Towards the quantitative characterisation of piglets' robustness to weaning: a modelling approach

Weaning is a critical transition phase in swine production in which piglets must cope with different stressors that may affect their health. During this period, the prophylactic use of antibiotics is still frequent to limit piglet morbidity, which raises both economic and public health concerns such as the appearance of antimicrobial-resistant microbes. With the interest of developing tools for assisting health and management decisions around weaning, it is key to provide robustness indexes that inform on the animals' capacity to endure the challenges associated with weaning. This work aimed at developing a modelling approach for facilitating the quantification of piglet resilience to weaning. A total of 325 Large White pigs weaned at 28 days of age were monitored and further housed and fed conventionally during the post-weaning period without antibiotic administration. Body weight and diarrhoea scores were recorded before and after weaning, and blood was sampled at weaning and 1 week later for collecting haematological data. A dynamic model was constructed based on the Gompertz-Makeham law to describe live weight trajectories during the first 75 days after weaning, following the rationale that the animal response is partitioned in two time windows (a perturbation and a recovery window). Model calibration was performed for each animal. Our results show that the transition time between the two time windows, as well as the weight trajectories are characteristic for each individual. The model captured the weight dynamics of animals at different degrees of perturbation, with an average coefficient of determination of 0.99, and a concordance correlation coefficient of 0.99. The utility of the model is that it provides biologically meaningful parameters that inform on the amplitude and length of perturbation, and the rate of animal recovery. Our rationale is that the dynamics of weight inform on the capability of the animal to cope with the weaning disturbance. Indeed, there were significant correlations between model parameters and individual diarrhoea scores and haematological traits. Overall, the parameters of our model can be useful for constructing weaning robustness indexes by using exclusively the growth curves. We foresee that this modelling approach will provide a step forward in the quantitative characterisation of robustness.

Association of genetic variants and expression levels of porcine FABP4 and FABP5 genes

The FABP4 and FABP5 genes, coding for fatty acid transport proteins, have long been studied as positional candidate genes for SSC4 QTL affecting fat deposition and composition traits in pigs. Polymorphisms in these genes, FABP4:g.2634_2635insC and FABP5:g.3000T>G, have previously been associated with fatness traits in an Iberian by Landrace cross (IBMAP). The aim of the present work was to evaluate the functional implication of these genetic variants. For this purpose, FABP4 and FABP5 mRNA expression levels in 114 BC1_LD animals (25% Iberian × 75% Landrace) were analyzed using real-time quantitative PCR in backfat and muscle. FABP4 gene expression in backfat, but not in muscle, was associated with FABP4:g.2634_2635insC. In contrast, FABP5:g.3000T>G was not associated with gene expression levels. An expression-based genome-wide association study highlighted the FABP4:g.2634_2635insC polymorphism as the polymorphism most associated with FABP4 gene expression in backfat. Furthermore, other genomic regions associated in trans with the mRNA expression of FABP4 in backfat and FABP5 in muscle were also identified. Finally, two putative transcription binding sites for PPARG and NR4A2 may be affected by the FABP4:g.2634_2635insC polymorphism, modifying FABP4 gene expression. Our results reinforce FABP4 as a candidate gene for fatness traits on SSC4.

Analysis of the porcine APOA2 gene expression in liver, polymorphism identification and association with fatty acid composition traits

APOA2 is a protein implicated in triglyceride, fatty acid and glucose metabolism. In pigs, the APOA2 gene is located on pig chromosome 4 (SSC4) in a QTL region affecting fatty acid composition, fatness and growth traits. In this study, we evaluated APOA2 as a candidate gene for meat quality traits in an Iberian × Landrace backcross population. The APOA2:c.131T>A polymorphism, located in exon 3 of APOA2 and determining a missense mutation, was associated with the percentage of hexadecenoic acid [C16:1(n-9)], linoleic acid [C18:2(n-6)], α-linolenic acid [C18:3(n-3)], dihomo-gamma-linolenic acid [C20:3(n-6)] and polyunsaturated fatty acids (PUFAs) in backfat. Furthermore, this SNP was associated with the global mRNA expression levels of APOA2 in liver and was used as a marker to determine allelic expression imbalance by pyrosequencing. We determined an overexpression of the T allele in heterozygous samples with a mean ratio of 2.8 (T/A), observing a high variability in the allelic expression among individuals. This result suggests that complex regulatory mechanisms, beyond a single polymorphism (e.g. epigenetic effects or multiple cis-acting polymorphisms), may be regulating APOA2 gene expression.

Water quality assessment using satellite-derived chlorophyll-a within the European directives, in the southeastern Bay of Biscay

The implementation of water quality European Directives requires an intensification of water quality monitoring, within the limits of the Exclusive Economic Zone. Remote sensing technologies can provide a valuable tool for frequent, synoptic, water-quality observations, over large areas. The aim of this study is to assess the ecological status of Basque coastal water bodies using satellite imagery from MODIS sensor, together with optical and chlorophyll-ain situ measurements. Thus, sea surface satellite-derived chl-a algorithms, the OC3 M, OC5 and a Local empirical algorithm, were compared against in situ measurements using satellite in situ match-ups, 90th Percentile (P90) monthly values for the 2005-2010 period. The OC5 algorithm corresponded most accurately with in situ measurements performed in the area, hence, it was selected. A P90 chlorophyll-a map was created with this algorithm to apply the classification scheme required by the directives. The classification of water bodies, based upon satellite-derived chlorophyll-a, could improve considerably the assessment of water quality.

The Early Systemic Prophylaxis of Infection After Stroke Study

Background and Purpose— Early infection after stroke is frequent but the clinical value of antibiotic prophylaxis in acute stroke has never been explored.

Objective and

Methods— The Early Systemic Prophylaxis of Infection After Stroke (ESPIAS) is a randomized, double-blind, placebo-controlled study of antibiotic prophylaxis in patients older than 18 years with nonseptic ischemic or hemorrhagic stroke enrolled within 24 hours from clinical onset. Interventions included intravenous levofloxacin (500 mg/100 mL/d, for 3 days) or placebo (0.9% physiological serum) in addition to optimal care. A sample size of 240 patients was calculated to identify a 15% absolute risk reduction of the primary outcome measure, which was the incidence of infection at day 7 after stroke. Secondary outcome measures were neurological outcome and mortality at day 90.

Results— Based on a preplanned futility analysis, the study was interrupted prematurely when 136 patients had been included. Levofloxacin and placebo patients had a cumulative rate of infection of 6% and 6% ( P =0.96) at day 1; 10% and 12% ( P =0.83) at day 2; 12% and 15% ( P =0.66) at day 3; 16% and 19% ( P =0.82) at day 7; and 30% and 33% ( P =0.70), at day 90. Using logistic regression, favorable outcome at day 90 was inversely associated with baseline National Institutes of Health Stroke Scale (OR, 0.72; 95% CI, 0.59 to 0.89; P =0.002) and allocation to levofloxacin (OR, 0.19; 95% CI, 0.04 to 0.87; P =0.03).

Conclusions— Prophylactic administration of levofloxacin (500 mg/100 mL/day for 3 days) is not better than optimal care for the prevention of infections in patients with acute stroke.

