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J D'Cunha

Publications and source records attributed to J D'Cunha.

9 recordsLinked to original sources
PubMed2006

Minimally invasive cancer surgery improves patient survival rates through less perioperative immunosuppression.

The import of the immune system to cancer survival is paramount. Immune effector cells are intimately involved in the patient's response to cancer. People with decreased immune function develop cancer more frequently. In the early stages of solid organ malignancies, surgery can potentially be curative. Surgical intervention, in and of itself, is immunosuppressive. Surgical resections are traditionally performed through large incisions. Technologic advances have allowed minimally invasive surgery (MIS) to evolve to the point it is now being used for cancer treatment. Recent minimally invasive series have reported improved survival and recurrence rates, as compared with historical data. We hypothesized that outcome differences for cancer patients undergoing open surgery vs. MIS are due to differential inhibition of immune effector cell function, in response to the different surgical stimulus. This increased immunosuppression after open surgery could potentially inhibit immune effector cell tumor surveillance as well as inhibit scavenging of any residual or micrometastatic disease or of tumor cells shed at the time of the operation. The less immunosuppressive MIS may leave immune function above a threshold level where remaining tumor is cleared. This difference would lead to less recurrence and to survival advantages. A deeper understanding of the integral components of the immune response to surgery would open the door for immunomodulation strategies and be of great clinical utility in guiding neoadjuvant, surgical, or adjuvant therapeutic decisions.

Carcinoma, Non-Small-Cell Lung↗
PubMed1996

In vitro and in vivo secretion of human ISG15, an IFN-induced immunomodulatory cytokine.

ISG15, a 15-kDa protein of unique primary amino acid sequence, functions intracellularly as a ubiquitin homologue and a cytokine that induces production of IFN-gamma and augments NK/lymphokine-activated killer cell proliferation and function. ISG15 is secreted from monocytes and lymphocytes, and in this study we have characterized in vitro and in vivo production of ISG15 in response to IFN-alphabeta. Low levels of ISG15 were present constitutively in PBMCs; dose-dependent ISG15 synthesis was observed in response to IFN-alpha or IFN-beta, but not IFN-gamma. High m.w. conjugates, present in PBMC extracts constitutively, were enhanced after IFN-alpha or IFN-beta treatment. Metabolic labeling experiments demonstrated that IFN-beta-induced ISG15 was released from primary cultures of peripheral blood CD3+ (including both CD4+ and CD8+ subpopulations). Furthermore, ISG15 was released from viable cell lines of monocyte, T lymphocyte, B lymphocyte, and epithelial origins. Since ISG15 was secreted in response to IFN treatment in vitro, its levels in the serum of healthy human volunteers treated with IFN-beta(ser) were quantitated by asymmetric sandwich ELISA. Both single and multiple doses of IFN-beta(ser) increased serum ISG15 levels significantly (p < 0.01) over baseline. A maximum 7.3-fold enhancement of serum ISG15 was obtained after multiple injections of 8 million units of IFN-beta(ser). Significant change was observed at 24 and 48 h of multiple 0.02-million-unit injections, yielding 1.2- and 1.7-fold increases over basal levels, respectively. These studies suggest that ISG15 is a novel member of the cytokine cascade that is synthesized and released in response to IFN-beta both in vitro and in vivo.

Adenocarcinoma↗
PubMed1996

Immunoregulatory properties of ISG15, an interferon-induced cytokine.

ISG15 is a 15-kDa protein of unique primary amino acid sequence, which is transcriptionally regulated by interferon (IFN) alpha and IFN-beta. Because it is synthesized in many cell types and secreted from human monocytes and lymphocytes, we postulated that ISG15 might act to modulate immune cell function. ISG15 stimulated B-depleted lymphocyte proliferation in a dose-dependent manner with significant proliferation induced by amounts of ISG15 as low as 1 ng/ml (58 pM). Maximal stimulation of [3H]thymidine incorporation by B-depleted lymphocytes occurred at 6-7 days. Immunophenotyping of ISG15-treated B-depleted lymphocyte cultures indicated a 26-fold expansion of natural killer (NK) cells (CD56+). In cytotoxicity assays, ISG15 was a potent inducer of cytolytic activity directed against both K562 (100 lytic units per 10(6) cells) and Daudi (80 lytic units per 10(6) cells) tumor cell targets, indicating that ISG15 enhanced lymphokine-activated killer-like activity. ISG15-induced NK cell proliferation required coculturing of T and NK cells, suggesting that soluble factor(s) were required. Measurement of ISG15-treated cell culture supernatants for cytokines indicated production of IFN-gamma (> 700 units/ml). No interleukin 2 or interleukin 12 was detected. IFN-gamma itself failed to stimulate lymphocyte proliferation and lymphokine-activated killer cell activation. Further, induced expression of IFN-gamma mRNA was detected by reverse transcription-PCR in T lymphocytes after ISG15 treatment but not in NK cells. Enhancement of NK cell proliferation, augmentation of non-major histocompatibility complex-restricted cytotoxicity, and induction of IFN-gamma from T cells identify ISG15 as a member of the cytokine cascade and suggest that it may be responsible for amplifying and directing some of the immunomodulatory effects of IFN-alpha or IFN-beta.

