Vibration-induced compaction of granular suspensions.

We investigate the compaction dynamics of vibrated granular suspensions using both digital imaging technique and MRI measurements. Starting from initialy loose packings, our experimental data suggest the existence of two stages in the compaction dynamics: a fast stage at short times where a rising compaction front propagates through the granular suspension and a slow stage at large times where the packing compacts slowly and homogeneously. The compaction dynamics in each stage can be well fitted to usual stretched exponential laws with stretching exponents equal to 2 and 0.45, respectively. The transition time between these two stages, τ c , depends on the fluid viscosity, vibration intensity and grain diameter. We show that τ c (-1) and the velocity of the front decrease roughly linearly with the lubrication Peclet number, Pe lub related to the competition between the lubrication stress induced by vibrations and the granular pressure.

Daylight photodynamic therapy with methyl aminolevulinate cream is effective and nearly painless in treating actinic keratoses: a randomised, investigator-blinded, controlled, phase III study throughout Europe.

BACKGROUND: Unmet needs exist in actinic keratosis (AK) treatment. Daylight photodynamic therapy (DL-PDT) has shown good efficacy and safety results compared to conventional PDT (c-PDT) in a recent Phase III multi-centre randomised controlled trial in Australia among 100 subjects with AKs. OBJECTIVES: Demonstrate non-inferior efficacy and superior safety of DL-PDT compared to c-PDT in treating multiple mild and/or moderate facial/scalp AKs. METHODS: Phase III, 12 week, multi-centre, randomised, investigator-blinded, controlled, intra-individual study conducted at different latitudes in Europe. AKs of adult subjects were treated once with methyl aminolevulinate (MAL) DL-PDT on one side of the face and MAL c-PDT contralaterally. Endpoints for DL-PDT concerned efficacy (non-inferiority regarding complete lesion response at week 12) and safety (superiority regarding subject's assessment of pain after treatment, on an 11-point numeric rating scale). Safety evaluation also included incidence of adverse events. Subject satisfaction was described using a questionnaire at baseline and last visit. RESULTS: At week 12, the total lesion complete response rate with DL-PDT was similar (non-inferior) to c-PDT (70% vs. 74%, respectively; 95% CI [-9.5; 2.4] in PP analysis, confirmed in ITT analysis). In addition, efficacy of DL-PDT was demonstrated regardless of weather conditions (sunny or cloudy). DL-PDT was nearly painless compared to c-PDT (0.7 vs. 4.4, respectively; P < 0.001), better tolerated and resulted in higher subject satisfaction. CONCLUSION: DL-PDT in comparison with c-PDT was as effective, better tolerated and nearly painless with high patient satisfaction, and may be considered a treatment of choice to meet needs of patients with mild or moderate facial/scalp AKs.

A review of pre-admission advanced airway management in combat casualties, Helmand Province 2013.

OBJECTIVES: Airway compromise is the third leading cause of potentially preventable combat death. Pre-hospital airway management has lower success rates than in hospital. This study reviewed advanced airway management focusing on cricothyroidotomies and supraglottic airway devices in combat casualties prior to admission to a Role 3 Hospital in Afghanistan. METHODS: This was a retrospective review of all casualties who required advanced airway management prior to arrival at the Role 3 Hospital, Bastion, Helmand Province over a 30-week period identified by the US Joint Theatre Trauma Registry. The notes and relevant X-rays were analysed. The opinions of US and UK clinical Subject Matter Experts (SME) were then sought. RESULTS: Fifty-seven advanced airway interventions were identified. 45 casualties had attempted intubations, 37 (82%) were successful and of those who had failed intubations, one had a King LT Airway (supraglottic device) and seven had a rescue cricothyroidotomy. The other initial advanced airway interventions were five attempted King LT airways and seven attempted cricothyroidotomies. In total, 14 cricothyroidotomies were performed; in this group, there were nine complications/significant events. CONCLUSIONS: The SMEs suggested that dedicated surgical airway kits should be used and students in training should be taught to secure the cricothyroidotomy tube as well as how to insert it. This review re-emphasises the need to 'ensure the right person, with the right equipment and the right training, is present at the right time if we are to improve the survival of patients with airway compromise on the battlefield'. The audit reference number is RCDM/Res/Audit/1036/12/0368.

