[Desmoid tumors (apropos of a clinical case)]

The authors, starting from a case of desmoid tumour of abdominal wall, they had the opportunity to observe, discuss its possible etiopathogenetic factors, and confirm the validity of operation as the only therapy.

Visual desynchronization of cortical EEG impaired by lesions of superior colliculus in rats

It is unclear whether rats with lesions of the superior colliculus (SC) neglect visual stimuli because a) they fail to notice the stimuli or b) they notice the stimuli but fail to make specific orienting movements of the eyes and head toward them. To investigate this issue, we used an index of "noticing" that does not involve overt orienting movements, namely, desynchronization of the cortical electroencephalogram (EEG) in drowsy animals. In the first experiment, large collicular lesions with some invasion of surrounding areas severely impaired EEG desynchronization to a brief overhead flash of light but did not significantly affect desynchronization to brief bursts of white noise. No impairment was found after control lesions of cerebral cortex overlying the superior colliculus or of striate cortex. A subsequent experiment found that the visual impairment was still present when lesions were confined to the superior colliculus. It appears that rats with lesions of the superior colliculus can, in certain circumstances, fail to notice visual stimuli and that in rats, the superior colliculus is concerned not only with specific orienting movements to visual stimuli but also with visual desynchronization of the cortical EEG.

Feeding induced by injections of muscimol into the substantia nigra of rats: unaffected by haloperidol but abolished by large lesions of the superior colliculus

Intense activation of central dopamine systems has been associated with oral stereotyped behaviour, whereas less intense stimulation of these systems can increase feeding in non-deprived animals. There are several lines of evidence which suggest that the gamma-aminobutyric acid-containing striatonigral and nigrotectal projections are essential pathways mediating dopamine-related oral stereotypy. The present series of experiments was conducted to examine whether the same output route also mediates dopamine-related feeding. In the first experiment it was shown that bilateral injections of a sub-stereotypic dose of muscimol (0.05 nM) into the substantia nigra increased feeding of non-deprived rats. In Experiment II the feeding response was further characterised by demonstrating that food intake was initially suppressed for 30 min after which it was potentiated for 90 min. In Experiment III it was shown that a single dose of haloperidol (0.4 mg/kg), which was adequate to suppress overall food intake, was ineffective in preventing the increase in feeding produced by intranigral muscimol (0.05 nM). In contrast, it was demonstrated in Experiment IV that large lesions of the superior colliculus completely abolished the muscimol-induced increase in feeding. These results suggest that the striatonigral and nigrotectal projections may be important efferent pathways for both the oral stereotypy and the feeding responses linked with central dopamine transmission.

Reduced locomotor activity as an acute effect of damage to superior colliculus in rats

Rats with either electrolytic or radiofrequency lesions of the superior colliculus were tested in an open-field within 24 h of operation. They crossed significantly fewer squares and spent more time motionless then control animals, an effect that disappeared upon retesting 13 days later. Previously reported locomotor hyperactivity thus appears to be a chronic but not an acute effect of collicular damage in rats.

[Renal leiomyoma (presentation of a clinical case)]

The authors report a case of symptomatic renal leiomyoma. Such neoplasm is very rare and, as to the symptomatic form, only some tens of cases are recorded.

[Spontaneous rupture of the transplanted kidney]

The spontaneous breakage of a kidney is a rare complication which may occur in the first weeks after a transplantation. The cause which can determine it is not yet cleared up, although the Authors think the greatest responsibility for this can be ascribed to rejection. In this work the authors report the experience and casuistry of the Transplantation Centre of Verona.

Altered cell cycle distributions of cultured human lymphoblasts during cytotoxicity related to adenosine deaminase inhibition

