Search PubMed⌕ Search

Biomedical subjects

C Johansson

Publications and source records attributed to C Johansson.

At least 109 records · Page 6Linked to original sources

Chronic intracerebroventricular administration of beta-endorphin augments natural killer cell cytotoxicity in rats.

We have studied the effect of chronic intracerebroventricular (i.c.v.) infusion of different opioid peptides on natural killer (NK) cell mediated cytotoxicity in vivo in the spontaneously hypertensive rat (SHR). The in vivo NK cell activity was measured as the clearance of 51Cr-labelled YAC-l lymphoma cells from the lung tissues. Further, the phenotype of lymphocytes in spleen and peripheral blood was analysed by flow cytometry (FACS). All opioid drugs were administered i.c.v. for 6 days with osmotic minipumps releasing 1.0 microliter/h. beta-Endorphin (10 or 20 micrograms/rat per day) significantly increased NK cell cytotoxicity in vivo. The opioid receptor antagonist naloxone (10 mg/kg, i.p.) given immediately before the injection of YAC-lymphoma cells, completely abolished the effects of i.c.v. administered beta-endorphin. Corresponding doses of beta-endorphin administered subcutaneously (s.c.) with minipumps for 6 days did not significantly affect NK cell cytotoxicity. Neither Leu- or Met-enkephalin (20 micrograms/rat per day) nor dynorphin (20 micrograms/rat per day) administered i.c.v. had any significant effects on NK cell activity. In beta-endorphin treated SHR, the percentage of cells with NK cell phenotype (OX52+/CD5-) in peripheral blood was not significantly different from that of controls, while the percentage of cells with T cell phenotype (CD5+/OX52-) was significantly decreased. The percentage of splenic NK cells (OX52+/CD5-) and T cells (CD5+/OX52-) was also unchanged by beta-endorphin treatment i.c.v. These results suggest that of the opioid peptides administered i.c.v., only beta-endorphin augments in vivo NK cell mediated cytotoxicity. We thus conclude that these effects most probably are centrally and opioid receptor mediated effects, since beta-endorphin in the same dose administered peripherally does not influence in vivo NK cell cytotoxicity.

Administration, Cutaneous↗

Hyaluronan localization in the rabbit larynx.

BACKGROUND: The larynx is a complex organ composed of different connective tissue elements. So far, the extracellular matrix of the larynx has not been thoroughly described. Hyaluronan is a matrix polysaccharide with physicochemical effects and biological cell functions in soft connective tissues. METHODS: The histochemical distribution of hyaluronan (hyaluronic acid, hyaluronate) was studied in tissue sections from various levels of the rabbit larynx by means of a hyaluronan-binding protein and avidin biotin peroxidase staining. Microwave-aided fixation was used to retain the extracellular location of hyaluronan. RESULTS: Hyaluronan accumulated chiefly in the subepithelial lamina propria and in the connective tissue enclosing striated muscle fibres of the thyroarytenoid muscle and vocalis muscle. This localization contrasted sharply with the weak staining for hyaluronan in muscles external to the thyroid cartilage. Intensive staining for hyaluronan was found in perivascular and periglandular connective tissue, as in the vacuoles of the hyaline cartilage of the thyroid, cricoid and arytenoid cartilages, and to a lesser extent in the lacunae of the chondrocytes and in the perichondrium of the elastic cartilage of the epiglottis. CONCLUSIONS: Hyaluronan was heterogenously distributed in the rabbit larynx. It was abundant in intrinsic laryngeal muscles performing small, precise, and rapid movements and in the subepithelium at the glottic level, where it may facilitate mucosal movements. The abundant hyaluronan in the subglottic region may be involved in the control of vascular leakage and edema formation.

Animals↗

Lanthanide-based susceptibility contrast agents: assessment of the magnetic properties.

