Appetite and tuberculosis: Is the lack of appetite an unidentified risk factor for tuberculosis?

Different risk factors have been identified as associated with tuberculosis (TB), an important and common one is malnutrition, however, the causes of malnutrition have not been studied in detail, the lack of food and poverty are among the most frequent in developing countries but others are yet to be identified. We hypothesized that chronic lack of appetite can be one of the causes of malnutrition associated to TB and therefore be a potential independent risk factor for latent tuberculosis infection (LTBI) or TB disease. If this is true, contact subjects with LTBI who have poor appetite will be at higher risk for getting the disease and people with the disease will be at risk for poor treatment outcomes.     

Microsurgical anatomy of the Adamkiewicz artery–anterior spinal artery junction

Purpose

The aim of this study is to describe the anterior spinal artery–Adamkiewicz artery (ASA–AKA) junction and establish a classification allowing defining the neurological risk in either thoracoabdominal aorta aneurysm treatment and in anterior or transforaminal thoracolumbar spine surgery.

Methods

Fifteen spinal cords of fresh cadavers were dissected. Both lumbar arteries and ASA were injected with strongly diluted red-colored silicon.

Results

The dural crossing of AKA was located on the left side in 86 % of cases, between T8 and T10 in 73.33 % of cases and L1–L2 in 26.67 % of cases. The average diameter of the ascending branch of AKA was 1.10 mm (range 0.8–1.9 mm), and its average length was 30.27 mm (range 12.3–60 mm). The AKA’s arch average diameter was 11.3 mm (range 9–20 mm) with an open downward angle average of 20.1° (range 11°–30°). The descending branch of AKA which was a continuation of ASA had an average diameter of 1.33 mm (range 0.8–1.86 mm). The ASA at the top of the arch had an average diameter of 0.74 mm (range 0.2–1.77 mm). According to these findings, we have proposed a new classification with two types of junctions. The type I and its variant correlated to high neurological risk were present in 93.33 % of cases. The type II, correlated to medium or low neurological risk, was present in 6.67 % of cases.

Conclusion

These anatomical findings allow a planning of the neurological risk before thoracoabdominal aorta aneurysm or thoracolumbar anterior or transforaminal spine surgery.

     

Aging of the immune system: a risk factor for autoimmunity?

Aging of the immune system, or immunosenescence, is characterized by changes in T cell subsets, cellular and molecular level alterations and thymic atrophy, resulting in a decline of T and B cell function. These alterations have been shown to be accompanied by a loss of ability to recognize "self" and "foreign" antigens. Therefore the development of autoimmune responses like production of autoantibodies has been hypothesized to be secondary to thymus involution with a decline of na?ve T cells and accumulation of clonal T cells with activation due to "neoantigens" during the aging process. Altered apoptosis and altered T cell homeostasis have been emphasized to promote a chronic inflammatory state and lead to the concept of a immune-risk phenotype. However, it has to be proven which kinds of mechanisms turn the immune system to manifest autoimmune disease and how speculated defects in T cell differentiation and interaction leading to premature aging of the immune system may contribute to the development of autoimmune diseases.     

The human choriocapillaris: evidence for an intrinsic regulation of the endothelium?

The aim of the present study was to describe the ultrastructure of particular cells observed in the microvascular bed of the healthy human choroid, in close relation to the wall of the microvessels and resembling the periadventitial cells of other vascular areas of the human body. Serial sections of 12 fresh human eyes were studied by transmission electron microscopy. In all the eyes, the sections were obtained by cutting from the same zones (inner and outer choroid at the posterior pole of the eye). Standard techniques were used for transmission electron microscopy. Round cell bodies were found in the inner choroid at the posterior pole of the eye, mainly located in the intercapillary connective tissue. The cells were composed of an electron-transparent cytoplasm containing a few small mitochondria, and a dilated smooth surface of endoplasmic reticulum, at some points continuous with the nuclear membrane. These cells showed processes forming contact with the capillary wall. Some of these processes extended to the elastic layer of Bruch's membrane, but none had contact with the retinal pigment epithelium. A thin basement membrane surrounded both the cell bodies and processes. We believe that these cells are special cells resembling some type of periendothelial cells also localized in other microvascular districts of the human body. The close topographic correlation with the endothelial cells seems to indicate that these special cells play a role in the intrinsic control of proper endothelial functions.     

Does the use of antibiotics in early childhood increase the risk of asthma and allergic disease?

