shukoor65/lab-rag-model huggingface dataset:
Intermittent short-term negative pressure ventilation and increased oxygenation in COPD patients with severe hypercapnic respiratory failure. With the aim of testing a method that allows increasing concentrations of oxygen to be administered to patients with severe hypoxemia and hypercapnia while avoiding the risk of increasing respiratory acidosis, we studied 17 male patients with advanced chronic obstructive pulmonary disease (COPD) and severe hypercapnic respiratory failure. During 6 h and on one day only, all patients were given intermittent negative pressure ventilation (INPV) together with oxygenation starting at a concentration of 24 percent and increasing to 30 percent. Using this procedure, it was possible to raise arterial PaO2 to safe levels (from 47.2 +/- 3 mm Hg to 61.5 +/- 6 mm Hg, p less than 0.001) without increasing hypercapnia, and a significant drop in PaCO2 levels (from 74.4 +/- 9 mm Hg to 65.6 +/- 12 mm Hg, p less than 0.005) was even observed. One hour after INPV ended, the mean values of PaO2, PaCO2, oxygen saturation, and pH were also significantly better than prestudy values. We conclude that INPV and oxygen therapy with increasing oxygen flow could constitute an alternative option to intubation and mechanical ventilation in cases of severe hypercapnic respiratory failure due to advanced COPD.
Sustained ventricular tachycardia associated with sarcoidosis: assessment of the underlying cardiac anatomy and the prospective utility of programmed ventricular stimulation, drug therapy and an implantable antitachycardia device. The presentation, cardiac anatomy and utility of programmed ventricular stimulation in seven patients with sustained ventricular tachycardia associated with sarcoidosis are described. The mean patient age was 38 +/- 8 years. Pulmonary involvement was apparent in three patients and no systemic manifestations of sarcoidosis were present in one patient. All patients had electrocardiographic abnormalities at rest and six had a left ventricular ejection fraction less than 45%. All seven patients had left ventricular wall motion abnormalities and five had mitral valve dysfunction. Sustained ventricular tachycardia was easily induced in all patients. Spontaneous sustained ventricular tachycardia was not prevented with corticosteroid administration. Despite antiarrhythmic drug therapy, two patients had sudden cardiac death and an additional four had recurrence of ventricular tachycardia. Four patients had an automatic cardioverter-defibrillator implanted and received drug therapy; all four received appropriate shocks. This report represents the largest descriptive series of consecutive patients with sustained ventricular tachycardia associated with sarcoidosis. Antiarrhythmic drug therapy of ventricular tachycardia in patients with sarcoidosis, even when guided with programmed ventricular stimulation, is associated with a high rate of arrhythmia recurrence or sudden death, or both. Thus, implantation of an automatic antitachycardia device (cardioverter-defibrillator) should be considered as primary therapy in such patients. Furthermore, sarcoidosis should be excluded, with Kveim skin testing if necessary, in any patient with sustained ventricular tachycardia of unknown origin.
Detection of DNA sequence polymorphisms by enzymatic amplification and direct genomic sequencing. The discovery of RFLPs and their utilization as genetic markers has revolutionized research in human molecular genetics. However, only a fraction of the DNA sequence polymorphisms in the human genome affect the length of a restriction fragment and hence result in an RFLP. Polymorphisms that are not detected as RFLPs are typically passed over in the screening process though they represent a potentially important source of informative genetic markers. We have used a rapid method for the detection of naturally occurring DNA sequence variations that is based on enzymatic amplification and direct sequencing of genomic DNA. This approach can detect essentially all useful sequence variations within the region screened. We demonstrate the feasibility of the technique by applying it to the human retinoblastoma susceptibility locus. We screened 3,712 bp of genomic DNA from each of nine individuals and found four DNA sequence polymorphisms. At least one of these DNA sequence polymorphisms was informative in each of three families with hereditary retinoblastoma that were not informative with any of the known RFLPs at this locus. We believe that direct sequencing is a reasonable alternative to other methods of screening for DNA sequence polymorphisms and that it represents a step forward for obtaining informative markers at well-characterized loci that have been minimally informative in the past.
