Monte Carlo modelling of large scale NORM sources using MCNP

The representative Monte Carlo modelling of large scale planar sources (for comparison to external environmental radiation fields) is undertaken using substantial diameter and thin profile planar cylindrical sources. The relative impact of source extent, soil thickness and sky-shine are investigated to guide decisions relating to representative geometries. In addition, the impact of source to detector distance on the nature of the detector response, for a range of source sizes, has been investigated. These investigations, using an MCNP based model, indicate a soil cylinder of greater than 20 m diameter and of no less than 50 cm depth/height, combined with a 20 m deep sky section above the soil cylinder, are needed to representatively model the semi-infinite plane of uniformly distributed NORM sources. Initial investigation of the effect of detector placement indicate that smaller source sizes may be used to achieve a representative response at shorter source to detector distances.

Monte Carlo modeling of ion chamber performance using MCNP

Ion Chambers have a generally flat energy response with some deviations at very low (<100 keV) and very high (>2 MeV) energies. Some improvements in the low energy response can be achieved through use of high atomic number gases, such as argon and xenon, and higher chamber pressures. This work looks at the energy response of high pressure xenon-filled ion chambers using the MCNP Monte Carlo package to develop geometric models of a commercially available high pressure ion chamber (HPIC). The use of the F6 tally as an estimator of the energy deposited in a region of interest per unit mass, and the underlying assumptions associated with its use are described. The effect of gas composition, chamber gas pressure, chamber wall thickness, and chamber holder wall thicknesses on energy response are investigated and reported. The predicted energy response curve for the HPIC was found to be similar to that reported by other investigators. These investigations indicate that improvements to flatten the overall energy response of the HPIC down to 70 keV could be achieved through use of 3 mm-thick stainless steel walls for the ion chamber.

Changes in non-22-kilodalton (kDa) isoforms of growth hormone (GH) after administration of 22-kDa recombinant human GH in trained adult males

GH is being used by elite athletes to enhance sporting performance. To examine the hypothesis that exogenous 22-kDa recombinant human GH (rhGH) administration could be detected through suppression of non-22-kDa isoforms of GH, we studied seventeen aerobically trained males (age, 26.9 +/- 1.5 yr) randomized to rhGH or placebo treatment (0.15 IU/kg/day for 1 week). Subjects were studied at rest and in response to exercise (cycle-ergometry at 65% of maximal work capacity for 20 min). Serum was assayed for total GH (Pharmacia IRMA and pituitary GH), 22-kDa GH (2 different 2-site monoclonal immunoassays), non-22-kDa GH (22-kDa GH-exclusion assay), 20-kDa GH, and immunofunctional GH. In the study, 3 h after the last dose of rhGH, total and 22-kDa GH concentrations were elevated, reflecting exogenous 22-kDa GH. Non-22-kDa and 20-kDa GH levels were suppressed. Regression of non-22-kDa or 20-kDa GH against total or 22-kDa GH produced clear separation of treatment groups. In identical exercise studies repeated between 24 and 96 h after cessation of treatment, the magnitude of the responses of all GH isoforms was suppressed (P < 0.01), but the relative proportions were similar to those before treatment. We conclude: 1) supraphysiological doses of rhGH in trained adult males suppressed exercise-stimulated endogenous circulating isoforms of GH for up to 4 days; 2) the clearest separation of treatment groups required the simultaneous presence of high exogenous 22-kDa GH and suppressed 20-kDa or non-22-kDa GH concentrations; and 3) these methods may prove useful in detecting rhGH abuse in athletes.

The response of molecular isoforms of growth hormone to acute exercise in trained adult males

Circulating GH consists of multiple molecular isoforms, all derived from the one gene in nonpregnant humans. To assess the effect of a potent stimulus to pituitary secretion on GH isoforms, we studied 17 aerobically trained males (age, 26.9 +/- 1.5 yr) in a randomized, repeat measures study of rest vs. exercise. Exercise consisted of continuous cycle ergometry at approximately 80% of predetermined maximal oxygen uptake for 20 min. Serum was assayed for total, pituitary, 22-kDa, recombinant, non-22-kDa, 20-kDa, and immunofunctional GH. All isoforms increased during, peaked at the end, and declined after exercise. At peak exercise, 22-kDa GH was the predominant isoform. After exercise, the ratios of non-22 kDa/total GH and 20-kDa GH/total GH increased and those of recombinant/pituitary GH decreased. The disappearance half-times for pituitary GH and 20-kDa GH were significantly longer than those for all other isoforms. We conclude that 1) all molecular isoforms of GH measured increased with and peaked at the end of acute exercise, with 22-kDa GH constituting the major isoform in serum during exercise; and 2) the proportion of non-22-kDa isoforms increased after exercise due in part to slower disappearance rates of 20-kDa and perhaps other non-22-kDa GH isoforms. It remains to be determined whether the various biological actions of different GH isoforms impact on postexercise homeostasis.

