Gastric emphysema and pneumatosis intestinalis in two common marmosets with duodenal dilation syndrome.

BACKGROUND: Common marmosets (Callithrix jacchus) are widely used as primate experimental models in biomedical research. Duodenal dilation with chronic vomiting in captive common marmosets is a recently described life-threatening syndrome that is problematic for health control. However, the pathogenesis and cause of death are not fully understood. CASE PRESENTATION: We report two novel necropsy cases in which captive common marmosets were histopathologically diagnosed with gastric emphysema (GE) and pneumatosis intestinalis (PI). Marmoset duodenal dilation syndrome was confirmed in each case by clinical observation of chronic vomiting and by gross necropsy findings showing a dilated, gas-filled and fluid-filled descending duodenum that adhered to the ascending colon. A diagnosis of GE and PI was made on the basis of the bubble-like morphology of the gastric and intestinal mucosa, with histological examination revealing numerous vacuoles diffused throughout the lamina propria mucosae and submucosa. Immunostaining for prospero homeobox 1 and CD31 distinguished gas cysts from blood and lymph vessels. The presence of hepatic portal venous gas in case 1 and possible secondary bacteremia-related septic shock in case 2 were suggested to be acute life-threatening abdominal processes resulting from gastric emphysema and pneumatosis intestinalis. CONCLUSIONS: In both cases, the gross and histopathological findings of gas cysts in the GI tract walls matched the features of human GE and PI. These findings contribute to clarifying the cause of death in captive marmosets that have died of gastrointestinal diseases.

Lipidome Profiling of Phosphorus Deficiency-Tolerant Rice Cultivars Reveals Remodeling of Membrane Lipids as a Mechanism of Low P Tolerance.

Plants have evolved various mechanisms for low P tolerance, one of which is changing their membrane lipid composition by remodeling phospholipids with non-phospholipids. The objective of this study was to investigate the remodeling of membrane lipids among rice cultivars under P deficiency. Rice (Oryza sativa L.) cultivars (Akamai, Kiyonishiki, Akitakomachi, Norin No. 1, Hiyadateine, Koshihikari, and Netaro) were grown in 0 (-P) and 8 (+P) mg P L-1 solution cultures. Shoots and roots were collected 5 and 10 days after transplanting (DAT) in solution culture and subjected to lipidome profiling using liquid chromatography-mass spectrometry. Phosphatidylcholine (PC)34, PC36, phosphatidylethanolamine (PE)34, PE36, phosphatidylglycerol (PG)34, phosphatidylinositol (PI)34 were the major phospholipids and digalactosyldiacylglycerol (DGDG)34, DGDG36, 1,2-diacyl-3-O-alpha-glucuronosylglycerol (GlcADG)34, GlcADG36, monogalactosyldiacylglycerol (MGDG)34, MGDG36, sulfoquinovosyldiacylglycerol (SQDG)34 and SQDG36 were the major non-phospholipids. Phospholipids were lower in the plants that were grown under -P conditions than that in the plants that were grown under +P for all cultivars at 5 and 10 DAT. The levels of non-phospholipids were higher in -P plants than that in +P plants of all cultivars at 5 and 10 DAT. Decomposition of phospholipids in roots at 5 DAT correlated with low P tolerance. These results suggest that rice cultivars remodel membrane lipids under P deficiency, and the ability of remodeling partly contributes to low P tolerance.

Effects of enhanced insect feeding on the faecal microbiota and transcriptome of a family of captive common marmosets (Callithrix jacchus).