The -174G/C polymorphism of the interleukin 6 gene is a hallmark of lacunar stroke and not other ischemic stroke phenotypes

BACKGROUND AND PURPOSE

The CC genotype of the -174 G/C interleukin (IL)-6 polymorphism has been associated with lacunar stroke. However, it remains unsettled whether this polymorphism is also associated with other ischemic stroke phenotypes.

METHODS

The -174 G/C IL-6 polymorphism was genotyped in patients with lacunar stroke (n = 89), stroke due to large vessel disease (n = 82), cardioembolism (n = 53), stroke of undetermined cause (n = 49) and in white controls without any history of stroke (n = 105) by PCR and restriction enzyme analysis. Independent predictors of the -174 G/C IL-6 genotypes were assessed using multivariate logistic regression models adjusted for demographics, risk factors and disease state.

RESULTS

The prevalence of the CC genotype was 8.5% in large vessel disease, 7.5% in embolism, 19.1% in lacunar stroke, 14.3% in stroke of undetermined cause and 8.6% in controls. The CC genotype was independently associated with lacunar stroke only (adjusted OR 3.22, 95% CI 9.09-1.12). Contrarily, there were no significant differences in genotype and allele distribution in the remainder of ischemic stroke phenotypes. Pooling of patients with nonlacunar stroke did not show any independent association with the CC genotype as compared with controls (OR 1.01, 95% CI 2.77-0.36).

CONCLUSIONS

The unique association between the CC genotype of the -174 G/C IL-6 polymorphism and lacunar stroke suggests a particular susceptibility of small deep penetrators of cerebral arteries to IL-6-mediated inflammatory damage.

alpha(1)-antichymotrypsin polymorphism: a risk factor for hemorrhagic stroke in normotensive subjects

BACKGROUND AND PURPOSE

Although genetic factors may be important in the pathogenesis of ischemic stroke (IS), little is known on the potential role of genes in most cases of hemorrhagic stroke (HS). Preliminary data showed that the TT genotype of the alpha(1)-antichymotrypsin (ACT) gene polymorphism was associated with HS, although it remained unsettled whether prevalence of this polymorphism might differ between hypertensive and normotensive HS.

METHODS

Ninety-nine patients with HS, 182 patients with IS (symptomatic control subjects), and 80 asymptomatic control subjects were genotyped for the ACT polymorphism using polymerase chain reaction amplification. Chronic hypertension was recorded in 66 patients with HS.

RESULTS

The ACT-TT genotype was more prevalent in patients than in asymptomatic or symptomatic control subjects: 26%, 15%, and 16%, respectively. The ACT-TT genotype was obtained in 33% of HS who lacked arterial hypertension (P<0.05). After adjustment for age, gender, and vascular risk factors, the ACT-TT genotype remained independently associated with HS (OR 2.80, 95% CI 1.19 to 6.58, compared with asymptomatic control subjects; OR 1.79, 95% CI 0.95 to 3.40, compared with symptomatic control subjects). In analyses restricted to HS in normotensive patients, the ORs were 3.10 (95% CI 1.10 to 8.68) and 2.53 (95% CI 1.04 to 6.18), respectively.

CONCLUSIONS

These findings confirm in a larger series of patients the association between the ACT-TT genotype and HS. This polymorphism is more prevalent in normotensive bleedings. Pathological studies will be required to establish whether the ACT-TT genotype facilitates proteolytic rupture of vessels that harbor amyloidotic changes or another form of nonhypertensive cerebral angiopathy.

Nonconvulsive status epilepticus associated with cephalosporins in patients with renal failure

PURPOSE

Nonconvulsive status epilepticus is an unusual complication of cephalosporin therapy, with only a few isolated cases reported.

SUBJECTS AND METHODS

We reviewed the clinical and electroencephalographic (EEG) characteristics of 10 patients with renal failure in whom developed alteration of consciousness without convulsions associated with continuous epileptiform EEG activity while being treated with cephalosporins.

RESULTS

Nonconvulsive status epilepticus developed in 5 men and 5 women, with a mean (+/- SD) age of 69 +/- 14 years, while receiving intravenous cephalosporins (ceftriaxone, 2 patients; ceftazidime, 2; and cefepime, 6). All patients had renal failure; 1 also had hepatic failure. Patients presented with progressive disorientation or agitation, sometimes associated with mild facial or limb myoclonus, that had begun 1 to 10 days (mean, 5 +/- 2 days) after starting cephalosporin treatment. The EEG showed continuous or intermittent bursts of generalized, high-voltage, 1 to 2 Hz sharp wave activity or sharp and slow wave activity that resembled, but could be differentiated from, the triphasic waves seen in metabolic encephalopathies. Intravenous clonazepam suppressed the epileptiform activity completely in 5 patients and partially in the other 5. Cephalosporins were withdrawn, and antiepileptic therapy was started for all patients. All patients improved, 2 in less than 24 hours and the remainder within 2 to 7 days.

CONCLUSIONS

Cephalosporins can cause nonconvulsive status epilepticus in patients with renal failure. The clinical picture is difficult to differentiate from a that of metabolic encephalopathy unless an EEG is obtained. Physicians should be aware of this potentially dangerous complication.

Examination of motor output pathways in patients with corticobasal ganglionic degeneration using transcranial magnetic stimulation

The alien hand sign (AHS) is often encountered in patients with corticobasal ganglionic degeneration (CBGD), revealing a unilateral dysfunction of the motor system of unknown pathophysiology. We examined the possibility of an abnormal cortical representation of hand muscles in 10 patients with probable CBGD and a prominent AHS. Cortical maps were obtained from the responses to magnetic stimuli applied with a figure of eight coil at an intensity of 110% above motor threshold. For comparison, the same study was carried out in 10 normal volunteers, eight patients with Parkinson's disease and eight patients with Alzheimer's disease. AHS patients had a larger extension of the cortical map to stimulation of the hemisphere contralateral to the AHS in comparison with the ipsilateral hemisphere. Furthermore, in six patients, focal stimulation of the hemisphere ipsilateral to the AHS gave rise to ipsilateral responses, delayed by a mean of 7.7 +/- 2.2 ms with respect to those recorded in the same muscle to contralateral stimulation. None of the other patients or control subjects had ipsilateral responses. Our results indicate an enhanced excitability, or reduced inhibition, of the motor area of the hemisphere contralateral to the AHS. The delay of the ipsilateral responses is compatible with a disinhibited transcallosal input.

Gynecological factors and body mass index as determinants of bone mass in normal postmenopausal women. A study with peripheral quantitative computed tomography (pQCT)

OBJECTIVE

This paper studied the influence of several gynecological factors (years since menopause (YSM), age at menarche and gynecological age or reproductive life) simultaneously with anthropometric factors as determinants of bone mass in 189 healthy postmenopausal women.

METHODS

Bone mass was determined by peripheral quantitative computed tomography.

