Spontaneous generation of functional osteoclasts from synovial fluid mononuclear cells as a model of inflammatory osteoclastogenesis

In osteoimmunology, osteoclastogenesis is understood in the context of the immune system. Today, the in vitro model for osteoclastogenesis necessitates the addition of recombinant human receptor activator of nuclear factor kappa‐B ligand (RANKL) and macrophage colony‐stimulating factor (M‐CSF). The peripheral joints of patients with rheumatoid arthritis (RA) and spondyloarthritis (SpA) are characterized by an immune‐mediated inflammation that can lead to bone destruction. Here, we evaluate spontaneous in vitro osteoclastogenesis in cultures of synovial fluid mononuclear cells (SFMCs) activated only in vivo. SFMCs were isolated and cultured for 21 days at 0.5–1.0 × 10⁶ cells/mL in culture medium. SFMCs and healthy control peripheral blood monocytes were cultured with RANKL and M‐CSF as controls. Tartrate‐resistant acid phosphatase (TRAP) positive multinucleated cells were found in the SFMC cultures after 21 days. These cells expressed the osteoclast genes calcitonin receptor, cathepsin K, and integrin β3, formed lacunae on dentin plates and secreted matrix metalloproteinase 9 (MMP9) and TRAP. Adding RANKL and M‐CSF potentiated this secretion. In conclusion, we show that SFMCs from inflamed peripheral joints can spontaneously develop into functionally active osteoclasts ex vivo. Our study provides a simple in vitro model for studying inflammatory osteoclastogenesis.     

Opposite effects of phospholipase A2 on [3H]AMPA binding in adult and neonatal membranes.

In the present study, we compared the effect of phospholipase A2 (PLA2) treatment of synaptic membranes from adult and neonatal rats on the characteristics of [3H]AMPA binding sites. Whereas PLA2 treatment of membranes from adult rats produces an increased affinity for [3H]AMPA binding, the same treatment in neonatal rats results in a decrease in the maximal number of binding sites. Since activation of PLA2 has been proposed to play a critical role in the formation of long-term potentiation (LTP), possibly mediated through a modification of the AMPA receptors, the results strengthen the hypothesis that PLA2-induced modification of [3H]AMPA binding sites is an important component of synaptic plasticity.     

Anal sphincter size measured by endosonography in healthy volunteers. Effect of age, sex, and parity.

The anal sphincter muscles consist of the circular internal and external sphincters together with the sling-shaped associated puborectalis muscle. Ten men, 10 women with no vaginal deliveries, and 10 women with one or more vaginal deliveries were studied with anal endosonography using a 7 MHz multiplanar endoprobe. The thickness of the internal sphincter and the thickness, length, and cross-sectional area of the external sphincter were measured and related to age, sex, and parity. Reproducibility was assessed by similar measurements on different days in 10 volunteers. Anal sphincter size was the same in men and women and was not affected by the number of child births. Internal sphincter muscle thickness increased with age. Anal manometry and electromyography with an anal sponge were performed in all volunteers but the results did not correlate to any of the anal sphincter dimensions. Our conclusion is that although there are some limitations, endosonography can be used to determine the size of the anal sphincter muscles.     

Arterial P CO2 and lung ventilation in man exposed to 1-5% CO2 in the inspired gas

Conflicting results have been published on the shape of the curve relating the change in lung ventilation to the change in alveolar or arterial PCO2 induced by increased inspired CO2 (the CO2 sensitivity). In this study eight human subjects with in-dwelling arterial cannulae were each exposed to five different levels of increased inspired CO2 (1-5%). Arterial PCO2 and ventilation were measured in the 7th minute of each period of CO2 exposure. Each CO2 exposure period was flanked by control periods in which similar measurements were carried out during air breathing. We found non-linear increases in both ventilation and arterial PCO2 with increasing levels of inspired CO2. When 5% CO2 in air was inspired the arterial PCO2 increased by about 15% of the inspired CO2 load. There was no significant non-linearity in the relation between change in alveolar ventilation (normalized to body surface) and change in arterial PCO2. The inter-individual variation in CO2 sensitivity was less when alveolar ventilation was normalized to the CO2 output rather than to body surface area. We conclude that the sensitivity to CO2 is close to constant within the range 0-5% CO2 in the inspired gas.     

