Search PubMed⌕ Search

Biomedical subjects

C Johansson

Publications and source records attributed to C Johansson.

At least 127 records · Page 7Linked to original sources
PubMed1996

PET and parathyroid L-[carbon-11]methionine accumulation in hyperparathyroidism.

UNLABELLED: The study was designed to characterize L-[methyl-11 C]methionine accumulation in abnormal parathyroid tissues of hyperparathyroidism (HPT). METHODS: Thirty-four patients with primary (n = 32) or secondary HPT were investigated with PET before primary or reoperative (n = 25) parathyroid surgery. Parathyroid 11C-methionine accumulation was analyzed for integrated uptake values in defined tissue volumes standardized for the injected dose and body weight (SUV), four contiguous pixels of maximal accumulation (SUVhs), SUV multiplied by area of region of interest (SUVr) and by the excised tissue weight (SUVw). Transport rate constants (slope, slopehs) were calculated according to Patlak's formula using plasma 11C activity corrected for 11C-methionine metabolites. RESULTS: True-positive localization was achieved in 85% of patients in whom 81% of the excised parathyroid lesions were visualized; no false-positive results were obtained. Corresponding proportions were 59% and 57% for CT and 55% and 52% for ultrasound, respectively. In the true-positive cases, parathyroid SUV, SUVhs and transport rate constants were consistently higher (p < 0.01) than in the thyroid, pharynx-esophagus, neck muscle and apical lung. Parathyroid SUV, SUVhs and SUVr increased with intact serum parathyroid hormone and calcium values (p = 0.0001-0.031), and weight of the excised tissue correlated with SUV and SUVhs (p = 0.024, 0.044). Parathyroid SUVhs varied strongly with the transport rate constants (p = 0.0008), and SUVr as well as s-calcium values differed significantly between parathyroid adenomas (n = 11), chief cell hyperplasias (n = 13), inadvertent implants (n = 3) and parathyroid cancers (n = 3). CONCLUSION: Carbon-11-methionine PET has potential application in preoperative localization and metabolic characterization of abnormal parathyroid tissues in human HPT.

Adenoma↗
PubMed1995

Phosphorylation of the Goodpasture antigen by type A protein kinases.

Collagen IV is the major component of basement membranes. The human alpha 3 chain of collagen IV contains an antigenic domain called the Goodpasture antigen that is the target for the circulating immunopathogenic antibodies present in patients with Goodpasture syndrome. Characteristically, the gene region encoding the Goodpasture antigen generates multiple alternative products that retain the antigen amino-terminal region with a five-residue motif (KRGDS). The serine therein appears to be the major in vitro cAMP-dependent protein kinase phosphorylation site in the isolated antigen and can be phosphorylated in vitro by two protein kinases of approximately 50 and 41 kDa associated with human kidney plasma membrane, suggesting that it can also be phosphorylated in vivo. Consistent with this, the Goodpasture antigen is isolated from human kidney in phosphorylated and non-phosphorylated forms and only the non-phosphorylated form is susceptible to phosphorylation in vitro. Since this motif is exclusive to the human alpha 3(IV) chain and includes the RGD cell adhesion motif, its phosphorylation might play a role in pathogenesis and influence cell attachment to basement membrane.

Amino Acid Sequence↗
PubMed1995

Characterization and expression of multiple alternatively spliced transcripts of the Goodpasture antigen gene region. Goodpasture antibodies recognize recombinant proteins representing the autoantigen and one of its alternative forms.

Collagen IV, the major component of basement membranes, is composed of six distinct alpha chains (alpha 1-alpha 6). Atypically among the collagen IV genes, the exons encoding the carboxyl-terminal region of the human alpha 3(IV) chain undergo alternative splicing. This region has been designated as the Goodpasture antigen because of its reactivity in the kidney and lung with the pathogenic autoantibodies causing Goodpasture syndrome. The data presented in this report demonstrate that, in human kidney, the gene region encompassing the Goodpasture antigen generates at least six alternatively spliced transcripts predicting five distinct proteins that differ in their carboxyl-terminus and retain, except in one case, the exon that harbors the characteristic amino-terminus of the antigen. Goodpasture antibodies specifically recognize recombinant proteins representing the antigen and the alternative form that retains the amino-half of the antigen, suggesting that this moiety could be involved in the in vivo binding of the pathogenic antibodies. Furthermore, the sera of control individuals contain autoantibodies against the antigen that can be differentiated from those causing the syndrome based on their specific reactivities, suggesting that the binding of the pathogenic autoantibodies to a specific determinant likely trigger a distinct and unique cascade of events causing the disease.

