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C J Lees

Publications and source records attributed to C J Lees.

At least 19 recordsLinked to original sources
PubMed2004

Multisystem evaluations of the long-term effects of tibolone on postmenopausal monkeys.

This long-term study (2 years) was designed to compare the effects of tibolone (LoTib at 0.05 mg/kg and HiTib at 0.2 mg/kg) with those of conjugated equine oestrogens (CEE) alone (0.042 mg/kg) and CEE continuously combined with medroxyprogesterone acetate (MPA) (0.167 mg/kg) on coronary artery atherosclerosis, bone, mammary gland and uterus in ovariectomised cynomolgus monkeys fed a moderately atherogenic diet. Despite reductions in plasma concentrations of high density lipoprotein cholesterol in tibolone-treated monkeys, there was no exacerbation of coronary artery atherosclerosis. Tibolone was equivalent to, or slightly better than, CEE and CEE + MPA in protecting against postmenopausal bone loss and loss of bone strength. Tibolone also resulted in less stimulation of breast and endometrial tissue compared with CEE and CEE + MPA. In conclusion, the results suggest that tibolone is a cardiovascular-safe treatment that is effective for the prevention of osteoporosis and that may have advantages over CEE or CEE + MPA with regard to endometrial and breast safety.

Animals↗
PubMed2001

Requirements for the promotion of allogeneic engraftment by anti-CD154 (anti-CD40L) monoclonal antibody under nonmyeloablative conditions.

The promotion of alloengraftment in the absence of global immune suppression and multiorgan toxicity is a major goal of transplantation. It is demonstrated that the infusion of a single modest bone marrow dosage in 200 cGy-irradiated recipients treated with anti-CD154 (anti-CD40L) monoclonal antibody (mAb) resulted in chimerism levels of 48%. Reducing irradiation to 100 or 50 cGy permitted 24% and 10% chimerism, respectively. In contrast, pan-T-cell depletion resulted in only transient engraftment in 200 cGy-irradiated recipients. Host CD4(+) cells were essential for alloengraftment as depletion of CD4(+) cells abrogated engraftment in anti-CD154-treated recipients. Strikingly, the depletion of CD8(+) cells did not further enhance engraftment in anti-CD154 mAb-treated recipients in a model in which rejection is mediated by both CD4(+) and CD8(+) T cells. However, anti-CD154 mAb did facilitate engraftment in a model in which only CD8(+) T cells mediate rejection. Furthermore, CD154 deletional mice irradiated with 200 cGy irradiation were not tolerant of grafts, suggesting that engraftment promotion by anti-CD154 mAb may not simply be the result of CD154:CD40 blockade. Together, these data suggest that a CD4(+) regulatory T cell may be induced by anti-CD154 mAb. In contrast to anti-CD154 mAb, anti-B7 mAb did not promote donor engraftment. Additionally, the administration of either anti-CD28 mAb or anti-CD152 (anti-CTLA-4) mAb or the use of CD28 deletional recipients abrogated engraftment in anti-CD154 mAb-treated mice, suggesting that balanced CD28/CD152:B7 interactions are required for the engraftment-promoting capacity of anti-CD154 mAb. These data have important ramifications for the design of clinical nonmyeloablative regimens based on anti-CD154 mAb administration.

Animals↗
PubMed2001

Levormeloxifene prevents increased bone turnover and vertebral bone loss following ovariectomy in cynomolgus monkeys.

