PubMed Health⌕ Search

Biomedical subjects

D Long

Publications and source records attributed to D Long.

At least 73 records · Page 4Linked to original sources
PubMed1992

[Propofol versus etomidate in short-time urologic surgery].

Thirty patients, scheduled for short urological surgical procedures and ranked ASA 1 or 2, were randomly assigned to two homogenous groups. In group P, they were given a 2 mg.kg-1 bolus of propofol and 10 micrograms.kg-1 of alfentanil, followed by a continuous infusion of propofol (5 mg.kg-1.h-1) and 5 micrograms.kg-1 doses of alfentanil. In group E, they were given a 0.3 mg.kg-1 bolus of etomidate, followed by an infusion (1.5 mg.kg-1.h-1). The doses of alfentanil were the same as in group P. Further doses of either propofol (0.5 mg.kg-1) or etomidate (0.2 mg.kg-1) were used should anaesthesia prove not to be deep enough. The patients were not intubated, and breathed spontaneously. Surgery lasted a mean of 18.3 +/- 11.8 min (group P) and 18.8 +/- 9.4 min (group E). The following parameters were studied: the amount of each agent required for maintenance of anaesthesia, the duration of apnoea at induction, the quality of anaesthesia and of muscle relaxation, adverse effects (coughing, trismus, restlessness, nausea, vomiting), the time required for recovery, and its quality. In group P, there was a 27% decrease in arterial pressure, without any tachycardia or hypoxia, together with a quick recovery of excellent quality. On the other hand, in group E, there was little or no haemodynamic alteration, but there often was a trismus at induction. Hypoxia also occurred during induction with etomidate, being severe enough in one case to require tracheal intubation and artificial ventilation. The reasons for this hypoxia seemed to be the apnoea and the trismus, which tends to hinder assisted ventilation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Disulfide bond structure of glycoprotein D of herpes simplex virus types 1 and 2.

Glycoprotein D (gD) is a structural component of the herpes simplex virus envelope which is essential for virus penetration. The function of this protein is highly dependent on its structure, and its structure is dependent on maintenance of three intact disulfide bonds. gD contains six cysteines in its ectodomain whose spacing is conserved among all its homologs in other alphaherpesviruses as well as Marek's disease virus. For other proteins, conservation of cysteine spacing correlates with conservation of disulfide bond structure. We have now solved the disulfide bond structure of gD-1 and gD-2 of herpes simplex virus types 1 and 2, respectively. Two approaches were used. First, we constructed 15 double-Cys mutants of gD-1, representing all possible disulfide pairs. In each case, codons for cysteines were changed to serine. We reasoned that if two cysteines normally form a disulfide bond, double mutations which eliminate one proper bond should be less harmful to gD structure than double mutations which eliminate two disulfide bonds. The mutated genes were cloned into a eucaryotic expression vector, and the proteins were expressed in transiently transfected cells. Three double mutations, Cys-1,5, Cys-2,6, and Cys-3,4 permitted gD-1 folding, processing, transport to the cell surface, and function in virus infection, whereas 12 other double mutations each produced a malfolded and nonfunctional protein. Thus, the three functional double-Cys mutants may represent the actual partners in disulfide bond linkages. The second approach was to define the actual disulfide bond structure of gD by biochemical means. Purified native gD-2 was cleaved by CNBr and proteases, and the peptides were separated by high-performance liquid chromatography. Disulfide-linked peptides were subjected to N-terminal amino acid sequencing. The results show that cysteine 1 (amino acid [aa] 66) is bonded to cysteine 5 (aa 189), cysteine 2 (aa 106) is bonded to cysteine 6 (aa 202), and cysteine 3 (aa 118) is bonded to cysteine 4 (aa 127). Thus, the biochemical analysis of gD-2 agrees with the genetic analysis of gD-1. A similar disulfide bond arrangement is postulated to exist in other gD homologs.

Amino Acid Sequence↗
PubMed1991

[Resuscitation during renal transplantation in children].

