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Biomedical subjects

I Eriksson

Publications and source records attributed to I Eriksson.

At least 37 records · Page 2Linked to original sources
PubMed1996

Composite polytetrafluroethylene/vein bypass grafts: conventional distal vein segment or vein cuff?

OBJECTIVES: To determine the current status of PTFE vein composite grafts, we reviewed our experience with 205 composite reconstructions and compared the results of conventional distal vein segment to that of distal vein cuff. DESIGN: Retrospective review. SETTING: Department of Surgery, University Hospital. PATIENTS AND METHODS: The series included 85 women and 102 men with a median age of 70. The indications for surgery were claudication in 30, rest pain in 71 and ulcer/gangrene in 103. The site of the distal anastomosis was the popliteal artery in 111 and crural artery in 94. The graft consisted of a proximal PTFE graft anastomosed to a distal segment of reversed saphenous vein in 169 or to a modified distal Miller cuff in 36 operations after 1992. RESULTS: Cumulative life table primary patency rates for the whole series at 12, 24 and 36 months were 39%, 32% and 25% respectively. Limbs with good run-off demonstrated significantly better patency rates compared to limbs with poor run-off (55% and 17% at 12 months, 35% and 11% at 36 months, p = 0.04). The patency rate of femorocrural grafts with poor run-off was only 4% at 12 months. The overall limb salvage rates at 12 and 36 months were 63% and 55%, respectively. Similar results were obtained in limbs with distal reversed vein segment and distal vein cuff. CONCLUSION: The results of this study suggest that for infrainguinal bypass grafting where the saphenous vein is unavailable, a composite PTFE-vein graft might be an acceptable alternative in limbs with good run-off. Although not a randomised study, the results using a distal reversed vein segment of a cuff were similar.

Adult↗
PubMed1995

Heparin proteoglycans synthesized by mouse mastocytoma contain chondroitin sulphate.

Proteoglycans (PGs), biosynthetically labelled with [35S]sulphate, were isolated from mouse mastocytoma tissue. Chromatography on antithrombin (AT)-Sepharose resulted in the separation of the 35S-labelled PGs into three fractions: PGs with no affinity for the gel (NA-PGs), PGs with low affinity (LA-PGs), and PGs with high affinity (HA-PGs) for antithrombin. Whereas NA-PGs contained almost exclusively chondroitin sulphate (CS), the AT-binding PGs contained 80-85% heparin and 15-20% CS. [35S]CS-containing macromolecules obtained from the HA-PG fraction after removal of the heparin polysaccharide chains were rechromatographed on AT-Sepharose. A majority of these 35S-labelled macromolecules no longer showed affinity for AT. These experiments indicate that the [35S]CS recovered in the AT-binding PGs is present in hybrid PGs. Polysaccharide chain-length determination demonstrated that the heparin chains were somewhat larger (M(r) approximately 30,000) than the CS chains in the NA-PGs (M(r) approximately 25,000). CS chains in the hybrid PGs were slightly smaller (M(r) approximately 20,000). Characterization of the sulphated CS disaccharides from NA- and HA-PGs showed that they contained similar amounts (20%) of disulphated disaccharides of [GlcA-GalNAc(4,6-di-OSO3)] type. The monosulphated CS-disaccharides were O-sulphated at C-4 of the galactosamine units. Analysis by gel chromatography of the [35S]CS components isolated from HA-PGs after heparinase treatment showed that a major portion of these contained one CS chain only. Calculations of the number of CS and heparin chains in AT-binding PGs, based on polysaccharide composition and polysaccharide chain length, indicate that all heparin-containing PGs are hybrids.

Animals↗
PubMed1995

Decreased cytochrome-c oxidase activity and lack of age-related accumulation of mitochondrial DNA deletions in the brains of schizophrenics.

Defects in mitochondrial energy production have been implicated in several neurodegenerative disorders, such as Parkinson disease and amyotrophic lateral sclerosis. To study the contribution of mitochondrial defects to Alzheimer disease and schizophrenia, cytochrome-c oxidase (COX) activity and levels of the mtDNA4977 deletion in postmortem brain tissue specimens of patients were compared with those of asymptomatic age-matched controls. No difference in COX activity was observed between Alzheimer patients and controls in any of five brain regions investigated. In contrast, schizophrenic patients had a 63% reduction of the COX activity in the nucleus caudatus (P < 0.0001) and a 43% reduction in the cortex gyrus frontalis (P < 0.05) as compared to controls. The average levels of the mtDNA4977 deletion did not differ significantly between Alzheimer patients and controls, and the deletion followed similar modes of accumulation with age in the two groups. In contrast, no age-related accumulation of mtDNA deletions was found in schizophrenic patients. The reduction in COX activity in schizophrenic patients did not correlate with changes in the total amount of mtDNA or levels of the mtDNA4977 deletion. The lack of age-related accumulation of the mtDNA4977 deletion and reduction in COX activity suggest that a mitochondrial dysfunction may be involved in the pathogenesis of schizophrenia.

