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At least 73 records · Page 4Linked to original sources
PubMed1987

[10 years' experience using a modified Shouldice surgical technic for inguinal hernia in adults. II. Which factors modify the recurrence of inguinal hernia?].

Many factors seem to influence the recurrence rate after adult inguinal hernia repair. A statistical analysis of data derived from 726 transversalis fascia repairs examined by the authors (with a follow-up rate of 82.5% and a mean follow-up time of 5.5 years) revealed a significantly higher recurrence rate in patients with chronic bronchitis (p less than 0.05) or with postoperative complications (p less than 0.001). Lower recurrence rates were found after resection of lipomas of the cord (p less than 0.01) or cremasteric muscle resection (p less than 0.05). No significant difference of recurrence rate could be established for following parameters: Sex, side, age distribution, profession, prostatism, obesity, type of hernia (direct, indirect, combined, sliding), suture material (silk, polyglycolic acid), surgeon, anesthesia (local, spinal, full), elective or emergency operation, and whether the repair was unilateral or simultaneously bilateral. Recurrent repairs showed no significantly higher recurrence rate than primary repairs.

Adult↗
PubMed1984

Cancer therapy with chemically modified enzymes. II. The therapeutic effectiveness of arginase, and arginase modified by the covalent attachment of polyethylene glycol, on the taper liver tumor and the L5178Y murine leukemia.

Monomethoxypolyethylene glycol (PEG) was attached covalently to arginase. PEG-arginase was effective in prolonging the survival times of mice injected with the Taper liver tumor, whereas unmodified arginase was ineffective. PEG-arginase was more effective than arginase in the in vitro destruction of L5178Y mouse leukemia. However, neither PEG-arginase nor arginase inhibited the in vivo growth of this tumor.

Animals↗
PubMed1984

Low-density lipoproteins modified by lipid transfer protein have altered biological activity.

Low-density lipoproteins (LDL) were modified by incubation with very-low-density lipoproteins (VLDL) and lipid transfer protein(s) to yield LDL particles that were enriched in triacylglycerol, depleted in cholesteryl esters, and contained apolipoprotein C. The uptake and degradation of these 125I-labeled modified LDL particles by cultured skin fibroblasts was reduced by approx. 30% when compared with LDL that had not been exposed to lipid transfer protein. Incubation of fibroblasts for 24 h in the presence of modified LDL resulted in less inhibition of LDL receptor activity and sterol synthesis than did incubation with control LDL. Both the degradation of 125I-labeled modified LDL and the effect of unlabeled modified LDL on the regulation of LDL binding and sterol synthesis were progressively decreased as the extent of modification of the LDL was increased. Even when identical amounts of modified LDL or control LDL protein were degraded, less inhibition of LDL receptor activity and sterol synthesis was observed with modified LDL than with control LDL, suggesting that the effects of modified LDL on these regulatory events are related to both the reduced degradation of the modified lipoprotein particles and to the alteration in its chemical composition. Uptake and degradation of modified LDL by human monocyte-derived macrophages in culture was reduced in a manner similar to that observed in the cultured fibroblasts, and was considerably less than that observed with acetylated LDL. No differences were observed between modified LDL prepared by exposure to lipid transfer activity in the lipoprotein deficient fraction of serum or when partially purified lipid transfer was used. Modified LDL, with similar composition to that used in the experiments, has been observed in certain diabetic and non-diabetic hypertriglyceridemic states. Thus, it is possible that the cellular metabolism of LDL in vivo might be altered in the presence of hypertriglyceridemia.

Acetates↗
PubMed1992

Alkaloid-modified sodium channels from lobster walking leg nerves in planar lipid bilayers.