Serial-flow cytometric analysis of DNA content of T lymphoblasts (MOLT-4) and B lymphoblasts (MGL-8) was performed to correlate the cytotoxic properties of adenosine deaminase inhibition with alterations of DNA synthesis and disruptions of the cell cycle. The addition of deoxyadenosine up to 50 mumol/L potently decreased the growth of T lymphoblasts, and these changes were enhanced with the addition of 100 mumol/L homocysteine thiolactone. These conditions caused a virtual absence of cells from S and G2M phases after 24 hours. The DNA distribution was similar in cells cultured for 24 hours in 50 mumol/L deoxyguanosine or 2.5 mumol/L hydroxyurea. These observations suggested accumulation of cells in the G1 phase. T lymphoblasts cultured with up to 50 mumol/L adenosine had a substantial decrease in growth, which was not modified by the addition of homocysteine thiolactone. Cell cycle distributions of T lymphoblasts cultured for 24 to 48 hours under these conditions showed mild decreases in the G2M population. The addition of adenosine up to 50 mumol/L decreased the growth of B lymphoblasts, and these changes were enhanced by the addition of 100 mumol/L homocysteine thiolactone. These conditions induced mild decreases in the S-phase population in B lymphoblasts. The addition of deoxyadenosine, even with homocysteine thiolactone, did not modify growth in B lymphoblasts and the cell-cycle distributions were indistinguishable from distributions of control populations after 24 and 48 hours. The observations provide independent support for a reduction of DNA synthesis associated with cytotoxicity during adenosine-deaminase inhibition.(ABSTRACT TRUNCATED AT 250 WORDS)

Dissociation of stimulation-bound feeding and apomorphine-induced gnawing by lesions of superior colliculus

The intense stereotyped gnawing induced by high doses of apomorphine is almost abolished by large bilateral lesions of the superior colliculus. It has been argued that the feeding produced by electrical stimulation of the lateral hypothalamic area is closely related to dopamine-mediated oral stereotypies; if so, it might be expected that lesions of the superior colliculus would also disrupt stimulation-bound feeding. Feeding was obtained from 14 hypothalamic electrodes in 8 hooded Lister rats. Subsequent electrolytic lesions of the superior colliculus had no overall effect on this behaviour from 13 of the 14 electrodes, even though the lesions reduced the gnawing induced by 8-20 mg/kg apomorphine to less than 10% of its preoperative intensity. It is concluded that stimulation-bound feeding and apomorphine-induced gnawing are not dependent on identical neural circuitry, and therefore stimulation-bound feeding is probably not mediated by the nigrotectal pathway.

[New attitudes in the therapy of splenic injuries]

The serious sepses, even deadly, which can follow an operation of splenectomy because of the reduced immunological capacities persuaded the Authors to confirm the necessity to safeguard spleen especially after lesions due to traumata.

[Gastric leiomyoma (presentation of 3 clinical cases)]

Gastric leiomyoma represents a rather rare report in abdominal surgery, above all because it very often shows no symptoms. Among the non-epithelial gastric neoplasms, it occupies the second place after lymphoma. After describing its anatomo-pathological aspects and clinical features, the authors report their casuistry, including three observations of such neoplasm, and point out that both the endoscopic inspection and the bioptic abstraction, contextually performed, were not so useful in formulating a sure preoperative diagnosis.

Effect of hyperprolactinemia and age on the hypogonadism of uremic men on hemodialysis

Primary hypogonadism has been commonly reported among uremic men on hemodialysis, characterized by low testosterone levels, increased luteinizing hormone and sometimes follicle-stimulating hormone levels. Little is known about the influence of hyperprolactinemia and age on this hypogonadism. In 149 hemodialysis patients and in 60 healthy subjects the serum levels of testosterone (T), gonadotropins (LH and FSH) and prolactin (PRL) were assessed through radioimmunoassay. Mean +/- SD hormone levels were: T 274 +/- 125 ng/100 ml, lower than controls; LH 44.7 +/- 46.1 mlU/ml and FSH 17.6 +/- 18.4 mIU/ml, both higher than controls. PRL 31.3 +/- 49.4 ng/ml, higher than controls. A positive correlation between LH and FSH, a negative correlation between PRL and both T and LH was found. Moreover T and FSH were correlated with age only in the normoprolactinemic patients. These data suggest: a common damaging mechanism by uremia on both interstitial and tubular structures of the testis; a central antigonadal influence of hyperprolactinemia even if a direct action on the testis cannot be excluded; a worsening action of age on the gonadal function of these patients.