Growth hormone (GH) effects on bone and collagen turnover in healthy adults and its potential as a marker of GH abuse in sports: a double blind, placebo-controlled study. The GH-2000 Study Group

The effects of GH on bone remodeling in healthy adults have not been systematically investigated. An analysis of these effects might provide insights into GH physiology and might yield data useful for the detection of GH doping in sports. The aim of this study was to evaluate the effects of GH administration on biochemical markers of bone and collagen turnover in healthy volunteers. Ninety-nine healthy volunteers of both sexes were enrolled in a multicenter, randomized, double blind, placebo-controlled study and assigned to receive either placebo (40 subjects) or recombinant human GH (0.1 IU/kg day in 29 subjects and 0.2 IU/kg x day in 30 subjects). The treatment duration was 28 days, followed by a 56-day wash-out period. The biochemical markers evaluated were the bone formation markers osteocalcin and C-terminal propeptide of type I procollagen, the resorption marker type I collagen telopeptide, and the soft tissue marker procollagen type III. All variables increased on days 21 and 28 in the two active treatment groups vs. levels in both the baseline (P < 0.01) and placebo (P < 0.01) groups. The increment was more pronounced in the 0.2 IU/kg-day group and remained significant on day 84 for procollagen type III (from 0.53 +/- 0.13 to 0.61 +/- 0.14 kU/L; P < 0.02) and osteocalcin (from 12.2 + 2.9 to 14.6 +/- 3.6 UG/L; P < 0.02), whereas levels of C-terminal propeptide of type I procollagen and type I collagen telopeptide declined after day 42 and were no longer significantly above baseline on day 84 (from 3.9 +/- 1.2 to 5.1 +/-1.5 microg/L and from 174 +/- 60 to 173 +/- 53 microg/L, respectively). Gender-related differences were observed in the study; females were less responsive than males to GH administration with respect to procollagen type III and type I collagen telopeptide (P < 0.001). In conclusion, exogenous GH administration affects the biochemical parameters of bone and collagen turnover in a dose- and gender-dependent manner. As GH-induced modifications of most markers, in particular procollagen type III and osteocalcin, persist after GH withdrawal, they may be suitable markers for detecting GH abuse.

Responses of markers of bone and collagen turnover to exercise, growth hormone (GH) administration, and GH withdrawal in trained adult males

To examine the interactions between acute exercise and GH on markers of bone and collagen turnover and to assess the potential for detecting GH abuse in athletes using these markers, we studied 17 aerobically trained males (age, 26.9+/-1.5 yr). Sequential studies of exercise, GH administration, and GH withdrawal were undertaken. A randomized, controlled study of rest vs. exercise showed that exercise did not change serum osteocalcin; other markers of formation increased transiently (each P<0.001): bone-specific alkaline phosphatase (+16.1%), carboxyterminal propeptide of type I procollagen (+14.1%), and procollagen III N-terminal extension peptide (+5.0%). The carboxyterminal cross-linked telopeptide of type I collagen, a bone resorption marker, increased 9.7% (P = 0.018) in response to exercise. A randomized, double blind, placebo-controlled, parallel study of recombinant human GH treatment (0.15 IU/kg x day) for 1 week increased serum osteocalcin (net increase preexercise, +/-10.0%; P = 0.017), carboxyterminal propeptide of type I procollagen (+17.6%; P = 0.002), procollagen III N-terminal extension peptide (+48.4%; P = 0.001), and carboxyterminal cross-linked telopeptide of type I collagen (53.3%; P = 0.009). Disappearance half-times after cessation of recombinant human GH for pre- and postexercise markers ranged from 248-770 h. We conclude 1) endurance exercise transiently activates bone and collagen turnover; 2) brief GH administration results in similar but quantitatively greater augmentation; and 3) these data will assist in designing a GH detection strategy.

Safety and efficacy of NeuroBloc (botulinum toxin type B) in type A-responsive cervical dystonia

OBJECTIVE

To determine the safety and efficacy of botulinum toxin type B (BoNT/B) in patients with cervical dystonia (CD).

BACKGROUND

BoNT/B is a form of chemodenervation therapy for the treatment of patients with CD.

METHODS

The authors performed a 16-week, randomized, multicenter, double-blind, placebo-controlled trial of BoNT/B in patients with CD who continue to respond to botulinum toxin type A. Placebo, or 5,000 U or 10,000 U of BoNT/B was administered in two to four muscles involved clinically in CD. The Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS)-Total score at week 4 was the primary efficacy measure. Clinical assessments and adverse events were recorded for treatment day 1 and at weeks 2, 4, 8, 12, and 16.

RESULTS

A total of 109 patients were enrolled randomly across all three treatment groups. The mean improvement in the TWSTRS-Total scores in each group at week 4 was 4.3 (placebo), 9.3 (5,000 U), and 11.7 (10,000 U). For the prospectively defined primary contrast (10,000 U versus placebo), highly significant differences were noted for the primary (TWSTRS-Total, baseline to week 4, p = 0.0004) and supportive secondary (Patient Global Assessment, baseline to week 4, p = 0.0001) outcome measures. Improvement in pain, disability, and severity of CD occurred for patients who were treated with BoNT/B when compared with placebo-treated patients. Overall, improvements associated with BoNT/B treatment were greatest for patients who received the 10,000-U dose. The duration of treatment effect for BoNT/B was 12 to 16 weeks for both doses.

CONCLUSION

Botulinum toxin type B (NeuroBloc) is safe and efficacious at 5,000 U and 10,000 U for the management of patients with cervical dystonia.

Safety and efficacy of NeuroBloc (botulinum toxin type B) in type A-resistant cervical dystonia

OBJECTIVE

To determine the safety and efficacy of botulinum toxin type B (BoNT/B) in patients with type A-resistant cervical dystonia (CD).

BACKGROUND

Local intramuscular injections of BoNT are an effective therapy for CD. After repeated use, some patients become resistant to therapy. BoNT/B, effective in type A toxin-responsive patients, is proposed as an alternative therapy for type A-resistant patients.

METHODS

The authors performed a 16-week, double-blind, placebo-controlled trial of BoNT/B in type A-resistant patients with CD. After resistance to therapy was confirmed with the frontalis-type A test, placebo or 10,000 U BoNT/B was administered in a single session into two to four clinically involved muscles. The Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) was the primary efficacy measurement. TWSTRS-Total, three visual analog scales (Patient Global Assessment of Change, Principal Investigator Global Assessment of Change, Patient Analog Pain Assessment), and adverse events were assessed at baseline and weeks 2, 4, 8, 12, and 16.

