Showing papers by "University of Turku published in 1984"

Nutrient stress: an explanation for plant anti-herbivore responses to defoliation

Abstract: A hypothesis is put forward that the long-lasting inducible responses of trees to herbivores, particularly lepidopteran defoliators, may not be active defensive responses, but a by-product of mechanisms which rearrange the plant carbon/nutrient balance in response to nutrient stress caused by defoliation. When defoliation removes the foliage nutrients of trees growing in nutrient-poor soils, it increases nutrient stress wich in turn results in a high production of carbon-based allelochemicals. The excess of carbon that cannot be diverted to growth due to nutrient stress is diverted to the production of plant secondary metabolites. The level of carbon-based secondary substances decays gradually depending on the rate at which nutrient stress is relaxed after defoliation. In nutrient-poor soils and in plant species with slow compensatory nutrient uptake rates the responses induced by defoliation can have relaxation times of several years. The changes in leaf nitrogen and phenolic content of mountain birch support this nutrient stress hypothesis. Defoliation reduces leaf nitrogen content while phenolic content increases. These responses of mountain birch to defoliation are relaxed within 3–4 years.

The adolescent back. A field survey of 370 Finnish schoolchildren.

Abstract: In this study, dealing with the early diagnosis and prevention of back pains, adolescent postural faults especially in the sagittal plane were examined with a standardized physical examination technique suitable for use in schools; the strength and flexibility of muscles affecting the back were investigated; neck and/or back symptoms were screened; and the association of background factors and the findings of the physical examination with symptoms was evaluated. The material consisted of a total of 370 11, 13, 15 and 17-year-old comprehensive and senior secondary school pupils from a small suburban municipality, selected by random sampling. The subjects were quite evenly distributed in terms of different age and sex groups. The physical examination of the back, with evaluation of symptoms, took place in the autumn of 1981 in the premises of school health care, and 58 of the examined subjects were referred on the basis of symptoms and/or findings to an X-ray examination of the thoracic and/or lumbar spine. The X-rays were taken in the spring of 1982. 1 Back pain history. Relation between present neck and/or back symptoms, background variables and findings in physical examination. 7.6% of the subjects reported previous neck and/or back symptoms that had interfered with their school work or leisure activities. Present, mainly mild neck and/or back symptoms were reported by 19.7%. Girls reported symptoms more often than boys (p less than 0.05), and the occurrence of symptoms increased with age (p less than 0.001). Roughly one third of the subjects had frequent symptoms. Pains were most often localized in the low back (p less than 0.001) and were most frequently associated with sitting or physical activities. Most subjects who had suffered from previous symptoms also reported symptoms at the time of the study. These more chronically symptomatic subjects accounted for 6.2% of the total material. 2.9% of siblings under 11 years, 8.0% of siblings 11-17 years, and 13.7% of siblings over 17 years of age had at some time prior to the study complained of recurrent neck and/or back symptoms. Of mothers, 19.0% and of fathers, 15.4% reported neck and/or back symptoms that were continual and/or reduced working ability. The mother (p less than 0.01) and/or the father (p less than 0.05) of a subject reporting frequent symptoms, also reported neck and/or back symptoms.(ABSTRACT TRUNCATED AT 400 WORDS)

Rat testicular endogenous steroids and number of Leydig cells between the fetal period and sexual maturity.

Abstract: Endogenous androgens (androstenedione, testosterone, 5a-dihydrotestosterone and 5a-androstane-3a,1713-diol), and some of their C21 precursors (pregnenolone, progesterone and 17-hydroxyprogesterone) were measured in rat testes between Day 18.5 of pregnancy and Day 64 postpartum, and correlated with numerical densities of Leydig cells. The latter parameter showed an early maximum on Day 19.5 of the fetal period, a nadir on Day 15 postpartum, and a gradual increase thereafter. The two dominating androgens, testosterone and 5a-androstane-3a,17(3-diol, had similar levels until 15 days of age, but the 5a-diol predominated thereafter. The total steroid content per Leydig cell was highest on Day 18.5 of gestation (77 ng/10’ cells). A decline started already in utero, and reached a nadir of 5 ng/10’ cells on Day 29. Thereafter, a slight increase occurred with advancing age. It is concluded that: 1) The fetal testis has highest Leydig cell and endogenous steroid concentrations. A nadir in these parameters is seen 2-4 wk postpartum. The Leydig cell concentration increases around puberty on Days 40-60, but only a slight concomitant increase occurs in steroids. 2) A sharp decline in steroid content per Leydig cell occurs during the last fetal days, but the postnatal decline of testicular steroids is due to Leydig cell loss. 3) The new Leydig cell generation after 15 days has a persistently low steroid concentration through puberty. 4) The relative proportions of endogenous steroids are similar in the fetal and immature testes, but the pubertal increase in steroidogenesis is characterized by increased ratios of C19/C21 steroids, 5a-reduced/3-keto-4-ene androgens, and 1 7�3-hydroxy/1 7-keto androgens.

