A new method for the detection of phospholipase A2 variants: identification of isozymes in the venoms of newborn and adult Bothrops asper (terciopelo) snakes

A new method for the identification of phospholipase A2 isozymes in snake venoms is described. The technique is based on the separation of the venom components by isoelectric focusing in agarose gels, transfer of the protein bands by diffusion onto nitrocellulose paper and detection of the phospholipolytic activity of the enzymes by a hemolytic assay either in agarose gels or by benzidine reaction on a solid matrix. Striking differences in the electrophoretic patterns of the phospholipase A2 isozymes between the Atlantic and Pacific venoms and between the newborn and adult venoms from Bothrops asper specimens were observed. The method allowed the detection of 9 different phospholipase A2 isozymes in the venom of adult Atlantic, 7 isozymes in the venom of adult Pacific, and 2-3 isozymes in the venoms of newborn specimens. Horse polyvalent antivenom varied in its capacity to neutralize the phospholipolytic activity of the different isozymes in the same venom and among different venoms.

Laboratory diagnosis in thyroid auto-allergic diseases

Different parameters of humoral and cellular immunologic sensitization have been described in thyroid autoallergic disease, however, the percutaneous biopsy of the gland remains as one of the principal parameters of diagnostic confirmation, wherein the possible error of the sample being taken in an area not affected by the disease. The present study assesses two different parameters of immunologic sensitization, humoral and cellular as they are determination of thyroid antimicrosomal antibodies by hemagglutination and leukocyte inhibition migration tests against the same microsomal antigen. Both types of sensitization are proposed as being relevant, and can be found present alone or combined in the same patient, which suggests that the determination of antibodies is the most useful proof with diagnostic motives, but this should be followed by the determination of leukocyte inhibition migration when the result is negative.

A role for anaphylactic sensitization in tumor control

In order to evaluate the possible preventive role of an anaphylactic condition on tumor development, C57BL/6J mice were immunized or hyperimmunized by the intraperitoneal route with egg albumin in alum before the chemical induction of fibrosarcoma. Preimmunization using a protocol which elicits an optimal IgE response produced: (1) a significant reduction of tumor incidence; (2) an increase of survival time, and (3) a decrease of tumor growth rate in animals with higher IgE titers (greater than 640). On the other hand, hyperimmunized mice, which were suppressed in their anti-egg albumin IgE response, showed no changes in tumor incidence and survival time when compared to controls. Our results suggest a suppressive effect on tumor development related to the ability of the animal to mount an IgE response to antigens unrelated to the tumor.

[Aicardi syndrome]

The association in young girls of flexion spasms of early beginning, partial or total agenesis of the corpus callosum, severe chororetinopathy and frequent skeletal anomalies is known as the Aicardi syndrome. On occasion of two observations a review of the literature is made.

Plasma gonadotrophins profile in relation to body composition in underprivileged boys

The plasma concentrations of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) were measured in 250 underprivileged boys (UP boys) aged 9.0 to 15.9 years living in a State orphanage and in 357 clinically healthy boys of the same age (with weight and height between the 3rd and 97th percentile for Mexican standards) and correlated with chronological age (CA), weight, height and calculated lean body mass (LBM) and total body fat (TBF). On a group basis, UP boys had a 2 years delay in the onset of clinical signs of puberty as well as a mild degree of malnutrition. In both groups of boys, the mean weights at time of initiation of the adolescent growth spurt in weight and at time of peak velocity of weight gain were very close to each other and similar to the values reported for Caucasian boys. The same phenomenon was true for their heights and the amounts of LBM and TBF (whether as an absolute value or as a percentage of body weight). Based on CA mean plasma FSH concentrations in UP boys were lower than normal from 11.0 to 13.9 years and the subsequent steep rise of this hormone occurred 2 years later than in healthy boys; however, when analyzed as a function of body weight, height or LMB, no such quantitative or qualitative differences emerged. On the other hand, mean plasma LH concentrations in UP boys were higher than in healthy boys only up to certain CA (< 12.9 years), weight (< 42.9 kg), height (< 147.0 cm), LBM (< 35.0 kg) or TBF (< 9.0 kg); however, no steep rise in plasma LH was observed in contrast to healthy boys. Therefore, although from a chronologic view point UP boys had a delayed onset in plasma gonadotrophins changes, they did occur in association with the attainment of similar weight, height and LBM as in healthy boys. This observation seems to support further the hypothesis of a close association between a 'critical' level of LBM (and not body fat) and the initiation of puberty, both in healthy and multiply deprived boys.

