Impact of deep brain stimulation (DBS) on olfaction in Parkinson's disease: Clinical features and functional hypotheses

Deep brain stimulation (DBS) is a surgical therapy typically applied in Parkinson's disease (PD). The efficacity of DBS on the control of motor symptoms in PD is well grounded while the efficacity on non-motor symptoms is more controversial, especially on olfactory disorders (ODs). The present review shows that DBS does not improve hyposmia but can affect positively identification/discrimination scores in PD. The functional hypotheses suggest complex mechanisms in terms of cerebral connectivity and neurogenesis process which could act indirectly on the olfactory bulb and olfactory pathways related to specific cognitive olfactory tasks. The functional hypotheses also suggest complex mechanisms of cholinergic neurotransmitter interactions involved in these pathways. Finally, the impact of DBS on general cognitive functions in PD could also be beneficial to identification/discrimination tasks in PD.

[Olfaction in depressive disorders: Issues and perspectives]

Research on sensorial interactions with psychiatric diseases and particularly with the depressive syndrome has mainly focused on visual or auditory processes and much less on olfaction. The depressive illness is one of the most frequent psychiatric diagnoses in the community, with approximately one in five women and one in eight men experiencing a major depressive episode during their lifetime. Although genetic, epigenetic, neuroanatomical, neurochemical, neuroendocrinological and neuroimmunological changes can be detected during depression, the etiology of depression remains partly unclear. The current explanatory models are based on two main factors, i.e. pharmacological dysfunctions and stress effects. In this way and because of strong connections between olfactory pathways and cerebral areas implied in mood regulation and emotions (i.e. the limbic system and prefrontal areas), the interactions between olfaction and depression could constitute a relevant way of research at three different levels. First, olfactory dysfunction observed in depression could serve the diagnosis and contribute to a better understanding of mechanisms implied in thymic pathologies. Published papers show a decrease of olfactory sensitivity in major depression which does not occur in bipolar or saisonal depression. Second, it has been shown that olfactory deficits could induce depressive symptoms. In this context, an animal model (olfactory bulbectomized rat) reinforces the hypothesis of the important role of olfaction in depression based on neuroanatomical and neurochemical observations. Third, several publications have demonstrated that odors can positively impact the depressive mood. Thus, a remediation by odors in depression appears to be a promising way. From several decades, the olfaction/depression interactions have been covered by a broad literature. Thus, the present review will not propose an exhaustive examination but aims to point out the most recently published papers and highlight their contributions to the understanding of olfactory processes implied in depression.

Just noticeable difference in olfaction: a discriminative tool between healthy elderly and patients with cognitive disorders associated with dementia

Olfactory dysfunction appears to be one of the earliest signs of several age-related neurodegenerative disorders, including Alzheimer`s disease (AD) or Parkinson`s disease (PD). To rate performance and olfactory deficits in patients with cognitive disorders, various olfactory tasks have been used such as odor detection, discrimination, recognition memory, identification and naming but no study has been focused on just noticeable difference (JND), a sensitive tool of detection. The aim of this study was to investigate and compare variations in JNDs in healthy elderly and in patients with cognitive disorders associated with dementia. The results showed significantly higher olfactory JNDs in a population with cognitive disorders associated with dementia - i.e. a lower olfactory detection performance - compared to a control population paired in age, gender and education level. Additionally, the findings of the present study showed strong correlations between cognitive performances and JND scores in the control population contrary to the patient population. These findings are discussed in relation to the relevance of using olfactory JNDs in the diagnosis of dementias.

Lateralisation in wine olfactory threshold detection: comparison between experts and novices

The study of olfactory lateralisation in humans has given rise to many publications, but few studies have been focused on possible differences in relation to the experience towards specific odorants. The aim of the present study was to compare unilateral detection thresholds for three wines between expert and novice judges. Additionally, irritation and hedonic valence were also evaluated using monorhinal stimulations. Results showed that the novices had lower detection thresholds with the left nostril--whatever the wine--compared to the experts. Concerning hedonic rating, no nostril difference existed in the expert group contrary to the novice group, which evaluated wines as more pleasant with the left than with the right nostril. Irritation rating appeared not to be lateralised in both groups. However, the novices rated the three wines as more irritant than the experts with the right as well as with the left nostril. These findings suggest that the level of experience induced specific differences in terms of lateralisation between wine experts and novices.

