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PubMed1975

Problems of a temporary adolescent psychiatrist.

I have tried to describe just less than one year of learning experience on my part in one type of adolescent unit. Only 16 inpatients were treated at a time while I was there: there were only 25 discharges and 19 admissions in my time. We knew we were making little inroad into our whole regional problem of adolescent disturbance; but we believe that as a team, able to work closely with each other and with our patients and their relatives, in a therapeutic community of undogmatic ideology, we were able to give a little to almost all and, to those who did best, a great deal. Very few ex-inpatients lost all touch with us. Nearly all came back from scattered homes for our Christmas discotheque. Even our very modest aim, to reset and then foster the natural development of the personalities of our patients, rather than break them down in deep analysis and radically reconstruct them, required an intensity of psychotherapeutic effort which engaged all we had to offer, and often drained us at the end of the day. Yet those who joined us transiently, particularly student nurses and medical students, seemed to find the experience significant--occasionally deeply so--and came back to visit us. Our social worker has now departed to have a baby. Our three senior nurses have left, two to university as mature students, one to prepare for a no. 7 post. Possibly the intensity of the demand upon them would have made them leave, anyway. For myself, it was a year of development of my psychotherapeutic sensitivity and of close working with a valued team of colleagues in a setting new to me, which I shall never forget.

Adolescent↗

PubMed1995

Distribution and development of beta-adrenergic receptors in the rat olfactory bulb.

Beta-adrenergic stimulation appears to be involved in the establishment of both learned olfactory preferences and functional changes in the olfactory bulb of young rats. We examined the postnatal development of beta-adrenergic receptors within the main olfactory bulb to determine the density and distribution of these receptors. To quantify beta-adrenergic receptor density, olfactory bulb homogenates from postnatal day (PND) 1, 6, 12, and 19 rats were assessed for receptor binding with 125I-iodopindolol. In addition, receptor autoradiography was performed with the selective beta 1 antagonist ICI 89,406 and selective beta 2 antagonist ICI 118,551 on tissue sections from PND 1-30 rats to examine the distribution of the beta-adrenergic receptor subtypes. We observed both an increase in receptor density with increasing age and the formation of distinct spatial distributions of the two beta receptor subtypes within the bulbar lamina. Beta-adrenergic receptors were located in both deep and superficial layers of the bulb. Specifically, beta 1 receptors were present in the granule cell, internal plexiform and glomerular layers. beta 2 receptors were present in the granule cell, internal plexiform, external plexiform, and glomerular layers. High levels of beta 2 receptors also were visible in the meningeal layers between the two bulbs. High densities of beta 1 and beta 2 adrenergic receptors were present within different sets of individual glomeruli by PND 12-19, and the number of these foci increased with age. The knowledge of beta-noradrenergic receptor localization in the bulb may provide the basis for understanding the action of norepinephrine on neural processes in the developing olfactory bulb.

Animals↗

PubMed1999

Delayed reverberation through time windows as a key to cerebellar function.

We present a functional model of the cerebellum comprising cerebellar cortex, inferior olive, deep cerebellar nuclei, and brain stem nuclei. The discerning feature of the model being time coding, we consistently describe the system in terms of postsynaptic potentials, synchronous action potentials, and propagation delays. We show by means of detailed single-neuron modeling that (i) Golgi cells can fulfill a gating task in that they form short and well-defined time windows within which granule cells can reach firing threshold, thus organizing neuronal activity in discrete 'time slices', and that (ii) rebound firing in cerebellar nuclei cells is a robust mechanism leading to a delayed reverberation of Purkinje cell activity through cerebellar-reticular projections back to the cerebellar cortex. Computer simulations of the whole cerebellar network consisting of several thousand neurons reveal that reverberation in conjunction with long-term plasticity at the parallel fiber-Purkinje cell synapses enables the system to learn, store, and recall spatio-temporal patterns of neuronal activity. Climbing fiber spikes act both as a synchronization and as a teacher signal, not as an error signal. They are due to intrinsic oscillatory properties of inferior olivary neurons and to delayed reverberation within the network. In addition to clear experimental predictions the present theory sheds new light on a number of experimental observation such as the synchronicity of climbing fiber spikes and provides a novel explanation of how the cerebellum solves timing tasks on a time scale of several hundreds of milliseconds.

Action Potentials↗

PubMedDate not supplied

Mechanical and infectious complications of central venous cannulation in children: lessons learned from a 10-year experience placing more than 1000 catheters.

