The role of radiotherapy in elderly women with early-stage breast cancer treated with breast conserving surgery

OBJECTIVE

To analyze the impact of adjuvant radiotherapy (RT) on ipsilateral breast recurrence (IBR) and overall survival (OS) in patients older than 69 years with early-stage breast cancer.

METHODS

From January 2007 to June 2015, we analyzed retrospectively 137 women with estrogen receptor-positive T1-2 invasive breast cancer, with negative axillary lymph nodes, dividing them into 2 subgroups: 70 to 79 years and older than 79 years.

RESULTS

After a median follow-up of 43.2 months, the 3-year IBR-free survival in patients treated with surgery plus RT was 98.8% and 92.1% in patients treated with surgery alone, with a significant difference (p = .01). Radiotherapy did not impact overall survival (p = .10). A higher percentage of patients aged between 70 and 79 years received RT after conservative surgery if compared with the older subgroup (p < .01).

CONCLUSIONS

In elderly women, adjuvant RT reduced the IBR, but did not improve OS.

Novel Hits in the Correction of ΔF508-Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) Protein: Synthesis, Pharmacological, and ADME Evaluation of Tetrahydropyrido[4,3-d]pyrimidines for the Potential Treatment of Cystic Fibrosis

Cystic fibrosis (CF) is a lethal genetic disease caused by mutations of the gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR) with a prevalence of the ΔF508 mutation. Whereas the detailed mechanisms underlying disease have yet to be fully elucidated, recent breakthroughs in clinical trials have demonstrated that CFTR dysfunction can be corrected by drug-like molecules. On the basis of this success, a screening campaign was carried out, seeking new drug-like compounds able to rescue ΔF508-CFTR that led to the discovery of a novel series of correctors based on a tetrahydropyrido[4,3-d]pyrimidine core. These molecules proved to be soluble, cell-permeable, and active in a disease relevant functional-assay. The series was then further optimized with emphasis on biological data from multiple cell systems while keeping physicochemical properties under strict control. The pharmacological and ADME profile of this corrector series hold promise for the development of more efficacious compounds to be explored for therapeutic use in CF.

A homogeneous HTRF assay for the identification of inhibitors of the TWEAK-Fn14 protein interaction

The TWEAK-Fn14 pathway is upregulated in models of inflammation, autoimmune diseases, and cancer. Both TWEAK and Fn14 show increased expression also in the CNS in response to different stimuli, particularly astrocytes, microglia, and neurons, leading to activation of NF-κB and release of proinflammatory cytokines. Although neutralizing antibodies against these proteins have been shown to have therapeutic efficacy in animal models of inflammation, no small-molecule therapeutics are yet available. Here, we describe the development of a novel homogeneous time-resolved fluorescence (HTRF)-based screening assay together with several counterassays for the identification of small-molecule inhibitors of this protein-protein interaction. Recombinant HIS-TWEAK and Fn14-Fc proteins as well as FLAG-TWEAK and Fn14-FLAG proteins and an anti-Fn14 antibody were used to establish and validate these assays and to screen a library of 60 000 compounds. Two HTRF counterassays with unrelated proteins in the same assay format, an antiaggregation assay and a redox assay, were applied to filter out potential false-positive compounds. The novel assay and associated screening cascade should be useful for the discovery of small-molecule inhibitors of the TWEAK-Fn14 protein interaction.

Chlorantraniliprole/lambda-cyhalothrin, a new insecticide mixture to control Tuta absoluta and Spodoptera littoralis in tomato

A study was performed in the period May-July 2011 by Bioagritest test facility according to EPPO guidelines and Principles of Good Experimental Practice (GEP), in the land of Eboli (SA), southern Italy, with the purpose to test a new insecticide mixture in the defense strategies of processing tomato against Tuta absoluta and Spodoptera littoralis. The insecticide mixture Chlorantraniliprole 100 g/lambda-Cyhalothrin 50 g/l 0,4 It/ha was applied in a tomato field in four (A-B-C-D) application timings (a.t.) alone (treatment 2) and in two a.t. (A-B) combined with emamectin benzoate 0.5%, 1,5 Kg/ha (a.t. C-D) (treatment 3). Its effect in containing insect populations was compared with that exerted by emamectin benzoate 0.5%, 1,5 Kg/ha (a.t. A-B-C-D) (treatment 4) and the combination of chlorantraniliprole 35%, 0.115 Kg/ha (a.t. A-B) and indoxacarb 30% 0.125 Kg/ha (a.t. C-D) (treatment 5). Application of treatments (trt.) and mode of assessment (2 assessments), recording and measurements followed the guidelines foreseen by EPPO Standards PP1/150 and PP1/275. The lepidoptera infestation in the tomato crop was very high on both the leaves and fruits, and this enabled us to evaluate the efficacy of the tested products in conditions of severe pests infestation. If we consider the leaf damage, either as number of mines by T. absoluta or as % of leaf erosion by S. litteralis, all the treatments values were statistically lower than control, but with no difference among them. But when using as an infestation threshold the percentage of damaged fruits (much more relevant in economic terms), we observed statistically significant differences among treatments. Actually, treatment with chlorantraniliprole-lambda-cyhalothrin mixture was significantly more effective than the one with emamectin benzoate in reducing the attack of T. absoluta on tomato fruits, in both dates of assessments. As concerns damage by S. littoralis on the fruits, at the first assessment, trt. 2 and trt. 5 significantly reduced the percentage of infested berries in comparison with the control, whereas the infestation was not significantly reduced by trt. 3 and trt. 4. At the second assessment, no statistically significant difference between the four different treatments was observed. Since the infestation of tomato fruits by S. littoralis was much lower than the one caused by T. obsoluta, the overall performance of the four insecticide treatments was mainly due to the control effects towards T. obsoluta.

Modified adenine (9-benzyl-2-butoxy-8-hydroxyadenine) redirects Th2-mediated murine lung inflammation by triggering TLR7

Substitute adenine (SA)-2, a synthetic heterocycle chemically related to adenine with substitutions in positions 9-, 2-, and 8- (i.e., 9-benzyl-2-butoxy-8-hydroxyadenine), induces in vitro immunodeviation of Th2 cells to a Th0/Th1 phenotype. In this article, we evaluate the in vivo ability of SA-2 to affect Th2-mediated lung inflammation and its safety. TLR triggering and NF-kappaB activation by SA-2 were analyzed on TLR-transfected HEK293 cells and on purified bone marrow dendritic cells. The in vivo effect of SA-2 on experimental airway inflammation was evaluated in both prepriming and prechallenge protocols by analyzing lung inflammation, including tissue eosinophilia and goblet cell hyperplasia, bronchoalveolar lavage fluid cell types, and the functional profile of Ag-specific T cells from draining lymph nodes and spleens. SA-2 induced mRNA expression and production of proinflammatory (IL-6, IL-12, and IL-27) and regulatory (IL-10) cytokines and chemokines (CXCL10) in dendritic cells but down-regulated TGF-beta. Prepriming administration of SA-2 inhibited OVA-specific Abs and Th2-driven lung inflammation, including tissue eosinophilia and goblet cells, with a prevalent Foxp3-independent regulatory mechanism. Prechallenge treatment with SA-2 reduced the lung inflammation through the induction of a prevalent Th1-related mechanism. In this model the activity of SA-2 was route-independent, but adjuvant- and Ag dose-dependent. SA-2-treated mice did not develop any increase of serum antinuclear autoantibodies. In conclusion, critical substitutions in the adenine backbone creates a novel synthetic TLR7 ligand that shows the ability to ameliorate Th2-mediated airway inflammation by a complex mechanism, involving Th1 redirection and cytokine-mediated regulation, which prevents autoreactivity.

