123rc/medical_text huggingface dataset:
A randomized double-blind crossover comparison of four rate-responsive pacing modes. The aim of this study was to compare, both subjectively and objectively, four modern rate-responsive pacing modes in a double-blind crossover design. Twenty-two patients, aged 18 to 81 years, had an activity-sensing dual chamber universal rate-responsive (DDDR) pacemaker implanted for treatment of high grade atrioventricular block and chronotropic incompetence. They were randomly programmed to VVIR (ventricular demand rate-responsive), DDIR (dual chamber demand rate-responsive), DDD (dual chamber universal) or DDDR (dual chamber universal rate-responsive) mode and assessed after 4 weeks of out-of-hospital activity. Five patients, all with VVIR pacing, requested early reprogramming. The DDDR mode was preferred by 59% of patients; the VVIR mode was the least acceptable mode in 73%. Perceived "general well-being," exercise capacity, functional status and symptoms were significantly worse in the VVIR than in dual rate-responsive modes. Exercise treadmill time was longer in DDDR mode (p less than 0.01), but similar in all other modes. During standardized daily activities, heart rate in VVIR and DDIR modes underresponded to mental stress. All rate-augmented modes overresponded to staircase descent, whereas the DDD mode significantly underresponded to staircase ascent. Echocardiography revealed no difference in chamber dimensions, left ventricular fractional shortening or pulmonary artery pressure in any mode. Cardiac output was greater at rest in the dual modes than in the VVIR mode (p = 0.006) but was similar at 120 beats/min. Beat to beat variability of cardiac output was greatest in VVIR mode (p less than 0.0001), with DDIR showing greater variability than DDD or DDDR modes (p less than 0.05). Mitral regurgitation estimated by Doppler color flow imaging was similar in all modes, but tricuspid regurgitation was significantly greater in VVIR than in dual modes (p less than 0.03). Subjects who preferred the DDDR mode and those who found the VVIR mode least acceptable had significantly greater increases in stroke volume when paced in the DDD mode than in the ventricular-inhibited (VVI) mode at rest (22%) when compared with subjects who preferred other modes (2%, p = 0.03). No other objective variable was predictive of subjective benefit from any rate-responsive pacing mode. Thus, dual sensor rate-responsive pacing (DDDR) is superior objectively and subjectively to single sensor (VVIR, DDIR and DDD) pacing and subjective benefit from dual chamber rate-augmented pacing is predictable echocardiographically.
Clinical outcome of seriously ill surgical patients with intra-abdominal infection depends on both physiologic (APACHE II score) and immunologic (DTH score) alterations. The delayed-type hypersensitivity (DTH) response and the APACHE II score in 118 patients with surgical infections were measured prospectively and related to outcome. Logistic regression analysis generated the equation: [formula: see text]. The risk assessment as calculated by this model was compared to that using the APACHE II system alone in a separate group of 354 patients. There was an improvement in the predictive capacity of the APACHE II + DTH equation compared to APACHE II alone, as shown by a better fit of expected and observed deaths, an improved Goodman-Kruskal G statistic, and a larger area under the receiver operating characteristic curve. It is concluded that the DTH response (a broad marker of immunocompetence) is an independent prognostic factor in surgical patients and can be used in combination with the APACHE II score (a measure of acute physiology) to estimate better the outcome of surgical patients.
Recurrence rate after discontinuation of long-term mebendazole therapy in alveolar echinococcosis (preliminary results). The recurrence rate was investigated in 19 patients with non-resectable alveolar echinococcosis after discontinuation of a long-term therapy with mebendazole (average treatment 4.3 years). A control group consisted of 14 patients who underwent radical surgery and finished a course of prophylactic postoperative mebendazole treatment of 2 years. In the controls, no recurrence was observed after a post-therapy period averaging 3.5 years. In contrast, recurrence occurred in 7/19 patients (37%) with non-resectable alveolar echinococcosis an average of 1.6 years after discontinuation of the long-term mebendazole therapy. The absence of clinically detectable recurrence in the remaining 12 patients seems to be due either to spontaneous inactivation of alveolar echinococcosis preceding chemotherapy or too short post-therapy surveillance. The patients with recurrence responded favorably to reintroduction of chemotherapy. The data indicate that mebendazole therapy is parasitostatic rather than parasiticidal.
