123rc/medical_text huggingface dataset:
Preoperative radiotherapy in operable rectal cancer. The effect of preoperative radiotherapy (31.5 Gy in 3.5 weeks) in operable rectal cancer was examined with respect to resectability and prognosis after two surgical procedures, abdominoperineal resection, or low anterior resection. Preoperative radiation did not influence the surgeon's selection of low anterior resection, which was similar (40 percent) in each group. Radiation improved five-year survival probability and decreased the incidence of local recurrence significantly after low anterior resection. In contrast, no improvement of treatment results was found in patients treated by abdominoperineal resection after radiotherapy.
Porokeratoses: immunohistochemical, light and electron microscopic evaluation. Punch biopsy specimens of 14 patients with porokeratosis of Mibelli (n = 1), disseminated superficial porokeratosis (n = 6), disseminated superficial actinic porokeratosis (n = 4), porokeratosis plantaris, palmaris et disseminata (n = 2), and punctate porokeratosis (n = 1) were obtained for light and electron microscopy for evaluation of possible differences between these clinical variants. Langerhans cells in close contact with early degenerating keratinocytes could be observed in the epidermis. To study the cellular composition of the epidermal inflammatory infiltrate immunohistochemistry was performed. These studies demonstrated that the predominant cell type in these infiltrates are helper T cells, intermingled with Leu-6+ Langerhans cells. Despite the clinical variation and possible different etiologic or triggering mechanisms, the immunohistochemical and morphologic changes in all types of porokeratosis are the same and seem to represent a uniform reaction pattern.
Recurrent acute fatty liver of pregnancy associated with a fatty-acid oxidation defect in the offspring. A case of a 29-year-old woman who has had two episodes both clinically and biochemically consistent with acute fatty liver of pregnancy is described. These episodes occurred in two successive pregnancies, and liver biopsy confirmed the diagnosis in the second pregnancy. Both pregnancies were managed by prompt fetal delivery; on both occasions this led to a complete biochemical resolution of the liver function abnormalities. Two healthy babies were delivered by ceasarian sections. This case is of particular importance because a rapidly progressive and devastating illness developed in both infants, leading to death at 6 1/2 and 6 months, respectively. The illness in both babies was characterized by wide-spread fatty infiltration of several vital organs and a failure of any treatment to influence the outcome of that illness. Studies suggested that the illness in the children was caused by a still ill-defined disorder of fatty acid oxidation. The biochemical disorder evidenced in this family is discussed, in an attempt to shed light on the etiology of acute fatty liver of pregnancy.
Increased glucose metabolism in the medulla of patients with palatal myoclonus. Hypertrophic degeneration of the inferior olivary nuclei is the pathologic substrate for palatal myoclonus, but the physiologic correlate of this finding is uncertain. Using the 2-[18F]fluoro-2-deoxy-D-glucose and PET method, we determined the local cerebral metabolic rate of glucose utilization in seven patients with palatal myoclonus (following stroke or infection, or idiopathic), one patient with oculopalatal myoclonus (following a stroke affecting the brainstem), and nine normal subjects. The metabolism of glucose in the medulla of the patients with palatal myoclonus was significantly greater than that of the normal subjects. This may well have been due to increased metabolism of the inferior olivary nuclei. Glucose metabolism in the medulla of the patient with oculopalatal myoclonus was normal. These findings suggest that the inferior olivary nuclei, or a region of the brainstem encompassing the inferior olivary nuclei, are hypermetabolic in palatal myoclonus and may be the generators of the involuntary movements in palatal myoclonus.
