123rc/medical_text huggingface dataset:
In vivo ultraviolet irradiation of human skin results in profound perturbation of the immune system. Relevance to ultraviolet-induced skin cancer [published erratum appears in Arch Dermatol 1991 Sep;127(9):1368] Ultraviolet exposure of human skin deletes the function of antigen-presenting Langerhans cells normally resident within the epidermis. Langerhans cells are capable of activating T-lymphocytes by presenting antigens (such as nickel or tumor antigens) to T-lymphocytes. Such activated T-lymphocytes may be involved in the development of contact dermatitis and the immune surveillance of immunogenic skin cancers. Deletion of the function of Langerhans cells does not result in abrogated epidermal antigen presentation since ultraviolet irradiation simultaneously induces the appearance of another epidermal antigen-presenting cell population that is distinct from the Langerhans cell population and seems to induce suppression of the immune response. Suppression of the immune response following ultraviolet irradiation in murine models is critical for growth of immunogenic ultraviolet-induced skin neoplasm. Thus, ultraviolet irradiation of human skin may facilitate the growth of human neoplasms, and the spreading of skin-associated infections due to induction of suppressor T cells.
Simian virus 40 small tumor antigen and an amino-terminal domain of large tumor antigen share a common transforming function. The 82-residue amino-terminal sequences of simian virus 40 large tumor antigen (TAg) and small tumor antigen (tAg) are identical. Genetic analysis of TAg lacking amino acids 1-82 revealed that it was transformation-defective, as revealed by the agar growth assay, except when introduced in the presence of tAg. Since the latter, alone, lacks overt transforming activity, it would appear that the function of the sequence common to TAg and tAg is necessary, but not sufficient, for TAg transforming activity and that tAg can provide that function or its equivalent in trans. Thus, tAg may, in part, be viewed as a "portable" copy of a TAg functional domain.
The Senegal DNA haplotype is associated with the amelioration of anemia in African-American sickle cell anemia patients. We have previously determined that in African sickle cell anemia (SS) patients three different beta-like globin gene cluster haplotypes are associated with different percent G gamma (one of the two types of non-alpha chains comprising hemoglobin F [HbF]), mean percent HbF, and percent dense cells. We report now that in adult New York SS patients, the presence of at least one chromosome with the Senegal haplotype is associated with higher Hb levels (1.2 g/dL higher) than is found for any other non-Senegal haplotype (P less than .004). The percent reticulocytes and the serum bilirubin levels were lower in these patients. When the effect of alpha-gene number was analyzed by examining a sample of SS patients with concomitant alpha-thalassemia, the same results were obtained. Because the HbF level is significantly higher among the Senegal haplotype carriers in this sample, the inhibitory effect on sickling of this Hb variant may be one of the reasons for the haplotype effect. We conclude that the Senegal beta-like globin gene cluster haplotype is associated with an amelioration of the hemolytic anemia that characterizes sickle cell disease.
Scleroderma esophagus. Scleroderma (systemic sclerosis) is a connective tissue disorder characterized by thickening and fibrosis of the skin and visceral involvement that may include the heart, lungs, kidneys, and gastrointestinal tract. At least 40-50% of patients with scleroderma experience esophageal symptoms such as heartburn and dysphagia, while up to 90% of patients have esophageal dysfunction on objective testing at some point in their disease. The disease results in smooth muscle dysfunction that causes esophageal aperistalsis and reduced lower esophageal sphincter pressures. Gastroesophageal reflux with poor acid clearance results with an increased incidence of complications such as peptic stricture and Barrett's esophagus. Aggressive medical therapy is necessary to prevent these and other complications of gastroesophageal reflux.
