Does increased nuchal translucency indicate a fetal abnormality? A retrospective study to clarify the clinical significance of nuchal translucency in Japan

The results of a chromosomal test by genetic amniocentesis in 58 cases with an increased nuchal translucency (NT; > or =3 mm thickness) revealed 47 cases showing a normal karyotype (81%) and 11 cases (19%) showing an abnormal karyotype. However, the cases of a normal karyotype with increased NT also included those with fetal abnormalities. Among the 49 cases in which NT was observed during the first trimester and then subsequently disappeared, chromosomal abnormalities were observed in five, and fetal abnormalities other than chromosomal abnormalities were observed in two. Meanwhile, all nine cases in which an increased NT remained or in which NT continued to increase in size during the second trimester were diagnosed as having cystic hygroma, and chromosomal abnormalities were found in six cases (67%). It should be noted that the shape of increased NT includes NT with a notch (notched NT) and NT without a notch (smooth NT). Among the 20 cases of notched NT, chromosomal abnormalities were observed in eight (40%), and cystic hygroma was observed in nine (45%). On the other hand, among the 38 cases of smooth NT, chromosomal abnormalities were observed in three (7.9%), but no cystic hygroma was observed. Our results confirm that increased NT does not always indicate a fetal abnormality. Whether NT thickness should be measured as a screening tool for fetal abnormalities remains controversial. However, increased NT may be detected by chance, because a maternal-fetal medical examination using ultrasonography is usually performed in Japan. It is therefore considered to be extremely important to establish a system in which cases are referred to obstetricians who are licensed clinical genetic specialists to obtain appropriate genetic counseling whenever increased NT is clinically observed.     

Can mitochondrial DNA mutations cause sperm dysfunction?

Very low levels of somatic mitochondrial (mt)DNA deletions have been identified in the semen of infertile men. It has been suggested that these mutations cause infertility through an effect on sperm motility, but there has been no direct evidence to show that mutant mtDNA can affect sperm function. We have carried out semen analysis on a male harbouring the A3243G mtDNA mutation and show that high levels of mutant mtDNA strongly correlate with low sperm motility.     

Can phages cause Alzheimer’s disease?

Alzheimer's disease (AD) is a progressive neurodegenerative disorder with progressive dementia. Multiple processes have been implicated in AD, notably including abnormal beta-amyloid production, tau hyperphosphorylation and neurofibrillary tangles (NFTs), synaptic pathology, oxidative stress, inflammation, protein processing or misfolding, calcium dyshomeostasis, aberrant reentry of neurons into the cell cycle, cholesterol synthesis, and effects of hormones or growth factors. The complexity of the disease, which affects numerous molecules, cells, and systems and impedes attempts to determine which alterations are specifically associated with early pathology. Chlamydia pneumoniae is an obligate intracellular bacterium. Infection with this organism has been suggested to be a risk factor for AD. C. pneumoniae has two phages phiCPAR39 and phage related to phiCPG1. HYPOTHESIS: we propose that these two phages by entering into mitochondria of chlamydia's host cell can work as slow viruses and can initiate AD.     

Can oral levofloxacin cause of flexor digitorum profundus rupture?

Fluoroquinolones are broad-spectrum antibacterial agents. Reports of Achilles tendon rupture as a possible side effect of the quinolones have been previously presented but mechanism of the side effect of the medication is still unknown. Tendon rupture in the forearm associated with fluoroquinolone use has not been reported. We present a patient who underwent levofloxacin treatment for skin infections and subsequently developed left small finger flexor digitorum profundus rupture. We propose that this rupture may be related to the side effect of the medication. If it is, clinicians have to be aware of possible tendon ruptures in the upper extremity due to side effects of quinolones and patients have to be informed about it.     

Can traditional “cupping” treatment cause a stroke?

The case study of a patient who developed haemorrhagic stroke after ‘cupping’ to the cervical area is presented. We consider the various manners in which cupping might induce haemorrhagic or ischemic stroke with particular reference to the relevant pathologies of the major cervical arteries. The other possible causes due to the induced cupping stresses are also examined using a computer based simulation study. Cupping of the cervical area may cause a haemorrhagic stroke by an acute rise in blood pressure. The tensile radial stresses generated by cupping may potentially facilitate the development of a dissection in the presence of an intimal tear. Moreover, the possible presence of micro-inclusions can intensify the local stress concentration for a thin cap.     

