Ultrasonography view for acute ankle injury: comparison of ultrasonography and magnetic resonance imaging.

INTRODUCTION: We aim to asses the diagnostic performance of ankle ultrasonography in patients presenting with acute ankle sprain injury, with comparison to MRI (Manyetik Rezonans Imaging). MATERIALS AND METHODS: The study included patients who applied to the hospital within 48 h after an ankle sprain, and who presented with signs of pain, swelling, and tenderness in the ankle. Ankle ultrasonography examination was performed and an ankle MRI took place the same day. RESULTS: 30 patients were included in the study. 53.3% (n = 16) were female. The mean age was 30 ± 6.4 years. The ultrasonography examination determined 76.6% (n = 23) of the patients to have anterior talofibular ligament (ATFL) injury, 33.3% to have (n = 10) CFL injury, and 33.3% to have (n = 10) anterior inferior tibia-fibular ligament (AITFL) injury. The MRI of the patients determined 73.3% (n = 22) of the patients to have ATFL injury, 43.3% (n = 13) to have calcaneal fibular ligament (CFL) injury, and 33.3% to have (n = 10) AITFL injury. The ATFL, CFL, and AITFL injuries diagnosed on ultrasonography correlated with the MRI results (ICC = 0.875, ICC = 0.879, and ICC = 0.858). However, among the ATFL injuries observed on MRI, 26.6% (n = 8) were grade I, 26.6% (n = 8) were grade II, and 20% (n = 6) were grade III injuries. Of the ATFL injuries observed on ultrasonography, 46.6% (n = 14) were grade I, 8.6% (n = 2) were grade II, and 30.4% (n = 7) were grade III injuries. CONCLUSIONS: Findings on all types of ATFL, CFL and AITFL appear to have a higher degree of correlation. Ultrasonography could have an added role as a triaging tool, to fast-track MRI.

Thermoplastic elastomers containing antimicrobial and antiviral additives for mobility applications.

The transmission of the SARS-CoV-2 coronavirus has been shown through droplets generated by infected people when coughing, sneezing, or talking in close contact. These droplets either reach the next person directly or land on nearby surfaces. The objective of this study is to develop a novel, durable, and effective disinfecting antimicrobial (antiviral, antibacterial, and antifungal) styrene-ethylene/butylene-styrene (SEBS) based thermoplastic elastomers (TPE). TPE incorporated with six different formulations was investigated for mechanical and antiviral performance. The formulations consist of a combination of zinc pyrithione (ZnPT), sodium pentaborate pentahydrate (NaB), disodium octaborate tetrahydrate (DOT), and chlorhexidine (CHX). ZnPT and DOT incorporated TPE showed a reduction of microbes such as bacteria by up to 99.99%, deactivated Adenovirus, Poliovirus, Norovirus, and reduced a strain of the coronavirus family by 99.95% in 60 min on TPE samples. Control samples had higher tensile strengths among all formulations and tensile strength decreased by around 14%, 21% and 27% for ZnPT and DOT combinations compared to control samples. The elongation at break decreased by around 7%, 9% and 12% with ZnPT and DOT combinations, where it reached minimum values of 720%, 702% and 684%, respectively. The 100% Modulus and 300% Modulus slightly increased with ZnPT and NaB combination (reaching values from 1.6 to 1.9 MPa and 2.6-2.9 MPa respectively) in comparison with control samples. The MFI also decreased with antimicrobial and antiviral additives (decreasing values from 64.8 to 43.3 g/10 min). ZnPT and NaB combination showed the lowest MFI (43.3 g/10 min) and reduced the MFI of control sample by around 33%. TPE samples containing ZnPT and DOT combination showed biocidal activity against the microorganisms tested and can be used to develop antimicrobial products for multiple touchpoints within a vehicle and micro-mobility.

Efficacy of Miltefosine and Artemether on Infected Biomphalaria Alexandrina Snails with Schistosoma Mansoni: Immunological and Histological Studies.

Biomphalaria alexandrina snails have received much attention due to their great medical importance as vectors for transmitting Schistosoma mansoni infection to humans. The main objective of the present work was to assess the efficacy of miltefosin a synthetic molluscicidal drug and artemether a natural molluscicidal drug. The correlation between immunological and histological observations from light and electron microscopy of the hemocytes of B. alexandrina post treatment with both drugs was also evaluated. LC50 and LC90 values were represented by 13.80 ppm and 24.40 ppm for miltefosine and 16.88 ppm and 27.97 ppm for artemether, respectively. The results showed that the treatment of S. mansoni-infected snails and normal snails with sublethal dose of miltefosine (LC25=8.20 ppm) and artemether (LC25=11.04 ppm) induced morphological abnormalities and a significant reduction in hemocytes count.

