123rc/medical_text huggingface dataset:
Limb-salvage surgery in the treatment of osteosarcoma in skeletally immature individuals. Sacrifice of major growth plates during resection and fixed-length reconstruction of a limb in a skeletally immature child with osteosarcoma may result in a significant limb-length inequality as growth progresses. A limb-length discrepancy in the humerus may cause minor cosmetic problems but does not generally result in a significant functional deficit. In the lower extremity, tumors about the knee, including the distal femur and proximal tibia, usually present the dilemma of whether limb salvage by arthrodesis, osteoarticular allograft, or endoprosthetic replacement would result in a significant limb-length inequality and whether amputation of the extremity is a preferable procedure. The techniques of rotationplasty and an expandable endoprosthesis have been successfully used for treating skeletally immature patients with osteosarcoma of the distal femur. With regard to survival and function, the results obtained with these innovative methods are favorable compared with those of a high above-knee amputation.
Detection and location of myocardial infarction using technetium-99m sestamibi imaging at rest. Technetium-99m (Tc-99m) sestamibi imaging at rest has been used to detect and localize myocardial infarction. The largest study to date is a cooperative study of 146 patients in 17 institutions. There were 24 normal subjects and 122 patients with documented myocardial infarction based on clinical, enzymatic or electrocardiographic criteria. The presence of segmental myocardial perfusion defects was compared to the presence of a Q wave on the electrocardiogram or wall motion abnormality on gated blood pool scans, performed within 48 hours of the Tc-99m sestamibi study. Of the 122 infarct patients, 118 (97%) showed perfusion abnormalities by Tc-99m sestamibi imaging. A perfusion defect was found in 110 (99%) of 111 patients with a Q wave and a wall motion abnormality, 113 (99%) of 114 patients with a wall motion abnormality and 113 (98%) of 115 patients with a Q wave. Of the 24 normal subjects, 22 (92%) had normal Tc-99m sestamibi images. In 75% of 1,986 segments, both a Tc-99m sestamibi defect and a regional wall motion abnormality on gated blood scans were present. In 11% of segments, wall motion was normal but Tc-99m sestamibi imaging was abnormal; in 14% of segments, wall motion was abnormal and Tc-99m sestamibi images were normal. In the 24 control subjects, 99% of the segments were normal. Thirty-eight patients had coronary angiography. A close relation existed between the coronary anatomy and myocardial Tc-99m sestamibi uptake. All 9 territories supplied by an occluded vessel and poor collaterals had grade 0 uptake (scale 0 to 2: 0 = markedly reduced; 2 = normal).
Isovolumic hemodilution with dextran 40 in the rat: effect on the development of peripheral edema and various physiologic parameters. Low molecular weight dextran 40 (D40), 40,000 daltons, is a potential therapeutic agent for cerebral ischemia because it increases local cerebral blood flow. However, the evaluation of D40 in the rat has been difficult due to systemic effects. We evaluated the effects of isovolumic hemodilution with D40 on the development of peripheral edema, mean arterial pressure, hematocrit (Hct) and total blood volume in 18 rats, during 30 min or 4 hr i.v. infusions, in animals with and without previous challenge with D40. Reduction of Hct without peripheral edema to a mean of approximately 31% was only achieved in the animals challenged with i.p. D40 24 hr before hemodilution and who received D40 over a period of 4 hr. Infusion of D40 over a period of 30 min was associated with shorter survival time, compared to the 4-hr infusion group (P less than .005). In the pretreated, rapidly infused group, total blood volume per body weight decreased significantly over time (P less than .005) and the mean arterial blood pressure dropped, but not significantly (P less than .07), whereas no change in Hct was detected and there was a trend toward increased peripheral edema, relative to the slowly infused groups. We conclude that reduction of Hct can be achieved successfully with i.p. administration of D40 24 hr before the study combined with infusion of the agent during a 4-hr period, without significant peripheral edema and early hypotension. This procedure should be used to avoid allergic reactions when evaluating hemodilution with D40 in rats.
