Diagnosis and management of Staphylococcus aureus infections of the skin and soft tissue

Infections involving the skin and soft tissue are common and range from superficial, localized and sometimes self-limiting infections to deep, rapidly spreading and potentially life-threatening infections. Skin infections caused by Staphylococcus aureus include primary pyodermas, while those involving the soft tissues include cellulitis and pyomyositis. Surgical site infections and infections in intravenous drug users are also commonly caused by S. aureus. The severity of the infection determines the choice of treatment. There are few studies that have critically appraised the use of antibiotics in skin and soft tissue infections, and most guidelines are based on expert opinion. The beta-lactam group of antibiotics are the mainstay of treatment for methicillin-susceptible S. aureus infections. For methicillin-resistant S. aureus (MRSA) infections, both with community-acquired and hospital-acquired strains--which are becoming an increasing problem--the antibiotic choice is determined by local susceptibility patterns. Macrolides, clindamycin and cotrimoxazole are options for community-acquired MRSA, while vancomycin is reserved for treatment of infections caused by multiresistant MRSA strains and for patients with suspected endocarditis or severe sepsis. Although a number of the newer antibiotics such as linezolid and quinopristin/dalfopristin have been shown to have good activity against MRSA, these agents should only be used with specialist advice.

Portable gas analyser Cosmed K4b2 compared to a laboratory based mass spectrometer system

AIM

The purpose of this study was to systematically test the accuracy of an automated, portable, gas analysis system, the Cosmed K4b2 with a laboratory based mass spectrometer system, the Morgan EX670 across a number of gas and ventilation parameters.

METHODS

Eight subjects (mean+/-SE) age, 23.7+/-1.1 y, height, 1.78+/-0.01 m, mass, 74.4+/-2.1 kg performed a V.O2max test and a submaximal exercise test at 150, 200, 250 and 300 Watts (W), on an SRM cycle ergometer. The Morgan EX670 system and the K4b2 were randomly connected in series, using the same breath for the calculation of gas and ventilatory parameters.

RESULTS

The K4b2 system reads significantly higher than the Morgan EX 670 for both VO2 and V.CO2 at 250 (VO2/V.CO2: p<0.05, p<0.002), and 300 W (VO2/V.CO2: p<0.002, p<0.005). Unsystematic bias between the 2 analysers varies between 1% and 16% and systematic bias between 3% and 8%.

CONCLUSION

There are some significant unsystematic and systematic differences between these 2 systems and laboratories should endeavour to utilise either one or the other piece of equipment to test their subjects.

T-cell responses to human papillomavirus type 16 among women with different grades of cervical neoplasia

Infection with high-risk genital human papillomavirus (HPV) types is a major risk factor for the development of cervical intraepithelial neoplasia (CIN) and invasive cervical carcinoma. The design of effective immunotherapies requires a greater understanding of how HPV-specific T-cell responses are involved in disease clearance and/or progression. Here, we have investigated T-cell responses to five HPV16 proteins (E6, E7, E4, L1 and L2) in women with CIN or cervical carcinoma directly ex vivo. T-cell responses were observed in the majority (78%) of samples. The frequency of CD4+ responders was far lower among those with progressive disease, indicating that the CD4+ T-cell response might be important in HPV clearance. CD8+ reactivity to E6 peptides was dominant across all disease grades, inferring that E6-specific CD8+ T cells are not vitally involved in disease clearance. T-cell responses were demonstrated in the majority (80%) of cervical cancer patients, but are obviously ineffective. Our study reveals significant differences in HPV16 immunity during progressive CIN. We conclude that the HPV-specific CD4+ T-cell response should be an important consideration in immunotherapy design, which should aim to target preinvasive disease.

Transjugular liver biopsy is a safe and effective intervention to guide management for patients with a congenital bleeding disorder infected with hepatitis C

The prevalence of hepatitis C virus (HCV) infection in adult patients with a congenital bleeding disorder (CBD) approaches 95% and is a major cause of morbidity and mortality. Histological examination of the liver remains the cornerstone of management decisions in patients without a CBD. The reluctance to perform liver biopsies in patients with a CBD has been a major limitation in the management of these patients. We are currently the only haemophilia centre in Australasia performing liver biopsies in patients with a CBD for the purpose of guiding prognostic and therapeutic decisions. We report here the results of our centre's experience with transjugular liver biopsy (TJLB) in patients with a CBD. An adequate specimen for histological assessment was attained from all of the patients. There were no major complications recorded. Patients were hospitalized for < or = 48 h for haemostasis prophylaxis. The diagnostic specimen obtained from patients was integral in guiding their future management. We suggest that with a coordinated multidisciplinary approach, TJLB can be performed in patients with a CBD.

