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PubMed2005

Viscoelasticity of the trachea and its effects on flow limitation.

To test the hypothesis that peak expiratory flow is determined by the wave-speed-limiting mechanism, we studied the time dependency of the trachea and its effects on flow limitation. For this purpose, we assessed the relationship between transmural pressure and cross-sectional area [the tube law (TL)] of six excised human tracheae under controlled conditions of static (no flow) and forced expiratory flow. We found that TLs of isolated human tracheae followed quite well the mathematical representation proposed by Shapiro (Shapiro AH. J Biomech Eng 99: 126-147, 1977) for elastic tubes. Furthermore, we found that the TL measured at the onset of forced expiratory flow was significantly stiffer than the static TL. As a result, the stiffer TL measured at the onset of forced expiratory flow predicted theoretical maximal expiratory flows far greater than those predicted by the more compliant static TL, which in all cases studied failed to explain peak expiratory flows measured at the onset of forced expiration. We conclude that the observed viscoelasticity of the tracheal walls can account for the measured differences between maximal and "supramaximal" expiratory flows seen at the onset of forced expiration.

Compliance↗

PubMed1997

Examination of telomere lengths in muscle tissue casts doubt on replicative aging as cause of progression in Duchenne muscular dystrophy.

The mean telomere length (TL) of somatic cells indicates their replicative age. In comparison with normal leukocytes (-0.03 kbp/y, 6.2 kbp at 80 y), we found advanced TL shortening in premature aging due to ataxia-telangiectasia or the Nijmegen chromosomal breakage syndrome. Duchenne muscular dystrophy (DMD) has been related to replicative senescence of satellite cells (SCs) caused by increased fiber turnover. Therefore, we determined TLs in DMD muscle. Because the regenerated fiber nuclei are produced by SCs. telomeres of both fiber and SC nuclei should be shortened. In DMD the SC number is increased. We determined that up to the age of 7 y the sum of fiber and SC nuclei should be large enough (73%) for the detection of TL shortening. Normal muscle fibers have negligible turnover rates, and, as expected, we did not find age-related TL shortening (10-83 y, n = 24, 8.3 +/- 0.5 kbp). Surprisingly, there was only slight TL shortening in patient muscles (DMD, 0.3-4.8 y, n = 4, 8.3 +/- 0.7 kbp; 5-7 y, n = 7, 7.9 +/- 0.4 kbp; limb-girdle muscular dystrophy 2C, 13 y, 7.6 kbp; Becker muscular dystrophy, 7 y, 8.5 kbp). Similarly, the peak positions of the telomere blots varied only slightly (DMD, 10.0 +/- 0.9 kbp; normal: 10.7 +/- 0.9 kbp). In accordance with our TL findings we derived less than 4 annual doublings per SC from published histologic data on DMD.

Adolescent↗

PubMed2006

Exceptionally narrow homogeneous linewidth in erbium-doped glasses.

We show that rare-earth (RE-) doped glasses can have homogeneous linewidths as narrow as 287 kHz at (4)He temperatures. This is far narrower than others reported in glasses in the same temperature range and is suitable for precise spectral hole burning and spatial-spectral holographic applications. It is known that cw spectral hole burning linewidth measurements of RE ions in glasses are hindered by the presence of spectral diffusion but, even in glasses, application of a magnetic field can freeze out RE spin-spin interactions responsible for spectral diffusion and isolate the remaining contribution of two-level systems (TLSs). The Er(3+):2G2S glasses have unusually low TLS contributions, making it possible to study the real homogeneous linewidth using photon echo measurements. The contribution from TLSs is only 170 T(1.3) kHz when subjected to a field of 5 T.

Journal Article↗

PubMed2002

Psychobiological and evolutionary perspectives on coping and health characteristics following loss: a twin study.

An analysis of coping, grief and health characteristics is reported for a bereaved monozygotic (MZ) and dizygotic (DZ) same-sex twin sample. The data were examined with reference to psychobiological and evolutionary perspectives on behavior. A Coping Scale, included as part of a comprehensive Twin Loss Survey (TLS), assessed coping with daily responsibilities and activities 1-2 months before the co-twin's death, 1-2 months following the co-twin's death and currently. A Grief Intensity Scale obtained judgments of grief 1-2 months following the loss, and currently. Information on physical symptoms was available from the Somatization Scale of the Grief Experience Inventory. Psychobiological and evolutionary perspectives specified hypotheses for two twin groups: one model was specified to reflect bereavement experiences immediately following loss of the co-twin (retrospective twin group); a second model represented present bereavement response (current twin group). Consistent with psychobiological theory, twins' social closeness showed a positive association with grief intensity which, in turn, affected somatic symptoms and coping efficacy in predicted directions. With respect to evolutionary psychological theory, the effect of zygosity on current grief implicated correlates of genetic relatedness as factors in the bereavement process.

