Lymphoid cells in afferent and efferent intestinal lymph: lymphocyte subpopulations and cell migration.

Gut wall emigrating cells have been characterized in the intestinal lymph. The intestinal lymph duct was cannulated in 6-month-old minipigs. Under non-restraining conditions the efferent lymph from the mesenteric lymph nodes was collected in seven normal animals. Lymph coming directly from the gut (afferent lymph) was also collected in 18 pigs after resection of the mesenteric lymph node chains 3 months previously. The intestinal lymph flow was similar in both groups (around 18 ml/h). The lymphoid cell yield was 1.2 +/- 1.0 x 10(6)/h in control animals, while in mesenteric lymph node resected pigs it was around 20 times higher (26.2 +/- 17.6 x 10(6)/h). In the gut-derived lymph 76.5 +/- 8.8% T lymphocytes were observed (CD4+, 48.1 +/- 15.5%; CD8+, 53.6 +/- 12.7%). The percentage of immunoglobulin-positive cells was lower (IgM+, 10.1 +/- 4.5; IgA+, 1.7 +/- 1.1). In 14 mesenteric lymph node resected pigs a mean of 5.6 +/- 3.1 x 10(8) lymphocytes from the gut lymph were labelled in vitro with a fluorescent dye and retransfused. The labelling index of fluorescent cells in the intestinal lymph increased rapidly and remained at a high level until 44 h after cell transfusion. A four-to-ten times lower labelling index was found in the spleen, various lymph nodes and Peyer's patches. Most of the recovered lymphocytes were T cells. This model provides access to the cell pool leaving the gut wall, thus allowing an examination of its role in the gastrointestinal tract and other mucosal-lined organs.     

X-linked mixed deafness (DFN3): cloning and characterization of the critical region allows the identification of novel microdeletions

We have found that the microsatellite marker AFM207zg5 (DXS995)maps to all previously described deletions which are associatedwith X-linked mixed deafness (DFN3) with or without choroideremiaand mental retardation. Employing this marker and pHU16 (DXS26)we have identified two partially overlapping yeast artificialchromosome clones which were used to construct a complete 850kb cosmid contig. Cosmids from this contig have been testedby Southern blot analysis on DNA from 16 unrelated males withX-linked deafness. Two novel microdeletions were detected inpatients which exhibit the characteristic DFN3 phenotype. Bothdeletions are completely contained within one of the known DFN3-deletions,but one of them does not overlap with two previously describeddeletions in patients with contiguous gene syndromes consistingof DFN3, chorolderemia, and mental retardation. Assuming thatonly a single gene is involved, this suggests that the DFN3gene spans a chromosomal region of at least 400 kb.     

Contrasting in vitro effects of retinol and mononuclear cell factor on young and old human cartilage

Studies with young animal cartilage have shown that retinol and mononuclear cell-factor (MCF) cause in vitro breakdown of the cartilage, mediated by the living chondrocyte (indirect degradation). We studied the effects of retinol and MCF on healthy human articular cartilage of different ages, measuring the effects on proteoglycan (PG) content of the cartilage, and on PG synthesis during 8 days of culture. This study shows: Retinol and MCF induce indirect degradation of young, but not of old human cartilage of the humeral head; Both retinol and MCF suppress PG synthesis of young and stimulate PG synthesis of old cartilage; The effects of retinol and MCF on cartilage PG content and on PG synthesis are related to the metabolic state of the chondrocyte; Therefore mononuclear cell-factor may have a destructive or beneficial effect on cartilage depending on whether proteoglycan synthesizing activity is high or low, respectively.     

