123rc/medical_text huggingface dataset:
Sialosyl-Tn. A novel mucin antigen associated with prognosis in colorectal cancer patients. Colon cancers typically produce mucin. However, it is not known whether tumor mucin plays a biological role in cancer cell behavior. To address this issue, the expression of a mucin-associated antigen, sialosyl-Tn, was examined by immunohistochemical study in 128 primary colorectal carcinoma specimens from 137 patients who underwent curative surgical resection. Antigen expression was correlated with disease-free and overall 5-year survival. Sialosyl-Tn antigen expression occurred in 112 (87.5%) tumors, and was independent of age, gender, tumor location, Dukes' stage, depth of invasion, degree of differentiation, and ploidy status. Survival at 5 years for patients with sialosyl-Tn-negative versus sialosyl-Tn-positive tumors was 100% versus 73% (P less than 0.05) and disease-free survival was 94% versus 73%, respectively (P = 0.12). Although more advanced Dukes' stage, deeper invasion, and aneuploidy were all associated with poorer overall 5-year survival, antigen-negative tumors within each of these groups had much better prognoses than antigen-positive tumors. Multivariate regression analysis revealed that tumor ploidy (P less than 0.001) and sialosyl-Tn expression (P less than 0.05) were the two variables of most importance for predicting both disease-free and overall survival. The authors conclude that sialosyl-Tn expression is an independent predictor of poor prognosis in colon cancer, and therefore suggest that qualitative mucin alterations may reflect important differences in the biological behavior of these neoplasms.
Evaluation of methods for detecting venous reflux. Perspectives in venous insufficiency. Using 793 limbs with nonobstructive venous reflux, we evaluated a number of techniques used for the assessment of venous reflux. The venous Doppler examination was found to be a reliable screening tool with excellent sensitivity and good specificity. Photoplethysmography was 97% sensitive in patients with ambulatory venous hypertension; however, in milder forms of reflux, it was less sensitive. The major drawback of photoplethysmography was the large number of false-positive results obtained. Ambulatory venous pressure measurement and another pressure-based technique, Valsalva-induced foot venous pressure measurement, defined overlapping but different normal and abnormal limbs. Descending venography, when performed as described by Kistner et al, was found to be a reliable tool to assess reflux with more than a 90% sensitivity. The horizontal technique of performing descending venography and nucleotide descending venographies had unacceptably low sensitivity and were abandoned. Features of venous reflux as outlined by these modern technical tools are described.
Failure of nutritional recovery after total gastrectomy. Malnutrition is reported to be an inevitable consequence of total gastrectomy, although there are few data to support this contention. Six patients of median age 63 years underwent total gastrectomy for malignancy. At follow-up (median 45 months, range 25-60 months) each patient was clinically tumour-free and underwent dietary assessment, faecal fat and nitrogen measurement and routine haematological testing. Protein and fat stores, measured by neutron activation analysis and the tritiated water dilution technique, were compared with the same measurements made before operation and with predicted values. Mean (s.d.) dietary intake (2224(381) kcal day-1 and 81(15)g protein day-1) met the patients' estimated requirements. Mean(s.d.) serum albumin and faecal nitrogen values were normal but there was notable steatorrhoea (21(17) g day-1). Body composition measurements revealed profound deficiencies of body-weight (P less than 0.02), protein (P less than 0.01) and fat (P less than 0.02) before operation which were not corrected by an apparently curative total gastrectomy (P less than 0.05), although further deterioration was prevented.
Perception and action in 'visual form agnosia'. A single case study of a patient with 'visual form agnosia' is presented. A severe visual recognition deficit was accompanied by impairments in discriminating shape, reflectance, and orientation, although visual acuity and colour vision, along with tactile recognition and intelligence, were largely preserved. Neuropsychological and behavioural investigations have indicated that the patient is able to utilize visual pattern information surprisingly well for the control of hand movements during reaching, and can even read many whole words, despite being unable to make simple discriminative judgements of shape or orientation. She seems to have no awareness of shape primitives through Gestalt grouping by similarity, continuity or symmetry. It is proposed that many of these perceptual disorders might be the combined result of (1) a selective loss of the cortical elaboration of the magnocellular visual processing stream, and (2) a selective output disconnection from a central processor of visual boundaries and shape primitives in the occipital cortex.