Effects of pyridine inhalation exposure on olfactory epithelium in mice

Olfactory neurons in the nasal mucosa have the capacity to regenerate continuously along the lifespan by neurogenesis processes starting with progenitor cells close to the basal lamina. The cellular turnover into olfactory neuroepithelium may be modified by environmental stimuli insofar as nasal mucosa is directly in contact with airborne chemicals. However, few studies have been focused on selective changes, especially those concerning mature olfactory neurons and basal cells during specific inhalation exposure. Among chemicals, solvents are known to induce changes in smell abilities and concomitant histological and cellular modifications related to the type of molecule, concentration and time of exposure. This study was designed to characterize smell sensitivity (using behavioral tests) and immunohistochemical effects on olfactory neuroepithelium induced by pyridine exposure in mice. Olfactory marker protein (OMP) and proliferating cell nuclear antigen (PCNA) were used to characterize respectively mature olfactory neurons and basal cells. Results showed that inhalation exposure to pyridine had no impact on smell sensitivity whatever the concentration used and the time of exposure. These findings were in agreement with immunohistochemical measurements showing the same cellular kinetic whatever the condition of exposition to pyridine. Indeed, OMP-positive cells increased and PCNA-positive cells decreased as early as the beginning of exposure and cell amounts remained stable at this level until the end of exposure. These findings suggest that pyridine could have the property to rapidly activate a cellular turnover from basal cell progenitors. Rather than toxic effects, the present findings suggest that the metabolites of pyridine might have cell cycle activation properties.

Just noticeable difference in olfaction is related to trigeminal component of odorants

Many studies have dealt with the interrelationships between both olfactory and trigeminal systems but a poorly explored question concerns the role of each system in the detection processes, especially in the just noticeable difference (JND). The aim of this study was to investigate variations in JNDs for three odorants in relation to their trigeminal component, i.e. low, middle, high. The results indicated that the higher the trigeminal component, the lower the JND, suggesting a better capacity to perceive intensity changes for pungent odorants than for relatively pure odorants.

Just noticeable difference in olfaction is related to trigeminal component of odorants

Many studies have dealt with the interrelationships between both olfactory and trigeminal systems but a poorly explored question concerns the role of each system in the detection processes, especially in the just noticeable difference (JND). The aim of this study was to investigate variations in JNDs for three odorants in relation to their trigeminal component, i.e. low, middle, high. The results indicated that the higher the trigeminal component, the lower the JND, suggesting a better capacity to perceive intensity changes for pungent odorants than for relatively pure odorants.

Peripheral and central levels in nasal trigeminal sensitization and desensitization

In order to investigate the role of central and peripheral mechanisms in nasal trigeminal sensitization/desensitization processes, the present work recorded psychophysical (intensity ratings) and psychophysiological (skin conductance) responses to allyl isothiocyanate volatile nasal stimulation--during normal breathing--in monorhinal condition after a controlateral stimulation of the other nostril. Insofar as both nostrils are anatomically separated, modifications in responses can be interpreted as a central regulation process. Results showed that sensitization was clearly related to central mechanisms contrarily to desensitization which depended only of peripheral level.

Carbon dioxide effects on olfactory functioning: behavioral, histological and immunohistochemical measurements

Most studies on toxic inhalation focus on solvent effects and few have dealt with gases on olfactory functioning. Among gases, the effects of carbon dioxide on general physiology have been well investigated contrary to the impact on olfactory neuroepithelium. Thus, this work was designed to evaluate in mice the possible effects of 3% CO(2) in two exposure periods: a 5h/day and a 12h/day conditions. Behavioral, histological and immunohistochemical observations were conducted every 2 weeks, i.e. before (W0), during (W2, W4) and after exposure (W6, W8). Firstly, behavioral evaluations of odor sensitivity showed differences in relation to the odor tested, i.e. no effect with congener urine odor and a reinforcement of 2,4,5-trimethythiazoline (TMT) (predator odor) repulsion. Secondly, histological evaluations showed a similar evolution of the epithelium thickness, i.e. a decrease along the exposure as well as during the post-exposure period and an increase of cell number (whatever the phenotype) although the kinetic appeared different in both experimental conditions. Thirdly, immunohistochemical quantification of olfactory marker protein (OMP)- and proliferating cell nuclear antigen (PCNA)-positive cells revealed that the number of mature olfactory neurons increased at the early beginning of exposure period in both conditions. While a decrease was observed in the following weeks (W4-W8) for the 12h/day condition, a stable amount of OMP-positive cells was maintained in the 5h/day condition. In contrast, the number of PCNA-positive cells followed a similar evolution, i.e. a constant decrease along the experiment. These findings indicate that the effects of CO(2) inhalation exposure are selectively dose-dependent.

