123rc/medical_text huggingface dataset:
Mechanisms of gas-exchange impairment in idiopathic pulmonary fibrosis. To investigate the mechanisms of pulmonary gas-exchange impairment in idiopathic pulmonary fibrosis (IPF) and to evaluate their potential relationship to the CO diffusing capacity (DLCO), we studied 15 patients with IPF (mean DLCO, 52% of predicted) at rest (breathing room air and pure O2) and during exercise. We measured pulmonary hemodynamics and respiratory gas-exchange variables, and we separated the ventilation-perfusion (VAQ) mismatching and O2 diffusion limitation components of arterial hypoxemia using the multiple inert gas elimination technique. At rest VA/Q mismatching was moderate (2 to 4% of cardiac output perfusing poorly or unventilated lung units), and 19% of AaPO2 was due to O2 diffusion limitation. During exercise VA/Q mismatch did not worsen but the diffusion component of arterial hypoxemia increased markedly (40% AaPO2, p less than 0.005). We observed that those patients with higher pulmonary vascular tone (more release of hypoxic pulmonary vasoconstriction) showed less pulmonary hypertension during exercise (p less than 0.05), less VA/Q mismatching [at rest (p less than 0.005) and during exercise (p less than 0.0025)], and higher arterial PO2 during exercise (p = 0.01). We also found that DLCO corrected for alveolar volume (KCO) correlated with the mechanisms of hypoxemia during exercise [VA/Q mismatching (p less than 0.025) and O2 diffusion limitation (p less than 0.05)] and with the increase in pulmonary vascular resistance elicited by exercise (p less than 0.005). In conclusion, we showed that the abnormalities of the pulmonary vasculature are key to modulate gas exchange in IPF, especially during exercise.
The endophthalmitis vitrectomy study [editorial] Endophthalmitis after cataract surgery can be a disastrous complication that may result in functional loss of an eye. All patients with this problem should receive direct injection of intravitreal antibiotics. The roles of initial vitrectomy and of intravenous antibiotics in treating this condition are controversial. Through a prospective, randomized, clinical trial, these issues can be assessed. We encourage ophthalmologists close to each clinical center to refer patients with postoperative endophthalmitis to these clinics. Questions concerning the Endophthalmitis Vitrectomy Study can be addressed to the principal investigator at the nearest clinical trial center.
Gallstone clearance: a randomized study of extracorporeal shock wave lithotripsy and chemical dissolution Following extracorporeal shock wave lithotripsy it is not known whether gallstone fragments are cleared from the gallbladder without the use of oral dissolution therapy. To assess the efficacy of lithotripsy and dissolution therapy, alone or in combination, 35 patients were randomized to one of three treatment groups: lithotripsy alone, dissolution therapy alone or combined lithotripsy and dissolution therapy. All patients had symptomatic gallstones, functioning gallbladders and comparable stone profiles. Lithotripsy was administered using a piezoelectric lithotripter. Dissolution therapy consisted of combined bile acid and terpene. Clearance was assessed at 6 months using ultrasound and oral cholecystography. Patients with less than 50 per cent stone clearance at the end of 6 months were considered failures. The number of patients with total or partial clearance in the combined group (7/10) was significantly greater than those in the lithotripsy alone group (0/10, P less than 0.002). Gallstone clearance following lithotripsy appears to be dependent upon dissolution therapy.
Magnetic resonance imaging white matter lesions and cognitive impairment in hypertensive individuals. To search for a morphologic basis of cognitive impairment possibly associated with essential hypertension, we studied 35 otherwise asymptomatic hypertensive individuals (mean age, 38.7 years; range, 22 to 49 years) and 20 normotensive control subjects (mean age, 37.9 years; range, 26 to 49 years) using neuropsychologic tests and magnetic resonance imaging. Irrespective of drug treatment, hypertensive individuals performed significantly worse than did control subjects when assessed for verbal memory and total learning and memory capacity, while there were no differences in test results of visual memory, attention, vigilance, and reaction time. The hypertensive individuals also described themselves as less active but ranked similar on five other mood subscales. Punctate high-signal intensities of the white matter were found almost twice as often in the hypertensive group (38%) as in the control group (20%). There was no difference in test performance between hypertensive individuals with and those without white matter lesions, however. Our results confirm the presence of subtle neuropsychologic deficits and indicate a higher frequency of white matter signal abnormalities in essential hypertension, as shown on magnetic resonance imaging, but do not indicate a correlation of these findings with each other.
