Digital chest imaging: comparison of two film image digitizers with a classification task

A classification test was used to compare the results of digitizing chest radiographs with a linear diode array camera and a laser scanner. The ability of B readers to classify a pneumoconiosis test set from original radiographs and the digitized images was compared. The classification of profusion was impaired when images were digitized with the diode array camera but not when they were digitized with the laser scanner. The impairment found with images digitized with the linear diode array camera was overcome with use of a zoom function at the display station. The size of areas of opacification was overestimated on images from both scanners. Variation between and within observers (kappa approximately equal to 0.6) was consistent over observers and over modalities.

Alteration of the connective tissue network of striated muscle in copper deficient rats

The connective tissue network in striated muscle, consisting principally of collagen is arranged in a three dimensional network and is intimately associated with muscle function. Previous studies have shown that animals maintained on a copper-deficient diet undergo myocardial hypertrophy and exhibit cardiovascular lesions such as ventricular aneurysms that eventually rupture. A deficiency of copper in the diet is known to inhibit lysyl oxidase, a metalloenzyme requiring copper as a cofactor and which is also responsible for collagen and elastin crosslinking. Examination by scanning and transmission electron microscopy of skeletal and cardiac muscle from rats maintained on copper-deficient diets showed both gross and microscopic lesions to the connective tissue network. Immunohistochemical staining by light microscopy with antibodies against lysyl oxidase showed that the enzyme was equally present in both control and experimental animals. Fluorescent staining for antibodies against collagen types I and III showed similar results. From these studies we concluded that the collagen secreted during hypertrophy was not crosslinked by lysyl oxidase due to the absence of the copper cofactor. This resulted in the failure of the connective tissue network to transmit and distribute the increased force associated with myocardial hypertrophy and resulted in myocardial aneurysms.

Long-term follow-up of survivors of prehospital sudden cardiac death treated with coronary bypass surgery

Although coronary artery bypass surgery is beneficial to patients with severe coronary artery disease, its role in preventing the recurrence of prehospital cardiac arrest in patients is not clear. In this article, we report on the long-term follow-up of 49 survivors of prehospital coronary arrest who had coronary artery bypass surgery. Prior to their prehospital cardiac arrest, 14% of the patients had a history of unstable angina. Coronary angiograms obtained after prehospital cardiac arrest showed that 71% of the patients had three-vessel coronary artery disease and 6% had single-vessel disease. The mean left ventricular ejection fraction was 45%. There were four postoperative deaths; three were caused by pump failure, and one was caused by refractory ventricular arrhythmias. After a maximum follow-up period of 102 months (mean of 55.4 months), there were seven cardiac deaths; five of the patients died of recurrent ventricular fibrillation, and two patients' deaths were related to refractory heart failure. Actuarial analyses of the 49 patients showed that the probability of survival at 6 months, 1 year, 2 years, 3 years, and 5 years was 92%, 92%, 89%, 82%, and 72%, respectively. After surgery, 35 of the 45 patients who were discharged from the hospital were asymptomatic, and 23 of the 32 patients who were employed when their prehospital cardiac arrest occurred returned to their employment. We concluded that coronary artery bypass surgery is beneficial to certain survivors of prehospital sudden death. After surgery, most patients are asymptomatic and capable of returning to their employment and the recurrence of prehospital sudden death is low.

Indium 111 platelet imaging for the detection of deep venous thrombosis and pulmonary embolism in patients without symptoms after surgery

Indium 111 platelet imaging for the detection of deep vein thrombosis and pulmonary emboli was performed in 171 patients after abdominal and pelvic surgery. Fifteen patients were found to have inadequate circulating blood pools of indium 111 platelets, making the study nondiagnostic. Of 156 patients with technically satisfactory images, 46 (29.5%) had images consistent with deep venous thrombosis and/or pulmonary emboli. The incidence, time of occurrence, and location of thromboemboli was similar to those of other reports of postoperative patients groups studied by iodine 125 fibrinogen uptake testing. Eighty patients had normal indium 111 platelets and 30 patients had diffusely distributed indium 111 platelets found in the operative field, suggesting accumulation in a postoperative hematoma. None of these results was confused with a diagnosis of deep venous thrombosis. When compared with another accurate diagnostic test in 23 patients, indium 111 platelet imaging was found to have a sensitivity of 100% and specificity of 90%. The technique of indium 111 platelet imaging is performed easily in patients after surgery with some limitations as to the use of donor platelets and the occasionally altered imaging of the operative site. This diagnostic technique enjoys the distinct advantage in that it allows surveillance of the legs, pelvis, abdomen, and chest by a single method, making it a near-ideal method of postoperative thromboembolism surveillance.

