shukoor65/lab-rag-model huggingface dataset:
Anatomy of the tricuspid annulus. Circumferential myofibers as the structural basis for atrial flutter in a canine model. BACKGROUND. Little anatomic information is available on the annular myocardium. This study was conducted to determine the anatomic substrate for atrial flutter due to circus movement around the tricuspid annulus in the Y-shaped incision canine model of atrial flutter. METHODS AND RESULTS. We studied photographs of the annular myocardium serial histological sections, made in either of three different planes, and compared these with photographs of the intact and blocked gross heart specimens. We found that the annulus is the most caudal region of the atrial wall. The epicardial aspect of the annulus abuts the ventricular septum or the aortic root in the medial region; in other regions, it is covered by the fat of the coronary sulcus. Its endocardial aspect is delimited by the tricuspid leaflets inferiorly and by the pectinate muscle bundles superiorly, except in the medial region where the pectinate muscle bundles are absent. The annular myocardium is bilaminated. A continuous subepicardial circumferential lamina is the most prominent and is robust in the anterior, lateral, and posterior regions, but it attenuates to a fine muscular connection in the medial region. Myofibers of its superior border merge with the pectinate muscle bundles or are admixed in the medial region with myocardium at the base of the medial atrial wall. Its inferior border makes little contact with the annulus fibrosus about the ring; however, in the medial region, these myofibers insert into fibrous tissue superior to the septal leaflet. A discontinuous, subendocardial perpendicular lamina contains myofibers that descend from the atrium; most of these myofibers insert into the annulus fibrosus about the ring, but the lamina is absent in the anteromedial region. CONCLUSIONS. We conclude that the continuous circumferential lamina provides the anatomic substrate for circus movement of excitation in this model.
Correlation of circulating von Willebrand factor levels with cardiovascular hemodynamics. BACKGROUND. Valvular heart disease is associated with a decreased platelet circulating time and a thrombotic tendency. The possibility that these events are related to changes in von Willebrand factor (vWF), a multimeric glycoprotein released from endothelial cells and platelets that mediates platelet adhesion to the vascular subendothelium, has not been examined. METHODS AND RESULTS. We measured the vWF antigen (vWF:Ag) concentration in 43 patients undergoing cardiac catheterization for the evaluation of mitral (n = 17) or aortic (n = 10) stenosis or nonvalvular heart disease (n = 16). Mean vWF:Ag concentration was significantly higher in patients with mitral stenosis than in those without (212 +/- 84 versus 150 +/- 79 units/dl, p less than 0.02); this elevation was associated with a significant elevation of pulmonary vascular resistance (PVR) in the patients with mitral stenosis (186 +/- 49 versus 133 +/- 81 dynes-sec-cm-5, p less than 0.02). The vWF:Ag levels in the entire group of patients (regardless of the presence or type of valvular disease) varied directly with PVR (r = 0.72, p less than 0.0001) and with pulmonary artery pressure (r = 0.60, p less than 0.0001) and inversely with cardiac output (r = 0.64, p less than 0.0001). Changes in PVR, pulmonary artery pressure, or cardiac output could not be correlated with circulating levels of fibrinogen or beta-thromboglobulin, which may be released from activated platelets, nor with the endothelial cell product tissue plasminogen activator. CONCLUSIONS. The association of high vWF:Ag levels with increased PVR and decreased cardiac output in patients both with and without mitral stenosis suggests a hemodynamically induced increase in the endothelial release of vWF, which might contribute to a thrombotic tendency in these patients.
