123rc/medical_text huggingface dataset:
Maximum blood flow rates for arterial cannulae used in neonatal ECMO. The arterial cannulae used in neonatal ECMO cause hemolysis and red blood cell damage at elevated blood flows. Hemolysis in extracorporeal circuits has been found to occur with shear stress greater than 132 dynes/cm2, turbulence as measured by Reynold's number greater than 1,000, and velocity greater than 120 to 200 cm/sec. These parameters need to be considered when sizing the proper arterial cannula for a required flow rate. In-vitro measurements of the pressure drop across six arterial cannulae at varying flow rates were performed using human blood with a hematocrit of 43%. Shear stress, Reynold's number, velocity, and pressure drop were calculated for each catheter at flow rates from 50 to 1,000 cc/min. The maximum mean flow rate to maintain the shear stress, Reynold's number, velocity, and pressure drop within the accepted range, was determined for each cannula. Recommended maximum blood flow rates for each of the six cannulae are given. Internal diameter, length, and cannula geometry appear to be the factors most affecting the flow achievable without causing red blood cell damage and hemolysis. Ten French Biomedicus, 10 French Cook, and 10 French Elecath arterial cannulae appear best suited to deliver the range of blood flow rates used in neonatal ECMO.
Right hemothorax: an unusual presentation of ruptured aortic dissection. This report presents the case of a 55-year-old male with rupture of a descending thoracic aortic dissection into the right hemithorax who successfully underwent prosthetic graft replacement of the involved segment of the aorta through left thoracotomy.
Coronary flow and mental stress. Experimental findings. The hemodynamic, electrocardiographic, and coronary flow responses to a psychological test were studied in 13 pigs both in the absence (group 1, n = 8) and the presence (group 2, n = 5) of a transient occlusion of the left anterior descending coronary artery. The psychological test consisted of presenting food to a fasting but restrained animal for 3 minutes. In group 1, stress increased the heart rate from 128 +/- 5 to 176 +/- 8 beats/min (mean +/- SEM) and arterial pressure from 93 +/- 4 to 112 mm Hg. Comparing the individual increase in rate-pressure product with the increase in coronary conductance during the test, a parallel response was found in only two animals, whereas a relatively lower coronary conductance was observed in the remainder, suggesting vasoconstriction. Clinical signs of ischemia or life-threatening arrhythmias were never observed in this group of animals. Each group 2 animal underwent two occlusions of the left anterior descending coronary artery, randomly performed on separate days both in the presence and the absence of the food deprivation stress. When the latter was applied in the presence of occlusion, all animals developed ventricular fibrillation in less than 2 minutes (mean, 81.4 seconds). Conversely, only one animal had ventricular fibrillation when a 3-minute occlusion was performed without exposure to stress. This occurred despite the fact that more severe ischemia (as detected by an increase in left ventricular end-diastolic pressure and decreases in dP/dt and systolic pressure) was recorded at 3 minutes of occlusion.
Intraoperative monitoring of the facial nerve during decompressive surgery for hemifacial spasm. In 11 consecutive patients, intraoperative electromyographic (EMG) recordings were made from the facial muscles during microvascular decompression for hemifacial spasm. In one patient, recordings could not be obtained for technical reasons, and two patients had no abnormality. In the remaining eight patients, the abnormal response resolved before decompression in two, resolved immediately at the time of decompression in five, and failed to resolve in one. All patients were relieved of their hemifacial spasm. In the five patients whose abnormalities resolved at the time of decompression, there was a precise intraoperative correlation between decompression of the nerve and disappearance of the abnormal EMG response. In three cases, this was a useful guide to the need to decompress more than one vessel. These results confirm the findings of Moller and Jannetta, support the use of this technique for intraoperative monitoring of facial nerve decompression procedures, and provide strong circumstantial evidence that vascular cross-compression is an important etiological factor in hemifacial spasm.