Epidemiological investigation of risk factors for campylobacter colonization in Norwegian broiler flocks.

An epidemiological investigation was conducted to identify risk factors related to hygiene and husbandry practices which determine the introduction of Campylobacter spp. into broiler chicken flocks. All 176 broiler farms in an area in southeastern Norway participated in the study. Each farm was represented by one flock selected at random during a one-year period. The flocks were examined for campylobacter colonization at slaughter, and the flock managers were subsequently interviewed about hygiene and husbandry practices. Campylobacter spp. were recovered from 32 (18%) of the flocks. The proportion of colonized flocks varied geographically and seasonally with a peak in the autumn. The following variables were found to be independently associated with an increased risk of campylobacter colonization using logistic regression analysis: (i) feeding the broilers undisinfected water (odds ratio (OR) = 3.42, P = 0.045), (ii) tending other poultry prior to entering the broiler house (OR = 6.43, P = 0.007), (iii) tending pigs before entering the house (OR = 4.86, P = 0.037), (iv) geographic region (Hedmark versus Ostfold county) (OR = 2.91, P = 0.023, (v) season (autumn versus other seasons) (OR = 3.43; P = 0.008). Presence of rats on the farm was associated with an increased risk, but this factor did not reach statistical significance (OR = 3.96, P = 0.083). Preventive measures should include disinfection of drinking water and strict hygienic routines when the farm workers enter the rearing room. The results indicate that disinfection of drinking water is the preventive measure most likely to have the greatest impact on the prevalence of campylobacter among broiler chicken flocks in the study area (population attributable fraction = 0.53).     

Projection systems and terminal localization of dorsal column afferents: an autoradiographic and horseradish peroxidase study in the rat

Projection systems from the gracile nucleus and the cuneate nuclear complex to their terminal sites in the mesencephalon, diencephalon, and cerebellum were examined by means of anterograde autoradiography and retrograde horseradish peroxidase methods. Three projection systems emerge from the dorsal column nuclei, decussate via internal arcuate fibers, and form the contralateral medial lemniscus (ML). At the obex, some fibers split off the ML and course dorsolaterally, forming an ascending lateral system which fits the "lemniscal adjunct channel" (LAC) concept of Graybiel ('72). The ML continues rostrally as the "main lemniscal line channel" (MLLC). At the inferior colliculus, some LAC fibers terminate in the pontine nuclei, parabrachial, dorsal reticular nuclei, and the external and ventral medial part of the central nucleus of the inferior colliculus. More rostrally at the level of the superior colliculus, terminal fields are found in the medial nucleus of the medial geniculate body, the suprageniculate, pretectal, and mesencephalic reticular nuclei, marking the end of the LAC. In the diencephalon, gracile fibers leave the MLLC and form a crescentlike terminal field along the extreme lateral border of the ventral posterior lateral nucleus (VPL) of the thalamus. Cuneate MLLC fibers terminate in a bandlike formation in the VPL medial to the gracile termination. The third fiber system, the cuneocerebellar projection, emerges from the cuneate, the external cuneate nuclei, and the "cellular bridge" and immediately enters the ipsilateral inferior cerebellar peduncle. Upon entering the cerebellum, the major fiber component remains ipsilateral and terminates as vertical bands in vermal and paravermal lobules, and lobules I through IVa. The posterior cerebellar lobe contains terminal bands in lobules VII-IX, the copula pyramidis, and the paramedian lobule. It is concluded that the dorsolateral fiber system conforms to Graybiel's LAC. It is more divergent and probably less modality specific, whereas the medial lemniscal system conforms to the MLLC, which is said to be modality specific, less divergent, and locked to specific sensory-motor response characteristics. The topography of cerebellar terminal bands indicates that there is sensory-motor representation from all parts of the body to all parts of the cerebellum, at least in the rat.     

