Expression and signal transduction of calcium-sensing receptors in cartilage and bone

We previously showed that Ca2+-sensing receptors (CaRs) are expressed in chondrogenic RCJ3.1C5.18 (C5.18) cells and that changes in extracellular [Ca2+]([Ca2+]o) modulate nodule formation and chondrogenic gene expression. In the present study, we detected expression of CaRs in mouse, rat, and bovine cartilage and bone by in situ hybridization, immunocytochemistry, immunoblotting, and RT-PCR; and we tested the effects of CaR agonists on signal transduction in chondrogenic and osteogenic cell lines. In situ hybridization detected CaR transcripts in most articular chondrocytes and in the hypertrophic chondrocytes of the epiphyseal growth plate. Expression of CaR transcripts was weak or absent, however, in proliferating and maturing chondrocytes in the growth plate. In bone, CaR transcripts were present in osteoblasts, osteocytes, and bone marrow cells, but rarely in osteoclasts. A complementary DNA was amplified from mouse growth plate cartilage, which was highly homologous to the human parathyroid CaR sequence. Immunocytochemistry of cartilage and bone with CaR antisera confirmed these findings. Western blotting revealed specific bands (approximately 140-190 kDa) in membrane fractions isolated from growth plate cartilage, primary cultures of rat chondrocytes, and several osteogenic cell lines (SaOS-2, UMR-106, ROS 17/2.8, and MC3T3-E1). InsP responses to high [Ca2+]o were evident in C5.18 cells and all osteogenic cell lines tested except for SaOS-2 cells. In the latter, high [Ca2+]o reduced PTH-induced cAMP formation. Raising [Ca2+]o also increased intracellular free [Ca2+] in SaOS-2 and C5.18 cells. These studies confirm expression of CaRs in cartilage and bone and support the concept that changes in [Ca2+]o may couple to signaling pathways important in skeletal metabolism.

Refrigerated storage improves the stability of the complete blood cell count and automated differential

A CBC count was performed on 113 random patient and 21 control specimens before and after 24-hour room temperature (RT) storage; 98 random patient and 20 control specimens also were analyzed before and after 24 hour 4 degrees C storage. The Cell-Dyn 3500 (Abbott Laboratories, Abbott Park, IL) was used for analysis. RT storage showed a decline in WBC count using the optical but not the impedance method, resulting in a large number of WBC flags. An increase in mean corpuscular volume also was seen for patient specimens. The automated WBC differential showed a decrease in the percentage of neutrophils and an increase in the percentage of lymphocytes, owing primarily to neutrophil degeneration. These changes also were seen in the manual differential to a similar degree. Storage of specimens at 4 degrees C largely prevented all of these changes. The implementation of refrigerated specimen storage is a simple, inexpensive method to improve the accuracy of CBC results for aged specimens on automated hematology analyzers.

"Slow" code: perspectives of a physician and critical care nurse

"Slow" codes are not conducted frequently, but even their limited use is controversial from an ethical point of view. Physicians and nurses may view the rationale for a "slow" code differently. A critical care nurse and a physician were interviewed regarding their experiences with and their views about "slow" codes.

Embryo and yolk compositional relationships in broiler hatching eggs during incubation

Developmental relationships between yolk, embryo body, and embryo liver compositions during incubation were determined in two trials. In Trial 1, embryo body moisture, fat, and CP contents and embryo liver moisture and fat contents were determined. In Trial 2, relative yolk weights, moisture, fat, and fatty acid contents, relative wet and dry embryo weights and moisture contents, and relative wet and dry liver weights and moisture contents were determined. In Trial 1, embryo moisture decreased sigmoidally between Days 6 and 21, whereas embryo fat increased between Days 12 and 21 of incubation; embryo CP displayed sequential fluctuations throughout incubation. However, an overall significant decrease in embryo CP occurred between Days 6 and 21. Liver fat content increased between Days 12 and 21, whereas liver moisture decreased through Day 18, with a subsequent increase by Day 21. In Trial 2, relative yolk weight and moisture content decreased, whereas percentage yolk lipid content increased between Days 6 and 15. Relative wet and dry embryo weights changed in a similar manner, with rapid increases between Days 12 and 18 of incubation. Embryo moisture and CP were negatively correlated to embryo fat content. Furthermore, relative embryo and liver DM were related to yolk palmitic acid concentration, whereas yolk oleic acid was correlated only with liver DM. In conclusion, embryos and their livers displayed differential accumulations of moisture and DM during incubation, and these differences exhibited distinctive associations with various yolk fatty acids.

