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Biomedical subjects

Mark M Schubert

Publications and source records attributed to Mark M Schubert.

At least 19 recordsLinked to original sources
PubMed2006

Evidence that TRPC4 supports the calcium selective I(CRAC)-like current in human gingival keratinocytes.

We previously demonstrated that high external [Ca(2+)] activated two Ca(2+) currents in human gingival keratinocytes (HGKs): an initial small I(CRAC)-like current and a second large nonspecific cation current (Fatherazi S, Belton CM, Cai S, Zarif S, Goodwin PC, Lamont RJ, Izutsu KT; Pflugers Arch 448:93-104, 2004). It was recently shown that TRPC1, a member of the transient receptor potential protein family, is a component of the store-operated calcium entry mechanism in keratinocytes. To further elucidate the molecular identity of these channels, we investigated the expression of TRPC4 in gingival tissue and in cultured keratinocytes, and the effect of knockdown of TRPC4 expression on the Ca(2+) currents and influx. Immunohistochemistry showed TRPC4 was present in gingival epithelium as well as in HGKs cultured in different [Ca(2+)]s. Results from tissue and cultured HGKs demonstrated TRPC4 expression decreased with differentiation. Knockdown of TRPC4 in proliferating HGKs with antisense oligonucleotides significantly reduced the intracellular [Ca(2+)] increase obtained upon exposure to high external [Ca(2+)]. Antisense knockdown of TRPC4 expression was confirmed by reverse transcriptase polymerase chain reaction, Western blot, and immunofluorescence microscopy of transfected HGKs. Immunofluorescence microscopy and patch clamp measurements in Lucifer-yellow-tagged, antisense-treated HGKs showed attenuation of TRPC4 expression levels as well as attenuation of the I(CRAC)-like current in the same cell, whereas the large nonspecific cation current was unchanged but significantly delayed. Cells transfected with a scrambled TRPC4 oligonucleotide showed no change in either the I(CRAC)-like or nonspecific currents. The results indicate that TRPC4 is an important component of the I(CRAC)-like channel in HGKs.

Calcium↗
PubMed2006

Surgical treatment of erythroleukoplakia in lower lip with carbon dioxide laser radiation.

Erythroplakia is considered to represent a premalignant condition and is felt to be at high risk to progress to oral cancer development. When the lesion presents with red and white mucosal alterations concomitantly, the term erythroleukoplakia is used. However, in erythroleukoplakia lesions, the red or erythroplakia areas have been shown to be most likely to demonstrate dysplastic changes compared to the white hyperkeratotic areas. We present a case of patient with erythroleukoplakia involving the lower lip that was treating with carbon dioxide laser radiation (CO2) with 0.8 mm focus, 5 W, power density of 2.5 W/cm2 in continuous. After the surgery, the vaporized surface was protected with a fibrinolisine + chloramphenicol cream. To date, after 6 months, there has been no clinically evident recurrence on the vermilion area. The functional and esthetic results observed were judged to be excellent.

Adult↗
PubMed2006

Alimentary tract mucositis in cancer patients: impact of terminology and assessment on research and clinical practice.

BACKGROUND AND SIGNIFICANCE: The field of terminology and assessment of oral and gastrointestinal mucosal injury caused by high-dose cancer therapies in cancer patients has undergone important evolution in recent years. The advances are important for several clinical and research reasons. These reasons include improved patient management and design and conduct of clinical trials based on molecularly targeted therapies. For several decades leading up to the 1980s, terminology was characterized by varying use of "mucositis" and "stomatitis" to describe oral mucosal inflammatory changes and ulceration caused by cancer treatments. In addition, oral mucositis was viewed principally as an epithelial event and one that likely did not intersect with causative mechanisms associated with gastrointestinal mucositis. The term "stomatitis" was directed to oral toxicities and seemed to isolate these conditions from parallel events occurring throughout the alimentary tract and potentially other tissues as well. These perspectives and varying use of these terms resulted in several dilemmas, including (1) difficulty in accurately reporting incidence and severity of oral mucositis and, (2) an under-appreciation of potential significance of alimentary tract mucosal toxicity relative to overall course of therapy, patient quality of life, and in some cases, survivorship. These and related components of the model relative to mucositis have undergone strategic shifts over the past 15 years. A 1989 National Institutes of Health Consensus Development Conference targeted oral mucositis research as one of the key areas for investigation relative to causation, clinical impact, and potential links with other complications in cancer patients. Research in this area over the past 15 years has evolved such that oral and gastrointestinal mucositis are now appropriately framed as a continuum of pathobiologic changes over time, with clinical impact that may well contribute to overall symptom clustering in selected patient cohorts. OBJECTIVES: This paper will review history, current status, and new research directions associated with terminology and assessment of mucosal injury in cancer patients in the context described above.