Stimulatory effects of maitotoxin on insulin release in insulinoma HIT cells: role of calcium uptake and phosphoinositide breakdown. In hamster insulinoma (HIT) cells, maitotoxin (MTX) induces a time-dependent and concentration-dependent release of insulin that requires the presence of extracellular calcium. The response is nearly completely blocked by cinnarizine and cadmium, but is not inhibited by the L-type calcium channel blocker nifedipine or by manganese. MTX induces 45Ca+ uptake in these cells in a dose-dependent mode, and the uptake is blocked with cinnarizine, nifedipine and cadmium, and is partially inhibited by manganese. MTX induces phosphoinositide breakdown in HIT cells, and the response is partially blocked by cadmium, but is not affected by nifedipine, cinnarizine or manganese. High concentrations of potassium ions also induce insulin release and calcium uptake in HIT cells. Both effects of potassium are blocked partially by nifedipine, cadmium and cinnarizine. High concentrations of potassium do not induce phosphoinositide breakdown in HIT cells. The results suggest that MTX-elicited release of insulin is attained by two mechanisms: 1) a nifedipine-sensitive action, which results from MTX-induced activation of L-type calcium channels, which can be mimicked with high potassium concentrations; and 2) a nifedipine-insensitive action, which may be initiated by the activation of phosphoinositide breakdown by MTX. Such an activation of phospholipase C would result in the formation of 1,4,5-inositol trisphosphate, a release of intracellular calcium and then release of insulin to the extracellular space. Cinnarizine is proposed to block both MTX-elicited mechanisms, the first by blockade of calcium channels and the second by blocking 1,4,5-inositol trisphosphate-induced release of internal calcium. Either mechanism alone appears capable of eliciting release of insulin.
Implications of peritoneal cytology for staging of early pancreatic cancer. Cytologic examination of peritoneal washings was performed in 40 patients with pancreatic ductal adenocarcinoma (35 head, 5 body) whose tumors had been selected as potentially resectable by computed tomographic (CT) findings. Saline (100 mL) was instilled and aspirated at laparoscopy in 27 patients and at laparotomy in 13. Malignant cells were found in the peritoneal washings in 12 of 40 patients (30%): 29% in cancers of the pancreatic head versus 40% in the body; 33% at laparoscopy versus 23% at laparotomy; and in 4 of 8 patients with ascites versus 8 of 32 without ascites. The cytology was positive in 6 of 8 patients (75%) who had a prior percutaneous needle biopsy versus 6 of 32 (19%) of those who did not (p less than 0.01). Liver metastases were found in six patients, all with negative cytology. One of 10 pancreatic head cancers with positive cytology was resectable versus 13 of 25 with negative cytology (p less than 0.05). Survival was significantly longer in patients with negative cytology. We conclude that (1) pancreatic cancer sheds malignant cells into the peritoneum early and commonly; (2) laparoscopic lavage is an effective means of cytologic study; (3) ascites is not a precondition for cytologic study, nor does its presence necessarily imply carcinomatosis; (4) intraperitoneal spread of cancer cells may be promoted by tumor biopsy; (5) cytologic findings provide an additional index of resectability; and (6) cytologic findings appear to correlate with duration of survival. This study shows that even "localized" pancreatic cancer is often not contained and suggests caution with biopsy of potentially curable lesions.
Headaches in dementia. We investigated 288 elderly subjects with various degree of dementia, focusing on headaches. Seventy-three of 288 elderly subjects (25.3%) complained of some headaches. The most common type was the tension-type headache, from which 43 of the 73 subjects with headaches (58.9%) suffered. The degree of cognitive disturbances, evaluated by Hasegawa's intelligence scale, significantly correlated to the prevalence of headaches, and indicated that patients with dementia appeared to have less headaches. The methodological issues and views on headache research in dementia were assessed, and it is concluded that the field is a difficult one, with potential for error.
Use of H2-receptor antagonists in children. H2-receptor antagonists (H2RAs) have evolved into the mainstay of anti-acid therapy for pediatric patients, replacing antacids and other modes of therapy. Much of the experience and data used for therapeutic decisions in children, however, have been extrapolated from adult studies. Ranitidine and cimetidine have been studied most extensively in the adult and pediatric populations. Both raise gastric pH and achieve other therapeutic endpoints; however, cimetidine appears to have a greater frequency of both adversed effects and drug interactions. H2RAs are the preferred agents for prevention of stress ulcers, ulcer disease, and reflux esophagitis in the pediatric population.
