Showing papers by "University of Milan published in 1974"
TL;DR: This review deals primarily with analytical and preparative isoelectric focusing (IEF) in gel media and reports the analysis of glycoproteins, immunoglobulins, lipoprotein, membrane proteins, peptides and metalloproteins to the study of biological systems.
380 citations
TL;DR: The results, obtained in 3–4-month-old rats, indicate that the kidneys of adult hypertensive rats are involved in the maintenance of hypertension, and may also initiate hypertension in young normotensive recipients.
Abstract: 1. From a single strain of Wistar rats two lines of normotensive rats (NR) and two lines of hypertensive rats (SHR) were developed by selective breeding. 2. One line of normotensive rats and one of hypertensive rats were used as recipients and the remaining two were used as donors for cross-transplantation of kidneys from hypertensive to normotensive rats and vice versa. Transplantations between the two hypertensive lines and the two normotensive ones were carried out to provide animals for control studies. 3. Normotensive recipients of kidneys from SHR developed hypertension whereas the recipients of kidneys from NR remained normotensive. The serum urea changes were equal in both groups. 4. Transplantation of normotensive kidneys reduced the blood pressure of hypertensive recipients, but transplantation of hypertensive kidneys did not alter blood pressure. The serum urea concentrations were higher in the recipients of hypertensive kidneys. These results, obtained in 3–4-month-old rats, indicate that the kidneys of adult hypertensive rats are involved in the maintenance of hypertension. 5. To evaluate whether the kidneys from hypertensive rats may also initiate hypertension, young normotensive recipients were given kidneys taken from the NR or SHR strain while the latter were still normotensive. Transplantation of kidneys from these SHR donors resulted in significantly higher blood pressure values and serum urea concentrations than transplantation of kidneys from NR donors.
344 citations
TL;DR: A single oral dose of 2–Br–α–ergocryptine (CB154) lowers considerably plasma GH levels in 7 acromegalic patients and lasts about 4–5 hrs.
Abstract: A single oral dose of 2–Br–α–ergocryptine (CB154) lowers considerably plasma GH levels in 7 acromegalic patients. The effect is present 2 hrs following the ingestion and lasts about 4–5 hrs.
185 citations
Book•
23 Jul 1974TL;DR: In 1868 His showed that the nerve cells of the spinal ganglia take their origin from the ectoderm, and more precisely from a thin band of ectoderman flanking each side of the neural plate and interposed between it and the somatic ecto-brae.
Abstract: Before 1868 it was generally thought (see, eg, Remak, 1851; Bidder and Kupffer, 1857) that the spinal ganglia arise from the mesoblast of the protoverte-brae (old term for somites) In 1868 His showed that the nerve cells of the spinal ganglia take their origin from the ectoderm, and more precisely from a thin band of ectoderm (Zwischenstrang, neural crest) flanking each side of the neural plate (Fig 1 a) and interposed between it and the somatic ectoderm (Hornblatt) On this subject His (1879) wrote in a later paper “ die spinalen Ganglien aus einem schmalen Substanzstreifen hervorgehen, welche zwischen der Medullarplatte und dem Hornblatte gelegen ist und dessen Material ich als Zwischenstrang bezeichnet habe”
145 citations
TL;DR: In this paper, the conceptual significance of the absolute electrode potential is examined starting from the recent polemic between Bockris1 and Gileadi and Stoner3 and the results of this polemic are critically reviewed and shown to be questionable.
130 citations
01 Jan 1974
TL;DR: The concept of surface acidity was originally introduced with the aim of justifying the presence of some substances formed in catalytic chemical reactions, not as a consequence of suppositions about the nature of surface active sites of solid catalysts.
Abstract: The concept of surface acidity was originally introduced with the aim of justifying the presence of some substances formed in catalytic chemical reactions, not as a consequence of suppositions about the nature of surface-active sites of solid catalysts. The formation of such substances in some reactions (e.g., cracking, isomerization, or polymerization) can be better explained by admitting the formation of reaction intermediates having the structure of a carbonium ion, which can be formed by interaction between the reacting substance (hydrocarbon) and an acid center. As an example, in the cracking of alkylaromatics catalyzed by decationated zeolites, the following reaction mechanism is generally accepted:
123 citations
TL;DR: A satisfactory correlation between the stimulatory effect on proton extrusion and that on K + uptake appears to exist even in the very first phase of treatment with FC, provided the segments are preincubated in buffers at pH 5.5.
