Molecular Identification of a Nocardiopsis dassonvillei Blood Isolate

Nocardiopsis dassonvillei is an environmental aerobic actinomycete seldom isolated in cutaneous and pulmonary infections. We herein report the first N. dassonvillei blood isolate in a patient hospitalized for cholangitis. Although morphological characteristics and biochemical tests allowed a presumptive identification of this isolate, cell wall fatty acid chromatographic analysis confirmed identification at the genus level, and 16S rRNA gene sequencing achieved definite identification. This study illustrates the usefulness of 16S rRNA gene sequencing as a routine method for the identification of actinomycetes.     

Langerhans-like dendritic cells generated from cord blood progenitors internalize pollen allergens by macropinocytosis, and part of the molecules are processed and can activate autologous naive T lymphocytes

Background: The safety and efficacy of sublingual immunotherapy have been demonstrated in moderate allergic asthma and seasonal rhinitis. However, not much is known about the precise mechanism of action of the allergen when it crosses the oral mucosa. Objective: To define this mechanism, we investigated the role of Langerhans’ cells in the capture and internalization of allergens. Methods: We generated dendritic cells in vitro with the phenotypic characteristics of Langerhans-like dendritic cells (LLDCs) from cord blood CD34⁺ progenitors. We used two recombinant major allergens: Bet v 1 and Phl p 1 labeled with FITC. Results: Internalization of allergens and control proteins was dose- and time-dependent and related to the immature state of the cells. LLDCs internalized allergens with a high efficiency in comparison with control molecules. Allergens were only internalized by macropinocytosis, as demonstrated by the use of various inhibitors. Addition of intracellular pH-modifying molecules indicated that only a part of the allergens was accumulated in acidic vesicles, whereas the majority remained in other cytoplasmic structures. Pulse-chase experiments calculated a half-life of 4 hours, suggesting that part of the molecules were not metabolized in the lysosome. Allergen internalization by LLDCs might be followed by processing in some experiments, as demonstrated by activation of autologous T lymphocytes in 4 of 9 experiments. Conclusion: These elements showed that Langerhans’ cells present in mucosa might play an active role in immune responses to allergens. (J Allergy Clin Immunol 2000;105:1194-1201.)     

BLOOD AND BONE MARROW CELLS OF THE DOMESTIC FOWL

1. A simple, direct method of counting leucocytes of the fowl is described. 2. Twenty-nine complete, morphological studies of the blood of eleven domestic fowls are recorded. 3. The characteristics of the cells found in the blood and bone marrow are described in detail and their relative numbers reported. 4. The supravital technique, using neutral red and Janus green, enables one to separate and classify accurately the confusing cells of the blood and bone marrow. 5. These studies provide a basis for future experimental studies on the blood and bone marrow cells of the fowl.     

Presence of crystalline inclusions in the peripheral nerve of a patient with IgA lambda monoclonal gammopathy of undetermined significance

Association of a peripheral neuropathy with an IgA monoclonal gammopathy of undetermined significance (MGUS) is not commonly observed and is sometimes considered as coincidental. We present a case in which the nerve biopsy revealed the presence of crystalline inclusions in the endoneurium, a very unusual finding. A 75‐year‐old man complained of paresthesiae in both feet and unsteady gait for 6 months. He had no weakness, but deep tendon reflexes were absent and vibratory sensation distally diminished in both legs. An IgA lambda MGUS was evidenced in his serum at 10.2 g/L with 7% plasma cells in his bone marrow and no lytic lesion at skeletal examination. A superficial peroneal nerve biopsy was performed and showed numerous crystalline inclusions in the endoneurium. These were located in the cytoplasm of macrophagic histiocytes or free in the vicinity of nerve fibers. There was also a marked loss of myelinated nerve fibers and several “onion bulb” formations surrounding either isolated remyelinating fibers or small clusters of remyelinating fibers. Such crystalline inclusions have mainly been observed in the cytoplasm of plasma cells in cases of multiple myeloma, and correspond to non‐secreted IgA or IgG immunoglobulins with a kappa or rarely lambda light chain. Such inclusions have also been reported in the cytoplasm of the epithelial cells from corneal fragments, in patients with multiple myeloma or IgG MGUS, and in the tubular cells from the kidney of patients with multiple myeloma and a nephrotic syndrome. In the literature, there is only one very briefly mentioned case of neuropathy associated with a myeloma and with crystalline inclusions present in the epineurium. Thus, in dysglobulinemic neuropathy, nerve fibers can be damaged by three kinds of interstitial deposits, easily identified by immunohistochemistry and at ultrastructural examination: the well known amyloid fibrils, granulo‐fibrillar deposits and also crystalline inclusions.     

