EGSNRC Monte Carlo study of the effect of photon energy and field margin in phantoms simulating small lung lesions

The dose distribution in small lung tumors (coin lesions) is affected by the combined effects of reduced attenuation of photons and extended range of electrons in lung. The increased range of electrons in low-density tissues can lead to loss of field flatness and increased penumbra width, especially at high energies. The EGSNRC Monte Carlo code, together with DOSXYZNRC, a three-dimensional voxel dose calculation module has been used to study the characteristics of the penumbra in the region of the target-lung interfaces for various radiation beam energies, lung densities, target-field edge distances, target size, and depth. The Monte Carlo model was validated by film measurements made in acrylic (simulating a tumor) imbedded in cork (simulating the lung). Beam profiles that are deemed to be acceptable are defined as those in which no point within the planning target volume (target volume plus 1 cm margin) received less than 95% of the dose prescribed to the center of the target. For parallel opposed beams and 2 cm cube target size, 6 MV photons produce superior dose distribution with respect to penumbra at the lateral, anterior, and posterior surfaces and midplane of the simulated target, with a target-field edge distance of 2.5 cm. A lesser target-field edge distance of 2.0 cm is required for 4 MV photons to produce acceptable dose distribution. To achieve equivalent dose distribution with 10 and 18 MV photons, a target-field edge distance of 3.0 and 3.5 cm, respectaively, is required. For a simulated target size of 4 cm cube, a target-field edge distance of 2, 2.5, and 3 cm is required for 6, 10, and 18 MV photons, respectively, to yield acceptable PTV coverage. The effect, which is predominant in determining the target dose, depends on the beam energy, target-field edge distance, lung density, and the depth and size of the target.     

Tuberculous orchiepididymitis diagnosed by nucleic acid amplification test: A case report

Symptoms of tuberculous orchiepididymitis in a 39-year-old male started with swelling of left scrotum, followed by fistula formation with suppurative discharge. There was no any improvement produced by antibiotics. Surgical extirpation of inflammatory destroyed testicle and epidydimis was performed. Presence of tubercle bacilli was not shown by bacteriological analysis of testicle tissue. Tuberculous etiology was suggested after histopathological examination of testis and epididymis. Exudate from surgical wound was examined on presence of Mycobacterium tuberculosis DNA. Etiology of orchiepididymitis was proved by positive assay and inflammatory process was completely cured by antituberculotics therapy. By this report it was clearly shown that sometimes only molecular methods could confirm etiology of inflammatory process.     

Menetrier's disease associated with ulcerative colitis

In this paper a 21 year old patient was presented with Ménétrier's disease, associated with ulcerative colitis. The first symptoms of ulcerative colitis occurred at the age of eleven, since when the patient has been conservatively treated several times because of the exacerbations of the disease. During control examinations presence of polyploid changes in stomach was discovered by upper endoscopy. Gastrectomy was suggested because the patient had excessive anemic syndrome which required weekly substitutional therapy with deplasmatic eritrocytes, as well as hypoproteinemia, while multiple polyploid changes suspect for malignancy were gastroscopically identified. Patient accepted surgical treatment, and was transferred to the Clinic of Surgery. Total gastrectomy was performed, and patohistological finding confirmed Ménétrier's disease. After two weeks, the patient was released from the hospital in good general condition, with regular clinical and laboratory findings.     

Analysis of 585 burn patients hospitalized over a 6-year period. Part III: Psychosocial data

We have examined the physical and psychosocial aberrations found in a series of 585 hospitalized burn patients. The implications of this data have been discussed as they apply to identifying persons at high risk for burn injury, and as they apply to estimation of the prognosis in severe burn injury. This is a step towards identifying a psychosocial profile for the evaluation of burned patients.     

Discovery and verification of amyotrophic lateral sclerosis biomarkers by proteomics

Recent studies using mass spectrometry have discovered candidate biomarkers for amyotrophic lateral sclerosis (ALS). However, those studies utilized small numbers of ALS and control subjects. Additional studies using larger subject cohorts are required to verify these candidate biomarkers. Cerebrospinal fluid (CSF) samples from 100 patients with ALS, 100 disease control, and 41 healthy control subjects were examined by mass spectrometry. Sixty‐one mass spectral peaks exhibited altered levels between ALS and controls. Mass peaks for cystatin C and transthyretin were reduced in ALS, whereas mass peaks for posttranslational modified transthyretin and C‐reactive protein (CRP) were increased. CRP levels were 5.84 ± 1.01 ng/ml for controls and 11.24 ± 1.52 ng/ml for ALS subjects, as determined by enzyme‐linked immunoassay. This study verified prior mass spectrometry results for cystatin C and transthyretin in ALS. CRP levels were increased in the CSF of ALS patients, and cystatin C level correlated with survival in patients with limb‐onset disease. Our biomarker panel predicted ALS with an overall accuracy of 82%. Muscle Nerve 42: 104–111, 2010     

Mitogen-stimulated lymphocyte proliferation and pituitary hormones in major depression

To assess cellular immune status and the hypothalamic-pituitary (HP) axis in patients with major depression, we examined peripheral blood mononuclear cells (PBMC) and measured the plasma levels of cortisol, adrenocorticotropin hormone (ACTH), growth hormone (GH), and prolactin (PRL). Twenty patients with major depression were compared with 20 control subjects matched for age, sex, and race. The dose-response curves for concanavalin-A (Con-A) and phytohemagglutinin (PHA) stimulation were not significantly different between the two groups. The patients had decreased Con-A-stimulated T-lymphocyte proliferation when compared to the control subjects, but only at the lowest suboptimal concentration of Con-A. None of the four concentrations of PHA-stimulated proliferation were different between the two groups, neither was PHA-induced interleukin-2 production. Within the patient group only, plasma prolactin (PRL) correlated significantly with stimulated lymphocyte proliferation using two optimal concentrations of PHA and one optimal concentration of Con-A, when the proliferation was expressed using the stimulation index.     

Identifying steep psychometric function slope quickly in clinical applications

Knowledge of an observer’s psychometric function slope is potentially useful in clinical visual psychophysics (for example, perimetry), however, the short test times necessary in a clinical setting typically prevent slope estimation. We explore, using computer simulation, the performance of several possible procedures for estimating psychometric function slope within limited presentations (aiming for approximately 30 or 140 trials). Procedures were based on either adaptive staircase or Bayesian techniques, and performance was compared to a Method of Constant Stimuli. An adaptation of the Ψ algorithm was best performing, being able to reliably identify steep from flat psychometric functions in less than 30 presentations, however reliable quantification of shallow psychometric functions was not possible.