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The objective of this piece is to propose reasons that change the way air traffic controllers and others learn and work in air navigation, but also how they can improve workloads, due to the implementation of holographic radar. This research also aims to describe how this could reduce the cognitive load of an operator, thanks to the improvement of visual perspective and capacity of analysis, in order to more easily control an aircraft. Seeing that the visual facilitation is well known, radar is able to represent in three dimensions and in detail that which could not previously be perceived. This makes a substantial difference in the comfort and ease of training new controllers. In conjunction with operators, the objective of this technology is to save both hours and cost of training. This is of tremendous benefit, as some countries spend millions of dollars trying to educate the personnel in charge of air traffic control. In addition, a goal of this technology is the further improvement in air safety in a sector that demands more jobs and more availability to people in the industry, with an increasing number of aircraft in the world. This makes air traffic control one of the more demanding careers in the global arena. [ABSTRACT FROM AUTHOR]

Introduction With the rising trends in breast cancer throughout the world, the traditional modus of intraoperative tissue dissection using a scalpel, scissors, or electrocautery needs to be re-evaluated in the wake of newer modalities, such as electrothermal bipolar vessel sealing (EBVS) devices, which may theoretically reduce the postoperative complications and morbidity in these patients. Aim and objective The objective of this study is to compare an EBVS device to electrocautery (diathermy) in modified radical mastectomy (MRM), based on selected intraoperative and postoperative outcomes. Study procedure This was a comparative cross-sectional section study that included 60 patients with operable breast cancer (stages I and II, TNM classification, and post-neoadjuvant stage III disease). Patients were divided into two groups for surgery: one group underwent an MRM using the EBVS device (Group A), while the other group had the procedure performed using conventional electrocautery (Group B), as per the surgeon's choice depending on theatre slot and equipment availability. Intraoperatively, the total operative time, time for raising the flaps, time taken for breast tissue dissection, time for axillary dissection, and blood loss were recorded. Postoperative parameters included total drainage volume, number of days of drainage, seroma formation, and other complications. Patients were followed up for one month after surgery, with early postoperative complications such as wound infection, upper limb lymphedema, seroma, flap necrosis, and nerve injuries being documented. Results The groups were found to be comparable in terms of the age distribution, TNM staging, stage grouping, and nodal status of the patients. The EBVS device group demonstrated statistically significant advantages in total operative time, axillary dissection time, flap raising time, breast tissue dissection time, intraoperative blood loss, total drainage volume, and days of drainage. However, no statistically significant difference was found between the two devices in terms of seroma formation, early postoperative complications, and duration of postoperative stay at the hospital. Conclusion While the use of EBVS in MRM provides a considerable decrement in the total operative duration, duration of the various steps of surgery, intraoperative blood loss, and postoperative volume and duration of drainage, these devices do not offer an evident advantage in terms of the postoperative complications or morbidity., Competing Interests: Human subjects: Consent was obtained or waived by all participants in this study. Institutional Ethical Committee, Government Medical College, Thrissur, Thrissur, India issued approval IEC/GMCTCR/2020/042. Animal subjects: All authors have confirmed that this study did not involve animal subjects or tissue. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Chirukandath et al.)

Three isotopes of scandium─ 43 Sc, 44 Sc, and 47 Sc─have attracted increasing attention as potential candidates for use in imaging and therapy, respectively, as well as for possible theranostic use as an elementally matched pair. Here, we present the octadentate chelator 3,4,3-(LI-1,2-HOPO) (or HOPO), an effective chelator for hard cations, as a potential ligand for use in radioscandium constructs with simple radiolabeling under mild conditions. HOPO forms a 1:1 Sc-HOPO complex that was fully characterized, both experimentally and theoretically. [ 47 Sc]Sc-HOPO exhibited good stability in chemical and biological challenges over 7 days. In healthy mice, [ 43,47 Sc]Sc-HOPO cleared the body rapidly with no signs of demetalation. HOPO is a strong candidate for use in radioscandium-based radiopharmaceuticals.