Brain protection: physiological and pharmacological considerations. Part I: The physiology of brain injury. Ischaemia, whether focal or global in nature, produces a sequence of intracellular events leading to increased cell permeability to water and ions including Ca++. There is a loss of cellular integrity and function, with increased production of prostaglandins, free radicals, and acidosis with lactate accumulation. These events may be exacerbated by glucose administration. Pharmacological agents aimed at alleviating ischaemic injury could be directed at decreasing cerebral metabolic requirements for oxygen, improving flow to ischaemic areas, preventing Ca+(+)-induced injury, inhibition of free radical formation, lactate removal, inhibition of prostaglandin synthesis, and prevention of complement-mediated leukocyte aggregation. Part I of this paper describes some of the pathophysiological events leading to ischaemic brain injury. Part 2 of this paper will consider the current agents available for brain protection.
Emergency adenotonsillectomy for acute postoperative upper airway obstruction Peri-operative acute upper airway obstruction may be life-threatening. A case is reported of a child with severe adenotonsillar hypertrophy who developed acute upper airway obstruction after a routine surgical procedure and required emergency adenotonsillectomy. The importance of pre-operative assessment is stressed.
Superiority of retrograde cardioplegia after acute coronary occlusion. Because antegrade cardioplegia may limit the distribution of cardioplegia beyond a coronary occlusion, this study was undertaken to determine whether retrograde coronary sinus cardioplegia provides superior myocardial protection during revascularization of an acute coronary occlusion. In 20 adult pigs, the second and third diagonal branches were occluded with a snare for 1 1/2 hours. Animals were then placed on cardiopulmonary bypass and underwent 30 minutes of ischemic arrest with multidose, potassium, crystalloid cardioplegia. In 10 animals, the cardioplegia was given antegrade through the aortic root, whereas in 10 others, it was given retrograde through the coronary sinus. After the arrest period, the coronary snares were released and all hearts were reperfused for 3 hours. Postischemic damage in the myocardium beyond the occlusions was assessed by wall motion scores using two-dimensional echocardiography (4 = normal to -1 = dyskinesia), the change in myocardial pH from preischemia, and the area of necrosis/area of risk (histochemical staining). Hearts protected with retrograde coronary sinus cardioplegia had less tissue acidosis (change in pH = 0.08 +/- 0.03 versus 0.41 +/- 0.13; p less than 0.05), higher wall motion scores (2.0 +/- 0.6 versus 1.3 +/- 0.3; not significant), and less myocardial necrosis (43.4% +/- 3.6% versus 73.3% +/- 3.5%; p less than 0.0001). We conclude that retrograde coronary sinus cardioplegia provides more optimal myocardial protection than is possible with antegrade cardioplegia after revascularization of an acute coronary occlusion.
Comparison of outcomes of double and single lung transplantation for obstructive lung disease. The Toronto Lung Transplant Group. Single lung transplantation has recently been applied with success in patients with obstructive lung disease. Such patients were previously managed by bilateral pulmonary transplantation. Between November 1986 and January 1990, 18 patients underwent transplantation for obstructive lung disease in our center. Eleven double lung transplants and seven single lung transplants were performed in patients having a mean age of 43.4 and 44.1 years, respectively. Operative death occurred in two of 11 double lung transplantations and one of seven single lung transplantations. Each patient underwent preoperative and 3-month postoperative pulmonary function tests, arterial blood gas analyses, nuclear lung scans, and 6-minute walk tests. There was no difference in the preoperative values for any of these parameters. Double lung recipients had significantly higher forced expiratory volume in 1 second and forced vital capacity than single lung recipients. However, the ratios of forced expiratory volume in 1 second to vital capacity were not different. Arterial oxygen and carbon dioxide tension were not different between the two procedures. Whereas double lung transplantations caused a slight preponderance of perfusion to the right lung, the transplanted lung in single lung recipients received a mean of 79.5% +/- 12.3% of predicted flow and only 61.6% +/- 5.0% of predicted ventilation. Three-month 6-minute walk distances were markedly improved in both groups, with double lung recipients achieving 573.0 +/- 44.7 m in comparison with the 528.0 +/- 43.0 m achieved by the single lung recipients. Single lung transplantation is a satisfactory option in patients with obstructive lung disease and might offer significant advantages to the older patient population, in which risk of double lung transplantation is high.