Hypomutability in Fanconi anemia cells is associated with increased deletion frequency at the HPRT locus. Fanconi anemia (FA) is an inherited human disorder associated with a predisposition to cancer and characterized by anomalies in the processing of DNA cross-links and certain monoadducts. We reported previously that the frequency of psoralen-photoinduced mutations at the HPRT locus is lower in FA cells than in normal cells. This hypomutability is shown here to be associated with an increased frequency of deletions in the HPRT gene when either a mixture of cross-links and monoadducts or monoadducts alone are induced. Molecular analysis of mutants in the HPRT gene was carried out. In normal cells the majority of spontaneous and induced mutants are point mutations whereas in FA deletion mutations predominate. In that case a majority of mutants were found to lack individual exons or small clusters of exons whereas in normal cells large (complete or major gene loss) and small deletions are almost equally represented. Thus we propose that the FA defect lies in a mutagenic pathway that, in normal cells, involves bypassing lesions and subsequent gap filling by a recombinational process during replication.
Studies of myocardial protection in the immature heart. V. Safety of prolonged aortic clamping with hypocalcemic glutamate/aspartate blood cardioplegia. This study tests the hypothesis that multidose, hypocalcemic aspartate/glutamate-enriched blood cardioplegia provides safe and effective protection during prolonged aortic clamping of immature hearts. Of 17 puppies (6 to 8 weeks of age, 3 to 5 kg) placed on vented cardiopulmonary bypass, five were subjected to 60 minutes of 37 degrees C global ischemia without cardioplegic protection and seven underwent 120 minutes of aortic clamping with 4 degrees C multidose aspartate/glutamate-enriched blood cardioplegia ([Ca++] = 0.2 mmol/L), preceded and followed by 37 degrees C blood cardioplegic induction and reperfusion. Five puppies underwent blood cardioplegic perfusion for 10 minutes without intervening ischemia to assess the effect of the cardioplegic solution and the delivery techniques. Left ventricular performance was assessed 30 minutes after bypass was discontinued (Starling function curves). Hearts were studied for high-energy phosphates and tissue amino acids. One hour of normothermic ischemia resulted in profound functional depression, with peak stroke work index only 43% of control (0.7 +/- 0.1 versus 1.7 +/- 0.2 gm x m/kg, p less than 0.05). There was 70% depletion of adenosine triphosphate (7.6 +/- 1 versus control 20.3 +/- 1 mumol/gm dry weight, p less than 0.05) and 75% glutamate loss (6.6 +/- 1 versus control 26.4 +/- 3 mumol/gm, p less than 0.05). In contrast, after 2 hours of aortic clamping with multidose blood cardioplegia preceded and followed by 37 degrees C blood cardioplegia, there was complete recovery of left ventricular function (peak stroke work index 1.6 +/- 0.2 gm x m/kg) and maintenance of adenosine triphosphates, glutamate, and aspartate levels at or above control levels adenosine triphosphate 18 +/- 2 mumol/gm, aspartate 21 +/- 1 versus control 2 mumol/gm, and glutamate 25.4 +/- 2 mumol/gm). Puppy hearts receiving blood cardioplegic perfusion without ischemia had complete recovery of control stroke work index. We conclude that methods of myocardial protection used in adults, with amino acid-enriched, reduced-calcium blood cardioplegia, can be applied safely to the neonatal heart and allow for complete functional and metabolic recovery after prolonged aortic clamping.
Immediate postoperative mammogram for failed surgical excision of breast lesions In a series of 200 consecutive preoperative needle localizations of non-palpable breast lesions, 128 lesions (64%) were calcified and 72 lesions (36%) were noncalcified on preoperative mammograms. Radiographs of the surgical specimen failed to confirm excision of 11 lesions (5.5%), seven calcified and four noncalcified. These 11 patients were taken directly from the surgical suite to the radiology suite, where an immediate postoperative mammogram was obtained. In five patients (2.5%), immediate postoperative mammograms showed surgical failure with the lesion still present. In six patients (3.0%), immediate postoperative mammograms showed that the lesion had been removed, even though the lesion had not been identified on surgical-specimen radiographs. No errors occurred in the interpretation of immediate postoperative mammograms, a fact corroborated by examination of surgical specimens obtained at repeat surgery in three patients and identification of skin calcifications in two patients, and with follow-up mammograms in six patients. Whenever a discrepancy between preoperative localization radiographs and surgical-specimen radiographs exists, the authors suggest immediate postoperative mammography to improve the diagnostic process.
