A net carbohydrate and protein system for evaluating cattle diets: II. Carbohydrate and protein availability

The Cornell Net Carbohydrate and Protein System (CNCPS) has a submodel that predicts rates of feedstuff degradation in the rumen, the passage of undegraded feed to the lower gut, and the amount of ME and protein that is available to the animal. In the CNCPS, structural carbohydrate (SC) and nonstructural carbohydrate (NSC) are estimated from sequential NDF analyses of the feed. Data from the literature are used to predict fractional rates of SC and NSC degradation. Crude protein is partitioned into five fractions. Fraction A is NPN, which is trichloroacetic (TCA) acid-soluble N. Unavailable or protein bound to cell wall (Fraction C) is derived from acid detergent insoluble nitrogen (ADIP), and slowly degraded true protein (Fraction B3) is neutral detergent insoluble nitrogen (NDIP) minus Fraction C. Rapidly degraded true protein (Fraction B1) is TCA-precipitable protein from the buffer-soluble protein minus NPN. True protein with an intermediate degradation rate (Fraction B2) is the remaining N. Protein degradation rates are estimated by an in vitro procedure that uses Streptomyces griseus protease, and a curve-peeling technique is used to identify rates for each fraction. The amount of carbohydrate or N that is digested in the rumen is determined by the relative rates of degradation and passage. Ruminal passage rates are a function of DMI, particle size, bulk density, and the type of feed that is consumed (e.g., forage vs cereal grain).

Behavioural improvements with thalamic stimulation after severe traumatic brain injury

Widespread loss of cerebral connectivity is assumed to underlie the failure of brain mechanisms that support communication and goal-directed behaviour following severe traumatic brain injury. Disorders of consciousness that persist for longer than 12 months after severe traumatic brain injury are generally considered to be immutable; no treatment has been shown to accelerate recovery or improve functional outcome in such cases. Recent studies have shown unexpected preservation of large-scale cerebral networks in patients in the minimally conscious state (MCS), a condition that is characterized by intermittent evidence of awareness of self or the environment. These findings indicate that there might be residual functional capacity in some patients that could be supported by therapeutic interventions. We hypothesize that further recovery in some patients in the MCS is limited by chronic underactivation of potentially recruitable large-scale networks. Here, in a 6-month double-blind alternating crossover study, we show that bilateral deep brain electrical stimulation (DBS) of the central thalamus modulates behavioural responsiveness in a patient who remained in MCS for 6 yr following traumatic brain injury before the intervention. The frequency of specific cognitively mediated behaviours (primary outcome measures) and functional limb control and oral feeding (secondary outcome measures) increased during periods in which DBS was on as compared with periods in which it was off. Logistic regression modelling shows a statistical linkage between the observed functional improvements and recent stimulation history. We interpret the DBS effects as compensating for a loss of arousal regulation that is normally controlled by the frontal lobe in the intact brain. These findings provide evidence that DBS can promote significant late functional recovery from severe traumatic brain injury. Our observations, years after the injury occurred, challenge the existing practice of early treatment discontinuation for patients with only inconsistent interactive behaviours and motivate further research to develop therapeutic interventions.

A net carbohydrate and protein system for evaluating cattle diets: I. Ruminal fermentation

The Cornell Net Carbohydrate and Protein System (CNCPS) has a kinetic submodel that predicts ruminal fermentation. The ruminal microbial population is divided into bacteria that ferment structural carbohydrate (SC) and those that ferment nonstructural carbohydrate (NSC). Protozoa are accommodated by a decrease in the theoretical maximum growth yield (.50 vs .40 g of cells per gram of carbohydrate fermented), and the yields are adjusted for maintenance requirements (.05 vs .150 g of cell dry weight per gram of carbohydrate fermented per hour for SC and NSC bacteria, respectively). Bacterial yield is decreased when forage NDF is < 20% (2.5% for every 1% decrease in NDF). The SC bacteria utilize only ammonia as a N source, but the NSC bacteria can utilize either ammonia or peptides. The yield of NSC bacteria is enhanced by as much as 18.7% when proteins or peptides are available. The NSC bacteria produce less ammonia when the carbohydrate fermentation (growth) rate is rapid, but 34% of the ammonia production is insensitive to the rate of carbohydrate fermentation. Ammonia production rates are moderated by the rate of peptide and amino acid uptake (.07 g of peptide per gram of cells per hour), and peptides and amino acids can pass out of the rumen if the rate of proteolysis is faster than the rate of peptide utilization. The protein-sparing effect of ionophores is accommodated by decreasing the rate of peptide uptake by 34%. Validation with published data of microbial flow from the rumen gave a regression with a slope of .94 and an r2 of .88.