Levormeloxifene, a nonsteroidal selective estrogen receptor modulator (SERM), has been evaluated for its effects on bone in cynomolgus monkeys (Macaca fascicularis). Adult female monkeys were imported from Indonesia and randomized into six groups of 25-28 animals each (n = 158). Animals in one group were sham ovariectomized (sham) and received vehicle. Animals in the remaining five groups were ovariectomized and received either vehicle (ovx); 17beta-estradiol at 0.016 mg/kg (est); or levormeloxifene at 0.5 (L1), 1 (L2), or 5 (L3) mg/kg. Lumbar spine and whole body bone mass were measured by dual-energy X-ray absorptiometry (DXA) pretreatment and at 6 and 12 months following the initiation of treatment. Bone mass at the femoral neck was measured by peripheral quantitative computed tomography (pQCT) at 0 and 12 months. Serum markers of bone turnover, including bone-specific alkaline phosphatase (BSAP), osteocalcin (BGP), tartrate-resistant acid phosphatase (TRAP), and urinary collagen C-terminal extension peptides (CrossLaps), were measured at 0, 6, and 12 months. Ovariectomy resulted in an increase in these markers; the increase was prevented by estradiol or levormeloxifene. Estradiol or levormeloxifene inhibited loss of lumbar spine bone mineral density (BMD) following ovariectomy compared with untreated monkeys (ovx -5.0%; sham -0.4%; est +0.2%; L1 -3.6%, L2 -2.0%, L3 -2.5%). Estradiol, but not levormeloxifene, prevented loss of BMD at the femoral neck (ovx -7.4%; sham -3.1%; est -3.6%; L1 -8.0%, L2 -6.5%, L3 -7.8%), and whole body bone mineral content (BMC) (ovx -7.6%; sham -1.9%, est -2.9%; L1 -6.2%, L2 -6.1%, L3 -6.7%). Bone loss at each site was correlated with bone turnover as measured by serum and urine biomarkers. There was no dose effect of levormeloxifene.

Animals↗
PubMed2000

Host T cells resist graft-versus-host disease mediated by donor leukocyte infusions.

Delayed lymphocyte infusions (DLIs) are used to treat relapse occurring post bone marrow transplantation (BMT) and to increase the donor chimerism in recipients receiving nonmyeloablative conditioning. As compared with donor lymphocytes given early post-BMT, DLIs are associated with a reduced risk of graft-vs-host disease (GVHD). The mechanism(s) responsible for such resistance have remained incompletely defined. We now have observed that host T cells present 3 wk after lethal total body irradiation, at the time of DLI, contribute to DLI-GVHD resistance. The infusion of donor splenocytes on day 0, a time when host bone marrow (BM)-derived T cells are absent, results in greater expansion than later post-BMT when host and donor BM-derived T cells coexist. Selective depletion of host T cells with anti-Thy1 allelic mAb increased the GVHD risk of DLI, indicating that a Thy1(+) host T cell regulated DLI-GVHD lethality. The conditions by which host T cells are required for optimal DLI resistance were determined. Recipients unable to express CD28 or 4-1BB were as susceptible to DLI-GVHD as anti-Thy1 allelic mAb-treated recipients, indicating that CD28 and 4-1BB are critical to DLI-GVHD resistance. Recipients deficient in both perforin and Fas ligand but not individually were highly susceptible to DLI-GVHD. Recipients that cannot produce IFN-gamma were more susceptible to DLI-GVHD, whereas those deficient in IL-12 or p55 TNFRI were not. Collectively, these data indicate that host T cells, which are capable of generating antidonor CTL effector cells, are responsible for the impaired ability of DLI to induce GVHD. These same mechanisms may limit the efficacy of DLI in cancer therapy under some conditions.

Animals↗
PubMed2000

Immunotherapy with mannan-MUC1 and IL-12 in MUC1 transgenic mice.

Mice immunised with oxidised mannan-MUC1 fusion protein (M-FP) develop MHC restricted CD8(+) cytotoxic T cells. We now demonstrate that in MUC1/HLA-A2 transgenic mice, IL-12 gives enhanced CTL, CTLp and tumor protection. CTLp in MUC1 transgenic mice with M-FP were 1/55,000, and with IL-12, this increased to 1/19,000, with improved tumor protection. Thus, IL-12 is important for effective CTL responses to MUC1 in transgenic mice.

