Melricflash/CW_MedAbstractsAlt huggingface dataset:
A three-dimensional system for long-term culture of human colorectal adenomas. Studies of the adenoma-carcinoma sequence in the colon and rectum have been limited by the paucity of experimental models of adenoma growth and progression. Progress recently was reported in the development of monolayer culture systems. The principal objective of this study was to develop a primary culture system for colorectal adenomas that would simulate three-dimensional in vivo growth. We used a calcium alginate encapsulation technique that was previously described for established tumor cell lines. Briefly, fresh resected specimens were washed, minced into small multicellular particles called microadenomas, and encapsulated in 1% calcium alginate pellets. The pellets were maintained in minimum essential medium containing 10% fetal bovine serum at 37 degrees C in humidified atmosphere of 95% air, 5% CO2. Ten of eleven adenomas, including six tubular, three tubulovillous, and one villous have been successfully cultured for 34 to 162 days. Cell viability was confirmed histologically by light and electron microscopy. The cells were characterized as epithelial by morphologic features and ultrastructural studies, which showed a high degree of cellular differentiation, including villous brush borders and many desmosomes. Both tubular and villuslike structures have been observed in vitro, correlating in some cases with the histology of the parent adenoma. Measurements of proliferative activity by [3H]thymidine autoradiography or immunohistochemical staining with the monoclonal antibody Ki-67 demonstrated growth fractions of 9% to 25%. A simple, highly efficient primary culture system was developed for the long-term maintenance of adenomas that promotes three-dimensional growth patterns and growth rates analogous to those seen in vivo. This model provides an opportunity to develop an experimental system for longitudinal studies of pathologic and molecular parameters in adenoma progression to carcinoma. 

Category: neoplasms
Diagnostic utility of lower extremity radiographs of young children with gait disturbance. The diagnostic utility of lower extremity radiographs was evaluated using 84 outpatients 1 to 5 years of age with gait disturbance whose lower extremities appeared physically normal. Chief complaints included limp (65 children [77%]), refusal to walk or stand (37 children [44%]), and frequent falling (6 children [7%]). A total of 43 children (51%) had more than one complaint. The mean age of patients was 26 months and the median duration of symptoms was 1 day. Trauma was reported in 43 (51%) cases and fever in 14 (17%). Results of radiographical studies appeared normal in 81 children (96%), demonstrated soft tissue swelling in 2 children, and revealed a bony island in 1 child. In 1 patient admitted to the hospital for failure to thrive and irritability, and whose radiographic results appeared normal, findings consistent with osteomyelitis later developed. Of the remaining children, 68 (81%) were available for follow-up observation 4 to 28 months after the initial visit and all reported spontaneous resolution of the initial complaint. It was concluded that in a well-appearing child with an otherwise normal physical examination results, an acute gait disturbance is likely to be a self-limiting condition and radiographs are unlikely to contribute to the diagnosis. 

Category: nervous system diseases
Tethered cord syndrome from a choristoma of mullerian origin. Case report. The authors report a case of tethered cord syndrome due to a choristoma of mullerian origin located in the spinal cord at the lumbosacral junction. Two similar cases were found upon review of the literature. The embryology of this lesion is discussed. 

Category: neoplasms
The internist in the management of head and neck cancer. The general internist has an important role in the management of head and neck squamous cell cancers. This heterogeneous group of cancers must be accurately diagnosed and staged before planning treatment. Curability is directly related to stage at presentation and, because most patients with such cancers present to internists first, these physicians must be familiar with presenting symptoms and must be suspicious enough to refer patients with symptoms for appropriate evaluation. The work-up of patients with suspected unknown primary cancer presenting as adenopathy is detailed, and the physician is cautioned not to immediately proceed to open biopsy. As many as 10% of such primary cancers remain undetected, although, with proper therapy, the 5-year survival rate for squamous cell cancer of the head and neck is 60%. Those patients cured of head and neck cancer still face significant psychosocial and medical problems, including hypothyroidism, xerostomia, and a 20% rate of second primary cancer. Head and neck cancer is highly preventable; 75% of cases are related to tobacco and alcohol use. Smokeless tobacco has gained popularity among young Americans and is associated with an increased incidence of head and neck cancer at several sites. Education is crucial, and internists must seek strategies to stop patients from using tobacco products. Other etiologic factors include industrial carcinogens, Epstein-Barr virus, and diet. Retrospective serologic and dietary recall studies of vitamin A suggest an etiologic role of diet; vitamin A analogs have been tested in preneoplastic lesions. To reduce mortality from head and neck cancers, the general internist must play a central role in prevention and early detection. 

