Search PubMed⌕ Search

Biomedical subjects

B Larsson

Publications and source records attributed to B Larsson.

At least 145 records · Page 8Linked to original sources
PubMed1995

The Beck Depression Inventory: testing and cross-validating a second-order factorial structure for Swedish nonclinical adolescents.

The intent of the present study was to test for the validity and equivalency of a second-order factorial structure of the Beck Depression Inventory for and across three independent samples (n1 = 661; n2 = 239; n3 = 196) of nonclinical Swedish adolescents. The model under study derived from a cross-validated study of Canadian high school adolescents. Model fitting, testing and equating were based on the analysis of covariance structures within the framework of a confirmatory factor analytic model. Of major importance was the tenability of the hypothesized model for Swedish adolescents. Only minor differences where found among samples, which involved correlated errors and one cross-loading (Sample 2). Results are expected to be of substantial interest to both researchers and clinicians whose concerns focus on depression as it bears on this population.

Adolescent↗
PubMed1995

Serum concentrations of thyroid hormones in calves with a transient or persistent infection with bovine viral diarrhoea virus.

Calves persistently infected with bovine viral diarrhoea virus (BVDV) often appear small for their age and it is possible that the virus interferes with their body metabolism by affecting the production of hormones. In this study, the serum concentrations of thyroxine (T4) and triiodothyronine (T3) were measured in calves with transient or persistent BVDV infections. The mean (SD) concentrations of T3 and T4 were lower (P < 0.001) in the persistently infected calves (1.79 [0.67] and 69.2 [23.8] nmol litre-1, respectively) from three dairy herds than in age-matched control calves (2.39 [0.72] and 93.4 [22.1] nmol litre-1, respectively). In each herd, the thyroid hormone levels were also lower in the persistently infected calves than in the controls, the differences being significant (P < 0.05) with the exception of the T3 level in one herd. The girth of the infected calves over the heart was less (P < 0.001) than that of the controls, and, among the infected calves but not among the controls, there was a significant correlation between heart girth and the levels of T3 (r = 0.72, P < 0.001) and T4 (r = 0.60, P < 0.01). Six calves not previously exposed to BVDV were infected through nose-to-nose contact with a persistently infected calf. Their T3 and T4 levels were decreased seven days (P < 0.05 and not significant, respectively) and nine days (P < 0.001 and P < 0.01, respectively) after the infection, when the clinical signs of the disease appeared.

Animals↗
PubMed1995

Facilitatory effect of pituitary adenylate cyclase activating polypeptide on micturition in normal, conscious rats.

In unanaesthetized, normal rats, continuous cystometry revealed that pituitary adenylate cyclase activating peptide (PACAP-27), administered intrathecally or intra-arterially near the bladder, stimulated micturition. The localization of PACAP-27 in the rat lower urinary tract was studied by immunohistochemistry, and the direct effects on the smooth muscles of the rat detrusor and urethra were investigated in vitro. In the intact rat, 1.0 nmol of PACAP-27 administered intrathecally as well as intra-arterially close to the bladder, but not intravenously, increased micturition pressure, decreased micturition volume and bladder capacity, and facilitated spontaneous bladder contractions. PACAP-27 immunoreactive structures were extremely scarce in the lower urinary tract, and the peptide had negligible effects on isolated detrusor muscle contracted by carbachol or stimulated electrically, or on urethral preparations contracted by noradrenaline. These results suggest that PACAP-27 has facilitatory actions on micturition both at the spinal cord and peripheral ganglionic levels.

Animals↗
PubMed1995

Long-term oral refeeding of patients with cirrhosis of the liver.