Over a 4 yr-period, 60 children (aged 10 months to 17 yr) received 66 kidney transplants with the same surgical intensive care program, the fist 48 hr-period of which has been analysed in this study. Thirty percent of recipients were transplanted without previous dialysis and in 8%, body weight was below 10 kg at the time of surgery. The duration of anesthesia was 4.4 +/- 1.0 h and 32% received locoregional anesthesia. The mean duration for cold ischemia was 14.7 +/- 11.7 h and 26 +/- 7 min for warm ischemia; diuresis began during the operation in 79% of the patients. Routine vascular filling consisted of standard isotonic solute (11 +/- 4 ml/kg/h) associated with mannitol infusion; 59% of recipients required 20% human serum albumin and 42% blood transfusion. Post-operative diuresis was 7.4 +/- 6.0 ml/kg/h during the first 24 h, and sometimes resulted in hypovolemic episodes; 9% of the patients had primary non-functioning kidneys (4 transient acute tubular necrosis; 2 vascular thrombosis) and 4% required dialysis; the 1-yr survival rate was 82% for the grafts and 98% of the patients.

Adolescent↗
PubMed1991

[Postoperative analgesia for nephrectomy].

The aim of this study of post-nephrectomy acute pain in 30 patients was to compare three methods of postoperative analgesia and determine which one could be the most satisfactory. Ten patients received epidural analgesia with pethidine (400 mg.24 h-1 for 48 hrs). Ten other patients received intrapleural analgesia with bupivacaine (0.2 mg.kg-1.h-1 of 0.5% bupivacaine with 1/200,000 epinephrine). The ten remaining patients received systemic IV analgesia (2 g of propacetamol every 6 hrs and 0.15 mg of buprenorphine every 6 hrs). According to results of pain evaluation score (VAS) epidural analgesia with pethidine (VAS less than 2.5) appeared to be the best tested analgesic method. IV systemic analgesia (VAS less than 5) was less effective. Intrapleural bupivacaine (VAS greater than 5) was ineffective but apparently not toxic (serum concentration less than 1,200 ng.ml-1).

Acetaminophen↗
PubMed1990

The role of arachidonic acid and oxygen radicals on cerebromicrovascular endothelial permeability.

Arachidonic acid release from tissue membranes and/or formation of free radical species have been considered to affect blood-brain barrier permeability and formation of brain oedema. To determine whether exogenous arachidonic acid or H2O2 may alter blood-brain barrier permeability, we examined their effect on cultured endothelium derived from cerebral microvessels of human and animals. Release of 51Cr from labeled endothelium exposed to these substance was used as a main marker for the assessment of endothelial injury. The results of these studies indicate that endothelial cells (EC) are susceptible to exogenous arachidonic acid or H2O2 insult irrespective of their origin. However human endothelial cells are less affected than animal EC by H2O2-generated systems. The findings suggest that a disturbance of the existing balance between the endogenous antioxidant properties of EC and exogenous oxidant leads to EC injury.

Animals↗
PubMed1990

Hematological and biochemical changes during a short triathlon competition in novice triathletes.

Short-course 'sprint' triathlons have become popular in recent years, often as a precursor to the longer full-course triathlons. We undertook a study investigating the haematological and biochemical changes that occur in novice triathletes between the start and finish and after each of the three legs of a short sprint triathlon involving swimming, cycling and running. The changes that occurred in the triathlon included a significant (P less than 0.003) decrease in weight from 71.7 kg, SD 7.9 to 70.3 kg, SD 7.6. Throughout the time span of the triathlon, the white blood cell count increased significantly (P less than 0.001), as did the platelet count (P less than 0.005) and plateletcrit (P less than 0.001). There were no significant changes during the period of the race in any of the other haematological variables measured. The biochemical variables measured were glucose, triglycerides, sodium, potassium, calcium, lactate dehydrogenase, creatinine and aspartate aminotransferase. Triglyceride, calcium and potassium values did not change between the pre- and post-race samplings. All other biochemical parameters showed a significant change (P less than 0.05 or better). Changes that occurred in the haematological and biochemical parameters between stages were many and varied. There was also a significant change in plasma volume during the swimming event (P less than 0.001), but this returned to normal during the later stages of the triathlon. In conclusion the changes that occurred during the triathlon were many and were similar to those reported elsewhere in the literature for longer events.(ABSTRACT TRUNCATED AT 250 WORDS)

Aspartate Aminotransferases↗
PubMed1990

Cysteine mutants of herpes simplex virus type 1 glycoprotein D exhibit temperature-sensitive properties in structure and function.