Category: neoplasms
Nerve growth factor binding domain of the nerve growth factor receptor. A structural analysis of the rat low-affinity nerve growth factor (NGF) receptor was undertaken to define the NGF binding domain. Mutant NGF receptor DNA constructs were expressed in mouse fibroblasts or COS cells, and the ability of the mutant receptor to bind NGF was assayed. In the first mutant, all but 16 amino acid residues of the intracellular domain of the receptor were removed. This receptor bound NGF with a Kd comparable to that of the wild-type receptor. A second mutant contained only the four cysteine-rich sequences from the extracellular portion of the protein. This mutant was expressed in COS cells and the resultant protein was a secreted soluble form of the receptor that was able to bind NGF. Two N-terminal deletions, in which either the first cysteine-rich sequence of the first and part of the second cysteine-rich sequences were removed, bound NGF. However, a mutant lacking all four cysteine-rich sequences was unable to bind NGF. These results show that the four cysteine-rich sequences of the NGF receptor contain the NGF binding domain. 

Category: general pathological conditions
The role of the physician in the late diagnosis of primary malignant tumors of the small intestine. Survival from primary malignancies of the small intestine has not improved during the last four decades. One reason for this is the advanced stage of disease at the time of surgery. In order to determine why diagnosis is made late, we reviewed the records of all patients with small bowel malignancy diagnosed between 1967 and 1988. The time from the onset of symptoms to the first medical contact and the time from medical contact until diagnosis were evaluated in 77 patients. The average delay in diagnosis attributable 1) to the patient failing to report symptoms was less than 2 months, 2) to the physician not ordering the appropriate diagnostic test was 8.2 months, and 3) to the radiologist failing to make the diagnosis was 12 months. Thus, the major delay in diagnosis was after medical help was sought and not from the onset of symptoms to first medical consultation. Physicians must increase their sensitivity to the subtle but persistent symptoms that necessitate a small bowel evaluation. 

Category: neoplasms
Morphological changes in unmyelinated nerve fibres in the sural nerve with age. Quantitative changes in unmyelinated nerve fibres in sural nerves obtained at autopsy were evaluated in 28 normal adults. The following conclusions were reached. (1) The density of unmyelinated axons showed no significant correlation with age, but the densities of (2) Schwann cell subunits with axons, (3) Schwann cell subunits without axons, (4) single protrusions of Schwann cells and (5) collagen pockets, and (6) the mean number of Schwann cell profiles per axon, all showed positive correlations with age. Additionally, (7) the percentage of subunits containing unmyelinated axons and (8) the mean number of axons in single axon-containing Schwann cell subunits demonstrated negative correlations with age. The density of Schwann cell nuclei related to unmyelinated fibres did not show a significant change with age. The age-dependent changes in unmyelinated nerve fibres thus mainly consist of an increased production of processes by Schwann cells in the absence of cell multiplication. A decrease in unmyelinated nerve fibre density or a compensatory increase of small unmyelinated axons did not occur in these normal adults. In terms of relative sensitivity for the detection of the earliest changes in unmyelinated fibres, the indices (6) and (7) are considered to be useful and superior to the conventional assessment of unmyelinated axon density and diameter distribution. These two indices are not influenced by postmortem swelling of the axons and Schwann cells. Measurements of unmyelinated axon density and size distribution will continue to be useful in the assessment of more advanced pathological conditions. 