A previous study has shown that malnourished, clinically stable patients with liver cirrhosis are in protein and energy balance at their spontaneous dietary intake and that an improvement in nutritional status cannot be anticipated at this intake (Nielsen et al. 1993). In the present study we examined to what extent oral intake could be increased by nutritional support, and to what extent dietary protein would be retained with increased intake. The techniques used for balance studies were also validated since this information is not available for patients with liver cirrhosis. Fifteen malnourished patients with alcoholic liver cirrhosis were given increasing amounts of a balanced ordinary diet for 38 (SE 3) d. Intakes of protein and energy were recorded by weighing servings and leftovers on food trays. Protein intake was calculated from food tables. Total N disposal was calculated after measurement of urinary N excretion, and protein balance was calculated from the N balance. A validation study of protein balance in a subgroup of patients (analysis of N in food by the duplicate portion technique, correction for incomplete recovery of urine by measurement of urinary para-aminobenzoic acid (PABA) after administration of PABA tablets, and measurement of faecal N) did not change protein balance values. Protein intake increased from 1.0 (SE 0.1) g/kg per d to 1.8 (SE 0.1) g/kg per d. With increasing protein intake, 84 (SE 8)% of the increase in intake was retained. The rate of protein retention was not saturated at the intakes obtained in this study. Protein intolerance was only encountered in one patient. Available evidence indicates that the requirement for achieving N balance is increased in these patients but protein retention is highly efficient with increased intake. Protein retention is dependent on energy balance. Energy intake was calculated from food tables and total energy expenditure was calculated by the factorial method. A validation study was performed in a subgroup of patients. The energy contents of food sampled by the duplicate portion technique, and of urine and faeces were measured by bomb calorimetry. Resting energy expenditure (REE) was measured by indirect calorimetry before and at the end of the study, and O2 uptake during bicycle exercise was measured before and at the end of the study. The measured intake of metabolizable energy was on average 13% lower than the value given in food tables. Calculated energy expenditure was not changed by the validation study.(ABSTRACT TRUNCATED AT 250 WORDS)

Dietary Proteins↗
PubMed1995

Influence of batches of bovine oocytes on the outcome of an intact zona pellucida binding assay and in vitro fertilization.

A series of experiments was performed in vitro to determine the variation between batches of abattoir-derived bovine oocytes to bind and to be fertilized by frozen-thawed spermatozoa provided by a single ejaculate from a bull with high field fertility after artificial insemination. Fourteen batches of oocytes, collected over a 90-day period, were divided randomly into two equal groups at each sampling period. One group of oocytes was subjected to in-vitro maturation and subsequently in-vitro fertilization (IVF) while the other group was used as intact oocytes in a zona binding assay (ZBA). Fertilized oocytes were evaluated for penetration and pronuclear formation and, in the ZBA, the number of spermatozoa bound to each oocyte was registered. Neither the results of the ZBA nor the IVF results varied significantly (p = 0.45) between batches. Furthermore, when a sperm concentration of 0.5 x 10(6)/ml was used, the number of spermatozoa bound to the zona pellucida correlated significantly with the frequency of oocytes penetrated after IVF (r = 0.76). The results suggest that variation between the batches of oocytes has no detrimental significance for the application of intact zona pellucida binding or IVF for assaying frozen-thawed bull semen, provided that a large number of oocytes/batch (> 15) are assayed.

Animals↗
PubMed1995

Pituitary adenylate cyclase-activating polypeptide, helospectin, and vasoactive intestinal polypeptide in human corpus cavernosum.

