Search results

Filter

Filetype

Your search for "*" yielded 533999 hits

Frequent carbon input primes decomposition of decadal soil organic matter

Soil organic matter (SOM) decomposition in response to global change represents a critical uncertainty in coupled carbon (C) cycle-climate models. Much of this uncertainty arises from our limited mechanistic knowledge of the effects of organic C input frequency on SOM decomposition. Based on a three-source-partitioning isotopic approach (14C glucose addition to soil continuously labeled by C4 plan

Immunoreactivity of recombinant human glandular kallikrein using monoclonal antibodies raised against prostate-specific antigen

The gene encoding human glandular kallikrein (KLK2) was expressed in Escherichia coli, and the corresponding protein (hK2) was produced by fermentation. The hK2 was characterized by Western blotting and epitope map using monoclonal antibodies (MAbs) specific for another protease, prostate- specific antigen (PSA) with high structural identity (80%). MAbs that recognized three different epitopes wer

Cloning and characterization of the α1-antichymotrypsin produced by human prostate tissue

BACKGROUND. α1-antichymotrypsin (ACT) forms stable complexes with prostate-specific antigen (PSA), a serine protease, and this complex is the major form of PSA in the blood circulation. α1-antichymotrypsin occurs in the blood in approximately 105 molar excess to PSA, mainly due to hepatic production, but local prostatic production of ACT has been demonstrated by immunohistochemistry and in situ hy

Enzymatic activation of a doxorubicin-peptide prodrug by prostate- specific antigen

New approaches to target cytotoxic therapy specifically to metastatic prostate cancer sites are urgently needed. As such an approach, an inactive prodrug was synthesized by coupling the primary amine of doxorubicin to the COOH-terminal carboxyl of a seven-amino acid peptide carrier (i.e., Mu-His- Ser-Ser-Lys-Leu-Gln-Leu). The seven-amino acid peptide was documented to be hydrolyzable specifically

Biomarkers of cellular aging during a controlled human malaria infection

Cellular aging is difficult to study in individuals with natural infection, given the diversity of symptom duration and clinical presentation, and the high interference of aging-related processes with host and environmental factors. To address this challenge, we took advantage of the controlled human malaria infection (CHMI) model. This approach allowed us to characterize the relationship among ce

Silk scaffolding drives self-assembly of functional and mature human brain organoids

Human pluripotent stem cells (hPSCs) are intrinsically able to self-organize into cerebral organoids that mimic features of developing human brain tissue. These three-dimensional structures provide a unique opportunity to generate cytoarchitecture and cell-cell interactions reminiscent of human brain complexity in a dish. However, current in vitro brain organoid methodologies often result in intra

Specific and efficient peptide substrates for assaying the proteolytic activity of prostate-specific antigen

Prostate-specific antigen (PSA) is a serine protease secreted by hath normal prostate glandular celts and prostate cancer cells. The major proteolytic substrates for PSA are the gel-forming proteins in semen, semenogelin (Sg) I and II. On the basis of the PSA cleavage map for Sg I and II, a series of small peptides (ie., ≤ 7 amino acids) was synthesized and coupled at the COOH terminus to 7-amino-

Characteristics of screening detected prostate cancer in men 50 to 66 years old with 3 to 4 ng./Ml. Prostate specific antigen

Purpose: We defined the yield and nature of prostate cancer in the setting of population based, randomized prostate specific antigen (PSA) guided screening in men with PSA levels between 3 and 4 ng./ml. who were 50 to 65 years old at the time of randomization. Materials and Methods: Sextant biopsies were performed in 243 men with PSA of 3 to 4 ng./ml. Therapy decisions were based on core cancer le

Immunohistochemical and in situ hybridization studies of β- microseminoprotein in the human gastric mucosa

β-Microseminoprotein is a 10-kDa disulphide-rich protein with unknown function which is present in the mucus of the airways, gastrointestinal tract and urogenital tract. In this paper, an investigation of the distribution of β-microseminoprotein in the human stomach is reported. Immunohistochemistry and in situ hybridization were used. β-Microseminoprotein was found to be localized mainly in the a