The isoflavone genistein inhibits LPS-stimulated TNFa, but not IL-6 expression in monocytes from hemodialysis patients and healthy subjects

BACKGROUND

Whole blood and peripheral blood mononuclear cells from hemodialysis (HD) patients show increased production and secretion of inflammatory cytokines. We determined the contribution of blood monocytes to the production of inflammatory cytokines in whole blood from HD patients.

METHODS

Whole blood and isolated mononuclear cells from HD patients and healthy control subjects were preincubated with the isoflavone genistein and stimulated with LPS. TNFalpha, IL-6 and IL-10 formation in the whole blood was measured with ELISA and intracellular cytokine formation in CD 14-positive monocytes was determined by flow cytometry.

RESULTS

Unstimulated blood levels of TNFalpha, IL-6 and IL-10 were significantly elevated in HD patients compared to controls, but intracellular monocyte content of these cytokines was identical between groups. LPS induced a robust TNFalpha response in both whole blood and monocytes, and TNFalpha formation was 2.3-fold higher in blood from HD patients compared to controls. A similar trend was observed in monocytes. Conversely, LPS stimulation increased IL-6 levels >1000-fold in whole blood, albeit without a noticeable difference between groups. Only minor increases in monocyte IL-6 content were observed. The isoflavone genistein did not inhibit IL-6 formation and did not alter basal TNFalpha levels, but genistein selectively blocked LPS-induced TNFalpha formation in whole blood and monocytes from both groups.

CONCLUSION

Intracellular levels of TNFalpha, IL-6 and IL-10 in monocytes are indistinguishable between HD patients and healthy controls. However, monocytes from HD patients are selectively primed for enhanced TNFalpha secretion in response to LPS. The selective inhibition of monocyte TNFalpha production by genistein may explain the anti-inflammatory action of this phytochemical observed in vivo.

CYP2D6 genetic variation in healthy adults and psychiatric African-American subjects: implications for clinical practice and genetic testing

Limited information is available on the frequency of the many CYP2D6 alleles found in African-Americans. DNA was isolated and genetic testing was performed on samples from 222 African-Americans, healthy controls (n=131), and psychiatric patients (n=91). Each DNA was tested for CYP2D6 alleles *2, *3, *4, *5, *6, *7, *8, *9, *10, *11, *14, *15, *17, *18, *19, *20, *25, *26, *29, *30, *31, *35, *36, *37, *40, *41 and *43 and 8 multiple copy alleles (*1xn, *2xn, *4xn, *41xn, *2Lxn, *17xn, *35xn and *10xn) using the AmpliChip CYP450 prototype microarray assay, along with allele-specific-PCR and PCR restriction fragment length polymorphism methods. No significant difference was noted between controls and psychiatric patients in any CYP2D6 allele frequencies. Three subjects were genotyped as poor metabolizers (1.4%; 0.0-2.9%, 95% confidence intervals (CI)), and 10 were classified as ultrarapid metabolizers (4.5%; 1.8-7.2%, 95% CI). A new CYP2D6 allele (*58) and two new duplicated CYP2D6 alleles (*17xn and *2Lxn) not previously reported were also identified. The frequency of the CYP2D6 overexpression in African-Americans may represent a greater therapeutic challenge than its deficiency based on these results. The most common alleles found in African-Americans including CYP2D6*1, *17 and *41 need to be investigated more closely for race-specific allelic variations and the mechanism responsible for differences in allele function more closely examined. The diversity of CYP2D6 alleles suggests that nucleotide arrays or similar methods are needed to efficiently test for the most prominent/relevant CYP2D6 alleles in humans.

Effect of soy protein-rich diet on renal function in young adults with insulin-dependent diabetes mellitus

BACKGROUND

Diabetic nephropathy is the most frequent cause of end-stage renal disease in the Western world. Dietary intake, including protein amount and type, seems to affect the progression of renal disease. This pilot study tested the hypothesis that substituting soy protein for animal protein in the diets of diabetics would help correct glomerular hyperfiltration.

METHODS

Twelve young adults (aged 29.9 +/- 2.4 years) with type 1 diabetes mellitus (duration of diabetes 15.1 +/- 2.3 years) and hyperfiltration (glomerular filtration rate, GFR > 120 ml/min/1.73 m2) completed a crossover, dietary intervention trial. After a four-week assessment of baseline characteristics and dietary habits, subjects were assigned to either a control or soy diet for eight weeks after which each subject was crossed over to the alternative diet for another eight-week period.

RESULTS

Mean GFR was significantly reduced (p < 0.02) after eight weeks on the soy diet (143 +/- 7.4 ml/min/1.73 m2) compared with baseline (159 +/- 7.7 ml/min/ 1.73 m2) and control diets (161 +/- 10.0 ml/min/1.73 m2). Urinary excretion of the soy isoflavones was significantly higher (p < 0.01) at the end of the soy diet (genistein 1,014.6 +/- 274.1 nmol/h, daidzein 2,645.1 +/- 989.6 nmol/h) compared with baseline (genistein 53.7 +/- 31.1 nmol/h, daidzein 151.1 +/- 74.1 nmol/h) and control diets (genistein 41.1 +/- 13.3 nmol/h, daidzein 127.5 +/- 54.0 nmol/h). The soy diet significantly reduced total and LDL cholesterol by 7% and 9%, respectively.

CONCLUSIONS

Implementation of a soy-based diet appears to reduce the GFR and total and LDL cholesterol of young adults with type 1 diabetes and glomerular hyperfiltration, thus affecting positively their clinical profile.

Estrogen disrupts chemokine-mediated chemokine release from mammary cells: implications for the interplay between estrogen and IP-10 in the regulation of mammary tumor formation

Chemokines are pro-inflammatory cytokines that function to attract immune cells to the sites of tissue inflammation, injury or infection. We have formulated the hypothesis that release of one chemokine can serve, in a local paracrine or endocrine fashion, to induce the release of other chemokines from neighboring mammary cells. We set out to investigate whether specific chemokines could promote the release of other chemokine members from mammary cells, and whether estrogen could serve to disrupt the release of these chemokines from mammary cells. We found that treatment with the chemokine IP-10 resulted in significant increases in the amount of MIP-1alpha and MCP-1/JE released from murine mammary cells. Estrogen co-treatment significantly blocked the ability of IP-10 to trigger the release of MIP-1alpha and MCP-1/JE. Suppressive effects of estrogen were reversed upon co-treatment with 4-hydroxytamoxifen. Estrogen treatment significantly decreased expression of proteins corresponding to the chemokine receptors CXCR3 and CCR5 on mammary cells. Exposure of female mice to IP-10 in vivo significantly decreased the ability of estrogen to support the growth of CCL-51-based tumors in mammary tissue. Our results suggest that exposure of mammary tissue to estrogen may decrease the release of local chemokines from mammary cells, potentially increasing the risk of tumor growth through decreased immune surveillance. Ongoing studies are investigating the possible mechanisms through which IP-10 stimulates the release of chemokines from mammary cells, and how the action of IP-10 may serve to decrease mammary tumor formation.

