123rc/medical_text huggingface dataset:
Restenosis after balloon angioplasty. A practical proliferative model in porcine coronary arteries. A model of proliferative human restenosis was developed in domestic pigs by using deep injury to the coronary arterial media. Metal wire coils were delivered percutaneously to the coronary arteries of 11 pigs with an oversized, high-pressure (14 atm) balloon and were left in place for times ranging from 28 to 70 days. During placement, the balloon expanded the coils and delivered them securely within the arterial lumen. Light microscopic examination of the vessels confirmed fracture of the internal elastic lamina by the coil. An extensive proliferative response occurred in 10 of the 11 pigs and was associated with a luminal area narrowing of at least 50% in all but one pig. The histopathologic features of the proliferative response were identical to those observed in human cases of restenosis after angioplasty. Immunohistochemical studies confirmed the prominence of smooth muscle cells in the proliferative tissue. A similar response was obtained in two of five porcine coronary arteries in which balloon inflation only was performed, without coil implant. This model is practical and inexpensive and closely mimics the proliferative portion of human restenosis both grossly and microscopically. Thus, it may be useful for understanding human restenosis and for testing therapies aimed at preventing restenosis after balloon angioplasty or other coronary interventional procedures.
Cup containment and orientation in cemented total hip arthroplasties. We reviewed the radiographs of 864 Charnley and STH (Zimmer) cemented total hip arthroplasties with a mean follow-up of seven years (maximum 16 years). Survivorship analysis was used to assess the correlation between radiographic performance and the bony containment or the coronal orientation of the acetabular cup. The cup orientation and containment were interrelated; all vertically oriented cups were completely contained, whereas 25% of more horizontal cups were only partially contained. Completely contained cups had significantly lower incidences of complete cement-bone radiolucency (p = 0.02) and of wear (p = 0.09). Vertically oriented cups had a lower incidence of continuous radiolucency than neutrally oriented cups, but this was not statistically significant (p = 0.25). Our results confirm the importance of complete bony containment, and also indicate that it is better to accept vertical orientation and obtain full bony coverage than to have a more horizontal orientation with partial containment.
Severe hypotension due to intramyometrial injection of prostaglandin E2 Treatment of postpartum haemorrhage because of uterine atony with intramyometrial prostaglandin E2 1 mg, in an anaesthetised patient resulted in life-threatening hypotension. Anaesthetists should be aware of the potential cardiovascular side effects of prostaglandins.
Evolution of the continuity equation in the Doppler echocardiographic assessment of the severity of valvular aortic stenosis. The use of Doppler techniques has greatly enhanced the noninvasive ultrasound technique for evaluation of valvular aortic stenosis. M-mode and two-dimensional echocardiography could not reliably distinguish patients with severe aortic stenosis from those with milder obstructions. The hemodynamic information offered by Doppler complemented echocardiographic imaging and provided an alternative modality for evaluation of patients with aortic stenosis. By application of the modified Bernoulli equation, the pressure gradient across the stenotic aortic valve could be estimated by Doppler echocardiography. Though helpful and widely used, the information provided by the pressure gradient across the valve about the severity of the obstruction was not complete. The assessment of valvular aortic stenosis therefore includes an estimation of the valve area by application of the continuity equation. This review examines the maturation of the continuity equation by Doppler techniques and discusses the implications of the procedure.
A monoclonal antibody against the CD18 leukocyte adhesion molecule prevents indomethacin-induced gastric damage in the rabbit. The role of leukocyte adherence in the mechanism of gastropathy induced by nonsteroidal antiinflammatory drugs was investigated using a rabbit model. Gastric damage was induced by intragastric instillation of indomethacin [5 mg/mL] for a period of 30 minutes. Histologically, this treatment resulted in extensive vascular congestion and leukocyte margination within the mucosa. Pretreatment with a monoclonal antibody [IB-4] directed against the common beta subunit of the CD11/CD18 adhesion glycoprotein complex significantly (P less than 0.05) reduced both the vasocongestion and the prevalence of leukocyte margination. Macroscopically, indomethacin treatment resulted in the formation of numerous hemorrhagic lesions in the corpus region of the stomach. Pretreatment with IB-4 reduced the extent of gastric hemorrhagic damage by approximately 85% (P less than 0.001). Damage in the group pretreated with IB-4 did not differ significantly from that in rabbits that did not receive indomethacin. In separate experiments, the dose of IB-4 used was shown to completely suppress the recruitment of granulocytes in response to two different agonists. These results support the hypothesis that leukocyte adherence to the vascular endothelium is an important event in the pathogenesis of ulceration induced by nonsteroidal antiinflammatory drugs. Leukocytes might contribute to ulceration by occluding microvessels, thereby reducing mucosal blood flow, and by releasing various mediators, proteases, and free radicals that can produce tissue necrosis.
