Imaging thermally damaged tissue by Polarization Sensitive Optical Coherence Tomography

Polarization Sensitive Optical Coherence Tomography (PS- OCT) was used to image the reduction of birefringence in biological tissue due to thermal damage. Through simultaneous detection of the amplitude of signal fringes in orthogonal polarization states formed by interference of light backscattered from turbid media and a mirror in the reference arm of a Michelson interferometer, changes in the polarization due to the optical phase delay between light propagating along the fast and slow axes of birefringent media were measured. Inasmuch as fibrous structures in many biological tissues in uence the polarization state of light backscattered, PS-OCT is a potentially useful technique to image the structural properties of turbid biological materials. Birefringence of collagen, a constituent of many biological tissues, is reduced by denaturation that takes place at a temperature between 56-65 0 C, thus providing an "optical marker" for thermal damage. Images showing reduction of birefringence due to thermal damage in porcine tendon and skin are presented and demonstrate the potential of PS-OCT for burn depth assessment.

Cloning, expression, purification, and characterization of the 6-phosphogluconate dehydrogenase from sheep liver

The mRNA encoding the 51-kDa subunit of 6-phosphogluconate dehydrogenase (6PGDH) from sheep liver was reverse-transcribed and amplified. The resulting cDNA was reamplified in N-terminal and C-terminal segments and spliced to generate a full-length clone, and an internal cDNA fragment was also amplified. The full-length clone containing the complete coding sequence of the 6PGDH cDNA was sequenced and found to contain two mutations and two deletions in the internal region and two mutations outside of the internal region, an A to G point mutation at position 1407 that resulted in the amino acid change Gln 445 to Arg and a silent mutation at position 1426. The internal clone was sequenced and shown to be free of any mutations; therefore the internal piece was used to replace the same region in the full-length clone to correct the mutations in this region. The mutation at position 1407 which was outside of the internal region was corrected using site-directed mutagenesis. The cDNA with the correct codon was then subcloned into the bacterial expression vector pQE-30 and overproduced in Escherichia coli strain M15. A protein with a subunit molecular weight of 51,000 was expressed at a level of about 4.5% of the total soluble protein in M15 as judged by SDS/PAGE. Cloning into pQE-30 adds six histidines and a short linker to the N-terminus of the enzyme. The recombinant 6PGDH with His-tag was purified using the Ni-NTA affinity column supplied by Qiagen. The purification procedure resulted in a homogeneous protein by SDS/PAGE with 22.4-fold purification with an overall yield of 61%. The recombinant enzyme exhibits kinetic parameters within error identical to those measured for native sheep liver enzyme.

Nitric oxide production and MDR expression by human brain endothelial cells

The endothelium both initiates and responds to a cascade of events triggered by cytokines. Enhanced formation of NO, especially by inducible nitric oxide- synthase (i NOS), is largely stimulated by tumor necrosis factor (TNF). Nitrogen oxides are reactive intermediate molecules functioning in neural transmission, and vasodilatation. The aim of our study was to investigate the effect of TNF and Staphylococcus aureus, a TNF inducing agent on the NO production of brain endothelial cells in vitro. The effect of the same agent was investigated on the MDR expression of endothelial cells. Both TNF and Staphylococcus aureus resulted in enhanced NO production. Western blot analysis showed enhanced expression of iNOS, which could be inhibited by pentoxifylline, an inhibitor of TNF synthesis. Flow cytometric analysis revealed that the brain capillary endothelial cells exerted P-glycoprotein expression, which was not influenced by TNF. However, the mdr function itself in these cells was decreased by TNF. Cultured endothelial cells are excellent tools for the investigation of the possible connection between the NO production and MDR function, and for the estimation the effect of different agents influencing these activities, which might be important in blood-brain barrier function.