RESULTS

An overall evaluation showed that YSM correlated negatively with trabecular and cortical bone density (BMDTrab and BMDCorti) (P<0.05 in both cases). Age at menarche correlated negatively with BMDCorti (P<0.05) and gynecological age correlated positively with BMDTrab (P<0.05). Classifying the women according to their body mass index (BMI), the YSM correlation persisted in those subjects whose BMI was >25 kg/m(2), and in age at menarche and gynecological age of women whose BMI was <25 kg/m(2) (P<0.05). After separating women according to their age at menarche, their gynecological age and BMI, the only significant difference that persisted was in BMDTrab which was lower in the group with gynecological age <33 years, with a BMI <25 kg/m(2) (P=0.020). Parity and smoking had no impact on our results. By multiple regression, with BMD as the dependent variable and the gynecological factors as independent variables, we only observed significance between YSM and BMDCorti (P<0.005). The same was observed after separating women according to their BMI in the >25 kg/m(2) group (P<0.05).

CONCLUSIONS

Our data stress the importance of YSM on BMDTrab and BMDCorti, of age at menarche on BMDCorti and of gynecological age on BMDTrab. However, YSM is the gynecological factor that mainly determines BMD. The differences observed between measurements taken with pQCT and other methods commonly used to estimate bone mass indicate that results obtained with one technique cannot be extrapolated to other methods.

Alpha(1)-antichymotrypsin gene polymorphism in patients with stroke

BACKGROUND AND PURPOSE

A role for proteolytic enzymes has been suggested in the pathogenesis of stroke. In a search for new genetic factors, we investigated the gene polymorphism of the serine protease inhibitor alpha(1)-antichymotrypsin (ACT) in patients with stroke.

METHODS

Two hundred twenty patients with acute ischemic stroke (n=182) and primary intracerebral hemorrhage (n=38) and 70 control subjects without clinical cerebrovascular disease were genotyped for the ACT polymorphism.

RESULTS

The ACT-TT genotype was more frequent in patients with primary intracerebral hemorrhage than in patients with ischemic stroke (31.6% versus 16.4%, P:<0.05) or in control subjects (21.4%, P:=0.1). After adjusting for age, gender, and vascular risk factors, the ACT-TT genotype was associated with primary intracerebral hemorrhage, with an OR of 2.3 (95% CI 1.0 to 5. 2) compared with ischemic stroke and an OR of 1.8 (95% CI 0.85 to 9. 65) compared with controls.

CONCLUSIONS

Pending confirmation in a larger study, our results suggest that the ACT-TT genotype might be a risk factor for primary cerebral hemorrhage.

Comparison of the acute-phase response in patients with ischemic stroke treated with high-dose heparin or aspirin

Experimental studies have suggested that unfractionated heparin (UH) has antiinflammatory properties. It is unknown whether UH also has these properties in patients with acute ischemic stroke. Within 12-24 h of treatment onset we measured the acute-phase response as reflected by the erythrocyte sedimentation rate (ESR) and total number of leukocytes (x10(9)/l) in 706 consecutive patients with acute ischemic stroke treated with full-dose UH (n=450), or 300 mg/day aspirin (n=256). Clinical outcome (Mathew scale) at hospital discharge and the effect of factors such as treatment (UH and aspirin), and acute phase response were assessed using multivariate analyses adjusted for baseline confounders and incident complications. Separate models were created for patients with lacunar and nonlacunar stroke. Whereas there were not differences at baseline between the two treatment groups, total leukocyte counts (8. 0+/-4.1 vs. 8.6+/-3.2, P<0.01) and ESR (21.7+/-20.9 vs. 25.2+/-22.9, P<0.05) were statistically significantly lower in patients treated with UH. This effect of UH was more accentuated in patients with nonlacunar stroke. Overall, leukocytes (7.2+/-2.3 vs. 8.4+/-4.0, P<0. 01), and ESR (15.7+/-17.2 vs. 24.3+/-22.2, P=0.0001) were lower in patients with complete early recovery and this effect was restricted to patients with nonlacunar stroke. Whereas baseline impairment, symptomatic bleeding and stroke recurrence were independent negative outcome predictors, the use of UH was positively associated with early recovery in all patients. This study shows that full-dose UH reduces the acute-phase reaction that follows ischemic stroke more effectively than aspirin. The prognostic implications of such effect seem more notable in patients with nonlacunar stroke.

Circadian changes of heart rate in West syndrome

Patterns of circadian and ultradian rhythms in the heart rate (HR) are described in a full-term baby with birth asphyxia and convulsions. A 24h HR recording was carried out at the age of 1, 15, 56, 289, and 295 days; West syndrome diagnosis was made when the patient was 3 months old. The HR showed no circadian rhythm in the follow-up, whereas it is known that the circadian rhythm appears in healthy infants at the age of 1 month and remains thereafter. This observation may be an indirect indicator of the interference of West syndrome with centers of neurological maturity.

Progressive multifocal leukoencephalopathy following oral fludarabine treatment of chronic lymphocytic leukemia

Progressive multifocal leukoencephalopathy (PML) is a subacute demyelinating disorder of the central nervous system usually affecting immunocompromised individuals and is due to infection of the oligodendrocytes by the JC virus. A case of PML in a chronic lymphocytic leukemia (CLL) patient treated with fludarabine is reported, representing the second such instance in which the diagnosis of the neurological disorder was established by brain biopsy. A 61-year-old man with a 14-year history of B-cell type CLL, for which he had received chlorambucil therapy 10 years earlier, developed progressive paresis of both left extremities at 7 months of receiving low doses of oral fludarabine, when his CD4 count has decreased to 0.08 x 10(9)/l. Cranial magnetic resonance imaging revealed a subcortical focal lesion at the right precentral gyrus and a focal lesion at the right thalamus, and a stereotactic brain biopsy showed pathological findings consistent with PML, namely severe myelin breakdown, reactive astrocytosis, and abnormal, huge glial cells with large bizarre nuclei showing granular basophilic inclusions, whereas the presence of the JC virus was demonstrated by in situ hybridization. The present case, in addition to a few previously reported, calls attention to the possibility that severe neurological side effects can be associated with the immunosuppression provoked by the use of fludarabine in CLL patients.

Calcitonin versus clodronate in the prevention of ovariectomy-induced osteopenia in rats

The effects of salmon calcitonin and clodronate were compared in ovariectomised rats. Sixty female Wistar rats ( 260 g in weight) were fed the same diet and had the same living conditions. The rats were divided into the following groups: 15 rats with sham ovariectomy and no drug treatment (Sham-OVX); 45 rats with bilateral ovariectomy subdivided into 15 rats not receiving drug treatment (OVX group), 15 rats treated with subcutaneous salmon calcitonin, 2 U/kg/day every 2 days (OVX + CT group) and 15 rats treated with subcutaneous clodronate, 5 mg/kg/day every 2 days (OVX + Cl group). Sixty days after surgery, the rats were sacrificed and their femurs and fifth lumbar vertebrae were dissected and cleaned of soft tissue. Femur length, vertebral height, and bone mineral content and bone mineral density of the femur and fifth lumbar vertebra by dual-energy X-ray absorptiometry were measured. Calcitonin had a significant and stronger effect in preventing ovariectomy-induced osteopenia in the femur (OVX + CT vs OVX groups, p < 0.0001); both calcitonin and clodronate had a significant effect on the fifth lumbar vertebra, which was greater in the calcitonin group (OVX + CT vs OVX + Cl groups, p<0.005). These findings indicate that calcitonin has a protective effect on both the axial (trabecular bone) and peripheral (cortical bone) skeletons, but clodronate only has a protective effect on the axial skeleton.

