Changes in contractile properties of muscle after strength training in man

Summary Thirty young male adults matched in two experimental groups (n=12) and a control group (n=6) were investigated before and after an 8-week strength training period. Group A trained with few repetitions and maximal loads, whereas group B had more repetitions with smaller loads. Both groups lifted the same total load during each training period, four times a week. Maximal voluntary strength (MVS) of a shot-put arm movement, muscular excitability and contractile properties (time to peak of contraction with threshold stimuli, half relaxation time) were measured in M. deltoideus and M. triceps brachii, C. longum, for two durations of stimulation. Increases of 14.8% (group A) and 12.2% (group B) in MVS were observed. Muscle excitability significantly increased in all types of training and both muscles. Significant shortening of the contraction time, dependent on the type of training, was observed in both studied muscles. It appears that the strength training in group A involved the fast fibers of both muscles, whereas in group B the training influence was less marked, and affected both fast and slow fiber types.     

Inner hair cell responses to the velocity of basilar membrane motion in the guinea pig

Triangular wave acoustic stimulation at 200 Hz produced the expected square wave cochlear microphonic at the round window membrane and within the scala media. Intracellular recordings from inner hair cells (IHC) of the first cochlear turn showed a combination waveform having both spike impulse and square wave features. The IHC response suggests a sensitivity of these cells to both the displacement and to the velocity of basilar membrane motion.     

Prediction of the non-specific cardiodepressant effects of beta-adrenoceptor blocking agents in vitro and in vivo by means of the Hansch analysis

Hydrophobicity (n-octanol/buffer partition coefficients) of six 1-alkylamino-3-(2-nitrilophenoxy)-propan-2-ol derivatives with different substituents at the amino group (Kö 1439, Kö 1561, Kö 1560, Kö 1313, Kö 1366, Kö 1500), and of five 1-isopropylamino-3-(alkylphenoxy)-propan-2-ol derivatives with different ring substituents (Kö 592, Kö 707, Kö 1030, Kö 1124, Kö 1292), with β-adrenoceptor blocking properties, was correlated with the non-specific cardiodepressant effects of the drugs. Influence on the conduction velocity of the frog heart was studied in vitro and influence of the drugs on dp/dt_max in anaesthetized cats after β-adrenoceptor blockade was measured in vivo. The physicochemical and pharmacological data were analysed by the method of Hansch.The partition coefficients of the β-adrenoceptor blocking drugs ranged more than three orders of magnitude. The differences in hydrophobicity were solely dependent on the sum of the hydrophobic substituents of the drug molecules at the phenyl ring and at the amino group. Slowing of conduction velocity in vitro was more pronounced the higher the partition coefficients of the two series of the Kö compounds investigated; multiple regression analysis revealed parabolic correlation equations between hydrophobicity and pharmacological effects, depending on the experimental conditions (incubation time, mode of stimulation of the preparation) used. A parabolic correlation was also observed between hydrophobicity and decrease of dp/dt_max in vivo. Similar correlation equations were obtained when the hydrophobic properties of the compounds were calculated according to the method of Hansch.From the physicochemical, pharmacological, and analytical data it is concluded that the non-specific cardiodepressant effects of β-adrenoceptor blocking drugs can be predicted for given pharmacological systems by determination or by calculation of the hydrophobicity of the drug molecules, irrespectively of the site of the hydrophobic substituents (whether at the ring system or at the amino group).     

Classification of Ophthalmic Artery Flow in Patients with Occlusive Carotid Artery Disease

Purpose

To investigate and classify the ophthalmic artery (OA) flow patterns in patients with occlusive carotid artery disease (OCAD).

Methods

Forty-three patients (52 eyes) with documented OCAD of ≧70% underwent orbital color Doppler imaging. The eyes were first divided into four groups by peak systolic velocity in OA (PSV_OA): group A, PSV_OA ≦ 0; group B, 0 < PSV_OA ≦ 10; group C, 10 < PSV_OA ≦ 40; and group D, PSV_OA > 40?cm/s, then further classified by the shape of the OA flow wave. The groups were then compared with respect to the collateral pathway (Co-Path), severity of the OCAD, and systemic diseases.

Results

Eyes with unidirectional reverse flow (group A₁) had a Co-Path from the ipsilateral external carotid artery and 70%–100% OCAD. Eyes with bidirectional reverse flow (group A₂) had no Co-Path, 75% OCAD, and impending ischemic heart disease (IHD). Group B eyes had dome-shaped OA flow waves with no Co-Path and 99%–88% OCAD. Group C₁ eyes, with normal flow waves, had a Co-Path from the contralateral internal carotid artery and 100% OCAD. Group C₂ eyes, with triangular-shaped flow waves, had no Co-Path, 93%–70% OCAD, and IHD. Group D eyes had normal high flow waves with no Co-Path, 75% OCAD, and hypertension.

Conclusions

The OA flow patterns were variously affected by collateral pathway, severity of OCAD, and systemic diseases.?Jpn J Ophthalmol 2006;50:224–228 © Japanese Ophthalmological Society 2006     

Tracing Method in the Assessment of Retinal Capillary Blood Flow Velocity by Fluorescein Angiography with Scanning Laser Ophthalmoscope

Purpose

To evaluate the feasibility of a new method (the tracing method) for measuring perifoveal capillary blood flow velocity (BFV).