A multicentre longitudinal observational study of changes in self reported health status in people with Parkinson's disease left untreated at diagnosis

BACKGROUND

The issue of when to start treatment in Parkinson's disease (PD) remains controversial. Some favour treatment at diagnosis while others opt for a "wait and watch" policy. The effect of the latter policy on the self reported health status of people with PD is unknown.

AIMS

To record self reported health status through longitudinal use of a validated PD specific questionnaire (PDQ-39) in untreated PD patients in multiple centres in the UK. To compare patients who were left untreated with those who were offered treatment during follow-up.

METHODS

A multicentre, prospective, "real life" observational audit based study addressing patient reported outcomes in relation to self reported health status and other sociodemographic details.

RESULTS

198 untreated PD were assessed over a mean period of 18 months. During two follow-up assessments, the self reported health status scores in all eight domains of the PDQ-39 and the overall PDQ-39 summary index worsened significantly (p<0.01) in patients left untreated. In a comparative group in whom treatment was initiated at or soon after diagnosis, there was a trend towards improvement in self reported health status scores after treatment was started.

CONCLUSIONS

This study addresses for the first time self reported health status, an indicator of health related quality of life, in untreated PD. The findings may strengthen the call for re-evaluation of the policy to delay treatment in newly diagnosed patients with PD.

Effects of toluene inhalation exposure on olfactory functioning: behavioral and histological assessment

Exposure to pollutant or toxic substances is known to induce adverse health effects but few studies have been devoted to study the impact on olfactory functioning although neuroreceptors in the nasal cavity are directly in contact with volatile molecules. Thus, this work was designed to evaluate in mice the potential modifications of the olfactory functioning during (1 month) and after (1 month) a prolonged toluene exposure at both sensitive/perceptive and cellular levels. Mice were exposed to 1000ppm of toluene for 5h/day, 5days/week for 4 weeks. Firstly, behavioral evaluation (T-maze test) to toluene sensitivity showed a constant decrease during all the 4 weeks of exposure (W1-W4) which continued during 2 weeks after the exposure (W5, W6). In contrast, during the last 2 weeks of the experiment (W7, W8), the sensitivity of mice to toluene went back to normal. Secondly, structural modifications, i.e. density of cells and thickness of olfactory epithelium were observed soon after the outset of exposure. The number of cells did not change at the beginning of exposure (W1, W2), decreased markedly later (W3, W4), increased significantly the first week of the recovery period (W5) and stayed stable during the following weeks (W6-W8). Concerning the thickness of neuroepithelium, the results at W1 showed a decrease followed by an increase suggesting an inflammatory process (W2, W3). In contrast, the results of W4 revealed an abrupt decrease of the thickness whereas the return to normal arose immediately at the outset of recovery period.

Evidence for autonomic responses to pungent chemical stimuli applied to the skin vs inhaled via the nasal cavity

AIM OF THE STUDY

Chemical stimuli can produce different sensations from tingling to pain. Responses to chemical stimuli differ in relation to many factors. This study aims at examining two factors, i.e. the localization of their application and the implied sensory modality.

METHODS

Twenty volunteer students participated in the experiment. Skin conductance responses (SCRs) were recorded to compare the autonomic nervous activation to maximal stimulation with the same irritant stimulus (mustard oil (MO) diluted at 25%) applied to the skin or delivered into the nasal cavity.

RESULTS

The SCRs obtained following maximal nasal stimulation with MO were significantly different from those obtained following maximal skin stimulation. Application of MO on skin elicited higher SCR amplitude as well as a longer rising time and latency when compared to nasal stimulation.

CONCLUSIONS

These findings indicate that the autonomic nervous activation following maximal chemical irritation differ in temporal, amplitude and shape response characteristics. These results are discussed in terms of cutaneous and nasal innervation's.

In vivo and in vitro cellular ingrowth into a new generation of artificial ligaments

Artificial ligaments are a useful tool in ligament reconstruction. Although the new generation of artificial ligaments shows encouraging clinical results, in contrast to earlier generations studies on the biological properties are lacking. Biopsies were taken from a ligament advancement reinforcement system (LARS) 6 months after implantation and investigated by histochemistry. An in vitro study seeding human fibroblasts or osteoblast-like cells (up to 10(6) cells for 21 days) on ligament pieces (5 x 5 mm) was conducted and analyzed by histochemistry. The biopsies showed complete cellular and connective tissue ingrowth in the LARS ligament. In vitro fibroblasts and osteoblast-like cells encapsulated the fibers by building a cellular net around them. To our knowledge, these findings demonstrate for the first time the cellular ingrowth into the LARS ligament. This mechanism might explain the strength and the inert behavior of the ligament without the synovialitis shown in clinical studies.

