Melricflash/CW_MedAbstractsAlt huggingface dataset:
Limb reconstruction with vascularized fibular grafts after bone tumor resection. Limb-salvage operations are being used with increasing frequency for patients with malignant bone tumors. For children, when a biologic reconstruction is desired, the choice is often between conventional and vascularized fibular grafts. An experimental study was performed in dogs to compare the two types of fibular grafts for bridging segmental defects in the radius and ulna. Twenty-six adult dogs were divided into two groups and studied at intervals of two, three, four, six, and 12 months after transplantation. The conventional grafts healed by creeping substitution i.e., they were first partially resorbed before new bone was laid down. In contrast, the vascularized fibulae maintained their normal structure and hypertrophied by subperiosteal new bone formation. The conventional fibulae eventually hypertrophied but much later than the vascularized grafts. The vascularized grafts were stronger at four and six months. Between six and 12 months, both grafts remodeled to resemble the size and shape of the forearm bones they were replacing. These experimental results have influenced the treatment of patients. Vascularized fibular grafts are ideal for diaphyseal defects greater than 10 cm long, especially in very young children, a poorly vascularized bed, or when bone healing is delayed by chemotherapeutic agents. To maximize hypertrophy, an external fixator is used to immobilize the graft rather than a plate, which acts as a stress shield. 

Category: neoplasms
The pathophysiology of anoxic injury in central nervous system white matter. White matter of the mammalian brain is susceptible to anoxic injury, but little is known about the pathophysiology of this process. We studied the mechanisms of anoxic injury in white matter using the isolated rat optic nerve, a typical central nervous system white-matter tract. Optic nerve function, measured as the area under the compound action potential, rapidly failed when exposed to anoxia. Postanoxic recovery was variable, depending on duration of the anoxic insult; after a standard 60-minute period of anoxia, the compound action potential recovered to 28.5% of control. Irreversible anoxic injury was critically dependent on extracellular Ca2+; maintaining the tissue in zero [Ca2+] solution throughout the anoxic period resulted in 100% compound action potential recovery. Increasing perfusate [Ca2+] during anoxia from zero to 4 mM resulted in progressively less recovery. Anoxic damage to the optic nerve appears to depend on the gradual accumulation (over tens of minutes) of Ca2+ in a cytoplasmic compartment. The inorganic Ca2+ channel blockers Mn2+ (1 mM), Co2+ (1 mM), or La3+ (0.1 mM) had no effect on recovery of the compound action potential after anoxia; only Mg2+ (10 mM) significantly improved recovery. Treatment with the dihydropyridine Ca2+ channel blockers nifedipine (1-10 microM) or nimodipine (1-40 microM) also had no effect on recovery from anoxia. Thus, Ca2+ influx during anoxia does not occur via conventional Ca2+ channels. Preliminary evidence suggests that this Ca2+ influx may occur via other cation channels that are imperfectly selective for Ca2+ or via the Na(+)-Ca2+ exchanger. 

Category: nervous system diseases
Fibrosing mediastinitis with coronary artery involvement. This case report describes a patient with chronic fibrosing mediastinitis involving the entire intrapericardial aorta, innominate artery, and the base of the heart with involvement of the proximal segments of the coronary arteries. This finding was unsuspected before emergency coronary artery bypass grafting. Coronary stenosis due to fibrosing mediastinitis is a rare complication of fibrosing mediastinitis. Owing to the extensive fibrosis, the normal bypass, cardiac preservation, and revascularization techniques required alteration and are discussed. 