Fifteen-year results of ambulatory compression therapy for chronic venous ulcers. A nonoperative approach to venous stasis ulceration of the lower extremity, consisting of initial bedrest, ulcer cleansing, dressing changes, and ambulatory elastic compression stocking therapy, has been maintained for over 15 years. All patients had class III, severe chronic venous insufficiency. One hundred five of 113 patients (93%) experienced complete ulcer healing in a mean of 5.3 months. One hundred two patients were compliant with elastic compression stockings, and 11 patients were noncompliant. Complete ulcer healing occurred in 99 of 102 patients (97%) who were compliant versus six of 11 patients (55%) who were noncompliant (p less than 0.0001). The influence of noncompliance, previous venous ulceration, previous venous surgery, previous known deep venous thrombosis, peripheral arterial insufficiency (ankle brachial systolic blood pressure index less than or equal to 0.60), pretreatment ulcer duration, ulcer size, age, sex, diabetes, smoking, and photoplethysmography venous refill time on ulcer healing was determined by logistic regression analysis. Only noncompliance with elastic compression stockings (p less than 0.0001) and a pretreatment ulcer duration of more than 9 months (p = 0.02) significantly decreased initial ulcer healing. Posthealing follow-up was available in 73 patients for a mean of 30 months. Fifty-eight patients (79%) continued to be compliant with stockings; 15 patients were noncompliant. Total ulcer recurrence in patients who were compliant was 16%. Five-year lifetable recurrence was 29%. All patients who were noncompliant had recurrent ulceration by 36 months. Previous ulceration, previous venous surgery, and peripheral arterial insufficiency had no effect on ulcer recurrence (p greater than 0.05).
Endothelial dysfunction and subendothelial monocyte macrophages in hypertension. Effect of angiotensin converting enzyme inhibition. Hypertension is associated with an impairment of endothelium-dependent relaxation. The angiotensin converting enzyme inhibitors captopril and cilazapril can prevent this endothelial dysfunction. We recently observed that long-term treatment with cilazapril could also prevent subendothelial infiltration by mononuclear cells in spontaneously hypertensive rats. This prompted us to examine whether, in spontaneously hypertensive rats, endothelial dysfunction and subendothelial infiltration by mononuclear cells are associated. These cells were characterized as monocyte macrophages. Infiltration by monocyte macrophages was quantified by morphometry. Endothelial function was estimated by calculating serotonin ratio (maximal contraction to serotonin on isolated arterial rings with endothelium over maximal contraction on paired rings without endothelium). The regional distribution of endothelial dysfunction and subendothelial monocyte macrophages was similar. Both were maximal in the carotid artery, less in the aorta, and nonexistent in the renal artery. A 2-week treatment with cilazapril decreased both endothelial dysfunction (serotonin ratio decreased by 32%) and the number of subendothelial monocyte macrophages in the aorta, which decreased by 38%. We conclude that in spontaneously hypertensive rats, endothelial dysfunction and subendothelial monocyte macrophage infiltration are associated and that cilazapril can decrease both. The observation that angiotensin converting enzyme inhibitors affect subendothelial accumulation of monocyte macrophage may lead to a better understanding of the mechanism of action of this class of drugs.
Comparison of four subarachnoid solutions in a needle-through-needle technique for elective caesarean section. We have used both spinal and extradural anaesthesia with a 26-gauge, long spinal needle through a 16-gauge Tuohy needle for elective Caesarean section. Four different subarachnoid solutions of bupivacaine were compared: 0.5% heavy bupivacaine alone, or with adrenaline, fentanyl or adrenaline and fentanyl. The incidence of complications and time of regression of the sensory block were analysed. The technique is recommended because it allows rapid onset of anaesthesia and the advantages of an extradural catheter. The subarachnoid solution of choice was 0.5% heavy bupivacaine 12.5 mg with fentanyl 10 micrograms.
Severe congestive heart failure. How successful are drug and transplant therapies? Severe congestive heart failure is a fatal illness. Aggressive use of proven medical regimens, including vasodilators and angiotensin-converting enzyme inhibitors, may prolong survival time for some patients. Those with refractory symptoms and seriously reduced left ventricular function, impaired exercise capacity, and complex or frequent ventricular arrhythmias should be considered for cardiac transplantation. Candidacy for transplantation is based on the absence of other illnesses that would limit survival or diminish the likelihood of success of the transplant. With the introduction of potent immunosuppressive agents, particularly cyclosporine (Sandimmune), survival rates after transplantation have improved to 90% at 1 year. Major problems include organ rejection, serious infection, development of coronary artery disease in the transplanted heart, and the limited donor organ supply.
