123rc/medical_text huggingface dataset:
Malnutrition and carbohydrate malabsorption in children with vertically transmitted human immunodeficiency virus 1 infection. The nutritional needs of children with human immunodeficiency virus infection are poorly understood. Twenty-eight children with vertically transmitted human immunodeficiency virus infection were evaluated for carbohydrate malabsorption using lactose hydrogen breath tests and d-xylose absorption studies. Lactose malabsorption was a common finding in human immunodeficiency virus-infected children and occurred in 8 of 20 patients who had no identifiable enteric pathogen. Lactose malabsorption occurred at an earlier age in human immunodeficiency virus-infected children than in an age-matched group of 45 symptomatic control children (P = 0.02). However, lactose malabsorption was not associated with higher rates of diarrhea or growth failure. Abnormalities in d-xylose absorption were not significantly associated with either diarrhea or growth failure. However, 39% of d-xylose studies (9 of 23) showed abnormal results and were significantly associated with enteric infections (P = 0.004). Abnormalities in small-bowel morphology were found in 4 of 9 children with growth failure, 3 of whom had an enteric infection and low d-xylose absorption. Lactose hydrogen breath testing and d-xylose testing showed carbohydrate malabsorption in 61% of children (17 of 28). This study demonstrates that human immunodeficiency virus-infected children are at risk for malabsorptive disorders, which are not always related to clinical symptoms. We speculate that human immunodeficiency virus may be directly involved in the development of lactose malabsorption. Carbohydrate malabsorption in human immunodeficiency virus-infected children may not be the only factor responsible for growth failure.
Hot spots for growth hormone gene deletions in homologous regions outside of Alu repeats. Familial growth hormone deficiency type 1A is an autosomal recessive disease caused by deletion of both growth hormone-1 (GH1) alleles. Ten patients from heterogeneous geographic origins showed differences in restriction fragment length polymorphism haplotypes in nondeleted regions that flanked GH1, suggesting that these deletions arose from independent unequal recombination events. Deoxyribonucleic acid (DNA) samples from nine of ten patients showed that crossovers occurred within 99% homologous, 594-base pair (bp) segments that flanked GH1. A DNA sample from one patient indicated that the crossover occurred within 454-bp segments that flanked GH1 and contained 274-bp repeats that are 98% homologous. Although Alu repeats, which are frequent sites of recombination, are adjacent to GH1, they were not involved in any of the recombination events studied. These results suggest that length and degree of DNA sequence homology are important in defining recombination sites that resulted in GH1 deletions.
Identification of lymphotoxin and tumor necrosis factor in multiple sclerosis lesions. Multiple sclerosis (MS) brain tissue, spleen, and PBMC were studied using immunocytochemistry and FACS for immunoreactivity for lymphotoxin (LT) and TNF. Both cytokines were identified in acute and chronic active MS lesions but were absent from chronic silent lesions. LT was associated with CD3+ lymphocytes and Leu-M5+ microglia cells at the lesion edge and to a lesser extent, in adjacent white matter. TNF was associated with astrocytes in all areas of the lesion, and with foamy macrophages in the center of the active lesion. In acute lesions, immunoreactivity for TNF in endothelial cells was noted at the lesion edge. No LT or TNF reactivity was detected in Alzheimer's or Parkinson's disease brain tissues but was present at lower levels in central nervous system (CNS) tissue from other inflammatory conditions, except for adrenoleucodystrophy which displayed high levels of LT in microglia. No increase in LT and TNF reactivity was detected in spleen and PBMC of MS patients suggesting specific reactivity within the CNS. These results indicate that LT and TNF may be involved in the immunopathogenesis of MS, and can be detected in both inflammatory cells and cells endogenous to the CNS.
