123rc/medical_text huggingface dataset:
The antihypertensive mechanism of delapril, a newly developed converting enzyme inhibitor, is related to the suppression of vascular angiotensin II release in the spontaneously hypertensive rat. Accumulating evidence suggests an important role of vascular renin-angiotensin system (RAS) in the local control of arterial tone. To further gain insight into the significance of vascular RAS in hypertension, we investigated the relationship between the antihypertensive action of delapril, a newly developed converting enzyme inhibitor (CEI), and its effects on vascular angiotensin II (Ang II) release in spontaneously hypertensive rats (SHR). Male SHRs were given delapril or its active metabolite (5-hydroxydelapril diacid; 5-hydroxy-DPD) orally (10 mg/kg/day) for 2 weeks. Isolated hind legs of these rats were perfused with angiotensinogen-free Krebs-Ringer solution, and Ang II released into the perfusate was directly determined by extraction with Sep-Pak C18 cartridges connected to the perfusion system. Both delapril and 5-hydroxy-DPD produced a sustained antihypertensive action. The spontaneous release of Ang II from isolated perfused hind legs of control SHRs was about 50 to 110 pg during the first 30 min of perfusion, and it remained stable up to 3 h. Another active metabolite, delapril diacid (DPD), when added to the perfusion medium (10(-9) to 5 x 10(-5) mol/L), suppressed the Ang II release in a dose-dependent manner. The maximal percent inhibition of Ang II released evoked by DPD (5 x 10(-6) mol/L) was approximately 51%. Oral pretreatment of either delapril or 5-hydroxy-DPD for 2 weeks suppressed the Ang II release by 61% and 73% for delapril and 5-hydroxy-DPD, respectively. These results suggest the presence of a functional RAS in vascular tissues, and that delapril exerts its antihypertensive effect through inhibition of vascular Ang II release in SHRs.
Right ventricular dysfunction in chronic obstructive pulmonary disease. Evaluation and management. Cor pulmonale is an important consequence of COPD. Although the incidence is not precisely known, it is seen more frequently in patients with hypoxemia, CO2 retention and severely reduced FEV1. When present, it limits peripheral oxygen delivery, increases shortness of breath, and reduces exercise endurance. It is also associated with higher mortality rates independent of other prognostic variables. Numerous factors may contribute to the development of cor pulmonale in patients with COPD, but its primary cause is chronic alveolar hypoxia resulting in pulmonary vasoconstriction, vascular remodeling and pulmonary hypertension. The physical exam, chest radiograph and ECG may be helpful in detecting the presence of cor pulmonale, but because of anatomic changes that occur in the chest, these tests are often insensitive in patients with COPD. Noninvasive diagnostic techniques utilizing Doppler echocardiography and radionuclide angiography allow for detection of RV dysfunction at an earlier stage and in most cases, preclude the need for right heart catheterization. LTO2 is the only therapy shown to improve survival in patients with COPD. However, statistical proof correlating improvements in pulmonary hemodynamics with increased survival is lacking. Bronchodilators, such as the beta 2 agonists and especially theophylline, may have beneficial effects on pulmonary hemodynamics in addition to their effect on respiratory function and are useful in COPD when RV dysfunction is present. Diuretics and phlebotomy are also useful in improving symptoms in appropriate patients. Vasodilators such as calcium channel blockers and ACE-inhibitors may improve pulmonary hemodynamics acutely, but may lower arterial PO2 by worsening ventilation-perfusion matching or blunt the improvement in pulmonary hemodynamics seen with supplemental oxygen. The long-term benefits of these agents have not been proven and their routine use in patients with cor pulmonale due to COPD cannot be recommended.
A technique for improving accuracy of the pulmonary artery diastolic pressure as an estimate of left ventricular end-diastolic pressure. Pulmonary artery diastolic pressure (PAD) is often used to estimate left ventricular end-diastolic pressure (LVEDP) when artifact, respiratory variation, or technical difficulties make the wedge pressure difficult to identify on the waveform. To determine which point on the PAD waveform best estimated LVEDP, we performed studies in 100 adults undergoing routine diagnostic cardiac catheterization. During normal spontaneous respiration, simultaneous recordings of the electrocardiogram, PAD, and LVEDP were obtained. Three end-expiratory measurements of PAD were recorded: at the lowest point on the waveform (PAD), at 0.04 seconds (PAD 0.04), and at 0.08 seconds (PAD 0.08) after the onset of the QRS complex. The PADs were correlated with LVEDP by linear regression. PAD 0.08 correlated best with LVEDP (r = 0.88, standard error of the estimate [SEE] = 3.6 mm Hg) whereas PAD 0.04 and PAD correlated slightly less strongly (r = 0.86, SEE = 4.0 mm Hg; r = 0.82, SEE = 4.4 mm Hg respectively). Therefore, when the wedge pressure is not easily determined, PAD 0.08 may be the best point on the waveform to use when attempting to estimate LVEDP in the clinical setting.