Back to basics: exploring the conceptual basis of nursing

It has long been recognized that nursing is essentially a practice-based discipline, underpinned by fundamental concepts which inform practice. The purpose of this paper is two-fold: first, to discuss the need for an exploration of these concepts of nursing as a foundation to pre-registration nursing programmes. Second, by utilizing a continuous quality improvement perspective, an evaluation of teachers' experiences with a cohort of adult and child health branch students is considered. It is concluded that a significant proportion of students found that a raised conceptual awareness served to promote theory-practice links.

Folding of coliphage T4 short tail fiber in vitro. Analysing the role of a bacteriophage-encoded chaperone

The morphogenesis of the Escherichia coli bacteriophage T4 depends on the presence of helper proteins which are not components of the mature virion. Two bacteriophage-encoded proteins, p57 and p38, are required for the assembly of the bacteriophage T4 tail fibers. In the absence of p57, two polypeptides of the long fiber (p34 and p37) and that of the short tail fiber (p12) fail to trimerize. Instead they form water-insoluble aggregates. Co-expression of the genes 12 and 57 in vivo caused the formation of only trimeric, water-soluble p12. The function of g57 cannot be replaced by overexpression of the host proteins GroEL/ES or parvulin. The mechanism of action of this helper protein has remained unknown, mainly because it has not been possible to determine its activity in vitro. Purified p12, denatured in 7 M urea, trimerized spontaneously in a slow reaction (half-time approximately 6 h) and with low yield. Upon renaturation, p12 forms native SDS-resistant trimers as indicated by spectroscopic and hydrodynamic measurements. Addition of p57 increased the rate of folding threefold and nearly doubled the yield. These experiments demonstrate that p57 acts as a molecular chaperone during folding of T4 tail fibers.

Treatment of occipital acne keloidalis by excision followed by secondary intention healing

OBJECTIVE

To demonstrate the principle of excision with healing by secondary intention in the treatment of occipital acne keloidalis, a chronic, inflammatory condition characterized by inflammation and hypertrophic scarring on the posterior aspect of the neck and the occipital aspect of the scalp.

SETTING

Academic teaching institution.

METHODS

Five consecutive patients with massive (> 10 x 15-cm) occipital keloids, all actively infected and growing, were treated by excision of the lesion deep to the dermis and hair follicles. Aggressive local wound care of the wound followed, with the end point being complete reepithelialization of the region.

RESULTS

Complete wound closure took place in all patients within 6 to 10 weeks. No complications or recurrences occurred. Cosmetic results were judged as fair to good. Follow-up ranged from 2 months to 4 years.

CONCLUSIONS

Successful treatment of occipital acne keloidalis with direct excision and secondary intention wound healing is demonstrated. While cosmetic results are not optimal, this form of treatment has produced stable scar beds without return of infection or keloids.

Cardiac troponin I and cardiac enzymes after electrophysiologic studies, ablations, and defibrillator implantations

Diagnostic electrophysiologic studies and defibrillator implantations with subsequent test discharges from the defibrillator do not cause an elevation in cardiac troponin I levels. All patients with an ablation had an elevation in the cardiac troponin I levels.

A novel mitochondrial DNA-like sequence in the human nuclear genome

We describe here a nuclear mitochondrial DNA-like sequence (numtDNA) that is nearly identical in sequence to a continuous 5842 bp segment of human mitochondrial DNA (mtDNA) that spans nucleotide positions 3914 to 9755. On the basis of evolutionary divergence among modern primates, this numtDNA molecule appears to represent mtDNA from a hominid ancestor that has been translocated to the nuclear genome during the recent evolution of humans. This numtDNA sequence harbors synonymous and nonsynonymous nucleotide substitutions relative to the authentic human mtDNA sequence, including an array of substitutions that was previously found in the cytochrome c oxidase subunit 1 and 2 genes. These substitutions were previously reported to occur in human mtDNA, but subsequently contended to be present in a nuclear pseudogene sequence. We now demonstrate their exclusive association with this 5842-bp numtDNA, which we have characterized in its entirety. This numtDNA does not appear to be expressed as a mtDNA-encoded mRNA. It is present in nuclear DNA from human blood donors, in human SH-SY5Y and A431 cell lines, and in rho(0) SH-SY5Y and rho(0) A431 cell lines that were depleted of mtDNA. The existence of human numtDNA sequences with great similarities to human mtDNA renders the amplification of pure mtDNA from cellular DNA very difficult, thereby creating the potential for confounding studies of mitochondrial diseases and population genetics.