Hyperprolactinemia and sexual disturbances among uremic women on hemodialysis

The investigation of a sample of 99 women on maintenance hemodialysis has shown the presence of sexual disturbances to a great extent: the rate of sexual intercourse and the ability to reach orgasm were significantly lower than in age-matched control women. 80% declared a reduction in their sexual desire and the frequency of intercourse was also lower as compared to the period prior to dialysis. Ageing decreased the sexual activity in both the ill and healthy population, but in uremic patients the sexual activity ended at an earlier age. The patients with hyperprolactinemia reported lower frequencies of intercourse and lower percentages of orgasm than normoprolactinemic ones. The incidence of sexual dysfunction and the role of hyperprolactinemia in this respect were similar to those which are found among male patients on hemodialysis.

[Urologic complications in kidney transplants: experience in 274 transplants]

The urological complications after a renal transplantation still represent an event anything but rare, ranging, according to the different statistics, from 0.9% up to 23%, with a mortality between 0 and 25%. In this work done by the Verona Centre the experience on 274 transplantations is reported. The urological complications weighed with 6.2% and absence of mortality among the patients. The importance of the prevention and precocious diagnosis is confirmed.

Head-dipping by rats with lesions of superior colliculus during extended testing in hole-board

It has previously been shown that rats with large lesions of the superior colliculus fail to head-dip during a 5 min hole-board test. To investigate whether this was a permanent deficit in exploratory behaviour arising from inability to produce the appropriate responses, collicular rats were tested in a hole-board for 60 min or more. The period before their first head-dip (mean 27 min 40 sec) was much longer than for unoperated animals (mean 22 sec), but subsequently the collicular rats showed a pattern of head-dipping that was similar (although not identical) to that of the control rats. It appears that rats with lesions of the superior colliculus are not permanently prevented from exploring the hole-board by inability to produce the required response, but rather that they may have difficulty in discovering certain features of novel environments.

Human papillomavirus structural antigens in squamous papillomas of the male urethra

Twenty-five squamous papillomas of the male urethra were examined for the presence of human papillomavirus (HPV) whole (structural) virion antigens by a peroxidase-antiperoxidase technique having immunospecificity against genus-specific (common) antigens of the papillomavirus genus. Eleven of 25 (44 per cent) lesions were positive for HPV. The positive reaction was invariably intranuclear in the superficial epithelium. Evidence suggests that these papillomas arise by HPV infection of metaplastic squamous epithelium and not transitional epithelium. This study shows that at least some squamous papillomas of the male urethra are associated with HPV infections and suggest that this lesion may play an important role in venereally transmitted diseases such as cervical dysplasia and condylomas of the vulva and anus.

A quantitative analysis of stereotyped gnawing induced by apomorphine

An apparatus was designed and constructed to enable a quantitative analysis of the stereotyped gnawing produced by the dopamine agonist apomorphine. Using this apparatus it was discovered that increasing the subcutaneous dose of apomorphine increased (1) the number of animals that gnawed, and (2) the duration of gnawing in those animals that gnawed at all doses. Other aspects of apomorphine-induced gnawing, in particular the latency to respond and the frequency and duration of individual gnaws, were relatively unaffected. Likely properties of the system responsible for the organization of sterotyped gnawing are discussed.

Suppression of apomorphine-induced oral stereotypy in rats by microinjection of muscimol into midbrain

Rats with large lesions of the superior colliculus do not display the oral stereotypy normally induced by high systemic doses of dopamine-agonists. It has been suggested that collicular lesions have such an effect because they destroy the GABAergic nigrotectal pathway. This suggestion was investigated by observing the effects of bilateral microinjections of the GABA-agonist muscimol into midbrain sites in rats given 8 mg/kg subcutaneous apomorphine. A low dose of muscimol (25 ng in 0.5 ul saline/side) injected into regions of the superior colliculus with nigrotectal innervation almost abolished apomorphine-induced licking and gnawing. Control microinjections of saline into the superior colliculus, or of muscimol into overlying cerebral cortex, were ineffective. This result is consistent with the GABAergic nigrotectal projection being important for the expression of dopamine-related oral stereotypy. It was also found, however, that 25 ng of muscimol suppressed oral stereotypy when microinjected into the mesencephalic reticular formation underlying the superior colliculus. The anatomical basis of this latter effect is uncertain.