Why cord blood?

Cord blood, donated by mothers after the birth of their children, has become an accepted source of related and unrelated hematopoietic stem cells for marrow reconstitution. We estimate that some 7-8000 unrelated-donor cord blood transplants have been performed worldwide since 1993. The development of cord blood as a source of hematopoietic stem cells for transplantation started with the early recognition of the presence in cord blood of colony-forming cells by Knudtzon in 1974. The first cord blood transplant from a human leukocyte antigen (HLA)-identical sib to a young patient with Fanconi anemia was performed by Gluckman in 1988 and opened the way for the subsequent development of a bank for donations for unrelated patients by our group at the New York Blood Center. It is now widely recognized that two transplant-dependent variables exert strong influence on the chance for long-term recipient survival: the hematopoietic stem and progenitor cell dose and the HLA match grade. Hence, despite the generally milder graft-vs-host disease after mismatched cord blood transplantation, large and ethnically diverse inventories of cord blood are needed to permit better HLA matches and long-term survivals. In this review, a number of issues that are relevant to the history and development of an effective system for cord blood banking are discussed.     

Can increased spatial resolution solve the crossing fiber problem for diffusion MRI?

It is now widely recognized that voxels with crossing fibers or complex geometrical configurations present a challenge for diffusion MRI (dMRI) reconstruction and fiber tracking, as well as microstructural modeling of brain tissues. This “crossing fiber” problem has been estimated to affect anywhere from 30% to as many as 90% of white matter voxels, and it is often assumed that increasing spatial resolution will decrease the prevalence of voxels containing multiple fiber populations. The aim of this study is to estimate the extent of the crossing fiber problem as we progressively increase the spatial resolution, with the goal of determining whether it is possible to mitigate this problem with higher resolution spatial sampling. This is accomplished using ex vivo MRI data of the macaque brain, followed by histological analysis of the same specimen to validate these measurements, as well as to extend this analysis to resolutions not yet achievable in practice with MRI. In both dMRI and histology, we find unexpected results: the prevalence of crossing fibers increases as we increase spatial resolution. The problem of crossing fibers appears to be a fundamental limitation of dMRI associated with the complexity of brain tissue, rather than a technical problem that can be overcome with advances such as higher fields and stronger gradients.     

Is increased colon subepithelial collagen layer thickness in diabetic patients related to collagenous colitis? An immunohistochemical study

In this study, we evaluated immunohistochemically whether increased thickness of the colon subepithelial collagen layer in diabetic patients relates to collagenous colitis. A total of 100 patients (25 in each group) were included in this study. There were diabetic patients with chronic diarrhea in the first group, diabetic patients without chronic diarrhea in the second group, non-diabetic patients with chronic diarrhea in the third group, and control patients in the fourth group. The endoscopic biopsy specimens were obtained from the rectum, sigmoid colon, and descending colon. The thickness of the subepithelial collagen layer was measured using the ocular micrometer method. The immunohistochemical staining was performed with type 1 collagen and fibronectin antibody. The thickness of the colon subepithelial collagen layer in diabetic patients with or without diarrhea was significantly greater than that in control patients. This thickened subepithelial collagen layer in diabetic patients was stained with fibronectin antibody, but not with type 1 collagen antibody in the immunohistochemical study. These immunohistochemical staining characteristics were not similar to those in collagenous colitis, but were similar to those in normal subjects. Increased colon subepithelial collagen layer thickness in diabetic patients does not relate to collagenous colitis.     

Can eccentric arterial plaques alone cause flow stagnation points and favour thrombus incorporation?

We have used an experimental model of aorta stenosis, with a Plexiglas plug, simulating a stable atheromatous plaque that promotes local turbulence and thrombosis. With animal survival of more than 24 h, we followed the partial fibrinolysis of the thrombus as well as its posterior organization and incorporation to the arterial wall as a neointima for up to 30 days. The mushroom plug form permitted the development of recirculation and stasis areas around it, favouring this evolution. Despite noted limitations, this study demonstrates that thrombus incorporation can contribute to plaque extension, as it can promote recirculation and stasis areas.