123rc/medical_text huggingface dataset:
Aspiration biopsy cytology of occult breast lesions by use of the "scouting needle". A prospective study of 261 cases. The increased use of mammography for the detection of impalpable breast lesions has resulted in a need for new diagnostic techniques. In a prospective study of 261 occult breast lesions, aspiration biopsy was done with a standard fine needle and syringe. This "scouting needle" technique permits the collection of diagnostic cytologic material in the clinician's office without specialized radiologic equipment. Thirty of 53 malignant lesions (57%) were detected cytologically. A benign cytologic diagnosis, which was made in 220 patients, did not preclude additional investigation. Aspiration biopsy using the "scouting needle" is a rapid, low-cost, easily performed, initial procedure which complements "watchful waiting." When diagnostic of carcinoma, it results in immediate surgical intervention and may obviate two-stage surgical treatment.
Coarctation of the aorta. Coarctation of the aorta is a common cardiovascular disorder with an unknown etiology. In the preductal type, blood flows from a patent ductus into the distal aorta. When the coarctation is juxtaductal or postductal, blood flows to the lower extremities by way of the subclavian arteries and collaterals. Plain films may show the reverse sign in postductal coarctation. Arteriography is the gold standard for making the diagnosis. However, magnetic resonance imaging will probably become an increasingly important diagnostic tool. The treatment of choice is surgery, with complete resection of the stenosed segment.
Mechanisms of vein graft atherosclerosis: LDL metabolism and endothelial actin reorganization. We have explored the effect of arterial hemodynamics on endothelial cell morphology and low-density lipoprotein metabolism in human saphenous vein segments harvested from tissue donors. An arterial pulsatile perfusion system was used to impose physiologic pressures and flows for 20 hours on saphenous vein and companion (control) femoral artery segments. A venous perfusion apparatus was also employed for the perfusion of a second (control) saphenous vein segment for the same period of time. Calculations of fluid shearing and wall tensile stresses were performed and related to induced changes in endothelial cell geometry and cytoskeletal actin organization and the incorporation, degradation, and localization of intact low-density lipoprotein within the vessel wall. Our results indicate that, compared with native arteries and veins, a 20-hour exposure of test saphenous veins to arterial hemodynamics induced (1) a significant increase in endothelial cell luminal surface area and perimeter independent of alignment with flow, (2) disassembly of the dense peripheral band of actin with a concomitant assembly of stress fibers, and (3) a two- to fourfold elevation in the undegraded low-density lipoprotein content, localized primarily within the subendothelial intima. Although the exact mechanisms underlying these results are uncertain, the focal accumulation of intramural low-density lipoprotein may be related to the loss of normal barrier function during endothelial cell enlargement, which is accompanied by transient cytoskeletal reorganization during the adaptation to arterial flow.
Epitope mapping of human thyroglobulin. Heterogeneous recognition by thyroid pathologic sera. Thyroglobulin is the major Ag of the thyroid gland involved in autoimmune pathologies. Epitope mapping was carried out with a rabbit polyclonal immune serum against fusion proteins expressed in prokaryotic cells. After screening of an initial human thyroglobulin cDNA library and subcloning of immunoreactive clones, seven epitopes were characterized and localized on the human thyroglobulin monomeric molecule. One was close to each extremity of the molecule, and five others were concentrated in the middle, covering a sixth of this 2748-amino-acid chain. The immunoreactivities of 18 autoimmune sera from different thyroid pathologies were tested against the seven previously characterized epitopes. Those from Hashimoto's thyroiditis were the most immunoreactive. Immune responses were heterogeneous for sera from different pathologies as well as for those from the same pathology. The central epitopes and the near-C-terminal epitope, however, were the epitopes most often recognized by the immune sera. These findings show that some autoepitopes overlap accurately with some heteroepitopes characterized by a polyclonal immune serum directed against the mature protein.