AN ELECTRON MICROSCOPE STUDY OF ISOLATED MITOCHONDRIA : METHOD AND PRELIMINARY RESULTS

1. The present paper constitutes a preliminary study of the morphology of mitochondria by means of electron microscopy. 2. The mitochondria that were the subject of this investigation were obtained from a lymphosarcoma of the rat. They were separated from the other components of the leukemic cells by a method of differential centrifugation, and thus made available for direct examination in the electron microscope. 3. In the purified form the mitochondria appeared as spherical bodies, the majority of them varying in size approximately from 0.6 to 1.3 µ in diameter. 4. Certain aspects of mitochondria in the electron microscope suggest that these elements are surrounded by a differentiated membrane. In some cases the limiting membrane seemed to be responsible for maintaining the general shape of the mitochondria, even when most of the mitochondrial substance had been lost. 5. By means of the electron microscope, it is possible to distinguish small elements, 80 to 100 mµ in diameter, within the body of certain mitochondria. Further work is suggested to establish whether these small granules are normal constituents of mitochondria, and what relation may exist between them and ordinary microsomes. 6. The nature of mitochondria as morphological units is discussed. Present evidence indicates that mitochondria constitute definite physical entities which can persist in the absence of the cytoplasm.     

Coherence treatment of postmenopausal osteoporosis with growth hormone and calcitonin

Summary Fourteen women with postmenopausal osteoporosis, all having at least one vertebral crush fracture, were randomly assigned to two treatment arms, each lasting 24 months. The coherence treatment group (7 patients) was treated in the following sequence: human growth hormone (hGH) 7 IU subcutaneously daily for 2 months, followed by 3 months of salmon calcitonin (CT), 100 MRC units every other day. After a 3 month rest period, this sequence was repeated twice. The contrast group (7 patients) was treated intermittently with salmon CT given in the same time periods and at the same dose as in the coherence treatment group. Bone mass was measured every 4 months by neutron activation analysis for total body calcium (TBCa) and by single photon absorptiometry for bone mineral content (BMC) of the distal radius. Although there were no significant differences between the two groups (two-way ANOVA), the rate of change in TBCa in the coherence treatment group was significantly different from zero (F=3.8,P<.05) and was +2.3%/year. The increase in bone mass appeared to be sustained throughout the 2 year study, in contrast with previous studies where a plateau effect was observed with calcitonin given alone or continuously with growth hormone. No significant change was found in bone histomorphometric values measured before and after treatment in 4 patients from each group.     

Increased Dosage of DYRK1A and Brain Volumetric Alterations in a YAC Model of Partial Trisomy 21

A yeast artificial chromosome (YAC) transgenic murine model of partial trisomy 21 overexpressing five human genes—including DYRK1A, which encodes a serine threonine kinase involved in cell cycle control—has been shown to present an increase in brain weight. We analyzed this new phenotype by measuring total and regional brain volumes at different ages, using a 7 Tesla magnetic resonance imaging volumetric approach. Volumetric measurements showed a total volume increase of 13.6% in adult mice. Changes in brain morphogenesis were already visible at a very early postnatal stage (postnatal days 2–7). Region‐specific changes were characterized from postnatal day 15 to 5 months. These results, made it possible to define region‐specific effects of DYRK1A overexpression, with the strongest increase seen in the thalamus–hypothalamus area (24%). Anat Rec, 291:254–262, 2008. © 2008 Wiley‐Liss, Inc.     

Physical Activity, Physical Fitness, and Coronary Heart Disease Risk Factors in Youth: The Québec Family Study

Objective. The relationships between physical activity, fitness, and CHD risk factors were investigated in 342 males and 268 females 9–18 years of age.Methods. Daily energy expenditure, moderate to vigorous physical activity, inactivity, and television viewing time were estimated. Indicators of physical fitness included submaximal work capacity, quadriceps muscle strength, sit-ups, and the sum of six skinfolds. Risk factors included mean arterial blood pressure and fasting blood levels of triglycerides, LDL-cholesterol, HDL-cholesterol, and glucose.Results. Canonical correlations between activity and risk factor profiles range from 0.22 to 0.45, while those between fitness and risk factor profiles range from 0.34 to 0.55, indicating that 5 to 20% and 11 to 30% of the variance in the risk profile is explained by activity and fitness, respectively.Conclusion. The results suggest that both physical fitness and level of habitual physical activity are strongly associated with CHD risk factors in this sample of youth.