Bladder function in the mentally retarded. A group of 21 mentally retarded patients with severe, long-standing urinary symptoms underwent urodynamical investigation. The most common abnormalities were detrusor areflexia and detrusor hyper-reflexia. Of 11 patients treated surgically, 10 derived marked benefit. Drugs were successful in reducing micturition problems in 3/6 patients. Severely retarded patients with spastic quadriplegia are difficult to investigate and if this is associated with detrusor hyper-reflexia it is impossible to treat them in any way. Severely retarded patients with detrusor areflexia and infrequent voiding can benefit from bladder outlet surgery. Patients with moderate (especially mild) retardation can be investigated and treated in the same way as non-retarded people.
Promoter deletion and loss of retinoblastoma gene expression in human prostate carcinoma. Mutational inactivation of the retinoblastoma gene (RB) is found in all retinoblastomas and in a subset of other human neoplasms, including sarcomas of bone or soft tissue and carcinomas of lung or breast. Exogenous copies of wild-type RB have been shown to suppress the tumorigenicity of several types of tumor cells with endogenous RB mutations, including a previously described human prostatic carcinoma cell line. To further support a role for RB inactivation in the genesis of prostate cancer, seven primary or metastatic prostate carcinoma specimens were examined for evidence of RB mutation. By the use of immunoblot analysis and immunostaining of histologic sections, RB-encoded protein was readily detected in tumor cells of five specimens, was equivocally detected in one specimen, and was apparently absent from tumor cells of one specimen. RB mutations in the latter case were precisely characterized as (i) a deletion of 103 nucleotides containing transcriptional start sites and (ii) loss of the second RB allele. The 103-base-pair deletion was sufficient to abolish the promoter activity of upstream DNA sequences in a heterologous expression system. These results (i) demonstrate that RB can be inactivated in vivo by mutation of its promoter, (ii) confirm the existence of RB mutations in some human prostate carcinomas, and (iii) suggest the use of immunohistochemical methods to screen for RB mutations in clinical samples of common adult neoplasms.
Prophylaxis of uric acid stones with alternate day doses of alkaline potassium salts. Uric acid stone formation ordinarily is prevented by increases in the urinary pH after meals. This postprandial alkaline tide is lost in patients who make such calculi. Single dose, alternate day administration of an alkaline potassium salt will increase urinary pH and simulate this normal physiological mechanism. An important part of the regimen is patient self-monitoring to verify that the urinary pH increases to greater than 6.8, 1 1/2 to 2 hours after the medication is taken. In contrast to multiple dose daily regimens, this mode of base administration is tolerated better and easier to follow. In 17 patients, 7 with the recurrent gravel/colic syndrome and 10 with prior stones, this regimen abolished calculus formation during an average followup of 2 1/2 years. However, further studies are needed before this regimen can be recommended as standard therapy for uric acid stone prophylaxis.
Thromboxane receptor blockade prevents pulmonary hypertension induced by heparin-protamine reactions in awake sheep We used competitive thromboxane A2-prostaglandin endoperoxide receptor blockade (SQ 30,741) as a probe to evaluate the role of thromboxane in ovine pulmonary vasoconstriction associated with protamine reversal of heparin anticoagulation. Control heparin-protamine reactions induced rapid release of thromboxane into arterial plasma (more than 1 ng/ml plasma), a 2.5-fold increase of pulmonary artery pressure, a 20% decrease of PaO2, and a 30% reduction in arterial white blood cell concentration. After giving SQ 30,741 despite similar thromboxane release into arterial plasma after heparin-protamine challenge, acute pulmonary hypertension was significantly reduced when 94% of pulmonary vascular smooth muscle thromboxane receptors were occupied with SQ 30,741 (p less than 0.01 at 1 minute after protamine versus control heparin-protamine reaction) and was completely abolished by a 10 mg/kg i.v. bolus (p less than 0.0001 at 1 minute after protamine versus control). Peripheral leukopenia was not affected by SQ 30,741 prophylaxis, but hypoxemia was prevented. We conclude that thromboxane causes pulmonary vasoconstriction in ovine heparin-protamine-induced pulmonary hypertension. Pulmonary vasoconstriction and hypoxemia can be completely prevented by thromboxane receptor blockade.