Pea aphid clonal resistance to the endophagous parasitoid Aphidius ervi

The physiological mechanism of resistance to the endophagous braconid Aphidius ervi Haliday (Hymenoptera, Braconidae) by a pink clone (PC) of Acyrthosiphon pisum (Harris) (Homoptera, Aphididae) has been investigated. Comparative data on parasitoid development and associated host biochemical changes in the resistant PC aphids and in a susceptible green clone (GC) of A. pisum are reported. When the PC aphids were attacked as early 4th instars, the developing parasitoid larvae showed a strongly reduced increase in size, compared to those synchronously developing in GC aphids, and were unable to produce a regular mummy. In contrast, parasitism of 2nd instar PC aphids, allowed completion of parasitoid development, but adults had a prolonged developmental time, due to a longer duration of parasitoid's final (3rd) instar. In all cases, teratocytes, cells deriving from the A. ervi serosal membrane, and the proteins abundantly synthesised by them, were never found in the haemolymph of parasitised PC aphids. Host castration, as demonstrated by total protein incorporation into reproductive tissues, was total in the majority of early (2nd instar) parasitised host aphids, while it was limited when later instars (4th) of PC aphids were parasitised. This is partly due to the absence of the cytolytic activity of teratocytes on host embryos, which, through their persistence, may compete for nutritional resources with the developing parasitoid larvae. In parasitised PC aphids, this competitive effect is further aggravated for the parasitoid by the absence of the regulated amino acid titre increase in the host haemolymph, which is regularly observed in GC aphids. Failure of teratocyte development in the PC clone of the pea aphid is, then, the major functional constraint accounting for the reduction/inhibition of A. ervi larval growth. The reported results allow to assess in vivo the role of teratocytes in the host physiological redirection and nutritional exploitation by the parasitoid, and to integrate and validate the proposed physiological model of host-parasitoid interactions in the system A. pisum-A.ervi.

Altered Bax expression and decreased apoptosis in bone marrow cells of lupus-susceptible NZB/W mice

Estrogen is believed to contribute to the development of the autoimmune disorder systemic lupus erythematosus (SLE) (lupus) in women. We hypothesized that estrogen might promote the development of lupus by altering apoptosis of bone marrow cells, perhaps through regulation of the apoptotic proteins Bax and Bcl-2. We compared the effects of estrogen (E2) and thrombopoietin (TPO) on the expression of Bax or Bcl-2 in bone marrow cells isolated from female non-lupus (NZW or NZB parental strains) or lupus-prone (NZB and NZW cross; NZB/W) mice. We report that the basal level of Bax in parental bone marrow cells was significantly greater than that of cells from NZB/W animals. Treatment of NZB or NZW marrow cells with E2 resulted in a significant decrease in Bax expression, which was completely reversed upon co-treatment with TPO. Bax expression was not significantly altered by E2 and/or TPO in NZB/W cells. Bcl-2 levels did not differ between murine strains under basal or hormone-treated conditions. Lower basal expression of Bax protein was associated with significantly less apoptosis for NZB/W marrow cells. In addition, there were significantly greater numbers of cells in bone marrow of lupus-susceptible animals. Our results indicate that bone marrow cells of NZB/W animals differ physiologically from those of NZW or NZB mice, and suggest that decreased expression of Bax in bone marrow precursors may lead to decreased apoptosis of mature blood cells in lupus-susceptible mice.

Metabolic and symbiotic interactions in amino acid pools of the pea aphid, Acyrthosiphon pisum, parasitized by the braconid Aphidius ervi

Aphidius ervi Haliday (Hymenoptera, Braconidae) is an endophagous parasitoid of the pea aphid, Acyrthosiphon pisum (Harris) (Homoptera, Aphididae). This parasitoid strongly redirects host reproduction and metabolism to favour nutrition and development of its juvenile stages. Parasite-regulated biosynthesis and mobilization of nitrogen metabolites determine a significant increase of host nutritional suitability. The aim of the present study was mainly to investigate the temporal changes of A. pisum amino acid pools, as affected by A. ervi parasitism, and to assess the role of the aphid bacterial endosymbiont Buchnera in determining the observed changes. In parasitized aphids, we observed a very significant increase in total free amino acids, compared with synchronous non-parasitized controls, starting from day 4 after parasitization (+51%). This trend culminated with more than doubling the control value (+152%) on day 6 after parasitization. However, a significant "parasitism" effect was observed only for 10 of the 28 amino acids detected. Tyrosine accumulation was the most prominent parasitoid-induced alteration, with a fourfold increase over control levels registered on day 6. In parasitized hosts, the amino acid biosynthetic capacity of Buchnera was unaltered, or even enhanced for the phenolic pool, and contributed greatly to the definition and maintainance of host free amino acid pools. The hypertyrosinemic syndrome was not dependent on food supply of the aromatic nucleus but was induced by parasitism, which likely enhanced the aromatic shuttle mediating phenylalanine transfer from bacteria to the host tissues, where tyrosine conversion occurs. This process is likely associated with a selective disruption of the host's functions requiring tyrosine, leading to the remarkable accumulation of this amino acid. The possible mechanisms determining these parasitism-induced host alterations, and their nutritional significance for the developing parasitoid larva, are discussed.

Racial differences in parathyroid hormone levels in patients with secondary hyperparathyroidism

AIM

African-Americans (AA) with normal renal function have higher parathyroid hormone (PTH) levels than Caucasians (C). This difference was also noted in cross-sectional studies of patients on dialysis. In this study, we evaluated patients with end-stage renal disease who have just began dialysis and who were not receiving any vitamin D therapy.

METHODS

A total of 363 patients were recruited (C: 260; AA: 103). All patients had serum calcium, phosphorus, alkaline phosphatase and intact PTH (iPTH) levels measured within 3 months of initiating dialysis.

RESULTS

Serum PTH levels were significantly higher in AA vs. C (383 +/- 33 vs. 246 +/- 19, p < 0.001). This difference was present despite similar calcium, phosphorus and alkaline phosphatase levels between the 2 groups and regardless of gender or diabetes status. However, PTH levels in patients younger than 47 years of age were similar in both groups.

CONCLUSION

PTH levels in ESRD patients over 47 years of age are higher in AA compared to C. The difference is, in part, due to an age-dependent reduction in PTH seen only in C. Further studies are needed to understand the mechanisms of these racial differences and to verify whether they mirror similar alterations at the level of the end-organ tissue.

Altered bone marrow cell sensitivity in the lupus-prone NZB/W mouse: regulation of CFU-GM colony formation by estrogen, tamoxifen and thrombopoietin

Estrogen is thought to contribute to the onset of systemic lupus erythematosus (SLE) in women through mechanisms that are not completely understood. Although estrogen serves as a negative regulator in normal hematopoietic development, little research has been conducted examining alteration in hematopoietic development triggered by estrogen in lupus-susceptible individuals. We examined whether estrogen and other factors could influence colony formation of bone marrow cells obtained from normal and lupus-susceptible mice. Bone marrow cells isolated from New Zealand Black (NZB) and lupus-prone New Zealand Black and New Zealand White cross (NZB/W) mice were cultured in the presence of granulocyte-macrophage colony stimulating factor (GM-CSF) alone or in combination with estrogen, thrombopoietin (TPO), tamoxifen, estrogen and TPO. or estrogen and tamoxifen, and plated in methylcellulose culture medium. Plates were scored for the number of CFU-GM (colony forming unit granulocyte-macrophage) colonies after 6d in culture. For females of both mouse strains, estrogen significantly decreased (P < 0.05) the number of GM colonies. Co-treatment of NZB/W cells, but not NZB cells, with TPO or tamoxifen reversed the suppressive action of estrogen (P < 0.05). In contrast, while estrogen did suppress colony formation from cells of NZB/W males (P < 0.05), neither TPO nor tamoxifen reversed this effect. Our results indicate that the sensitivity of bone marrow cells isolated from both female and male NZB/W lupus-prone mice to hormones/growth factors is qualitatively different from cells of NZB mice, and suggest that hematopoietic alterations at the level of the bone marrow may be related to the pathogenesis of SLE.