Category: general pathological conditions
Interleukin-6 mRNA and protein increase in vivo following induction of acute thrombocytopenia in mice. Induction of experimental thrombocytopenia in rodents results in the enhancement of megakaryocytic growth and differentiation. Interleukin-3 (IL-3) and IL-6, cytokines with a broad spectrum of biologic activities, stimulate megakaryocytopoiesis in vitro. To determine if expression of these factors might increase in response to experimental thrombocytopenia, we measured steady-state levels of IL-3 and IL-6 mRNA following rabbit antiplatelet serum (APS) injection. Groups of mice were injected intravenously with 0.2 mL APS while control animals received rabbit antilymphocyte serum (ALS), normal rabbit serum (NRS), or phosphate-buffered saline (PBS). At various times up to 72 hours after injection mice were exsanguinated and splenectomized. Platelet counts in the experimental animals were less than 12% of controls. Splenic RNA was hybridized in solution to 32P-UTP-labeled cRNA probes for IL-3 and IL-6. RNase-resistant hybrids were resolved on denaturing gels and visualized autoradiographically. IL-3 hybrids were undetectable at all time points tested, irrespective of the film exposure time or specific activity of the probe. Conversely, IL-6 hybrids were easily visualized and showed peak expression at 1.5 to 2.0 hours. By 3 hours, IL-6 mRNA had returned almost to the level of the controls. Similar results were observed in the bone marrow, although maximal IL-6 mRNA in that tissue was observed 4 hours following APS administration. To determine if this mRNA increment was associated with a concomitant increase in bioactive protein, serum was tested for its ability to stimulate IL-6-dependent B9 cells. At 1.75 hours following injection, experimental animals showed a small but significant increment in IL-6 activity compared with controls (200 +/- 30 U/mL IL-6 compared with 129 +/- 17 U/mL in ALS-injected controls, 106 +/- 17 U/mL in NRS-injected controls and 84 +/- 17 U/mL in PBS-injected controls). The data show that IL-6 mRNA and bioactive protein increase in response to acute immunothrombocytopenia, while no increment in IL-3 is detectable. These results suggest that IL-6 may play a role in the physiologic response to acute immunothrombocytopenia. 

Category: general pathological conditions
Spatial dispersion of magnetic stimulation in peripheral nerves. To assess the longitudinal dispersion of the stimulus induced by the magnetic coil, collision experiments were performed in seven normal ulnar nerves. A supramaximal electrical stimulus S1 was delivered at the wrist, and followed by a supramaximal stimulus S2 in the upper arm, which was either electrical (electrical collision studies), or magnetic (magnetic collision studies). The interstimulus interval was varied by 0.2 msec increments from the time of complete cancellation of the S2 evoked motor response onwards, to include the entire span of recovery of that compound motor action potential. Collision curves were obtained for both magnetic and electrical stimuli by plotting the amplitude of the motor response elicited by S2 as a function of the interstimulus interval. In all seven normal ulnar nerves, comparison of the collision curves showed that the S2 evoked motor response is restored significantly more slowly when magnetic stimulation is used. This finding is best explained by longitudinal dispersion of the stimulus induced by the magnetic coil relative to conventional electrical stimulation, the large fibers being stimulated further away from the coil than the small ones. This interpretation is confirmed by the findings obtained with the same method in two cases of ulnar neuropathy, and by comparison of different intensities of magnetic stimulation. 

Category: nervous system diseases
Distinguishing malignant mesothelioma from pulmonary adenocarcinoma: an immuno-histochemical approach using a panel of monoclonal antibodies. A panel of six monoclonal antibodies (MAbs) was employed to evaluate antigen expression in pulmonary adenocarcinomas and mesotheliomas. Monoclonal anti-human milk fat globulin (HMFG-2), anti-carcinoembryonic antigen (NP-2), anti-epithelial membrane antigen (EMA), anti-cytokeratin (PKK-1), anti-tumor-associated antigen 72 (B72.3), and anti-human myelomonocytic antigen (Leu M-1) antibodies were used to localize their respective antigens in formalin-fixed, paraffin-embedded tumors by using the avidin-biotin-complex immunoperoxidase technique. In all, 28 mesotheliomas obtained from Ohio State University Anatomic Pathology files and from a Southwest Oncology Group (SWOG) protocol were compared to 22 pulmonary adenocarcinomas by using this MAb panel. None of the mesotheliomas demonstrated positive staining with MAbs NP-2 (anti-CEA) or Leu M-1. However, 95% (21/22) of adenocarcinomas stained with one of these two antibodies. Although neither of these two MAbs stained all adenocarcinomas, each antibody demonstrated positive immunostaining in more than 90% of the adenocarcinomas studied. Therefore, MABs NP-2 and Leu M-1 are, individually, quite useful for distinguishing mesothelioma from adenocarcinoma. However, in our study, no single MAb could be used to distinguish these two tumor types in every case. MAb B72.3 stained 91% (20/21) adenocarcinomas but also stained 7% (2/28) of mesotheliomas. MAb HMFG-2 reacted positively with 95% of adenocarcinomas, but also stained 39% of the mesotheliomas, usually in a membranous pattern. MAbs EMA and PKK-1 were not found useful in distinguishing mesothelioma from adenocarcinoma. We conclude that MAbs Leu M-1 and NP-2 were both useful in distinguishing mesothelioma from pulmonary adenocarcinoma in that positive staining was demonstrated in adenocarcinomas and not mesotheliomas. 