Animals↗
PubMed2000

The effect of T1 and T2 cytokines on the cytotoxic T cell response to mannan-MUC1.

MUC1 is a mucin over-expressed in breast cancer and a proposed target for immunotherapy. By immunising mice with MUC1 conjugated to mannan (M-FP), CD8(+) MHC-class-I restricted cytotoxic T lymphocytes (CTL), of high CTL precursor (CTLp) frequency (1/8000) and with significant tumour protection, can be induced. The effect of various cytokines [interleukin-2 (IL-2), IL-4, IL-6, IL-7, interferon gamma (IFNgamma), and granulocyte/macrophage-colony-stimulating factor (GM-CSF)] on the MUC1 CTL immune response was investigated (a) by measuring the frequencies of CTLp in mice immunised with vaccinia virus constructs containing recombinant cytokines and M-FP, or (b) by immunising cytokine- or cytokine-receptor-knockout (-/-) mice with M-FP. Vaccinia virus (VV) constructs containing recombinant cytokines were used either individually or in combination in vivo with M-FP immunisation. M-FP immunisations combined with VV-IL-2, VV-IL-7 and VV-GM-CSF, and combinations of VV-IFNgamma + VV-IL-2, VV-IFNgamma + VV-IL-4 or VV-GM-CSF + VV-IL-7 increased CTLp frequencies up to threefold (1/17 666: M-FP + VV-GM-CSF + VV-IL-7) compared to M-FP (1/77 500) alone. By contrast, M-FP combined with VV-IL-4 decreased the CTLp frequency threefold whereas VV-IL-6 and VV-IFNgamma had no effect. Studies in cytokine- and cytokine-receptor-gene-knockout (-/-) mice demonstrated that mice that are IL-2 -/- and IL-7 receptor -/- produce the same CTLp response to M-FP as do control mice, whereas responses in the IL-6 -/-, IL-10 -/- and IFNgamma -/- mice were marginally improved and responses to M-FP in IL-4 -/- and tumour necrosis factor receptor 2 -/- mice were weaker. In spite of the increase in CTLp frequency, this was not reflected in an in vivo tumour model. Tumour challenges using MUC1(+) P815 cells, demonstrated that the addition of cytokines had little additive effect on the already effective tumour-regression capabilities of M-FP alone.

Amino Acid Sequence↗
PubMed1999

Histomorphometry and bone biomarkers in cynomolgus females: a study in young, mature, and old monkeys.

Although ovariectomized cynomolgus monkeys are used extensively for studies examining perimenopausal changes in the skeleton, very little is known about the changes that occur naturally during growth and aging in these animals. To evaluate the changes in bone during growth and aging in female cynomolgus monkeys, 29 monkeys ranging from 3 years to >22 years of age were given a bone fluorochrome label and iliac biopsies were collected. Serum and urine were collected at the time of biopsy to determine alkaline phosphatase (ALP), osteocalcin, tartrate-resistant acid phosphatase (TRAP), serum and urinary calcium, estradiol, urinary creatinine, and urinary CrossLaps levels. The biopsies from 8 young (3-4 years of age), 13 mature (11-16 years of age) and 8 old (>22 years of age) were analyzed histomorphometrically. ALP, TRAP, and urinary CrossLaps levels were lower in the mature and old monkeys when compared with the young group. Urinary calcium/urinary creatinine levels increased with age. Bone volume (BV/TV), trabecular number (Tb.N), bone formation rate (BFR), and activation frequency (Ac.f) were greatest in the young monkeys and declined in the older groups. The biomarker and histomorphometric indices in the young animals reflect the growth that was occurring in this group. The older monkeys do not appear to differ significantly between 10 and 22 years of age.

Acid Phosphatase↗
PubMed1999

Effect of treatment for 6 months with human parathyroid hormone (1-34) peptide in ovariectomized cynomolgus monkeys (Macaca fascicularis).