Venting of Heat and Carbon Dioxide from Urban Canyons at Night

Turbulent fluxes of carbon dioxide and sensible heat were observed in the surface layer of the weakly convective nocturnal boundary layer over the center of the city of Marseille, France, during the Expérience sur Sites pour Contraindre les Modèles de Pollution Atmosphérique et de Transport d’Emission (ESCOMPTE) field experiment in the summer of 2001. The data reveal intermittent events or bursts in the time series of carbon dioxide (CO2) concentration and air temperature that are superimposed upon the background values. These features relate to intermittent structures in the fluxes of CO2 and sensible heat. In Marseille, CO2 is primarily emitted into the atmosphere at street level from vehicle exhausts. In a similar way, nocturnal sensible heat fluxes are most likely to originate in the deep street canyons that are warmer than adjacent roof surfaces. Wavelet analysis is used to examine the hypothesis that CO2 concentrations can be used as a tracer to identify characteristics of the venting of pollutants and heat from street canyons into the above-roof nocturnal urban boundary layer. Wavelet analysis is shown to be effective in the identification and analysis of significant events and coherent structures within the turbulent time series. Late in the evening, there is a strong correlation between the burst structures observed in the air temperature and CO2 time series. Evidence suggests that the localized increases of temperature and CO2 observed above roof level in the urban boundary layer (UBL) are related to intermittent venting of sensible heat from the warmer urban canopy layer (UCL). However, later in the night, local advection of CO2 in the UBL, combined with reduced traffic emissions in the UCL, limit the value of CO2 as a tracer of convective plumes in the UBL.

Anaesthetic management of a neonate with congenital cyst adenoid malformation

We report the anaesthetic management of a male neonate with congenital cyst adenoid malformation (CCAM) of the lung who underwent thoracotomy for resection of CCAM 24 h after birth and again at 24 days. The initial operation involved a 10-day admission to a paediatric intensive care unit (PICU) requiring ventilation, and was complicated by a pneumothorax. This report concentrates on the anaesthetic management for the second thoracotomy. The combination of intra-operative remifentanil infusion and the use of ultrasound to confirm correct placement of epidural catheter allowed on-table tracheal extubation and a shorter stay in PICU. The use of one-lung ventilation (OLV) allowed for better surgical access and enabled complete resection of the lesion.

Early versus delayed surgical treatment of open tibial fractures: effect on the rates of infection and need of secondary surgical procedures to promote bone union

The purpose of this study was to evaluate whether there was any significant difference in the rates of infection and of secondary surgical procedures to promote bone union, between early(6 h or less after arrival to hospital) and delayed(more than 6 h) surgical treatment of open tibial fractures. Three hundred and eighty-three open tibial fractures were evaluated. 184 fractures had early and 199 had delayed surgical treatment. The rates of infection and secondary surgical procedures to promote bone union of the two groups were compared with univariate and multivariate statistical methods. There was no statistically significant difference between early and delayed treatment groups with respect to overall infection (53/184 versus 51/199 infection rates, P = 0.96), deep infection (8/184 versus 8/199 infection rates, P = 1.0), and rates of secondary surgical procedures to promote bone union (24/184 versus 20/198, P = 0.77). We were unable to demonstrate any significant difference in infection rates or need of secondary procedures to promote bone union, between early and delayed surgical treatment of open tibial fractures.

Early results of autologous chondrocyte implantation in the talus

Autologous chondrocyte implantation (ACI) has been used most commonly as a treatment for cartilage defects in the knee and there are few studies of its use in other joints. We describe ten patients with an osteochondral lesion of the talus who underwent ACI using cartilage taken from the knee and were prospectively reviewed with a mean follow-up of 23 months. In nine patients the satisfaction score was 'pleased' or 'extremely pleased', which was sustained at four years. The mean Mazur ankle score increased by 23 points at a mean follow-up of 23 months. The Lysholm knee score returned to the pre-operative level at one year in three patients, with the remaining seven showing a reduction of 15% at 12 months, suggesting donor-site morbidity. Nine patients underwent arthroscopic examination at one year and all were shown to have filled defects and stable cartilage. Biopsies taken from graft sites showed mostly fibrocartilage with some hyaline cartilage. The short-term results of ACI for osteochondral lesions of the talus are good despite some morbidity at the donor site.