Effects on bone loss of manganese alone or with copper supplement in ovariectomized rats. A morphometric and densitomeric study

OBJECTIVE

The aim of this study was to examine the effect of manganese (Mn) alone and with the addition of copper (Cu) in the inhibition of osteopenia induced by ovariectomy (OVX) in rats. STUDY CONDITIONS: Four lots of 100-day-old female Wistar rats were divided into experimental groups of 15 each. One group received a diet supplemented with 40 mg/kg of Mn per kilogram of feed (OVX+Mn). The second group received the same diet as the first, but with an additional 15 mg/kg of copper (OVX+Mn+Cu). The third group of 15 OVX and the fourth group of 15 Sham-OVX received no supplements. At the conclusion of the 30-day experiment, the rats were slaughtered and their femurs and fifth lumbar vertebrae were dissected. Femoral and vertebral length were measured with caliper and bones were weighed on a precision balance. The bone mineral content (BMC) and bone density (BMD) of the femur (F-BMC, mg and F-BMD, mg/cm(2)) and the fifth lumbar vertebra (V-BMC, mg and V-BMD, mg/cm(2)) were measured separately with dual energy X-ray absorptiometry.

RESULTS

The F-BMD, mg/cm(2) was lower in the OVX than in the Sham-OVX group (P<0.0001) and in the other two groups receiving mineral supplements (P<0.005 in both). F-BMC, mg was significantly lower in the OVX group than in the other three (P<0.0001 in all cases). Calculations for V-BMC, mg and V-BMD, mg/cm(2) are similar to findings in the femur.

CONCLUSIONS

These data show that a Mn supplement is an effective inhibitor of loss of bone mass after OVX, both on the axial and the peripheral levels, although this effect is not enhanced with the addition of Cu.

Ex vivo response to aspirin differs in stroke patients with single or recurrent events: a pilot study

The dose of aspirin for secondary stroke prevention and the clinical meaning of ex vivo platelet abnormalities are debated. We assessed prospectively 39 noncardioembolic stroke patients in which 300 mg/day aspirin had proved effective (n=24) or ineffective (n=15) to prevent recurrent ischemic events. We evaluated platelet aggregation induced by arachidonic acid, adenosine diphosphate and epinephrine, and the sensitivity of platelets to increasing concentrations of the synthetic thromboxane mimetic U46619. Aggregation studies were repeated while subjects received 300 (study phase 1), and 600 (study phase 2) mg/day aspirin, respectively. Overall, arachidonic acid-induced platelet aggregation was less effectively inhibited during study phase 1 compared to phase 2. Arachidonic acid and epinephrine promoted a stronger platelet aggregation in aspirin nonresponders than in aspirin responders while taking 300 mg/day aspirin. On the other hand, 600 mg/day effectively inhibited platelet function in both clinical groups. A lower sensitivity to thromboxane receptors was also found during phase 1 of the study, although the response was similar between aspirin responders and nonresponders. This pilot study suggests that 300 mg/day aspirin is less effective than 600 mg/day to block the cyclooxygenase pathway in noncardioembolic stroke and, incomplete cyclooxygenase inhibition is associated with recurrent thromboembolic events despite adequate aspirin compliance. It is likely that patients could receive a more efficacious stroke prevention if the dose of aspirin is tailored to individual needs as reflected by laboratory findings.

Effects of promethazine on bone mass and on bone remodeling in ovariectomized rats: A morphometric, densitometric, and histomorphometric experimental study

The effect of promethazine on bone is debated. We studied the effect of promethazine on bone and the mechanism of action involved by densitometric and histomorphometric measurements in female Wistar rats (100 days old, mean weight 25 +/- 20 g). A control group of 15 rats was not manipulated. An experimental group of 15 rats were ovariectomized (OVX) at 100 days of life and fed a diet supplemented with 4.8 mg/kg promethazine hydrochloride (OVX + Prom). The group that underwent OVX and a group of 15 rats that underwent sham ovariectomy (Sham-OVX) were not treated with promethazine. After 30 days, all the rats were killed. Their femur and 5th lumbar vertebra were dissected and cleaned of soft tissue. Femoral length and vertebral height were measured with a caliper and bones were weighed on a precision balance. The bone mineral content (BMC) and bone mineral density (BMD) of the whole right femurs and 5th lumbar vertebras were measured by dual-energy X-ray absorptiometry (DXA). Trabecular bone volume (Cn-BV-TV%), trabecular number (Tb-N mm(-1)), trabecular thickness (Tb-Th microm), and trabecular separation (Tb-Sp microm) were measured in the femurs by histomorphometric study of nondecalcified bone. Our results showed that promethazine significantly inhibited postovariectomy loss of bone mass (P < 0. 0001) by significantly reducing bone resorption, as shown by the smaller trabecular spaces observed in the treated OVX rats (P < 0. 0001).

Effects of alprazolam supplementation on vertebral and femoral bone mass in rats on strenuous treadmill training exercise

The ability of alprazolam to diminish cortisol response and favor ovarian function could make it useful in the prevention of osteopenia in athletes in selected cases. A sample of 45 female Wistar rats, all 93 days old and with a mean initial weight of 267 +/- 17 g, were studied. Rats were exposed to a high-performance level of exercise and were divided into two groups-one group received an alprazolam supplement and one did not-and compared with controls to determine the effect of alprazolam on bone mass as measured by dual-energy X-ray absorptiometry (DKA). Exercise consisted of treadmill running on 5 out of 7 days during a period of 11 weeks. A steep grade treadmill inclination was used to stimulate high-intensity muscle activity. Final inclination was 17.5 degrees and treadmill speed was 45 cm/second. Upon completion of the experiment, all the rats were killed and the femur and 5th lumbar vertebra were dissected and cleaned. Length, weight, bone mineral content (BMC), and density (BMD) of the whole right femur and 5th lumbar vertebra were measured. In the exercise only group (no alprazolam), the length, weight, BMC, BMD, and femur BMC/final rat weight ratio of the femur, and the vertebral weight, vertebral BMD and BMC, and vertebral BMC/final rat weight ratio were lower than in the control and the exercise-alprazolam groups (P < 0.0167 - < 0.0001). Alprazolam preserves bone mass in rats exposed to intense exercise.

Transient dissociation of bone metabolism induced by high performance exercise: a study in elite marathon runners

Bone metabolism parameters were studied in 18 elite marathon runners (11 men and 7 women) who participated in the Marathon World Cup held at San Sebastian, Spain in 1993. Measurements were made before the race, immediately after the race, and 24 hours after the race. The most interesting finding was increased alkaline phosphatase (P < 0. 0001) and decreased tartrate-resistant acid phosphatase (P = 0.0035), which suggests that exercise produced uncoupling of the bone cell metabolism. Serum calcium corrected for proteins did not increase with exercise and at the end of the race there was a negative correlation between cortisol, which was significantly higher (P < 0. 0001), and corrected serum calcium (r = 0.53, P = 0.026) that was not present at baseline. Running time showed a significant negative correlation with baseline serum cortisol (r = -0.67, P = 0.0015) and a significant positive correlation with body mass index (r = 0.53, P = 0.0207). The increase in alkaline phosphatase persisted 24 hours after the race, which suggests that exercise produced an intense and sustained effect on osteogenic capacity.