Methods

The BFV in the perifoveal capillaries was measured in 12 eyes of healthy subjects and 12 eyes of patients with clinically significant macular edema (CSME) by fluorescein angiography using a scanning laser ophthalmoscope by either the tracing method or the conventional method. A randomized crossover design was employed to assign the subjects to each method.

Results

The number of capillaries recognized by the tracing method in healthy subjects and in patients with CSME was significantly higher than that recognized with the conventional method (P = 0.0134 and P = 0.0108, respectively). The number of fluorescent dots detected by the tracing method in healthy subjects and in patients with CSME was also significantly higher than that detected with the conventional method (P = 0.0002 and P = 0.0137, respectively). Accurate detection of the movement of fluorescent dots and analysis of BFV were possible with the tracing method. The BFV varied within each perifoveal capillary, and the mean BFV also varied according to capillary location in the macula.

Conclusion

The new tracing method is useful for analyzing the retinal capillary BFV in healthy subjects and in patients with CSME. Jpn J Ophthalmol 2006;50:25–32 © Japanese Ophthalmological Society 2006     

肝素改善妊娠中晚期脐动脉血流异常的临床效果

目的评价肝素对改善妊娠中晚期脐动脉收缩期最大血流速度(S)与舒张末期血流速度(D)的比值异常的临床效果。方法将脐动脉血流S/D比值大于相应孕周的第95百分位以上的67例妊娠中晚期妇女共72例胎儿(5例双胎)分为研究组35例孕妇(38例胎儿),对照组32例孕妇(34例胎儿),知情同意后,研究组用肝素6250U或12500U+5%葡萄糖500ml、静脉滴注,4~6h内滴完,每天1次,平均治疗(37±21)d,范围1~10d;对照组应用低分子右旋糖酐500ml,丹参30ml+10%葡萄糖500ml,东莨菪碱20mg+10%葡萄糖500ml,静脉滴注,每天1次,平均治疗(67±28)d,范围3~14d。定期复查脐动脉血流S/D比值(3~5d1次,严重者每天1次)。结果研究组平均每天脐动脉血流S/D比值下降037,对照组平均每天脐动脉血流S/D比值下降014,两组研究结果比较,差异有统计学意义(P<005)。研究组所需治疗时间显著短于对照组,两组比较,差异也有统计学意义(P<001)。对照组中有10例胎儿脐动脉血流S/D比值进行性升高,2例胎儿脐动脉血流S/D比值出现无穷大,即舒张末期缺如而致胎儿死亡。结论肝素治疗妊娠中晚期脐动脉血流S/D比值异常升高,效果显著,疗程更短。     

Predicting fetal anemia by using reference centile charts for liver length, spleen perimeter and umbilical vein maximum flow velocity in Thai fetuses throughout gestation

AIM: To create reference centile charts for liver length, spleen perimeter and umbilical vein maximum flow velocity (UVVmax) in Thai fetuses in order to predict fetal anemia in Thai fetuses. METHODS: The study was a prospective, cross-sectional study, carried out at the Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Faculty of Medicine, Siriraj Hospital, Mahidol University. A total of 780 pregnant women between 13 and 40 weeks' gestation, who attended the antenatal clinic at Siriraj Hospital, Mahidol University, Bangkok, were recruited. Each fetus was measured only once for the purpose of this study. The mean and standard deviation (SD) were estimated at each week of gestation using linear regression modeling. A total of 752 fetuses were measured for fetal liver length, spleen perimeter and UVVmax. Linear regression models were fitted to estimate the mean 95% confidence interval for liver length, spleen perimeter and UVVmax at each gestational age. The centile charts of those parameters were also presented. CONCLUSION: Reference centile charts for fetal liver length, spleen perimeter and UVVmax of Thai fetuses were created.     

Motor nerve conduction velocity in volunteers ingesting inorganic lead for 49 days

Summary Eleven male volunteers (20 – 30 yr) ingested Pb acetate for 49 days. Lead concentration in blood was kept at about 400 ppb from the third week. Ulnar motor nerve conduction velocity was determined and compared to ten control subjects. A decrease greater than 13% for fast conducting fibres and greater than 15% for slow fibres could be excluded.     

Paralytic Strabismus in Children: Etiologic Incidence and Management of the Third,Fourth, and Sixth Nerve Palsies

The results of a retrospective study of the etiologic incidence of all cases of third, fourth, and sixth nerve palsies in patients at Wills Eye Hospital and St Christopher's Hospital are reported. A total of 121 patients ranging in age from birth to sixteen were studied. Thirty-two cases of third nerve palsy, eighteen cases of fourth nerve palsy, and sixty-two cases of sixth nerve palsy were identified in this series. Nine additional cases illustrated combinations of multiple nerve involvement. With few exceptions, acquired third nerve palsy in children is an ominous sign whereas the congenital form is generally indicative of developmental anomaly or birth trauma. Acquired sixth nerve palsy in a child is always a matter of concern since it may represent the first sign of a brain-stem glioma. Active force studies may be carried out periodically to assess the speed of recovery and indicate when it is time to initiate a more aggressive role in the surgical management. The surgical results in children with paralytic strabismus that have been carefully evaluated offer a favorable prognosis.