Short communication: Adipocyte sizes in the digital fat pad and their relationship to body condition in dairy cows.

Lameness and body condition are closely related. Recent studies have shown that cows with low body condition score (BCS) have a greater risk for developing lameness than cows with higher BCS. Among other reasons, this relationship might be related to the reduced thickness of the digital fat cushion in lean cows. The digital cushion is not a homogeneous structure but consists of different fat pads and connective tissue. We hypothesized that either high or low BCS will result in concordant adipocyte sizes in the fat pads of the digital cushion and subcutaneous tailhead fat irrespective of the localization of the latter. Right front claws were collected from 18 Holstein Friesian cows. Cows were selected according to their BCS: 9 cows with BCS <3 (low BCS) and 9 cows with BCS ≥3 (high BCS). After dissecting the horn capsule of the lateral claw, samples of the axial and abaxial fat pads were prepared for histomorphological examinations (adipocyte size measurement) and protein abundance of vascular endothelial growth factor A (VEGF-A) via Western blotting. In addition, fat samples were excised from the tailhead of all cows and used for the same purposes. Adipocyte size in tailhead fat was greater in high-BCS than in low-BCS cows. Similar differences between the BCS groups were apparent for adipocytes from the axial fat pad, although adipocytes in tailhead fat were larger than those in the digital cushion. In contrast to that in the axial fat pad and tailhead fat, adipocyte size in the abaxial fat pad was similar in cows from both BCS groups. A relationship between adipocyte size and VEGF-A protein was only confirmed for the axial fat pad, not for the other fat depots. When comparing BCS groups, differences in VEGF-A protein abundance between high-BCS and low-BCS cows were also limited to the axial fat pad, being absent in tailhead fat and the abaxial fat pad. Taken together, our results show that the fat pads from the digital cushion should not be considered uniform adipose tissue locations but rather discrete units reacting differently to fat mobilization.

Primary health care for people with an intellectual disability: an exploration of consultations, problems identified, and their management in Australia.

BACKGROUND: People with an intellectual disability (ID) have more complex and different patterns of health care needs than the general population. They experience a greater burden of multi-morbidity, high levels of undetected and unmanaged health issues, and premature mortality than the general population. Primary care has a key role in the health care of people with an ID. Currently, very little is known about the consultation type and length, problems managed, and how general practitioners (GPs) manage these problems for people with an ID compared with the general population. This information would provide valuable insights into how GPs are achieving the health guidelines and facilitating people with an ID to achieve the highest attainable standard of health. METHODS: A secondary analysis of data was collected from January 2003 to December 2012 from the Bettering the Evaluation and Care of Health (BEACH) programme. Consultation type, consultation length in minutes, problem(s) managed during the consultation, medications, treatments provided, and referrals made, pre and post age-sex standardisation, at all GP encounters with people identified in the encounter record as having an ID ('ID' encounters, n = 690) were compared with those at 'non-ID' encounters (n = 970 641). Statistical significance was tested with 95% confidence intervals. RESULTS: This study identified significant differences in consultation types, consultation length, problem(s) managed during the consultation, medications, treatments provided, and referrals made at 'ID' encounters compared with 'non-ID' encounters. 'ID' encounters had more indirect encounters, longer consultations, more problems managed, but an under management of common health conditions in people with an ID. Administrative rather than medically related actions dominated clinical treatments for people at 'ID' encounters, and they received fewer procedural treatments, referrals to specialists, and medications compared with those at 'non-ID' encounters. CONCLUSION: The significant differences in consultations, problems identified and managed suggest that GPs may require additional support to (1) identify and manage common medical conditions experienced by people with an ID; (2) manage the increased time required for consultations; and (3) directly consult with people with an ID. Further research is required to determine why GPs managed problems in a significantly different way for people with an ID.

Primary health care for people with an intellectual disability: an exploration of demographic characteristics and reasons for encounters from the BEACH programme.

