Aflatoxin B1 contamination of feedstuff on a dairy farm in Northern Peru and aflatoxin M1 concentrations in raw milk

Research regarding aflatoxin contamination levels in Peru is limited, although aflatoxin M1 (AFM1) and aflatoxin B1 (AFB1) require surveillance because of their toxicity. European regulations state that the harmonised maximum level (ML) is 5 μg/kg for AFB1 in feedstuffs and 0.05 μg/kg for AFM1 in milk. Our study aimed to determine the annual variation levels of AFB1 in ingredients used in feedstuffs for dairy cows and those of AFM1 in milk at a typical intensive dairy farm in Northern Peru. For 1 year, milk (n=529) and feedstuff samples (n=235) were collected and aflatoxin levels were determined using a lateral flow immunoassay. We found that 16% of milk samples had AFM1 contamination above the ML. AFM1 level was significantly higher (P<0.05) in December (end of spring) than that in all other months. Throughout the year, the most used feedstuffs were maize, soybean meal and whole soybean. Among the maize samples (n=77), 2.59% had an AFB1 level above the ML, whereas 45% had an AFB1 level below the ML. On the other hand, neither the soybean meal (n=69) nor whole soybean samples (n=64) had an AFB1 level above the ML, 46.4 and 20%, respectively. In 50% (n=10) of cottonseed meal samples, AFB1 level was above the ML; in 20% of wheat middling samples, it was above the ML. Cottonseed and wheat middling samples were used for 2 and 5 months, respectively. AFB1 level in feedstuff showed a significant difference in December (P<0.05) compared with other months, specifically for maize and soybean meal. As the AFM1 level in milk results from AFB1 contaminated feedstuff, our results emphasise the need to implement specific quality measures to reduce contamination.

Mortality of Adult Patients With Cancer Admitted to an Intensive Care Unit in Chile: A Prospective Cohort Study

Purpose

Increasing numbers of reports have shown acceptable short-term mortality of patients with cancer admitted into the intensive care unit (ICU). The aim of this study was to determine the mortality of critically ill patients with cancer admitted to the ICU in a general hospital in Chile.

Materials and Methods

This was a prospective cohort trial in which we included all patients with cancer admitted to the ICU between July 2015 and September 2016. Demographic, physiologic, and treatment data were registered, and survival at 30 days and 6 months was evaluated. A prespecified subgroup analysis considering the admission policy was performed. These subgroups were (1) ICU admission for full code management and (2) ICU trial (IT).

Results

During the study period, 109 patients with cancer were included. Seventy-nine patients were considered in the full code management group and 30 in the IT. The mean age of patients was 60 years (standard deviation [SD], 15), and 56% were male. Lymphoma was the most frequent malignancy (17%), and 59% had not received cancer treatment because of a recent diagnosis. The mean Acute Physiology and Chronic Health Evaluation and Sequential-Related Organ Failure Assessment scores were 22.2 (SD, 7.3) and 7 (SD, 3), respectively. There were no differences in vasopressor, fluid, or transfusion requirements between subgroups. Lactate levels, Sequential-Related Organ Failure Assessment scores (day 1, 3, and 5), complications, and ICU length of stay were similar. In the entire cohort, 30-day and 6-month mortality was 47% and 66%, respectively. There was no difference in mortality between subgroups according to the admission policy.

Conclusion

Patients admitted to the ICU in a developing country are at high risk for short-term mortality. However, there is a relevant subgroup that achieves 6-month survival, even among patients who undergo an IT.

Anatomy of the olfactory mucosa

The classic notion that humans are microsmatic animals was born from comparative anatomy studies showing the reduction in the size of both the olfactory bulbs and the limbic brain relative to the whole brain. However, the human olfactory system contains a number of neurons comparable to that of most other mammals, and humans have exquisite olfactory abilities. Major advances in molecular and genetic research have resulted in the identification of extremely large gene families that express receptors for sensing odors. Such advances have led to a renaissance of studies focused on both human and nonhuman aspects of olfactory physiology and function. Evidence that olfactory dysfunction is among the earliest signs of a number of neurodegenerative and neuropsychiatric disorders has led to considerable interest in the use of olfactory epithelial biopsies for potentially identifying such disorders. Moreover, the unique features of the olfactory ensheathing cells have made the olfactory mucosa a promising and unexpected source of cells for treating spinal cord injuries and other neural injuries in which cell guidance is critical. The olfactory system of humans and other primates differs in many ways from that of other species. In this chapter we provide an overview of the anatomy of not only the human olfactory mucosa but of mucosae from a range of mammals from which more detailed information is available. Basic information regarding the general organization of the olfactory mucosa, including its receptor cells and the large number of other cell types critical for their maintenance and function, is provided. Cross-species comparisons are made when appropriate. The polemic issue of the human vomeronasal organ in both the adult and fetus is discussed, along with recent findings regarding olfactory subsystems within the nose of a number of mammals (e.g., the septal organ and Grüneberg ganglion).