First Report of Branched Broomrape (Phelipanche ramosa) on Celeriac (Apium graveolens) in Eastern France.

Branched broomrape, Phelipanche ramosa (L.) Pomel (syn. Orobanche ramosa L.), is a chlorophyll-lacking, obligate root parasitic plant that infests Brassicaceae, Solanaceae, and legumes (3). In western France, P. ramosa has invaded oilseed rape fields since the 1990s, causing significant yield losses (1). This crop has now become the primary host for the parasite, along with buckwheat (Fagopyrum esculentum L.), hemp (Cannabis sativa L.), and tobacco (Nicotania tabacum L.). In September 2013, a field survey indicated that a celeriac (Apium graveolens L. var. Prinlz) crop on clay soil in the Champagne-Ardennes region (48°20'19″ N, 04°01'57″ E, 140 m above sea level, eastern France) was infested with branched broomrape where hemp had been grown 4 years before. The celeriac field was planted to wheat (Triticum aestivum L.) in 2012 in rotation with lentils (Lens culinaris Medik.) in 2011. About 2% of the total celeriac field was infested and the estimated yield losses were approximately 25% for this infested area. The host symptoms observed were a slower growth of celeriac, along with leaf chlorosis, lower fruit production, and numerous abortions. The infestation of the celeriac crop was confirmed by verifying the attachment of branched broomrape to the celeriac roots. Broomrape plant heights were between 4.5 and 21 cm. The stems were erect, branched, frail, rather hairy, and bulging. Scale leaves were limited to 4 to 10 mm long, thick, acuminate, alternate scales. The flowers were numerous (between 4 and 51) and were 8.3 to 14.5 mm long. They were borne in the axils of scaly bracts. They had an irregular, curved shape, and a light mauve color. They did not have distinct peduncles and were grouped in rather long floral scapes during advanced flowering. The corolla tube was 10 to 15 mm long and its restricted part stood higher than the divisions of the calyx. It had ciliate, if not hairy, lobes. The calyx was more or less hairy, zygomorphous, with four lobes, and 6 to 8 mm long. Two bracteoles were situated on either side of the calyx. The four stamens observed were didynamous and borne 4 to 5 mm above the corolla base. The dorsifixed bilocularis, longitudinally dehiscent anthers were glabrous or covered with a fine down along sutures. Georges Sallé, (retired) Professor of Botanics at the University Pierre et Marie Curie, Paris, confirmed the identity of P. ramosa based on morphological characteristics (1). Celeriac infection by branched broomrape was confirmed using a developed assay (2). P. ramosa infecting celeriac roots was described by counting the numbers of individuals having reached ontogenic stages according to Gibot-Leclerc et al. (2). To our knowledge, this is the first study reporting P. ramosa infection on celeriac in eastern France. Since celeriac is produced in rotation with lentils, branched broomrape could pose a serious threat to production of these crops. References: (1) M. Blamey and C. Grey-Wilson. La Flore d'Europe Occidentale. Edition Flammarion, Paris, 2003. (2) S. Gibot-Leclerc et al. Flora 207:512, 2012. (3) M. C. Press and G. K. Phoenix. New Phytol. 166:737, 2005.

Off-resonance effects and selectivity profiles in pulsed nitrogen-14 nuclear quadrupole resonance.