Purpose: Manocept™ constructs are mannosylated amine dextrans (MADs) that bind with high affinity to the mannose receptor, CD206. Tumor-associated macrophages (TAMs) are the most numerous immune cells in the tumor microenvironment and a recognized target for tumor imaging and cancer immunotherapies. Most TAMs express CD206, suggesting utility of MADs to deliver imaging moieties or therapeutics to TAMs. The liver Kupffer cells also express CD206, making them an off-target localization site when targeting CD206 on TAMs. We evaluated TAM targeting strategies using two novel MADs differing in molecular weight in a syngeneic mouse tumor model to determine how varying MAD molecular weights would impact tumor localization. Increased mass dose of the non-labeled construct or a higher molecular weight (HMW) construct were also used to block liver localization and enhance tumor to liver ratios., Procedures: Two MADs, 8.7 kDa and 22.6 kDa modified with DOTA chelators, were synthesized and radiolabeled with 68 Ga. A HMW MAD (300 kDa) was also synthesized as a competitive blocking agent for Kupffer cell localization. Balb/c mice, with and without CT26 tumors, underwent dynamic PET imaging for 90 min followed by biodistribution analyses in selected tissues., Results: The new constructs were readily synthesized and labeled with 68 Ga with ≥ 95% radiochemical purity in 15 min at 65 °C. When injected at doses of 0.57 nmol, the 8.7 kDa MAD provided 7-fold higher 68 Ga tumor uptake compared to the 22.6 kDa MAD (2.87 ± 0.73%ID/g vs. 0.41 ± 0.02%ID/g). Studies with increased mass of unlabeled competitors showed reduced liver localization of the [ 68 Ga]MAD-8.7 to varying degrees without significant reductions in tumor localization, resulting in enhanced tumor to liver signal ratios., Conclusion: Novel [ 68 Ga]Manocept constructs were synthesized and studied in in vivo applications, showing that the smaller MAD localized to CT26 tumors more effectively than the larger MAD and that the unlabeled HMW construct could selectively block liver binding of [ 68 Ga]MAD-8.7 without diminishing the localization to tumors. Promising results using the [ 68 Ga]MAD-8.7 show a potential path to clinical applications., (© 2023. The Author(s).)

One in eight women will be diagnosed with breast cancer in their lifetime and approximately 25% of those cases will be HER2-positive. Current methods for diagnosing HER2-positive breast cancer involve using IHC and FISH from suspected cancer biopsies to quantify HER2 expression. HER2 PET imaging could potentially increase accuracy and improve the diagnosis of lesions that are not available for biopsies. Using two previously discovered HER2-targeting peptides, we modified each peptide with the chelator DOTA and a PEG2 linker resulting in DOTA-PEG2-GSGKCCYSL (P5) and DOTA-PEG2-DTFPYLGWWNPNEYRY (P6). Each peptide was labeled with 68Ga and was evaluated for HER2 binding using in vitro cell studies and in vivo tumor xenograft models. Both [68Ga]P5 and [68Ga]P6 showed significant binding to HER2-positive BT474 cells versus HER2-negative MDA-MB-231 cells ([68Ga]P5; 0.68 ± 0.20 versus 0.47 ± 0.05 p < 0.05 and [68Ga]P6; 0.55 ± 0.21 versus 0.34 ± 0.12 p < 0.01). [68Ga]P5 showed a higher percent injected dose per gram (%ID/g) binding to HER2-positive tumors two hours post-injection compared to HER2-negative tumors (0.24 ± 0.04 versus 0.12 ± 0.06; p < 0.05), while the [68Ga]P6 peptide showed significant binding (0.98 ± 0.22 versus 0.51 ± 0.08; p < 0.05) one hour post-injection. These results lay the groundwork for the use of peptides to image HER2-positive breast cancer.