We sought to better describe the expected incidence of mechanical and infectious complications associated with central venous cannulation of critically ill children. We undertook a retrospective analysis of a prospective data collection of 1056 consecutive percutaneous central venous catheters inserted under the supervision of an experienced surgeon. There were 245 (23%) subclavian (SC), 118 (11%) internal jugular (IJ), and 693 (66%) femoral (F) catheters placed in 289 children with an average age of 6.4 +/- 5.1 years (range, 4 weeks to 18 years) admitted to a burn intensive care unit. Catheter sepsis occurred in 7.4% of SC, 7.6% of IJ, and 4.9% of F catheters (NS, P = .25), for an overall sepsis rate of 5.8%. The number of catheter lumens did not impact infection rate. Infection rates increased in catheters left in situ more than 10 days, increasing to 37.5% at 14 days. Acute mechanical complications occurred in three insertions (0.3%), including two (0.8%) SC, zero (0%) IJ, and one (0.1%) F catheters (NS, P = .20). All three were arterial cannulations that were recognized and treated successfully without surgery. There were no pneumothoraces, vascular lacerations, acute thromboses, or catheter emboli. There were six (0.6%) cases of deep venous thrombosis that occurred in cannulated sites: one (0.4%) SC, two (1.6.%) IJ, and three (0.4%) F sites (NS, P = .23). Patient age did not influence complication rates. A total of 239 (23%) of the CVCs were placed in infants less than 24 months; 273 (26%) 2 to 5 years, 259 (25%) 6 to 10 years, and 285 (27%) >10 to 18 years. Catheter sepsis occurred in 6.7%, 5.9%, 6.2%, and 4.6%, respectively (NS, P = .75). There was no difference in rates of infection or mechanical complication between younger and older children. When closely supervised by an experienced surgeon, a low rate of infection (5.8%), acute mechanical complication (0.3%), and deep venous thrombosis (0.6%) accompanies central venous cannulation of critically ill children.

Adolescent↗

PubMed1991

Versatile controlling system for cryopreparation techniques in electron microscopy.

A new setup for freeze-substitution and a versatile controlling system has been developed. Our goal was to build a simple system allowing precise control of the physical parameters of freeze-substitution experiments to learn more about their influences on the cellular ultrastructure and immunoreactivity of macromolecules. An improved apparatus for freeze-substitution, based on liquid nitrogen cooling, and a universal software for controlling the complex preparation protocols from cryofixation to final polymerization are described. This controlling system has the following advantages: it allows precise control and registration of temperature profiles, reconstruction of each individual step of previous experiments, and optimization of working conditions. The setup of the freeze-substitution apparatus is designed to run many different substitution media in parallel; freeze-substitution (cryostat), embedding (working platform), and polymerization are carried out at separate places; therefore, more experiments can be done simultaneously. The ergonomic working platform allows exchange of media at controlled temperature and easy handling; survey of the temperature in individual tubes is possible, and the system is protected from water condensation and uncontrolled warming by the deep freezer.

Computers↗

PubMed2003

Cognitive sciences and psychoanalysis: a possible convergence.

This paper compares the psychoanalytic description of inner experience with that of the cognitive sciences, which see it in terms of information processing. The two observational standpoints relate to the same mental events. The author considers the possibility of bringing the two descriptions into line with each other and of their mutual translation. The "information" processed in the deep, unconscious, affective, internal experience of a relational context must be identified. This may be possible if a general theory of mental functioning that allows for the data of psychoanalytic observation in terms of semantics, memory, and communication can be formulated. The author examines the theoretical tradition of psychoanalysis, and draws attention to the uncertainties to which Freud's metapsychology gives rise. The energy/drive theory was not only descriptive and clinical in nature, but also had explanatory value, which put psychoanalysis in contact with the other mental sciences of the time. This explanatory value is no longer valid today, and psychoanalytic theories since Freud seem to have disregarded the aspect of "explanation," leaving a theoretical void that has isolated psychoanalysis from the other sciences of the mind. The author contends that object theories may be an appropriate starting point for the exploration of experience in terms of learning processes and of memory traces, and suggests a psychoanalytic cognitivism, coupled with a personal theory to explain the development of the mind.

Cognitive Science↗

PubMed2004

Continuing psychological care.