[The efficacy on natural extrinsic stain of Colgate whitening dentifrice--eight-week study]

OBJECTIVE

To assess the effect on natural extrinsic dental stain by use of a dentifrice containing 1% tetrasodium polyphosphate (TSPP), 7% sodium tripolyphosphate (STPP), 0.243% sodium fluoride and 10% high cleaning silica (HCS) over an eight-week period was compared to a sodium fluoride/silica placebo dentifrice without stain removal ingredients.

METHODS

Ninety one subjects were selected and stratified into two balanced groups randomly assigned to use the test dentifrice or the placebo dentifrice. The two groups were well balanced with regard to their mean baseline stain index scores, gender and tobacco habits. Subjects were instructed to brush their teeth twice daily (morning and evening) for one minute with their assigned dentifrice and a commercially available soft bristled toothbrush. Extrinsic dental stain examinations, which included mean stain area and mean stain intensity, were conducted at baseline, four and eight weeks. The same dental examiner conducted examinations on the subjects at each examination.

RESULTS

After eight-week use of their assigned products, those subjects in the TSPP/STPP/HCS dentifrice group demonstrated a statistically significant (P = 0.0001) stain reduction of 37.1%, as compared to the fluoride placebo dentifrice group without stain removal ingredients.

CONCLUSION

The use of a dentifrice containing 1% tetrasodium polyphosphate, 7% sodium tripolyphosphate, 0.243% sodium fluoride and 10% high cleaning silica is effective in reducing natural extrinsic dental stain, when compared to a placebo fluoride dentifrice.

The role of glutamine in skeletal muscle ischemia/reperfusion injury in the rat hind limb model

OBJECTIVES

Ischemia/reperfusion injury is a commonly occurring event with severe pathologic consequences. Reperfusion initiates both the local and systematic damage in part through rapid oxygen generation. The glutathione system is a major mechanism of reducing this oxidative stress. If this system can be maintained or augmented during this stress then less damage may occur. Glutamine provides the source of glutamate to this system and has been shown to preserve total glutathione levels after injury/ischemia to both hepatic and gut models. To test this effect, we looked at glutamine and its role in ischemia/reperfusion injury in a rat hind limb model.

METHODS

Fifty male HSD/Holtzman rats weighing 350-400 g were randomized to receive glutamine (3% sol) or normal saline via intraperitoneal injections. The groups were then subjected to 2 hours of ischemia to their hind limbs using the Tourni-Cot method. Animals were then randomized to reperfusion groups of 30 minutes, 2 hours, and 4 hours. Muscle tissue assays were performed for lipid peroxidation (LPO), total glutathione (GSH), and myeloperoxidase (MPO). Peripheral blood was analyzed for creatinephosphokinase levels (CPK).

RESULTS

Animals that received glutamine showed a general trend of less lipid peroxidation products than the normal saline groups. In animals that received glutamine and underwent 2 hours of ischemia and reperfusion times of 0 minutes, 30 minutes, and 2 hours, there were significantly less percent changes in lipid peroxidation products from controls (4.6% vs 48.2%, P <0.05), (18.9% vs 123%, P <0.05), (12.6% vs 115%, P <0.05). A general trend upward was noted in CPK levels in both groups. In animals receiving 2 hours of ischemia and 30 minutes of reperfusion, there was a significantly greater level of creatinephosphokinase (CPK) calculated as percent change from control in the normal saline group as compared with the glutamine group (209.2% vs 92.7%). Myeloperoxidase assay of muscle tissue revealed a progressive increase as the reperfusion times grew. In animals receiving 2 hours of ischemia and 30 minutes of reperfusion, the normal saline group had a significantly larger percent increase from controls than the group that received glutamine (1126.4% vs 108%, P <0.05). Also, in those animals receiving 4 hours of reperfusion, the normal saline group had a significantly higher percent increase in MPO content than the glutamine group (6245% vs 108%, P <0.05). Total glutathione levels decreased rapidly as reperfusion occurred in both the normal saline and glutamine groups. No significant difference between the groups was noted.