Background: Ending December 2019, the world had to face to COVID-19. Latin America and the Caribbean suffered the effects where the contiguous and the number of deaths has been significant. Studies indicate that older adults with some degree of cognitive impairment are at greater risk of worsening their cognitive status and mental health, for this reason it's exposed that social isolation and loneliness has harmful effects on the health of this population. This mini-review inquires on the effects of COVID-19 due to social isolation on neuropsychiatric symptoms (NPS) in Latin American older adults with and without dementia., Method: A search was carried out in PubMed, SCOPUS, and ScienceDirect identifying all articles published up to July 31, 2021 using the keywords "social isolation", "lockdown", "quarantine", "COVID-19",, "neuropsychiatric symptoms ", "neurobehavioral", "dementia"," mild cognitive impairment "," Older People ", "aging", "elderly". Two independent reviewers screened and selected appropriate articles and a third researcher helped resolve disagreements. The selected articles met the following criteria: written in English, Spanish or Portuguese, original article; focused on elderly subjects, articles that provided information on the NPS effects in Latin American populations during the COVID-19 pandemic. The review was based on the PRISMA Statement and used the SIGN criteria., Result: From 61 articles recovered from electronic databases (PubMed, Science Direct and Scopus) 10 of them were chosen for this review. The majority of the articles reported in a general way a negative impact on the mental health of the population in Latin America. They referred to a significant increase in the anxiety and depression symptoms. The majority of the articles were studies developed in Brazil, Argentina and Chile., Conclusion: The COVID-19 has shown a negative impact on the mental health of older adults. Latin America is a region with important socio-sanitary problems which increase the impact of the pandemic in SNP, especially in older adults. It's necessary to increase the studies in Latin America that glimpse the real situation in the region., (© 2021 the Alzheimer's Association.)

Vitamin H (biotin) is delivered to the fetus transplacentally by an active biotin-transport mechanism and is critical for fetal development. Our objective was to develop a comprehensive MRI technique for mapping biotin transporter activity in the murine placenta. Visualization of transporter activity can employ MRI's unique T 2 *-dependent signal 'off-switch', which is triggered by transporter mediated aggregation of biotinylated contrast agent (b-BSA-Gd-DTPA). MRI data were collected from pregnant mice after administration of b-BSA-Gd-DTPA and analyzed using a new sub-voxel biophysical signal model. Validation experiments included competition with native biotin, comparative tests using PET, histology, and ICPMS. MRI signal was governed by binding, aggregation, and clearance of biotin (confirmed by histology). Signal dynamics reflected the placenta's perfusion pattern modulated by biotin transporter activity and trophoblast mediated retention, and were in congruence with a three-compartment sub-voxel model. Pre-saturation of the transporters with free biotin suppressed b-BSA-Gd-DTPA uptake. The results were confirmed by PET, histology and ICPMS. The presented MRI-based platform allows to track activity of essential molecular transporters in the placenta, reflecting a transporter-mediated uptake, followed by retention and aggregation, and recycling associated with the large b-BSA-Gd-DTPA conjugate. The presented DCE-MRI technique can furthermore be used to map and characterize microstructural compartmentation and transporter activity without exposing the fetus to contrast media.

Background: Renal artery stenosis (RAS) causes renal injury partly via microvascular (MV) endothelial dysfunction and damage. Vascular endothelial growth factor (VEGF) is crucial for preservation of microvasculature and promotes vascular proliferation and endothelial repair. We have previously shown that MV rarefaction is associated with decreased VEGF in the kidney exposed to chronic RAS, accompanied by deteriorated renal function and fibrosis. We hypothesized that preserving the renal microcirculation in the stenotic kidney will halt the progression of renal damage., Methods: Unilateral RAS was induced in 16 pigs. In eight, VEGF (0.05 micrograms/kg) was infused intra-renally at the onset of RAS. After 6 weeks, single-kidney haemodynamics and function were assessed using in vivo multi-detector computed tomography (CT). Renal microvessels, angiogenic pathways and morphology were investigated ex vivo using micro-CT, real-time PCR and histology., Results: Blood pressure and degree of RAS was similar in RAS and RAS + VEGF pigs. Single-kidney renal blood flow (RBF) and glomerular filtration rate (GFR) were reduced in RAS compared to Normal (221.1 +/- 46.5 and 29.9 +/- 3.8 vs. 522.5 +/- 60.9 and 49.3 +/- 3.4 mL/min, respectively, P < 0.05), accompanied by decreased cortical MV density and increased renal fibrosis. Pre-emptive administration of VEGF preserved MV architecture, attenuated fibrosis and normalized RBF and GFR (510.8 +/- 50.9 and 39.9.1 +/- 4.1 mL/min, P = not significant vs. Normal)., Conclusions: This study underscores the importance of the renal microcirculation in renovascular disease. Intra-renal administration of VEGF preserved renal MV architecture and function of the stenotic kidney, which in turn preserved renal haemodynamics and function and decreased renal fibrosis. These observations suggest that preventing renal MV loss may be a potential target for therapeutic approaches for patients with chronic renovascular disease.