Pressor systems in hypertension and congestive heart failure. Role of vasopressin [clinical conference] Elevated peripheral vascular resistance, which characterizes hypertension and congestive heart failure (the latter regardless of absolute blood pressure level) is maintained to a large extent by the combined effects of three major neurohormonal pressor mechanisms: the renin-angiotensin system, the sympathoadrenal system, and arginine vasopressin. Blockade of one of these mechanisms may lead to compensatory stimulation of the others, thus offsetting in part the hemodynamic benefits of a specific intervention. Combination therapy, designed to attack all three systems (with use of an angiotensin converting enzyme inhibitor, a sympathetic blocker such as clonidine, and an antagonist of the vasopressor action of vasopressin), may help in the treatment of such cases. To illustrate this strategy, two experimental studies, one case of malignant hypertension, and one case of congestive heart failure are presented.
Side effects of nalbuphine while reversing opioid-induced respiratory depression: report of four cases. Nalbuphine hydrochloride, an agonist-antagonist opioid, is reported to reverse the respiratory depression of moderate doses of fentanyl (20 micrograms.kg-1) and still provide good analgesia. We report four patients having abdominal aortic aneurysm repair in which we attempted to reverse the respiratory depression of large doses of fentanyl (50-75 micrograms.kg-1) with nalbuphine (0.3 mg.kg-1, 0.1 mg.kg-1 or 0.05 mg.kg-1). Nalbuphine reversed respiratory depression in all four patients and the respiratory rate increased from 10 to 23 breaths per minute, end-tidal CO2 decreased from 7.0 +/- 0.3 per cent to 5.6 +/- 0.7 per cent, and peak inspiratory pressure after 0.1 seconds increased from 4 +/- 1.4 to 13 +/- 2.6 mmHg. However, hypertension, increased heart rate, and significant increase in analogue pain scores accompanied reversal of respiratory depression. Agitation, nausea, vomiting, and cardiac dysrhythmias also were observed frequently. We do not recommend the use of nalbuphine to facilitate early extubation of the trachea after large doses of fentanyl for abdominal aortic surgery.
Increase in skin-flap survival by the vasoactive drug buflomedil. The effect of buflomedil to protect skin tissue from ischemia and necrosis was studied in random cutaneous flaps. Measurements were performed by intravital microscopy on the microcirculatory level of capillary perfusion in a flap model in the hairless mouse. In 30 hairless mice, single-pedicle flaps measuring 6 x 16 mm were raised perpendicular to the spine of the animal. This flap develops a reliable amount of necrosis at its distal edge over a period of 7 days. A group of 10 mice received intravenous injections of buflomedil in doses of 3 mg/kg per day diluted in 0.1 ml normal saline beginning 4 hours before flap elevation and for 6 consecutive days postoperatively. In addition, 10 further animals received the same treatment except that it was started 5 minutes after flap elevation. In 10 mice serving as controls, normal saline in equal volumes as in the experimental groups was applied. By means of intravital microscopy, functional vessel density (FVD) was determined in 2.5-mm increments from the flap's base to its distal edge at 1, 6, and 24 hours after elevation. Skin-flap survival was quantified by measuring the necrotic area on day 7 by means of digital planimetry. Functional vessel density was preserved in the distal flap of animals pretreated with buflomedil, revealing a higher functional vessel density at 10.0 mm (p less than 0.01), 12.5 mm (p less than 0.05), and 15.0 mm (p less than 0.001) from the flap's base as compared with controls.
Epidural hematoma: an unusual presentation. The authors present a patient with a traumatic epidural hematoma who complained only of headache and presented to the emergency department 48 hours after a fall. Mental status and neurological examination were normal. This delayed presentation is more commonly seen when a subdural hematoma is present but may result from epidural bleeding. Delayed formation of a traumatic epidural hematoma may occur when the following are present: elevated intracranial pressure, hypovolemic shock, a concomitant mass lesion, coagulopathy, bleeding from dural or diploic veins, a dural sinus laceration, a traumatic pseudoaneurysm, or an arteriovenous fistula. Although criteria for computed tomography of patients with head injuries remain variable in the literature, delayed presentation of epidural bleeding must be considered in the differential diagnosis of posttraumatic headache irregardless of the time interval or neurological presentation.
