238 research outputs found
Variations in the gonadal artery with a single common trunk: embryological hypotheses by observation
Background: A gonadal artery originates as a branch of the abdominal aorta and renal artery inferior to the level of origin of the renal arteries. Variations in multiple right testicular arteries (RTAs) arising from the abdominal aorta are common. We aimed to re-evaluate the unusual courses of gonadal arteries with a single common trunk in relation to the inferior vena cava and left renal vein and explain the developmental anatomy. Materials and methods: The observational cross-sectional study was performed on 54 Japanese adult cadavers (29 men and 25 women). We examined the literature and developed embryological hypotheses on the single common trunk of the gonadal artery. Results: The gonadal artery, testicular artery, and ovarian artery arose from the abdominal aorta in 93.1%, 96.3%, and 89.6% of cases, respectively, and from the renal artery in 4.9%, 3.7%, and 6.3% of cases, respectively. We found two rare variations in the RTAs observed during the routine dissection of two male cadavers; in these two cases, a single common trunk of the RTAs originated from the abdominal aorta. A single common trunk was found in 3.7% of cadavers, 2.0% of sides, and 2.0% of arteries in the gonadal artery and in 6.9% of cadavers, 3.8% of sides, and 3.7% of arteries in the testicular artery. All cases of the single common trunk, including those in past reports, were observed only in men. Conclusions: Knowledge of the variations in RTAs has important clinical consequences for invasive and non-invasive arterial procedures. In addition, this variation provides a new interpretation of the embryology of the gonadal artery. Variations similar to our findings have not been previously reported. Therefore, different variations concerning the RTA should be considered during surgical and non-surgical evaluations
Gene Regulation by MAPK Substrate Competition
SummaryDeveloping tissues are patterned by coordinated activities of signaling systems, which can be integrated by a regulatory region of a gene that binds multiple transcription factors or by a transcription factor that is modified by multiple enzymes. Based on a combination of genetic and imaging experiments in the early Drosophila embryo, we describe a signal integration mechanism that cannot be reduced to a single gene regulatory element or a single transcription factor. This mechanism relies on an enzymatic network formed by mitogen-activated protein kinase (MAPK) and its substrates. Specifically, anteriorly localized MAPK substrates, such as Bicoid, antagonize MAPK-dependent downregulation of Capicua, a repressor that is involved in gene regulation along the dorsoventral axis of the embryo. MAPK substrate competition providesĀ a basis for ternary interaction of the anterior, dorsoventral, and terminal patterning systems. A mathematical model of this interaction can explain gene expression patterns with both anteroposterior and dorsoventral polarities
Hepatocelluar nodules in liver cirrhosis: hemodynamic evaluation (angiography-assisted CT) with special reference to multi-step hepatocarcinogenesis
To understand the hemodynamics of hepatocellular carcinoma (HCC) is important for the precise imaging diagnosis and treatment, because there is an intense correlation between their hemodynamics and pathophysiology. Angiogenesis such as sinusoidal capillarization and unpaired arteries shows gradual increase during multi-step hepatocarcinogenesis from high-grade dysplastic nodule to classic hypervascular HCC. In accordance with this angiogenesis, the intranodular portal supply is decreased, whereas the intranodular arterial supply is first decreased during the early stage of hepatocarcinogenesis and then increased in parallel with increasing grade of malignancy of the nodules. On the other hand, the main drainage vessels of hepatocellular nodules change from hepatic veins to hepatic sinusoids and then to portal veins during multi-step hepatocarcinogenesis, mainly due to disappearance of the hepatic veins from the nodules. Therefore, in early HCC, no perinodular corona enhancement is seen on portal to equilibrium phase CT, but it is definite in hypervascular classical HCC. Corona enhancement is thicker in encapsulated HCC and thin in HCC without pseudocapsule. To understand these hemodynamic changes during multi-step hepatocarcinogenesis is important, especially for early diagnosis and treatment of HCCs
Factors associated with in-hospital mortality following intracerebral hemorrhage: a three-year study in Tehran, Iran
BACKGROUND: Primary intracerebral hemorrhage (ICH) is one of the common vascular insults with a relatively high rate of mortality. The aim of the current study was to determine the mortality rate and to evaluate the influence of various factors on the mortality of patients with intracerebral hemorrhage (ICH). Demographic characteristics along with clinical features and neuroimaging information on 122 patients with primary ICH admitted to Sina Hospital between 1999ā2002 were assessed by multivariate analysis. RESULTS: Of 122 patients diagnosed with intracerebral hemorrhage, 70 were men and 52 were women. Sixtynine percent of subjects were between 60 to 80 years of age. A history of hypertension was the primary cause in 67.2% of participants and it was found more frequent compared to other cardiovascular risk factors such as a history of ischemic heart disease (17.2%), diabetes mellitus (18%) and cigarette smoking (13.1%). The overall mortality rate among ICH patients admitted to the hospital was 46.7%. About one third of the deaths occurred within the first two days after brain injury. Factor independently associated with in-hospital mortality were Glasgow Coma Scale (GCS) score (ā¤ 8), diabetes mellitus disease, volume of hematoma and and intraventricular hematoma. CONCLUSION: Higher rate of mortality were observed during the first two weeks of hospitalization following ICH. Neuroimaging features along with GCS score can help the clinicians in developing their prognosis
A gross anatomical study of the styloid process of the temporal bone in Japanese cadavers
Background: The incidence of an elongated styloid process (SP) and average length and diameter of SP have not been reported using Japanese cadavers. Data on the female-to-male ratio of an elongated SP vary. We calculated the average length and diameter of SP in Japanese cadavers and compared SP lengths between sexes.