CONCLUSIONS

Total glutathione levels during reperfusion were not significantly different in the groups receiving glutamine versus normal saline. Glutamine may provide an initial protective effect on reperfusion injury after moderate reperfusion times in the hind limb model as defined by CPK and LPO levels. Glutamine may blunt neutrophil recruitment after longer reperfusion times (4 hours) in the ischemic hind limb. Total glutathione levels decreased significantly after moderate levels of ischemia (2 hours) and reperfusion (30 minutes, 2 hours).

Recognition specificity of monoclonal antibodies which protect mice against Salmonella typhimurium infection

We used enzyme-linked immunosorbent assay (ELISA), competitive inhibition ELISA, flow cytometry and western immunoblots to study the antigenic specificity of two monoclonal antibodies (mAbs) raised against the cell surface antigens of Salmonella typhimurium. These mAbs (SH6.11 and WB60.4) protect CAF1 (Ity(r)) mice against endotoxemia and mouse typhoid. We found that SH6.11 and WB60.4 recognize Salmonella serogroup B-specific lipopolysaccharide O4 and O5 factors, respectively. These mAbs did not bind to Salmonella serotypes that belong to serogroup A, D1, E4, G2, or R and did not cross-react with other enteric and nonenteric bacterial species.

An experimental model for the endometriosis in athymic mice

Endometriosis is an adhesion disorder characterized by the presence of endometrial tissue in ectopic sites outside the uterus. The disease is associated with dysmenorrhea, pelvic pain and infertility. Although endometriosis is the most common gynecologic disorder, relatively little is known regarding its etiology, pathogenesis and the course of the disease. This situation is primarily due to the absence of experimental systems to examine the mechanism of endometrial cell adhesion, role of inflammatory cells and the interactions of epithelial, and stromal cells with the peritoneum and ovarian tissue leading to the development of this disorder. Dissociated human endometrial cells were suspended in peritoneal fluids of individuals with and without endometriosis and were injected into the peritoneal cavity of athymic mice. This led to development of ectopic adhesions of endometrial cells at the peritoneal and ovarian surfaces. Endometrial cells which were marked with fluorescent lipophylic dyes, prior to intraperitoneal injection, could be visualized without surgery at such sites. The studies demonstrate a model for endometriosis in athymic mice.

Renal MR angiography at 1.0 T: three-dimensional (3D) phase-contrast techniques versus gadolinium-enhanced 3D fast low-angle shot breath-hold imaging

OBJECTIVE

The purpose of this study was to evaluate the diagnostic usefulness of three different MR angiographic techniques at 1.0 T.

SUBJECTS AND METHODS

In 22 patients with renal artery stenosis confirmed at intraarterial catheter angiography, we also performed unenhanced and gadolinium-enhanced three-dimensional phase-contrast MR angiography and gadolinium-enhanced single breath-hold three-dimensional fast low-angle shot MR angiography. We determined circulation time to optimize signal acquisition in gadolinium-enhanced breath-hold MR angiography after bolus injection of contrast material.

RESULTS

Sensitivity, defined as the detection of a hemodynamically significant stenosis (>50% luminal narrowing), was 85% for enhanced phase-contrast MR angiography, 91% for gadolinium-enhanced MR angiography, and 95% for unenhanced phase-contrast MR angiography. The combination of unenhanced phase-contrast MR angiography and gadolinium-enhanced MR angiography yielded 100% sensitivity for hilar artery stenoses. There were 13 false-positive findings with unenhanced phase-contrast MR angiography, 10 with enhanced phase-contrast MR angiography, and four with gadolinium-enhanced MR angiography (specificity: 38%, 52%, and 79%, respectively). Accessory renal arteries were not seen on unenhanced or enhanced phase-contrast MR angiography (0/8 patients) but were detected with gadolinium-enhanced MR angiography in five of the eight patients. Interobserver agreement (kappa = .62) was best with gadolinium-enhanced MR angiography. The quality of the images was unsatisfactory for adequate evaluation of segmental renal arteries with all three MR angiographic techniques.

CONCLUSION

A combination of unenhanced phase-contrast MR angiography and gadolinium-enhanced MR angiography at 1.0 T proved useful as a screening protocol for renal artery stenosis.

