A phase I trial to assess the value of recombinant human granulocyte colony stimulating factor (r-MetHuG-CSF,filgrastim) in accelerating the dose rate of chemotherapy for intermediate and high-grade non-Hodgkin's lymphoma (NHL)

In a multi-centre phase I study we investigated the possibility of reducing the interval between courses of standard CHOP (cyclophosphamide 750 mg/mdoxorubicin 50 mg/mvincristine 2 mgs day 1, and prednisolone 40 mg/m² days 1–8) from 21 days to 15 days and then 10 days using granulocyte colony stimulating factor (r-MetHuG-CSF (Amgen)-filgrastim) to accelerate neutrophil recovery. Patients received CHOP followed by G-CSF 5 μg/kg s.c. from day 2 to the day before the next course (e.g. days 2–14 for the 15-day interval). A total of 28 patients with newly diagnosed intermediate grade or high grade NHL were studied. Four patients were studied at a 21-day interval, six patients were treated at a 15-day interval and subsequently six patients at a 10-day interval. Following analysis of this initial cohort, a further 12 patients were evaluated; four at the 15-day interval, and eight at the 10-day interval. No dose-limiting toxicity was seen in the four patients receiving 21-day CHOP. Dose-limiting toxicity was seen in 4/10 patients treated at the 15-day interval (M:F 7:3, median age 55·5, range 39–67 years). This consisted of infection in two patients, recurrent infection and debility in a third, and mucositis in a fourth. Seven patients experienced one or more infectious episodes requiring antibiotics (median number of episodes: 2, range 1–4). Fourteen patients (M:F 4:3, median age 47·5, range 25–63 years) were treated at the 10-day interval. Dose-limiting toxicity was seen in six patients. This consisted of severe mucositis in three patients, neutropenia and thrombocytopenia on two separate occasions in one patient, and steroid-induced gastritis in two patients. Nine patients had one or more documented infections (median: 2, range 1–3) requiring antibiotics, of which six were severe (WHO grade 3 or 4). One patient died of Pneumocystis carinii (PCP) pneumonia. In summary, G-CSF (filgrastim) will facilitate the shortening of the dosage interval between cycles of CHOP chemotherapy due to accelerated hematological recovery. However, non-hematological toxicity due to the shorter dosage interval is increased and infective episodes are frequent. © 1996 John Wiley & Sons, Ltd.     

Determination of metabolites of a novel platinum anticancer drug JM216 in human plasma ultrafiltrates

The present study describes the application of on-line liquid chromatography-electrospray ionisation in conjunction with a high resolution magnetic sector mass spectrometer to identify metabolites of a platinum(IV) anticancer drug JM216 bis(acetato)amminedichloro(cyclohexylamine)platinum(IV)] in human plasma. Four metabolites were identified following incubation of JM216 in human plasma: JM118 [amminedichlorocyclohexylamineplatinum(II)], a platinum(II) complex; JM383 [bis(acetato)amminedihydroxo(cyclohexylamine)platinum(IV)]; JM518 [bis(acetato)amminechloro(cyclohexylamine)hydroxoplatinum(IV)] and its isomer JM559. The platinum complexes mass spectra were dominated by the natriated [M + Na]⁺ ion. Elemental compositions of these natriated ions were confirmed by accurate mass measurement on a magnetic sector mass spectrometer in the course of LC/MS analysis. This study demonstrates the capability of direct LC-ESI/MS with accurate mass measurement for analysis of platinum complexes in biological samples. Our results suggest that LC-ESI/MS is a powerful technique for structure elucidation of novel metabolites, and could make valuable contributions to drug metabolism research.     

Fluctuation broadening in carbon nanotube resonators

We simulated the behavior of suspended carbon nanotube resonators over a broad range of temperatures to explore the physics of semiflexible polymers in underdamped environments. We find that thermal fluctuations induce strong coupling between resonance modes. This effect leads to spectral fluctuations that readily account for the experimentally observed quality factors Q ∼ 100 at 300 K. Using a mean-field approach to describe fluctuations, we analytically calculate Q and frequency shifts in tensioned and buckled carbon nanotubes and find excellent agreement with simulations.     

Enhanced NO inactivation and hypertension induced by a high-fat, refined-carbohydrate diet