Characteristics of US adults with the metabolic syndrome and therapeutic implications

BACKGROUND

The third Adult Treatment Panel (ATP III) of the National Cholesterol Education Program defines clinical criteria for diagnosis of the metabolic syndrome, which increases cardiovascular risk and is a target for therapy.

AIM

We analysed the third National Health and Nutrition Examination Survey (NHANES III; 1988-94) to determine how many US adults meet these criteria and are recommended for lipid-modifying drug therapy by ATP III.

METHODS

NHANES III data were used to estimate the number of individuals with the metabolic syndrome and the number recommended for treatment by ATP III, based on 1990 census data.

RESULTS

An estimated 36.3 million (23%) US adults have the metabolic syndrome. Of these, 84% met the criterion for obesity, 76% for blood pressure, 75% for HDL-C, 74% for triglycerides and 41% for glucose. Most (54%) are in the higher risk categories of ATP III, yet only 39% overall are recommended for drug therapy by ATP III cutpoints; of these, most will achieve LDL-C targets with reductions of 35-40%. Of the 15.3 million individuals with the metabolic syndrome and triglycerides > or = 2.26 mmol/l (200 mg/dl), non-HDL-C is above ATP III recommendations in 11.6 million.

CONCLUSIONS

Of the large number of Americans with the metabolic syndrome, ATP III recommends drug therapy for only a minority, because LDL-C typically is not substantially elevated. Instead, high triglycerides and low HDL-C are more common; clinical trial data are needed to determine whether optimal therapy should focus on reductions in LDL-C or on comprehensive improvements to the lipid profile.

Beliefs and practices of patients with advanced cancer: implications for communication

The aim of this study was to investigate the beliefs that patients with advanced cancer held about the curability of their cancer, their use of alternatives to conventional medical treatment, and their need to have control over decisions about treatment. Of 149 patients who fulfilled the criteria for participation and completed a self-administered questionnaire, 45 patients (31%) believed their cancer was incurable, 61 (42%) were uncertain and 39 (27%) believed their cancer was curable. The index of need for control over treatment decisions was low in 53 patients (35.6%) and high in only 17 patients (11.4%). Committed users of alternatives to conventional medical treatments were more likely to believe that their cancer was curable (P<0.001) and to have a higher need for control over decisions about treatment (P<0.004). The mean need for control scores were highest in patients who believed that their cancer was curable, or who were uncertain about the curability of their cancer, but who acknowledged that their oncologist had reported that the cancer was incurable. The diverse beliefs, attitudes and actions of these patients were consistent with a range of psychological adaptions to a life-threatening illness, some realistic and others illusory. Illusory responses influence what communication can achieve in daily oncology practice.

Short course intravenous benzylpenicillin treatment of adults with meningococcal disease

BACKGROUND

Short-course treatment of meningococcal disease (including meningitis) with 4-5 days of an i.v. beta-lactam is of proven efficacy. Since April 1998, all adult patients with meningococcal disease admitted to Auckland Hospital were prospectively treated with 3 days of i.v. benzylpenicillin.

AIMS

To assess the clinical features, laboratory findings, disease complications and outcome of patients with meningococcal disease prospectively treated with 3 days of i.v. benzylpenicillin.

METHODS

A retrospective chart review of all adult patients with meningococcal disease admitted to Auckland Hospital from April 1998 to December 2002 was conducted.

RESULTS

Ninety patients with definite (n = 72) or -probable (n = 16) meningococcal disease were admitted during the study period. Two were excluded on the basis of treatment duration. The remaining 88 patients received a mean +/- standard deviation duration of treatment of 3.1 +/- 0.5 days (excluding those who died while receiving treatment). Six patients (7%) died, four of whom while on treatment. There were no relapses.

CONCLUSION

Three days of i.v. benzylpenicillin for the treatment of adults with meningococcal disease is effective.

Comparison of EUS-guided 19-gauge Trucut needle biopsy with EUS-guided fine-needle aspiration

BACKGROUND AND STUDY AIMS

The accuracy of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) depends on immediate specimen review by a cytopathologist. Stromal tumors, lymphoma, and well-differentiated pancreatic cancer are difficult to diagnose on the basis of cytology alone. To overcome these limitations, a 19-gauge Trucut needle has been developed to obtain histological samples at EUS. This pilot study compares the specimen adequacy and diagnostic accuracy of EUS-guided Trucut needle biopsy (EUS-TNB) with EUS-FNA.