Category: cardiovascular diseases
Clonal origin of pituitary adenomas. As the pathogenesis of pituitary adenomas remains unclear, the tumor clonal composition of these common neoplasms was studied. Clonality was determined in female patients by analysis of restriction fragment length polymorphisms of the X-chromosome genes hypoxanthine phosphoribosyl transferase and phosphoglycerate kinase in conjunction with their respective methylation patterns. Peripheral lymphocyte DNA was screened from 62 female patients undergoing transsphenoidal surgery for pituitary adenoma. Eleven patients were heterozygous for the BglI site on PGK, 4 for the BamHI site on HPRT, and 1 patient for both sites. Of these 16 patients, 3 had acromegaly, 4 had Cushing's disease, 7 had hyperprolactinemia, and 2 were clinically nonfunctional. After surgery, morphological study, including immunohistochemistry and electron microscopy of the pathological specimens, allowed a direct comparison between clonality and tumor cell type. Control fresh normal pituitary tissue was found to be polyclonal. The following tumors were monoclonal: all 3 somatotroph adenomas, 4 of 4 lactotroph tumors, 3 of 4 corticotroph cell adenomas, a gonadotroph adenoma, and a nonsecretory adenoma. A mixed plurihormonal adenoma was polyclonal, as were 2 tumors consisting of adenomatous lactotrophs interspersed with nontumorous adenohypophyseal pituitary tissue and one corticotroph adenoma mixed with normal pituitary tissue. Functional pituitary adenomas derived from somatotrophs, corticotrophs, or lactotrophs and nonsecretory tumors are monoclonal in nature, suggesting that somatic cell mutations precede clonal expansion of these cells and play a major role in pituitary tumorigenesis. 

Category: neoplasms
Inflammatory pseudotumor of the liver. Inflammatory pseudotumor of the liver is an extremely rare entity. Because of its unusual clinical presentation and confusing histologic picture, a diagnosis of malignancy is frequently made. Thus the surgeon is closely involved with the case and extensive procedures are not uncommon. However, this lesion is benign and will even regress spontaneously, making radical surgical procedures contraindicated. The difficulty lies in establishing an accurate diagnosis and the histologic pitfalls of this particular process. Conservative therapy can then be applied, avoiding surgical morbidity. 

Category: neoplasms
Eosinophilia-myalgia syndrome associated with ingestion of L-tryptophan: muscle biopsy findings in 4 patients. Muscle biopsies of 4 patients with the eosinophilia-myalgia syndrome associated with ingestion of L-tryptophan showed lymphocytic infiltrates with occasional eosinophils largely restricted to interstitial fibrous tissue and perivascular areas. There was inflammation and fibrosis of muscle spindle capsules in 3 patients. In the 2 sickest patients, there was profound muscle atrophy, affecting both muscle fiber types. 

Category: general pathological conditions
A phase I trial of cisplatin in hypertonic saline and escalating doses of 5-fluorouracil by continuous intravenous infusion in patients with advanced malignancies. Thirty-four patients with incurable solid tumors were treated in a Phase I trial with a fixed dose of high-dose cisplatin (CDDP) administered in hypertonic saline and escalating doses of infusional 5-fluorouracil (5-FU). Five treatment levels of 5-FU, ranging from 500 to 900 mg/m2/day for 5 days, were studied. Leukopenia, thrombocytopenia, and oral mucositis were the dose-limiting toxicities encountered. Nephrotoxicity was minimal. Ototoxicity and peripheral neuropathies were rare and mild in this patient group, but most patients received only a small number of treatment cycles. Diarrhea was not dose-limiting. Two complete responses (one non-small cell lung cancer and one sweat gland carcinoma) were observed. No other major responses were noted. With the dose of CDDP set at 35 mg/m2/day for 5 consecutive days, the maximum tolerated dose (MTD) of a concurrent 5-day 5-FU infusion was found to be 900 mg/m2/day. The recommended dosages for Phase II trials are 35 mg/m2/day CDDP and 800 mg/m2/day 5-FU for 5 consecutive days. Cancers of the lung, breast, gastrointestinal tract, and genitourinary tract would be reasonable targets for Phase II studies. 

Category: neoplasms
Rigid fixation of internal orbital fractures. When large portions of the internal orbit are destroyed (two to four walls), standard bone-grafting techniques for immediate and late orbital reconstruction may not yield predictable eye position. Critical bone support is most often deficient inferomedially. CT analysis of orbital volume in cases where eye position was unsatisfactory reveals that displacement of bone grafts is one mechanism of the unsatisfactory result. Other mechanisms include undercorrection and bone-graft resorption. In order to minimize postoperative bone-graft displacement, titanium implants were used to span large defects in the internal orbit to provide a platform for bone-graft support. Twenty-six implants were placed in immediate and 12 were placed in late orbital reconstructions. More reliable bone-graft position resulted. Two late infections have occurred resulting in implant removal in a 3-year period. 