Common marmosets have been widely used in biomedical research for years. Nutritional control is an important factor in managing their health, and insect intake would be beneficial for that purpose because common marmosets frequently feed on insects in natural habitats. Here, we examined the effect of enhanced insect feeding on the gut by analysing the faecal microbiota and transcripts of captive marmosets. A family consisting of six marmosets was divided into two groups. During the seven-day intervention period, one group (the insect feeding group, or Group IF) was fed one cricket and one giant mealworm per marmoset per day, while the other (the control group, or Group C) was not fed these insects. RNA was extracted from faecal samples to evaluate the ecology and transcripts of the microbiota, which were then compared among time points before (Pre), immediately after (Post), and two weeks after the intervention (Follow_up) using total RNA sequencing. The gut microbiota of marmosets showed Firmicutes, Actinobacteria, Bacteroidetes, and Proteobacteria as dominant phyla. Linear discriminant analysis showed differential characteristics of microbiota with and without insect feeding treatment. Further analysis of differentially expressed genes revealed increases and decreases in Bacteroidetes and Firmicutes, respectively, corresponding to the availability of insects under both Post and Follow_up conditions. Significant changes specific to insect feeding were also detected within the transcriptome, some of which were synchronized with the fluctuations in the microbiota, suggesting a functional correlation or interaction between the two. The rapid changes in the microbiota and transcripts may be achieved by the microbiota community originally developed in the wild through marmosets' feeding ecology. The results were informative for identifying the physiological impact of insect feeding to produce a better food regimen and for detecting transcripts that are currently unidentifiable.

Seasonal and geographical differences in the ruminal microbial and chloroplast composition of sika deer (Cervus nippon) in Japan.

To understand the nutritional status of culled wild sika deer (Cervus nippon), we compared the ruminal microbes of deer living in habitats differing in food composition (Nagano winter, Nagano spring, and Hokkaido winter) using next-generation sequencing. Twenty-nine sika deer were sampled. Alpha and beta diversity metrics determined via 16S and 18S rRNA amplicon-seq analysis showed compositional differences. Prevotella, Entodinium, and Piromyces were the dominant genera of bacteria, fungi and protozoa, respectively. Moreover, 66 bacterial taxa, 44 eukaryotic taxa, and 46 chloroplastic taxa were shown to differ significantly among the groups by the linear discriminant analysis effect size (LEfSe) technique. Total RNA-seq analysis yielded 397 significantly differentially expressed transcripts (q < 0.05), of which 48 (q < 0.01) were correlated with the bacterial amplicon-seq results (Pearson correlation coefficient > 0.7). The ruminal microbial composition corresponded with the presence of different plants because the amplicon-seq results indicated that chloroplast from broadleaf trees and Stramenopiles-Alveolates-Rhizaria (SAR) were enriched in Nagano, whereas chloroplast from graminoids, Firmicutes and the dominant phylum of fungi were enriched in Hokkaido. These results could be related to the severe snow conditions in Hokkaido in winter and the richness of plants with leaves and acorns in Nagano in winter and spring. The findings are useful for understanding the nutritional status of wild sika deer.

Sulfide catabolism ameliorates hypoxic brain injury.

The mammalian brain is highly vulnerable to oxygen deprivation, yet the mechanism underlying the brain's sensitivity to hypoxia is incompletely understood. Hypoxia induces accumulation of hydrogen sulfide, a gas that inhibits mitochondrial respiration. Here, we show that, in mice, rats, and naturally hypoxia-tolerant ground squirrels, the sensitivity of the brain to hypoxia is inversely related to the levels of sulfide:quinone oxidoreductase (SQOR) and the capacity to catabolize sulfide. Silencing SQOR increased the sensitivity of the brain to hypoxia, whereas neuron-specific SQOR expression prevented hypoxia-induced sulfide accumulation, bioenergetic failure, and ischemic brain injury. Excluding SQOR from mitochondria increased sensitivity to hypoxia not only in the brain but also in heart and liver. Pharmacological scavenging of sulfide maintained mitochondrial respiration in hypoxic neurons and made mice resistant to hypoxia. These results illuminate the critical role of sulfide catabolism in energy homeostasis during hypoxia and identify a therapeutic target for ischemic brain injury.

Phase transitions of brain evolution that produced human language and beyond.