Golgi structure correlates with transitional endoplasmic reticulum organization in Pichia pastoris and Saccharomyces cerevisiae

Golgi stacks are often located near sites of "transitional ER" (tER), where COPII transport vesicles are produced. This juxtaposition may indicate that Golgi cisternae form at tER sites. To explore this idea, we examined two budding yeasts: Pichia pastoris, which has coherent Golgi stacks, and Saccharomyces cerevisiae, which has a dispersed Golgi. tER structures in the two yeasts were visualized using fusions between green fluorescent protein and COPII coat proteins. We also determined the localization of Sec12p, an ER membrane protein that initiates the COPII vesicle assembly pathway. In P. pastoris, Golgi stacks are adjacent to discrete tER sites that contain COPII coat proteins as well as Sec12p. This arrangement of the tER-Golgi system is independent of microtubules. In S. cerevisiae, COPII vesicles appear to be present throughout the cytoplasm and Sec12p is distributed throughout the ER, indicating that COPII vesicles bud from the entire ER network. We propose that P. pastoris has discrete tER sites and therefore generates coherent Golgi stacks, whereas S. cerevisiae has a delocalized tER and therefore generates a dispersed Golgi. These findings open the way for a molecular genetic analysis of tER sites.

Oxidative damage to mitochondrial DNA and activity of mitochondrial enzymes in chronic active lesions of multiple sclerosis

Soluble products of activated immune cells include reactive oxygen species (ROS) and nitric oxide (NO) with a high potential to induce biochemical modifications and degenerative changes in areas of inflammation in the central nervous system (CNS). Previously, we demonstrated an increased production of ROS by activated mononuclear cells (MNC) of patients with multiple sclerosis (MS) compared to those of controls, and development of oxidative damage to total DNA in association with inflammation in chronic active plaques. The current study aimed to determine whether mitochondrial (mt)DNA is affected by oxidative damage, and whether oxidative damage to mitochondrial macromolecules (including mtDNA) is associated with a decline in the activity of mitochondrial enzyme complexes. Using molecular and biochemical methods we demonstrate a trend for impaired NADH dehydrogenase (DH) activity and a possible compensatory increase in complex IV activity in association with oxidative damage to mtDNA in chronic active plaques. Immunohistochemistry confirms the increase of oxidative damage to DNA predominantly located in the cytoplasmic compartment of cells in chronic active plaques. These observations suggest that oxidative damage to macromolecules develops in association with inflammation in the CNS, and may contribute to a decline of energy metabolism in affected cells. As observed in neurodegenerative diseases of non-inflammatory origin, decreased ATP synthesis can ultimately lead to cell death or degeneration. Therefore, elucidation of this pathway in MS deserves further studies which may identify neuroprotective strategies to prevent tissue degeneration and the associated clinical disability.

The mechanics of the knee and prosthesis design

The mechanisms controlling and limiting movement and serving to transmit load between the femur and the tibia are discussed. Having accounted for the transmission of all components of force and couple across the joint and noted the load-bearing role of the menisci, some principles which might guide the design of knee prostheses are deduced. It is shown that current designs transgress some of these principles. An experimental prosthesis is then described, which incorporates analogues of the natural menisci. The possible practical application of this novel principle has been studied in cadaveric human joints and in living patients.