Effects of porcine sometotropin on calcium and phosphorus balance and markers of bone metabolism in finishing pigs

Six sets of four littermate barrows initially averaging 75.5 kg BW were equally fed (within blocks) fortified corn-soybean meal diets (1.30% lysine) containing two concentrations of Ca (.50 and 1.00%) and P (.45% and .90%) in a 34-d test. One-half of the pigs were injected with 4 mg of porcine ST (pST)/d. Following a 7-d adjustment period, total collection of feces and urine was performed during two periods (d 1 to 10 and d 20 to 30) for the determination of Ca and P apparent digestibility (absorption) and retention. Pigs were bled after each period (d 10, 20, and 30) for the determination of serum metabolites associated with Ca, P, and bone metabolism. Feed intake for the 30-d period averaged 2,020 g/d. There were no treatment x period interactions, so the absorption and retention data were pooled across periods. The absorption and retention of Ca and P were greater (P<.01) in pigs fed the higher Ca and P levels. Within each Ca and P level, pST reduced (P<.01) fecal Ca and P excretion. Administration of pST did not affect urinary P excretion, but it increased (P<.03) urinary Ca excretion in pigs fed the low-Ca diet. The absorption and retention of Ca and P were increased (P<.01) by pST; however, the increases in Ca retention and P absorption and retention on an absolute basis (g/d) were more pronounced in pST-treated pigs consuming the higher Ca and P diet (interaction, P<.10). Serum concentrations of 1,25-dihydroxyvitamin D3, osteocalcin, and IGF-I on d 10 and 30 were increased (P<.07) with pST administration. However, the increases in 1,25-dihydroxyvitamin D3 and osteocalcin in pST-treated pigs were more pronounced when the lower dietary Ca and P levels were fed (interaction, P<.08). Urinary excretion of hydroxyproline increased (P<.01) with pST administration, but this effect was more pronounced in pST-treated pigs fed the lower Ca and P diet (interaction, P<.09). These results suggest that pST increases the absorption and retention of Ca and P independent of dietary Ca and P level. However, serum measures associated with Ca, P, and bone metabolism in pST-treated pigs were dependent on the Ca and P content of the diet, suggesting an effect of pST on the homeostatic control of Ca, P, and bone metabolism.

In vitro and in vivo effects of genistein on murine alveolar macrophage TNF alpha production

The present study was performed to determine whether genistein could inhibit in vivo LPS-induced alveolar macrophage TNFalpha production and thus reduce the alveolar neutrophil influx following LPS. In vitro incubation with genistein completely inhibited LPS-induced TNFalpha production by alveolar macrophages (AM) from BALB/c mice. Subsequently mice were pretreated with intraperitoneal genistein or vehicle, then received nasal LPS to induce an alveolitis. Genistein was then administered every eight hours for five days following LPS. At 24 hours after LPS, the bronchoalveolar lavage (BAL) TNFalpha and ex vivo TNFalpha production from AM, were lower in the genistein treated animals. As well, total BAL white blood cell (WBC) count was reduced in the genistein as compared to the vehicle-only group. The percent neutrophils and the resolution of neutrophils were similar between genistein and vehicle groups. Therefore, genistein was able to decrease AM TNFalpha production, and was associated with a decrease in BAL WBC count post-LPS.

Serum levels and metabolic clearance of the isoflavones genistein and daidzein in hemodialysis patients

Genistein and daidzein are biologically active isoflavones that are especially abundant in soybeans. After intestinal absorption, circulating genistein and daidzein are eliminated primarily by the kidneys. This study was undertaken to assess the metabolism of genistein and daidzein in patients with end-stage renal disease (ESRD) on hemodialysis therapy, and to test whether this treatment modality can replace the lack of kidney function, with respect to the elimination of the isoflavones. Twenty-three hemodialysis patients and 10 healthy subjects were studied. While consuming a self-selected low isoflavone diet, baseline blood levels were undetectable in eight of 10 healthy subjects and in 14 of 23 dialysis patients. The remaining participants had detectable levels, with the nine dialysis patients displaying much higher blood concentrations than the two healthy control subjects. After the evening intake of one dose of an isoflavone-rich soy protein isolate drink, the early morning blood levels of genistein and daidzein were higher in seven dialysis patients than in eight healthy subjects (genistein 1271+/-321 versus 425+/-104, P<0.05; daidzein 1304+/-352 versus 292+/-78, P<0.05). The blood clearance of the isoflavones was studied in two healthy subjects and in three dialysis patients. Genistein and daidzein were eliminated within 2 d in the healthy subjects, but had not returned to baseline in two of three ESRD patients, 7 d after intake. The half-life of both compounds was estimated to be 10-fold longer in the ESRD patients than in the healthy subjects. Finally, genistein and daidzein levels were measured before and after dialysis in five patients, both while on their regular diet and after one dose of a soy protein isolate drink. In both instances, the dialysis treatment did not affect the blood isoflavone levels. In conclusion, approximately one-third of hemodialysis patients eating the standard American renal diet experience high blood levels of the isoflavones genistein and daidzein, while the remaining two-thirds have undetectable levels. After ingestion of isoflavone-rich food such as soy products, all patients have detectable levels that remain very high for several days due to lack of renal excretion.

The phytoestrogen genistein reduces bone loss in short-term ovariectomized rats

The incidence of fractures and of osteoporosis differs between Oriental and Western Caucasian women. This may depend, at least in part, on nutritional factors, including dissimilarities in dietary intake of phytoestrogens. To investigate this possibility, 2-month-old female rats were ovariectomized (OVX) or sham-operated (SHAM), fed a casein-based diet, injected daily with subcutaneous genistein (GEN), the most abundant and best characterized phytoestrogen, or vehicle (Veh) and killed 21 days after surgery. As expected, ovariectomy resulted in loss of bone mineral density (BMD) and in uterine atrophy. However, administration of 5 micrograms GEN per gram body weight (b.w.) ameliorated the ovariectomy-induced loss of BMD (189 +/- 2 mg/cm2 in OVX and 192 +/- 2 in OVX with 5 micrograms GEN/g b.w. per day; p < 0.05). One microgram GEN per gram body weight did not affect the BMD loss and the effect of the 5 micrograms and 25 micrograms GEN per gram body weight were statistically not different. A trend toward reduced uterine atrophy (21% reduction) was noted with the 25 micrograms GEN dose, but not with the 1 microgram and 5 micrograms doses. A separate experiment with 2 x 2 factorial design was conducted to elucidate the mechanism by which GEN ameliorates ovariectomy-induced bone loss. In this experiment, histomorphometry demonstrated a dramatic reduction in trabecular bone volume after ovariectomy (7.6 +/- 0.7% of total bone volume in SHAM-Veh vs 3.3 +/- 0.2% in OVX-Veh; p < 0.01) and less bone loss in OVX rats injected with 5 micrograms GEN per gram per day (3.3 +/- 0.2% of total bone volume in OVX-Veh vs 5.2 +/- 0.4% in OVX-GEN; p < 0.01). Administration of GEN was associated with higher bone formation rate per tissue volume and with a trend toward a higher number of osteoblasts per bone perimeter. The parameters of bone resorption were not affected by GEN. The concentration of serum osteocalcin and the urinary excretion of deoxypyridinoline provided corroborating results. Since production of proinflammatory cytokines is intimately involved in the pathogenesis of postmenopausal osteoporosis, the effect of GEN on lipopolysaccharide-induced in vitro production of Tumor necrosis factor-alpha (TNF alpha) was tested in monocytic cells from the same four rat groups. Production of TNF alpha was markedly elevated in OVX-Veh as compared with the SHAM-Veh rats, but this was blocked by GEN in the OVX rats. This study shows that GEN reduces both trabecular and compact bone loss after ovariectomy and that this protective effect differs from that of estrogen, since it depends on stimulation of bone formation rather than on suppression of bone resorption. Lack of action of GEN on uterine atrophy supports the possibility that this GEN dose affects target tissues via non-estrogenic mechanisms. Modulation of cytokine production may be involved in the effect of GEN on bone.

