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Biomedical subjects

C Johansson

Publications and source records attributed to C Johansson.

At least 73 records · Page 4Linked to original sources
PubMed1999

Validation of cough-induced leak point pressure measurement in the evaluation of pharmacological treatment of stress incontinence.

To improve routines in clinical practice and research, it is important that new tests are thoroughly evaluated before they gain widespread application. This includes establishing the reliability and validity of the new test. The purpose of this study was to establish the construct and criterion validity of cough-induced leak point pressure (CILPP) measurement. Data on CILPP, maximum urethral pressure (MUP), and a short-term pad test from a phase-I trial of a new pharmacological agent (LS 4416), developed for the treatment of stress incontinence, was used to test the validity of CILPP. Fifteen post-menopausal women with stress incontinence were studied. Phenylpropanolamine (PPA) was used as a positive control. Administration of PPA produced a statistically significant increase in MUP and CILPP. There was a significantly better effect of treatment, expressed as an increase in MUP at 1.5 hr, when PPA was used than with placebo or LS 4416. When CILPP was used to detect change after therapy, PPA produced a significantly greater increase in CILPP than did placebo (least square mean of difference 17.25, P = 0.0202). There was a moderate but statistically significant correlation between CILPP and the short-term Pad Test. Construct validity was demonstrated by the ability of CILPP to detect limited improvement in patients with stress incontinence. Criterion validity was established by the correlation of CILPP to a short-term Pad Test. We propose that, thanks to its greater methodological qualities, leak point pressure measurement should be adopted as a standard method to ascertain the effect of treatment in patients with stress incontinence. Neurourol. Urodynam. 18:591-602, 1999.

Aged↗
PubMed1999

Clinical outcome of Screw Vent implants. A 7-year prospective follow-up study.

The clinical results of 85 Screw Vent implants are described with respect to 7-year success, including radiographically detectable bone loss, survival and prosthetic quality. The 1-year results of the same material have been reported previously (De Bruyn et al. 1992). Implants were considered as successful when they were meeting with the success criteria proposed by the European Academy for Periodontology. From the 85 implants originally installed, 16 failed during the 7-year interval (18.8%), 6 were unaccounted for (7%), 21 (24.7%) did not meet the success criteria yet survived and 42 implants (49.4%) were successful. The success rate was 65.2% for the mandibular and 43.5% for the maxillary implants. Implant failures were irrespective of implant length, smoking habits, prosthetic quality or oral hygiene level. From 24 patients with a corresponding number of 60 implants, radiographs were available for bone loss analysis. The mean bone loss after 7 years was 2.92 mm (range -0.5 to 6.3) 18 out of 60 examined implants (30%) showed unacceptable radiological bone loss beyond the critical value of 2.7 mm. Implant material analysis and histomorphometric analysis of a retrieved implant are discussed. In the present clinical study, the Screw Vent implant system does not meet the success criteria proposed by the European Academy for Periodontology. The ongoing bone loss increases the risk for future implant failures and peri-implant disease.

Alveolar Bone Loss↗
PubMed1999

Stability of implants as anchorage for orthopedic traction.

The aim of this animal study was to investigate the stability of osseointegrated fixtures when used as anchorage for orthopedic traction with extreme force magnitude. Three Brånemark fixtures were placed in the left zygomatic arch and three in the right of five adult dogs. An orthopedic nonaxial force of 5 N was applied using an intraoral coil system. The initial displacement immediately after force application was measured by means of speckle interferometry. After 2 months of continuous loading, bone adaptation and mineralization around all implants were analyzed. All the loaded implants were immobile. Significant marginal bone loss at the abutment-fixture interface (<1 mm) was observed around each loaded fixture implant. Bone remodeling was significantly more pronounced at the tension side of the implants, irrespective of fixture length. Radiographical and histological analyses showed bone with normal trabecular pattern around the implants.

Adaptation, Physiological↗
PubMed1999

Peripheral blood T-cell receptor beta-chain V-repertoire in atopic dermatitis patients after in vitro exposure to Pityrosporum orbiculare extract.

