RC Groups Research Articles

Effects of light-dark cycle manipulation on critical velocity and anaerobic running capacity in Wistar rats

The aim of the study was to assess the effect of the light-dark cycle on the critical velocity (CV) and the anaerobic capacity (ARC) of running rats. The entire experiment utilised two separate groups under two conditions: a regular light-dark cycle 12/12 hours (light on from 6:00 to 18:00 - RC group) and an altered light-dark cycle 12/12 hours (light on from 18:00 to 6:00 - AC group). First, running rat groups were selected. The animals were submitted to four exercise tests (25, 30, 35 and 40 m/min) performed until exhaustion. The times to exhaustion for each running intensity were recorded (tlim). The CV and ARC were estimated from the linear regression of ‘velocity vs. 1/tlim’, where the CV and ARC were the linear and slope coefficients, respectively. The running rat groups showed a significant difference in percent selection under the two light cycles (16.4% and 28.9% of running rats in the RC and AC groups, respectively). The CV was highest in the AC condition (CVRC = 22.7±0.8 m/min and CVAC = 25.5±0.4 m/min), but the ARC (ARCRC = 22.80±2.76 m and ARCAC = 21.80±4.93 m) and the linear fit (R2 RC = 0.88±0.03 and R2 AC = 0.85±0.02) were not different in both conditions These results indicate that caution is necessary when varying the circadian rhythm of rats submitted to running exercise, especially because their aerobic condition is improved when an altered light-dark cycle is used.

Emergence of ageing-related changes in insulin secretion by pancreatic islets of male rat offspring of mothers fed a low-protein diet

Maternal low-protein (LP) diets programme β-cell secretion, potentially altering the emergence of ageing of offspring pancreatic function. We hypothesised that isolated pancreatic islet β-cell secretory responses are blunted in offspring exposed to LP during development and age-related reduction is influenced by the developmental stage of exposure to decreased nutrition. We studied male offspring of rats fed control (C) or LP protein (R) diets in pregnancy, first letter and/or lactation second letter of CC, RR, CR or RC groups. Serum glucose, insulin and homeostatic model assessment (HOMA) were measured. Pancreatic islets were isolated and in vitro insulin secretion quantified in low (LG - 5 mM) or high glucose (HG - 11 mM). Body weight and serum values between groups were similar at all ages. Insulin and HOMA rose with age and were highest at postnatal day (PND) 450 in all groups. At PND 36, insulin secretion was greatest in RR and RC. Only CC increased insulin secretion to HG. By PND 110, restricted groups responded less to LG but increased secretion to HG. By PND 450, CC offspring alone increased secretion to HG. Despite minimal differences in circulating insulin and glucose, reduced maternal protein intake affected insulin secretion at all ages. In addition, ageing reduced function in all R groups compared with CC by PND 110 and further by PND 450 most markedly in RC. We conclude that maternal LP diet during pregnancy and/or lactation impairs offspring insulin secretory response to a glucose challenge and alters the trajectory of ageing of pancreatic insulin secretion.

Nutritional recovery with rice bran did not modify energy balance and leptin and insulin levels

To investigate the effect of nutritional recovery with rice bran on energy balance, leptin and insulin levels. Weaned Wistar rats were fed on a 17% (Control - C) or 0.5% (Aproteic - A) protein diet for 12d. After this, rats were kept on a C diet (C) or recovered with control (Recovered Control - RC) or control plus recovered rice bran diet (Recovered Rice Bran - RRB). Despite the increased food intake, group A exhibited lower carcass fat associated to low serum leptin. RRB and RC groups showed lower carcass weight and energy intake and expenditure. Energy expenditure was positively associated with food intake and carcass weight. Negative correlations between HOMA-IR and energy expenditure and energy intake were observed. Nutritional recovery with rice bran did not modify energy balance, leptin and insulin levels.