1. The distribution and effects of pituitary adenylate cyclase-activating polypeptide (PACAP-27 and -38), helospectin (Hel-1 and Hel-2), and vasoactive intestinal polypeptide (VIP), were investigated in isolated preparations of human corpus cavernosum (CC). 2. Immunohistochemistry revealed coinciding profiles of nerve structures that showed immunoreactivities for VIP and PACAP, and VIP and Hel. Confocal microscopy showed the co-existence of VIP- and PACAP-immunoreactivities, and VIP- and Hel-immunoreactivities in most (90%) varicose nerve structures. 3. As determined by radioimmunoassay, the amounts of VIP, PACAP-27, and PACAP-38 in the preparations were 61.7 +/- 11.6, 0.1 +/- 0.05, and 3.7 +/- 0.5 pmol g-1 wet weight of tissue (pmol g-1 wet wt.), respectively. In tissue from patients with diabetes, the content of VIP was lower (13.7 +/- 0.5 pmol g-1 wet wt.), whereas that of PACAP (-27 and -38) was unchanged. 4. Cyclic nucleotide levels were determined in preparations exposed to PACAP-27, PACAP-38, Hel-1, Hel-2, and VIP. All the peptides, but Hel-2, significantly increased the concentrations of cyclic AMP, whereas the levels of cyclic GMP were unchanged. 5. The peptides concentration-dependently relaxed noradrenaline-contracted preparations. The order of potency was VIP > PACAP 27 > Hel-1 > Hel-2 > PACAP-38. 6. Hel-1, VIP and PACAP-27 effectively counteracted electrically induced contractions. At 10(-6) M, the highest peptide concentration used, the inhibitory effects obtained reached 96 +/- 3%, 87 +/- 6%, and 80 +/- 3%, respectively. 7. The results suggest that PACAP and Hel-1 are co-localized with VIP in nerve structures within the human cavernous tissue, and that the peptides are effective relaxants of CC preparations in vitro. The role of the investigated peptides for penile erection remains to be established.

Adult↗
PubMed1995

Distribution and effects of pituitary adenylate cyclase activating peptide in cat and human lower oesophageal sphincter.

1. The localization, tissue concentrations, and effects of pituitary adenylate cyclase activating peptide (PACAP) 27 and 38 were investigated in cat and human lower oesophageal sphincter (LOS), and compared with those of vasoactive intestinal peptide (VIP) and helospectin. 2. PACAP-immunoreactive nerve structures were found in the cat and human LOS, with an abundance in the circular smooth muscle layer. PACAP 27-immunoreactivity was often co-localized with VIP-immunoreactivity. 3. In cat tissue, PACAP (PACAP 27 plus PACAP 38) concentrations were 50 fold lower than VIP concentrations; in human tissue they were 10 fold lower. 4. PACAP 27, PACAP 38, helospectin I, and VIP induced concentration-dependent relaxations in circular smooth muscle preparations from cat and human LOS. The order of potency was: VIP > helospectin I > or = PACAP 27 > PACAP 38. NG-nitro-L-arginine, scopolamine, or apamin, did not influence the relaxant effects of PACAP 27 or VIP. 5. In cat preparations, both cyclic AMP and cyclic GMP levels were increased after exposure to PACAP 27 and helospectin I, whereas exposure to VIP was followed by an increase in cyclic AMP levels only. In human preparations, there was an increase in cyclic AMP levels without any change in cyclic GMP levels. 6. These results suggest that in the cat and human LOS, PACAP 27 and VIP can occur within the same nerve structures. PACAP 27 has a potent relaxant action, but its functional importance has to be established.

Animals↗
PubMed1995

Genetic influence in headaches: a Swedish twin study.

The heritability of liability to self-reported migraine and nonmigrainous headaches was examined in two large cohorts from the Swedish Twin Registry consisting of 6448 (the older cohort) and 12,884 (the younger cohort) like-sexed twin pairs. Higher concordance rates were consistently found for lifetime migraine among the monozygotic twins than in the dizygotic twins, as well as for migraine headaches of the recurrent disabling type. In addition, a higher concordance rate was found among the monozygotic twins than in dizygotic twins in a "mixed" group of possible tension-type or mild migraine headaches (or both). The results of structural equation model-fitting analyses showed that genetic effects for migraine headaches were stronger for the females (estimates ranging from 49% to 58%) than for the males (39% to 44%) in the two cohorts. Unique nonshared environmental effects were greatest for the "mixed" group in both sexes (estimates ranging from 60% to 69%). The results are discussed in view of similar large-scale twin studies examining the heritability of liability to migraine.

Adolescent↗
PubMed1995

Relationship between dental caries and risk factors for atherosclerosis in Swedish adolescents?

