Decorin production by the human decidua: role in decidual cell maturation.

Decidualization involves the proliferation and differentiation of fibroblast-like endometrial stromal cells into epithelioid-shaped and secretory 'decidual' cells in response to steroid hormones. Human decidual cells produce insulin-like growth factor-binding protein-1 and prolactin (PRL), two well-recognized markers of decidual cell maturation and a proteoglycan decorin (DCN). We reported that DCN restrains the human trophoblast renewal, migration, invasion and endovascular differentiation needed for uterine arterial remodeling during normal pregnancy. DCN overproduction by the decidua is associated with a hypo-invasive placenta and a serious pregnancy disorder, pre-eclampsia (PE). Furthermore, elevated maternal plasma DCN levels during the second trimester is a predictive biomarker of PE. While these paracrine roles of decidua-derived DCN on trophoblast physiology and pathology have been well-defined, it remains unknown whether DCN plays any autocrine role in decidual cell development. The objectives of this study were to examine: the kinetics of DCN production during decidualization of human endometrial stromal cells; gestational age-related changes in DCN production by the first trimester decidua; and a possible autocrine role of DCN on decidual cell maturation. We found that DCN production is enhanced during decidualization of both primary and immortalized human endometrial stromal cells in vitro and during early gestation in decidual samples tested ex vivo, and that it is important for endometrial stromal cell maturation into a decidual phenotype. Decorin-depleted human endometrial stromal cells exposed to decidualizing stimuli failed to mature fully, as evidenced by fibroblastoid morphology, reduced insulin-like growth factor-binding protein-1 and PRL expression, and reduction in cellular ploidy. We identified heart and neural crest derivatives-expressed protein 2, and progesterone receptor as potential downstream mediators of DCN effects.

CASA-based sperm kinematics of environmental risk factor-exposed human semen samples designated as normozoospermic in conventional analysis.

This study was conducted after an initial epidemiological survey of patients in and around Calcutta, India, concerning their lifestyle history, degree of risk exposure and semen analysis based on conventional WHO criteria. It was found that a large group of exposed patients were showing normozoospermic semen parameters in conventional semen analysis. Hence, a selected group of subjects, designated as normozoospermic in routine analysis, but under risk factor exposure, were selected for a repeat computer aided semen analysis (CASA) and were compared with a control group. The parameters considered among CASA results were: curvilinear velocity (VCL), straight-line velocity, average path velocity (VAP), straightness index (STR), lateral head displacement (ALH) and beat cross frequency. The results depict a significant decline in the mean values of VCL (P = 0.029) and STR (P = 0.007) in the tobacco-exposed group when compared with the unexposed group. On the other hand, there was a significant decline in the mean values of VCL (P = 0.014) and ALH (P = 0.040) in the heavy metal-exposed group when compared with the unexposed group. The other parameters did not show significant change in either group. Semen samples that had been designated normozoospermic in conventional analysis were seen to be influenced by risk factors at the level of sperm motion kinetics.

Coenzyme Q10 ameliorates cadmium induced reproductive toxicity in male rats.

This study aimed at investigating the protective role of CoQ10 against cadmium (Cd)-induced reproductive toxicity in male rats. Adult male Wistar rats were exposed to an acute dose of Cd (25 mg/kg bwt; Cd group), Cd+CoQ10 (25 mg/kg bwt Cd+10 mg CoQ10; Cd-Q10 group) and distilled water (control) in vivo for 15 consecutive days and semen quality was assessed. A significant reduction was noted in sperm concentration, progressive motility, morphology and DNA integrity in both Cd- and Cd-Q10 groups in comparison to control indicating Cd-induced testicular lipid per oxidation (LPO) and decline in indigenous antioxidant defense system as measured by total antioxidant capacity (TAC) (p<0.05). However, simultaneous co-administration of CoQ10 along with Cd (Cd-Q10 group) was able to improve sperm concentration, motility, progressive motility, morphology, DNA integrity, and testicular TAC as well as lower LPO compared to Cd group (p<0.05). Results indicate that used dose of CoQ10 is capable of moderately ameliorating reproductive toxicity of Cd by improving semen quality and reducing testicular oxidative stress.

Conformational changes of prion protein and nucleic acid arising from their interaction and relation of the altered structures in causing prion disease.

Nucleic acids catalyse the conversion of alpha-helical prion protein to the beta-structured protein oligomers and amyloids structurally similar to the infectious isoform of protein. Simultaneously, the prion protein, similar to gene regulating proteins, bends, unwinds and condenses nucleic acid. These properties might be related to the biological function and prion infection.

Osmolyte trimethylamine N-oxide converts recombinant alpha-helical prion protein to its soluble beta-structured form at high temperature.