The relationship of plasma gonadotrophins and steroid concentrations to body growth in girls

Plasma concentrations of luteinizing hormone (LH), follicle-stimulating hormone (FSH), 17 alpha-hydroxyprogesterone (17 alpha-OHP), 17 beta-oestradiol (Oe2) and progesterone (P) were measured in 352 healthy girls aged 6.0 to 15.9 years, as a function of age (CA), weight, height and calculated lean body mass (LBM) and total body fat (TBF). The earliest hormonal changes were a fall in mean plasma FSH concentrations together with a small but significant rise in plasma Oe2 well in advance of any sign of pubertal development. The next changes were a progressive rise in plasma FSH and 17 alpha-OHP concentrations without further increments in plasma Oe2; these changes corresponded to a mean body weight of 29.8 kg, a mean height of 132.0 cm (initiation of the adolescent growth spurt), a mean LBM of 24.7 kg and a mean TBF of 5.1 kg. The last events were a progressive rise in plasma LH and Oe2 and less marked in P, which occurred in association with a mean body weight of 40.0 kg, a mean height of 142.0 cm (time of peak velocity of weight and height gain), a mean LBM of 31.8 kg and a mean TBF of 9.1 kg. Significant quadratic equations were disclosed between plasma FSH and LH versus CA, weight, height and LBM, and a significant linear correlation was observed between each gonadotrophin and TBF. These results show an association, not necessarily causal, between a 'critical level' of body composition and hormonal changes at the start of the adolescent growth spurt, as well as with late hormonal events at the time of peak velocity in weight and height gain. On the other hand, LBM rather than TBF seems more closely associated with the initiation and progression of puberty.

The relationship of plasma gonadotropins and androgen concentrations to body growth in boys

Plasma concentrations of luteinizing hormone (LH), follicle-stimulating hormone (FSH), 17 alpha-hydroxyprogesterone (17α-OPH), androstenedione (Δ4) and testosterone (T) were measured in 543 healthy boys aged 6.0 to 15.9 years (with weight and height between the 3rd and 97th percentile for Mexican standards) as a function of chronologic age (CA), weight, height, surface area (SA) and calculated lean body mass (LBM) and total body fat (TBF).

The earliest hormonal event was a clear rise in plasma 17α-OHP, either prior or simultaneously to at steady increase in plasma FSH, far ahead of any sign of puberty. These changes were closely followed by a continuous rise in plasma Δ4. Thereafter, there was a prolonged period of low but progressively increasing plasma FSH levels in the face of constantly low LH levels. However, a brisk rise in plasma LH and FSH occurred at a mean weight of 35.4 kg, at a height of 144.5 cm and when LBM was 32.0 kg. Simultaneously, plasma 17α-OHP began to fall, Δ4 reached a plateau and soon after, a marked rise in plasma T was documented. When plasma LH and FSH concentrations were plotted against CA, weight, height, SA and LBM a significant quadratic equation was disclosed in each case. Both gonadotrophins did not correlate with TBF. Multiple variance analysis demonstrated that LBM and SA had the most marked effect on LH, while LBM was the most important variable affecting plasma FSH concentrations. The present data suggest the association between a "critical level" of body composition and the major hormonal events in boys, regardless of a cause-effect relationship. A critical level of LBM (20–23 kg) and not of TBF was attained at time of the initial hormonal changes, as well as at the time of the major changes in plasma gonadotrophins (32–35 kg).