We have recently demonstrated that long-term consumption of a high-fat, refined-carbohydrate (HFS) diet induces hypertension (HTN) in normal rats compared with a low-fat, complex-carbohydrate (LFCC) diet. Limited evidence suggests that high-fat or high-sugar diets cause enhanced generation of reactive oxygen species (ROS). We therefore hypothesized that by inducing oxidative stress, the HFS diet may promote nitric oxide (NO) inactivation and HTN. To test this hypothesis, female Fischer rats were placed on either the HFS or the LFCC diet starting at 2 months of age. Blood pressure, urinary NO metabolites (NO(x)), and total renal NO synthase activity were monitored, and the tissue abundance of nitrotyrosine (NT), which is the stable "footprint" of NO oxidation by ROS, was determined. The HFS diet group exhibited a gradual rise in arterial blood pressure and were hypertensive by 18 months. This trend was accompanied by a marked accumulation of NT in all tested tissues, an initial rise and a subsequent fall in NO synthase activity, and a fall in urinary NO(x) excretion. The HFS diet-fed animals had a blunted blood pressure response to the NO synthase inhibitor N:(omega)-nitro-L-arginine methyl ester (L-NAME) compared with the LFCC diet group, which showed a marked hypertensive response to L-NAME. L-NAME-induced HTN was reversible with L-arginine in the LFCC diet group; however, HTN was not corrected by L-arginine supplementation in the HFS diet group. These findings point to enhanced ROS-mediated inactivation and sequestration of NO, which may contribute to the reduction of bioactive NO and HTN in the HFS diet-fed animals.     

Alteration to will as an experience of technology and nursing

This paper presents one finding to arise from a recent qualitative research study that examined ways of understanding technology in surgical nursing, and examines its implications for nursing and health care practice. Although the research reported identified eight qualitatively different ways of understanding technology, this paper examines the specific experience that technology can alter will (volition). The experience described is a new area of knowledge and is in need of further examination and research. Nonetheless, it is significant to understanding technology, contemporary nursing practice and the provision of health care services. The paper concludes with some suggested approaches for curtailing the experience and a discussion related to challenges that arise from the finding that technology can alter the free will of nurses.     

Mutation of the GABAA receptor M1 transmembrane proline increases GABA affinity and reduces barbiturate enhancement

All GABA(A) receptor (GABAR) subunits include an invariant proline in a consensus motif in the first transmembrane segment (M1). In receptors containing bovine alpha1, beta1 and gamma2 subunits, we analyzed the effect of mutating this M1 proline to alanine in the alpha1 or beta1 subunit using 3 different expression systems. The beta1 subunit mutant, beta1(P228A), reduced the EC(50) for GABA about 10-fold in whole cell recordings in HEK293 cells and L929 fibroblasts. The corresponding alpha1 subunit mutant (alpha1(P233A)) also reduced the GABA EC(50) when expressed in Xenopus oocytes; alpha1(P233A)beta1gamma2S receptors failed to assemble in HEK293 cells. Binding of [(3)H]flumazenil and [(3)H]muscimol to transfected HEK293 cell membranes showed similar levels of receptor expression with GABARs containing beta1 or beta1(P228A) subunits and no change in the affinity for [(3)H]flumazenil; however, the affinity for [(3)H]muscimol was increased 6-fold in GABARs containing beta1(P228A) subunits. In L929 cells, presence of the beta1(P228A) subunit reduced enhancement by barbiturates without affecting enhancement by diazepam or alfaxalone. Single channel recordings from alpha1beta1gamma2S and alpha1beta1(P228A)gamma2L GABARs showed similar channel kinetics, but beta-mutant containing receptors opened at lower GABA concentrations. We conclude that the beta1 subunit M1 segment proline affects the linkage between GABA binding and channel gating and is critical for barbiturate enhancement. Mutation of the M1 proline in the alpha1 subunit also inhibited receptor assembly.     

A systematic review of the use of atypical antipsychotics in autism

Conventional antipsychotic medication is commonly prescribed to patients with autistic spectrum disorder. However, a high incidence of severe adverse reactions highlights the need to find more favourable treatments. Atypical antipsychotics may combine efficacy in ameliorating some autistic symptoms with a lower incidence of some adverse reactions. This article reviews the use of atypical antipsychotics in autistic disorder, with particular focus on behaviour, cognition and physical well-being. Thirteen studies using risperidone, three using olanzapine, one using clozapine, one using amisulpride and one using quetiapine were identified. Few firm conclusions can be drawn due to the limitations of the studies; however, there is an indication that risperidone may be effective in reducing hyperactivity, aggression and repetitive behaviours, often without inducing severe adverse reactions. Olanzapine and clozapine may also be effective; however, there is little evidence for using amisulpride or quetiapine in this population. Randomized trials are required to clarify the effectiveness of these agents.     

Medical education in Egypt

Modern medical training in Egypt was started by Antoine Clot Bey in 1837 and became part of the university programme in 1919. At present, it comprises six years of university education, followed by one year of internships and one year of compulsory employment with a state-owned hospital. There are now 13 medical faculties in Egypt, using three different curricula: traditional, Islamic and innovative. Their implementation is hampered by the large number of students (15,500 men and 7500 women), the low salaries and motivation of the instructors, the teaching in English rather than Arabic and the lack of recent study materials. It is therefore rather difficult to compare the effectiveness of the Egyptian system with that in the Netherlands. Due partly to the differences in language and culture, Dutch authorities are reluctant to recognise Egyptian medical diplomas.