We previously constructed seven mutations in the gene for glycoprotein D (gD) of herpes simplex virus type 1 in which the codon for one of the cysteine residues was replaced by a serine codon. Each of the mutant genes was cloned into a eucaryotic expression vector, and the proteins were transiently expressed in mammalian cells. We found that alteration of any of the first six cysteine residues had profound effects on protein conformation and oligosaccharide processing. In this report, we show that five of the mutant proteins exhibit temperature-sensitive differences in such properties as aggregation, antigenic conformation, oligosaccharide processing, and transport to the cell surface. Using a complementation assay, we have now assessed the ability of the mutant proteins to function in virus infection. This assay tests the ability of the mutant proteins expressed from transfected plasmids to rescue production of infectious virions of a gD-minus virus, F-gD beta, in Vero cells. Two mutant proteins, Cys-2 (Cys-106 to Ser) and Cys-4 (Cys-127 to Ser), were able to complement F-gD beta at 31.5 degrees C but not at 37 degrees C. The rescued viruses, designated F-gD beta(Cys-2) and F-gD beta(Cys-4), were neutralized as efficiently as wild-type virus by anti-gD monoclonal antibodies, indicating that gD was present in the virion envelope in a functional form. Both F-gD beta(Cys-2) and F-gD beta(Cys-4) functioned normally in a penetration assay. However, the infectivity of these viruses was markedly reduced compared with that of the wild type when they were preincubated at temperatures above 37 degrees C. The results suggest that mutations involving Cys-106 or Cys-127 in gD-1 confer a temperature-sensitive phenotype on herpes simplex virus. These and other properties of the cysteine-to-serine mutants allowed us to predict a disulfide bonding pattern for gD.

Animals↗
PubMed1990

[Antibiotic prophylaxis with cefotiam in transurethral resection of the prostate].

UNLABELLED: Over a period of 7 months, 50 patients underwent a trans-urethral resection of the prostate (TURP), this intervention is classified as "clear-contamined". The antibiotic prophylactic protocol, the subject of this study, was the following: cefotiam 2 g IV with the induction of anesthesia, 1 g 3 hours later and 1 g IV with the removal of the urethral catheter. RESULTS: there were 3 early post-operative urinary tract infections, one of these patients was symptomatic, at the time of removal of the urethral catheter. Most of these infections were due to Enterococcus faecalis bacteria. There was 4 late post-operative symptomatic urinary tract infections at days 15, 20, 50, and 120 respectively. All these late infections were due to Streptococcus faecalis. In total, there was a 10% rate of urinary tract infections in the critical 30 days period following the TURP. All the blood cultures were negative. These results lead us to conclude that the short term preventive treatment using the cefotiam, cephalosporin which has a strong prostatic tissue penetration, reduces the rate of post TURP urinary tract infections.

Aged↗
PubMed1989

Perception of teratogenic risk by pregnant women exposed to drugs and chemicals during the first trimester.

We assessed the perception of teratogenic risk by 80 women attending an antenatal consultation service for drug, chemical, and radiation exposure. Women exposed to agents not known to be teratogenic assigned themselves a risk of 24% +/- 2.8% for major malformation before the relevant medical literature was delivered to them and 14.5% +/- 3% thereafter. These women accurately estimated the risk for major malformation in the general population (5.6% +/- 1.3%). The tendency to terminate pregnancy when exposed to a nonteratogen significantly decreased after the consultation. Eleven patients exposed to drugs known to be teratogenic assigned a risk of 36.2% +/- 11.7% before the interview and did not change their perception thereafter (36.7% +/- 15.8%). Similarly, their tendency to continue or terminate pregnancy did not change; three of them eventually chose to terminate the pregnancy. Advising women about their teratogenic risk early in pregnancy may prevent unjustified termination of many pregnancies and may help to inform women exposed to proven teratogens about the known risk.

Abortion Applicants↗
PubMed1989

New high O2 carrying perfluorochemical emulsions: toxicity, radiosensitivity of GM-CFC and development of metastases in mice.

The effects of two new concentrated perfluorochemical emulsions based on F-66E and PFOB, which carry significantly more oxygen than Fluosol-DA 20%, were tested on normal tissues (toxicity and radiation response) and on the development of metastases from Lewis Lung Carcinoma (3LL) in female C57 BL/6 mice. Twenty one days after injection of F-66E or PFOB emulsions (15 ml/kg body weight), the spleen and liver weights were significantly increased but had returned to normal after 2-3 months. Splenomegaly already observed in 3LL bearing mice was significantly increased by F-66E emulsion injection. The radiosensitivity of GM-CFC was not altered when unanesthetized GM-CFC was not altered when unanesthetized mice were pretreated with F-66E emulsions and/or carbogen 1 hr prior to and during irradiation. The rate of tumor take and the period before detection of tumors were not modified when an emulsion of F-66E was injected simultaneously or 10 days after 3LL cells. Mean survival of mice, and the number of metastases on lung surfaces were similar in F-66E injected mice and control mice.