BACKGROUND: People with an intellectual disability (ID) have complex and different patterns of healthcare needs. Poor participation in primary health care contributes to the high levels of undetected and unmanaged health issues and premature deaths of people with an ID. Limited research is available on the characteristics of people with an ID, their reasons for consulting general practitioners (GPs), and if these differ to people without an ID. Gaining such insights may provide an avenue to better understand patterns of primary care use and potential gaps in usage by people with an ID given their complex health profile compared with people without an ID. METHOD: A secondary analysis of data collected January 2003 to December 2012 from The Bettering the Evaluation and Care of Health programme was used. Participant characteristics and their reasons for encounter, pre- and post-age-sex standardisation, at all GP encounters with people identified in the encounter record as having an ID ('ID' encounters, n = 690) were compared with those at 'non-ID' encounters (n = 970 641). Statistical significance was tested with chi-squared statistics or 95% confidence intervals as appropriate. RESULTS: This study identified significant differences in participant characteristics and their reasons for consulting GPs at ID encounters compared with non-ID encounters. Participants at ID encounters had a skewed demography, an over-representation of presentations for psychological, social and 'general and unspecified' reasons, and an under-representation of presentations for core physical health and preventive health measures. Administrative rather than medically related reasons dominated presentations to general practice at ID encounters. CONCLUSION: There are significant differences in the characteristics of participants and their reasons for presentation to general practice in Australia for participants at ID encounters compared with non-ID encounters. This work suggests that there is a difference in service use patterns between these two groups. These findings may suggest that people with an ID experience barriers to participating in essential primary healthcare services.

Differential regulation of human and mouse telomerase reverse transcriptase (TERT) promoter activity during testis development.

In adult testis, telomerase activity is exclusively detectable during the early steps of spermatogenesis and is downregulated during differentiation to spermatozoa. Knowledge about telomerase activity during testis development from birth to adulthood is still scarce. Telomerase activity is regulated primarily via the transcriptional initiation of TERT expression which encodes its catalytic subunit. We used the hTERTp-lacZ transgenic mouse model that expresses the bacterial lacZ reporter gene under the control of an 8.0-kbp human TERT promoter fragment to analyze simultaneously endogenous mouse Tert gene expression as well as human TERT promoter activity during mouse testis development. We show that human TERT promoter activity increased during puberty and was highest in adult mouse testis whereas mouse Tert expression and telomerase activity were found to be high in testis from the earliest time point tested (6 days postpartum). Histological analysis revealed that beta-galactosidase expression, encoded by the lacZ reporter gene, is present in all seminiferous tubules in adult testis, but in a subset of tubules before puberty. We further analyzed the expression of SCF/ c-KIT, which was described to regulate spermatogonia proliferation and mouse Tert expression, in prepubertal and adult testis by immunohistochemistry. Whereas SCF and c-KIT were detectable in all seminiferous tubules, a spatial and preclusive expression pattern of human TERT promoter activity and activated c-KIT (p-c-KIT Tyr 567/569) was observed in prepubertal testes.

Early diffusion-weighted MRI predicts regional neuronal damage in generalized status epilepticus in rats treated with diazepam.

We applied diffusion-weighted MRI (DWI) in the pilocarpine-induced status epilepticus (SE) model to investigate the evolution of acute phase changes in brain diffusion with and without early anticonvulsive therapy correlated to long-term SE-induced neuronal cell loss. Hereby, DWI was performed before (baseline) and serially between 3 and 120 min after onset of SE in untreated and treated animals (n=15 in each group). Anticonvulsive-treated animals received 20 mg/kg diazepam at 15 min after onset of SE. Apparent diffusion coefficients (ADC) were calculated for the parietal, temporal and piriform cortex, thalamus, hippocampus and amygdala and compared to baseline. Neuronal cell loss was quantified at 2 weeks after onset of SE utilizing cresyle-violet-staining. The results of ADC-mapping demonstrated a significant transient increase in ADC (to 116+/-4% of baseline) in the very acute phase starting 3 min after SE onset, lasting for 10 min in both groups. In untreated animals, there was a significant gradual decline in ADC to 75+/-12% of baseline while this decline in diazepam-treated animals was significantly less pronounced (P<0.05) and ADC recovered to 93+/-6% of baseline. There was good correlation between neuronal cell loss in specific brain regions at 2 weeks after SE and maximal decrease in ADC (r>0.79). In conclusion, serial DWI is a sensitive noninvasive technique for early detection, monitoring and prediction of SE-induced neuronal alterations. Using ADC-mapping, verification of early anticonvulsive therapy in SE seems to be possible as there is good correlation between the maximal decrease in ACD in the acute phase of SE and late neuronal cell loss.

