Phimosis in male dromedary camels: Clinical findings and changes in the hemogram,nitric oxide metabolites,and testosterone concentrations

The objectives of this study were to elucidate the clinical findings in male dromedary camels with phimosis (PHI, n = 43) and to investigate the association of this syndrome with the hemogram, nitric oxide metabolites (NOMs), and testosterone concentrations. History and signalment were obtained, and a breeding soundness examination was performed. The penis was exteriorized after administration of a pudendal nerve block. Abnormal masses obtained from the prepuce and penis were prepared for histopathology. Blood samples for hemogram assessment were taken from the diseased animals and from 10 healthy control males. Total nitrates/nitrites were determined in sera using the Griess assay. Testosterone was estimated in sera using ELISA. Phimosis associated with detectable pathologic lesions, mainly including ulcerative posthitis and lacerated glans penis, was present in 34 (79.1%) of the 43 cases (PHI-P), whereas the remaining nine (20.9%) of the 43 cases had no noticeable lesions (PHI-N). The PHI-P group showed higher leukocyte counts (P = 0.001), especially neutrophils (P = 0.0001), and greater NOM concentrations (P = 0.002) than the PHI-N and control groups. However, testosterone concentrations did not differ among groups. In conclusion, PHI in the male dromedary camels was mainly associated with ulcerative posthitis and laceration of the glans penis. The presence of pathologic lesions in cases with PHI was associated with leukocytosis, neutrophilia, and high NOM concentrations.     

Influence of stimulation by electroejaculation on myocardial function,acid–base and electrolyte status,and hematobiochemical profiles in male dromedary camels

This study was carried out to evaluate the effect of electroejaculation (EEJ) on myocardial function, acid–base balance, and hematobiochemical profiles in male dromedary camels. Twenty sexually mature, apparently healthy male camels were assigned to EEJ. Parallel, eight naturally mated male camels were enrolled as a control group. Three blood samples were collected from each camel: just before (T0), directly after (T1), and 24 hours after (T2) EEJ or natural mating. The serum concentrations of the cardiac biomarker troponin I (cTnI), blood gas parameters, and hematobiochemical profiles were determined. Nineteen camels were ejaculated by the end of the second circuit and one by the end of the first circuit. In both groups, the mean heart and respiratory rates had increased significantly immediately after the procedure, but returned to normal values 24 hours after the procedure. The mean serum concentration of cTnI had increased significantly in all camels after EEJ, but not in controls. However, at 24 hours post-EEJ, the serum concentration of cTnI did not differ significantly compared with baseline values. The blood pH and base excess had decreased, and the PCO₂ and lactic acid had increased after EEJ. The EEJ provoked decreases in hematocrit and mean corpuscular volume. In the control group, the base excess, HCO₃⁻, TCO₂, anion gap, and lactic acid increased slightly after mating but did not reach a significant level compared with premating values. It is concluded that EEJ in camels results in a reversible myocardial injury, changes in the acid–base status, and increase the lactic acid concentration.     

Skull base tumors: a comprehensive review of transfacial swing osteotomy approaches

Numerous techniques have been proposed for the resection of skull base tumors, each one unique with regard to the region exposed and degree of technical complexity. This study describes the use of transfacial swing osteotomies in accessing lesions located at various levels of the cranial base. Eight patients who underwent transfacial swings for exposure and resection of cranial base lesions between 1996 and 2002 were studied. The mandible was the choice when wide exposure of nasopharyngeal and midline skull base tumors was necessary, especially when they involved the infratemporal fossa. The midfacial swing osteotomy was an option when access to the entire clivus was necessary. An orbital swing approach was used to access large orbital tumors lying inferior to the optic nerve and posterior to the globe, a region that is often difficult to visualize. Gross total tumor excision was possible in all patients. Six patients achieved disease control and two had recurrences. The complications of cerebrospinal fluid leak, infection, hematoma, or cranial nerve damage did not occur. After surgery, some patients experienced temporary symptoms caused by local swelling. The aesthetic result was considered good. Transfacial swing osteotomies provide a wide exposure to tumors that occur in the central skull base area. Excellent knowledge of the detailed anatomy of this region is paramount to the success of this surgery. The team concept is essential; it is built around the craniofacial surgeon and an experienced skull base neurosurgeon.     