The T2* contrast efficacy of paramagnetic contrast agents is dependent on their magnetic properties. Vibrating sample magnetometry (VSM) and the Live Chan NMR method have been used to evaluate the influence of ligand structure on the bulk magnetic susceptibility (BMS) of low-molecular weight (LMW) lanthanide chelates. VSM was also used for the BMS assessment of LMW lanthanide chelates covalently attached to cross-linked starch particles. The ligand structure had no influence on the BMS of the gadolinium (Gd) and dysprosium (Dy) chelates. The mean BMS value of the Dy-chelates was 1.8 fold higher than that of the Gd-chelates. The holmium (Ho) DTPA-BMA chelate had a similar BMS to that of Dy-DTPA-BMA while the lowest BMS was found for europium (Eu(III)) DTPA-BMA. The covalent attachment of Gd-DTPA and Dy-DTPA to a cross-linked starch particle had no impact on their intrinsic magnetic properties. The BMS data were in good accordance with those obtained for non-particulate bound LMW Dy- and Gd-chelates. The magnetic susceptibility of the Gd-DTPA labeled particles was described by the Curie law, indicative of no magnetic interactions between Gd-DTPA molecules. The magnetic susceptibility of the Dy-DTPA labeled particles followed the Curie-Weiss law with a Curie-Weiss temperature of about-2 K, indicating magnetic interactions. The magnetic susceptibility of Dy-DTPA will, however, not be affected by such magnetic interactions at physiological temperatures.

Contrast Media↗

Continence is improved after the Ripstein rectopexy. Different mechanizms in rectal prolapse and rectal intussusception?

PURPOSE: This study was undertaken to evaluate anal manometric changes after Ripstein's operation for rectal prolapse and rectal intussusception and to study the clinical outcome following the operation, with special reference to anal incontinence. METHODS: Forty-two patients with rectal prolapse or rectal intussusception were subjected to anorectal manometry preoperatively and seven days and six months postoperatively. A detailed history was obtained from each patient preoperatively and six months postoperatively. RESULTS: Preoperatively, patients with rectal intussusception had higher maximum resting pressure (MRP) (52+/- 23 mmHg) than patients with rectal prolapse (34 +/- 20 mmHg; P < 0.01). In the group of patients with rectal prolapse, there was a postoperative increase in MRP after six months (P < 0.001) but not after seven days. Maximum squeeze pressure (MSP) did not increase. Neither MRP nor MSP increased postoperatively in patients with internal rectal procidentia. Continence was improved postoperatively both in patients with rectal prolapse (P < 0.01) and rectal intussusception (P < 0.01). There was no postoperative increase in rectal emptying difficulties. CONCLUSION: Ripstein's operation often improved anal continence in patients with rectal prolapse and rectal intussusception. This improvement was accompanied by increased MRP in patients with rectal prolapse, indicating recovery of internal anal sphincter function. No postoperative increase in MRP was found in patinets with rectal intussusception. This suggests an alternate mechanism of improvement in patients with rectal intussusception.

Adult↗

Endoscopic dilation of rectal strictures: a prospective study of 18 cases.

PURPOSE: This study was performed to prospectively evaluate results of endoscopic balloon dilation of strictures of the rectum. METHODS: Eighteen patients with symptoms of rectal strictures at endoscopy or barium enema were treated on 49 occasions with balloon dilation during sigmoidoscopy. RESULTS: Twelve patients were completely satisfied with relief of their symptoms after treatment. Two patients considered the results as poor, and four patients were not subject to follow-up evaluation. One patient had a perforation during the dilation procedure but was completely relieved at follow-up examination. CONCLUSIONS: Endoscopic balloon dilation of strictures in the rectum is a safe method. The method is simple and can be performed on an outpatient basis. The technique shows good results even in narrow strictures.

Aged↗

A population-based study on the association between dementia and hip fractures in 85-year olds.

