The choroidal artery to the fourth ventricle and its radiological significance

The choroidal artery to the fourth ventricle has been studied in 25 brain specimens and 100 normal posterior fossa angiograms, including 25 angiotomograms. Its variable origin, course and radiological significance have been stressed.     

Enhanced expression of transforming growth factor beta during megakaryoblastic differentiation of K562 leukemia cells

Platelet alpha granules contain several growth factors such as the transforming growth factor beta (TGF-beta) that are released during blood clotting and are thought to participate in the repair of tissue injury; however, the site of synthesis of platelet TGF-beta has not been demonstrated. We studied TGF-beta expression during megakaryoblastic differentiation of the chronic myeloid leukemia cell line K562 in vitro. These cells have mainly erythroid characteristics but acquire several megakaryoblastic properties when treated with the phorbol diester 12-0-tetradecanoyl-13-phorbolacetate (TPA). During four subsequent days of megakaryoblastic differentiation the amount of the 2.5-kilobase (kb) TGF-beta mRNA increased about eightfold, and a novel 2.3-kb mRNA species was induced in the K562 cells. This occurred concomitantly with distinct induction patterns of platelet-derived growth factor A (PDGF-A) and c-sis (PDGF-B chain) RNAs and several platelet antigens. The expression of erythroid markers such as glycophorin A decreased. Culture media of TPA-differentiated K562 cells also contained TGF-beta polypeptides as shown by a sensitive radioreceptor assay and by immunoprecipitation after metabolic labeling of the cells. These polypeptides were not seen in culture media from dimethyl sulfoxide- or sodium butyrate-treated cells. Unlike in several other cells, exogenously added TGF-beta 1 or 2 affected neither TGF- beta nor PDGF RNA expression in K562 cells.     

Absence of hematopoietic tissue factor pathway inhibitor mitigates bleeding in mice with hemophilia

Tissue factor pathway inhibitor (TFPI) blocks thrombin generation via the extrinsic blood coagulation pathway. Because the severe bleeding in patients with hemophilia occurs from deficiency of intrinsic blood coagulation pathway factor VIII or IX, pharmacological agents that inactivate TFPI and, therefore, restore thrombin generation via the extrinsic pathway, are being developed for treatment of hemophilia. Murine models of combined TFPI and factor VIII deficiency were used to examine the impact of TFPI deficiency on bleeding and clotting in hemophilia. In breeding studies, Factor VIII null (F8(-/-)) did not rescue the embryonic death of TFPI null (Tfpi(-/-)) mice. Tfpi(+/-) did not alter the bleeding phenotype of F8(-/-) mice. However, total inhibition of intravascular TFPI through injection of anti-TFPI antibody mitigated tail vein bleeding. Interestingly, tail blood loss progressively decreased at doses greater than needed to totally inhibit plasma TFPI, suggesting that inhibition of a sequestered pool of TFPI released at the injury site mitigates bleeding. Because TFPI is sequestered within platelets and released following their activation, the function of platelet TFPI was examined in F8(-/-) mice lacking hematopoietic cell TFPI that was generated by fetal liver transplantation. Blood loss after tail transection significantly decreased in Tfpi(+/-);F8(-/-) mice with hematopoietic Tfpi(-/-) cells compared with Tfpi(+/-);F8(-/-) mice with Tfpi(+/+) hematopoietic cells. Additionally, following femoral vein injury, Tfpi(+/-);F8(-/-) mice with Tfpi(-/-) hematopoietic cells had increased fibrin deposition compared with identical-genotype mice with Tfpi(+/+) hematopoietic cells. These findings implicate platelet TFPI as a primary physiological regulator of bleeding in hemophilia.     

Nutrient Content and Compliance with Sodium Standards in Elementary School Meals in the United States Pre- and Post-COVID-19

Various federal policies have weakened school meal nutrition standards in the United States since the passage of the Healthy, Hunger-Free Kids Act in 2010, including temporary school meal nutrition waivers to promote post-COVID-19 pandemic recovery. This study used school menu and nutrient data from a nationally representative sample of 128 elementary school districts to examine differences in nutrients (average calories, total fat, saturated fat, sodium, total sugar, and fiber) and alignment with United States Department of Agriculture (USDA) sodium targets in 2019 (pre-pandemic) and in 2022 (post-pandemic). Data were analyzed using analysis of variance accounting for repeated measures within school districts, adjusting for geographic region and urbanicity. Small differences in the nutrient content for both breakfast and lunch were observed between 2019 and 2022. Most weeks met USDA sodium Target 1 for breakfast (≥95% of weeks) and Target 1 (≥96% of weeks) and Target 1A for lunch (≥92% of weeks) in both 2019 and 2022, although compliance decreased slightly when condiments were included. Additionally, meals provided on average 57 g of total sugar. Overall, many meals are already in alignment with lower sodium targets. Simple strategies, such as offering lower sodium condiments, can further reduce sodium in school meals. The total sugar levels observed highlight that the USDA should consider limits on added sugars in school meals.     

Increased height in diabetes mellitus corresponds to the predicted and the adult height

This study was conducted to analyse the effect of childhood-onset diabetes mellitus on adult height. The height at time of diagnosis of 35 children with insulin-dependent diabetes mellitus (IDDM) was compared with growth reference data. Predictions of the adult height were made at the time of diagnosis using the target height and the Tanner-Whitehouse II method. The adult height was compared with both the predicted values and the height of healthy adults. The height at time of diagnosis of the prepubertal children was increased compared with growth reference data, in contrast to pubertal children who had normal heights. Only the prepubertal boys were taller at time of diagnosis. The adult height of the prepubertal patients was taller than growth reference data. The mean adult height in all patients did not differ significantly from the predicted heights. In conclusion, the increased height at the start of IDDM in prepubertal children persists until adulthood.     

Physics of ultrasound

Ultrasound is a form of non-ionizing radiation that uses high-frequency sound waves to image the body. It is a real-time investigation which allows assessment of moving structures and also facilitates measurement of velocity and directionality of blood flow within a vessel. It can be used for a variety of purposes in the intensive care setting, for example to aid central venous catheter and pleural drain insertion. When using this imaging modality it is vital to understand the relevant physical principles and how the images are created. This article will explain these principles, including the use of Doppler ultrasound and the interpretation of common artefacts.     

Anterior commissure: anatomic-MR correlation and use as a landmark in three orthogonal planes

Correlation of cryomicrotomic and myelin-stained sections of human cadaver heads with spin-echo magnetic resonance (MR) images documents that MR imaging routinely displays the anterior commissure in three orthogonal planes as a distinct white-matter tract that resembles bicycle handlebars. The anterior commissure crosses the midline at the upper end of the lamina terminalis, just anterior to the anterior columns of the fornices. To each side of midline, it curves antero-inferolaterally and then postero-inferolaterally through the lateral nucleus of the globus pallidus to course with the white matter of the external and extreme capsules toward the middle and inferior temporal gyri. Because the anterior commissure is easily recognizable in all three planes at differing pulse sequences, the commissure has proved to be a major landmark for identification of the complex anatomy of this region, especially in sagittal sections.     

Spermatic vein embolization with hot contrast material: fertility results

Spermatic venography with hot contrast material embolization was undertaken in 81 patients with varicoceles and infertility. Long-term follow-up information was available in 91% of the patients, and there was an overall conception rate of 40.5%. Embolization with hot contrast material was easily performed without special embolization devices and proved to be a safe and effective technique.