Biomedical subjects

K Takakuwa

Publications and source records attributed to K Takakuwa.

At least 19 recordsLinked to original sources

PubMed2002

The effect of multiple pregnancies on lumbar bone mineral density in Japanese women.

OBJECTIVE: To elucidate the effect of multiple pregnancies on lumbar spine bone mineral density (BMD). METHODS: The BMD of the lumbar spines (L2-L4) of 1,113 healthy women was measured within 7 days of childbirth. In addition 113 women had spine BMD measurements after their next delivery. RESULTS: In the cross-sectional study, there was no apparent effect of parity on lumbar BMD. In the longitudinal study, the mean BMD after the next delivery was significantly higher than that after the initial delivery (1.019 +/- 0.115 g/cm(2) vs. 1.006 +/- 0.117 g/cm(2), P = 0.001, paired t test) with a percent change (DeltaBMD%) of 1.4 +/- 4.2%. Multiple regression analysis to identify independent predictors of DeltaBMD% showed a negative correlation with maternal age at the subsequent delivery (P = 0.033) but no correlation of DeltaBMD% with the length of lactation between the scans. CONCLUSION: Multiple pregnancies may not reduce maternal lumbar BMD, although the percentage decrease in BMD was greater in older women at the subsequent delivery. The length of lactation between the scans had no effect on these results.

Body Weight↗

PubMed2002

Circulating CD34+ cells to predict the adequate harvest of peripheral blood progenitor cells in platinum-based chemotherapy.

OBJECTIVE: The aim of this study was to clarify the appropriate timing for peripheral blood progenitor cells (PBPC) harvesting after platinum-based mobilization chemotherapy by measurement of the circulating CD34+ cell concentrations. PATIENTS AND METHODS: PBPC were collected for autotransplantation via a total of 68 leukaphereses in 16 patients with gynecological cancer. Circulating CD34+ cell concentrations were measured by CD34-side scatter parameter analysis. RESULTS: Data could be fitted into a linear regression line described by the equation y = 0.33 + 4.14 x (x) (R2 = 0.256), where y = the number of harvested colony-forming unit granulocyte macrophage (CFU-GM (x10(5)/kg) and x = the percentage of circulating CD34+ cells and y = 1.747 + 44.53 x (x) (R2= 0.475), where y = the number of harvested CD34+ cells (x10(6)/kg) and x = the percentage of circulating CD34+ cells. Failure to mobilize sufficient CFU-GM numbers (>1 x 10(5)/kg) occurred in 29 of 31 leukaphereses when the percentage of circulating CD34+ cells was less than 0.10%. CONCLUSIONS: Harvesting procedure may be avoided when circulating CD34+ cells showed less than 0.10% after platinum-based mobilization chemotherapy.

Adult↗

PubMed2002

Successful prenatal treatment of congenital heart block with ritodrine administered transplacentally.

Congenital heart block (CHB) is rather rare, and a poorer prognosis has been documented in fetuses with a ventricular rate <55 beats per minutes (bpm), in which therapeutic interventions during pregnancy have been warranted. We present a case of CHB associated with maternal anti-SSA/Ro antibody, diagnosed at 28 weeks' gestation. Fetal echocardiography revealed atrioventricular dissociation, with an atrial rate of 170 bpm and a ventricular rate of 54 bpm. To increase the fetal heart rate, maternal intravenous ritodrine infusion was undertaken, fetal ventricular rate was rapidly increased to 65 bpm. The pregnancy successfully continued until term, and a female infant weighing 2919 g was delivered by cesarean section with Apgar scores of 8 and 8 and 1 and 5 min. The infant is now 12 months of age and growing normally on oral terbutaline without pacing. In a case of fetal heart block, maternal administration of ritodrine may be a therapeutic intervention to improve the fetal and neonatal prognosis.

Adult↗

PubMed2002

Circulating highly fluorescent reticulocytes to predict the adequate harvesting of peripheral blood progenitor cells in platinum-based chemotherapy.

We prospectively evaluated whether peripheral blood progenitor cells (PBPC) yield from a single leukapheresis could be predicted by measurement of circulating highly fluorescent reticulocytes (HFR). PBPC were collected from 46 leukaphereses in 15 patients with gynecological cancer following platinum-based chemotherapy. Once a level of at least 5.0% HFR was achieved, sufficient PBPC were collected in a single harvest in 71% of the procedures. Whereas, failure to mobilize sufficient PBPC occurred in 24 of 28 leukaphereses when the percentage of circulating HFR was less than 5.0%. In conclusion, circulating HFR may aid in the efficiency of PBPC collections in platinum-based chemotherapy.