Protective effect of carbon dioxide against bacterial peritonitis induced in rats

Carbon dioxide (CO(2)) has been used in the food industry as an antimicrobial agent. This study aimed to investigate whether CO(2) pneumoperitoneum might act similarly as an antimicrobial agent in the infected peritoneal cavity. Peritonitis was induced in 58 rats by intraabdominal injection of an Escherichia coli inoculum (6 x 105 colony-forming units [CFU]/ml). Control rats were injected with saline solution. The rats were randomly divided into four groups: rat control (RC, n = 15), bacterial inoculation control (BIC, n = 10), bacterial inoculation and laparotomy (BIL, n = 17), and bacterial inoculation and CO(2) pneumoperitoneum (BIP, n = 16). The survival rates and histopathologic changes in the abdominal wall muscles, spleen, liver, intestines, and omentum were evaluated, and the samples were classified as "preserved" or "inflamed" (acute inflammation or tissue regeneration). The survival rates for the four groups were as follows: RC (100%), BIP (75%), BIL (53%), and BIC (30%). With regard to survival rates, statistically significant differences were observed between the following groups: RC and BIC (p = 0.0009), RC and BIL (p = 0.0045), BIP and BIC (p = 0.0332), and RC and BIP (p = 0.0470). No significant differences regarding survival rates were observed between the BIL and BIC groups or between the BIP and BIL groups. With regard to the number of inflamed samples per group, a statistically significant difference was observed between the BIC and RC groups and the BIL and RC groups (p = 0.05). Carbon dioxide pneumoperitoneum has a protective effect against bacterial peritonitis induced in rats.

Radiotherapy With or Without Concurrent Chemotherapy for Lymph Node Recurrence After Radical Surgery of Thoracic Esophageal Squamous Cell Carcinoma

To retrospectively compare the outcomes of patients with lymph node recurrence after radical surgery of esophageal cancer, when given radiotherapy with or without concurrent chemotherapy. Between January 1996 and December 2005, the data from 73 patients with lymph node recurrence after radical surgery of thoracic esophageal squamous cell carcinoma were retrospectively reviewed. The patients were separated into two groups: radiochemotherapy (RC, 31 patients) and radiotherapy alone (RA, 42 patients). Patients in the RC group received at least two cycles of 5-fluorouracil/cisplatin chemotherapy concurrently with radiotherapy. The median duration of follow-up was 11 months (range, 2-48). The overall survival rate for all patients was 46.7% and 4.7% at 1 and 3 years, respectively. The median overall survival time was 9 months (95% confidence interval, 6.96-11.04) and 17 months (95% confidence interval, 13.61-20.39) for RA and RC groups, respectively. The survival rate at 1 and 3 years was 62.5% and 10.5% in the RC group and 33.8% and 0% in the RA group (p = .0049, log-rank test; hazard ratio for death, 0.52; 95% confidence interval, 0.30-0.92). Acute toxicities were more frequent in the RC group than in the RA group. No significant differences were found in the late toxicity profiles between the two groups. The results of the present retrospective analysis suggest that RC should be considered an effective and well-tolerated treatment of patients with thoracic esophageal squamous cell carcinoma and postoperative lymph node recurrence.

Dual-energy MDCT: Comparison of pulmonary artery enhancement on dedicated CT pulmonary angiography, routine and low contrast volume studies

Purpose The aim of this study was (a) to compare arterial enhancement in simultaneously acquired high- and low-kilovoltage images; and (b) to determine whether low tube-voltage imaging would permit PE evaluation on routine chest CT studies or CTPA studies performed with a low volume of contrast media. Materials and methods We compared 20 CTPA studies (CTPA group), 20 routine thoracic CT studies (RT group) and 10 CTPA studies performed with reduced volume of contrast media (RC group). HU values were measured in all groups at 80 kVp and 140 kVp images in multiple pulmonary arterial segments bilaterally. The diagnostic quality of the central and peripheral vascular enhancement and the image noise were evaluated at both energies using a five-point scale. Results For all patients, the mean CT attenuation values were greater at 80 kVp than 140 kVp images ( p < 0.001). At 80 kVp, CTPA group attenuation values were greater than RT group ( p = 0.03) with a similar trend at 140 kVp ( p = 0.08). At both 140 kVp and 80 kVp, CTPA group attenuation values were greater than RC group ( p = 0.02 and p = 0.03, respectively). Qualitative analysis showed that at 140 kVp CTPA studies had better global image quality scores than RT ( p = 0.003) and RC ( p = 0.001) groups. However, at 80 kVp, there was no significant difference of global image quality between CTPA and the other groups ( p = 0.4 and p = 0.5, respectively). Although measurable image noise was greater at 80 kVp than 140 kVp ( p < 0.001), qualitative analysis revealed lower image noise at 80 kVp images. Conclusion DECT at 80 kVp increases arterial enhancement in both CTPA and routine studies. For routine studies this results in central and peripheral enhancement quality equivalent to that of CTPA studies. Low tube-voltage imaging allows marked contrast volume reduction for CTPA. In selected cases, satisfactory lower radiation dose CT might be achievable using lower kVp imaging alone.