Moderately high consumption of ethanol suppresses bone resorption in ovariectomized but not in sexually intact adult female rats

Epidemiological studies suggest that moderate consumption of alcoholic beverages may be beneficial for bone in postmenopausal women. To investigate prospectively these uncontrolled observations, female rats were divided in four groups of 10 animals each and treated with 1) ovariectomy (OVX) and 2.5% ethanol diet (OVX-ETOH group), 2) OVX and control diet (OVX-C group), 3) sham surgery and 2.5% ethanol diet (SHAM-ETOH group), or 3) sham surgery and control diet (SHAM-C group). Three weeks after surgery, bone histomorphometry revealed that the OVX-C group, as expected, had lower trabecular bone volume and higher parameters of bone formation and resorption than the SHAM-C group (p < 0.01). Intake of ethanol did not change these parameters in the SHAM rats, but in the OVX rats it was associated with sharp reduction in parameters of bone resorption (p < 0.01) without a concomitant effect on parameters of bone formation. The cytokines are believed to contribute to accelerated bone resorption during the early postmenopausal period. Indeed, the peripheral blood monocytic cells (PBMC) from the OVX-C rats produced higher amounts of TNF-alpha than the PBMC from the SHAM-C rats (p < 0.05) and administration of ethanol prevented this increase in OVX rats but had no effect in SHAM rats. In summary, short-term intake of moderate doses of ethanol was associated with markedly different effects in rats with and without ovarian function. Although ethanol had no significant effect on the bone tissue and TNF-alpha production of the SHAM rats, it was associated with markedly lower parameters of bone resorption and less TNF-alpha production in the OVX animals. This suggests that exposure to low-dose ethanol may protect from osteopenia following cessation of ovarian function.

The determination of serum concentrations of osteocalcin in growing pigs and its relationship to end-measures of bone mineralization

Osteocalcin, a 49-amino acid, gamma-carboxyglutamic acid-containing protein produced by the osteoblast, has been shown in laboratory animals to be a better marker of bone turnover than alkaline phosphatase. To determine serum osteocalcin levels in growing pigs, we isolated pure porcine osteocalcin and developed a double-antibody RIA. To evaluate the effects of dietary Ca and P levels on serum osteocalcin, 36 individually penned crossbred pigs (19.5 kg initial BW) were fed fortified corn-soybean meal diets (.95% lysine) containing four levels of Ca (.42, .66, .90, 1.14%) and P (.35, .55, .75, .95%) in a 30-d test. Increasing dietary Ca and P improved body weight gain quadratically (P < .02). Most bone traits improved quadratically (P < .05) with increasing Ca and P. Pigs were bled on d 0, 10, 20, and 30 to determine serum levels of alkaline phosphatase, 1,25-dihydroxyvitamin D3, and osteocalcin. Osteocalcin decreased (P < .02) linearly with increasing Ca and P on d 10, 20, and 30. However, this effect was much more pronounced on d 20 and 30. Alkaline phosphatase decreased with the first incremental increase in dietary Ca and P, but was not affected by higher levels on any day measured. Osteocalcin was inversely correlated with growth rate (r = -.54, P < .01), bone strength (r = -.57, P < .01), metacarpal ash (r = -.29, P < .10), femur ash (r = -.60, P < .01), and femur ash weight (r = -.65, P < .01). Similar results were found for 1,25-dihydroxyvitamin D3. Alkaline phosphatase was not correlated with performance or most bone traits on d 30. Based on this model, these results suggest that serum osteocalcin and 1,25-dihydroxyvitamin D3 are better predictors of bone mineralization and(or) turnover in pigs than serum alkaline phosphatase.

Isolation and complete amino acid sequence of osteocalcin from canine bone

Osteocalcin was purified in high yield and to homogeneity from the diaphysis of dog femora by the following steps: (1) acid demineralization of bone powder, (2) solid-phase extraction of acid-soluble proteins on Sep-Pak C18 cartridges, (3) gel filtration on Sephadex G-50, and (4) fast protein liquid chromatography on an Accell-QMA anion-exchange column. Starting from 30 g washed bone powder, approximately 7-10 mg pure protein was obtained in 2 days. The key step is the initial solid-phase extraction of osteocalcin from a large volume of a demineralized bone solution. The primary structure was established by automated sequence analyses of two tryptic peptides, of two endoproteinase Glu-C carboxy-terminal peptides, and of the first 30 amino acid residues of the intact protein. Dog osteocalcin contains 49 amino acids, has a molecular mass of 5654 daltons, contains no Thr, Met, Hyp, or Trp, has a disulfide bond between Cys 23 and 29, and is fully gamma-carboxylated at residues 17, 21, and 24. Dog osteocalcin does not contain a pair of basic amino acids found at positions 43-44 in most other osteocalcins from mammals and birds. A computer search for homology indicated 88, 90, 84, 88, 66, and 57% sequence identity of dog osteocalcin with human, bovine, cat, monkey, chicken, and swordfish osteocalcin, respectively, and weaker homologies with the gamma-carboxylated domains of blood-clotting proteins and the Pro-rich N-terminal extensions of myosin light-chain A1 and beta-crystalline B1. The possible relevance of these homologies to the structure and potential functions of osteocalcin is discussed.

Development and characterization of a polyclonal antiserum-based radioimmunoassay for dog osteocalcin

Determination of the serum concentration of the protein osteocalcin (OC) is useful for the noninvasive evaluation of bone metabolism. Because the dog is an excellent experimental model for the study of bone, we produced and characterized a polyclonal antiserum specific for dog OC and used it to develop a radioimmunoassay (RIA) for the measurement of the concentration of this protein in dog serum. The antiserum expresses higher affinity for Ca(2+)-bound than for Ca(2+)-free OC (B50 at 10(-5) versus 2 x 10(-4) dilution). Also, in the presence of Ca2+ affinity is higher for the carboxylated than for the decarboxylated form of the protein, and under Ca(2+)-free conditions the affinity is equal for the two forms. The study of peptide fragments of OC demonstrates competitive binding of the peptide comprising amino acids 20-44 but not of other fragments; this suggests that the antigenic epitope of dog OC is located in the midmolecular region of the protein. The RIA displays excellent sensitivity for the measurement of OC in blood (detection limit 0.31 ng/ml), with intraassay and interassay variations of 4.6 and 6.8%, respectively. Analysis of gel chromatography fractions of normal dog serum shows that greater than 90% of the antigenic material coelutes with purified radiolabeled dog OC. Test of parallelism reveals lack of interference of serum constituents with the binding assay. The antiserum displays limited species specificity since it cross-reacts with human OC, but not with the protein from rodents.(ABSTRACT TRUNCATED AT 250 WORDS)

Direct assay of membrane-associated protein kinase C activity in B lymphocytes in the presence of Brij 58

This paper describes a simple and direct procedure for assaying Ca(2+)-dependent protein kinase C (PKC) activity in membrane fractions isolated from purified murine B lymphocytes (B cells) treated with phorbol 12-myristate 13-acetate (PMA). The results indicate that membrane-bound PKC in B cells, treated with PMA, can be measured directly in the presence of 0.5% Brij 58 by assaying the transfer of 32P from [gamma-32P]ATP to histone type III-S. This method obviates the need for partial purification of the protein kinase by ion-exchange chromatography prior to assaying PKC activity. The properties of membrane-associated PKC activity in B cells have been characterized, and the kinetics of PMA-induced translocation of PKC in cultured murine B cells, the rat glial tumor clone C6, and primary neonatal osteoblastic cells have been defined by this direct assay. The results obtained with B cells and the other cell lines indicate that this direct assay procedure could be useful for studies on the factors controlling PKC translocation in a variety of cultured mammalian cells.