A net carbohydrate and protein system for evaluating cattle diets: III. Cattle requirements and diet adequacy

The Cornell Net Carbohydrate and Protein System (CNCPS) has equations for predicting nutrient requirements, feed intake, and feed utilization over wide variations in cattle (frame size, body condition, and stage of growth), feed carbohydrate and protein fractions and their digestion and passage rates, and environmental conditions. Independent data were used to validate the ability of the CNCPS to predict responses compared to National Research Council (NRC) systems. With DMI in steers, the CNCPS had a 12% lower standard error of the Y estimate (Sy.x) and three percentage units less bias than the NRC system. For DMI in heifers, both systems had a similar Sy.x but the NRC had four percentage units less bias. With lactating dairy cows' DMI, the CNCPS had a 12% lower Sy.x. Observed NEm requirement averaged 5% under NRC and 6% under CNCPS predicted values at temperatures above 9 degrees C but were 18% over NRC and 9% under CNCPS at temperatures under 9 degrees C. Energy retained was predicted with an R2 of .80 and .95 and a bias of 8 and 4% for the NRC and CNCPS, respectively. Protein retained was predicted with an R2 of .75 and .85 with a bias of 0 and -1% for NRC and CNCPS, respectively. Biases due to frame size, implant, or NEg were small. Body condition scores predicted body fat percentage in dairy cows with an R2 of .93 and a Sy.x of 2.35% body fat. The CNCPS predicted metabolizable protein allowable ADG with a bias of 1.6% with a Sy.x of .07 kg compared to values of -30% and .10 kg, respectively for the NRC system.

Phase I trial of docetaxel with estramustine in androgen-independent prostate cancer

PURPOSE

To evaluate the toxicity, efficacy, and pharmacokinetics of docetaxel when combined with oral estramustine and dexamethasone in a phase I study in patients with progressive metastatic androgen-independent prostate cancer.

PATIENTS AND METHODS

Thirty-four men were stratified into minimally pretreated (MPT) and extensively pretreated (EPT) groups. Estramustine 280 mg PO tid was administered 1 hour before or 2 hours after meals on days 1 through 5, with escalated doses of docetaxel from 40 to 80 mg/m2 on day 2. Treatment was repeated every 21 days.

RESULTS

Thirty-four patients were assessable for toxicity and 33 for response. In the MPT patients, dose-limiting myelosuppression was reached at 80 mg/m2, with six patients experiencing grade 3/4 granulocytopenia. In EPT patients, escalation above 70 mg/m2 was not attempted. Fourteen MPT (70%) and six EPT (50%) patients had a > or = 50% decline in serum PSA on two consecutive measurements taken at least 2 weeks apart. The overall 50% PSA response rate was 63% (95% confidence interval [CI], 28% to 81%). Of the 18 patients with bidimensionally measurable disease, five (28%; 95% CI, 11% to 54%) achieved a partial response. At the time of entry onto the study, 15 patients required narcotic analgesics for bone pain; after treatment, eight (53%) discontinued their pain medications. The area under the curve for docetaxel increased linearly from 40 to 70 mg/m2. At 80 mg/m2, the measured area under the curve was 8.37 (standard deviation, 0.724), which was significantly higher than the previously reported values.

CONCLUSION

The recommended phase II dose of docetaxel combined with estramustine is 70 mg/m2 in MPT patients and 60 mg/m2 in EPT patients. This combination is active in men with androgen-independent prostate cancer.

The ovary as a source of alpha-ecdysone in an adult mosquito

The ovaries of the mosquito Aedes aegypti cultured in vitro secrete material that behaves like ecdysone in a radioimmunoassay. The material was identified as alpha-ecdysone by high-resolution liquid and gas-liquid chromatography. Secretion reached a maximum 16 hr after a blood meal as shown by bioassay and direct determination. Ovariectomy reduced the concentration of ecdysone in the adult after a blood meal. Qualitative analysis of whole-body extracts indicated beta-ecdysone to be the principal species present. Thus the ovaries appear to secrete a prohormone, alpha-ecdysone, which is converted to beta-ecdysone. Beta-ecdysone plays a significant role in stimulating egg development in the adult mosquito and may have reproductive roles in other insects.