Activities of Daily Living↗

PubMed2000

The role of the use of different host plants in the maintenance of the inversion polymorphism in the cactophilic Drosophila buzzatii.

Inversion polymorphisms often have been associated with fitness variation. Cactophilic Drosophila buzzatii has been used widely for the study of the maintenance of chromosomal variation. The purpose of this paper is to address the relative importance of variable selection regimes associated with the use of three different host cacti and antagonistic pleiotropy in the maintenance of chromosomal variation. Using homokaryotypic stocks derived from several lines homozygous for four second-chromosome arrangements, we show that inversions significantly affect first-instar larva to adult viability (VT), developmental time (DT) and adult thorax length (TL). We also show that the effects of inversions on DT and VT are dependent on the cactus rearing media. The effects of polymorphic gene arrangements on life-history traits suggest the existence of trade-offs between early and late fitness components. The dosage of arrangement 2st, the ancestral gene order, was negatively correlated with DT and TL, whereas flies carrying the derived arrangements 2j and 2jq7 had longer DTs and larger TLs. Arrangements 2st and 2jq7 increased viability, at least in one of the cactus media tested. Our results suggest that environmental heterogeneity, as represented by the use of different cactus hosts and the trade-off between DT and TL, may be involved in the maintenance of the polymorphism. In addition, our data suggest that the chromosomal phylogeny may be decoupled from the evolution of the genes affecting life-history traits linked to the inversion system.

Animals↗

PubMedDate not supplied

Security, privacy, and confidentiality issues on the Internet.

We introduce the issues around protecting information about patients and related data sent via the Internet. We begin by reviewing three concepts necessary to any discussion about data security in a healthcare environment: privacy, confidentiality, and consent. We are giving some advice on how to protect local data. Authentication and privacy of e-mail via encryption is offered by Pretty Good Privacy (PGP) and Secure Multipurpose Internet Mail Extensions (S/MIME). The de facto Internet standard for encrypting Web-based information interchanges is Secure Sockets Layer (SSL), more recently known as Transport Layer Security or TLS. There is a public key infrastructure process to 'sign' a message whereby the private key of an individual can be used to 'hash' the message. This can then be verified against the sender's public key. This ensures the data's authenticity and origin without conferring privacy, and is called a 'digital signature'. The best protection against viruses is not opening e-mails from unknown sources or those containing unusual message headers.

Computer Security↗

PubMed1994

Echoplanar MR imaging of the liver in patients with focal hepatic lesions: quantitative analysis of images made with various pulse sequences.

OBJECTIVE: We undertook this study to evaluate pulse-sequence performance in terms of liver signal-to-noise ratio (SNR) and lesion-liver contrast-to-noise ratio (CNR) on T1- and T2-weighted echoplanar MR imaging. SUBJECTS AND METHODS: Forty-nine patients referred for MR imaging of the liver were examined at 1.5 T with echoplanar MR imaging using spin-echo, inversion-recovery, and gradient-echo pulse sequences. T2-weighted spin-echo (TE = 25, 50, 100, and 150 msec), T1-weighted inversion-recovery (T1 = 100, 380, 600, and 800 msec), and T2*-weighted gradient-echo (TE = 20 msec) images were acquired after one excitation (TR = infinite), using a 128 x 128 data matrix. T2-weighted spin-echo (TE = 20, 50, 100, and 150 msec) images were also obtained with two excitations (TR = 6 sec), resulting in a 128 x 256 data matrix. Signal intensity measurements were made to calculate liver SNR and lesion-liver CNR. RESULTS: Single-excitation, T2-weighted, spin-echo images at a minimum TE of 25 msec provided the highest liver SNR (p < .05). Single-excitation, T2-weighted, spin-echo images at TEs of 50 and 100 msec, and T1-weighted inversion-recovery images at Tls of 100 and 380 msec provided the highest lesion-liver CNR (p < .05). However, the latter two pulse sequences had considerably inferior liver SNR (p < .05). CONCLUSION: Single-excitation, T2-weighted, spin-echo images provide both superior liver SNR and superior lesion-liver CNR. These results can be used to guide technique selection when echoplanar MR imaging is used to examine the liver.

Echo-Planar Imaging↗

PubMed1975

Dynamics of tolbutamide, glucose, and insulin interrelationships following varying doses of intravenous tolbutamide in normal subjects.