This article draws together thoughts derived from an experienced clinical psychologist's practice, with parents of ill and premature infants in the context of a psychological service for children and parents in a paediatric and maternity teaching hospital. Parents were those referred by attendant neonatologists in intensive neonatal care who observed acute distress. Referral was usually some weeks after birth and help continued until after discharge, in some instances after the death of the infant. The particular approach adopted was that of offering parents a therapeutic contact which, allowed them talk over these thoughts and feelings for which they had little other skilled listening environment. Parents chose the opportunity of a safe, calm and confidential contact to explore deep feelings and draw on their own strengths and an understanding of their own vulnerabilities. The novel insights derived and the clinical material presented were used to develop an understanding of the issues a support service should address. Key aims are described and should be incorporated to restore and enhance personal strengths and the mother child relationship hence contributing to positive outcome in infant development. Reference is made to the importance of understanding how women achieve soothed states and restoration of empowerment when birth presents extra challenge.

Child Development↗

PubMed2004

Everyday uses of adult orthodontics.

Adults are now much more in favor of receiving orthodontic treatment than in the past. The baby boomer generation has a deep desire to keep their "youngness" and is willing to invest in such. Along with this attitude has come the ability to treat malocclusions and other clinical deficiencies with new products that decrease the treatment time. Nickel titanium wire has revolutionized the mechanics of treatment, so that often only one wire need be used throughout treatment, and the time of care has been reduced. Invisalign has resulted in higher acceptance rates for treatment that was passed up before. Although Invisalign has its limitations, for most basic alignment, it can provide a nice result. Patients who might come to an office for Invisalign can be open to braces if Invisalign will not correct their problem. In this article, several uses of adult orthodontics have been shown. It behooves the general practitioner to refer those cases that can benefit from the multiple uses of orthodontics. Should the GP desire to learn to perform any or all of the tooth movements necessary to create a more desired outcome, there are several marketed orthodontic courses that will provide the knowledge necessary. Finally, I encourage those who would enjoy treating patients with orthodontic needs. I have found it to be very rewarding to work toward a shared outcome that is often a less invasive treatment. Patients really enjoy the results.

Adult↗

PubMed1994

The distribution of tyrosine hydroxylase-immunoreactive fibers in the human entorhinal cortex.

The entorhinal cortex plays an important role in learning and memory, and it has been implicated as a site of dysfunction in some neuropsychiatric disorders such as schizophrenia. The organization of many components of the neural circuitry of this region, including dopaminergic afferents, has not been studied in detail. Using immunohistochemical techniques, we examined the density and laminar distribution of axons immunoreactive for tyrosine hydroxylase, the rate limiting enzyme in catecholamine biosynthesis, in the entorhinal cortex of eight control human brains. The density of tyrosine hydroxylase-containing axons decreased from rostral to caudal regions of entorhinal cortex. In addition, there was a prominent medial to lateral gradient of increasing fiber density. This gradient extended into the adjacent transentorhinal cortex, which contained the highest density of labeled axons of the regions studied. The laminar distribution of tyrosine hydroxylase-containing fibers also differed among the subdivisions of the entorhinal cortex. A bilaminar pattern of labeled axons in layers deep I-superficial II and in deep layer VI was present in the intermediate and caudal subdivisions of entorhinal cortex. In contrast, the olfactory and rostral subdivisions, as well as portions of the transentorhinal region, contained a trilaminar pattern, with a high density of tyrosine hydroxylase-immunoreactive axons in layers deep I-superficial II, deep III-IV and deep VI. In addition, radially-oriented bands of labeled fibers were observed extending between deep layer I and layer III, particularly in the rostral subdivision of the entorhinal cortex. In summary, tyrosine hydroxylase-containing afferents to the human entorhinal cortex are distributed in a characteristic regional and laminar pattern, and the lateral regions of the entorhinal cortex and the adjacent transentorhinal cortex are particularly densely innervated. These data contribute to the understanding of the normal circuitry of the human entorhinal cortex, and are of potential relevance to the pathophysiology of certain neuropsychiatric disorders, such as schizophrenia.

Adult↗

PubMed1999

Automatic activation of the medial temporal lobe during encoding: lateralized influences of meaning and novelty.

