Monoclonal antibody against human bone alkaline phosphatase

Summary A monoclonal antibody which reacts preferentially with human bone alkaline phosphatase (AP) has been developed using human osteosarcoma bone AP as an immunogen. The antibody with the highest selectivity shows about three- and a-half fold greater binding to bone than to liver AP. The selectivity was confirmed using mixtures of authentic samples of the bone and liver isoenzymes. Its selectivity was also shown by measurements of bone AP in sera from patients with either bone or liver diseases. Such a selective antibody could lead to the development of a monoclonal antibody highly specific for bone AP which can be used for a more sensitive approach for quantitative analysis of the isoenzyme.

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Résumé Un anticorps monoclonal qui réagit préférentiellement avec les phosphatases alcalines (PA) de l'os humain a été obtenu en utilisant comme immunogène la PA osseuse d'un ostéosarcome humain. L'anticorps ayant la sélectivité la plus élevée présente une liaison trois fois et demie plus importante avec la PA osseuse qu'avec la PA hépatique. La sélectivité a été confirmée en utilisant des mélanges d'échantillons d'isoenzymes osseux et hépatiques. Sa sélectivité a été également démontrée par des mesures de la PA osseuse dans le sérum de patients présentant des maladies osseuses ou hépatiques. Un tel anticorps sélectif peut mener à obtenir un anticorps monoclonal hautement spécifique vis-à-vis de la PA osseuse, qui pourra être utilisé pour améliorer la sensibilité de l'analyse quantitative de l'isoenzyme.

     

Arthrographic indicators for decision making about femoral varus osteotomy in Legg-Calvé-Perthes disease

Purpose  There is not always a good outcome after a femoral varus osteotomy (FVO) in those with Legg-Calvé-Perthes disease (LCPD), even when the severity warrants surgical treatment. The purpose of this study was to find arthrographic indicators for decision making regarding the likely surgical outcome of a FVO. Methods  We used an image of an abduction position during preoperative arthrography under general anesthesia that simulated the post-operative relationship between the femoral head and the acetabulum. In the image, we defined two indicators of how deeply the deformed epiphysis was contained within the acetabulum: an acetabular head index in abduction and an epiphyseal slip-in index. Finding the contact point between the top of epiphysis and acetabulum was the key for the epiphyseal slip-in index measurement. In 37 patients (38 hips) who underwent FVOs based on our inclusion criteria, these two indices were measured retrospectively and were analyzed for a correlation with surgical outcome. Surgical outcome was evaluated using a combination of three factors: sphericity of the femoral head (Stulberg’s classification), acetabular cover (acetabular head index), and the slope of acetabular roof. Results  The outcome was acceptable in 20 hips (52.6%) and unacceptable in18 hips (47.4%). There was a statistically significance difference in epiphyseal slip-in index between the acceptable group (21.9 ± 2.8%) and the unacceptable group (15.0 ± 4.4%) (P < 0.0001). An index of 20% or more determined a safe zone for predicting an acceptable outcome with 80% sensitivity, 89% specificity, and a 7.2 likelihood ratio. However, the acetabular head index in abduction showed no such statistical significance. Conclusions  In this study, we found that the epiphyseal slip-in index was a reliable indicator for predicting the effectiveness of a FVO. It is worth measuring this index when a surgeon is considering a FVO for a patient with severe LCPD. (Level of Evidence Level III.)     

Expression of the enkephalin precursor gene in C6 rat glioma cells: regulation by beta-adrenergic agonists and glucocorticoids

Cultured C6 rat glioma cells contain mRNA coding for preproenkephalin (A), the precursor of methionine- and leucine-enkephalin. The abundance in untreated cells was determined by blot hybridization methods to be 3-6 pg per micrograms total RNA. Treatment of confluent cells for 12 h with 10 microM (-)-norepinephrine, which activates C6 adenylate cyclase, transiently elevated preproenkephalin mRNA to 3.3 and 7.7 times the control in the absence and presence of the glucocorticoid dexamethasone, respectively. Hydrocortisone and corticosterone also potentiated the effect of norepinephrine. However, glucocorticoids alone did not alter the preproenkephalin mRNA abundance. The effect of norepinephrine + dexamethasone was blocked by the beta-adrenergic antagonist propranolol but not by the alpha-adrenergic antagonist phentolamine. Forskolin, which directly activates adenylate cyclase, similarly elevated the preproenkephalin mRNA abundance; its effect was also potentiated by dexamethasone. C6 cells contain Met-enkephalin-containing protein resembling proenkephalin (apparent Mr 30,000) but little Met-enkephalin, suggesting a low level of proper precursor processing. Treatment with norepinephrine + dexamethasone raised the content of proenkephalin-like protein 11-fold. Thus, preproenkephalin mRNA levels in C6 cells are regulated synergistically by adenosine 3':5'-cyclic monophosphate and glucocorticoids. These results suggest modes of regulation of proenkephalin biosynthesis in normal rat enkephalinergic cells.     

