Dosimetry in radiotherapy of the lower portion of the body in Hodgkin's disease. Dose distribution within the target volume dependent on radiotherapy

The dose distribution of three radiations (Co-60, Co-6, and 10 MV continuous radiation) within the target volume was evaluated. It is shown that a much more constant reference dose can be achieved with cobalt, whereas continuous radiation causes a more homogeneous dose distribution in the target volume. With the irregular field developed by us, the therapy success could be endangered by too low dosages within the target volume.     

Has the age of patients with bilateral cheilognathoplatoschisis at the time of palatoplasty an influence on maxillary size development?]

The author reports of the biometrical analysis of 91 models obtained from 9--16-year-old patients with bilateral cheilognathopalatoschisis who had undergone pedicle flap operation (without insertion of bone material) at ages 4--6 years. It was found that the time of operation had exerted no effect on the state of development of the maxillae at ages 9--16 years.     

Multimodality monitoring in severe traumatic brain injury

Traumatic brain injury (TBI) is a major cause of morbidity and mortality with widespread social, personal, and financial implications for those who survive. TBI is caused by four main events: motor vehicle accidents, sporting injuries, falls, and assaults. Similarly to international statistics, annual incidence reports for TBI in Australia are between 100 and 288 per 100,000. Regardless of the cause of TBI, molecular and cellular derangements occur that can lead to neuronal cell death. Axonal transport disruption, ionic disruption, reduced energy formation, glutamate excitotoxicity, and free radical formation all contribute to the complex pathophysiological process of TBI-related neuronal death. Targeted pharmacological therapy has not proved beneficial in improving patient outcome, and monitoring and maintenance of various physiological parameters is the mainstay of current therapy. Parameters monitored include arterial blood pressure, blood gases, intracranial pressure, cerebral perfusion pressure, cerebral blood flow, and direct brain tissue oxygen measurement (ptiO₂). Currently, indirect brain oximetry is used for cerebral oxygenation determination, which provides some information regarding global oxygenation levels. A newly developed oximetry technique, has shown promising results for the early detection of cerebral ischemia. ptiO₂ monitoring provides a safe, easy, and sensitive method of regional brain oximetry, providing a greater understanding of neurophysiological derangements and the potential for correcting abnormal oxygenation earlier, thus improving patient outcome. This article reviews the current status of bedside monitoring for patients with TBI and considers whether ptiO₂ has a role in the modern intensive care setting.     

Specific high-performance liquid chromatographic assay for nitroglycerin in dosage forms.

A specific assay for nitroglycerin dosage forms using high-performance liquid chromatography was developed. Sublingual nitroglycerin tablets are dissolved in 25 ml of water and injected directly into the chromatograph. Chromatographic conditions are: mobile phase, 60% methanol in water; flow rate, 2 ml/min; column, microparticulate reversed phase; and detection, 200 nm. The glyceryl mononitrate and dinitrate degradation products of nitroglycerin are separated from nitroglycerin and can be identified by altering the mobile phase composition of methanol.     

Delayed diagnosis in subarachnoid haemorrhage

OBJECTIVE: To determine the outcome in patients with subarachnoid haemorrhage from a ruptured aneurysm, particularly in those in whom the diagnosis was delayed. DESIGN: A two-year retrospective study of medical records of patients admitted to Westmead Hospital between July 1988 and June 1989. SETTING: A tertiary level teaching hospital. PATIENTS: Ninety-four patients treated for subarachnoid haemorrhage. In 15 cases the diagnosis was delayed. MAIN OUTCOME MEASURES: Death, disability, or functional recovery. RESULTS: Overall, 40 (42.5%) patients died, 14 (15%) were disabled, and 40 made a functional recovery. Of the 62 patients who were treated surgically 38 (61%) made a functional recovery compared with two of the 32 (6%) who were not. Of the 15 in whom the diagnosis was delayed seven (47%) made a functional recovery. Confirmation of the diagnosis was delayed in four of the latter group because a cranial computed tomography scan showed no abnormalities. CONCLUSIONS: Earlier diagnosis, allowing early definitive surgical treatment, may improve the outcome in aneurysmal subarachnoid haemorrhage. The results of a computed tomography scan are diagnostic only if they are positive--a negative result must be interpreted in conjunction with the clinical picture.     

Report: workshop on mediastinal grey zone lymphoma

There are several indications that classical Hodgkin lymphoma (cHL) and at least a proportion of cases of Primary Mediastinal B cell Lymphoma (PMBL) are derived from B cells at similar stages of differentiation and share common pathogenic mechanisms. The first indication was the existence of mediastinal grey zone lymphomas as identified in the 4th International Symposium on HL, with clinical, histological and immunohistochemical features intermediate between cHL and PMBL. Second, both tumor types resemble a cell that is developmentally situated in-between the germinal center reaction and a plasma cell. Third, cHL and PMBL were found to have similar gene expression profiles, including the lack of immunoglobulin expression and low levels of B cell receptor signalling molecules, and the secretion of molecules like the chemokine TARC and the prominent expression of IL-13 receptors. Fourth, both entities were found to have common genomic aberrancies, notably in 2p15 and 9p24, the sites of the REL oncogene and the tyrosine kinase gene JAK2, respectively. Further comparison of both lymphoma types may provide further insight in the pathogenic mechanisms and allow the design of diagnostic algorithms to sort out the small number of so-called mediastinal grey zone lymphomas, that appear to be intermediate between PMBL and cHL.     

Specific unresponsiveness in rats with prolonged cardiac allograft survival after treatment with cyclosporine. Mediation of specific suppression by T helper/inducer cells

DA rats grafted with major histocompatibility complex-incompatible PVG heart grafts and treated with cyclosporine (CY) for 10 d do not reject their grafts, and develop a state of specific unresponsiveness toward PVG allografts. Cells from these animals tested in an adoptive transfer assay were incapable of restoring PVG graft rejection, and capable of specifically inhibiting the capacity of adoptively transferred normal lymph node cells (LNC) to do so. They effected third party Wistar/Furth (W/F) graft rejection, however. Adoptive transfer assays with purified subpopulations of the lymphocytes that mediated this effect showed that W3/25+ T cells of the helper/inducer subclass, when injected alone, failed to restore rejection, and were also able, when injected with normal LNC or the W/25+ cells separated from them, to prevent these cells from effecting rejection. MRC OX8+ T cells of the cytotoxic/suppressor subclass, B cells, and serum from rats with long-surviving grafts all failed to inhibit the allograft responsiveness of normal LNC, and thus were not identified as mediators of the state of specific unresponsiveness. These results show that the specific unresponsiveness that develops in rats with long-surviving grafts, and which, in part at least, is responsible for prolonged graft survival, is due to an alteration in the alloreactivity of the helper/inducer subclass of T cells. These cells not only lack the capacity to initiate a rejection response against the alloantigens of the graft, but also have the ability to inhibit the capacity of normal W3/25+ cells to do so.