Search PubMed⌕ Search

Biomedical subjects

S Eriksson

Publications and source records attributed to S Eriksson.

At least 289 records · Page 16Linked to original sources

[The Norrköping study. Cephalosporins are often the implicating factors in Clostridium difficile infections].

In a retrospective study carried out at Norrköping Central Hospital, the incidence of Clostridium difficile-associated diarrhoea and colitis was found to be correlated to in-patient consumption (in terms of defined daily doses) of the implicated anti-microbial agents. The third generation cephalosporin, cefotaxime, was implicated 38 times more often than small spectrum penicillins. In general, the cephalosporins were predominantly responsible, accounting for 46 per cent (67/147) of the episodes but only 12 per cent of overall consumption of antibiotics at the hospital. These findings are in accord with data previously published in the nationwide report by the Medical Product Agency, Uppsala.

Adolescent↗

Serum dehydroepiandrosterone sulfate in Alzheimer's disease and in multi-infarct dementia.

Circulating levels of dehydroepiandrosterone sulfate (DHEAS) and cortisol were studied in 86 patients with dementia; 45 with Alzheimer's disease and 41 with multi-infarct dementia. Compared to an elderly control group, after adjustment for age and sex, patients with Alzheimer's disease were found to have lower serum levels of DHEAS. We found a covariation between serum albumin and DHEAS levels, which may be of importance regarding peripheral hormone concentration in patients with dementia. These findings may provide evidence for a role of DHEAS in amnestic disorder in humans, either reflecting or contributing to the course of dementing diseases.

Aged↗

Diverging substrate specificity of pure human thymidine kinases 1 and 2 against antiviral dideoxynucleosides.

The two thymidine (dThd) kinases in human cells, the cytosolic, S-phase-specific TK1 and the mitochondrial, constitutively expressed TK2 were purified to homogeneity as judged from sodium dodecyl sulfate-gel electrophoresis. The substrate specificity of TK1 and TK2 toward natural substrates and important nucleoside analogues was compared. With TK1, the Km values for 5-fluorodeoxyuridine (FdUrd), 3'-azido-2',3'-dideoxythymidine (AZT), and 3'-fluoro-2',3'-dideoxythymidine (FLT) were 2.2, 0.6, and 2.1 microM as compared to 0.5 microM for dThd and 9 microM for deoxyuridine (dUrd). With TK2, dUrd, deoxycytidine (dCyd), and 5-fluorodeoxyuridine (FdUrd) were efficiently phosphorylated, but with distinctly different kinetics: Michaelis-Menten kinetics with dCyd, dUrd, and FdUrd; negative cooperativity with dThd. Negative cooperativity was also observed with AZT, although this drug was a very poor substrate for TK2 with a Vmax of 5-6% of that with dThd. FLT, 2',3'-dideoxycytidine (ddCyd), and arabinofuranosylcytosine (araC) were not substrates for TK2, and 2',3'-didehydrodideoxy-thymidine (D4T) was not a substrate for TK1 or TK2. On the other hand, AZT, FLT, and D4T were competitive inhibitors with Ki values of 0.6, 6, and 2073 microM for TK1, and 2, 10, and 78 microM for TK2, respectively. The much lower tolerance for modifications of the deoxyribose moiety of TK2 as compared to TK1 is important for the design of new antiviral nucleoside analogues intended for use in cells with different expression of TK1 and TK2.

Antiviral Agents↗

Comparison of the substrate specificities of human thymidine kinase 1 and 2 and deoxycytidine kinase toward antiviral and cytostatic nucleoside analogs.

Deoxynucleoside kinases are required for the 5'-phosphorylation of deoxynucleoside analogs used in chemotherapy. Cytoplasmic thymidine kinase (TK1), deoxycytidine kinase (dCK) and mitochondrial thymidine kinase (TK2) were completely purified from human leukemic spleen and their capacities to phosphorylate 43 nucleoside analogs were compared. TK1 showed the most restricted substrate specificity but tolerated 3'-modifications of the sugar ring and some 5-substitutions of the pyrimidine ring. TK2 showed a much broader specificity and phosphorylated pyrimidine bases with bulky 5-substitutions, including cytosine analogs, while sugar analogs with substituents other than OH in the 2' and 3' positions were very poor substrates. dCK showed a very broad specificity phosphorylating several cytosine analogs with 2' and 3' modifications as well as acyclic sugar analogs. Purine deoxyribonucleosides were also efficiently phosphorylated by dCK but in this case sugar modifications led to drastically decreased activity.

Antiviral Agents↗

Characterization of human deoxycytidine kinase. Correlation with cDNA sequences.

Existing data on the structure of human deoxycytidine kinase (dCK) diverge. A monomeric 60 kDa form has been isolated and the cloning of a cDNA coding for 626 amino acids corresponding to a 71 kDa protein has been reported. However, pure dCK isolated from leukemic spleen is a dimer of 30 kDa subunits. Amino acid sequences of peptides from digests of this protein are now presented. None of the peptide structures obtained correspond to the cDNA for the 71 kDa protein, but to a cDNA for a 30.5 kDa dCK recently cloned. Furthermore, homology of the peptide sequences od dCK to parts of thymidine kinases and protein-tyrosine kinases are detected.

