Water loss by evaporation from the abdominal cavity during surgery.

During abdominal surgery of different degrees of severity the evaporative water loss from wounds and exteriorized bowels was measured by recording the rate of vapour concentration increase in a closed measuring chamber placed over the exposed abdominal cavity. In an animal experiment on 4 rabbits the excessive evaporation of water from exteriorized bowels (15 g/h) gradually decreased and stabilized at approximately 50% of the initial value after 20 min of exposure. In surgical patients the loss by evaporation from a minor incision with only slightly exposed viscera was only 2.1 +/- 0.5 g/h, while moderate incisions with partly exposed but non-exteriorized intestines showed a loss of 8.0 +/- 1.0 g/h. During major exposure with exteriorized bowels a profuse evaporation of 32.2 +/-2.9 g/h was recorded. This evaporation constitutes an additional water loss of a magnitude exceeding the total cutaneous perspiration of healthy adults at rest. Simultaneously the surface temperature of exposed bowels fell by 3.5 degrees C. The evaporative water loss from abdominal exposures is of clinical importance only in time-consuming procedures comprising exposure and exteriorization of the intestines.


[Benign chondroma of the thyroid cartilage. Apropos of a case].

Benign chondroma of the thyroid cartilage is a rare condition with a good prognosis if surgical treatment is radical. After presenting a personal case the authors briefly review the literature (Acta chir. belg., 1977, 76, 563-566.


Surgery of differentiated thyroid adenocarcinomas.

The authors present a retrospective study of 110 patients operated for adenocarcinoma of the thyroid between 1950 and 1975, and submitted to standard postoperative radiotherapy. Clinical manifestations are poor and preoperative scintigraphy display a cold tumor in 80 percent of those performed. The preoperative cytodiagnosis confirms malignancy in 90 percent of cases approximately, thereby reducing the number of complementary reoperations. In the latter the rate of complications. Increases from 25 percent to 44 percent. Three are twice as many recurrent nerve palsies and parathyroid resections in total thyroidectomies as compared to subtotal. However after radical resection local recurrences and metastases are 4 times less frequent. Under combined radio-surgical treatment 82 percent of patients are alive with a mean survival time of 9.4 years; 9 percent have died of their disease after a mean 4.1 years and 9 percent have died of an unrelated condition an average 7.2 years after. The authors favor total or near-total, i.e. extracapsular homolateral and intracapsular controlateral, thyroidectomy for follicular and papillar adenocarcinomas alike, followed by local radiotherapy and destruction by 131 iodine (Acta chir. belg., 1977,76, 553-561).


Surgical management of gastroduodenal haemorrhage.

We have presented a retrospective study of the surgical management of 299 patients bleeding from duodenal ulcer, gastric ulcer or gastritis. The overall mortality rate was 15%-5% for elective and 25% for emergency operations. The mortality increased with age and reached 50% for emergency operations in patients over the age of 70. Patients with low admission haemoglobin values, who had episodes of hypovolemic shock or who required immediate transfusions were also at risk. A Billroth I gastric resection proved to be the safest operative procedure. Based on our results, we are supporting a program calculated to reduce the mortality attending gastroduodenal bleeding, especially in those patients requiring an emergency operation. The basic principles of this program are constant observation, prompt diagnosis and early surgical intervention.


Traumatic diaphragmatic hernia. Report of 50 cases.

The writers report a clinical series of 50 patients with traumatic diaphragmatic hernia. There were 36 hernias on the left side and 14 on the right. Stab or bullet wound was the cause of the hernia in 27 cases. The other 23 cases were due to traffic accidents or other blunt injuries. Immediate operative repair was done in 30 cases; in 20 cases the operation was carried out after a time interval of 11.5 years post trauma on an average. Plain chest X-ray, barium meal or enema and pneumoperitoneum were the most valuable diagnostic tools. Visceral injuries were discovered in 53% of cases caused by traffic accidents. The omentum, stomach, colon and spleen were the organs most frequently herniated. In two cases perforation of the stomach occurred before the operation. There were three cases of pericardial rupture associated with the diaphragmatic hernia in the series. The repair was done via thoracotomy in 28 cases, via laparotomy in 4 cases; and both thoracotomy and laparotomy were carried out in 18 cases. The hospital mortality was 2%. One of the patients died of peritonitis and renal failure following perforation of the stomach and intestines on the 9th postoperative day. Recurrence of the hernia occurred twice in one case. Re-examination revealed striction of the diaphragmatic movement in 11 cases. The clinical features, diagnosis and operative treatment are discussed.


[Surgical management of acute deep thrombosis].

By means of existing literature, the author presents a survey of the present considerations regarding deep venous thrombosis. The second part deals with the author's own experience with 20 patients treated surgically by him for deep venous thrombosis of the lower limbs. His results prove to be excellent with just over 1/2 and satisfactory to excellent with almost 3/4 of the patients (Acta chir. belg., 1977, 76, 567-574).


Critical evaluation of several years' activity aimed at the diagnosis of asymptomatic diabetes in the Province of Florence. Revision of method.

The authors have based this critical evaluation on the methods at present adopted for mass screening for symptomatic diabetes in a group of 39,405 subjects, in full working activity. The results obtained from these tests confirm the social importance of this illness in the active population. However, the authors suggest that the glycosuria test be abandoned as the primary discriminating criterium and suggest that blood glucose assay in specimens drawn two hours after a standard glucose and load (50 g as proposed by WHO) and the singling out of potential diabetic individuals by reason of their family and physiological background be adopted for this purpose. The relationship between diabetes, obesity, dysmetabolism and cardiovascular alterations lead us to stress once more the importance of primary prevention, aimed at correcting the eating habits and life style of patients with a potential predisposition to the illness.


Identification of tryptophan metabolites in the healthy epidermis of diabetics.

The urinary excretion of metabolites of the tryptophan leads to niacin pathway after an L-tryptophan load in patients with potential and latent diabetes, and in a third of those with chemical diabetes, was normal. In the remaining subjects with chemical diabetes and in those with clinical diabetes it was altered and characterized by an increase of xanthurenic acid and by a reduction of kynurenines and 3-hydroxyanthranilic acid. The thin-layer chromatographic pattern of tryptophan metabolites in the epidermis of patients with potential, latent, chemical, clinical diabetes was characterized by the kynurenine pathway metabolites that were also present in the epidermis of healthy subjects. Morevoer, the above pattern was characterized by the appearance of 5-hydroxytrptamine, and in patients with chemical and clinical diabetes by the appearance of xanthurenic acid.


Effect of diphenylhydantoin on patterns of insulin secretion in obese subjects.

The effect of short-term treatment with diphenylhydantoin (DPH) on the insulin secretion patterns during OGTT and on the daily insulin profile was studied in obese patients. DPH treatment for 3 days with a dose of 300 mg/die (100 mg, 3 times daily) significantly decreased the insulin release after glucose ingestion, but did not alter the basal insulin level. No effect on the fasting glucose concentration as well as on the glucose profiles during OGTT was observed after short-term DPH treatment. A smaller decrease of plasma free fatty acid concentration during OGTT performed after DPH administration confirmed the inhibitory effect of the drug on insulin release. Short-term DPH treatment was also shown to decrease markedly the postpradial insulin release in obese patients. No difference was noted between plasma 11-OHCS and serum HGH concentrations during OGTT before and after DPH treatment. The possible therapeutic role of DPH in obesity is discussed.


Insulin release in hyperuricemic patients.

The insulin response to oral glucose and to i.v tolbutamide was stuied in a group of hyperuricemic subjects and in a group of weight-matched controls. Glucose tolerance was impaired only in obese hyperuricemic subjects. Insulin response to oral glucose was enhanced in hyperuricemic subjects. Tolbutamide gave rise to a sharp increase in IRI levels already 2 min after the injection and this rise was significantly higher in hyperuricemic subjects than in controls. The same result was observed also after i.v. fructose. The interpretation of these data is not easy. Uric acid plasma level and obesity do not seem to be directly involved because an abnormal IRI response has been observed also after a rapid fall in uric acid plasma level after allopurinol treatment and is evident also in lean subjects. In our opinion the problem is more complex and must be considered from the point of view of a change involving carbohydrate as well as purine metabolism.


A precise radioimmunochemical method for determination of free insulin and insulin bound to serum proteins, including antibodies.

Polyethyleneglycol precipitation of insulin antibodies and insulin-antibody complexes is associated with co-precipitation of part of the free insulin. The recovery of free insulin was found to depend both on the quantity and quality of the antibodies and varied between 94% and 40%. Thus, the concentrations of free and total insulin may be lowered up to 2.5-fold in different sera containing endogenous antibodies. A critical evaluation of these results led to the development of a more reliable method for the assay of total and free insulin, based on individual radioisotopic determinations of the recovery of insulin extracted by PEG. The recovery of insulin added to sera containing antibodies as determined by the present method is within the range of 100 +/1 2.5%. In sera not containing antibodies total insulin concentration was found to be up to 5-times higher than that of IRI and to reach values above 250 muU/ml whereas whereas indirect IRI (i-IRI) may increase over 25 times with age.


On the nature of syndrome delineation.

Perhaps half of all patients with multiple abnormalities have known, recognized syndromes. The other half represent unknown entities that need to be further delineated. The significance of syndrome delineation cannot be overestimated. As an unknown syndrome becomes delineated, its phenotypic spectrum, its natural history, and its risk of recurrence become known, allowing for better patient care and family counseling. The process of syndrome delineation is discussed in terms of unknown genesis syndromes of the previsionally-unique and recurrent-pattern types, and known-genesis syndromes of the pedigree, chromosomal, biochemical-defect, and environmentally-induced types. Several special syndrome categories are defined, including the chance syndrome, variant additive syndrome, association syndrome, exceptional chromosomal syndrome, and exceptional monogenic syndrome. Finally, a population definition of a syndrome is developed.


Type A2 brachydactily: report of a new family.