Long-Term Effects of Pharyngeal Flaps on the Upper Airways of Subjects with Velopharyngeal Insufficiency

To investigate the long-term effects of pharyngeal flap surgery (PFS) on nasal and nasopharyngeal dimensions of patients with velopharyngeal insufficiency (VPI) and to correlate the findings with the onset of respiratory complaints after surgery. Prospective study in 58 nonsyndromic patients with repaired cleft palate and VPI, evaluated 2 days before and 5 months (POST1) and 1 year (POST2) after PFS, on average. Patients were divided into two groups: one consisting of patients with postoperative respiratory complaints (RC group) and the other without complaints (NRC group). Superiorly based PFS. Respiratory complaints (self reports of mouth breathing, snoring, and other sleep obstructive events) assessed at POST1 and POST2, and minimum nasal (NCSA) and nasopharyngeal (NPA) cross-sectional areas assessed by rhinomanometry at POST2. Respiratory complaints were reported by 55% and 36% of the patients evaluated at POST1 and POST2, respectively. Posterior rhinomanometry showed a significant postoperative reduction of mean NCSA in the RC and NRC groups (p < .05), to subnormal levels in some of them. The decrease was more pronounced in the RC group. No significant changes in NCSA were observed by anterior rhinomanometry. Similar results were obtained when NPA was assessed by modified anterior rhinomanometry. In the long-term, PFS yielded a significant reduction in upper airways dimensions beyond what should be expected and associated with persistent respiratory complaints in some cases.

Identification of dentine sialoprotein in gingival crevicular fluid during physiological root resorption and orthodontic tooth movement

Root resorption is an unwanted effect of orthodontic tooth movement. Analysis of dentine proteins in gingival crevicular fluid (GCF) is a potentially safer method of quantifying root resorption compared with conventional radiographic methods. This study aimed to identify and quantify the dentine-specific matrix protein, dentine sialoprotein (DSP), released into GCF during physiological root resorption and orthodontic tooth movement. GCF was collected using micropipettes from 50 second primary molar sites undergoing physiological root resorption in 9- to 14-year olds [coronal group (Rc) with advanced resorption (n = 33) and apical group (Ra) with minimal resorption (n = 17)] and 20 subjects aged 8-14 years with erupted mandibular second premolars (control group). In addition, GCF was collected from 20 patients undergoing treatment with fixed appliances at two time points, immediately prior to orthodontic intervention (T0) and 12 weeks following commencement of fixed appliance therapy (T1). GCF samples were analysed for DSP using an immunoassay and levels semi-quantified using image analysis. To determine differences between the means of the various experimental and control groups, data based on the relative optical density volumes, were statistically analysed using a parametric t-test. DSP was raised in sites that were undergoing physiological resorption compared with the non-resorbing controls (P < 0.05). Notably, DSP was detected in some control samples. There was no difference in DSP levels for the Rc or Ra groups. DSP was also raised in GCF samples of teeth at 12 weeks following commencement of fixed appliance therapy (P < 0.001). The results highlight the potential for measuring DSP in GCF as a biomarker to monitor root resorption. Dentine is likely to be the major source for DSP in GCF, although alternative origins of bone and cementum are possible.

Intermittent hyperthermia enhances skeletal muscle regrowth and attenuates oxidative damage following reloading

Skeletal muscle reloading following disuse is characterized by profound oxidative damage. This study tested the hypothesis that intermittent hyperthermia during reloading attenuates oxidative damage and augments skeletal muscle regrowth following immobilization. Forty animals were randomly divided into four groups: control (Con), immobilized (Im), reloaded (RC), and reloaded and heated (RH). All groups but Con were immobilized for 7 days. Animals in the RC and RH groups were then reloaded for 7 days with (RH) or without (RC) hyperthermia (41-41.5 degrees C for 30 min on alternating days) during reloading. Heating resulted in approximately 25% elevation in heat shock protein expression (P < 0.05) and an approximately 30% greater soleus regrowth (P < 0.05) in RH compared with RC. Furthermore, oxidant damage was lower in the RH group compared with RC because nitrotyrosine and 4-hydroxy-2-nonenol were returned to near baseline when heating was combined with reloading. Reduced oxidant damage was independent of antioxidant enzymes (manganese superoxide dismutase, copper-zinc superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase). In summary, these data suggest that intermittent hyperthermia during reloading attenuates oxidative stress and improves the rate of skeletal muscle regrowth during reloading after immobilization.