Cerebrospinal fluid fistula and endoscopic sinus surgery. Seven cases of cerebrospinal fluid fistulae occurring as a result of endoscopic sinus surgery in a total of 800 ethmoidectomies are discussed, along with 1 case referred for consultation. One cerebrospinal fluid fistula was intrasphenoid, 4 were posterior ethmoid/base of skull, 2 were anterior ethmoid, and 1 was ethmoid cribriform. Six of 8 fistulae were closed endoscopically. The sphenoid sinus cerebrospinal fluid fistula was closed successfully with fibrin glue and Gelfoam. Five cerebrospinal fluid fistulae were closed successfully using fascia, muscle, and Gel-foam. Two cerebrospinal fluid fistulae were treated conservatively, and only 1 stopped. Anatomic and technical aspects related to the occurrence of cerebrospinal fluid fistulae are discussed. Management and treatment of cerebrospinal fluid fistulae occurring during and after endoscopic sinus surgery is emphasized. When identified intraoperatively or delayed, cerebrospinal fluid fistulae can be managed successfully by endoscopic technique.
Beta-adrenergic effects on carbohydrate metabolism in the unweighted rat soleus muscle. The effects of insulin on carbohydrate metabolism in atrophied rat soleus muscle are increased after unweighting by tail-cast suspension. This work has been extended by testing the effect of unweighting on the response of carbohydrate metabolism to isoproterenol, a beta-adrenergic agonist. Isoproterenol promoted glycogen degradation more in the unweighted than in the weight-bearing soleus but showed no differences in the extensor digitorum longus, which is unresponsive to hindlimb unweighting. In soleus muscles depleted of glycogen, to avoid varied inhibitory effects of glycogen on glycogen synthesis, isoproterenol inhibited this process more in the unweighted muscle. Isoproterenol did not have a greater inhibitory effect on net uptake of 2-deoxy-D[1,2-3H]glucose by the unweighted muscle. Measurements of intracellular 2-deoxy-[3H]glucose 6-phosphate and 3-O-methyl-D-[1-3H]glucose, which cannot be phosphorylated, showed that isoproterenol inhibited glucose phosphorylation but not transport. This effect could be explained by an increase of glucose 6-phosphate, an inhibitor of hexokinase. At 100 microU insulin/ml but not at a lower amount (10 microU/ml), isoproterenol inhibited hexose phosphorylation more in the control than in the unweighted muscle. This result may be explained by greater insulin antagonism in the unweighted muscle owing to increased insulin sensitivity. However, insulin antagonism of isoproterenol stimulation of glycogenolysis or inhibition of glycogenesis was not altered by unweighting. Therefore, for some aspects of carbohydrate metabolism, the unweighted muscle has an increased response to beta-adrenergic activation, just as this muscle shows increased responses to insulin.
Stunned myocardium and myocardial collagen damage: differential effects of single and repeated occlusions. It has been suggested that collagen loss and damage is responsible for the dysfunction seen in stunned myocardium. To test this hypothesis we compared collagen in canine hearts stunned by repeated occlusion with collagen in hearts stunned by a single occlusion. Regional contractile function was equally depressed in both groups: segment shortening at 1 hour after reperfusion averaged 37% +/- 9% versus 32% +/- 9% of preocclusion values in repeated and single occlusion models, respectively. Midmyocardial collagen content was not different in either single occlusion (10.5% +/- 0.4%) or repeated occlusion models (9.5% +/- 0.7%) when compared with nonischemic hearts (8.5 +/- 0.8%). Collagen damage, which was revealed with polarized light microscopy, was seen in 5 of 6 dogs after repeated occlusion but was not apparent after a single occlusion. Thus although both models of stunned myocardium produce similar dysfunction, there was no apparent collagen loss. Furthermore, collagen damage was only seen after repeated occlusion. Therefore it appears unlikely that collagen damage is a primary mechanism of stunned myocardium.
Surgical treatment of endomyocardial fibrosis: a new approach. Endomyocardial fibrosis has been treated surgically for many years. For complete removal of fibrosis from both ventricles by the classic technique, each atrioventricular (AV) valve was removed and replaced with a prosthesis. Relapse of endomyocardial fibrosis has not been observed after surgical correction. Reoperations have been carried out because of complications of valve prostheses. A new surgical technique for removal of ventricular fibrous tissue with preservation of the mitral and tricuspid valves was used in nine consecutive patients with endomyocardial fibrosis. Initial results show a reduction of pulmonary hypertension, mean right and left atrial pressures and end-diastolic pressures in both ventricles. Tricuspid annuloplasty was performed in seven patients and mitral annuloplasty in five. No valve prosthesis was used. There was no death and New York Heart Association functional class improved from class III or IV in the preoperative period to class I or II in the postoperative period. These data suggest that resection of endocardial fibrous tissue can be indicated early in the clinical course and performed with preservation of the AV valves.