Mastalgia refractory to drug treatment. Management of the patient with mastalgia who fails to respond to first line therapy is a difficult problem and there is a group of patients who do not respond to any therapy. A group of 126 patients with mastalgia who failed to respond to first line therapy and completed further treatment options was studied. The response rate of those with cyclical mastalgia fell to 57 and 25 per cent for second and third line therapy respectively. Equivalent figures for non-cyclical mastalgia were 24 and 21 per cent. Danazol maintains a high response rate after the failure of other drugs, whereas the second line response to bromocriptine and evening primrose oil is poor. Unresponsive patients were matched to a group of patients who responded to first line therapy, and reproductive and historical factors were compared using the chi 2 test, but failed to identify which patients would respond to therapy.
Endothelial cell adhesiveness for human T lymphocytes is inhibited by transforming growth factor-beta 1. Recombinant human transforming growth factor-beta (TGF-beta) was found to inhibit the adhesive phenotype of human umbilical vein endothelial cells for human PBL, purified T lymphocytes, and PHA-activated lymphoblasts. TGF-beta inhibited lymphocyte attachment to resting human umbilical vein endothelial cells and also to endothelial monolayers stimulated with the pro-inflammatory cytokines TNF-alpha and IL-1 beta. Our investigations also show that the ability of endothelial cells to respond to TGF-beta by altering their adhesiveness is lost with prolonged culture of the cells. However, this loss is selective as TGF-beta inhibits cell proliferation in both early and late passage endothelial cells. These results suggest that in vivo TGF-beta may inhibit the adhesive phenotype of endothelial cells and also may limit the immunologic response occurring at the endothelial cell barrier.
Parotid gland and facial nerve trauma: a retrospective review. Included in this study are all patients with trauma to the parotid region seen at our center from 1979 to 1989. There was a total of five patients with injury to the parotid area: two patients with isolated facial nerve injury; one with isolated parotid duct injury; two with combined duct and nerve injury. There were four males and one female, with a mean age of 34 years (range, 16 to 62 years). The three patients with parotid duct injury required other procedures for associated trauma. A total of eight nerve branches were severed in four patients. Seven of the eight nerve branches (82.5%) were primarily repaired, with excellent functional results. Two of the three ductal injuries were repaired primarily over a stent, and one was ligated. No complications resulted from either treatment. Based on our clinical experience and review of the literature, we suggest that the treatment of parotid region injuries should include: 1) a complete initial assessment; 2) primary repair of parotid duct transection within 24 hours when possible; 3) primary repair of all facial nerve injuries, although delayed nerve repair remains a viable alternative; and 4) nonsurgical treatment of sialoceles and fistulae.
Long-term results of operation for non-small cell lung cancer in the elderly. We surgically treated 185 patients with non-small cell lung cancer who were 70 years old or older. The operative mortality rate was 3%, and the 5-year survival rate was 48%. The mortality and prognosis were similar to those in younger patients. The number of elderly patients who smoked heavily or who had ventilatory defects was high, but the incidence of pneumonectomy was low. There were no differences based on age in regard to histological type, TNM classification, and curability. Pulmonary complications occurred in 21% of the elderly patients and were correlated with preoperative pulmonary function and smoking habits. When the elderly are to undergo elective pulmonary resection for lung cancer, the preoperative evaluation of pulmonary function should be thorough, and both preoperative and postoperative physical therapy should be given. If postoperative pulmonary function is predicted to be less than 0.8 L/m2 of vital capacity and 0.6 L/m2 of forced expiratory volume in 1 second, a limited resection or nonsurgical therapy should be considered.