Coupling-Constant Metamorphosis and Duality between Integrable Hamiltonian Systems

Abstract: We introduce a noncanonical ("new-time") transformation which exchanges the roles of a coupling constant and the energy in Hamiltonian systems while preserving integrability. In this way we can construct new integrable systems and, for example, explain the observed duality between the H\'enon-Heiles and Holt models. It is shown that the transformation can sometimes connect weak- and full-Painlev\'e Hamiltonians. We also discuss quantum integrability and find the origin of the deformation $\ensuremath{-}\frac{5}{72}{\ensuremath{\hbar}}^{2}{x}^{\ensuremath{-}2}$.

Relationship of the human salivary peroxidase system to oral health.

Abstract: The human salivary peroxidase system (SPS) contributes in several ways to the maintenance of good oral health. The SPS is one of the non-immunoglobulin defense factors which regulate the quantity and species distribution of oral micro-organisms. The SPS also prevents toxic accumulations of hydrogen peroxide (H2O2) and it inactivates many carcinogenic and mutagenic compounds. The salivary glands secrete a peroxidase enzyme (salivary peroxidase) as well as the thiocyanate ion (SCN-, derived from diet). The enzyme catalyzes the oxidation of SCN- by hydrogen peroxide (H2O2). The H2O2 is excreted by oral bacteria and by host cells in amounts which vary with the state of cellular metabolism, the diet and other factors. Oxidized forms of SCN- temporarily inhibit the growth, respiration and metabolism of most species of oral bacteria. The major oxidized form generated in the mouth is the hypothiocyanite ion (OSCN-) which must reach a minimum threshold concentration before bacterial inhibition occurs. This threshold concentration varies from species to species. The concentration of OSCN- in the mouth rises and falls with the availability of H2O2. This natural rise and fall, together with bacterial variation in sensitivity to OSCN- inhibition, suggests a role for the SPS in the regulation of the oral microflora. As a result of the rapid consumption of H2O2 by the SPS, host cells are protected from a toxic build up of this potent oxidizing agent. The major product of the reaction, OSCN-, does not harm human cells. Many carcinogenic and mutagenic compounds may serve as substrates for the SPS and be oxidized to less harmful compounds.

Cellular regulation of plasminogen activator secretion during spermatogenesis.

Abstract: The secretion of plasminogen activator (PA) has been found to be highly stage-specific during rat spermatogenesis. It is maximal in Stages VII and VIII of the cycle. At these stages, seminiferous tubules contain primitive type A1 spermatogonia, preleptotene and midpachytene primary spermatocytes, round and maturation-phase spermatids and Sertoli cells. The last cell types are the most likely sources of PA. To investigate which cell type might be involved in the regulation of PA secretion, we have sequentially isolated 1-mm segments of rat seminiferous tubules from Stages VI-lX with transillumination-assisted microdissection and measured PA secretion using 125 I-labeled fibninogen as substrate. In another experiment, spermatogenia were killed by 300 rads of x-rays and PA secretion was analyzed during the absence of desired germ cell classes. The results support the idea that upon their detachment from the basal lamina, preleptotene-stage primary spermatocytes have the major stimulatory action on the PA secretion of the seminiferous tubules. Other phenomena such as spermiation, phagocytosis of residual bodies or opening up of the Sertoli cell junctions seem to influence PA secretion to a lesser extent.

Low nutritive quality as defence against herbivores: induced responses in birch.

Abstract: The effects of artificial defoliation of birch trees in the previous year on the consumption and utilization of food by a geometrid larva, Epirrita autumnata, were studied in laboratory. The leaves were collected from two sites on a slope of a fell. Defoliation had a significant retarding effect on approximate digestibility, efficiency of conversion of ingested food, relative consumption rate and relative growth rate but not on efficiency of conversion of digested food. The effects were to the same direction with leaves from the two sites, but the response was stronger with leaves from the zone defoliated by Epirrita during mid-sixties. The defensive nature of the response(s) of birch to defoliation is discussed in the light of these results. It is concluded that contrary to the hypothesis of Moran and Hamilton (1980) no increase in the consumption incurred by individual trees could be shown in this system.