In contrast to early failures, recent functional brain imaging studies have shown that medial temporal lobe (MTL) structures are active during performance of a variety of tasks. These studies have revealed three properties of the MTL that are consistent with its critical role in establishing new declarative memories. First, the MTL is automatically engaged whenever an event is experienced, with the side of activation (left, right) dependent on the nature of the material presented (verbal, nonverbal). Second, the strength or amount of activity depends on how well the material is encoded. Deep encoding will produce more MTL activity than shallow encoding. Depth of encoding-related increases in activity are more commonly seen on the left, because deep encoding is nearly always synonymous with encoding for meaning, and, therefore, depends on left-lateralized language mechanisms. Third, the amount of MTL activity depends on novelty. Unfamiliar events and contexts will produce more MTL activity than familiar events and contexts. Novelty-related increases are more commonly seen on the right, perhaps reflecting the greater role of the right hemisphere in maintaining tonic attention and arousal. These findings suggest a hemispheric division of labor involving encoding for meaning (left) and novelty detection (right), both of which lead to better remembering.

Arousal↗

PubMed1991

Physiology of short-term verbal memory.

These studies document a series of brain events accompanying short-term memory functions. For auditory verbal material the sequence involves at least two different sites within auditory cortex subserving sensory and cognitive processes of memorization. During the scanning of the short-term store structures within the medial temporal lobes, presumably the hippocampus, are active. There is an inconsistency between these results and the clinical observations of the need for an intact dominant parietal lobe for auditory short-term memory to function normally. Magnetic recordings showed no focal dipolar source of activity in the parietal lobe during any aspect of auditory short-term memory. The discrepancy could be accounted for by considering the parietal lobe lesion as "disconnecting" the lateral temporal cortex from the deep medial hippocampal structures thereby impeding auditory short-term functions (Geschwind, 1965). These studies show that the physiological analysis of brain events in the msec range can provide information about relatively complex cognitive processes underlying short-term memory. The magnetic and electrical recording methods provide a noninvasive way to study human brain functions involved in cognition that can then be correlated with behavioral measures of specific cognitive activities.

Brain↗

PubMed2001

The use of source memory to identify one's own episodic confusion errors.

In 4 category cued recall experiments, participants falsely recalled nonlist common members, a semantic confusion error. Errors were more likely if critical nonlist words were presented on an incidental task, causing source memory failures called episodic confusion errors. Participants could better identify the source of falsely recalled words if they had deeply processed the words on the incidental task. For deep but not shallow processing, participants could reliably include or exclude incidentally shown category members in recall. The illusion that critical items actually appeared on categorized lists was diminished but not eradicated when participants identified episodic confusion errors post hoc among their own recalled responses; participants often believed that critical items had been on both the incidental task and the study list. Improved source monitoring can potentially mitigate episodic (but not semantic) confusion errors.

Adult↗

PubMed2005

Prophylaxis for and treatment of deep venous thrombosis after stroke: the Post-Stroke Rehabilitation Outcomes Project (PSROP).

Deep venous thrombosis (DVT) is a common and preventable complication after a stroke. Although the treatment of DVT is simple and straightforward, its prevention remains controversial. The Post-Stroke Rehabilitation Outcomes Project (PSROP) database was used to describe the incidence and temporal sequence of DVT and trends in the prevention and treatment of DVT. Of the 1,161 patients in the PSROP database, 383 (32.99%) patients without DVT and 8 (0.69%) with DVT had no documented orders for anticoagulant medications. Sixty-five (5.60%) patients had DVTs during the inpatient rehabilitation facility stay. Of 10 (0.86%) patients with DVTs in the common femoral vein, 4 (40%) were diagnosed within 24 hours of admission. Nine (90%) of these 10 patients were classified as moderate or severe strokes. All patients with common femoral DVT received appropriate therapy. Although much is known about the prevention, diagnosis, and treatment of poststroke DVT, clinicians need to learn and apply treatment protocols to prevent DVTs and allow more quality time for rehabilitation.

Age Factors↗

PubMed1992

[A case of cerebral infarction presenting as retrosplenial amnesia].

We report a 73-year-old right-handed female who presented with an acute amnesic syndrome. On November 18, 1991, she was admitted to a local hospital complaining of sudden-onset vertigo and nausea, but immediately after the admission she developed an amnesic syndrome. On November 27, she was transferred to our hospital for further assessment of her memory disturbance. Neurologically she was normal except for mild right hemianopsia and increased deep tendon reflexes in the extremities. Neuropsychological assessments were performed over 3 weeks. She was always alert, attentive, and cooperative. She had no confabulation. On the Wechsler Adult Intelligence Scale revised (WAIS-R), her total IQ was 110. Frontal, verbal, and perceptual functions and motor performance were normal. She had no signs of a callosal disconnection. Despite these preserved functions, her memory function was obviously disturbed. Several memory betteries showed that her recent memory for both verbal and visual modalities was impaired, while her immediate memory such as digit span was preserved. For remote memory her retrograde episodic memory concerning both personal and public events was almost intact, although she had a profound anterograde amnesia. In particular she recalled her personal information about just-premorbid events in detail. On the other hand, her semantic memory, for example understanding of proverbs, geography, and scientific law, was preserved. Taken together, her procedural memory on learning tasks, such as "Tower of Hanoi" and mirror drawing, was intact. Computed tomography demonstrated a low-density area medial to the trigon of the left ventricle.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMedDate not supplied