Does cholesterol screening result in negative labeling effects? Results of the Massachusetts Model Systems for Blood Cholesterol Screening Project. Several previous studies that looked at the effects of labeling individuals as hypertensive found increases in psychosocial distress, diminished feelings of well-being, or absenteeism. Other studies found no such effects. Thus far, similar studies relating to labeling for high blood cholesterol levels have not been published. The Massachusetts Model Systems for Blood Cholesterol Screening Project investigated whether labeling effects occurred as a result of the community-based screening, education, and referral programs it conducted in Worcester and Lowell. Nine questions concerning perceptions of physical and psychological well-being were asked on a questionnaire given to screening participants. The same questions were asked as part of a follow-up questionnaire given to all individuals identified as having high blood cholesterol levels at one of the screenings. Comparison of the baseline and follow-up results did not demonstrate significant overall negative effects among any age, sex, racial, income, or educational groups. On the contrary, responses to many of the questions revealed small but statistically significant improvements in perceptions of physical and psychological well-being. The absence of negative labeling effects may be attributable to the positive, supportive approach to participant counseling taken by the project.
Aerobic work capacity in patients with chronic fatigue syndrome OBJECTIVE--To determine the aerobic work capacity of patients with the chronic fatigue syndrome and compare it with that of two control groups, and to assess the patients' perception of their level of activity before and during illness. DESIGN--A symptom limited exercise treadmill test with on line gas analysis and blood sampling was used. Subjects were assessed by one investigator, who was blind to the group which they were in. SETTING--Department of medicine, Royal Victoria Hospital, Belfast. SUBJECTS--13 Patients (10 women, three men) who fulfilled the diagnostic criteria for chronic fatigue syndrome. Two control groups of similar age, sex, and body weight: 13 normal subjects (10 women, three men) and seven patients (five women, two men) with the irritable bowel syndrome. MAIN OUTCOME MEASURES--Aerobic work capacity as assessed by several variables such as length of time on treadmill, heart rate, and biochemical measurements; Borg score; and visual analogue scores of perceived level of physical activity. RESULTS--The patients with the chronic fatigue syndrome had a reduced exercise capacity compared with that of the other subjects, spending a significantly shorter time on the treadmill. They had a significantly higher heart rate at submaximal levels of exertion and at stage III exertion had significantly higher blood lactate concentrations. Using a Borg score, they showed a significantly altered perception of their degree of physical exertion with a mean score of 8.2 compared with 6.6 and 5.3 for the normal subjects and patients with the irritable bowel syndrome respectively. Using a visual analogue scale they indicated that they had a greater capacity for activity before illness than had the patients with the irritable bowel syndrome, but the scores were not significantly different between the two groups. Both groups of patients indicated reduced activity at the time of testing. Normal controls and patients with the irritable bowel syndrome aspired to a greater level of activity than their current level, but the patients with the chronic fatigue syndrome aspired to a level similar to that which they had had before their illness. CONCLUSIONS--Patients with the chronic fatigue syndrome have reduced aerobic work capacity compared with normal subjects and patients with the irritable bowel syndrome. They also have an altered perception of their degree of exertion and their premorbid level of physical activity.