Proton magnetic resonance spectroscopic imaging for metabolic characterization of demyelinating plaques

We used proton magnetic resonance (MR) spectroscopic imaging to determine the serial changes in MR signals from choline, creatine, lactate, and N-acetylaspartate in and around a large demyelinating lesion followed over a period of 8 months. Elevated lactate and choline signals were observed at the first examination 3 days after the onset of symptoms. Reduced N-acetylaspartate signals were observed a few days afterward. The abnormal metabolite signals varied in different regions of the lesion and extended beyond the borders of abnormal signal intensity seen on conventional MR imaging (MRI). On the last examination at 8 months when the lesion appeared much smaller on MRI, choline signals from the center of the lesion were still high, but were falling. Choline signals outside the lesion on MRI had returned to normal as had lactate signals everywhere. Importantly, there was no recovery of N-acetylaspartate signals in or adjacent to the lesion on MRI. This serial study demonstrates the potential of MR spectroscopic imaging for characterizing the chemical pathological evolution of demyelinating lesions in ways that conventional MRI cannot. We propose that abnormal signals from choline can indicate recent regional demyelination, while persistent abnormal signals from N-acetylaspartate can provide an index of irreversible damage in the nervous system.

Plasma leptin is partly cleared by the kidney and is elevated in hemodialysis patients

Leptin, the gene product of the ob gene, is important in the control of appetite in rodents and may have an important role in humans. The clearance of leptin from the circulation is unknown. As the leptin receptor is present in the kidney, we evaluated the role of the kidney in removing circulating leptin in humans. We measured leptin in aortic and renal vein plasma in 8 patients with intact renal function and 6 patients with impaired renal function who were undergoing elective cardiac catheterization. Renal blood flow was measured in all patients to calculate net mass balance across the kidney. In patients with intact renal function there is net renal uptake of 12% of circulating leptin, whereas in patients with renal insufficiency there is no renal uptake of leptin. In a separate cohort of 36 patients with end-stage renal failure on hemodialysis, peripheral leptin levels factored for body mass index was increased by > fourfold as compared to a group of healthy controls (N = 338). In addition, plasma leptin is not cleared by hemodialysis with a modified cellulose membrane. Additional studies are required to evaluate the role of leptin in mediating the anorexia of uremia.

Cortisol secretion and metabolism in anorexia nervosa

We studied cortisol secretion and metabolism in 10 women with anorexia nervosa. The 24-hour mean plasma cortisol concentration was 8.9 mug per deciliter (controls, 4.9) (P less than 0.01). Secretory patterns showed normal circadian rhythms. Cortisol half-life was prolonged from 60 to 78 minutes (P less than 0.01), and metabolic clearance rate was decreased from 359 to 177 liters per day (P less than 0.001). Cortisol production was normal (19.4 mg per day). Urinary cortisol was slightly elevated in two of five patients. These findings, as well as the increased tetrahydrocortisol/tetrahydrocortisone ratio (1.2 vs 0.65, P less than 0.01), also appear in hypothyroid patients. Thyroid-function studies showed normal total and free thyroxine and thyrotropin, but low plasma tri-iodothyronine levels (52.7+/-13.2 vs. 137.8+/-24.1 ng per deciliter in the controls, P less than 0.001). In five additional patients with anorexia nervosa studied before and after short-term tri-iodothyronine administration, metabolic abnormalities decreased as plasma tri-iodothyronine levels rose to or above normal.