Revisiting the Vomeronasal System From an Integrated Perspective

"Olfactory subsystems" is a relatively new terminology to refer to the different regions of the nasal cavity featuring olfactory sensory neurons. In mice, the olfactory chemical cues are detected in four well delimited areas: the main olfactory epithelium, the septal organ, Grüneberg's ganglion, and the sensory epithelium of the vomeronasal organ. Nevertheless, such distribution is by no means exhibited by all mammals. In microsmatic mammals -humans included- the only existing olfactory subsystem is the main olfactory epithelium. This raises the question of whether the lack of certain olfactory structures in those species implies that they are unable to identify certain olfactory signals, or on the contrary, their main olfactory epithelium assumes such role. It would be interesting to determine, in the context of biomedical research, if the sense of smell in humans is fully or partially endowed with the wide range of functions assigned to the vomeronasal system in mice. If it is not, presumptive implications of the lack of such functions should be addressed in human health and well-being. Anat Rec, 299:1488-1491, 2016. © 2016 Wiley Periodicals, Inc.

Dog and mouse: toward a balanced view of the mammalian olfactory system

Although the most intensively studied mammalian olfactory system is that of the mouse, in which olfactory chemical cues of one kind or another are detected in four different nasal areas [the main olfactory epithelium (MOE), the septal organ (SO), Grüneberg's ganglion, and the sensory epithelium of the vomeronasal organ (VNO)], the extraordinarily sensitive olfactory system of the dog is also an important model that is increasingly used, for example in genomic studies of species evolution. Here we describe the topography and extent of the main olfactory and vomeronasal sensory epithelia of the dog, and we report finding no structures equivalent to the Grüneberg ganglion and SO of the mouse. Since we examined adults, newborns, and fetuses we conclude that these latter structures are absent in dogs, possibly as the result of regression or involution. The absence of a vomeronasal component based on VR2 receptors suggests that the VNO may be undergoing a similar involutionary process.

The nasal cavity of the sheep and its olfactory sensory epithelium

Macro and microdissection methods, conventional histology and immunohistochemical procedures were used to investigate the nasal cavity and turbinate complex in fetal and adult sheep, with special attention to the ethmoturbinates, the vestibular mucosa, and the septal mucosa posterior to the vomeronasal organ. The ectoturbinates, which are variable in number and size, emerge and develop later than the endoturbinates. The olfactory sensory epithelium is composed of basal cells, neurons, and sustentacular cells organized in strata, but numerous different types are distinguishable on the basis of their thickness and other properties; all variants are present on the more developed turbinates, endoturbinates II and III. Mature neurons and olfactory nerve bundles express olfactory marker protein. We found no structure with the characteristics that in mouse define the septal organ or the ganglion of Grüneberg. Our results thus suggest that in sheep olfactory sensory neurons are exclusively concentrated in the main olfactory epithelium and (to a lesser extent) in the vomeronasal organ.

Anatomical Variations of the Blood Vascular System in Veterinary Medicine: The Internal Iliac Artery of the Dog: Part One

Traditional veterinary anatomical models describe the branches of the caudal gluteal artery as the iliolumbar, cranial gluteal, lateral caudal, satellite of the ischiatic nerve and dorsal perineal arteries. However, some classical veterinary anatomy textbooks often indicate variations the general organization of the arterial tree, without giving any pattern of origin or illustrations of the different branching. The aim of this study was to investigate the presumptive variability of the caudal gluteal artery. Two hundred and thirty-two pelvic halves from 116 adult dogs were examined. Twelve anatomical variations were found, nine occurring in more than 5% of the dogs, and three in <5%. A 'long-type' internal iliac artery, which means short caudal gluteal and internal pudendal arteries, was identified, while a 'perineal trunk' was observed as an interesting arterial variation. If the caudal segment alone is taken into consideration, identical vascular patterns in both hemi-pelvises are found in 17% of the dogs. Significant statistical correlation was found for four different types of anatomic variations and gender, two types of variations and body size, one type of variation for body side and one type of variation for head shape.