Materials and methods: Twenty-seven sides (right and left of bodies) in males and 51 sides in females were analyzed. Measurements were obtained from the inferior external acoustic meatus to the distal tip of the SP. SP diameters at the proximal base, midpoint, and distal tip were measured. SP >30 mm was considered elongated. We used Welchās t-test for the statistical analysis. Fisherās exact two-tailed test was also performed to analyze the female-to-male elongation ratio. A p-value <0.05 was considered statistically significant.
Results: SP elongation prevalence was 29.5% in our sample. The average full length was 27.04Ā±7.88 mm overall; the average diameters were 5.41Ā±1.77 mm at the proximal base and 2.21Ā±1.22 mm at the distal tip. The average SP measurement was 26.81Ā±5.92 mm in males and 27.16Ā±8.79 mm in females (p=0.74). The female-to-male ratio of SP elongation was 1:2 (p=0.041). Females had longer full lengths of non-elongated SPs than males (p=0.004). Males had wider diameters at the proximal base of elongated SPs than females (p=0.017).
Conclusions: The average length of SP was 27.04 mm in the Japanese population and about 30% of the Japanese presented SPā„30 mm. Male had significantly higher rate than female among the SPā„30 mm, and female had significantly longer SPs than male among the SP<30 mm. Anatomically, the SP gets narrow as distally goes. Our anatomical findings would be beneficial to creating treatment plans, diagnosis, and surgery
Variations on Fibrinogen-Erythrocyte Interactions during Cell Aging
Erythrocyte hyperaggregation, a cardiovascular risk factor, is considered to be caused by an increase in plasma adhesion proteins, particularly fibrinogen. We have recently reported a specific binding between fibrinogen and an erythrocyte integrin receptor with a Ī²3 or Ī²3-like subunit. In this study we evaluate the influence of erythrocyte aging on the fibrinogen binding. By atomic force microscopy-based force spectroscopy measurements we found that increasing erythrocyte age, there is a decrease of the binding to fibrinogen by decreasing the frequency of its occurrence but not its force. This observation is reinforced by zeta-potential and fluorescence spectroscopy measurements. We conclude that upon erythrocyte aging the number of fibrinogen molecules bound to each cell decreases significantly, due to the progressive impairment of the specific fibrinogen-erythrocyte receptor interaction. Knowing that younger erythrocytes bind more to fibrinogen, we could presume that this population is the main contributor to the cardiovascular diseases associated with increased fibrinogen content in blood, which could disturb the blood flow. Our data also show that the sialic acids exposed on the erythrocyte membrane contribute for the interaction with fibrinogen, possibly by facilitating its binding to the erythrocyte membrane receptor
Association of bone morphogenetic protein-2 gene polymorphisms with susceptibility to ossification of the posterior longitudinal ligament of the spine and its severity in Chinese patients
A caseācontrol study was conducted to examine the association between two single nucleotide polymorphisms (SNPs) in exon 2 of the bone morphogenetic protein-2 gene (BMP-2) and ossification of the posterior longitudinal ligament (OPLL), and to investigate whether SNPs of the Ser37Ala (T/G) and the Ser87Ser (A/G) in the BMP-2 gene are associated with genetic susceptibility to OPLL and its severity in Chinese subjects. The Ser87Ser (A/G) SNP has been implicated in bone mineral density (BMD) and increases the risk of OA in women. The Ser37Ala (T/G) SNP is associated with BMD and the rate of bone loss in osteoporosis and osteoporosis fractures. A total of 57 OPLL patients and 135 non-OPLL controls were studied. Radiographs of the cervical spine were analyzed to determine the presence and the severity of OPLL. The association of two SNPs with the occurrence and the extent of OPLL were statistically evaluated. There was a significant association between the Ser37Ala (T/G) polymorphism and the occurrence of OPLL in the cervical spine. However, no significant association was found between the Ser37Ala (T/G) polymorphism and the more number of ossified cervical vertebrae in OPLL patients. There was a significant association between the Ser87Ser (A/G) polymorphism and the more number of ossified cervical vertebrae in OPLL patients. However, there was no statistical difference between the Ser87Ser (A/G) SNP and the occurrence of OPLL in the cervical spine. In addition, the Ser87Ser (A/G) polymorphism in male patients and in female patients showed no statistical difference between cases and controls. The present results demonstrate that BMP-2 Gene is not only a factor associated with the occurrence of OPLL, but also a factor related to more extensive OPLL. The āGā allele in the Ser37Ala (T/G) polymorphism is associated with the occurrence of OPLL, but not more extensive OPLL in the cervical spine. The āGā allele in the Ser87Ser (A/G) polymorphism promotes the extent of OPLL, whereas the āAā allele in the Ser87Ser (A/G) polymorphism restricts ectopic ossification in the cervical spine at least in Chinese subjects
Effect of manipulation of primary tumour vascularity on metastasis in an adenocarcinoma model
