Beware of ‘the vein that easily bleeds’: Accessory right colic vein

In this short article, we highlight the venous drainage of the right colon with special emphasis on the accessory right colic vein. This vein is easily torn during mobilization of the right colon. It is, however, seldom mentioned in the Western anatomy or surgical textbooks.      

Association of normal weather periods and El Niño events with hospitalization for viral pneumonia in females: California, 1983-1998

OBJECTIVES: This study examined associations between weather and hospitalizations of females for viral pneumonia during normal weather periods and El Ni?o events in the California counties of Sacramento and Yolo, San Francisco and San Mateo, and Los Angeles and Orange. METHODS: Associations between weather and hospitalizations (lagged 7 days) for January 1983 through June 1998 were evaluated with Poisson regression models. Generalized estimating equations were used to adjust for autocorrelation and overdispersion. Data were summed over 4 days. RESULTS: Associations varied by region. Hospitalizations in San Francisco and Los Angeles increased significantly (30%-50%) with a 5 degrees F decrease in minimum temperature. Hospitalizations in Sacramento increased significantly (25%-40%) with a 5 degrees F decrease in maximum temperature difference. The associations were independent of season. El Ni?o events were associated with hospitalizations only in Sacramento, with significant decreases for girls and increases for women. CONCLUSIONS: The results suggest that viral pneumonia could continue to be a major public health issue, with a significant association between weather and hospitalizations, even as the global mean temperature continues to rise. An understanding of population sensitivity under different weather conditions could lead to an improved understanding of virus transmission.     

Axonal sprouting following lesions of the rat substantia nigra

Parkinson's disease is characterized by the progressive loss of dopaminergic neurons in the substantia nigra pars compacta. Symptoms do not appear until most nigral neurons are lost, implying that compensatory mechanisms are present. Sprouting has been proposed as one of these mechanisms. This study quantified the extent of compensatory axonal sprouting following injury of dopaminergic neurons within the substantia nigra pars compacta. Specifically, the extent of the axonal arbour and axonal varicosity morphology was measured after partial destruction (with 6-hydroxydopamine) of the substantia nigra of the adult male rat. Four months later, the substantia nigra was injected with the anterograde neuronal tracer dextran-biotin to trace the full extent of individual axons. An unbiased estimate of neuron number was performed in each animal. This demonstrated nigral neuronal loss ranging from 10 to 90% on the side that received the injection whilst a 7% reduction was observed in the side contralateral to the lesion. Coincident with this loss, some nigral neurons lose tyrosine hydroxylase expression. Vigorous axonal sprouting was observed in the terminal arbours of lesioned animals and was associated with an increased axonal varicosity size. Axonal varicosities and branching points were primarily confined to the dorsal 1.5mm of the caudate-putamen, an area predominantly innervated by nigral neurons. It appears that dopaminergic neurons were responsible for this sprouting because the density of dopamine transporter immunoreactive varicosities in the caudate-putamen was maintained until about a 70% loss of neurons. It was concluded that substantial compensation in the form of sprouting and new dopaminergic synapse formation occurs following lesions of the substantia nigra pars compacta.     

Cell-free fetal deoxyribonucleic acid in maternal circulation as a marker of fetal-maternal hemorrhage in patients undergoing external cephalic version near term

OBJECTIVE: Our aim was to investigate whether external cephalic version performed near term increases the concentration of cell-free fetal deoxyribonucleic acid in maternal plasma. STUDY DESIGN: Forty-five patients who had singleton male fetuses and were undergoing external cephalic version at or beyond 36 weeks of gestation were recruited during a 20-month period. Maternal venous blood samples were taken before and within 10 minutes after external cephalic version. Deoxyribonucleic acid was extracted from the plasma samples. The amount of fetal deoxyribonucleic acid was quantified by means of the SRY gene on the Y chromosome as a fetal marker. The change in SRY gene concentration before and after external cephalic version was compared by paired sample t test. RESULTS: There was a significant increase in the concentration of fetal deoxyribonucleic acid in maternal serum after external cephalic version (before, 296 +/- 209 copies per milliliter; after, 369 +/- 228 copies per milliliter; P =.014). This increase in the concentration of deoxyribonucleic acid was most profound among the nulliparous patients after a successful version and in the presence of a posterior placenta. The location of the placenta was found to be the most significant factor accounting for the change in the deoxyribonucleic acid concentration. CONCLUSIONS: External cephalic version near term imposed a significant disturbance to the maternalplacental interface. Fetal deoxyribonucleic acid is a sensitive marker that is useful in the assessment of subclinical fetal-maternal hemorrhage.     