Male perineogenital anatomy and clinical applications in genital reconstructions and male-to-female sex reassignment surgery

To determine the possibility of providing alternative surgical techniques for male genital reconstruction and for male-to-female sex reassignment surgery, the authors undertook an anatomic investigation of the perineogenital region in male cadavers. Anatomic dissection was performed on 14 male adult human cadavers (fresh and formalin-preserved) studying the main afferent vessels to the anterior perineal region and their mean internal diameters: deep external pudendal artery (0.60 mm), superficial perineal artery (0.50 mm), and funicular artery (0.37 mm). We established their exact topography, together with vascular anatomic variations, main vascular anastomosis circuits (base of the penis, scrotal septum, and perineal fat and lateral spermatic-scrotal fascia), angiosomes, anatomy of the rectovesical septum cavity, and their "critical" key points of dissection. The authors discuss the clinical possibility of elevation of a "tree" of previously described paragenital-genital flaps including mainly those based on the terminal branches of the internal pudendal vascular system, the erectile tissue pedicled flaps, and finally, flaps of the external pudendal system. The authors indicate the concrete vascularization system for each flap.     

Urogenital vasculature and local steroid concentrations in the uterine branch of the ovarian vein of the female tammar wallaby (Macropus eugenii)

The urogenital vasculature of the tammar comprises 4 major paired arteries and veins: the ovarian, the cranial urogenital, the caudal urogenital and the internal pudendal artery and vein. The ovarian artery and vein and their uterine branches which supply the ovary, oviduct and uterus, ramify extensively. Each anterior urogenital artery and vein supplies the caudal regions of the ipsilateral uterus, lateral and median vagina and cranial parts of the urogenital sinus. The caudal urogenital arteries and veins supply the urogenital sinus and caudal regions of the bladder. The internal pudendal artery and vein vascularize the cloacal region, with some anastomoses with branches of the external pudendal vessels. Anastomoses connect the uterine branch of the ovarian artery with the uterine branch of the cranial urogenital and cranial branches of the caudal urogenital arteries, and connect the caudal urogenital and the internal pudendal arteries. Anastomotic connections between the left and right arterial supply also occur across the midline of the cervical regions of the uteri and the anterior lateral vaginae. Similar connections are seen in the venous system. The uterine branch of the ovarian artery ramifies extensively very close to the ovary, giving a plexiform arrangement with the ovarian veins, and also with the uterine venous system on the lateral side of each uterus. This plexiform structure provides an anatomical arrangement which could allow a local transfer of ovarian hormones from ovarian vein into the uterine arterial supply, and thence to the ipsilateral uterus. Progesterone concentrations in plasma from the mesometrial side of the uterine branch of the ovarian vein are markedly higher than in tail vein plasma, especially during the 'Day 5 peak' early in pregnancy, and also at full term. There is also a marked decrease in progesterone concentration from all sites immediately before birth as previously reported for peripheral plasma. These results support the suggestion of a countercurrent transfer mechanism, at least for progesterone, and possibly other hormones, between the ovarian vein and uterine artery. Such a local transfer could explain the different morphological responses of the endometria of the two adjacent uteri during pregnancy in macropodid marsupial species.     

An intracellular study of pudendal afferent inputs onto tail motoneurons in the spinalized cat

Postsynaptic potentials, elicited by stimulation of the sensory pudendal (SPud) and superficial perineal nerves (SPeri) on both sides, were recorded from motoneurons innervating tail muscles in the non-anaesthetized and spinalized cat. The stimulation of SPud and SPeri on both sides predominantly produced excitatory postsynaptic potentials (EPSPs) in all kinds of tail motoneurons (70-95%). The inhibitory postsynaptic potentials (IPSPs) were often observed in motoneurons innervating ventral tail muscles (30-33%). The means of averaged central latencies of EPSPs and IPSPs ranged from 4.3 to 7.3 ms, and from 4.6 to 8.4 ms, respectively. The findings suggests that polysynaptic neuronal pathways from pudendal nerve to tail motoneurons produce tonic activities of all tail muscles to raise the tail in micturation, defecation and sexual movements which are induced by stimulation of pudendal nerves.     