Anatomy, histochemistry, and immunohistochemistry of the olfactory subsystems in mice

The four regions of the murine nasal cavity featuring olfactory neurons were studied anatomically and by labeling with lectins and relevant antibodies with a view to establishing criteria for the identification of olfactory subsystems that are readily applicable to other mammals. In the main olfactory epithelium and the septal organ the olfactory sensory neurons (OSNs) are embedded in quasi-stratified columnar epithelium; vomeronasal OSNs are embedded in epithelium lining the medial interior wall of the vomeronasal duct and do not make contact with the mucosa of the main nasal cavity; and in Grüneberg's ganglion a small isolated population of OSNs lies adjacent to, but not within, the epithelium. With the exception of Grüneberg's ganglion, all the tissues expressing olfactory marker protein (OMP) (the above four nasal territories, the vomeronasal and main olfactory nerves, and the main and accessory olfactory bulbs) are also labeled by Lycopersicum esculentum agglutinin, while Ulex europaeus agglutinin I labels all and only tissues expressing G_αi2 (the apical sensory neurons of the vomeronasal organ, their axons, and their glomerular destinations in the anterior accessory olfactory bulb). These staining patterns of UEA-I and LEA may facilitate the characterization of olfactory anatomy in other species. A 710-section atlas of the anatomy of the murine nasal cavity has been made available on line.

The risk of extrapolation in neuroanatomy: the case of the Mammalian vomeronasal system

The sense of smell plays a crucial role in mammalian social and sexual behaviour, identification of food, and detection of predators. Nevertheless, mammals vary in their olfactory ability. One reason for this concerns the degree of development of their pars basalis rhinencephali, an anatomical feature that has been considered in classifying this group of animals as macrosmatic, microsmatic or anosmatic. In mammals, different structures are involved in detecting odours: the main olfactory system, the vomeronasal system (VNS), and two subsystems, namely the ganglion of Grüneberg and the septal organ. Here, we review and summarise some aspects of the comparative anatomy of the VNS and its putative relationship to other olfactory structures. Even in the macrosmatic group, morphological diversity is an important characteristic of the VNS, specifically of the vomeronasal organ and the accessory olfactory bulb. We conclude that it is a big mistake to extrapolate anatomical data of the VNS from species to species, even in the case of relatively close evolutionary proximity between them. We propose to study other mammalian VNS than those of rodents in depth as a way to clarify its exact role in olfaction. Our experience in this field leads us to hypothesise that the VNS, considered for all mammalian species, could be a system undergoing involution or regression, and could serve as one more integrated olfactory subsystem.

[The Latin American Psychiatrist: profile and degree of satisfaction with the specialty]

OBJECTIVES

The primary objective is to describe the profile of the psychiatric members of a national psychiatry association in 19 Latin American countries (Argentina, Bolivia, Brazil, Colombia, Costa Rica, Cuba, Dominican Republic, Ecuador, Chile, El Salvador, Guatemala, Honduras, Mexico, Nicaragua, Peru, Panama, Paraguay, Uruguay, and Venezuela). Secondary objectives are to evaluate job satisfaction and examine the factors related with job satisfaction.

METHODS AND MATERIALS

A total of 8,028 psychiatrists, members of a national psychiatry association in Latin America, were identified. A probabilistic stratified sample of 2465 psychiatrists was designed and they were asked to fill out an anonymous electronic survey.

RESULTS

A sample of 1,292 Latin American psychiatrists was obtained between April 2005 and July 2006 (52.4% of the designed sample). Response rates were superior to 70% in 11 countries. Mean age was 48.2 years, mean experience was 18.2 years; 63.8% were male and 99.9% of the surveyed psychiatrists were working as psychiatrists. Most of the respondents declared being satisfied with their quality of life (70.8%), a slightly larger percentage reported they were satisfied with their work (86.4%). However, 35.3% of the psychiatrists reported being unsatisfied with the income perceived for their economic activity as psychiatrists. Factors associated with job dissatisfaction are described.

CONCLUSIONS

In Latin America, there is lower satisfaction with the incomes obtained from psychiatric practice and with the quality of life level. Nonetheless, the level of commitment with the profession in itself and job satisfaction remain similar to those reported in developed countries.

Anatomical, immnunohistochemical and physiological characteristics of the vomeronasal vessels in cows and their possible role in vomeronasal reception

The general morphology of the vomeronasal vessels in adult cows was studied following a classic protocol, including optical, confocal and ultrastructural approaches. This anatomical work was completed immunohistochemically. The vomeronasal organ in cows is well developed, and its vessels are considerable in size. This fact allowed some functional properties of the vomeronasal arteries to be evaluated and, for the first time, their isometric tension to be recorded. Our functional studies were in agreement with the immunohistochemistry, and both corroborated the morphological data on the similarity between the vomeronasal vessels and those of the typical erectile tissue. In consequence, the vasoconstriction and vasodilation of the vomeronasal vessels would facilitate an influx and outflow of fluids in the vomeronasal organ, that is to say, this organ in cows would be able to work as a pump mechanism to send chemical signals to the vomeronasal receptor neurones.

