Thermal response of a dental tissue induced by femtosecond laser pulses.

This paper reports a theoretical and experimental study for thermal transport in a thin slice of human tooth induced by a 120 fs, 800 nm pulse laser at a repetition rate of 1 kHz. The surface reflectivity of enamel and the convection heat transfer coefficient were determined using an inverse heat transfer analysis. Instead of a fully three-dimensional modeling, two simplified two-dimensional (2D) planar and axisymmetric heat conduction models were proposed to simulate the temperature fields. The temperature responses obtained from the 2D planar and axisymmetric model agree well with the experimental measurements. On the other hand, the one-dimensional (1D) result significantly differs from the 2D axisymmetric one, suggesting that care should be taken when a 1D thermal model is considered for estimating temperature response.

Analyses of PRMT1 proteins in human colon tissues from Hirschsprung disease patients.

BACKGROUND: Protein arginine methyltransferase 1 (PRMT1) catalyzes the majority of arginine methylation in cells and plays important roles in the differentiation and development of neurons. It is also implicated in the regulation of nitric oxide synthetase (NOS). Hirschsprung disease (HSCR) is characterized by the absence of intramural ganglion cells in the nerve plexuses of the distal gut. METHODS: Western blot analyses revealed reduced PRMT1 protein levels in the aganglionosis segments of HSCR patients. Immunohistochemistry detected PRMT1 expression in the colonic mucosa, the enteric nervous system (ENS) and endothelial cells. Specific and strong PRMT1 expression in neuron cell bodies of the plexus was demonstrated by immunofluorescent double-labeling with neuron-specific marker HuC/D. KEY RESULTS: In the mucosa, PRMT1 was detected at all crypt cells. Intensive PRMT1 staining was detected in the submucosal and the myenteric plexuses in normal or oligoganglionosis segments. Aganglionosis segments from HSCR patients contain no plexuses, and thus not labeled with PRMT1. The phenomenon is specific to the megacolon of HSCR as strong PRMT1 staining was observed in plexuses of the rectal ectasia segments (dilated rectum and distal sigmoid not related with aganglionosis) from anorectal malformation patients. Furthermore, PRMT1 was also present in the same neuronal cells expressing neuronal NOS in the plexuses. CONCLUSIONS & INFERENCES: We suggest that PRMT1 can be a useful marker for HSCR. This study is the first illustration of PRMT1 protein expression in human tissues from non-cancerous disease and set up the base for further investigations of PRMT1 function in ENS development and intestinal motility.

Paclitaxel and filgrastim for hematopoietic progenitor cell mobilization in patients with hematologic malignancies after failure of a prior mobilization regimen.

Paclitaxel and G-CSF have been evaluated for HPC mobilization in breast cancer and found to have tolerable toxicity with a predictable time to initiate leukapheresis. However, this approach has not been reported in patients with hematologic malignancies failing prior mobilization. We report a case-series of 26 adults given paclitaxel and G-CSF for HPC mobilization after failure of an initial mobilization. Patients received paclitaxel 250 mg/m(2) followed by G-CSF 10-16 mcg/kg/day. Compared to the initial regimen, paclitaxel mobilization produced greater CD34+ cell yields (median 1.53 x 10(6) CD34+ cells/kg vs. 0.79 x 10(6) CD34+ cells/kg, p = 0.004). Seventy-six percent of patients initiated leukapheresis on day 8, the remainder on day 9 or 10. Three patients developed febrile neutropenia resulting in one death prior to leukapheresis. Overall, 73% of patients proceeded with autologous HPC transplant. This case-series suggests paclitaxel may be an option for HPC mobilization in patients failing prior regimens.

Mice deficient in hepsin, a serine protease, exhibit normal embryogenesis and unchanged hepatocyte regeneration ability.

Hepsin, a liver-enriched novel serine protease, has been implicated in participating with normal cell growth, embryogenesis, and blood coagulation pathway. To study its function in vivo, we have disrupted the mouse hepsin gene by homologous recombination. Targeted disruption of the hepsin gene and ablation of hepsin message were demonstrated by Southern blotting, Northern blotting and RT-PCR analysis. Homozygous hepsin -/- mice were viable, fertile, and exhibited no gross abnormalities, as judged by the size, weight and blood coagulation (PT) assays. However, the serum concentration of the bone form of alkaline phosphatase, aspartate aminotransferase, and alanine aminotransferase of the hepsin -/- mice was mildly elevated, in spite of no obvious pathological change of hepatocytes. To examine whether hepsin is involved in controlling cell growth in adult tissues, 70% hepatectomy was applied to the hepsin -/- mice. Liver regeneration proceeded normally in the hepsin -/- mice as judged by the liver mass restoration rate. These results suggest that loss of hepsin function causes no effect in cell growth and embryogenesis in vivo, which is in contradiction to the studies using in vitro cell culturing system. Moreover, gross mass regeneration of liver after damage proceeds normally in the absence of functional hepsin.

Peripheral blood stem cell mobilization with cyclophosphamide in combination with G-CSF, GM-CSF, or sequential GM-CSF/G-CSF in non-Hodgkin's lymphoma patients: a randomized prospective study.

