Comment on "Linear superposition in nonlinear equations".
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Comment↗
Biomedical subjects
M Jaworski
Publications and source records attributed to M Jaworski.
GLOB-1: a prospective randomised clinical phase III trial comparing vinorelbine-cisplatin with vinorelbine-ifosfamide-cisplatin in metastatic non-small-cell lung cancer patients.
BACKGROUND: The standard doublet, vinorelbine-cisplatin, was compared with a triplet of vinorelbine-ifosfamide-cisplatin, in terms of survival, in patients with advanced non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS: From February 1998 to June 1999, 259 chemonaïve patients entered the study and were randomised to receive either vinorelbine-cisplatin (NP; vinorelbine 30 mg/m(2) on days 1, 8 and 15 with cisplatin 80 mg/m(2) on day 1) or vinorelbine-ifosfamide-cisplatin (NIP; vinorelbine 25 mg/m(2) on days 1 and 8, ifosfamide 3 g/m(2) on day 1 and cisplatin 75 mg/m(2) on day 1), with both regimens being repeated every 3 weeks. All patients had stage IV or relapsed disease and a performance score of 0 or 1. RESULTS: The overall response rate was 34.6% for NP and 35.7% for NIP. Median and 1-year survival rates were 10.0 months and 38.4% for NP, and 8.2 months and 33.7% for NIP, respectively. A median of four cycles was administered in each arm. The major World Health Organization grade 3-4 toxicities for NP and NIP, respectively, were: neutropenia (20.3% compared with 9% of cycles), anaemia (4.1% compared with 5% of cycles), nausea and vomiting (22.2% compared with 19.4% of patients) and alopecia (5.6% compared with 29.8% of patients). Four toxic deaths occurred in the NP arm and eight in the NIP arm. CONCLUSIONS: The different schedules of vinorelbine in the two arms led to a greater survival in the NP arm without impairing the tolerance profile, although this is not statistically significant. This confirms that the two-drug combination NP is a reference treatment for metastatic NSCLC. The role of three-drug combinations remains questionable in this subset of patients.
Adolescent↗
Dielectric resonator-based side-access probe for muscle fiber EPR study.
We present a novel dielectric resonator (DR)-based resonant structure that accommodates aqueous sample capillaries in orientations that are either parallel (i.e., side-access) or perpendicular to the direction of an external (Zeeman) magnetic field, B(0). The resonant structure consists of two commercially available X-band DRs that are separated by a Rexolite spacer and resonate in the fundamental TE(01delta) mode. The separator between the DRs is used to tune the resonator to the desired frequency and, by appropriately drilled sample holes, to provide access for longitudinal samples, notably capillaries containing oriented, spin-labeled muscle fibers. In contrast to the topologically similar cylindrical TE(011) cavity, the DR-based structure has distinct microwave properties that favor its use for parallel orientation of lossy aqueous samples. For perpendicular orientation of a dilute (6.25 microM) aqueous solution of IASL spin label, the S/N ratio was at least one order of magnitude better for the side-access DR-based structure than for a standard TE(102) cavity. EPR spectra acquired for maleimide spin-labeled myosin filaments also revealed ca. 10 times better S/N ratio than those obtained with a standard TE(102) cavity. For the side-access DR with sample capillaries oriented either parallel or perpendicular to the external magnetic field, the Q- and filling factors are in good agreement with the theoretical estimates derived from the distribution of magnetic (H(1)) and electric (E(1)) components.
Animals↗
[Progress in measurement of the calcaneus using ultrasonic methods in children and adolescents].