A new family with the A2 type brachydactily is described. It is the first one observed in Italy and the sixth of the world literature. Brachymesophalangy of index fingers and/or second toes is the typical osseous malformation which was present in 14 individuals from 4 generations. The defect is transmitted by an autosomal dominant gene with high penetrance and variable expressivity.


Structural analysis of the ridge count data of Australian Europeans using multivariate analysis.

Multivariate analyses are used to study the structural patterns of ridge counts of fingers. There is a significant difference between the ridge counts of two hands, chiefly due to the first and fourth fingers. There is asymmetry in the covariance matrix of the ridge counts. The correlations between fingers are significant and the decrease in correlation with increasing distance between fingers is not significant.


Partial deletion of 1q, following a pericentric inversion, in a boy with multiple minor morphologic anomalies and mental retardation.

In a 3 3/4 year old boy with mental and physical retardation, a chromosome analysis from lymphocyte cultures revealed a partial deletion of chromosome 1q following a pericentric inversion. The chromosomes of the parents were normal. The clinical picture of the patient included the following characteristics: prominent occiput, small chin, deep-seated and dysplastic ears, abnormal vortices of the hair, divided tip of the tongue, high palate, small finger and toe nails, inguinal hernia both sides, undescended but normal sized testes, hypotonic musculature and overextensible joints, retardation of ossification in the left hand by 6-12 months, slight osteoporosis, EQ approximately 0.5.


Triple mosaicism with two autosomally unbalanced cell lines in a phenotypically normal oligospermic man.

The chromosomal analysis of a phenotypically normal, moderately oligospermic man is reported. He presented a triple mosaic complement with two autosomally unbalanced cell lines. The cytogenetic results are discussed, and the importance of such investigations in men attending infertility clinics emphasized.


Dermatoglyphics study of the Shompen of Great Nicobar.

The finger and palm prints of 20 male and 18 female Shompen of Great Nicobar were examined. The distribution of finger patterns and of palmar main line formulae showed significant sex differences. Main line index was higher on right than on left hands in both sexes. Axial triradius t was most frequently observed on both hands in the two sexes.


[Infant mortality: heredity and environment].

An analysis of familial liability to infant mortality is presented. Heritability estimates for three periods of the demographic evolution of an isolated population (Isle-aux-Coudres, Quebec) are provided. Average heritability is on the order of 27%. This is interpreted as being partly due to sibs common environment and partly to dominance variance effects of genes. The real additive variance of the familial liability might well be nil.


Genetic aspects in myasthenia gravis. A family study of 264 Finnish patients.

The prevalence of myasthenia gravis (MG) in Finland was 264 patients per 4.7 mil. inhabitants or 0.006 per cent. Of these 264 patients 19 (17 females and 2 males) were familial cases from eight families. MG occurred in 11 siblings, in two mothers and their child, and in six cousins. MG was not found in three or more successive generations. The familial MG resembled the non-familial disease. No concordance of MG among five sets of twins was found. The birth localities of gradparents seemed to have a slight tendency for accumulation, but no definite clusters were formed. Consanguinity between parents was found in seven of 192 families. An increased frequency of collagen or thyroid diseases was found both in patients and parents, but they were not specially accumulated to the relatives of familial myasthenics. Neither autosomal nor sex-linked, dominant or recessive, nor some other uniform mode of inheritance in MG could be confirmed. Some genetical predisposition to MG seems to exist, but it may be common to autoimmunity as a whole.


The cerebrovascular permeability to protein after bicuculline and amphetamine administration in spontaneously hypertensive rats. Evidence for increased resistance of pressure-induced blood-brain barrier dysfunction.

Hemodynamic and morphometric studies on spontaneously hypertensive rats (SHR) have suggested that the lumen to wall ratio of the resistance vessels is decreased due to hypertrophy of the media. As the tension in the vessel wall increases with the pressure and the radius and decreases with the vessel wall thickness, such vessels would be expected to withstand higher pressure than vessels of normotensive rats (NR) unless local wall defects were present. Bicuculline-induced epileptic activity and amphetamine intoxication, two conditions with cerebral vasodilatation and high blood pressure, give rise to extensive protein leakage in the brain of NR. Consistent with the hypothesis presented above, less protein leakage occurred in brains of SHR than in brains of NR after amphetamine and bicuculline administration.


Cluster headache associated with primary hyperlipidemia.

Two brothers suffering from cluster headache of the chronic variant as well as hyperlipidemia are described. The mother very likely suffered from the same combination. Eleven consecutive cases of cluster headache were studied for lipid abnormalities. Among five patients of the intermittent type, one suffereed from xantelasmata but had normal blood lipids. Among six patients of the chronic variant two had essential hyperlipidemia type IV. An etiological relationship between some cases of cluster headache and hyperlipidemia is therefore suggested.


Cell proliferation in bone marrow and thymus following soft tissue damage.

Earlier experiments by the author have shown that an increase in mitosis in bone marrow and thymus occurs after fractures and bone marrow aspiration. In this paper it is shown that soft tissue damage causes a statistically certain increase in mitosis both in bone marrow and thymus after 1 day. A possible explanation for this is liberation of a mitogenic kinin.


The modulus of elasticity and flexural strength of some acrylic bone cements.

The modulus of elasticity and flexural strength were measured for three bone cements, CMW Bone Cement, Surgical Simplex, and Palacos R. with various additions and prepared as in actual use. A distinct afterpolymerization was demonstrated in all three brands. The addition of blood lowered the E-modulus wheras radio-opaque media seemed to render them somewhat stiffer. The rupture values demonstrated the inhomogeneity of the final product in all three brands. The possible clinical significance of the findings is discussed.


Changes in bone formation during immobilization and development of experimental osteoarthritis.

The effect of immobilization on bone formation in the knee and hip was studied by means of oxytetracycline. One leg of 11 growing and 13 adult rabbits was immobilized so that the knee was held in extension but the hip was free. In the knee, degenerative changes developed consistently with a severity proportional to the length of the immobilization time. In most of the rabbits given oxytetracycline 1-13 days before they were killed considerably more oxytetracycline was incorporated in the bone in the immobilized knee region and slightly more in the hip region of the same leg than in the corresponding areas of the other leg. This indicates an increased turnover of bone tissue in the immobilized leg compared with the non-immobilized leg.


Arthroplasty of the elbow using J-K membrane. An analysis of 31 cases.

A study of the end results of arthroplasty of the elbow has been made; 31 cases were evaluated clinically and roentgenographically an average of 19 years after operation. The arthroplasty was performed with a minimum of bone resection using chromicized fascia lata (J-K membrane) as an interposition. The maximum range of motion was regained within 3 months and was maintained during the follow-up period. No patient in this series suffered from pain or instability of the joint though radiological signs of osteoarthritis were common.


Spinal nerve block. A diagnostic test in sciatica.

The cause of sciatica has been studied by blocking spinal nerves of the lumbosacral plexus in intervertebral foramina. The nerve, which is singled out with the aid of an image intensifier, is injected with 1 ml of 1 per cent Xylocain. If the Xylocain injection eliminates the sciatic pain, the surgeon may be confident that a true nerve-root compression is involved, and he can then explore as far as he finds necessary. The correlation between the site of compression and the level indicated by the test was confirmed by operation in 19 patients.


Infantile and adolescent idiopathic scoliosis in the same individual.

A patient with an infantile, resolving type of idiopathic scoliosis is presented. By the age of 10 years, 4 years after complete spontaneous correction, the girl had developed a structural, progressive idiopathic scoliosis to the opposite side.


The surgical technique for hindquarter amputation. A report of 19 cases.

The surgical technique for hindquarter amputation is described in a step-by-step manner. Since 1955 we have performed 19 such operations for eradication of malignant bone and soft tissue tumors in the pelvic, hip and upper thigh regions. Three hindquarter amputations were performed for local recurrence following initial wide excision. The overall 5-year survival rate for our 19 patients was 42.1 per cent. Malignant soft tissue tumors appear to have a much better 5-year survival rate than malignant bone tumors (60 per cent vs. 22.2 percent). We feel that surgery is still the treatment of choice. However, in the presence of proper indications, chemotherapy and radiotherapy should be added to surgery in order to prolong survival time and save lives.


A study of radiographic variations of the hip joint.

Anteroposterior radiographs of the pelvis were studied in 920 patients free of hip joint diseases. The average joint space was between 3 and 4 mm in width. Narrowing of the superior joint space was seen in 13 percent of the hips and may represent the earliest finding in osteoarthritis. It was noted as early as the second and third decade in some patients. Other changes noted were narrowing of the lateral joint space, uniform narrowing of the space, an irregular joint space and tilting of the femoral head on the neck.


Subcapital fractures of the femur treated with two thin Smith-Petersen nails.

The results of treatment of 71 patients with subcapital fractures of the femur, fixed with two thin Smith-Petersen nails, are presented, after a follow-up time of between 2 and 4 years. Excellent results of treatment were achieved in 39 out of 60 cases and good results in 11 cases. Six cases of ischemic necrosis of the femoral head were recorded, and there were four cases with pseudarthrosis of the femoral neck, one developed because of postoperative infection and three were attributed to an imperfect operative technique. The method is recommended for subcaptial femoral neck fractures amenable to closed reduction and internal fixation. Pseudarthrosis may be prevented by good reduction of the fracture and a careful nailing technique.


Total hip replacement in ankylosing spondylitis.

Eighteen total hip replacements were performed in 10 patients with ankylosing spondylitis. The mean observation time was 3.8 years. Seven hips had been operated on before total hip replacement (THR); 6 Were ankylotic before THR. The results as regards pain relief and increased walking distance were good. All hips improved in mobility after THR and this improvement was maintained during the observation time. Six of the 10 patients went back to full-time work. The differences between patients with ankylosing spondylitis and rheumatoid arthritis, as regards indications for and rehabilitation after THR, are discussed.


Tuberculosis as a late complication of total hip replacement.

A case of tuberculosis developing in a hip joint which had undergone total prosthetic replacement arthroplasty 7 years previously is described. The patient had no manifestation of active systemic tuberculosis although calcified mesenteric nodes were noted on abdominal X-ray. It is assumed that hip joint infection occurred during a bacteraemia following activation of a latent tuberculous focus in the mesenteric lymph nodes.