Adult↗

PubMed2002

Aberrant cytokine production by peripheral blood mononuclear cells in recurrent pregnancy loss?

BACKGROUND: Successful pregnancy may depend on a Th2-type cytokine response, whilst, conversely, a poor pregnancy outcome may be associated with an increase in Th1 cytokines and a concomitant decrease in Th2 cytokines. This prospective study was designed to elucidate whether a failure of the cytokine shift pre-dated miscarriage and was therefore likely to be an aetiological factor in recurrent pregnancy loss (RPL). METHODS: Cytokine production by stimulated peripheral blood mononuclear cells from 46 pregnant women who had previously suffered idiopathic RPL during early pregnancy was compared with 25 gestationally age-matched pregnant controls and 11 non-pregnant women. RESULTS: Production of IFN-gamma was lower in pregnant than in non-pregnant women and even lower in RPL pregnant women (P = 0.0191). IL-10 was increased in pregnant women compared with non-pregnant controls, and further increased in RPL patients (P = 0.026). IL-4 was also increased in women with RPL (P = 0.0001). No differences in IFN-gamma, IL-10 or IL-4 secretion were observed in RPL patients who subsequently miscarried compared with those who successfully completed the pregnancy. RPL women with a successful reproductive outcome had similar concentrations of TNF-alpha to pregnant women, RPL women who subsequently miscarried had significantly lower levels than either pregnant women (P = 0.02) or non-pregnant controls (P = 0.0004). CONCLUSIONS: Contrary to our hypothesis, the cytokine shift, which appears to characterize normal pregnancy, was accentuated rather than diminished in RPL pregnant women.

Abortion, Habitual↗

PubMed2001

Effects of a beta 3 adrenergic receptor agonist on bone and bone marrow adipocytes in the tibia and lumbar spine of the ovariectomized rat.

The object of this study was to investigate the effects of a b3 adrenergic receptor agonist (ARa) and estrogen on bone remodeling and bone marrow adipocyte differentiation. Ten-week-old female Sprague-Dawley rats underwent sham operation (Sham) or were ovariectomized (OVX) and were divided into four groups: Sham, Sham+ARa, OVX, and OVX+ARa groups. They were given orally the b3-ARa, BRL 35135, or vehicle daily for 4 weeks and their tibial and lumbar spinal bone and fat histomorphometric parameters were measured. In tibial proximal metaphysis, the adipocyte number per bone marrow unit volume (N.A/MV), and the percent adipocyte volume (AV/MV) values of the OVX and OVX+ARa groups were significantly higher than the Sham and Sham+ARa groups (P = 0.004, P = 0.008 in OVX, respectively), but ARa administration had no effect on bone remodeling or adipocyte differentiation. N.A/MV and AV/MV correlated negatively with the bone volume (BV/TV, r = -0.67, P = 0.001; r = -0.62, P = 0.004, respectively), and they correlated with the bone resorption parameters, i.e., the eroded surface (ES/BS), osteoclast surface (Oc.S/BS), and osteoclast number (N.Oc/BS) in tibial proximal metaphysis. In tibial distal metaphysis, the adipocyte volume per cell (AV/N.A) values of the OVX and OVX+ARa groups were significantly higher than those of the Sham and Sham+ ARa group (P = 0.003 in OVX). In the lumbar spine, the AV/N.A values of the Sham+ARa and OVX+ARa groups were significantly lower than the Sham and OVX groups values (P < 0.0001 in ARa administration), but OVX did not affect adipocyte differentiation. Beta3-ARa administration affects the bone marrow adipocyte differentiation, which is site-specific difference, although mainly negative in the context of bone.

Adipocytes↗

PubMed2001

HLA-class I antigens in patients with unexplained recurrent abortion.