Changes in muscle strength and EMG median frequency after anterior cruciate ligament reconstruction

The purpose of this study was to monitor neuromuscular changes in quadriceps femoris muscle at 1 and 3 months after anterior cruciate ligament reconstruction (ACLR). Changes in isometric muscle strength (MVC), voluntary activation and surface electromyogram (EMG) parameters were examined in relation to knee stability, pain and swelling in 31 patients (25 M, 6 F) mean (SD) 30(8) years. Physically inactive (RC) and sports participants (SC) acted as controls. Median frequency (Hz) and amplitude (mV) of rectus femoris using Fast Fourier Transform (FFT) 2(11) was calculated during 5-s isometric contractions at 100, 75, 50 and 25% of MVC. One month after surgery, a significant correlation (P < 0.01) was found between activation (%) and MVC of injured knee extensors. By 3 months, most patients were pain free and had achieved full activation but still had muscle weakness. At 1 and 3 months post-surgery and for all levels of MVC contraction, the median frequencies of the injured limbs were significantly lower (P < 0.05) compared to the SC group as were those of the RC group. There was a significant lowering of the median frequencies of the uninjured limbs compared to the SC group at 75 and 100% of MVC. The EMG amplitude of the uninjured and injured limbs mirrored those of the SC and RC groups, respectively. These results support the view that muscle activation patterns were altered following ACL injury and surgical repair and may contribute to subsequent changes in muscle fibre properties during detraining and subsequent retraining.

Superior 12-Year Survival After at Least 4-Year Continuous Remission with Tandem Transplantations for Multiple Myeloma

BackgroundComplete response has been considered a surrogate for favorable long-term outcome in multiple myeloma. Data on the impact of the duration of response on prognosis are lacking. Patients and MethodsOf the 899 patients enrolled in Total Therapy trials (Total Therapy 1, N = 231; Total Therapy 2, N = 668), 254 survived for > 5 years. The prognostic impact of continuous (Rc) versus discontinuous (Rd) 4-year remission after 5-year survival was examined along with laboratory features present at baseline and at 5 years. ResultsMost baseline prognostic features were evenly distributed among Rc and Rd groups; however, a greater proportion of Rc patients were enrolled in Total Therapy 2 (60%) compared with Rd (19%; P < 0.001). Twelve-year survival (7 years after the 5-year landmark) was 66% with Rc and only 30% with Rd. Hypodiploidy and deletion 13, present in 24 patients at baseline, were associated with a 12-year survival of only 20%. Among the 200 patients lacking these cytogenetic abnormalities, Rc (n = 141) defined a superior 12-year survival rate of 70% versus 35% among those with Rd (n = 59). Initial quality of response (complete response) or having received the scheduled tandem transplantations did not affect post-5-year survival. ConclusionFive-year Rc appears to be an important prerequisite for prolonged subsequent overall survival.

Superior 12-yr Survival (66% vs 30%) with 5-yr Continuous (Rc) vs “Discontinuous” Remission (Rd): Results of Total Therapies 1 & 2 (TT1,2) for Multiple Myeloma (MM).