We designed a randomized, prospective three-arm mobilization study to determine the kinetics of peripheral blood stem cell (PBSC) mobilization in 60 non-Hodgkin's lymphoma (NHL) patients primed with cyclophosphamide (CTX) in combination with granulocyte colony-stimulating factor (G-CSF) (arm A), granulocyte-macrophage (GM)-CSF (arm B) or GM-CSF/G-CSF (arm C). We also compared mobilization and transplant-related toxicities, pre- and post-transplant support and the probability of survival among the three arms. To date, 35 patients have been enrolled in the study; 13 patients have been enrolled in arm A, 10 patients in arm B, and 13 patients in arm C. Successful collection of the target of > or = 2 X 10(6) CD34+ cells/kg in one to four apheresis collections was 10/13, 6/10, and 7/12 in arms A, B, and C, respectively. The differences between arms were not statistically significant. The median time to achieve the target CD34+ cells in patients who successfully mobilized the target CD34+ cells was 3 days, 2 days, and 1 day, in patients in arms A, B, and C, respectively. The time for neutrophil engraftment was 11, 10, and 10 days in arms A, B, and C, respectively. The time for platelet engraftment was 11 days for patients in all arms of the study. Most importantly, no significant differences were observed among the three arms in the duration of neutropenic fever, the extent of mucositis, diarrhea, and nausea/vomiting, or in the number of units of platelets or red cells transfused after transplantation. Risk factors associated with poor mobilization were > or = 3 regimens of chemotherapy prior to mobilization, older age, and disease histology (follicular versus diffuse). Therefore, we conclude that the type of growth factor used for mobilization did not play a major role in the outcome of mobilization and recommend mobilizing NHL patients before they receive multiple regimens of chemotherapy.

Successful PBSC mobilization with high-dose G-CSF for patients failing a first round of mobilization.

PBSC are the preferred source of stem cells for autologous transplantation. However, regardless of the mobilization procedure used, 10%-20% of patients fail to collect an adequate number to ensure prompt engraftment. There is as yet no standard mobilization procedure for patients who fail a first mobilization attempt. Here, we describe a highly efficient strategy to obtain an adequate number of stem cells for patients who failed a first mobilization attempt. Seventy-four patients with various hematologic malignancies underwent initial mobilization with various regimens including hematopoietic growth factors with or without chemotherapy. In 72% of patients, > or =2 x 10(6) CD34+ stem cells/kg were collected in the initial mobilization attempt, and patients engrafted in a median of 10 days for neutrophils and 12 days for platelets. Eighteen patients failed to mobilize adequate numbers of stem cells, defined as the inability to collect 0.2 x 10(6) CD34+ stem cells/kg/day in the first 2-3 days. These patients had their apheresis halted. Patients were immediately given G-CSF (32 microg/kg/day) for 4 days as a second attempt at mobilization. Eighty-eight percent of these patients achieved the target of > or =2 x 10(6) CD34+ cells/kg, with a median duration of apheresis of 5 days (including the first and second mobilizations). The mean CD34+ cells/kg/day increased after administration of high-dose G-CSF from 0.16 after the first mobilization attempt to 0.61 (p = 0.0002) after the second mobilization. All patients engrafted in a median of 11 and 13 days for neutrophils and platelets, respectively. We conclude that patients whose apheresis yield is <0.4 x 10(6) CD34+ cells/kg after the first two apheresis collections can be successfully mobilized if high-dose G-CSF is administered immediately and continued until achieving > or =2 x 10(6) CD34+ stem cells/kg.

Cokeromyces recurvatus infection in a bone marrow transplant recipient.

Diarrhea is common after bone marrow transplants. We report Cokeromyces recurvatus infection in a transplant recipient with diarrhea. Treatment with mystatin was effective.

Allogenic bone marrow transplantation for leukemias and aplastic anemia.

Bone marrow transplantation is the only curative treatment in adult patients with AML who fail to attain a complete remission or who experience a relapse. Unfortunately, the median age for patients with AML is estimated to be 62 years, which precludes allogeneic BMT for a significant number of patients with AML. For patients with relapsed AML who lack an HLA-identical donor or who are too old to undergo allogeneic BMT, autologous BMT should be considered since current standard salvage chemotherapy regimens do not produce durable remissions in the overwhelming majority of patients. The role of allogeneic and autologous BMT was initial postremission therapy is controversial. Ongoing studies may define the optimal postremission therapy for adult patients with AML in first remission.

Guidelines for the selective ordering of admission chest radiography in adult obstructive airway disease.

STUDY OBJECTIVE: To validate previously developed guidelines for the selective use of chest radiography in adults admitted for exacerbation of obstructive airway disease. DESIGN: Prospective, observational cohort study using criteria developed in a previous retrospective study. PARTICIPANTS: Unselected convenience sample of 128 adults with obstructive airway disease who did not respond to standard emergency department treatment and required admission. SETTING: Municipal hospital ED and inpatient medical service. INTERVENTIONS: Patients were categorized as "complicated" or "uncomplicated" according to previously developed criteria. Management was recorded as altered if the patient's physician answered the question, "Did the chest radiography alter your management of this patient?" affirmatively. RESULTS: Of 27 patients whose management was altered by the chest radiography, 26 were classified as complicated, for a sensitivity of 96% (95% confidence interval [CI], 81, 100). One of 44 admissions classified as uncomplicated had management altered by the chest radiography (negative predictive value, 98%, 95% CI, 88, 100). This chest radiography was later reread as normal. Classification as an uncomplicated patient with obstructive airway disease was strongly associated with either a normal chest radiography or a radiographic finding that was clinically unimportant (P = .0002). CONCLUSION: Patients with acute exacerbation of obstructive airway disease who are otherwise uncomplicated do not benefit from routine admission chest radiography. The use of this simple clinical strategy would safely reduce the number of chest radiographs by about one-third in this and similar patient populations, decreasing both health care costs and exposure to ionizing radiation.