In order to clarify the genetic background of recurrent spontaneous abortion, the frequency of HLA-A, -B, and -C alleles was analyzed in eighty-nine patients with a history of unexplained primary recurrent abortion. The frequency of each HLA-A, -B, and -C antigen allele was calculated in patients with recurrent abortion and their husbands, and compared with the frequencies in the general population represented by 207 individuals in the Niigata district of Japan. The incidence of individuals homozygous for the HLA-A, -B, and -C alleles was also compared between the patient group and the control group. The frequency of HLA-B35 in the patient group (5 of 89, 5.6%) was significantly lower than in the general population (40 of 207, 19.3%) (Odds Ratio, 0.25; 95% Confidence Interval, 0.09-0.65; P < 0.005; Pc, not significant). The frequencies of other HLA-A, -B, and -C alleles were not significantly different between the patient group and the general population. No significant difference in the frequency of HLA-A, -B, and -C alleles was observed between the husband group and the general population. The incidence of individuals homozygous for HLA-A, -B, or -C alleles in the patient group was not significantly different from the general population. The significantly lower frequency of HLA-B35 in patients with unexplained recurrent abortion suggests that the Th2-associated immune reactions may be lacking in such patients, as it has been reported that an enhanced Th2 response in conjunction with a decreased T Th1 response is a common immune reaction in HLA-B35-positive individuals.

Abortion, Habitual↗

PubMed2001

Ovarian function after radical hysterectomy with ovarian preservation for cervical cancer.

OBJECTIVE: To investigate the function of preserved ovaries following radical hysterectomy in premenopausal women with cervical carcinoma and to attempt to identify clinical factors influencing ovarian function. STUDY DESIGN: Between 1991 and 1998, 33 premenopausal patients with International Federation of Gynecology and Obstetrics stage IB and II cervical cancer underwent radical hysterectomy with ovarian preservation, including lateral ovarian transposition in 20 patients. In 12 cases of squamous cell carcinoma with deep stromal invasion or a suspicious, positive node, neoadjuvant chemotherapy was performed. Postoperative whole pelvic radiotherapy was administered to 11 patients. Ovarian function was evaluated by serum FSH level during the follow-up period, 12 months to 9 years. RESULTS: Fifteen of 33 patients became climacteric after treatment. Ten of 12 patients over 40 years old became climacteric, as did 5 of 21 under 39 (P = .0013). Using multiple regression analysis, a significant correlation between ovarian dysfunction and age (under 40) was observed (P = .0286). No ovarian recurrence or symptomatic ovarian cyst was observed in preserved ovaries during the study period. CONCLUSION: Ovarian preservation is safe in patients under 40 years old undergoing radical hysterectomy even if they received additional treatment, such as neoadjuvant chemotherapy or postoperative radiotherapy with ovarian transposition.

Adenocarcinoma↗

PubMed2000

Effects of pregnancy and lactation on trabecular bone and marrow adipocytes in rats.

Changes in the structure and metabolism of trabecular bone and marrow adipocytes in rats during pregnancy and the early stage of postpartum were evaluated by investigating bone mineral density (BMD) and bone and fat histomorphometry. Forty-nine female virgin Sprague-Dawley rats aged 200 days were mated and divided into seven groups: (1) beginning controls; (2) antepartum-on-day-7; (3) antepartum-on-day-21; (4) nonlactating on the fourth postpartum day; (5) nonlactating on the sixth postpartum day; (6) nonlactating on the eighth postpartum day; (7) lactating on the eight postpartum day. The significant decreases occurred in the trabecular bone at the end of pregnancy and lactation, and the bone formation increases and the bone structure is almost recovered in nonlactating rats within 6 days of postpartum. The percent adipocyte volume, adipocyte number, and unit adipocyte volume significantly decreased during postpartum whether lactating or nonlactating, and they significantly showed negative correlation with the osteoid volume values. The serum triglyceride value and body weight of the seven groups correlated significantly with the unit adipocyte volume value (r = 0.49, P = 0.004; r = 0.58, P = 0.0005, respectively). We concluded that bone resorption and formation are regulated separately during late pregnancy and lactation and that the recovery of BMD from lactation appears to rely on an acceleration of bone formation. Furthermore, the metabolism of the marrow adipocyte may be correlated with bone formation rates, serum triglyceride value, and body weight during pregnancy and early stage of puerperium.

Absorptiometry, Photon↗

PubMed2000

HLA-DQB1 and HLA-DPB1 genotypes in severe preeclampsia.