Myocardial perfusion imaging with technetium-99m sestamibi SPECT in the evaluation of coronary artery disease. Technetium-99m (Tc-99m) sestamibi is a new myocardial perfusion imaging agent that offers significant advantages over thallium-201 (Tl-201) for myocardial perfusion imaging. The results of the current clinical trials using acquisition and processing parameters similar to those for Tl-201 and a separate (2-day) injection protocol suggest that Tc-99m sestamibi and Tl-201 single photon emission computed tomography (SPECT) provide similar information with respect to detection of myocardial perfusion defects, assessment of the pattern of defect reversibility, overall detection of coronary artery disease (CAD) and detection of disease in individual coronary arteries. Tc-99m sestamibi SPECT appears to be superior to Tc-99m sestamibi planar imaging because the former provides a higher defect contrast and is more accurate for detection of disease in individual coronary arteries. Research is currently under way addressing optimization of acquisition and processing of Tc-99m sestamibi studies and development of quantitative algorithms for detection and localization of CAD and sizing of transmural and nontransmural myocardial perfusion defects. It is expected that with the implementation of the final results of these new developments, further significant improvement in image quality will be attained, which in turn will further increase the confidence in image interpretation. Development of algorithms for analysis of end-diastolic myocardial images may allow better evaluation of small and nontransmural myocardial defects. Furthermore, gated studies may provide valuable information with respect to regional myocardial wall motion and wall thickening. With the implementation of algorithms for attenuation and scatter correction, the overall specificity of Tc-99m sestamibi SPECT should improve significantly because of a substantial decrease in the occurrence of attenuation-related image artifacts.
Incisional parapubic hernias. A parapubic hernia, distinct from other lower abdominal wall hernias, is identified as a particular type of incisional hernia. This hernia results from the disruption of the musculotendinous elements of the abdominal wall as they insert into the pubis. This disruption is brought about by either the destruction of these musculotendinous tissues at their lower end or the resection of portions of the pubic bone as is sometimes done in suprapubic radical prostatectomies for easier access to the prostate. Seven cases have been identified and reported. Men and women were seen to make up a clinical picture that is suggestive of the diagnosis, namely, multiple previous operations through the lower abdominal wall, procedures of a gynecologic or urologic nature, a herniation that mimics an incisional or inguinal hernia, and a defect that cannot possibly be corrected without the use of a prosthesis. When the diagnosis is accurately established, the polypropylene mesh is inserted in the preperitoneal space and anchored laterally to the ligaments of Cooper and in between to the arcuate pubic ligament and the periosteum of the posterior aspect of the pubis. Excellent results have been obtained, and the success must be ascribed to the recognition of the parapubic hernia as a distinct entity.
Short-term changes in renal function, blood pressure, and electrolyte levels in patients receiving cyclosporine for dermatologic disorders. We compared the changes in renal function, blood pressure (BP), and concentrations of serum potassium, magnesium, and urate (uric acid) in two groups of patients not given transplants. Group 1, comprising 21 psoriatic patients, was treated with 14 mg/kg per day of oral cyclosporine for 4 weeks in a prospective, placebo-controlled study; group 2, comprising 28 patients with diverse cutaneous diseases, was given 6 mg/kg per day of oral cyclosporine for 1 to 3 months in a prospective, open-labeled study. Renal function (determined by serum urea nitrogen [SUN] and creatinine levels and urinalysis), BP, serum electrolyte levels (potassium and magnesium), and urate level were measured weekly for the first 4 weeks in both groups, and then, after 2 and 3 months of therapy, in group 2 only. During the first 4 weeks in group 1 patients, there were significant increases in values of SUN, creatinine, BP, potassium, and urate, and a significant decrease in the serum magnesium value. When data for the two groups were combined, the changes from pretherapy values in each of the above measures (except systolic BP) during the first 4 weeks correlated significantly with cyclosporine trough levels. In group 2, the changes that occurred in the first 4 weeks in the SUN value, SUN/creatinine ratio, and BP were magnified over the subsequent 8 weeks of treatment. In the combined group for the first 4 weeks of therapy, duration of therapy, independent of cyclosporine trough levels, correlated with changes in SUN, creatinine, and urate levels, but not with changes in the potassium or magnesium level or in BP. We conclude that the cyclosporine blood level was a better discriminant than cyclosporine dosage in the analysis of renal dysfunction and hypertension in these patients.
