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.

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.

[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.

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.

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.

The vomeronasal organ of the cat

The vomeronasal organ of the cat was studied macroscopically, by light microscopy and by immunohistochemical techniques. Special attention was paid to the general distribution of the various soft tissue components of this organ (duct, glands, connective tissue, blood vessels and nerves.) Examination of series of transverse sections showed that the wall of the vomeronasal duct bears 44 different types of epithelium: simple columnar in the caudal part of the duct, respiratory and receptor respectively on the lateral and medial walls of the middle part of the duct, and stratified squamous rostrally. The pattern of distribution of other soft tissue components was closely associated with that of epithelium types. In areas where the duct wall was lined with receptor epithelium, nerves and connective tissue were present between the epithelium and the medial sheet of the vomeronasal cartilage. Most glands and blood vessels were located lateral to those areas of the duct wall lined with respiratory epithelium. Numerous basal cells were present in the sensory epithelium. Understanding of the distribution of the soft tissue components of this organ may shed light on its function.

Anatomy and cholinergic innervation of the sinus paranalis in dogs

Conventional methods have been used to study the general configuration of the wall of the Sinus paranalis in dogs. Apocrine tubular glands, elastic fibres and smooth-muscle fibres are the more significant elements of the wall, together with the epithelium and connective tissue. By means of the immunohistochemical method described in this paper, the results provide histochemical evidence for the presence of an AChE-positive reaction, and supposedly cholinergic nerve fibres in the wall of the dog anal sacs, mainly associated with subepithelial smooth muscle, vessels, and glands.

[Nutritional status and plasma amino acid levels in hemodialysis]

The objective of this work is to study the relation between the variations of the plasmatic aminogram, and the nutritional state of the patient with chronic kidney failure on hemodialysis. We studied 79 patients with chronic kidney failure undergoing hemodialysis treatment, with and evolution of 46 +/- 37 months. They were subjected to a dietary questionnaire, and anthropometric study after dialysis (body mass index, triceps skin fold, muscular circumference of the arm), and determination of the levels of serum amino acids after a pre-dialysis nocturnal fast half way through the week, and finally a record is made of the number of times each patient was hospitalized in the 6 months prior to the study. In the amino acids with a pyruvate origin, there is a significant reduction of alanine (p: 0.002), serine (p: 0.004), and methionine (p: 0.001), and a significant increase of glycine, cystathionine, and cystine (p: 0.0001), with the Glycine/Serine coefficient being elevated (p: 0.001). All amino acids with a ketoglutarate origin are increased significantly (p < 0.007), except glutamine which is decreased (p: 0.0009), and arginine which does not show any significant differences. The essential amino acids are decreased in relation to the non-essential ones (p: 0.0001), although if they are compared with the normal values, only threonine is decreased (p: 0.001). Of the rest, histidine, isoleucine (p: 0.0001) and phenylalanine (p: 0.001) are significantly increased. The tyrosine/phenylalanine coefficient is decreased (p: 0.001). The daily ingestion of protein is correlated negatively with alanine, proline, hydroxyproline, and aspartic acid. The anthropometric parameters are correlated positively with the branched amino acids, alanine and proline. Finally, the number of hospital admissions in the last 6 months, is correlated positively with valine, leucine, phenylalanine, and glutamic acid. In conclusion, we consider that the increase of the glycine/serine, phenylalanine/serine and non essential/essential coefficients, is related to alterations of the metabolism, intrinsic to the condition of uremia, while the alterations of the levels of branched amino acids is related to the nutritional condition of the patients.

Comparative anatomy of the vomeronasal cartilage in mammals: mink, cat, dog, pig, cow and horse

The vomeronasal cartilages of mink, cat, dog, pig, cow and horse were studied by dissection, microdissection and by means of series of transverse sections. In all the species studied the cartilage is of hyaline type and the medial sheet is well-defined and perfectly moulded to the adjacent bone. However, interspecies differences are apparent in the manner in which the medial sheet associates and eventually fuses with the cartilage of the incisive duct; the morphology of the horse vomeronasal cartilage is particularly distinctive in this respect. The lateral sheet of the vomeronasal cartilage, although always present, has a different arrangement in each species studied. Similarly, the gaps in the lateral sheet (corresponding to the opening of the vomeronasal organ) differ among the species studied in form, location and number.

Structural, morphometric, and immunohistological study of the accessory olfactory bulb in the dog

BACKGROUND

The study of the morphological, morphometric, and immunohistological characteristics of the accessory olfactory bulb (AOB) in the dog is the main goal of this work.

METHODS

Horizontal sections of the AOB where stained by four different methods (haematoxilin/eosin, Tolivia, Nissl, and Bielchowsky). The avidin-biotin-peroxidase complex (ABC) was used, whereas the monoclonal antibodies to neuron-specific enolase, neurofilaments, glial fibrillary acidic protein, and synaptophysin were selected for the immunohistological study. A computer-assisted image analysis was employed in order to define the morphometric characteristics of de AOB.