Localization and expression of ADAM2 in the dromedary camel testis,epididymis and sperm during rutting season

ADAM2 (fertilin β) is a sperm surface protein reported in several mammalian species. However, the presence of ADAM2 in the male reproductive system and sperm of the camel is not well known. The present study was to clarify the localization and expression of ADAM2 in the dromedary camel testis, epididymis and spermatozoa during rutting season using immunohistochemistry (IHC) and the quantitative real-time polymerase chain reaction (qPCR). Tissue samples were obtained from the testis (proximal and distal) and epididymis (caput, corpus, and cauda) from eight mature male camels. Epididymal and ejaculated sperms were collected from four other fertile camels. IHC analysis clearly showed the localization of ADAM2 protein in the spermatocytes and the round and elongated spermatids of the testis, in the epithelial cells along the epididymis tract, on the posterior head of the sperm within the cauda epididymis, and on the acrosomal cap of both the epididymal and ejaculated sperm. The expression of camel ADAM2 mRNA was significantly higher (P < 0.05) in the testis when compared with the epididymis. These findings may suggest an important role of ADAM2 in the fertility of male dromedary camels.     

Haematological and biochemical blood reference values for Canary Island camels (Camelus dromedarius), an endangered dromedary species

The purpose of this research was to develop reference values for haematological and biochemical variables in the Canary camel breed (Camelus dromedarius). 114 clinically healthy dromedary camels were assessed. Age, sex, and pregnancy status was also recorded. The reference range for red blood cells (RBCs) was 8.45 – 13.65 X10⁶/µL, haemoglobin (HGB) was 10.61 – 15.29 g/dL, packed cell volume (PCV) was 19.93 – 32.51 %, and white blood cells (WBCs) 7.35 – 18.36 X10³/µL. A correlation was established between the haemoglobin concentration (HGB) (g/dl) and packed cell volume (PCV) obtaining a linear regression (HGB = 0.31 PCV + 4.67). Young animals had higher RBC and WBC values than adult animals. Additionally, blood urea nitrogen (BUN), phosphorus, calcium, albumin/globulin (A/G) ratio, alkaline phosphatase, cholesterol, and lipase were higher in young animals compared with adults. Female dromedary camels showed higher values for the three main variables: RBC, HGB and PCV, but no differences between sexes were detected in the biochemical variables results. The WBC count was higher in non-pregnant females than in pregnant animals. These results provide references values for the Canary camel breed and may contribute to the understanding of differences in 18 haematological and biochemical parameters in dromedary camels with a potential impact in health and welfare for this species.     

Evolution of the therian face through complete loss of the premaxilla

The anatomical framework of the jawbones is highly conserved among most of the Osteichthyes, including the tetrapods. However, our recent study suggested that the premaxilla, the rostralmost upper jaw bone, was rearranged during the evolution of therian mammals, being replaced by the septomaxilla at least in the lateral part. In the present study, to understand more about the process of evolution from the ancestral upper jaw to the therian face, we re-examined the development of the therian premaxilla (incisive bone). By comparing mouse, bat, goat, and cattle fetuses, we confirmed that the therian premaxilla has dual developmental origins, the lateral body and the palatine process. This dual development is widely conserved among the therian mammals. Cell-lineage-tracing experiments using Dlx1-CreER^T2 mice revealed that the palatine process arises in the ventral part of the premandibular domain, where the nasopalatine nerve distributes, whereas the lateral body develops from the maxillary prominence in the domain of the maxillary nerve. Through comparative analysis using various tetrapods, we concluded that the palatine process should not be considered part of the ancestral premaxilla. It rather corresponds to the anterior region of the vomerine bone of nonmammalian tetrapods. Thus, the present findings indicate that the true premaxilla was completely lost during the evolution of the therian mammals, resulting in the establishment of the unique therian face as an evolutionary novelty. Reconsideration of the homological framework of the cranial skeleton based on the topographical relationships of the ossification center during embryonic development is warranted.     