Capillary hemangioma of the right main bronchus treated by sleeve resection in infancy. Respiratory distress developed in a 5-month-old female infant with roentgenographic evidence of hyperinflation of the right lung. Bronchoscopy revealed a vascular tumor extending from the medial wall of the right main bronchus leading to a check-valve mechanism. Radionuclide lung scans showed ventilation and perfusion of the right side reduced to 36 and 11% of the total lung ventilation and perfusion, respectively. At the age of 7 months a sleeve of the right main bronchus was resected and a reanastomosis performed. The operation specimen contained a capillary hemangioma measuring 1.2 X 0.6 cm. The postoperative course was uneventful. Perfusion of the right lung had markedly improved 6 months after the operation, and at the age of 2 yr and 9 months it was completely normal. Capillary hemangiomas must be considered a cause of bronchial obstruction in infancy, and surgery can be performed successfully.
Regulatory elements of the erythropoietin gene. Because the human hepatoma cell line Hep3B produces erythropoietin (Epo) in a regulated fashion, it can be used to investigate the cis-acting regulatory elements of the Epo gene. Comparison of primate and mouse sequences shows strong homology not only in the coding sequence but also within the 5' flanking region, the first intron, and the 3' flanking region. These portions of the Epo gene were inserted 5' and 3' to a reporter gene, human growth hormone (GH). 5A is a 1,192-base pair (bp) HindIII-Xbal fragment that extends from 378 bp 5' to the cap site through the first intron. To obviate the problem of false initiation of translation from the Epo ATG start codon, this site was changed to TAG by site-directed mutagenesis. 3A is a 255-bp Accl-BglII fragment that extends 67 bp upstream from the Epo termination codon and covers most of the 3' noncoding region of homology. The plasmid DNAs were transfected by electroporation into Hep3B cells with RSVCAT as an internal standard to correct for transfection efficiency. One aliquot of cells was exposed to 50 mumol/L CoCl2 or to 1% O2. At the end of the incubations, GH and Epo were measured in the cell media and the cell pellet was assayed for CAT. Production of GH was stimulated 1.7-fold by cobalt or hypoxia. Furthermore, addition of 3A to the GH gene, irrespective of orientation, stimulated GH production 2.6-fold with CoCl2 and 2.3-fold with hypoxia. Stable cell lines were produced by cotransfection of the above constructions, along with the selectable marker pSV-Neo. In two clones, exposure to hypoxia resulted in much more marked (16-fold) induction of GH. Stimulus of both GH and Epo production by hypoxia was partially abrogated by carbon monoxide. These results demonstrate the presence of promoter and enhancer elements within the human Epo gene that are appropriately responsive to hypoxia and cobalt.
Transduodenal sphincteroplasty with transampullary septectomy for stenosing papillitis. The papilla of Vater and its sphincter of Oddi, lying at the confluence of the bile and pancreatic ducts in man, have long been suspected as a source of upper abdominal pain. Enlarging the opening of the transpapillary segment of the bile and major pancreatic ducts by using a transduodenal sphincteroplasty with transampullary septectomy resulted in death in a patient with a peripapillary diverticulum and pancreas divisum. Eight-six patients followed for 1 to 10 years experienced a 75% success rate. Thirty-six patients had a marked stenosis of their duct of Wirsung, suggesting that their pain was primarily from the pancreas. The remainder had either a generalized narrowing (40 patients) or a normal (7 patients) papilla. Pain was not satisfactorily resolved in patients with an associated pancreas divisum, chronic pancreatitis, and recurrent episodes of acute pancreatitis with alcoholism.