Effect of induced uterine retroversion on bone mass in rats

OBJECTIVE

To evaluate the effect of surgical uterine retroversion on bone mass in rats.

STUDY DESIGN

Forty-five female Wistar rats were assigned randomly to three groups: 15 unmanipulated rats, 15 rats that underwent uterine retroversion, and 15 rats that underwent sham uterine retroversion (exposure of the uterus to air followed by closure of the abdominal cavity). Sixty days later the rats were killed and their femurs were dissected. Femurs were weighed and measured, and femoral bone mineral content (BMC) and bone mineral density (BMD) were determined by dual energy X-ray absorptiometry.

RESULTS

In the group of rats that underwent uterine retroversion, BMC, BMD, and BMC corrected for final body weight were significantly lower (P<0.001) than in the unmanipulated control and sham uterine retroversion groups.

CONCLUSION

Our findings indicate that uterine retroversion induced a loss of bone mass. We could not determine the mechanism of bone loss; in our opinion, these problem merits further investigations, which currently occupy our interest.

Changes in body composition in women treated with gonadotropin-releasing hormone agonists

OBJECTIVE

The changes that agonists of gonadotropin-releasing hormone (GnRH) produce in mineral bone mass are known, but, as far as we know, those produced by these agents in other body compartments are unknown.

METHODS

We studied these changes using dual-energy X-ray absorptiometry in 50 eugonadal women treated with decapeptyl (Triptoreline), 3.75 mg injected intramuscularly, at 28-day intervals for 6 months.

RESULTS

There were significant increases in fat content (9.5%, P < 0.0005) and weight (1.3%, P < 0.01), and significant decreases in fat-free mass (-1.9%, P < 0.0001) and water content (-1.8%, P < 0.0002). Bone mass was lost in the axial skeleton (-3.6%, P < 0.0001) but not in the peripheral skeleton.

CONCLUSIONS

The changes induced in body composition by the GnRH agonists are similar to those of natural menopause.

Comparison of the bone robusticity index and bone weight/bone length index with the results of bone densitometry and bone histomorphometry in experimental studies

In experimental studies of bone in rats, two morphometric indices reflecting bone density have been proposed, the bone robusticity index and bone weight/bone length index. In rats, the bone mineral content (BMC) and bone mineral density (BMD) of a selected bone can be determined using dual-energy X-ray absorptiometry (DXA); bone volume can be measured by histomorphometry and other techniques. This study was undertaken to compare two morphometric indices (bone robusticity and bone weight/bone length) with the results of DXA and histomorphometry. Forty female Wistar rats (100 days old, mean weight 239+/-12 g) were studied: 20 controls and 20 ovariectomized rats (OVX). The morphometric indices and BMD differed significantly (Friedman test) in the overall group of rats; no differences were observed in the control group, but significant differences were apparent in the OVX group (p<0.0001). The morphometric indices correlated more closely with BMC than with BMD; the femur length/ femur weight index had closer correlations than the robusticity index. Nonetheless, both morphometric indices differed significantly from BMD determined by DXA under abnormal conditions, which makes them unreliable for use in these circumstances.

T score of trabecular and cortical bone in normal postmenopausal women

OBJECTIVE

The T score of the cortical and trabecular bone compartments (T score of BMDTrab and T score of BMDCorti) was calculated in healthy postmenopausal women to determine which bone compartment loses more bone mass.

MATERIAL AND METHODS

A total 134 healthy postmenopausal women (mean age 55.1 +/- 6.4 years) and 67 healthy premenopausal women (mean age 36.0 +/- 8.6 years) were studied. Determinations were made using peripheral quantitative computed tomography (pQCT) of the nondominant forearm. The postmenopausal women were divided into groups by years since menopause (YSM): two early postmenopausal groups: < 5 YSM and 6-10 YSM; and two late postmenopausal groups: 11-20 YSM and > 20 YSM.

RESULTS

There was a significant correlation between the T score of BMDTrab and the T score of BMDCorti (P < 0.0001). Both correlated negatively and significantly with age (P < 0.001 and P < 0.0001, respectively) and neither correlated with weight. The Wilcoxon test showed no significant differences between the trabecular and cortical T scores in the overall group of women. By YSM, only the > 20 YSM group showed significant differences (P < 0.005). The ANOVA post hoc Bonferroni/Dunn test showed a significant difference in the T score of BMDTrab by YSM only in the < 5 YSM versus 11-20 YSM groups (P = 0.007) and in the < 5 YSM versus > 20 YSM groups (P < 0.0001). The T score of BMDCorti by YSM differed significantly only between the < 5 YSM versus 11-20 YSM groups (P < 0.0001) and between the 11-20 YSM and > 20 YSM groups (P < 0.005).

CONCLUSION

In contrast with what has been postulated in recent studies, our results showed that postmenopausal bone loss was similar in the cortical and trabecular bone compartments in the first 20 years after menopause. Trabecular bone loss was greater than cortical bone loss in late menopause (> 20 years).

Total and regional bone mass and biochemical markers of bone remodeling in metastatic prostate cancer

BACKGROUND

The osteolytic activity of metastases of prostate cancer was evaluated in relation to total body bone mineral content (TBBMC) and regional bone mineral content (RBMC).

METHODS

Bone mass was determined by dual-energy X-ray absorptiometry (DXA). Tartrate-resistant acid phosphatase (TRAP) was measured as a biochemical marker of bone resorption.

RESULTS

In 32 patients (mean age 72+/-4 years) compared with 32 controls (mean age 73+/-5 years), there were significant differences in TRAP (P < 0.0001), TBBMC (P < 0.0001), and RBMC in the pelvis (P < 0.0001), legs (P=0.0001), and trunk (P<0.05), but not in the arms and head (P=ns). In the overall group of subjects, the correlation between TBBMC and TRAP was r=-0.68, P < 0.0001. The correlations remained significant in the patient and control groups separately.

CONCLUSIONS

The loss of bone mass observed in patients with metastatic prostate cancer was caused mainly by the predominance of bone resorption in the osteoblastic metastases.