Monitoring of acute generalized status epilepticus using multilocal diffusion MR imaging: early prediction of regional neuronal damage.

BACKGROUND AND PURPOSE: Diffusion-weighted MR imaging (DWI) has emerged as tool for noninvasive and early detection of neuronal alterations. The aim of this study was to investigate the evolution of acute phase changes in different brain regions during experimental status epilepticus (SE) using DWI correlated with SE-induced neuronal cell loss. METHODS: DWI was performed in 20 rats before (baseline) and 3, 5, 10, 15, 20, 30, 45, 60, 90, and 120 minutes after onset of pilocarpine-induced SE. Apparent diffusion coefficients (ADCs) were calculated for the parietal cortex, temporal cortex, pyriform cortex, hippocampus, amygdala, and thalamus and compared with baseline. Neuronal cell loss was quantified at different time points after SE using cresyl-violet-staining. RESULTS: ADC-mapping demonstrated a significant transient increase in ADC (to 116 +/- 4% of baseline) in the very acute phase, starting 3 minutes after SE onset, lasting for 10 minutes, followed by a significant gradual decline in ADC in all animals. Compared with surviving animals (76 +/- 7%), decline in ADC was significantly lower for the animals who died within 2 hours for all regions of interest (63 +/- 6.5%, 0.45 +/- 0.03 x 10(-3) mm(2)/s) except the thalamus (P < .01, analysis of variance). There was good correlation between neuronal cell loss in specific brain regions 2 weeks after SE and maximal decrease in ADC (r > 0.76). CONCLUSION: Serial ultrafast DWI is a sensitive noninvasive technique for early detection and monitoring of seizure-induced neuronal alterations. Using ADC-mapping differentiation of regional severity of neuronal damage may be possible because there is good correlation between the maximal decrease in ADC in the acute phase of SE and late neuronal cell loss.

Increased expression and activation of poly(ADP-ribose) polymerase (PARP) contribute to retinal ganglion cell death following rat optic nerve transection.

Excessive activation of the nuclear enzyme poly(ADP-ribose) polymerase (PARP) by free-radical damaged DNA mediates necrotic cell death in injury models of cerebral ischemia-reperfusion and excitotoxicity. We recently reported that secondary retinal ganglion cell (RGC) death following rat optic nerve (ON) transection is mainly apoptotic and can significantly but not entirely be blocked by caspase inhibition. In the present study, we demonstrate transient, RGC-specific PARP activation and increased retinal PARP expression early after ON axotomy. In addition, intravitreal injections of 3-aminobenzamide blocked PARP activation in RGCs and resulted in an increased number of surviving RGCs when compared to control animals 14 days after ON transection. These data indicate that secondary degeneration of a subset of axotomized RGCs results from a necrotic-type cell death mediated by PARP activation and increased PARP expression. Furthermore, PARP inhibition may constitute a relevant strategy for clinical treatment of traumatic brain injury.

Cerebral perfusion alterations during the acute phase of experimental generalized status epilepticus: prediction of survival by using perfusion-weighted MR imaging and histopathology.