Chest infection following head and neck surgery: a pilot study. This paper reports the results of a pilot study which examined factors associated with chest infection following head and neck surgery. The overall rate of chest infection was 11%, but was 20% in those patients having a tracheotomy. No infection developed in patients with an intact airway. Other factors which emerged as possibly important were the duration of surgery and heavy regular alcohol intake. We recommend that prophylactic antibiotics be continued for at least 48 h in patients requiring a tracheotomy as part of their head and neck surgery. This is against the trend of shorter antibiotic regimens recommended for prevention of wound infections.
Incarceration of colonoscope in an inguinal hernia. "Pulley" technique of removal. Because of its relative safety, colonoscopy has become an accepted diagnostic and therapeutic procedure in the evaluation of patients with colorectal disorders. Many unusual complications of colonoscopy have been described, but only anecdotal reports of hernial incarceration have been published. We present a case of a right-sided hernial incarceration of the colonoscope that would not permit reduction of the hernia nor removal of the instrument by conventional means. The mechanism of incarceration, which dictates the size of hernia at risk for incarceration, is explained. The "pulley" technique, which was used to remove the instrument without surgical intervention, is described.
Evaluation of the fine needle aspiration biopsy in the preoperative selection of cold thyroid nodules. From 1980 to 1988 the authors examined by fine needle aspiration biopsy (FNAB) 4609 patients with solitary thyroid nodules or multinodular goiters. A total of 5605 "cold" thyroid nodules were evaluated and classified, on the basis of the cytologic findings, as malignant, follicular lesions (probably malignant and probably benign) and benign. Then the authors compared the preoperative cytologic findings with the postoperative histologic results in 827 nodules from patients who underwent surgery. In the 805 thyroid nodules in which an adequate cytologic specimen was obtained, false-negative results were 2.3% and false-positive findings were 1.1% By comparing cytologic and histologic diagnoses, preoperative FNAB resulted in the ability to accurately assess the risk of cancer in a thyroid nodule; since 250 nodules were identified as malignant, the risk of a "cold" thyroid nodule being cancer was 4.46% in this series.
Dystonia in Parkinson's disease, multiple system atrophy, and progressive supranuclear palsy. Adult-onset dystonia-parkinsonism is a syndrome in search of a pathology. We therefore reviewed the literature on dystonic manifestations in autopsy-proven cases of multiple system atrophy (MSA), progressive supranuclear palsy (PSP), and idiopathic Parkinson's disease (PD). Only 6 of 140 autopsy reports of MSA remarked on the presence of dystonia in life, but personal observations suggest prominent antecollis may develop at some stage in up to 1/2 of sufferers. Similarly, very few (15/118) clinicopathologic observations on PSP included convincing dystonic manifestations, in contrast to some clinical reports where blepharospasm and early limb dystonia were prominent. Virtually any form of focal and segmental dystonia may sometimes occur with clinically diagnosed PD, with occasional descriptions of hemidystonia-hemiparkinsonism. However, there is pathologic confirmation of this diagnosis in only 1 case. With many patients thought clinically to have PD proving pathologically to have another cause for their parkinsonism, the true frequency and the range of dystonic manifestations acceptable in PD remain unknown.