Background: The extension of overall survival (OS) in MM has been partly linked to increasing CR rates especially with high-dose melphalan. Data bases of TT1 and TT2 were examined to determine whether 5-yr Rc was key to prolonged OS.Patients and Methods: TT1 enrolled 231 and TT2 668 patients (median follow-up, 4 years). Pre-study characteristics of Rc vs Rd patients surviving >= 5yrs were compared. Furthermore, subsequent OS was examined in the context of pre-treatment variables, TT2 vs TT1 and Rc vs Rd. Only those Rd patients who were event-free (CR or PR) at least 1 year prior to the 5-yr landmark were included in this analysis.Results: Among 231 TT1 + TT2 patients surviving >= 5yrs, more TT2 patients were Rc compared to Rd (60% vs 19%, p<0.001) and more older patients were Rc (at least 65: 13% vs 3%, p=0.019). Importantly, baseline LDH, B2M, CRP, albumin, presence of cytogenetic abnormalities (CA) and whether thalidomide was part of TT2 were evenly distributed among Rc and Rd groups. Furthermore, the 5-yr risk profile of Rc patients was lower than that of Rd patients: lower bone marrow plasma cell % (at least 33%: 0% vs 14%, p=0.003), higher albumin (less than 3.5g/dL: 7% vs 16%, p=0.047), higher Hb (less than 10g/dL: 4% vs 16%, p=0.023), less frequent CA13 (1% vs 11%, p=0.007). Rc patients had significantly longer subsequent survival than those with Rd (12-year survival from enrollment and 7 yrs post-landmark: 66% vs 30%, p<0.001) (Figure). In addition to Rc, univariately significant factors for post 5-year OS were data at 5 years on CA, albumin, B2M, CRP and creatinine. Rc and no CA at 5yrs were the key factors favoring long subsequent survival; thus, 12-yr OS rates decreased from 57% in the 94 patients with Rc/noCA to 44% in 44 with noRC/noCA; 8 of 9 noRc/CA patients have died by year eight; 1 of the 8 Rc/CA patients has died.Conclusion: 5-yr Rc appears to be an important prerequisite for prolonged subsequent OS, which could be significantly increased with better therapy (TT2 vs TT1). Post-5-yr favorable survival predictors included several laboratory data at 5yrs, especially absence of CA. [Display omitted]

Individual cognitive‐behavioural anger treatment for people with mild‐borderline intellectual disabilities and histories of aggression: A controlled trial

Anger is a significant predictor and activator of violent behaviour in patients living in institutional settings. There is some evidence for the value of cognitive-behavioural treatments for anger problems with people with intellectual disabilities. In this study, a newly designed treatment targeted at anger disposition, reactivity, and control was provided to intellectually disabled offenders with aggression histories living in secure settings. About forty detained patients with mild-borderline intellectual disabilities and histories of serious aggression were allocated to specially modified cognitive-behavioural anger treatment (AT group) or to routine care waiting-list control (RC group) conditions. AT group participants received 18 sessions of individual treatment. The AT and RC groups were assessed simultaneously at 4 time points: screen, pre- and post-treatment, and at 4-month follow-up using a range of self- and staff-rated anger measures. The effectiveness of the treatment was evaluated using ANCOVA linear trend analyses of group differences on the main outcome measures. The AT group's self-reported anger scores on a number of measures were significantly lower following treatment, compared with the RC wait-list condition, and these improvements were maintained at follow-up. Limited evidence for the effectiveness of treatment was provided by staffs' ratings of patient behaviour post-treatment. Detained men with mild-moderate intellectual disabilities and histories of severe aggression can successfully engage in, and benefit from, an intensive individual cognitive-behavioural anger treatment that also appears to have beneficial systemic effects.

Impact of Coronary Collaterals on Outcome Following Percutaneous Coronary Intervention (from the National Heart, Lung, and Blood Institute Dynamic Registry)

Coronary collateral circulation is beneficial in patients with coronary artery disease, but controversy still exists regarding the association between angiographic collaterals and outcome after percutaneous coronary intervention (PCI). We compared the baseline characteristics and cumulative 1-year event rates of consecutive patients undergoing PCI by target vessel collateral status-no angiographic evidence of collateral circulation (NC; n = 5051), treated artery supplied collaterals (SC; n = 239), and treated artery received collaterals (RC; n = 893)-using the National Heart, Lung, and Blood Institute Dynamic Registry. Patients in the SC group were older and had more previous coronary bypass surgery, myocardial infarction, co-morbid illness, and heart failure than the NC and RC groups and had less often undergone revascularization for acute myocardial infarction (p <0.01 for all). The total angiographic PCI success was comparable for the SC and NC groups but higher than for the RC group (94.1% vs 94.4% vs 83.9%, respectively; p <0.001). Overall stent use was 77.5% and was highest in the SC group (82.4%, p <0.001). At 1 year, significant differences in outcome were observed by collateral status. Compared with the NC group, patients with PCI of a SC artery had higher adjusted mortality (relative risk [RR] 1.95, 95% confidence interval [CI] 1.27 to 3.01, p = 0.002) and death/myocardial infarction (RR 1.75, 95% CI 1.26 to 2.45, p <0.001) rates. Patients with PCI of a RC vessel, conversely, had lower adjusted death/myocardial infarction (RR 0.72, 95% CI 0.54 to 0.96, p = 0.02) and repeat revascularization (RR 0.73, 95% CI 0.59 to 0.91, p = 0.005) rates. In conclusion, our results suggest that PCI on collateralized vessels is warranted, but that patients with PCI in arteries that supply collaterals are a high-risk group that may benefit from closer follow-up and complete revascularization.