A potential negative side effect of intermittent parathyroid hormone (PTH) therapy to treat osteoporosis is the loss of cortical bone concomitant with increased cancellous bone mass. We addressed this issue by studying the effects of PTH on whole-body, axial, and appendicular bone mass in an animal model with haversian cortical bone remodeling. Ovariectomized, young adult female cynomolgus monkeys were assigned to placebo (n = 9) or PTH groups (n = 10). The PTH group received 10 microg/kg synthetic human PTH(1-34) peptide by subcutaneous injection, 3 days/week for 6 months, and the placebo group received vehicle. Multiple endpoints of bone mass, strength, and turnover in the axial and appendicular skeleton were assessed, including dual-energy X-ray absorptiometry (DEXA), quantitative computed tomography (qCT), analysis of serum (calcium, phosphorus, alkaline phosphatase, osteocalcin, and tartrate-resistant acid phosphatase) and urinary (calcium and creatinine) biomarkers, histomorphometry, and biomechanical testing. Compared with placebo-treated animals, PTH-treated monkeys had no change in whole-body bone mass, but a 6.7% increase in spinal areal bone mineral density (aBMD) was observed. Cortical bone mass measured by qCT at appendicular sites was not affected by PTH treatment, but there were significant increases in cancellous bone mass in the proximal tibia, and a similar trend in the distal radius. Small, transient increases in serum and urinary calcium were observed, but there were no treatment-related effects on other biochemical endpoints. Increased bone formation rate (BFR/BV) in the midradius and midfemur was accompanied by a nonsignificant increase in midfemur porosity. Increased vertebral cancellous bone volume (BV/TV) was associated with greater trabecular and interstitial thickness with no effect on wall thickness. Increases in bone strength were observed in both axial (vertebral maximum stress and load at fracture) and appendicular (femoral neck fracture load) skeleton. Together, these results indicate that PTH therapy in the cynomolgus monkey results in a net gain of spinal and appendicular cancellous bone mass with no adverse effect on cortical bone.

Absorptiometry, Photon↗
PubMed1999

Cytokine production from murine CD4 and CD8 cells after mannan-MUC1 immunization.

Immunotherapy with oxidized mannan-MUC1 fusion protein (M-FP) leads to a T1 immune response characterized by the generation of cytotoxic T lymphocytes (CTL), few antibodies, secretion of interleukin-2 (IL-2), IL-12, and interferon-gamma and tumor protection. Immunotherapy with reduced M-FP or fusion protein (FP) alone leads to a T2 immune response characterized by the generation of MUC1 antibodies, few CTL, IL-4 secretion, and no tumor protection. In these studies, cytokine production from T cells was measured from cultures containing whole spleens. We now report the cytokine secretion patterns from spleen cells separated into CD4+ and CD8+ T cells obtained from mice immunized with either oxidized M-FP, reduced M-FP or FP, or the simultaneous administration of oxidized M-FP and FP. Immunization with oxidized M-FP led to the secretion of T1 cytokines from CD8+ T cells (IL-2, IFN-gamma, and tumor necrosis factor-alpha [TNF-alpha]) and from CD4+ T cells (IL-2 and IFN-gamma). IL-12 production, presumably from activated macrophages, was observed in CD8+ but not CD4+ cultures. Immunization with either reduced M-FP or FP led to the secretion of predominantly T2 cytokines from CD4+ T cells (IL-4 and IL-10) and IL-2 production in both CD4+ and CD8+ T cell cultures. The simultaneous immunization of both oxidized M-FP and FP led to the production of both T1 and T2 cytokines from CD8+ T cells (IL-2, IFN-gamma, and TNF-alpha) and CD4+ cells (IL-2, IFN-gamma, IL-4, and IL-10) and IL-12 production in CD8+ cultures that is, both types of immune responses could occur together. The results demonstrate that the cellular immune response observed in oxidized M-FP-immunized mice is indeed dependent on the T1 cytokine profile secreted by CD8+ T cells, and the simultaneous production of both T1 and T2 cytokines is not cross-inhibitory.