The yeast Pityrosporum orbiculare belongs to the normal cutaneous flora but is also considered to be one of the factors that may contribute to atopic dermatitis (AD). In the present study we investigated the possibility that P. orbiculare can act with superantigen activity in AD. P. orbiculare-reactive T-cell lines (TCLs) were obtained after stimulation of peripheral blood mononuclear cells (PBMC) with P. orbiculare extract. T-cell receptor beta-chain V-segment (TCRBV) usage was investigated using monoclonal antibodies and flow cytometry. We could not find any difference in TCRBV usage between AD patients (n = 10) and healthy controls (n = 5), either in fresh PBMC or in P. orbiculare-reactive TCLs. Compared with their original PBMCs the P. orbiculare-reactive TCLs showed a decreased usage of several TCRBVs, although increased usage of certain TCRBVs could be seen in some of the individuals. Further analysis of the CDR3-length polymorphism exhibited a shift in CDR3-length distribution, indicating oligoclonal expansion of T cells specific to different antigens in the P. orbiculare extract. In conclusion we have not found any evidence for superantigen activity in P. orbiculare extract, but our data support the importance of classical major histocompatibility complex (MHC)-restricted allergens in P. orbiculare.

Adolescent↗
PubMed1999

Cross-linked hyaluronan (Hylan B gel): a new injectable remedy for treatment of vocal fold insufficiency--an animal study.

After injection of hylan B gel (Hylaform), the vocal folds of rabbits were studied by light microscopy at various time-points up to 12 months. Hylan B gel is a viscoelastic cross-linked and insoluble hyaluronan derivative which behaves as a soft gel. It is non-immunogenic, non-toxic and non-inflammatory and has already been used in plastic surgery for intradermal implantations. Macroscopic examination of the injected vocal folds revealed a bulging in six of the animals, but on microscopical examination the hylan B gel was encountered in all of them. Already after 1 month, and increasingly so up to 12 months, there was an ingrowth of new connective tissue, with collagen, fibroblasts and hyaluronan within the gel. No inflammatory reaction or any sign of a foreign body reaction was observed throughout the study. Hylaform may well become useful as an injection material for augmentation of vocal folds in the treatment of vocal fold insufficiency.

Animals↗
PubMed1999

The neuronal selective nitric oxide inhibitor AR-R 17477, blocks some effects of phencyclidine, while having no observable behavioural effects when given alone.

We have previously shown that the non-specific nitric oxide synthase inhibitor L-NAME blocks the behavioural effects of phencyclidine, but not d-amphetamine. To characterise the specificity of these effects, we used the specific neuronal nitric oxide synthase inhibitor AR-R 17477 in two rat models of psychosis: the prepulse inhibition of the acoustic startle response and locomotor activity. In biochemical assays, AR-R 17477 was shown to be selective for the neuronal nitric oxide synthase isoform. Test drugs were given subcutaneously. AR-R 17477 (0.5, 1 and 5 mg/kg) antagonised phencyclidine-induced hyperlocomotion, while higher doses (10 and 20 mg/kg) were less efficaceous. AR-R 17477 (1 mg/kg) antagonised phencyclidine-induced deficit in prepulse inhibition of the acoustic startle response, while a higher dose (15 mg/kg) was less active. AR-R 17477 did not affect startle amplitude or prepulse inhibition of the acoustic startle response, did not affect locomotion and did not induce any changes in gross behaviour (sniffing, rearing, etc.) as determined in a subjective observation study. AR-R 17477 (1 mg/kg) did not alter the effect of d-amphetamine in prepulse inhibition of the acoustic startle response. Using radiotelemetry in rats, L-NAME (10 mg/kg subcutaneously) increased blood pressure and decreased heart rate while AR-R 17477 (10 mg/kg) did not have any significant effect on these parameters. The results show that a neuronal nitric oxide synthase inhibitor antagonises the effects of phencyclidine on prepulse inhibition of the acoustic startle response and locomotor activity, without exhibiting significant behavioural effects of its own and suggest that our earlier results with L-NAME depended upon an inhibition of neuronal nitric oxide synthase and not on an inhibition of endothelial nitric oxide synthase or inducible nitric oxide synthase. The observed effects are unlikely to be related to an effect on cardiovascular function.

Amidines↗
PubMed1999

Month of birth and risk of developing insulin dependent diabetes in south east Sweden.