Metoprolol and Propranolol in The Prophylactic Treatment of Classical and Common Migraine. A Double-Blind Study:

Abstract: In a double-blind, cross-over study the effect and tolerance of the non-selective beta-blocker propranolol in a dosage of 80 mg twice daily was compared to that of the beta 1-selective beta-blocker metoprolol 200 mg once daily in Durules (a controlled-release formulation) The attack frequency, migraine days, severity score, consumption of acute medication and subjective evaluation were the main parameters used for evaluation Thirty-six patients with classical or common migraine were included Thirty-three completed the investigation It is concluded from the results that there are no differences in efficacy between metoprolol and propranolol regarding the studied parameters Both drugs reduced the migraine symptoms compared to the run-in period and were generally well tolerated

Systolic trellis automatat

Abstract: In the second part of this paper we discuss mainly various programming techniques for systolic automata. These techniques are used to derive theoretical results e.g. the closure of (homogeneous) systolic automaton under Boolean operations, or that every linear context free language can be accepted by a homogeneous systolic automaton and that their languages have time complexity 0(n2)

Familial congenital diaphragmatic defects: aspects of etiology, prenatal diagnosis, and treatment.

Abstract: We present 14 familial cases from five Finnish families affected with a life-threatening congenital diaphragmatic defect (CDD) and review data on 53 previously published familial cases. CDD occurred in three sibs and their half brother's son, and probably in all four offspring of parents consanguineous as both first and second cousins. In the remaining three Finnish families and in the vast majority of the previously reported familial cases, only two sibs were affected. Two thirds of those affected were males both in the Finnish and the overall series. Pedigree data, delayed fusion of the diaphragm as the primary pathogenetic mechanism, varying anatomical structure of the defective hemidiaphragm, association with other congenital anomalies, and data on animal experiments are more in accordance with multifactorial determination than with recessive inheritance. This does not exclude other genetic causes in some familial cases. The recurrence risk for sibs after one affected sib is about 2%. As the prognosis, especially in familial cases of CDD has remained grave, the development of fetal surgical treatment is desirable. This emphasizes the future role of prenatal diagnosis by ultrasound.

Solubility of calcium salts, enamel, and hydroxyapatite in aqueous solutions of simple carbohydrates

Abstract: The solubility of various Ca(II) salts, hydroxyapatite, and powdered human dental enamel in the presence of simple carbohydrates was studied by determining the complex strength between Ca(II) and the carbohydrates. In 1.0 M CaSO4, the following simplified sequence of complex strengths was obtained for the more common carbohydrates: Na-citrate greater than D-sorbitol greater than xylitol greater than D-mannitol greater than D-fructose greater than D-glucose greater than D-xylose. Whereas the more soluble Ca(II) compounds (like CaSO4) exerted measurable complexation with xylitol, no such complexation was found with hydroxyapatite and enamel powder. This also concerned other alditols. Calculation of the stability constants (K) showed sorbitol (K = 0.81 M) and xylitol (K = 0.67 M) to form stronger complexes in saturated CaSO4 than other alditols. The most suitable coordination site appeared to be a vicinal cis-cis-triol. Precipitation studies showed that 0.5 M xylitol and 0.5 M sorbitol significantly retarded the formation of calcium phosphate precipitates from a solution of Ca(II) and phosphate, compared with the effect caused by glucose, sorbose, or xylose. The effect caused by xylitol and sorbitol was explained in terms of partial displacement of water molecules in the primary hydration layer of Ca(II) ions, caused by competition between polyol and water molecules. In the presence of aldoses and ketoses, virtually instantaneous precipitation occurred. These results suggest that open-chain alditols may influence the chemical reactions of Ca(II) in plaque, saliva, and caries lesions. Alditols do not function as demineralizing agents of the teeth, however. Through the retarding effect on calcium phosphate precipitation, alditols may favorably govern remineralization of carious lesions.