Locomotor activity of rats in open field after microinjection of procaine into superior colliculus or underlying reticular formation

Whereas large lesions of the superior colliculus in rats increase locomotor activity in the open field, bilateral collicular microinjections of muscimol (an agonist of the inhibitory neurotransmitter GABA) have been reported to reduce open-field activity. This difference might be due to muscimol's acting on a subpopulation of collicular neurones, or to some feature of the microinjection technique. The issue was investigated by observing open-field behavior after reversible lesions produced by bilateral microinjections of the local anaesthetic procaine (10-300 micrograms in 0.5 microliter) into midbrain sites. Injections of procaine into the superior colliculus produced effects similar to those reported after muscimol injections: both locomotor activity and other exploratory responses were suppressed, with the rats spending much of their time motionless in an alert posture. In contrast, animals with injections of procaine into the mesencephalic reticular formation (MRF) ventral to the superior colliculus resembled rats given large collicular lesions: they showed very striking increases in locomotor activity, while their rearing and exploratory head movements were reduced. It is suggested that in some experiments large collicular lesions may have increased locomotor activity in the open field because they invaded underlying MRF. However, it is also possible that in rodents the acute effects of collicular inactivation, as assessed by microinjection of muscimol or procaine, are different from the chronic effects that are observed in experiments with electrolytic or radiofrequency lesions.

Increased food intake following the manipulation of intracerebral dopamine levels with gamma-hydroxybutyrate

The administration of gamma-hydroxybutyric acid (GHB) initially causes a temporary "sleep-like" state during which there is an increase in forebrain dopamine levels. The present series of experiments examined whether in the period following the GHB-induced behavioural depression, when accumulated dopamine is dispersed, there is any behavioural evidence of increased dopaminergic activity. The first experiment, in which GHB was injected directly into the cerebral ventricles, demonstrated that in the immediate post-recovery period rats exhibited various forms of stereotyped oral behaviour and stereotyped sniffing. Unexpectedly, it was also observed that if food were present animals preferred to eat. The nature of this feeding response was examined in two further experiments. Firstly, it was shown that in the period following the behavioural depression animals would perform, in a dose-dependent fashion, an operant response which was rewarded by food. Secondly, the GHB-induced increase in feeding was abolished by the pre-treatment of animals with either the dopamine synthesis inhibitor alpha-methyl-p-tyrosine, or the dopamine receptor blocker haloperidol. These data indicate that (i) in the period when it is known that the GHB-induced accumulation of dopamine is dispersing, there is behavioural evidence of increased dopaminergic activity; (ii) the feeding response is not a simple oral reflex; and (iii) in addition to being essential for food intake dopaminergic transmission may play a direct role in the production of feeding.

Screening for breast cancer in a high-risk series

A unique cohort of women at increased risk of breast cancer because of prior X-ray treatment of acute mastitis and their selected high-risk siblings were offered periodic breast cancer screening including physical examination of the breasts, mammography, and thermography. Twelve breast cancers were detected when fewer than four would have been expected based on age-specific breast cancer detection rates from the National Cancer Institute/American Cancer Society Breast Cancer Demonstration Detection Projects. Mammography was positive in all cases but physical examination was positive in only three cases. Thermography was an unreliable indicator of disease. Given the concern over radiation-induced risk, use of low-dose technique and of criteria for participation that select women at high risk of breast cancer will maximize the benefit/risk ratio for mammography screening.

Oral behaviour induced by intranigral muscimol is unaffected by haloperidol but abolished by large lesions of superior colliculus

It has been suggested that the GAbAergic striatonigral projection may form part of the efferent pathway responsible for the expression of dopamine-related oral behaviour. Consistent with this suggestion are reports that bilateral injection of the GABA agonist muscimol can produce stereotyped gnawing and biting. We report here two experiments on this effect: (1) A dose of the dopamine receptor blocker haloperidol (0.4 mg/kg), which effectively antagonised oral stereotypy induced by systemically administered apomorphine or intranigral carbachol, had no effect on either the latency or the intensity of the gnawing produced by intranigral muscimol (1 nM); (2) large lesions involving the superior colliculus which effectively suppressed the oral stereotypy induced by 8 mg/kg apomorphine completely abolished the gnawing induced by intranigral injection of muscimol. Collicular lesions suppressed both the gnawing which occurred spontaneously and that elicited by a perioral probe. These findings are consistent with the view that the substantia nigra is a relay station between the caudate nucleus and the superior colliculus in an efferent pathway mediating dopamine-related oral behaviour. In addition, they raise the possibility that such behaviour is produced by the sensitisation of a collicular-mediated perioral reflex.

