Pig prothrombin: purification and properties

A procedure for the preparation of highly purified pig prothrombin is described. Compared to the initial clotting activity of the starting plasma, this protein was purified 776 times with a final yield of 8 per cent. The purified zymogen showed a specific activity of 1,460 NH units/mg of protein , a molecular weight of 65,000 as determined by SDS-polyacrylamide disc gel electroesis, E 1.0 mg/ml 1.0 cm, 280 nm = 1.45 at pH 7.0 and the following amino acid composition: Asx 51, Thr 38, Glx 62, Pro 23, Gly44, Ala 25, Half-Cys 30, Val 35, Met 3, Ile 30, Leu 32, Tyr 19, Phe 22, Lys 36, His 8, Arg 28, and Trp 13, which accounts for a minimum molecular weight of 59,370 (carbohydrates not computed). Alanine was found as the only N-terminal residue. Carboxypeptidases A and B failed to release any C-terminal residue. By hydrazinolysis however 0.4 mole of serine was released per mole of prothrombin. The activation of crude and chromatographed pig prothrombin was investigated.     

Differences in physicochemical and antigenic properties of chlamydial strains

Antigenic analysis of Chlamydia psittaci, C. trachomatis, and Lymphogranuloma venereum (LGV) revealed basic physicochemical differences among the three chlamydial strains. These were manifested in structural, isoelectric points, absorption spectra, and in the characteristics of the chromophobe-containing proteins. The effective period of sonication for C. psittaci and C. trachomatis is around 60 min during which the linkages most susceptible to external sonication forces were broken, releasing all attainable cellular components. Denaturation studies demonstrated that less than 50% of protein content of C. psittaci was denatured after 1 h of sonication, only 5% in the case of C. trachomatis. The protein and carbohydrate content of the most reactive fractions in macrophage-spreading inhibition test were different for LGV and C. trachomatis. The structural differences appear to determine the antigenic properties observed among the chlamydial strains as well as the specificity and probably the mechanisms (s) of cellular immune reactivity to Chlamydiae. This in turn may explain the failure of chlamydial vaccines, prepared from stock strains, to protect immunized children against 'wild' chlamydial strains.     

Neural basis for the genesis and control of digitalis arrhythmias

The author discussed the increase in the frequency of traumatic paralyses of the ocular muscles, and reported 6 cases of inferior oblique muscle paresis caused by local blunt or sharp traumas (haematoma, contusion, rupture, incarceration) and one case of traumatic Brownian pseudo-paralysis. The localisation of the injuries in 3 cases was on the inferior temporal part and in the other 3 cases on the superior part of the bulbar conjunctiva. Atypical horizontal deviation and characteristic vertical deviation, torsion and torticollis were observed in the majority of cases. One patient recovered spontaneously. 3 patients became asymptomatic after correction by prisms and one after recession of contralateral superior rectus muscle. The symptoms remained unchanged in the case of a "blow out" fracture (in spite of operation) and a Brown's syndrome (without treatment).     

Assessing the development of daily living skills in patients with spina bifida

The development of independence in daily living skills of 256 patients with spina bifida was assessed by means of a new Functional Activities scoring system. The score was derived from nine categories of activity; five are to do with self-care, three with locomotion and one with social interaction. The reasons for the variation in achievement between individuals with the same degree of paralysis are discussed, as are the differences in learning curves for single activities. The scoring system enables a quantitative assessment to be made of the current status of an individual patient, and enables more realistic therapeutic goals to be set.     

Diabetes mellitus, arterial hypertension and serum levels of renin

Plasmatic renin levels were measured in 17 adults patients with diagnosis of diabetes mellitus and systemic arterial hypertension. None of them was under antihypertensive therapy. The results obtained showed lessening of renin levels in 13 cases, normal levels in two cases, no valuable results in one and Significative increase in other. Renal biopsy was performed in 8 patients and in all cases nephropathies were demonstrated; only one of them had normal renin levels. We have concluded that more than 75% of our cases were hyporeninemic hypertensive patients. Our findings are according with other medical papers that have been published before. Finally, we try to explain the mechanisms upon which theorethical causes are based.     

Fractures of the humerus in children

Fractures of the humerus above the distal epiphysis are not common fractures in children. Treatment should be directed toward maintenance of alignment with healing expected without fail. Contrary to experience with adults with the same fractures, children seldom have residual functional or cosmetic problems if one aligns the fractures and protects the healing process.     

A study of thyroid disease in family practice

Thyroid disease is relatively common in family practice, yet is often undiagnosed or poorly managed. This study examines several aspects of thyroid disease in a large, semirural family practice setting and exemplifies the type of practical clinical research that can be done in family medicine. An overall prevalence of approximately one percent was determined for thyroid disease in this practice. In a series of 85 patients, the ratio of hypothyroidism:hyperthyroidism:euthyroid goiter was 9:2:1 respectively. Initial signs and symptoms recorded for these patients conformed closely to the findings in other large series. Eighty percent of the patients with idiopathic hypothyroidism never had enlarged glands, whereas 100 percent of the patients with hypothyroidism associated with Hashimoto's thyroiditis had enlarged glands. Laboratory aids such as serum thyroid stimulating hormone (TSH), anti-thyroid antibodies, and radioactive iodine uptake (RAIU) and scans were inadequately utilized. Medical and/or surgical consultation was obtained in 17.5 percent of patients with hypothyroidism, 80 percent of patients with hyperthyroidism, and 63 percent of those with euthyroid goiter. Currently 95 percent of the hypothyroid patients and 100 percent of the hyperthyroid patients are euthyroid.     

Preparation and properties of mitochondria derived from synaptosomes

A method has been developed whereby a fraction of rat brain mitochondria (synaptic mitochondria) was isolated from synaptosomes. This brain mitochondrial fraction was compared with the fraction of "free" brain mitochondria (non-synaptic) isolated by the method of Clark & Nicklas (1970). (J. Biol. Chem. 245, 4724-4731). Both mitochondrial fractions are shown to be relatively pure, metabolically active and well coupled. 2. The oxidation of a number of substrates by synaptic and non-synaptic mitochondria was studied and compared. Of the substrates studied, pyruvate plus malate was oxidized most rapidly by both mitochondrial populations. However, the non-synaptic mitochondria oxidized glutamate plus malate almost twice as rapidly as the synaptic mitochondria. 3. The activities of certain tricarboxylic acid-cycle and related enzymes in synaptic and non-synaptic mitochondria were determined. Citrate synthase (EC 4.1.3.7), isocitrate dehydrogenase (EC 1.1.1.41) and malate dehydrogenase (EC 1.1.1.37) activities were similar in both fractions, but pyruvate dehydrogenase (EC 1.2.4.1) activity in non-synaptic mitochondria was higher than in synaptic mitochondria and glutamate dehydrogenase (EC 1.4.1.3) activity in non-synaptic mitochondria was lower than that in synaptic mitochondria. 4. Comparison of synaptic and non-synaptic mitochondria by rate-zonal separation confirmed the distinct identity of the two mitochondrial populations. The non-synaptic mitochondria had higher buoyant density and evidence was obtained to suggest that the synaptic mitochondria might be heterogeneous. 5. The results are also discussed in the light of the suggested connection between the heterogeneity of brain mitochondria and metabolic compartmentation.