Differential diagnosis of mut and cbl methylmalonic aciduria by DNA-mediated gene transfer in primary fibroblasts. Methylmalonic aciduria can be caused by mutations in the gene encoding the methylmalonyl coenzyme A mutase apoenzyme (mut) or genes required for the provision of cofactor B12 (cbl). The mut and cbl forms are classically differentiated by somatic cell complementation. We describe a novel method for differential diagnosis of mut and cbl methylmalonic aciduria using DNA-mediated gene transfer of a methylmalonyl CoA mutase cDNA clone. Gene transfer of a functional methylmalonyl CoA mutase cDNA clone into mut fibroblasts reconstitutes holoenzyme activity measured by metabolism of [14C]-propionate in culture. Identical gene transfers into cbl fibroblasts have no effect. This method is used for the differential diagnosis of mut and cbl genotypes in cells from patients with a clinical diagnosis of methylmalonic aciduria and is shown to be a facile, sensitive, and specific method for genetic diagnosis. This work establishes the principle of using DNA-mediated gene transfer to identify the genotype of diseases which can result from mutations at several different genetic loci. This type of differential genotypic diagnosis will be particularly important for establishing the applicability of somatic gene therapy in individual patients.
Effect of captopril injection in patients with moderate to severe hypertension. The effect of intravenous captopril was studied in 24 white patients who had moderate to severe hypertension. Patients received incremental doses of 1 to 10 mg delivered at 10 min intervals over 50 to 80 min. Blood pressure (BP) was lowered within 5 to 10 min after the initial dose was administered and continued to decline, reaching a maximum response after 20 min (2 to 4 mg). At this time group mean BP fell from 175 +/- 3/111 +/- 1 to 166 +/- 3/97 +/- 2 mm Hg (P less than 0.01). Additional dose increments to an average cumulative dose of 40 mg did not increase the initial effect. No adverse side effects or symptomatic hypotension occurred in any subject. There was a significant correlation between diastolic BP decreases observed in response to intravenous captopril and subsequent long-term oral captopril therapy. The addition of hydrochlorothiazide increased the proportion of patients reaching normotension. We conclude that small intravenous bolus injections of captopril appear to be effective rapidly and are well tolerated in moderate to severe essential hypertension. Short-term intravenous administration seems to predict the response to chronic oral captopril therapy.
Mayer-Rokitansky-Kuster-Hauser syndrome with splenosis. A case report. This is the first reported case of simultaneously occurring pelvic splenosis and Mayer-Rokitansky-Kuster-Hauser syndrome. No other congenital or anatomic abnormalities were observed in the patient, and she had no history of abdominal trauma or surgery. Endometriosis was suspected initially during laparoscopy for pelvic pain. After tissue removal at laparotomy, the histologic evaluation established the diagnosis of splenosis. Biopsy at laparoscopy should be considered to confirm the diagnosis in the presence of a congenital anomaly and lesions suspected of being endometriotic.
Adenocarcinoma in Barrett's esophagus. A clinicopathologic study of 65 cases. The natural history of Barrett's esophagus, particularly the prevalence and incidence of malignant changes in it, remains controversial. Furthermore the prognosis of surgically treated patients with carcinoma in Barrett's esophagus has not been elucidated fully. To examine these and other issues, the records of 65 patients with carcinoma in Barrett's esophagus presenting at the Lahey Clinic Medical Center from January 1973 to January 1989 were reviewed. During this period, 241 patients with documented Barrett's esophagus were seen, for a prevalence of carcinoma of 27%. Adenocarcinoma in Barrett's esophagus accounted for 30% of the surgically treated carcinomas of the thoracic esophagus during this period. All but four of these patients were men. Symptoms of chronic reflux were present in less than one half of the patients and dysphagia was often the presenting symptom. In eight patients the carcinoma was discovered on routine surveillance endoscopy, and in four patients progression of disease from benign columnar epithelium to dysplasia to carcinoma was documented. Tumors developed in six patients who had undergone previous antireflux surgery, and in four other patients a second carcinoma developed in residual Barrett's epithelium after a previous resection. Of the 65 patients, 61 (94%) were considered to have operable disease, all of whom underwent resection. Two patients (3.3%) died within 30 days of operation. The resected specimens were staged as follows: stage 0, 4; stage I, 10; stage II, 17; stage III, 25; stage IV, 4. Of the resected specimens, 73% showed areas of dysplasia adjacent to the tumor. The overall adjusted actuarial 5-year survival rate was 23.7%. The 3-year survival rate was 100% for patients with stage 0 carcinoma, 85.7% for patients with stage I carcinoma, 53.6% for patients with stage IIA carcinoma, 45% for patients with stage IIB carcinoma, 25.2% for patients with stage III carcinoma, and 0% for patients with stage IV carcinoma. The premalignant nature of Barrett's esophagus requires endoscopic surveillance to detect early carcinoma because symptoms often occur late or are absent. Antireflux surgery does not protect against the development of carcinoma. All of the Barrett's epithelium must be resected because a second carcinoma may develop in residual columnar epithelium. Severe dysplasia should be considered an indication for resection. Although operability and resectability rates are high, long-term survival is not. Early detection is mandatory if long-term survival is to be achieved.