Environmental factors very early in life may be important for later development of insulin dependent diabetes. Because several of these factors, such as infections, vary with season, we predicted a difference in birth pattern compared with the general population among children who develop diabetes. In a population based study we analysed all 1248 children from seven paediatric departments in the south east part of Sweden to evaluate whether there is such a relation. There was a significant difference in birth pattern in patients with diabetes compared with the general population. Children who developed diabetes at the age of 10-15 years accounted for most of this difference. Boys had a more pronounced difference in birth pattern than girls. Children diagnosed with diabetes during years of high incidence, as well as children with an infection before diagnosis of diabetes, showed a significantly different birth pattern compared with the background population. These results indicate that there is a difference in birth pattern in children who develop diabetes compared with the background population. This supports the theory that environmental factors early in life play a role in the development of diabetes many years later.

Adolescent↗
PubMed1999

Cardiovascular phenotype and temperature control in mice lacking thyroid hormone receptor-beta or both alpha1 and beta.

We have used a telemetry system to record heart rate, body temperature, electrocardiogram (ECG), and locomotor activity in awake, freely moving mice lacking thyroid hormone receptor (TR)-beta or TR-alpha1 and -beta (TR-alpha1/beta). The TR-alpha1/beta-deficient mice had a reduced heart rate compared with wild-type controls. The TR-beta-deficient mice showed an elevated heart rate, which, however, was unresponsive to thyroid hormone treatment regardless of hormonal serum levels. ECG revealed that the TR-beta-deficient mice had a shortened Q-Tend time in contrast to the TR-alpha1/beta-deficient mice, which exhibited prolonged P-Q and Q-Tend times. Mental or pharmacological stimulation of the sympathetic nervous system resulted in a parallel increase in heart rate in all animals. A single injection of a nonselective beta-adrenergic-receptor blocker resulted in a parallel decrease in all mice. The TR-alpha1/beta-deficient mice also had a 0.4 degrees C lower body temperature than controls, whereas no difference was observed in locomotor activity between the different strains of mice. Our present and previous results support the hypothesis that TR-alpha1 has a major role in determining heart rate under baseline conditions and body temperature and that TR-beta mediates a hormone-induced increase in heart rate.

Adrenergic beta-Antagonists↗
PubMed1999

Histologic evaluation of guided vertical ridge augmentation around implants in humans.

Recent experimental and clinical case reports demonstrated vertical ridge regeneration in atrophic posterior mandibles and maxillae. Although the results from these clinical cases are quite encouraging there is a lack of human histologic data on the newly regenerated tissue around commercially available titanium implants. The aim of the present study was to perform a qualitative and quantitative histologic analysis of the bone response to previously exposed implant threads after treatment with guided bone regeneration in a series of patients. A total of 30 Nobel Biocare implants were consecutively placed in 6 patients with partially edentulous mandibles. Of these implants, 6 were planned for removal after 1 year, whereas the remaining 24 implants were inserted to function as support for a fixed partial denture. The 6 experimental implants were intentionally allowed to protrude occlusally 5 to 7 mm from the bone crest without counter-sinking. The exposed implant threads were completely covered by autogenous bone chips. After a 12-month healing period the 6 experimental implants were removed with trephine burs. Bone-to-metal contact and bone density in the implant threads were measured. Clinically, all implants were stable and there was complete tissue fill of the space underneath the membranes. Histologically, a substantial amount of new bone had formed underneath the membrane in all cases. Histomorphometrically, there was a lower bone-to-metal contact percentage in the exposed compared to the nonexposed region in every case. With respect to bone density, there was a mean of 43.2% in previously exposed regions compared to 60.3% in previously nonexposed regions.

Adult↗
PubMed1998

The neuropeptide Y/agouti gene-related protein (AGRP) brain circuitry in normal, anorectic, and monosodium glutamate-treated mice.

Neuropeptide Y (NPY) and the endogenous melanocortin receptor antagonist, agouti gene-related protein (AGRP), coexist in the arcuate nucleus, and both exert orexigenic effects. The present study aimed primarily at determining the brain distribution of AGRP. AGRP mRNA-expressing cells were limited to the arcuate nucleus, representing a major subpopulation (95%) of the NPY neurons, which also was confirmed with immunohistochemistry. AGRP-immunoreactive (-ir) terminals all contained NPY and were observed in many brain regions extending from the rostral telencephalon to the pons, including the parabrachial nucleus. NPY-positive, AGRP-negative terminals were observed in many areas. AGRP-ir terminals were reduced dramatically in all brain regions of mice treated neonatally with monosodium glutamate as well as of mice homozygous for the anorexia mutation. Terminals immunoreactive for the melanocortin peptide alpha-melanocyte-stimulating hormone formed a population separate from, but parallel to, the AGRP-ir terminals. Our results show that arcuate NPY neurons, identified by the presence of AGRP, project more extensively in the brain than previously known and indicate that the feeding regulatory actions of NPY may extend beyond the hypothalamus.