Doppler assessment of left ventricular filling pattern in silent ischemia in patients with Prinzmetal's angina. Spontaneous angina is an ideal condition in which to study left ventricular (LV) dysfunction induced by acute myocardial ischemia. In 6 patients with Prinzmetal's angina, LV diastolic function during 16 episodes of spontaneous angina was studied by simultaneous recordings of electrocardiographic (ECG), echocardiographic and hemodynamic parameters. In particular, pulsed Doppler echocardiography measured peak velocity of early (E) and late (A) transmitral flow and E/A ratio, as indexes of relative early versus late LV filling. During the ischemic attacks, the time sequence of pulsed Doppler echocardiographic and ECG changes showed 3 distinct phases: (1) "waxing phase: transmitral flow changes with minimal ECG modifications (E/A = 0.85 +/- 0.1); (2) "steady" phase: maximal ECG changes (E/A = 0.9 +/- 0.1); and (3) "waning" phase: regression of the ECG changes (E/A = 1.26 +/- 0.15). In each phase, E/A ratio showed a significant difference from the baseline value (E/A = 1.17 +/- 0.2) as a result of changes in E, suggesting that myocardial ischemia affects mainly the early phase of diastole. In the waxing phase, LV diastolic dysfunction preceded systolic abnormalities, as documented by a significant reduction of E/A ratio in the absence of alterations in LV ejection fraction, as well as in systemic arterial and pulmonary wedge pressures. Finally, all the recorded parameters were consistent with LV "contractile rebound" occurring in the waning phase and affecting both diastole and systole.
Selection of therapy for stage III breast cancer. Locally advanced breast cancer is a heterogenous group including both operable and inoperable lesions. Local surgery or radiation alone produces poor survival rates, indicating micrometastases at diagnosis. Systemic chemotherapy as part of multimodality regimens has increased the length and rate of disease-free survival.
Epilepsy. As surgical treatments for adult and pediatric forms of epilepsy have become more refined, methods for noninvasive localization of epileptogenic foci have become increasingly important. Detection of focal brain metabolic or flow abnormalities is now well recognized as an essential step in the presurgical evaluation of many patients with epilepsy. Positron emission tomography (PET) scanning is most beneficial when used in the context of the total clinical evaluation of patients, including scalp EEG, invasive EEG, neuropsychologic testing, etc. Metabolic PET studies also give insight into pathophysiologic mechanisms of epilepsy. The dynamic nature of the interictal hypometabolism observed with 18[F]FDG in some patients suggests that excitatory or inhibitory neurotransmitters and their receptors may be involved. An exciting current application of PET scanning is the use of tracers for neurotransmitter receptors in the study of epilepsy patients. Mu and non-mu opiate receptors have been extensively studied and are beginning to give new insights into this disorder. Increased labeling of mu receptors in temporal neocortex using 11C-carfentanil has been demonstrated and, in some patients, supplements the clinical localization information from 18[F]FDG studies. Increased mu opiate receptor number or affinity is thought to play a role in anticonvulsant mechanisms. Specificity of increased mu receptors is supported by the absence of significant changes in non-mu opiate receptors. Other brain receptors are also of interest for future studies, particularly those for excitatory neurotransmitters. Combined studies of flow, metabolism, and neuroreceptors may elucidate the factors responsible for initiation and termination of seizures, thus improving patient treatment.
Age effects susceptibility to pulmonary barotrauma in rabbits. OBJECTIVE: We studied the effect of age on the development of pulmonary barotrauma after mechanical ventilation with high peak inspiratory pressures (PIP). DESIGN: Young (4 to 6 wk old) and adult rabbits were ventilated for 1 hr at PIPs of 15, 30, and either 45 cm H2O (young group) or 55 cm H2O (adult group). MEASUREMENTS AND MAIN RESULTS: The pulmonary capillary filtration coefficient (Kf,c) was measured in an isolated lung perfusion system after the animals were killed. In young rabbits, Kf,c increased significantly from the 15 cm H2O PIP value in both the 30 cm H2O (55%) and 45 cm H2O (507%) PIP groups, whereas Kf,c was increased in adult rabbits only in the 55 cm H2O (113%) PIP group. Kf,c was significantly (p less than .01) higher in young rabbits than in adult rabbits after ventilation, with every level of PIP being 91% higher at 15 cm H2O PIP and 440% higher at 45 to 55 cm H2O PIP. Also, a greater incidence of pneumothorax and airleaks was observed in the young rabbits. Pressure-volume loops demonstrated that the young rabbits had more compliant lungs and chest wall than adult rabbits. CONCLUSIONS: These data indicate that the lungs of young rabbits had a higher baseline microvascular permeability and were more susceptible to the development of ventilator-induced increased microvascular permeability. More compliant lungs and chest wall and the larger distending volumes attained at each peak airway pressure appear to be the mechanisms.
