Human thyroid blood flow response to endogenous, exogenous human, and bovine thyrotrophin measured by electromagnetic flowmetry

1981 ◽  
Vol 98 (4) ◽  
pp. 540-548 ◽  
Author(s):  
Lennart Tegler ◽  
Jan Gillquist ◽  
Bo Anderberg ◽  
Gunilla Jacobson ◽  
Björn Lundström ◽  
...  

Abstract. Human thyroid blood flow (TBF) was studied with electromagnetic flowmetry during operation. Measurements were made of the effect on TBF of injections of bovine TSH into one inferior thyroid artery in 6 patients; 6 other patients were given human TSH, and in 10 patients measurements were made both of TBF and endogenous TSH released after administration of TRH in a peripheral vein. The TBF increased after all three types of injection. The mean of the TBF maxima after bovine TSH was 2.26 ± 0.35 (mean ± sem) relative to basal TBF, after human TSH 1.97 ± 0.28, and after TRH 1.64 ± 0.20. In the three groups combined it was 1.92 ± 0.16. The TBF was often increased already during the first recording period 1–10 min after TSH or TRH administration. The mean TBF was approximately doubled at 30–50 min. There were considerable inter-individual variations in the latent time and maximum response of TBF, especially after human TSH, but we found no correlation between the response and the TSH serum concentration in any group. A prompt, but inter-individually varying, increase in TBF was confirmed. This increase is suggested to be secondary to an increased intrafollicular metabolic activity and not primarily regulating the thyroid function.

1971 ◽  
Vol 34 (5) ◽  
pp. 665-671 ◽  
Author(s):  
Norval M. Simms ◽  
George S. Kush ◽  
Don M. Long ◽  
Merle K. Loken ◽  
Lyle A. French

✓ Acute intracranial hemodynamic alterations consequent to arterial air embolism were studied in the dog using the radioxenon clearance technique. In eight dogs, the mean pre-embolic (control) hemispheric flow was 28.3 ml/100 gm/min. Following the injection of varying amounts of air into the right vertebral artery, there was an augmentation in the measured cerebral blood flow in all animals. Statistical analysis revealed the flow response to be independent of the amounts of air used in these experiments. The mean post-embolic cerebral blood flow was 39.3 ml/100 gm/min, representing a statistically significant increase of 11.0 ml/100 gm/min. Although the post-embolic supernormal flow may be due to the interaction of multiple pathophysiologic factors, air-induced traumatic vasodilatation is advocated as the most important pathogenetic mechanism. Prolonged vasodilatation with loss of autoregulation results in physiological shunting of blood through the affected capillary beds. Alterations in the intracerebral vasculature due to arterial air embolism are compared with studies by other investigators who have observed the effects in extracerebral vessels.


2005 ◽  
Vol 25 (1_suppl) ◽  
pp. S198-S198
Author(s):  
Joseph R Meno ◽  
Thien-son K Nguyen ◽  
Elise M Jensen ◽  
G Alexander West ◽  
Leonid Groysman ◽  
...  

1996 ◽  
Vol 76 (01) ◽  
pp. 111-117 ◽  
Author(s):  
Yasuto Sasaki ◽  
Junji Seki ◽  
John C Giddings ◽  
Junichiro Yamamoto

SummarySodium nitroprusside (SNP) and 3-morpholinosydnonimine (SIN-1), are known to liberate nitric oxide (NO). In this study the effects of SNP and SIN-1 on thrombus formation in rat cerebral arterioles and venules in vivo were assessed using a helium-neon (He-Ne) laser. SNP infused at doses from 10 Μg/kg/h significantly inhibited thrombus formation in a dose dependent manner. This inhibition of thrombus formation was suppressed by methylene blue. SIN-1 at a dose of 100 Μg/kg/h also demonstrated a significant antithrombotic effect. Moreover, treatment with SNP increased vessel diameter in a dose dependent manner and enhanced the mean red cell velocity measured with a fiber-optic laser-Doppler anemometer microscope (FLDAM). Blood flow, calculated from the mean red cell velocity and vessel diameters was increased significantly during infusion. In contrast, mean wall shear rates in the arterioles and venules were not changed by SNP infusion. The results indicated that SNP and SIN-1 possessed potent antithrombotic activities, whilst SNP increased cerebral blood flow without changing wall shear rate. The findings suggest that the NO released by SNP and SIN-1 may be beneficial for the treatment and protection of cerebral infarction


1996 ◽  
Vol 75 (05) ◽  
pp. 731-733 ◽  
Author(s):  
V Cazaux ◽  
B Gauthier ◽  
A Elias ◽  
D Lefebvre ◽  
J Tredez ◽  
...  

