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61.
The uptake of 57Co-cyanocobalamin (CN-Cbl) and its conversion to 5- deoxyadenosylcobalamin (Ado-Cbl), methylcobalamin (Me-Cbl), and hydroxocobalamin (OH-Cbl) has been studied in phytohemagglutinin (PHA)- transformed lymphocytes from normal subjects and patients with patients with pernicious anemia. Uptake and conversion were much greater by PHA- stimulated lymphocytes than by mature non-transformed lymphocytes. In normal cells, uptake of 57Co-CN-Cbl and synthesis of the cobalamin coenzymes were approximately linear between 3 and 48 hr incubation. Ado- Cbl was the major cobalamin formed, and after 72 hr the cells contained about twice as much Ado-Cbl as Me-Cbl. Uptake by lymphocytes from patients with untreated pernicious anemia (PA) was greater than that by normal lymphocytes, but the proportions of Ado-Cbl and Me-Cbl synthesized by each were similar. Folic acid and methyltetrahydrofolate enhanced synthesis of Me-Cbl both in normal and in PA cells, while methotrexate and 5-fluorouracil depressed it. This depression was overcome by 5-formyltetrahydrofolate, suggesting that an uninterrupted folate cycle may play an important role in Me-Cbl synthesis. 相似文献
62.
Sullivan EV; Lim KO; Mathalon D; Marsh L; Beal DM; Harris D; Hoff AL; Faustman WO; Pfefferbaum A 《Cerebral cortex (New York, N.Y. : 1991)》1998,8(2):117-124
Quantitative magnetic resonance imaging (MRI) studies from our laboratory
have reported that patients with schizophrenia show a widespread cortical
gray matter volume deficit, which is especially pronounced in the
prefrontal and anterior superior temporal cortices. The present study
compared two separate samples of schizophrenic patients -- 71 men from a
Veterans Administration (VA) hospital and a sample of 57 severely ill men
from a state hospital (SH) -- in an effort to test whether the pattern of
brain volume abnormalities previously observed in VA schizophrenic patients
can be generalized to other groups of schizophrenic patients. MRI-derived
brain volumes of gray matter, white matter and sulcal cerebrospinal fluid
(CSF) in six cortical regions, and CSF in the lateral and third ventricles
were computed. All MRI volumes were adjusted for normal variation in head
size and age and were expressed as standardized Z-scores, which also
permitted structures of different sizes to be compared directly. The two
schizophrenic groups displayed similar patterns of volume abnormalities:
cortical gray matter but not white matter volume deficits that were
widespread but especially notable in the prefrontal and temporal regions.
The regional gray matter deficits in the SH group were generally greater
than those in the VA group, particularly in the prefrontal and posterior
superior temporal regions. Both schizophrenic groups had abnormally large
volumes of the cortical sulci and lateral and third ventricles; however,
the SH group showed greater enlargements, the most prominent occurring in
the ventricles and temporal sulci. The overlapping patterns of cortical
gray matter deficits in the two groups provide evidence for generality of
this pattern of regional brain volume abnormalities in schizophrenia.
相似文献
63.
Surgical cholecystectomy is associated with a high morbidity and mortality in elderly patients with acute calculous cholecystitis and underlying cardiac or pulmonary disease. Currently there are few alternatives for treating these patients. The authors have used percutaneous cholecystolithotomy in 11 such high-risk patients for definitive treatment of gallbladder calculi. In all 11 patients all stones were successfully removed from the gallbladder and cystic duct. The entire procedure--from initial tube placement to final tube removal--lasted 17-40 days (mean, 21 days). There were two complications: one minor--local wound infection--and one major--bile peritonitis with eventual death. Percutaneous cholecystolithotomy is an effective alternative therapy for acute calculous cholecystitis in elderly, debilitated patients. 相似文献
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66.
We recently reported the positional cloning of a homeobox gene involved in
the pathogenesis of Rieger syndrome, RIEG1 , and its mouse homolog, Rieg1 .