Alternative Splicing↗
PubMed1995

Anchorage of TiO2-blasted, HA-coated, and machined implants: an experimental study with rabbits.

The purpose of this study was to evaluate the histometrical and biomechanical anchorage of TiO2-blasted implants and TiO2-blasted implants coated with hydroxyapatite. The control implants were machined. Twenty-six rabbits had a total of 156 implants placed in the proximal part of the tibia. Each rabbit had a machined, a TiO2-blasted, and a TiO2-blasted, HA-coated implant placed in each tibia. After a healing period of 3 and 12 weeks, respectively, the implants placed in the right tibia were used for removal torque test, and the implants placed in the left tibia were used for histomorphometrical measurements. Preoperatively, implants from the same batches were examined topographically with a TopScan 3D system. The TiO2-blasted implants demonstrated significantly higher removal torque values than the machined implants, and they also had a significantly more irregular surface. Furthermore, significantly higher bone-to-implant contact length fractions were measured adjacent to the TiO2-blasted implants in contrast to the machined implants. The advantages of a TiO2-blasted surface were more pronounced after 3 weeks than after 12 weeks. The results demonstrated that it was possible to influence the anchorage of implants by altering the surface structure morphology. The new method with TiO2 blasting on the titanium surface improves the anchorage of implants but is not yet practicable for HA coating.

Animals↗
PubMed1995

Not only Th2 cells but also Th1 and Th0 cells express CD30 after activation.

To investigate whether the CD30 molecule, expressed only by a minority of T and B cells, defines a subtype of T helper cells, Pityrosporum orbiculare-specific CD4+ T cell clones were assessed for CD30 protein and gene expression. The clones were defined as Th1, Th0, and Th2 according to their cytokine mRNA profile detected by reverse transcription PCR (RT-PCR). The kinetics of CD30 expression after OKT3 (anti-CD3) stimulation was analyzed by flow cytometry, immunocytochemistry, and RT-PCR. OKT3 activation induced a high expression of CD30 in cells of both Th1 and Th0 as well as Th2 type after 1-3 days. A difference between the clones was noted in that the Th2 clones remained highly positive in CD30 expression, whereas expression in the other clones started to decline from day 3. These data indicate that CD30 is expressed in activated CD4+ T cells of all three subtypes, and that the expression is sustained in Th2 cells.

Base Sequence↗
PubMed1995

Localization of the human soluble epoxide hydrolase gene (EPHX2) to chromosomal region 8p21-p12.

Epoxide hydrolases have an important function in organisms in that they catalyze the transformation of potentially toxic or carcinogenic epoxides into the corresponding diols. In this study, the chromosomal localization was determined for the human gene encoding soluble epoxide hydrolase. A polymerase chain reaction fragment corresponding to the C-terminal region of the mouse protein was used to isolate a cosmid clone from a human genomic library. By fluorescence in situ hybridization to metaphase chromosomes, the soluble epoxide hydrolase gene was then localized to chromosomal region 8p21-p12.

Animals↗
PubMed1995

Results of rectocele repair. A prospective study.

PURPOSE: This study was designed to evaluate the results of rectocele repair and parameters that might be useful in selecting patients for this operation. METHODS: Twenty-five patients with symptom-giving rectoceles were prospectively evaluated with a standardized questionnaire, physical examination, defecography, colon transit studies, anorectal manometry, and electrophysiology. Patients underwent posterior colporrhaphy and perineorrhaphy. They were followed postoperatively (mean, 1.0 year) with the same questionnaire, physical examination, defecography, anorectal manometry, and electrophysiology. RESULTS: Constipation had improved postoperatively in 21 of 24 constipated patients (88 percent). At postoperative follow-up 13 patients (52 percent) had no constipation symptoms, 8 (32 percent) had occasional symptoms, and 4 (16 percent) had symptoms more than once per week. Four patients with rectocele at preoperative defecography, but not at physical examination, had favorable outcomes following surgery. The majority of patients not using vaginal digitalization preoperatively had improved with respect to constipation. All patients with pathologic transit studies had various degrees of constipation postoperatively. Constipation was not improved in two of five patients with preoperative paradoxic sphincter reaction. CONCLUSIONS: Rectocele is one cause of constipation that can be treated with good results. Preoperative use of vaginal digitalization is not mandatory for a good postoperative result. Defecography is an important complement to physical examination. Patients with pathologic transit study might have a less favorable outcome of rectocele repair with respect to constipation. More studies about the significance of paradoxic sphincter reaction in these patients are indicated.