Serial magnetic resonance imaging of hamstring anterior cruciate ligament autografts during the first year of implantation. A preliminary study. A prospective, observational study was performed to document the serial changes in the magnetic resonance signal of devascularized, hamstring ACL autografts during the 1st year of implantation. Twenty-one ACL deficient knees (14 chronic, 7 acute) were reconstructed. Instability developed in five knees within the first 6 months of graft implantation (24%). Magnetic resonance examinations were performed at 1, 6, 12, 24, 36, and greater than 48 weeks postoperatively (repetition time 1500, echo delay time = 50). A total of 104 scans were reviewed (average, five per knee). The ACL graft was divided into four unequal size zones for analysis. The proximal, middle, and distal thirds of the intraarticular portion of the graft and the portion of the graft within the tibial tunnel were independently analyzed. The magnetic resonance signal in each portion of the graft was graded on a scale with (I) being a normal signal, (II) greater than 50% of the total volume of the graft having a normal signal, (III) less than 50% of the graft having a normal signal, and (IV) 100% of the graft having an increased signal. The increased magnetic resonance signal of the ACL graft was observed to be regionalized and confined to the distal two-thirds of the intraarticular portion of the graft. The portion of the graft exiting the femoral tunnel and within the tibial tunnel retained a normal magnetic resonance signal. The increases in magnetic resonance graft signal were time-dependent, became well established by 3 months, and remained unchanged at 1 year. The clinical outcome could not be predicted based on the magnetic resonance signal of the graft.
Concealed entrainment as a guide for catheter ablation of ventricular tachycardia in patients with prior myocardial infarction. Fifteen consecutive patients with drug-refractory, recurrent, sustained, monomorphic ventricular tachycardia and a history of remote myocardial infarction underwent catheter ablation of ventricular tachycardia. Shocks of 100 to 300 J were delivered to sites at which pacing during ventricular tachycardia resulted in concealed entrainment, in which the ventricular tachycardia accelerated to the pacing rate, there was a long stimulus to QRS interval and there was no change in the configuration of the QRS complex during pacing at several rates compared with the configuration during ventricular tachycardia, thus identifying a zone of slow conduction in the reentrant circuit. Concealed entrainment was demonstrated in nine (60%) of 15 patients, and the stimulus to QRS intervals were 90 to 400 ms. At sites of concealed entrainment, the endocardial activation time relative to the QRS complex during ventricular tachycardia ranged from -125 to +50 ms, the timing of the local electrogram relative to the QRS complex was the same during entrainment as during ventricular tachycardia and the pace map during sinus rhythm was discordant with that of the ventricular tachycardia in seven patients. In the six patients in whom a site of concealed entrainment could not be identified, the target site for ablation was selected on the basis of identification of an isolated mid-diastolic potential, activation mapping and pace mapping. The mean (+/- SD) cumulative number of joules delivered to the target site was 306 +/- 140. A successful long-term clinical outcome was achieved in 9 of the 15 patients (mean follow-up 20 +/- 7 months). The clinical success rate was the same whether the target site was selected on the basis of concealed entrainment (five of nine, 56%) or on the basis of the other mapping techniques (four of six, 67%). In conclusion, the responses to pacing suggest that sites at which there is concealed entrainment may be located within a zone of slow conduction in the ventricular tachycardia reentry circuit, although not necessarily in an area critical for the maintenance of reentry. The long-term clinical efficacy of catheter ablation targeted to sites of concealed entrainment is about 60%, similar to the results achieved when conventional mapping techniques are used.
