Jasmonic acid induces changes in growth and polypeptide composition of fern gametophytes

We studied morphology of gametophytes of the fern Platycerium bifurcation 20 to 45 days after spore sowing. In addition, we examined the effects of 0.01, 0.1, 1, 10 or 100 μM jasmonic acid (JA) on their growth and polypeptide composition. Gametophytes cultured for 20 days on modified Knop’s medium were oblong to round in outline. 3-5 rhizoids appeared mainly on the basal cell and 2-3 unicellular hairs formed on the margins. After 30 days in culture, slightly heart-shaped gametophytes produced numerous rhizoids and hairs. Gametophytes cultured for 45 days were cordate and the first antheridia were observed on the ventral side. Hairs, frequently branched, appeared on gametophyte surface. The effect of JA on the growth of gametophytes was age-dependent. After 20 and 30 days in culture, JA had no pronounced effect in comparison to the control (medium without JA), while after 40 days at concentrations exceeding 0.1 μM JA growth of gametophytes was inhibited. Analysis of soluble proteins from 2 month old JA-treated gametophytes revealed some alterations in polypeptide patterns when compared to the control. The most marked was an increase in a 92-93 kDa polypeptide band at 10 and 100 μM JA in the medium

The influence of leukocyte telomere lenght on teriparatide treatment response in patients with severe osteoporosis

S staranjem prebivalstva se povečuje tudi število bolezni, ki so povezane s staranjem. Obstaja več kazalcev za določanje biološke starosti organizma, največkrat se uporablja dolžina telomer. Telomere so heterokromatinske strukture na koncu kromosomov, ki se skrajšajo z vsako celično delitvijo, občutljive pa so tudi na oksidativni stres in vnetje. Nekaj študij je dokazalo povezavo med krajšimi telomerami in osteoporozo. Osteoporoza je presnovna bolezen kosti, za katero sta značilni nizka kostna masa in porušena mikroarhitektura kostnega tkiva, kar vodi do povečane lomljivosti kosti. Obstaja več zdravil, ki se uporabljajo za preprečevanje izgube kostne mase, eno od novejših je osteoanabolno zdravilo teriparatid, ki se v Sloveniji predpiše le bolnikom s hudo obliko bolezni. V magistrski nalogi smo preučevali vpliv dolžine telomer v levkocitih na uspešnost terapije s teriparatidom. To je prva študija, ki preučuje to povezavo. Iz polne krvi preiskovank odvzete pred začetkom zdravljenja smo izolirali DNA in s kvantitativno verižno reakcijo s polimerazo v realnem času določili relativno dolžino telomer v levkocitih. S korelacijo smo dokazali negativno povezavo med kronološko starostjo in dolžino telomer v levkocitih (p = 0,019), mejno statistično značilna negativna korelacija pa je med dolžino telomer v levkocitih in razliko v mineralni kostni gostoti po 24 mesecih terapije na mestu ledvenih vretenc (p = 0,060) in celotnega kolka (p = 0,073). Z linearno regresijo smo ugotavljali vplive relativne dolžine telomer v levkocitih, kronološke starosti, starosti ob menopavzi, terapije z vitaminom D in kalcijem, indeksom telesne mase, časa zdravljenja s teriparatidom, vpliv mineralne kostne gostote (MKG) pred začetkom zdravljenja ter prekinitve zdravljenja na uspešnost terapije s teriparatidom, ki smo jo opredelili s spremembo v MKG na različnih mestih. Po 24 mesecih terapije je na spremembo na predelu vrata stegnenice značilno vplivala začetna MKG (p = 0,013), na predelu ledvenih vretenc mejno statistično značilno vpliva starost ob menopavzi (p = 0,084), na predelu celotnega kolka pa ima značilen vpliv vnos kalcija (p = 0,049) in mejno statistično značilen vpliv dolžina telomer v levkocitih (p = 0,064). Primerjali smo kakšne so dolžine telomer v levkocitih pri bolnicah z uspešnim in bolnicah z neuspešnim odzivom na zdravljenje ter ugotovili, da imajo bolnice, ki se niso odzvale na zdravljenje, daljše telomere v levkocitih. Na podlagi rezultatov sklepamo, da z enkratno meritvijo dolžine telomer v levkocitih ne moremo napovedati uspešnosti terapije s teriparatidom, saj imajo mlajše bolnice daljše telomere in večjo mineralno kostno gostoto, za zdravljenje s teriparatidom pa je značilno, da imajo boljši prirast v mineralni kostni gostoti bolnice z nižjo začetno mineralno kostno gostoto.Aging of the world\u27s population is associated with increasing number of age-related diseases. The biological age of an organism can be determined by many markers, the most common is telomere length. Telomere is a heterochromatin structure on the chromosome end which gets shorter with every cell division and is susceptible to oxidative stress and inflammation. Some studies report association between shortened telomere length and osteoporosis. Osteoporosis is a metabolic bone disease, determined by low bone mass and microarchitectual deterioration which leads to higher incidence of fractures. There are many drugs to prevent bone loss, including the osteoanabolic drug teriparatide. In Slovenia, it is prescribed only to patients with the most severe cases of osteoporosis. In our research we studied the effect of leukocyte telomere length on teriparatide treatment. This is the first study to evaluate this relationship. We isolated DNA from whole blood which was taken before treatment, measured the leukocyte telomere length by using real-time polymerase chain reaction, and statistically analysed the association. The results show negative correlation between chronological age and leukocyte telomere length (p = 0,019), and week negative correlation between leukocyte telomere length and changes in bone mineral density in lumbar spine (p = 0,060) and in total hip (p = 0,073). We evaluated the effects of leukocyte telomere length, chronological age, age at the menopause, vitamin D and calcium intake, body mass index, time of teriparatide treatment, bone mineral density (BMD) before the treatment and at the termination time of the treatment on therapy outcome with linear regression. The success of treatment was determined by changes in BMD at different sites. After 24 months of therapy the changes in BMD at the femoral neck are affected by the BMD before treatment (p = 0,013), at lumbar spine by age at the beginning of menopause (p = 0,084) and at total hip by calcium intake (p = 0,049) as well as leukocyte telomere length (p = 0,064). The leukocyte telomere length was compared between patients with good response to teriparatide therapy and those with no response. Longer telomeres were observed in patients with no response to the treatment. We conclude that one-time measurement of leukocyte telomere length cannot be used to predict the outcome of teriparatide treatment. Teriparatide is more efficient in patients with lower bone mineral density at the beginning of the therapy. In our case, the patients with longer telomeres were younger and therefore had better bone mineral density which resulted in lower response to teriparatide therapy