Alkaloid-modified, voltage-dependent sodium channels from lobster walking leg nerves were studied in planar neutral lipid bilayers. In symmetrical 0.5 M NaCl the single channel conductance of veratridine (VTD) (10 pS) was less than that of batrachotoxin (BTX) (16 pS) modified channels. At positive potentials, VTD- but not BTX-modified channels remained open at a flickery substate. VTD-modified channels underwent closures on the order of milliseconds (fast process), seconds (slow process), and minutes. The channel fractional open time (f(o)) due to the fast process, the slow process, and all channel closures (overall f(o)) increased with depolarization. The fast process had a midpoint potential (V(a)) of -122 mV and an apparent gating charge (z(a)) of 2.9, and the slow process had a V(a) of -95 mV and a z(a) of 1.6. The overall f(o) was predominantly determined by closures on the order of minutes, and had a V(a) of about -24 mV and a shallow voltage dependence (z(a) approximately 0.7). Augmenting the VTD concentration increased the overall f(o) without changing the number of detectable channels. However, the occurrence of closures on the order of minutes persisted even at super-saturating concentrations of VTD. The occurrence of these long closures was nonrandom and the level of nonrandomness was usually unaffected by the number of channels, suggesting that channel behavior was nonindependent. BTX-modified channels also underwent closures on the order of milliseconds, seconds, and minutes. Their characterization, however, was complicated by the apparent low BTX binding affinity and by an apparent high binding reversibility (channel disappearance) of BTX to these channels. VTD- but not BTX-modified channels inactivated slowly at high positive potentials (greater than +30 mV). Single channel conductance versus NaCl concentrations saturated at high NaCl concentrations and was non-Langmuirian at low NaCl concentrations. At all NaCl concentrations the conductance of VTD-modified channels was lower than that of BTX-modified channels. However, this difference in conductance decreased as NaCl concentrations neared zero, approaching the same limiting value. The permeability ratio of sodium over potassium obtained under mixed ionic conditions was similar for VTD (2.46)- and BTX (2.48)-modified channels, whereas that obtained under bi-ionic conditions was lower for VTD (1.83)- than for BTX (2.70)-modified channels. Tetrodotoxin blocked these alkaloid-modified channels with an apparent binding affinity in the nanomolar range.

Alkaloids↗
PubMed1987

Gastric acid and pancreatic polypeptide responses to modified sham feeding. Effects of truncal and parietal cell vagotomy.

The effects of truncal vagotomy and parietal cell vagotomy on gastric acid secretion and plasma gastrin and pancreatic polypeptide release were studied in 28 duodenal ulcer patients under basal conditions and after modified sham feeding and infusion of pentagastrin (2 micrograms/kg/h). Before vagotomy gastric acid output in response to modified sham feeding was significantly higher than basal acid secretion in all subjects tested and reached about 45% of the pentagastrin maximum. No difference in the increase in acid response, or in the pancreatic polypeptide response to modified sham feeding was found between patients with high and low basal secretion. Plasma gastrin concentration was unaltered by modified sham feeding before and after truncal vagotomy or parietal cell vagotomy, although after vagotomy it tended to reach higher values than before this procedure. After truncal vagotomy, basal pancreatic polypeptide concentration was decreased and modified sham feeding-induced pancreatic polypeptide increment was completely eliminated. Four weeks after parietal cell vagotomy, the modified sham feeding-induced increment in plasma pancreatic polypeptide was significantly decreased and observed only in seven of 12 patients. Four to five years after parietal cell vagotomy all subjects responded to modified sham feeding with pancreatic polypeptide increment similar to that before vagotomy and in three of 12 patients acid response to modified sham feeding was seen. This study indicates that truncal vagotomy eliminates gastric acid and plasma pancreatic polypeptide responses to vagal excitation while parietal cell vagotomy abolishes gastric acid response and reduces temporarily the pancreatic polypeptide response to modified sham feeding (possibly because of transient impairment of the vagal innervation of the pancreas). (2) A high ratio of basal to maximal acid output in non-operated duodenal ulcer patients is not associated with a low acid response to modified sham feeding, nor with a high pancreatic polypeptide concentration, and (3) Restitution of the pancreatic polypeptide response to modified sham feeding five years after parietal cell vagotomy does not indication ineffective denervation of the parietal cells.

Adolescent↗
PubMed1983

Sequence specificity of tRNA-modifying enzymes. An analysis of 258 tRNA sequences.

The specificity and recognition of tRNA-modifying enzymes may be accounted for in part by nucleotide sequences which are localized next to the modifiable nucleoside. In order to determine the sequence specificity of tRNA-modifying enzymes, we have surveyed 55 published tRNA sequences from Escherichia coli, Salmonella typhimurium and T4 phage. For each modified nucleoside, the nucleotide sequence surrounding the modification site was determined for all tRNAs known to contain the modified nucleoside. Subsequently all tRNAs not containing the modified nucleoside were examined for the absence of the putative recognition site. We present the detailed analysis of 12 modified nucleosides for which we found a strong correlation between the modified nucleoside and the local nucleotide sequence. This suggests that these sequences may be recognition sites for tRNA-modifying enzymes. For each of the 12 modified nucleosides we have identified a recognition sequence present in the tRNA set containing the modification and not in the set without it. All 203 other published tRNA sequences were then examined to see if the sequence specificity rules apply to other organisms, including both prokaryotes and eukaryotes. In several cases a good adherence was found, indicating conservation of the putative recognition sequences.

Animals↗