Thalassemic children's understanding of illness: a study of cognitive and emotional factors

A study that explored children's understanding of the body and illness was conducted with 23 thalassemic outpatients and 27 healthy controls. The findings were supportive of a developmental progression in children's understanding that is reflective of their underlying cognitive maturity. Behavioral compliance was related to psychiatric adjustment. There was a trend toward poorer psychiatric adjustment in children with impaired understanding of their illness. These findings hold implications for both educational and psychiatric intervention with this group. Optimal health care of chronically ill children requires knowledge of the developmental course and interplay of children's cognition and their familial and personal adjustment.

Mitral valve prolapse requiring surgery. Clinical and pathologic study

The clinical, hemodynamic, surgical, and pathologic findings in 30 patients who required mitral valvular surgery and who had a preoperative diagnosis of mitral valve prolapse were reviewed. The mean age of the patients was 59.5 years; 28 patients were over 45 years of age and 10 were over 60 years. Surprisingly, 20 were males. A long history of systolic murmur was common, whereas symptoms of heart failure were of abrupt onset. At the time of surgery, a local holosystolic murmur typical of mitral regurgitation was present, although a mid- to late systolic click was not heard in any of the patients. Electrocardiographic abnormalities were present in all patients, with 13 patients demonstrating atrial fibrillation. Only four patients had a normal heart size radiographically. Echocardiography confirmed the radiographic findings, in that 27 patients demonstrated left atrial and ventricular enlargement. All 29 patients undergoing cardiac catheterization and angiography demonstrated a prolapsing mitral valve with severe regurgitation. Surgical and pathologic examination revealed findings characteristic of a myxomatous valve in all patients, with 19 also demonstrating ruptured chordae tendineae. This study demonstrates that heart failure requiring valvular surgery occurs in a subset of patients with mitral valve prolapse. In this subset, males predominate and most are over 50 years of age. These patients may be asymptomatic for many years, demonstrating mild to moderate mitral valvular regurgitation, before heart failure develops.

Probing the structure of 16 S ribosomal RNA from Bacillus brevis

A majority (approximately 89%) of the nucleotide sequence of Bacillus brevis 16 S rRNA has been determined by a combination of RNA sequencing methods. Several experimental approaches have been used to probe its structure, including (a) partial RNase digestion of 30 S ribosomal subunits, followed by two-dimensional native/denatured gel electrophoresis, in which base-paired fragments were directly identified; (b) identification of positions susceptible to cleavage by RNase A and RNase T1 in 30 S subunits; (c) sites of attack by cobra venom RNase on naked 16 S rRNA; and (d) nucleotides susceptible to attack by bisulfite in 16 S rRNA. These data are discussed with respect to a secondary structure model for B. brevis 16 S rRNA derived by comparative sequence analysis.

Surgical anatomy of the upper eyelid fascia

There is a network of fascia in the upper eyelid that serves to transmit and distribute the motor power of the levator palpebrae muscle to the superficial tissues. The architecture of this network was studied intraoperatively. The results demonstrate that there is a superficial fascia under the orbicularis muscle which fuses with the levator aponeurosis at the level of the lid fold. Below the fold, these fascia remain fused or "conjoined." Thus, the fold in the upper eyelid reflects the union of fascia occurring internally and dose not result simply from the levator aponeurosis inserting into the skin. This article describes the anatomy and surgical identification of the upper eyelid fascia. I contend that the fascia constitutes an important internal framework for the upper eyelid, shaping the lid fold while elevating the tarsal plate in perfect synchrony. For the surgeon, visualizing the fascial architecture is a great aid in the correction of a variety of difficult eyelid deformities.

