Activity and cyclic AMP-dependent regulation of nociceptin/orphanin FQ gene expression in primary neuronal and astrocyte cultures

The regulation of nociceptin/orphanin FQ (N/OFQ) gene expression by neuronal activity and by activation of the cyclic AMP signaling pathway in primary neuronal and astroglial cultures is described. Neuronal activity mimicked by veratridine-mediated depolarization profoundly increased N/OFQ gene expression in primary striatal neurons. Calcium entry through L-type, but not N-type, voltage-sensitive calcium channels activated by depolarization appears to be involved, because nitrendipine and nifedipine, but not omega-conotoxin, reduced the induction of N/OFQ expression by veratridine. A selective inhibitor of calcium/calmodulin kinases (KN-62) also antagonized the depolarization-induced increase in N/OFQ mRNA levels, suggesting a role for these enzymes in the activity-dependent induction of N/OFQ gene expression. Constitutively expressed transcription factors may mediate N/OFQ gene expression levels, because veratridine induction of N/OFQ transcription was insensitive to the protein synthesis inhibitor cycloheximide. Regulation of N/OFQ gene expression by depolarization and cyclic AMP is not restricted to striatal neurons, because similar regulation was also observed in neuronal cultures derived from the cerebral cortex. Veratridine did not increase N/OFQ mRNA levels in primary astrocyte cultures; however, elevated intracellular cyclic AMP levels lead to a dramatic, 30-fold induction of N/OFQ mRNA levels in these cells.

Protein kinetics determined in vivo with a multiple-tracer, single-sample protocol: application to lactase synthesis

Precise analysis of the kinetics of protein/enzyme turnover in vivo has been hampered by the need to obtain multiple tissue samples at different times during the course of a continuous tracer infusion. We hypothesized that the problem could be overcome by using an overlapping (i.e., staggered) infusion of multiple stable amino acid isotopomers, which would take the place of multiple tissue samples. We have measured, in pigs, the in vivo synthesis rates of precursor (rapidly turning over) and mature (slowly turning over) polypeptides of lactase phlorizin hydrolase (LPH), a model for glycoprotein synthesis, by using an overlapping infusion of [2H3]leucine, [13C1]leucine, [13C1]phenylalanine, [2H5]phenylalanine, [13C6]phenylalanine, and [2H8]phenylalanine. Blood samples were collected at timed intervals, and the small intestine was collected at the end of the infusion. The tracer-to-tracee ratios of each isotopomer were measured in the plasma and jejunal free amino acid pools as well as in purified LPH polypeptides. These values were used to estimate kinetic parameters in vivo using a linear steady-state compartmental model. The fractional synthesis rates of the high-mannose, complex glycosylated and mature brush-border LPH polypeptides, so determined, were 3.3 +/- 1.1%/min, 17.4 +/- 11%/min, and 0.089 +/- 0.02%/min, respectively. We conclude that this multiple-tracer, single-sample protocol is a practicable approach to the in vivo measurement of protein fractional synthesis rates when only a single tissue sample can be obtained. This method has broad application and should be particularly useful for studies in humans.

Ca2+/calmodulin-dependent transcriptional activation of delta-opioid receptor gene expression induced by membrane depolarization in NG108-15 cells

Regulation of gene expression is one of the mechanisms by which neuronal activity elicits long-term changes in neuronal phenotype and function. Although activity-dependent induction of immediate-early genes has been extensively studied, much less is known about the late-response genes. We have investigated the activity-dependent regulation of delta-opioid receptor (DOR) mRNA levels in NG108-15 cells. Transsynaptic activation was mimicked by depolarization with 55 mM KCl or veratridine. Both treatments lead to a time-dependent increase of DOR mRNA levels. Ca2+ entry through L-type voltage-dependent Ca2+ channels activated by depolarization appears to be involved, because L-type channel blockers reduced the induction of DOR expression. Ca2+ binding to calmodulin is the next step in the signal transduction pathway, because a calmodulin antagonist, W7, reduced the effect of veratridine. A selective inhibitor of calmodulin kinases (KN-62) and cyclosporin, an inhibitor of calcineurin, also antagonized the depolarization-induced increase in DOR mRNA levels, which indicates that both calcium/calmodulin-dependent enzymes are involved in the activity-dependent induction of DOR gene expression. Induction of DOR gene expression by an activity-dependent increase in intracellular Ca2+ concentration may serve as a feedback regulatory mechanism because activation of DOR leads to hyperpolarization and lower excitability of neurons.