In order to alleviate base-line distortions in nitrogen-14 NQR spectra originating from pulse breakthrough, low power radio-frequency (rf) pulses were applied. It is recalled that the required power is four times lower than that for an equivalent NMR experiment. This is easily explained by the fact that, in NMR, half the amplitude of the rf field is active. Moreover, the selectivity profile (i.e. the peak amplitude as a function of the difference between the carrier frequency and the resonance frequency) exhibits a shape which is, in most cases, more favorable in NQR than in NMR. An appropriate theory has been developed for explaining these experimental observations. It is concluded that low power NQR is perfectly feasible and should even be recommended for most applications, provided that the line-width of the NQR signal is not too large.

Indirubin, the active constituent of a Chinese antileukaemia medicine, inhibits cyclin-dependent kinases.

Indirubin is the active ingredient of Danggui Longhui Wan, a mixture of plants that is used in traditional Chinese medicine to treat chronic diseases. Here we identify indirubin and its analogues as potent inhibitors of cyclin-dependent kinases (CDKs). The crystal structure of CDK2 in complex with indirubin derivatives shows that indirubin interacts with the kinase's ATP-binding site through van der Waals interactions and three hydrogen bonds. Indirubin-3'-monoxime inhibits the proliferation of a large range of cells, mainly through arresting the cells in the G2/M phase of the cell cycle. These results have implications for therapeutic optimization of indigoids.

Reports of abnormal cervical cancer screening tests in systemic sclerosis.

OBJECTIVE: To assess the prevalence of abnormal cervical cancer screening (Pap tests) reported by women with SSc onset before the age of 50 yrs. METHODS: Female members of a Canadian multi-centre SSc cohort completed standardized assessments and were questioned regarding a history of an abnormal Pap test. Potential correlates examined included demographics, reproductive history, smoking, diffuse vs limited SSc type, immunosuppressant exposure and SSc duration. RESULTS: In the 320 women with SSc onset before the age of 50 yrs, the life-time prevalence of an abnormal Pap test (according to self-report) was 25.4% (95% CI CI 20.9, 30.4%). By comparison, self-reported prevalence of abnormal Pap tests among general population Canadian females was recently reported at 13.8% (95% CI 11.6, 16.4%). Women with diffuse SSc (n = 142), tended to have a higher prevalence of self-reported cervical dysplasia (31.7%) compared with those with limited disease (20.7%), but the CIs overlapped. A multivariate logistic regression found a significant positive association between self-reported abnormal Pap test and diffuse disease [odds ratio (OR) 1.87; 95% CI 1.01, 3.47]. An independent association of an abnormal Pap test with smoking (OR 2.43; 95% CI 1.23, 4.78) and with younger age at disease onset was also noted. CONCLUSIONS: We noted a high prevalence of abnormal Pap tests self-reported in our sample. Increased risk was seen among those with diffuse SSc, and also among smokers and those with a younger age at disease onset. Thus, it seems prudent to ensure that adequate attention is paid to cervical cancer screening for women with SSc.

Exploiting chemical libraries, structure, and genomics in the search for kinase inhibitors.

Selective protein kinase inhibitors were developed on the basis of the unexpected binding mode of 2,6,9-trisubstituted purines to the adenosine triphosphate-binding site of the human cyclin-dependent kinase 2 (CDK2). By iterating chemical library synthesis and biological screening, potent inhibitors of the human CDK2-cyclin A kinase complex and of Saccharomyces cerevisiae Cdc28p were identified. The structural basis for the binding affinity and selectivity was determined by analysis of a three-dimensional crystal structure of a CDK2-inhibitor complex. The cellular effects of these compounds were characterized in mammalian cells and yeast. In the latter case the effects were characterized on a genome-wide scale by monitoring changes in messenger RNA levels in treated cells with high-density oligonucleotide probe arrays. Purine libraries could provide useful tools for analyzing a variety of signaling and regulatory pathways and may lead to the development of new therapeutics.

Transcription of the mouse secretory protease inhibitor p12 gene is activated by the developmentally regulated positive transcription factor Sp1.