Tissue plasminogen activator (tPA) plays important roles in the brain after excitotoxic injury. It is released by both neurons and microglia and mediates neuronal death and microglial activation. Mice lacking tPA are resistant to excitotoxicity and show very limited microglial activation. Activated microglia are neurotoxic in culture, but this phenomenon is not well documented in vivo. To further understand the sequence of events through which tPA mediates microglial activation and neurodegeneration, we have generated mice that exhibit restricted expression of tPA through introduction of tPA transgenes under the control of neuronal- or microglial-specific promoters into tPA-deficient mice. Neither strain of transgenic mice shows abnormal brain morphology or inflammation in the absence of injury, and unilateral intrahippocampal kainate injections into the transgenic mice induced excitotoxicity and microglial activation reminiscent of wild-type mice. However, there are differences in the kinetics of the resulting pathology. The neuronal tPA-expressing mice exhibit accelerated microglial activation compared with wild-type or microglial tPA-expressing mice. However, microglial tPA-expressing mice exhibit greater neurodegeneration. These data suggest a model in which tPA plays different roles after kainate injection depending on whether it is released by neurons or microglia. We propose that tPA, initially secreted from injured neurons, acts as a cytokine to activate microglia at the site of injury. These activated microglia then secrete additional tPA, which promotes extracellular matrix degradation, neurodegeneration, and self-proliferation. We suggest that an approach to attenuate microglia-mediated neuronal death in vivo might be to pharmacologically prevent microglial activation.

Two bioassays were conducted to determine the maintenance requirement and efficiency of utilization of dietary Lys in young chicks. New Hampshire x Columbian males were used in Assay 1 and Avian x Avian males were used in Assay 2. In each assay, chicks were given free access for 10 d to crystalline amino acid (AA) diets containing graded levels of L-Lys.HCl. Doses of Lys represented 5, 40, 55, 70, and 95% of its ideal level in Assay 1; all other AA were set at 100% of their ideal levels, except for the lowest Lys level, in which the other AA were maintained at a 15% excess. In Assay 2, doses of Lys represented 5, 10, 40, 55, 70, and 95% of ideal; all other AA were maintained at minimized excess levels that were 15% (of ideal) above the various doses of Lys. After 24 h of feed deprivation, chicks were killed for whole-body protein and AA analysis. In Assay 1, protein accretion (r2 = 0.95) and Lys accretion (r2 = 0.98) were linear (P < 0.01) functions of Lys intake. Slope of the Lys accretion regression line indicated that 75.8% of the crystalline Lys ingested (above maintenance) was retained. The Lys required for zero protein accretion was 12 mg/d or 45 mg/d per kg3/4, whereas the Lys required for zero Lys accretion was 30.3 mg/d or 114 mg/d per kg3/4. With Avian x Avian chicks, protein accretion (r2 = 0.99) and Lys accretion (r2 = 0.99) were linear (P < 0.01) functions of Lys intake. Slope of the Lys regression line indicated that 79.3% of the Lys ingested was retained. The Lys requirement for zero protein accretion was 2.5 mg/d or 6.9 mg/d per kg3/4. The Lys maintenance requirement for zero Lys accretion, however, was 32.3 mg/d or 89.1 mg/d per kg3/4. The data demonstrated that at nitrogen equilibrium, chicks are in negative Lys balance but are in positive balance of glycine and proline.

One hundred and sixteen crossbred male chicks were used in two battery trials to establish the biological efficacy and toxicity of D-allothreonine (D-allo-Thr) relative to L-Thr. In the efficacy trial, graded doses of D-allo-Thr or L-Thr were added to a Thr-deficient (0.24% L-Thr) chemically defined diet and fed to chicks during the period 10 to 21 d posthatching. Addition of 0, 0.09, and 0.18% L-Thr produced marked linear (P < 0.01) growth and feed efficiency responses, but addition of 0.18 or 0.36% D-allo-Thr did not elicit a response in either weight gain or feed efficiency. In the toxicity trial, 2% D-allo-Thr or 2% L-Thr were added to a conventional 23% CP corn-soybean meal starter diet. During an 11-d feeding period, neither weight gain nor voluntary feed intake were affected (P > 0.10) by 2% additions of either compound. This experiment demonstrates that chicks cannot metabolize D-allo-Thr to L-Thr and that neither L-Thr nor D-allo-Thr are growth depressing when provided in a large surfeit.