Bibliometrics↗
PubMed2006

Alimentary mucositis: putting the guidelines into practice.

BACKGROUND: The Mucositis Study Group of the Multinational Association of Supportive Care in Cancer and International Society of Oral Oncology completed an evidence-based review of the literature for the management of alimentary mucositis. DISCUSSION: The present manuscript puts these guidelines into clinical practice by presenting two cases of alimentary mucositis from cancer therapy. These cases illustrate the impact of oral and gastrointestinal mucositis on patient care.

Antineoplastic Agents↗
PubMed2006

Developing evidence-based guidelines for management of alimentary mucositis: process and pitfalls.

INTRODUCTION: It is important yet difficult to maintain currency in clinical oncology practice. The emergence of new diagnostic technologies and new paradigms for cancer treatment combine to produce a rapidly changing clinical approach to patients aided by the increasing use of multidisciplinary care teams and development of evidence-based protocols. METHODS: Teams of experts review the literature in a given area and produce management guidelines and protocols for use by practicing clinicians. Traditionally within Hematology/Oncology, these guidelines have been directed to management of a given tumor type. However, in recent years, attention has increasingly turned to supportive oncology; for example, there are now management guidelines for conditions such as neutropenic fever [Hughes et al. Clinical Infectious Diseases 34(6):730-751, 2002], antiemetic (The Antiemetic Subcommittee of the Multinational Association of Supportive Care in Cancer Annals of Oncology 17:20-28, 2006) and most recently, mucositis [Rubenstein et al. Cancer 100(9 Suppl):2026-2046, 2004]. It is critical that any guideline process should include education, evaluation, and timely update in its remit, because guidelines become highly compromised if their existence is not widely known, if they do not facilitate clinical practice, or if they are not reflective of contemporary medical literature. RESULTS: The Mucositis Study Group (MSG) of the Multinational Association for Supportive Care in Cancer/International Society for Oral Oncology was created in 1998 to specifically address the multiprofessional approach to clinical care, research, and education associated with mucosal injury in cancer patients. A specific outcome has been the development of evidence-based guidelines for the management of mucositis [Rubenstein et al. Cancer 100(9 Suppl):2026-2046, 2004; The Mucositis Study Group of MASCC/ISSO 2005]. The original guidelines [Rubenstein et al. Cancer 100(9 Suppl):2026-2046, 2004] and a companion paper discussing the science behind mucositis [Sonis et al. Cancer 100(9):1995-2025, 2004], were published in 2004. The MSG has recently updated the guidelines [The Mucositis Study Group of MASCC/ISSO 2005]. DISCUSSION: This paper discusses the process involved and the lessons learned that might help other groups planning to undertake a similar project.

Effect Modifier, Epidemiologic↗
PubMed2006

Amifostine in the management of radiation-induced and chemo-induced mucositis.

INTRODUCTION: Mucositis is a significant complication of cancer therapy, with important clinical and economic implications. In June 2005, the Mucositis Study Group of the Multinational Association of Supportive Care in Cancer/International Society for Oral Oncology (MASCC/ISOO) conducted an evidence-based update review of the literature on mucositis. The goal of this literature review is to update previously published guidelines for the management of mucositis. RESULTS: This article reports the findings of the subgroup charged with reviewing the literature related to amifostine.

Amifostine↗
PubMed2006

Anti-inflammatory agents in the management of alimentary mucositis.

BACKGROUND: Alimentary mucositis is a significant complication of cancer therapy, with important clinical and economic implications. MATERIALS AND METHODS: In June 2005, the Mucositis Study Group of the Multinational Association of Supportive Care in Cancer/International Society for Oral Oncology conducted an evidence-based review of the literature on alimentary mucositis. The goal of this literature review was to update previously published guidelines for the management of mucositis. RESULTS: This article reports the findings of the subgroup charged with reviewing the literature related to anti-inflammatory interventions. Considerable preclinical and clinical evidence suggests that the use of anti-inflammatory agents may be a promising approach to reduce the severity of mucositis. However, there was not enough evidence to support any new guidelines advocating the use of any specific anti-inflammatory intervention. CONCLUSION: Thus, there is a need for well-designed clinical trials evaluating the use of anti-inflammatory agents in the management of mucositis.