Left ventricular performance after mitral reconstruction for mitral regurgitation

Depressed left ventricular performance is often observed after mitral valve replacement for mitral regurgitation and is generally attributed to increased impedance to left ventricular ejection. We analyzed preoperative and postoperative catheterization data in 10 of 18 patients who underwent mitral reconstruction with preservation of the native valves and found a significant (p less than 0.05) fall in left ventricular end-diastolic volume index (from 143 +/- 39 to 84 +/- 21 ml/m2) and end-systolic volume index (from 50 +/- 24 to 32 +/- 12 ml/m2), with no significant change in ejection fraction (0.66 +/- 0.1 versus 0.62 +/- 0.1). These findings contrast with studies reported by others in comparable patients who had mitral valve replacement with no improvement in volume indices and a decline in ejection fraction postoperatively. We suggest that some of the left ventricular dysfunction observed after mitral replacement may be due simply to excision of the native valve. Mitral repair retains the tethering effect of chordal attachments and may thus prevent postoperative left ventricular dilatation and moderate the increase in wall stress that results from increased impedance to left ventricular ejection.

Long-term survival after prehospital sudden cardiac death

One hundred thirty-nine survivors of prehospital sudden cardiac death were followed after their hospital discharge. Eighty patients were studied with coronary angiography and cardiac catheterization; 34 of these underwent coronary bypass surgery. After a maximum follow-up of 105 months, 89 patients were still alive. The probability of survival at 6 months, 1 year, 2 years, 3 years, 4 years, and 5 years was 88%, 86%, 78%, 70%, 63%, and 59%, respectively. Of the 43 cardiac deaths, 37 (86%) were secondary to documented recurrent ventricular fibrillation or occurred suddenly. Twelve percent of the total population had recurrent ventricular fibrillation in the first year following the initial cardiac arrest, 16% within 2 years, and 22% within 3 years. Of the 37 survivors dying from recurrent ventricular fibrillation, 32% died within the first 3 months following hospital discharge, 46% in the first year, 64% within 2 years, and 78% within the first 3 years. Most survivors were capable of resuming normal activities after hospital discharge. Only 7% demonstrated permanent neurologic impairment. Sixty-eight percent of the patients who were employed at the time of their prehospital sudden cardiac arrest returned to full-time employment. In the subset of 34 surgically treated patients, there have been six (18%) cardiac deaths. Four of these deaths were related to recurrent ventricular fibrillation, with one of these deaths occurring in the immediate postoperative period. The other three deaths related to recurrent ventricular fibrillation occurred 36 months (two deaths) and 49 months following the initial prehospital cardiac arrest.

Silicone implant under a skin graft for breast reconstruction after radical mastectomy

A case is presented of a young woman after radical mastectomy and skin graft to demonstrate that a skin graft can provide adequate cover for reconstructing the breast with a silicone implant.

Intravenous injections of nicotine induce very rapid and discrete reductions of hypothalamic catecholamine levels associated with increases of ACTH, vasopressin and prolactin secretion

The present findings show that nicotine given i.v. can within minutes induce increases of ACTH, vasopressin and prolactin secretion in the male rat, giving further evidence for the existence of nicotine-like cholinergic receptors involved in the regulation of these hormones. These changes were associated with rapid reductions of NA levels in the subependymal layer of the median eminence, in the nuc, dorsomedialis hypothalami and in the anterior and posterior periventricular hypothalamic area as revealed by quantitative microfluorimetrical measurements of CA fluorescence. Intraindividual correlations indicate the involvement of an inhibitory noradrenergic mechanism in the subependymal layer of the median eminence in the regulation of ACTH secretion, the involvement of noradrenergic mechanisms in the posterior periventricular area in the regulation of prolactin secretion and the involvement of dopaminergic mechanisms in the medial palisade zone of the median eminence in the regulation of prolactin secretion. A rapid rise of prolactin secretion seems to be associated mainly with a reduction of NA levels in the posterior periventricular area indicating the existence of a possible facilitatory noradrenergic mechanism in this region regulating prolactin secretion.

Effect of intracerebroventricular injection of nicotinic acetylcholine receptor antibodies on ACTH, corticosterone and prolactin secretion in the male rat

The aim of the present study was to investigate the involvement of CNS nicotinic receptors for acetylcholine in the secretory activity of the hypothalamo-hypophyseal-adrenal axis and prolactin (PRL). Adult male rats received a daily intraventricular injection of partially purified nicotinic acetylcholine receptor antibodies (anti-AChR) obtained from a female patient with myasthenia gravis, for 5 consecutive days. Control animals were treated similarly with immunoglobulins obtained from a healthy woman. Blood samples were withdrawn either under basal conditions or following ether stress. Treatment with anti-AChR increased basal ACTH and corticosterone (CS) levels (by approximately two-fold) but completely inhibited the responses of these hormones and PRL to ether stress. In control animals, normal basal and stress-induced responses of ACTH, CS and PRL were observed. This study demonstrated the importance for nicotinic acetylcholine receptors in the mediation of basal and stress-induced adrenocortical activity as well as for the mediation of PRL secretion in response to stress.