Tolfenamic acid, metoclopramide, caffeine and their combinations in the treatment of migraine attacks

Abstract: Tolfenamic acid is a fenamate which inhibits prostaglandin (PG) biosynthesis and may act as a PG antagonist as well. Caffeine and metoclopramide are used in combination with analgesics and ergotamine in the treatment of migraine attacks, but controlled clinical studies on fixed combinations with analgesics are rare. The effects of orally given tolfenamic acid (200 mg), caffeine (100 mg), metoclopramide (10 mg), tolfenamic acid + caffeine (200 mg + 100 mg), tolfenamic acid + metoclopramide (200 mg + 10 mg) and placebo were studied in 49 migraine patients (3 men, 46 women) in a double-blind randomized cross-over study comprising 482 migraine attacks. The patients were allowed to take either one or two capsules of each preparation for an attack. Additional drugs were allowed after 3 h. Parameters characterizing the effects and side-effects of the drugs were registered. Tolfenamic acid and its combinations were found to be effective in the treatment of acute migraine, but caffeine and metoclopramide alone did not differ from placebo. Combination with metoclopramide was better than tolfenamic acid alone as judged by the smaller dose needed and the intensity of attack. Between tolfenamic acid alone and its caffeine combination there were no statistically significant differences.

Immunoglobulin class-specific antibody response in respiratory syncytial virus infection measured by enzyme immunoassay.

Abstract: Immunoglobulin class-specific enzyme immunoassay (EIA) was used for determination of antibody responses in sera collected from 26 children with acute primary respiratory syncytial virus (RSV) infections. All 26 patients had IgG antibody responses with a significant titer increase in 24 (92%); an IgM antibody response was detected in 19 of the 26 (73%). From patients aged 6 months or less only 5 of 8 produced detectable IgM antibodies, whereas all patients aged 1-2 years did so. IgM antibodies appeared within 1 week after onset of illness and persisted from 20 days to 2-3 months. An IgA antibody response was observed in 20 of 26 (77%) patients with a significant titer increase detected in 17 of 26 (65%) patients. In some patients the persistence of IgA antibodies followed that of the IgM antibodies, but in others the IgA antibody titers remained stable up to the end of the follow-up. The most sensitive assay system for serological diagnosis of acute RSV infection in children was the determination of titer increases by IgG antibody.

On various joint measurements of position and momentum observables in quantum theory

Abstract: In this paper the problem of simultaneous measurability of complementary physical quantities, and the relevance of the uncertainty relations to this question, is analyzed. Formalizing carefully the crucial notations involved in the problem it is shown that the well-known apparently contradictory viewpoints on the subject matter are all true in pointing to a different aspect of one and the same fundamental fact expressed here as complementarity.

Stimulated salivary flow rate, pH and lactobacillus and yeast concentrations in medicated persons

Abstract: – Flow rate, pH and lactobacillus and yeast counts of paraffin-stimulated whole saliva were analyzed in an adult population of 463 medicated persons. Of the very large number of drugs only a few groups were found to decrease salivation to such an extent that they can be considered to cause dental harm. Persons using neuroleptics, tricyclic antidepressants or antihypertensives were nevertheless found to produce stimulated saliva at rates significantly lower than unmedicated persons. Age had no influence on the flow rate, but postmenopausal age seems to predispose medicated women to a decrease in salivary flow. Higher microbial counts were found in the medicated men.

IMPAIRED B LYMPHOCYTE FUNCTION DURING OPEN-HEART SURGERY Effects of Anaesthesia and Surgery

Abstract: B lymphocyte function in vitro was measured in patients undergoing open-heart surgery. Conventional balanced anaesthesia, or high-dose fentanyl anaesthesia was used. Pokeweed mitogen (PWM) induced lymphocyte transformation was depressed at the end of the operation, but the response to formalinized Stapkylococcus aureus Cowan I (StaCw) was not. The numbers of immunoglobulin producing and secreting cells measured by an indirect protein A plaque-forming cell assay decreased after PWM-stimulation, but remained unchanged after StaCw stimulation at the end of the operation. IgG, IgM and IgA secretion by PWM- and StaCw-stimulated lymphocytes, into the culture medium, was depressed in the period after operation. Depressed immune functions occurred after open-heart surgery, but not in association with anaesthesia alone before surgery. The decreases were not mediated by hydrocortisone-sensitive suppressor cells. Minor differences between the two anaesthetic techniques were found in lymphocyte proliferative responses

Stimulated salivary flow rate, pH and lactobacillus and yeast concentrations in non-smokers and smokers.