Metacarpal radiogrammetry by computed radiography in postmenopausal women with Colles' fracture and vertebral crush fracture syndrome

Based on the hypothesis that the underlying osteoporotic mechanism of Colles' fracture in postmenopausal women is similar to that of other osteoporotic fractures, that is, cortical bone resorption as opposed to cancellous bone resorption, the rate of corticoendosteal bone loss was compared in 40 normal postmenopausal women [average age 68.4 +/- 7.1 years; 20 +/- 4 years since menopause (YSM)], in 35 postmenopausal women with Colles' fracture (age 69.4 +/- 7.5 years, 22 +/- 8 YSM), in 35 normal postmenopausal women with vertebral crush fracture (age 69.4 +/- 7.5 years, 22 +/- 8 YSM, and in 35 normal premenopausal women (age 36.1 +/- 7.9 years). Radiogrammetry by digital radiography of the second metacarpal was used to measure external (ED) and internal (ID) diameter, cortical thickness (CCT), cortical area (CA), and the ratio of cortical area to total area (CA/TA). The ID values of the groups of postmenopausal women were subtracted from the ID value of the premenopausal women and the result was divided by YSM to obtain the rate of corticoendosteal resorption/year (DeltaC), CA resorption year (DeltaCA) and CA/TA resorption/year (DeltaCA/TA). ID, DeltaC, DeltaCA, and DeltaCA/TA all were larger in the postmenopausal women with Colles' and vertebral crush fractures than in the normal postmenopausal women (ANOVA: all P < 0.0001). ID, CCT, DeltaC, CA, DeltaCA, and DeltaCA/TA did not differ between the two groups of postmenopausal women with fractures. DeltaC was 87% greater in postmenopausal women with vertebral crush fracture and 116% greater in women with Colles' fracture than in normal postmenopausal women. These results indicate that the loss of cortical bone is an important factor in Colles' fracture in postmenopausal women.

Ultrasonographic bone velocity in pregnancy: a longitudinal study

OBJECTIVE

Longitudinal changes in bone mass were evaluated with use of ultrasonography and bone remodeling markers in 40 normal pregnant women in relation to their calcium intake.

STUDY DESIGN

The study took place at the University of Alcalá Hospital in Madrid. Biochemical markers of bone remodeling and ultrasonographic bone propagation velocity in the proximal phalanxes of fingers 2 to 5 were measured in all three trimesters of pregnancy. Wilcoxon, unpaired and paired t tests, and analysis of variance were used.

RESULTS

Ultrasonographic bone propagation velocity (meters per second) was lower in the second and third trimesters of pregnancy (p < 0.0001) compared with the respective preceding trimesters and in the third trimester in the overall group of pregnant women. Tartrate-resistant acid phosphatase and alkaline phosphatase levels increased significantly (p < 0.0001) in parallel with the ultrasonographic bone propagation velocity decrease.

CONCLUSIONS

Gestation was accompanied by a reduction in ultrasonographic bone propagation velocity that was greater in women with low calcium intake.

Effects of zinc supplementation on vertebral and femoral bone mass in rats on strenuous treadmill training exercise

The hypothesis that a zinc (Zn) deficit may cause osteopenia in athletes is well founded. In rats exposed to strenuous exercise, we evaluated the effect of a zinc supplement on femoral and vertebral bone mass determined by dual-energy X-ray absorptiometry. Four lots of 93-day-old female Wistar rats were studied. A control group of 30 rats were not manipulated (Zn- Ex- group). The experimental group of 40 rats was fed a diet supplemented with an additional 20% of Zn/kg of feed; this group was divided into two groups of 20 rats each, one that did not exercise (Zn+ Ex-) and one that did (Zn+ Ex+). A group of 15 rats exercised but did not receive a zinc supplement (Zn- Ex+ group). Training consisted of treadmill running for 5 out of 7 days over an 11-week period. Initial speed, running time, and treadmill speed were increased gradually. Analysis of variance with the Bonferroni/Dunn test showed that the length, weight, bone mineral content (BMC), and bone mineral density (BMD) of the femur were less in the Zn- Ex+ group than in the others (p < 0.008), and the weight, BMC, and BMD of the fifth lumbar vertebra also were lower in the Zn- Ex+ group than in the others (p < 0.008). These findings confirm the adverse effects of strenuous exercise (treadmill running) on bone tissue in rats and the effectiveness of zinc supplementation in preventing it.

[Chronobiological profile of arterial blood pressure and heart rate in a family group determined by automatic monitoring]

Over a week, blood pressure (systolic, mean and diastolic) and heart rate were determined in a family, by means of automatic, uninterrupted monitoring. The chronobiological profile for each family member was prepared in time series of various periodicities. An ample circadian component and a lesser circaseptan component were apparent. Clear phase differences were identified among the four cardiovascular variables studied. The chronobiological profile of the children was closer to that of the father than to that of the mother.

Comparison of three bone densitometry methods in osteoporotic women

Three techniques of bone mass measurement were evaluated in the diagnosis of postmenopausal osteoporosis; the overlap in the measurements and the capacity for discriminating was determined among 51 postmenopausal normal (mean age 66.6 +/- 8.4 years) and 42 postmenopausal osteoporotic women (mean age 68.5 +/- 7.5 years). All bone mass was evaluated by total body bone mineral content (BMCTB), density (BMDTB), ultrasound bone velocity (UBV) in proximal phalanxes 2-5 of the nondominant hand (UBV = mean value of all ultrasound measurements), and peripheral quantitative computed tomography of the nondominant forearm (pQCT). BMCTB was found to be significantly better (P < 0.0001) for diagnosing postmenopausal osteoporosis than the other methods; both cortical and trabecular pQCT measurements were more discriminating than the corresponding UBV measurements (P < 0.001). T-score values in normals, subjects versus osteoporotic ones were BMCTB -1.15 +/- 0.79 versus -3.17 +/- 0.74; BMDTB -1.01 +/- 0.97 versus -3.28 +/- 0.81; UBV -1.51 +/- 1.02 versus -2.34 +/- 1.21; trabecular-pQCT -0.40 +/- 0.72 versus -1.57 +/- 0.37; cortical-pQCT -1.00 +/- 0.87 versus -2.67 +/- 0.53; and total-pQCT -0.65 +/- 1.01 versus -2.34 +/- 0.27, respectively. The overlap in values between the postmenopausal normal and postmenopausal osteoporotic groups was 50% with UBV, 6% with BMCTB, 9% with BMDTB, 25% with cortical pQCT, and 42% with trabecular pQCT. BMCTB, BMDTB, UBV, and pQCT correlated well with each other as measurements of bone mass, but BMCTB was more discriminating than the other measurements in the diagnosis of osteoporosis.

Influence of soft tissue (fat and fat-free mass) on ultrasound bone velocity: an in vivo study

RATIONALE AND OBJECTIVES

The authors determine the relative effect of soft-tissue compartments, body fat (percent [%Bfat] and weight [Bfat kg]) and fat-free mass (FFM kg), on measurements of ultrasound bone velocity (UBV m/second).

METHODS

The authors measured UBV in proximal phalanxes and body fat and fat-free mass by near infrared interactance in 40 healthy premenopausal women (mean age +/- standard deviation 28.2 +/- 3.8 years).

RESULTS

Correlation study (Fisher's r to z) showed that UBV correlated negatively with %Bfat (r = -0.61, P < 0.0001), Bfat kg (r = -0.56, P = 0.0001) and marginally with body weight (r = -0.33, P = 0.0403), but did not correlate with FFM kg or H2O L (both r = -0.08, P not significant). When the correlation test was adjusted for weight and age (partial correlation), the negative correlation between UBV and %Bfat persisted (r = -0.54, P < 0.0005; and r = -0.63, P < 0.0001, respectively) and the correlation with FFM kg, adjusted for weight, became positive and significant (r = 0.55, P < 0.0005).

CONCLUSIONS

These results, to our knowledge, are the first to be obtained by in vivo evaluation of UBV in relation to body fat and fat-free mass. Body fat, but not fat-free mass, was the main factor affecting UBV. This confirms the deficiency of UBV measurements, considering that obesity is a protective factor for bone mass.