New polymorphic microsatellite loci for different camel species

New microsatellite loci were screened and sequenced from the genomic DNA of male Camelus bactrianus. Among 32 loci, 23 were amplified in bactrian and dromedary species, 19 in llama and 20 in alpaca. The different species had similar fragment lengths per locus, with more striking similarities between bactrian and dromedary and between llama and alpaca, respectively. Seven loci had more than 10 alleles each, nine were monomorphic in all species, and one was monomorphic in Old World and polymorphic in New World camels. The results show that the informative microsatellite loci can be widely applied to several species.     

Behavioral indicators to detect ovarian phase in the dromedary she-camel

This pilot study was conducted to test the hypothesis that female camels behave differently in various ovarian phases in the presence of a restrained male camel. The aim was to identify behavioral patterns which could be used as indicators to detect ovulatory phase by visual observation in the presence of a restrained virile bull. Twenty-four healthy, nonpregnant, and nonlactating adult females were used. Transrectal ultrasonography was performed for each animal once a week over a 3-week period to determine the phase of the ovarian cycle. Females were considered to be in the ovulatory phase (O) when there was at least one preovulatory follicle (12<Ø<19 mm) protruding from the ovarian surface, and in the nonovulatory phase (NO), when growing follicles, regressing follicles, or corpora lutea were detected. Immediately after examination, each female was freely exposed to a restrained bull for 15 minutes, and her behaviors were filmed. The videos were analyzed through a focal animal-sampling ethogram (states: looking at the male; looking outside; standing close to the male; searching; and lying down; events: interaction with the male; urination; defecation; sound emission; and steps). A score for tail position (tail score: 1 = close to the vulva, 2 = horizontal, 3 = vertical) and for interest in the bull (male time score: from 1 to 5; 1 = <20% of observation period spent near the bull; 5 = more than 80%) were recorded. Ovulatory phase camels showed higher interest in the male than nonovulatory phases: they stood close to the male for longer periods (P = 0.0159), interacted with the male more frequently (P = 0.0004), and tended to lie down in front of him (P = 0.1202). Moreover, ovulatory phase had a significant effect on male time score (P < 0.01), mature follicular ovarian phase being associated with higher scores. Seeking the male has already been proposed as a behavioral indicator of estrus in camels, this has now been confirmed using a standardized ethogram. The present results clarify that camels behave differently in different ovarian phases and that monitoring their behavior in the presence of a restrained bull could help detect their ovulatory phase. This would have profound implications for enhancing fertility in dromedary camels by improving timing of mating or artificial insemination.     

Hierarchical nature of morphological integration and modularity in the human posterior face

Morphological integration and modularity are important points of intersection between evolution and the development of organismal form. Identification and quantification of integration are also of increasing paleoanthropological interest. In this study, the "posterior face," i.e., the mandibular ramus and its integration with the associated midline and lateral basicranium, is analyzed in lateral radiographs of 144 adult humans from three different geographic regions. The null hypothesis of homogenously pervasive morphological integration among "posterior-face" components is tested with Procrustes geometric morphometrics, partial least squares, and singular warps analysis. The results reveal statistically significant differences in integration. Only loose integrative relationships are found between midline and lateral components of the basicranium, which may indicate the presence of at least two different basicranial modules. This modularity can be interpreted in terms of spatiotemporal dissociation in the development of those basicranial structures, and gives support to hypotheses of independent phylogenetic modifications at the lateral and midline basicranium in humans. In addition, morphological integration was statistically significantly stronger between the middle cranial fossa and the mandibular ramus than between the ramus and the midline cranial base. This finding confirms previous hypotheses of a "petroso-mandibular unit," which could be a developmental consequence of well-known phylogenetic modifications in coronal topology of the posterior face and base in hominoid evolution, related to middle cranial fossa expansion. This unit could be involved in later evolutionary tendencies in the hominid craniofacial system.     