Spinal gas collection demonstrated at CT.

In 234 consecutive CT examinations of the lumbar spine, gas collection was observed in 4 cases with disk herniation, and in 6 cases of disk protrusion. In 3 cases free gas was found in the epidural space, and one patient presented an intraspinal gas-filled "bleb". Gas collection in intervertebral disk spaces and facet joints was found in a total of 60 patients. The CT findings and surgical results were compared to determine whether gas collection contributes to clinical symptoms. In most cases the presence of gas was not clinically important, but in one patient it presented as a spinal mass, causing pain and radiculopathy.     

Association between condylar morphology and changes in bony microstructure and sub‐synovial inflammation in experimental temporomandibular joint arthritis

J Oral Pathol Med (2011) 40 : 111–120 Background: In juvenile idiopathic arthritis involvement of the temporomandibular joints (TMJs) is often associated with mandibular growth deviations. The relation between the growth deviations and severity of the inflammation, condylar shape, the micro‐architecture, and the quality of the bone has not previously been investigated. This paper studies the effect on the bony structures in mandibular condylar development in rabbits with antigen‐induced arthritis. Methods: Included were 42 juvenile rabbits with ovalbumin‐induced arthritis of the TMJs treated with intraarticular saline, intraarticular etanercept or subcutaneous etanercept. A TMJ from each animal was scanned using micro‐computed tomography and structural parameters were calculated. Three‐dimensional reconstructions of the mandibular condyle were scored blindly as normal or abnormal. TMJs were stratified for condylar morphology and were evaluated against data on trabecular structural parameters, inflammation, degree of mineralization, overall mandibular growth, and mineral apposition rate. Results: Abnormal morphology were seen in 15/32 animals available for data analysis. Erosions were an uncommon finding. Abnormal morphology was strongly related to the degree of inflammation. The trabecular separation was larger in group with abnormal morphology than in the group with normal morphology. Abnormal condylar morphology was not associated with overall mandibular growth. No differences were observed in mineral apposition rate. No differences in structural parameters were seen according to treatment modality. Conclusion: We showed that severe inflammation in the TMJs during mandibular development was associated with morphological changes in the mandibular condyle. These changes were predominantly seen at the macro‐morphological level and only very few differences were structural.     

Percutaneous endoscopic gastrostomy (PEG) for enteral nutrition in patients with stroke

BACKGROUND: The use of percutaneous endoscopic gastrostomy (PEG) for enteral nutrition in patients admitted for stroke is difficult, varying and needs specific consideration. There is therefore need for more data on this patient group. We examined the indications, survival, tube removal and time with PEG in stroke patients and in other patients with PEG with the aim of providing guidance for the management of enteral nutrition via PEG in stroke patients. METHODS: Retrospective assessment of data from all stroke patients and patients with other diseases (control group) who had received PEG for enteral nutrition during a period of 8.5 years. RESULTS: Eighty-three stroke patients with dysphagia received PEG after unsuccessful use of nasogastric tubes or long-term tube feeding. Early mortality rate was 19% in the stroke group, 26% in the older group (>74 years) and 12% in the younger group (60-74 years). The PEG tubes were later removed due to swallowing recovery in 20% of the older group and in 31% of the younger group. At 90 days, 50%-60% still needed PEG. The stroke patients were older compared to the control group (n = 115); 30-day mortality was similar but more patients recovered the ability to swallow. CONCLUSIONS: Stroke patients are older than other patients who receive PEG; 27% have swallowing recovery and more than 75% have long-term need for PEG. Nasogastric tubes often fail, and the need for early PEG placement (within 2 weeks) must be assessed in appropriate patients. The patient's prognosis, the objective of nutritional treatment, duration of dysphagia, age and comorbidity should all be taken into consideration.