Surgical complications with the cochlear multiple-channel intracochlear implant: experience at Hannover and Melbourne. The surgical complications for the first 153 multiple-channel cochlear implant operations carried out at the Medizinische Hochschule in Hannover and the first 100 operations at the University of Melbourne Clinic, The Royal Victorian Eye and Ear Hospital, are presented. In the Hannover experience the major complications were wound breakdown, wound infection, electrode tie erosion through the external auditory canal, electrode slippage, a persistent increase in tinnitus, and facial nerve stimulation. The incidence of wound breakdown requiring removal of the package was 0.6% in Hannover and 1.0% in Melbourne. The complications for the operation at both clinics were at acceptable levels. It was considered that wound breakdown requiring implant removal could be kept to a minimum by making a generous incision and suturing the flap without tension.
Reperfusion adjunctive therapy. The beneficial effects of coronary thrombolytic therapy may be enhanced by certain adjunctive therapies. Some of these are of proven value, some appear to offer no benefit in spite of theoretical advantages, and some remain to be evaluated in clinical trials. Acetylsalicylic acid markedly enhances the mortality reduction of thrombolytic therapy and should be used routinely. There is a strong theoretical rationale for the use of heparin, but evidence for its benefit exists primarily in small angiographic trials, and convincing clinical benefit has not yet been demonstrated. Early intravenous beta-blockers were shown in the prethrombolysis era to confer modest benefit, but extensive data on their adjuvant use with thrombolysis are available from only one trial. Intravenous nitrates were demonstrated to reduce mortality in the prethrombolysis era, and are soon to be evaluated in trials employing thrombolytic therapy. The calcium channel blockers, in spite of a variety of theoretical benefits, have proved to be of no value acutely, and in the subacute setting, only diltiazem appears to confer benefit in the subgroup of patients with non-O-wave infarction. Angiotensin-converting enzyme inhibitors are likely to be of value in survivors of acute myocardial infarction with left ventricular dysfunction, and benefits observed with acute use in experimental infarction are now being evaluated in clinical trials.
Delayed detection of coarctation in infancy: implications for timing of newborn follow-up. During a recent 5-year period, 74 patients younger than 6 months of age were diagnosed with coarctation of the aorta. Coarctation was correctly diagnosed in only 22% of patients prior to referral despite readily apparent femoral pulse abnormalities in 86%. Infants whose symptoms were detected between 5 and 14 days of age were significantly more ill than infants outside this age range and had a high mortality rate (25%). The number of associated cardiac defects was not related to the severity of clinical illness in this group, suggesting that closure of the ductus arteriosus is the primary determinate of disease severity. Observations in two patients suggested that a detectable pulse discrepancy occurs between 3 and 5 days postnatally. Upper extremity hypertension was found commonly in infants after 5 days of age despite the presence of congestive heart failure. Earlier detection of coarctation in the newborn requires a diligent cardiovascular and peripheral pulse examination between 3 and 7 days of life, upper extremity and lower extremity blood pressure measurement, and a high index of suspicion.
Grading white matter lesions on CT and MRI: a simple scale. We developed and tested a simple three-point scale for grading white matter lesions in anterior and posterior regions of the brain. Twenty four CT scans and 24 MRI scans were separately judged by 11 and five observers, respectively, on the presence and severity of white matter lesions. The observers were radiologists and neurologists. For CT scans, these periventricular changes were graded according to their extent as absent, or partly involving the white matter, or extending up to the subcortical region. The MRI lesions were graded as no lesion or only a single one, multiple focal lesions, and multiple confluent lesions. The pairwise agreements of all possible combinations of observers for each scan were corrected for chance (kappa statistics; maximal agreement 1.0). The weighted kappa value, for anterior and posterior regions combined, was 0.63 for CT scans, and 0.78 for MRI scans. This three-point scale for two separate regions seems suitable as a basis for cross-sectional or longitudinal studies of large series of patients.