One explanation for the clinical association between tumour vascularity and probability of metastasis is that increased primary tumour vascularity enhances haematogenous dissemination by offering greater opportunity for tumour cell invasion into the circulation (intravasation). We devised an experimental tumour metastasis model that allowed manipulation of primary tumour vascularity with differential exposure of the primary and metastatic tumour site to angiogenic agents. We used this model to assess the effects of local and systemic increases in the level of the angiogenic agent basic fibroblast growth factor on metastasis. BDIX rats with implanted hind limb K12/TR adenocarcinoma tumours received either intratumoural or systemic, basic fibroblast growth factor or saline infusion. Both intratumoural and systemic basic fibroblast growth factor infusion resulted in significant increases in tumour vascularity, blood flow and growth, but not lung metastasis, compared with saline-infused controls. Raised basic fibroblast growth factor levels and increase in primary tumour vascularity did not increase metastasis. The clinical association between tumour vascularity and metastasis is most likely to arise from a metastatic tumour genotype that links increased tumour vascularity with greater metastatic potential
Crosstalk between Spinal Astrocytes and Neurons in Nerve Injury-Induced Neuropathic Pain
Emerging research implicates the participation of spinal dorsal horn (SDH) neurons and astrocytes in nerve injury-induced neuropathic pain. However, the crosstalk between spinal astrocytes and neurons in neuropathic pain is not clear. Using a lumbar 5 (L5) spinal nerve ligation (SNL) pain model, we testified our hypothesis that SDH neurons and astrocytes reciprocally regulate each other to maintain the persistent neuropathic pain states. Glial fibrillary acidic protein (GFAP) was used as the astrocytic specific marker and Fos, protein of the protooncogene c-fos, was used as a marker for activated neurons. SNL induced a significant mechanical allodynia as well as activated SDH neurons indicated by the Fos expression at the early phase and activated astrocytes with the increased expression of GFAP during the late phase of pain, respectively. Intrathecal administration of c-fos antisense oligodeoxynucleotides (ASO) or astroglial toxin L-Ī±-aminoadipate (L-AA) reversed the mechanical allodynia, respectively. Immunofluorescent histochemistry revealed that intrathecal administration of c-fos ASO significantly suppressed activation of not only neurons but also astrocytes induced by SNL. Meanwhile, L-AA shortened the duration of neuronal activation by SNL. Our data offers evidence that neuronal and astrocytic activations are closely related with the maintenance of neuropathic pain through a reciprocal ācrosstalkā. The current study suggests that neuronal and non-neuronal elements should be taken integrally into consideration for nociceptive transmission, and that the intervention of such interaction may offer some novel pain therapeutic strategies
Spatial Distribution of Dominant Arboreal Ants in a Malagasy Coastal Rainforest: Gaps and Presence of an Invasive Species
We conducted a survey along three belt transects located at increasing distances from the coast to determine whether a non-random arboreal ant assemblage, such as an ant mosaic, exists in the rainforest on the Masoala Peninsula, Madagascar. In most tropical rainforests, very populous colonies of territorially dominant arboreal ant species defend absolute territories distributed in a mosaic pattern. Among the 29 ant species recorded, only nine had colonies large enough to be considered potentially territorially dominant; the remaining species had smaller colonies and were considered non-dominant. Nevertheless, the null-model analyses used to examine the spatial structure of their assemblages did not reveal the existence of an ant mosaic. Inland, up to 44% of the trees were devoid of dominant arboreal ants, something not reported in other studies. While two Crematogaster species were not associated with one another, Brachymyrmex cordemoyi was positively associated with Technomyrmex albipes, which is considered an invasive speciesāa non-indigenous species that has an adverse ecological effect on the habitats it invades. The latter two species and Crematogaster ranavalonae were mutually exclusive. On the other hand, all of the trees in the coastal transect and at least 4 km of coast were occupied by T. albipes, and were interconnected by columns of workers. Technomyrmex albipes workers collected from different trees did not attack each other during confrontation tests, indicating that this species has formed a supercolony along the coast. Yet interspecific aggressiveness did occur between T. albipes and Crematogaster ranavalonae, a native species which is likely territorially dominant based on our intraspecific confrontation tests. These results suggest that the Masoala rainforest is threatened by a potential invasion by T. albipes, and that the penetration of this species further inland might be facilitated by the low density of native, territorially dominant arboreal ants normally able to limit its progression
- ā¦