We have previously shown that a trans-acting protein produced in some tissue culture cells positively control the transcriptional activity directed by the mouse p12 promoter. This nuclear protein exerts its positive activity by interacting with a regulatory sequence designated p12.A and located between the TATA and CCAAT box elements on the p12 gene promoter. Using DNase I and dimethyl sulfate methylation interference footprinting techniques coupled with gel retardation assays, we found evidence that the protein which binds to the p12.A element is the well-known transcription factor Sp1. Mutational analysis in transient transfection assays confirmed the positive activity exerted by this protein in every cell line tested. In agreement with this observation, we detected a p12.A-Sp1 binding activity in nuclear extracts prepared from all cell lines used. However, a similar binding activity could not be detected in a number of nuclear extracts prepared from normal mouse tissues. In this report, we provide the evidence that the lack of Sp1-binding activity results from the degradation of Sp1 in the kidney, liver, and pancreas of the mouse.

[Vulvar dermatitis and iron deficiency]. / Vulvite par carence en fer.

BACKGROUND: Many mucocutaneous signs associated with iron deficiency are described in the current dermatologic and haematologic literature but genital mucosa involvement has never been reported. CASE REPORT: We report a case of iron deficiency anaemia revealed by psoriasis-like vulvar dermatitis. The vulvar involvement dramatically improved after iron therapy. In the case reported herein, iron deficiency resulted from three mechanisms: increased loss (menorrhagia), inadequate dietary iron intake (vegetarian diet) and inadequate absorption (iron absorption inhibitors such as tea). DISCUSSION: Iron deficiency may be responsible for genital mucosa involvement. Iron deficiency investigation must determine the presence of blood loss and dietary habits (assessment of iron levels and ingestion of iron absorption inhibitors). Certain dietary recommendations are essential to avoid the failure of iron supplementation.

Functionalization of pectin with laccase-mediated oxidation products of ferulic acid.

Pectin is a natural biopolymer extracted mostly from citrus peel, sugar beet and apple pomace. In order to improve its functional properties and then to enlarge the field of its potential applications, functionalization reaction of citrus pectin with ferulic acid (FA)-oxidation products was performed in aqueous medium, at 30°C and pH7.5, in the presence of Myceliophthora thermophila laccase as biocatalyst. The conjugation between FA-oxidation products and pectin was confirmed using FTIR, UV-Vis and LC-MS analyses. The obtained results suggested that covalent bonds were between the pectin carboxyl groups and FA-oxidation products between the pectin carboxyl groups and FA-oxidation products. The determination of the total phenolic content showed that the modified pectin contained 5 times more phenols than the native pectin. In view of these results, this enzymatic procedure appears as a promising way to provide new pectin-based polymers that are expected to present new properties of interest.

Total knee arthroplasty after opening- versus closing-wedge high tibial osteotomy. A 135-case series with minimum 5-year follow-up.