Parenteral nutrition selectively decreases protein synthesis in the small intestine

We investigated the effects of an elemental diet fed parenterally or enterally on total mucosal protein and lactase phlorizin hydrolase (LPH) synthesis. Catheters were placed in the stomach, jugular vein, and carotid artery of 12 3-day-old pigs. Half of the animals were given an elemental regimen enterally and the other half parenterally. Six days later, animals were infused intravenously with [2H3]leucine for 6 h and killed, and the midjejunum of each animal was collected for analysis. The weight of the midjejunum was 8 +/- 1.5 and 17 +/- 1.6 g in parenterally fed and enterally fed piglets, respectively. LPH activities (mumol.min-1.g protein-1) were significantly higher in parenterally vs. enterally fed piglets. Total small intestinal LPH activities were lower in parenterally vs. enterally fed animals. The abundance of LPH mRNA relative to elongation factor-1 alpha mRNA was not different between groups. The fractional synthesis rate of total mucosal protein and LPH was significantly lower in parenterally fed animals (67 +/- 7 and 66 +/- 7%/day, respectively) than in enterally fed animals (96 +/- 7 and 90 +/- 6%/day, respectively). The absolute synthesis rate (the amount of protein synthesized per gram of mucosa) of total mucosal protein was significantly lower in parenterally fed than in enterally fed piglets. However, the absolute synthesis rate of LPH was unaffected by the route of nutrient administration. These results suggest that the small intestine partially compensates for the effects of parenteral feeding by maintaining the absolute synthesis rate of LPH at the same levels as in enterally fed animals.

Lactase phlorizin hydrolase synthesis is decreased in protein-malnourished pigs

We have examined the effect of protein malnutrition on brush border (BB) lactase phlorizin hydrolase (LPH) synthesis in young pigs. Two groups of four 3-wk-old pigs were fed diets containing either 19 g soy protein, 63 g carbohydrate and 5 g fat per 100 g diet (a protein-sufficient diet) or 3 g soy protein, 85 g carbohydrate and 5 g fat per 100 g diet (a protein-deficient diet). After 8 wk of consuming the diets, pigs were infused intravenously with 2H3-leucine for 8 h, then killed. The jejunum was collected for measurement of lactase activity, LPH mRNA abundance and the rate of LPH post-translational synthesis. Lactase activities did not differ between groups (mean 8.1 +/- 1.2 micromol x min(-1) x g mucosa(-1)). LPH mRNA abundance relative to elongation factor-1alpha mRNA (the constitutive/reference mRNA) was significantly (P < 0.05) higher in well-nourished pigs (0.36 +/- 0.03%) than in protein-malnourished pigs (0.21 +/- 0.02%). The rate constants of BB LPH post-translational synthesis were also significantly higher in the well-nourished (103 +/- 9% x d(-1)) than in the protein-malnourished pigs (66 +/- 8% x d(-1)). Further, the absolute synthesis rate of BB LPH, a measure of the amount of enzyme synthesized per gram of tissue, was significantly higher in well-nourished than in protein-malnourished pigs (in arbitrary units, 892 +/- 90 vs. 450 +/- 34, respectively). Thus, protein malnutrition affects both LPH mRNA abundance and post-translational processing in young pigs.