In an earlier study on a selected group of adolescents with high caries prevalence we found dietary habits that resembled those considered to promote the development of atherosclerosis. In the present study we have compared DMF-score with factors traditionally associated with the risk for development cardiovascular diseases (CVD). All 15-yr-olds living in an urban community in Northern Sweden 1987-1989 were included. Medical variables related to the risk of developing CVD were evaluated in groups of adolescents with various levels of manifest caries expressed as decayed and filled surfaces (DFS). The proportion of individuals with no medical risk factor at an unfavorable level was significantly higher in a caries free than in a high-caries (DFS > or = 9) group. Adolescents with two or more medical factors reaching unfavorable levels had a significantly higher caries score than the group with no factor at unfavorable level. A significant positive correlation was found for the whole group between DFS-score and relative body weight (body mass index) in an univariate correlation test as well as multiple linear regression analysis. The hypothesis that high caries score can be an indicator for unfavorable levels of traditional risk factors for CVD is not contradicted by the results in the present study but supported by the observed covariation with BMI. We therefore suggest that dietary counseling to adolescents with a high caries score in combination with a moderate obesity can be of advantage in reducing the caries risk as well as the risk for development of CVD at higher ages.

Adolescent↗
PubMed1995

Distribution and function of nitric oxide-containing nerves in canine corpus cavernosum and spongiosum.

Specimens of penile erectile tissue from the corpus cavernosum (CC) and corpus spongiosum (CS) of beagle dogs were investigated with reference to morphological and functional aspects of the nitric oxide (NO) system. Using immunohistochemistry, the smooth muscle bundles of the CC were found to contain a rich innervation, as seen by the pan-neuronal marker, protein gene product 9.5. A large number of nerves also stained positively for acetylcholine esterase. There was a moderate to rich supply of nerves containing NO synthase, which was frequently co-localized with vasoactive intestinal polypeptide. CS preparations from the proximal penis (the spongious bulb) had an innervation similar to that of the CC. However, CS preparations from the distal penis had a distinctly lower density of nerves than the proximal part, and spongious tissue from the glans penis was practically devoid of nerves. In isolated preparations of proximal and distal CC and CS, contracted by noradrenaline, electrical field stimulation (EFS) produced frequency-dependent relaxations. The responses were less pronounced in preparations from the distal penis, particularly in the CS. Pre-treatment with the NO-synthesis inhibitor NG-nitro-L-arginine abolished all relaxations. Carbachol effectively relaxed noradrenaline-contracted strips. The responses were similar in proximal preparations from the CC and CS, and significantly less pronounced in strips from the distal penis. NG-nitro-L-arginine significantly reduced the relaxant effect of carbachol. Preparations of spongious tissue from the glans penis did not react to high potassium solution, addition of noradrenaline, or EFS. The results demonstrate regional differences within the CS, both in innervation and functional responses.

Acetylcholinesterase↗
PubMed1995

Nitric oxide pathway in cat esophagus: localization of nitric oxide synthase and functional effects.

In the cat lower esophageal sphincter (LES) and esophageal body, nitric oxide synthase (NOS) immunoreactive nerves were abundant in the circular smooth muscle layer, especially in the LES region. NADPH diaphorase staining showed an identical pattern. The ability to form L-citrulline from L-arginine corresponded roughly to the distribution of NOS. Confocal microscopic analysis indicated colocalization within neurons of vasoactive intestinal peptide (VIP) in 65% of NOS-positive nerves. In LES circular smooth muscle preparations, electrically induced relaxations (single train stimuli) were generally abolished by NG-nitro-L-arginine (L-NNA). Continuous electrical stimulation for 2 min evoked a relaxation in the presence of L-NNA. This relaxation was inhibited by VIP antiserum and followed by a decrease in guanosine 3',5'-cyclic monophosphate, but not by any consistent change in adenosine 3',5'-cyclic monophosphate levels. K+ (124 mM) induced a biphasic relaxation, with L-NNA inhibiting the first phase but not the second. We conclude that nitric oxide (NO) has a major role as the mediator responsible for relaxation in the cat esophagus. NO seems also to initiate the release and enhance the effect of another transmitter.