Enhancement of ischaemic rabbit skin flap survival with the antioxidant and free-radical scavenger N-acetylcysteine. 1. The burst of damaging oxygen free-radicals at the time of reperfusion is one of the crucial factors affecting skin flap survival after an ischaemic interval. In these experiments the efficacy of the antioxidant and free-radical scavenger N-acetylcysteine in improving the survival of ischaemic rabbit epigastric skin flaps was tested. 2. At the time of reperfusion flaps were given: (1) balanced salt solution by intravenous whole-body administration, (2) N-acetylcysteine (200 mg/kg) by intravenous whole-body administration, (3) balanced salt solution by intra-arterial infusion into the flap, (4) N-acetylcysteine (20 mg/kg) by intra-arterial infusion into the flap, or (5) N-acetylcysteine (200 mg/kg) by intra-arterial infusion into the flap. Flap survival at 1 week, and tissue levels of parameters related to free-radical production, blood levels of thromboxane B2 and peripheral resistance during reperfusion were determined. 3. Compared with controls (groups 1 and 3) which had flap survival rates (expressed as percentage surface area surviving) of 27.1% and 31.6%, respectively. N-acetylcysteine treatment in group 2 (55.2%) and group 4 (51.9%) resulted in significant (P less than 0.05) improvements in flap survival. The survival rate in group 5 (37.7%) was not significantly better than that of the controls. 4. N-Acetylcysteine significantly reduced parameters related to free-radical production in the skin flap after 30 min of reperfusion, determined as tissue levels of malonyldialdehyde and protein oxidation products. There was also a significant decrease in peripheral resistance when low-dose N-acetylcysteine (group 4) was infused intra-arterially into the flap.
Interference between gastroesophageal reflux and sleep in near miss SIDS. GER may be considered as one of the triggering factors in some apparently life-threatening events or even SIDS. Also at the present time, many teams perform 24-h pH monitoring in at-risk infants and treat those with abnormal scores. However, further investigations are needed to answer the question: Which unknown additional factor(s) is present when a specific episode of GER causes apnea and/or bradycardia either during sleep or wakefulness?.
Evaluation and treatment of aneurysms of the vertebral artery: different strategies for different lesions. Aneurysms of the vertebral artery and its branches are relatively uncommon lesions. Their anatomy and presentation can be quite variable. A spectrum of aneurysms of the vertebral artery is presented to illustrate the neuroradiological evaluation, surgical treatment, and perioperative management of these complex lesions.
Bladder compliance in myelodysplastic children: effect of anti-reflux surgery and conservative treatment. Paediatric urology. Little is known about changes in bladder compliance and bladder capacity in myelodysplastic patients following anti-reflux surgery. A study group of 70 patients was divided as follows: group A included 20 myelodysplastic patients who had been operated on for reflux and whose subsequent treatment was conservative. Group B comprised 31 myelodysplastic patients who had been treated conservatively; a third group of 19 non-myelodysplastic patients, treated by anti-reflux surgery because of primary reflux, formed the control group. The follow-up period for group A averaged 61 months (extending from a urodynamic study 3 months after surgery to the most recent test). In group B the mean follow-up period between the initial test and the latest test was 86 months. Bladder compliance in group A patients did not increase significantly (from 5.5 to 6.9), but patients in group B did show a significant increase (from 5.9 to 10.7). Compliance in the 19 non-myelodysplastic patients decreased only marginally 6 months after surgery (from 29.6 to 26.3). Changes in bladder capacity showed a similar trend. In their most recent test, however, the bladder capacity of group A patients increased to the same volume as that of group B. A high correlation between radiological bladder deformity and bladder compliance was found. We propose a bladder compliance of 10.0 as the lower limit for myelodysplastic patients' preferred range. It was concluded that anti-reflux operations prevent any improvement in bladder compliance (but not in bladder capacity) compared with conservative treatment.