Collection, tumor contamination, and engraftment kinetics of highly purified hematopoietic progenitor cells to support high dose therapy in multiple myeloma

Unfractionated peripheral blood stem cell (PBSC) grafts contain measurable quantities of myeloma cells and are therefore a potential source of relapse posttransplantation. In contrast, fluorescence-activated cell sorting (FACS)-sorted CD34+ Thy1+ Lin- peripheral blood cells are substantially enriched for stem cell activity, yet contain virtually no clonal myeloma cells. A study was performed in patients with symptomatic myeloma, who had received 12 months or less of preceding standard chemotherapy, to evaluate the feasibility of large scale purification of primitive hematopoietic stem cells in order to study engraftment kinetics posttransplantation and the degree of tumor cell contamination of this cell population, based on polymerase chain reaction (PCR) analysis for the patient-specific complementarity-determining region III (CDR III). PBSC were mobilized with high dose cyclophosphamide and granulocyte-macrophage colony-stimulating factor (GM-CSF). A combination of elutriation and chemical lysis was used to deplete PBSC collections of monocytes, granulocytes, erythrocytes, and platelets. Subsequently, CD34+ Thy1+ Lin- progenitor cells were purified with high speed cell sorting. Of the 10 evaluable patients, nine met the required minimum criteria of >/=7.2 x 10(5) cells/kg to support tandem transplants. After high dose melphalan (200 mg/m2) eight engrafted successfully, although granulocyte (absolute neutrophil count [ANC] >0.5 x 10(9)/L, 16 days) and platelet recovery (platelets > 50 x 10(9)/L, 39 days) was substantially delayed when compared with unmanipulated PBSC grafts; one patient required infusion of a reserve graft because of lack of evidence of engraftment by day +28. Three patients proceeded to a second graft with high dose melphalan and total body irradiation; two required infusion of a reserve graft and both died of infectious complications; one showed delayed, but complete, engraftment after this myeloablative regimen. Two of the nine evaluable patients attained a clinical complete remission (CR). The grafts from three patients were tested for tumor contamination and contained no detectable clonal myeloma cells. Larger quantities of purified cells may be required to resolve the problem of delayed engraftment.

The 67-kd laminin receptor is preferentially expressed by proliferating retinal vessels in a murine model of ischemic retinopathy

Endothelial cell association with vascular basement membranes is complex and plays a critical role in regulation of cell adhesion and proliferation. The interaction between the membrane-associated 67-kd receptor (67LR) and the basement membrane protein laminin has been studied in several cell systems where it was shown to be crucial for adhesion and attachment during angiogenesis. As angiogenesis in the pathological setting of proliferative retinopathy is a major cause of blindness in the Western world we examined the expression of 67LR in a murine model of hyperoxia-induced retinopathy that exhibits retinal neovascularization. Mice exposed to hyperoxia for 5 days starting at postnatal day 7 (P7) and returned to room air (at P12) showed closure of the central retinal vasculature. In response to the ensuing retinal ischemia, there was consistent preretinal neovascularization starting around P17, which persisted until P21, after which the new vessels regressed. Immunohistochemistry was performed on these retinas using an antibody specific for 67LR. At P12, immunoreactivity for 67LR was absent in the retina, but by P17 it was observed in preretinal proliferating vessels and also within the adjacent intraretinal vasculature. Intraretinal 67LR immunoreactivity diminished beyond P17 until by P21 immunoreactivity was almost completely absent, although it persisted in the preretinal vasculature. Control P17 mice (not exposed to hyperoxia) failed to demonstrate any 67LR immunoreactivity in their retinas. Parallel in situ hybridization studies demonstrated 67LR gene expression in the retinal ganglion cells of control and hyperoxia-exposed mice. In addition, the neovascular intra- and preretinal vessels of hyperoxia-treated P17 and P21 mice labeled strongly for 67LR mRNA. This study has characterized 67LR immunolocalization and gene expression in a murine model of ischemic retinopathy. Results suggest that, although the 67LR gene is expressed at high levels in the retinal ganglion cells, the mature receptor protein is preferentially localized to the proliferating retinal vasculature and is almost completely absent from quiescent vessels. The differential expression of 67LR between proliferating and quiescent retinal vessels suggests that this laminin receptor is an important and novel target for future chemotherapeutic intervention during proliferative vasculopathies.