Retroviral transduction of protein kinase C-gamma into cytotoxic T lymphocyte clones leads to immortalization with retention of specific function. The molecular pathways that are responsible for delivering the proliferative signals from the cell surface to the nucleus in T lymphocytes are still unresolved, but recent data implicates protein kinase C (PKC) involvement in the TCR signaling pathway. To further address the role of PKC in T cell activation, the effects of high level expression of the PKC-gamma isoenzyme in murine CTL clones were examined. Unlike the parental cells that required periodic Ag stimulation for cell activation and growth, cells expressing a retrovirally transduced PKC-gamma gene propagated in culture independent of the need for Ag stimulation, although maintaining identical functional specificity to the parental CTL. Constitutive PKC-gamma expression may therefore mimic physiologic PKC activation, thereby abrogating the requirement for TCR-Ag interaction in T cell activation.
Influence of Doppler sample volume location on the assessment of changes in mitral inflow velocity profiles. Previous studies that have validated Doppler indexes of mitral inflow have used pulsed wave sample volume locations either at the level of the mitral valve anulus or at the tips of the mitral valve leaflets. Although significant differences between absolute values for peak velocities and velocity time integrals at these sample volume locations have previously been reported, no information exists that has compared changes in inflow profiles after an intervention to improve left ventricular filling. To address this question, 13 patients with severe pulmonary hypertension (mean pulmonary artery pressure, 50 +/- 13 mm Hg) caused by chronic thromboembolic disease were studied with use of Doppler echocardiography immediately before and after surgical reduction of pulmonary hypertension (pulmonary vascular resistance decreased from 916 +/- 413 to 233 +/- 89 dynes.sec.cm5). This clinical model has been shown to have abnormal mitral inflow velocity profiles that improve markedly after surgery. Doppler measures of early and late peak velocities were significantly lower both before and after surgery when sampling at the mitral anulus compared with the leaflet tips, although late filling parameters and the deceleration of early flow velocity tended to differ little. With surgery, the significant increase in peak early velocity and the ratio of early to late velocity was present regardless of the sample volume location (peak E at leaflet tips, 47.1 +/- 16.0 to 68.9 +/- 15.4 [p less than 0.001], and at anulus, 40.7 +/- 11.3 to 56.2 +/- 14.6 cm/sec [p less than 0.001]; peak E/A at leaflet tips, 0.95 +/- 0.4 to 1.55 +/- 0.9, and at anulus, 0.78 +/- 0.3 to 1.32 +/- 0.7 [both p less than 0.02]).
Ascites not due to congestive heart failure in a fetus with lupus-induced heart block. Hydrops developing in fetuses with lupus-associated heart block has usually been assumed to result from congestive heart failure. We present a case in which fetal ascites associated with complete heart block resolved promptly after administration of betamethasone and prednisone to the mother, who had anti-SSA and who developed clinical lupus erythematosus. This resolution occurred with no demonstrable change in fetal cardiac function. We conclude that an immune mechanism, rather than congestive heart failure, was responsible for the fetal ascites.
Peripheral vascular disorders. Assessment and intervention. Peripheral vascular diseases are being seen with increased frequency in the health care setting today. It is imperative that nurses have a clear understanding of arterial, venous, and lymphatic circulatory mechanisms as well as the pathophysiologic changes that accompany common diseases of these systems. Providing the ongoing assessment to obtain a diagnosis, establish the acute versus chronic nature of findings, monitor progression, plan care, and assess the response to treatment is an important role for the nurse in order to preserve function, life, and limb in these patients.
Vulvar Paget's disease. Is immunocytochemistry helpful in assessing the surgical margins? From January 1977 to December 1988, 19 patients with biopsy-proven Paget's disease of the vulva underwent simple or radical vulvectomy at the University of Miami/Jackson Memorial Medical Center. All vulvectomy specimens were evaluated immunocytochemically for the expression of carcinoembryonic antigen (CEA), epithelial membrane antigen (EMA) and low-molecular-weight keratins 8 and 18 (LMK), both in areas containing neoplastic cells and in histologically negative surgical margins. Neoplastic Paget's cells stained positively for CEA in all cases; they were positive for EMA and LMK in 18 and 17 cases, respectively. In all eight cases with underlying in situ or invasive carcinomas, CEA, EMA and LMK were localized in the underlying tumors as well. None of the histologically proven negative margins reacted for CEA, EMA or LMK on immunocytochemistry. CEA appears to be a valuable immunocytochemical marker for extramammary Paget's disease; EMA and LMK are also expressed by the majority of such cases. None of these markers, however, is of added value in identifying Paget's cells in surgical margins if those margins appear negative on routine hematoxylin-and-eosin staining.