The opacity of portal hypertension-related ascites correlates with the fluid's triglyceride concentration. To determine if an elevated triglyceride concentration can explain the opacity of some cirrhotic ascites specimens, the authors measured triglyceride concentration by Coulter DACOS (Hialeah, FL) on 133 paired serum and ascitic fluid specimens. The specimens were categorized as clear or cloudy by coded visual inspection. In addition, the ascitic fluid specimens were inspected for a lipid supernatant after 48 hours of refrigeration at 4 degrees C. The ascitic fluid triglyceride concentration of the 87 clear specimens was 1.9 +/- 1.0 mmol/L compared with 7.0 +/- 4.6 mmol/L for the opalescent specimens (P less than 0.001). Only 17% of the clear specimens demonstrated any lipid layer after refrigeration, compared with 94% of opalescent specimens (P less than 0.001). The triglyceride concentrations were not significantly different between the serum samples obtained from patients with clear compared with opalescent ascites. The opacity of portal hypertension-related ascites appears to be related to the triglyceride concentration of the fluid.
Spinal cord pial metastases: MR imaging with gadopentetate dimeglumine. The purpose of this investigation was to describe gadopentetate-dimeglumine-enhanced MR findings in metastatic disease to the pial lining of the spinal cord. Correlation was made with clinical data, other radiologic studies, and pathologic findings. Eighty-six patients with a known malignancy and unexplained neurologic signs or symptoms were studied with pre- and postcontrast T1-weighted images. In seven of these patients, abnormal enhancement of the pial lining of the cord was seen on the sagittal postcontrast T1-weighted images. This appeared as a thin rim of enhancement along the surface of the cord in six patients and as a focal, thick rim of enhancement in addition to the thin rim of enhancement in the seventh patient. Axial images confirmed the location along the pial lining in each case. Precontrast T1-weighted images in all seven cases and precontrast T2-weighted images in five cases failed to detect any focal abnormalities of the pial lining of the cord. Pathologic confirmation was available in five of the seven patients. Primary malignancies in these patients included breast carcinomas (two), lymphoma (one), leukemia (one), adenocarcinoma of the lung (one), prostate carcinoma (one), and malignant melanoma (one). Three of seven patients had metastatic disease evident only within the CNS, while four patients had widespread disease outside the CNS. We conclude that contrast-enhanced MR imaging is useful in the diagnosis of pial spread of metastatic disease in patients with a known primary malignancy and unexplained neurologic signs or symptoms.
Facial nerve monitoring in acoustic tumor surgery. Anatomic and functional preservation of the facial nerve during acoustic tumor surgery remains a primary goal. Intraoperative electromyographic facial nerve monitoring with auditory feedback has enabled the surgeon to more readily achieve this goal. We compared a group of monitored translabyrinthine acoustic tumor removals (N = 89) to a similar unmonitored group (N = 155) in regard to facial nerve function. Function was assessed immediately postoperatively, at time of discharge, and at 1 year postoperatively using the House six-point scale. Results were grouped as satisfactory, intermediate, or poor and were analyzed by tumor size. Facial nerve results were better at all time intervals in the monitored groups, although the difference was not statistically significant at the 1-year interval. There was no difference between monitored and unmonitored patients in the subgroups with tumors smaller than 2.5 cm in diameter. This study supports the usefulness of intraoperative facial nerve monitoring in improving facial nerve results, particularly in larger tumors.
Fatal persistent pulmonary hypertension presenting late in the neonatal period. Two cases of fatal idiopathic persistent pulmonary hypertension presented late in the neonatal period. Lungs were examined histologically by light and electron microscopy, and immunocytochemical studies were used to identify nerves. There was extension of medial smooth muscle distally along the arterial pathway so that most precapillary arteries had completely muscular walls, which in some cases completely obliterated the vessel lumen. Enlarged endothelial cells also contributed to the reduction in the size of the lumen. Nerve fibres accompanying muscular arteries were found in the alveolar region, more distal than is normal. The predominant neuropeptide was the vasoconstrictor tyrosine. Possible aetiological factors in persistent pulmonary hypertension of the newborn are increased muscularity of the peripheral pulmonary arteries antenatally, an increase in the number of vasoconstrictor nerves, or an imbalance in the production of leukotrienes and prostacyclins in the perinatal period.