Optical Monte Carlo modeling of a true portwine stain anatomy

A unique Monte Carlo program capable of accommodating an arbitrarily complex geometry was used to determine the energy deposition in a true port wine stain anatomy. Serial histologic sections taken from a biopsy of a dark red, laser therapy resistant stain were digitized and used to create the program input for simulation at wavelengths of 532 and 585 nm. At both wavelengths, the greatest energy deposition occurred in the superficial blood vessels, and subsequently decreased with depth as the laser beam was attenuated. However, more energy was deposited in the epidermis and superficial blood vessels at 532 nm than at 585 nm.

Identification of intron and exon sequences involved in alternative splicing of insulin receptor pre-mRNA

The insulin receptor exists as two isoforms, A and B, that result from alternative splicing of exon 11 in the primary transcript. We have shown previously that the alternative splicing is developmentally and hormonally regulated. Consequently, these studies were instigated to identify sequences within the primary RNA transcript that regulate the alternative splicing. Minigenes containing exons 10, 11, and 12 and the intervening introns were constructed and transfected into HepG2 cells, which contain both isoforms of the insulin receptor. The cells were able to splice the minigene transcript to give both A (- exon 11) and B-like (+ exon 11) RNAs. A series of internal deletions within intron 10 were tested for their ability to give A and B RNAs. Intron 10 contained two sequences that modulated exon 11 inclusion; a 48-nucleotide purine-rich sequence at the 5' end of intron 10 that functions as a splicing enhancer and causes an increase in exon 11 inclusion, and a 43-nucleotide sequence at the 3' end of intron 10 upstream of the branch point sequence that favors skipping of exon 11. Increasing the length of the polypyrimidine tract at the 3' end of intron 10 caused exon 11 to be spliced constitutively, indicating that a weak splice site is required for alternative splicing. Finally, point mutations, insertions, and deletions within exon 11 itself were able to regulate inclusion of the exon both positively and negatively.

Comparable engraftment kinetics following peripheral-blood stem-cell infusion mobilized with granulocyte colony-stimulating factor with or without cyclophosphamide in multiple myeloma

PURPOSE

To compare, in the setting of tandem autotransplantations for multiple myeloma (MM), two established methods of peripheral-blood stem-cell (PBSC) procurement with chemotherapy or hematopoietic growth factor alone.

PATIENTS AND METHODS

Between June 1994 and July 1995, 44 patients with MM were randomized to PBSC mobilization with either granulocyte colony-stimulating factor (G-CSF) 16 microg/kg (group 1; n = 22) or high-dose cyclophosphamide (HDCTX) 6 g/m2 plus G-CSF 5 microg/kg (group 2; n = 22). All 44 patients received melphalan 200 mg/m2 with their first autograft and 32 patients proceeded to a second transplantation.

RESULTS

Group 2 required a significantly longer time interval for completion of PBSC collection than group 1 (median, 22 v 8 days; P = .0001), greater frequency of hospitalization (100% v 32%; P = .0001), and increased transfusion of platelets (86% v 18%; P = .0001) and packed RBCs (86% v 55%; P = .02). Likewise, the incidence of fever and pneumonia/sepsis were higher in group 2 (P = .02 and P = .04, respectively). Surprisingly, despite greater CD34 cell quantities infused in group 2, median recovery times of granulocytes (both > 500/microL and 2,500/microL) and platelets (both > 50,000/microL and > 100,000/microL) were similar (all P > .7). Posttransplant toxicities were also similar.

CONCLUSION

Compared with HDCTX plus G-CSF, high-dose G-CSF alone is associated with lower morbidity, shorter duration of PBSC mobilization, and comparable hematopoietic recovery after transplantation, which should result in significant cost reduction. Considering the relatively limited antitumor activity of HDCTX (10% with > or = 50% tumor cytoreduction), PBSC mobilization with HDCTX should be limited to selected patients with persistent MM despite induction chemotherapy.