Cytochrome P450-2D6*4 polymorphism seminal relationship in infertile men.

This study aimed to assess cytochrome (CY) P450-2D6*4 polymorphism relationship with semen variables in infertile men. In all, 308 men were included; fertile normozoospermia (N) (n = 77), asthenozoospermia (A) (n = 70), asthenoteratozoospermia (AT) (n = 75) and oligoasthenoteratozoospermia (OAT) (n = 86). They were subjected to history taking, clinical examination, semen analysis, sperm acrosin activity, seminal malondialdehyde (MDA) and CYP450-2D6*4 genotyping. CYP450-2D6*4 wild-type allele was represented in 76.5% of N, 70% of A, 66.7% of AT and 57.7% of OAT men where homozygous gene mutation was present in 5.9% of N, 20% of A, 26.6% of AT and 26.9% of OAT men, respectively. Sperm acrosin activity, sperm concentration, sperm motility, linear sperm velocity and sperm normal forms were significantly higher, and seminal MDA level was significantly lower in men with CYP450-2D6*4 wild-type allele compared with men with homozygous mutation. It is concluded that CYP450-2D6*4 wild-type allele has higher frequency where homozygous-type allele has lower frequency in N men compared with A, AT and OAT men. Sperm acrosin activity index, sperm concentration, sperm motility, linear sperm velocity and sperm normal forms were significantly higher, and seminal MDA level was significantly lower in men with CYP450-2D6*4 wild-type allele compared with men with homozygous mutation.

Purification and characterization of Bacillus thuringiensis vegetative insecticidal toxin protein(s).

UNLABELLED: Bacillus thuringiensis subsp. aegypti C18 is an Egyptian isolate, obtained from dead pink bollworm larvae. Insecticidal active proteins against different insect were purified from BtaC18 strain during vegetative states. Both the bacterial pellet and cell-free supernatant obtained during vegetative growth had insecticidal activity against black cutworm (BCW). Bioassays revealed that the pellet after 48 h of growth is more potent and toxic against BCW. The toxin in the pellet was active at very high temperatures but lost toxicity after boiling or autoclaving. Proteins extracted from the BtaC18 pellet were further purified by ammonium sulfate precipitation, and the 40% fraction was then subjected to fast protein liquid chromatography (FPLC). Seven major protein peaks were detected after FPLC (Pi- a, b, c, d, e, f and g). Pic protein fraction was active against BCW with an estimated LC50  = 26 ng cm(-2) , Pid protein killed 50% of European corn borer (ECB) at 46 ng cm(-2) , and Pif showed insecticidal activity against western corn root worm (WCRW) with estimated LC50 was 94 ng cm(-2) . Based on the significant and high toxicity of Pic against BCW and Pif against WCRW, the 88- and 44-kDa proteins were further characterized by N-terminal amino acid sequencing. SIGNIFICANCE AND IMPACT OF THE STUDY: Insecticidal activity of Bacillus thuringiensis subsp. aegypti was determined, and its vegetative insecticidal protein was subjected to FPLC for protein purification. This work contributes to improve understanding the different toxins secreted during vegetative growth of Bt. Moreover, the N-terminal amino acid sequences of 88-kDa protein was only 92% identical to that of vip3A, and for 44 kDa was 92% identical with Cry35a, suggesting that we might have identified a new genes. Finally, we have proven these proteins to be novel insecticidal agents that may complement the use of known insecticidal proteins derived from Bacillus.

A Large Mass Displaying a Malignant Character on the Forearm: A Rare Case of Upper Extremity Pilomatrixoma.

In this study, a 50-year-old male patient had a painless swelling on his right forearm. The lump on the forearm started one year ago and increased in size in the last two months. The mass was 3x6 cm and had a malignant appearance on radiological imaging. The case was reported as pilomatrixoma in the histopathological examination after marginal excision. In this case report, we emphasized that pilomatrixoma is one of the diagnoses we considered in mass formations that can be seen in the upper extremity, although rare. The large mass displaying a malignant character in radiological imaging can be pilomatrixoma, and the Tru-cut biopsy before the final surgery may help diagnosis by preventing the surgeons from aggressive surgical treatment. The marginal excision shall be enough in the definitive treatment. With this study, we aimed to discuss the place of pilomatrixoma in the orthopedic literature, which is published chiefly by otolaryngology, pathology, and dermatology clinics and lacks in the orthopedic literature because it rarely involves the extremities.