Aged↗
PubMed1994

Biosynthesis of heparin. Different molecular forms of O-sulfotransferases.

O-Sulfotransferases involved in heparin biosynthesis were purified > or = 10,000-fold from detergent extracts of mouse mastocytoma tissue by sequential chromatographies on DEAE-Sephacel, heparin-agarose, blue Sepharose, and 3',5'-ADP-Sepharose. The resultant preparation catalyzed the transfer of 35S from 3'-phosphoadenosyl-5'-phospho-[35S]sulfate into N,O-desulfated, re-N-sulfated heparin. Anion-exchange high performance liquid chromatography of disaccharides obtained by deaminative cleavage of the 35S-labeled polysaccharide product revealed O-35S-sulfation at C-2 of L-iduronic acid and at C-6 of D-glucosamine units. SDS-polyacrylamide gel electrophoresis of semipurified enzyme followed by extraction of gel segments and renaturation of proteins consistently showed two distinct fractions of O-sulfotransferase activity, corresponding to proteins of approximately 20 and approximately 60 kDa. The approximately 60-kDa enzyme(s) catalyzed both the 2-O- and 6-O-sulfotransferase reactions, whereas the approximately 20-kDa fraction promoted iduronosyl 2-O-sulfation only. These results are discussed in relation to previous findings, indicating that some of the enzymes involved in heparin biosynthesis catalyze more than one reaction.

Animals↗
PubMed1994

cDNA cloning and sequencing of mouse mastocytoma glucosaminyl N-deacetylase/N-sulfotransferase, an enzyme involved in the biosynthesis of heparin.

A 110-kDa protein involved in heparin biosynthesis in mouse mastocytoma cells was previously shown to express both glucosaminyl N-deacetylase and N-sulfotransferase activity. In this study, the complete nucleotide sequence corresponding to this protein is reported. The mRNA, estimated to contain 3.9 kilobases encodes a protein with an M(r) of 101,092. The predicted domain structure of the protein resembles those of previously characterized Golgi proteins with an N-terminal cytoplasmic tail, a single membrane-spanning domain, and a large catalytic domain linked to the transmembrane domain through a "stem region." Comparison of the deduced amino acid sequence of the mouse mastocytoma protein and a previously cloned similar enzyme from rat liver demonstrated that while large portions of the proteins, corresponding essentially to the putative catalytic domains, were closely related, other portions, in particular in the N-terminal parts, were markedly different. The divergence was not due to species differences since two separate mouse transcripts could be identified that hybridized with probes specific for the two proteins. Also, functional differences were noted since the mastocytoma enzyme, contrary to the liver enzyme, requires a polycation cofactor for expression of N-deacetylase activity. The results are discussed in relation to the structural properties of heparin and heparan sulfate.

Amidohydrolases↗
PubMed1992

Urethral reconstruction with a new synthetic absorbable device. An experimental study.

Four centimeters of the canine urethra was replaced by a graft consisting of a polyglactin fiber mesh tube, coated with polyhydroxybutyric acid. Microscopic examination 8-12 months later showed almost complete regeneration of the urethral epithelium and the adjacent connective tissue. The neo-urethra was patent and there were no anastomotic strictures, nor was there any inflammatory reaction around the urethra. The validity of this concept in humans remains to be proved.

Animals↗
PubMed1991

Induction of DNA fragmentation in chronic B-lymphocytic leukemia cells.

Chronic lymphocytic leukemia of B cell type (B-CLL) is a neoplastic disorder characterized by the accumulation of small resting lymphocytes in the periphery. The phenotype of these cells suggests that they are "frozen" at an early stage of maturation. Glucocorticoid hormones are commonly used to treat patients with B-CLL, resulting in a reduction in the peripheral lymphocyte count by an undefined mechanism. Here we report that glucocorticoids stimulate DNA fragmentation characteristic of a suicide process known as apoptosis or programmed cell death (PCD) in suspensions of cells from patients with B-CLL. The effects can be mimicked by Ca2+ ionophore and involve a sustained increase in the cytosolic Ca2+ concentration. Specific antibodies binding to membrane-associated IgM on the leukemic cells can also induce PCD by a similar mechanism. Phorbol esters block DNA fragmentation and cell killing in response to all of the agents, suggesting that activation of protein kinase C desensitizes the cells to PCD. Targeting the B-CLL cells with antibodies that induce an unbalanced, sustained Ca2+ increase may therefore represent a rational strategy for the destruction of leukemic cells.