Broiler chicks were fed on chemically-defined crystalline amino acid diets containing graded levels of L-threonine (Thr) during the period 10-20 d post-hatching. Doses of Thr represented 5, 10, 15, 40, 55, 70 and 95% of its ideal level for maximal weight gain and feed efficiency. Other amino acids were maintained at minimized excess levels that were 15% (of ideal) above the various doses of Thr. Following 10 d of feeding and a 24 h fast, chicks were killed for whole-body protein and amino acid analysis. Using pen accretion means, weight gain (r2 0.98), protein accretion (r2 0.99), and Thr accretion (r2 0.99) were linear (P < 0.01) functions of Thr intake. Slope of the Thr accretion regression line indicated that 82% of the Thr intake was recovered in whole-body protein. At zero Thr intake, chicks lost 11.9 mg Thr/d. The Thr maintenance requirement was 45.7 mg/d per kg body weight 0.75. Increasing doses of Thr resulted in increased (P < 0.05) concentrations of methionine, isoleucine, histidine and lysine in whole-body protein. Other indispensable amino acids, including Thr, also tended to increase. Whole-body glycine, proline, serine and cystine concentrations decreased (P < 0.05) as Thr was increased in the diet. The maintenance need for Thr represented 5.5% of the total need for Thr. The data suggest that efficiency of Thr utilization is constant at all levels of Thr intake between 5 and 95% of the level required for maximal weight gain and feed efficiency.

Four experiments were conducted to determine the digestible Thr requirement of commercial broiler chickens (Ross x Hubbard) during the period 3 to 6 and 6 to 8 wk posthatching. Threonine-deficient corn-peanut meal basal diets (3,200 MEn/kg) contained 20% CP and 0.50% Thr for 3- to 6-wk-old birds, and 18.3% CP and 0.50% Thr for 6- to 8-wk-old birds. True digestibility assessment using cecectomized roosters indicated that Thr was 81% digestible in both basal diets. Thus, both diets contained 0.40% digestible Thr. Growth rate and feed efficiency of chicks fed the corn-peanut meal basal diets supplemented with surfeit Thr was equal to that of chicks fed a 20% CP Met-fortified corn-soybean meal diet. Graded doses of Thr produced marked responses (P < 0.05) in weight gain and feed efficiency in birds of both age groups. Maximal feed efficiency was achieved at 0.61% digestible Thr in 3- to 6-wk-old birds and at 0.52% digestible Thr in 6- to 8-wk-old birds. Extrapolating these digestible Thr requirements to total requirements for chicks consuming corn-soybean meal diets (Thr digestibility = 87%) results in estimates of 0.70 and 0.60% for broiler chickens during the growth periods 3 to 6 and 6 to 8 wk posthatching, respectively. These estimates are lower than those of NRC (1994) but are in close agreement with those obtained from ideal protein calculations, i.e., Thr requirements should be 70% of lysine requirements for chicks 3 to 8 wk of age.

Experiments were conducted with chicks during the period 10-20 d posthatching to assess valine accretion and protein accretion as a function of incremental valine intakes between 5 and 95% of its ideal level (requirement for maximal growth). Chemically defined crystalline amino acid diets were fed, and amino acids other than valine were maintained at minimized excess levels as valine was increased. With dietary valine concentrations representing 5, 10, 40, 55, 70 and 95% of the ideal level, weight gain (r2 = 0.98), protein accretion (r2 = 0.98) and valine accretion (r2 = 0.99) increased linearly (P < 0.01) as a function of valine intake. Slope of the valine accretion curve was 0.73 +/- 0.02, and there was no indication of decreased valine utilization as valine intake increased to 95% of its required level for maximal growth. Using the linear regression equation, i.e., valine accretion (Y) regressed on valine intake (X), the maintenance valine requirement (X at Y zero) was 18.4 mg/d or 48.8 mg/d per kg body weight3/4. Whole body valine was 4.72 g/100 g whole body protein accreted and was constant at all levels of valine intake. At zero protein accretion, however, valine accretion was negative (-3.8 mg/d). Thus, the valine requirement for zero valine accretion (48.8 mg/d per kg(3/4) was higher than the valine requirement for zero protein accretion (32.4 mg/d per kg3/4). In a subsequent experiment, also involving whole body valine and protein accretion, valine doses of 40, 55 and 70% of ideal were compared using amino acid-balanced diets (amino acids other than valine at 55, 70 and 85% of ideal levels, respectively) or imbalanced diets (amino acids other than valine at a constant 100% of their ideal levels). Straight-line (P < 0.01) valine and protein accretion responses occurred, but slope of the response curves (accretion vs. valine intake) was lower in the imbalanced series than in the balanced series. The results of these studies suggest a constant utilization above maintenance of absorbed valine over a wide range of valine intake.