Incidence and prevalence of amyotrophic lateral sclerosis in Harris County, Texas, 1985-1988. The incidence of amyotrophic lateral sclerosis was determined in Harris County, Texas, for the period 1985 through 1988. Amyotrophic lateral sclerosis cases were ascertained from four sources: area neurologists, hospitals, death certificates, and the Muscular Dystrophy Association. The age-adjusted incidences of 1.27 per 100,000 person-years in males and 1.03 per 100,000 person-years in females were lower than recent rates in the northern US, Canadian, and northern European studies but higher than rates in southern European studies. Comparisons with other recent incidence studies show less uniformity in occurrence of amyotrophic lateral sclerosis, in both the overall rates and in the age- and sex-specific patterns, than was suggested by mortality studies. The incidence of amyotrophic lateral sclerosis among blacks and whites was similar. Hispanic males had incidences similar to white males, although a deficit of female Hispanic cases was found in Harris County. The prevalence of amyotrophic lateral sclerosis peaked in the 65- to 74-year age group at 33 per 100,000 population among males and 19 per 100,000 population for females.
Extensive hepatic granulomas associated with peripheral T-cell lymphoma. A case of T-cell lymphoma presenting with marked hepatosplenomegaly and extensive hepatic granulomas is described. A 55-yr-old female experienced long-term liver damage showing histological triaditis with atypical lymphoid cell infiltration and erythrophagocytosis. The patient developed marked hepatosplenomegaly and eventually died of respiratory failure. Neither systemic lymphadenopathy nor hematological disorder was noted until her death. Autopsy revealed small atypical lymphoid cells positive for T-cell marker, as well as extensive infiltration of generalized organs, including the liver, spleen, and lungs. As a result of diffuse proliferation of atypical lymphoid cell admixed with variable reactive cells, mainly at the T-zone, the lymph nodes underwent effacement of normal architecture; however, the peripheral sinuses and the fibrous capsule remained relatively well preserved. These histological features were consistent with a diagnosis of peripheral T-cell lymphoma (PTL). It is interesting to note that there were numerous epithelioid granulomas admixed with a small number of atypical lymphoid cells within the hepatic parenchyma. The atypical lymphoid cells may be responsible for the granulomatous reaction in the liver. To our knowledge, there have been no other reported cases of PTL that presented with numerous epithelioid granulomas confined to the liver.
Perivalvular extension of infection in patients with infectious endocarditis. Perivalvular extension of infection is a not-infrequent and potentially fatal complication of bacterial endocarditis. Because the efficacy of various modalities in the diagnosis of such complications is not well established, a selective review of the published literature on this issue is worthwhile. The electrocardiogram is the easiest study to obtain. It is quite specific in identifying perivalvular extension of infection when conduction system disease is demonstrated but has a low degree of sensitivity overall. Transthoracic two-dimensional echocardiography, transesophageal echocardiography, and color-flow Doppler echocardiography are the most practical and useful techniques for diagnosis of perivalvular extension of infection. Magnetic resonance imaging also appears to be an effective tool in this setting; however, because of a paucity of clinical data, its precise utility has not yet been determined. Nuclear medicine studies and computed tomography play a minimal role. Cardiac catheterization is as useful as the echocardiographic techniques but is invasive, not as readily available, and significantly riskier in terms of complications. An approach to the diagnosis of perivalvular extension of infection is proposed on the basis of the literature review.
Microvascular angina. Cardiovascular investigations regarding pathophysiology and management. A significant minority of patients with chest pain who undergo cardiac catheterization are found to have angiographically normal coronary arteries. Over the past 25 years, several studies have shown that a subset have demonstrable abnormalities in coronary flow and cardiac function; however, only a minority of these patients have convincing evidence for myocardial ischemia during stress, and alternative mechanisms have been explored to explain the frequent and debilitating symptoms of pain experienced by the majority of these patients undergoing study. Abnormal visceral nociception appears to be a fundamental abnormality in this population, whether or not demonstrable abnormalities in coronary flow or cardiac function can be demonstrated.
