with various tumor types presenting with stage I or II disease, but point out that patients with high-grade tumors often present with advanced disease. All major salivary gland tumors should be approached according to the principles of cancer surgery. The minimum procedure is thus superficial or total parotidectomy with preservation of the facial nerve. In low-grade malignancies, the diagnostic procedure will have accomplished this definitive treatment. Salivary gland tumors are rare in the pediatric population. Such malignancies often defy radical treatment. Although cure rates in many categories of high-grade tumors are low, the only hope for survival is an initial aggressive surgical approach. Although radiation was used for recurrent disease only during the years of this study, it is currently being used as adjuvant therapy in almost all malignancies except low-grade mucoepidermoid. Recurrences are almost always fatal.

Lumpectomy vs mastectomy. The costs of breast preservation for cancer

Current data on the surgical management of breast carcinoma support the selective use of conservative surgery, ie, lumpectomy, axillary sampling, plus irradiation, rather than modified radical mastectomy. An economic comparison of these two forms of surgical therapy was conducted. Total charges for treatment (hospital and physician) of 79 patients with stage I or II breast cancer at our hospital during 1983 and 1984 utilizing either therapy demonstrated that mean total charges per patient for lumpectomy (N = 49) were $14,176 +/- $4262, and for mastectomy (N = 30) were $10,345 +/- $3134. Although hospital inpatient fees were significantly less for lumpectomy ($5741) than for mastectomy ($7328), mean total physician fees were significantly higher for lumpectomy ($4505). Radiotherapist fees and the substantial radiation therapy hospital outpatient charge for lumpectomy ($5015) made the mean total charges for lumpectomy significantly higher than for mastectomy.

Computerized model for evaluating the kinetics of in vitro release of valpromide from controlled-release tablets under nonsink conditions

A general mathematical model was developed to describe a dissolution system for tablets that have undergone attrition and maintained their geometric shape as concentration changed, i.e., starting with sink and ending with nonsink conditions. A computer program, designed for the microcomputer, was used to test the goodness of fit of the experimental data to the theoretical data by the chi 2 test. This program is more significant than a previous published program that relates to the more specific kinetic analysis of multidispersed powders undergoing dissolution under sink conditions. Concentration data obtained after dissolution tests of valpromide (2-propylvaleramide) controlled-release tablets performed under changing concentration conditions were checked in the two computerized models, which showed a better fit to the general model.

Alteration of type A behavior and its effect on cardiac recurrences in post myocardial infarction patients: summary results of the recurrent coronary prevention project

One thousand thirteen post myocardial infarction patients were observed for 4.5 years to determine whether their type A (coronary-prone) behavior could be altered and the effect such alteration might have on the subsequent cardiac morbidity and mortality rates of these individuals. Eight hundred sixty-two of these individuals were randomly assigned either to a control section of 270 participants who received group cardiac counseling or an experimental section of 592 participants who received both group cardiac counseling and type A behavioral counseling. The remaining 151 patients, serving as a "comparison group," did not receive group counseling of any kind. Using the "Intention-to-Treat" principle, we observed markedly reduced type A behavior at the end of 4.5 years in 35.1% of participants given cardiac and type A behavior counseling compared with 9.8% of participants given only cardiac counseling. The cumulative 4.5-year cardiac recurrence rate was 12.9% in the 592 participants in the experimental group that received type A counseling. This recurrence rate was significantly less (p less than 0.005) than either the recurrence rate (21.2%) observed in the 270 participants in the control group or the recurrence rate (28.2%) in those of the comparison group not receiving any special treatment. After the first year, a significant difference in number of cardiac deaths between the experimental and control participants was observed during the remaining 3.5 years of the study. Overall, the results of this study demonstrate for the first time, within a controlled experimental design, that altering type A behavior reduces cardiac morbidity and mortality in post infarction patients.