RESULTS

A total of 77 patients participated (38 placebo, 39 active). Improvements in severity, disability, and pain were documented in the BoNT/B-treated group. TWSTRS-Total scores were improved in the BoNT/B-treated group at weeks 4 (p = 0.0001), 8 (p = 0.0002), and 12 (p = 0.0129). All three visual analog scales demonstrated improvements at week 4 (p < 0.0001, 0.0001, and 0.001). A Kaplan-Meier analysis supported a duration of effect of 12 to 16 weeks in the active group. Dry mouth and dysphagia were self-limited adverse effects, reported more commonly in the BoNT/B group.

CONCLUSIONS

Botulinum toxin type B (BoNT/B) (NeuroBloc) is safe and efficacious for the management of patients with type A-resistant cervical dystonia with an estimated duration of treatment effect of 12 to 16 weeks.

Responses of the growth hormone (GH) and insulin-like growth factor axis to exercise, GH administration, and GH withdrawal in trained adult males: a potential test for GH abuse in sport

GH abuse by elite athletes is currently undetectable. To define suitable markers of GH doping, we assessed the effects of acute exercise, GH administration, and GH withdrawal on the GH/insulin-like growth factor (IGF) axis in athletic adult males. Acute endurance-type exercise increased serum GH, GH-binding protein (GHBP), total IGF-I, IGF-binding protein (IGFBP)-3, and acid-labile subunit (ALS), each peaking at the end of exercise. IGFBP-1 increased after exercise was completed. Free IGF-I did not change with exercise. Recombinant human GH treatment (0.15 IU/kg x day) for 1 week increased serum total IGF-I, IGFBP-3, and ALS, exaggerating the responses to exercise. IGFBP-2 and IGFBP-1 were trivially suppressed. After GH withdrawal, the GH response to identical exercise was suppressed. Total IGF-I, IGFBP-3, and ALS returned to baseline over 3-4 days. In summary, 1) acute exercise transiently increased all components of the IGF-I ternary complex, possibly due to mobilization of preformed intact complexes; 2) GH pretreatment augmented the exercise-induced changes in ternary complexes; 3) postexercise IGFBP-1 increments may protect against delayed onset hypoglycemia; 4) serum total IGF-I, IGFBP-3, and ALS may be suitable markers of GH abuse; and 5) differences in disappearance times altered the sensitivity of each marker for detecting GH abuse.

The effects of 10 years of recombinant human growth hormone (GH) in adult GH-deficient patients

The long term effects of GH replacement in adult GH-deficient (GHD) patients have not yet been clarified. We studied 21 GHD adults who originally took part in a randomized, double blind, placebo-controlled trial of GH treatment in 1987. After completion of that trial, 10 patients received continuous GH replacement for the subsequent 10 yr, whereas 11 did not. A group of 11 age- and sex-matched normal controls were also studied in 1987 and 1997. Lean body mass, as assessed by total body potassium measurement and computed tomography scanning of the dominant thigh, increased in the GH-treated group (P < 0.01 for both) only (P < 0.05 between groups for total body potassium). Low density lipoprotein cholesterol decreased in the GH-treated group (P < 0.05) only. Carotid intima media thickness was significantly greater (P < 0.05) in the untreated group than in the GH-treated group. Assessment of psychological well-being using the Nottingham Health Profile revealed improvement in overall score, energy levels, and emotional reaction in the GH-treated group compared with those in the untreated group (P < 0.02). In conclusion, GH treatment for 10 yr in GHD adults resulted in increased lean body and muscle mass, a less atherogenic lipid profile, reduced carotid intima media thickness, and improved psychological well-being.

Exercise-induced GH secretion is enhanced by the oral ingestion of melatonin in healthy adult male subjects

There is evidence that melatonin may play a role in modulating pituitary secretion, although the mechanisms are unclear. We examined the effects of a single dose of oral melatonin (5mg) on exercise-induced GH secretion. In a randomised, double-blind, placebo-controlled study, seven healthy male subjects undertook an initial period of graded bicycle ergometric exercise to determine maximum workload and oxygen uptake (VO(2max)). Subjects were subsequently studied on two further occasions, receiving either melatonin or placebo in random order at the onset of each study (-60min). At 0 min a period of bicycle exercise was performed for 8 min at a workload corresponding to 70% of that achieved at VO(2max). Serum GH and IGF-binding protein-1 (IGFBP-1) concentration was measured at 15-min intervals from the onset of the study until 120 min post-exercise. Blood was also sampled for the measurement of plasma glucose, insulin, non-esterified fatty acids, IGFBP-3, melatonin and vasopressin concentration. There was an exercise-induced increase in GH concentration following melatonin which was greater compared with placebo as assessed by both area under the curve (P<0.01) and peak increase in GH levels (P<0.01). The peak increase in IGFBP-1 levels post-exercise was also significantly greater following melatonin compared with placebo (P<0. 01) but did not quite reach levels of significance as measured by area under the curve (P=0.07). Since exercise-induced GH secretion is thought to be mediated predominantly through a hypothalamic pathway, it seems likely that melatonin facilitates GH secretion at a hypothalamic level.