Cellular and molecular mechanisms of memory: the LTP connection

Studies of the cellular and molecular mechanisms of memory formation have focused on the role of long-lasting forms of synaptic plasticity such as long-term potentiation (LTP). A combination of genetic, electrophysiological and behavioral techniques have been used to examine the possibility that LTP is a cellular mechanism of memory storage in the mammalian brain. Although a definitive answer remains elusive, it is clear that in many cases manipulations that alter LTP alter memory, and training regimens that produce memory can produce LTP-like potentiation of synaptic transmission.

Transmyocardial laser revascularization in the acute ischaemic heart: no improvement of acute myocardial perfusion or prevention of myocardial infarction

OBJECTIVE

Transmyocardial laser revascularization (TMLR) has been used to provide enhanced myocardial perfusion in patients not suitable for coronary revascularization or angioplasty. This study investigates the acute changes in myocardial perfusion after TMLR with a Holmium:Yttrium-Aluminium-Garnet (YAG) laser with a thermal imaging camera in a model of acute ischaemia, and confirms its midterm effects by post-mortem investigation of magnetic resonance imaging and histopathological examination.

METHODS

Acute myocardial ischaemia was induced by occlusion of the dominant diagonal branch in ten sheep. Perfusion measurements were undertaken first in the unaffected myocardium, then after temporary occlusion of the coronary to obtain a control measurement for ischaemic myocardium. Myocardial perfusion was then evaluated during reperfusion after release of coronary occlusion. Then the coronary was permanently occluded and 20.5+/-2 channels were drilled with the Holmium:YAG laser and perfusion was measured again. The other four sheep served as control with untreated ischaemia. All animals were sacrificed after 28 days following administration of gadolinium i.v. to serve as contrast medium for magnetic resonance tomography. The hearts were subjected to magnetic resonance tomography and histopathological examination.

RESULTS

Intraoperative perfusion measurements revealed a decreased perfusion after temporary occlusion and an increased perfusion in reperfused myocardium. After TMLR, no improvement of myocardial perfusion above the ischaemic level could be shown. Magnetic resonance images could neither confirm patent laser channels nor viable myocardium within ischaemic areas. On histology no patent endocardial laser channel could be detected. The transmural features were myocardial infarct with scar tissue.

CONCLUSIONS

In the presented sheep model with acute ischaemia, TMLR with a Holmium:YAG laser did not provide acute improvement of myocardial perfusion as assessed by a thermal imaging camera. This would suggest no direct contribution of newly created laser channels to myocardial perfusion. As chronic effects are concerned, no perfused laser channels could be identified by later magnetic resonance imaging or histology.

MR angiography and flow quantification of the internal mammary artery graft after minimally invasive direct coronary artery bypass

OBJECTIVE

Six patients who had undergone minimally invasive direct coronary artery bypass surgery were examined to evaluate an MR imaging protocol that provided information about cardiac function, bypass graft patency, and flow characteristics with a single examination.

CONCLUSION

Preliminary results suggest that our imaging protocol allows accurate follow-up of patients after minimally invasive direct coronary artery bypass surgery. Bypass graft patency was correctly determined in all patients. In four patients, anastomoses were visualized by MR angiography, and flow measurements revealed a volume range of 28-84 ml/min (native and grafted internal mammary arteries) and a trend for the flow values of bypass grafts to be lower than those of native vessels. Interobserver reproducibility was good (r = .99; slope, .98).

Full-thickness burn to the hand from an automobile airbag

An 18-year-old male was involved in a single car motor vehicle accident in which the driver's side airbag was deployed. He presented to the trauma center with complex injuries to the left hand, lacerations to the scalp, and a full-thickness burn to the ulnar aspect of the right hand that included the hypothenar area and the fifth digit. The patient was admitted to the trauma center and received immediate consultation from the burn service. He underwent debridement and split-thickness skin grafting of 50 cm2 of the right hand on postburn day 3. The graft became necrotic and the patient underwent debridement of the skin and the abductor minimi muscle of the right hand on postburn day 32. Split-thickness skin grafting and release of flexion contracture were successfully completed 18 days later. The police and fire departments reported that the airbag showed signs of thermal destruction. Upon request, Honda motors submitted information from the TRW safety systems and material safety data sheet (Mesa, Ariz, issued 1989) that showed that airbag canisters contain the chemicals sodium azide and cupric oxide. Water may react with sodium azide to form highly toxic and explosive hyfrazoic acid. These chemicals are converted to sodium hydroxide, which can cause significant chemical burns. In addition, these chemicals may ignite when exposed to live electrical wires or temperatures greater than 300 degrees F. We conclude that burns associated with damaged deployed airbags in motor vehicle accidents may be the results of both chemical and thermal injury. The extent of the burn wound may be underestimated, as our case illustrates. Full-thickness burns resulting from airbag deployment may require more aggressive initial debridement and treatment.