BACKGROUND AND PURPOSE: Persistent generalized status epilepticus (SE) is associated with alterations of cerebral perfusion (CP). Because perfusion-weighted MR imaging (PWI) allows noninvasive CP-determination, the aim of this study was to investigate CP alterations during acute experimental SE correlated with SE-induced neuronal cell loss. METHODS: The rat pilocarpine model was used to induce SE. Multilocal PWI was performed before (baseline) and 3, 15, 30, 60, and 120 minutes after onset of SE. Bolus-peak ratio (BPR) was calculated for the retrosplenial and piriform cortex, hippocampus, amygdala, and thalamus and compared with baseline. Neuronal cell loss was quantified at different time points after induction of SE by cresyle violet staining. RESULTS: Immediately after SE onset (3 minutes), BPR temporarily increased to 102%-130% in all regions, with a maximum in the amygdala (129 +/- 16%) and hippocampus (130 +/- 21%). At 15, 30, and 60 minutes, BPR decreased continuously to 57%-76%. BPR values <55% in the parietal and/or temporal cortex resulted in death. In surviving animals, BPR recovered to 66%-79% and there was a good correlation between neuronal cell loss in specific brain regions at 2 weeks after SE onset and maximal decrease in BPR (r > 0.73). CONCLUSION: PWI demonstrated a transient cerebral hyperperfusion immediately after SE onset, followed by a significant continuous decline to different perfusion levels. In our experimental setting, a decline of cortical BPR below 55% of baseline seems to be a prognostic threshold value associated with subsequent death. In surviving animals, there is good correlation between the maximal decrease in BPR in the acute phase of SE and late neuronal cell loss.

Cellular prion protein promotes post-ischemic neuronal survival, angioneurogenesis and enhances neural progenitor cell homing via proteasome inhibition.

Although cellular prion protein (PrP(c)) has been suggested to have physiological roles in neurogenesis and angiogenesis, the pathophysiological relevance of both processes remain unknown. To elucidate the role of PrP(c) in post-ischemic brain remodeling, we herein exposed PrP(c) wild type (WT), PrP(c) knockout (PrP-/-) and PrP(c) overexpressing (PrP+/+) mice to focal cerebral ischemia followed by up to 28 days reperfusion. Improved neurological recovery and sustained neuroprotection lasting over the observation period of 4 weeks were observed in ischemic PrP+/+ mice compared with WT mice. This observation was associated with increased neurogenesis and angiogenesis, whereas increased neurological deficits and brain injury were noted in ischemic PrP-/- mice. Proteasome activity and oxidative stress were increased in ischemic brain tissue of PrP-/- mice. Pharmacological proteasome inhibition reversed the exacerbation of brain injury induced by PrP-/-, indicating that proteasome inhibition mediates the neuroprotective effects of PrP(c). Notably, reduced proteasome activity and oxidative stress in ischemic brain tissue of PrP+/+ mice were associated with an increased abundance of hypoxia-inducible factor 1α and PACAP-38, which are known stimulants of neural progenitor cell (NPC) migration and trafficking. To elucidate effects of PrP(c) on intracerebral NPC homing, we intravenously infused GFP(+) NPCs in ischemic WT, PrP-/- and PrP+/+ mice, showing that brain accumulation of GFP(+) NPCs was greatly reduced in PrP-/- mice, but increased in PrP+/+ animals. Our results suggest that PrP(c) induces post-ischemic long-term neuroprotection, neurogenesis and angiogenesis in the ischemic brain by inhibiting proteasome activity.

Double-blind placebo-controlled administration of fluoxetine in restricting- and restricting-purging-type anorexia nervosa.

BACKGROUND: Anorexia nervosa is an often chronic disorder with high morbidity and mortality. Many people relapse after weight restoration. This study was designed to determine whether a selective serotonin reuptake inhibitor would improve outcome and reduce relapse after weight restoration by contributing to maintenance of a healthy normal weight and a reduction of symptoms. METHODS: We administered a double-blind placebo-controlled trial of fluoxetine to 35 patients with restricting-type anorexia nervosa. Anorexics were randomly assigned to fluoxetine (n = 16) or a placebo (n = 19) after inpatient weight gain and then were observed as outpatients for 1 year. RESULTS: Ten of 16 (63%) subjects remained on fluoxetine for a year, whereas only three of 19 (16%) remained on the placebo for a year (p =.006). Those subjects remaining on fluoxetine for a year had reduced relapse as determined by a significant increase in weight and reduction in symptoms. CONCLUSIONS: This study offers preliminary evidence that fluoxetine may be useful in improving outcome and preventing relapse of patients with anorexia nervosa after weight restoration.