Category: neoplasms
A computerized laboratory alerting system. A computerized laboratory alerting system (CLAS) has been developed as part of an ongoing effort to improve the quality of care at LDS Hospital. The system identifies potentially life-threatening conditions on the basis of laboratory findings and then generates appropriate warnings and transmits them to clinicians. Use of the system has led to a significant increase in the proportion of patients in life-threatening situations who have received appropriate care (50.8% before implementation vs. 62.5% afterward, P less than 0.05). Among patients with hypokalemia, falling potassium levels, hyperkalemia, hypokalemia during treatment with digoxin, hyponatremia, falling sodium levels, hypernatremia, hypoglycemia, or hyperglycemia, the average length of time spent in the life-threatening situation has decreased from 30.4 to 15.7 hours (P less than 0.05) and the average length of stay has decreased from 14.6 to 8.8 days (P less than 0.05). There has been little change in the proportion of patients with findings indicating metabolic acidosis who have received appropriate care (32.3 vs. 34.6%). We conclude that CLAS has an important role in patient care at our hospital. 

Category: general pathological conditions
Embolization with particles in thoracic intramedullary arteriovenous malformations: long-term angiographic and clinical results. To evaluate the long-term results of endovascular treatment with particles in the management of thoracic intramedullary arteriovenous malformations (AVMs), the authors retrospectively reviewed the angiographic and clinical findings in 35 patients. Follow-up was 1-15 years (mean, 6 years) in 28 patients and 6-10 months (mean, 7 months) in seven. A total of 158 embolization procedures were performed in 35 patients. Revascularization occurred frequently, necessitating multiple endovascular sessions. Long-term clinical evaluation showed clinical improvement, compared with the initial status before treatment, in 63% of the patients. Clinical aggravation due to embolization was observed in seven patients (20%) after 12 of the 158 endovascular sessions (8%). These results are better than those reported after surgery and indicate that embolization with particles is an efficient and safe tool in the treatment of thoracic intramedullary AVMs. 

Category: cardiovascular diseases
Left ventricular pseudoaneurysm complicating mitral valve replacement in a 4-year-old child with acute bacterial endocarditis. A 4-year-old child with acute bacterial endocarditis required mitral valve replacement. A left ventricular pseudoaneurysm developed following surgery. The etiology and diagnosis of this complication are discussed. 

