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Biomedical subjects

B Larsson

Publications and source records attributed to B Larsson.

At least 361 records · Page 20Linked to original sources
PubMed1982

Late results of salpingostomy combined with salpingolysis and ovariolysis by electromicrosurgery in 54 women.

In 1975 and 1976 all together 54 women were treated with electromicrosurgery for correction of infertility due to peritubal and periovarian adhesions combined with sactosalpinx. Besides the gentle and less traumatic microsurgical method, corticosteroids combined with oxyphenbutazone were given to prevent new adhesions. Hydropertubation was performed on the 2nd and 4th postoperative days. Twenty-one (39%) of the patients became pregnant, 4 of them twice. Out of the 21 patients, 17 gave birth to live children, while in 3 of the 21 patients spontaneous abortion occurred. One legal abortion was performed. No ectopic pregnancies were observed in this unselected material.

Adult↗
PubMed1982

A new melanoma seeker for possible clinical use: selective accumulation of radiolabelled thiouracil.

In a previous report we have shown that a few substances, especially thiouracil, are incorporated as false precursors into melanin during its synthesis. In the present investigation, we have intensified our studies on the incorporation of thiouracil into melanotic melanomas. Firstly, the distribution and retention of both 14C- and 35S-labelled thiouracil in mice with transplanted melanomas were studied. A high and selective accumulation was found in the melanotic tumours. The concentration in the rest of the body was low, with the exception of the thyroid gland. Secondly, melanoma-bearing mice were given increasing doses of thiouracil, and cultured melanoma cells were exposed to different concentrations of thiouracil, to investigate the relation between dose and uptake in melanomas and melanoma cells, respectively. A relatively linear increase in uptake with dose was found, indicating that the melanin incorporation of thiouracil is non-saturable up to subtoxic levels.

Animals↗
PubMed1982

Accumulation of 125I-labelled thiouracil and propylthiouracil in murine melanotic melanomas.

We have shown that thioamides are incorporated as false precursors into melanin during its synthesis. To be clinically useful in the diagnosis or therapy of melanotic melanomas, they would have to be tagged with an appropriate isotope or possibly a cytotoxic moiety. 125I-Thiouracil (125I-TU) is here shown to be accumulated in the melanin of melanotic melanomas transplanted into mice in a similar way as is 14C-thiouracil (14C-TU). 125I-TU gives tumour/liver and tumour/muscle ratios up to 22 and 778 respectively, at 4 days after administration. 125I-TU is accumulated by melanoma cells in vitro more effectively than 14C-TU (125I-TU/14C-TU, 2.7), while the in vivo accumulation into melanomas is slightly lower for 125I-TU as compared to 14C-TU (125I-TU/14C-TU, 0.35). This appears to be due to a partial deiodination (less than 14% of the dose within 4 days) and probably a more rapid excretion of 125I-TU or its metabolite(s). The accumulation of radioactivity in the thyroid can essentially be eliminated by pretreatment with potassium iodide and/or thyroxine. 125I-Propylthiouracil is also accumulated in melanotic melanoma cells in vivo and in vitro, but at a lower level than in 125I-TU and 14C-TU.

Animals↗
PubMed1982

Short-lived radionuclides in nutritional physiology. A model study with L-[Me-11C]methionine in the pig.

1. A "new" carbon radioisotope, 11C, for use in nutritional studies is presented. It has a 20 min half-life, and decays by positron emission giving annihilation photons of 511 keV energy (Wolf & Redvanly, 1977). Thus repeated studies can be made with short time intervals and the distribution of radioactivity in the experimental animal can be detected externally. 2. 11C was produced with a tandem Van de Graaff accelerator and L-[me-11C]methionine was synthesized and used in model experiments in the pig. The tracer was administered intravenously through a catheter in the jugular vein of pigs weighing between 40 and 100 kg. In a series of experiments, one pig received a low-methionine diet supplemented with DL-methionine to give three different levels of methionine intake. 3. The radioactivity distribution between liver and muscle was measured as a function of time by external detector for 2-3 h after administration. Blood and exhaled CO2 were sampled and measured for radioactivity. 4. The results indicate that 11C is a useful radionuclide in nutritional studies in intact large domestic animals.U

Animal Nutritional Physiological Phenomena↗
PubMed1982

Spontaneous motility of the pig oviduct in vitro.