Adjuvants, Immunologic↗
PubMed1996

Production of ISG-15, an interferon-inducible protein, in human corneal cells.

ISG-15, a 15-kDa protein encoded by an interferon (IFN)-stimulated gene (ISG), was produced in human corneal cell cultures prepared from donor corneas in response to each of three major types of IFN, IFN-alpha, IFN-beta, and IFN-gamma. IFN-alpha and IFN-beta induced more ISG-15 in the first 24 h of treatment than did IFN-gamma. ISG-15 was detectable within the first 3 h of treatment with either type I IFN, and production peaked at 24 h, whereas IFN-gamma did not induce detectable ISG-15 until 16 h and did not induce peak production until 48 h. Conjugates of ISG-15 to cellular proteins were detectable by Western blot beginning at 9 h after IFN-alpha or IFN-beta treatment. ISG-15 persisted in IFN-treated cells for as long as 96 h. Free, unconjugated, ISG-15 was secreted by keratocytes into cell culture medium. The extent and kinetics of production, the conjugation of ISG-15 to cell proteins, and the secretion of ISG-15 in human fibroblast derived from corneas were IFN type dependent and dose dependent.

Cells, Cultured↗
PubMed1993

Multiple transitions to non-B-DNA structures occur in the distal regulatory region of the rat prolactin gene.

The developmentally regulated rat prolactin (rPRL) gene presents a promising model system toward understanding the biological role of non-B-DNA structural elements. Two predominantly alternating purine-pyrimidine (APP) (dA-dC)n.(dG-dT)n repeats of 58 and 178 base-pairs flank the (A + T)-rich distal regulatory region. We have characterized several transitions to non-B-DNA structures within this region in negatively supercoiled plasmids by utilizing high resolution chemical probing. Each repeat undergoes a full-length conversion to a novel left-handed helical structure via the stepwise nucleation and propagation of discrete "segments". These segments are delimited by out-of-alternation bases that are susceptible to attack by potassium permanganate and thus appear to be significantly unstacked within the left-handed helices. Moreover, the spatial order of successive right- to left-handed DNA transitions within each repeat exhibits a clear polarity toward the distal regulatory region of the rPRL gene. An additional transition involving the long-range unpairing of (A + T)-rich sequences establishes a directional propagation toward the regulatory region. These data demonstrate a complex series of quasi-independent transitions to non-B-DNA structures that impinge upon a known regulatory control region.

Animals↗
PubMed1990

High speed DNA sequencing by capillary electrophoresis.

A major challenge of the Human Genome Initiative is the development of a rapid, accurate, and efficient DNA sequencing technology. A major limitation of current technology is the relatively long time required to perform the gel electrophoretic separations of DNA fragments produced in the sequencing reactions. We demonstrate here that it is possible to increase the speed of sequence analysis by over an order of magnitude by performing the electrophoresis and detection in ultra thin capillary gels. An instrument which utilizes these high speed separations to simultaneously analyze many samples will constitute a second generation automated DNA sequencer suitable for large-scale sequence analysis.

Base Sequence↗
PubMed1990

High-speed separations of DNA sequencing reactions by capillary electrophoresis.

Fluorescently labeled DNA fragments generated in enzymatic sequencing reactions are rapidly separated by capillary gel electrophoresis and detected at attomole levels within the gel-filled capillary. The application of this technology to automated DNA sequence analysis may permit the development of a second generation automated sequencer capable of efficient and cost-effective sequence analysis on the genomic scale.

Base Sequence↗
PubMed1990

An automated instrument for the performance of enzymatic DNA sequencing reactions.

An instrument has been developed for the automation of enzymatic DNA sequencing reactions. Up to 96 DNA templates contained in a microtiter plate can be processed for either radioactive or fluorescence-based sequence analysis in a three-hour period. The quality of the resultant data is comparable to that obtained manually. The system is simple, flexible and is readily adapted to the use of new polymerases or modified experimental protocols.

Automation↗