The brain capacity of human ancestors underwent two phase transitions, which were supported by preadaptations during the animal protolanguage period, resulting in the emergence of human language. The transitions were (1) the emergence of the primate cerebral cortex, with its unique characteristic of additional cortical areas together with size expansion, and (2) the replacement of natural selection as the main evolutionary mechanism by triadic niche construction, an interactive expansion of ecological-, neural-, and cognitive-niches. These phase transitions accelerated the expansion of the hominid brain, exceeding the neural capacity threshold required for the emergence of language. Extrapolating these developments enabled the researchers to predict a third phase transition, which may be induced by the current explosion of artificial intelligence, accelerating human cognitive capacities to the next threshold required for a novel mode of language.

Vasoactive-inotropic score as a predictor of morbidity and mortality in adults after cardiac surgery with cardiopulmonary bypass.

PURPOSE: The vasoactive-inotropic score (VIS) is a scale showing the amount of vasoactive and inotropic support. Recently, it was suggested that the VIS after cardiac surgery predicts morbidity and mortality in infants. The purpose of this study was to evaluate the VIS at the end of surgery as a predictor of morbidity and mortality in adult cardiac surgery. METHODS: A retrospective cohort study of 129 adult cardiac surgery patients was performed at a university hospital. The primary outcome was termed "poor outcome", which was a composite of morbidity and mortality. The secondary outcomes were the duration of intensive care unit (ICU) stay and time to first extubation. Multivariate logistic regression analysis was performed to evaluate the association between the VIS and poor outcomes. A proportional hazards model was used to evaluate the duration of the ICU stay and time to first extubation. RESULTS: After adjusting for the EuroSCORE, preoperative ejection fraction, and bypass time, a high VIS at the end of surgery was associated with a poor outcome with an adjusted odds ratio of 4.87 (95% confidence interval 1.51-18.94; p = 0.007). After controlling for the EuroSCORE and bypass time, patients with a high VIS experienced longer ICU stay (hazard ratio 1.62; 95% confidence interval 1.10-2.39; p = 0.015) and needed longer ventilation (hazard ration 1.87; 95% confidence interval 1.28-2.74, p = 0.001). CONCLUSIONS: The amount of cardiovascular support at the end of cardiac surgery may predict morbidity and mortality in adults.

Faecal transplantation for the treatment of Clostridium difficile infection in a marmoset.

BACKGROUND: The common marmoset has been used as an experimental animal for various purposes. Because its average weight ranges from 250 to 500 g, weight loss quickly becomes critical for sick animals. Therefore, effective and non-stressful treatment for chronic diseases, including diarrhoea, is essential. CASE PRESENTATION: We report a case in which faecal microbiota transplantation (FMT) led to immediate recovery from chronic and recurrent diarrhoea caused by Clostridium difficile infection. A male common marmoset experienced chronic diarrhoea after antibiotic treatments. The animal experienced severe weight loss, and a faecal sample was confirmed to be C. difficile-positive but was negative for protozoa. Metronidazole was partially effective at the first administration but not after the recurrence of the clinical signs. Then, oral FMT was administered to the subject by feeding fresh faeces from healthy individuals mixed with the marmoset's usual food. We monitored the faeces by categorization into four groups: normal, loose, diarrhoea, and watery. After the first day of FMT treatment, the marmoset underwent a remarkable recovery from diarrhoea, and after the fourth day of treatment, a test for C. difficile was negative. The clinical signs did not recur. The marmoset recovered from sinusitis and bilateral dacryocystitis, which also did not recur, as a by-product of the improvement in its general health caused by the cessation of diarrhoea after the FMT. CONCLUSION: This is the first reported case of successful treatment of a marmoset using oral FMT. As seen in human patients, FMT was effective for the treatment of recurrent C. difficile infection in a captive marmoset.

Sustained performance by common marmosets in a delayed matching to position task with variable stimulus presentations.