PATIENTS AND METHODS

A total of 18 patients underwent EUS-TNB and EUS-FNA. The specimen adequacy and diagnostic accuracy of the two techniques was compared. The technical performance and safety profile of the Trucut needle were also evaluated.

RESULTS

The EUS-TNB specimen was adequate for evaluation in 15/18 patients compared with 18/18 with EUS-FNA (83 % vs. 100 %, not significant). The diagnostic accuracy of EUS-TNB was not significantly different from EUS-FNA (78 % vs. 89 %). Two complications were encountered: one patient developed mediastinitis and required surgery; another had immediate bleeding that was managed conservatively. One technical problem was encountered: the Trucut needle failed to deploy after two passes when a gastric stromal cell tumor was being biopsied.

CONCLUSION

The diagnostic accuracy of the new EUS-TNB is comparable to that of EUS-FNA. In our experience, the overall efficacy and safety profile of the Trucut needle appears modest.

Cost-effectiveness of flexible intensive insulin management to enable dietary freedom in people with Type 1 diabetes in the UK

AIMS

To determine the cost-effectiveness of a structured treatment and teaching programme (STTP) combining dietary freedom with insulin adjustment for Type 1 diabetes.

METHODS

Incremental cost-effectiveness analysis based on effectiveness data from three RCTs in Germany, Austria, and Dose Adjustment for Normal Eating (DAFNE) in the UK, to model the long-term microvascular complications of Type 1 diabetes.

RESULTS

The STTP approach yields effectiveness gains at a lower cost compared with current standard practice for treatment of Type 1 diabetes. STTPs are likely to save 0.05 life years, yield 0.12 EuroQol 5 dimensions (EQ-5D) and 0.09 visual analogue scale (VAS) incremental quality-adjusted life years, and save approximately pound 2200 per patient treated discounted over 10 years.

CONCLUSIONS

Introducing STTPs as standard treatment for people with Type 1 diabetes in the UK may help to achieve the primary goal of the National Service Framework (NSF) for Diabetes by enabling individuals to manage their own lifestyle and condition. In doing so it could save valuable resources for the NHS and yield important morbidity and mortality gains.

Human intervertebral disc cell morphology and cytoskeletal composition: a preliminary study of regional variations in health and disease

Classically, intervertebral disc cells have been described as fibrocytic in the anulus fibrosus and chondrocytic in the nucleus pulposus. Recent animal studies, however, have suggested that disc cell morphology may be more complex than previously considered. Here, by utilizing labelling of components of the cytoskeleton in combination with confocal microscopy, we have examined the detailed morphology of human intervertebral disc cells in pathological and non-pathological tissue. Filamentous-actin- and vimentin-positive cells that appeared either fibrocytic or chondrocytic were observed in all intervertebral discs. However, in localized areas of the disc, stellate cells that extended multiple, branching cytoplasmic processes into their surrounding matrix were also seen. This stellate appearance formed a marked feature of disc cells regionally in certain pathologies, i.e. in cells of the outer anulus fibrosus in scoliotic discs and in inner anulus/nucleus pulposus cells in one spondylolisthetic disc. We conclude that the phenotypic variation of human intervertebral disc cells should be extended to include cells with a stellate appearance, which may be more prevalent in tissue that has been subjected to abnormal load or tension.

High resolution MRI of the brain at 4.7 Tesla using fast spin echo imaging

Over recent years, high field MR scanners (3 T and above) have become increasingly widespread due to potential advantages such as higher signal-to-noise ratio. However, few examples of high resolution images covering the whole brain in reasonable acquisition times have been published to date and none have used fast spin echo (FSE), a sequence commonly employed for the acquisition of T(2) weighted images at 1.5 T. This is mostly due to the increased technical challenges associated with uniform signal generation and the increasingly restrictive constraints of current safety guidelines at high field. We investigated 10 volunteers using an FSE sequence optimized to the 4.7 T environment. This sequence allows the acquisition of 17- and 34-slice data sets with an in-plane resolution of approximately 500 microm x 500 microm and a slice thickness of 2 mm, in 5 min 40 s and 11 min 20 s, respectively. The images appear T(2) weighted, although the contrast is due to the combined effects of chosen echo time, magnetization transfer, direct radio frequency saturation and diffusion as well as the T(1) and T(2) relaxation times of the tissue. The result is an excellent detailed visualization of anatomical structures, demonstrating the great potential of 4.7 T MRI for clinical applications. This paper shows that, with careful optimization of sequence parameters, FSE imaging can be used at high field to generate images with high spatial resolution and uniform contrast across the whole brain within the prescribed power deposition limits.