Effect of a calcium-entry blocker, nicardipine, on intrarenal hemodynamics in essential hypertension. The effects of a calcium-entry blocker, nicardipine, on intrarenal hemodynamics were studied in essential hypertension. A 4-week study was performed in eight patients with essential hypertension who were given a regular sodium diet in the first and third weeks, and a sodium-restricted diet in the second and fourth weeks. Nicardipine, 60 mg/d, was administered in the third and fourth weeks. The urinary sodium excretion rate (UNaV) was plotted on the y-axis against the mean arterial pressure (MAP) on the x-axis before and after the administration of nicardipine. Assuming the difference between MAP and the x-intercept of this renal function curve represents the effective filtration pressure across the glomerular capillaries, the intrarenal hemodynamics such as afferent arteriolar resistance (RA) and efferent arteriolar resistances (RE), glomerular pressure (PG), and gross filtration coefficient (KFG) were calculated. Although the MAP on regular salt diet was lowered from 125 +/- 3 to 109 +/- 2 mm Hg by nicardipine, neither the renal blood flow rate (RBF) (670 +/- 40 mL/min) nor the glomerular filtration rate (GFR) (79 +/- 2 mL/min) was altered. The RA was estimated to be reduced from 9,300 +/- 900 to 7,400 +/- 700 dyne.s.cm-5 (P less than 0.01), while no changes were noted in RE (4,900 +/- 400 dyne.s.cm-5), PG (50 +/- 1 mm Hg), or KFG (0.180 +/- 0.041 [mL/s]/mm Hg). Essential hypertension has been characterized by a prominent increase in RA, resulting in maintenance of normal PG. This Ca-entry blocker worked to normalize intrarenal hemodynamics in essential hypertension by dilating afferent arterioles alone.
Myocyte cell loss and myocyte cellular hyperplasia in the hypertrophied aging rat heart. To determine the effects of age on the myocardium, the functional and structural characteristics of the heart were studied in rats at 4, 12, 20, and 29 months of age. Mean arterial pressure, left ventricular pressure and its first derivative (dP/dt), and heart rate were comparable in rat groups up to 20 months. During the interval from 20 to 29 months, elevated left ventricular end-diastolic pressure and decreased dP/dt indicated that a significant impairment of ventricular function occurred with senescence. In the period between 4 and 12 months, a reduction of nearly 19% in the total number of myocytes was measured in both ventricles. In the subsequent ages, similar decreases in myocyte cell number were found in the left ventricle, whereas in the right ventricle, the initial loss was fully reversed by 20 months. Moreover, from 20 to 29 months, a 59% increase in the aggregate number of myocytes occurred in the right ventricular myocardium. In the left ventricle, a 3% increment was also seen, but this small change was not statistically significant. These estimations of myocyte cellular hyperplasia, however, were complicated by the fact that cell loss continued to take place with age. The volume fraction of collagen in the tissue, in fact, progressively increased from 8% and 7% at 4 months to 16% and 22% at 29 months in the left and right ventricles, respectively. In conclusion, myocyte cellular hyperplasia tends to regenerate the ventricular mass being lost with age in the adult mammalian rat heart.
Laparoscopic cholecystectomy using intracorporeal lithotripsy. Over a 13-month period (November 1988 to December 1989), we performed our first 104 laparoscopic cholecystectomies using an intracorporeal ultrasonic lithotripsy technique. The procedure in three of these patients was converted to an open operation because of hemorrhage with unexpected findings of cirrhosis in two patients and dense subhepatic adhesions in a third. Endoscopic retrograde cholangiopancreatography was successfully used in three other patients in whom common bile duct stones were identified. We encountered only three postoperative complications out of all the laparoscopic cholecystectomies performed. One complication was a biliary fistula that closed spontaneously 1 week after surgery. The remaining complications were attributable to abscesses, one subhepatic and one pelvic, which were aspirated and drained laparoscopically. There were no deaths. Advantages of the laparoscopic approach included decreased perioperative pain, shortened hospitalization, absence of scar, and more rapid return to prehospitalization activities.
Simplified method for estimating true aortic valve mean gradient from simultaneous left ventricular and peripheral arterial pressure recordings. Estimation of the aortic valve gradient by simultaneous recording of left ventricular and peripheral arterial pressures is subject to error due to delay and modulation of the arterial pressure contour as it propagates from the ascending aorta. This error can be corrected by averaging the mean gradients derived from unaltered and temporally aligned simultaneous left ventricular-peripheral arterial pressure tracings. In 26 patients with aortic stenosis and simultaneous recordings of ascending aortic and femoral arterial pressure we compared this method with a simplified approach in which the peripheral arterial pressure is partially aligned by advancing it against the left ventricular pressure by 50% of the time delay of the simultaneously recorded upstrokes. Gradients measured this way predicted the true aortic valve gradients (left ventricular-ascending aortic) with a mean difference of +1.1 mm Hg (range = +10 to -5 mm Hg). We recommend use of this simplified method of correction because it predicts true aortic valve gradient equally well as the averaging technique (r = 0.977 vs. 0.979) and requires half the time and effort.