Osteochondritis dissecans of the knee.

A case of osteochondritis dissecans of the knee is described in which the site of the lesion, on the supero-medial aspect of the lateral femoral condyle, is unique. This case supports the theory that direct recurrent minor trauma causes osteochondral fractures which remain ununited producing the characteristic lesion.


Osteoarthrosis following insufficiency of the cruciate ligaments in man. A clinical study.

Based on a series of 48 patients with old untreated ruptures of one or both cruciate ligaments, the development of osteoarthrotic changes was demonstrated by radiography and at operation. The changes were similar to those seen in animal experiments and developed in the same sequence. Osteophytes occurred in knees with anterior cruciate insufficiency after about 2 years; significant osteoarthrotic changes occurred after longer periods, and particularly in knees with damage to both cruciate ligaments.


The hallux and rheumatiod arthritis.

The purpose of this report is to consider involvement of the great toe by rheumatoid arthritis, defining significant deformities, describing clinical patterns and discussing the pathomechanics of these findings, in what is an ongoing disease. 200 consecutive patients admitted to hospital with classical or definite rheumatoid arthritis were screened for pain or deformity of the great toe. Feet that had undergone previous surgery or had other underlying pathology were excluded from the series. 194 feef were found to have halluceal involvement. Although hallux valgus was the commonest deformity it was found in combination with other significant deformities in many cases. Hallux rigidus was an important lesion in this series as was interphalangeal hyperextension. Other important lesions encountered were metatarsus primus varus and medial rotation of the toe; their relationship to hallux valgus is discussed.


[Antimicrobial and surgical treatment of tonsils. Bacteriological and histological data collected on 44 tonsillectomized children].

The tonsils of 44 operated children were submitted to bacteriological and histological examination. 22 children were given an oral penicillin during 5 days before tonsilectomy. Histological data and bacteriological cultures of pharyngeal exsudate and tonsillar material were very similar in the two groups of treated and non treated patients. These data suggest that, when preventive penicillinic treatment is given, it is worthy to consider the dose, the lasting and the route of administration of the prophylactic antibiotic therapy. Its unreliable activity, and the danger of bacteriemy at the moment of the operation plead for an adequate per-operative antibiotherapy.


Motor units activity of dog postural muscles in standing position.

Discharges of separate motor units (MU) of dog muscles are studied in standing position and under conditions of passive stretch and shortening of the muscles. In standing position the average discharge frequency in the fore leg extensors is found to be of the order of 25-30 imp/s. A doublet pattern of firing and recruitment and derecruitment of single MUs over different periods of time is observed. The transient processes of the instantaneous discharge frequency of single MUs are observed upon passive stretch and shortening of the muscles. Different types of transient processes are described, both during recruitment and derecruitment in standing-position, and during the passive changes in muscle length. A dependence is found of the transient processes in the velocity of the passive changes in length and the probably physiological mechanisms of these phenomena are discussed.


Significance of different feedbacks for the transient processes of the discharges of single motor units during step-like voluntary movements.

Studies are made of the transient processes of the discharges of single tonic low-threshold and phasic high-threshold motor units (MUs) during step-like voluntary movements performed in case of visual feedback by the result of the movement and in case of artificial auditory feedback by the sound of the MU impulses, as well as in cases of absence of exteroceptive feedback. The studies comprise isometric and isotonic flexion and extension in the elbow joint, the MUs studied being from m. biceps brachii. The previously observed differences of the transient processes in tonic and phasic MUs are found to exist not only during movements taking place under visual control but also under other conditions studied. Under conditions of articicial auditory feedback the subjects may or may not use this feedback for control of the motor response.


Firing of motor units upon flexion reflex in dogs.

A study is made of the changes in the transient processes of the instantaneous frequency of the discharges of preactive motor units (MU) in dog m. gastrocnemius and m. semitendinosus under conditions of flexion reflex caused by electrical stimulation. Surface electrodes are used to record the activity of the single MUs. Five types of transient processes are described mainly depending on the intensity of stimulation. A stimulus with weaker intensity leads to an increase in the instantaneous frequency of the discharges 60 ms after its application, followed by a decrease and later by a new increase. Inhibition phenomena are observed in cases of higher intensity. The interpretation of these data takes into consideration the mechanisms of recurrent inhibition and the role of some of the afferent inputs of the flexion reflex.


Modulation of the slow potentials frequency of the stomach under the effect of the intrinsic nervous system.

Chronic and in situ experiments on dogs have been carried out involving stomach transection at the level of incisura angularis. The electrical acivity of the muscle wall of the two stomach segments was recorded by silver bipolar ball-shaped electrodes. Two electrodes for myogenic stimulation were implanted in the distal segment. Transection caused dissociation of the slow potentials rhythm in both stomach segments: slow potentials frequency in the distal segment is considerably reduced. Infusion of cholino- and adreno-mimetics in the artery supplying the distal segment causes increase of the frequency of the slow potentials in the distal segment to reach the frequency of the proximal segment. Bocking of the intrinsic nervous system eliminates these responses. On the background myogenic stimulation induces increased frequency of the rhythm in the distal segment. It is concluded that the intrinsic nervous system plays a role in maintaining slow potentials frequency in the stomach at a higher level than the level characteristic of this stomach segment.


Effects of Serotonin and Histamine on the contractile activity of smooth-muscle strips of sheep complex stomach.

The effect of histamine and serotonin is studied on strips of the two smooth-muscle layers from the different sections of the complex stomach. Histamine in concentration of 10(-9) to 10(-4) g/ml has no visible effect on preparations from the rumen and reticulum. In strips from the omasum as well as from the proximal and antral regions of the abomasum inhibitory effect is observed mainly with respect to the spontaneous phasic activity of the strips. Serotonin in concentrations of 10(-8) to 10(-4) g/ml has an excitatory effect in almost all preparations studied. Of the forestomach strips it is mostpronouced in rumen strips. The effect consists in an increase of the tone of the preparations. In the proximal region of the abomasum is effect also consists in a rise of the tone, while in strips from the antral region it causes a rise in the amplitude and frequency of the phasic contractions. Serotonin in the concentrations tested has an inhibitory effect only on omasum preparations.


Changes of certain cardio-vascular parameters and the sympathetic nervous activity upon afferent vagal stimulation in cats.

Afferent stimulation of the cervical vagus in cats for 5 s upon bilateral vagotomy reduces systemic blood pressure by 15--50 percent. The maximum of this depressor reaction occurs 10--15 s after the beginning of the stimulation, its latency being 2--3 s. The decrease in the blood pressure is preceded by inhibition of the electrical activity of some preganglionic (n. splanchnicus) and postganglionic (n. cardiacus and n. renalis) sympathetic nerves with 100--200 ms latency. During the maximum pressure decrease activity appears in the above-mentioned nerves, afterwards the pressure begins to rise until its normalization. In addition to the decrease in systemic blood pressure changes are also observed in other cardio-vascular parameters, namely, decrease in the pressure in the left ventricle, decrease in the contractile force of the heart (dp/dt max) and of the heart rate.


Localization of the disappearance of a light target during tracking eye movements. II.

A light target moving with constant velocity and disappearing at a place determined by the experimenter, is presented to the subjects who track it visually and determine the locus of its disappearance with respect to a scale mounted on the screen. The result is that the disappearance of the target is systematically mislocated in the direction of the eye movement. The value of the mislocation depends on the target intensity. Under different experimental conditions the subjects localize target disappearance by steady fixation of the eyes. The resulting mislocation has entirely different characteristics compared with the first conditions. The theory that the phenomenon of mislocation is due only to wgnal latency in the visual pathways is rejected. A hypothesis is proposed concerning the participation of psychological factors in the process of localization.


Visual extrapolation of a line segment to the point of its intersection with a straight line. II.

The article describes three experiments to study visual extrapolation of a line segment to the point of its intersection with a straight line. Eye movements are shown to play no significant role in solving problems involving visual spatial extrapolation. It is also indicated that systematic mislocations of the point of intersection sought in cases of acute angles are preserved even when the motor response is substituted by verbal estimation. When the test line segment is presented for a very short time (tau =20 ms), the estimations of the subjects manifest great individual differences and considerable dispersion. The results of the experiments show that the ability of visual extrapolation is influenced by different and numerous factors and this ability does not reflect only the functioning of simple detectors for direction in the visual system.


Estimation of duration of an array of time interval and of its separate elements.

It is shown that when a human subject estimates verbally the duration of an array consisting of three intervals - two light intervals divided by a dark one - considerable underestimation is observed compared with estimates of the same duration in the control experiment. In case of separate estimation of the three intervals composing the array the sum of the estimates is much more precise even compared with estimates in the control. Perhaps in this case the system for time intervals estimation operates with two "internal clocks", each of which reads the duration of the dark and of the light intervals. In estimating the array of three intervals the subjects estimate the total array and they do not summate their separate estimations. It may be assumed that the system uses only one "clock" for measuring the duration of the total array.


Shifting of the brain stem physiological impedance after ovariectomy and oestradiol implantation in rabbits.

Experiments were carried out on female rabbits with electrodes implanted chronically into the midbrain, dorsal hippocampus and the cerebral cortex. Physiological impedance of the brain stem, i.e. the lowest energy of trains of electric impulses stimulating the midbrain modulated through a feedback by the hippocampal theta rhythm and maintaining EEG arousal pattern, served as a measure of excitability of the brain stem reticular formation. After ovariectomy performed in 12 female rabbits, a rise in the brain stem physiological impedance was observed in relation to control measurements -- by 84.8%, on the average. In 8 ovariectomized female rabbits the physiological impedance decreased by 47.4% after subcutaneous implantation of oestradiol benzoate tablets. After removal of the implanted tablets the impedance increased by a mean value of 100.1% in all the female rabbits.


Tissue catecholamine concentrations in spontaneously hypertensive rats.