At present, Dual Energy X-ray Absorptiometry (DEXA) method is a reference method to diagnose osteoporosis. This method allows to measure bone density and bone mass, however bone quality can not be estimated. Quantitative ultrasound (QUS) method provides information about bone structure. The aim of our work was the evaluation of QUS method in healthy children, establishing reference values in cross-sectional study of healthy children aged 7-18 yrs and to examine the annual change of ultrasound parameters in prospective study at pubertal. Group of 530 girls and 369 boys was recruited from Warsaw schools, and right heel was measured with Achilles Plus apparatus. Measurements were repeated after 1 year, in a subgroup of 153 children aged 9-13 yrs. The method was adapted for paediatric measurements by using limiter of ultrasonic wave and pads for positioning foot in water chamber. Speed of sound (SOS) and broadband ultrasound attenuation (BUA) were measured and Stiffness index was calculated. Width of heel, at the same location as QUS measurement, was also measured using calipers. SOS, BUA and Stiffness values increased by age in boys and girls. BUA and Stiffness values were significantly higher in 15, 16 and 17 year old boys than in age-matched girls (in 18 yrs--only Stiffness). However, there were no significant sex differences in annual increase of SOS, BUA and Stiffness, although the biggest increase was observed between the age of 13-14 yrs for boys and 11-12 yrs for girls. That may reflect pubertal spurt of body growth but that relationship was not confirmed by annual increases calculated from cross-sectional data. Statistically significant correlation of SOS, BUA and Stiffness with body mass, height, body mass index (BMI) and heel width was observed. Normalization of SOS, BUA and Stiffness on heel width decreased force of that correlation but it was still statistically significant. Dynamics of SOS, BUA and Stiffness increase by age was higher in boys than in girls. This phenomenon is probably related to higher peak bone mass in men than in women, and lower risk of fracture in men, especially concerning hip. Increase of speed of sound, broadband ultrasound attenuation and stiffness index by age, and their correlations with body mass, height and body mass index reflects bone growth in children and adolescents. Broadband ultrasound attenuation and Stiffness index show sex differences in bone development in adolescence. Higher dynamics of the increase of speed of sound, broadband ultrasound attenuation and Stiffness index by age in boys confirms faster bone mass accumulation in boys than in girls.
Absorptiometry, Photon↗
[Intrahepatic portocaval shunt as a new method for treating and prevention of bleeding from esophageal varices in portal hypertension].
UNLABELLED: The aim of this study was the presentation of percutaneous transjugular intrahepatic porto-systemic shunt (TIPS) and its place among the other methods of the treatment of esophageal variceal bleedings. In the period from June 1992 to December 1997, 31 cirrhotic patients with portal hypertension and recurrent variceal bleedings were submitted for TIPS. This group consisted of 14 female and 17 male patients, their age ranging from 17 to 68 years (average 52). According to Child-Pugh classification 4 patients represented group A, 11--group B and 16--group C. Each of these patient was admitted to our Department after recurrent bleeding, resistant to typical treatment: terlipressein infusion, balloon tamponade and endoscopic sclerotherapy. In 24 patients (78%) TIPS was performed successfully. In 7 cases TIPS was performed in candidates for orthotopic liver transplantation. CONCLUSIONS: TIPS is quite new, nearly 10 years old method for portal decompression. It is an effective and less invasive method than surgical procedures in the treatment of portal hypertension, especially in Child-Pugh group B and C patients if the sclerotherapy is not effective. It protects cirrhotic patients waiting for liver transplantation against the esophageal bleedings.
Adolescent↗
Double-stacked dielectric resonator for sensitive EPR measurements.
A new approximate method for predicting the resonant frequencies and for solving the field distribution problem of a cylindrical dielectric resonator (DR) is developed. The model proposed in this paper bridges the gap between rigorous and accurate finite-element or Green function-based numerical methods on the one hand and on the other hand, simple approximate solutions in which the field distribution can be described analytically, but the resulting frequency is accurate within a few percent only. In the method described here, the approximate solution for the microwave field distribution is modified by substituting different values of the radial separation constants inside and outside of the diskshaped DR. The model is generalized for the double-stacked DR structure and enables one to introduce corrections that take into account the presence of the shielding walls and of the cylindrical sample hole. Good agreement is found between experimental and calculated results for both the single and double-stacked structures that are designed around commercially available X-band DRs (9-10 GHz). For the resonant frequency of the lowest transverse-electric TEzero1 delta mode that is commonly used for EPR measurements, the accuracy of the method is better than 1%. Experimentally measured resonator filling factors are also in good agreement with those theoretically estimated. Both the theory and the experimental results suggest that the double-stacked DR structure with finite spacing between the ceramic cylinders is the most suitable for EPR measurements of long lossy samples.
Ceramics↗
Erratic evolution of glycerol-3-phosphate dehydrogenase in Drosophila, Chymomyza, and Ceratitis.
We have studied the evolution of Gpdh in 18 fruitfly species by sequencing 1,077 nucleotides per species on average. The region sequenced includes four exons coding for 277 amino acids and three variable-length introns. Phylogenies derived by a variety of methods confirm that the nominal genus Zaprionus belongs within the genus Drosophila, whereas Scaptodrosophila and Chymomyza are outside. The rate of GPDH evolution is erratic. The rate of amino acid replacements in a lineage appears to be 1.0 x 10(-10)/site/year when Drosophila species are considered (diverged up to 55 million years ago), but becomes 2.3 x 10(-10) when they are compared to Chymomyza species (divergence around 60 My ago), and 4.6 x 10(-10) when species of those two genera are compared with the medfly Ceratitis capitata (divergence around 100 My ago). In order to account for these observations, the rate of amino acid replacement must have been 15 or more times greater in some lineages and at some times than in others. At the nucleotide level, however, Gpdh evolves in a fairly clockwise fashion.