Distribution of three alpha-chain beta-hexosaminidase A mutations among Tay-Sachs carriers. DNA from 176 carriers of the Tay-Sachs gene was tested for the presence of the three mutations most commonly found among Ashkenazi Jews: the so-called insertion, splice junction, and adult mutations. Among 148 Ashkenazi Jews tested, 108 had the insertion mutation, 26 had the splice junction mutation, five had the adult mutation, and nine had none of the three. Among 28 non-Jewish carriers tested, most of whom were obligate carriers, four had the insertion mutation, one had the adult mutation, and the remaining 23 had none of the three.
Lymph nodes in incipient adult T-cell leukemia-lymphoma with Hodgkin's disease-like histologic features. Lymph nodes were examined from four patients with incipient adult T-cell leukemia-lymphoma (ATLL) who had mild lymphadenopathy, fatigue, no or a few atypical lymphocytes in their peripheral blood, and integrated proviral human T-cell lymphotrophic virus type I (HTLV-I) DNA in the nodes. The HTLV-I DNA was detected by southern blot analysis and/or polymerase chain reaction in the lymph nodes of all cases. The nodal architecture was preserved. Some scattered or aggregated highly lobular, cerebriform, or Reed-Sternberg-like giant cells were observed, with occasional mitoses and diffuse infiltration of small to medium-sized lymphocytes, with no or minimal nuclear abnormalities in the enlarged paracortex. The giant cells were usually positive for Ki-1 and also for UCHL-1 and other T-cell markers but negative for Ber-H2. Rearrangement and/or deletion of T-cell receptors were found in three of four patients. All patients died within 2 years, with transformation to overt leukemia-lymphoma occurring in three patients, and pulmonary carcinoma in one. The incipient or prelymphomatous phase of ATLL should be differentiated from Hodgkin's disease because of the distinctly different prognoses of these two diseases.
Correlates of survival and the Daumas-Duport grading system for astrocytomas. In order to examine the correlation between prognosis and the histological features of nuclear atypia, mitosis, endothelial proliferation, and necrosis in supratentorial adult astrocytomas, the authors reviewed 251 such cases treated at the Massachusetts General Hospital between 1972 and 1980. One point was given for the presence of each feature. The total number of features was translated into a grade as follows: none of the four features = Grade 1 (one patient), one feature = Grade 2 (36 patients), two features = Grade 3 (33 patients), and three or four features = Grade 4 (181 patients). The period of survival was significantly associated with grade, the presence or absence of each of the four histological features, patient's age, type of operation, radiation therapy, and extent of tumor (log rank, p less than 0.05). The variables associated with grade were age (p less than 0.001) and radiation therapy (p less than 0.02). After adjustment for these variables using a Cox proportional-hazards model, the difference in overall survival time between patients in Grades 2 and 3 was not statistically significant. When comparable groups of patients were examined in terms of age or receipt of radiation therapy, the median survival times differed markedly. Patients 50 years of age or less had a median survival time of 68 months (Grade 2 tumors), 29 months (Grade 3 tumors), and 13 months (Grade 4 tumors). Patients over 50 years of age had a median survival time of 6 months (Grade 2 and 4 tumors) and 9 months (Grade 3 tumors). Those patients who had received radiation therapy had a median survival time of 68 months (Grade 2 tumors), 21 months (Grade 3 tumors), and 11 months (Grade 4 tumors). Those patients who did not receive radiation therapy had a median survival time of 1 month (Grade 2 tumors) and 2 months (Grade 3 and 4 tumors); over half of these patients died within 2 months of surgery. This grading system, originally proposed by Daumas-Duport, et al., is simple, objective, and reproducible, and correlates well with survival times. The authors recommend that astrocytomas be graded on a scale of 1 to 4, with Grade 1 reserved for the rare adult supratentorial astrocytoma with none of the four histological features.