Strain variation in the frequency of Abelson murine leukemia virus-transformed fetal liver pre-B cells bearing complete immunoglobulin heavy chain rearrangements.

Fetal liver Abelson pre-B cell lines obtained from CBA/Tufts.xid and (CBA/Tufts.xid x CBA/Tufts)F1 mice have complete VDJH rearrangements on at least one allele. Such high frequencies of VDJH rearrangements have previously been observed in adult derived but not fetal liver derived Abelson pre-B cell lines. Genetic analyses suggest that CBA/Tufts.xid carries an autosomal dominant gene(s) that determines the predominance of VDJH rearrangements among transformants. This autosomal gene(s) might affect the intrinsic development of the early B cell lineage in the fetus or the fetal microenvironment, expanding pre-B cells of the "more mature" VDJH phenotype.

Characterization of the T cell receptor repertoire causing collagen arthritis in mice.

Collagen type II-induced arthritis (CIA) is generated in susceptible rodent strains by intradermal injections of homologous or heterologous native type II collagen in complete Freund's adjuvant. Symptoms of CIA are analogous to those of the human autoimmune disease, rheumatoid arthritis. CIA is a model system for T cell-mediated autoimmune disease. To study the T cell receptor (TCR) repertoire of bovine type II-specific T cells that may be involved in the pathogenesis of CIA in DBA/1Lac.J (H-2q) mice, 13 clonally distinct T cell hybridomas specific for bovine type II collagen have been established and the alpha and beta chains of their TCRs have been analyzed. These T cell hybridomas recognize epitopes that are shared by type II collagens from distinct species and not by type I collagens, and exhibit a highly restricted TCR-alpha/beta repertoire. The alpha chains of the TCRs employ three V alpha gene subfamilies (V alpha 11, V alpha 8, and V alpha 22) and four J alpha gene segments (J alpha 42, J alpha 24, J alpha 37, and J alpha 32). The V alpha 22 is a newly identified subfamily consisting of approximately four to six members, and exhibits a high degree of polymorphism among four mouse strains of distinct V alpha haplotypes. In addition, the beta chains of the TCRs employ three V beta gene subfamilies (V beta 8, V beta 1, and V beta 6), however the V beta 8.2 gene segment is preferentially utilized (58.3%). In contrast, the J beta gene segment usage is more heterogeneous. On the basis of the highly limited TCR-alpha/beta repertoire of the TCRs of the panel of bovine type II-specific T cell hybrid clones, a significant reduction (60%) of the incidence of arthritis in DBA/1Lac.J mice is accomplished by the use of anti-V beta 8.2 antibody therapy.

Prevention and treatment of murine experimental allergic encephalomyelitis with T cell receptor V beta-specific antibodies.

Experimental allergic encephalomyelitis (EAE) is a model system for T cell-mediated autoimmune disease. Symptoms of EAE are similar to those of multiple sclerosis (MS) in humans. EAE is induced in susceptible animal strains by immunization with myelin basic protein (MBP) and potent adjuvant. The major T cell response to MBP in B10.PL mice is directed towards an NH2-terminal epitope and involves T cells expressing either V beta 8.2 or V beta 13 gene segments. Animals treated with a TCR V beta 8-specific mAb have a reduced incidence of EAE. We report here that the in vivo administration of a combination of anti-V beta 8.2 and anti-V beta 13 mAbs results in a long-term elimination of T cells involved in the response to MBP. When given before MBP immunization, anti-TCR antibody treatment leads to nearly complete protection against EAE. Antibody treatment also results in a dramatic reversal of paralysis in diseased animals. Thus, treatment with a combination of V beta-specific antibodies is a very effective therapy for the prevention and treatment of EAE. It is hoped that the future characterization of TCR V gene usage in human autoimmune diseases may lead to similar strategies of immune intervention.

The organization of the mouse Igh-V locus. Dispersion, interspersion, and the evolution of VH gene family clusters.