Manual deep lamellar keratoplasty: alternative methods and air-guided technique.

PURPOSE: To describe the techniques proposed for performing deep lamellar keratoplasty (DLK) and to evaluate the efficacy of a new, modified technique. METHODS: Fourteen eyes in 11 patients with keratoconus of moderate degree were included. All patients underwent a DLK with manual dissection from a limbal side port after an air bubble injection in the anterior chamber. All patients had complete ophthalmologic examination 6 months after the suture removal, evaluating best corrected visual acuity, corneal thickness, endothelial cell count, and topographic astigmatism. RESULTS: One case (7.1%) was converted to penetrating keratoplasty because of microperforation. In the 13 successful cases, 10 eyes (71.4%) achieved 20/30 or better 6 months after suture removal. Mean postoperative pachymetry was 628.39 micro (SD 57.34). Specular microscopy 6 months after suture removal revealed average endothelial cell count of 2261 (SD 287/mm(2)). CONCLUSIONS: Comparing this modified DLK technique with other methods proposed by several authors, air-guided DLK seems to be safe and effective and, after a short learning curve, can be performed with a low risk of conversion to penetrating keratoplasty.

Adult↗

PubMed1974

Complementary lowering of the behavioural and physiological thermoregulatory set-points by tetrodotoxin and saxitoxin in the cat.

1. Injections of tetrodotoxin or saxitoxin (25 ng in 0.10 ml.) into a lateral cerebral ventricle caused deep body temperature of cats to fall approximately the same amount (2 degrees C) whether the animals were resting in the cold (4 degrees C) or were responding to escape heat.2. Continuous exposure to heat either prevented the hypothermic response or enhanced the level of tachypnoea required to lower body temperature. Tetrodotoxin also caused hypothermia when an animal was lever pressing to obtain heat in the cold environment.3. These results provide evidence that agents which alter the set-point for physiological thermoregulatory activity produce a complementary shift in the behavioural set-point as well.

Animals↗

PubMed2003

The self: clues from the brain.

Can we find a way of thinking about the self that is compatible with modern neuroscience? I think we can. First of all, we have to recognize that "the self" is not the same as "the conscious self," since much of who we are as individuals takes place out of conscious awareness. Second, we have to accept that some aspects of the self, especially the unconscious aspects, occur in and can be studied in other species, allowing us to relate these aspects of the self to detailed brain mechanisms. Finally, it also helps to think of the self in terms of memory. Obviously, much of who we are is based on memories learned through personal experience, including both conscious or explicit memories and unconscious or implicit memories. This is particularly important since much progress has been made in relating memory to the cells and synapses of the brain. By viewing the self as a network of memories the effort to relate the self to the brain can build on this progress. Emphasizing memory and experience does not take away from the fact that our genetic history also contributes to who we are. In fact, genes and experience, or nature and nurture, are, in the end, not different things, but different ways of doing the same thing-wiring the synapses of our brain. In many ways, the self is synaptic. This synaptic view of the self is not meant as a challenge to other views, such as spiritual, cultural, or psychological views. It is instead, just a way of understanding how these other aspects of who we are relate, deep down, to the brain.

Animals↗

PubMed1985

Radial maze in the water tank: an aversively motivated spatial working memory task.

An 8-arm radial maze with 40 X 40 X 12 cm channels was inserted into a circular tank (120 cm in diameter, 60 cm high) filled 30 cm deep with 25 degrees C opaque water. Rats (n = 13) had to escape from the central area of the maze (30 cm in diameter) onto an invisible bench (1 cm below water surface) at the far end of each channel. Twenty sec after each choice the bench was collapsed and the animal was forced to choose again until all 8 channels had been visited. From the very beginning rats performed better than chance. The acquisition and performance of this aversively motivated radial maze test is similar as in conventional elevated 8-arm radial mazes.

Animals↗