Pyogenic hepatic abscess. Presented is a case of spontaneous pyogenic hepatic abscess in a previously healthy young man without associated risk factors. This disease entity has a low incidence, however, it is associated with significant morbidity and mortality if diagnosis and treatment are delayed.
Delayed chest wall pain due to sternal wire sutures. This report describes 18 patients with disabling chest wall pain due to one or more sternal wire sutures. The pain occurred from 2 to 84 months after a median sternotomy. The pain was described either as sharp and stabbing or as a deep-seated ache. The involved wires had an exaggerated fibrous tissue reaction surrounding the twisted portion. The adjacent noninvolved wires had minimal reaction. In the last 7 patients, serial sections of the fibrous tissue revealed entrapment of one or more sensory nerve fibers. In 6 of the 7 electrical potentials were measured and found to be elevated, indicating wire damage during twisting. Ferroxyl tests confirmed the collection of iron ions at this anodic point as a result of corrosion. Removal of the involved wires and the fibrous tissue surrounding this anodic point relieved the symptoms of pain and tenderness resulting from entrapped sensory nerves.
Unusual cause of 'piriformis muscle syndrome'. The piriformis muscle syndrome is a controversial "clinical" syndrome primarily characterized by signs and symptoms of sciatic nerve compression at the region of the piriformis muscle as it passes through the greater sciatic notch. The syndrome is often referred to; however, cases are rarely reported, and it is generally an uncommon diagnosis. Of those cases reported, the incidence is six times more frequent in females than in males, and is typically temporally related to minor pelvic or buttock trauma. We describe a case of a 40-year-old woman presenting with signs and symptoms suggestive of piriformis muscle syndrome following a gynecologic procedure performed in the dorsal lithotomy position. Electromyographic findings were consistent with this clinical entity. Operative exploration, however, revealed the source of neural compression to be a pseudoaneurysm of the inferior gluteal artery adjacent to the piriformis muscle. The diagnostic features of this clinical syndrome are discussed.
Trisomy 13: a new recurring chromosome abnormality in acute leukemia. A new recurring chromosome abnormality was identified in 8 of 621 consecutive successfully karyotyped adults with de novo acute leukemia. These eight patients had trisomy 13 as the sole cytogenetic abnormality. On central morphologic review, five cases were classified as subtypes of acute myeloid leukemia, one as acute mixed lymphoid and myeloid leukemia, one as acute lymphoid leukemia, and one as acute undifferentiated leukemia. Blasts of all eight cases expressed one or more myeloid differentiation antigens. Three also expressed T-lineage-associated antigens; however, none of these had rearrangement of the T-cell receptor beta, gamma, or delta genes. Four of six cases tested were TdT positive. All eight patients with trisomy 13 were treated with intensive induction chemotherapy; only three entered a short-lived complete remission. Survival of patients with trisomy 13 ranged from 0.5 to 14.7 months, and was significantly shorter than that of the remaining patients (median 9.5 v 16.2 months, P = .007). We conclude that trisomy 13 is a rare, recurring clonal chromosome abnormality in acute leukemia associated with a poor prognosis. Malignant transformation of an immature hematopoietic precursor cell is suggested by the expression of antigens characteristic of both the myeloid and lymphoid lineage, the high incidence of TdT positivity, and the morphologic heterogeneity in these leukemias.