Insulin-like growth factors are mitogenic for human keratinocytes and a squamous cell carcinoma. Normal adult human keratinocytes in monolayer culture and SCL-1, a skin-derived squamous-cell carcinoma cell line, were investigated for the expression of receptors for insulin-like growth factors (IGF) and insulin. As demonstrated by affinity crosslinking, radiolabeled IGF-1, IGF-2, and insulin bound specifically to both cell types. Each cell expressed type I IGF receptors, with affinity for IGF-1 greater than IGF-2 much greater than insulin. Insulin receptors, with highest affinity for insulin, were also present on both cells. However, keratinocytes and SCL-1 cells differed in 125I-IGF-2 binding. 125I-IGF-2-bound to both type I and type II IGF receptors in normal keratinocytes, but bound predominantly to membrane-associated IGF binding proteins in SCL-1. IGF-1 was slightly more potent than IGF-2 in stimulating growth of both keratinocytes and SCL-1 cells. In keratinocytes, concentrations of IGF-1 ranging from 5-100 ng/ml, and of IGF-2 from 50-100 ng/ml, resulted in a significant increase in cell number. At the maximum dose of 100 ng/ml, either IGF-1 or IGF-2 caused a 2.3-times increase in cell number. In SCL-1 cells, IGF-1 was more potent than IGF-2 or insulin at lower concentrations, but either IGF-1 or IGF-2 at the maximal concentration of 333 ng/ml stimulated a 4.7-times increase in thymidine incorporation. The stimulatory effect of insulin in SCL-1 was 10-50 times less potent than that of the IGF. The effect of either IGF on SCL-1 was completely inhibited by the type I IGF receptor antibody alpha IR-3, suggesting that both IGFs are mitogenic through the type I IGF receptor. Insulin action was partially blocked by alpha IR-3, suggesting that insulin can act through both the insulin and type I IGF receptors. It thus appears that IGF-1 and IGF-2 are mitogens for normal and transformed human keratinocytes and that their actions are primarily mediated through the type I IGF receptor, whereas insulin is a mitogen through both the IGF-1 receptor and the insulin receptor.
Pain experiences of intensive care unit patients. The purpose of this study was to describe various dimensions of the pain experiences of intensive care unit (ICU) patients. A purposive, primarily surgical sample of 24 ICU patients from two hospitals was interviewed after transfer from ICU. All but one patient remembered their ICU stay. Although this and six other patients had no recall of pain, 63% of the sample rated their pain as being moderate to severe in intensity. In a subgroup of nine patients having cardiac surgery, mean morphine sulfate administration during the first three postoperative days was 14 mg/day. This group of patients reported a lack of total pain relief from analgesics. Patients also described various sources of their pain, difficulties they had in communicating their pain, and nonpharmacologic methods that helped relieve their pain. Results of this study clearly indicate that not only pain but its communication and treatment were significant problems for a substantial portion of this ICU sample. Further descriptive and experimental research of pain characteristics and treatment practices for ICU patients is urgently needed. Improvements in nursing practice that result from such research may make a substantial difference in the comfort and well-being of critically ill patients.
Cholinergic deficiency and frontal dysfunction in Parkinson's disease. To investigate the influence of central cholinergic deficit on cognitive function in Parkinson's disease (PD), we compared the neuropsychological performance of a group of 20 patients who were treated with anticholinergic drugs (mean daily dose, 10.2 mg) with that of a group of 20 patients who received no anticholinergics. The two groups were matched for all the variables of parkinsonism and levodopa therapy. At the dose used, there was no significant difference between the two groups of patients for intellectual, visuospatial, instrumental, and memory function. In contrast, in the group that received anticholinergics severe impairment was observed on tests believed to assess frontal lobe function. These results suggest that the lesion of the ascending cholinergic neurons, which has been demonstrated post mortem in PD, may play a role in the subcorticofrontal behavioral impairment of this disease.
Hyperglycemia presenting with occipital seizures. Seizures are common in hyperglycemia and are often the first manifestation, particularly in nonketotic hyperglycemia (NKH). Published reports emphasize partial motor seizures almost exclusively. In a 3-year period, we observed three patients in whom occipital seizures, documented by ictal EEG recording, were the initial symptom of hyperglycemia. One patient was mildly ketotic at first. Seizures were visual in two patients and visual and adversive in the third. Seizures regressed with correction of abnormal glucose levels and did not recur during follow-up of less than or equal to 1 year despite discontinuation of antiepileptic drugs (AEDs) in two. Computed tomography (CT) scans did not show correlative abnormalities. Although published reports suggest that frontal lobe structures are particularly susceptible to the epileptogenic effects of NKH, our experience indicates that in NKH epileptic foci may originate in other cortical areas, such as occipital.
The effect of spine fusion on respiratory function in Duchenne muscular dystrophy. Serial measures of respiratory function were made in 17 patients with Duchenne muscular dystrophy who underwent segmental spine fusion and in 22 patients who did not. No significant differences were observed between the 2 groups (operated vs. nonoperated) in terms of declining respiratory function. Nonetheless, all operated patients reported either improved sitting comfort, appearance, or both. Thus, our results suggest that there are distinct benefits from segmental spine fusion; however, there was no salutary effect upon respiratory function either in the short term or after up to 5 years follow-up.