SummaryDue to large inter-individual variations, the dose of vitamin K antagonist required to target the desired hypocoagulability is hardly predictible for a given patient, and the time needed to reach therapeutic equilibrium may be excessively long. This work reports on a simple method for predicting the daily maintenance dose of fluindione after the third intake. In a first step, 37 patients were delivered 20 mg of fluindione once a day, at 6 p.m. for 3 consecutive days. On the morning of the 4th day an INR was performed. During the following days the dose was adjusted to target an INR between 2 and 3. There was a good correlation (r = 0.83, p<0.001) between the INR performed on the morning of day 4 and the daily maintenance dose determined later by successive approximations. This allowed us to write a decisional algorithm to predict the effective maintenance dose of fluindione from the INR performed on day 4. The usefulness and the safety of this approach was tested in a second prospective study on 46 patients receiving fluindione according to the same initial scheme. The predicted dose was compared to the effective dose soon after having reached the equilibrium, then 30 and 90 days after. To within 5 mg (one quarter of a tablet), the predicted dose was the effective dose in 98%, 86% and 81% of the patients at the 3 times respectively. The mean time needed to reach the therapeutic equilibrium was reduced from 13 days in the first study to 6 days in the second study. No hemorrhagic complication occurred. Thus the strategy formerly developed to predict the daily maintenance dose of warfarin from the prothrombin time ratio or the thrombotest performed 3 days after starting the treatment may also be applied to fluindione and the INR measurement.


Circulation ◽  
1995 ◽  
Vol 92 (4) ◽  
pp. 796-804 ◽  
Author(s):  
Danilo Neglia ◽  
Oberdan Parodi ◽  
Michela Gallopin ◽  
Gianmario Sambuceti ◽  
Assuero Giorgetti ◽  
...  

Hypertension ◽  
1995 ◽  
Vol 26 (3) ◽  
pp. 497-502 ◽  
Author(s):  
Daniel Hayoz ◽  
Roger Weber ◽  
Blaise Rutschmann ◽  
Roger Darioli ◽  
Michel Burnier ◽  
...  

2021 ◽  
pp. 135245852199455
Author(s):  
Barnabas Bessing ◽  
Mohammad A Hussain ◽  
Suzi B Claflin ◽  
Jing Chen ◽  
Leigh Blizzard ◽  
...  

Background: While employment rates have increased in people with multiple sclerosis (PwMS), little is known about the longitudinal trends of work productivity. Objective: To describe the longitudinal patterns of work productivity and examine the factors associated with annual change of work productivity of PwMS. Methods: Study participants were employed participants of the Australian MS Longitudinal Study (AMSLS) followed from 2015 to 2019 with at least two repeated measures ( n = 2121). We used linear mixed models to examine if the within-individual variations in MS symptoms are associated with changes in work productivity. Results: The mean annual change in work productivity between 2015 and 2019 was −0.23% ( SD = 18.68%). Not the actual severity of symptoms but rather the changes in severity of symptoms that are associated with change in work productivity in the same year. In a multivariable model, every unit increase in mean annual change in ‘pain and sensory symptoms’, ‘feelings of anxiety and depression’, and ‘fatigue and cognitive symptoms’ were independently associated with 2.43%, 1.55% and 1.01% annual reductions in work productivity, respectively. Conclusion: Individual changes in work productivity are largely driven by the changes in symptom severity rather than the absolute severity. Stabilising/improving MS symptoms might improve work productivity.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yoshitaka Ueno ◽  
Takeshi Iwase ◽  
Kensuke Goto ◽  
Ryo Tomita ◽  
Eimei Ra ◽  
...  

AbstractWe investigated morphological changes of retinal arteries to determine their association with the blood flow and systemic variables in type 2 diabetes patients. The patients included 47 non-diabetic retinopathy eyes, 36 mild or moderate nonproliferative diabetic retinopathy (M-NPDR) eyes, 22 severe NPDR (S-NPDR) eyes, 32 PDR eyes, and 24 normal eyes as controls. The mean wall to lumen ratio (WLR) measured by adaptive optics camera was significantly higher in the PDR groups than in all of the other groups (all P < 0.001). However, the external diameter of the retinal vessels was not significantly different among the groups. The mean blur rate (MBR)-vessel determined by laser speckle flowgraphy was significantly lower in the PDR group than in the other groups (P < 0.001). The WLR was correlated with MBR-vessel (r = − 0.337, P < 0.001), duration of disease (r = 0.191, P = 0.042), stage of DM (r = 0.643, P < 0.001), systolic blood pressure (r = 0.166, P < 0.037), and presence of systemic hypertension (r = 0.443, P < 0.001). Multiple regression analysis demonstrated that MBR-vessel (β = − 0.389, P < 0.001), presence of systemic hypertension (β = 0.334, P = 0.001), and LDL (β = 0.199, P = 0.045) were independent factors significantly associated with the WLR. The increased retinal vessel wall thickness led to a narrowing of lumen diameter and a decrease in the blood flow in the PDR group.


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