Alopecia areata and cytomegalovirus infection in twins: genes versus environment?

BACKGROUND

Alopecia areata (AA) is hypothesized to be an organ-specific autoimmune disease mediated by T cells directed to the hair follicle. Genetic susceptibility may be conferred by HLA, and an environmental trigger, such as a viral infection, is suspected. The incidence of AA in the population is estimated to be 1.7%, with an average of one in four patients having a positive family history.

OBJECTIVE

Our purpose was to examine the concordance rate of AA among identical versus fraternal twins and the correlation between stress, cytomegalovirus (CMV) infection, and disease.

METHODS

Families with AA were solicited from dermatologists in the United States and through a Website on the Internet. HLA class 2 typing and identification of CMV early and late genes were performed by polymerase chain reaction (PCR) on genomic peripheral blood DNA. Serum antibodies for CMV were determined by enzyme-linked immunosorbent assay.

RESULTS

From 114 families, we identified 11 sets of monozygotic twins and 3 sets of dizygotic twins. The concordance rate was 55% for monozygotic twins and 0% for fraternal twins. Most identical twins were male. The severity of the AA phenotype varied and appeared most severe in the first affected twin. Five of 24 twins were CMV seropositive but CMV DNA was not detected in blood lymphocytes of any of the subjects when studied after the onset of AA. The presence of AA in twins was not correlated with evidence of CMV.

CONCLUSION

A 55% concordance rate in identical twins and AA occurring in families support a genetic component as well as possible environmental triggers that remain unknown.

Collection of more hematopoietic progenitor cells with large volume leukapheresis in patients with multiple myeloma

Reinfusion of mobilized peripheral blood stem cells (PBSC) after high dose chemotherapy accelerates hematopoietic recovery. Because of the relatively low content of hematopoietic progenitors in the peripheral blood even after mobilization, multiple leukapheresis procedures are necessary to reach the required target number of CD34 cells to ensure prompt engraftment post-transplantation. Our previous studies have shown that the highest proportions of hematopoietic progenitors cells (CD34) are collected during the first three days of apheresis, whereas peak levels of myeloma cells are observed during subsequent days. Therefore, large volume leukapheresis (LVL), defined as processing of greater than 3 blood volumes or a total of at least 15 liters, was explored in 23 myeloma patients, undergoing 91 procedures; 14 patients were mobilized with high dose cyclophosphamide (6g/m2) and hematopoietic growth factors and 9 with G-CSF only. CD34 yields were measured separately for the first and last two hours of collection. We observed no decrease in CD34 cells/kg during the last two hours of collection and when the LVL collections were compared to historical matched controls, mobilized with the same regimen, the median quantity of CD34 cells/kg/liter collected remained equivalent during all days of apheresis. When compared to G-CSF only, mobilization with high dose cyclophosphamide appeared to result in superior hematopoietic stem cell collections. Interestingly, the G-CSF group experienced a progressive decrease in platelets during consecutive days of LVL, while the opposite was seen in the cyclophosphamide group. LVL procedures were not associated with a higher complication rate than standard volume apheresis. We conclude that LVL procedures allow collection of more CD34 cell per session while not jeopardizing progenitor cell collections during subsequent sessions. Since more CD34 cells are collected, fewer days are required to attain the optimal target of progenitor cells. This should result in PBSC grafts with less tumor contamination.

Influence of bromodeoxyuridine radiosensitization on malignant glioma patient survival: a retrospective comparison of survival data from the Northern California Oncology Group (NCOG) and Radiation Therapy Oncology Group trials (RTOG) for glioblastoma multiforme and anaplastic astrocytoma

PURPOSE

To examine the effect of treatment using Bromodeoxyuridine (BrdU) during radiation therapy on malignant glioma patient survival by comparing historical survival data from several large clinical trials.