Four healthy adult subjects received intravenous tolbutamide (TOL) at six different doses (twenty-four tests): 0.0625 gm., 0.125 gm., 0.25 gm., 0.5 gm., 1.0 gm. and 1.5 gm. Blood glucose (BG), serum immunoreacctive insulin (IRI) and serum TOL levels were determined before and for 180 minutes after TOL. There was a highly significant correlation of the dose of TOL with the peak IRI (p less than .01), zero to ten minute IRI area (p less than .001), and zero to sixty minute IRI area (p less than .001) and with the decline in BG expressed as zero to sixty minute BG area (p less than .001). Similar significant correlations were observed between levels of TOL and both IRI and BG. At each dose level the IRI response correlated significantly with the BG fall. An additional eighteen subjects received the 1.0 gm. dose. In these, serum TOL levels did not correlate with either BG or IRI. These subjects also received intravenous glucose (0.5 gm. per kilogram body weight). BG levels did not correlate with IRI. However, there were striking correlations between TOL and glucose-stimulated peak IRI (p less than .001), zero to ten minute IRI area (p less than .05). The mean (plus or minus SEM) space of distribution for glucose (G.S.) and tolbutamide (TLS.) was found to be 13.45 plus or minus 0.71 and 6.34 plus or minus 0.31 L., respectively. There was a significant dose-response relationship exists between TOL and IRI. TOL- and glucose-induced IRI secretion dynamics suggest strong similarities between mechanisms of rapid IRI release and/or size of available IRI storage pools.

Adult↗

PubMed1999

Surgical treatment of T1-T2 glottic carcinomas.

Transoral laser surgery (TLS) is a safe, time and cost-effective method of treatment for early stage glottic squamous cell carcinoma. This technique is more controversial in case of local extension to other subsite or in case of limited mobility.

Carcinoma, Squamous Cell↗

PubMed1999

Communication security in open health care networks.

Fulfilling the shared care paradigm, health care networks providing open systems' interoperability in health care are needed. Such communicating and co-operating health information systems, dealing with sensitive personal medical information across organisational, regional, national or even international boundaries, require appropriate security solutions. Based on the generic security model, within the European MEDSEC project an open approach for secure EDI like HL7, EDIFACT, XDT or XML has been developed. The consideration includes both securing the message in an unsecure network and the transport of the unprotected information via secure channels (SSL, TLS etc.). Regarding EDI, an open and widely usable security solution has been specified and practically implemented for the examples of secure mailing and secure file transfer (FTP) via wrapping the sensitive information expressed by the corresponding protocols. The results are currently prepared for standardisation.

Computer Communication Networks↗

PubMed2001

Myxoid and round cell liposarcoma: a spectrum of myxoid adipocytic neoplasia.

Myxoid and round cell liposarcoma accounts for about 30% to 35% of all liposarcomas and, even if still classified by the World Health Organization (WHO) as 2 distinct subtypes, share both clinical and morphologic features. Lesions combining both patterns are frequent and wide agreement exists in considering round cell liposarcoma as the high grade counterpart of myxoid liposarcoma. Furthermore, myxoid and round cell liposarcoma share the same characteristic chromosome change represented most frequently by a reciprocal translocation t(12;16)(q13;p11) that fuses the CHOP gene with the TLS gene. Clinically, myxoid and round cell liposarcoma tend to occur in the limbs with a peak incidence ranging between the third and the fifth decade and exhibit overall a metastatic rate of approximately 30%. A peculiar tendency to metastasize to the soft tissue is observed that should not be interpreted as multicentricity. Microscopically, purely myxoid liposarcoma is composed by a hypocellular spindle cell proliferation set in a myxoid background and associated with a varying number of monovacuolated lipoblasts. The most helpful morphologic clue is represented by the presence of a thin-walled capillary network organized in a plexiform pattern. The most important morphologic variation observed in myxoid liposarcoma is represented by the occurrence of hypercellular areas that may exhibits an undifferentiated round cell morphology. On the basis of the percentage of hypercellularity/round cell formation, a myxoid/round cell liposarcoma (more than 25% hypercellular/round cell areas) and a round cell liposarcoma (more than 75% hypercellular/round cell areas) are somewhat arbitrarily recognized. Both the recognition and the quantification of hypercellular/round cell areas represents a crucial step in the evaluation of this liposarcoma subtype because hypercellularity appears to correlate with the clinical outcome. In consideration of the intrinsic difficulty in establishing accurately the percentage of high grade areas as well as of application of different cut off values, it appears safer to consider any amount of hypercellularity as prognostically relevant. Careful as well as extensive sampling is mandatory to permit detection of the smallest amount of hypercellularity. The differential diagnosis of myxoid liposarcoma includes benign lesions, such as myxoid spindle cell lipoma, intramuscular myxoma and lipoblastoma, and malignant ones such as low grade myxofibrosarcoma, and extraskeletal myxoid chondrosarcoma. In consideration of the great morphologic variability, the application of both immunohistochemistry and genetics has proved helpful in sorting out the more challenging cases.

