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Biomedical subjects

K Larsson

Publications and source records attributed to K Larsson.

444 records · Page 25Linked to original sources
PubMedDate not supplied

Effects of the dopamine D3 receptor ligand 7-OH-DPAT on male rat ejaculatory behavior.

As previously shown, 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT) produces a marked and highly characteristic facilitation of male rat ejaculatory behavior, and this effect is not sensitive to dopamine (DA) receptor antagonists of the D1 or D2 receptor families. The structural congener 7-OH-DPAT, primarily characterized as a DA D3 receptor selective ligand, produced a facilitation of male rat ejaculatory behavior, as evidenced by a dose-dependent decrease in the number of intromissions preceding ejaculation and in time to ejaculation. These effects could be antagonized by pretreatment with the DA D2/D3 receptor antagonist, raclopride. Thus, 7-OH-DPAT-induced effects on male rat ejaculatory behavior can be pharmacologically differentiated from effects produced by 8-OH-DPAT.

Animals↗
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Interposition arthroplasty of the elbow with rheumatoid arthritis.

Radiographic bone loss and clinical outcome were evaluated at a median of 6 years after interposition arthroplasty was performed in 35 elbows with rheumatoid arthritis. Seven early postoperative complications, two major and five minor, occurred. Three elbows subsequently required total elbow replacement. Clinical results were good in terms of pain relief but only fair in terms of joint mobility and stability. Radiographic elbow destruction progressed to a higher Larsen stage in half of the elbows. Measurements revealed humeral bone loss in two thirds of the elbows and ulnar bone loss in one third. In comparison with total elbow replacement, the long-term results of interposition arthroplasty were found to be inferior, with a total elbow replacement being required in one tenth of the elbows in the long term. In addition, bone loss often became extensive, making reoperation difficult or impossible. The authors recommend total elbow replacement as the first choice in the surgical treatment of the painful elbow with rheumatoid arthritis and cartilage destruction.

Adult↗
PubMedDate not supplied

Sodium nitroprusside-induced rat fundus relaxation is ryanodine-sensitive and involves L-type Ca2+ channel and small conductance Ca(2+)-sensitive K+ channel components.

1 The aim of this study was to examine whether sodium nitroprusside (SNP)-induced relaxation of rat fundus longitudinal smooth muscle involves ryanodine-sensitive Ca2+ release. 2 SNP (300 nM-30 microM) elicited concentration-dependent relaxation of precontracted (1 microM carbachol) rat fundus, an effect almost abolished by the selective guanylyl cyclase inhibitor, 1H-[1,2,4]oxadiazolo[4,3-a]quinoxaline-1-one (ODQ, 10 microM). 3 SNP-mediated relaxations were almost abolished by 10 microM ryanodine. 4 SNP-mediated relaxations were also reduced by either 1 microM apamin (a selective small conductance Ca(2+)-sensitive K+ channel, SKCa, inhibitor) or the selective L-type Ca2+ channel inhibitor, nicardipine (3 microM). 5 SNP-induced relaxations were insensitive to 1 mM tetraethylammonium chloride (an inhibitor of large-conductance Ca(2+)-sensitive K+ channels) and 1 microM glibenclamide (an ATP-sensitive K+ channel inhibitor). 6 These data suggest that SNP-mediated fundus relaxation occurs via a cGMP-mediated and ryanodine-sensitive mechanism which requires, at least in part, SKCa and L-type Ca2+ channel activity.

Animals↗
PubMedDate not supplied

A Western blot and molecular genetic investigation of the estrogen receptor beta in giant cell arteritis.

OBJECTIVE: The epidemiology of giant cell arteritis (GCA) may indicate a pathogenetic relationship between GCA and female sex hormone metabolism; GCA is two to four times more common in women compared with men. Our previous analyses gave no support for the hypothesis that the pathogenesis of GCA should be related to somatic mutations in the estrogen receptor alpha (ERalpha) gene. The object of the present study was to investigate the size of the estrogen receptor beta (ERBeta), and the size and nucleotide sequence of the ERBeta gene in temporal arteries in GCA. METHODS: The ERBeta protein was analyzed by Western blot technique and the ERBeta gene by RT-PCR and direct sequencing of the PCR product. RESULTS: Western blot analysis revealed an ERBeta of normal size. There were no aberrations in size or nucleotide sequence in the ERBeta gene in the GCA patients. CONCLUSION: The present observations gave no support for the hypothesis that somatic mutations in the ERBeta gene should be involved in the pathogenesis of GCA.

Aged↗
PubMedDate not supplied

The effect of mastitis on milk progesterone concentration in dairy cows.

A within cow comparison was made between milk progesterone levels in healthy and mastitic quarters. Material was collected from cows with mastitis induced by bacterial inoculation, or by inoculation with bacterial endotoxin. Furthermore material from cows with spontaneous subclinical mastitis was used. Milk progesterone levels were lowered due to mastitis. However, the decrease was not large enough to cause misinterpretation of where in the oestrous cycle (luteal phase or non-luteal phase) the samples were taken.

Animals↗
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Profiles of progesterone in milk and clinical ovarian findings in postpartum cows with ovarian dysfunctions.

Milk progesterone profiles, based on twice or once weekly sampling, were constructed for postpartum dairy cows. The cows were simultaneously examined by rectal palpation and clinical ovarian findings were related to the progesterone profiles. The combination of progesterone analysis and clinical examination may be used to optimize diagnostic accuracy and a number of practical recommendations are given on the basis of the results from this study.

Animals↗
PubMedDate not supplied

Ovulation rate and embryonic migration in cross-bred gilts.

The object of the investigation was to compare the activity between left and right ovaries in gilts slaughtered after their 1st, 2nd, 3rd or 4th detected oestrus and to relate the incidence of embryonic migration to the total number of foetuses present. The study comprised 254 cross bred gilts (Swedish Landrace X Swedish Yorkshire) not returning to oestrus within 24 days after A.I. with frozen semen. The gilts were slaughtered 5-8 weeks after A.I. The genital tracts were examined within two hours after slaughter. The number of corpora lutea and the number of normally developed foetuses were recorded. The results indicated that the left ovary had a higher ovulation rate than the right (P less than 0.001). The left ovary was also heavier than the right (0.01 less than P less than 0.05). The number of corpora lutea increased from oestrous number 2 to 4 (2 vs 4, 3 vs 4, 0.01 less than p less than 0.05). The oestrous number did not significantly influence the fertilization rate. The incidence of embryonic migration increased with increasing number of foetuses (0.01 less than p less than 0.05). Migration from left to right and from right to left occurred with the same frequencies.

Animals↗
PubMedDate not supplied

Clinical findings in post partum dairy cows.

The clinical findings in 183 post partum periods of dairy cows from an experimental herd are reported. Sixty-nine, 30, 46, and 38 post partum periods of the Swedish Red and White Breed, the Swedish Friesian Breed, crosses between these two breeds, and the Swedish Jersey Breed, respectively, were followed by clinical examination at 10-day intervals until first service. Heat detection was done three times daily and plasma progesterone assay at 10-day intervals. The highest occurrence of big follicles (12-15 mm) was between 21-30 days, coinciding with the time of first ovulation. Fifty percent of the cows had the 1st, 2nd and 3rd ovulation at 17, 36 and 56 days post partum, respectively, and the first, second and third ovulations came at 21.2, 39.1 and 58.3 days on average, with significant differences between parities and breeds. The first two oestrous cycles lasted 17.5 +/- 5.6 and 20.8 +/- 2.1 days without differences due to parity and breeds. The data indicate a complete uterine involution between 41 and 50 days post partum.

Animals↗