BACKGROUND: One of the mechanisms evoked to explain the increasing prevalences of asthma and allergy, in particular among children, is the 'Western lifestyle' or 'hygiene' hypothesis. As early childhood infections are assumed to hold a protective effect on the development of asthma and allergies, the use of antibiotics at that sensitive age may lead to an increased risk of asthma and allergy. OBJECTIVE: The aim of this study is to investigate the association between the use of antibiotics in the first year of life and the subsequent development of asthma and allergic disorders. METHODS: In a population-based sample of 7-and-8-year-old children questionnaire and skin prick test data were collected from 1206 and 675 subjects, respectively. Prevalence rates of asthma, allergic disorders and skin test positivity were compared between children with and without early life use of antibiotics, taking into account other possible risk factors including early respiratory infections. The effect of genetic predisposition was investigated by stratified analyses of children with and without parental hay fever. RESULTS: The use of antibiotics during the first year of life was significantly associated with asthma (OR = 1.7, 95% CI 1.0-3.1), hay fever (OR = 2.3, 95% CI 1.3-3.8) and eczema (OR = 1.3, 95% CI 1.0-1.8). No significant relationship was found with skin test positivity (OR = 1.1, 95% CI 0.7-1.7). After stratification for the presence of parental hay fever, children without parental hay fever did not show any significant associations between antibiotics use and asthma or allergy, whereas in children with parental hay fever the use of antibiotics was significantly related with asthma (OR = 2.3, 95% CI 1.1-5.1), hay fever (OR = 2.8, 95% CI 1.5-5.1) and eczema (OR = 1.6, 95% CI 1.0-2.6), and of borderline statistical significance with skin test positivity (OR = 1.6, 95% CI 0.9-3.0). CONCLUSION: Early childhood use of antibiotics is associated with an increased risk of developing asthma and allergic disorders in children who are predisposed to atopic immune responses. These findings support recent immunological understanding of the maturation of the immune system.     

Duplication of the left vertebral artery in a patient with dissection of the right internal carotid artery and Ehlers–Danlos syndrome: case report and review of the literature

Duplication of the left vertebral artery was observed in a 43-year-old Caucasian male with dissection of the right internal carotid artery during multidetector 64-row computer tomography and Doppler ultrasonography B-flow mode. Both duplicated segments arose from the left subclavian artery and united at levels C5–C6 to form a single vessel. The presented case describes precisely the origin and diameter of both vertebral arteries. Additionally, after all procedures associated with diagnosis and treatment of the patient, Ehlers–Danlos syndrome type IV was diagnosed. The lumen of the duplicated vertebral artery was smaller than normal; it can be concluded that this variant has clinical implications and should be taken into consideration when vertebral arteries need catheterization.     

What does the geometry of an arc reveal about methods of assessing spinal radiographs in scoliosis?

BACKGROUND: The shapes of an arc and scoliosis are the same. Therefore, the geometry of an arc can reveal the relationship between the angles within and around a scoliotic spine. OBJECTIVE: To look for angles which are functions of the geometry of an arc and can also be used for assessment of curve progression in scoliosis. DESIGN: Review of the geometry of an arc and that of scoliosis. METHOD: English literature on scoliosis (from 1930 to date), searched manually, via Internet and from colleagues, was reviewed. RESULTS: Methods of curve measurement in use presently are functions of the geometry of scoliosis. Three additional methods are proposed for assessment of curve progression in scoliosis. These methods are geometrically related with the previously known ones. CONCLUSION: All methods of assessment of curve progression in scoliosis are fundamentally the same and interchangeable. There is no reason for preference of one method over another method of curve measurement.     

Parasite-altered host behavior in the face of a predator: manipulation or not?

Parasitologists have generally accepted the idea that parasite-induced alterations in host behavior increase the chance for parasite survival and transmission or ensure the completion of its life cycle. The aim of the present study was to investigate modifications in the behavior of Taenia crassiceps-infected BALB/c mice in the face of a predator. The experiments showed modifications in the response of infected mice in comparison with uninfected controls on exposure to a predator final host. However, different studies lead us to suggest that the observed modifications are likely to be a secondary effect of the impact of the parasite on host physiology and immunity that favors its development and proliferation. Received: 9 June 2000 / Accepted: 28 August 2000     

Short telomeres in patients with vascular dementia: an indicator of low antioxidative capacity and a possible risk factor?