Treatment of fulminant hepatic failure with insulin and glucagon. A randomized, controlled trial. Insulin and glucagon are among the therapeutic modalities that have been investigated in the treatment of fulminant hepatic failure (FHF). We have completed a randomized, controlled trial of insulin and glucagon in 38 patients with FHF from either viral or toxin exposure. The control and treatment groups consisted of 21 and 17 patients, respectively, and did not differ significantly in etiology or admission laboratory values. Mortality was not significantly different between control and treatment groups and was 67% and 82%, respectively. Time from randomization to death or discharge was not significantly different between the two groups. Peak levels of alpha-fetoprotein were statistically higher in survivors than in nonsurvivors (P less than 0.01). We conclude that even though a type-2 error may exist, the combination of insulin and glucagon is not useful in the treatment of FHF.
Clinical and Doppler echocardiographic follow-up after percutaneous balloon valvuloplasty for aortic valve stenosis. Percutaneous balloon valvuloplasty has been shown to increase the aortic orifice area and to improve clinical symptoms. However, there are only few data concerning long-term results after balloon valvuloplasty. In this study, 36 patients (11 men, 25 women, mean age 75 +/- 8 years) were followed after balloon valvuloplasty for a period of up to 18 months by means of clinical parameters and repeated Doppler echocardiographic measurements after 1, 3, 6, 12 and 18 months. Invasive measurements revealed a decrease of the systolic peak gradient from 78 +/- 24 to 38 +/- 13 mm Hg (p less than 0.001), and an increase in the aortic orifice area from 0.58 +/- 0.23 to 0.93 +/- 0.2 cm2 (p less than 0.001). The Doppler echocardiographic approach revealed that the maximal instantaneous gradient decreased from 96 +/- 26 to 67 +/- 22 mm Hg (p less than 0.001). The aortic orifice area increased from 0.49 +/- 0.16 to 0.73 +/- 0.21 cm2 (p less than 0.001). Three patients (8%) died in the hospital. After hospital discharge, 16 patients (44%) died and 8 patients (22%) underwent successful aortic valve replacement after a mean follow-up of 8 +/- 6 months. Nine patients (25%) were alive after a follow-up period of 18 months. Seven of these (19%) remained clinically improved. During follow-up, the Doppler echocardiographic results revealed a continuous trend toward the preprocedural severity of the aortic valve stenosis. Progression of restenosis assessed by Doppler echocardiographic measurements was accelerated in the group of patients who subsequently died or underwent repeat balloon valvuloplasty or aortic valve replacement.
Autoimmunity and malignancy. In patients with autoimmune diseases malignancy is observed more frequently than in an age-matched control group. In strains of mice susceptible to autoimmune diseases, the incidence of lymphoreticular malignancies is increased. Although viruses have not been directly implicated in their pathogenesis or etiology, there are suggestions that slow viruses may be involved. Viruses have been found to be important in the development of lymphomas. Hence in genetically susceptible animals, viruses can initiate the autoimmune process. Prolonged stimulation of the autoimmune process or a prolonged state of immunodeficiency could trigger or activate genes or their products, which could result in the development of malignancy.
Scoring system for the preoperative evaluation of metastatic spine tumor prognosis. An assessment system for the prognosis of metastatic spine tumors was evaluated for 64 cases who had undergone surgery. Six parameters were employed in the assessment system: 1) the general condition, 2) the number of extraspinal bone metastases, 3) the number of metastases in the vertebral body, 4) metastases to the major internal organs (lungs, liver, kidneys, and brain), 5) the primary site of the cancer, and 6) the severity of spinal cord palsy. Each parameter ranged from 0 to 2 points. The total score obtained for each patient can be correlated with the prognosis, while being valuable in predicting it. However, the prognosis could not be predicted from a single parameter. In conclusion, an excisional operation should be performed on those cases who scored above 9 points, while a palliative operation is indicated for those who scored under 5 points.