Neural cell adhesion molecule is endocytosed via a clathrin-dependent pathway

Neural cell adhesion molecule (NCAM) constitutes a group of cell surface glycoproteins that regulate cell-cell interactions in the developing and adult brain. Endocytosis is a mechanism which dynamically controls the amount of cell surface NCAM expression and may involve the rapid changes occurring in NCAM expression under certain physiological or pathological conditions. However, the endocytic pathway of NCAM is presently unknown. Using astrocytes in culture and immunofluorescence we show that NCAM is internalized and that the immunolabelling presents a high degree of colocalization with clathrin, alpha-adaptin and transferrin, suggesting that NCAM is endocytosed by a clathrin-dependent pathway. Potassium depletion which disrupts clathrin-mediated endocytosis, inhibited internalization of NCAM. Electron microscopy and immunogold studies also demonstrate that the surface of clathrin-coated vesicles are also immunolabelled for both alpha-adaptin and PSA-NCAM, the highly sialylated isoform of NCAM. Furthermore, immunoprecipation studies demonstrate that NCAM is associated with both clathrin and alpha-adaptin, a component of adaptor complex AP-2, in brain, neurons and astrocytes. These findings indicate that NCAM is mainly endocytosed via clathrin-coated vesicles, suggesting a possible mechanism that may contribute to the rapid changes in NCAM expression at the cell surface.     

Transformation of kidney epithelial cells by a quinol thioether via inactivation of the tuberous sclerosis-2 tumor suppressor gene

Although hydroquinone (HQ) is a rodent carcinogen, because of its lack of mutagenicity in standard bacterial mutagenicity assays it is generally considered a nongenotoxic carcinogen. 2,3,5-Tris-(glutathion-S-yl)HQ (TGHQ) is a potent nephrotoxic metabolite of HQ that may play an important role in HQ-mediated nephrocarcinogenicity. TGHQ mediates cell injury by generating reactive oxygen species and covalently binding to tissue macromolecules. We determined the ability of HQ and TGHQ to induce cell transformation in primary renal epithelial cells derived from the Eker rat. Eker rats possess a germline inactivation of one allele of the tuberous sclerosis-2 (Tsc-2) tumor suppressor gene that predisposes the animals to renal cell carcinoma. Treatment of primary Eker rat renal epithelial cells with HQ (25 and 50 microM) or TGHQ (100 and 300 microM) induced 2- to 4-fold and 6- to 20-fold increases in cell transformation, respectively. Subsequently, three cell lines (The QT-RRE 1, 2, and 3) were established from TGHQ-induced transformed colonies. The QT-RRE cell lines exhibited a broad range of numerical cytogenetic alterations, loss of heterozygosity at the Tsc-2 gene locus, and loss of expression of tuberin, the protein encoded by the Tsc-2 gene. Only heterozygous (Tsc-2(EK/+)) kidney epithelial cells were susceptible to transformation by HQ and TGHQ, as wild-type cells (Tsc-2(+/+)) showed no increase in transformation frequency over background levels following chemical exposure. These data indicate that TGHQ and HQ are capable of directly transforming rat renal epithelial cells and that the Tsc-2 tumor suppressor gene is an important target of TGHQ-mediated renal epithelial cell transformation.     

Progressive deterioration of soft neurological signs in chronic schizophrenic patients

OBJECTIVE: Neurological signs are found to be increased in schizophrenia in cross-sectional studies. Whether they progress with time is an important issue in addressing the course of the illness. METHOD: The current study investigated different groups of neurological signs in 43 stable chronic schizophrenic patients over a 3-year period using an operationalized instrument. RESULTS: While symptoms and medication have remained largely unchanged in the 3-year period, significant increase in soft neurological signs (SNS) ('motor coordination', 'sensory integration' and 'disinhibition') has been observed. This contrasted with the stability of 'pyramidal', 'extrapyramidal', 'dyskinesia' and 'catatonia' signs. The increase in SNS appears not to be related to age, illness duration, symptoms or medication. CONCLUSION: This finding suggests that SNS represent a marker sensitive to a possible late deterioration process in the course of a schizophrenic illness.     

Safety and efficacy of internal cardioversion of atrial fibrillation in patients with impaired left ventricular systolic function

In patients with structural heart disease and left ventricular ejection fraction <40%, internal cardioversion is a safe and effective method for converting persistent atrial fibrillation. The acute success rate and atrial defibrillation requirement for cardioversion in these patients is comparable to patients with lone atrial fibrillation and structurally normal hearts.