Animals↗
PubMed1999

Daily treatment with human recombinant parathyroid hormone-(1-34), LY333334, for 1 year increases bone mass in ovariectomized monkeys.

PTH stimulates bone formation to increase bone mass and strength in rats and humans. The aim of this study was to determine the skeletal effects of recombinant human PTH-(1-34) [rhPTH-(1-34)] in monkeys, as monkey bone remodeling and structure are similar to those in human bone. Adult female cynomolgus monkeys were divided into sham-vehicle (n = 21), ovariectomized (OVX)-vehicle (n = 20), and OVX groups given daily s.c. injections of rhPTH-(1-34) at 1 (n = 39) or 5 (n = 41) microg/kg for 12 months. Whole body bone mineral content was measured, as was bone mineral density (BMD) in the spine, proximal tibia, midshaft radius, and distal radius. Serum and urine samples were also analyzed. rhPTH-(1-34) treatment did not influence serum ionized Ca levels or urinary Ca excretion, but depressed endogenous PTH while increasing serum calcitriol levels. Compared to that in the OVX group, the higher dose of rhPTH-(1-34) increased spine BMD by 14.3%, whole body bone mineral content by 8.6%, and proximal tibia BMD by 10.8%. Subregion analyses suggested that the anabolic effect of rhPTH-(1-34) on the proximal tibia was primarily in cancellous bone. Similar, but less dramatic, effects on BMD were observed with the lower dose of rhPTH-(1-34). Daily s.c. rhPTH-(1-34) treatment for 1 yr increases BMD in ovariectomized monkeys without inducing sustained hypercalcemia or hypercalciuria.

Animals↗
PubMed1998

Soy protein isolate diet does not prevent increased cortical bone turnover in ovariectomized macaques.

Forty-one ovariectomized, cynomolgus monkeys were divided into 4 groups and fed a casein and lactalbumin based diet with or without 17beta-estradiol, or a soy protein based diet with or without 17beta-estradiol for 7 months. Histomorphometry was done on cortical bone from the mid-shaft femur. 17beta-estradiol suppressed ovariectomy-induced increases in bone formation rates, regardless of dietary protein source. Soy protein alone did not prevent increased bone turnover and on the endosteal surface, it actually increased bone turnover when compared to casein/lactalbumin fed monkeys.

Animals↗
PubMed1998

Effects of pregnancy and lactation on bone in cynomolgus macaques: histomorphometric analysis of iliac biopsies.

The effects of pregnancy and lactation on bone histomorphometry have been studied extensively in rats and dogs. However, these models differ greatly in reproductive physiology compared with women. The purpose of this study was to evaluate histomorphometric changes in iliac crest bone biopsies taken from cynomolgus monkeys (Macaca fascicularis), animals similar to women both skeletally and reproductively. After fluorochrome labeling, paired iliac crest bone biopsies were collected and subjected to structural and dynamic histomorphometric analyses during the third trimester and 3 months postpartum in one group (n=16), at 3 and 9 months postpartum in the second group (n=14), and at 4 month intervals in a nonpregnant control group (n=6). Serum was collected at the time of surgery to measure total alkaline phosphatase (ALP), bone gla-protein (BGP), calcium, and estradiol. Trabecular thickness increased significantly between 3 and 9 months postpartum. Bone formation rates did not differ between control and pregnant monkeys, but were significantly increased during lactation (3 months postpartum) and remained elevated at 9 months postpartum. ALP and BGP levels were elevated at 3 months postpartum, compared with levels during pregnancy, and remained elevated at 9 months postpartum. Estradiol concentrations were greatly elevated during pregnancy, dropped below normal nonpregnant levels by 3 months postpartum, and remained suppressed at 9 months postpartum. These results suggest that, during the third trimester, the rate of bone turnover was not altered, but lactational demands for calcium were met in part by increased bone turnover.