Cation channels,cell volume and the death of an erythrocyte

Similar to a variety of nucleated cells, human erythrocytes activate a non-selective cation channel upon osmotic cell shrinkage. Further stimuli of channel activation include oxidative stress, energy depletion and extracellular removal of Cl^–. The channel is permeable to Ca²⁺ and opening of the channel increases cytosolic [Ca²⁺]. Intriguing evidence points to a role of this channel in the elimination of erythrocytes by apoptosis. Ca²⁺ entering through the cation channel stimulates a scramblase, leading to breakdown of cell membrane phosphatidylserine asymmetry, and stimulates Ca²⁺-sensitive K⁺ channels, thus leading to KCl loss and (further) cell shrinkage. The breakdown of phosphatidylserine asymmetry is evidenced by annexin binding, a typical feature of apoptotic cells. The effects of osmotic shock, oxidative stress and energy depletion on annexin binding are mimicked by the Ca²⁺ ionophore ionomycin (1 µM) and blunted in the nominal absence of extracellular Ca²⁺. Nevertheless, the residual annexin binding points to additional mechanisms involved in the triggering of the scramblase. The exposure of phosphatidylserine at the extracellular face of the cell membrane stimulates phagocytes to engulf the apoptotic erythrocytes. Thus, sustained activation of the cation channels eventually leads to clearance of affected erythrocytes from peripheral blood. Susceptibility to annexin binding is enhanced in several genetic disorders affecting erythrocyte function, such as thalassaemia, sickle-cell disease and glucose-6-phosphate dehydrogenase deficiency. The enhanced vulnerability presumably contributes to the shortened life span of the affected erythrocytes. Beyond their role in the limitation of erythrocyte survival, cation channels may contribute to the triggering of apoptosis in nucleated cells exposed to osmotic shock and/or oxidative stress.     

Molecular interaction of connexin 30.3 and connexin 31 suggests a dominant-negative mechanism associated with erythrokeratodermia variabilis

Connexins are homologous four-transmembrane-domain proteins and major components of gap junctions. We recently identified mutations in either GJB3 or GJB4 genes, encoding respectively connexin 31 (Cx31) or 30.3 (Cx30.3), as causally involved in erythrokeratodermia variabilis (EKV), a mostly autosomal dominant disorder of keratinization. Despite slight differences, phenotypes of EKV Mendes Da Costa (Cx31) and EKV Cram-Mevorah (Cx30.3) show major clinical overlap and both Cx30.3 and Cx31 are expressed in the upper epidermal layers. These similarities suggested to us that Cx30.3 and Cx31 may interact at a molecular level. Indeed, expression of wild-type Cx30.3 in HeLa cell resulted only in minor amounts of protein addressed to the plasma membrane. Mutant Cx30.3 was hardly detectable and disturbed intercellular coupling. In sharp contrast, co-expression of both wild-type proteins led to a gigantic increase of stabilized heteromeric gap junctions. Furthermore, co-expressed wild-type Cx30.3 and Cx31 coprecipitate, which demonstrates a physical interaction. Inhibitor experiments revealed that this interaction begins in the endoplasmic reticulum. These results not only provide new insights into epidermal connexin synthesis and polymerization, but also allow a novel molecular explanation for the similarity of EKV phenotypes.     

Multiple endometrial stromal nodules with sparse cysts and glands in the lung--a nodular variation of endometriosis that may mimic metastases of sarcoma

We report an unusual case of a nodular variation of pulmonary endometriosis. To our knowledge, there is no previous report on a morphological investigation of this entity. The etiology of this rare condition is still a matter of discussion. The well-circumscribed nodular mass is composed of cells identical to, or closely resembling, those of endometrial stroma containing sparse cysts and glands. Immunohistochemically, the cells showed an extensive co-expression of cytokeratin AE1/AE3 and vimentin and were highly positive for progesterone receptor (PRICA) and estrogen receptor (ERICA). Cells lining the cysts and glands as a monolayer were reactive for Ber-Ep4, cytokeratin Pan and cytokeratin AE1/AE3 and negative to all other markers used including PRICA and ERICA. The differential diagnosis of this entity included fibrous tumor of the pleura and metastatic low-grade-endometrial-stromal-sarcoma. The morphological findings are correlated with immunohistochemical studies and results of cell image analysis. This study details the clinicopathological features of the nodular variation of pulmonary endometriosis.     

Experimental investigation of a fast Monte Carlo photon beam dose calculation algorithm

An experimental verification of the recently developed XVMC code, a fast Monte Carlo algorithm to calculate dose distributions of photon beams in treatment planning, is presented. The treatment head is modelled by a point source with energy distribution (primary photons) and an additional head scatter contribution. Utility software is presented, allowing the determination of the parameters for this model using a single measured depth dose curve in water. The simple beam model is considered to be a starting point for more complex models being planned for future versions of the code. This paper is mainly focused on the influence of the different techniques on variance reduction and material property determination for dose distributions. It is demonstrated that XVMC and the simple beam model reproduce measured (by a diamond detector) relative dose distributions with an accuracy of better than +/-2% in various homogeneous and inhomogeneous phantoms. Furthermore, relative dose distributions in solid state phantoms have been measured by film. Also for these cases, measured and calculated dose distributions agree within experimental uncertainty. The short calculation time (depending on voxel resolution, statistical accuracy, field size and energy, a span of 1 min to 1 h using a present-day personal computer) and an interface to a commercial planning system will allow the implementation of the code for routine treatment planning of clinical electron and photon beams.     