OBJECTIVE: To clarify whether there are susceptible HLA-DQB1 or HLA-DPB1 alleles in women with preeclampsia. METHODS: The frequency of HLA-DQB1 and HLA-DPB1 alleles was analyzed in 47 women with previous severe preeclampsia and compared with that in 85 normal fertile women. The types of HLA-DQB1 and HLA-DPB1 alleles were assessed using a polymerase chain reaction-restriction fragment length polymorphism method. RESULTS: The frequency of HLA-DQB1*04 allele in previously preeclamptic women was 21.3% (20 of 94 loci) and in the controls was 11.2% (19 of 170 loci). Thus, the HLA-DQB1*04 allele frequency was significantly higher in preeclamptic women compared with controls (P <.05 by chi(2) test, OR 2.15, 95% confidence interval 1.08, 4.27). The frequency of other HLA-DQB1 alleles and all HLA-DPB1 alleles was not significantly different between groups. The incidence of homozygosity of HLA-DQB1 or HLA-DPB1 alleles in preeclamptic women was not significantly different compared with that of normal fertile women. CONCLUSION: These data suggest that women who have the HLA-DQB1*04 allele might be susceptible to preeclampsia.

Adult↗

PubMed2000

Screening of BRCA1 mutation using immunohistochemical staining with C-terminal and N-terminal antibodies in familial ovarian cancers.

We examined the subcellular localization of BRCA1 proteins using immunohistochemical staining with C-terminal (GLK-2 antibody) and N-terminal (Ab-2 antibody) monoclonal antibodies in 44 familial ovarian cancers. Among these, 24 cases were associated with 13 independent germ-line mutations of BRCA1, and loss of heterozygosity (LOH) at one or more BRCA1 microsatellite markers was found in all 21 informative tumors tested. With GLK-2 antibody, cytoplasmic staining was observed in 15 of 16 tumors (93.8%) with mutation in exon 11, and BRCA1 staining was absent in 8 of 8 tumors (100%) with mutation in exons other than exon 11. When immunohistochemical staining was performed with Ab-2 antibody, both nuclear and cytoplasmic staining were observed in 14 of 16 tumors (87.5%) with mutation in exon 11. Interestingly, nuclear staining was observed in 3 of 3 tumors (100%) with mutation downstream of exon 11, even though no staining was detected in 5 of 5 tumors (100%) with mutation upstream of exon 11. On the other hand, in familial ovarian cancers without BRCA1 mutations, nuclear staining or both nuclear and cytoplasmic staining was observed in 18 of 20 specimens (90%) and 20 of 20 specimens (100%) with GLK-2 antibody and with Ab-2 antibody, respectively. These results suggest that an immunohistochemical assay in combination with employing the C-terminal and the N-terminal antibodies appears to have potential as a reliable and useful technique for the screening of BRCA1 mutations, at least to predict the status of mutation, upstream or downstream of exon 11.

BRCA1 Protein↗

PubMed2000

Treatment with nafarelin for endometriosis in young women. Efficacy, safety and lipid metabolism. Niigata Nafarelin Study Group.

OBJECTIVE: To assess the efficacy, safety and effect on lipid metabolism of treatment with nafarelin acetate for clinical endometriosis symptoms in young women. STUDY DESIGN: A multicenter, open-label, nonrandomized clinical trial was conducted on subjects who were 19-29 years of age with clinical symptoms and signs of endometriosis demonstrated by laparoscopy, ultrasonography, magnetic resonance imaging, computed tomography or pelvic examination. For 24 weeks, 34 women received intranasal nafarel, 200 mg twice daily. The main outcome measures were changes in signs and symptoms, lumbar bone mineral density by dual energy X-ray absorptiometry and serum parameters of lipid metabolism. RESULTS: Symptoms and signs of endometriosis decreased significantly during treatment and at the first posttreatment menses. CA-125 level decreased significantly, from 84.0 +/- 20.2 U/mL at baseline to 13.4 +/- 1.9 at the 24th week (P = .0014). The mean high density lipoprotein cholesterol, total cholesterol, apoprotein A-I and A-II, lipoprotein (a) and remnant lipoprotein cholesterol levels significantly increased, and cholesterol ester transfer protein activity slightly increased, by the 24th week but fell to baseline values by the first posttreatment menses. Despite a low mean serum estradiol level (20 pg/mL) at the end of treatment, the reported incidence of hot flushes was low (24%), and only one woman withdrew because of hypoestrogenic symptoms. CONCLUSION: Twenty-four-week nafarelin treatment for clinical endometriosis symptoms in women < or = 29 years was safe and effective.

Absorptiometry, Photon↗

PubMed1999

Development of novel cationic liposomes for efficient gene transfer into peritoneal disseminated tumor.