The thermal unfolding of full-length human recombinant alpha-helical prion protein (alpha-PrP) in neutral pH is reversible, whereas, in the presence of the osmolyte N-trimethylamine oxide (TMAO), the protein acquires a beta-sheet structure at higher temperatures and the thermal unfolding of the protein is irreversible. Lysozyme, an amyloidogenic protein similar to prion protein, regains alpha-helical structure on cooling from its thermally unfolded form in buffer and in TMAO solutions. The thermal stability of alpha-PrP decreases, whereas that of lysozyme increases in TMAO solution. Light-scattering and turbidity values indicate that beta-sheet prion protein exists as soluble oligomers that increase thioflavin T fluorescence and bind to 1-anilino 8-naphthalene sulfonic acid (ANS). The oligomers are resistant to proteinase K digestion and during incubation for long periods they form linear amyloids>5 microm long. The comparable fluorescence polarization of the tryptophan groups and their accessibility to acrylamide in alpha-PrP and oligomers indicate that the unstructured N-terminal segments of the protein, which contain the tryptophan groups, do not associate among themselves during oligomerization. Partial unfolding of alpha-helical prion protein in TMAO solution leads to its structural conversion to misfolded beta-sheet form. The formation of the misfolded prion protein oligomers and their polymerization to amyloids in TMAO are unusual, since the osmolyte generally induces denatured protein to fold to a native-like state and protects proteins from thermal denaturation and aggregation.

Femtosecond laser written channel waveguides in tellurite glass.

We have made and characterized a new, erbium-doped tellurite glass that has high glass transition temperature. Addition of phosphate is found to increase the phonon energy. The peak emission cross section is 6 x 10(-21) cm(2) at 1537 nm and the fluorescence lifetime of the (4)I(13/2)-(4)I(15/2) transition is 4.1 ms. We have written 2-D channel waveguides in this glass using focused, 45-fs pulses from an amplified Ti:sapphire laser at different laser energies and writing speeds. Migration of atoms towards the periphery of the waveguides occurs, leading to refractive index changes. Channels show waveguiding at 1310 nm which is promising for the fabrication of integrated lasers and broadband amplifiers.

Diffusion properties of clathrin on the surface of isolated mouse liver nuclei by the fluorescence recovery after photobleaching technique.

Clathrin labeled with eosin maleimide showed physicochemical properties similar to the native clathrin. The diffusion coefficients of clathrin protomers and cages measured at 20 degrees C by the fluorescence recovery after photobleaching technique (FRAP) were found equal to (9 +/- 1).10(-8) cm2.s-1 and (3 +/- 0.4.10(-8) cm2.s-1, respectively. After incubation with isolated mouse liver nuclei suspended in an aqueous buffer, FRAP measurements showed that 78% of clathrin was immobilized on the nuclear surface. This immobile fraction might correspond to aggregates of molecules resembling coated pits. The mobile fraction had a diffusion coefficient of 2.5.10(-9) cm2.s-1 which was reduced seven times when the suspension medium of the nuclei contained 50% sucrose, showing that the aqueous phase exerted an important drag on the clathrin molecules motion diffusing on the nuclear surface.

Interaction of negatively charged liposomes with nuclear membranes: adsorption, lipid mixing and lysis of the vesicles.

Fluorescence energy transfer studies reveal that negatively charged lipid vesicles interact with nuclei from mouse liver cells. This interaction was observed with charged lipid vesicles composed of PA or PS but not with the uncharged PC or PE:PC vesicles. The vesicles were prepared by bath sonication and contained either a fluorescent marker in the lipid bilayer or in the vesicular interior. The negatively charged vesicles showed an adsorption to the nuclear membrane visible by fluorescence microscopy. The results obtained by resonance energy transfer experiments are interpreted in terms of a mixing of the lipids from the vesicles with the nuclear membrane. Encapsulation studies documented a staining of the nuclei only if the dye molecules of high or low molecular weight were encapsulated inside negatively charged vesicles. As consequence of the vesicle-nuclei interaction morphological changes on the nuclear surface became visible.

Fusion of negatively charged liposomes with clathrin-uncoated vesicles.

The interaction of lipid vesicles with uncoated vesicles from bovine brain has been studied by fluorescence energy transfer between fluorescent lipid analogs (NBD-PE, Rh-DOPE), by loss of fluorescence self-quenching (NBD-PE, carboxyfluorescein) and by freeze-fracture electron microscopy. The fluorescence techniques monitor the mixing of membranous lipids and the induced release of encapsulated material. The results demonstrate a mixing of the negatively charged lipid (PA, PS) vesicles with the uncoated vesicles. In parallel with the lipid mixing a release of intravesicularly encapsulated material takes place. Lipid vesicles composed of zwitterionic lipids (PC, DOPC, PC:PE) do not specifically interact with uncoated vesicles. The electron micrographs reveal single fusion events. Studies on the kinetics are consistent with a fusional mechanism of the negatively charged lipid vesicles with uncoated vesicles.