Unfading acral microlivedo. A discrete marker of thrombotic skin disease associated with antiphospholipid antibody syndrome. Small erythematous or cyanotic lesions on the hands and feet of four patients with antiphospholipid antibodies are described. These discrete lesions outline capillaries and do not disappear when pressure is applied. The histologic features are identical to those described in skin thrombotic syndrome associated with antiphospholipid antibodies, that is, microthrombi in dermal vessels without inflammation. In addition to indicating antiphospholipid antibodies in apparently healthy patients, this sign could be a marker of risk for large-vessel thrombosis.
Capillary leakage in inflammation. A study by vascular labeling. The local injection of pure inflammatory mediators induces venular leakage. To test the effect of endogenous mediators from dying tissue on vascular leakage, the authors devised an experimental model simulating an infarct, whereby living vessels would be exposed to fragments of organs undergoing aseptic necrosis. Tissues from donor rats were implanted aseptically in the cremasteric sac. Control rats were implanted with materials deemed to be as close as possible to nonirritating: boiled tissues and spheres of Teflon or glass. At different points the rats were injected intravenously with carbon black and killed an hour later. Whole cremaster mounts showed that vascular labeling was strictly venular up to 8 hours, mixed with capillary labeling between 12 and 24 hours, and mainly or exclusively capillary at 48 hours. Histology showed an acute inflammatory infiltrate in the labeled areas. A similar but weaker labeling pattern accompanied by milder inflammation was seen in controls. These results indicate that the vascular leakage in aseptic inflammation is biphasic, first venular, then capillary; and that the capillary phase is induced by the inflammatory reaction itself, possibly through a form of diffuse angiogenesis.
Trends in basal cell carcinoma, squamous cell carcinoma, and melanoma of the skin from 1973 through 1987. Major increases have occurred in the incidence of basal cell carcinoma and squamous cell carcinoma of the skin, as well as in cutaneous malignant melanoma during the period 1973 through 1987 in British Columbia. The greatest increases in basal and squamous cell carcinomas are on the head and neck. This indicates that exposure to sunlight is the major causative factor. The greatest increase in melanoma is on the trunk in men and on the lower limbs in women. The dramatic increases in nonmelanoma skin cancers in British Columbia, a relatively low sunlight area, suggest that major prevention programs are needed in areas that are not considered "sunspots.".
The origin of epidermal melanocytes. Implications for the histogenesis of nevi and melanomas. Among the most venerable concepts in dermatopathology is Unna's 19th century notion of Abtropfung, ie, that melanocytes drop off from the epidermis to the dermis during the histogenesis of melanocytic tumors. Paradoxically, however, Unna's basic premise of an epidermal origin for melanocytes has been seriously questioned for over 40 years, based on experimental evidence favoring a neural crest origin for melanocytes. Recent work has strengthened the evidence for a neural crest origin of epidermal melanocytes, and it has been suggested that the concept of Abtropfung be replaced by the concept of Hochsteigerung. The concept of Hochsteigerung holds that melanocytes migrate up from the dermis into the epidermis-not only in normal development, but also during normal tissue maintenance. It now seems likely that the precursor of melanocytes, in both normal and abnormal differentiation, may not be a melanoblast (a primitive cell committed to melanocytic differentiation) but rather a pluripotential cell. Although axon-investing Schwann cells have been the traditional focus as the closest relative of the epidermal melanocyte, recent studies suggest that another nerve sheath cell, the perineural cell, might be a better candidate. These concepts have profound implications for the histogenesis of melanocytic nevi and melanomas.
Postoperative lumbar spinal instability occurring or progressing secondary to laminectomy. The manifestations and pathomechanism of postoperative lumbar spinal instability, occurring or progressing secondary to laminectomy, was clarified by means of functional radiographic analysis in a series of 46 patients over 40 years of age. The relation between instability and the clinical symptoms also is discussed. In patients under 60 years of age, instability at the operated level tended to appear in cases of wide laminectomy more often than in cases of partial laminectomy. Occurrence or progress of instability seems to be promoted by resection of the posterior spinal elements rather than the disc. It is further considered that the postoperative aggravation of clinical symptoms may be influenced not only by instability, but also by the other factors.