Prevalence of Cryptosporidium-like infection in one-humped camels (Camelus dromedarius) of northwestern Iran

Cryptosporidium is a ubiquitous enteropathogen protozoan infection affecting livestock worldwide. The present study was carried out to determine the prevalence of Cryptosporidium infection in different age groups of dromedary camels in northwestern Iran from November 2009 to July 2010. A total number of 170 fecal samples were collected and examined using modified Ziehl-Neelsen (MZN) staining under light microscope. Examination of stained fecal smears revealed that 17 camels (10%) were positive for Cryptosporidium-like. The prevalence of Cryptosporidium-like was significantly higher in camel calves (< 1 years old) (20%) than other age groups, in which the diarrhoeic calves had the prevalence of 16%. In adult camels the prevalence was 6.5%. There was no significant difference in the prevalence of Cryptosporidium-like between male and female camels. It is concluded that Cryptosporidium infection is a problem in camel husbandry and could be of public health concern in the region.     

The efficacy of controlled internal drug release (CIDR) in synchronizing the follicular wave in dromedary camels (Camelus dromedarius) during the breeding season

The present study aimed to evaluate the efficacy of controlled internal drug release (CIDR) to synchronize the follicular wave in dromedary camels (Camelus dromedarius) during the breeding season through ovarian monitoring, evaluating sexual receptivity, and measuring progesterone (P4) and estradiol (E2) levels during and after CIDR treatment. Sixteen camels received a new CIDR containing 1.9 g of P4 for 14 days. Ultrasound ovarian monitoring was performed on the day of insertion and every 3 days until the CIDR was withdrawn. Ultrasound examinations were continued day in day out after the CIDR was withdrawn for 10 days. According to the ultrasound examinations, the percentages of camels in the breeding (follicles: 12–18 mm) and nonbreeding phases were calculated. Blood samples were collected day after day during the experimental period (24 days) from the day that the CIDR was inserted. The serum P4 and E2 concentrations were analyzed using ELISA kits. The sexual receptivity of the camels was tested daily during the course of the experiment. The results revealed that 2 and 4 days after the CIDR was withdrawn, the percentage of camels in the breeding phase (68.75% and 75.00%, respectively) was significantly (P < 0.05) higher than that in the nonbreeding phase (31.25% and 25.00%, respectively). The percentage of camels that were abstinent during CIDR treatment was significantly (P < 0.05) higher than that observed for those who were incompletely receptive or completely receptive. The P4 levels increased significantly (P < 0.05) 2 days after CIDR insertion (1.73 ng/mL) and reached maximum values (2.94 ng/mL) at Day 12. Significant (P < 0.05) decreases in the P4 levels were observed 2 to 4 days after CIDR withdrawal (1.01 and 0.80 ng/mL, respectively). The P4 levels reached minimum values (0.18–0.22 ng/mL) at Day 20 through the end of the experiment. The E2 levels differed insignificantly during and after CIDR treatment in dromedary camels. In conclusion, the treatment of dromedary camels with CIDR produced a uniform increase in serum concentrations of P4 that could completely prevent sexual receptivity but could not suppress the follicular wave. After CIDR withdrawal, the P4 levels fell and induced the emergence of a new follicular wave, and most of the camels were in the breeding (ovulatory) phase 2 to 4 days after withdrawal. Therefore, CIDR can be used to synchronize the follicular wave in dromedary camels.     

Synchronisation of ovarian follicular waves in the dromedary camel (Camelus dromedarius)