Tissue concentrations of noradrenaline (NA), dopamine (DA) and adrenaline (A) were compared in spontaneously hypertensive (SHR) and normotensive (NCR) rats, aged 1, 3, 8, 14 and 24 weeks The organs analyzed included the brain, subdivided into prosencephalon and rhombencephalon, heart, adrenal glands and kidney. Brain catecholamines were significantly lower in SHR than in NCR, and the difference appeared already at the age of 3 weeks. Concomitant increase was found in the adrenal NA and A concentrations of the SHR. Concentration of NA in the heart decreased in the SHR following onset of hypertension. It is concluded that the diminished NA, DA and A concentrations in the brain as well as the augmented adrenal NA and A levels in the SHR may be causally related to the development of hypertension, while the heart NA level reflects the secondary, hypertension -- related changes.


The effect of noise and vibration on motor activity and behavioral tests in rats.

The investigations were carried out on 80 Albino rats. It was found that a single exposure to noise alone or noise coupled with vibratio;n increase locomotor and exploratory activities of the rats. On the other hand, repeated exposures to noise and low frequency vibration failed to change the exploratory activity and behavioral tests of rats. No significant differences were found between the effects of noise alone and associated with vibration.


THe dynamics of erythropoiesis inhibition in posttransfusion polycythaemia in the rat.

The dynamics of erythropoiesis inhibition as the consequence of polycythaemia induced in rats by four to six transfusions of homologous erythrocytes was studied in detail. It was found, that, in rats with polycythaemia elicited by two transfusions of erythrocytes, erythropoiesis inhibition occurs 67h after the first transfusion and it is most pronounced in the period between 115-187 h. The hemopoietic system is not completely free from the inhibitory influence of polycythaemia up to 283 h after the first transfusion. Maintenance of a state of polycythaemia for 17 days by repeated transfusions strongly and durably inhibits the haemopoietic system. The red blood cell system remained for this whole period under the inhibitory effect.


Seasonal changes of the structure and function of prolactin cells in the pituitary gland of Vipera berus (L.).

A selective staining by the indirect immunofluorescence method has been used for prolactin cells (PRL-cells) in the pituitary gland of Vipera berus (L.). The PRL-cells showed significant seasonal changes as judged by their morphological features, their number and localization in the pars distails. In the functional cycle of the cells 4 periods could be distinguished: 1 -- spring (March --May), when the release of the hormone as well as its increasing accumulation were observed; 2 -- early summer (June -- July), when the accumulation of the hormone in the gland reached the maximum and prevailed the release; 3 -- late summer (August), when was observed a rapid PRL release with a simultaneous exhaustion of cell reserves: 4 -- autumn (September), was characterized by small PRL content in the cells and its inconsiderable release.


Changes in erythropoietic activity of the rat plasma in the course of posttransfusion polycythaemia.

The aim of this study was to determine the erythropoietic activity of the plasma of polycythaemic rats and of one of its protein fractions playing a role in erythropoiesis regulation. The erythropoietin activity and that of the erythropoiesis inhibitor varied in the examined plasma samples at definite time periods after induction of polycythaemia. It was demonstrated that the most suitable time of plasma collection for the inhibitor investigation is the period between 115 and 187 h after the first transfusion, and that in some cases separation of this factor from erythropoietin present simultaneously in the plasma is indispensable in order to reveal the inhibitory activity. The erythropoiesis inhibitor administered jointly with erythropoietin was found to exert no influence on erythropoiesis either in normal or in polycythaemic recipients of the tested plasma.


Some aspects of obtaining rat semen by electroejaculation method.

Some physical conditions of the electroejaculation method elaborated by Scott and Dziuk and Kalasiewicz and Wolański have been modyfied. A positive result of ejaculation was obtained in 92.6% of the rats examined when the electric stimuli was applied with the energy of 4--7 times lower than that used by the cited authors. The presented method may prove useful in cases when the same animal is to be used repeatedly.


The effect of short term thermal stress on the heart and respiration rates of conscious and anaesthetized chickens.

Heart and respiration rates were measured in eight 6-week-old, White Rock chicks at different ambient temperatures: 24--26 degrees C (neutral), 6.5--8.5 degrees C (low) and 3,95--43.5 degrees C (high). The animals were exposed to these temperatures for 10 min. In both groups the low ambient temperature did not influence the respiration rate, whereas the high temperature caused a significant increase of the respiration rates both in the conscious and anaesthetized birds. In both groups no significant changes in the heart rate at different temperatures were found. Statistically significant differences in the heart and respiration rates between the conscious and anaesthetized chickens were noted only at the low environmental temperature.


Application of a tape recorder ZK-246 for four-channel recording of some physiological phenomena.

A method of simultaneous recording of our physiological phenomena on a magnetic tape was described. A block construction of a transducer enabling four-channel record on a two channel, stereophonic tape recorder has been presented.


Further studies on the influence of ions on the muscle fibre resting potential in the cricket Acheta domesticus.

Experiments were carried out on tergosternal muscle fibres of the house cricket Acheta domesticus. Conventional microelectrode methods were used. All the investigated fibres depolarized with time (0, 60, 120 min) in statistically significant manner. Replacing CL- in the physiological solution by carbonate prevents this depolarization. Citrate anions added to the bath depolarize the fibers. Acetate does not change the resting potential. Increasing osmolarity by adding 100 or 200 mM saccharose exerts no significant influence on the level of the resting potential. Lowering the level of sodium ions leads to a slight but significant depolarization. The present work confirmed the opinion that skeletal muscle fibers of Acheta domesticus are at rest multiionic electrodes.


Substance P isolated from bovine hypothalamus: amino acid composition.

Using the method of Chang and Leeman for isolation the sialogogic undecapeptide from bovine hypothalamus partly purified Substance P was obtained. The final steps of purification were omitted to prevent losing of other peptides possessing biological activity of Substance P. The qualitative and quantitative content of amino acids in the hypothalamic extract was determined and fourteen amino acids were found. Four of them were not present in the sialogogic undecapeptide or neurotensin. It can be concluded that in the hypothalamic tissue apart from sialogogic undecapeptide and neurotensin, there are other peptides related to these two.


Dependence of vitamin B12 levels on the growth rate of cells cultured in vitro.

Vitamin B12 content has been determined in different kinds of cells grown in vitro and in the culture media. The results indicate a dependence of the vitamin levels on the growth rate and growth characteristics.


A new approach to the direct measurement of tension within the outer layers of the left ventricular wall of the dog heart.

Tension was measured within the outer layers of the left ventricular wall of the dog heart with the strain-gauge force transducer coupled to the wall at diastole without the distortion of its geometry. The transducer still attached to the wall or its segments was calibrated with the passive forces and with the known active force on the isolated, beating heart. The differences between the readings of the transducer and the calibrating force did not exceed 20% and in most experiments they were much smaller. The transducer was practically insensitive to the force perpendicular to the measured one. The proposed method seems to be more reliable than the formerly used by these and other authors.


Distribution of oxytocic and vasopressor activity in the rat diencephalon.

The oxytocic and vasopressor activity was studied in five 1 mm thick, horizontal sections of the rat diencephalon. The diencephalon was cut frozen in dry ice. The sections obtained from identical parts of the diencephalon of 10 rats were homogenized together in 0.9% NaCl solution acidified with glacial acetic acid. The homogenate was heated to 100 degrees C for 5 min and centrifuged. The oxytocic activity of extracts was determined in vitro by, the method of Holton using the rat myometrium. The vasopressor activity was determined in vivo recording blood pressure in the carotid artery of rat by the method of Dekańaski. Oxytocic activity was found in all five sections of diencephalon and vasopressor activity in only two sections. The first section included the median eminence and ventral hypothalamus together with the supraoptic nucleus, the second section included the the dorsal hypothalamus with paraventricular nucleus, the third section--the ventral thalamus, the fourth section--the middle part of thalamus, the fifth section--the dorsal thalamus.


Effect of exercise on glycogen level in muscles and liver in rats.

The effect of exercise of glycogen level in skeletal muscles and liver was studied in Wistar rats. The previously untrained animals were subjected to one-time exercise in form of swimming in water at 32 degrees C for 10, 20 and 30 min. The glycogen level in the muscles (in g per 100 g of tissue) fell down during the first 10 minutes of the exercise by a mean value of 0.45 g. During the following 10 minutes the decrease was smaller amounting on the average to 0.1 g. After 30 min the glycogen level in the muscles was about 0.1 g/100 g of tissue. Respective falls of glycogen level in the liver were on the average 0.99 g and 0.40 g/100 g of tissue. After 30 min of exercise the glycogen level in the liver was 1.2 g/100 g of tissue. The fall of glycogen level in the muscles was similar at all times during exercise in all animals, but in the liver fairly significant differences were observed in the first 10 min between individual groups of rats. Later on during exercise the differences in the liver glycogen falls decreased.


Absorption of amino acids from the small bowel and their activity in releasing of cholecystokinin.

The ability of essential and nonessential amino acids to stimulate the release of CCK was investigated in dogs using a bioassay procedure based on the perfusion of intestinal Thiry-Vella loops and determing the increase of pancreatic protein response as well as the potentiation of pancreatin bicarbonate secretion by a background doses of secretin (0.2 units/kg/h). All essential amino acids, except threonine, and all nonessential amino acids except cysteine were effective in CCK release when perfused in equimolar concentration (50-mM) through the intestinal loop. The peak pancreatic protein in response to tryptophan was about 89% of the maximal response to exogenous CCK in a dose of 25 units/kg/h. These data have also indicated that tryptophan and phenyloalanine are able to release small amounts of secretin.


Effect of dehydration on renal blood flow in dog.