Scintigraphic measurement of oropharyngeal transit in man. Scintigraphic studies of the oropharyngeal transit of a liquid bolus were performed in 15 healthy controls, 12 patients with symptoms of oral-pharyngeal dysphagia, and 13 patients with neuromuscular disease, who did not have dysphagia. Gamma camera imaging of the head, neck, and upper thorax was undertaken, in the lateral projection, during the swallowing of the radiolabeled bolus of water. Inspection of summed images permitted the selection of regions of interest (ROI) to represent the mouth, pharynx, and upper esophagus. Transit times between each ROI were calculated and compared. Significant prolongation of bolus transit time between the mouth and esophagus was present in both patients with and without dysphagia (0.59 +/- 0.38 sec and 0.33 +/- 0.7 sec; mean +/- SD, respectively) compared with controls (0.26 +/- 0.04 sec P less than 0.001, P less than 0.01, respectively, Mann-Whitney U test). Repeat studies in 25 individuals indicated that the transit measurements were more reproducible between swallows in normal subjects than in patients with symptoms. Deglutitive scintigraphy provides a noninvasive technique for the quantitative study of swallowing and its disorders.
Diabetes mellitus and hypertension. Hypertension and diabetes mellitus are chronic medical conditions that frequently coexist. In the United States, it is estimated that 10 million persons suffer from diabetes mellitus, 60 million from hypertension, and 3 million from the combination of the two. There may be a causal relationship between hypertension and diabetes. Obesity may be a precipitating factor for both hypertension and non-insulin-dependent diabetes mellitus. Those with insulin-dependent diabetes mellitus generally become hypertensive only with the onset of nephropathy. Glucose tolerance, insulin resistance, and hyperinsulinemia frequently occur with essential hypertension and may be aggravated by hypertension therapy, especially with diuretics and beta-blockers. Hyperinsulinemia may be an important common factor promoting sodium retention, sympathetic nervous system stimulation, and inhibition of the sodium pump. The Working Group on Hypertension in Diabetes has outlined a flexible modified version of the stepped-care approach to the treatment of hypertension in diabetes. Management is complex because diabetes is associated with autonomic neuropathy, sexual dysfunction, hyperlipidemia, and fluid and electrolyte disorders. All these problems can be exacerbated by antihypertensive treatment. Nonpharmacologic measures, which address weight reduction and sodium restriction, are logical, but aggressive antihypertensive medication is invariably necessary. Diuretics and/or beta-blockers were the mainstay of treatment until the introduction of angiotensin-converting enzyme (ACE) inhibitors and calcium channel blockers. These newer agents have no deleterious effects on carbohydrate metabolism and are generally better tolerated. Antihypertensive therapy may slow the rate of deterioration in diabetic nephropathy. This was first shown with diuretics, beta-blockers, and hydralazine and more recently with ACE inhibitors, which provide effective blood pressure control and a significant drop in albuminuria without affecting the glomerular filtration rate adversely. ACE inhibition may also lead to increased insulin sensitivity and glucose disposal rate. Long-term trials are needed to assess the effects of these new agents on the treatment of hypertension in the diabetic population.
GTPase-activating protein interactions with the viral and cellular Src kinases. GTPase-activating protein (GAP), which regulates the activities of Ras proteins, is implicated in mitogenic signal transduction by growth-factor receptors and oncoproteins with tyrosine kinase activity. Oncogenic viral Src (p60v-src) encoded in Rous sarcoma virus possesses elevated tyrosine kinase activity compared with its nononcogenic normal homolog, cellular Src (p60c-src). To examine molecular interactions between GAP and the two Src kinases, immunoprecipitates of Src or GAP prepared from cell lystates were resolved by gel electrophoresis and analyzed by an immunoblot procedure with antibodies to GAP or Src used as probes. Results suggest that p60c-src is associated with a complex containing GAP in immunoprecipitates from lysates of normal rat and chicken cells. However, GAP is not phosphorylated in p60c-src immunoprecipitates subjected to in vitro kinase reactions. By contrast, GAP undergoes tyrosyl phosphorylation in vitro when immunoprecipitates of p60v-src prepared from transformed cell lysates are incubated with ATP. Our findings suggest that p60v-src and p60c-src associate with complexes containing GAP and provide a biochemical link between both kinases and GAP/Ras signal transduction pathways. These results are consistent with the hypothesis that GAP has a role in mediating normal functions of p60c-src as well as oncogenic activities of p60v-src.