Alkaline Phosphatase↗
PubMed1998

Changes in bone mass and bone biomarkers of cynomolgus monkeys during pregnancy and lactation.

A substantial amount of calcium is transferred from the mother to the fetus and infant during pregnancy and lactation. Involvement of the skeleton in meeting this demand should be reflected in changes in bone mass and turnover. The purpose of the study was to determine the effects of pregnancy, lactation, and recovery on the skeleton in 43 young (prepeak bone mass) female monkeys. Whole body (WBBMC) and lumbar vertebrae 2-4 bone mineral content were determined by dual x-ray absorptiometry at baseline and 1, 4, and 10 months postpartum. Alkaline phosphatase, bone Gla protein, and urinary crosslinks were measured at baseline, during the third trimester, and 1, 4, and 10 months postpartum. Compared to nonpregnant, nonlactating monkeys, pregnant monkeys had similar rates of bone mass gain (nonpregnant, nonlactating WBBMC, 25+/-9 mg/day; pregnant WBBMC, 20+/-14 mg/day). Compared to pregnant monkeys, lactating females had increased bone turnover, as indicated by elevated bone biomarker levels (lactating alkaline phosphatase, 259+/-20 IU/L) and decreased bone mass (lactating WBBMC, -99+/-21 mg/day). Densitometry showed that bone mass gain in the lactating monkeys did not compensate for lactational loss by 10 months postpartum (WBBMC, 6.95+/-9 mg/day). This lack of recovery may have been due to the fact that serum estrogen concentrations were just beginning to return to baseline at 10 months postpartum. In conclusion, the cynomolgus monkey skeleton responds similarly to that of women during pregnancy and lactation. Recovery from lactational bone loss is not complete by 10 months postpartum.

Absorptiometry, Photon↗
PubMed1997

Decreased bone mass and strength in ovariectomized cynomolgus monkeys (Macaca fascicularis).

Agents for prevention or treatment of osteoporosis must now be tested in a large animal species that exhibits bone remodeling. Ovariectomized, nonhuman primates provide one such model, and they consistently develop osteopenia accompanied by high bone turnover rates. The goal of this study was to further characterize this model, and particularly to determine the effect of ovariectomy on bone strength in vertebrae and femoral necks. Longitudinal evaluations of spinal bone mass and serum markers of bone turnover were performed in 19 sham-ovariectomized (SHAM) and 18 ovariectomized (OVX), domestically reared cynomolgus monkeys, aged > 9 years. OVX monkeys lost bone relative to both baseline values and SHAM controls. Serum markers of bone turnover were increased by OVX. After 72 weeks, both vertebral bone compressive strength and femoral neck breaking strength were significantly decreased in OVX animals compared with SHAM. Ovariectomized cynomolgus monkeys, like postmenopausal women, develop accelerated bone loss, increased bone turnover, and reduced bone strength, and provide a suitable large animal model for efficacy studies with agents for prevention or treatment of osteoporosis.

Alkaline Phosphatase↗
PubMed1995

The immunogenicity of MUC1 peptides and fusion protein.