Animals↗
A minimal medium for growth of Pasteurella multocida.
We developed a minimal medium supporting the growth of both toxigenic and nontoxigenic strains of Pasteurella multocida to optical densities of > 0.5 (600 nm). P. multocida P1059 (ATCC 15742), one of a number of strains which can cause fowl cholera, was used as the model strain in this study. The medium was composed of 17 ingredients including cysteine, glutamic acid, leucine, methionine, inorganic salts, nicotinamide, pantothenate, thiamine, and an energy source. Leucine was not required for growth but was stimulatory, and thiamine could be replaced by adenine. An additional 46 strains of P. multocida were tested, and 40 out of 46 (87%) strains grew as well as strain P1059 through a minimum of 10 serial transfers. P. multocida toxin (PMT) was produced when cells of a known toxigenic strain (P4261) were cultivated in the minimal medium. No growth of Pasteurella Haemolytica or Pasteurella trehalosi strains was observed in this minimal medium.
Animals↗
Ultrasound bone measurement in pediatric subjects.
Ultrasound bone measurement in healthy (n = 71) and osteopenic (n = 18) children aged 6 through 13 years of both sexes has been evaluated using the Achilles densitometer (Lunar Corporation). Measurements on the os calcis included speed of sound (SOS), broadband ultrasound attenuation (BUA), and a calculated "stiffness" index. The Achilles was adapted for children by a special positioning procedure that included the use of foot shims, and beam collimation on the receiving transducer. The precision of ultrasound results was comparable to that in adults (0.2% for SOS, 1.5% for BUA, and 1.8% for stiffness). SOS, BUA, and stiffness values increased with age in both sexes. Ultrasound measurements were correlated with bone mineral density (BMD in g/cm2) of the heel, AP spine (L2-L4), and total body by dual X-ray absorptiometry (DXA) densitometry (Lunar DPX-L). SOS, BUA, and stiffness measurements were significantly lower in osteopenic children (Z approximately -1.9 to -2.5) (P < 0.0001) than in normal age-matched controls. Total body BMD showed a higher Z-score than stiffness (-3.3 versus -2.5), but stiffness showed a greater percentage decrease (-30% versus -18%). In conclusion, ultrasound measurements of bone in children provide both good precision and discrimination of normals from osteopenic patients.
Adolescent↗
[Measurements of calcaneus bone density by ultrasonography in children and adolescents].
In recent years the interest in growing in the use of ultrasonographic method for the assessment of bony tissue density. However, studies using this method were conducted almost exclusively in adult patients. The aim of this study was to apply this method for measurements in children in wide age range (7-18 years) and to determine value range of the parameters SOS, BUA and Stiffness for children in Warsaw in age and sex groups. The studies included 233 children of either sex, aged 7-18 years, healthy on medical examination coming from Warsaw schools. Achilles (Lunar Corp. WI, USA) bone densitometer was used with producer's software, 1.5c version. During examination with the Achilles device, the velocities of ultrasound beam passage through the calcaneus (SOS m/s) and the damping factor of ultrasound wave depending on its frequency (BUA db/MHz) were measured. Additionally the so called "stiffness factor" was calculated. The Achilles device was adapted for measurements in children reducing the diameter of the measuring beam to 1 cm and using pads positioning the child's foot in the device. Equal increase of SOS, BUA and Stiffness parameters with age was observed with the exception of the SOS parameter in girls which increased intensively from 7 to 12 years of age while over 12 years of age its increase was slight. Using linear regression analysis it was found that the values of SOS, BUA and Stiffness parameters depended directly proportionally on age, body weight and height. Respective correlation factors (r) were from 0.49 (body weight-SOS to 0.80 (height-BUA). The observed dependence of the SOS, BUA and Stiffness parameters on body weight, height and especially age enables presuming that the results of calcaneus density measurements by ultrasonographic method reflect the skeletal development in children.
Adolescent↗
[Measurements of bone mineral density of the calcaneus in children with ultrasonic methods].
The study aimed at determining precision and accuracy of the ultrasound technique measuring bone mineral density in the calcaneus bone in children. Bone densitometer of Achilles type was adapted for measurements in children. Ultrasound beam was narrowed and a system of special pads positioning the foot were used for this purpose. Precision (CV (%) SOS: phantom 0.42, patients -0.42; BUA: phantom 1.46, patients -3.03) and accuracy of this technique were determined in comparison with dual energy X-ray absorptiometry as well as its value in diagnosis of osteopenia in childhood. An increase in SOS and BUA with the age was found. A decrease in these parameters was noted in children with osteopenia, comparing with the values in healthy children. Significant correlations (r ranging from 0.50 to 0.91) between ultrasound and DEXA techniques were seen. The results suggest that ultrasound technique might be useful in pediatric densitometry.