Hormonal and morphological study of the pituitaries in reeler mice

Reelin is a neuronal glycoprotein that plays a crucial role in brain layer formation during prenatal development. The reeler mutant mouse lacks Reelin, leading to abnormalities in the neuronal layering of cerebral cortex and cerebellum, producing ataxia, tremor and abnormal locomotion. Reeler mice are reported to have growth retardation and most of them are sterile or unable to bring up their newborns. Since the brain is one of the main regulator of pituitary hormone secretion and no information was reported regarding pituitary function and structure in these mutant mice, we studied pituitary endocrine activity and morphology in reeler mice. Mice were classified in three groups as reeler homozygote (RHM), reeler heterozygote (RHT) or control (CO). Pituitary hormone blood levels were assessed by enzyme immunoassay (EIA) and immunoradiometric assay (IRMA). Animals and their pituitaries were weighted and pituitaries were studied by histology, immunohistochemistry and electron microscopy. Results showed statistically significant differences in body weight and in adrenocorticotropic hormone (ACTH) and luteinizing hormone (LH) blood levels between the three groups. In contrast, growth hormone (GH) blood levels showed a high individual variation and no decrease in reeler groups compared with CO. Morphological studies revealed no differences in pituitary cell types except that somatotrophs appeared to be slightly smaller in RHM and RHT. Although it seems that pituitary hypofunction is not responsible for growth retardation, more studies are needed to obtain a deeper insight into the endocrine status of these mutant mice to elucidate the cause of their low body weight and reproductive behaviour.

Diversity of the vomeronasal system in mammals: The singularities of the sheep model

The enormous morphological diversity and heterogeneity of the vomeronasal system (VNS) in mammals--as well as its complete absence in some cases--complicates the extrapolation of data from one species to another, making any physiological and functional conclusions valid for the whole Mammalian Class difficult and risky to draw. Some highly-evolved macrosmatic mammals, like sheep, have been previously used in interesting behavioral studies concerning the main and accessory olfactory systems. However, in this species, certain crucial morphological peculiarities have not until now been considered. Following histological, histochemical and immunohistochemical procedures, we have studied the vomeronasal organ (VNO) and the accessory olfactory bulb (AOB) of adult sheep. We have determined: (1) that all structures which classically define the VNO in mammals are present and well developed, providing the morphological basis for functional activity. (2) that, conversely, there is only a scant population of scattered mitral/tufted cells. One morphological consequence of both details is that the strata of the AOB in adult sheep are not as sharply defined as in other species; moreover, the small number of the mitral/tufted cells in the AOB may imply that the VNS of adult sheep is not capable of functioning in the way a well-developed VNS does in other species. (3) the zone to zone projection from the apical and basal sensory epithelium of the VNO to the anterior and posterior part of the AOB, respectively, typical in rodents, lagomorphs and marsupials, is not present in adult sheep.

General organization of the perinatal and adult accessory olfactory bulb in mice

The vomeronasal system is currently a topical issue since the dual functional specificity, vomeronasal system-pheromones, has recently been questioned. Irrespective of the tools used to put such specificity in doubt, the diversity of the anatomy of the system itself in the animal kingdom is probably of more importance than has previously been considered. It has to be pointed out that a true vomeronasal system is integrated by the vomeronasal organ, the accessory olfactory bulb, and the so-called vomeronasal amygdala. Therefore, it seems reasonable to establish the corresponding differences between a well-developed vomeronasal system and other areas of the nasal cavity in which putative olfactory receptors, perhaps present in other kinds of mammals, may be able to detect pheromones and to process them. In consequence, a solid pattern for one such system in one particular species needs to be chosen. Here we report on an analysis of the general morphological characteristics of the accessory olfactory bulb in mice, a species commonly used in the study of the vomeronasal system, during growth and in adults. Our results indicate that the critical period for the formation of this structure comprises the stages between the first and the fifth day after birth, when the stratification of the bulb, the peculiarities of each type of cell, and the final building of glomeruli are completed. In addition, our data suggest that the conventional plexiform layers of the main olfactory bulb are not present in the accessory bulb.

The prenatal maturity of the accessory olfactory bulb in pigs

The morphological development of the accessory olfactory bulb of the fetal pig was studied by classical and histo-chemical methods, and the vomeronasal organ and nasal septum were studied histochemically. Specimens were obtained from an abattoir and their ages estimated from their crown-to-rump length. The accessory olfactory bulb was structurally mature in fetuses of crown-to-rump length 21-23 cm, by which time the lectin Lycopersicum esculentum agglutinin stained the same structures as in adults (in particular, the entire sensory epithelium of the vomeronasal organ, the vomeronasal nerves, and the nervous and glomerular layers of the accessory olfactory bulb). These results suggest that the vomeronasal system of the pig may, like that of vertebrates such as snakes, be functional at birth.