METHODS

A retrospective analysis of patient data from Radiation Therapy Oncology Group (RTOG) trials 74-01, 79-18, and 83-02 and the Northern California Oncology Group (NCOG) study 6G-82-1 was conducted. Patient data was supplied by both groups, and analyzed by the RTOG. Pretreatment characteristics including age, extent of surgery, Karnofsky Performance Status (KPS), and histopathology were collected; the only treatment variable evaluated was the use of BrdU during radiation therapy. Radiation dose, dose-fractionation schedule, use of chemotherapy, and/or type of chemotherapy was not controlled for in the analyses. Univariate and multivariate analyses were conducted to examine the potential treatment effect of BrdU on patient survival.

RESULTS

Data from 334 patients treated with BrdU on NCOG 6G-82-1 and 1743 patients treated without BrdU on 3 RTOG studies was received. Patients were excluded from the review if confirmation of eligibility could not be obtained, if the patient was ineligible for the study they entered, if central pathology review was not done, or if radiotherapy data was not available. Patients treated according to the RTOG studies had to start radiotherapy within 4 weeks of surgery; no such restriction existed for the NCOG studies. To ensure comparability between the studies, patients from the NCOG studies who began treatment longer than 40 days from surgery were also excluded. The final data set included 296 cases from the NCOG studies (89%) and 1478 cases from the RTOG studies (85%). For patients with glioblastoma multiforme (GBM) the median survival was 9.8 months in the RTOG studies and 13.0 months in the NCOG trial (p < 0.0001). For patients with AA the median survival was 35.1 months for the RTOG studies and 42.8 months in the NCOG trial (p = 0.126). Univariate results showed consistent results favoring BrdU among patients over 30 years of age, across the extent of surgery, and for GBM patients. A proportional hazards regression model that included treatment, histopathology, KPS, age, and extent of surgery demonstrated that treatment with BrdU was included in the best model only for the GBM group of patients (risk ratio 0.83).

CONCLUSIONS

Because of the heterogeneity of the treatment groups, including potentially important differences in pathology reviewers assessment of nonglioblastoma cases, differences in radiation dose and schedules, and chemotherapy during or after radiation, these analyses cannot provide the definitive answer as to whether BrdU given during radiation therapy improves survival in patients with malignant glioma. There does appear to be a favorable treatment effect seen in patients with GBM, with a lesser effect in patients with AA.

Phasing the mirror segments of the Keck telescopes: the broadband phasing algorithm

To achieve its full diffraction limit in the infrared, the primary mirror of the Keck telescope (now telescopes) must be properly phased: The steps or piston errors between the individual mirror segments must be reduced to less than 100 nm. We accomplish this with a wave optics variation of the Shack-Hartmann test, in which the signal is not the centroid but rather the degree of coherence of the individual subimages. Using filters with a variety of coherence lengths, we can capture segments with initial piston errors as large as +/-30 microm and reduce these to 30 nm--a dynamic range of 3 orders of magnitude. Segment aberrations contribute substantially to the residual errors of approximately 75 nm.

Solving a real-world problem using an evolving heuristically driven schedule builder

This work addresses the real-life scheduling problem of a Scottish company that must produce daily schedules for the catching and transportation of large numbers of live chickens. The problem is complex and highly constrained. We show that it can be successfully solved by division into two subproblems and solving each using a separate genetic algorithm (GA). We address the problem of whether this produces locally optimal solutions and how to overcome this. We extend the traditional approach of evolving a "permutation + schedule builder" by concentrating on evolving the schedule builder itself. This results in a unique schedule builder being built for each daily scheduling problem, each individually tailored to deal with the particular features of that problem. This results in a robust, fast, and flexible system that can cope with most of the circumstances imaginable at the factory. We also compare the performance of a GA approach to several other evolutionary methods and show that population-based methods are superior to both hill-climbing and simulated annealing in the quality of solutions produced. Population-based methods also have the distinct advantage of producing multiple, equally fit solutions, which is of particular importance when considering the practical aspects of the problem.