Distinct expression of APO-1/Fas and caspase-8 in the human growth plate

Chondrocytes in the growth plate undergo a characteristic sequel of differentiation processes, finally leading in their death by apoptosis. The mechanisms that mediate these remarkable biological phenomenon are still widely unknown. For this study, growth plates from five resected polydactylic infantile fingers were taken and immunostained for APO-1 and Caspase-8, two apoptosis-mediating proteins. The expression of both proteins was examined in the resting zone, proliferating zone, and hypertrophic zone, representing the maturation stages of the growth plate. Positive cells for APO-1 and Caspase-8 were found in all zones of the physis with a significant increase from the resting to the hypertrophic zone (from 17.4% to 33.067% for APO-1 and from 13.17% to 28.22% for Caspase-8). Our findings suggest that both APO-1 and Caspase-8 are involved in chondrocyte development in the growth plate, predominantly near to the closure area.

Lateralization in human nasal chemoreception: differences in bilateral electrodermal responses related to olfactory and trigeminal stimuli

The study of olfactory lateralization in humans has given rise to many publications, but the findings have often been contradictory. There is growing evidence to suggest that the nature of the olfactory stimulus influences the processes of lateralization. An important factor could be the trigeminal component. Indeed, most odorants simultaneously stimulate both olfactory (CN I) and trigeminal (CN V) systems which differ in terms of their central projections, ipsilaterally for CN I and contralaterally for CN V. The aim of this study was to investigate variations in psychophysiological measurements between a nasal input with low (phenyl ethyl alcohol (PEA)) and high (allyl isothiocyanate (AIC)) intranal trigeminal stimulation. In a first experiment (20 subjects), the intensity, hedonicity and irritation levels of stimulus were tested with a psychophysical evaluation to study the possible influences of perceptual characteristics. A second experiment (37 subjects) used bilateral electrodermal recordings and compared the skin conductance responses (SCRs) for both nasal inputs on either monorhinal and birhinal stimulations. Firstly, the electrodermal activity (EDA) results showed no differences between the two nostrils for PEA as well as AIC, but differences in relation to the type of stimulus, e.g. higher amplitude in response to AIC versus PEA. Secondly, the results indicated bilateral differences in EDA recordings related to the nature of the stimulus and are discussed in terms of hemispheric asymmetric activation.

Quality of odor and olfactory lateralization processes in humans

The study of olfactory lateralization processes in humans has given rise to many publications, but the resulting data have not been homogeneous. Sensorial cerebral asymmetry depends on several factors (nature of task, characteristics of subjects, etc.) and could also depend on the quality of the stimulus, especially in olfaction. This field appears to be widely unexplored and the quality of odor is a complex property. The aim of this study was to investigate variations in psychophysiological measurements (bilateral electrodermal recordings) related to the quality of odors. Electrodermal asymmetries were used as a function of differential hemispheric activation. Two major characteristics of odor were explored, the hedonic valence (pleasant/unpleasant) and the trigeminal component (irritant/non-irritant). The results obtained in a sample of 30 right-handed subjects (15 males and 15 females) showed a predominance of the right hemisphere in the treatment of olfactory information not depending on the quality of odor, except the trigeminal-nerve activation.

The potency of acyclovir can be markedly different in different cell types

Acyclovir is an acyclic guanine analog with a considerable activity against herpes simplex viruses. We studied the antiherpetic activity of acyclovir in macrophages and fibroblast cell lines. Utilising a plaque reduction assay we found that acyclovir potently inhibited the HSV-1 replication in macrophages (EC50) = 0.0025 microM) compared to Vero (EC50 = 8.5 microM) and MRC-5 (EC50 = 3.3 microM) cells. The cytotoxicity of acyclovir was not detected at concentrations < or = 20 microM, thus the selective index in macrophages was >8000. This marked difference in antiherpetic activity between macrophages and fibroblasts was not observed with Foscarnet and PMEA. We suggest that this potent antiviral effect of acyclovir is mainly due to a proficient phosphorylation of the drug and/or a favourable dGTP/acyclovir triphosphate ratio in macrophage cells.

Sex differences in human olfaction: between evidence and enigma

The sex of individuals plays an important part in determining their olfactory abilities, with females generally being superior to males. The present review examines the way in which sex differences influence sensitivity, identification, familiarity, and recognition of odours. It also examines whether sex differences are more pronounced with some odours than others, and how sex differences are affected by the manner of testing. Two different explanations for the superiority of females over males in olfaction are evaluated.