Endosalpingosis as a cause of chronic pelvic pain. Endosalpingosis, a condition characterized by ectopic oviduct epithelium, is diagnosed histologically by the appearance of benign ciliated and nonciliated columnar cells in an abnormal location. Endosalpingosis is typically without symptoms. Our unusual case report shows symptomatic endosalpingosis first seen with chronic pelvic pain. Various aspects of this disease will also be discussed.
Refractory parastomal ulcers: a multidisciplinary approach. Chronic parastomal ulcers in patients with ileostomy or colostomy stomas are unusual. Previous reports have implicated infections, fistulas, recurrent inflammatory bowel disease (IBD), pyoderma gangrenosum, and trauma. Over the past 8 years we have evaluated 10 cases of such refractory parastomal ulcers that occurred at a mean of 11 years after stomal surgery. Eight patients had had an ileostomy for IBD while two had undergone colostomy for colon cancer. Five patients with IBD were diagnosed as having pyoderma gangrenosum ulcerations. They required systemic treatment for a mean of 25 weeks to effect ulcer healing. The other five patients had either parastomal ulcers on the basis of dermatoses (contact dermatitis, eczema, or bullous pemphigoid) or contact ulcers due to face-plate pressure and parastomal dermatitis. These patients received topical treatment with healing of ulcers in a mean of 4 weeks. We conclude that parastomal ulcers occurring in patients without IBD or IBD patients without classic pyoderma gangrenosum require early dermatologic evaluation as they respond relatively quickly to appropriate local therapy.
Successful CPR in a severely hypothermic patient using continuous thoracostomy lavage. Severe hypothermia with cardiopulmonary arrest often requires prolonged resuscitation while rewarming procedures are implemented. A 63-year-old male in cardiopulmonary arrest with a core body temperature of 23.7 C was resuscitated successfully after core rewarming by means of a two-chest-tube continuous thoracostomy lavage procedure. This lavage procedure resulted in effective and rapid rewarming after other conventional rewarming methods had failed.
Elevated intracranial pressure and computed tomography of the brain in fulminant hepatocellular failure. Cerebral herniation is a leading cause of death in patients with fulminant hepatocellular failure. Classical signs of elevated intracranial pressure are often absent in these patients. A reliable noninvasive method by which the presence of cerebral edema could be determined is much needed. To assess the efficacy of computed tomography of the brain in this setting, we compared the radiographic findings to the intracranial pressure measured by an epidural monitor in patients with fulminant hepatic failure. Unfortunately, a considerable difference existed between the presence of cerebral edema diagnosed by computed tomography of the brain and elevation of the intracranial pressure. Our observations suggest that in patients with fulminant hepatic failure and advanced hepatic encephalopathy, computed tomography of the brain is of little value in detecting cerebral edema. Pressure monitoring is most important to establish the presence and guide the therapy of intracranial hypertension.
Biotype as determinant of natural immunising effect of cholera. To test the hypothesis that clinical Vibrio cholerae O1 infections protect against recurrent cholera, treated cholera episodes in a rural Bangladesh population of 188,153 people who were followed between 1985 and 1988 were analysed. Of the 2214 people with initial episodes of cholera, 7 had a second episode. The incidence of cholera was 61% lower in subjects who had had an earlier episode than in those without such an episode. Whereas initial episodes of classical cholera were associated with complete protection against subsequent cholera, initial episodes of El Tor cholera were associated with negligible protection.