Evaluation of drug therapy for treatment of hypertensive urgencies in the emergency department. Oral nifedipine (N) and clonidine (C) are often used in the treatment of hypertensive urgencies; however, until recently, there were no comparative studies using the same patient population. The authors reviewed the records of hypertensive patients treated in the emergency department between October 1, 1987 and September 30, 1988. Selected patients had a diastolic blood pressure (DBP) of greater than 115 mm Hg without evidence of acute end organ damage. Patients were stratified into three treatment groups: N, C, and group 3 (G3). G3 received a variety of drug therapies but not exclusively N or C. Systolic blood pressure (SBP), DBP, mean arterial pressure (MAP), percent decrease in MAP (%MAP), time to lower blood pressure, admissions, and discharges were evaluated. Efficacy and safety were defined as reaching a DBP less than 110 mm Hg but %MAP of no greater than either 25% or 40%, respectively. Thirty-five N, 32 C, and 27 G3 patients were identified with no statistical difference between groups in race, gender, pretreatment SBP, DBP, or MAP. N, C, and G3 significantly reduced SBP, DBP, and MAP (P less than .01). Comparing N, C, and G3, no differences were observed in %MAP, admissions, discharges, efficacy, or safety. Time required to decrease blood pressure differed between all three groups (44 +/- 32 N v 77 +/- 57 C v 152 +/- 94 min G3) (p less than .05). These results indicate that N, C, and a variety of drug therapies are equally effective and safe in the treatment of hypertensive urgencies.
Role of basic fibroblast growth factor in vascular lesion formation. In the present study we investigated whether basic fibroblast growth factor (bFGF) plays a role in the proliferative response of smooth muscle cells (SMCs) to denuding injury. Rat carotid smooth muscle was found to express the mRNA for bFGF, and bFGF protein was found to be present in rat aorta by immunoblot analysis. Systemically administered bFGF was a potent mitogen for vascular SMCs in arteries denuded with a balloon catheter, increasing replication from 11.5% in controls to 54.8%. Denudation with a device (filament loop), which causes only minimal damage to medial SMCs, showed a similar increase in replication (1.3% versus 43.3%) after bFGF infusion. In unmanipulated vessels, however, SMCs were unresponsive to infused bFGF. Infusion of a "mitotoxin" (bFGF conjugated to saporin) caused a greater than 50% decrease in the number of viable SMCs in the arterial wall after balloon injury. Prolonged administration of bFGF (12 micrograms/day for 2 weeks) after balloon injury caused an approximately twofold increase in intimal thickening. These results show that bFGF, which is synthesized by the arterial wall, could be a potent mitogen for SMCs in vivo and suggest that any release of endogenous bFGF may be capable of stimulating SMC proliferation, which may subsequently lead to intimal lesion formation.
Single lumen ileum with myectomy: a possible alternative to the pelvic reservoir in restorative proctocolectomy. An alternative procedure to construction of a pelvic ileal reservoir was assessed which avoids the need for a pouch, while providing an adequate rectal substitute and good continence. Thirty-six female adult beagles were allotted randomly to undergo total colectomy with (a) ileo-anal anastomosis alone, (b) ileo-anal anastomosis with two 15 cm myectomies, (c) ileo-anal anastomosis and myectomy with an ileo-ileal valve, or (d) ileo-anal anastomosis with a duplicated J pouch. The animals were studied before operation and at 4-weekly intervals for 20 weeks after operation. Mortality rates were similar. Ileal compliance was increased significantly by myectomy from 0.64 ml/mmHg (median, interquartile range 0.49-0.78) after ileo-anal anastomosis alone to 1.65 mmHg (1.16-1.93), P less than 0.01, an increase which was maintained. Ileal capacity was also increased both by myectomy and by the J pouch: ileo-anal anastomosis = 85 ml (75-100 ml), ileo-anal anastomosis and myectomy = 139 ml (116-156 ml), ileo-anal anastomosis and myectomy and ileo-ileal valve = 125 ml (range 85-145 ml), ileo-anal anastomosis and J pouch = 130 ml (range 75-165 ml) (P less than 0.01). Bowel function in the other three groups was markedly superior to ileo-anal anastomosis alone. Mean transit time was significantly less after ileo-anal anastomosis, 5.2 h (2.6-8.2 h) than after both ileo-anal anastomosis and myectomy, 10.5 h (9.6-13.9 h), P less than 0.05 and ileo-anal anastomosis and J pouch, 11.0 h (8.4-13.0 h), P less than 0.05, but addition of an ileo-ileal valve did not produce a further increase in transit time, 12.9 h (range 10.5-14.5 h), P = n.s. Myectomy of single lumen ileum may be a useful alternative to a pelvic ileal reservoir in restorative proctocolectomy.