This study was designed to compare the efficacy of various treatments intended to synchronise follicular wave cycles in dromedary camels by removing the existing follicle of unknown size and replacing it with a follicle capable of ovulating at a known time. Camels were randomly assigned to one of five groups and treated with either (1) 5mg oestradiol benzoate (i.m.) and 100mg progesterone (i.m.; E/P, n=15), (2) 20 icrog GnRH analogue, buserelin (i.m.; GnRH, n=15), (3) 20 microg buserelin (i.m.) on Day 0 (T=0) and 500 microg prostaglandin on Day T+7 (GnRH/PG n=15), (4) transvaginal ultrasound-guided follicle ablation of all follicles > or =0.5 cm (ABL, n=15) or (5) 5 ml saline (i.m; Controls n=15). All camels were subsequently injected with 20 microg buserelin 14 days after the first treatment was given. The ovarian response was monitored daily by transrectal ultrasonography and the intervals from treatment to follicular wave emergence and also the day on which the new dominant follicle reached 1.3 cm was recorded. Amongst the treatment groups the mean interval from treatment to new follicle wave emergence and treatment to time taken for the new dominant follicle to reach 1.3 cm in diameter was shortest in the ABL group (2.3+/-0.5 days and 8.8+/-1.1 days respectively, P=0.044) and longest in the E/P group (6.4+/-0.8 days and 12.2+/-1.0 days respectively, P<0.001) whereas the GnRH and GnRH/PG groups were intermediate (3.0+/-0.5 days and 11.1+/-0.8 days GnRH; and 4.5+/-0.5 days and 10.7+/-0.7 days GnRH/PG). A total of 11/15 camels in both the GnRH and GnRH/PG groups had dominant follicles between 1.3 and 1.9 cm 14 days post treatment, of which 21 of the 22 follicles ovulated after GnRH injection on T+14. The ABL, E/P and control groups however, showed greater variability in follicle size with less camels having dominant follicles between 1.3 and 1.9 cm than the GnRH and GnRH/PG groups and more in the > or =2.0 cm or follicle regressing groups, therefore fewer of these camels ovulated (ABL n=7; E/P n=9; Control n=6) after GnRH injection on Day T+14. In conclusion, two GnRH injections 14 days apart or two GnRH injections 14 days apart and PG on Day 7 after the first GnRH were the most effective methods to synchronise ovulation rate in dromedary camels at a fixed time interval of 14 days after treatment.     

Impotentia generandi in male dromedary camels: Clinical findings,semen characteristics,and testicular histopathology

The objective of this study was to describe the clinical findings, semen characteristics, and testicular histopathology in male dromedary camels affected with impotentia generandi (IG). According to the history, 82.6% (38/46) of the cases were classified as primary-IG (P-IG; never been able to impregnate a female), whereas 17.4% (8/46) were classified as secondary-IG (S-IG; acquired infertility). Only one scrotal testis was observed in four cases, and no scrotal testis was observed in one case. Overall, testicular length, width, and depth were 6.46 ± 0.2, 3.41 ± 0.1, and 2.8 ± 0.08 cm, respectively. Within the P-IG males, 42.2% of the testes were classified as small, 47.9% as normal, and 9.9% as large. Within the S-IG males, 0.0% of the testes were classified as small, 80% as normal, and 20% as large. Ejaculate volume, total sperm number in the ejaculate, and sperm motility, viability, and abnormal morphology were 4.4 ± 0.3 mL, 25.7 ± 1.0 × 10⁶, 18.7 ± 3.1%, 25.2 ± 3.4%, and 46.6 ± 3.7%, respectively. Azoospermia was observed in 30.4% of the cases, asthenospermia was observed in the 25% of the cases, and necrospermia was observed in 10% of the cases. The proportion of abnormal sperm was between 20% and 50%, and between 60% and 94% in 56.2% and 34.4% of the cases, respectively. Hypospermatogenesis, arrested spermatogenesis, Sertoli cell–only syndrome, and testicular degeneration were the main histopathological findings. In conclusion, IG in male dromedary camels appears to be related mainly to testicular dysfunction, which alters semen quality and reduces fertility.     

Mosaic Evolution of the Basicranium in <Emphasis Type="Italic">Homo</Emphasis> and its Relation to Modular Development