Occurrence of uveal melanoma in contact with a chorioretinal cryocoagulation scar. A case of a uveal melanoma arising in an eye previously treated with cryocoagulation for a horseshoe retinal tear is described. In the anterior border of the tumor, a notch, clearly fitting the curve of the chorioretinal scar was observed. Possible mechanisms which may be responsible for the local arrest of the tumor extension are discussed.
Neonatal diarrhea at a maternity hospital in Rangoon Between 1981 and 1986, 1,540 infants born at the Central Women's Hospital in Rangoon were transferred to the Sick Baby Unit because of diarrhea (15.4 per 1,000 live births). Rates among cesarean infants were five times as high as those of infants born vaginally (51.0 and 10.3 per 1000 live births, respectively). One hundred eighty-four of the infants with diarrhea died (case fatality rate = 12 percent). We conclude that neonatal diarrhea is endemic in this large maternity hospital in Burma, and that control efforts should be targeted especially to cesarean and low birthweight infants.
The sequelae of Haemophilus influenzae meningitis in school-age children. BACKGROUND. Previous data on the consequences of Haemophilus influenzae type b meningitis for school-age children have been inconsistent, and much of the information on risk factors has been inconclusive. The present study was designed to evaluate the sequelae of this disease with a protocol for the comprehensive assessment of neuropsychological function. METHODS. Ninety-seven school-age children (mean age, 9.6 years), each of whom had a school-age sibling, were recruited from a survey of the medical records of 519 children treated for H. influenzae type b meningitis between 1972 and 1984 (at a mean age of 17 months) at the children's hospitals of Toronto, Ottawa, and Montreal. Of the 97 children, 41 had had an acute neurologic complication. Sequelae were assessed by comparing the index children with their nearest siblings on the basis of standardized measures of cognitive, academic, and behavioral status. RESULTS. Only 14 children (14 percent) had persisting neurologic sequelae: sensorineural hearing loss in 11 (unilateral in 6 and bilateral in 5), seizure disorder in 2, and hemiplegia and mental retardation in 1. Although the total sample of index children scored slightly below the siblings in reading ability, the 56 children without acute-phase neurologic complications (58 percent) were indistinguishable from their siblings on all measures. The differences between the groups were small even for the 41 pairs in which the index child had had an acute neurologic complication (mean full-scale IQ, 102 for the index children vs. 109 for the siblings). Sequelae were also associated with lower socioeconomic status and a lower ratio of glucose in cerebrospinal fluid to that in blood at the time of the meningitis. Behavioral problems were more prominent in index boys than index girls and in those who were older at the time of testing, but sex and age were not related to cognitive or academic sequelae. CONCLUSIONS. We find a favorable prognosis for the majority of children who are treated for meningitis caused by H. influenzae type b.
Subtrochanteric fractures treated with interlocking nailing. In a prospective study of 31 subtrochanteric fractures treated with Grosse-Kempf interlocking nails with a followup period of at least 1 year, there was a 87.1% (27/31) union rate, and a union period of 4.2 +/- 1.8 months. Knee range of motion in 28 acute traumatic cases was on average 127.5 +/- 23.0 degrees. The significant complications included: nail breakage, 3.2% (1/31); nonunion without nail breakage, 9.7% (3/31); neglected femoral fracture with malunion, 3.2% (1/31). The interlocking nailing has the advantages of: a) closed method, b) weight-sharing principle, c) shortening prevention, d) non-rigid fixation. From the theoretical and clinical comparison among the various implants, we conclude that closed interlocking nailing is one of the better instruments for subtrochanteric fracture treatment, and moreover, the most reasonable of all. However, for the higher level subtrochanteric fractures, reconstruction-style locking nails should be chosen.