Three experiments were conducted with commercial broiler chicks to determine the SAA requirement during the growth period 3 to 6 wk posthatching. A 20% CP corn-peanut meal basal diet (3,200 kcal ME(n)/kg) was analyzed to contain 0.23% Met and 0.28% cystine. True digestibility assessment in cecectomized cockerels revealed that Met and cystine in the basal diet were 81 and 75% digestible, respectively. Therefore, the basal diet contained 0.19% digestible Met and 0.21% digestible cystine. When fully fortified with DL-Met, growth rate and feed efficiency of chicks fed the corn-peanut meal diet were equal to that of chicks fed a 20% CP Met-fortified corn-soybean meal diet. In the SAA requirement assay, Ross x Hubbard male chicks were fed graded increments of DL-Met (0.03%) and L-cystine (0.03%) to achieve digestible SAA concentrations of 0.40, 0.46, 0.52, 0.58, 0.64, and 0.70%. Weight gain and feed efficiency responded quadratically (P < 0.01) to increasing doses of SAA. The estimated requirement for maximal feed efficiency was higher than that for maximal weight gain. Both visual appraisal and curve fitting procedures suggested a requirement of close to 0.61% digestible SAA. When extrapolated to a corn-soybean meal diet where SAA true digestibility is 87.5%, the total SAA requirement calculates to be 0.70% of the diet. However, because commercial corn-soybean meal diets typically contain supplemental Met, which is only 81% efficient (wt:wt) in furnishing cystine, the estimated total SAA requirement for chicks fed 20% CP Met-fortified corn-soybean meal diets with 3,200 kcal of ME/kg would probably approximately 0.72% of the diet. A DL-Met vs L-cystine supplementation assay suggested that digestible cystine can supply no more than 52% of the total requirement for digestible SAA of chicks during the 3- to 6-wk growth period.

Two chick experiments were conducted to compare the growth-promoting efficacy as well as the toxicity of a new source of L-tryptophan and L-lysine, Tryptosine (16.1% tryptophan, 56.3% lysine). A corn-feather meal-soybean meal basal diet was made singly deficient in either lysine or tryptophan, and graded doses of lysine or tryptophan from either Tryptosine or feed-grade sources of lysine and tryptophan were supplemented. Linear (P < .01) weight gain responses occurred, and responses to lysine or tryptophan in Tryptosine were similar to those obtained with equal doses of lysine or tryptophan provided by feed-grade sources of L-lysine.HCI or L-tryptophan. The toxicity trial involved additions of 1, 2, or 4% lysine with .29, .58, or 1.16% tryptophan to a lysine- and tryptophan-adequate corn-soybean meal diet. Both amino acids were provided as either Tryptosine or as feed-grade sources of lysine and tryptophan. Weight gain and feed intake were reduced in a linear fashion (P < .01) as levels of the two excess amino acids increased. The decreases caused by Tryptosine were similar to those caused by equivalent levels of excess feed-grade lysine and tryptophan.