Visual pathways and acuity hooded rats

Three experiments on the effects of lesions of the visual system on contrast-detection in hooded rats are described, in which the ability of rats to detect stationary high-contrast square-wave gratings of various fundamental frequencies presented in the central visual field was measured before and after operation. The results suggested the following conclusions: (i) The pathways from retina to striate cortex via dorsal lateral geniculate nucleus (dLGN) conveys information about high spatial frequencies sufficient for normal detection of these gratings, that is up to about 1 cycles/deg. It may be the only pathway to carry this information, and may thus play a unique role in the analysis of fine detail. The high-frequency information is probably relayed from striate cortex to extrastriate cortex, rather than to subcortical sites. (ii) The superior colliculus receives information from the retina up to at least 0.7 cycles/deg, which it then relays to extrastriate visual cortex, probably via the lateral posterior nucleus of the thalamus. (iii) Neither the projections from superior colliculus to other, non-thalamic sites nor the remaining pathways from the retina (e.g. to ventral LGN) appear to carry contrast information higher than 0.3 cycles/deg. These sets of projections therefore do not appear to be used for precise analysis of stationary scenes. These findings suggest that there are considerable similarities between the visual systems of rats and other mammals with respect to the routing of information about stationary spatial contrast, and may help to explain the results of some experiments that have used tasks besides contrast-detection to assess the visual capacities of rats after lesions.

Meridional variation in visual acuity of hooded rats reared in a carpentered environment

Resolution acuity in people is frequently better for horizontal and vertical gratings than for obliques. An animal model of this oblique effect might be of help in elucidating its underlying neural mechanisms. Rats were chosen because laboratory rats area reared in a 'carpentered environment' apparently similar to those proposed to cause the oblique effect in people, and because electrophysiological experiments suggest that orientation selective units in rats' visual cortex may prefer horizontal and vertical stimuli. The acuity of eight laboratory-reared hooded rats was measured with high-contrast horizontal, vertical, and oblique gratings. The animals learned to detect low-frequency square-wave gratings with slightly fewer errors if they were horizontal or vertical than if they were oblique, but the effects of grating orientation on acuity were not significant. Refraction of the rats' eyes gave no evidence of astigmatism. These results suggest that the rat may not be a good animal model for studying the mechanisms that underlie meridional variations in acuity in people, and raise questions concerning both the neural bases of resolution acuity, and the validity of the 'carpentered environment' hypothesis.

Visual discrimination learning in rats with lesions of superior colliculus: door-push and approach errors in modified jumping stand

It has been suggested that, for some species, lesions of the superior colliculus affect visual discrimination learning, but only in certain conditions: (a) when problems are first learnt only after operation, or (b) when discriminanda require detailed scanning, or (c) when “approach” responses to the discriminanda are measured, rather than the response of actually touching them. These suggestions were examined in rats learning visual discriminations in a modified jumping-stand apparatus, after sustaining large lesions of the superior colliculus (and in some cases also of the pretectum). The lesions produced open-field hyperactivity and reduced exploration, indicating effective tectal damage, but the rats learnt a series of difficult discriminations in a door-push task as fast as normal rats, and they did not make more approach errors. Their main abnormality in the discrimination apparatus was that they looked less often between the stimulus doors before stepping across to one of them from the central platform. It is suggested that in rats, as in other animals, lesions of the superior colliculus disrupt the control of scanning head and eye movements; in rats, however, such disruption need not affect discrimination learning (at least in some kinds of apparatus), possibly because the retina of the rat has a relatively poorly developed area centralis.