The association between dementia and hip fracture was studied in a representative sample of 85-year olds (N = 485). The diagnosis of dementia was made according to the DSM-III-R. The prevalence of hip fracture was obtained by history and inspection of the hip. Bone mineral density was measured with dual photon absorptiometry of the right calcaneus. Hip fracture was associated with both Alzheimer's disease (p < 0.01) and vascular dementia (p < 0.01) in women, but not in men. Among women with dementia, the rate of hip fracture was more than twice that found in the general population (32.7% vs 13.6%). Bone density was not associated with dementia or hip fracture. Body mass index and body weight were lower in women with dementia and in women with hip fracture. The prevalence of hip fracture was also increased in subjects who used psychotropic drugs, especially tricyclic antidepressants. A logistic multiple regression analysis showed that dementia, use of antidepressants and gender independently contributed to hip fracture. The reason why subjects with dementia are at increased risk for hip fractures may be that these subjects have a defective neuromuscular regulation, gait apraxia, use more antidepressants, and have a lower body mass index. Another explanation of the association may be that surgery and anesthesia give rise to systemic hypotension that leads to cerebral hypoperfusion and ischemic and neuronal death in vulnerable brain areas, and as a consequence may lead to dementia or worsen the symptoms in subjects already affected by dementia.

Aged↗

Experimental study of turned and grit-blasted screw-shaped implants with special emphasis on effects of blasting material and surface topography.

In the rabbit tibia, commercially pure titanium implants blasted with 25-microns Al2O3 and TiO2 particles respectively were inserted and studied with respect to removal torque and histomorphometry. In the rabbit femur, as-machined implants and implants blasted with 75-microns Al2O3 particles were histomorphometrically compared. Before implant insertion, the differently produced surface topographies were characterized numerically and visually. The tibial implants blasted with different materials and the same sized (25 microns) blasting particles demonstrated similar results. Comparing implants blasted with 75-microns Al2O3 particles to as-machined implants, the blasted specimens exhibited a statistically significant higher bone-to-metal contact after 12 weeks in the rabbit bone.

Aluminum Oxide↗

Association between urinary incontinence and urinary tract infections, and fractures in postmenopausal women.

OBJECTIVE: The association between urinary disorders, such as ongoing urinary incontinence (UI), history of urinary incontinence (HIST-UI) and urinary tract infections (UTI), and fractures in peri- and postmenopausal women was assessed in an epidemiological study. SUBJECTS AND METHODS: The sample consisted of 10000 women from seven birth cohorts, born between 1900 and 1940, who were investigated regarding urinary disorders, fractures and reproductive history by means of a postal questionnaire. RESULTS: The overall response rate was 74.6%. The respondents (n = 7459) represented 53% of the total population from the respective birth cohorts. There was a significant independent correlation between UI, HIST-UI and UTI, respectively, and fractures after the age of 30. In subjects with HIST-UI, tobacco smokers compared to non-smokers had significant more fractures in both the 1930 and 1940 birth cohorts (P < 0.01). Logistic multiple regression in the 1930 and 1940 cohorts demonstrated that age (P < 0.001), HIST-UI (P < 0.001) and tobacco smoking (P < 0.05), respectively, had an independent explanatory value for fractures. CONCLUSION: The prevalence of fractures increased with increasing age, in smokers compared to non-smokers and in women with a history of UI.

Age Factors↗

An earlier fracture as a risk factor for new fracture and its association with smoking and menopausal age in women.

OBJECTIVES: The purpose of this study was to investigate whether a previous fracture is a risk factor for fracture later in life and its association with tobacco smoking, menopausal age and the use of oral contraceptives. This is an epidemiological population study based on a questionnaire. A sample of 10000 women from seven birth cohorts between 1900-1940 was obtained at random from the population register. The overall response rate was 74.6%. The responders (n = 7459) represented 53% of the total population. METHODS: The women from all these birth cohorts were questioned regarding a possible history of fractures and the year in which they were sustained. The questionnaire also included questions about menopausal age, use of oral contraceptives, previous gynaecological operations and possible oestrogen medication. The women from the 1900-1920 birth cohorts were questioned in detail about urogenital disorders, while tobacco smoking data were recorded only for the 1930 and 1940 birth cohorts. RESULTS: The relative risk of sustaining a further fracture was significantly related to fracture premenopausally before 40 years of age and later fracture postmenopausally after 60 years of age (1.29; 0.97-1.70) compared to controls (0.78; 0.59-1.03)(P = 0.03). Both an early menopause and tobacco smoking were associated significantly with repeated fractures, while use of oral contraceptives had a protective effect against repeated fractures in the 1940 birth cohort. Logistic multiple regression showed that a fracture was a significant independent risk factor for further fracture in both cohorts 1900-1920 (P < 0.01) and 1930-1940 (P < 0.05). CONCLUSIONS: This study suggests poorer protective resources against new fractures among women with previous fractures, and that lack of oestrogen menopausally can partly explain the enhanced risk of fracture, not only during the menopause but also later in life when a hip fracture may have immense consequences. The results should draw our attention to emphasise the need for active treatment of patients with established osteoporosis because of the increased risk of new fractures later in life.