Safety and Effects on Lipid Parameters of Rubus coreanus and Atractylodes japonica in Ovariectomized Rats

Defatted methanol extracts of the medicinal plants, Rubus coreanus Miq. (RC) and Atractylodes japonica Koidzumi (AJ) were added at the levels of 0.1, 0.5, or 2% (w/w) to high cholesterol diets and fed to ovariectomized Sprague-Dawley female rats, weighing 212.6±1.8 g for four weeks. Weight gains were lower in RC and AJ groups than the control group, but there were no changes in uterus weights. Serum levels of triglyceride decreased by 20～27% in the experimental groups fed 0.1% of each extract (0.1RC and 0.1AJ), compared with that of control (Ovx). Serum cholesterol levels were not changed in the RC groups but increased in the group fed 2% of the AJ extract. Liver levels of cholesterol and triglyceride were reduced in both the RC and AJ groups. Microscopic observation revealed that there were no morphological alterations in liver, lung, heart, spleen and kidney tissues of the experimental groups. Plasma levels of albumin, BUN, creatinine, sodium, potassium and phosphate in the RC and AJ groups were in normal ranges. Serum GOT and GPT activities were, however, higher in the 2.0AJ than Ovx group. These results suggest that the extracts of the Rubus coreanus Miq. and Atractylodes japonica Koidzumi at dietary levels as low as 0.1% may be utilized as hypotriglyceridemic ingredients for functional foods.

Bipedal Loading During Recovery from Lactation Increases Femoral Skeletal Mass in Rats

0423 During lactation the maternal skeleton can lose as much as 4.8% BMD in the femoral neck and 5.1% in the lumbar spine in humans (Sowers et al., 1993). Bone lost during lactation can partially recover (Bowman & Miller, 1999). Mechanical loads to the skeleton play a major role in the accumulation and maintenance of skeletal mass and strength. PURPOSE: To determine the effects of bipedal loading during recovery from lactation on femoral skeletal mass. A secondary aim was to determine if bipedal loading during lactation could mitigate bone mass loss at the femur. METHODS: Nulliparous rats (N = 32) were mated and were permitted to go through two reproductive cycles. The day after the second parturition rats were randomized into four groups: Lactation (Lac; n = 8), Lactation, Raised Cage (Lac RC, n = 8), Lactation Recovery (Lac-Rec, n = 8), and Lactation Recovery, Raised Cage (Lac-Rec RC, n = 8). Lac and Lac RC groups were sacrificed after 21 days of lactation and the recovery groups continued on for an additional 6 weeks to assess loading during the recovery period. Femurs were excised at necropsy and were dehydrated, defatted, and weighed to obtain dry weight (g). The bones were ashed in a muffle furnace and weighed again to determine ash weight (g). RESULTS: There were no significant differences between Lac and Lac RC on femoral dry weight (0.652 ± 0.018 vs. 0.623 ± 0.017 g, p = 0.26) or ash weight (0.394 ± 0.011 vs. 0.374 ± 0.011 g, p = 0.22). Lac-Rec RC had greater femoral dry weight (0.724 ± 0.012 vs. 0.681 ± 0.013, p = 0.03) and femoral ash weight (0.450 ± 0.008 vs. 0.423 ± 0.009, p = 0.04) than Lac-Rec. CONCLUSIONS: Bipedal loading during recovery from lactation induced increases in skeletal mass. Bipedal loading during lactation had no effect, possibly because energy needs during lactation are too great. Supported by NIH grant AR044806.