Grating detection and visual acuity after lesions of striate cortex in hooded rats

The ability of rats to detect high-contrast square-wave gratings over a range of spatial frequencies was measured before and after ablation of striate cortex. The animals relearnt to detect low-frequency gratings very quickly after operation, and their acuity was reduced from 1.0 c/deg to about 0.7 c/deg. These effects were in striking contrast to those produced by larger posterior cortical ablations, which included both striate and prestriate cortex (Dean 1978); after the larger lesions, rats required many weeks of retraining to detect even low-frequency gratings and their acuity was reduced to 0.3 c/deg. The difference in the effects of the two lesions suggested that the rats with striate ablation were using information about spatial contrast that was relayed either by spared remnants of the geniculo-cortical pathway, or by the pathway from superior colliculus to prestriate cortex via the lateral posterior nucleus. To try and distinguish between these possibilities, the destriate rats were given a further lesion of the superior colliculus. This second lesion severely disrupted contrast detection: the animals made about as many errors as rats with large posterior cortical removal in relearning to detect a low-frequency grating, which is about 20 to 30 times as many as after either striate cortex or superior colliculus lesions alone. This result suggests that rats, like other mammals, can use spatial information conveyed in the tectocortical path when striate cortex has been destroyed.

Rewarding effects of hypothalamic self-stimulation altered by unilateral lesions of superior colliculus in rats

The effects of unilateral lesions of the superior colliculus were determined on self-stimulation of the medial forebrain bundle. It was found that the lesions had different effects depending upon the precise location of the stimulating electrode: self-stimulation on far-laterally located electrodes was abolished while on more medially placed electrodes this behaviour was enhanced. These data are inconsistent with explanations of intracranial self-stimulation which treat it as a unitary phenomenon.

Are rats short-sighted? Effects of stimulus distance and size on visual detection

Behavioural evidence concerning short-sightedness in rats is apparently conflicting: in some experiments rats have performed poorly with visual stimuli further than about 60 cm distant, while in others they have made efficient use of more distant cues, for example to find their way through mazes. However, in the experiments suggesting short-sightedness, the physical size of the stimuli was not varied, so that stimulus distance and visual angle were confounded. In the present experiment, therefore, the size and distance of the stimuli to be detected were varied independently. Over the range tested (30–160 cm), distance was found to produce relatively slight effects on the smallest detectable visual angle, and these tended to diminish with practice. Thus, no good evidence was found for short-sightedness in rats up to 160 cm, a finding consistent with current views of the structure and image-forming capacities of the rat's eye. The smallest detectable targets were, however, surprisingly large in view of the rat's visual acuity (which is about 1c/deg): at the distances tested, animals required considerable training to run reliably to targets subtending less than 5–10° of visual angle. Difficulties in responding to stationary stimuli of this size are likely to restrict severely the use that rats make of vision both in the laboratory and in their natural surroundings.

A flow system for partial automation of plating efficiency tests

A flow system that sterilely deposits a known number of cells into a collection vessel has been constructed and evaluated. In this device, the cells from a single-cell suspension flow through a nozzle that constrains them to the center of the emerging jet. The cells in the jet are illuminated by a 0.5-mW helium-neon laser; they are detected, sized and counted on the basis of the light scattered as they pass through the laser beam. The device has been used for plating efficiency tests in a tissue culture laboratory. We found that it saved considerable labor by eliminating the dilution step from the standard plating efficiency procedure. The biologic effect of machine plating was determined by comparing plating efficiencies of KHT, CHO-T5, and CHO-AA8 cells established by hand plating with those established by machine plating. Results indicate that machine plating reduces the plating efficiency of the CHO-T5 cells while the plating efficiencies of the CHO-AA8 and KHT cells are unaffected.

Gnawing and changes in reactivity produced by microinjections of picrotoxin into the superior colliculus of rats

Lesions of the superior colliculus in rats attenute the oral stereotypy produced by systemic administration of dopamine agonists. Current evidence suggest that such drugs affect the superior colliculus by reducing transmission in the inhibitory GABAergic nigrotectal pathway. To investigate whether the superior colliculus plays a direct role in producing stereotyped oral movements, the present experiment therefore examined the effects of collicular microinjections of the GABA antagonist picrotoxin on the behaviour of rats observed in an open-field. Gnawing was observed after injections of picrotoxin (25 ng) into sites in the intermediate and deep layers of the superior colliculus, consistent with the superior colliculus playing a direct part in producing the stereotyped gnawing seen after systemic administration of dopamine agonists. However, gnawing was only observed after a period in which the animal showed strong avoidance reactions to stimuli that normally evoked orienting or little reaction. This change in reactivity was observed after injections of picrotoxin into all parts of the colliculus, but the most sensitive (responding to doses as low as 12.5 ng) were mainly in the superficial and intermediate layers. It appears that there may be more than one GABAergic system within the superior colliculus.