Dose-dependent effects of aluminum on osteocalcin synthesis in osteoblast-like ROS 17/2 cells in culture

This in vitro study evaluates the effect of aluminum (Al3+) on osteocalcin, a small protein that is produced by the osteoblast. After stimulation with various doses of 1,25-dihydroxyvitamin D3 [1,25(OH)2D3; 10(-11) to 10(-9) M], osteocalcin was consistently lower in the culture medium of ROS 17/2 osteoblastic cells conditioned with 5 microM Al(3+)-saturated transferrin (AlTR) than in apotransferrin (ApoTR)-treated controls. In a second experiment, cultures were conditioned with various doses of AlTR or ApoTR (1.6-8.0 microM) and stimulated with 10(-9) M 1,25(OH)2D3. High doses of AlTR (4.8-8.0 microM) resulted in lower medium and unchanged intracellular content of osteocalcin than treatment with equal amounts of ApoTR. However, in the same experiment, lower doses of AlTR or ApoTR (1.6 and 3.2 microM) yielded different results, i.e., increased medium and intracellular contents of osteocalcin in the Al(3+)-treated cells. Expression of osteocalcin mRNA was not altered in cultures conditioned with low (1.6 microM) or high (8.0 microM) concentrations of AlTR or ApoTR. Similarly, no effect of Al3+ was observed on total protein content, the rate of total protein synthesis, and the degradation of secreted osteocalcin in cultures conditioned with various doses of AlTR or ApoTR. These findings suggest that AlTR affects osteocalcin synthesis in a specific manner, without concomitant effects on the rate of total protein synthesis or on the rate of degradation of osteocalcin. This effect is dose dependent, i.e., low doses of AlTR stimulate and high doses suppress osteocalcin synthesis and/or secretion, and it appears to be posttranscriptional, since the expression of osteocalcin mRNA is not affected.

Biochemical Evidence of Metabolic Bone Disease in Women Following Roux-Y Gastric Bypass for Morbid Obesity

Twenty-six female patients were recalled for examination 10 years after a Roux-Y gastric bypass (RGB) procedure for morbid obesity, to determine whether there was biochemical and/or bone densitometry evidence of metabolic bone disease. These patients were compared with seven control patients who had achieved weight loss by dietary restriction. The serum calcium (4.3 +/- 0.03 vs 4.6 +/- 0.06 mEq/l; p = 0.002) was decreased in the RGB group. Both the serum alkaline phosphatase level (121.0 +/- 7.6 vs 87.3 +/- 8.3 U/I; p = 0.018) and the serum osteocalcin (12.6 +/- 1.2 vs 9.5 +/- 1.9 µg/ml; p = 0.078) level increased in the RGB group. The 1,25(OH) vitamin D level (50.5 +/- 2.5 vs 40.5 +/- 4.9 pg/ml; p = 0.152) was similar for both groups; the 25(OH) vitamin D level (24.3 +/- 1.6 vs 35.9 +/- 3.4 ng/ml; p = 0.008) was decreased in the RGB group as compared with the control group. Bone mineral density was elevated in three of the lumbar measurement sites, and marginally decreased (0.90 +/- 0.02 g/cm(2) vs 1.03 +/- 0.06 g/cm(2); p = 0.067) in the femoral neck of the RGB group compared with the controls. This biochemical pattern suggests the development of metabolic bone disease following the RGB.

Regulation of 25-hydroxyvitamin D3 metabolism in cultures of osteoblastic cells

This study was designed to investigate the mechanisms involved in the regulation of the conversion of 25-hydroxyvitamin D3 (25-OHD3) to 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] and 24,25-dihydroxyvitamin D3 [24,25-(OH)2D3] in primary cultures of osteoblastlike cells from neonatal mouse calvariae. These cells, when incubated with tritiated 25-OHD3 ([3H]25-OHD3), spontaneously synthesized [3H]24,25-(OH)2D3 20-50 times more efficiently than [3H]1,25-(OH)2D3 at a rate of conversion that was substrate dependent and linear from 1 to 36 h. Gas chromatography-mass spectrometry verified the identity of the dihydroxylated metabolites. The calcium ionophore A23187 (5 microM) consistently stimulated the synthesis of 1,25-(OH)2D3 while suppressing the production of 24,25-(OH)2D3. This effect was sustained for 36 h and was dose dependent for concentrations from 0.05 to 10 microM. Furthermore, A23187 stimulated cAMP production and indomethacin (50 ng/ml) blocked the A23187-induced production of cAMP and 1,25-(OH)2D3 but had no effect on the suppression of 24,25-(OH)2D3 by A23187. This led to other experiments to find out whether the stimulative effect of A23187 on 1,25-(OH)2D3 synthesis is mediated by prostaglandins or cAMP, or both. PGE2 (10(-8)-10(-6) M) increased the production of 1,25-(OH)2D3 and of 24,25-(OH)2D3. Forskolin (0.01-10 microM) and dibutyryl cAMP (0.1-10 mM) increased the production of both metabolites but to a lesser degree than PGE2. These data suggest that osteoblastlike cells are stimulated by A23187 to increase the synthesis of 1,25-(OH)2D3 through mechanisms involving prostaglandins and cAMP. The synthesis of 24,25-(OH)2D3 is suppressed by A23187 through different mechanisms.

Bone changes occurring early after cessation of ovarian function in beagle dogs: a histomorphometric study employing sequential biopsies

The beagle dog model has been established by our laboratory as a useful animal model to study bone loss after cessation of ovarian function. Previously we demonstrated bone loss associated with an osteoblastic insufficiency at 4 months after ovariohysterectomy (OHX). This study was designed to evaluate by four sequential monthly bone biopsies the development and course of the histologic bone abnormalities after OHX. We found cancellous bone volume, trabecular density, and wall thickness to be decreased (p less than 0.05) and trabecular separation increased (p less than 0.05) as early as 1 month after OHX. After 2 months, there was a decrease in mineralizing surface and mineral apposition rate (p less than 0.05). Volume and surface of osteoid were increased after 3 months (p less than 0.05), and there was an increase in the number of osteoblasts (p less than 0.01). No histologic signs of increased resorption were observed during the experiment. However, the findings of low bone volume with decreased trabecular density and increased separation without a change in trabecular plate thickness 4 weeks after OHX suggest that a dramatic increase in resorption must have taken place soon after OHX. These results point to an early phase of initiation of bone loss related to hyperresorption followed by a maintenance phase of low bone mass ascriblastic insufficiency. The events that stimulate the early initiating phase after cessation of ovarian function, the factors contributing to it, and the direct demonstration of hyperresorption await further studies.