Induction of translatable mRNA for dopa decarboxylase in Drosophila: an early response to ecdysterone

Ecdysteroid titer and dopa decarboxylase (aromatic-L-amino-acid carboxy-lyase, EC 4.1.1.28) activity were determined throughout the life cycle of Drosophila melanogaster. Five peaks in the amount of hormone were observed, which preceeded five dopa decarboxylase peaks by times ranging from 5 to 58 hr. Late in the third instar the hormone and enzyme maxima are nearly coincident. The increase in enzyme activity observed at this time is paralleled by an increase in translatable dopa decarboxylase mRNA. To obtain evidence that ecdysterone induces the appearance of this mRNA we made use of the temperature-sensitive ecd1 mutant. Garen et al. [Garen, A., Kauvar, L. & Lepesant, J.-A. (1977) Proc. Natl, Acad. Sci. USA 74, 5099-5103] have shown that when third instar mutant larvae are kept at 29 degrees C, the ecdysteroid titer remains low. In such larvae we show that the normal increase in dopa decarboxylase activity fails to appear, and no translatable dopa decarboxylase mRNA can be detected. Exogenous feeding of ecdysterone to these larvae results in a rapid synthesis of dopa decarboxylase in the epidermal cells. In addition, a parallel increase in translatable dopa decarboxylase mRNA occurs, which may be a primary response of these target cells to ecdysterone.

A versatile set of vectors for constitutive and regulated gene expression in Pichia pastoris

The budding yeast Pichia pastoris is an attractive system for exploring certain questions in cell biology, but experimental use of this organism has been limited by a lack of convenient expression vectors. Here we describe a set of compact vectors that should allow for the expression of a wide range of endogenous or foreign genes in P. pastoris. A gene of interest is inserted into a modified pUC19 polylinker; targeted integration into the genome then results in stable and uniform expression of this gene. The utility of these vectors was illustrated by expressing the bacterial beta-glucuronidase (GUS) gene. Constitutive GUS expression was obtained with the strong GAP promoter or the moderate YPT1 promoter. The regulatable AOX1 promoter yielded very strong GUS expression in methanol-grown cells, negligible expression in glucose-grown cells, and intermediate expression in mannitol-grown cells. GenBank Accession Numbers are: pIB1, AF027958; pIB2, AF0279959; pIB3, AF027960; pIB4, AF027961.

Skeletal muscle membrane lipids and insulin resistance

Skeletal muscle plays a major role in insulin-stimulated glucose disposal. This paper reviews the range of evidence in humans and experimental animals demonstrating close associations between insulin action and two major aspects of muscle morphology: fatty acid composition of the major structural lipid (phospholipid) in muscle cell membranes and relative proportions of major muscle fiber types. Work in vitro and in vivo in both rats and humans has shown that incorporation of more unsaturated fatty acids into muscle membrane phospholipid is associated with improved insulin action. As the corollary, a higher proportion of saturated fats is linked to impairment of insulin action (insulin resistance). Studies in vitro suggest a causal relationship. Among polyunsaturated fatty acids (PUFA) there is some, but not conclusive, evidence that omega-3 (n-3) PUFA may play a particular role in improving insulin action; certainly a high n-6/n-3 ratio appears deleterious. In relation to fiber type, the more highly oxidative, insulin-sensitive type 1 and type 2a fibers have a higher percentage of unsaturated fatty acids, particularly n-3, in their membrane phospholipid, compared to the insulin-resistant, glycolytic, type 2b fibers. These variables, however, can be separated and may act in synergy to modulate insulin action. It remains to establish whether lifestyle (e.g., dietary fatty acid profile and physical activity), genetic predisposition, or a combination are the prime determinants of muscle morphology (particularly membrane lipid profile) and hence insulin action.

THE RELATIONSHIP BETWEEN DEGENERATIVE CHANGES AND LOAD-BEARING IN THE HUMAN HIP

1. A predictable pattern of degeneration occurs on both the femoral head and the acetabulum and this pattern is age dependent.

2. The degenerative areas on the femoral head are related to habitual non-use.

3. The hip is shown to be anatomically incongruent, and the dome of the acetabulum, a predictable area of degeneration, is shown also to be an area of habitual non-use.

4. The possible relationships between age-dependent degenerative changes and senile degenerative joint disease is discussed and the importance of changing geometry stressed.