Sterol-dependence of gastric protective activity of unsaturated phospholipids. The major aim of this study was to investigate the gastric protective effect of unsaturated phospholipids and to determine the ability of neutral lipids to enhance this activity. We found that although a liposomal suspension of unsaturated phosphatidylcholine (PC) administered intragastrically failed to protect rats from acid-induced gastric ulcer formation, addition of cholesterol to unsaturated PC induced a dose-dependent protective response with the maximally effective dose, reducing lesion score greater than 70%. This effect also was seen with the plant sterol, beta-sitosterol (reducing lesion score by 81.6 +/- 36%) but was blocked if cholesterol was esterified to fatty acids of varying chain length. Addition of sterols to liposomes of saturated dipalmitoylphosphatidylcholine, in contrast, attenuated the gastric protective action of the saturated PC. It appears that the protective mechanism elicited by sterols and unsaturated PC is not mediated by alterations in gastric emptying rate or prostaglandin biosynthesis, although maintenance of surface hydrophobicity may be involved. These results suggest that the sterol may promote the packing of adjacent unsaturated phospholipid molecules of either the cell membrane or a putative extracellular hydrophobic lining of the gastric epithelium to provide the mucosa with protection against luminal acid.
Colorectal adenocarcinoma in patients less than 40 years of age. From 1973 to 1985, 105 patients under 40 years of age were treated for colorectal adenocarcinoma at Roswell Park Cancer Institute. There were 51 males and 54 females. The mean age was 32 years. The majority of patients were treated for left colon or rectal carcinomas. Ninety-seven of 105 patients underwent surgical resection of their primary cancer, 70 (67 percent) of which were potentially curative. Twenty-seven patients underwent palliative resections. Dukes' A or B lesions were not seen in patients less than 20 years old, whereas these early lesions were seen in 11 percent of patients 20 to 29 years old and in 26 percent of patients greater than 30 years of age. The mean survival for patients between 20 and 29 years was 39 months and 46 months for patients 30 years and older.
Transgenic mice susceptible to poliovirus. Poliovirus-sensitive transgenic mice were produced by introducing the human gene encoding cellular receptors for poliovirus into the mouse genome. Expression of the receptor mRNAs in tissues of the transgenic mice was analyzed by using RNA blot hybridization and the polymerase chain reaction. The human gene is expressed in many tissues of the transgenic mice just as in tissues of humans. The transgenic mice are susceptible to all three poliovirus serotypes, and the mice inoculated with poliovirus show clinical symptoms similar to those observed in humans and monkeys. Rabbit antipoliovirus serum detects the antigens mainly in motor neurons in the anterior horn of the spinal cord and in nerve cells in the medulla oblongata and pons of the paralyzed transgenic mice. Therefore, cell types sensitive to poliovirus in the central nervous system of the transgenic mice appear to be identical to those of humans and monkeys. Furthermore, many more doses of oral poliovirus vaccine strains than of the virulent strains are required to cause paralysis in the transgenic mice. This may reflect the observation that the virulent strain multiplies more efficiently in the central nervous system than the attenuated strain. Thus, the transgenic mice may become an excellent new animal model to study molecular mechanisms of pathogenesis of poliovirus and to assess oral poliovirus vaccines.