Lifestyle risk factors for intrahepatic stone: Findings from a case–control study in an endemic area, Taiwan

Background and Aim:  To examine associations between lifestyle risk factors and intrahepatic stone (IHS), we conducted a case–control study in Taiwan, which has the highest incidence of IHS in the world.
Methods:  Study subjects were 151 patients newly diagnosed with IHS at Chang Gung Memorial Hospital between January 1999 and December 2001. Two control subjects per case were selected randomly from patients who underwent minor surgery at the same hospital and from family members or neighbors of the hospital staff. Controls were matched to each case by age and gender. Information on lifestyle factors was collected using a self-administered questionnaire. Strength of associations was assessed using odds ratios derived from conditional logistic models.
Results:  Female patients were significantly shorter than female controls. Compared to subjects with two or fewer children, odds ratios for those with six or more children were 20.4 in men (95% confidence interval, 1.89–221) and 2.82 (0.97–8.22) in women. Increasing level of education lowered the risk of intrahepatic stone (trend P  = 0.004 for men and < 0.0001 for women). Women who had consumed ground-surface water for a long period had a somewhat increased risk (trend P  = 0.05).
Conclusion:  Lower socioeconomic status and poor hygiene may be involved in the development of intrahepatic stones.     

Clinical and immunohistochemical studies of subependymal giant cell astrocytomas associated with tuberous sclerosis.

Two cases of TS associated with brain tumors had severe psychomotor retardation and early onset of long-term intractable convulsions, compared with cases without tumors. In one case, the tumor was partially cystic and progressed rapidly. Immunohistochemical studies of neuron specific enolase, glial fibrillary acidic protein and myelin basic protein revealed differences in positivity between cell types and between cases. These results suggested that the origin of the tumor cells could be variably differentiated cells.     

Synthetic Alginate is a Carrier of OP-1 for Bone Induction

Bone morphogenetic proteins (BMPs) can induce bone formation in vivo when combined with appropriate carriers. Several materials, including animal collagens and synthetic polymers, have been evaluated as carriers for BMPs. We examined alginate, an approved biomaterial for human use, as a carrier for BMP-7. In a mouse model of ectopic bone formation, the following four carriers for recombinant human OP-1 (BMP-7) were tested: alginate crosslinked by divalent cations (DC alginate), alginate crosslinked by covalent bonds (CB alginate), Type I atelocollagen, and poly-D,L-lactic acid-polyethyleneglycol block copolymer (PLA-PEG). Discs of carrier materials (5-mm diameter) containing OP-1 (3–30 μg) were implanted beneath the fascia of the back muscles in six mice per group. These discs were recovered 3 weeks after implantation and subjected to radiographic and histologic studies. Ectopic bone formation occurred in a dose-dependent manner after the implantation of DC alginate, atelocollagen, and PLA-PEG, but occurred only at the highest dose implanted with CB alginate. Bone formation with DC alginate/OP-1 composites was equivalent to that with atelocollagen/OP-1 composites. Our data suggest DC alginate, a material free of animal products that is already approved by the FDA and other authorities, is a safe and potent carrier for OP-1. This carrier may also be applicable to various other situations in the orthopaedic field.     

Intraoperative direct measurement of hepatic arterial buffer response in patients with or without cirrhosis.

The hepatic arterial buffer response (HABR) is an intrinsic regulatory mechanism of the hepatic artery (HA) that compensates for reductions in portal venous (PV) blood flow. Whether this response is maintained in patients with cirrhosis (LC) is unclear. The aim of the present study was to examine whether HABR is maintained in patients with LC using direct blood flow measurements. PV and HA blood flow were intraoperatively measured and compared in patients with (LC group, n = 39) or without (control group, n = 22) cirrhosis at baseline (baseline HABR) and after PV clamping (acute HABR) using an ultrasound transit-time flowmeter. In contrast to the proportional relationship between the baseline PV and HA blood flow observed in the control group, HA blood flow and the HA-PV flow ratio increased when PV blood flow decreased in the LC group, suggesting that the baseline HABR had already been activated. Acute HABR, evaluated by the absolute and relative changes in HA blood flow and by the buffer capacity, was blunted in the LC group (P < 0.001, P < 0.01, and P = 0.01, respectively). An association between the degree of acute HABR impairment and the level of baseline HABR activation (HA-PV flow ratio) could not be confirmed in the LC group. In conclusion, the baseline HABR appears to be continuously activated in patients with LC; this phenomenon probably results in the impairment of the acute HABR.     

MR study of normal joint function using a low field strength system

A functional MR study was performed using a 0.064 T permanent magnet MR system. The shoulder joints, elbow joints, hip joints, and knee joints of three volunteers (mean height and weight, 176 cm and 71 kg, respectively) were examined at incremental joint angles in three to eight stages during flexion-extension, abduction-adduction, or pronation-supination movement. Each set of 16 images was obtained in 4 min, 49 s using three-dimensional Fourier transformation methods with gradient echo pulse sequences. The images were evaluated in static mode and sometimes in cine mode. The findings obtained about the physiology of these normal joints was generally compatible with findings previously accumulated in the field of kinesiology. The study suggests that this method can be useful for in vivo study of kinesiology and pathogenesis of diseases and that patients with most types of contracture or deformity can be examined by MR imaging.