Abstract: The effect of smoking habit on flow rate, pH and lactobacillus and yeast counts of paraffin stimulated whole saliva was analyzed in an unmedicated adult population of 462 nonsmokers and 180 smokers. Regular but not immediate smoking was not associated with any significant changes in the salivary flow rate. The pH of stimulated whole saliva was in both sexes lower in smokers than in non-smokers, the differences between the groups being statistically significant. Smoking did not affect salivary yeast counts, but smokers did show increased proportions of high lactobacillus counts.

B-L antigens (Class II) of the chicken major histocompatibility complex control T-B cell interaction

Abstract: The detailed study of the genetic control of T-B cell interactions in the chicken has been hampered by the lack of defined major histocompatibility complex (MHC) recombinant chicken lines. In the present study we have used some recently described MHC recombinant chicken lines separating regions encoding antigens that are homologous to class I and class II antigens of mammals in adoptive bursa cell transfer experiments, in which bursa cells from newly hatched chicks were transplanted into cyclophosphamide (Cy)-treated chicks. Subsequent immunizations of the recipients with a thymus-dependent antigen (SRBC) and a thymus-independent antigen (Brucella abortus) showed that the generation of germinal centers in the spleen and the production of antibodies to SRBC required identity between donor and recipient class II antigens (B-L antigens), whereas response to Brucella antigen did not require identity at any of the known MHC loci of the chicken. The results thus reveal that also in the chicken class II (B-L) region genes encode cell-surface glycoproteins that serve as restriction elements in T-B cell cooperation.

Multiple scenario approach and strategic behaviour in European companies

Abstract: Summary Nowadays, scenarios are a popular subject in management literature. However, information available about how extensively scenarios are used and the possible motives for their use, as well as their effects on strategic behaviour in companies, has hitherto been very limited. Results of a survey among Fortune's top 1000 companies in the U.S.A. in 1977 and 1981 showed a growing corporate interest in scenarios. A survey of the use of scenarios in large Western European companies in 1981 provided evidence of similar interest in Europe. In this article, results of the European survey are presenited and the diJferences between user and non-user attitudes towards the future among European firns analysed and the implications for strategic behaviour outlined.

Effect of guar gum, a fibre preparation, on digoxin and penicillin absorption in man

Abstract: The effect of guar gum on the absorption of digoxin and phenoxymethyl penicillin was studied in a double blind study in 10 healthy volunteers. Guar gum reduced serum digoxin concentration during the early absorption period, but a similar amount of digoxin was found in 24 h urine whether given with or without guar gum. Both the peak penicillin concentration and the area under the serum curve were significantly reduced by the gum.

Binding of fluorescein isothiocyanate conjugated lectins to rat spermatogenic cells in tissue sections Enhancement of lectin fluorescence obtained by fixation in Bouin's fluid

Abstract: The testes from three months old Sprague-Dawley rats were fixed in Bouin's fluid or neutral buffered 10% formalin, embedded in paraffin, sectioned and after deparaffination stained with the following fluorescein isothiocyanate coupled lectins: PNA, WGA, Con A, RCA, SBA, DBA and UEA. The results show that there are considerable differences in the staining pattern of various spermatogenic cells between different lectins. The fixation in Bouin's fluid enhanced the staining of all the lectins compared to formalin fixation in which only a weak staining could be seen in the acrosomes of spermatids after WGA or PNA staining. PNA and WGA stained specifically the acrosome of the developing spermatids, which was seen from the beginning of the acrosome formation and lasted up to late spermiogenesis. However, the staining with PNA decreased in the late spermatids whereas the intensity of the staining remained unchanged with WGA. Con A did not stain the acrosome but stained unspecifically the cytoplasm of all spermatogenic cells. RCA stained faintly the acrosome throughout the spermatid differentiation. DBA and UEA stained specifically the chromosomes of B spermatogonia. DBA also faintly stained the cell membranes of early spermatids. SBA did not show any specific staining of the spermatogenic cells. Based on this it is suggested that the carbohydrates and glycoproteins which are known to be present in the acrosome are formed already in the beginning of the acrosome formation. The decrease in the PNA staining in late spermatids possibly reflects the fact that the receptor molecules are not synthesized in late spermatids but are formed in earlier developmental stages and are thereafter preserved in the acrosome.(ABSTRACT TRUNCATED AT 250 WORDS)