Urinary excretion of catecholamines in healthy subjects in relation to body growth

The daily urinary excretion of dopamine (DA), noradrenaline (NA) and adrenaline (A) was investigated in 43 clinically healthy males and 37 females, aged 13 days to 37.5 years. There was a progressive increase in the daily output of each catecholamine (μg/24 h) with increasing age (P < 0.025 to < 0.001), and the opposite was seen when values were expressed as μg/g creatinine (P < 0.05 to < 0.025). However, when values were expressed as μg/m2/24 h no significant differences were disclosed among the different age groups, except for a transient rise in DA excretion in the group 1.0–4.9 years. A significant linear correlation was observed between chronological age and urinary DA (r = 0.814, P < 0.05), NA (r = 0.837, P < 0.05) and A (r = 0.839, P < 0.05), and also between body weight and each one of the catecholamines (DA: r = 0.731, P < 0.05; NA: r = 0.839, P < 0.05; A: r = 0.720, P < 0.05). However, a quadratic correlation existed between height and DA (r = 0.759, P < 0.05), NA (r = 0.853, P < 0.05) and A (r = 0.814, P < 0.05). Each one of these models could explain up to 73% of the observed variability. It is suggested that: a) the most convenient form to express the daily urinary excretion of catecholamines is as μg/m2/24 h; b) the excretion of these compounds increased at a faster rate approximately after 130.0—135.0 cm of height; c) this height-related greater increase in the output of catecholamines occurs simultaneously with previously reported increases in haemoglobin and haematocrit and significant changes in plasma concentrations of thyroid hormones; d) although the mechanisms involved in these changes remain to be clarified, it is interesting to note that they occur at a time when oxygen requirements are greater consecutive to the rapid increase of lean body tissues.

Derepression of beta-1,3-glucanases in Penicillium italicum: localization of the various enzymes and correlation with cell wall glucan mobilization and autolysis

The localization of the derepressible beta-1,3-glucanases of Penicillium italicum and the cell wall autolysis under conditions of beta-1,3-glucanase derepression (24 h in a low-glucose medium) were studied. About 15% of the total activity was secreted into the culture medium during the 24-h period and consisted of similar amounts of each of the three beta-1,3-glucanases (I, II, III) produced by this species. Treatment of derepressed mycelia with periplasmic enzyme-inactivating agents resulted in a loss of 45% of the mycelium-bound beta-1,3-glucanase. Analysis of periplasmic enzymes solubilized by 2 M NaCl or by autolysis of isolated cell walls revealed that only beta-1,3-glucanases II and III were bound to the cell wall. These two enzymes were capable of releasing in vitro reducing sugars from cell walls, whereas beta-1,3-glucanase I was not. In addition, the autolytic activity of cell walls isolated from derepressed mycelium was greater than that of cell walls isolated from repressed mycelium. The incubation of the fungus in the low-glucose medium also resulted in the in vivo mobilization of 34% of the cell wall beta-1,3-glucan, and this mobilization was fully prevented by cycloheximide, which also blocked derepression of beta-1,3-glucanases. Derepression of beta-1,3-glucanase seems to be coupled to the mobilization of cell wall glucan.

[Idiopathic primary pulmonary hemosiderosis. Report of three cases (author's transl)]

Three cases of idiopathic primary pulmonary hemosiderosis are reported. Hemosiderin was demonstrated in macrophages (siderophages) in all three cases. In one of them, isotopic examination with radioiron and in an other one, a pulmonary biopsy were performed. All the patients received corticosteroids. The first case had a good evolution in spite of five years without therapy. The second case showed a bad therapeutic response and required immunosuppressive drugs. The third case with a short follow-up is doing well. Literature is reviewed, and considerations about etiopathogeny, clinical features, roentgenographic and therapeutic aspects of the disease are made.