We have constructed a panel of Abelson murine leukemia virus-transformed pre-B cells to study the organization of the mouse VH gene families. Based on the analyses of VH gene deletions on 51 chromosomes with VH gene rearrangements, we have inferred a map order of the Igh locus that holds for both the Igha and Ighb haplotypes. We show that members of each VH gene family are generally clustered, although three family clusters (VHS107, VH36-60, VGAM3.8) are dispersed in two or three subregions of the locus. Members of two VH gene families, VHQ52 and VH7183, are extensively interspersed and map within the same subregion. An examination of the distribution of VH group members (VH II, I, and III) within the locus suggests that two major duplications may, in part, explain the dispersed pattern of VH family clusters. The relationship of VH organization and functional expression is discussed in terms of position-dependent and complexity-driven models.

Validation of an algorithm of time-dependent electro-clinical risk stratification for electrographic seizures (TERSE) in critically ill patients.

OBJECTIVE: The clinical implementation of continuous electroencephalography (CEEG) monitoring in critically ill patients is hampered by the substantial burden of work that it entails for clinical neurophysiologists. Solutions that might reduce this burden, including by shortening the duration of EEG to be recorded, would help its widespread adoption. Our aim was to validate a recently described algorithm of time-dependent electro-clinical risk stratification for electrographic seizure (ESz) (TERSE) based on simple clinical and EEG features. METHODS: We retrospectively reviewed the medical records and EEG recordings of consecutive patients undergoing CEEG between October 1, 2015 and September, 30 2016 and assessed the sensitivity of TERSE for seizure detection, as well as the reduction in EEG time needed to be reviewed. RESULTS: In a cohort of 407 patients and compared to full CEEG review, the model allowed the detection of 95% of patients with ESz and 97% of those with electrographic status epilepticus. The amount of CEEG to be recorded to detect ESz was reduced by two-thirds, compared to the duration of CEEG taht was actually recorded. CONCLUSIONS: TERSE allowed accurate time-dependent ESz risk stratification with a high sensitivity for ESz detection, which could substantially reduce the amount of CEEG to be recorded and reviewed, if applied prospectively in clinical practice. SIGNIFICANCE: Time-dependent electro-clinical risk stratification, such as TERSE, could allow more efficient practice of CEEG and its more widespread adoption. Future studies should aim to improve risk stratification in the subgroup of patients with acute brain injury and absence of clinical seizures.

In silico Targeting, inhibition and analysis of polyketide synthase enzyme in Aspergillus ssp.

Aflatoxins are toxic and carcinogenic components produced by some Aspergillus species such as Aspergillus flavus. Polyketide synthases enzyme (PKS) plays a central role in aflatoxin s biosynthesis of in Aspergillus flavus, especially the product template (PT) domain, which controls the aldol cyclization of the polyketide forerunner during the biosynthesis of the aflatoxin pathway process. Here, we apply the in silico approaches to validate 623 natural components obtained from the South African Natural Compound Database (SANCDB), to distinguish the PT domain s prospected inhibitors. From the 623 compounds, docking results showed that there are 330 different compounds with energy binding lower than the natural substrate (palmitic acid or PLM) of the Product Templet domain (PT). Three factors were selected to determine the best 10 inhibiting components; 1) energy binding, 2) the strengthen chemical interactions, 3) the drug-likeness. The top ten inhibiting components are kraussianone 6, kraussianone 1, neodiospyrin, clionamine D, bromotopsentin, isodiospyrin, spongotine A, kraussianone 3, 14ß-Hydroxybufa-3,5,20,22-tetraenolide and kraussianone 7. The chemical interactions between 3HRQ domain and the natural substrate in the active site amino acids are highly similar to the 3HRQ with the top ten components, but the main differences are in the binding energy which is the best in the top ten ligands. Those ten components give successful inhibition with PT domain which will lead to the formula to be used for inhibition and control aflatoxin contamination of agriculture crop yields and lessen the degree of harming and sicknesses that are coming about because of acquiring measures of aflatoxin.

Real-world outcomes according to treatment strategies in ALK-rearranged non-small-cell lung cancer (NSCLC) patients: an Italian retrospective study.