Sex differences in human olfaction: between evidence and enigma

The sex of individuals plays an important part in determining their olfactory abilities, with females generally being superior to males. The present review examines the way in which sex differences influence sensitivity, identification, familiarity, and recognition of odours. It also examines whether sex differences are more pronounced with some odours than others, and how sex differences are affected by the manner of testing. Two different explanations for the superiority of females over males in olfaction are evaluated.

Complexity of olfactory lateralization processes revealed by functional imaging: a review

Currently available techniques used in neurosciences and particularly cerebral imaging are contributing to a better understanding of human perception and the treatment of sensorial information. In this field, the chemical senses (taste and smell) have received little attention when compared with the auditory, visual and tactile senses. Nevertheless, recent research has been trying to overcome this. Brain regions involved in the processing of olfactory information have been investigated in several studies including a large number dealing with the question of lateralization. However, functional asymmetry in olfaction has still not been resolved and the resulting data have not been homogeneous. In this field, the contribution of cerebral imaging studies is very important insofar as it shows that the processes of functional lateralization in olfaction depend on many factors (nature of stimulus, nature of task, characteristics of subjects ...) that future research will have to consider.

Effects of pleasant and unpleasant ambient odors on human voice pitch

The perception of odors is well identified as having strong emotional correlates. It is also well known that the acoustic characteristics of the voice differ according to the emotional state. This study compared some acoustic features of the voice of 18 subjects reading the same text in pleasant (lavender) and unpleasant (pyridine) ambient odor conditions. The results revealed that the pitch of the voice was higher in the pleasant than in the unpleasant condition. These findings are consistent with the hypothesis of local and functional convergences of encoding vocal emotion and hedonic perception of odors.

Intercorrelations among tests of lateralisation in the BALB/c mouse

In order to examine the reliability of lateralised behaviours, BALB/c mice were tested in three different situations: the Collins paw preference test (PPT), the rotatory swimming test (RST), and the T maze test (TMT). The results showed a significant correlation between the scores of lateralisation in the PPT and the RST, but a lack of lateralisation in the TMT. Considering the tasks involved in these tests, these results appear to support the hypothesis of close links between lateralised behaviours, emotional processes, and neural pathways.

Comparison between monorhinal and birhinal olfactory stimulations in bilateral electrodermal recordings

The study of olfactory lateralization in human subjects has given rise to many publications, but the findings have often been contradictory. Most research used either birhinal or monorhinal stimulations, but rarely a comparison between these two types of olfactory input. The aim of this study was to investigate variations in psychophysiological measurements and test each side of the nose and binasal performances. This work used bilateral electrodermal recordings and compared the skin conductance responses (SCRs) for a pleasant odorant (isoamyl acetate) and an unpleasant odorant (triethylamine) in a suprathreshold concentration on 30 dextral subjects (16 females and 14 males). First, the results reported no differences between the two nostrils but differences in electrodermal activity (EDA) in relation to the odorant: 1) higher amplitude in response to unpleasant versus pleasant odorant; 2) no differences between monorhinal and birhinal stimulations for the unpleasant odour but higher amplitude in response to birhinal versus monorhinal for the pleasant odour. Second, the results showed constant bilateral differences in EDA recordings and are discussed in terms of hemispheric asymmetry activation.

Olfaction and hemispheric asymmetry: unilateral stimulation and bilateral electrodermal recordings

The study of hemispheric asymmetry in olfaction in human subjects has given rise to many publications, but the findings have often been contradictory. This study used bilateral electrodermal activity recordings with unilateral stimulation as a measure of functional hemispheric asymmetry. A specific odorant (lavender) was used by monorhinic (single nostril) stimulation on 30 dextral subjects (20 females and 10 males). Intraindividually, the results showed no difference between the two nostrils, but all subjects exhibited a constant direction of electrodermal asymmetry: 20 subjects systematically showed a greater response amplitude for the right hand and 10 subjects systematically showed a greater response amplitude for the left hand, whatever hemisphere stimulated.

Behavioral lateralization during spontaneous smelling tasks

The smelling behavior of 52 right-handed subjects was videotaped during tasks involving identification and recognition of different odors. Analysis showed that men more often used the right nostril than the left whatever the odor. There was no significant difference for the women. These results support a more marked cerebral asymmetry in men than in women and a main involvement of the right cerebral hemisphere in the olfactory processes at least by right-handed men.