Animals↗
PubMed1998

Domains, specific residues and conformational states involved in hydride ion transfer and proton pumping by nicotinamide nucleotide transhydrogenase from Escherichia coli.

Nicotinamide nucleotide transhydrogenase constitutes a proton pump which links the NAD(H) and NADP(H) pools in the cell by catalyzing a reversible reduction of NADP+ by NADH. The recent cloning and characterization of several proton-pumping transhydrogenases show that they share a number of features. They are composed of three domains, i.e., the hydrophilic domains I and III containing the NAD(H)- and NADP(H)-binding sites, respectively, and domain II containing the transmembrane and proton-conducting region. When expressed separately, the two hydrophilic domains interact directly and catalyze hydride transfer reactions similar to those catalyzed by the wild-type enzyme. An extensive mutagenesis program has established several amino acid residues as important for both catalysis and proton pumping. Conformational changes mediating the redox-driven proton pumping by the enzyme are being characterized. With the cloned, well-characterized and easily accessible transhydrogenases from E. coli and Rhodospirillum rubrum at hand, the overall aim of the transhydrogenase research, the understanding of the conformationally driven proton pumping mechanism, is within reach.

Binding Sites↗
PubMed1998

Application of synchrotron radiation in investigation of metal-ion release from a hip replacement prosthesis.

The aim of the present study was to measure very low concentrations of Al, V, Fe, Cr and other metal elements in a matrix of P, S, Cl, Ca and other constituent elements of the human body. These metal elements were released from a failed total hip replacement prosthesis into the surrounding tissues. The experimental results have been compared with those from proton-induced X-ray emission spectroscopy of the same specimen.

Journal Article↗
PubMed1998

Abnormal heart rate and body temperature in mice lacking thyroid hormone receptor alpha 1.

Thyroid hormone, acting through several nuclear hormone receptors, plays important roles in thermogenesis, lipogenesis and maturation of the neonatal brain. The receptor specificity for mediating these effects is largely unknown, and to determine this we developed mice lacking the thyroid hormone receptor TR alpha 1. The mice have an average heart rate 20% lower than that of control animals, both under normal conditions and after thyroid hormone stimulation. Electrocardiograms show that the mice also have prolonged QRS- and QTend-durations. The mice have a body temperature 0.5 degrees C lower than normal and exhibit a mild hypothyroidism, whereas their overall behavior and reproduction are normal. The results identify specific and important roles for TR alpha 1 in regulation of tightly controlled physiological functions, such as cardiac pacemaking, ventricular repolarisation and control of body temperature.

Animals↗
PubMed1998

Human hormone-sensitive lipase: expression and large-scale purification from a baculovirus/insect cell system.

Hormone-sensitive lipase (HSL) is a key enzyme in lipid metabolism and overall energy homeostasis in mammals. It catalyzes the rate-limiting step in the hydrolysis of triglyceride stores in the adipocytes, delivering free fatty acids for their use as energy substrates. HSL activity is under acute hormonal and neural control, mediated through reversible phosphorylation of the enzyme. Emerging data from clinical studies indicate that HSL deficiency or malfunction is associated with several pathological situations in humans. In order to perform a biochemical characterization of human HSL, and to elucidate its molecular properties, purification of homogeneous protein in large amounts is required. Here, we describe the expression and purification of a catalytically active recombinant human HSL. The process allows the purification of milligram amounts of homogeneous protein, and should provide a valuable tool for a thorough molecular characterization of the enzyme.

Amino Acid Sequence↗
PubMed1998

Paradoxical sphincter reaction is influenced by rectal filling volume.