Immunopathology of olfactory mucosa following injury to the olfactory bulb. Removal of the olfactory bulb was performed on rats in an attempt to elucidate the processes of olfactory dysfunction following head injury. Degeneration and regeneration of the olfactory mucosa were examined, histopathologically and immunohistochemically. We used antisera to olfactory marker protein (OMP) and neuron specific enolase (NSE) as a marker of the mature olfactory receptor neurons. Following rapid degeneration after bulbectomy, the olfactory receptor neurons regenerated. OMP and NSE containing cells re-appeared 49 days later. However, the cell population of the neuroepithelium did not revert to the numbers observed in the non-operated neuroepithelium, even three months later. The lack of a connection between regenerated axons and the olfactory bulb may result in immature neuronal replacement and reduce the number of olfactory receptor neurons.
Antigen-induced cross-linking of the IgE receptor leads to an association with the detergent-insoluble membrane skeleton of rat basophilic leukemia (RBL-2H3) cells. Cross-linking of the IgE receptor on the surface of rat basophilic leukemia cells by multivalent Ag (DNP-BSA) causes a rapid conversion to a detergent-insoluble form. There is a concurrent increase in the amount of filamentous actin associated with the plasma membrane. Both the degree of receptor detergent insolubility and the rise in F-actin content are rapid with a half-maximal response of less than 1 min and can be rapidly reversed by the addition of monovalent Ag (DNP-lysine). These two early steps in the triggering of rat basophilic leukemia cells can be dissociated from each other by pretreatment of the cells with either cytochalasin or sodium azide. These reagents block the increase in F-actin but have no effect on receptor detergent insolubility. This indicates that microfilaments are not responsible for detergent insolubility of the receptor and that it may be the membrane skeleton that is interacting with the complex. This was further confirmed by the finding that cross-linking of the IgE receptors on the surface of purified plasma membranes also leads to detergent insolubility of the receptor. Therefore, all of the components necessary for detergent insolubility of the receptor are present in the plasma membrane, and cytoplasmic components are not needed. These results suggest that detergent insolubility and immobility of the cross-linked receptors are caused by multivalent interaction with the membrane skeleton. Actin filaments may then interact with these receptor-membrane skeletal complexes in order to produce large scale clustering and capping. The membrane skeleton may therefore be acting as an intermediate structure between the cell-surface receptors and microfilaments.
Dominant negative regulation of the mouse alpha-fetoprotein gene in adult liver. Transcription of the mouse alpha-fetoprotein gene is activated in the developing fetal liver and gut and repressed in both tissues shortly after birth. With germline transformation in mice, a cis-acting element was identified upstream of the transcription initiation site of the alpha-fetoprotein gene that was responsible for repression of the gene in adult liver. This negative element acts as a repressor in a position-dependent manner.
Incidence and prevalence of ulcerative colitis in the upper Galilee, Northern Israel, 1967-1986. An epidemiological study of ulcerative colitis was performed in the Upper Galilee, Israel, over a 20-yr period (1967-1986). The average annual incidence of ulcerative colitis was 2.23 per 100,000 population, and the prevalence on December 31, 1986, was 44.58 per 100,000. Considering the fact that strict steps were taken to include only definite cases, these figures are probably an underestimation. An increase of the average annual incidence from 0.88 in the period 1967-1976 to 3.79 in 1977-1986 was found. When the data were stratified according to ethnic groups, the highest average annual incidence and the highest point prevalence was found in Israeli-born Jews (6.9 and 138.2 per 100,000 population, respectively). When Jewish residence patterns were compared, the highest average annual incidence and point prevalence were found among Kibbutz members (5.52 and 110.39, respectively), and the lowest (1.94 and 38.76) among Moshav inhabitants. There were 10 Arab patients with an average annual incidence of 0.96 and a point prevalence of 19.27. There were 25 women and 28 men (female:male ratio of 0.89). Among the Jews, the female:male ratio was 1.04. Peak incidence was found in the 25- to 34-yr-old range. No second peak was noticed. Anemia was demonstrated in 66.6% of the women and 27.5% of the men in our study. We suggest that the increase in UC incidence and prevalence in Israeli and Asia/africa-born Jew and in Arabs in the Upper Galilee points toward environmental factors in the etiology of this disease.