Allopurinol↗
PubMed2006

Ancillary therapy and supportive care of chronic graft-versus-host disease: national institutes of health consensus development project on criteria for clinical trials in chronic Graft-versus-host disease: V. Ancillary Therapy and Supportive Care Working Group Report.

The Ancillary Therapy and Supportive Care Working Group had 3 goals: (1) to establish guidelines for ancillary therapy and supportive care in chronic graft-versus-host disease (GVHD), including treatment for symptoms and recommendations for patient education, preventive measures, and appropriate follow-up; (2) to provide guidelines for the prevention and management of infections and other common complications of treatment for chronic GVHD; and (3) to highlight the areas with the greatest need for clinical research. The definition of "ancillary therapy and supportive care" embraces the most frequent immunosuppressive or anti-inflammatory interventions used with topical intent and any other interventions directed at organ-specific control of symptoms or complications resulting from GVHD and its therapy. Also included in the definition are educational, preventive, and psychosocial interventions with this same objective. Recommendations are organized according to the strength and quality of evidence supporting them and cover the most commonly involved organs, including the skin, mouth, female genital tract, eyes, gastrointestinal tract, and lungs. Recommendations are provided for prevention of infections, osteoporosis, and steroid myopathy and management of neurocognitive and psychosocial adverse effects related to chronic GVHD. Optimal care of patients with chronic GVHD often requires a multidisciplinary approach.

Ancillary Services, Hospital↗
PubMed2005

Evidence that TRPC1 contributes to calcium-induced differentiation of human keratinocytes.

External calcium ion concentration is a major regulator of epidermal keratinocyte differentiation in vitro and probably also in vivo. Regulation of calcium-induced differentiation changes is proposed to occur via an external calcium-sensing, signaling pathway that utilizes increases in intracellular calcium ion concentration to activate differentiation-related gene expression. Calcium ion release from intracellular stores and calcium ion influx via store-operated calcium-permeable channels are key elements in this proposed signaling pathway; however, the channels involved have not yet been identified. The present report shows that human gingival keratinocytes (HGKs) also undergo calcium-induced differentiation in vitro as indicated by involucrin expression and morphological changes. Moreover, TRPC1, which functions as a store-operated calcium channel in a number of cell types, including epidermal keratinocytes, is expressed in both proliferating and differentiating HGKs. Transfection of HGKs with TRPC1 siRNA disrupted expression of TRPC1 mRNA and protein compared with transfection with scrambled TRPC1 siRNA. Cells with disrupted TRPC1 expression showed decreased calcium-induced differentiation as measured by involucrin expression or morphological changes, as well as decreased thapsigargin-induced calcium ion influx, and a decreased rate of store calcium release. These results indicate that TRPC1 is involved in calcium-induced differentiation of HGKs likely by supporting a store-operated calcium ion influx.

Calcium↗
PubMed2005

Bisphosphonate-associated osteonecrosis of mandibular and maxillary bone: an emerging oral complication of supportive cancer therapy.

BACKGROUND: The current report presented 17 patients with cancer with bone metastases and 1 patient with osteopenia who received treatment with bisphosphonates and who subsequently developed osteonecrosis of the mandible and/or maxilla. METHODS: The authors reviewed information on 18 patients who were referred to oral medicine or oral surgery specialists for evaluation and treatment of mandibular and/or maxillary bone necrosis from June 2002 to September 2004. To be included in the current review, patients must have been treated with either pamidronate or zoledronic acid to control or prevent metastatic disease, or with alendronate for osteoporosis. All patients with cancer had received chemotherapy while receiving bisphosphonate management. RESULTS: The 17 patients with cancer were receiving active medical care for a malignancy. Cancer treatment included a variety of chemotherapeutic agents. They presented with metastatic disease to bone and were treated intravenously with the bisphosphonates pamidronate or zoledronic acid for a mean time of 25 months (range, 4-41 mos). There were 14 females and 4 males with a mean age of 62 years (range, 37-74 yrs). Malignancies included breast carcinoma (n = 10), multiple myeloma (n = 3), prostate carcinoma (n = 1), ovarian carcinoma (n = 1), prostate carcinoma/lymphoma (n = 1), and breast/ovarian carcinoma (n = 1). One female patient with osteopenia received alendronate. The most common clinical osteonecrosis presentations included infection and necrotic bone in the mandible. Associated events included dental extractions, infection, and trauma. Two patients appeared to develop disease spontaneously, without any clinical or radiographic evidence of local pathology. Despite surgical intervention, antibiotic therapy, hyperbaric oxygen therapy, and topical use of chemotherapeutic mouth rinses, most of the lesions did not respond well to therapy. Discontinuation of bisphosphonate therapy did not assure healing. However, 1 patient with cancer healed after discontinuation of bisphosphonate therapy for 4 months. CONCLUSIONS: The findings in the patient population combined with recent literature reports suggested that bisphosphonates may contribute to the pathogenesis of the oral lesions. The risk factors and precise mechanism involved in the formation of the osteonecrosis are not known. This condition represents a new oral complication in patients with cancer and can be termed bisphosphonate-associated osteonecrosis. Lesions in patients with osteoporosis are worrisome and need to be further evaluated.