Previous experiments indicated that true digestible Lys values for soybean and cottonseed meals obtained with the precision-fed cecectomized rooster assay were accurate estimators of Lys bioavailability for chick growth. This study was conducted to determine whether the digestible Lys in overheated soybean meal (SBM) was totally bioavailable for protein synthesis. Soybean meal alone or mixed with dextrose (SBM:dextrose ratio = 3:1) was autoclaved at 114 C and 97 kPa for 0 to 60 min. True digestibility of Lys in SBM was determined using the precision-fed cecectomized rooster assay. Bioavailability was then assessed by chick growth assay using purified crystalline amino acid diets deficient in Lys that were supplemented with varying levels of crystalline L-Lys.Cl or a SBM. Multiple regression slope-ratio methodology indicated that the digestible Lys in unautoclaved SBM was 100% bioavailable. For SBM autoclaved for 40 or 60 min and SBM-dextrose autoclaved for 20 min, bioavailability of digestible Lys based on weight gain or carcass Lys gain was 81 to 87% and significantly less (P < 0.05) than 100%, whereas bioavailability values based on feed efficiency and carcass N gain did not differ (P > 0.05) from 100%. Bioavailability values for digestible Lys in SBM:dextrose autoclaved for 30 min ranged from 55 to 73% for all performance criteria. Partitioning the response criteria, so that only the response to the supplemental Lys source (not the basal diet) was being evaluated, increased the bioavailability values for all treatments except SBM:dextrose autoclaved for 30 min. The results of this study indicated that digestible Lys in severely heat-damaged SBM measured by the precision-fed cecectomized rooster assay was not totally bioavailable for protein synthesis.

Previous research showed that formulation of chick diets containing cottonseed meal (CSM) using true digestible amino acid (AA) values was superior to formulation based on total AA; however, optimum growth performance could not be obtained from high CSM diets even when formulated on a digestible AA basis. Therefore, two experiments were conducted to determine whether the digestible AA in CSM were totally bioavailable or utilizable for protein synthesis. Soybean meal (SBM) was also evaluated for comparison. True digestibility of Lys and Val in CSM and SBM were determined using the precision-fed cecectomized rooster assay. Bioavailability was then assessed by chick growth assay using purified crystalline AA diets deficient in Lys or Val that were supplemented with varying levels of the test AA, CSM,SBM, or AA mixtures simulating the digestible AA composition of CSM and SBM. Multiple regression slope-ratio methodology indicated that bioavailability of the digestible Lys in CSM and the digestible Lys and Val in SBM did not differ (P > 0.05) from 100% for most response parameters. Bioavailability of the digestible Val in CSM ranged from 78 to 96% depending on response parameter. Bioavailabilities of crystalline Lys and Val in the AA mixtures simulating CSM and SBM were generally lower than the bioavailabililties of the digestible Lys and Val in CSM and SBM. The results of this study indicated that the digestible Lys and Val in SBM and CSM as measured by the precision-fed cecectomized rooster assay are totally or almost totally bioavailable for protein synthesis.

The results of previous experiments indicated that performance of chicks fed corn-cottonseed meal (CSM) diets was inferior to performance of chicks fed a corn-soybean meal (SBM) diet and that true digestibilities of amino acids (AA) in CSM were lower than those in SBM. Therefore, the current study evaluated the formulation of diets containing expander-solvent CSM on an equivalent total AA basis vs an equivalent digestible AA basis compared to a corn-SBM diet. True digestibility of AA in the CSM, corn, and SBM were determined using the precision-feeding assay, with cecectomized roosters and TMEn was determined using conventional roosters. One-week-old male chicks were then fed diets containing corn and SBM only or diets containing increasing levels of CSM from 5 to 40% that were formulated to be equal in total or digestible AA to the corn-SBM diet. All diets contained 20.7% CP and 3,200 kcal TMEn/kg. Weight gain and feed efficiency of chicks fed 20% or more CSM on a total AA basis were less (P < .05) than those of chicks fed the corn-SBM diet. Growth performance of chicks fed up to 20% CSM on a digestible basis was equivalent to that of chicks fed the corn-SBM diet, but dietary levels of 30 or 40% CSM depressed performance even on a digestible basis. Increasing most essential AA by 15% in the 40% CSM (digestible basis) diet had no effect on performance. True digestible AA and ME values determined in chicks were similar to those determined in roosters. These results indicate that formulation of diets containing CSM on a digestible AA basis is superior to formulation on a total AA basis and that at least 20% CSM could be fed to chicks if the diet contains adequate levels of digestible AA and Fe to bind gossypol. The results also indicated that the depression in performance from feeding 30 or 40% CSM diets was not associated with dietary AA levels.