The Monte Carlo modelling of in vivo X-ray fluorescence measurement of lead in tissue

A Monte Carlo model has been developed, using the EGS4 code, to model the in vivo x-ray fluorescence (XRF) measurement of Pb in non-superficial bone/tissue. Unlike previous work in this field the current model incorporates a correction for Doppler broadening of the Compton scatter peak due to the electron momentum distribution of the medium (tissue/water) in which the photons are Compton scattered by convolving the Compton peak of the Monte Carlo generated spectrum with a modified Compton profile for water. This correction improves the agreement between the measured spectral shape obtained using an experimental in vivo x-ray fluorescence Pb analyser with a 109Cd/180 degrees source/geometry combination, measuring a bone phantom at depth in water and the generated spectral shape obtained from the equivalent Monte Carlo model. The model enables improved estimates to be made of the spectral background beneath the Pb Kalpha1 and Kalpha2 x-ray peaks compared with estimates based on simpler models that assume that Compton interactions are with 'free' electrons and hence permits better optimization of in vivo analyser system design.

Relationships among ewe milk production and ewe and lamb forage intake in Suffolk and Targhee ewes nursing single or twin lambs

Suffolk and Targhee ewes (30 each) with single or twin lambs were used in four periods beginning in late gestation and continuing through weaning to evaluate breed differences in milk production, lamb BW, and DMI by ewes and lambs. In Periods 1 (late gestation) and 2 (early lactation), ewes (Period 1) and ewes with lambs (Period 2) were individually penned, fed .45 kg of barley x ewe(-1) x d(-1) and allowed ad libitum access to chopped alfalfa. Ewes and lambs grazed native range in Periods 3 and 4. Grazed forage DMI was estimated using chromic oxide. Estimates of milk production were obtained by handmilking. Average lamb age was 4, 45, and 73 d at the beginning of Periods 2, 3, and 4, respectively. Milk production tended (P = .20) to be greater for Suffolk than for Targhee ewes. Targhee ewes produced 85% more (P = .001) wool than Suffolk ewes. From 33 d prepartum to 89 d postpartum, Suffolk ewes consistently weighed more (P = .001) than Targhee ewes. Suffolk ewe BW loss (-.15 kg/d) was greater (P = .01) than Targhee ewe BW loss (-.02 kg/d) from 33 d prepartum to 6 d postpartum. From 6 to 89 d postpartum BW gain did not differ (P = .69; .05 kg/d) between breeds. From birth to 89 d postpartum, Suffolk lambs consistently weighed more than Targhee lambs (P = .003). From birth to 89 d postpartum, ADG was greater for Suffolk than for Targhee lambs (P = .006). Targhee ewes consumed 25% more (P = .01) feed over the course of the study than did Suffolk ewes. Grazed forage DMI by Targhee lambs was 26% greater (P = .01) than DMI by Suffolk lambs. When meat production is the primary income from sheep, one potential advantage of Suffolks compared with Targhees is more rapid gain with less feed intake.

Bioenergetics of rat prostate cancer cell migration

BACKGROUND

Increased cell motility and increased glycolysis are two well-known hallmarks of cancer. We undertook these studies to determine whether increased glycolysis is required for prostate cancer cell locomotion.

METHODS

We studied the highly metastatic MatLu cell line, which is a variant of the Dunning R-3327 rat prostate adenocarcinoma model. Using videomicroscopy and computer image analysis, we compared the speed of migration of cells grown in serum-free medium in either the presence or absence of glucose.

RESULTS

We found that cells grown in glucose-free, conditioned medium maintained speeds of migration and intracellular ATP levels for 24 hr which were equivalent to those of cells grown in conditioned medium containing glucose. In contrast, migration was significantly inhibited by growth in glucose-free, unconditioned medium. We also tested the effect of antimycin A and rotenone, two inhibitors of mitochondrial electron transport, on cell migration and ATP levels. Antimycin A had no significant effect on either feature, while rotenone slightly inhibited cell migration without affecting ATP levels.

CONCLUSIONS

1) Glycolysis is not necessary for rat prostate cancer cell locomotion in the presence of conditioned medium. 2) MatLu cells grown in the absence of both serum and conditioned medium require glucose to maintain cellular ATP levels and cell migration. 3) MatLu cells in conditioned medium adapt to inhibition of glycolysis or mitochondrial respiration by increasing the activity of the uninhibited pathway.

The Australian Multicenter Trial of Growth Hormone (GH) Treatment in GH-Deficient Adults