Rieg1 (also independently described as Pitx2) is highly homologous to the
Ptx1/Potx gene product, suggesting that there may be additional members of
this novel Pitx family. The Pitx genes play an important role in eye,
tooth, pituitary and umbilical region development as evidenced by Rieger
syndrome and iris hypoplasia phenotypes, resulting from mutations in the
RIEG1 gene and by expression studies. In order to characterize further the
Pitx gene family we searched mouse cDNA libraries to identify additional
members. A new gene was isolated which encodes a homeoprotein with strong
homology to the other Pitx proteins and 97-100% identity in the homeodomain
itself, suggesting that this is a third member of the family, Pitx3 . In
whole mount in situ hybridization on mouse embryos ranging from 8.5 to 11.5
days post-coitum (d.p.c.), Pitx3 mRNA was seen only in the developing lens
starting at day 11. Hybridization on cross- sections revealed strong
signals in the lens vesicle in 11 d.p.c. embryos and throughout the lens,
particularly in the anterior epithelium and equator region in 15 d.p.c.
embryos. Pitx3 was mapped close to aphakia on mouse chromosome 19. The
aphakia homozygous mouse is characterized by small eyes lacking a lens,
which fail to develop beyond 11 d.p.c. These data make Pitx3 a strong
candidate gene for the aphakia phenotype in the mouse and suggest a role
for the human homolog in congenital lens malformations.
相似文献
67.
Jacobson AF; Parker JA; Royal HD; Silverman KJ; Gervino EV; Kolodny GM 《Radiology》1987,163(3):691-695
In patients undergoing exercise thallium-201 myocardial scintigraphy, activity in the inferior wall on anterior images may appear diminished when the standard supine view is used, but normal when the view is acquired with the patient upright. To determine the clinical significance of this observation, the distribution of thallium-201 activity was semiquantitatively assessed in supine and upright anterior images obtained immediately after exercise in 93 patients (65 men, 28 women). The presence of inferior wall and coronary artery disease was established with coronary angiography or from documentation of previous myocardial infarction. Supine and upright images were compared with use of receiver operating characteristic curves. In male patients diagnostic accuracy for identification of both inferior wall and coronary artery disease was improved through the use of the upright anterior image. In women, there was no significant difference in reader performance with upright and supine images. Upright anterior images should be routinely obtained in men in order to reduce the frequency of false-positive identification of inferior wall defects. 相似文献
68.
69.
Field small-plot experiments studied the effects of sediments of waste water from Saransk disposal systems. The content of toxic heavy metals (lead, arsenic, and cadmium) in the waste-water sediments, was shown to be not greater than their maximum permissible concentrations (32, 2, and 10 mg per kg of dried soil, respectively). With the use of waste-water sediments, the content of manganese, copper, tin, nickel, vanadium, beryllium, cobalt, iron, and chromium was found to correspond to their baseline level in the soil and plants. 相似文献
70.
IM BRZUSZCZAK J. ZHAO C. BELL D. STIEL I. FIELDING J. PERCY R. SMITH EV O'LOUGHLIN 《Journal of gastroenterology and hepatology》1996,11(9):804-810
Cyclic AMP-dependent Cl secretion is the major secretion pathway in human intestine. The aim of the present study was to examine mechanisms involved in cAMP-dependent anion secretion in human small and large intestine. Surgical resection specimens from both jejunum and distal colon were studied under short circuited conditions. Addition of the phosphodiesterase inhibitor IBMX induced an increase in the short-circuit current (Isc) equivalent to the net increase in Cl secretion. The Isc was inhibited by diphenylamine decarboxylate (DPC; Cl channel blocker), bumetanide (basolateral Na+/K+/2Cl cotransporter), BaCl2 (basolateral K+ channel) and Cl free buffer in both segments and indomethacin (cyclo-oxygenase inhibitor) in colon alone. Diphenylamine decarboxylate appears to directly inhibit secretion in jejunum, although its inhibitory effect is possibly mediated by inhibition of cyclo-oxygenase in the colon. A small component of IBMX-stimulated Isc was inhibited by acetazolamide. Cyclic AMP-dependent secretion is largely apical Cl secretion, although a small component appears to be HCO3. Secretion is dependent on basolateral K+ channels and Na+/K+/2Cl cotransporters and, in the colon, is inhibited by indomethacin, implying a role for cyclo-oxygenase metabolites. The chloride channel blocker DPC inhibits secretion in both areas. This class of compounds may have potential for treatment of secretory diarrhoea. 相似文献