Working memory is used to solve various cognitive problems by maintaining information for some time and then by refreshing this information after certain purposes are achieved. In the present study, we explored the ability of common marmosets to perform a delayed matching to position (DMTP) task in a controlled environment using operant conditioning. The DMTP task requires the subjects to respond to the sample stimulus and to select one of two comparison stimuli with a position matching that of the sample stimulus after a programmed delay period. Positional arrangement of the sample and comparison stimuli, which were quasi-randomly determined in each trial, was employed to prevent the subjects from using any strategies based on their own body positions or orientations. The delay intervals between presentations of the sample and comparison stimuli were fixed at 0.5 and 1s in the initial phases and were then varied between 5 intervals per delay set (e.g., 0.5, 1, 2, 4, and 8s) intermixed in a session. The longest delay interval within a set was gradually increased after the marmosets achieved the criterion of each task. The subjects were successfully trained in the procedure and showed accurate performance even following delays of more than 100 s. The response times in the trials suggested that they used different strategies depending on the delay interval length. Thus, the present study shows the robust ability of common marmosets in a task requiring positional memory, which is related to their foraging strategy observed in the wild.

Draft Genome Sequence of Bifidobacterium aesculapii DSM 26737T, Isolated from Feces of Baby Common Marmoset.

Bifidobacterium aesculapii DSM 26737(T) was isolated from feces of baby common marmoset. Here, we report the draft genome sequence of this organism. This paper is the first published report of the genomic sequence of B. aesculapii.

Transposition and its generalization in common marmosets.

Whether animals use relational cues in transposition tests has long been considered a controversial issue. In the present study, we examined whether common marmosets could generalize relational responses to untrained stimulus pairs and further apply these generalizations to unknown shapes. The subjects were trained to perform simple discrimination tasks using a pair of stimuli. The stimuli differed in size, and the subjects were required to select the larger or smaller of the 2 sizes, depending on the given contingencies. After experiencing several reversals, the subjects were examined using 2 different tests: transposition and shape generalization. In the transposition test trials, in which squares of different sizes than those used in the training trials were presented, the subjects selected the stimulus based on the relative size of the stimulus. In the shape generalization tests, sets of 5 novel shapes with the same relative sizes were presented with the training stimuli. The subjects' performance indicated successful transposition to the novel stimulus pairs, and further analysis showed that transposition was more likely to occur when the test stimuli shared physical features, such as the outer length and the number of line segments, with the trained stimuli. Thus, the present study demonstrated the robust ability of transposition in common marmosets based on relative size, both with and without common shape features, and offered a possible method for specifying the critical stimulus features through which transposition can be more readily observed.

Hand preference depends on posture in common marmosets.

Postural conditions are known to affect hand use in many primate species. It remains to be examined how posture and task differences modulate, or interact with, hand use in common marmosets (Callithrix jacchus). Three experimental conditions were introduced to assess the occurrence of preferential hand use as a function of posture and size of aperture for the subjects to grasp and retrieve the food item bi- or unimanually: ground level condition for requiring quadrupedal posture with enough space for food reaching with both hands, large hole (4 cm in diameter) condition for requiring upright posture with available space for both hands, and small hole (2 cm in diameter) condition for requiring upright posture with available space for only one hand. While the distribution of hand preference did not significantly differ among the three conditions at the group level, eight out of twelve marmosets did not change hands when identical upright postures were required in large and small hole conditions. Some marmosets simultaneously used both hands when both hands were free to reach the food items; however, the number of left hand users increased when the marmosets were forced to use either hand to pass through the reduced hole size. Significant correlations in hand use between the upright posture conditions were observed, whereas no correlation was observed between the different posture conditions. These results suggest that, although preferential hand use was not found at group level, posture, but not size of aperture, has effects on hand use in individual common marmosets.

Sequential learning and rule abstraction in Bengalese finches.

The Bengalese finch (Lonchura striata var. domestica) is a species of songbird. Males sing courtship songs with complex note-to-note transition rules, while females discriminate these songs when choosing their mate. The present study uses serial reaction time (RT) to examine the characteristics of the Bengalese finches' sequential behaviours beyond song production. The birds were trained to produce the sequence with an "A-B-A" structure. After the RT to each key position was determined to be stable, we tested the acquisition of the trained sequential response by presenting novel and random three-term sequences (random test). We also examined whether they could abstract the embedded rule in the trained sequence and apply it to the novel test sequence (abstract test). Additionally, we examined rule abstraction through example training by increasing the number of examples in baseline training from 1 to 5. When considered as (gender) groups, training with 5 examples resulted in no statistically significant differences in the abstract tests, while statistically significant differences were observed in the random tests, suggesting that the male birds learned the trained sequences and transferred the abstract structure they had learned during the training trials. Individual data indicated that males, as opposed to females, were likely to learn the motor pattern of the sequence. The results are consistent with observations that males learn to produce songs with complex sequential rules, whereas females do not.