Bipedal Loading During Recovery from Lactation Increases Femoral Skeletal Mass in Rats

0423 During lactation the maternal skeleton can lose as much as 4.8% BMD in the femoral neck and 5.1% in the lumbar spine in humans (Sowers et al., 1993). Bone lost during lactation can partially recover (Bowman & Miller, 1999). Mechanical loads to the skeleton play a major role in the accumulation and maintenance of skeletal mass and strength. PURPOSE: To determine the effects of bipedal loading during recovery from lactation on femoral skeletal mass. A secondary aim was to determine if bipedal loading during lactation could mitigate bone mass loss at the femur. METHODS: Nulliparous rats (N = 32) were mated and were permitted to go through two reproductive cycles. The day after the second parturition rats were randomized into four groups: Lactation (Lac; n = 8), Lactation, Raised Cage (Lac RC, n = 8), Lactation Recovery (Lac-Rec, n = 8), and Lactation Recovery, Raised Cage (Lac-Rec RC, n = 8). Lac and Lac RC groups were sacrificed after 21 days of lactation and the recovery groups continued on for an additional 6 weeks to assess loading during the recovery period. Femurs were excised at necropsy and were dehydrated, defatted, and weighed to obtain dry weight (g). The bones were ashed in a muffle furnace and weighed again to determine ash weight (g). RESULTS: There were no significant differences between Lac and Lac RC on femoral dry weight (0.652 ± 0.018 vs. 0.623 ± 0.017 g, p = 0.26) or ash weight (0.394 ± 0.011 vs. 0.374 ± 0.011 g, p = 0.22). Lac-Rec RC had greater femoral dry weight (0.724 ± 0.012 vs. 0.681 ± 0.013, p = 0.03) and femoral ash weight (0.450 ± 0.008 vs. 0.423 ± 0.009, p = 0.04) than Lac-Rec. CONCLUSIONS: Bipedal loading during recovery from lactation induced increases in skeletal mass. Bipedal loading during lactation had no effect, possibly because energy needs during lactation are too great. Supported by NIH grant AR044806.

Pound for pound? Comparing the costs incurred by subjects following four commercially available weight loss programmes

Obesity is increasing in severity and prevalence representing a major public health issue within the UK. Studies suggest that, at any one time, most US and UK adults are trying to lose or maintain weight (Offer, 2001). As a result the demand for weight loss schemes is high. As obesity is most prevalent amongst low income groups (James et al., 1997), the financial implication of following such programmes requires investigation. This study aimed to quantify and compare the costs incurred by subjects undertaking one of four commercially available weight loss programmes.Subjects comprised of the Surrey cohort (n = 35) of a multi‐centre weight loss trial and were randomized to one of four programmes: Weight Watchers (WW), the Slim‐Fast Plan, Rosemary Conley's Diet and Fitness Plan (RC) or the Dr Atkins’ New Diet Revolution (Atkins). Participants were all aged between 21 and 60 years, had an initial body mass index in the range of 27–36 kg m−2 and were otherwise healthy. Seven‐day estimated food diaries were completed at baseline and after 2 months of dieting and were used to calculate the weight of food consumed. The cost was subsequently based on the prices quoted on the Tesco's website. Total food and alcohol were calculated for each subject at baseline and at 2 months and total programme cost was calculated at 2 months (food costs and any additional costs as a result of programme membership fees, supplementary vitamins, etc). Food group expenditure was calculated to investigate the contribution of meat, fruit, vegetables and alcohol to total costs and change in costs. Parametric and nonparametric statistics (according to the data distribution) were used to compare change in mean costs over time (paired t‐tests, Wilcoxon signed ranks test) and by programme followed (anova).No significant differences in baseline costs were observed between the four groups with whole sample mean food costs of £20.53 (SD 5.10). The Atkins group showed a significant increase in food expenditure at 2 months (Z = −2.24, p = 0.03) whereas all other groups decreased their spending on food, significantly so for the RC and WW subjects (Z = −1.96, p = 0.05; Z = −2.67, p = 0.01). As a result, significant differences in percentage change in food expenditure were recorded across groups (χ2 = 16.47, p = 0.001) with the Atkins group significantly different from both RC and WW groups. Although all programmes incurred initial ‘start‐up’ costs, only the Atkins diet had ongoing total programme costs at 2 months that were significantly greater than baseline expenditure. Increases in meat expenditure were significantly greater within the Atkins group compared with subjects following the other programmes (F = 4.01, p = 0.02). However, contrary to expectations, no significant increases in spending on fruit and vegetables were seen, with a significant decrease in expenditure on fruit observed across the whole sample and within the WW group (Z = −2.40, p = 0.02 and Z = −2.07, p = 0.04 respectively).This study suggests that commercial weight loss programmes, including those requiring the purchase of meal replacements, are not necessarily associated with an increase in food expenditure. However, the Atkins diet did result in an increase in food expenditure and as all the programmes are subject to potentially prohibitive ‘start‐up’ costs, such as joining fees, the issue of access for those population groups most at risk from obesity remains.