The effect of dehydration on intrarenal blood flow was investigated in 11 dogs, using polarographic determination of H2-gas desaturation for measuring local blood flow in inner cortex (ICF) and outer cortex (OCF). Dehydration was induced by 48 h water deprivation +2-300 mg ethacrynic acid (EA) per os the day before the experiment. Compared to a control group (n=9) ICF was markedly reduced to 2.40 +/- 0.47 ml/min X g (control 3.23 +/- 0.64) whereas OCF 3.29 +/- 0.80 ml/min X g was nearly unchanged (control 3.59 +/- 0.85). The ratio OCF/ICF was increased to 1.37 (1.11). Further dehydration by hypertonic peritoneal dialysis for 3 h increased Hct to 60 +/- 4 and further reduced OCF and ICF, without significant change of the OCF/ICF-ratio. At Hct above 55 sudden and intermittent changes in local cortical blood flow were recorded randomly at individual electrode sites, showing ischemic periods lasting for 1 to 60 min. Such flow changes were observed in 13 of 14 expts. and were not accompanied by changes in RBF. It is concluded that moderate dehydration causes a greater reduction of ICF than of OCF. Severe dehydration gives in addition rise to patchy, intermittent ischemia in both cortical layers.


Regulation of motor activity of omasum after blockade of vagus nerves.

In 3 sheep with subcutaneously exposed vagus nerves and with chronic large fistula of the rumen pharmacological analysis of the motor activity of omasum was carried out after blockade of vagus nerves. The contractions of omasal canal, reticulum and rumen were recorded by the baloon method. After blockade of the vagus nerves with anesthetics the proper pharmacological agents were administered in intravenous injections. In the light of the obtained results it was found that contractions of the omsal canal, persisting after vagal blockade, are independent of the influence of the autonomic system and they are probably due to myogenic automatism. It has been also demonstrated that both alpha and beta adrenergic receptors participate in regulation of the tonous of omasum musclular layers.


Electrochemical method for continuous determination of enzymatic acetylocholine hydrolysis.

An electrochemical method was elaborated for the continuous determination of enzymatic hydrolysis of acetylcholine. In the electrochemical system applied the aqueous solution of the enzyme is separated from the aqueous solutions of substrates by a semipermeable membrane. In this way cholinesterase is used many times for reactions. Changes in the concentration of hydrogen ions were determined with molybdenum electrodes, one of which was used as an indicator and immersed in enzyme solution and the other served for comparison and was immersed in the solution of acetylcholine flowing to the measuring system.


Influence of muscle length on the force-velocity relation of K+-contractures in smooth muscle from rabbit urinary bladder.

Force-velocity relations of K+-contractures of longitudinal smooth muscle from rabbit urinary bladder were studied by isotonic quick release at 37 degrees C. In order to minimize the influence of parallel elasticity the study was limited to the rising part of the length-tension curve. The force-velocity data fitted well with Hill's equation. The in situ length of the strip at a bladder volume of 10 ml is called L10. This length is 50% of that at which maximum active tension is developed. At L10 Vmax was 0.29 muscle lengths per second and it was estimated to be 0.36 lengths/s at optimum length. Constant b in Hill's equation had a value of 0.052 L10/s and it was unaffected by length changes over the interval 0.69 L10-1.44L10. At L10 a/Po was 0.17. In the interval given above, a/Po decreased with increasing length in proportion to the increase in Po, indicating that a was also length independent. According to Hill's equation [V = b(Po - P)/(P + a)], V should increase in proportion to (Po - P) when the muscle length is increased if a and b are constants. Such a linear relation was found at shorter lengths but at lengths close to or at the length for maximum active tension, V increased more than (Po - P). Two possible explanations were considered; firstly that b/(P + a) increased, and secondly that the load on the contractile element could be less that P due to an influence of the considerable tension in the parallel elastic element at these lengths. The series elastic recoil of the active muscle amounted to 3-4% of the muscle length when released to zero tension.


The functions of bile ducts in sheep.

Pressure changes in the gallbladder and the bile flow and pressure changes in the common bile duct were determined in sheep. The experiments were conducted on animals with external junction of choleslochus and cholecystostomy performed previously. The experiments demonstrated pressure in the sheep of the functional sphincter of Mirizzi at the boundary between the intrahepatic and extrahepatic bile ducts. A correlation was demonstrated also between the function of this sphincter and that of Oddi's sphincter. The conditions for bile filling of the extrahepatic bile ducts and gallbladder were determined. The process of bile excretion into the duodenum and the role  of bile duct sphincters in this process are discussed. Attention is called to the relationship between the pressure in the gallbladder and the tonus of bile duct sphinters.


The effect of propylthiouracil (PTU) on heat production in chickens maintained on different levels of nutrition.

Using the method of forced feeding on higher and lower levels, two groups of chickens differring in growth rate were obtained. In the chickens of the two groups 72 measurements of heat production were made. Chickens of these groups were compared considering either the same age or similar body weight. It has been found that propythiouracil treatment (120 mg/kg duging 10 consecutive days) decreases heat production in the chickens of both groups. However, this effect was much more pronounced in the birds maintained on the higher level of nutrition and growing more rapidly than in those maintained on the lower level of nutrition and growing slowly.


Methodological aspects of testicular blood flow measurements in rats.

3 techniques for the measurement of testicular blood flow in anesthetized adult rats were compared. Direct measurement of testicular venous outflow yielded values more than 3 times lower than those obtained Xe-133 clearance and radioactive microsphere techniques due to the surgical procedures involved in spermatic venous cannulation. There was an agreement between flow values obtained with Xe-133 clearance (17.8 +/- 3.5 ml/100 g X min) and radioactive microspheres (19.9 +/- 5.5 ml/100 g X min). A homogeneous distribution of microspheres to different segments of the testis indicates that Xe-133 clearance is an adequate technique for testicular blood flow measurements. However, for some experimental purposes the radioactive microsphere technique is more versatile than Xe-133 clearance because of its capacity of measuring several organ flows simultaneously.


Characteristics of aortic baroreceptors with non-medullated afferents arising from the aortic arch of rabbits with chronic renovascular hypertension.

The characteristics of 47 non-medullated and 54 medullated fibres arising from aortic arches of 6 hypertensive rabbits have been investigated. The threshold for activation of the aortic C-fibres lay between 78 and 190 (mean 122) mmHg. The threshold for activation of 54 medullated aortic baroreceptors in the same animals was from 70 to 140 (mean 109) mmHg. At the awake mean arterial blood pressure (MABP) of these hypertensive rabbits (143 mmHg) all the medullated fibres were active as were 78% of the C-fibres. In contrast in a group of normotensive animals 91% of the medullated and only 28% of the non-medullated fibres were active. Pressure response curves were constructed for 19 C-fibres and 12 medullated fibres from the hypertensive animals. At a MABP of 110 mmHg the firing in the non-medullated fibres was 2.0 Hz as compared with 19.0 Hz in the medullated fibres and at the awake MABP mean firing was 9.0 Hz in the non-medullated fibres and 48.0 Hz in the medullated fibres. The firing at awake MABP was considerably higher in the hypertensives (9.0 Hz) as compared with the normotensives (1.1 Hz). Thus these data indicate that although the aortic C-fibres are reset in chronic hypertension, they are reset less than the medullated aortic baroreceptors from the same animal. It is suggested that arterial baroreceptor C-fibres may have an important role in the tonic control of the circulation in hypertension.


Release of 3H-acetylcholine from isolated guinea pig ileum. A radiochemical method for studying the release on the cholinergic neurotransmitter in the intestine.

Innervated strips of longitudinal muscle of guinea pig ileum were incubated with 3H-choline in the presence of physostigmine, after which the efflux of tritiated metabolites was studied. Under resting conditions 3H-acetylcholine, 3H-choline and other tritiated metabolites were released into the incubation medium. Analysis of the kinetics of the release of the metabolites indicated that the release occurred from at least 2 different compartments. Under the unstimulated conditions used, between 72 and 78% of the radio-activity remained in a third, non-releasable compartment. The release of 3H-acetylcholine showed spontaneous fluctuations which were positively correlated to spontaneous variations of the isometric tension of the preparation. Electrical field stimulation at low frequency (0.5 Hz) consistently increased the release of 3H-acetylcholine. The release of 3H-choline was increased only slightly or not at all by the electrical stimulation. For studying stimulation-evoked release of 3H-acetylcholine, it is suggested that the measurement of the total quaternary amine release is of similar value to measurement of 3H-acetylcholine itself. This approach considerably simplified the method. During 5 consecutive stimulation periods of 150 pulses each, the increase in the release of total quaternary amines diminished with time. By taking into account the reduction of the stores of radioactivity in the tissue during the experiment, correction for the negative trend could be made. When the preparation was stimulated with between 30 and 3000 pulses a close correlation was found between the increase in the release of total quaternary amines and the number of pulses delivered. The volley output of the quaternary amines was not constant, however, but diminished by increasing stimulation frequency.


Difference in sensitivity of parotid glands brought about by disuse and overuse.

The sensitivity to methacholine of the parotid glands in rats maintained on a liquid diet (aiming at sensitization) for a period of 2 weeks or 3-4 weeks was compared with that of the parotid glands in rats on a pelleted bulk diet (aiming at desensitization). In the rats on the liquid diet, it was found that the dose needed to evoke a just perceptible secretion of saliva was smaller, that the secretion started earlier and continued over a longer time period, and further that the amount of saliva secreted expressed per gland weight in response to submaximal doses of the sialogogue drug was bigger when compared with the rats on the pelleted bulk diet. These findings are interpreted as signs of a higher degree of sensitivity of the glands in the rats on the liquid diet than of those in the rats on the pelleted bulk diet.


Serum testosterone compared with serum zinc in man.

Serum zinc was measured in 154 male and 95 female blood donors. Men had higher serum zinc levels than women, the difference being statistically significant (p less than 0.001). The correlations between serum zinc and serum testosterone, serum zinc and serum FSH and serum zinc and serum LH were studied in 40 men aged 28-60 years and a statistically significant positive correlation was found only between serum zinc and serum testosterone in men of age 36-60 years (p less than 0.005). These results do not support the theory that slight zinc deficiency primarily effects pituitary gonadotropins but indicate that it would rather act on testicular level.


Regional brain uptake of noradrenaline following mechanical or osmotic opening of the blood-brain barrier.