Inhibition of the peroxidative degradation of haem as the basis of action of chloroquine and other quinoline antimalarials

The malaria parasite feeds by degrading haemoglobin in an acidic food vacuole, producing free haem moieties as a by-product. The haem in oxyhaemoglobin is oxidized from the Fe(II) state to the Fe(III) state with the consequent production of an equimolar concentration of H2O2. We have analysed the fate of haem molecules in Plasmodium falciparum-infected erythrocytes and have found that only about one third of the haem is polymerized to form haemozoin. The remainder appears to be degraded by a non-enzymic process which leads to an accumulation of iron in the parasite. A possible route for degradation of the haem is by reacting with H2O2, and we show that, under conditions designed to resemble those found in the food vacuole, i.e., at pH5.2 in the presence of protein, free haem undergoes rapid peroxidative decomposition. Chloroquine and quinacrine are shown to be efficient inhibitors of the peroxidative destruction of haem, while epiquinine, a quinoline compound with very low antimalarial activity, has little inhibitory effect. We also show that chloroquine enhances the association of haem with membranes, while epiquinine inhibits this association, and that treatment of parasitized erythrocytes with chloroquine leads to a build-up of membrane-associated haem in the parasite. We suggest that chloroquine exerts its antimalarial activity by causing a build-up of toxic membrane-associated haem molecules that eventually destroy the integrity of the malaria parasite. We have further shown that resistance-modulating compounds, such as chlorpromazine, interact with haem and efficiently inhibit its degradation. This may explain the weak antimalarial activities of these compounds.

Exploring family relationships in cancer risk counseling using the genogram

OBJECTIVES

The genogram is a tool that has facilitated counseling in family therapy and social work for many years. It is hypothesized that genograms may also be useful in genetic counseling, because they help the counselor to acquire more objective and consistent information from the client, as well as to incorporate family dynamics and psychosocial issues into the counseling approach.

MATERIALS AND METHODS

A pilot study of genograms used as an adjunct to genetic counseling was performed at Fox Chase Cancer Center's Family Risk Assessment Program. A questionnaire was developed to elicit genograms from 38 women at risk for familial breast and/or ovarian cancer. After standard pedigree expansion, a series of questions was asked about the consultand's relationship with other family members, communication patterns within the family, attitudes toward genetic testing, family reactions to cancer, roles individuals play in the family, and significant historical or anniversary events. Relationships were defined by the consultand as close, very close, conflictual, fused and conflictual, distant, or estranged.

RESULTS

The majority of relationship types reported by 38 individuals was "very close" or "close." Eighty-one % reported having close/very close relationships with their spouses, 83% reported close/very close relationships with their mothers, and 70% reported close/very close relationships with their fathers. The degree of familial cohesion as depicted by the genogram correlates positively with scores obtained on the standardized Social Adjustment Scale Self-Report (P = 0.01).

CONCLUSIONS

Given the family-wide implications of genetic testing, the genogram may offer important guidance in family-targeted interventions.

Subharmonic imaging with microbubble contrast agents: initial results

The subharmonic emission from insonified contrast microbubbles was used to create a new imaging modality called Subharmonic Imaging. The subharmonic response of contrast microbubbles to ultrasound pulses was first investigated for determining adequate acoustic transmit parameters. Subharmonic A-lines and gray scale images were then obtained using a laboratory pulse-echo system in vitro and a modified ultrasound scanner in vivo. Excellent suppression of all backscattered signals other than from contrast microbubbles was achieved for subharmonic A-lines in vitro while further optimization is required for in vivo gray scale subharmonic images.