Non-furosemide-related renal calcifications in premature infants with bronchopulmonary dysplasia.

Renal calcification is a known complication of long-term furosemide therapy in infants with bronchopulmonary dysplasia (BPD). In a prospective study the clinical course and long-term renal sequelae of renal calcifications of 19 consecutive premature neonates (birthweight < 1250 g) with bronchopulmonary dysplasia who did not receive furosemide were examined. Infants were divided into two different groups on the basis of ultrasound evidence of renal calcifications (RC group) or absence of renal calcifications (NRC group). Serial examinations, performed at the age of 1, 2, 3, 6, 9 and 12 months, showed that 12 infants at the mean age of 68.5 +/- 12.8 days of life had renal calcifications (63%), and 3 of them had nephrolithiasis; 8 had bilateral renal calcifications. Among the 9 survivors, 2 had chronic renal calcifications at the age of 9 months; however, all normalized at the age of 12 months. Twelve infants received hydrochlorothiazide and spironolactone (63%), 17 had prolonged courses of xanthines and dexamethasone (89.5%), while furosemide was not part of the routine pharmacological administration. Statistical analysis showed that birthweight, gestational age, Apgar score and length of parenteral nutrition were comparable in the RC and NRC group infants. Mean serum creatinine, creatinine clearance, fractional sodium excretion and urinary calcium excretion values during the 12-month study period were comparable in the RC and NRC groups. Mechanical ventilation and hospital stay length were instead associated with renal calcification occurrence. The strongest indicator of renal calcification risk for this high-risk population is the severity of the unresolved acute lung disease, where different facets of respiratory management, other than the addition of furosemide, represent sufficient stimuli and renal injury to potentiate stone formation.

Acid aspiration prophylaxis for emergency Caesarean section

Over a 3.5 year period, 384 patients requiring emergency Caesarean section under general anaesthesia received at random one of six acid aspiration prophylaxis regimens as soon as the decision was made for surgery. In the first phase of the study, sodium citrate administered orally 0.3 M, 30 ml (group C, n = 120) was compared with metoclopramide 10 mg administered intravenously and sodium citrate (group MC, n = 65). In the second phase, all patients received sodium citrate, and either intravenous administration of ranitidine 50 mg (group RC, n = 50), omeprazole 40 mg (group OC, n = 50), ranitidine 50 mg with metoclopramide 10 mg (group RMC, n = 50) or omeprazole 40 mg with metoclopramide 10 mg (group OMC, n = 49). Gastric contents were aspirated using a 16 FG Salem sump tube and acidity measured with a pH meter. Non-parametric tests were used for comparisons. There was no difference in gastric volume or pH between groups C and MC, or among OC, RC, OMC and RMC. After pooling the data, median (range) gastric volume in groups C and MC (55 (0-360) ml) was greater than in groups OMC and RMC (40 (3-270) ml, p < 0.05). Median (range) pH was lower in groups C and MC (4.97 (0.76-6.99)) than in groups OC, RC, OMC and RMC (5.76 (1.11-7.5), p < 0.001). The proportion of patients with pH < 3.5 and volume > 25 ml in the C and MC groups (43/185) was greater than that in the OC, RC, OMC and RMC groups (18/199, p < 0.001). Ranitidine and omeprazole administered intravenously were equally effective adjuncts to sodium citrate in reducing gastric acidity for emergency Caesarean section. Compared with sodium citrate alone, the addition of either ranitidine, omeprazole or metoclopramide alone did not reduce gastric volume while small reductions in gastric volume were seen with the addition of metoclopramide and either ranitidine or omeprazole.