The passage of noradrenaline from the cerebrovascular circulation into the brain (vessel walls and parenchyma) was studied quantitatively and regionally by a modification of Oldendorf's technique for determination of brain uptake index. Using 14C-ethanol as the highly diffusible internal standard, the index for noradrenaline varied between 2.7 and 4.5% in different regions, confirming the poor penetration of this neurotransmitter. The barrier was impaired transiently as evidenced by Evans blue extravasation, through osmotic opening by internal carotid injection of a hyperosmolar urea solution or mechanical disruption by a short-lasting elevation of the intracarotid hydrostatic pressure. This resulted in a 3-4-fold increase in the passage of noradrenaline from the circulation into the brain.


Low intensity training, inactivity and resumed training in sedentary men.

The effects of a low intensity training regimen, consisting of two 7-week periods with an interspersed 8-week inactivity period were investigated in 16 sedentary men. A follow-up was made on 7 subjects after 38 additional weeks' training. Systemic as well as local effects were studied using exercise tests and leg muscle biopsies. The two 7-week training periods both resulted in a 6% increase in Vo2 max and a lowered heart rate during submaximal work. No persisting training effects were detected by exercise tests after inactivity. In skeletal muscle, however, striking differences in enzyme activity pattern and ultrastructure were observed between the two periods, indicating that some training effect of importance for muscle metabolic adaptation might have persisted during inactivity. It is suggested that such an effect might be associated with the local oxygen supply. During the 38-week training period there was a large increase in muscle metabolic capacity, but no change in maximal oxygen uptake. This separation of systemic and local training effects indicates a lack of a direct causal relationship between muscle metabolic potential and max imal oxygen uptake. It is suggested that the elevated muscle oxidative capacity is of importance for an increased endurance capacity.


Impulse dependent adaptation in Helix pomatia neurones: effect of the impulse on the firing pattern.

In neurones of the ventral ganglion of Helix pomatia an adaptation type is demonstrated where the impulses contribute to the adaptation, as if a slowly changing outward current were associated to every impulse. The current appears to be accumulated from impulse to impulse and the accumulated current to decrease towards zero in the interval between the impulses. This type of adaptation is called impulse dependent. A method to distinguish between impulse dependent adaptation and impulse independent adaptation is described. Typical adaptation curves for the impulse dependent adaptation are shown. With a strong adaptation there is a linear relation between the steady state frequency and the applied stimulus. When stimuli of short duration are applied repetitively, neurones with impulse dependent adaptation respond with spikes on an increasing fraction of the stimuli as the stimulus strength is increased. A simplified model of the adaptation is proposed, and the firing pattern of the cells is compared with that of the model. In this way numerical values of the model parameters have been estimated.


Impulse dependent adaptation in Helix pomatia neurones: demonstration of the adaptation conductance.

By conventional voltage clamp methods an increase in membrane conductance after a depolarizing pulse is demonstrated in neurones of Helix pomatia. This increase decays exponentially with a time constant in the range of 5--20 s. The rise of the conductance during the depolarization can be represented by 3 exponentials with time constants from 12 ms to 1 s. The steady state value of the conductance depends on the membrane potential in a sigmoid manner. The conductance gives rise to an outward current, which appears to be carried by potassium ions. The firing pattern of the cell is governed by the conductance. A short, rectangular potential change, a pulse clamp, is used to disturb the firing pattern of the freely firing cell. The effect on the firing pattern depends on the height and duration of the clamp pulse in the same manner as the conductance increase. The normal firing produces similar changes in the membrane conductance.


In vivo turnover rate of acetylcholine in rat brain parts at elevated steady-state concentration of plasma choline.

Cortical and striatal turnover rates of acetylcholine TR(ACh) were estimated by applying steady-state tracer kinetics in rats killed by microwave irradiation following a constant i.v. infusion of 3H-Ch. In control rats TR(ACh) was 3.6 nmol . g-1 . min-1 in the cortex and 23.8 nmol . g-1 . min-1 in the striatum. When steady-state plasma concentrations of Ch were increased from 17 to 140 mumol . 1-1 by a 15-min infusion of unlabelled Ch the corresponding TR(ACh) were 3.6 nmol . g-1 . min-1 and 21.4 nmol . g-1 . min-1, respectively. These results indicate that increased plasma levels of Ch are not accompanied by increased synthesis of brain ACh.


Effect of the preceding day's energy intake on the total energy cost of light exercise.

The effect of a variation in the preceding day's dietary energy intake-4, 10 and 18 MJ-on the oxygen consumption and respiratory quotient at rest and at work before and after a test meal (4 MJ) was investigated. 7 normal male subjects were studied at 3 different experimental situations. During the first day the subjects had an energy intake of 10 MJ and normal activity. The following morning measurements of V(O2) and V(CO2) were performed at rest and at work on a bicycle ergometer (36 W) before and after the test meal. The same measurements were performed on the following day but the dietary intake between the two sets of measurement was then either 6, 0 or 14 MJ. No significant effect was found of the preceding day's dietary energy intake on the oxygen consumption or on the energy transformed during rest, during exercise before and after the test meal. The results do not support the conclusions of previously published studies, proposing a significant feed-back mechanism tending to control the body energy content by regulation of the energy expenditure through chemical or mechanical uncoupling.


Capillary pressure in deep and superficial glomeruli of the rat kidney.

A new technique has been developed to make deep renal cortical structures in rats accessible for micropuncture: The left kidney is dissected free and immobilized in a lucite cup. A lense-shaped slice, 1--2 mm thick and about 5 x 5 mm wide, is cut off from the dorsal aspect of the kidney. Blood oozing from the cut surface is removed by flushing with saline and suction by microsponges. The bleeding stops in 1--3 min and causes none or only transient fall in arterial pressure (PA). Up to 40 glomeruli become visible and remain circulated for several hours, as shown by injection of dye or silicone rubber. Glomerular capillary pressures (PG), measured with servocontrolled counter pressure (Wiederhielm), showed no consistent change with time and no correlation to PA. Average PG +/- S.E. in mmHg (number of glomeruli in parentheses) were: Wistar rats (WR), Inactin anesthesia, 57.8 +/- 1.4 (41), Membumal anesthesia, 58.1 +/- 1.3 (13). Sprague Dawley rats, Inactin, 58.1 +/- 1.7 (14). In WR, PG was lower in deep than in midcortical glomeruli: less than or equal to 0.4 mm below kidney surface, 57.9 +/- 1.8 (20); 0.5--0.9 mm: 60.5 +/- 1.5 (20) and greater than or equal to 1.0 mm: 53.8 +/- 2.5 (13). Pressure in Bowman's capsule: 11.2 +/- 0.6 (30). The observed PG is higher than previously reported on the Munich mutant strain of WR, and suggests that glomerular filtration equilibrium is not reached.


Catecholamines and pancreatic hormones during autonomic blockade in exercising man.

The importance of autonomic nervous activity for the pancreatic hormonal response to exercise in man was studied. 7 men ran at 58% of V(O2)max (determined without administration of drugs) to exhaustion during alpha-adrenergic blockade with phentolamine (P), during parasympathetic blockade with atropine (A), or without drugs (C). At rest phentolamine increased the plasma concentrations of both insulin and norepinephrine. During exercise norepinephrine concentrations increased and were in P experiments 3 times the concentrations in C experiments. Insulin always declined during exercise but in P experiments never decreased below basal levels. At identical times neither glucagon nor glucose differed significantly in the different expts. Thus during exercise alpha-adrenergic blockade increased insulin concentrations but did not diminish the glucagon response. Nor was this response increased when beta-receptor stimulation in P experiments was intensified by the particularly high catecholamine concentrations. The concentrations of FFA, glycerol and lactate were highest in P experiments and identical in A and C experiments. These findings indicate that during prolonged moderate exercise in man insulin secretion is depressed by stimulation of alpha-adrenergic receptors whereas glucagon secretion is not influenced by adrenergic receptors. Stimulation of beta-adrenergic receptors enhances lipolysis but neither lipolysis nor pancreatic hormonal secretion is influenced by cholinergic activity during exercise.


K+-permeability of the blood-brain barrier, investigated by aid of a K+-sensitive microelectrode.

The K+-permeability of the blood-brain barrier at the capillary level was estimated from determinations of brain extracellular K+-concentration in response to an isotonic bolus containing KCl injected into the carotid artery. A very low permeability appeared from the fact that the extracellular K+-concentration--measured by aid of K+-sensitive microelectrodes--remained unchanged during the passage of the bolus. An upper limit for the blood-brain barrier K+-permeability in the rat was estimated to be 2.8 X 10(-7) cm. with s-1.


Apnoea and bradycardia from submersion in "chronically" decerebrated cats.

In "chronically" but not in acutely decerebrated cats, submersion of the head caused apnoea and marked bradycardia, associated with a maintained or slightly raised arterial pressure. Since these reflex adjustments, though very reproducible, occurred with a varying latency and could be induced also by nasal injection of water, they appeared to be, at lest in part, elicited from the upper respiratory passages. Thus, a terrestrial mammal, reputed to shun any form of immersion, can exhibit adjustments during head submersion, similar to those in habitually diving species. This response pattern is basically organized at the lower brainstem level.


A genetic study of affective disorders.

First and second degree relatives of 99 probands with affective disorders (49 unipolar and 50 bipolar subjects) were studied. The high risk values obtained for affective disorders were shown to be compatible with those found by other authors, although the prevalence of the illness in the population of Lombardy appears to be much lower than in other countries. Very low rates of suicide and alcoholism were found in our sample. Data obtained by analysis of the affected pairs of relatives rule out the hypothesis of a dominant X-linked gene if the bipolar and the unipolar forms are considered genetically separated entities. Results compatible with a polygenic condition, partially shared by bipolar patients, were found using Slater's and Smith & Falconer's methods. Our data, however, cannot rule out the dominant hypothesis.


Masked "myxedema madness".