Amino Acid Oxidoreductases↗
PubMed1995

[The combined use of photodynamic therapy with ionizing radiation on breast carcinoma cells in vitro].

PURPOSE: The photodynamic therapy is a technique by which the tumor cells are selectively sensitized to destruction by light of an appropriate wavelength. The aim of this work is to analyze the biological effectiveness of photochemical reactions induced by laser light in tumor cells exposed to photosensitizers. MATERIAL AND METHODS: The toxicity of the 2 photosensitizers zinc phthalocyanine (ZnPC) and meso-tetrahydroxyphenylchlorine (m-THPC) as well as the biological effect of the combination of sensitizers with laser light were tested in vitro by means of a colony forming assay. In addition, the influence on the photodynamic reaction of a previous exposure of the tumor cells to ionizing radiation has been tested. RESULTS: For both sensitizers doses of 5 micrograms per milliliter of culture medium showed low toxicity, i.e. the survival of the treated cells exceeded 90%. For laser treatments the dose permitting 90% survival was determined to be around 10 J/cm2. With these doses, the combined application of photosensitizers and laser light proved to be very effective and resulted in a nearly complete reduction of survival. As expected, irradiation of the cells with doses of 1 and 2 Gy of X-rays reduced the survival to 66 and 47%, respectively, compared to untreated controls. Cells surviving such treatment showed no changes either in the response to treatments with photosensitizers or to combined applications of photosensitizers and laser light. CONCLUSION: The effects of photodynamic treatment by ionizing radiation seem to be additive and independent of each other. So, our preliminary results are quite encouraging and point out the need of further detailed studies in view of the intended clinical application of this new kind of a local treatment.

Breast Neoplasms↗
PubMed1995

Nitric oxide synthase-containing neurons in rat parasympathetic, sympathetic and sensory ganglia: a comparative study.

In rats, the distribution of nerve structures staining for NADPH-diaphorase, and showing immunoreactivities for nitric oxide synthase (NOS), tyrosine hydroxylase and various neuropeptides was studied in sensory ganglia (dorsal root, nodose and trigeminal ganglia), in sympathetic ganglia (superior cervical, stellate, coeliac-superior and inferior mesenteric ganglia), parasympathetic ganglia (sphenopalatine, submandibular, sublingual and otic ganglia), and in the mixed parasympathetic/sympathetic ganglia (major pelvic ganglia). The coincidence of neuronal cell bodies with strong NOS-immunoreactivity and strong NADPH diaphorase reactivity was almost total. The relative proportions of NOS-immunoreactive nerve cell bodies were largest in parasympathetic ganglia and major pelvic ganglia followed by sensory ganglia. In sympathetic ganglia no NOS-immunoreactive neuronal cell bodies could be detected. In parasympathetic and major pelvic ganglia, there was a very significant neuronal co-localization of immunoreactivities for NOS and vasoactive intestinal polypeptide (VIP). This was almost total in major pelvic ganglia, in which NOS-/VIP-immunoreactive nerve cell bodies were separate from sympathetic (tyrosine hydroxylase-/neuropeptide Y-immunoreactive), suggesting that NOS-/VIP-immuno-reactive neurons might also be parasympathetic.

Animals↗
PubMed1994

Nitric oxide synthase-containing, peptide-containing, and acetylcholinesterase-positive nerves in the cat lower oesophagus.

The innervation of the cat lower oesophagus, including the lower oesophageal sphincter, was studied by enzyme histochemistry, immunohistochemistry, and confocal microscopy. In the lower oesophageal sphincter, and at a level 2 cm above it, no apparent differences were seen in the nerve distribution pattern. Among the nerve populations studied, acetylcholinesterase (AChE)-positive nerves were the most abundant in both these regions. The density of AChE-positive nerves was particularly marked in the circular muscle layer. A rich supply of nitric oxide synthase (NOS)-containing nerves was identified by using an antiserum against neuronal NOS, or by enzyme histochemical staining for NADPH diaphorase activity. Vasoactive intestinal peptide (VIP)-immunoreactive nerves had a similar distribution pattern as NOS-immunoreactive nerves, and nerves displaying immunoreactivity for NOS and VIP often showed profiles coinciding with AChE-positive nerves. As judged by confocal microscopy, immunoreactivities for helospectin, pituitary adenylate cyclase-activating peptide (PACAP) and VIP, to a large extent were found in the same nerves. At a level 7 cm above the lower oesophageal sphincter, the total nerve supply was less than in the sphincter itself and 2 cm above it. Immunoreactivity towards VIP, PACAP and helospectin was also found to co-exist with NOS and neuropeptide Y within the same nerve structures. It is concluded that there is an intricate innervation pattern in the feline lower oesophagus reflecting the complexity in the regulation of its motility.