Adipocytes↗

PubMedDate not supplied

Laser lingual tonsillotomy.

The classic surgical procedures for treatment of complaints caused by hyperplasia and chronic inflammation of the lingual tonsil are difficult, and may involve serious complications. Eleven patients with hyperplasia of the lingual tonsil were treated with a Tungsram TLS 61 CO2 laser coupled to an operating microscope. The average duration of hospitalization was 3-4 days. The advantages of the use of a CO2 laser are haemostasis, sealing of the nerve endings, decrease of postoperative pain, and no postoperative oedema, which is important because of the closeness of the larynx. There were no serious complications either during surgery or in the postoperative period, and the complaints of all 11 patients were eliminated or reduced.

Adult↗

PubMed2003

UV- and MMS-induced mutagenesis of lambdaO(am)8 phage under nonpermissive conditions for phage DNA replication.

Mutagenesis in Escherichia coli, a subject of many years of study is considered to be related to DNA replication. DNA lesions nonrepaired by the error-free nucleotide excision repair (NER), base excision repair (BER) and recombination repair (RR), stop replication at the fork. Reinitiation needs translesion synthesis (TLS) by DNA polymerase V (UmuC), which in the presence of accessory proteins, UmuD', RecA and ssDNA-binding protein (SSB), has an ability to bypass the lesion with high mutagenicity. This enables reinitiation and extension of DNA replication by DNA polymerase III (Pol III). We studied UV- and MMS-induced mutagenesis of lambdaO(am)8 phage in E. coli 594 sup+ host, unable to replicate the phage DNA, as a possible model for mutagenesis induced in nondividing cells (e.g. somatic cells). We show that in E. coli 594 sup+ cells UV- and MMS-induced mutagenesis of lambdaO(am)8 phage may occur. This mutagenic process requires both the UmuD' and C proteins, albeit a high level of UmuD' and low level of UmuC seem to be necessary and sufficient. We compared UV-induced mutagenesis of lambdaO(am)8 in nonpermissive (594 sup+) and permissive (C600 supE) conditions for phage DNA replication. It appeared that while the mutagenesis of lambdaO(am)8 in 594 sup+ requires the UmuD' and C proteins, which can not be replaced by other SOS-inducible protein(s), in C600 supE their functions may be replaced by other inducible protein(s), possibly DNA polymerase IV (DinB). Mutations induced under nonpermissive conditions for phage DNA replication are resistant to mismatch repair (MMR), while among those induced under permissive conditions, only about 40% are resistant.

Bacteriophage lambda↗

PubMed2005

Efficacy and safety of recombinant urate oxidase (rasburicase) for treatment and prophylaxis of hyperuricemia in children undergoing chemotherapy.

Rasburicase has been defined as a potent urolytic agent for management of malignancy-associated hyperuricemia. We reviewed the data of 26 children with malignancy at risk for TLS who received rasburicase for treatment or prophylaxis of acute hyperuricemia, producing a significant decrease in uric acid level in all the patients. Tolerance of treatment was excellent. Rasburicase is a safe, highly and rapidly effective agent in the treatment and prevention of malignancies-associated acute hyperuricemia.

Adolescent↗

PubMed2005

Clinical application of monitoring mycophenolic acid trough concentration in heart transplant recipients--single center's experience.