Mosaic evolution describes different rates of evolutionary change in different body units. Morphologically these units are described by more relationships within a unit than between different units which relates mosaic evolution with morphological integration and modularity. Recent evidence suggests mosaic evolution at the human basicranium due to different evolutionary rates of midline and lateral cranial base morphology but this hypothesis has not yet been addressed explicitly. We this hypothesis and explore how mosaic evolution relates to modular development. Evolutionary data sets on midline (N = 186) and lateral (N = 86) basicranial morphology are compared with 3D data on pre- and postnatal basicranial ontogeny (N = 71). Our results support the hypothesis of mosaic evolution and suggest a modular nature of basicranial development. Different embryological basicranial units likely became differently modified during evolution, with relatively stable midline elements and more variable lateral elements. In addition, developmental data suggests that modularity patterns change throughout ontogeny. During prenatal ontogeny lateral basicranial elements (greater sphenoid wings and petrosal pyramids) change together compared with the midline base. Close to birth the greater sphenoid wings keep a spatially stable position, while the petrosal pyramids become dissociated and shifted posteriorly. After birth the greater sphenoid wings and petrosal pyramids change again jointly and with respect to midline cranial base elements. This sequential pattern of integration and modularization and re-integration describes human basicranial ontogeny in a way that is potentially important for the understanding of evolutionary change. Phylogenetic modifications of this pattern during morphogenesis, growth, and development may underlie the mosaic evolution of the hominin basicranium.     

The anatomy of the solute Girvanicystis batheri (?Chordata) from the Upper Ordovician of Scotland and a new species of Girvanicystis from the Upper Ordovician of South Wales

Detailed anatomical study of the solute Girvanicystis batheri from the Girvan starfish bed (Ashgill) has enabled the oral partition, hydropore, gonopore and the possible opening of a branchial slit to be identified. The distal part of the alimentary tract and the stomach were located in the posterior part of the head. Structures preserved as steinkernen are interpreted as a brain and left cranial nerve. The gross anatomy of G. batheri supports the hypothesis that it was a suspension feeder. Girvanicystis batheri is characterized by large plates on the dorsal surface of the head, 20 rings of the feeding arm and a nodular median plate on the ventral surface of the head. A new species of Girvanicystis, G. casteri , is described from the Sholeshook limestone (Ashgill) of South Wales. Girvanicystis casteri is distinguished from G. batheri in that the former has narrower head, a longer feeding arm and a spine on the median plate of the ventral surface of the head. Girvanicystis batheri has characters in common with the cornute Ceratocystis perneri , namely large plates of the skeleton of the head, right and left marginal flanges, opposite dorsal fore tail plates and alternate ventral fore tail plates, which suggest that G. batheri may also be a stem chordate.     

Mouse Shh is required for prechordal plate maintenance during brain and craniofacial morphogenesis

In humans, holoprosencephaly (HPE) is a common birth defect characterized by the absence of midline cells from brain, facial, and oral structures. To understand the pathoetiology of HPE, we investigated the involvement of mammalian prechordal plate (PrCP) cells in HPE pathogenesis and the requirement of the secreted protein sonic hedgehog (Shh) in PrCP development. We show using rat PrCP lesion experiments and DiI labeling that PrCP cells are essential for midline development of the forebrain, foregut endoderm, and ventral cranial mesoderm in mammals. We demonstrate that PrCP cells do not develop into ventral cranial mesoderm in Shh^−/− embryos. Using Shh^−/− and chimeric embryos we show that Shh signal is required for the maintenance of PrCP cells in a non-cell autonomous manner. In addition, the hedgehog (HH)-responding cells that normally appear during PrCP development to contribute to midline tissues, do not develop in the absence of Shh signaling. This suggests that Shh protein secreted from PrCP cells induces the differentiation of HH-responding cells into midline cells. In the present study, we show that the maintenance of a viable population of PrCP cells by Shh signal is an essential process in development of the midline of the brain and craniofacial structures. These findings provide new insight into the mechanism underlying HPE pathoetiology during dynamic brain and craniofacial morphogenesis.     

Localization and distribution of catecholaminergic structures in the nervous system of Phocanema decipiens (nematoda)

The nervous system of Phocanema decipiens was examined with both the formaldeyhyde-induced and the glyoxylic acid fluorescence histochemical techniques. Green catecholaminergic structures were observed in 4 cephalic papillary nerves, 2 fibres with varicosities in the nerve ring as well as the ventral nerve cord and a pair of lateral nerves.The papillary nerves, extending from the nerve ring to the lips region, have cell bodies which are located anterior or adjacent to the nerve ring. Cell bodies of the lateral nerves are found within the lateral cord tissue posterior to the nerve ring. Each of these neurons has 3 processes—one joins with the nerve ring, the other merges with the ventral nerve cord and the third ends abruptly within the lateral cord.