Regulation of delta-opioid receptor mRNA levels by receptor-mediated and direct activation of the adenylyl cyclase-protein kinase A pathway

The effects of activation of the adenylyl cyclase-protein kinase A pathway on the expression of delta-opioid receptor mRNA in the NG108-15 neuroblastoma x glioma cell line has been investigated. Activation of prostaglandin E1 (PGE1) receptors, which are positively coupled to adenylyl cyclase, resulted in a reduction in delta-receptor messenger RNA levels. Direct stimulation of adenylyl cyclase by forskolin or treatment of cells with the cyclic AMP analogue dibutyryl cyclic AMP (db-cAMP) mimicked the effect of PGE1. Down-regulation in receptor protein levels, as measured by loss of radioligand binding sites, was also observed and its extent correlated well with the decrease in the amount of delta-opioid receptor transcripts. D-Ser2-Leu-enkephalin-Thr6 (DSLET) inhibition of adenylyl cyclase activity was also diminished after db-cAMP treatment. Inhibitors of protein kinase A (PKA) partially reversed the PGE1- and db-cAMP-mediated repression of the delta-opioid receptor mRNA levels. The rate of degradation of delta-opioid receptor mRNA in the presence of actinomycin D was not altered in response to db-cAMP, suggesting that mRNA stability is not reduced by PKA action. The regulation of delta-opioid receptor mRNA levels by db-cAMP was not sensitive to the protein synthesis inhibitor cycloheximide, suggesting that de novo protein synthesis is not required in this process.

Lactase phlorhizin hydrolase turnover in vivo in water-fed and colostrum-fed newborn pigs

We have estimated the synthesis rates in vivo of precursor and brush-border (BB) polypeptides of lactase phlorhizin hydrolase (LPH) in newborn pigs fed with water or colostrum for 24h post partum. At the end of the feeding period, piglets were anaesthetized and infused intravenously for 3h with L-[4-3H]- phenylalanine. Blood and jejunal samples were collected at timed intervals. The precursor and BB forms of LPH were isolated from jejunal mucosa by immunoprecipitation followed by SDS/PAGE, and their specific radioactivity in Phe determined. The kinetics of precursor and BB LPH labelling were analysed by using a linear compartmental model. Immunoisolated LPH protein consisted of five polypeptides [high-mannose LPH precursor (proLPHh), complex glycosylated LPH precursor (proLPHe), intermediate complex glycosylated LPH precursor (proLPH1i) and two forms of BB LPH]. The fractional synthesis rate (Ks) of proLPHh and proLPHc (approx. 5%/min) were the same in the two groups but the absolute synthesis rate (in arbitrary units, min-1) of proLPHh in the colostrum-fed animals was twice that of the water-fed animals. The Ks values of proLPHi polypeptides were significantly different (water-fed, 3.89%/min; colostrum-fed, 1.6%/min), but the absolute synthesis rates did not differ. The Ks of BB LPH was not different between experimental treatment groups (on average 0.037%/min). However, the proportion of newly synthesized proLPHh processed to BB LPH was 48% lower in colostrum-fed than in water-fed animals. We conclude that in neonatal pigs, the ingestion of colostrum stimulates the synthesis of proLPHh but, at least temporarily, disrupts the processing of proLPH polypeptides to the BB enzyme.

The rabbit ileal lipid-binding protein. Gene cloning and functional expression of the recombinant protein

A bile-acid-binding protein of Mr 14000 has been previously identified by photoaffinity labeling in rabbit ileal brush border membrane vesicles [Kramer et al. (1993) J. Biol. Chem. 268, 18035-18046]. This peripheral membrane-associated protein was purified and identified as an ileal lipid-binding protein. It was further shown to be identical to the cytosolic 14-kDa bile-acid-binding protein from the same tissue. Starting with sequence information from tryptic fragments, we cloned and sequenced the gene and its transcript. It has four exons (123, 176, 90, 115 bp) and three introns (1372, 2291, 3137 bp) and a similar structure as the genes from other members of the fatty-acid-binding protein family. The deduced protein has 128 amino acid residues and a calculated molecular mass of 14404 Da. It exhibits high similarity to its human (83%), mouse (77%), rat (76%) and porcine (72%) counterparts. Furthermore, the recombinant protein was produced in Escherichia coli and shown to be identical to native protein from ileal tissue. Functionality of the recombinant protein was demonstrated by labeling with various photoaffinity derivatives of bile acids. Ranking of the photolabeling efficiency of these probes towards the recombinant protein was comparable to the respective ranking towards the native protein. Polyclonal antibodies that were raised in hens against the recombinant protein, specifically recognized the ileal lipid-binding protein in the brush border membrane and cytosol from rabbit ileum. In contrast, no labeling was observed with jejunal tissue. Our results suggest a specific role of the membrane-associated ileal lipid-binding protein for the process of ileal bile acid uptake.