PURPOSE: Paradoxical sphincter reaction is frequently found in constipated patients but sometimes also in incontinent patients and in asymptomatic subjects. Its significance in defecation disorders has, therefore, been debated. The aim of the present study was to investigate whether paradoxical sphincter reaction is influenced by rectal filling volume. PATIENTS AND METHODS: Eighteen patients with defecation disorders and paradoxical sphincter reaction shown by electromyography were reinvestigated with an extended electromyographic investigation while in the lying position and while in the sitting position, with 50-ml, 100-ml, and 150-ml water-filled rectal balloons. RESULTS: All 18 patients showing paradoxical sphincter reaction in the first investigation also showed the reaction at the second investigation in the lying position with a 0-ml volume of rectal contents. In the sitting position, with a volume of 150 ml of rectal contents, the increase in electromyographic activity disappeared in seven patients (39 percent) and no longer showed paradoxical sphincter reaction. Electromyography showed decreased activity in one patient and unchanged activity in six patients during straining. A closing reflex was seen after completed straining in all of these seven patients. CONCLUSIONS: The present study demonstrates that paradoxical sphincter reaction diagnosed by electromyography is influenced by the rectal filling volume and might diminish when the rectum is filled with contents. The conventional electrophysiologic technique in the diagnosis of paradoxical sphincter reaction might, therefore, overdiagnose this condition.

Adult↗
PubMed1998

Bone mineral density is a predictor of survival.

The purpose of this study was to examine the relationship between bone mineral density (BMD) and survival in both sexes and to compare BMD with other established risk factors such as blood pressure and cholesterol. A population-based prospective study of 1924 individuals (850 men, 1074 women) was performed in Göteborg from 1980 to 1983. Measurements of BMD were obtained in 1468 (76%) of the participants (653 men, 815 women). This selection of individuals generated 10,965 person years, and death was registered for 289 men and 197 women in the 7-year period (2661 days) after bone mineral measurement. Later information on date of death was obtained from the official population register. This information covers 7 years from the time of survey of the last examined participant (in Dec. 1983). At the beginning of the study, BMD was measured in the calcaneus by dual photon absorptiometry (DPA), and blood pressure, serum cholesterol, serum triglycerides, and body mass index (BMI) were also recorded. The study was coordinated with the National Register of Causes of Death and the National Cancer Register. A modified version of the Cox proportional hazards model was used to calculate and determine the age-adjusted relations between nontrauma mortality and BMD. When the various quartiles of BMD were compared prospectively from 70, 75, and 79 years of age with survival figures during the 2661-day follow-up period, the first and the second quartiles with the lowest BMD at entry showed the lowest survival rate in both men (P = 0.01) and women (P = 0.01). A decrease of 1 SD of BMD in a univariate analysis was associated with a 1.39-fold increase in mortality in both men (95% confidence interval 1.25-1.56, P < 0.001) and women (95% confidence interval 1.22-1.58, P < 0.001), and a multivariate analysis demonstrated a relative risk of 1.23 (95% confidence interval 1.10-1.41, P < 0.001) in men and 1.19 (95% confidence interval 1.02 to 1.39, P = 0.019) in women. All relations were adjusted for sex, age, and follow-up. This study indicates that BMD is a predictor of survival, especially for subjects over 70. Bone mineral density was found to be a better predictor of death than blood pressure and cholesterol. This study indicates that, after adjustments have been made for diseases, low bone mass is an independent predictor of mortality and might be a marker of general health or functional aging. Its measurement might therefore be a valuable tool in general health investigations.

Aged↗
PubMed1998

Effects of a cognitive-behavioral pain-management program.

A cognitive behavioral multidisciplinary pain management program was evaluated in two separate outcome studies; one controlled study (study I) and one study conducted on a consecutive sample with a long-term follow-up (study II). The 4-week inpatient treatment program included education sessions, goal setting, graded activity training, pacing, applied relaxation, cognitive techniques, social skills training, drug reduction methods, contingency management of pain behaviors, and planning of work return. The outcome of study I showed significant between-group differences in favor of the treatment group on measures of occupational training at 1-month follow-up, activity level in the sparetime at post-treatment and at follow-up, and decreased catastrophizing and pain behaviors at post-treatment. In study II significant improvements over time were found on measures of sick leave, pain intensity, pain interference, life control, affective distress, activity level in the sparetime, physical fitness and use of analgetics at 2-month follow-up and at 1-year follow-up. The results of the two outcome studies reported show that cognitive behavioral multidisciplinary pain management programs can successfully be applied to Swedish musculoskeletal pain patients.

Adaptation, Psychological↗