Antibodies, Monoclonal↗
PubMed1991

Bypass grafting to the popliteal artery in limbs with occluded crural arteries.

Intraoperative completion angiograms of 47 femoropopliteal bypasses in limbs with occluded crural arteries were reviewed to identify the angiographic determinants of early outcome. Of 28 limbs in which the foot vessels were available for analysis, only 2 (7%) had an intact pedal circulation, and 18 limbs demonstrated no crural arteries suitable for distal reconstruction. The overall cumulative patency rate was 51% with a 76% limb salvage rate at 12 months. All seven grafts performed onto a popliteal artery segment of less than 8 cm occluded in the early period. The status of crural and foot arteries and the number of collaterals did not correlate well with early patency. Limbs with no patent crural artery that were analyzed in the poor angiographic runoff group, according to our previously reported classification, demonstrated relatively higher patency rates than the other subgroups with poor runoff. In cases where angiography demonstrates a poor runoff for distal revascularization, popliteal bypass with occluded crural arteries might achieve acceptable patency rates.

Adult↗
PubMed1991

Muscle ATP and lactate and the release of myoglobin and carbanhydrase III in acute lower-limb ischaemia.

Serum-myoglobin and carbanhydrase III (S-CAIII), a specific muscle enzyme, were measured on admission, during surgery and in the postoperative period in 23 patients with acute lower-limb ischaemia and in 21 patients with chronic limb ischaemia in order to evaluate these molecules as possible markers of the degree of clinical ischaemia. The muscle contents of ATP and lactate were determined in muscle biopsies from patients with acute ischaemia on admission. Unlike S-myoglobin and S-CAIII they discriminated between cases which required subsequent amputation from those which did not. Clinical signs of ischaemia were, however, of no value in this respect and there were no correlations between clinical signs or the duration of ischaemia and S-myoglobin or S-CAIII or the contents of ATP or lactate in muscle tissue. The levels of S-myoglobin and S-CAIII correlated well (r = 0.95, p less than 0.0001). In patients who subsequently required an amputation S-myoglobin increased ten-fold (i.e., from 24-48 h postoperatively in acute arterial ischaemia and from 3 h postoperatively in patients with chronic limb ischaemia). In patients with a successful revascularisation S-myoglobin returned to normal levels. It is concluded that in this investigation S-myoglobin had no prognostic value on admission and that S-myoglobin analyses in the postoperative course may be useful for making clinical decisions concerning impending recirculation failures.

Acute Disease↗
PubMed1991

Natural history of patients with abdominal aortic aneurysm.

Factors determining the outcome for patients with abdominal aortic aneurysm (AAA) were analysed in a retrospective population-based study of 187 consecutively diagnosed AAAs at one hospital during a 9-year period. All aneurysms were diagnosed by ultrasound, and those cases that were not primarily operated upon, were followed by repeat ultrasound examinations. An expansion rate of more than 0.4 cm/year was seen in 27% of the aneurysms and a tendency towards a higher rate of expansion could be seen with larger lesions. The overall cumulative rupture rate was 12% at 5 years. For patients with small (less than 5 cm) aneurysms it was 2.5% at 7 years, and no aneurysm could definitively be shown to be smaller than 5 cm at the time of rupture. The rupture risk was significantly higher (28% at 3 years) for larger aneurysms (greater than or equal to 5 cm). The only reliable predictor for rupture was aneurysm size. The overall cumulative survival was 51% at 5 years. Patients with large aneurysms did not have a significantly shorter survival although a tendency for this to be the case was found. There was a significant difference between the proportion of deaths caused by aneurysm rupture in patients with small aneurysms when compared to those with large aneurysms, 5.5 and 53%, respectively. The expansion rate for AAA was highly individual and aneurysm diameter was the only recognisable predictor of rupture. The rupture rate for AAAs smaller than 5 cm was lower than previously reported.

Aged↗
PubMed1991

Abdominal aortic aneurysm with perianeurysmal fibrosis: experience from 11 Swedish vascular centers.