Mucin 1 (MUC1) is highly expressed in breast cancer, has an ubiquitous distribution and, due to altered glycosylation, peptides within the VNTR are exposed. These peptides are the target for anti-MUC1 antibodies, which give a differential reaction on cancer compared with normal tissue. The amino acids, APDTR or adjacent amino acids, are highly immunogenic in mice for antibody production (after immunisation with either breast cancer cells, human milk fat globule (HMFG) or the VNTR peptide). In addition, human studies show that this region of the MUC1 VNTR functions as target epitopes for cytotoxic T cells. We have performed preclinical and clinical studies to examine the immune responses to MUC1 in mice and humans: (a) MUC1+ 3T3 or P815+ 3T3 cells in syngeneic mice are rejected, with the generation of both cytotoxic T lymphocyte (CTL) and DTH responses and a weak antibody response and a weak antibody responses; this type of immunity gives rise to total resistance to re-challenge with high doses of these tumors; (b) immunisation with peptides (VNTR x 2), a fusion protein (VNTR x 5), or HMFG leads to no CTLs, DTH, good antibody production and weak tumour protection (to 10(6) cells, but not 5 x 10(6) cells) (possibly a TH2 type response); (c) immunisation with mannan-fusion protein (MFP) gives rise to good protection (resistance to 50 x 10(6) cells), CTL and DTH responses and weak antibody responses (possibly a TH1 type response, similar in magnitude to that obtained after tumor rejection); (d) established tumors can be rapidly rejected by delayed treatment of MFP; (e) the CTL responses are MHC restricted (in contrast to the human studies); (f) APDTR appears not to be the T cell reactive epitope in mice. On the basis of these findings, two clinical trials are in progress: (a) VNTR x 2 (diphtheria toxoid) which gives rise to some T cell proliferation, DTH and antibody responses in some patients and (b) an MFP trial. The ability to alter the immune response towards cellular immunity with mannan or to humoral immunity with peptides, allows the immune response to be selectively manipulated.

Animals↗
PubMed1995

Development of osteopenia in ovariectomized cynomolgus monkeys (Macaca fascicularis).

Spinal osteopenia that is due in part to failure to gain bone has previously been reported in ovariectomized nonhuman primates. In these studies, development of osteopenia over one year was followed by dual-energy x-ray absorptiometry in both domestically-reared and feral ovariectomized (OVX) and sham-ovariectomized (SHAM) cynomolgus monkeys. To promote development of absolute osteopenia, the domestically-reared animals were all older than nine years and were fed a diet containing 0.14% calcium for most of the experimental period. Both SHAM and OVX feral animals fed 0.6% calcium gained bone mass, with significantly lower rates of gain in SHAM monkeys. OVX domestically-reared monkeys lost bone during one year, while SHAM domestically-reared animals showed no significant change from baseline. Thus, relative osteopenia developed in both experiments, but only the domestically-reared animals developed absolute osteopenia. Nonhuman primates are the only animal model shown to develop absolute osteopenia after ovariectomy. These data suggest that absolute osteopenia develops after ovariectomy in monkeys with stable pre-ovariectomy bone mass which are fed a level of calcium comparable to that consumed by American women.

Absorptiometry, Photon↗
PubMed1995

Effect of treatment for 3 months with human parathyroid hormone 1-34 peptide in ovariectomized cynomolgus monkeys (Macaca fascicularis).

Clinical data suggest that PTH may increase cancellous bone mass at the expense of cortical bone in human beings. In this study, the effects of PTH on whole body, axial and appendicular bone mass were studied in an animal model with Haversian cortical bone remodelling. Ovariectomized, young adult, female cynomolgus monkeys were assigned to Placebo (n = 9) or PTH groups (n = 10). The PTH group received 10 micrograms/kg synthetic human PTH(1-34) peptide by SC injection, 3 days/week for 3 months and the Placebo group received vehicle. Spinal and whole body bone mass were measured by DXA, and proximal tibia, distal radius and mid-radius bone mass were measured by quantitative computed tomography (QCT) at baseline and 3 months. Small, transient increases in serum calcium were observed 4 hours after injection with PTH. Compared to placebo-treated animals, PTH-treated monkeys had no change in whole body bone mass, but a 5% increase in spinal bone mineral density. Cortical bone mass measured by QCT at appendicular sites was not affected by PTH treatment, but there were significant increases in cancellous bone mass in the proximal tibia, and a similar trend in distal radius. PTH stimulated dramatic bone gain in the lumbar spine and at appendicular trabecular bone sites during three months' treatment. There was no evidence of cortical bone loss during the same period.

Absorptiometry, Photon↗