Delayed treatment with intravenous basic fibroblast growth factor reduces infarct size following permanent focal cerebral ischemia in rats.

Basic fibroblast growth factor (bFGF) is a polypeptide that supports the survival of brain cells (including neurons, glia, and endothelia) and protects neurons against a number of toxins and insults in vitro. This factor is also a potent dilator of cerebral pial arterioles in vivo. In previous studies, we found that intraventricularly administered bFGF reduced infarct volume in a model of focal cerebral ischemia in rats. In the current study, bFGF (45 micrograms/kg/h) in vehicle, or vehicle alone, was infused intravenously for 3 h, beginning at 30 min after permanent middle cerebral artery occlusion by intraluminal suture in mature Sprague-Dawley rats. After 24 h, neurological deficit (as assessed by a 0- to 5-point scale, with 5 = most severe) was 2.6 +/- 1.0 in vehicle-treated and 1.5 +/- 1.3 in bFGF-treated rats (mean +/- SD; N = 12 vs. 11; p = 0.009). Infarct volume was 297 +/- 65 mm3 in vehicle- and 143 +/- 135 mm3 in bFGF-treated animals (p = 0.002). During infusion, there was a modest decrease in mean arterial blood pressure but no changes in arterial blood gases or core or brain temperature in bFGF-treated rats. Autoradiography following intravenous administration of 111In-labeled bFGF showed that labeled bFGF crossed the damaged blood-brain barrier to enter the ischemic (but not the nonischemic) hemisphere. Whether the infarct-reducing effects of bFGF depend on intraparenchymal or intravascular mechanisms requires further study.

Basic fibroblast growth factor protects against excitotoxicity and chemical hypoxia in both neonatal and adult rats.

Basic fibroblast growth factor (bFGF) is a polypeptide growth factor that promotes neuronal survival. We recently found that systemic administration of bFGF protects against both excitotoxicity and hypoxia-ischemia in neonatal animals. In the present study, we examined whether systemically administered bFGF could prevent neuronal death induced by intrastriatal injection of N-methyl-D-aspartate (NMDA) or chemical hypoxia induced by intrastriatal injection of malonate in adult rats and 1-methyl-4-phenylpyridinium (MPP+) in neonatal rats. Systemic administration of bFGF (100 micrograms/kg) for three doses both before and after intrastriatal injection of either NMDA or malonate in adult rats produced a significant neuroprotective effect. In neonatal rats, bFGF produced dose-dependent significant neuroprotective effects against MPP+ neurotoxicity, with a maximal protection of approximately 50% seen with either a single dose of bFGF of 300 micrograms/kg or three doses of 100 micrograms/kg. These results show that systemic administration of bFGF is effective in preventing neuronal injury under circumstances in which the blood-brain barrier may be compromised, raising the possibility that this strategy could be effective in stroke.

Increased expression of basic fibroblast growth factor (bFGF) following focal cerebral infarction in the rat.

Basic fibroblast growth factor (bFGF) is a polypeptide with potent trophic effects on brain neurons, glia, and endothelial cells. In the current study, we used Northern blotting, in situ hybridization, and immunohistochemical techniques to examine bFGF expression in brain following focal infarction due to permanent occlusion of the proximal middle cerebral artery in mature Sprague-Dawley rats. We found a four-fold increase in bFGF mRNA in tissue surrounding focal infarcts at 1 day after ischemia. In situ hybridization showed that this increase was found throughout several structures in the ipsilateral hemisphere, including frontoparietal, temporal, and cingulate cortex, as well as in caudoputamen, globus pallidus, septal nuclei, nucleus accumbens, and olfactory tubercle. Increased bFGF mRNA expression was associated with cells having the distinct morphological appearance of astroglia in these structures. Immunohistochemistry showed an increase in the size and number of bFGF-immunoreactive (IR) nuclei in these same structures, as well as a shift from nuclear to nuclear plus cytoplasmic localization of immunoreactivity, beginning at 1 day, and peaking at 3 days after ischemia. Double immunostaining identified bFGF-IR cells as astroglia in these structures. (An exception was the piriform cortex, in which both increased bFGF mRNA levels and increased bFGF-IR was found in neurons at 1 day after ischemia). Overall, the peak of increased bFGF expression preceded the peak in expression of the astroglial marker GFAP within the ipsilateral hemisphere. Increased bFGF expression may play an important role in the glial, neuronal, and vascular changes occurring after focal infarction.