Progressive cerebrovascular atherosclerosis and consecutive stroke are among the most common causes of dementia. However, specific risk factors for vascular dementia are still not known. Human telomeres shorten with each cell division in vitro and with donor age in vivo. In human fibroblasts in vitro, the telomere shortening rate decreased with increasing antioxidative capacity. There was a good intra-individual correlation between the age-corrected telomere lengths in fibroblasts and peripheral blood mononuclear cells. In 186 individuals including 149 geriatric patients (age range, 55-98 yr), leukocyte telomeres in patients with probable or possible vascular dementia were significantly shorter than in three age-matched control groups, namely in cognitively competent patients suffering from cerebrovascular or cardiovascular disease alone, in patients with probable Alzheimer's dementia, and in apparently healthy control subjects. No correlation was found to polymorphisms in the apolipoprotein E and glutathione-S-transferase genes. Telomere length may be an independent predictor for the risk of vascular dementia.     

Can the transverse foramen/vertebral artery ratio of double transverse foramen subjects be a risk for vertebrobasilar transient ischemic attacks?

The C6 is the cervical vertebra into which the vertebral artery enters the passage of the transverse foramen and it is the vertebra most affected by double transverse foramina. There is currently little information about the relation between the vertebral artery and the double transverse foramen in C6. We aimed to test whether subjects with a double transverse foramen in C6 have a reduced transverse foramen/vertebral artery ratio when compared with normal anatomy subjects who possess a single transverse foramen which may be a risk for transient vertebral artery stenosis. We measured the area of the transverse foramen and the vertebral artery in 27 double transverse and 56 normal anatomy subjects using computed tomography angiography. We found significant differences in the area of the transverse foramen between double transverse and normal subjects (P < 0.001) but not between the vertebral artery area of double transverse and normal subjects (P = 0.829). The subjects with double transverse foramina have a reduced transverse foramen/vertebral artery ratio, which may be a possible risk for transient vertebral artery stenosis.     

Atherosclerosis in HIV patients: a new face for an old disease?

As we have become more familiar with the pathogenesis of atheroma, it has become recognized atherogenesis is mainly an inflammatory disease. Therefore, it is not surprising that a body of evidence demonstrates that endothelium injury is associated with the progression and severity of HIV infection. Another important question is: do antiretroviral drugs increase or reduce endothelial injury? Various studies support the hypothesis that HAART does induce activation of endothelial function. Thus, HIV virus as well as immune reconstitution and HAART itself promote premature endothelial activation. Such a prominent role played by inflammatory events could affect the structure of the arterial lesions in HIV patients that could present different characteristics with respect to the classical atheroma. In fact, in two HIV patients with severe stenosis of the carotid, histology revealed extensive inflammatory infiltration of the vascular wall. The characteristics of these lesions were similar to those of arteritis. Another study evidenced that the ultrasonographic structure of the lesions in HIV patients substantially differ from those found in atherosclerosis, sharing similar characteristics with arteritis. We hypothesize that the atherosclerotic lesions in HIV patients develop in two distinct phases: the first one characterized by an inflammation of the vascular wall, and subsequently, the lesions could evolve towards the classic feature of the atheroma. The lesions in the first phase are probably determined by immunodeficiency, immune reconstitution, and the same effect of HAART. In the second phase they could be maintained by the classic risk factors.     

Accumulation of mitochondrial genome variations in Persian LQTS patients: a possible risk factor?

BackgroundLong QT syndrome (LQTS) is among arrhythmia disorders of the heart that causes sudden cardiac death in young individuals. As yet, most of investigations have focused on nuclear genome for finding genetic defects in this disorder, but some of the cases with LQTS cannot be explained by mutations of identified genes. On the other hand, it has been reported that the activity of ion channels in cardiomyocytes is sensitive to ATP level. It prompted us to focus on the mitochondrial DNA and monitor the point mutations of genome which are probably the cause of respiratory chain defects and reduced ATP generation.MethodsWe searched about 55% of the mitochondrial DNA (mtDNA) by temporal temperature gradient gel electrophoresis (TTGE), and DNA fragments showing abnormal banding patterns were sequenced for identification of exact mutations.ResultsIn 39 patients (33 familial and 6 sporadic cases), for the first time, we detected 35 mtDNA mutations in which 8 were novel (23%) and 27 (77%) have been reported in other mitochondrial diseases. Our results showed that these mutations in LQTS patients were higher than those in normal controls (P<.0001), and the number of mutations in LQTS patients with syncope is higher than in patients without syncope (P<.001).ConclusionsAs the mitochondrion's ATP synthesis is important in heart, it is possible that mutations and their accumulation in mtDNA could constitute a predisposing factor that in combination with environmental factors may trigger the syncope in patients with LQTS.