Surgical treatment of thyrotropin-secreting pituitary adenomas. Thyrotropin-secreting pituitary adenomas have been diagnosed more frequently as radiographic techniques and biochemical assays have improved; however, they remain uncommon and are unfamiliar to most neurosurgeons. This report concerns eight patients with hyperthyroidism, inappropriately elevated levels of serum thyrotropin and alpha-subunit, and radiographic evidence of pituitary tumor. All underwent surgery and had pathological confirmation of a thyrotropin-secreting adenoma, and most had been subjected to prior ablation of the thyroid gland. Only one tumor was a microadenoma; the others ranged in size from 1.4 to 12 cm, and invasion of parasellar structures was common. Thyrotropin, triiodothyronine, thyroxine, and alpha-subunit were measured preoperatively and at intervals postoperatively. Coexistent hormonal abnormalities (which occurred in all patients) included acromegaly and hyperprolactinemia and were also monitored. All four patients who had tumors less than 2 cm in diameter remain alive. Complete extirpation of tumor in these patients produced rapid correction of all hormonal abnormalities and resolution of clinical hyperthyroidism. The other four patients had larger invasive tumors: two died soon after surgery, one died of disseminated tumor 8 years after presentation, and one remains alive with residual tumor. Tumors secreting thyroid-stimulating hormone are less easily cured by surgery than are other types of pituitary adenoma because of the large size and invasive features that many attain during the delay to diagnosis; medical therapy can subdue the tumor but not cure it. The experience with these patients establishes the importance of early diagnosis and surgical excision for successful treatment, and demonstrates the utility of modern diagnostic techniques for finding these lesions. As occurs in Nelson's syndrome after adrenalectomy for Cushing's disease, ablation of the target organ may allow the tumor to convert to a more clinically malignant form which is resistant to cure.
Needle aspiration and pressure sutures for auricular pseudocyst. Auricular pseudocyst is an asymptomatic cystic swelling of the upper portion of the auricle. Various therapeutic approaches have been employed with variable success. We report our results with nine patients treated by needle aspiration and bolstered pressure sutures applied over both aspects of the cyst for 1 week. Treatment resulted in complete resolution with no recurrence of the lesion in any of the patients. This procedure is simple, does not require an operating room setting, and is more comfortable and more acceptable aesthetically by the patient.
The central (intraosseous) calcifying odontogenic cyst: an analysis of 215 cases. This study reviews and analyzes the clinical, radiographic, and histomorphologic features of the 215 cases of central calcifying odontogenic cyst (CCOC) reported in the literature. Based on the present information, a clinicopathologic classification of calcifying odontogenic cyst is proposed. The CCOC is also compared with its peripheral counterpart and the differences discussed.
Role of oxygen-derived free radicals in the pathogenesis of gastric mucosal lesions in rats. The role of oxygen-derived free radicals and lipid peroxidation in the pathogenesis of acute gastric mucosal erosion was investigated in rat models produced by burn shock stress, by treatment with regional hyperthermia, platelet activating factor, and compound 48/80, and by ischemia-reperfusion. In all experimental models, the increase in the gastric erosions and in TBA reactants in the gastric mucosa were significantly inhibited by the treatment with superoxide dismutase (SOD) and/or catalase. Pretreatment with allopurinol, a competitive inhibitor of xanthine oxidase, prevented considerably the gastric injury (a) induced by burn shock, (b) produced by treatment with compound 48/80, and (c) caused by ischemia-reperfusion. By the treatment with anti-rat neutrophil antibody, the gastric mucosal injuries induced by regional hyperthermia, platelet activating factor, and compound 48/80 were significantly inhibited; however, burn shock and ischemia-reperfusion injuries were not inhibited. These results suggest that oxygen-free radical and lipid peroxidation contribute to the formation of gastric mucosal lesions, and that the sources of oxygen radicals seem to be different among these experimental models.