Adult↗
PubMed2005

Molecular identification of an invasive gingival bacterial community.

A woman with neutropenia developed gingival hyperplasia. Biopsy showed invasion of gingival tissue with mats of filamentous organisms, and molecular analysis by polymerase chain reaction and fluorescence in situ hybridization revealed Capnocytophaga sputigena, Leptotrichia species, and Fusobacterium nucleatum. Oral bacterial flora may cause invasive gingival disease with hyperplasia in immunocompromised patients.

Capnocytophaga↗
PubMed2005

A phase I/II study of mycophenolate mofetil in combination with cyclosporine for prophylaxis of acute graft-versus-host disease after myeloablative conditioning and allogeneic hematopoietic cell transplantation.

Abstract In a phase I/II study, the combination of cyclosporine (CSP) and mycophenolate mofetil (MMF) was investigated as graft-versus-host disease (GVHD) prophylaxis after myeloablative conditioning and hematopoietic cell transplantation from an HLA-matched sibling donor. In phase I, 3 groups, each with 10 or 11 patients, received MMF (15 mg/kg) from day 0 to day 27 at decreasing dose intervals of every 12, 8, and 6 hours to determine a safe and effective total daily dose. At the 45 mg/kg/d dosage level, 4 of 11 patients developed only grade II GVHD, and a concentration at steady state of mycophenolic acid (the active moiety of MMF) consistent with a therapeutic range described for solid-organ transplantation was achieved. There was a suggestion of increased toxicity without improved efficacy at the 60 mg/kg/d dosage level. Accordingly, the 45 mg/kg/d dosage was therefore selected for phase II, and another 15 patients were added to this group from the phase I study (n=26). The concentrations at steady state for this dosage at days 0, 6, 13, 20, and 27 were 2.73, 3.02, 3.20, 2.62, and 2.64 microg/mL, respectively. No toxicities were attributed to MMF at this dose. The median time to engraftment after hematopoietic cell transplantation was 15 days (range, 10-20 days). The incidence of acute GVHD was 62%, which was comparable to a group of historical controls receiving CSP and methotrexate (MTX) for GVHD prophylaxis. Although a significant improvement in the prevention of GVHD was not suggested, compared with CSP and MTX, MMF in combination with CSP could be considered in cases in which MTX is contraindicated.

Adolescent↗
PubMed2004

Predictors of oral mucositis in patients receiving hematopoietic cell transplants for chronic myelogenous leukemia.

PURPOSE: Oral mucositis is a nearly universal and often severe complication following hematopoietic cell transplantation (HCT). The objective of this study was to evaluate factors predicting oral mucositis severity among 133 patients undergoing allogeneic HCT for chronic myelogenous leukemia. PATIENTS AND METHODS: All patients were transplanted between 1992 and 1999, were >or= 18 years of age, received either cyclophosphamide/total-body irradiation (TBI) or busulfan/cyclophosphamide conditioning regimens, and received four doses of methotrexate for graft-versus-host disease prophylaxis post-transplant. Oral mucositis was measured by a trained examiner every 2 to 3 days using the Oral Mucositis Index (OMI). Multiple linear regression analysis was used to identify predictors of mean OMI during days 6 to 12, 1 to 18, and the maximum OMI score between days 1 to 18. RESULTS: TBI containing conditioning regimens, body mass index >or= 25, and methylenetetrahydrofolate reductase 677 TT genotype were found to be predictive of higher mean OMI scores (P <.05). Pretransplant multivitamin supplement use was associated with lower mean OMI scores compared to those who did not use supplements. Smoking status, race, pretransplant treatment with interferon-alfa or hydroxyurea, and patient/donor ABO compatibility were not associated with mean OMI scores. CONCLUSION: Patients who are scheduled to receive conditioning regimens containing TBI, have a pretransplant body mass index >or= 25, or carry the methylenetetrahydrofolate reductase 677 TT genotype should be considered at greater risk of developing oral mucositis following HCT. Future studies should investigate whether multivitamin supplementation before HCT could reduce mucositis severity.