Bazex syndrome (acrokeratosis paraneoplastica). An analytic review. Bazex syndrome (acrokeratosis paraneoplastica) is characterized by a psoriasiform eruption that favors acral sites and has been associated with an underlying malignancy in all reported cases. Of the 93 patients in this series, 89 were male with a mean age of 60 +/- 8.5 years. Squamous cell carcinomas of the head and neck and squamous cell tumors of unknown primary with cervical lymph node metastases were the most commonly associated neoplasms, suggesting that the factor(s) responsible for the development of the syndrome are relatively specific for tumors of the upper aerodigestive tract. The cutaneous lesions were erythematous to violaceous in color and had associated scale; the most frequently observed sites of involvement were the ears, nose, hands, and feet, including the nails. In 63% of the cases, the cutaneous lesions preceded the initial symptoms or diagnosis of the tumor by an average of 11 months (range, 1-72) and, in general, the eruption was resistant to a variety of topical treatments. Occasionally, a reappearance of the papulosquamous lesions signaled the recurrence of the tumor (6 cases) or the appearance of skin lesions coincided with the development of metastatic disease (3 cases). In 91% (64/70) of the patients, the skin eruption either improved significantly following treatment of the underlying malignancy or did not improve in the setting of persistent tumor. However, even when all of the skin lesions cleared, the nail dystrophy often persisted. Fifteen of the patients developed vesicles, bullae, and crusts in addition to papulosquamous lesions. Possible explanations include the formation of an epidermal-dermal split via a bullous lichen planus-like mechanism, or the coexistence of two diseases; i.e., acrokeratosis paraneoplastica plus either porphyria cutanea tarda, bullous pemphigoid, or epidermolysis bullosa acquisita. One possible explanation for the development of the characteristic cutaneous eruption is an immune reaction, humoral or cellular, directed against a common antigen present on the tumor and the normal skin. Alternatively, tumor production of a keratinocyte growth factor such as TGF-alpha may be involved in the induction of the psoriasiform skin lesions.
Attenuation of IL-2-induced multisystem organ edema by phalloidin and antamanide. Interleukin 2 (IL-2) is a potent cytokine with diverse effects, including the ability to stimulate lymphocyte differentiation into cells capable of lysing tumor. Its therapeutic efficacy is limited because of side effects such as breakdown of the microvascular barrier and edema. Control of the microvascular barrier is in part regulated by endothelial cell cytoskeletal contractile proteins. This study tests whether the cyclopeptides that maintain actin filament organization and distribution and reduce macromolecular flux across the endothelial cell junction in vitro would similarly maintain barrier tightness and prevent early edema produced by IL-2 in vivo. Anesthetized rats were treated at 30-min periods with intravenous saline (0.5 ml, n = 41), phalloidin (20 micrograms in 0.5 ml, n = 21), or antamanide, (20 micrograms in 0.5 ml, n = 21), starting 30 min before the 1-h infusion of 10(6) U of recombinant human IL-2 or saline. Six hours after the start of IL-2, there was edema in the saline/IL-2 group, as measured by increased wet-to-dry ratios (W/D) in the lungs, heart, and kidney. With saline/IL-2, bronchoalveolar lavage (BAL) fluid contained an elevated protein concentration and higher plasma thromboxane levels compared with controls. The number of neutrophils sequestered in the lungs was more than twice that of saline controls. Phalloidin significantly attenuated edema in lung and reduced BAL protein leak. Antamanide treatment was as effective in limiting lung and heart edema, but, in contrast to phalloidin, antamanide prevented kidney edema and did not lead to an alteration in the liver W/D. Antamanide also prevented BAL fluid protein leak.
Telangiectatic osteosarcoma. Telangiectatic osteosarcoma is a rare variant of osteosarcoma. In the original report from the authors' institution, a poor prognosis was noted. The authors have updated their experience with this entity. The prognosis for patients with telangiectatic osteosarcoma has improved remarkably. The prognosis in the present series seems to be the same as that for conventional osteosarcoma. Adjuvant chemotherapy seems to help in salvaging patients with metastatic disease. However, in this small series, survival of patients without metastasis is apparently not influenced by whether they received chemotherapy.