Hyperkalaemia during rapid blood transfusion and hypovolaemic cardiac arrest in children. A morbidity and mortality review documented a high occurrence of hyperkalaemia in cardiac arrests associated with rapid blood transfusion, which resulted in further study. In order to stimulate events during rapid blood transfusion and cardiac arrest, the central circulation was modeled as a linear one compartment, and used to stimulate a child who suffered a hypovolaemic cardiac arrest and was resuscitated with rapid blood transfusion (RBT). The simulation suggested that the combination of RBT and a low cardiac output state could be associated with hyperkalaemia, if the potassium concentration in the plasma fraction of the transfused blood was greater than or equal to 10 mmol.L-1. In an associated clinical study the plasma potassium concentration during cardiac arrest was documented from a retrospective review of 138 cardiac arrests in a paediatric population. Patients were divided into two groups. The RBT-group received a rapid blood transfusion during resuscitation. The non-RBT group did not receive blood during resuscitation. During cardiac arrest the plasma [K] in the non-RBT group was 5.63 +/- 2.39 mmol.L-1 compared with 8.23 +/- 1.99 mmol.L-1 in the RBT-group (P less than 0.05). The hyperkalaemia during cardiac arrest in the RBT-group could be explained as a consequence of RBT to a hypovolaemic child with a low cardiac output.
Post-caesarean section analgesia: a comparison of epidural butorphanol and morphine. Epidural butorphanol 1, 2 and 4 mg were compared with morphine, 5 mg, for postoperative analgesia in 92 consenting, healthy, term parturients who had undergone Caesarean section under epidural lidocaine anaesthesia in a randomized double-blind study. Postoperative pain was assessed using a visual analogue scale and recorded with heart rate, blood pressure and respiratory rate. The demographic characteristics, and the incidences of primary and repeat Caesarean sections, were not different among the four treatment groups. At 15, 30, 45 and 60 min after treatment the median pain scores following butorphanol were similar and lower than those following morphine (P less than 0.05). Calculated median percentage pain relief values for butorphanol were higher than morphine at each of these times (P less than 0.05). At 90 min and 2 hr the pain scores and pain relief values were similar. Beyond 45 min the number of patients requesting supplemental medication and dropping out of the study increased progressively in both the butorphanol and morphine treated patients. The attrition profiles for butorphanol were different from morphine (P less than 0.01). The median time in the study was greater than 24 hr for morphine, and 3, 2.5 and 4 hr for butorphanol, 1, 2 or 4 mg, respectively. No patient developed a clinically important change in heart rate or blood pressure, and none experienced a decrease in respiratory rate below 12 breaths.min-1. One of 69 patients (1.4 per cent) who received butorphanol developed pruritus compared with ten (43 per cent) of 23 patients who received morphine. The global assessments of the adequacy of analgesia were indistinguishable between morphine and butorphanol. Epidural butorphanol provides safe, effective postoperative analgesia, has a prompt onset, and a limited duration.
Percutaneous mitral valvuloplasty in surgical high risk patients. Among 126 consecutive patients undergoing percutaneous mitral valvuloplasty, 34 were judged to be at high risk for surgery on the basis of age greater than 70 years (n = 13), New York Heart Association functional class IV (n = 11), ejection fraction less than or equal to 35% (n = 3), severe pulmonary hypertension (n = 7), need for associated coronary bypass (n = 4) or additional valve surgery (n = 20) or severe pulmonary disease (n = 3). Baseline features of the high risk group were substantially worse than those of the other patients: age (65 +/- 11 versus 49 +/- 12 years; p = 0.0001) and echocardiographic score (9.4 +/- 1.8 versus 8.2 +/- 1.5; p = 0.005) were higher, whereas cardiac output (2.9 +/- 0.9 versus 4.1 +/- 1.2 liters/min; p = 0.0001) and mitral valve area (0.9 +/- 0.4 versus 1.1 +/- 0.3 mm2; p = 0.002) were lower. Three high risk patients experienced technical failures and three others had major complications. Among the remaining 28 patients, 18 (65%) had a complete hemodynamic success, 4 (14%) an incomplete success and 6 (21%) hemodynamic failure. Stepwise logistic regression analysis retained echocardiographic score as the only factor independently predictive of success. The percent increase in mitral valve area also correlated with echocardiographic score (r = 0.51, p less than 0.01).