A novel series of cationic lipids has been found, by in vivo screening, to be effective for gene transfer into peritoneal disseminated tumor. O,O'-Ditetradecanoyl-N-(alpha-trimethylammonioacetyl)diethan olamine chloride (DC-6-14), having dimyristyl acid, has shown the highest transfection activity in vitro, provided that 10% fetal bovine serum is present. To enhance the transfection efficiency of DC-6-14, we added dioleoylphosphatidylethanolamine (DOPE) and/or cholesterol (Chol) as helper lipids in various ratios. Cationic liposomes containing DC-6-14, DOPE, and Chol in molar ratios of 1:0.75:0.75 and 1:1:0.8 maintained efficient transfection activity under serum-containing conditions in HRA, mEIIL, and ES-2 cell lines in vitro, as determined by luciferase assay. With our novel liposomes, transfection efficiencies were higher in cells proliferating faster than in cells proliferating slower, depending on mitotic activity as represented by labeling index. In the mEIIL peritoneal disseminated tumor model, cancer cells were specifically transfected with the lacZ gene. Gene transfer was observed by X-Gal staining not only in floating cancer cells in the ascites, but also in the peritoneal disseminated cancer tissue. The percentage of LacZ-positive cells was about 1%, which was significantly higher than with commercially available Lipofectin (0.38%), LipofectACE (0.62%), or LipofectAMINE (0.23%). In the mEIIL peritoneal disseminated tumor-nude mouse model, herpes simplex thymidine kinase gene (HSV tk) transfer with our novel liposomes, followed by ganciclovir (GCV) treatment, resulted in significantly longer survival compared with control mice (p < 0.05, Cox-Mantel). These results suggest that these liposomes show promise as tools in gene therapy for patients with intraperitoneal disseminated cancer.

Animals↗

PubMed1999

Association of vitamin D and estrogen receptor gene polymorphism with the effect of hormone replacement therapy on bone mineral density in Japanese women.

OBJECTIVE: We studied whether vitamin D receptor and estrogen receptor gene polymorphism is associated with the effect of hormone replacement therapy on lumbar-spinal bone mineral density in Japanese women. STUDY DESIGN: The subjects were 82 Japanese women aged 40 to 64 years (49.7 +/- 0.6 years, mean +/- SEM) who had taken hormone replacement therapy for >1 year. Genomic deoxyribonucleic acid was extracted from blood and analyzed for restriction fragment length polymorphism with the restriction endonucleases Taq I, Apa I, and Fok I for vitamin D receptor and Pvu II and Xba I for estrogen receptor. RESULTS: The subjects with genotype TT had a significantly higher percentage change in bone mineral density per year than those with the Tt genotype (2.8% +/- 0.6% vs -0.8% +/- 1.4%, P =.019). The serum level of pyridinoline cross-linked carboxy-terminal telopeptide of type I collagen decreased by 13% during 1 year of hormone replacement therapy in subjects with the TT genotype (P =. 001) but did not change in women with the Tt genotype. In multiple regression analysis including age, height (centimeters), weight (kilograms), and polymorphisms of the vitamin D receptor and estrogen receptor genes, only age and Taq I polymorphism of the vitamin D receptor gene were associated independently with change in bone mineral density (P =.001 and.004, respectively). CONCLUSION: Taq I polymorphism of the vitamin D receptor gene is associated with the effect of hormone replacement therapy on lumbar-spinal bone mineral density and bone resorption markers in Japanese women. Analysis of the vitamin D receptor alleles may prove useful for selection of the optimum therapy for osteoporosis management.

Adult↗

PubMed1999

Suppressive effect of anticardiolipin antibody on the proliferation of human umbilical vein endothelial cells.

OBJECTIVE: To determine whether sera that show a positive anticardiolipin test result have a suppressive effect on the proliferation of endothelial cells collected from human umbilical veins. DESIGN: Retrospective in vitro study. SETTING: University hospital outpatient clinic for the treatment of infertility. PATIENT(S): Thirteen patients with recurrent fetal miscarriages who were positive for anticardiolipin antibody and 14 patients with recurrent miscarriages who were negative for anticardiolipin antibody. INTERVENTION(S): Serum was obtained from each patient. MAIN OUTCOME MEASURE(S): Suppressive effect of the sera on the culture of human umbilical vein endothelial cells. RESULT(S): The proliferation of human umbilical vein endothelial cells decreased significantly in cultures that contained sera showing positive anticardiolipin antibody activity that had been collected from patients with recurrent fetal miscarriages. CONCLUSION(S): The results strongly suggest that anticardiolipin antibody has a suppressive effect on the proliferation of human umbilical vein endothelial cells.