INTRODUCTION: High tibial osteotomy (HTO) is effective in treating isolated medial osteoarthritis of the knee, but subsequent deterioration is inevitable, and total knee arthroplasty (TKA) is then an option. The present study sought to compare TKA following medial opening-wedge HTO (OW-HTO) versus lateral closing-wedge HTO (CW-HTO) in terms of intraoperative data and clinical results. The study hypothesis was that there is no significant difference in clinical results or complications in TKA following OW-HTO or CW-HTO. MATERIAL AND METHOD: A retrospective multicenter (9 centers) study was conducted for the French Society of Orthopedic Surgery and Traumatology (SoFCOT), including 135 TKAs following HTO (58 OW and 77 CW) at a minimum 5 years' follow-up. Mean interval between HTO and TKA was 134 months and was longer in case of CW-HTO (P<0.0001). Mean age at TKA was 65.4 years and older in case of CW-HTO (P=0.021). Tibial slope was greater in case of OW-HTO (P=0.024). Prior to TKA, 55.7% of patients could walk without canes, 98.4% found stairs difficult or impossible and only 19.1% could manage a walking distance greater than 1000m. Mean flexion was 110°; 54.2% of patients showed frontal knee stability and 87.8% sagittal stability; 60.1% had a mechanical axis in varus, without difference according to OW- or CW-HTO. RESULTS: Hardware was almost systematically removed (in 98.5% of cases): in the same step for OW-HTO (P=0.018) or often in 2 steps for CW-HTO. The primary approach was generally re-used (54.2%), but less frequently in the CW-HTO group (P=0.0004). Lateral or medial ligament release was not associated in respectively 78.2% and 79.7% of cases. The TKA implant was usually without stem (87.2%) and was fitted using a conventional technique (74.4%). At a mean 87 months' follow-up, 78.5% of patients could walk without canes, stairs were still difficult or impossible for 67%, and 74.1% could now walk further than 1000m; mean flexion was 110.5°. Overall, 91.5% of patients showed frontal knee stability and 98.2% sagittal stability, without difference according to OW- or CW-HTO. There were 15 complications within 3 months, more often in the OW-HTO group (12.3%) although not significantly, and with no difference in severity. Late complications comprised loosening (5.5%) and infection (3.6%) and were more frequent in the CW-HTO group (12%) (P<0.05). DISCUSSION: The study hypothesis was partially confirmed. The only technical differences concerned hardware removal, often performed in two steps in case of CW-HTO, and TKA approach, which differed from the primary approach in case of CW-HTO. Clinical results were comparable between OW- and CW-HTO, but late complications were more frequent in the CW-HTO group. LEVEL OF EVIDENCE: III; comparative retrospective study.

Properties and potential-applications of chemical inhibitors of cyclin-dependent kinases.

Cyclin-dependent kinases (CDKs) trigger and co-ordinate the cell division cycle phases. They also play a role in neuronal cells and in the control of transcription. Intensive screening has led in the past few years to the identification of a series of chemical inhibitors of CDKs. Some of these compounds display remarkable selectivity and efficiency (IC50 <25 nM). Many have been co-crystallised with CDK2, and their atomic interactions with the kinase have been analysed in detail: all are located in the ATP-binding pocket of the enzyme. These inhibitors are antimitotic, they arrest cells in G1 and, at higher doses, in G2/M. Furthermore, they facilitate or even trigger apoptosis in proliferating cells. In contrast, they protect neuronal cells from apoptosis. The potential use of these inhibitors is being extensively evaluated in cancer chemotherapy (clinical trials, Phase I and II). Possible clinical applications are being investigated in other fields: cardiovascular (restenosis, tumoural angiogenesis, atherosclerosis), nephrology (glomerulonephritis), dermatology (psoriasis), parasitology (unicellular parasites such as Plasmodium, Trypanosoma, Toxoplasma, etc.), neurology (Alzheimer's disease), viral infections (cytomegalovirus, human immunodeficiency virus, herpes). We anticipate the discovery of novel selective and powerful inhibitors in the near future, and hope for their efficient applications in various human diseases.

Overlapping cis-acting elements located in the first intron of the gene for type I 3 beta-hydroxysteroid dehydrogenase modulate its transcriptional activity.