GH treatment in adults with GH deficiency has numerous beneficial effects, but most studies have been small. We report the results of an Australian multicenter, randomized, double-blind, placebo-controlled trial of the effects of recombinant human GH treatment in adults with GH deficiency. GH deficiency was defined as a peak serum GH of < 5 mU/liter in response to insulin-induced hypoglycemia. Patients were randomly assigned to receive either GH (0.125 U/kg per week for 1 month and 0.25 U/kg per week for 5 months) or placebo. After 6 months, all patients received GH. The primary end points were biochemical responses, body composition, quality of life, and safety. One hundred sixty-six patients (72 females and 91 males) with a mean age of 40 +/- 1 yr (+/- SEM; range 17-67 yr) were recruited. Serum insulin-like growth factor-I (IGF-I) increased from a standard deviation score of -2.64 +/- 0.27 (range -8.8 +3.82; n = 78) to +1.08 +/- 2.87 (range -7.21 to +6.42) at 6 months in the GH/GH group; 38% of the whole group were above the age-specific reference range following treatment [17.6% and 68.9% with subnormal (< 2 SD) or normal (+/- 2 SD) pretreatment levels, respectively]. Fasting total cholesterol (P = 0.042) and low-density lipoprotein cholesterol (P = 0.006) decreased over the first 6 months. Fat-free mass increased in the first 6 months whether measured by bioelectrical impedance (P < 0.001) or dual energy x-ray absorptiometry (DEXA; P < 0.001). Total-body water increased in the first 6 months whether measured by bioelectrical impedance (P < 0.001) or deuterium dilution (P = 0.002). Fat mass measured by DEXA (P < 0.001), skinfold thicknesses (P < 0.001), and waist/hip ratio (P = 0.001) decreased in the first 6 months. Most changes in body composition were complete by 3 months of treatment and maintained to 12 months. Whole-body bone mineral density (BMD) (by DEXA) was unaffected by GH treatment. Self-reported quality of life was considered good before treatment, and beneficial treatment effects were observed for energy, pain, and emotional reaction as assessed by the Nottingham Health Profile. In the initial 6 months, adverse effects were reported by 84% of patients in the GH and 75% in the placebo group, with more symptoms relating to fluid retention in the GH group (48% vs. 30%; P = 0.016). Such symptoms were mild and resolved in 70% of patients despite continued treatment. Resting blood pressure did not change over the initial 6 months. In summary, GH treatment in adults with GH deficiency resulted in 1) prominent increases in serum IGF-I at the doses employed, in some cases to supraphysiological levels; 2) modest decreases in total- and low-density lipoprotein cholesterol, together with substantial reductions in total-body and truncal fat mass consistent with an improved cardiovascular risk profile; 3) substantial increases in lean tissue mass; and 4) modest improvements in perceived quality of life. The excessive IGF-I response and side-effect profile suggests that lower doses of GH may be a required for prolonged GH treatment in adults with severe GH deficiency.

BotB (botulinum toxin type B): evaluation of safety and tolerability in botulinum toxin type A-resistant cervical dystonia patients (preliminary study)

Botulinum toxin (BTX) injection is considered the treatment of choice for patients with cervical dystonia (torticollis). We conducted a pilot, open-label, dose-escalation study with BTX type B in 12 patients who no longer responded clinically to injections with BTX type A. At the doses tested, BTX type B was safe and well tolerated without evidence of dose-limiting toxicity in this patient population. Mild-to-moderate adverse events generally resolved quickly and included asthenia, pain, nausea, dysphagia, hypertonia, and tremor. No serious adverse events or antibodies to type-B treatment were reported. Low-dosing-session (100-899 units) and high-dosing-session (900-1,500 units) groups were defined based on units administered per dosing session. Toronto Western Spasmodic Torticollis Rating Scale-Severity Scale (TWSTRS-Severity), Patient Analogue Pain Scale, and Physician and Patient Global Assessment Scales were measured during this study. The TWSTRS-Severity mean maximum percent improvement from baseline demonstrated a 9.9% versus 28.8% difference between the low-dose and high-dose groups, respectively. EFfectiveness was noted for the high-dose group on the Patient Analogue Pain Scale but not on the Global Assessment Scales.

Botulinum toxin type B: a double-blind, placebo-controlled, safety and efficacy study in cervical dystonia

We enrolled and treated 122 patients with idiopathic cervical dystonia in a double-blind, placebo-controlled safety and efficacy study of botulinum toxin type B (BotB). Both A-responsive and A-resistant patients were enrolled. Patients received intramuscular injections of either BotB (2,500 U, 5,000 U, or 10,000 U) or placebo. The primary outcome measure of efficacy was the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS)-Total score at 4 weeks following study drug administration. Secondary measures of efficacy were TWSTRS-Severity, -Disability, and -Pain subscale scores, and Analog Pain Assessment, Investigator Global Assessment, Patient Global Assessment, and Sickness Impact Profile scores. Duration of effect was estimated with an intent-to-treat analysis of responders. Safety measures included clinical parameters, laboratory tests, and adverse events. The primary and most of the secondary analyses indicated a statistically significant treatment effect and a dose response. BotB is safe, well tolerated, and efficacious in the treatment of cervical dystonia at the doses tested.

The redox/DNA repair protein, Ref-1, is essential for early embryonic development in mice

The DNA-binding activity of AP-1 proteins is modulated, in vitro, by a posttranslational mechanism involving reduction oxidation. This mode of regulation has been proposed to control both the transcriptional activity and the oncogenic potential of Fos and Jun. Previous studies revealed that reduction of oxidized Fos and Jun by a cellular protein, Ref-1, stimulates sequence-specific AP-1 DNA-binding activity. Ref-1, a bifunctional protein, is also capable of initiating the repair of apurinic/apyrymidinic sites in damaged DNA. The relationship between the redox and DNA repair activities of Ref-1 is intriguing; both activities have been suggested to play an important role in the cellular response to oxidative stress. To investigate the physiological function of Ref-1, we used a gene targeting strategy to generate mice lacking a functional ref-1 gene. We report here that heterozygous mutant mice develop into adulthood without any apparent abnormalities. In contrast, homozygous mutant mice, lacking a functional ref-1 gene, die during embryonic development. Detailed analysis indicates that death occurs following blastocyst formation, shortly after the time of implantation. Degeneration of the mutant embryos is clearly evident at embryonic day 5.5. These findings demonstrate that Ref-1 is essential for early embryonic development.

An enhanced immune response in mice lacking the transcription factor NFAT1

Transcription factors of the NFAT family are thought to play a major role in regulating the expression of cytokine genes and other inducible genes during the immune response. The role of NFAT1 was investigated by targeted disruption of the NFAT1 gene. Unexpectedly, cells from NFAT1 -/- mice showed increased primary responses to Leishmania major and mounted increased secondary responses to ovalbumin in vitro. In an in vivo model of allergic inflammation, the accumulation of eosinophils and levels of serum immunoglobulin E were increased in NFAT1 -/- mice. These results suggest that NFAT1 exerts a negative regulatory influence on the immune response.