A chance to cut is a chance to cure? Fifty-seven patients underwent local excision of an invasive distal rectal cancer as an initial operative procedure with curative intent. Five-year survival was 82.5%, and the rectal cancer specific mortality rate was only 10.5%. The level of wall invasion, vascular permeation, tumor ulceration, mobility, and differentiation were the criteria studied for prognosis. Poor prognostic factors included mucinous cell differentiation and full thickness invasion, and in these cases, abdominoperineal resection was recommended. None of the 27 patients without these adverse prognostic factors died from rectal cancer. The other factors did not appear to influence the outcome, and local excision of distal rectal cancer would be the treatment of choice in such selected patients.
Traffic of peripheral B and T lymphocytes to hyperplastic, preneoplastic thymuses of AKR mice. AKR mice develop hyperplasia of the thymus before the development of retrovirus-associated lymphoma at that site. This hyperplasia, first detectable in AKR/J mice by 4 weeks of age and in AKR/C mice by 4 to 5 months of age, is characterized by an enlarged thymic medulla that contains T and B lymphocytes. In contrast to the general population of thymocytes, most of these T and B lymphocytes have a mature immunophenotype that includes expression of high levels of the MEL-14-defined (gp90) 'homing receptor' for peripheral lymph node high endothelial venules. In vivo homing studies reveal a marked increase in traffic of peripheral lymphocytes (T more than B) to the hyperplastic thymuses of old AKR mice as compared to histologically normal thymuses of age-matched BALB/c and C57BL/Ka mice or young AKR mice. These changes correlate chronologically with changes in retrovirus antigen expression in AKR thymuses and suggest a role for the traffic of lymphocytes from the periphery to the thymus in response to local antigenic stimulation in the pathogenesis of thymic hyperplasia in AKR mice.
Diabetic nephropathy: can the natural history be modified? Those diabetic patients who progress to advanced kidney disease constitute a subpopulation that is particularly vulnerable to the angiotoxic effects of the insulin-dependent disorder. Until the predisposing factors are identified, the most effective way to arrest renal deterioration is by controlling those currently recognized risk factors that accelerate the glomerulopathy. Treatments that normalize blood pressure, reduce dietary protein intake, and control hyperglycemia have been shown to retard the progression of diabetic nephropathy.
Overexpression of HER-2/neu in endometrial cancer is associated with advanced stage disease. Prior studies have shown that overexpression of HER-2/neu occurs in one third of breast and ovarian cancers and that overexpression is associated with poor prognosis. We used a monoclonal antibody to assess immunohistochemically the level of HER-2/neu expression in normal and malignant endometrium. In 24 normal endometrial samples light to moderate (1+ to 2+) staining for HER-2/neu was seen in the glands, and there was no variation in intensity of staining during the menstrual cycle. Among 95 endometrial adenocarcinomas, nine (9%) were found to have heavier staining for HER-2/neu than was seen in normal endometrium (3+). High expression of HER-2/neu was found in 27% of patients with metastatic disease compared with 4% of patients with disease confined to the uterus (p less than 0.005). High HER-2/neu expression also was associated with absence of estrogen receptor (p less than 0.005) and with increased mortality from cancer. Further studies are needed to determine the significance of HER-2/neu overexpression in endometrial cancer.
Electroencephalographic parameters in assessing the cognitive function of children with epilepsy. Many biological and psychological possibilities have to be considered when attempting to explain cognitive dysfunction in the individual child with epilepsy. Electroencephalographic (EEG) information, which may be particularly relevant in some children, has mainly been studied in relation to the possible direct effects of seizure discharges on learning and behavior. Such discharges can be divided into transient, brief or prolonged. Prolonged seizure discharges includes nonconvulsive status epilepticus during wakefulness and status epilepticus during slow-wave sleep. In addition to the influence of seizure discharges, preliminary findings suggest that some children with epilepsy might have a subtle disorder of arousal mechanisms in sleep, possibly associated with impaired daytime performance.
Dislocation after primary arthroplasty for subcapital fracture of the hip. Wide range of movement is a risk factor. Dislocation is the most frequent serious complication following total hip replacement for subcapital femoral fracture. We report a prospective study, using matched groups, which compared the range of hip movement following hip replacement for arthritis and for fracture. The range of movement was significantly greater in the fracture group. We suggest that this is a predisposing factor for dislocation.