112 citations
TL;DR: Results indicate that combined application of TRH and DA-like drugs is a better tool for investigating the secretory pattern of acromegalic patients than usual dynamic tests.
Abstract: In 29 acromegalic patients growth hormone (hGH) responses were studied following administration of synthetic TRH (200 μg, iv), l-dopa (500 mg orally), TRH following l-dopa and after administration of 2-Bromo-α-ergocryptine (CB 154, 2.5 mg orally). A majority of patients fell into two groups, those in whom growth hormone changed substantially with each test and those in whom growth hormone levels remained stable. A minority of these acromegalics responded to only one of the test situations. In the same patients, the application of the classical functional tests, viz., insulin hypoglycemia, arginine infusion and glucose loading, did not allow a distinction between “responders” and “nonresponders.” These results indicate that combined application of TRH and DA-like drugs is a better tool for investigating the secretory pattern of acromegalic patients than usual dynamic tests. Use of the anomalous hGH responses to TRH and to dopaminergic drugs in acromegaly appears to offer additional promise for fur...
110 citations
01 Jan 1974
TL;DR: The biology of Artemia is characterized by two phenomena: parthenogenesis and polyploidy, especially interesting because it is rare among animals.
Abstract: Artemia is a genus belonging to Branchiopoda Anostraca (Crustacea). Until recently this genus was considered to be comprised of a single species, Artemia salina, while now at least three specific entities are known. Artemia, commonly called the brine shrimp for its natural habitat, which is salt ponds (e.g., in African cases), salt lakes (e.g., the Great Salt Lake), and salterns of Europe, Asia, Africa, and America, is geographically widely spread, and lives gregariously. The brine shrimp can stand drought while in the embryo stage, protected by a shell—i.e., in the cyst stage, commonly referred to as the egg or permanent egg. Growing Artemia in the laboratory is now an easy task; it may be fed on yeast or, with much better results, on green unicellular algae, such as Dunaliella (Ballardin and Metalli, 1963). The life cycle (from the egg or the larva laid viviparously) includes, on the average, 4–5 weeks for the attainment of sexual maturity. The number of offspring produced by a single female, although varying widely, may reach 200–300. The biology of Artemia is characterized by two phenomena: parthenogenesis and polyploidy. The latter is especially interesting because it is rare among animals; both facts were established by the classic investigations of Brauer (1893) and of Artom (1906, 1907, 1911, 1912, 1921, 1924, 1931).
97 citations
TL;DR: The results reported herein show that the proton extrusion effect of these growth-promoting agents, in pea internode segments as well as in squash cotyledons, is accompanied by a significant increase of the negative transmembrane potential.
96 citations
TL;DR: The rate of synthesis and the turnover of cytoplasmic membrane proteins were determined in the acinar cells of guinea pig pancreas with the aim of investigating the mechanisms by which the intracellular transport of secretion products occurs.
Abstract: The rate of synthesis and the turnover of cytoplasmic membrane proteins were determined in the acinar cells of guinea pig pancreas with the aim of investigating the mechanisms by which the intracellular transport of secretion products occurs. These cells are highly specialized toward protein secretion. By means of in vitro pulse-chase experiments and in vivo double-labeling experiments, using radioactive L-leucine as the tracer, it was found that the turnover of secretory proteins is much faster than that of all membranes involved in their transport (rough and smooth microsome and zymogen granule membranes). Sodium dodecyl sulfate-polyacrylamide disk gel electrophoresis of membrane proteins revealed that in each of these membranes there is a marked heterogeneity of turnover; generally the high molecular weight polypeptides have a shorter half-life than the low molecular weight polypeptides. These data indicate that the membranes participating in the intracellular transport of secretory proteins are not synthesized concomitantly with the latter. Rather, they are probably reutilized in several successive secretory cycles. The possible relevance of these findings to other secretory systems is discussed.
TL;DR: Spontaneously hypertensive rats (SHR) have been obtained by selective inbreeding of rats with high blood pressure by concurrently developed by breeding normal blood pressure rats, and a significantly higher organ weight/body weight ratio for heart and kidneys was found in SHR.
TL;DR: It is suggested that type I are tension receptors placed in parallel with the structures supporting the transmural pressure, whereas type II receptors are in series with these structures.