Tool-use learning by common marmosets (Callithrix jacchus).

One of the most critical and common features of tool use is that the tool essentially functions as a part of the body. This feature is likely rooted in biological features that are shared by tool users. To establish an ideal primate model to explore the neurobiological mechanisms supporting tool-use behaviours, we trained common marmosets, a small New World monkey species that is not usually associated with tool use, to use a rake-shaped tool to retrieve food. Five naive common marmosets were systematically trained to manipulate the tool using a 4-stage, step-by-step protocol. The relative positions of the tool and the food were manipulated, so that the marmosets were required to (1) pull the tool vertically, (2) move the tool horizontally, (3) make an arc to retrieve a food item located behind the tool and (4) retrieve the food item. We found considerable individual differences in tool-use technique; for example, one animal consistently used a unilateral hand movement for all of the steps, whereas the others (n = 4) used both hands to move the tool depending on the location of the food item. After extensive training, all of the marmosets could manipulate the rake-shaped tool, which is reported in this species for the first time. The common marmoset is thus a model primate for such studies. This study sets the stage for future research to examine the biological mechanisms underlying the cognitive ability of tool use at the molecular and genetic levels.

An experience of vascular access for hemodialysis in Brazil.

BACKGROUND: The analysis of hemodialysis services is relevant for the quality of life of patient. In this study we investigated the profile of vascular access used for hemodialysis patients in our Unit. METHODS: We evaluated 219 patients of both genders aged over 18 years old who have undergone implant or manufacture of vascular hemodialysis access. We excluded patients on renal replacement therapy by peritoneal dialysis. RESULTS: Associated diseases were hypertension and diabetes mellitus. 161 had arteriovenous fistula, with 153 held by the same dialysis and nine of them were still maturing. 27 patients on dialysis used central venous catheter. 148 were indigenous and five were made using polytetrafluoroethylene prosthesis (PTFE). Among the 27 patients with central venous catheters, ten used short-term catheter and 17 used long-term catheter. The most frequent type of fistula use was on the radio distal cephalic, in 85 patients (52.5%), followed by radio cephalic proximal in 26 patients (16%). The number of fistulas in dialysis patients conducted by this kind of therapy ranged from one to ten and in 64 patients (41.83%) fistula was the first and only to be made. Among the fistula for dialysis patients, the highest prevalence was radio cephalic fistula in 111 patients (72.5%) and mean duration of use was 48.1 months, ranging from two months to 17 years. CONCLUSION: Our Unit of hemodialysis is above the limits established by international norms.

Modulation of physical understanding by common marmosets (Callithrix jacchus).

The understanding of physical causality in common marmosets was tested using support problems in which a pair of sheets was presented to determine whether subjects would choose the sheet that had a food item on it (i.e., the sheet was supporting the food item). In two experiments, the conditions were manipulated in terms of the length of the sheet, the distance between the sheet and the food item, the presence of a gap separating the two sheets, and the size of the food item. In Experiment 1, the marmosets had difficulty rejecting an irretrievable food item when it was located closer to them than a retrievable item. Although their performance was strongly affected by the size of the irretrievable food item, they quickly learned to reject that alternative. In contrast, no improvement was found when one sheet was divided into two pieces such that the food item could not be retrieved when its near side was pulled. A similar response tendency was observed in Experiment 2, in which the effects of the large food item were examined in three different conditions. Thus, common marmosets were influenced by the perceptual features of the food in solving the support problems, as are other non-human primates. In addition, they consistently failed to appreciate the presence of a gap and, therefore, failed to reject the distracter alternative. However, all animals rapidly learned that the size of the food item was an irrelevant variable, and some showed an elementary conceptual understanding of support. These findings suggest that marmosets' physical understanding may improve with experience.