Incidence of the mucopolysaccharidoses in Northern Ireland

An epidemiological study of the mucopolysaccharidoses (MPS) in Northern Ireland using multiple ascertainment sources was carried out and the incidence rate for the period 1958-1985 was estimated. An incidence of approximately 1 in 76,000 live births was obtained for MPS 1H (Hurler phenotype); 1 in 280,000 for MPS 1 H/S (Hurler/Scheie phenotype); 1 in 140,000 live births (1 in 72,000 male live births) for MPS II (Hunter syndrome); 1 in 280,000 for MPS III (Sanfilippo syndrome) and 1 in 76,000 for MPS IV A (Morquio syndrome type A). No cases of MPS IS (Scheie phenotype), MPS IV B (Morquio syndrome type B) or MPS VI (Maroteaux-Lamy syndrome) were ascertained during the study period. Three cases of non-immune hydrops fetalis born to consanguineous parents were thought to be due to beta-glucuronidase deficiency (MPS VII) on the basis of placental histology and enzyme studies on both parents but no living cases of MPS VII were ascertained. The overall incidence for all types of mucopolysaccharidosis was approximately 1 in 25,000 live births. A comparison is made with incidence estimates obtained from other published studies.

Pharmacokinetics and dose proportionality of beclomethasone from three strengths of a CFC-free beclomethasone dipropionate metered-dose inhaler

As part of a development program to offer alternatives to chlorofluorocarbon (CFC) containing metered-dose inhalers, beclomethasone dipropionate has been formulated in a CFC-free system at three strengths: 50, 100, and 200 micrograms/actuation ex valve. To measure serum levels and dose proportionality of the beclomethasone derived from beclomethasone dipropionate, 13 mild to moderate asthmatic patients received a single dose of eight inhalations from each strength according to a double-blind crossover design. Seven patients were studied over 4 h and six patients over 12 h. For the total doses of 400, 800, and 1600 micrograms studied over 12 h, Cmax and AUC increased in a ratio of 1:1.8:3.1. A good correlation was seen between the fine-particle mass delivered and the in vivo performance of the three strengths. From a clinical point of view, the predictable increases in serum levels with an increase in dose will permit the clinician to effectively titrate a patient with this product.

Childhood-onset schizophrenia. Progressive ventricular change during adolescence

BACKGROUND

There is controversy about progression in brain abnormalities in later-onset schizophrenia. This study looked for more striking progression in brain abnormalities during adolescence in a chronically ill, treatment-refractory sample of patients with childhood-onset schizophrenia who had had more prepsychotic developmental disturbance, but clinical and neurobiological characteristics similar to those of patients with treatment-refractory adult-onset schizophrenia who have poor outcome.

METHODS

Anatomic brain magnetic resonance images were obtained for 16 children and adolescents with onset of schizophrenia by 12 years of age and 24 temporally yoked, age- and sex-matched healthy controls. Subjects were scanned on initial admission and rescanned after 2 years with the identical equipment and measurement methods.

RESULTS

Childhood schizophrenics showed a significantly greater increase in ventricular volume than did controls, for whom ventricles did not increase significantly (analysis of variance, diagnosis x time, F = 16.1, P < .001). A significant decrease in midsagittal thalamic area was also seen for the schizophrenics (P = .03), which was unchanged at rescan for controls. These differential brain changes correlated significantly with each other and tended to be predicted by both prepsychotic developmental abnormality (Premorbid Assessment Scale, P = .06) and Brief Psychiatric Rating Scale at follow-up (P = .07).

CONCLUSIONS

More consistent progressive ventricular enlargement was seen during adolescence for this childhood-onset sample than has been reported for adult-onset populations. The brain imaging results support other clinical data showing both early and late deviations in brain development for at least this rare subgroup of treatment-refractory, very-early-onset schizophrenic patients.