Identification of pheromones in mouse urine by head-space solid phase microextraction followed by gas chromatography-mass spectrometry

Given the key role of pheromones in animal communication and behaviour, there is need to identify the different classes of these molecules under varying physiological conditions. However, the highly volatile nature of pheromones and the fact that they occur at very low concentrations in urine makes this task all the more difficult. Herein, we present a method of detecting and identifying the five main pheromones known: 2-sec-butyl-4,5-dihydrothiazole, geraniol, indole, trans-beta farnesene and trans-alpha farnesene in individual urine microsamples taken from male mice. Urine volumes as small as 20 microl were subjected to solid phase microextraction (SPME) followed by gas chromatography-mass spectrometry (GC-MS). This selective analytical method permits the rapid detection of these pheromones free from cross-contaminants as a clearly distinguishable spectral signals. Highest recovery rates of natural pheromones were achieved by extraction on a carboxen/polydimethylsiloxane (CAR/PDMS) fibre of 85 microm film thickness. This selective, sensitive and accurate method will help address the question of possible links between certain pheromone classes, and social and reproductive behaviour in mice.

Low molecular weight constituents of male mouse urine mediate the pregnancy block effect and convey information about the identity of the mating male

Mouse urine contains a complex mixture of chemosignals including a variety of small volatile molecules that are bound to major urinary proteins. In addition to signalling maleness, male urine also conveys information about individuality, which allows recently mated female mice to distinguish the urinary chemosignals of the mating male from those of an unfamiliar male. The highly polymorphic nature of the major urinary proteins makes them a likely candidate for conveying individuality information in the context of the pregnancy block effect. This was investigated by comparing the pregnancy-blocking effectiveness of a high molecular weight urinary fraction, containing major urinary proteins, with that of a low molecular weight fraction containing volatile ligands. Not only was the high molecular weight fraction ineffective in blocking pregnancy, but it also appeared to be less important in signalling individuality than the low molecular fraction. The high molecular weight fraction was ineffective in inducing expression of the immediate early gene product egr-1 in the accessory olfactory bulb. In contrast, the low molecular weight fraction induced egr-1 expression in the mitral/tufted neurons in the anterior subregion of the accessory olfactory bulb, suggesting that they activate the V1R class of vomeronasal receptor neuron.

Development of the vomeronasal receptor epithelium and the accessory olfactory bulb in sheep

The morphological development of the vomeronasal organ (VNO) and accessory olfactory bulb (AOB) of the sheep from anlage to birth were studied by classical and histochemical methods using embryos and fetuses obtained from an abattoir with ages estimated from crown-to-rump length. Both VNO and AOB developed in a biologically logical sequence and completed their morphological development around day 98, at entry into the last third of the gestation period. A lectin with specificity for oligomeric N-acetylglucosamine labeled the sensory epithelium of the VNO, the vomeronasal nerves, and the nervous and glomerular layers of the AOB before birth. These results suggest that the vomeronasal system, which is well developed and functional in adult sheep, may be able to function at or even before birth in these animals (whereas in rodents, for example, this is precluded by the AOB not completing its development until after birth).

Differential development of binding sites for four lectins in the vomeronasal system of juvenile mouse: from the sensory transduction site to the first relay stage

Four lectins -the galactose-specific BSI-B(4) (from Bandeiraea simplicifolia), the N-acetyl-galactosamine-specific DBA (from Dolichos biflorus), the L-fucose-specific UEA-I (from Ulex europaeus) and the (oligomeric N-acetylglucosamine)-specific LEA (from Lycopersicum esculentum)- were used to study the vomeronasal organ, vomeronasal nerves and accessory olfactory bulb of the mouse on embryonic days 11, 13, 15, 17 and 19, during the first 3 weeks after birth, at age 25 days, and after reaching maturity. No lectins labelled any structure before the 17th day of gestation, and even on the 19th day staining was sporadic and/or diffuse. During the early postnatal period, the lectin binding patterns differed from those of adults, but the division of the accessory olfactory bulb into anterior, rostral posterior and caudal posterior regions was already present and was shown up by the four lectins in a way that was coherent with the known zone-to-zone correspondence between the apical and basal zones of the sensory epithelium and the anterior and posterior accessory olfactory bulb, respectively. By age 25 days, the staining patterns were essentially those of the adult mouse. BSI-B(4) appears to be specific for the accessory vs. the main olfactory bulb throughout life.

Morphogenesis and growth of the soft tissue and cartilage of the vomeronasal organ in pigs

The morphology of the soft tissue and supporting cartilage of the vomeronasal organ of the fetal pig was studied from early stages to term. Specimens obtained from an abattoir were aged by crown-to-rump distance. Series of transverse sections show that some time before birth all structures--cartilage, connective tissue, blood vessels, nerves, glands and epithelia--are well developed and very similar in appearance to those of the adult. Furthermore, in transmission electron microscopy photomicrographs obtained at this stage the vomeronasal glands exhibit secretory activity.