PURPOSE: Anaplastic lymphoma kinase (ALK) rearrangement confers sensitivity to ALK inhibitors (ALKis) in non-small-cell lung cancer (NSCLC). Although several drugs provided an impressive outcome benefit, the most effective sequential strategy is still unknown. We describe outcomes of real-life patients according to the treatment strategy received. PATIENTS: We retrospectively collected 290 ALK rearranged advanced NSCLC diagnosed between 2011 and 2017 in 23 Italian institutions. RESULTS: After a median follow-up of 26 months, PFS for crizotinib and a new generation ALKis were 9.4 [CI 95% 7.9-11.2] and 11.1 months [CI 95% 9.2-13.8], respectively, while TTF were 10.2 [CI 95% 8.5-12.6] and 11.9 months [CI 95% 9.7-17.4], respectively, being consistent across the different settings. The composed outcomes (the sum of PFS or TTF) in patients treated with crizotinib followed by a new generation ALKis were 27.8 months [CI 95% 24.3-33.7] in PFS and 30.4 months [CI 95% 24.7-34.9] in TTF. The median OS from the diagnosis of advanced disease was 39 months [CI 95% 31.8-54.5]. Patients receiving crizotinib followed by a new generation ALKis showed a higher median OS [57 months (CI 95% 42.0-73.8)] compared to those that did not receive crizotinib [38 months (CI 95% 18.6-NR)] and those who performed only crizotinib as target agent [15 months (CI 95% 11.3-34.0)] (P < 0.0001). CONCLUSION: The sequential administration of crizotinib and a new generation ALKis provided a remarkable clinical benefit in this real-life population, being an interesting option to consider in selected patients.

Predictive parameters of joint disease in DBA/1 transgenic mice.

We recently reported an accelerated onset of collagen-induced arthritis in DBAII mice overexpressing a T cell receptor Valpha11.1/Vbeta8.2 transgene as a preclinical animal model for age-associated T cell dysfunction. The accelerated onset is due to a transgenically sensitized T cell population that reacts to bovine type 11 collagen without prior in vivo sensitization. The model presents a readily observable distal joint phenotype that would allow preliminary aging and intervention studies to be evaluated by monitoring the presence or absence or degree of phenotypic expression of disease. In order to characterize clinical signs, we evaluated 69 transgenic mice in six different experiments for anticollagen antibody levels, and assigned each a modified arthritic score based on the degree of redness or swelling of the digital joints. We also correlated these parameters with signs of distress, including weight bearing, activity levels, and body posture. The average onset of disease was consistently within a 28 to 35-day period. The average arthritic score at the time of onset was 8. We found that none of the parameters predicted the onset of joint disease, but the modified scoring system reflected the severity of joint disease and predicted the degree of distress associated with the acute inflammation. The ability to determine the severity of joint disease by gross physical examination is a useful clinical feature because a numerical score is reflective of the degree of inflammation. Because the transgenic mouse model is a T cell-driven disease, the effect of aging on T cell activity can be monitored easily. In addition, the use of our modified arthritic scoring system makes it possible to conduct mouse experiments in a humane manner.

Protective action of timolol in acute myocardial ischemia.

Timolol, a beta-adrenoceptor blocking agent with little or no cardiodepressant activity, was studied in acute myocardial ischemia in cats. Timolol, at a dose of 25 mug/kg, blocked 75 to 80% of the cardiac response to isoproterenol. This dose also significantly reduced heart rate in cats subjected to acute myocardial ischemia by ligation of the left coronary artery. Timolol significantly prevented the spread of ischemic damage in the myocardium as assessed by (a) curtailing the increase in plasma creatine phosphokinase (CPK) activity, (b) preventing the loss of CPK from the ischemic portion of the myocardium, and (c) restoring the elevated S-T segment of the electrocardiogram toward normal. Timolol did not significantly retard the increase in fragility of lysosomes in ischemic myocardial tissue. The mechanism of the protective effect to timolol on the ischemic myocardium appears to be via reducing myocardial oxygen demand by decreasing heart rate.

The effects of captopril (SQ 14,225) on bradykinin-induced bronchoconstriction in the anesthetized guinea pig.

The effect of captopril (SQ 14,225) a potent inhibitor of angiotensin converting enzyme (ACE: kininase II) on the bronchoconstrictor response to bradykinin was studied in the anesthetized guinea pig. The i.v. administration of captopril caused a profound long lasting hypotension without affecting pulmonary resistance or dynamic compliance. Similarly, the i.v. administration of bradykinin caused small increases in pulmonary resistance and decreases in dynamic compliance which were not altered by the administration of captopril. However, after beta-receptor blockade with propranolol, bradykinin-induced changes in resistance and compliance were enhanced; additional captopril administration further potentiated the bradykinin effects. The prostaglandin synthetase inhibitor indomethacin antagonized the bradykinin-induced bronchoconstriction in beta-blocked animals and its potentiation by captopril. In the isolated perfused guinea pig lung, bradykinin caused a dose dependent release of a prostaglandin-like substance which was significantly increased by captopril and antagonized by indomethacin. These results suggest that bradykinin causes a prostaglandin-mediated bronchoconstriction. Captopril, a potent inhibitor of ACE, prevents the degradation of bradykinin thus potentiating the bradykinin-induced bronchoconstriction, an effect observed in intact animals only in the absence of pulmonary beta-receptor activation.