Age Factors↗

Urinary incontinence: a minor risk factor for hip fractures in elderly women.

OBJECTIVE: The aim of the study was to study the influence of urinary disorders as urinary incontinence on the prevalence of hip fracture in 85-year-old women. METHODS: A representative community-based population study was performed at the geriatric outpatient department of a university hospital in a sample consisting of 658 85-year-old women, of which 69% were living at home and 31% were living were living in institutions. The prevalence of hip fractures was registered and measurement with dual photon absorptiometry of the right calcaneum was performed. The subjects were questioned covering sociodemographic background, the occurrence, type, frequency and amount of urinary incontinence, medical examinations and investigations of the prevalence of hip fracture. RESULTS: Hip fracture was significantly associated with urinary incontinence (P < 0.001) for women and the odds ratio of hip fracture was twice that found in general population (OR = 2.42). Body mass index and weight were both significant higher (P < 0.01) among women with urinary incontinence and hip fracture. The frequency of urinary incontinence was also significant correlated to hip fracture (P < 0.001). Subjects with diabetes had a tendency to be associated with urinary incontinence (P < 0.06). In a logistic multiple regression analysis, body mass index, urinary incontinence and cancers were the only explanatory factors for hip fractures at 85 years of age. CONCLUSION: The association between postmenopausal urinary incontinence and hip fractures are multifactorial and whether this is a result of decreasing estrogen levels or a result of general aging process is still under debate. Women with urinary incontinence and earlier atrumatic multiple postmenopausal fractures should be considered a special target group for estrogen prophylaxis in order to prevent further severe fractures.

Aged↗

Is enteral nutrition optimally used in hospitalized patients? A study of the practice of nutrition in a Swedish hospital.

Thirty patients with parenteral nutrition were studied in order to evaluate if they could be given enteral nutrition instead. Based upon absolute and relative contraindications for enteral nutrition, we calculated that 80% of the patients were possible candidates for enteral nutrition. Long-term use of parenteral nutrition may cause complications. Besides metabolic and other advantages when enteral nutrition is used, economical gains are also important. We have calculated an estimated annual net profit of US$ 357,000 in our hospital, if enteral instead of parenteral feeding is used in patients suitable for the former type of feeding. This implies that it is really cost-beneficial to consider enteral nutrition in hospitalized patients. Although parenteral nutrition will continue to have its place in the management of different occasions, increased use of enteral nutrition may result in improved patient outcomes and improved cost-effectiveness.

Journal Article↗

Acute effects of C-peptide on the microvasculature of isolated perfused skeletal muscles and kidneys in rat.

The C-peptide has recently been suggested to have beneficial effects in several organs and improve glycaemic control in human type I diabetes, while there were no such effects in healthy controls. The exact mechanisms behind these effects are, however, not clear. In an attempt to study the actions of C-peptide on the microvasculature in normal rats during more controlled conditions, isolated rat hindquarters and kidneys were perfused with albumin solutions in order to obtain low basal concentrations of C-peptide. In rat hindquarters, infusion of C-peptide significantly increased the capillary filtration coefficients (CFC) from 0.035 +/- 0.002 to 0.044 +/- 0.002 mL min-1 100 g-1 mmHg-1 (P < 0.001, n = 9) and the permeability surface area product (PS) for vitamin B12 from 3.48 +/- 0.29 to 4.02 +/- 0.37 mL min-1 100 g-1 (P < 0.01, n = 6). Addition of C-peptide to the perfusate during infusion of sodium nitroprusside did not induce any additional alteration of CFC or PS. The vascular resistance was slightly decreased from 2.74 +/- 0.17 to 2.64 +/- 0.17 mmHg min 100 g mL-1 (P < 0.01, n = 9). These effects of C-peptide are compatible with increases in capillary surface area without alteration of the permeability per se. In isolated rat kidneys perfused at low temperature (8 degrees C) prepared to inhibit all metabolic processes. C-peptide induced no changes in glomerular filtration rate, total vascular resistance or fractional albumin clearance. Therefore, C-peptide causes active vasodilation of the normothermic microvasculature and hence recruitment of capillaries. These findings support the previous observations in man that C-peptide indeed has biological effects.