Adult↗
PubMed1995

Tissue specific basal expression of soluble murine epoxide hydrolase and effects of clofibrate on the mRNA levels in extrahepatic tissues and liver.

The soluble epoxide hydrolase mRNA level in liver was increased eight-fold upon administration of the hypolipidemic drug and peroxisome proliferator clofibrate for 7 days to mice. The soluble epoxide hydrolase mRNA was back at control levels within 1-2 days after clofibrate withdrawal. The highest expression was in liver, intestine and kidney. Lower levels were found in heart and muscle and very low levels were found in testes, lung, brain and spleen. The mRNA levels were increased in liver, kidney and heart by clofibrate.

Animal Feed↗
PubMed1995

Prepulse inhibition of acoustic startle, a measure of sensorimotor gating: effects of antipsychotics and other agents in rats.

Schizophrenic patients are deficient in various neurologic measures reflecting information processing. One such measure in prepulse inhibition (PPI) of acoustic startle, in which schizophrenics display less inhibition than normal subjects. PPI is also diminished in rats treated with psychotomimetic drugs such as amphetamine and phencyclidine. PPI has been suggested as a model relevant for studying the pathophysiology of schizophrenia. We studied the effect of a variety of antipsychotics and putative antipsychotics and some key reference compounds on the acoustic startle response (ASR) and PPI. Some, but not all, antipsychotics tested (mainly selective dopamine D2 antagonists) enhanced PPI. Remoxipride and clozapine, both of which are antipsychotics, and the very potent and highly selective D2 antagonist, NCQ-298, did not. It is concluded that enhanced PPI in otherwise untreated rats does not reflect antipsychotic efficacy. We further noted that the effect on PPI was independent of the effect on ASR.

Acoustic Stimulation↗
PubMed1995

A new method to obtain bone biopsies at implant sites peri-operatively: technique and bone structure.

This study aims at evaluating an objective method for the description of bone structure in the human mandible. Human bone biopsies were harvested at mandibular implant sites prior to insertion of self-tapping Mark II fixtures. Altogether 15 biopsies were taken from 12 patients. Three patients donated 2 biopsies each, one proximally and one distally taken. Ground sections of about 100 microns thickness were prepared prior to microradiography. These sections were ground to a final thickness of about 10 microns followed by histological staining. Histomorphometrical analyses were performed on the microradiographed plates and on the ground sections. On average there was a bone area of about 54% calculated on the microradiographed plates (the 100-microns sections) versus a mean bone area of 62% light microscopically (the 10-microns sections). Bone lengths were calculated on the 10-microns sections in the central part (mid-line) and on each side of the mid-line, revealing a mean of 58% in the former case and a mean of 61% in the latter case. The amount of bone varied between individuals and in different locations of the same jaw. The postoperative healing period following fixture installation is standardized regardless of bone structure. It may in the future be appropriate to more individualize this healing period based on an objective bone quality score.

Adult↗
PubMed1995

Down syndrome and celiac disease.

Down syndrome is associated with immune-related disorders such as hypothyroidism, insulin-dependent diabetes mellitus, and celiac disease. In this study we determined antigliadin antibodies (AGA) in 54 patients with Down syndrome; 22 had AGA values above the cutoff limit. Nineteen patients underwent intestinal biopsy, and total or subtotal villous atrophy was found in nine. There was a total of 65 patients with Down syndrome in our area of southern Sweden; two were already known to have celiac disease. The minimum prevalence of celiac disease in Down syndrome in this area in southern Sweden was 11 of 65 or 16.9%.

Adolescent↗
PubMed1995

Eccentric and concentric knee extensor muscle performance in professional ballet dancers.

Ballet dancers are exposed to great eccentric loading of the lower extremities due to a high frequency of repetitive jumps and leaps. The purpose of this study was to evaluate eccentric (ECC) and concentric (CON) knee extensor muscle endurance and strength in professional ballet dancers (six men and 11 women) in relation to moderately active control subjects (17 men and 18 women). A Biodex dynamometer was used for isokinetic torque measurements. The ECC endurance (total work per kilogram) was on average 31% greater in professional ballet dancers compared to control subjects, while the corresponding average difference for CON endurance was 7%. A greater ECC CON total work ratio was observed for ballet dancers (mean ballet, 2.07; mean control, 1.74). The ECC and CON strengths (peak torque per kilogram) were greater in professional ballet dancers compared to controls (27 and 22%). No intraindividual torque difference between left and right limbs was found. Men showed significantly greater strength (peak torque per kilogram) and endurance (total work per kilogram) compared to women, similar in both groups. No differences in the ECC/CON relationship between genders were observed. In essence, our results favor the hypothesis that repetitive loading of the lower extremities in ballet dance leads to a higher standard of ECC knee extensor endurance.