Intraoperative echocardiography of a dislodged Bjork-Shiley mitral valve disc. The successful management of a patient who suffered an outlet strut fracture of a Bjork-Shiley 60-degree convexo-concave mitral valve prosthesis is reported. Emergency operation was life-saving. Preoperative echocardiography assisted in making a prompt diagnosis, and intraoperative echocardiography allowed the detection and removal of the dislodged disc from the left ventricle at the time of the operation. The role of intraoperative echocardiography in the diagnosis of prosthetic strut fracture is emphasized.
Reperfusion inhibits elevated splanchnic prostanoid production after hemorrhagic shock [published erratum appears in Ann Surg 1991 Feb;213(2):91] The effect of reperfusion following hemorrhagic shock on splanchnic prostanoid release was studied. Anesthetized male rats were bled to a mean arterial blood pressure of 30 mmHg for 30 minutes and either killed or treated with shed blood for 60 minutes and then killed. The superior mesenteric arterial bed was cannulated and perfused in vitro with oxygenated Krebs. Collected venous effluent (up to 180 minutes) was analyzed for 6-keto-PGF1 alpha (PGI2 metabolite), PGE2, PGF2 alpha, and thromboxane B2 by radioimmunoassay in shock, shock plus reperfusion, and sham groups. The major prostanoid released was 6-keto-PGF1 alpha and was three times higher in the shock group compared to the sham group (p less than 0.05). Reperfusion of shed blood abolished the increase in 6-keto-PGF1 alpha found in the shock group (p less than 0.05). These data show that the attempt of the rat splanchnic bed to compensate for hemorrhagic shock by increasing release of PGI2 (potent vasodilator) was abolished during reperfusion of blood.
Clonogenic growth in vitro: an independent biologic prognostic factor in ovarian carcinoma A retrospective analysis was performed to investigate the prognostic value of growth in a human tumor clonogenic assay system for 84 ovarian cancer patients. A significant difference in survival probability (determined by the method of Kaplan-Meier) was found by univariate analysis between patients with ovarian carcinoma whose tumors manifested clonogenic growth (defined as growth of greater than or equal to five colonies per plate) and patients whose tumors did not grow. Clonogenic growth in vitro was associated with worse prognosis (P = .007, log-rank test). A number of generally accepted prognostic factors, International Federation of Gynecology and Obstetrics (FIGO) stage (P = .003), residual tumor mass (P less than .001), and grade (P = .011), were also of prognostic importance in our patient population. Multivariate analysis, based on the Cox regression model, identified clonogenic growth as a significant independent prognostic parameter in ovarian carcinoma (P = .031), in addition to the conventional risk factors. Estimation of survival of individual patients was best accomplished by combining the factors of residual tumor mass (P less than .05), age (P less than .01), and clonogenic growth (P less than .05) (in sequence of decreasing potential of risk).
Follow-up of patients who underwent arterial switch repair for transposition of the great arteries Thirty infants underwent arterial switch for transposition of the great arteries within the first week of life (mean age, 2.8 days). An additional three patients underwent repair at 5 1/2, 8, and 9 1/2 months of age. Six (18.2%) of 33 patients died. All the survivors were not receiving cardiac medications or diuretics at the time of the last follow-up visit. Examination of 24 of 27 survivors at 1 to 5 years of age revealed normal growth in 75% of the patients. Two patients had height, weight, and head circumference below the fifth percentile for age. Four patients had height and weight appropriate for age but head circumference below the fifth percentile. Neurodevelopmental testing yielded normal findings in 18 patients. Three patients were considered suspect and an additional three were abnormal neurodevelopmentally. Head circumference less than the fifth percentile, abnormalities on computed tomographic scans of the brain, and emergency balloon atrial septostomy or emergency switch operation were more likely to occur in patients who had low neurodevelopmental scores. We conclude that the majority of patients who undergo arterial switch repair demonstrate normal growth and development and no impairment of cardiovascular function. However, significant morbidity in the form of neurodevelopmental problems may occur.