Mu and delta opioid receptor gene expression after chronic treatment with opioid agonist

Levels of mRNA coding for mu and delta opioid receptors were evaluated by competitive PCR in regions of rat brain where adaptive changes in opioid regulation of adenylyl cyclase occur following chronic morphine treatment. Correlation between receptor protein and mRNA levels after exposure to full and partial agonists were also investigated in NG108-15 cells. Different basal gene expression levels of mu and delta opioid receptors were found in the caudate-putamen, nucleus accumbens, thalamus and periaquaductal gray. After continuous morphine treatment for 7 days both mu and delta opioid receptor mRNA levels were unchanged in all four regions compared with saline-treated controls. In NG108-15 cells marked down-regulation of delta opioid receptors as measured by radioligand binding was observed after 5 or 24 h full agonist (D-Ser3-Leuenkephalin; DSLET) treatment. Morphine, a partial agonist at delta receptors, did not reduce receptor number at either time point. The reduction in delta receptor binding after DSLET treatment was not accompanied by significantly diminished levels of delta receptor mRNA. Unaltered mu and delta receptor mRNA levels in brain after chronic morphine exposure make it unlikely that adaptive changes in the transcription of these genes play a role in the observed tolerance in opioid regulation of adenylyl cyclase.

Jejunal brush border hydrolase activity is higher in tallow-fed pigs than in corn oil-fed pigs

We tested the effect of dietary fat on the lipid composition and hydrolase activity of jejunal brush border membranes in piglets. Eighteen 5-wk-old piglets were divided into three groups and for 4 wk fed either an unsaturated low fat diet (3.2% corn oil), an unsaturated high fat diet (17.2% corn oil) or a saturated high fat diet (2.2% corn oil + 15% tallow). Brush border membranes were prepared from the jejunal mucosa and analyzed for cholesterol, phospholipid and fatty acids. The activities of sucrase-isomaltase, lactase-phlorizin hydrolase, maltase-glucoamylase, aminopeptidase and alkaline phosphatase were measured. Lactase-phlorizin hydrolase isoforms were immunopurified and separated by SDS-PAGE, and their relative proportions were measured by densitometry. The activities of the disaccharidases and alkaline phosphatase, but not aminopeptidase, were greater in animals fed the saturated high fat diet than in animals fed the unsaturated high fat diet. The fatty acid composition of the membranes generally reflected the composition of the diet. Correlation analysis demonstrated that the phospholipid, fatty acid and cholesterol compositions of the membranes were associated with the differences in brush border hydrolase activity.

In vivo sucrase-isomaltase and lactase-phlorizin hydrolase turnover in the fed adult rat

We estimated in vivo turnover rates of sucrase-isomaltase and lactase-phlorizin hydrolase in adult rats. Fed animals received a primed continuous infusion of phenylalanine (300 microCi, 150 mumol Phe/100 g of body weight for 30 s, then 7.5 microCi, 3.75 mumol Phe/min for 10 to 140 min). Sucrase-isomaltase and lactase-phlorizin hydrolase were immunoprecipitated from jejunal mucosal membranes; isoforms were separated by SDS-polyacrylamide gel electrophoresis. Endoglycosidase H digestions and (for lactase-phlorizin hydrolase) N-terminal amino acid sequencing were performed on all isoforms. Specific radioactivity of prosucrase-isomaltase and prolactase-phlorizin hydrolase isoforms reached isotopic equilibrium by 60 and 90 min, respectively. Specific radioactivity of brush border sucrase and lactase did not reach steady state. The isotope kinetic, N-terminal amino acid sequencing, and endoglycosidase H digestion data suggested that one of the high molecular weight lactase isoforms is a dimer of mature lactase. Compartmental modeling of specific radioactivity demonstrated that mean intracellular residence time is 59 min for prosucrase-isomaltase isoforms and 68 min for prolactase-phlorizin hydrolase isoforms. Mean residence time in the brush border was 5.8 h for sucrase and 7.8 h for lactase. Fractional synthesis rates were 414%/day for sucrase and 307%/day for lactase. Thus, in vivo brush border sucrase and lactase turn over at similar rates in the adult rat.