Hypothyroidism can present a wide range of psychiatric manifestations, including personality disturbance, neurotic traits and psychotic features. Psychiatric treatment techniques without recognition and correction of the endocrine root of the mental disturbance will result in a failure of treatment. However, severe hypothyroidism can exist with a poverty of classical signs and symptoms such that both internist and psychiatrist may easily overlook endocrine dysfunction as a possible etiology of the mental disorder. A case of long-standing paranoid illness whose etiology was severe myxedema with such a poverty of signs and symptoms is presented. Failure to recognize the endocrinopathy may not only produce recovery difficulties but also psychiatric and endocrine repercussions if psychotropic medications are given in such masked cases. These problems are considered with particular reference to lithium, and screening criteria to avoid this problem are discussed.


Obsessional stat es. A study in the relationship between abnormalities occurring at the time of birth and the subsequent development of obsessional symptoms.

The purpose of this study was to examine the theory that there is a positive relationship between the occurrence of abnormalities at the time of birth and the subsequent development of obsessional states. While an abnormal birth may result in minimal brain damage this is not necessarily the significant factor, as a separation of mother and baby in the immediate neonatal period, Which usually follows an abnormal birth, may be of more relevance. Observations are made on certain phenomenological aspects on obsessions in patients who give a history of abnormal birth as compared with those patients who have obsessional states and give a normal birth history. In the discussion comments are made upon the separation anxiety theory as being an important aetiological factor in the obsessional neurotic state.


Digitalis therapy in a 70-year-old population.

In the population study "70-year-old people in Gothenburg" 14% of the probands were found to be undergoing treatment with digitalis, 6% with digoxin, 6% with digitoxin and 2% with other glycosides. A comparison between results of the interview method and those of S-digoxin analyses indicates that the interview method was acceptable. As far as can be judged from S-digoxin analyses, only about 60% of the treated patients were on a dosage considered to be effective and free from obvious risks of side-effects. Out of the 130 70-year-olds who were on digitalis treatment, 37% had obvious symptoms of heart disease requiring such treatment, 34% lacked symptoms of arrhythmia and/or congestive failure but had heart volumes larger than those used as reference values in younger age groups, and 29% had no symptoms indicating digitalis treatment. At least 13% of the population had indications for digitalis therapy and about 75% of those apparently needing digitalis were on such treatment. Thus both over- and underdiagnosis of heart disease requiring digitalis therapy were common in this age group.


Studies on digitalis. XIV. Is there any correlation between hypomagnesemia and digitalis intoxication?

In a prospective study on digitalis intoxication, low serum magnesium was found in 90 patients, while 388 patients had values above 1.5 mEq/l. Hypomagnesemia was more frequent in women than in men, in those with low body weight and in those with advanced heart failure. More patients with hypomagnesemia than those without had nausea, anorexia, fatigue, flickering of vision and atrial tachycardia with block. Patients with hypomagnesemia also had lower serum potassium than normomagnesemic patients. There was, however, no significant difference in the prevalence of digitalis intoxication or in serum digitoxin concentration. Nor was there any correlation between serum digitoxin and serum magnesium levels.


The possible relation between postpartum exacerbation of hyperthyroidism and neonatal thyrotoxicosis.

Hyperthyroidism is generally considered to be ameliorated during pregnancy, and there appears to be a high incidence of postpartum exacerbation. These phenomena have to our knowledge not been related to neonatal thyrotoxicosis, a transient hyperthyroidism seen only in newborns of previous or current hyperthyroid mothers. The first of two siblings of a previously thyrotoxic mother had marked symptoms of neonatal thyrotoxicosis and high levels of thyroid hormones. The mother had not received antithyroid treatment during her first pregnancy. During her next pregnancy she was treated with propylthiouracil from the second trimester. This infant had only minimal thyrotoxic signs but almost as high levels of thyroid hormones during the neonatal period as the elder. The mother had no signs of postpartum exacerbation but her thyroid hormones were significantly elevated in the postpartum period analogous to the infants. Neither the mother nor the infants presented any increase in thyroid-stimulation hormone and long-acting thyroid stimulator during the hyperthyroid periods. The possibility is discussed, that postpartum exacerbation of hyperthyroidism and neonatal thyrotoxicosis may be related. They could be the result of a changed balance between a thyroid stimulator and an inhibitor after birth.


The effect of body temperature on thyroid hormone levels in patients with non-thyroidal illness.

During studies on the mechanism underlying the low serum T3 levels in euthyroid patients with various acute and chronic non-thyroidal illnesses, it became evident that body temperature may be one parameter associated with changes in serum T3 levels. Forty-nine hospitalized, euthyroid patients with hyperpyrexia caused by various non-thyroidal illnesses were studied. The levels of serum T3 were found to decrease gradually with increasing body temperature. T3 was already below the normal level +/- 2 S.D. at a body temperature of around 38 degrees C. Such low T3 levels as were seen at temperatures of above 40 degrees C are observed in thyroid patients only during severe hypothyroidism. The levels of T4 and TSH remained unchanged and within the normal range regardless of body temperature. The levels of reverse-T3 in the sera analyzed were found to be unchanged in some cases, while in others they paralleled body temperature. It is concluded that the body temperature must be taken into consideration when studying the serum levels of T3.


Effects of prolonged, strenuous exercise on lipids and thyroxine in serum.

Serum lipids and thyroxine were determined in 26 men participating in a 90-km cross-country ski race, before, immediately after, and on the following days. Serum cholesterol was unchanged immediately after the race, but then fell significantly and remained low during the observation period. During the race the fatty acid composition of serum free fatty acids changed towards the composition of ordinary adipose tissue. The compostiion of serum triglycerides showed similar but less pronouced changes. On the following days an increase in the arachidonic, and a decrease in the linoleic acid fraction of the total serum lipids were observed. Total thyroxine and free thyroxine in serum were significantly increased at the end of the race, but had returned to the pre-raced levels during the rest of the observation period. The observations correspond to the findings during acute, severe illness, and are compatible with the hypothesis that some of the changes in serum lipids following severe somatic stress are due to increased thyroid hormone activity.


Treatment of glomerulonephritis with drainage of the thoracic duct and plasmapheresis.

Nine patients with various types of severe glomerulonephritis were treated with drainage of the thoracic duct (n=8) and/or plasmapheresis (n=6) without the use of pharmacological immunosuppression. In most of the patients treatment produced a prompt temporary regression of albuminuria and creatininemia. In one patient renal function was substantially improved 8 months after the last period of treatment, in 2 patients the progress of the uremia was probably retarded. In the remaining 6 patients treatment had no obvious effect on the course of the illness. Drainage of the thoracic duct and plasmapheresis may be of benefit in the treatment of glomerulonephritis, but their proper utilization requires further studies.


Transient changes of sensory nerve functions in uraemia.

The neurophysiological parameters (conduction velocity, amplitude and rise time of the compound action potential) of two sensory nerves of the lower limb (N. suralis and peronaeus superficialis) were determined bilaterally in five patients. Measurements were carried out at least twice in each subject during a time of great metabolic change. Two patients were recovering from acute renal failure (a single haemodialysis had to be performed on one of them) and three were under chronic maintenance haemodialysis. In the case of the haemodialysis patients, measurements were performed on two successive days, before and after one haemodialysis session. All the neurophysiological parameters showed significant improvement in successive measurements. In one patient the follow-up after acute renal failure revealed a delayed deterioration of the nerve functions, but after one year the values were normal. From the results it seems probable that an acute metabolic disturbance may cause transient inhibition of nerve functions without morphological changes in the nerve fibres.


Management of septicemia and early death in acute leukemia.

The frequency of fever days was measured in 67 patients with acute leukemia in the initial phase until remission was obtained or the patient died. A total of 3411 hospital days were studied. Three antibiotic schedules were examined between 1970 and 1975. There were 50% fever days when penicillin and streptomycin were combined as initial antibiotics, 37% when cephalosporin and gentamycin were used, and 31% when, in addition, semi-isolation was used prophylactically and granulocytes were given in a therapeutic attempt (0.05 greater than p greater than 0.01). The corresponding frequencies of early death were 9/21 (43%), 6/23 (26%) and 5/23 (22%). Early death occurred on an average 14, 23 and 21 days after admission. The frequencies of remission (complete and partial) were 8/21 (38%), 12/23 (52%), and 13/23 (57%). A randomized subgroup (12 patients) with intestinal sterilization was studied separately. It had 28% fever days, which is significantly less (p less than 0.01) than in the 13 patients given the same systemic antibiotics without intestinal sterilization. Fever was significantly lower (0.05 greater than p greater than 0.01) on the day after a series of granulocyte transfusions than before, although only 10(9) granulocytes were given. However, this fever reduction may have been due to concomitant antibiotics.


The effects of pursuit eye movements on single unit activity in cat visual cortex.

The pursuit eye movements were assumed to be an indicator of the time periods when visual information is actively processed. The experiment was performed on cats with pretrigeminal transection of the brain stem. In such preparations only vertical eye movements were preserved. Under these conditions the following eye movements could be evoked by vertical movements of the stimulus at the periphery of the retina. The influence of these movements on the activity of units which had their receptive fields in area centralis was tested. Contralateral eye was immobilized and the position and preferred direction of the units' receptive fields was tested. Significant differences in neuron activity correlated with the pursuit eye movement were found in 22 percent of cells. It is suggested that the effect is due rather to the active state of visual system than to the peripheral stimulation of retina or the information incoming from extraocular muscles.


Stimulus intensity and conditioned suppression magnitude: dependence upon the type of comparison and stage of training.

Three groups of eight rats each were trained in conditioned emotional response (CER) using white noise of 70 dB, 50 dB, or both intensities as conditioned stimuli (CSi) given in unpredictable order. Between-subjects comparisons showed more rapid acquisition to the 70- than to the 50-dB CS. Rats presented with both intensities acquired the CER at a similar rate as those conditioned to the 70 dB value only, and within-subjects comparison did not reveal any CS intensity effects. During the next stage of the experiment all rats were presented with both intensities of white noise. The stimulus intensity effect found in within-subjects comparisons was greatest when the soft CS replaced the more intense value on half of trials. Weakening of the CER after reaching asymptotic conditioning was related to increased response rate at the beginning of CS action with greater suppression of bar presses before shock onset. This decreasing pattern of bar presses within CS action was far more consistent on 70-dB trials, indicating a stimulus intensity effect on the development of the inhibition of delay in CER training.