Paraesthesiae and tetany induced by voluntary hyperventilation. Increased excitability of human cutaneous and motor axons. Anxiety can induce hyperventilation, and the resultant hypocapnia and hypocalcaemia can lead to paraesthesiae and tetany. To define the nature of the disturbance created in peripheral nerve, the excitability of cutaneous and motor axons was monitored in 6 normal subjects requested to hyperventilate until paraesthesiae developed in the hands, face and trunk. This occurred when alveolar PCO2 (PACO2) had declined on average by 20 mmHg. Spontaneous EMG activity developed when PACO2 had declined by a further 4 mmHg. Changes in the excitability of cutaneous and motor axons were measured from changes in the compound action potentials evoked by stimulation of the median nerve at the wrist and recorded over the digital nerves of the index finger and over the thenar muscles, respectively. As PACO2 declined, the size of the compound sensory and muscle potentials evoked by a constant stimulus progressively increased, indicating an increase in axonal excitability. These changes occurred before paraesthesiae or tetany developed. In each subject there was a statistically significant inverse correlation between PACO2 and axonal excitability. Independent of this increase in axonal excitability, there was no significant change in the supernormal phase of the recovery cycle of cutaneous axons. Microneurographic recordings from the median nerve in 2 subjects revealed spontaneous bursting activity of cutaneous axons, perceived as paraesthesiae. It is concluded that the paraesthesiae and tetany induced by hyperventilation result solely from changes in the excitability of cutaneous and motor axons in the peripheral nerve, presumably due to an alteration in the electrical properties of the axonal membrane resulting from a reduced plasma [Ca2+]. The supernormal phase may entrain the ectopic discharge and thereby determine the maximal discharge frequency of impulses in ectopically generated trains, but does not otherwise contribute to the physiological disturbance.
Natural history and cardiac manifestations of homozygous familial hypercholesterolaemia. Forty-nine patients with homozygous familial hypercholesterolaemia (diagnosed on the basis of family history, xanthomatosis, total serum cholesterol and low-density lipoprotein receptor status) were studied over a period of 13 years, and underwent cardiovascular assessment. Eleven died, nine of myocardial infarction. Seven underwent coronary artery bypass, and another five had surgery to relieve supravalvular and valvular aortic stenosis. A distinctive pattern of disease was noted. Coronary ostial stenosis (four patients) and aortic root stenosis (six patients), both consequences of aortic root cholesterol deposition, were the typical manifestations of heart disease in childhood and adolescence. Adults developed severe coronary artery disease with a high incidence of main stem lesions (four of five patients). Surgery provided effective treatment for coronary artery disease and aortic outflow tract stenosis. Overall survival appeared to be better than reported in other studies which may reflect the 'receptor-defective' status of this group of patients.
Cerebral cysticercosis. We studied 143 cases of cerebral cysticercosis over a 30-year period. In 46 there was hydrocephalus due to cysts obstructing the cerebrospinal fluid pathways, with signs of hydrocephalus and cerebellar dysfunction. In 97 there were cysts in the cerebral parenchyma, causing symptoms of intracranial hypertension alone in 22 cases, with additional neurological deficits in the remainder. Before 1980 diagnosis was made by pneumoencephalography and ventriculography, but since then it has mostly been done by computed tomography. In 28 cases scanned, typical abnormalities were present in 25. Complement fixation tests were positive in serum in 74% of cases and in cerebrospinal fluid in 73%, and the enzyme-linked immunosorbent assay test was positive in serum in 90% and in cerebrospinal fluid in 92%. Treatment of cases with hydrocephalus was by removal of the cysts at craniotomy, with placement of a shunt where necessary. Intracranial hypertension caused by parenchymal cysts was treated with steroids and osmotic agents, if possible. In resistant cases subtemporal decompression was needed, unilateral in 55 cases and bilateral in eight. Mortality in the acute stage was 11%, with a further 20% at follow up.
Branch retinal vein occlusion: the pathogenetic role of blood viscosity. The pathogenesis of branch retinal vein occlusion has not been completely clarified. The role of abnormal blood viscosity in the appearance and evolution of the disease has recently been advocated. We studied 54 patients with long-standing branch retinal vein occlusion from a hemorrheologic point of view. Depending on the extension of retinal ischemia, two subgroups were identified. Hematocrit, blood and plasma viscosity, whole blood filterability, cell deformability, and fibrinogen levels were investigated. Thirty-five subjects of similar age, sex, and risk factors of diabetes and hypertension served as controls. Our results showed that blood viscosity is higher in patients with occlusion and particularly in those with severe retinal ischemia. Statistical analysis showed a direct correlation between blood viscosity and hematocrit.