Category: nervous system diseases
Ischemic optic neuropathy. ION typically affects the older population with a sudden decrease in vision, altitudinal visual field loss, and a swollen optic nervehead. Systemic hypertension and diabetes mellitus are the most commonly associated medical problems. Occlusion of the posterior ciliary arterial blood supply to the retrolaminar optic nerve leads to axoplasmic stasis and further compromise of vessels in the nerve substance, which causes the typical funduscopic appearance. Although there is no recognized medical treatment that can reverse the visual loss, a recent report suggests optic nerve sheath decompression for a select group of patients with a gradual decline in vision due to ION may be beneficial. When ION occurs in persons less than 50 years of age, such etiologies as juvenile diabetes mellitus, antiphospholipid antibody-associated clotting disorders, collagen-vascular disease, and migraines should be considered. Rarely, complications of intraocular surgery or acute blood loss may cause an ischemic event in the optic nerve. 

Category: cardiovascular diseases
A phase II multi-institutional trial of low-dose N-(phosphonacetyl)-L-aspartate and high-dose 5-fluorouracil as a short-term infusion in the treatment of adenocarcinoma of the pancreas. A Southwest Oncology Group study. Adenocarcinoma of the pancreas is a highly lethal malignancy and chemotherapy has had little impact on the natural history of this disease. PALA, used to potentiate 5-fluorouracil (5-FU), has been shown to have synergy in vivo and in vitro. Twenty-seven patients were treated with an intravenous push dose of PALA (250 mg/m2) followed 24 hours later with a 24-hour infusion of 5-FU (2600 mg/m2). This regimen was repeated weekly. There was one partial response of 21 eligible patients with an estimated response rate of 5%. Toxicity was severe with one toxic death and four patients experiencing Grade 4 toxicity. 5-Fluorouracil and PALA, given in the schedule described, do not appear to be effective against adenocarcinoma of the pancreas. 

Category: neoplasms
Mechanisms of hemolysis and anemia associated with acute antepartum pyelonephritis. Anemia develops in about a fourth of women whose pregnancy is complicated by pyelonephritis, although its exact mechanism has not been defined clearly. In this study of 18 women with antepartum pyelonephritis, although only a third had anemia (hematocrit less than 30 vol/dl), there was evidence for hemolysis in all 18. Specifically there was a mean decrease in hematocrit of 5 vol/dl from admission to discharge. With scanning electron microscopy, we compared erythrocyte morphologic aberrations that were found in women with renal infection with those of normally pregnant women, and the former had significantly increased proportions of echinocytes in particular, but schistocytes and spherocytes were increased also (total 10.3% vs 1.4%, p less than 0.0001). These changes, especially echinocytosis, have been induced in vitro by lipopolysaccharide, and they are known to lead to premature red blood cell destruction in vivo. We conclude that hemolysis with subsequent anemia in pregnant women with pyelonephritis is caused by lipopolysaccharide-induced red blood cell membrane damage. 

Category: general pathological conditions
Reliability of stimulated and spontaneous growth hormone (GH) levels for identifying the child with low GH secretion. The reliability of stimulated and spontaneous GH levels for identifying the child with low GH secretion has been the subject of debate. We compared the ability of GH concentrations after pharmacological stimulation with levodopa and clonidine and of spontaneous peak and 12-h pooled GH concentrations during sleep on a single night to estimate the maximum spontaneous GH secretion from 2 nights in 55 children, aged 5-16 yr, with heights below the 3rd percentile and/or height velocities below the 25th percentile for age, who had two consecutive overnight GH secretory profiles. Maximum stimulated GH concentrations correctly categorized 80% of children who had maximum spontaneous GH concentrations above and below 4 micrograms/L using a double monoclonal immunoradiometric assay for GH (Tandem-R HGH, Hybritech). The remaining 20% of children had stimulated GH concentrations below but spontaneous GH concentrations above 4 micrograms/L. Using this cut-off, the maximum GH concentrations from the first and second nights correctly categorized 98% and 95% of the children, respectively. Night to night variation in GH secretion was low in children who had low spontaneous GH secretion (maximum spontaneous peak and pool GH concentrations, less than 4 and less than or equal to 0.7 micrograms/L, respectively), and pooled GH concentrations from the 2 nights were concordant in 98% of the cases. We conclude that it is not uncommon for stimulated GH concentrations to underestimate spontaneous GH secretion. Even without acclimatization to the hospital setting, measurement of spontaneous GH secretion on a single night was more reliable for identifying the child with low endogenous GH secretion than was GH stimulation testing alone. 