Agonist-sensitive calcium stores in arteries from steroid hypertensive rats. The present study characterizes cellular calcium stores that are sensitive to norepinephrine and caffeine in arteries from deoxycorticosterone acetate hypertensive rats. Mesenteric arteries from normotensive and hypertensive rats were excised and cut into helical strips for isometric force recording. In calcium-free solution, phasic contractile responses to norepinephrine (5.9 x 10(-9) to 5.9 x 10(-6) M), but not caffeine (0.3-30 mM), were greater in hypertensive arteries. D-600, a calcium channel blocker, or removal of the endothelium did not alter phasic contractions to norepinephrine or caffeine. In contrast, contractions to both norepinephrine and caffeine were inhibited by ryanodine, a drug that depletes calcium from intracellular stores. An inhibitor of phospholipase C (2-nitro-4-carboxyphenyl N,N-diphenylcarbamate) attenuated contractions to norepinephrine but not those to caffeine. The augmented response to norepinephrine in hypertensive rats did not occur early after implantation of the mineralocorticoid, suggesting that this vascular change may not play a role in the development of high blood pressure in this experimental model. The augmented response to norepinephrine was reduced in mineralocorticoid-treated rats maintained on a low sodium diet, and these rats had blood pressures in the normotensive range. Because contractile responses to caffeine were not enhanced in arteries from hypertensive rats, we conclude that the cellular store for calcium is not enlarged compared with that in normotensive arteries. In contrast, the mobilization of calcium from cellular stores by norepinephrine is augmented in mineralocorticoid hypertension. This augmented response may be linked to altered phospholipase C activity and thus to an augmented action of inositol trisphosphate that releases calcium from intracellular sites.
Stage I and II subdiaphragmatic Hodgkin's disease. From January 1971 to December 1986, 521 patients with Hodgkin's disease were evaluated and treated at the Yale University School of Medicine or one of its close affiliates. A total of 258 patients had pathologic stage (PS) I or II disease, with 239 patients having Hodgkin's disease above the diaphragm (ADHD) and 19 patients having Hodgkin's disease below the diaphragm (BDHD). A comparison of patients with BDHD versus patients with ADHD showed that patients with BDHD were older (mean age, 42 versus 28 years of age, P = 0.005), were initially seen less often with nodular sclerosis subtype (32% versus 77%, P = 0.00001), and had a higher male: female ratio (2.8 versus 1.2, P = 0.12). Ten patients with BDHD (53%) had positive findings at staging laparotomy (0 of 4 clinical stage [CS] IA patients and 10 of 15 (67%) CS II patients). Radiation therapy alone was the initial treatment of choice for 74% of patients with BDHD versus 94% of the patients with ADHD. There was no statistical difference in the overall survival or relapse-free survival rates for patients with BDHD versus ADHD (10-year survival rates, BDHD = 73% and ADHD = 81%). However, patients with BDHD who initially had intra-abdominal disease had a statistically significant increase in death rate (60%) due to Hodgkin's disease compared with patients with BDHD who initially had only peripheral nodal disease (0%). Treatment recommendations for patients with BDHD should be tailored to the specific clinical presentation of each patient. For most PS IA/IIA patients initially seen with peripheral nodal disease, radiation therapy alone is a successful treatment program. However, combined modality therapy should be the treatment of choice for patients with BDHD initially seen with intra-abdominal disease.
Echographic diagnosis of anterior hyaloidal fibrovascular proliferation. High-resolution contact B-scan echographic imaging of the ciliary body and peripheral retina was performed on five eyes with anterior hyaloidal fibrovascular proliferation and media opacity by means of a wide (58 degrees) scanning arc. This technique determined the circumferential and anteroposterior extent of peripheral traction retinal detachment associated with anterior hyaloidal fibrovascular proliferation, which correlated highly with findings at subsequent vitrectomy. Final visual acuity of 20/400 or better was achieved in the two eyes (50%) with more limited peripheral traction detachment. In the presence of media opacity, anterior echographic imaging may allow early detection of traction retinal detachment associated with anterior hyaloidal fibrovascular proliferation and may be useful in characterizing the severity of this condition.