Early therapy of renal bone disease with calcitriol: a prospective double-blind study

The value of calcitriol administration in the management and prevention of renal bone disease was studied in a prospective double-blind manner in 16 patients with chronic renal impairment (creatinine clearance 20 to 59 ml per min). They were given either calcitriol at a dose of 0.25 to 0.5 micrograms daily (eight patients), or placebo. Transiliac crest bone biopsies were performed before entrance into the study and after 12 months of experimental observation. None of the patients were symptomatic or had biochemical or radiological evidence of bone disease. Of the thirteen patients who completed the study, initial serum 1,25(OH)2D levels were low in seven patients and parathyroid hormone levels were elevated in seven patients. Bone histology was abnormal in all patients. Calcitriol treatment was associated with a significant fall in serum phosphorus concentrations and alkaline phosphatase levels as well as with histological evidence of an amelioration of hyperparathyroid changes. In contrast to previous reports, no deterioration of renal function attributable to the treatment occurred, perhaps because a modest dose of calcitriol was employed combined with meticulous monitoring. Further investigation is required to determine whether alternative therapeutic strategies (smaller doses or intermittent therapy) may avoid the potential for suppressing bone turnover to abnormally low levels in the long term.

1,25(OH)2D3 administration in moderate renal failure: a prospective double-blind trial

This study represents the first randomized prospective, double-blind, placebo-controlled trial of the efficacy of 1,25(OH)2D3 on bone histology and serum biochemistry in patients with mild to moderate renal failure. Sixteen patients with chronic renal impairment (creatinine clearance 20 to 59 ml per min) received either 1,25(OH)2D3, at a dose of 0.25 to 0.5 microgram daily (eight patients), or placebo. Transiliac crest bone biopsies were performed before entrance into the study and after 12 months of experimental observation. None of the patients were symptomatic or had radiological evidence of bone disease. Of the thirteen patients who completed the study, initial serum 1,25(OH)2D levels were low in seven patients and parathyroid hormone levels were elevated in seven patients. Bone histology was abnormal in all patients. 1,25(OH)2D3 treatment was associated with a significant fall in serum phosphorus and alkaline phosphatase concentrations as well as with histological evidence of an amelioration of hyperparathyroid changes. In contrast to previous reports, no deterioration of renal function attributable to the treatment occurred, perhaps because a modest dose of 1,25(OH)2D3 was employed combined with meticulous monitoring. Further investigation is required to determine whether alternative therapeutic strategies (smaller doses or intermittent therapy) may avoid the potential for suppressing bone turnover to abnormally low levels in the long term.

Nail involvement in lichen planopilaris

A patient with lichen planopilaris with peculiar leukonychia is described. The histologic findings from examination of the nail biopsy specimen are discussed.

1,25-dihydroxyvitamin D3 corrects bone loss but suppresses bone remodeling in ovariohysterectomized beagle dogs

The decrease in intestinal calcium absorption and lower blood levels of 1,25-dihydroxyvitamin D [1,25-(OH)2D3] have been implicated in the pathogenesis of postmenopausal osteoporosis. This study evaluates the effects on bone of 1,25-(OH)2D3 therapy using the ovariohysterectomized dog model. The cessation of ovarian function was ascertained by an increase in serum LH levels 4 weeks after ovariohysterectomy, and significant bone loss was revealed four months after ovariohysterectomy. The bone loss was associated with an increase in the number of bone-forming cells and a decrease in the activity of these cells. The administration of 1,25-(OH)2D3 increased the activity of the bone cells and resulted in a reversal of all abnormalities in structural parameters of bone, including cancellous bone mass, trabecular wall thickness, trabecular plate separation, trabecular plate density, and trabecular plate thickness (which increased above normal). However, 1,25-(OH)2D3 therapy was also associated with a significant decrease in the number of bone-forming cells, resulting in lower bone formation at the tissue level. The results of this study indicate that 1,25-(OH)2D3 therapy can reverse the bone loss and osteoblastic insufficiency responsible for the maintenance of negative bone balance after the cessation of ovarian function. However, this therapy has a suppressive effect on bone cell number and bone turnover. This undesired side-effect of 1,25-(OH)2D3 therapy renders a chronic therapeutic regimen inefficient for the long term management of patients with osteoporosis. Intermittent 1,25-(OH)2D3 therapy or a sequential therapy using 1,25-(OH)2D3 along with substances known to increase the number of bone-forming cells is strongly suggested by these results.

Unusual severe nail involvement in dermatomyositis

An unusual case of nail involvement in dermatomyositis in which complete loss of several toenails was the only cutaneous sign of the disease is reported for its clinical interest.

Calcitriol, parathyroid hormone, and accumulation of aluminum in bone in dogs with renal failure

Accumulation of aluminum in bone is a frequent finding in patients requiring chronic dialysis and is associated with considerable morbidity and/or mortality. Until now, evidence seemed to point to relatively low circulating levels of parathyroid hormone as a contributing factor, but because levels of parathyroid hormone and calcitriol are interrelated, calcitriol might be also involved. In this study we employed an animal model to evaluate the single and combined effects of parathyroid hormone and calcitriol on bone aluminum accumulation. The results show significantly less aluminum accumulation in calcitriol-replete dogs independent of the presence or absence of parathyroid hormone. These results indicate that low levels of calcitriol may play a role in the development of aluminum related bone disease. Further studies are needed to demonstrate whether administration of calcitriol in patients with renal insufficiency will prevent development of aluminum-related bone disease.

1,25-Dihydroxyvitamin D maintains bone cell activity, and parathyroid hormone modulates bone cell number in dogs

The singular and combined effects of 1,25-dihydroxyvitamin D [1,25-(OH)2D] and PTH on bone were evaluated in a long term in vivo study in dogs. Dogs were rendered deficient in 1,25-(OH)2D and PTH by five sixths nephrectomy and parathyroidectomy. A control group was sham operated. Various combinations in status of 1,25-(OH)2D and PTH were produced by daily sc injections of 1,25-(OH)2D (1.25) and/or continuous infusion of 1-34 bovine PTH. These were 1.25+/PTH+, 1.25-/PTH-, 1.25+/PTH-, 1.25-/PTH+. Serum calcium levels were kept in the normal range by the administration of one or two of the hormones or by oral supplementation of calcium lactate. Histomorphometric evaluation of static and dynamic parameters of bone after 8 months of experimental observation revealed that deficiency in 1,25-(OH)2D and PTH resulted in decreased number and activity of bone-forming and resorbing cells. Administration of 1,25-(OH)2D increased the activity but not the number of bone cells. In contrast, administration of PTH increased the number but not the activity of bone cells. Tissue level activity was decreased when one or both hormones were deficient, and normal tissue level activity was found only when both hormones were given. These data are relevant for understanding and management of diseases with perturbations in vitamin D and/or PTH.

Effects of parathyroidectomy on circulating levels of 1 alpha,25-dihydroxyvitamin D and bone Gla protein in dialyzed patients

The effects of decreasing serum levels of PTH after parathyroidectomy on circulating levels of 1 alpha,25-dihydroxyvitamin D [1,25-(OH)2D] and bone Gla protein (BGP) were studied in seven patients treated with chronic maintenance dialysis. Before surgery, all patients had extremely elevated levels of PTH, low normal or low levels of 1,25-(OH)2D, high levels of BGP, and histological signs of excess PTH action on bone. The fall in PTH levels after surgery resulted in a further decline in 1,25-(OH)2D concentrations and a reduction in circulating BGP levels. This fall in serum 1,25-(OH)2D and BGP levels was not related to serum calcium or phosphorus. Administration of 1,25-(OH)2D3 from 4-6 months after surgery did not significantly affect serum levels of BGP or PTH. These data indicate that 1,25-(OH)2D is still under regulatory control of PTH in patients without excretory kidney function. This might reflect some remaining endocrine activity of the kidneys in these dialyzed patients or extrarenal production of 1,25-(OH)2D. In addition, the data show that serum BGP levels in renal failure are elevated due not only to impaired clearance but also to PTH-mediated acceleration in bone turnover. Therapy with 1,25-(OH)2D3 in these patients resulted in supraphysiological serum 1,25-(OH)2D levels which did not stimulate BGP production.