High levels of expression for the gene encoding human type I 3 beta-hydroxysteroid dehydrogenase (3 beta-HSDI) have been detected in placenta and skin but not in adrenals, which, however, express high levels of type II 3 beta-HSD. In this study, we addressed the issue of whether the differential pattern of cell-specific expression for type I 3 beta-HSD can be explained by the differential utilization of cis-acting regulatory elements present in the 3 beta-HSDI gene regulatory sequences. Deletion analyses indicated that removal of intron 1 strongly impaired the transcriptional activity directed by the 3 beta-HSDI basal promoter. Consequently, we focused our attention to the characterization of the 128 base pair first intronic sequence from the 3 beta-HSDI gene. A single protected region, designated the 3 beta I-A element, was identified by DNase I footprinting. Gel mobility shift assays indicated that at least four nuclear proteins with distinct biochemical and binding properties possess the ability to bind the 3 beta I-A element to produce four DNA-protein complexes (R1 to R4). However, the one producing R1, a 37-kilodalton protein that has been found in both human choriocarcinoma JEG-3 and adrenal cortex adenocarcinoma SW13 cells, as well as in all tested tissue culture cells, clearly accounts for the major 3 beta I-A-binding species. Site-directed mutagenesis provided the evidence that the 3 beta I-A element acts positively on the 3 beta-HSD-I gene promoter-mediated transcriptional activity upon transient transfection of both JEG-3 and SW13 cells. No homology has been found between the 3 beta I-A element and target sequences for other known transcription factors. In addition, of the four proteins binding the 3 beta I-A element, that producing R2 was identified as the positive transcription factor Sp1, whereas the identity of the remaining factors is still unknown. This is consistent with the presence of an Sp1 motif overlapping the 3 beta I-A element in intron 1, therefore pointing toward an important function played by this particular region in 3 beta-HSDI basal, but not cell-specific, gene expression.

Secretion of Streptomyces tendae antifungal protein 1 by Lactococcus lactis.

Lactococcus lactis, the model lactic acid bacterium, is a good candidate for heterologous protein production in both foodstuffs and the digestive tract. We attempted to produce Streptomyces tendae antifungal protein 1 (Afp1) in L. lactis with the objective of constructing a strain able to limit fungal growth. Since Afp1 activity requires disulfide bond (DSB) formation and since intracellular redox conditions are reportedly unfavorable for DSB formation in prokaryotes, Afp1 was produced as a secreted form. An inducible expression-secretion system was used to drive Afp1 secretion by L. lactis; Afp1 was fused or not with LEISSTCDA, a synthetic propeptide (LEISS) that has been described to be a secretion enhancer. Production of Afp1 alone was not achieved, but production of LEISS-Afp1 was confirmed by Western blot and immunodetection with anti-Afp1 antibodies. This protein (molecular mass: 9.8 kDa) is the smallest non-bacteriocin heterologous protein ever reported to be secreted in L. lactis via the Sec-dependent pathway. However, no anti-fungal activity was detected, even in concentrated samples of induced supernatant. This could be due to a too low secretion yield of Afp1 in L. lactis, to the absence of DSB formation, or to an improper DSB formation involving the additional cysteine residue included in LEISS propeptide. This raises questions about size limits, conformation problems, and protein secretion yields in L. lactis.

[Multinucleate cells angiohistiocytoma]. / Angiohistiocytome à cellules multinucléées.

INTRODUCTION: Multinucleate cell angiohistiocytoma is a rare entity. We report two unusual cases of this lesion. CASE REPORT: A 39 year-old man had presented since two years an arciform papular eruption of the forehead. A 40 year-old woman had a disseminated maculo-papular eruption since three years. Histological examination of skin samples of the two patients showed a dermal small vessel proliferation, associated with multinucleate cells, and confirmed the diagnosis of multinucleate cell angiohistiocytoma. DISCUSSION: Our cases, typical histologically, have unusual clinical presentation (first case observed in a man, and the second in a disseminated form). Multinucleate cell angiohistiocytoma is a rare benign vascular proliferation individualized in 1985. Clinically, the lesion consists in small circumscribed papules. Acral sites and notably of the dorsum of the hands are the more frequent topography. It generally occurs in women aged over 50 years. Histologically, there is a dermal proliferation of capillaries and venules, and a fibrosis associated with the interstitial mononucleate cells and multinucleate cells.

Molecular and functional characterization of a 5-HT4 receptor cloned from human atrium.