[Olfactory lateralization in humans: a review of the literature]

In the field of human perception, the chemical senses (taste and smell) have received little attention from neuroscience research when compared with auditory, visual and tactile senses. In the case of olfaction, it would appear that the publications over the last few years have been trying to overcome this lack of research. Many investigations have been carried out on lateralization, mainly in relation to specific pathologies (i.e., epilepsy, split-brain, lobotomy, etc.), while there have been few studies of healthy subjects. The results are often contradictory due particularly to special features of the olfactory system. However, consensus is emerging concerning, first, the fact that if both hemispheres are involved in the olfactory process, it is probable that one is more dominant than the other (many studies have revealed a greater impact on the right hemisphere in the treatment of olfactory information, but the dominance has not been clearly established). Second, the simple detection process would appear not to be lateralized whereas the higher-order olfactory tasks which involve memory processes and lexical aspects could be. The exact conditions governing lateralization still require more clarification by systematically taking into consideration the characteristics of the individual subjects, as well as those of the odorant stimuli and the test conditions. Finally, currently available techniques used in neurosciences and particularly cerebral imagery will contribute to a better understanding of the complexity of cerebral asymmetry in olfaction.

Differential effects of cyclopolyamines on the stability and conformation of triplex DNA

Linear polyamines are excellent promoters of triplex DNA formation. The effects of structural rigidization of polyamines on triplex DNA stability are not known at present. We wished to develop a series of polyamine analogs as secondary ligands for triplex DNA stabilization for antigene applications. To accomplish this goal, we synthesized cyclopolyamines by interconnecting the two amino or imino groups of linear polyamines with a --(CH2)n-bridge (n=3,4,5). Melting temperature (Tm) data showed that [4,3]-spermine and [4,4]-spermine stabilized poly(dA) x 2poly(dT) triplex at >25 microM concentrations (Tm = 71 degrees C at 100 microM). The dTm/dlog [polyamine] values for these compounds were 26 and 40, respectively. [4,3]-Spermine and [4,4]-spermine also stabilized triplex DNA formed by a purine-motif triplex-forming oligonucleotide, TG3TG4TG4TG3T with its target duplex, as determined by Tm, circular dichroism (CD) spectroscopy, and electrophoretic mobility shift assay (EMSA). In contrast, [4,4]-putrescine and [4,5]-putrescine as well as [4,5]-spermine had no triplex DNA stabilizing effect. CD spectra also showed triplex DNA aggregation and psi-DNA formation at >100 microM [4,3]-spermine. These data demonstrate that structural rigidization of linear polyamines has a profound effect on their ability to stabilize triplex DNA and provoke conformational transitions.

[Behavioral differences in childhood depression: study of blinking and auto-manipulation]

Different investigations have studied the evolution of childhood depression but little research has been based on the observation of behavior. This work aims at analysing two singular behaviors: eye blink and auto-manipulation. This paper compares the results obtained on day A(hospital admission, before treatment) and on day D (discharge, after clinical improvement) during a standardized interview recorded in video with children aged 8-13 years, hospitalized for a major depressive episode and for a control group. The results show a significant decrease in eye blink frequency and the mean auto-manipulation duration after clinical improvement. The discussion raises the question of the role of anxiety in the development of these behavioral modifications.

A survey of injection site lesions in fed cattle in Canada

During November 1996 to January 1997, a survey was conducted at 5 Canadian purveyors to measure the prevalence of injection site lesions in the top butt, boneless blade, outside round, inside round, and eye of the round. As trimmers were cutting these subprimals into steaks, technicians monitored each steak for grossly obvious scars. These scars were trimmed, weighed, and scored as either a "clear scar," "woody callus," or "cyst." All scars were subsequently examined histologically and classified as a "clear scar," "woody callus," "scar with nodules," "mineralized scar," or "cyst." Pieces were observed for broken needles while being processed and none were found. The estimated prevalence of injection site lesions was 18.8% (95% CI, 16.4% to 21.2%) in top butts, 22.2% (95% CI, 18.8% to 25.7%) in boneless blades, 4.9% (95% CI, 3.6% to 6.3%) in the eye of round, 1.8% (95% CI, 1.1% to 2.9%) in the inside round, and 7.6% (95% CI, 5.6% to 9.8%) in the outside round. Some top butts originated from American fed cattle; the estimated prevalence of lesions was 9.0% (95% CI, 5.9% to 12.9%) in American top butts and 22.3% (95% CI, 19.4% to 25.3%) in Canadian top butts. The median weight of the lesions varied among subprimals and ranged from 64 g to 117 g. Histologically, 13% of the scars were clear scars, 47% were woody calluses, 5% were mineralized scars, 34% were scars with nodules, 0.2% were cysts, and 0.9% were normal fat infiltrations. An economic analysis estimated an average loss of $8.95 per fed animal processed or $19 million dollars annually to the Canadian beef industry from injection scars.