Identification of herpes simplex virus DNA in lesions of erythema multiforme by the polymerase chain reaction. An association between erythema multiforme and herpes simplex virus infection has been supported by clinical studies and by the detection by immunofluorescence of herpes viral antigen in sera and skin biopsy specimens of patients with erythema multiforme. In rare cases, the virus has also been isolated in cultures of skin biopsy specimens of erythema multiforme. To investigate further the association between erythema multiforme and herpes simplex virus, we used the polymerase chain reaction for herpes simplex virus to examine skin lesions from patients with erythema multiforme. In this study herpes simplex virus DNA was detected in 11 of 31 biopsy specimens of erythema multiforme; six additional cases showed equivocal amplification results, which is suggestive of low amounts of viral DNA. Seven skin and mucosal biopsy specimens with the histologic changes of herpes virus infection served as positive controls: all were positive for herpes simplex virus DNA. Viral DNA was not detected in control biopsy specimens from skin excised for unrelated conditions. These studies support the association of herpes simplex virus in the pathogenesis of some cases of erythema multiforme. The polymerase chain reaction provides a quick and effective method of detecting herpes simplex virus in lesions of herpes-associated erythema multiforme. Furthermore, the polymerase chain reaction may delineate those cases of erythema multiforme that are etiologically related to herpes virus infection and therefore might be treated with acyclovir to prevent recurrence.
Total hip arthroplasties in patients younger than 45 years. A nine- to ten-year follow-up study. Eighty-one cemented total hip arthroplasties in patients younger than 45 years were reviewed with an average 9.2-year follow-up interval. The results were compared with the same group previously reported at an average follow-up time of 4.5 years. Clinically satisfactory results were 58% compared with 78% at 4.5 years. The revision rate almost tripled to 33%. Impending failure was present in 56% of those hips not yet revised. In the first study, technique was a primary determinant of success. In this report there was no influence of technique on the incidence of revision. Age did not influence revision rates either, with 35% in patients younger than 30 years and 32% in patients aged 30-45 years. Patients younger than 30 years had fewer satisfactory clinical results and a higher rate of impending failure. As in the first study, the best results were obtained in patients with inflammatory collagen disease aged from 30 to 45 years.
Silent myocardial ischemia and infarction in diabetics with peripheral vascular disease: assessment by dipyridamole thallium-201 scintigraphy. We investigated the incidence of silent myocardial ischemia and infarction as assessed by dipyridamole thallium scintigraphy in 30 diabetic patients with peripheral vascular disease and without clinical suspicion of coronary artery disease. Seventeen patients (57%) had thallium abnormalities, with reversible thallium defects compatible with ischemia in 14 patients (47%) and evidence of prior, clinically silent myocardial infarction in 11 patients (37%). Thallium abnormalities were most frequent in patients with concomitant hypertension and cigarette smoking (p = 0.001). These results suggest that unsuspected coronary artery disease is common in this particular group of patients with diabetes mellitus.
Clinical and anatomic considerations for surgery in femoropopliteal disease and the results of surgery. From 1980 to 1988 we performed 288 femoropopliteal bypass operations in 231 patients at the Oregon Health Sciences University. The indication for the procedure was claudication in 31% and the relief of limb-threatening ischemia in 64%. Operative mortality occurred after four of these operations (1.4%), including three deaths from myocardial infarction and one death from stroke. The femoropopliteal bypass patients were divided into groups for patency analysis, including those undergoing bypass surgery with a good quality greater saphenous vein versus alternate bypass conduits and patients undergoing primary limb bypass versus those undergoing repeat bypass after prior bypass failure. Our overall primary graft patency for all femoropopliteal grafts was 79% at 5 years. Patients undergoing bypass with a good quality greater saphenous vein had primary graft patency of 85% at 5 years. Patients undergoing bypass using a conduit other than greater saphenous vein had a 5-year patency of 73%. Patients undergoing repeat bypass after a prior failed bypass had a 5-year patency of 57%.