Nucleic acid and prion protein interaction produces spherical amyloids which can function in vivo as coats of spongiform encephalopathy agent.

The infectious agent of transmissible spongiform encephalopathies (TSE) has been considered to be PrP(SC), a structural isoform of cellular prion protein PrP(C). PrP(SC) can exist as oligomers and/or as amyloid polymers. Nucleic acids induce structural conversion of recombinant prion protein PrP and PrP(C) to PrP(SC) form in solution and in vitro. Here, we report that nucleic acids, by interacting with PrP in solution, produce amyloid fibril and fibres of different morphologies, similar to those identified in the diseased brains. In addition, the same interaction produces polymer lattices and spherical amyloids of different dimensions (15-150 nm in diameters). The polymer lattices show apparent morphological similarity to the two-dimensional amyloid crystals obtained from linear amyloids isolated in vivo. The spherical amyloids structurally resemble "spherical particles" observed in natural spongiform encephalopathy (SE) and in scrapie-infected brains (TSE). We suggest that spherical amyloids, PrP(SC)-amylospheroids, are probable constituents of the coat of the spherical particles found in vivo and the latter can act as protective coats of the SE and TSE agents in vivo.

DNA-induced partial unfolding of prion protein leads to its polymerisation to amyloid.

The full-length mouse recombinant prion protein (23-231 amino acid residues) contains all of its structural elements viz. three alpha-helices and a short two-stranded antiparallel beta-sheet in its C-terminal fragment comprising 121-231 amino acid residues. The incubated mixture of this prion protein fragment and nucleic acid results in the formation of amyloid fibres evidenced from electron microscopy, birefringence and fluorescence of the fibre bound Congo Red and Thioflavin T dyes, respectively. The secondary structure of the amyloid formed in nucleic acid solution is similar to the in vivo isolated prion protein 27-30 amyloid but unlike in it, a hydrophobic milieu is absent in the 121-231 amyloid. Thermal denaturation study demonstrates a partial unfolding of the protein fragment in nucleic acid solution. We propose that nucleic acid catalyses unfolding of prion protein helix 1 followed by a nucleation-dependent polymerisation of the protein to amyloid.

The prion protein has DNA strand transfer properties similar to retroviral nucleocapsid protein.

The transmissible spongiform encephalopathies are fatal neurodegenerative diseases that are associated with the accumulation of a protease-resistant form of the cellular prion protein (PrP). Although PrP is highly conserved and widely expressed in vertebrates, its function remains a matter of speculation. Indeed PrP null mice develop normally and are healthy. Recent results show that PrP binds to nucleic acids in vitro and is found associated with retroviral particles. Furthermore, in mice the scrapie infectious process appears to be accelerated by MuLV replication. These observations prompted us to further investigate the interaction between PrP and nucleic acids, and compare it with that of the retroviral nucleocapsid protein (NC). As the major nucleic acid-binding protein of the retroviral particle, NC protein is tightly associated with the genomic RNA in the virion nucleocapsid, where it chaperones proviral DNA synthesis by reverse transcriptase. Our results show that the human prion protein (huPrP) functionally resembles NCp7 of HIV-1. Both proteins form large nucleoprotein complexes upon binding to DNA. They accelerate the hybridization of complementary DNA strands and chaperone viral DNA synthesis during the minus and plus DNA strand transfers necessary to generate the long terminal repeats. The DNA-binding and strand transfer properties of huPrP appear to map to the N-terminal fragment comprising residues 23 to 144, whereas the C-terminal domain is inactive. These findings suggest that PrP could be involved in nucleic acid metabolism in vivo.

Acute intravascular hemolysis indicating thrombosis of Bjork-Shiley aortic prosthesis.

A patient with a Bjork-Shiley aortic prosthesis inserted two years and four months prior to receiving adequate anticoagulant therapy suddenly had severe intravascular hemolysis develop as a result of thrombosis of her aortic prosthesis. There was no notable hemodynamic compromise. The mechanism of the intravascular hemolysis is discussed.

Cutaneous infections due to Acanthamoeba in patients with acquired immunodeficiency syndrome.

We report 2 cases of cutaneous Acanthamoeba infection in patients with acquired immunodeficiency syndrome. The disease, which manifests as subcutaneous nodules, mimics other more commonly encountered clinical entities. A high index of suspicion, familiarity with the clinical and histologic appearance of skin lesions, and communication between clinicians and pathologists are crucial for early diagnosis and treatment of this potentially fatal infection.

