31P NMR spectroscopic study of bioenergetic changes in radiation-induced fibrosarcoma-1 after radiation therapy

The effects of localized gamma-irradiation on the in vivo 31P NMR spectra of RIF-1 tumors grown subcutaneously in C3H/HeN mice have been examined before and during the week after treatment. Increases in the ratio of phosphocreatine (PCr) to inorganic phosphate (Pi) and in tumor pH, and decreases in the ratio of Pi to the beta phosphorus resonance of the nucleotide triphosphates (beta NTP) were observed in irradiated tumors. The time course of changes in the 31P spectrum following treatment was the opposite of the pattern during untreated growth, and the magnitude and duration of the changes increased with increasing radiation dose, decreasing clonogenic cell survival and increasing growth delay. To examine the possibility that nontherapeutic systemic effects of the tumor irradiation were responsible for the changes observed, a number of animals bearing two tumors were examined. One tumor on each mouse was selectively irradiated. Changes in tumor volume, Pi/beta NTP, PCr/Pi, the ratio of phosphomonoesters to beta NTP, and tumor pH were all significantly different in the treated compared to the untreated tumor on each animal, indicating that these changes in 31P NMR spectra were a response to radiation therapy and not a systemic response to radiation toxicity.     

Transcultural nursing: a perspective derived from Jean-Paul Sartre

Transcultural nursing care is a well-established theoretical framework. This theory, developed by Madeleine Leininger, can have an impact on clinical practice, academic preparation and nursing research. The heightened interest in applying transcultural care and the increased need to espouse this framework have been triggered by constant population changes. This paper defines transcultural nursing care and expands its definition further by comparing and contrasting it with Jean-Paul Sartre's existentialist perspective. The two modes of existence as defined by Sartre are closely examined. Concrete examples are offered as cultural phenomena and the components of a cultural assessment are discussed and applied. The philosophical thesis is approached from a transcultural nursing perspective and existentialism is shown to serve as a foundation for transcultural nursing. The advantages and disadvantages of transcultural nursing practice and the preparation of transcultural nurses are finally addressed.     

A study of the longterm efficacy and toxicity of cyclosporine A in rheumatoid arthritis.

We determined the longterm efficacy and toxicity of cyclosporine A in rheumatoid arthritis (RA) in an open clinical trial, at a single centre, outpatient rheumatology clinic. The initial dose was 5 mg/kg/day increased to 10 mg/kg/day with adjustments for toxicity and plasma cyclosporine A levels. We measured efficacy by the Ritchie articular index, pain and function on a 10 cm visual analog scale, C-reactive protein (CRP) and erythrocyte sedimentation rate. Toxicity was evaluated by patient reports, serum creatinine, cyclosporine A levels and liver function tests. Median treatment duration was 29 months (16.5-38). At 24 months median reduction in Ritchie articular index was 50% (9-79); pain: 49% (21-77), with a 50% (4-76) improvement in function; and CRP fell by 72.5% (22-87). The main side effect was a 40% (27-47) decline in estimated creatinine clearance. We conclude that cyclosporine A at doses below 5 mg/kg/day is associated with clinically significant improvements in indices of disease activity in RA. Renal dysfunction was the most frequent side effect.     

Preserved vision in a case of morning glory syndrome: some pertinent questions

Morning glory syndrome, an unusual developmental anomaly of the optic nerve head, presenting with funnelled enlargement of the disc with a white dot in the centre and a peripheral vascular pattern along the disc margin, with features of typical entry and exit of retinal vessels on the optic nerve head and exceptionally good vision in the involved eye with old traumatic retinal detachment in the other, in a young Indian girl is described here for its rarity and indifferent clinical presentation. Various factors in its pathogenesis are postulated.     

Hyperpolarization moves S4 sensors inward to open MVP,a methanococcal voltage-gated potassium channel

MVP, a Methanococcus jannaschii voltage-gated potassium channel, was cloned and shown to operate in eukaryotic and prokaryotic cells. Like pacemaker channels, MVP opens on hyperpolarization using S4 voltage sensors like those in classical channels activated by depolarization. The MVP S4 span resembles classical sensors in sequence, charge, topology and movement, traveling inward on hyperpolarization and outward on depolarization (via canaliculi in the protein that bring the extracellular and internal solutions into proximity across a short barrier). Thus, MVP opens with sensors inward indicating a reversal of S4 position and pore state compared to classical channels. Homologous channels in mammals and plants are expected to function similarly.     

Sclerosing mucoepidermoid carcinoma of the parotid gland

Although mucoepidermoid carcinoma is the most common primary malignancy of the salivary glands, the sclerosing morphologic variant of this tumor is extremely rare, with only 6 reported cases. As its name suggests, sclerosing mucoepidermoid carcinoma is characterized by an intense central sclerosis that occupies the entirety of an otherwise typical tumor, frequently with an inflammatory infiltrate of plasma cells, eosinophils, and/or lymphocytes at its peripheral regions. The sclerosis associated with these tumors may obscure their typical morphologic features and result in diagnostic difficulties. Tumor infarction and extravasation of mucin eventuating in reactive fibrosis are 2 mechanisms of formation that have been suggested as underlying this morphologic variant. We describe herein another case of sclerosing mucoepidermoid carcinoma that was diagnosed in a 44-year-old woman and review the relevant literature. Morphologic evidence in support of the mucin extravasation hypothesis was identified, as small pools of mucin were present throughout the tumor. However, there was no concentration of the mucin pools near the areas with the most viable tumor cells, which would have provided evidence for a temporal sequence that eventuates in lack of mucin in the most sclerotic regions.     

