scholarly journals The relationship between plasma concentrations of progesterone, estradiol and testosterone and the ages of first egg laying in maturing pullets.

1988 ◽  
Vol 25 (2) ◽  
pp. 86-92 ◽  
Author(s):  
Hiroshi ITOH ◽  
Tomohiro KONO ◽  
Takehito KUWAYAMA ◽  
Kenji ICHINOE
2020 ◽  
pp. 96-104
Author(s):  
E. V. Titaeva ◽  
A. B. Dobrovolsky

Introduction. The direct oral anticoagulants (DOC) therapy does not require alaboratory control; however, it may be required to determine the anticoagulationlevel to choose a treatment strategy if alarge bleeding is developing or emergency surgery is needed.The objective of this experimental study was to investigate the relationship between the residual factor Xa (FXa) activity, anti-Xa activity units oflow molecular weight heparins (LMWH), and the apixaban and rivaroxaban plasma concentrations in a chromogenic anti-Xa assay.Material and methods. Concentrated DOC solutions were prepared by extracting apixaban and rivaroxaban from crushed tablets using methanol and dimethyl sulfoxide, respectively. The resulting solutions were added to the donor plasma pool until final inhibitor concentrations are achieved in the range from 10 to 100 ng/ml plasma. Anti-Xa activity was determined using an STA-compact analyser and the Liquid anti-Xa reagent kit, an analysis protocol, and calibrators designed to control the LMWH therapy. The effect on the thrombin formation dynamics was investigated using the thrombin generation test (TGT) and the PPR reagent as a trigger (final concentrations of tissue factor are 5 pM, and those of phospholipids are 4 μM). TGT curves were analysed using the Thrombinoscope program.Results. It was shown that in the anti-Xa activity test version designed to control the LMWH therapy, there is a high correlation (R2 > 0.98) between thelogarithm of the residual factor Xa activity and the content of apixaban and rivaroxaban in the range from 10 to 80 ng/ml. Rivaroxaban shows about 1.5 times more anti-Xa activity than apixaban at equal concentrations. It was also shown that apixaban and rivaroxaban at doses equal both in concentration and in anti-Xa activity differ in their effect on the thrombin formation dynamics and thrombin inactivation in the TGT.Conclusion. In the LMWH anti-Xa activity test version, the measured range of apixaban and rivaroxaban includes 30 ng/ml and 50 ng/ ml concentrations taken as “cut-off points” to determine the treatment tactics in emergency cases. However, thelack of certified DOC calibratorslimits the use of this test in clinical practice.


2021 ◽  
Vol 11 ◽  
pp. 204512532110371
Author(s):  
Amir Krivoy ◽  
Eromona Whiskey ◽  
Henrietta Webb-Wilson ◽  
Dan Joyce ◽  
Derek K. Tracy ◽  
...  

Background: Clozapine is the only medication licenced for treating patients with treatment-refractory schizophrenia. However, there are no evidence-based guidelines as to the optimal plasma level of clozapine to aim for, and their association with clinical and functional outcome. Objective: We assessed the relationship between clinical and functional outcome measures and blood concentrations of clozapine among patients with treatment-refractory psychosis. Methods: Data were reviewed in 82 patients with treatment-refractory psychosis admitted to a specialised tertiary-level service and treated with clozapine. Analysis focussed on the relationship between clozapine and norclozapine plasma concentrations and the patient’s clinical symptoms and functional status. Results: Clinical symptom improvement was positively correlated with norclozapine plasma concentrations and inversely correlated with clozapine to norclozapine plasma concentrations ratio. Clozapine concentrations showed a bimodal association with clinical improvement (peaks around 350 and 660 ng/ml). Clinical symptom improvement correlated with functional outcomes, although there was no significant correlation between the latter and clozapine or norclozapine plasma concentrations. Conclusion: Clozapine treatment was associated with optimal clinical improvement at two different peak plasma concentrations around 350 and 650 ng/ml. Clinical improvement was associated with functional outcome; however, functionality was not directly associated with clozapine concentrations. A subset of patients may require higher clozapine plasma concentrations to achieve clinical improvement.


1974 ◽  
Vol 12 (2) ◽  
pp. 6-8

Techniques are now available for estimating the plasma concentration of several drugs used in psychiatry. These techniques are clearly important for research but they can hardly be expected to improve the clinical management of patients unless the estimation is sensitive, reliable and reasonably quick; the method should be specific for the particular drug but should also specifically estimate any active metabolites. Even when reliable figures have been obtained, much more information is needed before they can be interpreted. The relationship between plasma (or plasma water) concentration and relevant tissue concentration (e. g. in the brain) must be known. Plasma samples should be taken at appropriate times, e. g. after the attainment of ‘steady-state’ conditions: plasma and tissue levels will then be in equilibrium. Diagnoses must be soundly based if inferences are to be drawn. Reliable methods of assessing clinical response must be available. These requirements pose difficult problems in psychiatry.