Influence of weight and gonadal status on total and regional bone mineral content and on weight-bearing and non-weight-bearing bones, measured by dual-energy X-ray absosorptiometry

OBJECTIVE

To evaluate the influence of weight on total body bone mineral content (BMCTB) and regional body bone mineral content (head, arms, trunk and legs). This was studied in accordance with gonadal status and the weight-bearing or non-weight-bearing status of each region.

METHODS

The study included 94 postmenopausal women (mean age 60.6 +/- 10.5 years), 36 perimenopausal women (mean age 49.0 +/- 2.3 years) and 60 premenopausal women (mean age 36.1 +/- 6.9 years). Full-body bone densitometry (DXA), for measuring total body bone and regional bone mineral content, was carried out in all the women.

RESULTS

Among these groups, the influence of 1 kg of body weight on total and regional bone mineral content (percent) did not differ (paired test P ns). In the overall group of women, paired comparison showed differences between the head and other zones measured (P = 0.036-0.004). In the overall group of women, no differences were found in the percent influence of 1 kg body weight on bone mineral content in any study zone (by ANOVA, Fisher's PLSD post hoc test and the Kruskal-Wallis test). In the overall group of women, Fisher's r to z test revealed a non-significant relationship between weight and the bone mineral content of the head (r = 0.49, P ns) but in every other region the relationship between weight and bone mineral content was significant (r = 0.36-0.54, P < 0.0001 in all).

CONCLUSIONS

The effect of body weight on BMCTB and regional did not differ significantly with either gonadal status or weight-bearing (legs) and non-weight-bearing bones (arms).

Influence of body mass index on the age-related slope of total and regional bone mineral content

The influence of body mass index (BMI) on T scores for total body bone mineral content (TBBMC) and regional bone mineral content (RBMC) was studied in 186 healthy women: 100 postmenopausal, 35 perimenopausal, and 51 premenopausal. The three groups were divided by BMI >25 kg/m2 and BMI <25 kg/m2 and the postmenopausal women were further subdivided by years since menopause (YSM): <10, 10-20, and >20. Tartrate-resistant acid phosphatase (TRAP) concentration was higher in perimenopausal and postmenopausal women with BMI <25 kg/m2 (P < 0.001). T scores for TBBMC and for axial or peripheral RBMC differed (P < 0.05 in all) between women with BMI >25 kg/m2 and BMI <25 kg/m2. The rate of perimenopausal and postmenopausal age-related slope of BMC, as reflected in all measurements, differed with BMI. In the overall group of women, the T score for TBBMC correlated significantly with BMI (r = 0.46, P < 0.0001); this correlation increased when adjusted for age (r = 0.62, P < 0.0001). BMI correlated with TRAP only in postmenopausal women (r = 0.57, P < 0. 0001). Yearly TBBMC decline was twice as high in postmenopausal women with BMI <25 kg/m2 (P = 0.0004) than in those with BMI >25 kg/m2; the decline of trunk RBMC was more significant (P < 0.0001). These findings confirm the influence of BMI and gonadal status on bone mass.

Complementary medical treatment for Colles' fracture: a comparative, randomized, longitudinal study

In 45 women with Colles' fracture, two types of complementary medical treatment (calcitonin with calcium [SCT+Ca] and calcium alone [Ca]) were compared with placebo. Consecutive patients were assigned randomly to one of the three study groups at the time of inclusion in the study: 15 women (68.6 +/- 5.7 years) were given 100 IU/day I.M. of SCT plus 1200 mg of elemental Ca for 10 successive days each month; 15 women (71.7 +/- 6.1 years) were given only 1200 mg of elemental Ca for 10 days each month; and 15 women (66.9 +/- 7. 9 years) were treated with placebo. Biochemical and radiogrammetric studies were made at baseline and after 1 year of treatment. In the SCT+Ca group tartrate-resistant acid phosphatase decreased (Wilcoxon test, P = 0.014) and the metacarpal index and the cortical and total area (CA/TA) ratio increased (both P = 0.001). In the group treated with Ca alone, no changes were observed. In the placebo group, the metacarpal index and CA/TA decreased (P = 0.015 and P = 0.007, respectively). Ca alone, at the dosage used here, inhibited bone loss after Colles' fracture. The addition of SCT to Ca administration not only impeded bone loss but significantly increased cortical bone mass.

Influence of electromagnetic fields on bone mass and growth in developing rats: a morphometric, densitometric, and histomorphometric study

The effect of electromagnetic fields on bone is debated. In an experimental study of this effect, we compared two lots of growing female rates (both lots n = 15, age 3 weeks, average weight 23.2 +/- 3.3 g), one of which was exposed to a 3-mT, 100-Hz, Helmholtz-type electromagnetic field for 24 hours a day for 30 days, and the other of which served as the control. Bone development and bone mass were evaluated by morphometry, densitometry, and histomorphometry. The rats were killed at 30 days and weighed. The right femurs were dissected, measured, and weighed; bone densitometry was used to determine femoral bone mineral content (BMC) and density (BMD), and histomorphometry of the nondecalcified bone was used to determine trabecular bone volume (Cn-BV-TV%), number (Tb-N mm) and thickness (Tb-Th microm), intertrabecular space (Tb-Sp microm) and growth cartilage thickness (Gc-Th microm). In the rats exposed to the electromagnetic field, BMC and BMD (P = 0.019 and P = 0.002, respectively) and Cn-BV-TV, Tb-N, Tb-Th (P = 0.005, P = 0.036, and P = 0.027, respectively) all were decreased, whereas Tb-Sp was increased (P = 0.002). There were no significant differences in initial and final body weight, or in final femur weight, femur length, and GC-Th. These findings indicate that electromagnetic fields of the type used here reduced bone formation and increased bone resorption without affecting bone development in rats.

Vertebral and metacarpal morphometry as indicators of nutritional improvement

Because of the importance of nutrition in the development of bone mass, we studied the nutritional state, and bone state by means of metacarpal radiogrammetric measurements and vertebral morphometry in a group of 40 premenopausal women born between 1960 and 1970, mean age 29 +/- 5 years, and in another group of 40 postmenopausal women born between 1934 and 1944, mean age 55 +/- 4 years. Both groups were considered normal, the main characteristic distinguishing them being that the women born between 1934 and 1944 grew up in a period of widespread malnutrition in Spain and the women born between 1960 and 1970 grew up in a period of normal nutrition. Protein, carbohydrate and fat intake in these two periods differed significantly (p < 0.0001 in the three cases by Fischer's exact test). The values of the metacarpal measurements, anterior height of the dorsal vertebrae from T-4 to T-12, and posterior height from L-1 to L-4 between the premenopausal and postmenopausal groups of women were significantly different (p < 0.001) (Anova test). These findings show the importance of nutrition in the development of bone mass during childhood.