Histochemical identification of carbohydrate moieties in the accessory olfactory bulb of the mouse using a panel of lectins

Lectin binding patterns in the olfactory bulb of the mouse were investigated using 12 biotinylated lectins. Three, with specificities for galactose, N-acetylgalactosamine and L-fucose, stained only the nervous and glomerular layers of the accessory olfactory bulb; four, with specificities for galactose or N-acetylglucosamine, stained these layers in both the accessory and the main olfactory bulbs; three, with specificities for N-acetylgalactosamine or L-fucose, effected general staining with little contrast between the background and the accessory olfactory bulb or other structures; the remaining two, both of them specific for mannose, stained no part of the tissue studied. In the nervous and glomerular layers of the accessory olfactory bulb six lectins stained the anterior and posterior halves with different intensities and two of these six similarly differentiated between rostral and caudal regions of the posterior half. We conclude that: (i) three lectins binding to different monosaccharides are specific stains for the vomeronasal system when used in this area of the mouse brain; (ii) it may be appropriate to distinguish three parts in the mouse accessory olfactory bulb, instead of the hitherto generally accepted two.

Retrograde labelling of mitral/tufted cells in the mouse accessory olfactory bulb following local injections of the lipophilic tracer DiI into the vomeronasal amygdala

It has recently become apparent that there are two classes of vomeronasal receptor neurons that project to functionally separate anterior and posterior sub-regions of the mammalian accessory olfactory bulb. However, anterograde tracing of the projections from these sub-regions, in the mouse, has revealed that the processing pathways are not segregated at the level of the vomeronasal amygdala. Both sub-regions have overlapping projections to the superficial lamina of the medial and posterior medial cortical nuclei of the amygdala. However, differential projections have been found in the opossum, in which only the posterior sub-region projects to the deeper laminae of the medial amygdala. Therefore, there may be species differences in these projections that are important for the control of reproductive behaviour. This study used an alternative approach of retrogradely tracing mitral/tufted cell projections from different nuclei of the vomeronasal amygdala back to the accessory olfactory bulb of mice. Local injections of the lipophilic tracer DiI were made into the antero-dorsal and postero-ventral divisions of the medial amygdala, and into the postero-medial cortical amygdala. In each case, provided the DiI affected the superficial lamina Ia, labelled mitral/tufted cells were found distributed throughout the anterior-posterior extent of the accessory olfactory bulb. These results confirm that mitral/tufted cells of the anterior and posterior sub-regions of the accessory olfactory bulb project to both the medial and postero-medial cortical nuclei of the amygdala. There was no evidence for differential projections from the anterior and posterior sub-regions accessory olfactory bulb in mice, as has been reported to occur in other species.

Biodistribution and radiation dosimetry of stabilized 99mTc-exametazine-labeled leukocytes in normal subjects

Labeling leukocytes with 99mTc-exametazime is a validated technique for imaging infection and inflammation. A new radiolabeling technique has recently been described that enables leukocyte labeling with a more stable form of 99mTc-exametazime. A normal value study of stabilized 99mTc-exametazime-labeled leukocytes has been performed, including biodistribution and dosimetry estimates in normal subjects.

METHODS

Ten volunteers were injected with stabilized 99mTc-exametazime-labeled autologous leukocytes to study labeled leukocyte kinetics and dosimetry in normal subjects. Serial whole-body imaging and blood sampling were performed up to 24 h after injection. Cell-labeling efficiency and in vivo viability, organ dosimetry, and clearance calculations were obtained from the blood samples and imaging data as well as urine and stool collection up to 36 h after injection.

RESULTS

Cell-labeling efficiency of 87.5% +/- 5.1% was achieved, which is similar to or better than that reported with the standard preparation of 99mTc-exametazime. In vivo stability of the radiolabeled leukocytes was also similar to in vitro results with stabilized 99mTc-exametazime and better than previously reported in vivo stability for nonstabilized 99mTc-exametazime-labeled leukocytes. Organ dosimetry and radiation absorbed doses were similar with a whole-body absorbed dose of 1.3 x 10(-3) mGy/ MBq. Urinary and fecal excretion of activity was minimal, and visual assessment of the images showed little renal parenchymal activity and no bowel activity up to 2 h after injection.

CONCLUSION

Cell labeling and in vivo stability appear improved compared with the leukocytes labeled with the nonstabilized preparation of 99mTc-exametazime. There are advantages in more cost-effective preparation of the stabilized 99mTc-exametazime and an extended window for clinical usage, with good visualization of abdominal structures on early images. No significant increase in specific organ and whole-body dosimetry estimates was noted compared with previous estimates using nonstabilized 99mTc-exametazime-labeled leukocytes.