Common headaches: type, duration, frequency and implications. Questionnaires completed by 327 preclinical medical and dental students showed that 97.9% had experienced headaches, most frequently attributed to insufficient sleep (38.8%), mental stress (38.8%), alcohol (38.5%), excess heat (36.7%), reading (31.5%), excess noise (29.9%) or light (27.7%), and sleeping too long (23.5%). The frequency and duration of these and other headaches are listed. 8% of the headache group had consulted a doctor. Only 2.1% of all students had never experienced a headache. Two hypotheses are examined: (1) can headaches be normal?--delineated by their disappearing soon after the noxious stimulus has ceased; (2) can pain in the head, as elsewhere in the body, act as a warning and therefore have protective, even survival value?.
Elapsed time from symptom onset and acute myocardial infarction in a community hospital. STUDY OBJECTIVE: Previous reports have emphasized that thrombolytic therapy for acute myocardial infarction should be initiated within three or four hours of symptom onset to obtain the best clinical outcomes. However, our clinical impression was that late arrivers, who often do not receive thrombolytic therapy, have a good short-term prognosis. Therefore, we investigated the relationships among the elapsed time from symptom onset, thrombolytic therapy, and short-term prognosis in acute myocardial infarction patients. The research hypothesis was that late arrivers have a better in-hospital prognosis because they have less severe disease that may involve spontaneous thrombolysis. DESIGN: Observational cohort study based on reviewing medical records and emergency department service logs. SETTING: 500-bed teaching hospital with medical school affiliation in northeastern Ohio. TYPE OF PARTICIPANTS: Four hundred consecutive patients with acute infarction confirmed by chest pain and positive ECGs or elevated cardiac enzymes. MEASUREMENTS AND MAIN RESULTS: Patients arriving early (elapsed time less than or equal to 1.5 hours) were more likely to be in Killip class III or IV (P = .04) or to have hypotension (P = .0004); and they experienced twofold increased odds of ventricular tachycardia (P = .007), cardiac arrest (P = .03), or death (P = .01). Patients arriving late (elapsed time greater than 3.5 hours) were more likely to have a history of angina (P = .002) and had a better short-term prognosis. CONCLUSIONS: Time of ED arrival after onset of acute myocardial infarction symptoms distinguishes two patient groups that differ in their risk of in-hospital complications. Late arrivers have better short-term prognoses and less (acutely) severe disease, and may have less need for thrombolytic therapy because of possible spontaneous thrombolysis. Patients with prior angina may need education on seeking care if their symptoms change.
Pulmonary tolerance of prophylactic aerosolized pentamidine in human immunodeficiency virus-infected patients. The effects of primary and secondary long-term prophylaxis of Pneumocystis carinii pneumonia with aerosolized pentamidine on pulmonary function in HIV+ patients were evaluated. Eighty-one patients, none of whom were drug addicts or had pulmonary Kaposi's sarcoma, were studied. Fifty patients were receiving AP as secondary prophylaxis, 36 monthly and 14 twice-monthly; eight patients with a history of PCP served as control subjects. Twenty-three patients were receiving AP as primary prophylaxis, 12 monthly and 11 twice-monthly. Pulmonary function tests, including spirometry, lung transfer capacity for carbon monoxide (Tlco) and alveolar-arterial oxygen gradient (P[A-a]O2) were evaluated at M1, ie, one month after the diagnosis of PCP, or at the beginning of the AP prophylaxis, and then at three-month intervals (M4 to M13). No differences were observed in the results of spirometry or P(A-a)O2. Among the patients receiving secondary prophylaxis, a significant increase (paired Student's t-test) in Tlco occurred at M7 compared to M1 in the group receiving monthly administrations (p less than 0.01) and in the untreated control group (p less than 0.05); there was no significant difference in Tlco at M13 compared to M1 in the 12 patients who received monthly administrations for this period or at M7 in the 14 patients receiving AP twice-monthly. No significant difference in Tlco was observed at M7 in the primary prophylaxis groups. These results indicate that pulmonary tolerance of AP, as reflected by pulmonary function tests, is good.