Altered endogenous growth hormone secretory kinetics and diurnal GH-binding protein profiles in adults with chronic liver disease

OBJECTIVE

Increased serum GH concentrations and GH responses to a variety of stimuli have been reported in patients with chronic liver disease (CLD). We investigated the pulsatile pattern of endogenous GH release and GH-binding protein (GHBP) and insulin-like growth factor-I (IGF-I) diurnal profiles in adults with cirrhosis, in comparison with healthy, matched control subjects.

DESIGN

Case-control, cross-sectional.

PATIENTS

Seven patients with biopsy proven cirrhosis, and sex, age, height, weight and oestrogen status matched controls.

MEASUREMENTS

Serum immunoreactive GH concentrations in samples collected at 20-minute intervals for 24 hours were analysed using a multi-parameter deconvolution method to simultaneously resolve endogenous GH secretory and disappearance rates. Diurnal patterns of GHBP (specific immunoprecipitation method) and serum IGF-I (RIA after acid-ethanol extraction) were assessed.

RESULTS

The mean daily GH secretion rate in patients with CLD was increased (210 +/- 93 vs 100 +/- 55 mU/I/day; P = 0.025), and GH disappearance half-time was prolonged (43 +/- 10 vs 24 +/- 9 min; P = 0.006) compared to controls. Detectable GH secretory bursts were more frequent in patients with CLD (10 +/- 1 vs 6 +/- 3/day; P = 0.038), but of similar mean mass (21 +/- 10 vs 17 +/- 8 mU/I) compared to controls. In patients with CLD, mean serum GHBP was slightly lower (63 +/- 36 vs 71 +/- 14% pooled control; P > 0.1). Fasting serum IGF-I concentrations (after size-exclusion HPLC) were lower in the patients with CLD (13 +/- 5 vs 21 +/- 2 nmol/l; P < 0.0001). Multiple regression analysis showed that GH secretion rate was increased in patients with CLD with higher Child's classifications (R2 = 0.86; P = 0.002) and with lower serum IGF-I concentrations measured after HPLC (R2 = 0.11; P = 0.044).

CONCLUSIONS

Adults with chronic liver disease have (1) increased total daily GH secretion rates, which appear to be influenced by disease severity and diminished serum IGF-I-mediated negative feedback; (2) markedly impaired endogenous GH clearance, possibly reflecting changes in hepatic GH-receptor status; and (3) GHBP levels which do not correlate with GH kinetics or serum IGF-I concentrations.

Summary of combined clinical analysis of controlled clinical trials with tizanidine

Data from three placebo-controlled and 11 active-controlled studies of tizanidine were combined to permit analysis of the subsets, which were too small to evaluate within the individual studies. Overall analysis of placebo-controlled data confirms the effectiveness of tizanidine in reducing muscle tone in patients with spasticity of spinal cord origin. Subset analyses suggest that patients with more severe spasticity are more likely to respond, but age, sex, and race were not predictive of response. Comparisons of tizanidine with active controls showed no differences in efficacy compared with baclofen or diazepam. However, when compared with controls, patients treated with tizanidine did not experience increased weakness. Furthermore, patients tolerated tizanidine better than the control medications. More patients experienced adverse events during tizanidine treatment than did patients receiving placebo. The most common adverse events reported were dry mouth, somnolence, asthenia, and dizziness. Mild elevations in liver function tests were noted occasionally, but improved in all patients with dose reduction or withdrawal. Three patients from the double-blind database reported formed visual hallucinations. All three cleared; two continued tizanidine, and one discontinued.

Relationships among ewe milk production and ewe and lamb forage intake in Targhee ewes nursing single or twin lambs

Targhee ewes with single or twin lambs were used in four trials during early lactation through weaning to evaluate ewe milk production (MP), kilograms of lamb weaned, and forage intake by ewes and lambs. During Trial 1, ewes with lambs were individually penned, fed .45 kg of barley-ewe-1.d-1 and allowed ad libitum access to chopped alfalfa hay. Trials 2, 3, and 4 were conducted on three different types of Western range environments. Forage intake of ewes in Trials 2, 3, and 4 and of lambs in Trials 3 and 4 was estimated using chromic oxide. Estimates of milk production were obtained by hand-milking. Average lamb age was 4, 50, 78, and 106 d at the beginning of Trials 1, 2, 3, and 4, respectively. Milk production was greater (P = .01) for ewes nursing twins than for those nursing singles at d 4 and 14 in Trial 1. In Trials 2, 3, and 4, all ewes had similar (P > .18) milk production. Ewe DMI during Trials 1 and 2 was greater (P < .05) for ewes nursing twin lambs than for those nursing singles. There was no difference (P > .88) in DMI between ewes with single and those with twin lambs in Trials 3 and 4. Forage DMI by twin lambs, expressed as either kilograms.ewe-1.day-1 or percentage of lamb BW, was higher (P = .01) than intake by single lambs in Trials 3 and 4.(ABSTRACT TRUNCATED AT 250 WORDS)

Evaluation of biological efficiency of free-grazing beef cows under semidesert conditions

Effects of cow BW, hip height, and estimated genetic potentials (EBV) for weaning weight direct and milk on cow productivity, fecal OM output, OM intake, and efficiency (kilograms of calf BW/kilogram of OM intake by the cow) were evaluated with 44 free-grazing crossbred cows under semidesert conditions. Calf BW were measured during early, mid-, and late lactation. Data were collected in four periods: Period 1 = late spring (early lactation), Period 2 = late summer (mid-lactation), Period 3 = mid-autumn (late lactation), and Period 4 = mid-winter (nonlactation). Calf BW increased linearly with cow BW (P < .01) in Periods 1, 2, and 3. Fecal OM output and OM intake increased with cow BW in Periods 2 (P < .01) and 4 (P < .01), and on average (P < .02). Overall efficiency decreased with increasing cow BW (P < .04). Taller cows excreted more fecal OM and had greater OM intake throughout the study (P < .02 to P < .11). Overall efficiency decreased with increasing cow hip height (P < .05). Weaning weight direct EBV of cows was related linearly to cow BW (P < .01 to P < .07) and to calf BW (P < .01 to P < .07). Calf weight in all periods increased linearly with milk EBV (P < .001). Overall, fecal OM output, OM intake, and efficiency were not affected by milk EBV.