Transfer function of sound transmission in subglottal human respiratory system at low frequencies. The amplitude of sound transmission from the mouth to a site overlying the extrathoracic trachea and two sites on the posterior chest wall was measured in eight healthy adult male subjects at resting lung volume over the 100- to 600-Hz frequency range. The ratios of the estimated magnitude spectra of transmission of each of the chest wall sites to the tracheal site were determined, with the resulting spectra representing effective transfer functions of transmission in the subglottal system. For the group, the transfer functions exhibited a single peak, which occurred at 143 +/- 13 Hz (mean +/- SD) with a quality factor (Q) of 2.0 +/- 0.2 for the upper chest wall site and at 129 +/- 6 Hz with a Q of 2.2 +/- 0.4 for the lower site. The trend of decreasing spectral energy with increasing frequency was indicated by roll-offs of -10 +/- 4 and -17 +/- 5 dB/octave from 300 to 600 Hz at the two sites, respectively. The fundamental radial mode of a model thoracic cavity, which is a large rigid cylinder filled with lossless lung tissue, provides a good estimate of the observed low-frequency resonance. This agreement suggests that thoracic cavity resonances may have particularly important effects on sound transmission at frequencies below approximately 250 Hz, where the magnitude of parenchymal attenuation appears to be small.
Lateral deviation of the eyes on forced lid closure in patients with cerebral lesions. We examined 35 patients with unilateral cerebral lesions to determine the incidence of lateral deviation of the eyes under forcefully closed lids and the reliability of this sign in predicting the side of the lesion. Only patients with radiologically confirmed unilateral lesions were studied. Over 70% of patients had contralateral ocular deviation (Cogan's "spasticity of conjugate gaze"), 20% had ipsilateral deviation, and less than 9% of the patients had no deviation. Lateral ocular deviation was as sensitive, but not as specific, as a unilateral Babinski plantar response in determining the side with the lesion. Contralateral deviation was more common with parietotemporal localization, suggesting that the phenomenon reflects an underlying disturbance of attentional mechanisms.
Leiomyosarcoma of bone. A clinicopathologic, immunohistochemical, and ultrastructural study of five cases. The authors identified five leiomyosarcomas (LMS) in a review of 13 nonmatrix-producing spindle cell sarcomas of bone. Only two were initially recognized as LMS; the others had been diagnosed as malignant fibrous histiocytoma (two) and fibrosarcoma (one). The patients, four of whom were women, ranged in age from 32 to 70 years. Sites included proximal humerus (two), distal femur (two), and rib (one). All tumors presented with clinical and radiographic features consistent with a diagnosis of primary bone neoplasms, although one probably represented a solitary metastasis from a primary uterine LMS. Radiographs showed lytic bone destruction with a moth-eaten appearance, and three cases had soft tissue extension. Histologically, all tumors showed broad, interlacing fascicles of spindle cells with pleomorphic nuclei, frequent mitoses, and necrosis. Two cases had a focal storiform pattern and bizarre multinucleated cells, and two other cases had focally prominent osteoclast-like giant cells. Extensive immunoreactivity for muscle actin was seen in all cases and for desmin in three. In each case, electron microscopy showed definite smooth muscle differentiation including cytoplasmic filaments with densities. At this writing, two patients are free of disease (including the patient with a presumed metastasis), one is alive with locally recurrent disease, and two are dead of disease. Experience suggests that LMS of bone is a distinct clinicopathologic entity that may be more common than previously recognized. Application of immunohistochemistry and electron microscopy to nonmatrix-producing bone sarcomas should facilitate diagnosis of additional cases.
Primary solid neoplasms of the greater omentum. Primary solid tumors of the greater omentum are rare, with only 42 reported cases. Malignant hemangiopericytomas constitute only three of these cases. The 40-year-old patient described in this report had abdominal pain, a palpable abdominal mass, early satiety, and weight loss. At laparotomy a large omental hemangiopericytoma was excised, and no other evidence of disease was grossly evident. Eighteen months after initial laparotomy, the patient had widespread progression of the tumor and, despite chemotherapy, died 2 months later. A review of reported cases shows that abdominal discomfort (56%) and mass (35%) are the most common clinical characteristics of a primary omental tumor. Weight loss, ascites, and peritoneal implants usually indicate malignancy. Rare long-term follow-up prevents definitive conclusions regarding therapy and prognosis. At present, surgical excision alone appears to be the treatment of choice, with no demonstrable benefit from either chemotherapy or radiation.