5-Hydroxytryptamine (5-HT) has been shown to exert positive inotropic, chronotropic, and lusitropic effects and to stimulate the L-type calcium channel current (I(Ca)) in human atrial tissue through activation of the pharmacologically defined 5-HT4 receptor subtype. However, the molecular nature of the receptor(s) involved in these effects is still unknown. In the present study, we report the molecular nature of a 5-HT4 receptor cloned from human atrium, h5-HT4A. Sequence analysis reveals that h5-HT4A displays a 93% protein identity with the short form of the 5-HT4 receptor recently isolated from rat brain. h5-HT4A mRNA is expressed in human atrium but not ventricle, and is also found in brain and GI tract. h5-HT4A transiently expressed in COS-7 cells displays a classical 5-HT4 pharmacological profile. However, affinities of the h5-HT4A receptor for agonists such as ML10302, BIMU1, renzapride or zacopride were 4-10-fold lower than the ones found in brain. Moreover, the stimulatory patterns of cAMP formation by h5-HT4A in response to the 5-HT4 agonists ML10302 and renzapride were very similar to the patterns of stimulation of I(Ca) obtained in response to these compounds in human atrial myocytes. We conclude that h5-HT4A likely mediates the effects of 5-HT in human atrium and may differ from 5-HT4 receptor isoforms present in the brain and GI tract.

Evolution of cortical responsiveness subsequent to multiple forelimb nerve transections: an electrophysiological study in adult cat somatosensory cortex.

Multiunit recordings along mediolateral rows in the primary somatosensory cortex of the animals described by C. Avendaño, D. Umbriaco, R.W. Dykes, and L. Descarries (1995, J. Comp. Neurol. 354:321-332) provided information about the functional status of the regions in and near the deafferented cortex. Responses changed along this axis from normally organized receptive fields in the hindlimb representation through a transition zone of unusually small receptive fields into the clearly deafferented forelimb representation, where receptive fields were uncommon and often had unusual characteristics. The most abrupt change along this axis was the appearance of a repetitive, bursting discharge pattern in the multiunit activity near the border of the deprived cortex. The appearance of this pattern was used as a reference to describe differences between normal and deprived cortices. The nature of these differences evolved with time. Much of the deprived cortex lacked identifiable receptive fields for months after the nerve transections and, 1 year later, still only about half of the recording sites within the deprived region displayed organized receptive fields. Some sites within the deprived region lacking definable receptive fields could be excited at long latencies by somatic stimuli anywhere on the body. With time, regions of normal cortex near the border with the deprived zone became more involved in these processes. Spontaneous activity and thresholds also changed with time in both normal and deprived cortices.(ABSTRACT TRUNCATED AT 250 WORDS)

Reevaluation of area 3b in the cat based on architectonic and electrophysiological studies: regional variability with functional and anatomical consistencies.

Most anatomical and electrophysiological studies of the cat primary somatosensory cortex rely on Hassler and Muhs-Clement's (J. Hirnforsch. 6:377-420, 1964) cyto- and myeloarchitectonic description distinguishing area 3a from area 3b; however, discrepancies in the delineation of these areas in published studies suggest that many workers have found it difficult to apply those criteria systematically. We examined the cytoarchitecture of area 3b in Nissl stained sagittal sections from which electrophysiological data had been obtained prior to sacrifice. Rostrocaudal rows of electrode penetrations placed at different mediolateral positions in the gyrus located regions responsive to stimulation of either cutaneous or deep structures. Small electrolytic lesions allowed these data to be related to the cytoarchitecture. A systematic study throughout the trunk and limb representations found cutaneous responses in cortical regions characterized by a thick and cell-dense granular layer IV, however these same regions had a variable population of medium-sized and/or large pyramidal cells in layer V. Pyramidal cells were practically absent from the forelimb representation, but were present to varying degrees in the trunk and hindlimb representations. Moreover, the relative thickness and cell-density in layer IV were greater in the forelimb than in the hindlimb representations. Deep responses were found in cortex characterized by a thinner layer IV. Since the characteristics of layer V in area 3a were variable, it was less useful for identification of the border between areas 3a and 3b. Clear changes in the intensity and laminar distribution of acetylcholinesterase staining occurred between areas 3a and 3b, making this a useful adjunct to the Nissl stain.