Nuclear localization of the human cytomegalovirus tegument protein pp150 (ppUL32)

The human cytomegalovirus (HCMV) basic phosphoprotein pp150, encoded by the UL32 gene, together with the two other major phosphoproteins, pp65 (ppUL83) and pp71 (ppUL82) and several minor structural proteins, form the tegument around the viral nucleocapsid. Experiments were undertaken to locate the area of assembly of tegument proteins pp150 and pp65 and nucleocapsids in fibroblasts, in order to assess the functional role of these two structural proteins in HCMV morphogenesis. Whereas pp150 expression starts during the cytoplasmic maturation of HCMV, pp65 is expressed in the early and late phases of HCMV gene transcription. Western blot analysis of isolated cell fractions showed that pp150 is initially (48 h post-infection) localized in the nucleus, associated either with the nuclear membrane or with viral assembly regions, and later (72 h post-infection) in the cytoplasm. By indirect immunofluorescence, pp150 and pp65 could be detected in nuclear subcompartments and were strongly associated with the nuclear membrane. Using immunogold analysis by electron microscopy, pp65 was exclusively detected within the matrix of cytoplasmic and extracellular dense bodies and of dense body-like structures in the nucleoplasm. These were localized in close contact with hypertrophic nucleoli, in the proximity of developing nucleocapsids and in special patches at the inner nuclear membrane. Positive immunostaining of pp150 was observed at the surface of developing nucleocapsids concentrated within viral assembly regions in the nucleoplasm. Additionally, the tegument of cytoplasmic and extracellular virions was stained, whereas dense bodies or nuclear dense body-like structures did not react. Thus, the acquisition of the tegument protein pp150 seems to start in special nuclear subcompartments of the HCMV-infected fibroblasts.

[Reaction time measures in depressed patients]

The work presented below is enclosed in a research on depressive retardation in children. It deals with the measurement of reaction time to sensori stimuli (visual or auditory) among children from 7 to 13 year old. Patients with major depressive episode were presented twice, before medication and at their discharge. The assessment which is performed to the nearest thousandth of a second thanks to a program developed on micro computer includes 5 test situations: 1. simple visual stimulation; 2. simple auditory stimulation; 3. choice situation between visual and auditory stimulation; 4. unlocated visual stimulation; 5. choice situation between two different visual stimulations. Generally speaking the best scores are logically achieved for the simple auditory tests followed by the simple visual test. The highest scores almost systematically appear for the test offering the choice between two different visual stimulations. For each of the five tests the values are always correlated between the two passation periods. These correlations mean that the passation time depends on each child. Those who achieved "good scores" in the depression phase before medication are the same who achieve good scores at their discharge and vice versa. These performances have no relation either with the age of the children. The analysis of the results brings out two factors: For simple stimuli tests, performances do not vary between the two passation periods and therefore show a motor normal function. On the other hand, for tests which involve a choice (and therefore decision making) before medication children react significantly more slowly than after improvement.(ABSTRACT TRUNCATED AT 250 WORDS)

Necrotizing effect of phenol on normal tissues and on tumors. A study on postoperative and cadaver specimens

We investigated the necrotizing effect of a 75% alcoholic solution of phenol on normal tissue harvested during surgery (muscles, fatty or connective tissue) or post mortem (peripheral nerves, arteries, epidermal tissue, joint and epiphyseal cartilage) and on tumor tissue (60 samples freshly harvested from patients suffering from bone tumors). The necrotizing effect was measured by determining the thickness of the cell layers demonstrating nuclear pyknosis or necrosis after 2 min of phenolization in a light microscope by ocular measurements in microns. No effect could be seen in epidermal tissue and in cartilage, whereas all other normal tissues exhibited necrotic zones between 40 and 500 microns. In all the tumors except those with chondromatous tissue, necrotic zones between 40 and 1000 microns were found. No difference in extension of the necrotic zone was seen between specimens from benign and malignant tumors and tumor-simulating processes. Phenolization cannot be recommended for the treatment of chondromatous tumors.

Devitalizing effects of phenol on bone marrow cells. Histologic study on cadaveric animal vertebrae

The devitalizing effects of 5-90 percent phenol for 30 seconds on bone marrow cells were examined on vertebral bodies of fresh animal cadavers. Evaluation was made by measuring the width of the zone of necrotic cells. The zone increased with rising phenol concentration up to 75 percent, reaching an average width of 0.75 mm. However, when protected by bone trabeculae, the cells escaped devitalization.