Category: general pathological conditions
Decreased protein binding of salicylates in Kawasaki disease. Because patients with Kawasaki disease have low serum concentrations of salicylates despite high doses, and because the free (unbound) drug is responsible for the pharmacologic effects of salicylates, we assessed salicylate protein binding in patients with Kawasaki disease. During the acute phase of the disease, protein binding of salicylate in 36 children with Kawasaki disease was 73 +/- 12%, significantly lower than during the subacute phase (90.4 +/- 8.7%; p less than 0.0005). Mean serum albumin concentration was 29.2 +/- 6.4 gm/L during the acute phase and 36.7 +/- 7.8 gm/L during the subsequent subacute phase (p less than 0.005). Salicylate protein binding was affected independently by both serum albumin and total salicylate levels. During the acute phase of Kawasaki disease, children had an average twofold increase in free salicylate compared with normoalbuminemic control subjects. A nomogram has been devised to derive free salicylate levels from the known total salicylate and serum albumin concentrations. 

Category: general pathological conditions
Transoesophageal echocardiography in the longitudinal axis: correlation between anatomy and images and its clinical implications. Transoesophageal echocardiographic imaging in the longitudinal axis is a recent addition to the non-invasive evaluation of congenital and acquired heart disease. The technique provides unique images of intracardiac anatomy but their interpretation remains difficult. A heart specimen was therefore cut according to the echocardiographic imaging planes to elucidate the morphological details. The results suggested that longitudinal transoesophageal imaging complements the transverse axis approach. It gave new imaging information on the right ventricular outflow tract and the pulmonary trunk, the atrioventricular valves, the interventricular septum, the cardiac apex, and the thoracic aorta. In particular, it showed the entire length of the right ventricular outflow tract. When longitudinal imaging was used in combination with transverse imaging almost all the thoracic aorta could be examined. Imaging in the longitudinal axis may also allow better assessment of the mechanisms of atrioventricular valve regurgitation. 

Category: cardiovascular diseases
Sumatriptan in acute migraine: pharmacology and review of world experience. The introduction of sumatriptan, a novel abortive antimigraine agent, has generated a significant amount of preclinical and clinical interest during the past few years. At the scientific level, sumatriptan is unique in terms of its selective pharmacological properties. The effects of sumatriptan in various experimental paradigms have led to new insights into the pathophysiology of migraine. At the clinical level, sumatriptan appears to be an effective abortive anti-migraine agent with minimal side effects. Its ability to decrease, rather than exacerbate, the nausea and vomiting of migraine appears to be an important advance in the treatment of migraine. 

Category: general pathological conditions
Postoperative active specific immunization in colorectal cancer patients with virus-modified autologous tumor-cell vaccine. First clinical results with tumor-cell vaccines modified with live but avirulent Newcastle disease virus [published erratum appears in Cancer 1991 Apr 15;67(8):2124] Sixteen patients with colorectal carcinoma Dukes' Stage B2, C, or D were treated with an autologous virus-modified tumor-cell vaccine after potential curative tumor resection (R0-Resection). An inoculum of 1 X 10(7) cells incubated with 32 hemagglutination units of nonirradiated Newcastle disease virus (NDV) was given intracutaneously up to four times at 10-day intervals. The delayed-type hypersensitivity (DTH) skin reaction was measured. The vaccination was well tolerated. In 11 of 16 patients an increasing reactivity against the vaccine was observed during the vaccination procedure. A challenge test using autologous tumor cells without NDV after the vaccination cycle revealed a specific antitumor sensibilization in 12 patients. The DTH response was not due to bacterial contamination or sensibility to the virus. Histologic examination of the vaccination site showed a dense infiltration of predominantly helper T-lymphocytes. We conclude that in most of the patients treated active, specific immunization led to a specific antitumor sensitivity. 