Several experiments were conducted with crossbred chicks during the period 8 to 22 d posthatching to establish the limiting order of amino acids (AA) in corn and dehulled soybean meal (SBM) and in a corn-SBM mixture. Cecectomized adult cockerels were used to determine true AA digestibilities in both corn and SBM, and AA fortification levels were based upon bringing digestible AA levels to their ideal levels (expressed as a percentage of CP). Ideal ratios (percentage of lysine) used were Lys, 100; sulfur AA (SAA), 72; Arg, 105; Val, 77; Thr, 67; Trp, 16; Ile, 67; His, 37; Phe+Tyr, 105; and Leu, 111. Diets were fed at 10% CP, but they contained corn or SBM in amounts that would just meet the ideal concentration of the AA in greatest excess (Leu for corn; Phe for SBM). Thus, the corn diets contained only 5.6% CP from corn whereas the SBM diets contained only 8.0% CP from SBM. Diets were adjusted to 10% CP from AA additions, with glutamate varying as necessary. The limiting order of AA in corn was 1) Lys, 2) Thr, 3) Trp, 4) Arg, Ile, and Val, 5) Met+cystine, 6) Phe+Tyr, and 7) His. In SBM, the limiting order was 1)Met+cystine, 2) Thr, 3) Lys and Val, 4) nonspecific amino nitrogen, and 5) His. The order of limiting AA in the corn-SBM mixture was 1) Met, 2) Thr, 3) Lys, 4) Val, 5) Arg, and 6) Trp.

The effect of overheating on the nutritive value of cottonseed meal (CSM) for chicks and protein solubility in .2% KOH was evaluated. One-week-old male chicks were assigned to seven diets consisting primarily of corn and unautoclaved commercial CSM (expander-solvent extracted) or CSM that had been autoclaved for 20, 40, 60, 90, or 120 min at 121 C and 105 kPa. The protein level of the diets was either 21 or 22%, and FeSO4.7H2O was added to bind any free gossypol in the CSM. A control corn-soybean meal diet was included for comparison. A sample of full-fat cotton seeds extracted with a mixture of water-acetone-hexane without heating (DFCS) was also evaluated. The true digestibility of amino acids in cecectomized cockerels was determined for DFCS, three samples of unautoclaved commercial CSM, and the commercial CSM that had been autoclaved for 60 or 120 min. Growth performance of chicks was depressed (P < .05) by feeding CSM autoclaved for 40 to 60 min or more. Growth performance of chicks fed CSM diets was inferior (P < .05) to that obtained from the corn-soybean meal diet. Protein solubility for the unautoclaved commercial CSM was less than for DFCS (70 vs 60%) and did not decrease until 90 min of autoclaving. Average amino acid digestibility was higher for DFCS than in CSM (85 vs 74%). The mean true digestibilities of lysine, methionine, and cystine in the three unautoclaved commercial CSM were 64, 72, and 72%, respectively. Digestibilities of amino acids in CSM were reduced by 60 and 120 min of autoclaving.(ABSTRACT TRUNCATED AT 250 WORDS)

A genomic library of Actinomyces viscosus T14V DNA in lambda gt11 was screened for expression of neuraminidase activities. Four recombinant clones were detected that gave blue fluorescence upon incubation with a fluorogenic substrate, 2'-(4-methylumbelliferyl)-alpha-D-N-acetylneuraminic acid. Of these, two were identical, and all of the neuraminidase-positive clones shared a common 3.4-kbp DNA region. Expression of the enzyme activities in Escherichia coli carrying the cloned DNA was independent of the lacZ promoter of the vector. Maxicell analysis revealed that the 3.4-kbp DNA insert directed synthesis of a protein with an apparent molecular mass of 100,000 Da. The protein from cell extracts of E. coli clones migrated as a single band that stained for enzyme activity after electrophoresis in a nondissociating polyacrylamide gel. Moreover, human erythrocytes incubated previously with cell lysates from neuraminidase-positive E. coli were hemagglutinated by Actinomyces spp. The enzyme expressed by E. coli was active on substrates containing alpha-2,3 and alpha-2,6 ketosidic linked sialyl residues. Similar substrate specificities were obtained for both the extracellular and cell-associated neuraminidases from A. viscosus T14V. The 3.4-kbp insert hybridized to DNA fragments in a Southern blot containing A. viscosus T14V chromosomal DNA that had been digested with various restriction endonucleases. Data from hybridization studies show that A. viscosus T14V contains a single copy of the neuraminidase gene.