Collicular picrotoxin alleviates akinesia but not sensory neglect in rats with bilateral 6-hydroxydopamine lesions of ventral midbrain

Anatomical and biochemical investigations have suggested that GABA transmission in the superior colliculus consequent upon activity of the nigrotectal pathway is increased following 6-hydroxydopamine (6-OHDA) lesions of the ascending dopamine systems. Moreover, it has been proposed that this increase in inhibitory activity within the colliculus may be responsible for the sensory neglect commonly observed after dopamine denervation. The present experiment sought to test this proposal by examining the effects of injections of the GABA antagonist picrotoxin into the superior colliculus of 6-OHDA lesioned rats, in the hope that the neglect caused by the 6-OHDA would be reversed. However, in 33 of 36 cases studied intracollicular microinjections of picrotoxin produced no detectable improvement in orientation to sensory stimuli, although a wide range of other behavioural effects was observed. These included stereotyped exploratory movements (e.g. head waving, walking, sniffing and rearing) similar to those produced in the 6-OHDA treated rats by systemic injection of apomorphine (0.1 mg/kg). These data indicate that 6-OHDA lesions of substantia nigra and ventral midbrain areas do not produce sensory neglect simply by increasing GABA transmission within the nigrotectal pathway. Instead, such an increase in nigrotectal activity may impair production of particular kinds of movement, possibly related to exploratory behaviour.

[Relation between cytomegalovirus infection and the so-called intolerance to azathioprine in renal transplantation]

Renal transplant recipients can develop hepatic function abnormalities or severe leucopenia after transplantation. Generally it is thought to be due to azathioprine intolerance and patients are treated by curtailment of immunosuppressive therapy, being subsequently at risk to lose their allograft because of rejection. Evidence of Cytomegalovirus (CMV) infection is also common after renal transplantation. It is generally thought that the majority of these infections are asymptomatic, but they can be accompanied by leucopenia and/or hepatic function abnormalities. Sixty-nine renal transplant recipients have been studied for at least three months in order to investigate the relationship between CMV and azathioprine intolerance after transplantation. Twenty-five out of 58 patients who underwent seroconversion to CMV (a fourfold or greater rise in titer of CMV antibodies) after transplantation or who had a high CMV titer (greater than or equal to 1 : 16) prior to transplant, developed azathioprine intolerance. None of 11 patients who before renal transplantation had low CMV titers and who did'nt underwent seroconversion did not tolerate azathioprine. Therefore the Authors advance the hypothesis that azathioprine intolerance following renal transplantation can be often due to an asymptomatic and unknown CMV infection.

Dissociation of d-amphetamine-induced locomotor activity and stereotype behaviour by lesions of the superior colliculus

To investigate the role of the nigrotectal pathway in the expression of the behavioral effects of increased dopamine transmission, the behavior of rats with lesions of the superior colliculus was studied in open-field and hole-board after systemic administration of d-amphetamine. The rats with collicular lesions had higher locomotor activity scores than controls after saline injections, and after all doses of amphetamine studied (0.5-24 mg/kg): the difference was particularly marked at the highest doses used (16 and 24 mg/kg). Stereotyped behavior, on the other hand, was less pronounced in the rats with collicular lesions, who unlike controls rarely showed stereotyped sniffing, head waving, or forepaw padding while moving about in either apparatus, and never licked or gnawed in the hole-board. This evidence suggests that the nigrotectal pathway may play a role in the expression of some of the stereotyped behaviors observed after the administration of dopamine agonists, but that it is not necessary for the increased locomotor activity produced by such drugs.

[Internal arteriovenous fistula in the antecubital region]

An assessment was made of the anterior cubital region as a vascular approach for primary and alternative dialysis. Reference is made to 36 fistulae in this area within 44 months' survival in the drawing of various conclusions with regard to surgical technique. End anastomosis of the median, cephalic or basilic vein laterally on the brachial or radial artery is recommended as a means of preventing or cutting down the more common complications associated with internal arteriovenous fitulae. The anastomosis should not exceed 6 mm in diameter. Complications led to loss of fistula function. In many cases, however, they did not prevent employment of the region for alternative approaches, such as superficialisation of the basilic vein or prosthesis.