Adult↗
PubMed1995

The plantar flexor muscle attachments on the tibia. A cadaver study.

Thirty-six tibiae from 11 female and 7 male cadavers were dissected. Anatomical and histological examinations of the plantar flexor muscle origins at the posteromedial border of the tibia were performed. Many individual variations in the type and size of muscle origin were observed. Muscle fibers and/or connective tissue in different proportions attached the muscle to the periosteum or directly to the cortical bone. The length of the attachments varied greatly and there was a considerable overlap of the muscles in some individuals. The attachments of the flexor digitorum longus overlapped the tibialis posterior and the flexor digitorum longus muscle was overlapped by the soleus muscle. In two cases the soleus muscle did not attach to the tibia at all. Our findings may shed some light on the question as to why some athletes sustain posteromedial tibial stress fractures and others develop shin splits or other posteromedial injuries from similar precipitating activity.

Aged↗
PubMed1995

Anti-neutrophil cytoplasmic antibodies in chronic inflammatory bowel disease. Prevalence and diagnostic role.

BACKGROUND: Anti-neutrophil cytoplasmic antibodies (ANCA), originally found to be associated with vasculitis, have been reported to be present in chronic inflammatory bowel disease. Most often the ANCA staining pattern is of the perinuclear type (p-ANCA), although nuclear and cytoplasmic stainings are seen. Single studies have shown some of the antibodies to react with lactoferrin or cathepsin G; however, most studies have not been able to determine a main antigenic specificity. We studied the prevalence of ANCA in sera from 155 patients with ulcerative colitis, 128 patients with Crohn's disease, and 51 patients with coeliac disease. The presence of ANCA was correlated to disease activity, extent, and age of onset of the diseases. Furthermore, we tried to characterize the antigen specificity by enzyme-linked immunosorbent assay (ELISA), using elastase, lactoferrin, myeloperoxidase, proteinase 3, and cathepsin G as antigens. METHODS: The sera were screened for ANCA by indirect immunofluorescence. Anti-nuclear antibodies (ANA) were analysed on HEp2 cells, and ELISA for specific ANCA was performed using the antigens mentioned. RESULTS: Most of the sera with positive immunofluorescence had the p-ANCA type of pattern. Seventy-eight of 155 (50.3%) of the patients with ulcerative colitis were ANCA-positive, compared with 31 of 128 (24.2%) of patients with Crohn's disease (p < 0.001). However, in the subgroup with Crohn's colitis, 16 of 44 (36.4%) were ANCA-positive. Only 4 of 51 patients (7.7%) with coeliac disease showed positive immunofluorescence (p < 0.001 compared with ulcerative colitis). Less than 10% of the samples were positive in the specific ELISA assays; thus other than the most well known granule proteins can be the target for ANCA in ulcerative colitis. CONCLUSION: ANCA occur significantly more often in ulcerative colitis than in Crohn's disease. However, the prevalence of ANCA is rather high in Crohn's colitis. ANCA are thus of limited value in differentiating Crohn's colitis from ulcerative colitis. ANCA found in inflammatory bowel disease are different from those associated with vasculitis. The antigen(s) responsible remain to be determined.

Adult↗
PubMed1994

Bone response to hydroxyapatite-coated and commercially pure titanium implants in the human arthritic knee.

Rough and smooth commercially pure (c.p.) titanium implants and hydroxyapatite-coated (HA-C) implants were inserted in arthritic human knees and left in situ in order to compare the response of bone to these three implants. Radiographic examination alone could not determine if bone apposition had occurred. After 3 and 6 months, histomorphometric analyses of undecalcified sections, 10 microns thick, revealed a statistical significance in the amount of bone apposition to rough-surfaced and HA-C implants as compared with smooth uncoated implants. Most of the rough-surfaced c.p. titanium implants and the HA-C implants had achieved bone apposition on the order of 50%. No statistically significant differences in apposition were seen between the rough-surfaced and HA-C implants. The smooth c.p. titanium implants were mostly encapsulated in fibrous tissue.

Arthritis↗