Averaged cortical evoked potentials to recognized and non-recognized verbal stimuli.

Averaged evoked potentials (AEPs) to visually presented neutral and emotionally significant words were recorded from the occipital area and vertex in 37 adults with normal vision. In the first experiment all the stimuli presented on the screen with time exposure 200 ms were supraliminal and were easily recognized by the subjects. In the second experiment time exposure of the stimuli was 15 ms. All the subjects were then unable to recognize the stimuli. The AEPs were observed to physically feeble but emotionally significant stimuli. Thus the analysis of semantic properties of the emotional word may take place in the cerebral cortex without its awareness.


Two-dimensional probabilistic images discrimination. I. Simultaneously presented pairs of patterns.

Reaction time and judgment of similarity or dissimilarity were studied in an experiment on two-dimensional probabilistic images (TDPIs) composed of rectangular black and white cells with statistical distribution of these elements 0.5-0.5. The subjects were asked to report verbally whether pairs of TDPIs, presented for 700 ms, appeared to them similar or not. Three sets of TDPIs differed as to the size of their "grain". Within the pairs "physically identical patterns", "statistically same patterns" or "different patterns" have been used. The statistically same patterns pairs reached the lowest (39 percent) judgment correctness. Reaction times for these pairs were generally longer than for others. In the case of identical patterns and statistically same patterns pairs the results indicated a general increase of the processing time as the size of grain had increased. There was a general tendency of reaction time shortening in successive sessions. These results suggest that correct discrimination of TDPIs does not depend primarily upon their grain.


Defensive passivity in adolescence.

There are potentially healthy adolescents who display excessive reluctance to move toward independent decision and action. This paper presents a clinical description of this "syndrome", conceptualizes it as a defensive maneuver against mourning and offers steps for therapeutic intervention.


The self concept of the adolescent with learning disabilities.

The Coopersmith Self Esteem Inventory (CSEI) was administered to 23 Ss diagnosed to have learning disabilities, and normally achieving seventh graders (N = 70) to investigate: a) whether differences exist between the self-esteem of the adolescent with learning disabilities and the normally achieving adolescent, b) the dimensions of self concept in which these differences occur, and c) the relationship between self concept and the number of years in the special classroom for the adolescent with learning disabilities. The data were fitted to a 2 X 2 (ability X school) fixed effects non-orthogonal multivariate analysis of variance model. A significant difference (p less than .05) in "social self-peer" self concept favoring the "normally" achieving S's was found. A trend was evidenced for more negative "general self" and "school-academic" self concepts for the learning disabilities sample. Number of years in the special class did not appear associated with self concept as measured by the CSEI.


The curfew bill as it relates to the juvenile and his family.

Curfew laws have been instituted in cities across the United States in an attempt to control the rise in juvenile crime. This article discusses the advantages and disadvantages of a curfew law for Baltimore City based on interviews with city officals and concludes that the law in its present form will not bring about any significant change in the rate of delinquency. Alternative are suggested that might better get to the source of the problem. These include more youth and family counseling services, rehabilitative facilities, work study programs and shelter areas.


The effects of a seven day camping experience on volunteer student counselors.

An investigation of the effects of a seven-day camp experience with disturbed adolescents on approximately sixty undergraduate "camp counselors" was conducted. Measures of the types of reinforcement preferred and used as well as an overall attitude toward disturbed adolescents were obtained and evaluated. The results indicated that the student counselors did not use the type of reinforcement that they felt was most important and they did not change their attitudes toward disturbed adolescents as a result of experience. The limitations of the study are discussed as well as some suggestions for future research into practicum sites for programs training teachers of the severely disturbed.


The ideal self and cognitive development in adolescence.

This study investigated the relationship between cognitive development level and the ideal self in adolescence, sampling 223 male and female 12- and 13-, and 15- and 16-year-old working and middle class English comprehensive school students, hypothesizing that maturity of the ideal self would be related to cognitive development. Correlations between cognitive developmental total score and ideal self score were significant for the whole sample and for both age groups. Regression analysis showed cognitive development score to be the major significant predictor of ideal self score at both age levels, with sex contributing additionally at the older age level.


Self-concept and delinquency proneness.

Contrary to the theory of the homeostatic model of self-concept, i.e., the expectancy that engaging in anti-social or pro-social behavior results typically in shifts in the self-concept (Graf, 1968; Deitz, 1970 shifts did not occur. Subjects, 12- 14-year-old boys enrolled in junior high school, delinquent prone (DP) and non-delinquent prone bright (NDPB), reacted to manipulation by engaging in reparative behavior as indicated via an aggression module in a fashion generally expected but the expected shift from chronic self-images did not occur. Both DP and NDPB viewed themselves similarly on self concept. The authors postulated that if shifts would occur for the delinquent prone it would be after they left school with its accompanying identification with a sub-culture outside the school setting.


Comparison of ethanol withdrawal syndrome in humans and rats.

Physical dependence upon ehtanol induced in rats is in several respects similar to the tremulous and convulsive components of the ethanol withdrawal syndrome observed in man. These include short duration of the induction period, pattern of continuous ethanol consumption, rectilinear clearance of blood ethanol during prodromal detoxication phase and the onset of the ethanol dependence phase at relatively high blood ethanol concentrations. During the ethanol withdrawal period two phases are distinguished in both species: (1) Prodromal detoxication phase characterized by a spectrum of signs and responses of ethanol intoxication. (2) Ethanol dependence phase characterized by a spectrum of withdrawal signs and reactions. The successive onset and disappearance of the two sets of signs and reactions during both phases of the ethanol withdrawal period constitute a continuum of effects and responses and represent a reversal in the CNS function from the extremes of ethanol depression to the extremes of hyperexcitability.


Role of catecholamines in the development of tolerance to barbiturates and ethanol.

The destruction of noradrenergic systems in brain by administration of 6-hydroxydopamine prior to chronic ethanol treatment prevented the development of tolerance to ethanol. Animals pretreated with 6-hydroxy dopamine also showed no cross tolerance to barbiturates. Destruction of noradrenergic systems prior to chronic treatment with barbiturates also partially prevented the development of tolerance to pentobarbital. 6-Hydroxydopamine pretreatment had little effect on the signs of physical dependence produced by ethanol. The possible dissociation of tolerance and dependence and the role of noradrenergic systems in these phenomena is discussed.


The effect of low dose intravenous alcohol on human information processing.

A model of multiple-stage information processing predicts alcohol to have a selective effect on mechanisms involving central processing rather than sensory input. However, behavioral effects at low alcohol doses administered orally can be overshadowed by fluctuations in gastrointestinal absorption and metabolism rate. Paid volunteers, who therefore received intravenous doses of alcohol and a barbiturate, were tested on tasks varying in sensory discriminability and in central processing difficulty. The low drug doses did not affect errors of stimulus encoding but increased error rate in memory comparison tasks. These results confirmed the predictions based on the mutiple-stage model.


Drinking practices and cognitive functioning.

The relationships between drinking practices and cognitive functioning were examined in a non-patient sample. Neither the amount of alcohol consumed over a lifetime nor current frequency of drinking occasions was significantly (ps greater than .05) correlated with cognitive test scores. However, the quantity of alcohol consumed per drinking occasion was inversely related to performance on tests of abstraction, adaptive abilities and concept formation. The results suggest that social drinking may have deleterious effects on cognitive processes.


The dipsogenic effect of alcohol and the loss of control phenomenon.

A counterbalanced within-subjects design was employed to assess the acute effects of alcohol ingestion on thirst and fluid intake and to relate these effects to the dehydration known to result from acute ingestion of alcohol. Fourteen male nonalcoholic social drinkers between the ages of 18 and 30 consumed 0.8 gm of alcohol/kg body weight during one experimental session and a placebo (0.05 gm/kg) of equal volume during the other. During the 90-minute drinking period and for one hour both before and afterward, urine specimens were collected. After the drinking period, blood alcohol levels and unobstrusive measures of ad lib drinking were recorded. In addition, subjects rated their degree of thirst three times during each session. Analyses of variance indicated that alcohol significantly increased both fluid intake and urine output, and decreased urine specific gravity. Moreover, thirst ratings were also significantly greater after alcohol than after placebo and fluid intake after alcohol was significantly correlated with prior measures of fluid balance, mean urine specific gravity, peak blood alcohol level and thirst. The implications of these results for the loss of control in alcoholism are discussed and a new theoretical account of the phenomenon is proposed.


Assessing the alcoholic's disposition to drink.

Reliable and valid techniques for assessing the alcoholic's disposition to drink would allow researchers to address many issues of clinical significance. This paper reviews some basic issues in behavioral assessment techniques, proposes several criteria for a reasonably general technique for assessing disposition to drink, and presents evidence relevant to the validity of one behavioral measure of disposition to drink. A study is presented which focuses on distinguishing good from poor treatment outcome subjects on the basis of their response patterns for alcohol during a simulated drinking binge. Alcoholic subjects were assigned to one of two treatment outcome groups based on treatment success evaluated at follow-up two months after hospital discharge. An analysis of the alcoholic's response patterns for alcohol during a simulated drinking binge revealed that good outcome subjects showed decreases in disposition to drink as their blood alcohol levels (BAL) rose, while poor outcome subjects showed increases in disposition to drink as their BAL increased. These results indicate that individual differences in behavioral response to alcoholization and withdrawal can index the alcoholic's potential for readdiction and relapse subsequent to hospital treatment and illustrate the role which behavioral assessment techniques can play in developing and refining models of human alcohol abuse.


On the possibility that opiate and ethanol actions are mediated by similar mechanisms.

Opiates and alcohol modify neuronal electrical activity in many sites of the nervous system. Both act as depressants or stimulants of cell firing depending upon the type of cell studied. Alcohol seems to act upon some nerves by changing their membrane ionic conductance, while opiates seem to affect synaptic events. However, all of the known neural actions of these substances involve calcium-dependent mechanisms. A hypothesis is proposed to account for these facts.