Use of buffer in dairy cow nutrition

Pred telitvijo krmimo krave z obroki, ki vsebujejo veliko vlaknine. Po telitvi pa se njihove potrebe hitro povečujejo in krma vsebuje čedalje več lahko prebavljivih ogljikovih hidratov, s čimer pokrivamo njihove velike potrebe po energiji. To pa v predželodcih povzroči zmanjšanje pH, saj sladkorji prehitro v preveliki količini fermentirajo v hlapne maščobne kisline. Nizek pH je neugoden, saj se prebava ostalih snovi upočasni. V mleku to vodi v zmanjšanje mlečne maščobe. Zato v krmo dodajamo pufre, ki nevtralizirajo vsebino predželodcev in s tem preprečijo zmanjšanje vsebnosti mlečne maščobe v mleku. Najbolj razširjen pufer je soda bikarbona. Je učinkovita pri nevtralizaciji vsebine predželodcev in deluje zelo hitro. Magnezijev oksid je močnejši pufer od sode, in ga običajno dodajamo v kombinaciji z njo za boljši učinek. Ena od možnosti je tudi uporaba morskih alg, ki jih pridobivajo na obalah Irskega morja in imajo ugodnejši učinek na vampov pH kot soda, njihovo delovanje pa je tudi daljše. pHiX-up je močan pufer ki ima 3× močnejši vpliv na vampov pH kot soda, vendar pa deluje zelo hitro in kratkotrajno. V obrok lahko dodajamo tudi gline ali kvasovke, ki imajo pozitivne učinke na vampov pH.Before calving, cows are fed diets high in fiber. After calving, their requirements increase rapidly and their diet contains an increased amount of easily fermentable carbohydrates. This leads to a drop in rumen pH as sugars are fermented very rapidly and extensively to short-chain fatty acids. A low pH is suboptimal and digestion of other nutrients is slowed. This leads to a decrease in milk fat. To neutralize the pH in the rumen and prevent milk fat drop, buffers are added to the feed. The most commonly used buffer is sodium bicarbonate. It is effective in neutralizing rumen acids, but its effect is not long lasting. Magnesium oxide is a more powerful buffer and is usually added in combination with sodium bicarbonate for better effect. Seaweed, produced on the shores of the Irish Sea, is also an alternative. They have a stronger effect on pH than sodium bicarbonate and their effect lasts longer. pHiX-up is a strong buffer that is 3× stronger than sodium bicarbonate, but its effect is short-lived. Other buffers that can be used are also clays or yeasts, which also increase the low pH in the rumen

Spore Germination and Early Gametophyte Development of Platycerium bifurcatum

Volume: 83Start Page: 79End Page: 8

Jasmonic acid induces changes in growth and polypeptide composition of fern gametophytes

We studied morphology of gametophytes of the fern Platycerium bifurcation 20 to 45 days after spore sowing. In addition, we examined the effects of 0.01, 0.1, 1, 10 or 100 μM jasmonic acid (JA) on their growth and polypeptide composition. Gametophytes cultured for 20 days on modified Knop’s medium were oblong to round in outline. 3-5 rhizoids appeared mainly on the basal cell and 2-3 unicellular hairs formed on the margins. After 30 days in culture, slightly heart-shaped gametophytes produced numerous rhizoids and hairs. Gametophytes cultured for 45 days were cordate and the first antheridia were observed on the ventral side. Hairs, frequently branched, appeared on gametophyte surface. The effect of JA on the growth of gametophytes was age-dependent. After 20 and 30 days in culture, JA had no pronounced effect in comparison to the control (medium without JA), while after 40 days at concentrations exceeding 0.1 μM JA growth of gametophytes was inhibited. Analysis of soluble proteins from 2 month old JA-treated gametophytes revealed some alterations in polypeptide patterns when compared to the control. The most marked was an increase in a 92-93 kDa polypeptide band at 10 and 100 μM JA in the medium

Spore Age and Sterilization Affects Germination and Early Gametophyte Development of Platycerium bifurcatum

Volume: 89Start Page: 124End Page: 13

Kako doseči samostojnost otroka pri opravljanju šolskih aktivnosti doma?: vodnik za starše

Vodnik je prvenstveno namenjen staršem otrok, ki imajo primanjkljaje na posameznih področjih učenja in se težje učijo, vendar verjamemo, da lahko v vodniku najdejo koristne informacije vsi, ki želijo pomagati svojemu otroku k večji samostojnosti pri šolskem delu doma