[The relationship between palmitoyl-coenzyme A synthetase activity and esterification of sn-glycerol 3-phosphate in rat liver mitochondria]

1. The specific activities for palmitoyl-CoA synthetase and for sn-glycerol 3-phosphate esterification, with palmitoyl-CoA generated either by the endogenous synthetase or from palmitoyl-(-)-carnitine, CoA and excess of carnitine palmitoyltransferase, were measured with rat liver mitochondria. 2. The mean specific activity of palmitoyl-CoA synthetase was approximately five- and seven-fold the rates of sn-glycerol 3-phosphate esterification from palmitate and palmitoyl-(-)-carnitine respectively. No significant correlation was found in different rats between the activities of palmitoyl-CoA synthetase and sn-glycerol 3-phosphate esterification from either acyl precursor. However, there was a significant correlation (r=0.83, P<0.001) between the rates of glycerolipid synthesis from palmitate and palmitoyl-(-)-carnitine. 3. The mean molar composition of the glycerolipid synthesized from palmitate was 58% lysophosphatidate, 31% phosphatidate and 11% neutral lipid. With palmitoyl-(-)-carnitine the equivalent values were 70, 23 and 7%, which were significantly different. 4. When palmitoyl-CoA synthetase had been inactivated by 60-70% after preincubation of mitochondria at 37 degrees C, it became rate-limiting in glycerolipid biosynthesis. Additions of 1-5mm-ATP prevented inactivation of palmitoyl-CoA synthetase. 5. Preincubation also inhibited the oxidation of palmitate, palmitoyl-CoA, palmitoyl-(-)-carnitine and malate plus glutamate. These inhibitions could not be prevented by addition of ATP. 6. Diversion of palmitoyl-CoA to form palmitoyl-(-)-carnitine did not inhibit sn-glycerol 3-phosphate esterification. 7. The palmitoyl-CoA pool synthesized by the palmitoyl-CoA synthetase was augmented by adding partially purified synthetase or carnitine palmitoyltransferase and palmitoyl-(-)-carnitine. No stimulation of palmitate incorporation into glycerolipids occurred. 8. At low concentrations of Mg(2+), palmitate, ATP and CoA the velocity with palmitoyl-CoA synthetase decreased more than that of glycerolipid synthesis from palmitate. 9. It is concluded that in the presence of optimum substrate concentrations the activity of sn-glycerol 3-phosphate acyltransferase and not of palmitoyl-CoA synthetase is rate-limiting in the synthesis of phosphatidate and lysophosphatidate in isolated rat liver mitochondria.

The effect of malnutrition on the inflammatory response as exhibited by the granuloma pouch of the rat

In the present experiments, Selye's granuloma pouch technique was applied to the study of the effect of host nutritional state on inflammation and the local tissue response. The normal response of well-nourished laboratory rats fed a diet containing 28% protein to the injection of 1% croton oil into a preformed subcutaneous air sac involved the accumulation of hemorrhagic exudate in the pouch lumen and the progressive thickening of the pouch wall, with the proliferation and maturation of fibroblasts and the eventual laying-down of collagen. In malnourished animals, fed a diet containing only 3-4% protein but adequate in all other nutrients, the above reactions were inhibited. This inhibitory effect was encountered after a relatively short period of deficiency and became more marked as the deficiency progressed. No consistent, clear-cut difference was seen in the leukocytic or neutrophilic response between the two dietary groups after the injection of 1% croton oil. A significantly higher proportion of accidental bacterial infections was found in the pouches of malnourished animals than in those of well-nourished animals. This was considered to be a possible consequence of the depressed inflammatory response in malnourished rats. The advantages of the granuloma pouch as an experimental procedure for the study of local reactions to different noxae, and the influence of malnutrition on these reactions have been discussed and suggestions for future studies presented.