Chromosome marker evidence for the bipotentiality of BFU-E

When mouse bone marrow cells are seeded in agar cultures containing erythropoietin or pokeweed mitogen stimulated spleen cell conditioned medium plus erythropoietin, megakaryocytes are found mixed with erythroid cells in approximately 40% of the erythropoietic bursts that develop in the cultures. Chromosome spreads of C-metaphases in such "megaerythro bursts" were prepared and stained in situ with a modification of the C-banding technique. In cultures seeded with mixtures of male and female cells, metaphases from individual megaerythro bursts were shown to be either all male of all female but not both. Moreover, tetraploid C-metaphases of megakaryocytes were found to be of the same sex as diploid C-metaphases of erythroid cells in the same megaerythro burst. These results provide evidence that in the mouse, a bipotential progenitor cell exists that has the capacity to give rise to cells of both the megakaryocytic and the erythrocytic lines of differentiation.     

Spontaneous rupture of renal pelvis

A seventy-seven-year-old female with progressive abdominal signs for twenty-four hours was found to have had a spontaneous rupture of the renal pelvis with massive urinary extravasation.     

Polymorphism of Bordetella pertussis isolates circulating for the last 10 years in France, where a single effective whole-cell vaccine has been used for more than 30 years.

We compared Bordetella pertussis isolates collected in France over the last 10 years, the vaccine strains used for more than 30 years, and isolates collected before the introduction of generalized vaccination. The analysis included serotyping, pulsed-field gel electrophoresis of chromosomal DNA after digestion with XbaI and SpeI, and sequencing of the pt S1 gene, encoding the S1 subunit of pertussis toxin, and the prn gene, encoding the adhesin pertactin. We found that the incidence of infection increases every 3 years. Ninety-five per cent of the isolates analyzed express type 3 fimbriae. Most of the isolates circulating since 1991, unlike the vaccinal strains, express a type A pertussis toxin and a type 2 pertactin. The isolates could be classified into five major groups by pulsed-field gel electrophoresis. Most of these groups correlated with the pertactin type expressed by the isolates. Pulsed-field gel electrophoresis is more discriminative than sequencing particular genes since it could differentiate isolates expressing type 2 pertactin into two subgroups: those circulating in 1993 to 1997 and those circulating in 1997 to 2001. This observation suggests that there has been continuous evolution of the B. pertussis population.     

The characteristics of the lobular arrangement indicate the dynamic role played by the infrapatellar fat pad in knee kinematics

The infrapatellar fat pad (IFP) is an intracapsular but extrasynovial structure, located between the patellar tendon, the femoral condyles and the tibial plateau. It consists of white adipose tissue, organised in lobules defined by thin connective septa. The aim of this study is the morphometric and ultrasonographic analysis of IFP in subjects without knee pathology during flexion‐extension movements. The morphometric study was conducted on 20 cadavers (15M, 5F, mean age 80.2 years). Ultrasound was performed on 24 volunteers with no history of knee diseases (5M, 19F, mean age: 45 years). The characteristics of the adipose lobules near the patellar tendon and in the deep portion of the IFP were evaluated. Numerical models were provided, according to the size of the lobules. At histological examination, the adipose lobules located near the patellar tendon were larger (mean area 12.2 mm² ± 5.3) than those at a deeper level (mean area 1.34 mm² ± 0.7, P < 0.001) and the thickness of the septa of the deepest adipose lobules (mean value 0.35 mm ± 0.32) was greater than that of the superficial one (mean value 0.29 mm ± 0.25, P < 0.001). At ultrasound, the IFP was seen to be composed of very large lobules in the superficial part (mean area 0.29 cm² ± 0.17 in extension), with a significant reduction in flexion (mean area 0.12 cm² ± 0.07, P < 0.01). The deep lobules were smaller (mean area 0.11 cm² ± 0.08 in extension) and did not change their values (mean area 0.19 cm² ± 0.52 in flexion, P > 0.05). In the sagittal plane, the reduction of thickness of the superficial layer (with large adipose lobules) during flexion was 20.6%, whereas that of the deep layer (with small adipose lobules) was 1.3%. Numerical simulation of vertical loads, corresponding to flexion of the knee, showed that stress mainly developed within the interlobular septa and opposed bulging of the lobules. The characteristics of the lobular arrangement of the IFP (large lobules with superficial septa in the superficial part and small lobules with thick septa in the deep one), significant changes in the areas and perimeters of the superficial lobules, and the reduced thickness of the superficial layer during flexion all indicate the dynamic role played by the IFP in knee kinematics.     

Sulci of the liver found after death: Their nature and potential teaching value

Accessory sulci of the liver are more commonly found after death than in life, raising questions as to their causation and possible classification. We have analyzed a group of 180 livers sampled from un‐embalmed (96) and embalmed cadavers (84). In un‐embalmed cadavers, no accessory sulci were found on the diaphragmatic surface in 58 cases. Diaphragmatic sulci were found in the right lobe of 38 livers. When removed from the abdominal cavity and placed flat on the examination table (the “bench position”) all 58 livers without sulci appreciable in the abdominal cavity showed the appearance of two sulci. The first ran from the right side of the inferior vena cava (IVC), curving anteriorly to the inferior border of the liver, at a point midway between the right extremity of the inferior border and the gallbladder fossa, concave towards the left. The second sulcus ran from the left side of the IVC, curving anteriorly to reach the inferior border of the liver at the level of the gallbladder fossa, concave towards the right. With progressive side‐to‐side manual compression, the sulci on the diaphragmatic surface become more evident. Division of the hepatic parenchyma along the two sulci exposed the right and middle hepatic veins respectively in more than 90% of cases. In embalmed cadavers, 24 livers showed antero‐posterior sulci in the superior surface, visible and palpable on the liver examined in situ. When the livers with sulci had been removed from the abdomen for further examination, the appearance of the superior surface did not change. In a removed liver, accessory sulci can be divided into true, “diaphragmatic,” sulci and “false” sulci due to the position of the free liver on the examination table. The “false” sulci may be considered as further morphological evidence of the functional anatomical division of the liver. Their demonstration may also be useful in teaching its topographical and surgical anatomy. Clin. Anat. 26:592–597, 2013. © 2012 Wiley Periodicals, Inc.     

Human embryonic stem cells: Distinct molecular personalities and applications in regenerative medicine

The field of stem cell biology is exciting because it provides researchers and clinicians with seemingly unlimited applications for treating many human diseases. Stem cells are a renewable source of pluripotent cells that can differentiate into nearly all human cell types. In this article we focus particularly on human embryonic stem (hES) cells, derived from the inner cell mass of the blastocyst and cultured for expansion while remaining undifferentiated, to explore their unique molecular personalities and clinical applications. The aim of this literature review is to reflect the interest in hES cells and to provide a resource for researchers and clinicians interested in the molecular characteristics of such cells. Clin. Anat. 32:354–360, 2019. © 2018 The Authors. Clinical Anatomy published by Wiley Periodicals, Inc. on behalf of American Association of Clinical Anatomists.