Treatment of spinal cord compression by epidural malignancy in childhood. Epidural spinal cord compression by a malignant tumor is a rare occurrence in children. Both the tumors involved and the extent of involvement of the vertebral column are different in children and adults. Often, the epidural tumor in a child is identified before significant spinal canal compromise has occurred, and these children frequently can be managed by radiation therapy and/or chemotherapy. There is a group of children, however, who have severe spinal canal encroachment by a tumor, as evidenced by a near complete or complete block on myelography. In this study, we report a group of patients with severe spinal cord compression, as documented by imaging studies. We compared the results of a decompressive laminectomy and subtotal tumor resection followed by adjuvant therapy with the results obtained with radiation therapy and/or chemotherapy alone. Thirty-three patients met the criteria for inclusion in the study. Twenty-six were treated with a laminectomy and adjuvant therapy, and 7 were treated without surgical intervention. With surgical therapy, 25 of 26 epidurals were either improved or stable, whereas 4 of 7 nonsurgical patients deteriorated. Especially notable was a decrease in pain in the operative patients immediately after their procedure. There was no surgical mortality or morbidity. The results of this study indicate that children with severe spinal cord compression as evidenced by a near complete or complete block on myelography or filling of 50% or more of the spinal canal on magnetic resonance imaging are best treated by a combination of surgical decompression and tumor removal followed by adjuvant therapy.
Comparison of FRTL-5 cell growth in vitro with that of xenotransplanted cells and the thyroid of the recipient mouse. The present work was designed to compare in vitro cell growth kinetics with in vivo growth under conditions as similar as possible using labeling with [3H]thymidine. To this purpose, FRTL-5 cells were cultured as monolayers and as three-dimensional spheroids embedded in collagen gels and transplanted simultaneously into nude mice treated with perchlorate and a low iodine diet. The growth of the transplants was compared to that of the thyroids in host mice. In the intact thyroid, the fraction of [3H]thymidine-labeled follicular cells (FLC; 24-h labeling) increased sluggishly to a maximum of 10% after 3 weeks of goitrogen exposure, with a subsequent autoregulatory decrease to 3% at 7 weeks. A 4-fold higher FLC was found in six adenomas, indicating focal failure of growth-restraining mechanisms. In nonconfluent monolayer cultures the FLC was as high as 90%, even within large individual clusters where cells are in tight mutual contact. Solid, highly cellular grafts growing from transplanted monodispersed cells showed an average FLC of 20%, which is 5 times higher than the FLC in the identically stimulated mouse thyroid. In collagen-embedded cells, forming three-dimensional spheroids, the mean FLC decreased from 70% at 1 week in vitro (40% in vivo) to 20% at 3 weeks both in vitro and in vivo, suggesting effective auto-regulation of excessive growth in both conditions. However, these FLC were again much higher than the 3% FLC in simultaneously assessed host thyroids. The difference remained throughout the 45-day period studied. We conclude that FRTL-5 cells growing as monolayers and as three-dimensional spheroids in vitro or after xenotransplantation in vivo invariably show much higher proliferation rates under comparable environmental conditions than the normal follicular epithelium in the thyroids of host mice. The one exception is the confluent monolayer with near-zero growth, while densely packed three-dimensional transplants still grow intensively. Although growth-retarding cell to cell interactions are also clearly operative in growing FRTL-5 cells, they are less effective than those dampening the replication rate of the thyrocytes within the monolayer hull of normal follicles. A local failure of these mechanisms, allowing growth rates comparable to those of grafted FRTL-5 cells results in adenoma formation in normal thyroids. These observations call for caution in the transfer of in vitro growth studies with FRTL-5 cells to in vivo conditions prevailing in the normal thyroid.
Potentially fatal asthma and syncope. A new variant of Munchausen's syndrome in sports medicine. We report a case of Munchausen's syndrome in a 19-year-old female college athlete who presented with potentially fatal asthma and recurrent syncopal episodes. Failure to control her asthma with the appropriate medications and the lack of objective findings on both physical examination and diagnostic testing raised the possibility of factitious disease. Munchausen's syndrome, although not described with any frequency in asthmatic patients, should be considered in the differential diagnosis of those patients refractory to aggressive medical management.