Calcium sensing in cultured chondrogenic RCJ3.1C5.18 cells

The availability of Ca2+ in the extracellular fluid plays an important role in regulating cartilage and bone formation. We hypothesized that chondrocytes detect changes in the extracellular [Ca2+] ([Ca2+]o) and modify their function. The effects of changing [Ca2+]o on the expression of matrix proteins were quantified by staining of cartilage nodules with alcian green and assessing RNA levels of cartilage-specific genes in chondrogenic RCJ3.1C5.18 (C5.18) cells. Alcian green staining in these cells decreased with increasing [Ca2+]o in a dose-dependent and reversible manner (ID50, approximately 2 mM Ca2+). RNA levels for aggrecan and type II collagen decreased with increasing [Ca2+]o (ID50, approximately 2.0 and 4.1 mM Ca2+, respectively). RNA levels for type X collagen and alkaline phosphatase were also reduced by high [Ca2+]o with ID50 values of approximately 2.9 and 1.6 mM Ca2+, respectively. These responses were rapid, in that increasing [Ca2+]o from 1.0 to more than 6 mM suppressed aggrecan RNA levels by about 50%, and lowering [Ca2+]o from 2.9 to 1.0 mM increased aggrecan RNA levels by about 300% within 4 h. As Ca2+ receptors (CaRs) mediate extracellular Ca2+ sensing in parathyroid and kidney, we assessed the expression of CaRs in these cells. C5.18 cells stained positively for CaR protein with an anti-CaR antiserum and for CaR RNA by in situ hybridization. An approximately 150-kDa protein was detected by immunoblotting with anti-CaR antiserum. CaR antisense oligonucleotides suppressed the expression of CaR protein and enhanced RNA levels of aggrecan in C5.18 cells. These data support the idea that CaRs are expressed in this cell system and may be involved in regulating chondrogenic gene expression.

[MR proton spectroscopy to monitor the concentration changes in cerebral metabolites following a TIPS placement]

BACKGROUND AND AIMS

In chronic liver dysfunction with portal hypertension the risk of variceal bleeding can be lowered by intrahepatic portosystemic shunting (TIPS). Although less pronounced than in surgical shunting, hepatic encephalopathy (HE) is a well-known undesired side effect. In cerebral proton MR spectroscopy (MRS), HE can be detected by a specific pattern of brain metabolite changes (increase of glutamine/glutamate (Glx) and decrease of myo-inositol (ml) and choline (Cho)). The aim of this study was to examine whether, after TIPS implantation, there is a correlation of the reduction of the portosystemic pressure gradient (PSPG) and the cerebral metabolite changes and their correspondence to the clinical status.

METHODS

We examined 10 cirrhotic patients (Child B, C) before and 3-20 days after TIPS implantation. Clinical examination was performed by a senior hepatologist. Localized MR spectra were acquired in parieto-occipital gray/white matter using a short echo time (TE = 5 ms) STEAM sequence.

RESULTS

After TIPS we found an increase of Glx/(Cr + PCr) of 13%-40% and a decrease of ml(Cr + PCr) of 6%-46% with a positive (Glx: r = 0.71) respectively negative (ml: r = -0.59) correlation to the reduction of the PSPG. 7/10 patients with a reduction of the PSPG of more than 9 mmHg (9-17 mmHg) showed a clinical impairment of their HE.

CONCLUSIONS

Short echo time cerebral MRS allows detection of finest HE specific metabolite changes and can therefore contribute positively to an individually optimized reduction of the PSPG during TIPS implantation.

Prostate cancer risk assessment program. A model for the early detection of prostate cancer

Prostate cancer is the most common form of cancer (except skin cancer) in men. Several factors have been associated with an increased risk for prostate cancer, including age, ethnicity, family history, lifestyle, and environmental exposures. Recognition of the importance of the interaction of these factors in prostate cancer has led to an interest in their evaluation as a model both for studying genetic susceptibility patterns and for studying and providing educational tools and preventive interventions. One such model has been developed at Fox Chase Cancer Center. Critical to the implementation of the model has been the establishment of the Prostate Cancer Risk Registry (PCRR) and Prostate Cancer Risk Assessment Program (PRAP). Together, they serve as a unique resource for investigating the interaction between environmental factors and genetic susceptibility patterns; exploring the early, premalignant biological markers of prostate cancer; and prospectively assessing the quality of life (QOL) of men at risk. In addition, PRAP facilitates the evaluation of models for prostate cancer risk counseling and screening in the community. This paper describes this model for early detection and risk reduction, along with preliminary data from its first two study aims. The program is particularly relevant in view of the wealth of genetic information emerging from the Human Genome Project.