Degeneration and regeneration of ganglion cell axons.

The retino-tectal system has been used to study developmental aspects of axon growth, synapse formation and the establishment of a precise topographic order as well as degeneration and regeneration of adult retinal ganglion cell (RGC) axons after axonal lesion. This paper reviews some novel findings that provide new insights into the mechanisms of developmental RGC axon growth, pathfinding, and target formation. It also focuses on the cellular and molecular cascades that underlie RGC degeneration following an axonal lesion and on some therapeutic strategies to enhance survival of axotomized RGCs in vivo. In addition, this review deals with problems related to the induction of regeneration after axonal lesion in the adult CNS using the retino-tectal system as model. Different therapeutic approaches to promote RGC regeneration and requirements for specific target formation of regenerating RGCs in vitro and in vivo are discussed.

First experiences with the use of CASA in mammary carcinoma.

The expression of the tumor marker CASA (cancer associated serum antigen) was studied in patients with mammary carcinoma; increased values were almost exclusively seen in cases of manifest metastasis. No correlation existed between tumor stage, lymph node involvement and grading. Marker levels were tested by means of enzyme-immune-assay of the firm medac (Hamburg), with a cut-off value set at 4 U/ml.

Optical activity in an isotropic gas of electrons with a preferred helicity.

An isotropic gas of electrons with a preferred spin helicity is shown to be optically active. Simultaneous eigenfunctions of the Dirac Hamiltonian and the helicity operator are constructed and used to derive explicit expressions for vertex functions for helicity states. The (covariant) response tensor is calculated for an electron gas described in terms of a spin-dependent occupation number. The possibility of detecting optical activity in an electron gas is discussed briefly.

Use of controlled vignettes in evaluation: does type of response method make a difference?

Two studies were performed using vignettes as a method in program evaluation. One study used a rating scale method. The second study used a forced choice decision method. The two studies were performed with students from the pre-Occupational Therapy (pre-OT) program, the Occupational Therapy (professional OT) program and the College of Business at Colorado State University. Students were asked to respond to a questionnaire about how a hypothetical job applicant with a cognitive disability would perform in one of three types of job settings: a segregated, sheltered workshop setting; an integrated supported employment setting; or an integrated competitive employment setting. The students in the Professional Occupational Therapy program had been part of a training grant, 'An integrated approach to personnel preparation for transition', which focused on the integration of transition competencies into an occupational therapy curriculum. The forced choice vignette method resulted in statistically significant positive outcomes toward supported employment and the influence of the training grant. The discussion focused on the different outcomes of the two studies relative to the methods applied and the use of vignettes as an evaluation tool to assess the impact of a modified curriculum. Attention was directed toward the problem of external validity when using vignettes (Gorman, C.D., Clover, W.H. & Doherty, M.E., (l978). Can we learn anything about interviewing real people from 'interviews' of paper people? Two studies of the external validity of a paradigm. Organizational Behavior and Human Performance, 22, 165-192.).

A newly discovered function of palatine tonsils in immune defence: the expression of defensins.