[Role and possibilities of pathology in the diagnosis of osteoporosis]

Iliac crest biopsy and clinical laboratory investigations are the important criteria to diagnose metabolic osteopathies and osteoporosis. The technic of iliac crest biopsy, the histological technic and the histomorphological and histometric criteria will be discussed. The necessity to compare clinical data with the histomorphology and the importance of surgical pathology, especially osteopathology, will be emphasized.

Fibrous metaphyseal defect

The tendon and ligaments inserted into the perichondrium of the epiphyseal plate were examined in 152 autopsy specimens of tubular long bones. In the region of two areas where tendons were inserted (Ranvier's nodes), the normal medullary tissue is replaced by fibroblastic tissue. A retrospective radiological examination of 155 fibrous metaphyseal defects shows that they are situated at characteristic sites on the circumference of the metaphysis of long tubular bones. This can be related to the insertion of a tendon or ligament near the epiphyseal growth plate which corresponds to areas found in the morphological study and is the site of origin of fibrous metaphyseal defects.

[Early stimulation: 10 years' experience]

Infancy psychomotor yield in lower socioeconomic levels can be damaged from the first year of life. This implies future consequences to individuals, family-and society. Early stimulation programs have demonstrated to improve psychomotor yield in the above mentioned children. In Temuco, Chile, in groups of children with different risks, that were incorporated to an early stimulation program, it has been seen that the lower the birth weight the greater the risk of future psychomotor deterioration, which is also true for children that survived neonatal meningitis. On the other hand, in children that presented hyperbilirubinemia, low Apgar scores and neonatal septicemia, no significant statistical differences in psychomotor development have been observed in comparison with those of similar birthweight but without these antecedents. In this study the Chilean Health Ministry's Evaluation and Psychomotor Stimulation Program is reviewed as to adapt it for children at greatest risk.

[Is high-density polyethylene suitable as an implant material in cement-free anchoring of hip endoprostheses? A histomorphologic study of an explanted polyethylene screw-in acetabula]

Firmly attached screw-in polyethylene acetabula which had been implanted for between 16 and 54 months were explanted after autopsies and subjected to macroscopic, radiologic and histologic examination. Metaplasias were seen around the threads and on the floor of the acetabulum. Their tendency to ossify represents an attempt at secondary stabilization. Due to the low stability of the polyethylene this causes increased wear on the floor of the acetabulum. The small defects in the polyethylene found in the threads, resembling damage done by mice, may be a sign of biodegradation. In view of the tissue reactions pointed out, the material stability of the polyethylene needs to be improved or implantation must be restricted to a very limited range of indications.

Reactions of surrounding tissue to the cementless hip implant Ti-6Al-4V after an implantation period of several years. Autopsy studies in three cases

Three femoral endoprosthetic stems implanted without cement, made of Ti-6Al-4V alloy, with implantation periods of between 2 and 4 years were examined histologically in the form of undecalcified thin ground sections after having been split into segments and embedded in plastic. During the implantation period total osseointegration in the metadiaphyseal region takes place, while in the proximal area reaction forms with direct contact between metal and bone on the one hand and with an interposed membrane of connective tissue and adjacent secondary bony shell on the other must be distinguished. The osseointegration of the stem is the result of a primary healing of the bone and is due to the biocompatibility of the metal alloy and to the primary stability obtained by the press-fit method.

Tissue reactions to titanium endoprostheses. Autopsy studies in four cases

Four cementless prosthetic hip implants of Ti-6Al-4V-alloy with and without longitudinal grooves and Al2O2 ceramic ball heads, with implant periods of 3, 4, 5, and 10 months, were sectioned and examined histologically in undecalcified thin ground sections. Especially on the medial and lateral sides of the prostheses, there was direct bone-to-metal contact without interposed connective tissue, spreading to the dorsal and ventral areas of the prosthesis shaft, which was considered osseointegration. This is based mainly on the technique of implantation with primary stability in the cortical bone by press-fit and on the bioinertness of the titanium alloy. Ungrooved prosthesis areas seem to favor bone growth at the shaft. The secondary bone ring, occurring on the dorsal and ventral areas of the prosthesis, with evidence of further bone remodeling with the passage of time, indicates that osseointegration is a dynamic process that continues to improve prosthetic stability.

Juxtaglomerular tumour: diagnostic renal vein renin measurements obscured by chronic captopril therapy

A case of juxtaglomerular tumour (sometimes called hemangiopericytoma) in a 17 year old boy, presenting with severe hypertension and hypokalemia, is described. Plasma renin activity was markedly elevated in both renal veins and failed to lateralise the tumour. This is attributed to chronic stimulation of renin secretion by Captopril treatment. Removal of the tumour cured the hypertension and hypokalemia.