The spontaneous motility of the pig oviductal isthmus and ampulla during the estrous cycle was recorded in vitro using an intraluminally located pressure microtransducer. A very high motility was recorded in the isthmic portion throughout the whole cycle, while the ampulla revealed an active pattern during the periovulatory period only. In proestrus the tubal pattern in both segments consisted of regular contractions of high frequency, increasing in amplitude when approaching estrus. During heat the motility changed abruptly, and was characterized by the presence of regular strong waves in the two tubal segments. This pattern might contribute to the transport of gametes to the fertilization site. After ovulation, during the time when ova are retained in the oviducts, the high preovulatory peaks disappeared. The isthmic pattern showed regular phasic contractions of high frequency and amplitude, while the ampullar motility was low. The ova are arrested at the level of the ampullar-isthmic junction (AIJ) during this period. During the short period when eggs are passing to the uterus, the ampullar motility remained low, while the isthmus showed a very active pattern with the presence of heavy contractions. This suggests the active participation of the isthmus in ovum descent. During the rest of the luteal phase, the ampulla maintained its stable low motility, while the isthmus showed an irregular although still active pattern characterized by heavy outbursts of increased activity superimposed on a consistent basal contractility.

Animals↗
PubMed1982

Thallium-201: autoradiography in pigmented mice and melanin-binding in vitro.

Autoradiography with 201Tl+ in C57Bl mice showed a strong labelling of the eye melanin and of pigmented hair follicles. An analysis of the affinity of thallium for pigment from cow eyes indicated a binding to three groups of sites and showed a marked sensitivity to the addition of H+-ions. The results are consistent with the conception that a binding of thallium occurs to the free carboxyl groups of the melanin and that the structure of the polymer has a marked influence on the affinity. Similar results have previously been obtained with other cations. There was no indication that the strong in vivo affinity of thallium to melanin is due to a more firm binding than for other cations which do not localize on melanin in vivo. Instead, the ability of cations to pass the melanocyte membranes and reach the melanin granules is probably decisive to whether a melanin binding will take place in vivo. Toxic effects on the eye and epilation are symptoms of thallium intoxication which may be related to its melanin binding. The fate of 201Tl+ in some other tissues is also described and discussed.

Animals↗
PubMed1982

The influence of repeated health examinations on mortality in a prospective cohort study, with a comment on the autopsy frequency. The study of men born in 1913.

In the Study of Men Born in 1913 it was possible to investigate the influence of repeated health examinations on mortality in a prospective cohort study. On January 1, 1963, 1010 men in the experimental group and 1956 in the control group were alive. The experimental group took part in repeated examinations in 1963, 1967, 1973 and 1980. Overt diseases were treated accordingly. Newly detected hypertension was also treated. By the end of a 15-year-long observation period, the cumulative mortality in the experimental group (14.5%) was not significantly lower than that in the control group (15.7%). In the experimental group, 855 took part. The mortality was significantly higher in the non-participating group. The autopsy frequency decreased for in-hospital deaths but increased for deaths outside hospital during the study period.

Autopsy↗
PubMed1982

Spontaneous motility of the oviduct in the anaesthetized pig.

Intraluminal pressure microtransducers were placed at the uterotubal junction, the proximal isthmus, the ampullary-isthmic junction and the mid-ampulla. Spontaneous motility occurred throughout the oestrous cycle in all segments. During oestrus there were regular, high amplitude peristaltic waves in all segments, superimposed on basal activity. On Day 1 of the cycle the pattern was mostly antiperistaltic, presumably related to sperm transport. During the periovulatory period the number of peristaltic and antiperistaltic waves became equal, perhaps in relation to the transport of gametes to the fertilization site. During Day 3 there was no peristaltic activity; the motility patterns of the isthmus and ampullary-isthmic junction were similar (regular phasic contractions of high frequency and amplitude) while the ampullary motility was low. On Day 4, when the eggs enter the uterine lumen, the ampullary-isthmic junction and particularly the isthmus showed strong contraction waves (mostly peristaltic) superimposed on the basal phasic activity. This suggests an active role of the smooth muscle of the lower oviducal segments in ovum descent. During the mid- and late-luteal phases, the isthmus remained motile, with an irregular base line, but lost the pattern of basal contractions that dominated the activity during the first 4 days of the cycle. The ampulla showed low levels of spontaneous motility throughout the rest of the cycle.

