Preparation of a crystalline tris-(N-methylpyridinium)-derivative of bovine insulin

The reaction between 2-chloro-N-methylpyridinium iodide and bovine insulin at pH 8.5 afforded a trisubstituted derivative as main product. Following purification on DEAE-Sephadex A-25, this derivative crystallized from a citrate buffer in the form of large rhombohedra very similar to native insulin. This observation was confirmed by zero-layer X-ray precession photography. Amino acid analysis indicated substitution at the B1-terminus and on two of the four tyrosine residues. In the mouse convulsion assay the derivative showed no biological activity.     

Aldosterone secretion during high sodium cerebrospinal fluid perfusion of the brain ventricles

Conscious sheep with permanent indwelling cannulae in the lateral ventricles and the cisterna magna were Na depleted and then perfused for 9 h with an artificial CSF solution. There were 3 experimental groups: Group I (n=5) received perfusion with aritifical CSF containing NA 170 MEq./1, Group II (n=7) received perfusion with artificial CSF containing Na 145 mEq./1, Group III (n=7) received no perfusion. In Group I the blood aldosterone level fell from 26.4 +/- 7.4 to 8.6 +/- 2.3 ng/100 ml by 9 h after perfusion. There was no significant change in plasma [Na] or [K], blood angiotensin II or plasma renin concentration. Blood cortisol and corticosterone levels rose. There was also a fall in post-perfusion. Group III showed no significant change in blood aldosterone concentration. Multivariate statistical analysis showed that the fall in aldosterone levels during 170 mEq./l Na perfusion could not be accounted for by changes, either alone or together, of ACTH as evidenced by alteration in blood cortisol or corticosterone, or by change of plasma [Na], [K] or renin concentrations. This data supports the hypothesis of an additional factor which may be of CNS origin being involved in the control of aldosterone secretion.     

Cost of management of patients with haemophilia

The cost of managing 114 adult haemophiliacs in the west of Scotland was assessed for the period 1 March 1971 to 28 February 1974. Altogether 23 of them (20%) accounted for 80% of the resources used. The cost of hospital treatment of these patients during the period was compared with the predicted cost of home treatment, given the availability of freeze-dried factor VIII concentrate in sufficient amounts. We calculate that adequate on-demand home treatment would cost only 16% more than the present treatment, which is substantially less efficient.     

Action potential fatigue in nonmyelinated nerve fibers: garfish olfactory and rabbit vagus nerve

With the new method the fecal flora of 13 clinically healthy dogs aged 3 to 42 months was analysed qualitatively and quantitatively. It was characterized by that bacteroidaceae constituted the most prodominant flora, catenabacteria, streptococci, peptostreptococci, lactobacilli and bifidobacteria were the next most numerous, enterobacteria consisted the accompanying flora. The numbers of Clostridium perfringens were remarkably fluctuated and seem to be influenced by the composition of the food ingested by the host. The total cultivable counts averaged log 10.8 +/- 0.2/g. The composition of the Lactobacillus flora and Bifidobacterium flora in the feces of 34 dogs from 3 different age groups was analysed. In the feces of all age groups L. acidophilus, L. salivarius and L. fermenti with 9 different types were found. Within the lactobacilli L. acidophilus type VI c, L. salivarius type VI a and L. fermenti type IV b were most frequently found. L. acidophilus types VI c and XI, L. salivarius types VI a and VI b could not be placed in any established types of each species, and were described as new types. Bifidobacteria were regularly found in large numbers in the feces of dogs aged 2 to 24 months. B. adolescentis and B. pseudolongum consisted the main Bifidobacterium flora.     

Urinary creatinine excretion and lean body mass

In a group of 34 adult and child subjects a high correlation (r = 0.988) was found between lean body mass, as determined by potassium-40 counting, and urinary creatinine excretion. The effect of technical errors was reduced by averaging the results of two or three 40K assays on each subject, and by making consecutive 3-day collections of urine. It appears that one can make a reasonable estimate of lean body mass from urinary creatinine excretion.     

河北大雀沟地区金成矿规律及找矿方向

河北省宣化—崇礼—赤城一带是冀西北重要的岩金产地,大雀沟地区位于该带东北部,近邻的大中型金矿床有黄土梁子、后沟、金家庄等。根据近年地质、物化探、槽探及钻探勘查成果,结合对该区金矿床地质特征、成矿规律进行的初步总结,认为矿床定位于碱性杂岩体的边缘构造夹持区,同时受到后期岩浆侵位影响;矿体严格受低次序构造控制,以脉状、透镜状就位于其中;钾长石化是该区最具特色的蚀变,矿石中金属硫化物含量偏低,属贫硫化物型。在此基础上,指出了进一步普查-详查的工作范围。     

无机盐对木瓜蛋白酶凝固大豆分离蛋白凝胶的影响

为研究食品中常见无机盐对木瓜蛋白酶凝固大豆分离蛋白凝胶的影响,以大豆分离蛋白(SPI)为原料,测定添加NaCl、KCl、CaCl2、MgCl2和MgSO4等常见无机盐后木瓜蛋白酶凝固SPI的时间、凝胶质构、凝固过程中pH值及蛋白质降解程度的变化。结果表明：添加一定浓度的无机盐可以缩短凝固时间并提高凝胶强度。相同离子强度下,Ca2+和Mg2+对凝固时间及凝胶强度影响均大于Na+和K+。添加无机盐可使SPI的pH值降低,加酶后pH值再次持续下降,但一定时间后趋于稳定。无机盐的种类和浓度对木瓜蛋白酶凝固SPI过程中蛋白质降解程度影响不明显。SPI中CaCl2的离子强度为15(CaCl2浓度为5mmol/L)时,将酶添加量从0.15%减少到0.1%,可使凝胶强度提高60%。因此,添加适量的一价及二价无机盐可显著缩短酶凝固时间并提高凝胶强度。添加Ca2+和Mg2+等二价阳离子盐类是提高木瓜蛋白酶凝固大豆蛋白凝胶强度的有效途径。