Pulse oximetry compared with Doppler ultrasound for assessment of collateral blood flow to the hand. Ischaemic injury to the hand after arterial cannulation is a rare but well documented complication and routine testing of the adequacy of collateral circulation is widely advocated. The widespread availability of the pulse oximeter in the operating theatre. its applicability in circumstances where the patient is unable to cooperate, and its dependence on pulsatile blood flow suggest that this device could potentially be usefully applied to the assessment of collateral blood flow. The reliability of the pulse oximeter to detect the presence or absence of collateral circulation was prospectively compared to Doppler ultrasound in 109 hands from 64 adult patients. Nine hands demonstrated inadequate ulnar collateral flow, one hand demonstrated inadequate radial collateral flow and a persistent median artery was found in one hand. In all patients the results of pulse oximeter testing (probe placed on the thumb correlated precisely with the results obtained with the Doppler device (probe located over the lateral aspect of the superficial palmar arch). These results demonstrate pulse oximetry to be a reliable method of assessing collateral blood flow to the hand before arterial cannulation.
Ionized calcium in blood: studies on patients with pulmonary disease. A new automatic ionized calcium analyser ICA 2 (Radiometer, Copenhagen, Denmark) was used for studies of ionized calcium (cCa2+) in the arterial blood of patients with a compensated respiratory acidosis due to chronic lung disease. The data for 16 patients showed an unexpectedly high level of variation in cCa2+ (range, 1.01-1.25 mmol l-1) despite the fact that there was only a small degree of variability in pH (range, 7.38-7.51). cCa2+ was not correlated with pH as has been observed in acute respiratory disturbances. A highly significant negative correlation was found between cCa2+ and base excess (BE) (r = -0.81, P less than 0.0001), and between cCa2+ and carbon dioxide tension (PCO2) (r = 0.71, P less than 0.002). These correlations differed from those reported previously in acute respiratory disturbances. CCa2+ showed a significant positive correlation with oxygen tension (PO2) (r = 0.71, P less than 0.002). It is concluded that cCa2+ in arterial blood from patients with chronic lung disease is correlated with acid-base and gas quantities in an entirely different manner to that observed in acute acid-base disturbances in normal adults.
Macrophages, microglial cells, and HLA-DR antigens in fetal and infant brain. Immunohistochemical reactions for macrophages, microglia, and HLA-DR antigens were tested on frozen sections of necropsy brain tissue from 20 fetuses and infants ranging in age from 18 weeks' gestation to 8 months post term. No primary central nervous system disease was present but there were four cases of sudden infant death syndrome (SIDS). Macrophages were detected in all the samples studied and were located in the germinal matrix zone, in perivascular spaces throughout the brain, and in the leptomeninges and subependymal layer. Well differentiated microglia were present in all cases examined after 35 weeks' gestation and less well ramified forms were seen at earlier stages of gestation. HLA-DR antigens were detected on a small number of macrophages, chiefly in a perivascular location, in all but three cases. The fewest reactive cells and the weakest reactions occurred in the youngest fetuses. One case of SIDS showed increased foci of microglia in perivascular white matter: this case and one other case of SIDS were the only cases with well ramified microglia that expressed HLA-DR antigens. These findings may be relevant to an understanding of local immune responses in fetal brain infections, including human immunodeficiency virus infection.
Immediate mandibular replacement using reconstruction plates. Mandibular reconstruction at the time of tumor resection remains a surgical dilemma. Primary reconstruction allows for immediate reconstitution of mandibular form and function. Various methods have been attempted, but none enjoys uniform success. With advances in the field of microvascular surgery have come numerous options in replacing these defects. These procedures, however, require special surgical teams and are associated with an increase in operative time as well as morbidity at the donor site. An alternative method involves the use of mandibular reconstruction plates to bridge the defect between segments. This review focuses on 19 patients whose jaws were reconstructed in this fashion. Although not free of complications, mandibular plate reconstruction offers the advantages of (1) lack of donor site morbidity, (2) expediency, (3) excellent mandibular contour, and (4) the ability to reconstruct the condyle when necessary. The technique, results, and complications associated with this procedure are discussed.