Identification of mislabeled specimen by molecular methods: case report and review

Specimen misidentification is a common cause of errors in surgical pathology. We report a case where bone-marrow biopsies from patients of different genders were mislabeled and molecular methods were applied to resolve the identity. A short tandem repeat (STR)-polymerase chain reaction-based assay, commonly used in paternity testing, was employed in an attempt to assign the correct identity to the specimens. However, the specimens had been processed by decalcification and the DNA yield was poor. One of the markers in the assay is the non-STR amelogenin locus that distinguishes the X and Y chromosomes. This amelogenin marker results in a product of low molecular weight, enabling unequivocal resolution of identity despite a poor DNA yield. The prevalence of errors in pathology due to specimen misidentifications is reviewed.     

Direct calibration of a reference standard against the air kerma strength primary standard, at 192Ir HDR energy

The primary standard of low air kerma rate sources or beams, maintained at the Radiological Standards Laboratory (RSL) of the Bhabha Atomic Research Centre (BARC), is a 60 cm3 spherical graphite ionization chamber. A 192Ir HDR source was standardized at the hospital site in units of air kerma strength (AKS) using this primary standard. A 400 cm3 bakelite chamber, functioning as a reference standard at the RSL for a long period, at low air kerma rates (compared to external beam dose rates), was calibrated against the primary standard. It was seen that the primary standard and the reference standard, both being of low Z, showed roughly the same scatter response and yielded the same calibration factor for the 400 cm3 reference chamber, with or without room scatter. However, any likelihood of change in the reference chamber calibration factor would necessitate the re-transport of the primary standard to the hospital site for re-calibration. Frequent transport of the primary standard can affect the long-term stability of the primary standard, due to its movement or other extraneous causes. The calibration of the reference standard against the primary standard at the RSL, for an industrial type 192Ir source maintained at the laboratory, showed excellent agreement with the hospital calibration, making it possible to check the reference chamber calibration at RSL itself. Further calibration procedures have been developed to offer traceable calibration of the hospital well ionization chambers.     

Interaction with 14-3-3 proteins promotes functional expression of the potassium channels TASK-1 and TASK-3

The two-pore-domain potassium channels TASK-1, TASK-3 and TASK-5 possess a conserved C-terminal motif of five amino acids. Truncation of the C-terminus of TASK-1 strongly reduced the currents measured after heterologous expression in Xenopus oocytes or HEK293 cells and decreased surface membrane expression of GFP-tagged channel proteins. Two-hybrid analysis showed that the C-terminal domain of TASK-1, TASK-3 and TASK-5, but not TASK-4, interacts with isoforms of the adapter protein 14-3-3. A pentapeptide motif at the extreme C-terminus of TASK-1, RRx(S/T)x, was found to be sufficient for weak but significant interaction with 14-3-3, whereas the last 40 amino acids of TASK-1 were required for strong binding. Deletion of a single amino acid at the C-terminal end of TASK-1 or TASK-3 abolished binding of 14-3-3 and strongly reduced the macroscopic currents observed in Xenopus oocytes. TASK-1 mutants that failed to interact with 14-3-3 isoforms (V411*, S410A, S410D) also produced only very weak macroscopic currents. In contrast, the mutant TASK-1 S409A, which interacts with 14-3-3-like wild-type channels, displayed normal macroscopic currents. Co-injection of 14-3-3ζ cRNA increased TASK-1 current in Xenopus oocytes by about 70 %. After co-transfection in HEK293 cells, TASK-1 and 14-3-3ζ (but not TASK-1ΔC5 and 14-3-3ζ) could be co-immunoprecipitated. Furthermore, TASK-1 and 14-3-3 could be co-immunoprecipitated in synaptic membrane extracts and postsynaptic density membranes. Our findings suggest that interaction of 14-3-3 with TASK-1 or TASK-3 may promote the trafficking of the channels to the surface membrane.     

The pectoralis major myocutaneous flap in head and neck reconstruction

The pectoralis major myocutaneous flap (PMMC flap) represents a landmark in the development of head and neck reconstructive surgery. After Stephan Ariyan first described its use for head and neck reconstruction in 1979, it has become tremendously popular and has revolutionised head and neck cancer surgery. Here, we present our initial experience with fourteen PMMC flaps in head and neck reconstruction. In most of the instances it was used for oral or oropharyngeal reconstruction. It was used for five other reconstructive tasks as well. Wound infection was the most common complication. There was no case of total flap loss. It has proven to be a reliable method of reconstuction in the head and neck.