Amino Acid Sequence↗

Role of re-resection in early gastric stump carcinoma.

Between 1971 and 1990, 26 patients were diagnosed as having an early carcinoma in the gastric remnant after ulcer surgery. Three patients with proximal tumour location were operated on with total gastrectomy. The surgical strategy in the remaining patients with tumour adjacent to the anastomosis was re-resection of at least 5-6 cm of the anastomotic area and restoration of gastrointestinal continuity with a Roux-en-Y loop. A margin of at least 2 cm from the carcinoma to the resection line was taken. There was no postoperative mortality. In three cases the preoperative endoscopic and histological judgement of tumour classification and stage was incorrect; when the surgical specimens were examined one patient was found to have advanced carcinoma and in the other two no malignancy could be found. Median follow-up was 15 years (range 3-19 years). During follow-up, six of the re-resected patients developed recurrences, all located in the gastric remnant. Four patients with recurrence underwent reoperation with total gastrectomy, one had exploratory laparotomy and one had no further surgery. No postoperative deaths occurred. Three of the six patients died from gastric carcinoma. We conclude that this surgical strategy failed to prevent local recurrence of an early form of gastric carcinoma, considered to be potentially curable in virtually all cases. Partial resection of the gastric remnant as the treatment of choice in patients with early gastric stump carcinoma cannot be recommended.

Adult↗

Catecholamine excretion in old age.

Catecholamine excretion was studied in two groups of nonhospitalized subjects, 60 and 80 years of age, N = 35 and 29, respectively. Urinary 24h dopamine excretion exhibited an age-related decline (p = 0.001). There was a sex difference for dopamine excretion; men had higher excretion levels (p = 0.04). Twenty-four-hour excretion of epinephrine and norepinephrine was slightly higher in 60- than in 80-year-old individuals (NS). Smoking was associated with a considerable increase in epinephrine (p = 0.001) and norepinephrine (p = 0.04) excretion. Body mass index was negatively correlated to epinephrine excretion (r = -0.27; p less than 0.05). When analyzed with a multi-way analysis of variance with analysis of covariance, significant influences of age on dopamine excretion, of creatinine clearance on dopamine and norepinephrine excretion, and of smoking on epinephrine excretion were seen. Thus, factors such as age, gender, body mass, kidney function and smoking habits considerably influence catecholamine excretion in elderly people.

Aged↗

Omeprazole treatment does not affect the metabolism of caffeine.

This study was performed to investigate the possible influence of repeated omeprazole dosing on the metabolism of caffeine, which has been shown to reflect the activity of one specific enzyme within the hepatic cytochrome P450 family, P450IA2. Ten healthy, nonsmoking young men participated in this placebo-controlled double-blind trial. Each subject was given omeprazole, 20 mg, every morning for 1 week and placebo every morning for 1 week in random order and separated by a 2-3 week washout period. On the sixth and seventh days of each period urine was collected twice daily, and urinary metabolites of caffeine were determined by high-performance liquid chromatography. The urinary metabolite ratio of three paraxanthine 7-demethylation products relative to a paraxanthine-hydroxylation product corresponds to caffeine clearance and, therefore, to P450IA2 activity. This calculated ratio was 4.8 (95% confidence interval, 3.9-5.6) in the placebo and 4.6 (95% confidence interval, 3.6-5.5) in the omeprazole period. These results show that the metabolism of caffeine was unaltered following omeprazole treatment, indicating that omeprazole treatment has no influence on cytochrome P450IA2 activity in the clinical situation.

Adult↗

Identification of PiZ gene products in liver tissue by a monoclonal antibody specific for the Z mutant of alpha 1-antitrypsin.

Globular inclusions of abnormal alpha 1-antitrypsin (AAT) in the rough endoplasmic reticulum of hepatocytes is a characteristic feature of AAT deficiency of the PiZ phenotype. It is also seen in some rare M-like Pi types (including M-Cagliari) having low plasma AAT levels and M-like mobility on isoelectric focusing. In this report the ability of a monoclonal antibody (ATZ 11) raised against PiZ hepatocytic AAT to identify AAT inclusions by immunohistochemical techniques is evaluated. The antibody was found to specifically and selectively identify the PiZ gene products in hepatocytes, but not M-Cagliari AAT. Application of the method thus allows distinction of PiZ gene carriers from PiM-like subjects in the absence of serum protein analysis.

Antibodies, Monoclonal↗

Intracellular metabolism of 3'-azidothymidine in isolated human peripheral blood mononuclear cells.