Cortical bone resorption in osteoporosis

A study was made of 110 women: 35 healthy premenopausal, 40 healthy postmenopausal, and 35 women diagnosed as having postmenopausal osteoporosis. The postmenopausal women had similar ages and years since menopause (YSM). In all of the women, total bone mass was evaluated by dual-energy X-ray absorptiometry and metacarpal morphometry was evaluated by radiogrammetry on the second metacarpal of the nondominant hand, performed by computed radiography. An external metacarpal diameter of >/=7.4 mm was required as proof of having developed an adequate peak bone mass. The endosteal diameter, which is indicative of bone resorption in both groups of postmenopausal women, obtained in the postmenopausal groups was subtracted from the endosteal diameter obtained in the premenopausal group and the resulting figure was divided by the years since menopause to calculate the rate of cortical bone resorption/year for each group. The endosteal diameters values differed in the three groups studied (P < 0.0001): 3.2 +/- 0.7 mm in the healthy premenopausal women; 3.9 +/- 0.6 mm in the healthy postmenopausal women; and 4.7 +/- 0.5 mm in the osteoporotic postmenopausal women. The rate of cortical bone resorption was 0.068 +/- 0.002 mm/YSM (years since menopause) in the osteoporotic postmenopausal women and 0.033 +/- 0.003 mm/YSM in the healthy postmenopausal women (P < 0. 0001). These figures reflect the importance of bone resorption, as opposed to deficient bone formation, as a cause of osteoporosis.

Heterogeneity of trabecular and cortical postmenopausal bone loss: a longitudinal study with pQCT

Eighty-one women were studied longitudinally to measure trabecular bone mineral density (BMDTrab) and cortical bone mineral density (BMDCorti) in the distal radius by peripheral quantitative computed tomography (pQCT) at intervals of about 1 year and to calculate the rate of percent change/year. Fifty-three women were naturally postmenopausal [mean age 63.3 +/- 5.3 years, age at menopause 50.7 +/- 3.8 years, 13 years since menopause (YSM)] and 28 had been ovariectomized (mean age 52.7 +/- 5.8 years, age at menopause 39.5 +/- 5.0 years, 13 YSM). There was no difference between groups (ANOVA) in the rate of percent change/years in BMDTrab (p = 0.692), but there was in BMDCorti (p = 0.020). When the women who had either gained or lost bone mass were compared (chi-square test), only BMDCorti differed significantly (p = 0.018). Considering > -2.5% change/years as the limit for rapid bone mass loss, BMDTrab values showed that 43% of the naturally postmenopausal women and 42.7% of the ovariectomized women had rapid bone loss (p ns). On the basis of BMDCorti values, 45% of the naturally postmenopausal women and 28.4% of the ovariectomized women had rapid bone loss (p = 0.018). Height, weight, body mass index (BMI), age, YSM, and years of reproductive life did not differ (ANOVA) between the women who gained or lost either BMDTrab or BMDCorti. Using Fisher's r to z and partial correlation adjusted for age and YSM of the percent change/year in BMDTrab and BMDCorti in the overall group and in each menopausal group, only BMDCorti differed.

Effect of lead on bone development and bone mass: a morphometric, densitometric, and histomorphometric study in growing rats

The effect of exposure to lead on the longitudinal development of bone and on bone mass was studied in rats. A group of 35, 50-day-old female Wistar rats was divided into a control group of 15 rats and an experimental group of 20 rats fed a diet supplemented with 17 mg of lead acetate per kg feed for 50 days. Total body bone densitometry (TBBMC) was performed the day before ending the 50-day experiment. On day 50, all rats were killed and their right femur and 5th lumbar vertebra were dissected. The bones were cleaned of soft tissue and femoral length and vertebral length were measured with a caliper and all bones were weighed on a precision scale. Final body weight (P < 0.05), TBBMC (P < 0.005), and femur weight (P < 0.005) were significantly lower in the control group. Femur length did not differ between groups, but the length of the 5th lumbar vertebra was greater in the control group (P < 0.05). Histomorphometry of the femur showed that Cn-BV/TV, Tb-N, Tb-Th were lower (P < 0.05 in all) and Tb-Sp was higher (P < 0.05) in the group given the lead-supplemented diet. These findings suggested lead-induced inhibition of axial bone development and a histomorphometric decrease in bone mass, produced mainly by enhanced resorption, and a densitometric increase in bone mass, produced by lead accumulation in bone.

Ultrasound bone velocity on proximal phalanges in premenopausal, perimenopausal, and postmenopausal healthy women

RATIONALE AND OBJECTIVES

The authors studied premenopausal, perimenopausal, and postmenopausal women to determine if ultrasound bone velocity (UBV) on proximal phalanges of women reflect bone changes related to gonadal status and age.

METHODS

A total of 166 healthy women-64 postmenopausal women (mean age 58.7 +/- 9.4 years), 41 perimenopausal women (mean age 49.5 +/- 2.9 years), and 61 premenopausal women (mean age 36.8 +/- 7.1 years)-were studied. All the women underwent UBV study of the 2nd to 5th proximal phalanges on the nondominant hand and the mean value of all ultrasound measurements was calculated.

RESULTS

The postmenopausal women had a UBV that differed significantly, one-way analysis of variance, from that of the perimenopausal women and premenopausal women (both P < 0.001). The UBV measurements of the perimenopausal women differed significantly from those of the premenopausal women (P < 0.01). Simple linear regression analysis of the relation between UBV and age showed that this was significant and negative in the overall group of women (r = -0.69; P < 0.0001), significant in the perimenopausal (r = -0.66; P < 0.001) and postmenopausal women (r = -0.69; P < 0.001) and nonsignificant in the premenopausal women (r = 0.08; P not significant). In the postmenopausal women, the correlation between UBV and years since menopause was larger (r = -0.71; P < 0.0001) than the correlation between UBV and chronological age.

CONCLUSIONS

Ultrasound bone velocity of the phalanx, as a method for measuring changes in bone with age, has a precision that makes it possible to detect changes in bone mass in perimenopausal women and may perform similarly to other bone mass measurements.

Effect of lead on bone and cartilage in sexually mature rats: a morphometric and histomorphometry study

The effect of exposure to lead on the longitudinal development of the femur and of its cartilage growth plate was studied in rats. A group of forty-five 50-day-old female Wistar rats was divided into a control group of 20 rats and an experimental group of 25 rats fed a diet supplemented with 17 mg of lead acetate per kilogram of feed for 50 days. On Day 50 all rats were killed and their right femurs were dissected. The femurs were cleaned of soft tissue and femoral lengths were measured with a Vernier caliper and thickness of growth cartilage (GPC-Th micron) by histomorphometry. Final body weights were significantly (P < 0.05) lower in the control group than in the rats given the lead-supplemented diet. Femur length did not differ between groups. Histomorphometry of the femur showed that the thickness of growth cartilage was higher (P < 0.05) in the control group. These findings suggested lead-induced inhibition of growth plate development. The growth plate may be one of the key target tissues accounting for the adverse effects of chronic lead exposure on skeletal development.

Resonance of about-weekly human heart rate rhythm with solar activity change

In several human adults, certain solar activity rhythms may influence an about 7-day rhythm in heart rate. When no about-weekly feature was found in the rate of change in sunspot area, a measure of solar activity, the double amplitude of a circadian heart rate rhythm, approximated by the fit of a 7-day cosine curve, was lower, as was heart rate corresponds to about-weekly features in solar activity and/or relates to a sunspot cycle.