Response to diet and cholestyramine in a patient with sitosterolemia. In this report, an 11-year-old boy with diffuse tendinous and tuberous xanthomatosis and a plasma sterol concentration of 555 mg/dL, consisting primarily of cholesterol, is described. Three months after changing from an unrestricted diet to a cholesterol-lowering diet, his plasma sterol concentration decreased to 221 mg/dL. Because of the degree and rapidity of his response to diet, sitosterolemia was suspected. According to results of capillary gas-liquid chromatography of his plasma sterols, there was a sitosterol concentration of 31.3 mg/dL (normal less than 1.0 mg/dL), establishing the diagnosis of sitosterolemia. Addition of cholestyramine therapy (8 g/d) to a low sterol diet further lowered his plasma sterol concentration to 173 mg/dL and led to complete regression of all tuberous xanthomata. Tendinous xanthomata regressed at a slower rate. These findings show that the diagnosis of sitosterolemia should be suspected in severely hypercholesterolemic children (total cholesterol greater than 400 mg/dL) whose plasma cholesterol level is highly responsive to dietary manipulation. The rapid and sustained lowering of plasma cholesterol and regression of xanthomata after treatment with diet and cholestyramine suggest that sitosterolemia is a treatable cause of premature atherosclerosis.
Increased arterial adrenaline is related to pain in uncomplicated myocardial infarction. Plasma levels of catecholamines, beta-thromboglobulin (BTG) and arginine vasopressin (AVP), and degree of pain were examined in 22 patients with suspected uncomplicated myocardial infarction within 24 h following onset of chest pain. Sixteen patients developed infarction with peak creatine phosphokinase at 1280 Ul-1 (range 293-3770 Ul-1). Fifteen healthy men served as controls (C). Arterial adrenaline levels were significantly higher in patients with pain (1.15 +/- 0.23 nmol l-1, n = 8, mean value +/- SEM) than in those without pain (0.60 +/- 0.10 nmol l-1, n = 14, P less than 0.05). Plasma catecholamines were moderately but significantly elevated in myocardial infarction; the concentration of arterial adrenaline was 0.83 +/- 0.14 nmol l-1 and that of arterial noradrenaline was 2.70 +/- 0.28 nmol l-1 compared with 0.44 +/- 0.04 nmol l-1 (P less than 0.025) and 1.47 +/- 0.05 nmol l-1 (P less than 0.0005), respectively, in C. One week later, plasma catecholamines had returned to baseline levels. Plasma BTG showed borderline elevation (1.0 +/- 0.1 pmol l-1) compared with C (0.6 +/- 0.1 pmol l-1, P = 0.04), and remained unchanged 1 week later. Plasma AVP was at baseline level. Uncomplicated myocardial infarction, regardless of size, was associated with only moderately increased sympathetic tone. Plasma adrenaline was related more to the degree of pain than to the presence of acute myocardial infarction. Arterial adrenaline may be a sensitive marker of sympatho-adrenal activity related to pain.
Localization of malignant melanoma using monoclonal antibodies. Finding a screening test to evaluate patients with cancer for occult metastatic disease, as well as imaging all known disease, is a goal of research efforts. Twenty-nine evaluable patients with deeply invasive (stage I), regional nodal (stage II), or systemic (stage III) melanoma underwent imaging by administration of a preparation of the antimelanoma antibody labeled with technetium 99m. Scan results indicated that 28 of 32 confirmed metastatic sites were imaged with this technique (88% sensitivity). Analysis of the individual positive sites revealed that nodal basins and visceral metastases accounted for the highest percentage of metastatic sites imaged, with 14 (88%) of 16 nodal basin metastases and all four visceral metastases being detected through imaging. Occult nodal disease was detected in the iliac nodal chain in two of the 29 patients. The imaging of benign tumors and nodal basins not containing disease accounted for a confirmed false-positive rate of 21%. Three (10%) of the 29 scan results were confirmed to be false-negative. In vivo tumor localization with monoclonal antibodies showed a sensitivity similar to that of other roentgenographic procedures for identifying metastatic disease and was useful in two of three patients in identifying occult iliac nodal disease, a region that is difficult to evaluate with physical examination and other imaging modalities.
Aplasia cutis congenita and arteriovenous fistula. Case report and review. We describe a child with congenital aplasia cutis congenita of the scalp and an occult giant posterior fossa arteriovenous fistula. Previous case reports of central nervous system malformations associated with aplasia cutis congenita are reviewed. The exact incidence of such malformations is unknown. All patients with aplasia cutis congenita should undergo a neurologic evaluation, and their families should be examined for similar lesions. Early central nervous system imaging and other workup may be required, especially if plastic surgery in the head region is being planned.