Abortion, Habitual↗

PubMed1999

Studies on the HLA-DRB1 genotypes in Japanese women with severe pre-eclampsia positive and negative for anticardiolipin antibody using a polymerase chain reaction-restriction fragment length polymorphism method.

The human leukocyte antigen (HLA)-DR genotype was determined in 54 Japanese women with severe pre-eclampsia in order to elucidate the relationship between HLA-DR antigen systems and pre-eclampsia. The patients were divided into two groups according to positivity for the anticardiolipin antibody (ACA), i.e. one patient group negative for ACA (n = 41) and the other patient group positive for ACA (n = 13). The frequency of each HLA-DRB1 allele in both groups was compared with that in 81 normally fertile Japanese women who had not experienced pre-eclampsia. The genotypes of HLA-DR antigens were determined using a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. The frequency of DRB1*04 and DRB1*0403 in the patient group positive for the ACA was significantly higher compared with that in the group of normal fertile women (P< 0.05). The frequency of each HLA-DRB1 allele was not significantly different between patient group with pre-eclampsia negative for ACA and group of normal fertile women. These results suggest a difference in the immunogenetic background between the patient groups with severe pre-eclampsia positive and negative for the ACA.

Adult↗

PubMed1999

Possible susceptibility of the HLA-DPB10402 and HLA-DPB104 alleles to unexplained recurrent abortion: analysis by means of polymerase chain reaction-restricted fragment length polymorphism method.

PROBLEM: To clarify whether HLA-DP antigens are associated with patient population of unexplained recurrent abortion. METHOD OF STUDY: The frequency of HLA-DPB1 alleles in patients with unexplained recurrent abortion, and the compatibility of HLA-DPB1 alleles between patient couples, were studied using a polymerase chain reaction (PCR)-restricted fragment length polymorphism (RFLP) method. Thirty patients who had a history of unexplained primary recurrent abortion, and their husbands, were typed for HLA-DPB1 genotype. Two hundred and ninety-nine base pair fragments from the second exon of HLA-DPB1 genes were selectively amplified using the PCR-primers. After amplification, the DNAs were digested with restriction endonucleases, and subjected to electrophoresis in a 12% polyacrilamide gel to determine HLA-DPB1 genotype. RESULTS: The frequency of HLA-DPB1*0402 and DPB1*04 alleles in the patient group (n = 30) was significantly increased, as compared to that in the normal fertile women (n = 30). The frequency of HLA-DPB1*04 allele in the patient group was significantly increased, as compared to that in the general population (n = 112). No significant compatibility of HLA-DPB1 alleles could be observed between patient couples and normal fertile couples. CONCLUSION: These findings suggest a possible new class II association with patient population of unexplained recurrent abortion.

Abortion, Habitual↗

PubMed1998

Bone structural and metabolic changes at the end of pregnancy and lactation in rats.

OBJECTIVE: The objective of this study was to elucidate the net change of bone structure and metabolism in the lumbar trabecular bone of rats at the end of the pregnancy and lactation. STUDY DESIGN: Female virgin Sprague-Dawley rats aged 200 days were mated, and bone mineral density by dual-energy x-ray absorptiometry, bone histomorphometry, and serum bone metabolic markers were measured at the end of pregnancy (day 22 of pregnancy), after delivery (day 5 post partum), and at the end of lactation (day 21 post partum). RESULTS: At the end of pregnancy bone mineral density, bone volume, trabecular thickness, and serum calcium decreased; serum parathyroid hormone increased; and the histomorphometric parameters indicated that bone resorption were higher than those variables in nonpregnant rats, but bone formation was suppressed, as demonstrated by the low histomorphometric parameters and by the low serum alkaline phosphatase levels. After delivery the bone mineral density of nonlactating rats recovered rapidly, as in nonpregnant rats, but nonlactating rats showed more bone formation by histomorphometry than nonpregnant rats did. At the end of lactation, bone mineral density and serum calcium levels decreased considerably, and lactating rats showed substantial bone formation, bone resorption, and high serum alkaline phosphatase levels. The correlation between the number of pups (x) of the lactating and nonlactating groups and the bone mineral density (y, in grams per square centimeter) showed simple linear regression (y = -0.0067 . x +0.2517, r = 0.949, p < 0.0001). CONCLUSIONS: These results indicate that significant decreases occur in the trabecular bone of rats at the end of pregnancy and lactation and that lactational intensity is related to bone mineral density.

Absorptiometry, Photon↗