A descriptive and comparative lectin histochemical study of the vomeronasal system in pigs and sheep

The accessory olfactory bulb (AOB) is the primary target of the sensory epithelium of the vomeronasal organ (VNO), and thus constitutes a fundamental component of the accessory olfactory system, which is involved in responses to behaviour-related olfactory stimuli. In this study we investigated the characteristics of the AOB, VNO, vomeronasal nerves (VNNs) and caudal nasal nerve (CdNN) in pigs and sheep, species in which olfaction plays a key behavioural role both in the neonatal period and in adulthood. The patterns of staining of the AOB by the Bandeiraea simplicifolia and Lycopersicon esculentum lectins were the same in the 2 species, whereas the Ulex europeus and Dolichos biflorus lectins gave different patterns. In both species, lectin staining of the AOB was consistent with that of the VNNs, while the CdNN did not label any of the structures studied. The entire sensory epithelium of the pig was labelled by Ulex europeus and Lycopersicum esculentum lectins, and all 4 lectins used labelled the mucomicrovillar surface of the sensory epithelium in sheep.

High-fat versus high-carbohydrate enteral formulae: effect on blood glucose, C-peptide, and ketones in patients with type 2 diabetes treated with insulin or sulfonylurea

Recently, two commercial enteral formulae for diabetic patients have been made available in Spain: a high-complex-carbohydrate, low-fat formulation (HCF) and a low-carbohydrate formulation (RCF). This study compares the effects of the two enteral nutritional formulae in patients with non-insulin-dependent diabetes mellitus (type 2 diabetes) treated with sulfonylurea or insulin. Fifty-two type 2 diabetes patients were randomly assigned to receive one of the two enteral formulae. Test enteral formula breakfast (250 cc) were consumed at approximately 0900 h after routine medications (insulin or oral agents) had been taken. Venous blood samples were obtained during fasting, before medication, and at 30 and 120 min after the start of the meal. The glycemic response of patients to the HCF was significantly greater than to RCF, but lower than in the sulfonyl type 2 diabetes treated groups. The incremental glucose response was within acceptable levels except in insulin treatment type 2 diabetes patients given HCF. Glucose, insulin, and C-peptide responses were higher in HCF than RCF groups. Two-factor analysis of variance on mean increments of blood glucose and C-peptide from basal levels to 30 min show the type of enteral nutrition as the main factor (P = 0.0010 and P = 0.0005, respectively). The RCF formula supplies 50.0% of energy as fat and 33.3% as carbohydrates, so it may be a ketogenic diet. It was found that both ketone bodies were higher after RCF than after HCF ingestion, but without statistical significance. We conclude that the partial replacement of complex digestible carbohydrates with monounsaturated fatty acids in the enteral formulae for supplementation of oral diet may improve glycemic control in patients with type 2 diabetes. The long-term effects of enteral diets high in monounsaturated fatty acids need further evaluation in patients with type 2 diabetes.

Lectin binding patterns in the vomeronasal organ and accessory olfactory bulb of the rat

A number of previous studies have indicated that lectin histochemistry is an obvious choice for characterizing the vomeronasal system. However, apparently inconsistent results have been obtained: notably, the affinity with which various lectins bind to the accessory olfactory bulb varies among taxa, even considering closely related species. In the present study, the binding patterns of seven lectins in the rat accessory olfactory bulb, vomeronasal nerves and vomeronasal duct were investigated. The Bandeiraea simplicifolia lectin bound exclusively to the vomeronasal nerve and glomerular layers of the accessory olfactory bulb, while the Ulex europeus and Lycopersicon esculentum lectins bound to these regions and additionally to the nerve and glomerular layers of the main olfactory bulb. Soybean agglutinin showed a similar pattern to that obtained with the Ulex europeus and Lycopersicon esculentum lectins, though it also faintly labelled other parts of the structures examined. The Vicia villosa and Erythrina cristagalli lectins were not specific for the vomeronasal system, since they labelled grey and white matters in structures including the lateral olfactory tract and the anterior olfactory nuclei. The Dolichos biflorus lectin did not bind to vomeronasal tissues. The observed patterns of binding in the accessory olfactory bulb were consistent with those observed in the vomeronasal nerves, but unlike those observed in the epithelium of the vomeronasal duct. This latter result probably reflects binding of lectins to sugar residues contained in secreted mucus rather than those in epithelial nerve endings.

The accessory olfactory bulb of the mink, Mustela vison: a morphological and lectin histochemical study

The distribution of binding sites for the lectins Ulex europaeus agglutinin I, Soybean agglutinin, Bandeiraea simplicifolia agglutinin I-isolectin B4, and Vicia villosa agglutinin in the mink olfactory bulb was investigated. All lectins except Ulex europaeus agglutinin I bound exclusively and systematically to a single area of the olfactory bulb. This area corresponded to that in which the vomeronasal nerves terminate, indicating that it is the accessory olfactory bulb, as confirmed by microdissection and by the study of transverse and parasagittal series of the olfactory bulb. The results, moreover, indicate that the accessory olfactory bulb of the mink comprises three isolated eminences, the largest in the dorsal part of the olfactory bulb, and the other two in the lateral and medial parts.