ENETS Consensus Guidelines for the Standards of Care in Neuroendocrine Neoplasms: Systemic Therapy - Biotherapy and Novel Targeted Agents

Systemic therapies established in the management of patients with neuroendocrine tumors (NETs) include somatostatin analogs and interferon-α, also referred to as biotherapy. Recent randomized controlled studies have extended the knowledge on the frequency of side effects associated with biotherapy. More recently, novel targeted drugs, such as the mammalian target of rapamycin inhibitor everolimus and the multiple tyrosine kinase inhibitor sunitinib, have been introduced in the management of NETs. Although targeted drugs are generally well tolerated, with most adverse events being of mild to moderate severity and manageable, novel targeted drugs exhibit a distinct adverse event profile that warrants guidance for appropriate diagnostic and therapeutic management. This is particularly important given the widespread and potentially long-term use of everolimus in a broad spectrum of NETs and of sunitinib in pancreatic NETs. This review will focus on the most relevant toxicities associated with biotherapy and novel targeted drugs and on their management. For each drug class indication, administration and dosing schedule, most frequent adverse events, actions and dose adjustments for adverse events as well as their monitoring are presented. This review further covers the evaluation of treatment effect, patient information, drug interactions, and information on pregnancy.

A prospective study of early pregnancy loss

The New York State Early Pregnancy Detection Study was a prospective study of early pregnancy loss, between implantation and menses, in 217 women attempting to become pregnant during 1989-1992. Women collected urine samples on three consecutive mornings during the late luteal phase of their menstrual cycle, for up to 12 cycles, contributing samples for 1253 menstrual cycles. Urinary human chorionic gonadotrophin (HCG), measured using an immunoradiometric assay, was the biomarker for pregnancy. We observed a range of early pregnancy loss (EPL) rates, from a low estimate of 11.0% to a high estimate of 26.9%, depending on the definition used and the subgroup analysed. Based on a definition of 3 days of HCG concentration > or = 4.00 pmol/l, 2 days > or = 5.33 pmol/l or the last day of HCG > or = 6.67 pmol/l, we identified 115 positive cycles; 95 cycles were clinically confirmed pregnancies and 20 cycles were EPL, giving an EPL rate of 17.4% [95% confidence interval (CI) 11.0-25.6]. In addition, we observed an EPL rate of 19.5% (95% CI 11.3-30.1) for samples collected within a 15 day window around menses, and a rate of 20.3% (95% CI 11.3-32.2) for samples limited to the first three menstrual cycles. Because studies use urine collection schemes other than daily sampling, the definition of pregnancy will be crucial in defining EPL.

Simple CPR: A randomized, controlled trial of video self-instructional cardiopulmonary resuscitation training in an African American church congregation

STUDY OBJECTIVE

Despite the proven efficacy of cardiopulmonary resuscitation (CPR), only a small fraction of the population knows how to perform it. As a result, rates of bystander CPR and rates of survival from cardiac arrest are low. Bystander CPR is particularly uncommon in the African American community. Successful development of a simplified approach to CPR training could boost rates of bystander CPR and save lives. We conducted the following randomized, controlled study to determine whether video self-instruction (VSI) in CPR results in comparable or better performance than traditional CPR training.

METHODS

This randomized, controlled trial was conducted among congregational volunteers in an African American church in Atlanta, GA. Subjects were randomly assigned to receive either 34 minutes of VSI or the 4-hour American Heart Association "Heartsaver" CPR course. Two months after training, blinded observers used explicit criteria to assess CPR performance in a simulated cardiac arrest setting. A recording manikin was used to measure ventilation and chest compression characteristics. Participants also completed a written test of CPR-related knowledge and attitudes.

RESULTS

VSI trainees displayed a comparable level of performance to that achieved by traditional trainees. Observers scored 40% of VSI trainees competent or better in performing CPR, compared with only 16% of traditional trainees (absolute difference 24%, 95% confidence interval 8% to 40%). Data from the recording manikin confirmed these observations. VSI trainees and traditional trainees achieved comparable scores on tests of CPR-related knowledge and attitudes.

CONCLUSION

Thirty-four minutes of VSI can produce CPR of comparable quality to that achieved by traditional training methods. VSI provides a simple, quick, consistent, and inexpensive alternative to traditional CPR instruction, and may be used to extend CPR training to historically underserved populations.