Hyperplastic polyps seen at sigmoidoscopy are markers for additional adenomas seen at colonoscopy. Asymptomatic individuals undergoing screening flexible sigmoidoscopy were prospectively studied. Polyps were found in 185 subjects. The endoscopist recorded an opinion on the polyps' histology based on endoscopic appearance. No polyps were removed at sigmoidoscopy. All subjects with rectosigmoid polyps then underwent colonoscopy and polypectomy. Of them, 99 subjects (54%) had at least one rectosigmoid adenoma, 69 (37%) had only hyperplastic polyps, and 17 (9%) had other findings. The endoscopists' opinion of the histopathology of polyps at sigmoidoscopy was correct for 61% of the lesions. Of subjects with adenomatous rectosigmoid polyps, 29% had additional adenomas at more proximal sites. Proximal adenomas were found in 28% of patients with hyperplastic rectosigmoid polyps. Patients with rectosigmoid hyperplastic polyps had the same risk for additional proximal adenomas as patients with rectosigmoid adenomatous polyps.
Collis gastroplasty: origin and evolution. In 1957 J. Leigh Collis published his innovative operation for treating the difficult problem of the irreducible hiatal hernia, esophagitis, and stricture. The design of the operation was based on the relatively primitive understanding of hiatal hernia and the newly emerging concept of reflux esophagitis. A variety of antireflux operations by different surgeons emerged over the years to follow. The original Collis gastroplasty has been subsequently modified with the addition of both partial and complete fundoplication procedures. The place of the modified Collis gastroplasty-fundoplication operations in today's approach to the problems of hiatal hernia and gastroesophageal reflux disease remains unsettled.
Detection of colorectal liver metastases using intraoperative ultrasonography. Intraoperative ultrasonography of the liver has been carried out in 99 patients undergoing surgery for colorectal cancer. Palpation of the liver, preoperative abdominal ultrasonography and computed tomography scanning were also performed in all patients. Metastases were identified in 26 of the 99 patients (26 per cent). Intraoperative ultrasonography diagnosed more metastases than palpation, abdominal ultrasonography or CT scanning, identifying metastases in 24 of the 26 patients, including six patients in whom the metastases were not detected by any other technique. Identification and localization of impalpable liver metastases is therefore possible using intraoperative ultrasonography.
The osteogenetic potential of fracture haematoma. Subperiosteal and intramuscular transplantation of the haematoma. We studied the precise role of the fracture haematoma in healing by the experimental transplantation of the haematoma at two days and four days after fracture of the rat femur to subperiosteal and intramuscular sites. We used bone marrow and peripheral blood haematomas for control experiments. The transplanted two-day fracture haematoma produced new bone by endochondral ossification at the subperiosteal site, but not at the intramuscular site. Four-day fracture haematoma produced new bone formation at both subperiosteal and intramuscular sites. These results suggest that fracture haematoma has an inherent osteogenetic potential.
Total knee arthroplasty in obese patients. We examined 182 patients (257 knees) who had had a total knee arthroplasty two to five six years earlier. The patients were grouped into five weight classes. Eighteen patients (twenty-seven knees) were considered moderately obese and twelve patients (twenty-seven knees), severely obese. The results in all but four knees were rated excellent or good. One patient needed a revision procedure for late infection, and the result was rated poor. Three results were rated fair. There was no discernible difference in the over-all scores among the five weight groups. However, 30 per cent of the knees of the moderately and severely obese patients had patellofemoral symptoms, whereas the incidence was 14 per cent in the other groups (p less than 0.03). No clear-cut association was found between obesity and either thrombophlebitis or complications related to the wound.
Cranial nerve palsy in childhood acute lymphoblastic leukemia and non-Hodgkin's lymphoma. Forty-five children with acute lymphoblastic leukemia or non-Hodgkin's lymphoma had cranial nerve palsy (CNP) as a complication of their disease. Twenty-two of these children had CNP initially and 23, at relapse, with or without previous hematologic relapse. Only one of the 23 patients with CNP at relapse was a long-term survivor. In contrast, 11 of the 22 children who had CNP initially survived in remission for 3+ months to 13+ years. Two factors are associated with an improved outcome for patients with CNP at diagnosis: treatment after 1979 (P less than 0.004) and male gender (P less than 0.01). Patients who received radiation therapy fared better than those for whom radiation was not given (disease-free survival at 2 years 53% versus 29%). The authors conclude that CNP signifies an aggressive or advanced disease requiring intensive systemic chemotherapy and that the role of irradiation should be examined for this group of patients.