Animals↗

Acute mental stress but not enforced muscle activity transiently increases natural cytotoxicity in spontaneously hypertensive rats.

The influence of acute mental stress and the effect of electrically induced skeletal muscle contractions on natural cytotoxicity in vivo was investigated in spontaneously hypertensive rats Natural cytotoxicity in vivo was measured as the clearance of injected 51Cr-labelled YAC-1 lymphoma cells from the lungs, which are specifically lysed by natural killer cells. The mental stress consisted of an air jet directed towards the animals in their cage for 25 min. During the mental stress there was a significant increase in natural cytotoxicity. Thus, retained radioactivity in the lungs was decreased to 74 +/- 6% of the control levels which was set to 100% (P < 0.01). This augmentation of YAC-1-cell clearance could be blocked with the beta-adrenergic receptor antagonist Timolol. Two hours after termination of the air stress, in vivo cytotoxicity had returned to control levels. In contrast, acute physical stress, consisting of electrically induced muscle contractions for 60 min, had no significant effects on in vivo cytotoxicity, either during the stimulation or 1, 2 or 24 h after the stimulation. Further, significantly increased plasma levels of adrenaline were seen after the air jet stress, but not after muscle stimulation. There were no significant changes in plasma noradrenaline levels either after air stress or muscle stimulation. These results indicate that changes in in vivo cytotoxicity after mild mental stress are dependent on increased plasma catecholamine levels while acute physical stress without changes in catecholamine levels, does not influence in vivo cytotoxicity.

Animals↗

Detection of Pityrosporum orbiculare reactive T cells from skin and blood in atopic dermatitis and characterization of their cytokine profiles.

BACKGROUND: Atopic dermatitis (AD) is associated with increased levels of serum IgE, and T-helper (Th) cells are thought to a play role in the pathogenesis. Individuals with AD often develop IgE antibodies against the yeast Pityrosporum orbiculare, a member of the normal cutaneous flora. OBJECTIVE: The role of P. orbiculare in atopic dermatitis was investigated by examining the T-cell reactivity for P. orbiculare. METHODS: Freshly isolated peripheral blood mononuclear cells (PBMC) were isolated from 10 AD patients with serum IgE antibodies against P. orbiculare, and from six healthy controls. The proliferative response after P. orbiculare stimulation, measured by [3H]thymidine incorporation, was examined in the PBMC and in T-cell clones (TCC) obtained from skin and blood of one patient. The cytokine profile of the TCC was determined by enzyme-linked immunosorbent assay (ELISA), radioimmunoassay (RIA) and reverse transcriptase-polymerase chain reaction (RT-PCR) following challenge with either P. orbiculare extract or anti-CD3 antibodies and phytohaemagglutinin. RESULTS: The PBMC response to P. orbiculare was significantly higher in the AD patients than in the control group (P < 0.05). Twenty-nine out of 36 tested TCC derived from one responding patient were reactive for P. orbiculare. The clones were CD2+ and CD4+, except for one CD8+ blood clone. A majority of the TCC derived from lesional skin showed a Th2- or Th2/Th0-like cytokine profile. A co-expression of interleukin-5 (IL-5) mRNA and IL-13 mRNA was detected in five out of six P. orbiculare-reactive clones analysed for their cytokine gene expression with RT-PCR. CONCLUSION: Our data suggest that P. orbiculare can induce a T-cell response in AD patients. The Th2-like profile of P. orbiculare-reactive TCC derived from lesional skin indicates that P. orbiculare may play a role in maintaining IgE-mediated skin inflammation in AD.