Animals↗
PubMed1989

[Antibiotic prophylaxis with cefotiam in percutaneous nephrolithotomy].

The percutaneous extraction of renal calculi in patients whose urines are sterile is considered to be a "clean-contaminated" surgery. The post-operatory infection is thought to be the result of the urethral catheter and the nephrostomy tube. The bacteria that are more after implicated are the Gram-negative bacteria. Therefore we found useful to give as a prophylactic treatment cefotiam, which is a 3rd generation cephalosporin, and have the advantage or reaching elevated urinary concentration as well as having a broad-spectrum activity on both Gram-negative bacteria and Staphylococcus. It has been used as follow: 1) with the anesthetic induction give 2 g IV push; 2) these give 1 g IV 12 hourly four times. It has been noted, that in all patients receiving this regimen, no post-operatory infection or urinary tract infection was found during the 48 hours following surgery. Therefore we think that due to the reasonable cost of the regimen, we advise it for this type of surgery.

Adult↗
PubMed1988

A combination of levobunolol and dipivefrin for the treatment of glaucoma.

This double-masked prospective study compared the ocular hypotensive efficacy and the safety of 0.5% and 1% levobunolol hydrochloride with 0.5% timolol maleate when each was administered topically twice daily in combination with 0.1% dipivefrin hydrochloride. Forty-three patients whose intraocular pressure was previously controlled by concomitant treatment with timolol and dipivefrin were randomly assigned to receive 0.5% or 1% levobunolol and 0.1% dipivefrin, or to continue to receive 0.5% timolol and 0.1% dipivefrin for three months. In the groups receiving levobunolol and dipivefrin concurrently, continued intraocular pressure control was achieved equal to that attained with timolol and dipivefrin before study entry. We concluded that concomitant treatment with levobunolol and dipivefrin is equal in both efficacy and safety to concomitant treatment with timolol and dipivefrin.

Drug Combinations↗
PubMed1988

Expression of herpes simplex virus type 1 glycoprotein D deletion mutants in mammalian cells.

Glycoprotein D (gD) is a viron envelope component of herpes simplex virus types 1 and 2. We have previously defined seven monoclonal antibody (MAb) groups which recognize distinct epitopes on the mature gD-1 protein of 369 amino acids. MAb groups VII, II, and V recognize continuous epitopes at residues 11-19, 272-279, and 340-356, respectively. MAb groups I, III, IV, and VI recognize discontinuous epitopes. Recent studies have focused on epitopes I, III, and VI. Using truncated forms of gD generated by recombinant DNA methods and proteolysis, epitopes III, IV, and VI were located within amino acids 1-233. A portion of discontinuous epitope I was located in a region within residues 233-275. For this study, we used recombinant DNA methods to create mutations in the gD-1 gene and studied the effects of those mutations on gD as expressed in mammalian cells. Plasmid pRE4, containing the coding sequence of gD-1 and the Rous sarcoma virus long terminal repeat promoter, was transfected into mammalian cells. The expressed protein, gD-1-(pRE4), was identical in size and antigenic properties to gD-1 from infected cells. Six in-frame deletion mutations were subsequently constructed by using restriction enzymes to excise portions of the gD-1 gene. Plasmids carrying these mutated forms were transfected into cells, and the corresponding proteins were examined at 48 h posttransfection for antigenicity and glycosylation patterns. Three deletions of varying size were located downstream of residue 233. Analysis of these mutants showed that amino acids within the region 234-244 were critical for binding of DL11 (group I), but not for other MAb groups. Three other deletion mutants lost all ability to bind MAbs which recognize discontinuous epitopes. In addition, much of the gD expressed by these mutants was observed to migrate as high-molecular-weight aggregated forms in nondenaturing gels. Each of these mutations involved the loss of a cysteine residue, suggesting that disulfide linkages play an essential role in the formation of discontinuous epitopes. The extent of glycosylation of the mutant gD molecules accumulated at 48 h posttransfection suggested altered carbohydrate processing. In one case, there was evidence for increased O-linked glycosylation. Those proteins which had lost a cysteine residue as part of the deletion did not accumulate molecules processed beyond the high-mannose stage. The results suggest that carbohydrate processing during synthesis of gD is very sensitive to alterations in structure, particularly changes involving cysteine residues.

Animals↗