Upper tract tumours following cystectomy for bladder cancer. Is routine intravenous urography worthwhile? The incidence and presentation of upper tract tumours were studied in 180 patients who had previously undergone cystectomy for transitional cell carcinoma of the bladder. Intravenous urography was performed routinely 3 months after cystectomy, 1 year later and at 3-yearly intervals thereafter. Ten patients developed upper tract tumours; 1 presented with loin pain and the remainder with haematuria. Six patients underwent nephroureterectomy and 5 of them lived for at least 4 years; 4 were inoperable and only 1 survived longer than 6 months. In this series, all patients with upper tract tumours presented with symptoms and routine intravenous urography failed to detect any asymptomatic lesions. Routine radiological assessment of the upper tracts to detect tumours is not justified following cystectomy.
Hypertension, cigarette smoking, and the decline in stroke incidence in eastern Finland. Finland has high rates of both cardiovascular disease and cardiovascular disease risk factors. We studied random samples of the population 30-59 years of age for risk factors in two provinces of eastern Finland in 1972 and 1977. We then followed both cohorts until 1985 through linkage with national hospital discharge and death certificate registers. The prevalence of hypertension and smoking in both provinces declined between 1972 and 1977, as did the stroke incidence in the 8-year period of follow-up of each cohort. We observed no differences in stroke incidence between the two provinces. The relative risk of stroke in the later period (1977-1985) was 0.71 and 0.58 for men and women, respectively, when compared with the earlier period (1972-1980). Overall, 28% of all stroke events could be attributed to hypertension, 17% to smoking, and 43% to these two factors jointly. The decrease in the prevalence of hypertension and smoking accounted for about 29% of the decline.
Rectal bleeding. Patient delay in presentation. Patient delay in presentation of rectal bleeding has been identified as a factor in delayed diagnosis among patients with colorectal cancer. The aim of this study was to identify demographic or psychological factors, or beliefs or behaviors related to delay in presentation of rectal bleeding. In 93 patients presenting with this symptom to their general practitioner, delay ranged from 0 to 249 days with a median of 7 days; 27 (29 percent) delayed more than 14 days. Delay was unrelated to age, sex, ethnic origin, competence in English, length of schooling, social status, availability of social support, measured psychologic traits, and to the belief that the cause might be cancer. The proportions delaying more than 14 days were statistically significantly elevated among those who were not worried by the bleeding (47 percent delayed); those who did not regularly look at their feces or the toilet paper after use (37 percent); and those who took some other action before presenting to their general practitioner (43 percent).
Vastus lateralis myocutaneous flap for reconstruction of defects around the groin and pelvis. We present our experience using the vastus lateralis myocutaneous flap for the repair of defects around the groin and pelvis. It is a relatively new technique, with many advantages over other flaps used in this area, though it has limitations. The history, anatomy and surgical technique of raising the flap are described and clinical cases are discussed. The importance of patient selection is highlighted.
Topical fibronectin and aprotinin for keratectomy wound healing in rabbits. We evaluated the effect of fibronectin (an adhesive protein) and aprotinin (a protease inhibitor) as single or combined topical therapies for primary healing and prevention of recurrent corneal epithelial defects in the rabbit keratectomy wound model. The biological activity of the prepared solutions of rabbit plasma fibronectin (0.6 g/L) was suggested by in vitro assays of rabbit corneal epithelial cell adhesion and gelatin-binding affinity. In the first experiment, we compared fibronectin, albumin (a control nonadhesive protein), and saline. In the second and third experiments, fibronectin supplemented with aprotinin, aprotinin alone, and saline were compared; aprotinin was used at concentrations of 40 and 1000 kallikrein inactivating units (KIU) per mililiter. Our results suggest that topical fibronectin, 0.6 g/L, as well as aprotinin at 40- and 1000-KIU/mL concentrations, given alone or in combination, neither promote corneal epithelial wound healing nor prevent recurrent corneal epithelial defects in rabbit keratectomy wounds.