TL;DR: The data show that the inhibition of cell protein synthesis in rat liver slices by ethanol is a consequence of alcohol metabolism, and suggest that this inhibition is due to acetaldehyde as well as to the shifting of the redox level in the cell.
TL;DR: It is suggested that the meaningful identification of nonsense patterns, which favors their recognition, is impaired as a consequence of left hemisphere lesions.
TL;DR: The hypothesis that the thrombus is a secondary phenomenon related to flow redistribution by collateral vessels in stenosed arteries is supported.
TL;DR: Many inheritance models of schizophrenia have been proposed, in view of its variable age at onset, variable familial occurrence and the relevant influence of a great number of environmental factors, but the real genetic predisposition to schizophrenia has not yet been experimentally verified.
Abstract: Many inheritance models of schizophrenia have been proposed, in view of its variable age at onset, variable familial occurrence and the relevant influence of a great number of environmental factors (Gottsman and Shields, 1967; Heston, 1970; Odegard, 1972). However, the real genetic predisposition to schizophrenia has not yet been experimentally verified, and genetic markers have to be looked for, i.e. we need some character, genetically determined, whose transmission is associated with schizophrenia transmission: the more polymorphous the character, the greater will be the probability of finding such associations.
TL;DR: Fusicoccin, a diterpene glucoside, is shown to induce in isolated cotyledons from germinating squash and radish seeds, an effect on cell enlargement markedly greater than that of benzyladenine and kinetin.
TL;DR: Experimental evidence has been obtained that sympathetic stimulation releases renin from the kidney independently of local vasomotor changes, suggesting that renin release is in some way dependent on neural mechanisms.
Abstract: 1 Factors involved in the neural control of renin release have been reviewed 2 Experimental evidence has been obtained that sympathetic stimulation releases renin from the kidney independently of local vasomotor changes 3 The reflex control of renin release on postural change has been established 4 The effect of diuretics on renin release has been studied and evidence of neural and non-neural mechanisms obtained 5 The effect of suprarenal aortic stenosis has been studied; the findings suggest that renin release is in some way dependent on neural mechanisms 6 The pathological significance of the neural control of renin release has been discussed
TL;DR: It is observed that the luminal PM is different in structure from the remainder of the PM, and is reminiscent of the membrane with which it is functionally associated, the membrane of the zymogen granule (ZG).
Abstract: THE acinar cells of the pancreas, as well as other exocrine protein secreting cells, are highly polarised. Release of secretion products, which occurs by exocytosis (fusion of the secretory granule membrane with the plasmalemma (PM) followed by opening at the point of fusion1, is limited to the restricted portion of the cell surface facing the secretory lumen. It is still unclear whether this selective localisation of discharge depends on the specific properties of the luminal portion of the PM. Studies carried out in other cell systems have indeed revealed that regions of the PM where specialised functions are located can exhibit distinct characteristics2–5. But in the pancreas a comparative analysis of the secretory portion of the PM relative to the non-secretory portion has never been reported. By the use of freeze-fractture we have now observed that the luminal PM is different in structure from the remainder of the PM. Rather it is reminiscent of the membrane with which it is functionally associated, the membrane of the zymogen granule (ZG).
TL;DR: The data demonstrate that both specificity and convergence regulate cardiovascular sympathetic spinal reflexes.
TL;DR: In this paper, the effects of fusicoccin on the germination of dormant, light-requiring or abscisic acid-inhibited seeds has been investigated.
Abstract: The effects of fusicoccin on the germination of dormant, light-requiring or abscisic acid-inhibited seeds has been investigated.
(1) Fusicoccin (10−6M) induces germination in dormant wheat seeds (Triticum durum cv. Cappelli; 1972 crop) and stimulates it in seeds already relieved from dormancy (1971 crop), with an effect similar to that of gibberellic acid.
(2) Fusicoccin (1.5 × 10−6M) is more active than the two phytohormones gibberellic acid and benzyladenine and than white light in stimulating light-requiring lettuce seeds (Lactuca sativa cv. Grand Rapids) to germinate. Germination of radish seeds (Raphanus sativus) is also accelerated by fusicoccin, while benzyladenine and gibberellic acid are less active in this material.