Acetylcholinesterase↗
PubMed1994

Cytotoxic susceptibility and defective MHC class I expression do not correlate with mutation of p53 in human carcinomas.

Twenty-nine samples of ex vivo ovarian and lung carcinomas were investigated for the relationship between the presence of mutated protein 53 (mp53) and cytotoxic susceptibility. Unaltered expression of MHC class I alleles was required for the cytotoxic susceptibility of tumour cells to the autologous ex vivo blood lymphocytes, i.e. all 4 sensitive tumours belonged to the group of 11 tumours without defect in MHC class I expression. In contrast, the susceptibility did not correlate with the presence of mp53, i.e. cases with mp53 were randomly distributed between the sensitive and resistant tumours (2/4 and 10/17 respectively). There was no correlation either between the p53 mutation and down-regulation of MHC class I alleles. The results suggest that in these tumours the mutated p53 is not the source of immunogenic peptides and that the lack of recognition of the tumours with mp53 is not caused by a defect in the expression of MHC class I molecules.

Adenocarcinoma↗
PubMed1994

A serum-free, cell-free culture system for development of bovine one-cell embryos up to blastocyst stage with improved viability.

With the aim of developing a serum-free, cell-free culture system for embryo development, in vitro-matured (IVM) and -fertilized (IVF) bovine oocytes were cultured in TCM 199 with the following supplements: 1) BSA alone (10 mg/ml); 2) BSA with ITS (5 mug/ml insulin, 5 mug/ml transferrin and 5 ng/ml selenium; BSAITS medium); 3) estrous cow serum alone (ECS; 10%); or 4) ECS with BOEC (bovine oviduct epithelial cells) (Experiment 1). In Experiment 2, embryos were cultured in BSAITS medium with or without feeding with fresh medium on Day 4 (day of insemination = Day 0). Embryos were evaluated on Day 2 for first cleavage, on Day 7 for morulae and blastocysts, and on Day 8 for blastocysts. Blastocysts from Experiment 1 were frozen in 10% glycerol in PBS, thawed and further cultured in ECS medium with BOEC for 48 h, and evaluated for formation of a distinct blastocoel, or expansion and hatching of blastocysts. In vivo-developed, Grade-1 and Grade-2, 7-d-old embryos served as control for the freezing, thawing and subsequent culture procedures. The percentage of first cleavage did not differ between the treatments (74 to 79% in Experiment 1 and 80 to 83% in Experiment 2). The percentage of blastocysts developed in BSAITS medium did not differ from that in ECS medium whether BOEC were present or not. However, medium with BSA alone had fewer blastocysts than any other culture system (P<0.05). Feeding embryos with fresh BSAITS medium on Day 4 did not lead to any further increase in the proportion of blastocysts. The culture systems had a significant effect on the post-thaw viability of blastocysts developed in them (P<0.001). Blastocysts developed in BSAITS medium had better (P<0.05) viability (14/38) than those from medium with ECS alone (1/27) or with ECS and BOEC (3/37). The post-thaw survival of control embryos was 80% (n=30). One of the three transfers of BSAITS-treated, frozen-thawed blastocysts resulted in a pregnancy. The results indicate that a serum-free, cell-free culture system can support the development of IVM-IVF bovine oocytes up to the blastocyst stage with better viability than a complex co-culture system.

Journal Article↗