Rapid detection of bovine type II collagen-specific T-cell hybridomas.

T-cell hybridomas are powerful tools in studying the fine specificities of antigen recognition by the T-cell receptor (TCR), the structure and genetic basis of the CD3-TCR complex, and the size of the TCR alpha/beta repertoire used in response to various antigens. A technical challenge in establishing T-cell hybridomas is the early identification of antigen-specific ones. We have established a rapid and efficient ELISA method for detecting antigen-specific T-cell hybridomas. Our ELISA technique significantly reduces the time and resources required for the primary screening of antigen-specific T-cell hybrids, eliminates the need of maintaining hundreds of rapidly growing nonspecific clones, and does not require the maintenance of IL-2/IL-4 dependent cell lines such as CTLL-2 or HT-2. In addition, the ELISA technique is designed to detect both types of CD4 T-cells: Th1 and Th2, by using a mixture of anti-IL-2 and anti-IL-4 monoclonal antibodies. Therefore, we believe that our ELISA technique provides a faster, less expensive, and higher throughput screening method for the early identification of antigen-specific T-cell hybridomas than the current bioassays.

Maternal transmission of Wolbachia in Phlebotomus papatasi (Scopoli).

Attempts have been made to transfer Wolbachia from infected to uninfected, laboratory-reared Phlebotomus papatasi, through mating, and to determine whether the incompatibility phenotype could be expressed through crosses between infected and uninfected flies. In order to test for the intraspecific transmission of Wolbachia in crosses between infected females and uninfected males, or those between uninfected females and infected males, a PCR based on Wolbachia -specific wsp primers was used to test the progeny of each cross and, subsequently, 50 individual flies from the F(3) generation. All the individual flies tested from the F(1) progeny of the crosses between infected males and uninfected females were found to be uninfected. In the crosses involving infected females and uninfected males, however, Wolbachia were found in the progeny of five matings out of the 23 that produced viable eggs. In the F(3), Wolbachia were not detected in any of the individuals resulting from the cross between uninfected females and infected males but they were detected in 52% (26) of the 50 tested individuals resulting from the cross between infected females and uninfected males. No evidence of cytoplasmic incompatibility (CI) was observed in any of the crosses. The absence of CI expression and relatively low frequencies of maternal transmission could hamper the potential use of Wolbachia in a transgenic strategy for the control of leishmaniases.

Dose distribution of therapeutic electron beams and automation of treatment planning.

Until the present time, there has been no mathematical evaluation of the therapeutic electron beams in tissue material. Electron treatments are becoming universally applied from betatrons and linear accelerators. There is, therefore, a need for dosimetric programming of hospital computers for electron treatment planning such as those used in photon beam dosimetry. In this study, we have developed a theoretical model for dose calculation in a clinical therapeutic electron beam (Osman, 1972 and 1973). On the basis of this proposed theory, one can predict dose profiles at any source to skin distance "SSD"' and at any depth in tissue "X". Our theoretical model is based on considering the clinical broad electron beam used in radiation therapy as being made up of an infinite number of identical and initially parallel pencil beam components, each of minute width, to which the existing theories (Lewis, 1950; Attix et al., 1968) on electron multiple scattering, in the concerned medium apply. Dose profiles in tissue, as obtained from this model, could provide useful information as input data for routine programs of treatment planning with high energy electron beams, using mini-computers. Further, it is also possible to account for any body inhomogeneity such as subcutaneous fat, lung, air volumes, body cavities, fluids and bone from the basic parameters of these media.

Influence of collimating design on central axis depth dose of 10-40 MeV electron beams.

Electron beam measurements were performed in this investigation on three different collimating arrangements in order to study their effect on central axis depth doses. The relative central axis doses for 10, 20 and 34 MeV as a function of area from 10 to 200 cm2 for rectangular, square and circular field sizes were studied at 2.6 and 4.8 gm/cm2 depths in a lucite phantom. Results are presented and are discussed in terms of electron contamination produced by the internal structure of the collimator used.