Bone lead measurement using X-ray fluorescence

An in-vivo x-ray fluorescence (XRF) bone lead analyser, based on the Somervaille design, has been constructed and tested as the first step towards developing a deep bone lead analyser to expand the range of bone tissue available for assessment, to include more deep seated bones such as the femur & vertebrae. These bones represent a major component of the total body bone tissue and therefore the lead body burden. A new test analyser, constructed by modification to the basic design of a superficial bone analyser, has been used to investigate the feasibility of using changes in source-detector geometry and collimation to improve deep bone lead sensitivity for in-vivo measurement techniques. Initial results indicate that the relative detection sensitivity of the test analyser is approximately 6 times that of the Somervaille based system. The results of examination of a series of lead loaded plaster of paris phantoms (0 ppm - 360 ppm) confirmed there was good correlation (r = 0.996, p < 0.0005) between the measured ratio (lead X-rays/coherent scatter photons) and the lead concentrations using data from both XRF analyser systems.

Distribution of body water in patients with cirrhosis: the effect of liver transplantation

We compared total body water and intracellular-extracellular distribution of body water between male patients with mild liver disease without ascites (n = 9), male patients with severe liver disease and gross ascites (n = 6) and a group of age-, sex-, height- and weight- matched controls (n = 6). In addition, we documented the effects of liver transplantation on intracellular, extracellular and total body water in 12 patients (6 men and 6 women) by means of deuterium oxide dilution and whole-body potassium counting. We saw no significant difference in total body water between the healthy controls, patients without ascites and patients with ascites (46.5 +/- 9.2 kg, 45.4 +/- 6.6 kg and 50.4 +/- 5.1 kg, respectively), although, as expected, extracellular water was increased in patients with ascites compared with healthy controls and cirrhotic patients without ascites (36.9 +/- 6.5 kg vs. 25.4 +/- 4.4 kg, p = 0.005; and 36.9 +/- 6.5 kg vs. 27.0 +/- 5.3 kg, p = 0.002, respectively). We found no difference between non-ascitic patients and healthy controls (25.4 +/- 4.4 kg vs. 27.0 +/- 5.3 kg). However, intracellular water was significantly reduced in patients with severe liver disease compared with that in controls (13.6 +/- 3.3 kg vs. 21.5 +/- 4.2 kg, p = 0.005) or patients without ascites (13.6 +/- 3.3 kg vs. 18.3 +/- 2.9 kg, p = 0.01). The reduction of intracellular water appears to be due to loss of body cell mass.(ABSTRACT TRUNCATED AT 250 WORDS)

Efficacy and safety of zonisamide: results of a multicenter study

The safety and efficacy of zonisamide (ZNS), a new antiepileptic drug, was tested in 167 adult participants who entered a historical-controlled 16-week open label, multicenter study. The median percent reduction from baseline of partial seizures was 51.8% in the fourth month of the study (baseline median = 11.5 sz/month; treatment weeks 13-16 = 5.5 sz/month). Persons completing the efficacy study successfully were eligible for a long-term safety study; 113 entered this study. Adverse effects involved principally the CNS and were similar to those seen with other antiepileptic drugs. Four persons (3.7%) developed kidney stones and were withdrawn from the study 250-477 days after starting ZNS. Because of the high percentage of kidney stones, development of ZNS was stopped in the United States but was continued in Japan.

Supraventricular tachycardia in patients with right hemisphere strokes

BACKGROUND AND PURPOSE

The physiological basis for the arrhythmias commonly observed after a stroke is not well understood. Based on evidence that the right and left cerebral hemispheres influence cardiac function in different ways, we sought to determine whether the nature and severity of cardiac arrhythmias in the context of an acute stroke vary in relation to whether the stroke is located in the left or the right hemisphere.

METHODS

Data were obtained from the medical records of nineteen patients with left hemisphere strokes and nineteen patients with right hemisphere strokes who had also had 24-hour electrocardiographic (Holter) recordings within 2 weeks of admission to a stroke unit. Written Holter monitor reports already on file were used for the data analysis.

RESULTS

All four patients with supraventricular tachycardia had right hemisphere strokes (p = 0.05). There was a nonsignificant trend for left hemisphere stroke patients to have more severe ventricular arrhythmias.

CONCLUSIONS

These data provide partial support for the hypothesis that the two cerebral hemispheres have a differential influence on the nature and severity of arrhythmias following an acute stroke. We speculate that parasympathetic tone was diminished ipsilateral to the affected hemisphere associated with a reciprocal rise in sympathetic tone on that side and recommend that a prospective study be undertaken to test this hypothesis more definitively.