In vitro stability of free prostate-specific antigen (PSA) and prostate- specific antigen (PSA) complexed to α1-antichymotrypsin in blood samples

Objectives. To study the in vitro stability of free and complexed forms of prostate specific antigen (PSA) in blood samples in order to establish guidelines for specimen handling, in particular for the clinical utility of the analysis of percentage free PSA. Methods. Blood samples were collected and processed to generate serum, heparin plasma, and EDTA plasma. Three different two-site immunoassays

A comparison of the free fraction of serum prostate specific antigen in men with benign and cancerous prostates : The best case scenario

Purpose: In most previous studies of free-to-total serum prostate specific antigen (PSA) ratios, the specimens from patients with prostate cancer or those with benign prostatic hyperplasia (BPH) have not been highly characterized. We compared preoperative sera from post-radical prostatectomy patients with clinically significant cancers of at least 2 cm.3 to sera from those with BPH and large, biop

Structural investigation of the alpha-1-antichymotrypsin : Prostate-specific antigen complex by comparative model building

Prostate-specific antigen (PSA), produced by prostate cells, provides an excellent serum marker for prostate cancer. It belongs to the human kallikrein family of enzymes, a second prostate-derived member of which is human glandular kallikrein-1 (hK2). Active PSA and hK2 are both 237-residue kallikrein-like proteases, based on sequence homology. An hK2 model structure based on the serine protease f

Isolation and characterization of the major gel proteins in human semen, semenogelin I and semenogelin II

Semenogelin I and semenogelin II constitute the major gel-forming proteins in human semen. The gel proteins were rapidly solubilized and separated from spermatozoa in ejaculates collected at pH 9.7 in buffer containing 4 mol/l urea and dithiothreitol. This protected the semenogelins from proteolytic degradation by prostate-specific antigen, and allowed their isolation by affinity chromatograph:g o

Alteration of the hormonal bioactivity of parathyroid hormone-related protein (PTHrP) as a result of limited proteolysis by prostate-specific antigen

Objectives. To discover whether the proteolytic activity of prostate- specific antigen (PSA) affects the structure and function of parathyroid hormone-related protein (PTHrP), as both are abundant components of human seminal plasma. Methods. The ability of PTHrP to act as a substrate was studied by incubating a synthetic polypeptide, consisting of 34 amino acid residues of the amino-terminal domai

Impaired Secretory Function of the Prostate in Men With Oligo‐Asthenozoospermia

ABSTRACT: The secretory function of the human prostate and the seminal vesicles is a prerequisite for gel formation and liquefaction of semen, but the relation to poor sperm motility and low sperm count in infertile men remains to be clarifyed. Our aim was to evaluate the secretory function of the prostate and the seminal vesicles in normozoospermic men (n=35) and in asthenozoospermic men, who wer

A prospective prostate cancer screening programme for men with pathogenic variants in mismatch repair genes (IMPACT): : initial results from an international prospective study

BACKGROUND: Lynch syndrome is a rare familial cancer syndrome caused by pathogenic variants in the mismatch repair genes MLH1, MSH2, MSH6, or PMS2, that cause predisposition to various cancers, predominantly colorectal and endometrial cancer. Data are emerging that pathogenic variants in mismatch repair genes increase the risk of early-onset aggressive prostate cancer. The IMPACT study is prospect

β microseminoprotein is not a prostate-specific protein. Its identification in mucous glands and secretions

β microseminoprotein (β inhibin, PSP94), an unglycosylated protein of 94 amino acids with unknown function, is one of the predominating proteins in the secretion of the human prostate gland. In this work the authors have demonstrated that the expression of β microseminoprotein is not restricted to the prostate and that the protein has a previously unrecognized widespread occurrence in the human bo

Three predominant proteins secreted by the human prostate gland

Analyses of the proteins of azoospermic ejaculates from subjects with defective seminal vesicles demonstrated that three prostatic‐secreted proteins were predominant. Prostatic acid phosphatase (PAP), prostate‐specific antigen (PSA; or γ‐seminoprotein), and β‐microsemi‐noprotein (β‐MSP; or β‐inhibin), were identified as the three predominant proteins secreted by the normal human prostate gland. Im