Possible mechanisms of abnormal norepinephrine sensitivity and reactivity of resistance vessels and the development of hypertension in spontaneously hypertensive rats. A hypothesis. This study examined structural and functional changes of mesenteric resistance vessels in early, developing, and established stages of hypertension development in spontaneously hypertensive rats in an attempt to identify possible mechanisms of the development and maintenance of hypertension. Our results suggest that the development of hypertension in spontaneously hypertensive rats may be caused by genetic structural and functional abnormalities of resistance vessels. Both abnormalities may be caused by hyperreactivity to norepinephrine through an altered signal transduction process, including the regulation of protein kinase C in smooth muscle cells of resistance vessels in spontaneously hypertensive rats.
Influence of chromosomal integration on glucocorticoid-regulated transcription of growth-stimulating papillomavirus genes E6 and E7 in cervical carcinoma cells. In most cervical carcinoma cells the E6 and E7 genes of specific human papillomaviruses are transcribed from viral sequences integrated into host cell chromosomes. Glucocorticoids activate the promoter elements of various human papillomaviruses in transient-expression assays. We have analyzed the effect of dexamethasone on the transcription rate of human papillomavirus 18 E6 and E7 genes integrated at different chromosomal sites in four cervical cancer cell lines. Dexamethasone led to an increase in the transcription rate of the integrated E6-E7 sequences in C4-1 and C4-2 cells but led to a decrease in SW 756 cells and did not affect the transcription rate in HeLa cells. However, when the viral promoter elements derived from HeLa or SW 756 cells, in which dexamethasone does not activate transcription of the integrated E6-E7 sequences, were tested in transient-expression assays within the same cell lines, dexamethasone consistently activated the viral promoter. It thus appears that dominant regulatory mechanisms presumably depending on the chromosomal integration site are able to override the response of the viral promoter to steroid hormones. The growth rate of all dexamethasone-treated cell lines correlated consistently with the expression of the papillomavirus E6 and E7 genes, supporting their role in the maintenance of the proliferative phenotype of cervical carcinoma cells. Since human papillomaviruses are integrated into the host cell genome at variable, presumably randomly selected chromosomal loci, regulatory mechanisms that influence viral gene expression, and hence cell growth, may differ among cancers of independent clonal origin.
Persistent primitive trigeminal artery-cavernous sinus fistulas: report of two cases. Two cases of persistent primitive trigeminal artery-cavernous sinus fistulas are presented. In one case, the fistula was treated by using a two-balloon tandem technique. This method was accomplished by introducing, inflating, and detaching a silicone balloon into the trigeminal artery, thus preserving the carotid and basilar blood flow. An unusual case of a similar fistula with only contralateral exophthalmos is also reported. The relationship between this type of fistula and the presence of aneurysms on the persistent primitive trigeminal artery and the relationship with traumatic events are discussed.
Development of language in six hemispherectomized patients. The development of language skills in the isolated right hemisphere was investigated by comparing the performance of 3 left hemispherectomized with that of the 3 right hemispherectomized patients and three groups of control subjects on baseline clinical measures of language and on production and judgement of morphological markers. The initial brain insult in the hemispherectomy patients of each group had occurred either during early, middle or late childhood. The left hemispherectomy patients were severely impaired in language processing across all three stages of language development. The consequences of a right hemisphere insult on language development were more restricted, with deleterious effects being apparent only in the case in which the lesion was acquired during early childhood.
A gene in the human major histocompatibility complex class II region controlling the class I antigen presentation pathway Major histocompatibility complex (MHC) class I molecules export peptides to the cell surface for surveillance by cytotoxic T lymphocytes. Intracellular peptide binding is critical for the proper assembly and transport of class I molecules. This mechanism is impaired as a result of a non-functional peptide supply factor gene (PSF) in several human mutant cell lines with genomic lesions in the MHC. We have now identified PSF in the MHC class II region by deletion mapping in mutants and chromosome-walking. PSF is homologous to mammalian and bacterial ATP-dependent transport proteins, suggesting that it operates in the intracellular transport of peptides.