Continuous extrapleural intercostal nerve block after pleurectomy. A randomised, double blind trial was carried out in 16 patients undergoing pleurectomy to assess the effect of continuous extrapleural intercostal block on postoperative pain and pulmonary function. Subjective pain relief was assessed on a linear visual analogue scale. Pulmonary function was measured on the day before operation and daily for five days after surgery. Eight patients received bupivacaine and eight placebo (saline). The mean pain scores at 4, 8, 16, and 24 hours were 13.3, 8.5, 6.1, and 10 mm respectively in the bupivacaine group compared with 56.3, 41, 46.7, and 35 in the control group; in addition, the bupivacaine group required less papaveretum. Twenty four hours after surgery mean values of peak expiratory flow, forced expiratory volume in one second, and forced vital capacity were reduced to 82%, 76%, and 76% of preoperative control values in the bupivacaine group, and to 39%, 32%, and 36% in the control group. The speed of recovery of pulmonary function was superior in the bupivacaine group. There were no complications related to the infusion. Continuous extrapleural intercostal nerve blockade with bupivacaine provides safe and effective postoperative analgesia and improves respiratory mechanics after pleurectomy.
Turbinate hypertrophy in habitual snorers and patients with obstructive sleep apnea: findings of acoustic rhinometry. Forty-five habitual snorers (mean respiratory disturbance index = 6) and 22 patients with obstructive sleep apnea syndrome (mean respiratory disturbance index = 36) were examined by polysomnography, radiocephalometry, rhinomanometry, nasopharyngeal videoendoscopy, and acoustic rhinometry. In 97% of these patients, hypertrophy of the inferior nasal turbinates was found by acoustic rhinometry, while increased nasal resistance of various degrees was measured in 93% of all patients by active anterior rhinomanometry. Acoustic rhinometry demonstrated that the most resistive segment was located in the anterior parts of the nasal cavity and was built up by two compartments: the region of the isthmus nasi and the region of the head of the inferior turbinate. In our snoring patients, the cross-sectional areas at the head of the inferior turbinate were always smaller than the cross-sectional areas in the isthmus nasi, which in normal controls presented the minimal cross-sectional values of the whole nasal cavity. While rhino-manometry can only measure the amount of nasal resistance, acoustic rhinometry can clearly determine the exact size and location of the different stenoses in the nasal cavity that contribute to the increased nasal resistance.
A case of vesical paraganglioma behind the symphysis pubis. We report on a 15-year-old boy with a vesical paraganglioma behind the symphysis pubis. Magnetic resonance imaging and transurethral intravesical ultrasonography were helpful in the preoperative localization of the lesion.
Non-specific aorto-arteritis (Takayasu's disease) in children. Digital subtraction panaorto-arteriography was performed in 32 consecutive children (21 females, mean age 10.8 years) with non-specific aorto-arteritis to assess digital subtraction angiography (DSA) in imaging these children and to study the patterns of involvement in the Indian sub-continent. Diagnostic quality DSA images were obtained in 21 out of 27 intravenous and nine out of 11 intra-arterial studies. Obstructive lesions were present in all the patients and commonly involved the abdominal aorta (24 patients) and renal arteries (20 patients). Aneurysms were seen in five patients and predominantly involved the descending thoracic aorta. Pulmonary artery involvement was uncommon (five out of 20 patients) and clinically silent. Based on clinical and angiographic features, percutaneous transluminal angioplasty was performed for the management of uncontrolled hypertension in eight patients (10 lesions). Initial success was obtained in eight procedures (80%). Re-stenosis occurred after 5.5 months in one patient, but was successfully re-dilated. The follow-up period ranged between 5 and 16 months (mean 9 months). Long-term efficacy of transluminal angioplasty in the management of these children is awaited.
Compulsive overeating. Compulsive overeating is a behavior used in an attempt to numb or nurture feelings that are threatening to the person. Emotional states are soothed by use of food. Treatment is designed to respond to internal, biologic causes of hunger and satiety while simultaneously allowing feelings to surface and be dealt with. Work on the inner child enables the person to identify and deal with unmet needs and correct distortions from childhood. The secondary gain realized from the extra weight is examined, and direct means of dealing with these needs explored. The focus of recovery is on learning to nurture the self, physically and emotionally.