Adolescent↗
PubMed2004

Calcium oscillations in gingival epithelial cells infected with Porphyromonas gingivalis.

The periodontal pathogen Porphyromonas gingivalis modulates epithelial cell signal transduction pathways including Ca2+ signaling, and internalizes within the host cell cytoplasm. Since nuclear and cytoplasmic [Ca2+] increases can induce different host cell responses, P. gingivalis-related [Ca2+] changes in these compartments were measured by digital fluorescent imaging microscopy. Non-deconvolved and deconvolved fura-2 images showed that P. gingivalis exposure caused human gingival epithelial cells cultured in physiologic [Ca2+] levels to undergo sustained oscillations of [Ca2+] in nuclear and cytoplasmic spaces. However, P. gingivalis invasion was not tightly correlated with intracellular [Ca2+] oscillations, since invasion could significantly precede, or even occur in the absence of, oscillations. [Ca2+] oscillations required a Ca2+ influx, which was completely inhibited by La3+ or 2-APB (2-aminoethoxydiphenyl borate), indicating Ca2+ entry was via a Ca(2+)-permeable channel. Ca2+ entry was likely not via a store-operated channel, since Ca2+ release from intracellular stores was not observed during cellular uptake of P. gingivalis. Hence, uptake of P. gingivalis in gingival epithelial cells induces oscillations in nuclear and cytoplasmic spaces by activating a Ca2+ influx through Ca2+ channels.

Biological Transport↗
PubMed2004

Managing pain in mucositis.

OBJECTIVE: To discuss pharmacologic and nonpharmacologic approaches available to manage pain. DATA SOURCE: Published journal articles, book chapters, clinical experience. CONCLUSION: Pain management requires treatment directed at the various factors involved in the pain experience. IMPLICATIONS FOR NURSING PRACTICE: Nurses need to assess pain daily and follow patients closely until mucositis resolves. Management targeted to specific dimensions of pain can improve the effectiveness of pain control.

Acute Disease↗
PubMed2004

Management of oral mucositis pain.

Effective pain control for mucositis requires constant attention and willingness on the part of managing clinicians to evaluate and adapt pain relieving strategies throughout the period of risk for oral mucositis. By utilizing the principles of a individualized, tiered approach to pain management, that address the multidimensional components of a patient's pain, maximum comfort can be consistently provided while reducing the risk for side-effects.

Adult↗
PubMed2003

Oropharyngeal mucositis in cancer therapy. Review of pathogenesis, diagnosis, and management.

Oropharyngeal mucositis is a common and treatment-limiting side effect of cancer therapy. Severe oral mucositis can lead to the need to interrupt or discontinue cancer therapy and thus may have an impact on cure of the primary disease. Mucositis may also increase the risk of local and systemic infection and significantly affects quality of life and cost of care. Current care of patients with mucositis is essentially palliative and includes appropriate oral hygiene, nonirritating diet and oral care products, topical palliative mouth rinses, topical anesthetics, and opioid analgesics. Systemic analgesics are the mainstay of pain management. Topical approaches to pain management are under investigation. The literature supports use of benzydamine for prophylaxis of mucositis caused by conventional fractionationated head and neck radiotherapy, and cryotherapy for short-half-life stomatoxic chemotherapy, such as bolus fluorouracil. Continuing studies are investigating the potential use of biologic response modifiers and growth factors, including topical and systemic delivery of epithelial growth factors and agents. Progress in the prevention and management of mucositis will improve quality of life, reduce cost of care, and facilitate completion of more intensive cancer chemotherapy and radiotherapy protocols. In addition, improved management of mucositis may allow implementation of cancer treatment protocols that are currently excessively mucotoxic but may produce higher cure rates. Continuing research related to the pathogenesis and management of mucositis will undoubtedly lead to the development of potential interventions and improved patient care.

Antineoplastic Agents↗