The palatine tonsils have an undoubted role in the immune defence system. After antigen contact an effective adaptive immune response by B- and T-cell lymphocytes will be released. In addition the palatine tonsils seem to exert influence to the defence by the innate immune system. Therefore, we studied the ability of palatine tonsils to express different alpha and beta defensins and to find out any distinctions in chronic inflamed tonsils. Total RNA of 49 specimens of hyperplastic tonsils and chronic tonsillitis with pathological provided evidence of Actinomyces israelii was isolated using TRIzol protocol, reverse transcribed and the HNP-1, HNP-4, HBD-1 and HBD-2 gene expression densitometric determined, standardised in relation to glycerinaldehyd-3-phosphatdehydrogenase gene expression, after a semiquantitative polymerase chain reaction was performed. mRNA of HNP-1, HNP-4, HBD-1 and HBD-2 was detected in tissue samples, but their amount differed within the two defensin families and tissue of origins. HBD-1 was detected in all 49 tissues of hyperplastic tonsils and chronic tonsillitis. Only in chronic inflamed tonsils the amount of HBD-2 mRNA expression was significant increased. In these specimens also mean relative expression rate of all defensins was observed to be manifestly increased. Palatine tonsils express mRNA for different alpha and beta defensins and this expression suggest a newly supposed function in immune defence: the participation in the innate, non-adaptive immune system. Thus, palatine tonsils have a potentially influence in the growth and control of the physiological mouth bacteria by their bactericidal activity.

The matricellular protein periostin contributes to proper collagen function and is downregulated during skin aging.

BACKGROUND: Periostin is a secreted 90kDa matricellular protein, which is predominantly expressed in collagen-rich tissues. Collagen is the most abundant protein in mammals and has great tensile strength. Recent investigations have shown that periostin influences collagen fibrillogenesis and biomechanical properties of murine connective tissues. OBJECTIVE: We investigated the function of periostin concerning collagen homeostasis during intrinsic and extrinsic skin aging. For this purpose, human skin samples of young and old donors as well as samples of photoaged and sun-protected skin areas were analyzed for periostin expression. Using in vitro models, we determined the cell types responsible for periostin expression and performed functional analyses with periostin knockdown cells. METHODS: TaqMan Real-Time PCR, UV irradiation, knockdown experiments, immunostaining, electron microscopy, collagen degradation assay, collagen crosslink analysis. RESULTS: Periostin expression is highest in the papillary dermis and downregulated during skin aging. Fibroblasts and non-follicular skin derived precursors were identified as main source for periostin expression in human skin. Periostin knockdown in fibroblasts has no effect on collagen expression, but results in an increased fibril diameter and aberrant collagen structure. This leads to an increased susceptibility of collagen toward proteases, whereas recombinant periostin protects collagen fibrils from degradation. CONCLUSION: Our data show that periostin plays an important role for proper collagen assembly and homeostasis. During skin aging periostin expression decreases and contributes to the phenotype of aged skin.

Selective upregulation and amplification of the lysyl oxidase like-4 (LOXL4) gene in head and neck squamous cell carcinoma.

Members of the lysyl oxidase family (LOX) are copper and lysyl-tyrosine quinone cofactor-containing amine oxidases that are important for the assembly and maintenance of components of the extracellular matrix. Our previous results demonstrated that a novel member, LOXL4, is overexpressed in head and neck squamous cell carcinoma (HNSCC) compared to normal squamous epithelium. Results of the current study showed overexpression of the LOXL4 transcript in 74% (46 of 62) of invasive HNSCC tumours and 90% of both primary and metastatic HNSCC cell lines. Significant correlation was found between LOXL4 expression and local lymph node metastases versus primary tumour types (p<0.01) and higher tumour stages (p<0.01). Immunocytochemistry demonstrated cellular overexpression of the LOXL4 protein that correlated with the increased mRNA transcription in HNSCC cells. HNSCC cell lines displayed in significant subset of nuclei increased copies of the LOX4 gene locus on chromosome 10q24, demonstrated by fluorescence in situ hybridization (FISH). Extensive metaphase cytogenetic analysis was performed on UTSCC19A cells, identifying an isochromosome i(10)(q10). Taken together, these results highlight LOXL4 expression as a distinctive trait and suggest a functional role for LOXL4 in the molecular pathogenesis of invasive head and neck carcinomas.