Aluminum-related bone disease in mild and advanced renal failure: evidence for high prevalence and morbidity and studies on etiology and diagnosis

To study aluminum-related bone disease, bone biopsies and serum biochemical measurements were done in 97 patients on maintenance dialysis and in 100 patients with mild to moderate renal failure. Bone histology, histochemical staining for aluminum and determination of bone aluminum content were done. Stainable bone aluminum was found in 50% of dialyzed patients and in 5% of nondialyzed patients. The finding of stainable bone aluminum in dialyzed patients was associated with high morbidity and mortality; it was not only seen in most patients with low turnover osteomalacia, but also in 47% of patients with mixed uremic osteodystrophy and in 1 patient with predominant hyperparathyroid bone disease. Patients with stainable aluminum had lower bone mass and decreased activity of bone-forming and -resorbing cells. Cumulative doses of aluminum-containing phosphate binders were a major risk factor. Aluminum in drinking water represents an additional risk factor. Neither serum biochemical tests nor single infusion of deferoxamine could be employed as diagnostic tools. Bone biopsies were the only means for diagnosis.

Role of parathyroid hormone in the glucose intolerance of chronic renal failure

Evidence has accumulated suggesting that the state of secondary hyperparathyroidism and the elevated blood levels of parathyroid hormone (PTH) in uremia participate in the genesis of many uremic manifestations. The present study examined the role of PTH in glucose intolerance of chronic renal failure (CRF). Intravenous glucose tolerance tests (IVGTT) and euglycemic and hyperglycemic clamp studies were performed in dogs with CRF with (NPX) and without parathyroid glands (NPX-PTX). There were no significant differences among the plasma concentrations of electrolytes, degree of CRF, and its duration. The serum levels of PTH were elevated in NPX and undetectable in NPX-PTX. The NPX dogs displayed glucose intolerance after CRF and blood glucose concentrations during IVGTT were significantly (P less than 0.01) higher than corresponding values before CRF. In contrast, blood glucose levels after IVGTT in NPX-PTX before and after CRF were not different. K-g rate fell after CRF from 2.86 +/- 0.48 to 1.23 +/- 0.18%/min (P less than 0.01) in NPX but remained unchanged in NPX-PTX (from 2.41 +/- 0.43 to 2.86 +/- 0.86%/min) dogs. Blood insulin levels after IVGTT in NPX-PTX were more than twice higher than in NPX animals (P less than 0.01) and for any given level of blood glucose concentration, the insulin levels were higher in NPX-PTX than NPX dogs. Clamp studies showed that the total amount of glucose utilized was significantly lower (P less than 0.025) in NPX (6.64 +/- 1.13 mg/kg X min) than in NPX-PTX (10.74 +/- 1.1 mg/kg X min) dogs. The early, late, and total insulin responses were significantly (P less than 0.025) greater in the NPX-PTX than NPX animals. The values for the total response were 143 +/- 28 vs. 71 +/- 10 microU/ml, P less than 0.01. There was no significant difference in the ratio of glucose metabolized to the total insulin response, a measure of tissue sensitivity to insulin, between the two groups. The glucose metabolized to total insulin response ratio in NPX (5.12 +/- 0.76 mg/kg X min per microU/ml) and NPX-PTX (5.18 +/- 0.57 mg/kg X min per microU/ml) dogs was not different but significantly (P less than 0.01) lower than in normal animals (9.98 +/- 1.26 mg/kg X min per microU/ml). The metabolic clearance rate of insulin was significantly (P less than 0.02) reduced in both NPX (12.1 +/- 0.7 ml/kg X min) and NPX-PTX (12.1 +/- 0.9 ml/kg X min) dogs, as compared with normal animals (17.4 +/- 1.8 ml/kg X min). The basal hepatic glucose production was similar in both groups of animals and nor different from normal dogs; both the time course and the magnitude of suppression of hepatic glucose production by insulin were similar in both in groups. There were no differences in the binding affinity, binding sites concentration, and binding capacity of monocytes to insulin among NPX, NPX-PTX, and normal dogs. The data show that (a) glucose intolerance does not develop with CRF in the absence of PTH, (b) PTH does not affect metabolic clearance of insulin or tissue resistance to insulin in CRF, and (c) the normalization of metabolism in CRF in the absence of PTH is due to increased insulin secretion. The results indicate that excess PTH in CRF interferes with the ability of the beta-cells to augment insulin secretion appropriately in response to the insulin-resistant state.

Plasma levels of bone Gla-protein reflect bone formation in patients on chronic maintenance dialysis

Predictive value of plasma levels of bone Gla-protein (BGP) for bone histology was evaluated in 30 chronically dialyzed patients. All patients underwent bone biopsies and serum biochemical parameters, including BGP, parathyroid hormone, and alkaline phosphatase; calcium and phosphate were measured at the time of biopsy. Bone histology showed renal osteodystrophy with low bone turnover and osteomalacia (LT-ROD) in 13 patients, and renal osteodystrophy with high bone turnover and prevailing hyperparathyroid bone disease (HT-ROD) in 17 patients. Values for BGP were above normal in LT-ROD (47.3 +/- 7.9 vs. 6.8 +/- 0.2 ng/ml) and extremely elevated in HT-ROD (831 +/- 170 ng/ml). Similar differences were not found with the other serum biochemical parameters, even though BGP correlated with parathyroid hormone (r = 0.64) and alkaline phosphatase (r = 0.85). There were significant correlations between BGP and cellular and non-cellular parameters of bone formation (r = 0.73 to 0.91). Weaker or no correlations were found between BGP and histologic parameters of bone, reflecting mainly mineralization or resorption. These correlations and the finding of significant differences in plasma BGP between LT-ROD and HT-ROD indicate that plasma levels of BGP reflect bone formation in uremia and predict underlying bone histology.

[Clinical study of the efficacy of oral potassium canrenoate and spironolactone in essential arterial hypertension]

A group of 13 male and 8 female out-patients (mean age: 40.57 years), with primary arterial hypertension, was submitted to two periods of treatment in a cross-over study with spironolactone and potassium canrenoate. Each preparation was given at the dose of 200 mg/day per os for 21 days, with a 10-day interval between treatments. Both preparations proved active on the systolic and diastolic pressure values controlled 7 days. However, potassium canrenoate showed a greater and more rapid effect, particularly on diastolic arterial pressure, as also demonstrated by the statistical analyses. PRA and aldosteronemia increased with both treatments, but this increase resulted significantly lower with potassium canrenoate. The minor stimulating action on the renin-angiotensin-aldosterone mechanism by potassium canrenoate may be the reason for its greater anti-hypertensive effect. Both treatments were perfectly tolerated locally and systemically.

[First experience with highly hydrophilic therapeutic soft contact lenses (With special reference to herpetic corneal disease) (author's transl)]

74 therapeutic problem-cases of various corneal diseases were treated with the highly hydrophilic Weicon 72 (W 72) which proved to be a valuable therapeutic tool. Additional applications of hypertonic saline and of industrial preparations of steroids, antivirals and antibiotics were tolerated without observable side effects. Additional therapy is often inevitable to achieve an optimal therapeutic effect. Nearly all treated cases of chronic herpetic keratitis - mainly metaherpetic corneal diseases - responded well or excellently to W 72 therapy. If, however, the indication for soft lens therapy is somehow inadequate, if additional therapy is wrong or not applied at all and if the patient does not keep strictly to the therapeutic regime undesired side effects are likely to develop.