Adolescent↗

Nitrous oxide: a valuable alternative for pain relief and sedation during routine colonoscopy.

BACKGROUND AND STUDY AIMS: Patient-administered nitrous oxide in 50% oxygen has lately come into use as an alternative to combined opioid and benzodiazepine medication for colonoscopic procedures. A randomized study was carried out comparing intramuscular pethidine hydrochloride 1 mg/kg with inhalation of Medimix (a mixture of nitrous oxide in oxygen 50%) for relief of pain and anxiety during colonoscopy. PATIENTS AND METHODS: Thirty-eight patients (19 in the pethidine group and 19 in the nitrous oxide group) were studied. The following parameters were measured: blood pressure, pulse rate, and arterial oxygen saturation. At the end of the colonoscopy and before the patients left the ward, pain, nausea, and general well-being were evaluated by the patients using a visual analogue scale. The colonoscopy time, investigation conditions and the total length of hospital stay were registered. RESULTS: Colonoscopy time and the colonoscopists' opinions concerning the investigation conditions did not differ between the groups. Pain relief and patient evaluation of the total procedure were also equal between the patient groups. However, there was less nausea among the Medimix patients. Three patients in the pethidine group had oxygen saturations below 92%. There was no desaturation during and five minutes after colonoscopy in the Medimix group. Patients in the Medimix group left the hospital on average 34 minutes earlier than patients in the pethidine group. CONCLUSIONS: We conclude that the use of nitrous oxide (Medimix) as an analgesic is as good as pethidine for colonoscopy. Medimix has clear advantages compared to pethidine in terms of reducing nausea and shortening the hospital stay.

Adult↗

Bone density, bone markers and bone radiological features in mastocytosis.

We examined the association between severity of disease in mastocytosis and skeletal manifestation and bone markers in 16 patients varying in extent of mastocytosis as determined by the urine excretion of methylimidazoleacetic acid. Both osteoporosis and osteosclerosis were found. Bone density in the hip was significantly higher (p < 0.05) in both men and women with an enhanced histamine metabolite excretion. Patients with only moderately increased mast cell mass had low bone mineral density in the hip, osteoporosis and vertebral fractures. The different skeletal disease patterns in mastocytosis might be the effect on osteoblasts and osteoclasts of biologically active substances. Mast cells release a number of vasoactive substances, including histamine which promotes osteoblasts and heparin and prostaglandin D2 which induce bone resorption by activation of osteoclasts. Systemic mastocytosis is a rare disease characterized by multi-organ infiltration by mast cells and with varying skeletal manifestations including osteoporosis. Treatment with bisphosphonates may be beneficial in arresting osteoporosis in this disorder.

Acid Phosphatase↗

Biapenem versus imipenem/cilastatin in the treatment of complicated intra-abdominal infections: report from a Swedish Study Group.

118 patients with complicated intra-abdominal infections participated in an open randomized comparative multicenter trial in order to compare the clinical and microbiological efficacy and safety of biapenem with imipenem/cilastatin (Tienam). 31 men and 27 women (mean age 52.3 years) were enrolled in the biapenem group, and 43 men and 17 women (mean age 52.3 years) in the imipenem/cilastatin group. The patients received either biapenem 500 mg every 8 h or imipenem/cilastatin 500 mg/500 mg every 6 h by intravenous infusion for up to 13 days (mean 6.5 days). 28/43 evaluable patients (65.1%) receiving biapenem and 27/40 evaluable patients (67.5%) in the imipenem/cilastatin group were clinically cured. The microbiological response was satisfactory in 28/43 evaluable patients (65.1%) receiving biapenem and in 27/40 evaluable patients (67.5%) receiving imipenem/cilastatin. No significant differences in clinical or microbiological efficacy between the two treatment groups were found. The present study shows that biapenem may be useful in the treatment of intra-abdominal infections.

APACHE↗