1998 ◽  
Vol 130 (3) ◽  
pp. 357-366 ◽  
Author(s):  
R. E. NEWMAN ◽  
S. J. McCONNELL ◽  
R. H. WESTON ◽  
M. REEVES ◽  
C. BERNASCONI ◽  
...  

In two experiments conducted at Badgery's Creek, NSW (Latitude 34°S) the roles of testosterone and the thyroid hormones triiodothyronine (T3) and thyroxine (T4) as possible initiators of the change in voluntary feed intake (VFI) associated with the seasonal reproductive behaviour (rut) in male fallow deer were investigated.In Expt 1, the association between changes in these hormones with the onset of the rut was assessed in deer in which the timing of this event was manipulated by changing the photoperiod, or by melatonin administration. Groups were maintained under either natural photoperiod (n=6; control), a constant long daylength (16 h light[ratio ]8 h dark; n=9; LD group) or a constant long daylength and implanted with melatonin capsules (n=5; LD+M group) for 7 months from December until the following July. Blood samples were obtained weekly and VFI recorded.Feed intake decreased by 94% from the last week of March for 3 weeks in the control group. Changes of a similar magnitude were measured in the LD and LD+M groups but these changes were advanced by 1 and 9 weeks respectively in these groups. In all groups, circulating testosterone concentrations increased markedly at a time corresponding with the decrease in VFI. The concentrations returned to basal levels with the resumption in VFI. A distinct decrease in plasma concentrations of T3 and T4 in all three groups was associated with the decrease in VFI, however, the relationship with T3 was less apparent.In Expt 2, the role of testosterone in the regulation of the decline in VFI was investigated. Fallow bucks were treated with testosterone enanthate every 4 or 5 days for 28 days up to 6 weeks prior to the expected onset of the rut. Plasma testosterone concentrations, which were increased 13-fold, resulted in a decline in VFI which was comparable to that observed in the subsequent rut. Plasma free fatty acid concentrations were correlated negatively with the decline in VFI.Thus, the seasonal increase in circulating testosterone concentrations plays an important role in initiating the fall in VFI associated with the rut. As the rut was still apparent in animals maintained under an extended photoperiod, it is possible that factors other than decreasing daylength act as the cue for the timing of the rut.


1999 ◽  
Vol 277 (5) ◽  
pp. E870-E875 ◽  
Author(s):  
Kentaro Nagaoka ◽  
Yasuo Nambo ◽  
Natsuko Nagamine ◽  
Shun-Ichi Nagata ◽  
Yumiko Tanaka ◽  
...  

The relationship between a selective increase in circulating immunoreactive (ir)-inhibin and the time of ovulation was investigated in mares. Concentrations of plasma ir-inhibin were measured every 4 h during the periovulatory period. Inhibin pro-αC, a precursor protein of the inhibin α-subunit, was also measured. The changes in ir-inhibin and inhibin pro-αC in circulation were parallel. Concentrations of both ir-inhibin and inhibin pro-αC in the plasma increased at the same time when ovulatory follicles ruptured, and the peak levels of circulating ir-inhibin and inhibin pro-αC were maintained for 4–8 h. There was no selective increase in plasma concentrations of estradiol-17β during the process of ovulation. These results suggest that the selective increase in ir-inhibin and inhibin pro-αC was caused by the absorption of follicular fluid after the rupture of ovulatory follicles. These results also suggest that the measuring of plasma concentrations of ir-inhibin or inhibin pro-αC in mares might be a useful method for detecting the time of ovulation.


1997 ◽  
Vol 273 (4) ◽  
pp. E815-E820 ◽  
Author(s):  
Kirk D. Fischer ◽  
Savita Dhanvantari ◽  
Daniel J. Drucker ◽  
Patricia L. Brubaker