(3) Fusicoccin (1.5 × 10−5M) removes almost completely the inhibitory effect of abscisic acid on germination of radish and lettuce seeds, whereas benzyladenine (10−4M) and gibberellic acid (3 × 10−4M) remove the inhibition only partially.
The possible relationship between these results and previous information on growth by cell enlargement is discussed in terms of the mechanism of action of fusicoccin as compared with natural hormones.
TL;DR: Oral administration of l-tryptophan induced a slight rise in plasma human growth hormone (hGH) in 21 normal women and 11 normal men, suggesting that the serotoninergic system does not play a stimulatory role in hGH secretion.
Abstract: Oral administration of 70 mg/kg of l-tryptophan (TP) induced a slight rise in plasma human growth hormone (hGH) in 21 normal women and 11 normal men. In 6 subjects, intravenous injection of insulin (0.1 IU/kg) or oral TP loading showed the latter stimulus to be by far less potent in eliciting hGH release. Combined treatment with TP and insulin (0.05 IU/kg iv) in 10 subjects blunted the hGH response which followed administration of insulin alone. Oral administration of 150 mg/kg of l-hydroxytryptophan in 7 women did not induce a significant increase in plasma hGH. These data suggest that the serotoninergic system does not play a stimulatory role in hGH secretion.
TL;DR: The results might suggest the existence of a mechanism partially responsible for the ventilatory response to carbon dioxide, since the administration of acetazolamide was found to block the eflects of CO2 on the discharge of stretch receptors.
TL;DR: The effect of an increased body temperature elicited by prolonged heavy exercise at normal ambient temperature in absence of any heat stress, on the maximal aerobic power and on heart rate has been studied.
Abstract: The effect of an increased body temperature (T
r) elicited by prolonged heavy exercise at normal ambient temperature in absence of any heat stress, on the maximal aerobic power (
$$\dot V_{O_2 \max } $$
) and on heart rate (HR) has been studied. The prolonged exercise consisted in running for 1 hr on a motor driven treadmill, this leading to an average increase of T
r of 1.2° C. Oxygen consumption (
$$\dot V_{O_2 } $$
), ventilation (V
I
), HR and T
r were measured at rest and every 10 min during the prolonged exercise. Before and after this exercise indirect measurement of
$$\dot V_{O_2 \max } $$
were made. After the exercise, HR in submaximal exercise was increased, the increase being less pronounced the heavier the exercise. The HR increment was 17.5 beats/min per 1° C rise in T
r in the exercise involving an oxygen comsumption of 22 ml/kg·min and it dropped to 7.5 b/min · °C when the O2 consumption increased to 32.4 ml/kg · · min.
$$\dot V_{O_2 \max } $$
as calculated indirectly from HR values in submaximal exercise remained essentially the same before and after the treadmill run.
TL;DR: Analysis of the FECG configuration helps to elucidate the pathophysiologic mechanisms involved in FHR changes and in some instances allows a more precise evaluation of the fetal state from a clinical standpoint.
TL;DR: TUMOUR-specific transplantation antigens (TSTA), have been detected on a wide range of experimental tumour cells and elicit weak immunogenic activity, and immunological techniques, such as active immunisation, passive transfer of antibodies or adoptive transfer of immune lymphocytes, have not been entirely satisfactory.
Abstract: TUMOUR-specific transplantation antigens (TSTA), have been detected on a wide range of experimental tumour cells and elicit weak immunogenic activity As a rule, little immune response of the host to autocthonous tumours or to implanted syngeneic tumours has been detected Furthermore, immunological techniques, such as active immunisation, passive transfer of antibodies or adoptive transfer of immune lymphocytes, have not been entirely satisfactory Attempts have also been made to increase the immunogenic properties of tumour cells by in vitro enzymatic treatments1 or in vitro coating of antigenic determinants on cancer cells2
TL;DR: In this paper, the high energy gamma ray telescope flown on SAS-2 was used to observe the Crab nebula and showed that the Crab is unique among strong X-ray sources in that major component in the low energy range (1 to 10 KeV) shows little or no temporal variation.
Abstract: Electromagnetic radiation from the Crab nebula were observed, showing that the Crab is unique among strong X-ray sources in that major component in the low energy range (1 to 10 KeV) shows little or no temporal variation. Observations of the Crab above 35 MeV were made with the high energy gamma ray telescope flown on SAS-2. The detector and technique are described in detail.