Effects of several antimalarials and phenothiazine compounds on the formation of coat structure from clathrin.

We have evaluated the effects of two phenothiazine and several antimalarial drugs on the rates of polymerization of 8S clathrin molecules to 300S coat structures. Most of the drugs investigated have been shown in other studies to inhibit receptor-mediated endocytosis through the coated pit regions of plasma membranes. The two types of drugs were found to accelerate the polymerization rate without having much effect on the size distribution of the polymer species. The activities of the drugs appear to depend on the dibasic moiety and a large, hydrophobic aromatic ring in their structures.

Recurrent spontaneous pneumothorax; an effective method of talc poudrage.

Between January 1977 and December 1978, 24 patients with recurrent or chronic spontaneous pneumothorax were treated in the Hong Kong University Cardiothoracic Centre at Grantham Hospital by talc pleurodesis. Talc poudrage had been carried out under local infiltration anesthesia by a technique that utilizes the Venturi principle and the help of an oxygen injector, used normally for ventilating a patient during bronchoscopy with a rigid bronchoscope. By using this method of poudrage, a uniform application of the powder over the whole pleural surface can be achieved and successful pleurodesis can be obtained in all patients under local anesthesia.

Coexistent bronchogenic carcinoma and active pulmonary tuberculosis.

Sixty-four cases of coexistent bronchogenic carcinoma and active pulmonary tuberculosis were diagnosed between 1969 and 1976. The majority were male chronic cigarette smokers in their fifth and sixth decades. Human bacilli were isolated in 48 patients (88.9 percent) and atypical bacilli in six patients (11.1 percent). All of the atypical bacilli and 8.3 percent of the human bacilli were found to be resistant to the first line antituberculous drugs. All patients, except two who died following resection, were given a course of antituberculous drugs with 93.8 percent successful sputum conversion. Uncontrolled or disseminated tuberculous infection was not observed. Forty-five patients (70.3 percent) underwent pulmonary resection. Median survival time of those who had curative resection was 14.3 months with a 5 year survival rate of 13.2 percent. Median survival times of those treated by palliative resection plus anticancer chemotherapy and by anticancer chemotherapy alone were 8.3 months and 11.1 months, respectively. None of these patients survived more than 30 months. It appears that, clinically, each disease runs its own course with little effect on the other.

An unusual lethal complication associated with Starr-Edwards prosthetic aortic valve holder.

This is the first report of an unusual fatal complication associated with the Starr-Edwards prosthetic aortic valve holder. The patient died 51 days after replacement of his aortic valve with a Starr-Edwards prosthetic aortic valve. The cause of death was coronary arterial embolus caused by a fragment broken off of the prosthetic aortic valve holder.

Ethical aspects of clinical practice.

HYPOTHESIS: Clinical ethics is grounded in the belief that medicine is an inherently moral enterprise. Sick persons ask physicians to help them get better and physicians profess to be morally committed and technically competent to help the sick. DATA SOURCES: MEDLINE literature search and review of published works on medical ethics, and the references cited therein. STUDY SELECTION: Critical studies containing supporting evidence were selected. DATA SYNTHESIS: The central ethical aspects of modern medical practice are clinical competence, respect for patients and their health care decisions, and maintaining the primacy of patient's need in the face of external pressure in a changing social, economic, and political climate. There is a need to teach both the cognitive and behavioral aspects of ethics. Development of these skills, in turn, depends on the character of the physician who will be applying these skills. CONCLUSIONS: The outcome of patient care can be improved by efforts made to secure informed consent of the patient. This also helps avoid ethical conflicts, confusion, and misunderstanding between patients and physicians. Clinical ethics should be an integral part of medical education at all levels in medical school, in the residency, and in continuing education.

Evaluation of a new diuretic, diapamide, in congestive heart failure.

The diuretic response of patients with congestive heart failure to establish doses of diapamide (750 mg) and furosemide (80 mg) was compared in an open, crossover study. Peak urine output occurred in the first 6 hours after administration of furosemide but somewhat later (12 to 18 hours) with diapamide. Both agents produced active diuresis and natriuresis in most patients. Comparisons of drug effect during the first days of each treatment period and analysis of the entire first treatment period indicated that urine output with furosemide was significantly greater than with diapamide. Urinary sodium excretion on the first day of treatment was not significantly greater with furosemide than with diapamide, nor were the differences significant on subsequent days. The observed differences between drugs on urinary potassium and chloride excretion were not statistically significant. The most frequently occurring adverse reaction was mild to moderate nausea, which was reported by five patients receiving diapamide and two patients receiving furosemide. Diarrhea and vomiting were also more frequent with diapamide. Diapamide would appear to serve a role between the milder thiazide diuretics and the more effective furosemide.