Genomic DNA microextraction: a method to screen numerous samples

Many experimental designs require the analysis of genomic DNA from a large number of samples. Although the polymerase chain reaction (PCR) can be used, the Southern blot is preferred for many assays because of its inherent reliability. The rapid acceptance of PCR, despite a significant rate of false positive/negative results, is partly due to the disadvantages of the sample preparation process for Southern blot analysis. We have devised a rapid protocol to extract high-molecular-weight genomic DNA from a large number of samples. It involves the use of a single 96-well tissue culture dish to carry out all the steps of the sample preparation. This, coupled with the use of a multichannel pipette, facilitates the simultaneous analysis of multiple samples. The procedure may be automated since no centrifugation, mixing, or transferring of the samples is necessary. The method has been used to screen embryonic stem cell clones for the presence of targeted mutations at the Hox-2.6 locus and to obtain data from human blood.

Supplemental corn grain for steers grazing native rangeland during summer

Effects of supplemental corn grain on forage OM intake (FOMI), digesta kinetics, ruminal fermentation patterns, in vitro OM digestibility (IVOMD), and in situ OM digestion were examined in steers grazing summer blue grama rangeland in northeastern New Mexico during July and August 1988. Sixteen ruminally cannulated steers (average BW 507 kg) were allotted to four treatments and individually fed whole-shelled corn at 0, .2, .4, and .6% of BW in a complete random design with repeated measurements over time. Forage OMI decreased linearly (P = .02) with increasing levels of supplemental corn; however, a tendency toward greater FOMI, as well as faster particulate and fluid passage, was observed when corn was fed at .2% of BW compared with 0, .4, or .6% of BW. Molar proportions of butyrate increased (P less than .10) but molar proportions of acetate and propionate, ruminal pH, and total VFA concentration did not change (P greater than .10) with added corn. Added corn linearly decreased (P less than .10) ruminal ammonia N concentrations in July, but patterns were inconsistent in August. A cubic response (P less than .05) for in situ OM disappearance with added corn was noted after 24, 72, and 96 h of incubation. Supplemental whole corn fed at .2% of BW had no detrimental effects and tended to increase FOMI. However, supplemental corn fed at .4 or .6% of BW decreased FOMI compared with 0 or .2% of BW.

Effects of milk intake on forage intake and performance of suckling range calves

A study to examine the relationships between milk intake, forage intake, and performance of Hereford-Angus suckling range calves was conducted during July, August, and September of 1984 and 1985. Twenty calves were used each year. The study was conducted at the Red Bluff Research Ranch located 56 km west of Bozeman, Montana. Average daily gain, milk intake (MI), forage digestibility, and fecal output (FO) were measured at 28-d intervals, beginning when the average calf age was 66 +/- 4 d. Milk intake was estimated using weigh-suckle-weigh techniques. Total fecal collections were used to measure FO. Forage digestibility and rates of passage were determined using nylon bag in situ techniques and external markers in ruminally cannulated calves of the same age. Fecal output by calves increased as body weight and age increased. Milk intake was higher (P less than .05) in 1985 than in 1984, but FO was higher (P less than .01) in 1984 than in 1985. Fecal output by calves was negatively correlated to MI in July (r = -.62; P less than .05) and August (r = -.56; P less than .05). No significant correlations were detected between MI and ADG (P greater than .10). Forage intake estimates were derived from FO, rate of passage, and in situ digestibility values. During July, calves consumed .3 kg more forage for each kilogram of reduction in fluid MI (P less than .05). In both August and September, calves consumed .6 kg more forage for each kilogram of reduction in fluid MI (P less than .10). Calves maintained similar digestible energy (DE) intake both years, although the source of DE varied.

Condensed tannins and nutrient utilization by lambs and goats fed low-quality diets

In the first of two experiments, four wether lambs (BW = 26.8 kg) and four wether Angora goats (BW = 31.7 kg) were used in two simultaneous 4 x 4 Latin squares to study the influence of condensed tannins (CT) on nutrient usage and concentrations of serum urea N, somatotropin (GH), and insulin (INS) when the animals were fed low-quality diets containing mountain mahogany (MM; Cercocarpus montanus) leaves. Diets were 8% CP and contained 25% or 50% MM (with hay or straw, respectively), either untreated or treated with polyethylene glycol (PEG; molecular weight 3,350) to reduce total reactive CT. Diets treated with PEG and 25% MM diets had less (P less than .05) CT than diets without PEG or those with 50% MM. Diets containing 50% MM resulted in greater N balance and lower serum urea N (P less than .01) than 25% MM diets. Concentrations of GH and INS were similar in animals fed the 25% and 50% MM diets. Reducing CT by adding PEG did not affect N balance or improve nutrient digestion by lambs or goats fed low-quality diets. In Exp. 2, four wether lambs (BW = 28.4 kg) were used in a 4 x 4 Latin square and fed the same diets as animals in Exp. 1 to study the influence of CT on ruminal fermentation and digesta kinetics. Dietary PEG treatment did not affect digesta kinetics except for a 30% increase in ruminal volume; 50% MM diets had faster particulate passage rates (P less than .05) than 25% MM diets. Ruminal ammonia N was greater (P less than .01) in lambs fed PEG-containing or 25% MM diets; however, rate of in situ NDF disappearance was not reduced by the lower ammonia N in the latter diets.

Evaluating and predicting outcome of acute cerebral vascular accident

An innovative evaluation method is used to study the outcomes and clinical predictions for 97 patients with acute cerebral vascular accidents. The technique involved the participation of several professional disciplines in selecting baseline and treatment variables and making independent predictions about the functional status of patients upon discharge from the stroke treatment center. The data suggest that (1) baseline variables were more important than treatment variables in the participants' predictions about the patients' short-term outcomes; (2) stroke unit staff members were generally successful in predicting patients' functional status; and (3) stroke extensions and other complications are important factors which affect stroke patients' short-term outcomes.