RESULTS

The general morphology of the AOB indicates that it comprises a thick glomerular layer and a thinner internal layer containing mitral/tufted, granular, and glial cells. The mitral/tufted cells have large pale-staining nuclei with intensely staining nucleoli. There does not appear to be a clearly defined granular layer. No reactivity with antibodies to neuron-specific enolase or to neurofilaments was observed in any part of the AOB, but there was some reactivity with an antibody to glial fibrillary acidic protein and widespread reactivity with an antibody to synaptophysin.

CONCLUSIONS

The stratification of the AOB is simpler and less well defined than that of the main olfactory bulb (MOB), unlike in rodents in which the structure of the AOB corresponds closely to that of the MOB. According to the scale of Frahm and Bhatnagar (1980. J. Anat., 130: 349-365) the AOB of the adult dog has an intermediate position.

Anatomical and immunohistological demonstration of the primary neural connections of the vomeronasal organ in the dog

Macro- and microdissection methods together with conventional histology and lectin immunohistochemistry have been used to identify the course of the vomeronasal nerves and their site of termination (accessory olfactory bulb; AOB) in the dog. The AOB in this species is small and variable in size, situated on the medial surface of the main olfactory bulb, and has an anatomical structure unlike that described for other mammals. The vomeronasal nerves and their terminal glomeruli in the AOB are easily identifiable by selective immunohistochemical staining using Ulex europeus agglutinin I.

Glucagon-like immunoreactivity in hypothalamic neurons of the rat

Antisera specific for three different regions of pancreatic proglucagon were used to examine the distribution of such immunoreactivity in rat hypothalamus. Neurons in the supraoptic and paraventricular nuclei were immunoreactive with an antiserum against glucagon, but not with antisera directed towards the aminoterminal region of proglucagon (glicentin) or the glucagon-like peptide I sequence in the carboxyl-terminal region of proglucagon. These findings confirm a previous report of glucagon-like immunoreactivity in the supraoptic and paraventricular nuclei, but indicate that, while this material is immunochemically related to glucagon, it is not derived from a proglucagon-like precursor.

Effect of benzo[a]pyrene on DNA synthesis and DNA polymerase activity of rat liver nuclei

When benzo[a]pyrene (B[a]P) was administered intraperitoneally to rats 48 hr before they were killed, the DNA-synthesizing capability of isolated rat liver nuclei was decreased as compared with control animals. B[a]P also inhibited in vitro DNA synthesis in nuclei purified from control animals; this effect was enhanced by NADPH. DNA polymerases solubilized from purified nuclei of B[a]P-treated animals were less active than those of control animals. DNA polymerase alpha was more inhibited than DNA polymerase beta. Purified rat liver nuclei devoid of cytoplasmic contamination possess an NADPH-dependent B[a]P hydroxylase activity. The observed inhibition of DNA synthesis in nuclei isolated from B[a]P-treated rats was increased by NADPH. Moreover, there was an increased inhibition of DNA polymerase activity by nuclear membranes obtained from B[a]P-treated animals when the incubations were performed in the presence of NADPH. Also, the derivative B[a]P-trans-9,10-dihydrodiol was a potent inhibitor of DNA polymerase alpha under conditions where DNA polymerase beta was less affected. These results suggest that nuclear B[a]P hydroxylase might be involved in the inhibition of DNA synthesis probably at the level of DNA polymerase alpha. As in the in vivo studies, the nuclear polymerase most affected by the hydrocarbon in vitro was DNA polymerase alpha.

Spavin: a proposed term for a non-fracture associated canine hock lesion

In accordance with macroscopic and microscopic features of the tarsal joint degeneration in the greyhound dog, the possibility of establishing a direct relation between this process and spavin or bone spavin is proposed. To date this has been considered limited to equine and occasionally bovine stock. This investigation has been carried out on three different levels: macroscopic, radiological and histological and has been completed with the corresponding graphic documentation.

The relation of the lymphatic system to hemolymph nodes in the sheep

Sublumbar lymphatic drainage was examined in fetal and adult sheep for potential connections with hemolymph (hemal) nodes. Despite numerous channels entering sublumbar lymph nodes there were no lymphatic communications with hemal nodes. In ovine ruminants hemolymph nodes are separate from the lymphatic system.

Modulation of rat liver aryl hydrocarbon (benzo[a]pyrene) hydroxylase activity by nutritional effects

Rats malnourished since birth and fed a protein-free diet for 2 wk showed almost undetectable levels of liver microsomal aryl hydrocarbon (benzo[a]pyrene) hydroxylase. Treatment with benzo[a]pyrene rapidly enhanced this activity to levels higher than those observed with untreated normal rats. The carbon-monoxide-reduced cytochrome P-450 spectral peak was shifted from 452 nm in malnourished untreated rats to 448 nm in malnourished benzo[a]pyrene-injected rats and resulted in increases in the intensity of several microsomal protein bands (MW range 46,000-60,000) separated by gel electrophoresis. Malnourished rats then fed with a protein diet exhibited an important increase in aryl hydrocarbon hydroxylase activity, an increase in the intensity of microsomal protein electrophoretic bands (MW range 46,000-60,000), and a shift of the carbon-monoxide-reduced cytochrome P-450 spectral peak from 452 nm to 450 nm. These results suggest that alterations in cytochrome P-450 species related to benzo[a]pyrene metabolism might explain the modulation of this activity by nutritional effects.