Resistant geriatric depressions and therapeutic response to monoamine oxidase inhibitors

Elderly depressed patients who met the research diagnostic criteria (RDC) for major depressive illness, resistant to other types of treatment, were treated with phenelzine, a nonselective monoamine oxidase (MAO) inhibitor, for a period of 2 to 7 weeks, following 2 weeks of placebo washout period. Dosage ranged from 15-75 mg daily. Clinical status of patients as well as vital signs, EKG, and platelet MAO inhibition were measured weekly. All responders at the end of this period were followed for 1 to 2 years. Analysis of the results showed a 65% response rate as measured by Hamilton, Global, and Self-rating Scales. No significant drug effect in cognitive functioning, as measured by objective cognitive tests, was observed. Clinical improvement was sustained for all participants throughout the follow-up period with no side effects. A direct relationship between platelet MAO inhibition and clinical response was found. The majority of the responders (70%) had achieved high platelet MAO inhibition values (greater than 80%), while most of the nonresponders had platelet MAO inhibition values of less than 80%. These findings have potential clinical and research implications for treating geriatric depression, especially the ones resistant to other forms of treatment.

Long-term follow-up of survivors of prehospital sudden coronary death

Fifty-two survivors of prehospital sudden coronary death (SCD) were studied with angiography and cardiac catheterization. Coronary bypass surgery (CAB) was performed and combined with medical therapy in 24 patients and 28 patients were treated with medical therapy alone. Severity of coronary artery disease (CAD), left ventricular function, and clinical characteristics are described in the surgical and medical groups. Most patients had at least two-vessel CAD and left ventricular dysfunction was common. Nineteen of the 24 surgical (79%) and 17 of the 28 medical patients (60%) had a primary dysrhythmia without an associated acute myocardial infarction (MI) as the cause of their SCD. After a maximal follow-up of 80 months (mean 38.2 months in surgical group, 32.2 months in medical group), there have been 12 deaths. Eight of the 10 cardiac deaths occurred in patients showed initial SCD was related to ventricular fibrillation (VF) not associated with acute MI. Four of these 10 deaths were in the surgical group and six were in the medical group. Two surgical patients died in the early postoperative period; the other two died from recurrent VF 36 and 48 months after SCD. No perioperative or postsurgical MIs have occurred and only two patients have angina. In the medical group, five of the six deaths were caused by recurrent VF. Twelve patients have symptoms: angina in eight, heart failure in five and myocardial infarction in three. Nine of the 12 surgical patients (75%) who were employed before their SCD are still employed, while seven of 15 medical patients (47%) are employed. We conclude that the majority of survivors of prehospital SCD have severe CAD, although an associated acute MI at the time of SCD is uncommon. Coronary bypass surgery can be successfully performed in many of these patients and most are asymptomatic after surgery. The long-term results appear encouraging, although further studies are necessary to confirm these results.

Corticotrophin and corticosterone secretory patterns following acute neurogenic stress, in intact and in variously hypothalamic deafferented male rats

Adult male rats, intact (N) or bearing complete (CHD), anterior (AHD), or posterior (PHD) hypothalamic deafferentations, were acutely exposed to either visual or audiogenic stimulation. At 2, 4, 10 or 30 min following the onset of stress exposure the animals were decapitated and trunk blood was collected for ACTH (RIA) and corticosterone (CS, CBG) determinations. Basal serum concentrations of both hormones were elevated in CHD and AHD, but not in PHD animals as compared to N animals. In N rats, exposure to both stresses resulted in elevated serum ACTH and CS concentrations, with the ACTH response to audiogenic but not visual stimulation being biphasic. In CHD animals, serum ACTH concentrations decreased, and those of CS were unchanged following stress exposure. While audiogenic stimulation caused elevation in serum levels of both hormones in AHD rats, the normal ACTH and CS response to visual stimulation were completely abolished by anterior hypothalamic deafferentation. In PHD animals, no ACTH response to either of the stress exposures was apparent; in spite of this, partial CS responses were elicited. These data thus describe the temporal aspects of the ACTH and CS secretory responses to different neurogenic stresses, and provide insight into the neural pathways mediating these responses.