Case records of 2026 patients operated on because of abdominal aortic aneurysms from 11 Swedish Vascular Centers were reviewed and revealed 98 cases (4.8%) of inflammatory abdominal aortic aneurysm. Also included in this case-control study was an analysis of a randomized group of 82 patients from the same centers who had noninflammatory abdominal aortic aneurysms. Four inflammatory aneurysms were ruptured, compared with 16 in the noninflammatory group (p less than 0.01). A higher proportion of patients with inflammatory abdominal aortic aneurysms had symptoms that led to radiographic investigations. The median erythrocyte sedimentation rate was 39 mm versus 19 mm (26% of patients with inflammatory abdominal aortic aneurysms had erythrocyte sedimentation rates greater than 50 mm; p less than 0.001), and the serum creatinine level was increased in 27 and 8 patients (p less than 0.01) in the inflammatory and noninflammatory groups, respectively. Preoperative investigations revealed ureteral obstruction in 19 patients with inflammatory abdominal aortic aneurysms, of whom 12 had preoperative nephrostomy or ureteral catheter placement. At operation, 20 additional patients exhibited fibrosis around one or both ureters. Although ureterolysis was performed in 19 patients, preoperative and postoperative creatinine levels did not differ between these patients and the conservatively treated ones. Duration of surgery (215 vs 218 minutes), intraoperative blood loss (2085 vs 2400 ml) and complications did not differ significantly between the groups. Overall operative (30-day) mortality was equal (11% vs 12%) but was increased for patients undergoing elective surgery for inflammatory abdominal aortic aneurysms (9% vs 0%; p = 0.03).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1991

Efficacy and safety of amikacin in systemic infections when given as a single daily dose or in two divided doses. Scandinavian Amikacin Once Daily Study Group.

Two hundred and twenty patients with serious infections verified or suspected to be of Gram-negative aetiology were treated in an open randomized comparative multicentre trial with amikacin 15 mg/kg/day given either as a single dose or in two divided doses at 12-h intervals. Amikacin was administered as a short-term iv infusion. When additional therapy was considered necessary piperacillin or ampicillin was recommended. The trial continues and an interim report on data from the 12 participating Scandinavian hospitals is presented. One hundred and forty-four patients have been evaluated for efficacy and 213 patients for safety. There were no significant differences between the two dosage regimens regarding efficacy and safety. A satisfactory clinical response was recorded in 129 (90%) of the evaluable patients. One serious adverse reaction was seen in a patient in the once-daily group. This was ototoxicity which was superimposed on a long standing hearing defect possibly caused by previous streptomycin therapy.

Adult↗
PubMed1991

A simple infusion method for measurement of intraoperative peripheral vascular runoff resistance.

A simple infusion system to assess the status of distal runoff was investigated on both hindlimbs of five mongrel dogs. Infusion catheters were placed in the superficial femoral arteries and the origin of the lower leg arteries was exposed for anatomic manipulation of the distal runoff. Saline solution was infused through the superficial femoral arteries at 64, 129, and 193 cm levels to calculate volume flow and index of resistance to flow. The in vitro part of the study was undertaken to analyze the effect of different-size catheters on flow rates in a rigid undistensible model. In the hindlimb study the flow differed significantly between two- and one-vessel runoff status at 50 and 100 mm Hg infusion pressures. In the in vitro study, in contrast to the hindlimb study, index of resistance to flow values for different-size catheters remained almost unchanged as the infusion pressure increased, demonstrating the distensibility of the runoff bed in dogs. A preliminary clinical study in 13 patients undergoing infrainguinal bypass surgery demonstrated a good correlation between angiographic runoff evaluation and intraoperative flow values. Valuable information can be obtained about the status of the distal runoff by this simple infusion method, which might be used to improve the prediction of outcome of infrainguinal bypass surgery.

Analysis of Variance↗
PubMed1990

Expression of a new set of glycolytic isozymes in activated human peripheral lymphocytes.

The combination of phorbol 12-myristate 13-acetate (PMA) and concanavalin A induces the expression of a new set of glycolytic isozymes in human peripheral lymphocytes. The induced isozyme for each enzyme tested (hexokinase, phosphofructokinase, enolase, pyruvate kinase and lactate dehydrogenase) is usually the muscle form, which is often associated with rapidly dividing tumor cells. Increases in a specific isozyme can account for the 2-5-fold increase in specific activities of the enzyme induced by Con A plus PMA. Increased specific activities and the appearance of the new isozyme forms both occur relatively late, and are probably associated with the G1 or S phase of the cell cycle.

Cells, Cultured↗