Feeding status affects in vivo prosucrase.isomaltase processing in rat jejunum

Fed and fasted (18 h) adult male rats received a primed constant infusion of [3H]leucine for 15 to 180 min. Prosucrase-isomaltase (pro-SI) and sucrase were isolated from mixed jejunal mucosal membranes by immunoprecipitation and separated from one another by polyacrylamide gel electrophoresis under denaturing and reducing conditions. The rate at which pro-SI was processed to sucrase was calculated on the assumption that the steady-state specific radioactivity of leucine in pro-SI defined the pool of amino acids used in the formation of brush border sucrase. At isotopic steady state, pro-SI achieved a specific radioactivity that was higher than that of mucosal free leucine in both feeding groups. The relationship between the isotopic equilibrium of the free amino acid pools and pro-SI was sensitive to feeding status; the specific radioactivity of pro-SI was 25 and 55% (P less than 0.05) of the blood specific radioactivity in fed and fasted animals, respectively. The fractional rate of pro-SI processing tended to be higher (P less than 0.07) in fed (407%/d) than in fasted animals (274%/d). We conclude that the general mucosal free amino acid pool is not the amino acid pool from which pro-SI is synthesized and that the rate of pro-SI processing from the endoplasmic reticulum-Golgi membranes to the brush border membrane is sensitive to the feeding status of the animal.

[Are patellar tension band reconstructions with absorbable materials possible? An animal experiment]

Different biodegradable tension band reconstructions of transverse osteotomies of sheep patella were tested in an experimental pilot study. Without postoperative immobilization, 4 metallic fixations in the control group dislocated secondarily 3 +/- 2 days after the operation. After tenotomy of the gastrocnemius muscle tendon, 6 other metallic fixations showed good bone healing after 12 weeks. Therefore all other fixations were immobilized postoperatively. In 5 of 6 tension band fixations with pure polydioxanone cords (PDS) ventral callus distraction started after 18 +/- 7 days, but total consolidation had taken place after 14 weeks. One PDS fixation failed for technical reasons. The combination of two axial polyglycolide rods (BIOFIX) with two ventral PDS cords showed different results: when rods 4.5 mm in diameter were used 1 fixation dislocated because the fragments were burst by the oversized rods. With rods 3.2 mm in diameter 3 other fixations were followed by complete consolidation with no dislocation after 12 weeks. Other tested combined fixation systems made up of polyglycolide and polylactide composites (cords, screws) failed secondarily, either because the fragments were burst by the oversized implants or because of the fragility of the polylactide cords. It was impossible to use polylactide screws as lag screws, because the screw heads gave way to torque. In an additional study we observed a decrease in tissue pH after implantation of polyglycolide rods in the medullary space of the tibia. Compared with the control medullary space without implants, the pH decreased from 7.38 to 6.92 at the point of greatest implant mass.(ABSTRACT TRUNCATED AT 250 WORDS)

Religious self and secular self: Clinical transitions

Clerical people, returning to secular life, may undergo shifts in self-experience, including alterations in internal object relations. Self-psychology, positing the importance to health of cohesion of all aspects of self, provides a theoretical model for exploring such shifts and their facilitation through psychoanalytic psychotherapy. A case of a released Roman Catholic priest is discussed to illustrate dynamic processes. Emphasis is on a clinical approach that does not require conversion of religious and spiritual self-experience into drive derivative formulations.

Synthesis of 2,2-dimethyl-4-hydroxy-4-androstene-3,17-dione as an inhibitor of aromatase

2,2-Dimethyl-4-hydroxy-4-androstene-3,17-dione (4) has been synthesized and has been shown to be a powerful competitive inhibitor of aromatase (Ki = 11.4 nM). However, compound 4 does not cause time-dependent loss of enzyme activity, in contrast to the unmethylated parent compound, 4-OHA.