Animals↗
PubMed1982

Effects of sublethal doses of gamma radiation on the developing rat brain. synthesis of nucleic acids.

Newborn rats were irradiated with 60Co gamma rays. Doses of 0, 0.8 or 1.6 Gy were given to the whole body. The body and brain weights, DNA and RNA contents of the brain and 3H-thymidine or H-uridine incorporated by the brain were measured at 5, 10, or 15 days after birth. A dose of 1.6 Gy produced alterations in the brain weight and the DNA and RNA contents of the brain while no clear effects could be detected after 0.8 Gy.

Animals↗
PubMed1982

Studies on the melanin affinity of haloperidol.

The general distribution of 3H-haloperidol was studied in mice by means of whole body autoradiography. Extensive accumulation and retention was observed in the melanin containing tissues. In the albino animals uptake was low in the corresponding tissues. Impulse counting of excised tissue pieces showed a maximum concentration in the pigmented eyes 24 hr after a single intravenous injection. In the pigmented eyes, about 1/5 of the radioactivity at 24 hr still remained 90 days after administration. In vitro, haloperidol was found to be bound to beef-eye melanin and dopamine melanin (structurally similar to the melanin present in the pigmented nerve cells in the human substantia nigra). The total binding capacity of beef-eye melanin was approximately twice that of dopamine melanin. Beef-eye melanin bound haloperidol to an extent twice that earlier reported for chlorpromazine and chloroquine, while the binding strengths were of about the same magnitude. Due to its high melanin affinity it is most probable that haloperidol accumulates extensively in the pigmented neurons of the substantia nigra in patients on long term therapy. Other compounds with melanin affinity such as phenothiazine derivatives and manganese are known to produce irreversible extrapyramidal disorders, degeneration and depigmentation of the pigmented nerve cells in the substantia nigra. In conclusion the melanin affinity may be an important factor in the pathogenesis of haloperidol induced tardive dyskinesia.

Animals↗
PubMed1981

Long-term clinical experience with the Cu-7-IUD. Evaluation of a prospective study.

In a prospective Swedish three-center study, totally 1446 women wearing a Cu-7-IUD were carefully followed for a minimum 2 years. Smaller subgroups have been followed for 4 years (n=278) or for even longer periods up to 8 years (n=48) with the same Cu-7-IUD in situ. Data are given concerning continuation rate, efficiency, expulsion, removals, pain, bleeding and risk for pelvic inflammatory disease. Prolonged use of the Cu-7-IUD beyond 2 years up to 4 years seems to be associated with fewer side effects and a lower incidence of accidental pregnancies than during the first 2 years of use. The computerized data confirm our earlier impression that the Cu-7-IUD provides a substantial efficacy and is associated with a relatively low rate of adverse effects.

Adolescent↗
PubMed1981

A multi-language, portable text-to-speech system for the disabled.

Previous experience with speech output aids for blind and non-vocal persons has shown great promise. The need for individual adjustments and the relatively small market, makes flexible, programmable aids necessary. A modular microprocessor text-to-speech system has been developed that is portable and battery-operated. This prototype has been adjusted to several different users. Programs for different languages have been developed. Connection of text sources is simplified by standardized interfaces. One special attachment is a 500 symbol Blissymbol board and a related Bliss-to-speech program that transforms the symbol string to well formed sentences.

Blindness↗
PubMed1981

Investigation of the mechanism of perforation of an intrauterine device in pigs and dogs.

In the last few years the risk of perforations in connection with the insertion and later use of intrauterine devices (IUDs) has been the subject of much discussion in Sweden. In this experimental study, which was carried out on five pigs and nine dogs and in which four different types of IUDs were used, the following clinical situations encountered in women were simulated: IUD in correct position in the uterus, IUD in an adverse position in the uterus, and IUD more or less inserted through the uterine wall. The animals were observed for 3 to 6 months. The findings indicate that, when perforation occurs, it is most probably ascribable to the insertion procedure.

Animals↗