Glucagon-like peptide 2 (GLP-2) has recently been identified as a novel intestinal growth factor. Because experimental diabetes is associated with bowel growth, we examined the relationship between GLP-2 and intestinal growth in rats made diabetic by streptozotocin (STZ) injection and treated with or without insulin for 3 wk. Ileal concentrations of the intestinal proglucagon-derived peptides, i.e., glicentin + oxyntomodulin, and GLPs 1 and 2, were increased by 57 ± 20% above those of controls in untreated STZ diabetes ( P < 0.05–0.001). Similar increases in plasma concentrations of glicentin + oxyntomodulin (77 ± 15% above controls, P < 0.01) and GLP-2 (91 ± 32% above controls, P < 0.05) were seen in untreated STZ diabetes. Both wet and dry small intestinal weight increased by 74 ± 20% above controls ( P < 0.01) in STZ diabetes, and macromolecular analysis indicated parallel increases in both protein ( P < 0.001) and lipid ( P < 0.05) content. Villus height ( P < 0.001) and crypt depth ( P < 0.01) were also increased in untreated diabetic rat intestine. Insulin therapy prevented the changes in plasma GLP-2 and intestinal mass seen in untreated STZ diabetes. Thus STZ diabetes is associated with both increased production of GLP-2 and enhanced bowel weight, thereby suggesting a role for GLP-2 in diabetes-associated bowel growth.


2009 ◽  
Vol 103 (2) ◽  
pp. 249-255 ◽  
Author(s):  
Jie Cao ◽  
Ying Zhang ◽  
Wei Chen ◽  
Xiujuan Zhao

Epidemiological studies suggest that a diet high in flavonoids protects against chronic diseases such as CVD and cancer. The objective of the present study was to evaluate the relationship between the intake of quercetin, kaempferol, isorhamnetin, apigenin and luteolin and their corresponding plasma concentrations, and further to explore whether these flavonoids can serve as biomarkers of their intake. Flavonoid intake and their plasma concentrations were analysed in ninety-two subjects consuming their habitual diet. Flavonoid intake was estimated with 7-d dietary records using available data on the flavonoid content of food. Plasma flavonoid concentrations were quantified by HPLC. In addition, we undertook a dietary intervention study to investigate plasma apigenin concentration after the consumption of celery leaf. The mean intake estimates of quercetin, kaempferol, isorhamnetin, apigenin and luteolin amounted to 13·58, 14·97, 12·31, 4·23 and 8·08 mg/d, respectively. The corresponding mean plasma concentrations were 80·23, 57·86, 39·94, 10·62 and 99·90 nmol/l. The mean 7 d intake of five flavonoids was positively correlated to their corresponding plasma concentrations, with correlation coefficients ranging from 0·33 to 0·51 (P < 0·05). In the dietary intervention study, the plasma apigenin concentration rose after celery leaf ingestion, and fell within 28 h to below the limit of detection (2·32 nmol/l). The present results suggest that quercetin, kaempferol, isorhamnetin, apigenin and luteolin are bioavailable from the diet. The levels of fasting plasma flavonoids seem to be suitable biomarkers of short-term intake. The combination of plasma flavonoids with their intake may prove useful when the possible health-protective effects of flavonoids are studied.


1972 ◽  
Vol 104 (7) ◽  
pp. 1055-1071 ◽  
Author(s):  
Akira Mutuura

AbstractIn the phylogenetic classification of the Lepidoptera, the position of the genital opening and its modifications help to clarify the relationship of the Zeugloptera to the lepidopterous suborders. Three different systems of the suborder classification of the Lepidoptera, into Homoneura and Heteroneura (Tillyard, Imms, etc.), Monotrysia and Ditrysia (Borner), and Dacnonypha, Monotrysia, and Ditrysia (Hinton), are not supported by evidence obtained in the study of the female genitalia.The development of the female terminalia is closely associated with the mode of oviposition. Several types of female terminalia are found in the primitive Lepidoptera (Hepialidae, Neopseustidae, Tischeriidae, Lyonetiidae, Agathiphagidae, Tineidae, Nepticulidae, and Eriocraniidae). They are divided into four categories: hepialid type — the eggs are dropped randomly; typical lepidopterous type — the eggs are laid on the surface of food plants; eriocraniid type — the eggs are laid inside the food plants; tineid type — the eggs are laid in crevices of food. Each of the types is derivable from the types occurring in Neopseustidae, Tischeriidae, Agathiphagidae, and Eriocraniidae, respectively. These types are still far removed from the type of female terminalia in Micropterygidae of the Zeugloptera.The modes of egg-laying as well as the morphological characters of the female genitalia must be taken into consideration in suborder classification of the Lepidoptera.A genealogical tree based on the female terminalia suggests four main branches: hepialid branch — includes Neopseustidae and Prototheoridae; typical lepidopterous branch — includes all Ditrysia and Nepticulidae; tineid branch — includes only Tineidae; eriocraniid branch — includes Incurvariidae, Prodoxidae, Adelidae, and Heliozelidae.


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