Category: neoplasms
Interleukin-6 (IL-6) is an intermediate in IL-1-induced proliferation of leukemic human megakaryoblasts. We have examined the in vitro effects of recombinant human (rh) interleukin-1 (IL-1) on the growth of purified megakaryoblasts obtained from patients with acute megakaryoblastic leukemia. We demonstrate that both IL-1 alpha and IL-1 beta treatment of these cells led to stimulation of DNA synthesis (as shown by increase of 3H-thymidine incorporation up to 35-fold) and also resulted in colony formation of leukemic megakaryoblasts. However, the stimulatory effect of IL-1 was dependent on endogenous production of IL-6, because addition of neutralizing monoclonal antibody (MoAb) to IL-6 abrogated the stimulatory activity of IL-1. In contrast, neutralizing MoAbs to granulocyte (G)-colony stimulating factor (CSF), granulocyte-macrophage (GM)-CSF, and macrophage (M)-CSF failed to counteract the growth-enhancing effects of IL-1. Leukemic megakaryoblasts accumulated IL-6 mRNA and released IL-6 protein into their culture supernatant when exposed to rh IL-1 but failed to disclose transcripts for G-, GM-, and M-CSF under these conditions. Analysis of IL-6 receptor (IL-6R) transcript levels demonstrated that megakaryoblasts constitutively expressed IL-6R mRNA and that these transcripts are down-regulated to undetectable levels upon exposure to IL-1 and IL-6. Increase of 3H-thymidine incorporation by megakaryoblasts could be duplicated by exogenous IL-6 that could be blocked by neutralizing MoAb to IL-6. In conclusion, our results suggest that leukemic megakaryoblasts could produce and secrete IL-6, and express IL-6R, and that the growth-enhancing effect of IL-1 on these cells is indirect, via production of IL-6 by leukemic cells. 

Category: neoplasms
Recurrence of Crohn's disease after resection. Recurrent Crohn's disease develops in most patients after surgical resection if the patient is followed for sufficient time. This review examines various aspects of recurrent Crohn's disease. It is concluded that Crohn's disease is a diffuse condition of the gastrointestinal tract and that radical resection of Crohn's disease does not prevent recurrence. Assorted factors thought to be associated with recurrence are examined and the relevance of these factors to the surgeon treating Crohn's disease is discussed. 

Category: digestive system diseases
Enlarged adenoid and adenoidectomy in adults: endoscopic approach and histopathological study. Adenoid enlargement is uncommon in adults and because examination of the nasopharynx by indirect posterior rhinoscopy is inadequate, many cases of enlarged adenoid in adults are misdiagnosed and accordingly maltreated. This study was conducted on 35 cases of enlarged adenoid aged between 20 and 42 years. The nasal endoscope was utilized to identify the adenoid mass. Adenoidectomy under transnasal endoscopic control was performed and all the excised material was sent for histopathological examination. Adenoidectomy resulted in marked improvement in 94 per cent of cases without major complications. Histopathological examination revealed non-specific inflammatory reaction in 15 cases (43 per cent), pure reactive changes, predominantly follicular hyperplasia, in two cases (6 per cent) and mixed pattern in 18 cases (51 per cent). Endoscopic follow-up for an average 17 months identified recurrence in only two patients. It was concluded that enlarged adenoid tissue in adults has some histopathological differences from that in children and adenoidectomy under transnasal endoscopic control is safe and reliable. 

Category: general pathological conditions
Neuroendocrine activity in congestive heart failure. The increased neuroendocrine activity in patients with congestive heart failure appears to be a generalized attempt to maintain blood pressure at the expense of reduced cardiac performance and salt and water retention. It is likely that baroreceptor dysfunction contributes to increased sympathetic nervous system activity in patients with congestive heart failure. The usual tonic inhibitory messages emanating from baro- and mechanoreceptors in the great vessels and heart fail to adjust sympathetic traffic from the brain to the periphery, leading to uninhibited sympathetic tone. Arginine vasopressin and plasma renin activity may be increased secondarily; however, plasma renin activity activation could also be induced by a low-salt diet and diuretic use. Preliminary baseline data indicate that patients with left ventricular dysfunction (ejection fraction less than or equal to 35%) but no or very mild symptoms of heart failure have increased plasma levels of norepinephrine, atrial natriuretic factor and arginine vasopressin, while plasma renin activity is normal, suggesting that neuroendocrine activity contributes to the pathogenesis of congestive heart failure. Neurohormones such as angiotensin II may alter gene expression, leading to changes in the shape and size of the cell. Remodeling of the heart and blood vessels is associated with both heart failure and hypertension. Angiotensin-converting enzyme inhibitors have been demonstrated to retard or reverse the remodeling process under certain experimental conditions. Studies are currently under way to test this possibility in patients. 

Category: cardiovascular diseases