Treatment of keratoconjunctivitis sicca with topical androgen

Objective: Androgens have been reported to influence lipid production of sebaceous glands and even many ocular tissues. The effect of topical androgen therapy on a 54-year-old patient with keratoconjunctivitis sicca (KCS) and decreased lipid phase of the tear film is reported. Methods: For assessment of the lipid phase of the tear film, break up time (BUT) and lipid layer thickness (LLT) were monitored during 6 months before treatment as well as 3 months while using a daily topical androgen therapy. Results: During the topical androgen therapy the pathological lipid phase of the tear film was completely restored indicated by the normalisation of the values of BUT and LLT. Conclusion: These findings are consistent with animal experiments indicating that topical administered androgen can restore the decreased lipid phase of the tear film. This may open up new therapeutic strategies for KCS.     

Endothelial nitric oxide synthase gene polymorphism in women with idiopathic recurrent miscarriage

BACKGROUND: Lack of endothelium-derived nitric oxide is associated with vasospasm and vascular infarction. We investigated the relationship between idiopathic recurrent miscarriage and a polymorphism of the gene encoding endothelial nitric oxide synthase (NOS3). METHOD: In a prospective case-control study, 105 women with idiopathic recurrent miscarriage and 91 healthy controls were investigated. We used the polymerase chain reaction to identify the different alleles of a 27 base pair tandem repeat polymorphism in intron 4 of the NOS3 gene. RESULTS: The wild type B allele was identified on 329 out of 392 chromosomes (frequency 0.84). The polymorphic A allele was present on 63 chromosomes (frequency 0.16). The genotype frequencies were as follows: 68% (B/B), 31% (A/B) and.5% (A/A). The distribution of genotype frequencies was significantly different between the study and control groups for allele A/B heterozygotes (NOS3(A/B)) (36.7 versus 23.8%, P = 0.03, OR 1.6, 95% CI 1.1--3.8). Only one individual was homozygous for the A allele (NOS3(A/A)). She was in the study group. Between women with primary and secondary recurrent miscarriages, no statistically significant difference between the distribution of NOS3(A/B) genotypes (28 versus 34%) was observed. CONCLUSIONS: These data support a role for the NOS3 gene as a genetic determinant of the risk of idiopathic recurrent miscarriage.     

Association between atrial fibrillation and central sleep apnea

BACKGROUND: We previously described an association between atrial fibrillation and central sleep apnea in a group of patients with congestive heart failure. We hypothesized that the prevalence of atrial fibrillation might also be increased in patients with central sleep apnea in the absence of other cardiac disease. METHODS AND RESULTS: We compared the prevalence of atrial fibrillation in a series of 60 consecutive patients with idiopathic central sleep apnea (apnea-hypopnea index > 10 events per hour, > 50% central events) with that in 60 patients with obstructive sleep apnea (apnea-hypopnea index > 10, > 50% obstructive events) and 60 patients without sleep apnea (apnea-hypopnea index < 10), matched for age, sex, and body mass index. Subjects with a history of congestive heart failure, coronary artery disease, or stroke were excluded from the study. The prevalence of atrial fibrillation among patients with idiopathic central sleep apnea was found to be significantly higher than the prevalence among patients with obstructive sleep apnea or no sleep apnea (27%, 1.7%, and 3.3%, respectively, P < .001). However, hypertension was most common and oxygen desaturation most extreme among patients with obstructive sleep apnea. CONCLUSIONS: We conclude that there is a markedly increased prevalence of atrial fibrillation among patients with idiopathic central sleep apnea in the absence of congestive heart failure. Moreover, the high prevalence of atrial fibrillation among patients with idiopathic central sleep apnea is not explainable by the presence of hypertension or nocturnal oxygen desaturation, since both of these were more strongly associated with obstructive sleep apnea.