UNLABELLED: The purpose of this study was to assess the clinical utility of mycophenolic acid (MPA) trough concentration monitoring in heart transplant recipients. METHODS: We reviewed 456 MPA plasma level measurements (EMIT/Dade-Behring) which were performed in 76 pts. after orthotopic heart transplantation (OHT): 57 M and 21 F, age 41.9 +/- 16, time after OHT (months) 17.6 +/- 24. Daily dose of mycophenolate mofetil (MMF) was 2-3 g before MPA measurement introduction, then it was adjusted to achieve MPA trough levels (TL) of 2-4 microg/ml. Additionally pts. received either cyclosporine-A (CyA) or tacrolimus and prednisone. We analyzed first MPA levels obtained in pts. without previous monitoring, then we looked for a relation between CyA or tacrolimus and MPA level, and finally we checked for a relation between MPA level and the side-effects of MMF RESULTS: In a group of 59 pts. without earlier MPA level monitoring we found that 36 pts. (61%) had MPA level below, 19 pts. (32%) within, and 4 pts. (7%) above target TL. We identified a group of 11 pts. (characterized by unstable CyA TLs and liver impairment) with a significant positive correlation between CyA and MPA level. For the remaining group of pts. we found a non-significant negative correlation between CyA and MPA concentrations. Target MPA TL was achieved in 40% of cases in pts. with CyA TL below 200 ng/ml (Axsym/Abbott), in 40% of cases in pts. with CyA TL 200-300 ng/ml, and in 27% of cases in pts. with CyA TL over 300 ng/ml. There was no correlation between tacrolimus and MPA level. MPA TL over 4 microg/ml occurred in 22% of results from pts. receiving tacrolimus (n=6) and 11% of pts. on CyA (n=17, p = 0.011). 90% of these pts. had symptoms of GI irritation, 33%--leucopoenia, and 14%--anemia. CONCLUSIONS: It is uncommon to achieve MPA TL of 2-4 microg/ml with typical doses of MMF, especially with concomitant high CyA TL. Typical side effects of MMF should be an indication to check MPA TL.

Adult↗

PubMedDate not supplied

Biological prognostic factors in adult soft tissue sarcomas.

Adult soft tissue sarcomas (STSs) are a rare group of highly heterogeneous neoplasms arising in different tissues. They are locally aggressive and can produce recurrence and distant metastasis. The most common metastatic sites are lung, lymph nodes, liver, bone and soft tissues. Staging for STSs has been based on some prognostic information: grade (low vs. intermediate/high grade), size (small vs. large tumors), depth of infiltration (superficial vs. deep neoplasms) and presence or not of distant metastasis. In the last 10 years, a plethora of new markers (proliferation markers and DNA alteration, P-gp, p53, TLS-CHOP, cyclins, survivin, TERT, PAX3-PAX7/FKHR, SYT-SSX1/2, VEGF, E-cadherin and beta-catenin, nm23, SKP-2, p27, CD40) has been studied with regard to their role in promoting progression (in a laboratory setting) and then determining prognosis and therapy (in a clinical setting). In the present survey, we focused on the role of new biological prognostic factors in STSs and also reported the quality of such studies with an ad hoc designed questionnaire.

Adult↗

PubMed2005

Round cell liposarcoma of scrotum with indolent course in young adult.

Myxoid/Round cell liposarcoma accounts for one-half of all liposarcomas and occurs as the second most common subtype. Both myxoid and round cell types share clinical, histological features and are accepted to represent a spectrum of lesions ranging from pure myxoid to near completely round cell liposarcoma. Round cell liposarcoma is highly metastatic and is classified as high grade and poorly differentiated myxoid sarcoma. Typical non-round cell myxoid liposarcoma is less metastatic and has more favorable prognosis. Karyotypic study of myxoid and round cell liposarcomas reveal a characteristic reciprocal translocation t (12;16)(q13;p11) resulting in the fusion of CHOP gene with TLS gene in more than 90% of cases. Most masses within the scrotal sac arise from the testis proper, and less likely from the extratesticular tissue. Liposarcoma represents approximately 20% of malignant extratesticular neoplasms, with the well differentiated subtype being the most common. Myxoid/round cell liposarcoma and round cell liposarcoma are rarely encounter in extratesticular soft tissue. We reported a rare case of round cell liposarcoma (high grade myxoid liposarcoma) of extratesticular tissue. To our knowledge, this is the first case of a large size (> 5cm) round cell liposarcoma arising from soft tissue within the scrotal sac of young adult with indolent course. Simple excision or enucleation are inadequate therapies and wide excision of the hemiscrotum including inguinal soft tissue and nodes is recommended. The role of retroperitoneal lymph node dissection and adjuvant chemotherapy remains controversial.

Adult↗

PubMed1991

[The use of CO2 laser in bone surgery].

Authors examined during the trial of a CO2 laser of type TUNGSRAM TLS-61 the possibility of its use in the orthopaedic surgery. The output necessary to cut the skin and bony tissue, the speed of cutting and the extension of tissue necrosis were determined in experiments in vitro and in vivo. According to their observation the fusion of the bone cut with CO2 laser takes the same time as after the traditional osteotomy, however in the first three weeks the callus formation falls behind. The possibility of a curved cutting and of the coagulation haemostasis may ensure a fine prospect to this method.

Animals↗