Absorptiometry, Photon↗
Integrated genetic databases in the study of neuropsychiatric diseases: inborn errors of cerebral metabolic pathways?
1. Genetic databases are an expanding and readily accessible repository of information on the mapping and sequencing of the human genome, and that of other model organisms. The integration and application of this information to neuropsychiatric disease is illustrated using neuroendocrine and neuropharmacologic data, computerized and other genetic databases. 2. This computer-assisted integrated approach to knowledge structures permits the rapid generation of hypotheses, the prompt identification of candidate gene loci, an explanation for genetic heterogeneity, and strategies for the use of potential linked markers. 3. Results using this integrated search strategy demonstrate that over 30 candidate loci for neuropsychiatric disease have currently been mapped in man (spread over 14 chromosomes in the human genome), and that at least 6 homologous loci have been mapped in mouse. 4. Using a metabolic pathway approach, it can be shown that the best current candidate gene locus for a subtype of schizophrenia located on chromosome 5q11-13 (HGML10 # SCZD1 and OMIM #181510) is in the serotonergic pathway, i.e. a receptor for 5-hydroxytryptamine (subtype 1A; HGML10 #HTR1A) which also maps in the same chromosomal region. 5. Parallels are suggested between inborn errors of metabolic pathways in the somatic endocrine system (using insulin-dependent diabetes mellitus as a paradigm) and the neurotransmitter and hormonal systems within the brain. 6. A subset of neuropsychiatric disorders may thus be viewed as inborn errors of cerebral metabolic pathways primarily affecting the biogenic amine pathways.
Animals↗
Cosmic-ray muons in the deep ocean.
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Journal Article↗
Magnetic field dependence of the Josephson current in two-dimensional tunnel junctions.
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Journal Article↗
Comment on "Annihilation and creation of a Korteweg-de Vries soliton"
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Journal Article↗
Townes syndrome. A distinct multiple malformation syndrome resembling VACTERL association.
An 8-year-old male is presented with clinical findings of Townes syndrome in an otherwise unaffected family. Additional abnormalities possibly representing low frequency associations of this autosomal dominant multiple malformation syndrome included a cardiac defect and hypospadias. Similarities exist between Townes syndrome and VACTERL association, which is generally regarded to be sporadic in nature. Recognition of Townes syndrome as a distinct entity is critical for implementing appropriate management in early childhood, including amplification of hearing impairments. Variable expressivity may occur in this disorder. Careful evaluation must be made, therefore, of the parents of an affected infant with an apparent sporadic case, in order to provide the couple with an accurate recurrence risk at genetic counseling.
Abnormalities, Multiple↗
Computed tomography of the head in the evaluation of microcephaly.
Eighty-five infants and children found to have microcephaly had computed tomographic (CT) brain scans performed. A greater degree of microcephaly correlated with the finding of atrophy or ventricular dilation on CT scan. Patients who had known preceding destructive brain insults had the highest incidence of abnormal findings on scans (20/22). Patients who had CNS dysfunction of unknown etiology had the lowest frequency of abnormal findings (12/33); however, in three of these patients, a previously unsuspected brain malformation was found on CT scan. Patients who had other congenital anomalies had an intermediate proportion of abnormal findings on CT scans (20/30), and in 11 of these scans, a previously unsuspected or only partly suspected brain malformation was diagnosed. Discovering previously unsuspected information or finding supportive data regarding the basis for the underlying disease process, being able to provide a more specific developmental prognosis and accurate genetic counseling, justifies the inclusion of a CT scan of the head in the evaluation of the microcephalic child.
Adolescent↗
[A case of multiple intracranial meningiomas].
A case of a 58-year old woman in whom two meningiomas were discovered and removed successfully is presented. One of the meningiomas belonged to tentorial meningioma and was localized in the posterior fossa, compressing the right cerebellar hemisphere and fourth ventricle and finally producing obstructive hydrocephalus. The second was parasagittal meningioma and was localized in the frontal region on the left side. The patient was operated in two stages--first ventricular drainage was applied and posterior fossa meningioma was successfully removed totally with coagulation of the dural attachment. In the second stage, one month after the first operation parasagittal meningioma was removed totally, dural attachment was thoroughly coagulated. The patient had a good outcome is self dependent and able to carry on normal activity.
Brain Neoplasms↗