Successful treatment of neonatal Citrobacter freundii meningitis with ceftriaxone. Citrobacter meningitis is an uncommon enteric gram-negative infection that afflicts neonates and young children. Approximately 30 percent of children treated or untreated die from the infection. We report a case of C. freundii meningitis that was resistant to ampicillin and was successfully treated with ceftriaxone, a third-generation cephalosporin. A 13-day-old, full-term baby was admitted to the hospital with a one-day history of fever up to 38.8 degrees C. On admission the infant had a temperature of 39.2 degrees C, pulse of 140 beats/min, and a respiratory rate of 32 breaths/min. Except for a slightly bulging fontanelle, the rest of the physical examination was within normal limits. Complete blood count revealed a white blood cell (WBC) count of 12.5 x 10(9)/L, with 0.66 polymorphonuclear cells, 0.10 bands, 0.18 lymphocytes, and 0.06 monocytes. A stat lumbar puncture showed 10 WBCs per high-power field with gram-negative rods. Empiric therapy with ampicillin 225 mg q12h and gentamicin 11 mg q8h was started. Both antibiotics were discontinued after culture and sensitivity results were positive for C. freundii in the blood and spinal fluid. The patient was successfully treated with nine days of ceftriaxone 250 mg q12h.
Trochanteric fractures. Mobility, complications, and mortality in 607 cases treated with the sliding-screw technique. Six hundred seven trochanteric fractures (563 patients) were treated with a sliding-screw technique and followed clinically and roentgenographically for at least one year. Of 351 patients admitted from their homes, 209 (60%) were discharged to their homes after an average of 18 days in the hospital. During the first year another 61 (17%) patients returned home after rehabilitation in a geriatric ward. Of 446 patients walking without support or with one cane before surgery, 360 (80%) had regained the same mobility after one year. The one-year mortality rate was 18%, while the ten-year rate was 74%. Compared with a control cohort, the mortality rate was increased during the first two years after fracture. The increase in mortality was influenced by advanced age, admission from long-term care institutions, male gender, and ambulatory or nonambulatory status before surgery. Forty-five (7.4%) were reoperated, 17 because of technical complications, three because of infection, and three because of nonunion. No further nonunions occurred. The deep infection rate was nine of 339 (2.7%) before and two of 268 (0.8%) after the introduction of antibiotic prophylaxis. Thromboembolic complications decreased from 4.1% to 1.2% after the introduction of dextran 70 as thromboembolic prophylaxis.
Patterns of cervical lymph node metastasis from squamous carcinomas of the upper aerodigestive tract. A consecutive series of 1,081 previously untreated patients undergoing 1,119 radical neck dissections (RNDs) for squamous carcinoma of the head and neck was reviewed to study the patterns of nodal metastases. Primary tumors were located in the oral cavity in 501 patients, in the oropharynx in 207 patients, in the hypopharynx in 126 patients, and in the larynx in 247 patients. Lymph node metastases were confirmed histologically in 82% of 776 therapeutic neck dissections, and micrometastases were discovered in 33% of 343 elective RNDs. Lymph node groups in the neck were described by levels (I to V). Predominance of certain levels was seen for each primary site. Levels I, II, and III were at highest risk for metastasis from cancer of the oral cavity, and levels II, III, and IV were at highest risk for metastasis from carcinomas of the oropharynx, hypopharynx, and larynx. Supramohyoid neck dissection (clearing levels I, II, and III) for NO patients with primary squamous cell carcinomas of the oral cavity and anterolateral neck dissection (clearing levels II, III, and IV) for NO patients with primary squamous cell carcinomas of the oropharynx, hypopharynx, and larynx are recommended.
Modification of pain on injection of propofol--a comparison between lignocaine and procaine. Pain on injection of propofol was assessed in a controlled, randomised study of 273 patients. They received either lignocaine 10 mg, procaine 10 mg or isotonic saline 0.5 ml, 15 seconds before the injection of propofol into a vein on the back of the hand. The incidence of pain on injection in the control group (51%) was comparable with other studies. Lignocaine and procaine both significantly reduced the pain (35% and 34% respectively, p less than 0.05) but there was no statistical difference between these two groups.