Category: cardiovascular diseases
Enhanced alpha 1-adrenergic responsiveness in cardiomyopathic hamster cardiac myocytes. Relation to the expression of pertussis toxin-sensitive G protein and alpha 1-adrenergic receptors. The pathogenesis of the myopathy occurring in the heart of the cardiomyopathic strain of the Syrian hamster is not well understood but is believed to be associated with abnormal calcium handling by myopathic cells. The purpose of this study was to determine whether the cardiomyopathy occurring in strain BIO 14.6 animals is associated with an enhanced alpha 1-adrenergic receptor-mediated rise in cytosolic calcium, whether a pertussis toxin-sensitive G protein is involved in coupling the alpha 1-adrenergic receptor to changes in intracellular calcium and whether enhanced alpha 1 responsiveness is associated with an increase in the level of expression of the alpha 1-adrenergic receptor or in the pertussis toxin-sensitive G protein or proteins. To test the hypothesis that the cardiomyopathic state is associated with a greater alpha 1-receptor-mediated rise in cytosolic calcium, we studied the effect of phenylephrine (in the presence of propranolol) on time-averaged cytosolic calcium concentration ([Ca2+]i) in isolated cardiac myocytes from cardiomyopathic and age-matched control hamsters. Phenylephrine caused a greater increase both in time-averaged [Ca2+]i (an increase of 48 +/- 8% versus 12 +/- 3%, p less than 0.01) and in contractility (+181 +/- 22% versus +35 +/- 9%, p less than 0.01) in cardiomyopathic than in normal cardiac myocytes. Exposure to pertussis toxin (200 ng/ml for 3 hours) attenuated the alpha 1-adrenergic receptor-mediated increase in contractility and time-averaged [Ca2+]i in both cardiomyopathic and normal cells. The level of pertussis toxin-sensitive G protein, as determined by pertussis toxin-mediated [32P]ADP-ribosylation, was 1.6-fold higher in cardiomyopathic versus normal hamster hearts. The density of alpha 1-adrenergic receptors, as measured by the antagonist radioligand [3H]prazosin and the affinity of the receptor for agonist and antagonist were similar in myopathic and normal heart membranes. Thus, in cardiac myocytes from hamsters, the alpha 1-adrenergic receptor-mediated effects on [Ca2+]i and contractility appear to be mediated by a pertussis toxin-sensitive G protein or proteins. In myocytes from cardiomyopathic hamsters, these alpha 1-adrenergic effects were increased in magnitude, as was the level of pertussis toxin-sensitive G protein, but there was no measurable alteration in the density or ligand binding properties of alpha 1-adrenergic receptors. 

Category: cardiovascular diseases
Chronic pain. Understanding of the etiology of chronic pain is growing rapidly as researchers seek to integrate physiologic and psychosocial mechanisms. When nurses assess clients with chronic pain, they should make their assessments using both verbal and nonverbal methods and realize that no one instrument is comprehensive enough to be used alone. The key to successful treatment of these difficult clients lies in the use of a comprehensive approach that takes the client seriously and integrates both physiologic and psychosocial approaches. 

Category: general pathological conditions
Long-term results of submandibular duct transposition for drooling. This study examines the long-term results and morbidity of submandibular duct transposition in drooling children. Twenty-two patients, aged 3 to 18 years, with neurological dysfunction and excessive drooling underwent submandibular duct transposition between 1984 and 1987. In January 1990, 20 patients were reviewed. Their degree of drooling pre-operatively, immediately post-operatively and currently was assessed. The rate of improvement and the occurrence of complications were noted. Drooling was 'much better' in the early post-operative period in 17 of the 20 patients, and this improvement was invariably noted within three weeks. In the three other patients drooling was 'better'. Deterioration occurred in only three patients over the entire follow-up period. Complications all occurred in the first 18 months following surgery; they consisted of salivary retention cysts in four and transient submandibular gland swelling in a fifth patient. 

Category: general pathological conditions
Mucin production by human colonic carcinoma cells correlates with their metastatic potential in animal models of colon cancer metastasis. Patients with mucinous colorectal cancers characteristically present with advanced disease, however, the relationship between mucin production by colon cancer cells and their metastatic potential remains unclear. We therefore sought to define the relationship between mucin production by human colon cancer cells and metastatic ability by employing animal models of colon cancer metastasis. LS LiM 6, a colon carcinoma cell line with high liver metastasizing ability during cecal growth in nude mice produced twofold more metabolically labeled intracellular mucin and secreted four- to fivefold more mucin into the culture medium compared to poorly metastatic parental line LS174T. This was accompanied by a similar elevation in poly(A)+ RNA detected by blot hybridization with a human intestinal mucin cDNA probe, and increases in mucin core carbohydrate antigens determined immunohistochemically. Variants of LS174T selected for high (HM 7) or low (LM 12) mucin synthesizing capacity also yielded metastases after cecal growth and colonized the liver after splenic-portal injection in proportion to their ability to produce mucin. Inhibition of mucin glycosylation by the arylglycoside benzyl-alpha-N-acetyl-galactosamine greatly reduced liver colonization after splenic-portal injection of the tumor cells. These data suggest that mucin production by human colon cancer cells correlates with their metastatic potential and affects their ability to colonize the liver in experimental model systems. 

Category: neoplasms