Azidothymidine (AZT) inhibits the replication of human immunodeficiency virus and it is the only drug so far licensed for treatment of acquired immunodeficiency syndrome (AIDS). A prerequisite for its antiviral activity is phosphorylation by cellular nucleoside kinases to the mono-, di-, and triphosphate levels. This study determined the capacity of isolated peripheral blood mononuclear cells (PBMC), resting or mitogen stimulated, from 36 different people of whom 5 were HIV+, to phosphorylate and accumulate intracellular AZT nucleotides. We found a large variation in the amount of products formed between PBMC treated at different times from the same individual as well as between the PBMC from different individuals. Resting PBMC showed the largest interindividual variation and their levels of AZT nucleotides were about 60-150-fold lower than in activated PBMC. The intracellular half lives of azidothymidine mono-, di-, and triphosphates, constituting, on the average, 96-99.2, 0.7-1.8, and 0.4-2.7% of total nucleotides at 0.08-1.6 microM AZT, respectively, were also determined. In mitogen-stimulated PBMC it was approximately 2.5 +/- 0.6 h for all the azidothymidine metabolites. The half-life for intracellular azidothymidine monophosphate in resting PBMC from two individuals was determined to 1.5 +/- 0.2 h. There appeared to be no significant difference in the AZT metabolism in PBMC from HIV-positive or-negative persons. A relative decrease in the intracellular formation of AZTDP and AZTTP from AZTMP was observed at concentrations of AZTMP above 1 microM. This fact may explain why lowering the doses of AZT still gives therapeutically efficient levels of the active metabolite AZTTP.

Adult↗

Biochemical effect of liver transplantation in two Swedish patients with familial amyloidotic polyneuropathy (FAP-met30).

Familial amyloidotic polyneuropathy (FAP) is an autosomal dominant inherited disorder characterized by progressive peripheral and autonomic neuropathy, associated with neural and systemic amyloid deposits. The amyloid fibrils contain a variant transthyretin (TTR) molecule (TTR met30), over 90% of which is produced in the liver. After liver transplantation in two patients with severe symptomatic FAP, only normal TTR was detectable in circulation. The two patients are being monitored at regular intervals, and, although in one patient there was no evidence of reduction in the quantity of amyloid present at 6 months, there had been no further progression of the neuropathy.

Adult↗

Neuropeptides in temporomandibular joints with rheumatoid arthritis: a clinical study.

There is evidence that neuropeptides play a role in the development of arthritis. Synovial fluid from arthritic temporomandibular joints in patients with rheumatoid arthritis was therefore investigated for presence of the neuropeptides calcitonin gene-related peptide, substance P, neurokinin A and neuropeptide Y. All four peptides were found in the synovial fluid above plasma level, but calcitonin gene-related peptide showed the highest concentration and substance P the lowest.

Adult↗

The value of routine biochemical tests in discriminating between malignant and benign pancreatic tumours.

The probability that routine hematological laboratory tests of liver and pancreatic function can discriminate between malignant and benign pancreatic tumours, incidentally detected during operation, was investigated. The records of 53 patients with a verified diagnosis of pancreatic carcinoma and 19 patients with chronic pancreatitis were reviewed with regard to preoperative total bilirubin, direct reacting bilirubin, alkaline phosphatase, glutamyltranspeptidase, aminotransferases, lactic dehydrogenase and amylase. Multivariate and discriminant analysis were performed to calculate the predictive value for cancer, using SYSTAT statistical package in a Macintosh II computer. Total and direct reacting bilirubin and glutamyltranspeptidase were significantly higher in patients with pancreatic carcinoma. However, only considerably increased levels of direct reating bilirubin were predictive of pancreatic carcinoma.

Adult↗

Partial deficiency of alpha 1-antichymotrypsin is associated with chronic cryptogenic liver disease.

alpha 1-Antichymotrypsin (ACT) and alpha 1-antitrypsin (AAT) are two closely related antineutrophil proteinase inhibitors. Whereas AAT deficiency is clearly linked to liver disease, an association between liver disease and partial ACT deficiency has not been established. In a previous study we noted an increased prevalence of liver abnormalities among subjects with heterozygous ACT deficiency. To study a possible association between partial ACT deficiency and liver disease, we screened 316 consecutive patients with biopsy-verified liver disease for partial ACT deficiency and compared the prevalence with that of an unselected adult population in a case-control study. In all, 9 of 316 patients had partial ACT deficiency, which is more than expected (prevalence ratio (PR), 2.46 (1.15-5.27), P less than 0.05). The prevalence of partial ACT deficiency was highest in the chronic active hepatitis (5 of 40; PR, 12.0 (5.33-27.0] and the cryptogenic cirrhosis (3 of 24; PR, 12.0 (4.38-32.9] subgroups. In the chronic active hepatitis subgroup two patients (PR, 8.16 (2.25-29.5] were ACT deficiency heterozygotes, thus partly explaining the high prevalence of partial ACT deficiency among patients with chronic liver disease. The majority (6 of 9) of the patients with partial ACT deficiency lacked autoimmune and viral markers and were thus cryptogenic. The present findings show that partial ACT deficiency and chronic cryptogenic liver disease are associated. To some extent (the true magnitude of which is at present unknown) partial ACT deficiency is caused by a rare trait, heterozygous ACT deficiency, which in parallel with heterozygous alpha 1-antitrypsin deficiency (PiMZ) also seems to be associated with chronic cryptogenic liver disease.

Female↗