Otogenic Fusobacterium necrophorum meningitis. A case of meningitis secondary to acute suppurative otitis media in a previously healthy child is reported. The only organism isolated from blood after aerobic and prolonged anaerobic culture was identified as Fusobacterium necrophorum. Complete recovery followed treatment with surgery and prolonged antibiotic therapy. The role of anaerobes in the development of meningitis, the isolation and identification of Fusobacterium necrophorum, the clinical presentations of F. necrophorum infection and the choice of antibiotics in the treatment of these infections are discussed.
Hindbrain ischemia produced by bilateral vertebral artery occlusion and moderate hypotension in spontaneously hypertensive rats. Hindbrain ischemia was induced by bilateral vertebral artery occlusion and moderate hypotension in spontaneously hypertensive rats (SHRs). Mean arterial blood pressure was lowered to 80 mmHg in SHRs and to 50 mmHg in Wistar-Kyoto rats (WKYs) by a controlled hemorrhage, and then the vertebral artery was bilaterally occluded through alar foramina of the first cervical vertebra. Following vertebral occlusion, blood flow of the cerebellum was significantly decreased to 9.4 +/- 2.0 mL/100g/min (+/- SEM) while flow of the cerebrum remained at 32.1 +/- 5.4 in SHRs. In contrast, cerebellar blood flow in WKYs was preserved at 24.2 +/- 2.9 mL/100g/min. Brain lactate, pyruvate, and adenosine triphosphate (ATP) were determined in SHRs after sixty minutes of hypotension with or without vertebral occlusion. Although infratentorial metabolites were actually unaltered in rats with hypotension alone, infratentorial lactate and lactate/pyruvate ratio significantly increased to 14.38 +/- 3.61 mmol/kg and 67.7 +/- 12.1, respectively, with a concomitant decrease in ATP in SHRs with hypotension and vertebral occlusion. Bilateral vertebral artery occlusion, together with moderate hypotension, was shown to produce a marked reduction of cerebellar blood flow and to induce ischemic metabolic changes in the infratentorial brain in SHRs.
Serial immunocytologic analysis of blood for tumor cells in two patients with neuroblastoma. Tumor surveillance tests are used to determine whether malignant cells are responsive or resistant to therapeutic regimens. For patients with neuroblastoma, conventional methods of surveillance are not sensitive enough. Because tumor cells are shed into the circulation, immunocytologic analysis of blood may function as a sensitive monitoring system. In this study, five blood samples were obtained from two patients with disseminated neuroblastoma at diagnosis and during therapy. These samples were analyzed with monoclonal antibodies and immunoperoxidase staining to determine whether circulating neuroblasts were present. In both patients, the presence or absence of circulating neuroblasts yielded information that was more sensitive than that from conventional tests. The authors conclude that immunocytologic analysis of blood should be included with conventional monitoring methods for surveillance of patients with disseminated neuroblastoma.
Multiple orbital tumors were cavernous hemangiomas. Two distinct masses in the left orbit were incidentally found in a 48-year-old woman during a computed tomographic scan done to evaluate neurologic complaints. Initial diagnostic considerations focused on a lymphoproliferative disorder or other systemic disease. Orbitotomy revealed two discrete tumors, both cavernous hemangiomas. Although uncommon, cavernous hemangioma should be considered in the differential diagnosis of the patient with multiple orbital lesions.
Primary sarcomas of the major salivary glands. Sarcomas arising in the major salivary glands are rare. This article presents the clinicopathologic features of 11 patients with primary sarcomas of the parotid gland (eight men and three women aged 7 to 75 years; mean age, 42 years). The 11 sarcomas were histologically typified as follows: three malignant fibrous histiocytomas and two each of neurosarcomas, rhabdomyosarcomas, fibrosarcomas, and osteosarcomas. Four patients experienced disease recurrences, and seven patients developed metastases. Seven patients died of their sarcomas, with a mean survival time of 30 months. Four patients were alive from 5 to 12 years (one each with angiomatoid malignant fibrous histiocytoma, embryonal rhabdomyosarcoma, fibrosarcoma, and neurosarcoma). Prognosis correlated with size of the neoplasm, type of sarcoma, and histologic grade. In this respect, salivary gland sarcomas behaved in identical fashion to their soft-tissue counterparts.