[A prospective multi-center clinical investigation of HIV-negative pulmonary cryptococcosis in China].

Objective: To investigate the current status of the diagnosis and treatment of pulmonary cryptococcosis in respiratory medicine and improve the understanding of the clinical characteristics of HIV-negative pulmonary cryptococcosis in China. Methods: A prospective multi-center open cohort study was designed to screen for pulmonary cryptococcosis in the general wards and intensive care units of the Department of Respiratory Diseases in 22 hospitals. The HIV-negative patients with positive cryptococcal etiological diagnosis based on smear culture, antigen detection and histopathology were enrolled in the study. The clinical data of enrolled patients were collected and analyzed. Results: A total of 457 cases of pulmonary cryptococcosis were enrolled, among which 3.28% (15/457) were disseminated infections. The case fatality rate was 0.88% (4/457). The majority of the cases were diagnosed by histopathological examinations (74.40%, 340/457) and cryptococcus antigen detection (37.64%, 172/457). Patients with pulmonary cryptococcosis accounted for 2.04‰ (457/223 748) of the total hospitalized patients in the Department of Respiratory Diseases during the same period, and the ratio was the highest in south and east China. Meanwhile, 70.24% (321/457) of the patients had no underlying diseases, while 87.75% (401/457) were found to have immunocompetent status. Cough and expectoration were the most common clinical symptoms in patients with pulmonary cryptococcosis. However, 25.16% (115/457) of the patients had no clinical symptom or physical signs. In terms of imaging features on pulmonary CT, multiple pulmonary lesions were more common than isolated lesions, and there were more subpleural lesions than perihilar or medial lesions. Morphologically, most of the lesions were middle-sized nodules (1-5 cm) or small-sized nodules (3 mm to 1 cm). The sensitivity of serum cryptococcus antigen test was 71.99% (203/282). Moreover, antigen-positive patients differed from antigen-negative patients in terms of basic immune status, clinical symptoms, imaging features and infection types. Meanwhile, immunocompromised patients differed from immunocompetent patients in terms of clinical symptoms, physical signs, infection-related inflammation indicator levels, imaging features, serum cryptococcus antigen positive rate and prognosis. Conclusions: The majority of cases of HIV-negative pulmonary cryptococcosis in China had no underlying disease or immunocompromised status, and the overrall prognosis was favorable. However, early diagnosis of HIV-negative pulmonary cryptococcosis remains challenging due to the complicated manifestations of the disease.

Synchrotron microangiography studies of angiogenesis in mice with microemulsions and gold nanoparticles.

We present an effective solution for the problem of contrast enhancement in phase-contrast microangiography, with the specific objective of visualising small (<8 microm) vessels in tumor-related microangiogenesis. Different hydrophilic and hydrophobic contrast agents were explored in this context. We found that an emulsified version of the hydrophobic contrast agents Lipiodol provides the best contrast and minimal distortion of the circulation and vessel structure. Such emulsions are reasonably biocompatible and, with sizes of 0 +/- 0.8 microm, sufficient to diffuse to the smallest vessel and still provide reasonable contrast. We also explored the use of Au nanoparticle colloids that could be used not only to enhance contrast but also for interesting applications in nanomedicine. Both the Lipiodol microemulsions and Au nanoparticle colloids can be conjugated with medicines or cell specific labeling agents and their small size can allow the study of the diffusion of contrast agents through the vessel leakage. This enables direct imaging of drug delivery which is important for cancer treatment.

A new iterative algorithm to reconstruct the refractive index.

The latest developments in x-ray imaging are associated with techniques based on the phase contrast. However, the image reconstruction procedures demand significant improvements of the traditional methods, and/or new algorithms have to be introduced to take advantage of the high contrast and sensitivity of the new experimental techniques. In this letter, an improved iterative reconstruction algorithm based on the maximum likelihood expectation maximization technique is presented and discussed in order to reconstruct the distribution of the refractive index from data collected by an analyzer-based imaging setup. The technique considered probes the partial derivative of the refractive index with respect to an axis lying in the meridional plane and perpendicular to the propagation direction. Computer simulations confirm the reliability of the proposed algorithm. In addition, the comparison between an analytical reconstruction algorithm and the iterative method has been also discussed together with the convergent characteristic of this latter algorithm. Finally, we will show how the proposed algorithm may be applied to reconstruct the distribution of the refractive index of an epoxy cylinder containing small air bubbles of about 300 micro of diameter.

beta1B integrin subunit contains a double lysine motif that can cause accumulation within the endoplasmic reticulum.

Human epidermal keratinocytes are one of the few cell types that express the beta1B splice variant of the beta1 integrin subunit. Although in transfection experiments beta1B acts as a dominant negative inhibitor of cell adhesion, we found that beta1B was expressed at very low levels in keratinocytes, both in vivo and in culture, and had a predominantly cytoplasmic distribution, concentrated within the endoplasmic reticulum. To examine why beta1B accumulated in the cytoplasm, we prepared chimeras between CD8alpha and the beta1A and beta1B integrin cytoplasmic domains. In transfected HeLa cells, both constructs reached the cell surface but the rate of maturation of the beta1B chimera was considerably retarded relative to beta1A. The beta1B cytoplasmic domain contains two lysine residues that resemble the double lysine motif characteristic of many proteins that are resident within the endoplasmic reticulum. Mutation of each lysine individually to serine had no effect on CD8beta1B maturation, but when both residues were mutated the rate of CD8beta1B maturation increased to that of CD8beta1A. Further analysis of beta1B function in keratinocytes must, therefore, take into account the low abundance of the isoform relative to beta1A and the potential for beta1B to accumulate in the endoplasmic reticulum.

Expression of involucrin in normal, hyperproliferative and neoplastic mouse keratinocytes.

Involucrin is a protein precursor of the epidermal cornified envelope. Although expression of the human protein has been documented extensively, studies in the mouse have been hampered by a shortage of good antibodies. We describe the production of recombinant mouse involucrin and preparation of rabbit antisera to the protein that work well by immunohistochemistry and Western blotting. We confirm that in normal mouse epidermis the onset of involucrin expression is in the upper spinous layers and inner root sheath of the hair follicle. Involucrin was also detected in the differentiating epithelial cells of normal tongue, oesophagus and bladder. Involucrin was expressed in a subpopulation of mouse keratinocytes cultured in standard or low calcium medium and the proportion of involucrin-positive cells increased during suspension-induced terminal differentiation. Western blotting of keratinocytes from several inbred mouse strains revealed a remarkable heterogeneity in the electrophoretic mobility of involucrin, reflecting inter-strain variation in the number of tandem repeats in the protein. In the hyperproliferative epidermis of healing wounds involucrin was expressed in most of the suprabasal layers. In epidermal papillomas and carcinomas involucrin expression correlated well with degree of histological differentiation. The sites of expression of the mouse protein were thus the same as those previously reported for human involucrin. With the development of the new antibodies we anticipate that involucrin will become as widely used a marker of keratinocyte differentiation in the mouse as it is in the human.