The dynamics of antegrade cardioplegia with simultaneous coronary sinus occlusion. Effects on aortic root infusion pressure, coronary sinus pressure, and myocardial cooling. It has been suggested that antegrade cardioplegia with coronary sinus occlusion improves homogeneous myocardial cooling and reduces myocardial injury in the presence of coronary artery occlusion. Little data are available on the exact relationships among the basic elements or this intervention, including antegrade infusion rate, aortic root pressure, the degree of coronary sinus occlusion, coronary sinus pressure, and myocardial cooling. The purpose of this study was to determine these relationships and to provide some basic guidelines for better understanding of this intervention. Twenty-two sheep were placed on cardiopulmonary bypass, the distal left anterior descending artery was occluded, and the proximal coronary sinus was snared. Sixteen combinations of infusion rate (3, 5, 7, or 9 ml/kg/min) and coronary sinus occlusion (total, subtotal, or moderate occlusion or no occlusion) were adopted for each 2 minutes of antegrade cardioplegia, yielding 96 measurements. Myocardial temperatures in the occluded and nonoccluded regions, aortic root infusion pressure, and coronary sinus pressure were measured during each infusion of cardioplegic solution. Coronary sinus occlusion was then released, and the whole heart was reperfused for 30 minutes for another infusion of cardioplegic solution and measurements. Results showed good degrees of linearity between infusion rate and aortic root infusion pressure for all coronary sinus occlusion and noninfusion groups (p less than 0.01). A positive effect of coronary sinus occlusion on aortic root infusion pressure was observed. The graded increases in infusion rate with various degrees of coronary sinus occlusion were constantly associated with elevation of coronary sinus pressure (p less than 0.01). It was also noted that myocardial temperatures in the region of the occluded left anterior descending artery were significantly lower in coronary sinus occlusion groups than in nonocclusion groups (p less than 0.01 or 0.05). Myocardial temperature in the nonoccluded region decreased significantly with the stepwise increases in infusion rate (p less than 0.01), but not with the increases in coronary sinus occlusion (not significant). Based on this and previous studies, we recommend that the induced coronary sinus pressure be safely maintained in the range of 25 to 35 mm Hg and that further studies be focused on the infusion rate of 5 ml/kg/min with subtotal or total coronary sinus occlusion for the intervention of antegrade cardioplegia plus coronary sinus occlusion.
Brain abscess associated with congenital pulmonary arteriovenous fistula. A case of brain abscess associated with congenital pulmonary arteriovenous fistula was presented and 52 reported cases were reviewed. The brain abscess was successfully treated with repeated aspiration and drainage, and the pulmonary arteriovenous fistula, located in the right lower lobe, was resected. The arteriovenous fistula occurs as a common pulmonary manifestation of hereditary hemorrhagic telangiectasia; however, no symptoms suggesting these two were noted in this case. Brain abscesses can be an initial clinical manifestation in asymptomatic pulmonary arteriovenous fistula. This possible association should be borne in mind in cases of brain abscesses of unexplained etiology.
Middle cerebral artery flow velocity waveforms in fetal hypoxaemia. In 81 small-for-gestational age fetuses (SGA) colour flow imaging was used to identify the fetal middle cerebral artery for subsequent pulsed Doppler studies. Impedence to flow (pulsatility index; PI) was significantly lower, and mean blood velocity was significantly higher, than the respective reference ranges with gestation. Fetal blood sampling by cordocentesis was performed in all SGA fetuses and a significant quadratic relation was found between fetal hypoxaemia and the degree of reduction in the PI of FVWs from the fetal middle cerebral artery. Thus, maximum reduction in PI is reached when the fetal PO2 is 2-4 SD below the normal mean for gestation. When the oxygen deficit is greater there is a tendency for the PI to rise, and this presumably reflects the development of brain oedema.
Bilateral renal cell carcinoma with metastasis to thyroid. A case of bilateral synchronous renal cell carcinomas with metastases to the regional lymph nodes and later to the thyroid gland was treated with aggressive surgical extirpation and adjuvant gamma interferon. The patient continues to have an excellent performance status sixteen months after initial diagnosis despite a large tumor burden at presentation.