[Treatment of malignant pathologic fractures. Results of a retrospective study]

In malignant pathological fractures, surgery is an essential part of the whole oncologic conception. In most cases it is combined with adjuvant therapies. Various surgical procedures are available for the different sites depending on the fact whether the operation is performed in a curative or palliative intent. Even in case of palliative indication with only a limited life expectancy, the indication for surgery is adopted more and more generously. A very important point is the wish of the patient. With our low complication rates, we have been able to facilitate the hard fates of many patients even if they had only short survival times.

[Experiences with the locking nail]

In case of clear indication, the locking nail system brings about good results in the treatment of problematic long bone fractures. The indication for primary static locking should be defined in a wide manner. Early loading is possible and is applied by us more and more in not adipose patients with static locking, too. From our point of view, the following factors are some of the drawbacks of the system: bolt loosening due to different causes, the impractical aiming device for distal locking, problems with the lavage of the medullary cavity in case of infection, pains in the knee joint after transcondylar implantation of a Steinmann nail. In case of long bones with narrow medullary cavities (young women) for which the thinnest nail has to be used, slotted nails bear the risk of distortion.

[Threatening preoperative conditions in hyperparathyroidism]

Within 10 years in 2 out of 44 patients with pHPT (4.5%) a hypercalcemic crisis, in 3 other patients symptoms of hypercalcemic syndrome were observed. A quick diagnosis of the life threatening situation and a therapy of decreasing calcium led to an elective operation.

[The value of arthroscopy in the diagnosis of knee injuries]

Arthrographic and arthroscopic findings of traumatized knee joints were compared by operation. It was found that endoscopic examination, particularly in case of damage to joint cartilage and cruciated ligaments, is superior to arthrographic examination. The lesions of meniscus could not always be detected radiologically. Hence, whenever there is a suspicious knee joint damage, arthroscopy should be performed liberally.

[Postoperative care of patients with chronic pancreatitis (author's transl)]

137 patients, who had had surgery of the pancreas, were followed up postoperatively; 72 of these had had resection of pancreas, 65 patients had organ preserving surgery. Diabetes occurred in 44% of the total group. Control of diabetes was adequate only in 19%. 89 patients had an insufficient exocrine pancreatic function; substitution with pancreatic enzyme products was not adequate in 39 patients in this group. 65% took up work again, the working ability being reduced by less than 33%. 14% of the whole group retired immediately after operation from working life, 6% remained jobless for longer periods of time. After surgery of the pancreas patients should be encouraged to active work; granting pensions too generously will increase the relapse rate of alcoholism. In 6 cases of subtotal surgery and in 21 cases of organ preserving surgery operation had to be done for a second time. A classification is proposed for evaluation of postoperative results.

[Cystadenoma of the pancreas, a potentially malignant tumor (author's transl)]

Cystadenomas occur rather rarely among the cystic lesions of the pancreas, but they nevertheless require special attention. These cystadenomas do have a tendency for malignant degeneration, especially their mucinous form with papillary proliferation of the epithelium; insofar cystadenomas have to distinguished from retention nor pseudocysts, resulting from pancreatitis or from traumatic lesions of the pancreas. Differentiation of cystadenomas and other cysts can neither be achieved by preoperative diagnostic procedures nor by macroscopic findings during surgery. Diagnosis however can be established after biopsy during surgery. A cystadenoma has to be suspected especially in women of middle age, who do not have any history of pancreatitis, abdominal trauma or alcoholism, if the lesion is localized in the corpus or tail are of the pancreas. Cystadenoma have to be treated as potentially malignant tumors. The therapy of choice is excision far out in normal tissue; this is the only way to prevent relapses and to avoid transition of the lesion into a carcinoma. Thus, it has to be postulated for all patients who are being operated upon because of cysts of the pancreas that multiple biopsies should be done from various parts of the cystic wall during surgery and that drainage of the cyst should be performed only if a cystadenoma can be excluded.