Supporting tissue and vasculature of the mammalian vomeronasal organ: the rat as a model

The blood supply and osseocartilaginous support structures of the vomeronasal organ of the rat were studied. The study focused on adults, though 3- to 18-day-old animals were also examined. The techniques used included dissection and microdissection, injection of the vascular system with Araldite or with Indian ink in agar or gelatine, conventional histology, and scanning and transmission electron microscopy. The results indicated that blood reaches the vomeronasal organ via a branch of the sphenopalatine artery, and drains into an associated vein. Within the organ, one vein stood out by virtue of its size; this vein is accompanied by lesser veins, together with arterioles, capillaries, and lymphatic vessels. Connective tissue was readily apparent, though its distribution was heterogeneous. Analysis of series of transverse sections indicates that, in adults, the capsule that encases the vomeronasal organ is bony; in younger animals, the capsule is bony externally and cartilaginous internally; in very young animals, the capsule is entirely cartilaginous. However, it was noted that the change from cartilage to bone was due not to ossification of the existing cartilage, but to physical displacement of that cartilage by an extension of the vomer and incisive bones. Taken together, these results confirm the importance of considering the morphology of the vomeronasal organ as a whole, since there are major changes from rostral to caudal ends. Secondly, our findings regarding blood supply and the nature of the capsule support the view that the vomeronasal organ acts as a pump.

Origin and regional distribution of the arterial vessels of the vomeronasal organ in the sheep. A methodological investigation with scanning electron microscopy and cutting-grinding technique

The origin and location of the arteries of the vomeronasal organ (VNO) in the sheep were studied by means of dissection, scanning electron microscopy of corrosion casts, and the cutting-grinding technique after injection with Araldite CY23-HY2967 via one of the carotid arteries. Dissection revealed that the most ventral of the three main branches of the sphenopalatine artery is responsible for the blood supply to the VNO. Scanning electron microscopy of corrosion casts revealed that the arterioles of the vomeronasal organ form a microvascular network. Cross sections of the region of the nasal cavity containing the VNO, obtained by the cutting-grinding technique, showed that the arterioles of the vomeronasal plexus are located medial and ventral to the vomeronasal duct. These results confirm the usefulness of the cutting-grinding technique as a complementary procedure in morphological studies of structures containing hard tissues.

The soft-tissue components of the vomeronasal organ in pigs, cows and horses

The soft-tissue components of the vomeronasal organ of the pig, the cow and the horse were studied with the aid of dissection, microdissection, and light microscopy and immunohistochemistry of series of transverse sections. In horses, the rostral end of the incisive duct was blind: thus, unlike in pigs and cows, there was no communication between the vomeronasal organ and the oral cavity. In all three species, the central part of the vomeronasal duct bore the 'typical' respiratory/ receptor epithelium lining on its lateral and medical walls. The rostral part of the duct was characterized by stratified columnar epithelium, while more caudal parts bore simple columnar type. The patterns of distribution of glands, blood vessels and nerves were closely associated with the patterns of distribution of duct linings. The distribution of soft-tissue components in pigs was less clearly defined than in cows and horses. Of the three species, nerves were detected in the rostral half of the vomeronasal parenchyma only in the horse.

Distribution of the arterial supply to the vomeronasal organ in the cat

BACKGROUND

The main goal of this work was to investigate the general distribution of arterial blood around and inside the vomeronasal organ (VNO) of the cat.

METHODS

Macro- and microdissection methods together with light and scanning electron microscopy were used. Heads were injected with an India ink/agar mixture (the VNO subsequently being cut in transverse, sagittal and horizontal sections), with clear latex (the VNO subsequently being cut in transverse sections), or with an epoxy resin to obtain casts for examination by scanning electron microscopy.

RESULTS

Dissection and microdissection show that the infraorbital, minor palatine, and descending palatine arteries have a common origin, rostral to the Rete mirabile arteria maxillaris. In transverse series and in the rostral half of the VNO, an arteriole is consistently observed between the vomeronasal duct and the lateral sheet of the vomeronasal cartilage. In this same segment, arterial branches with different orientations (perpendicular, horizontal, or transverse with respect to the main axis of the organ) are observed. Scanning electron microscopy of arterial casts shows that arterial vessels of the mucosa of the nasal septum have a direct relationship with the VNO.

CONCLUSIONS

Branches of the sphenopalatine artery are the chief route of blood supply to the VNO. The vomeronasal parenchyma has few arterial vessels, and these are usually situated in the same position. Differences observed between the arteries inside and outside the VNO and the dilation of both by isoproterenol support the idea that the VNO is similar to erectile tissue organs and that it may act as a physiological pump.