Total parenteral nutrition vs oral diet in autologous hematopoietic cell transplant recipients

Autologous HCT patients often have poor oral intake for 2-4 weeks post transplant. To compare outcomes between patients provided prophylactic total parenteral nutrition (TPN) or an oral diet (OD), 55 well nourished breast cancer/ hematopoietic cell transplantation (HCT) patients were randomized to TPN (n=27), beginning day -1, or OD (n=28). Parameters studied include length of stay (LOS), engraftment, infections, survival, weight, anthropometrics, handgrip strength, and quality of life (QOL) In all, 50% of OD patients were given TPN due to poor oral intake for 10 consecutive days. No significant differences were found between the groups for any of the above parameters except weight and anthropometrics, which were better maintained in the TPN group than the OD group. Trends were seen for increased infections, more stable handgrip strength, and improved QOL in the TPN group vs the OD group. Prophylactic TPN did result in a more intact nutritional status and preservation of lean body mass post transplant but did not impact LOS or survival when compared to OD. For this reason, TPN should be reserved for autologous HCT patients with pretransplant nutritional depletion, complications post transplant, or prolonged poor oral intake. These results should not be extrapolated to allogeneic HCT patients but are likely applicable to other well nourished autologous HCT patients.

Probabilistic methods in BCI research

This paper suggests a probabilistic treatment of the signal processing part of a brain-computer interface (BCI). We suggest two improvements for BCIs that cannot be obtained easily with other data driven approaches. Simply by using one large joint distribution as a model of the entire signal processing part of the BCI, we can obtain predictions that implicitly weight information according to its certainty. Offline experiments reveal that this results in statistically significant higher bit rates. Probabilistic methods are also very useful to obtain adaptive learning algorithms that can cope with nonstationary problems. An experimental evaluation shows that an adaptive BCI outperforms the equivalent static implementations, even when using only a moderate number of trials. This suggests that adaptive translation algorithms might help in cases where brain dynamics change due to learning effects or fatigue.

Illusions in advanced cancer: The effect of belief systems and attitudes on quality of life

Patients with advanced cancer frequently express positive attitudes and can be unduly optimistic about the potential benefits of treatment. In order to evaluate an illusory domain in the context of advanced cancer, we developed a scale of will to live and characterized the beliefs that patients held about the curability of their cancer, and how committed they were to using alternative treatments. A measure of quality of life was used as the dependent variable in order to assess the association between these attributes. After a preliminary exploration confirmed the presence of an illusory domain, these concepts were prospectively tested in 149 ambulant patients with advanced cancer who attended for palliative systemic treatment, radiation treatment or supportive care. The scale of global quality of life was reliable (Cronbach's alpha coefficient 0.72). The distribution of the scores of will to live was skewed, with no respondent scoring poorly, and the scale was reliable (Cronbach's alpha coefficient 0.82). The scale of belief in curability showed diverse beliefs. In some cases, there was a discrepancy between respondents' beliefs in curability and what they believed to be the report by their doctors. There was also an association between a committed use of alternative treatments and a belief in the curability of the cancer (p<0.001). In a multiple regression analysis, both will to live and performance status remained associated with better quality of life scores after adjustment for other relevant variables (p<0.05 and <0.001, respectively). These results suggest that positive illusory beliefs can be measured and are an important component of adaption for some patients with advanced cancer. Furthermore, this illusory domain may influence the perception and measurement of quality of life.

Time-resolved areal-density measurements with proton spectroscopy in spherical implosions

The temporal history of the target areal-density near peak compression of direct-drive spherical target implosions has been inferred with 14.7-MeV deuterium-helium-3 D3He proton spectroscopy of the 60-beam, 30-kJ UV OMEGA laser system. The target areal-density grows by a factor of approximately 8 during the time of neutron-production ( approximately 400 ps) before reaching 123+/-16 mg/cm(2) at peak compression in the implosion of a 950-micrometer-diam, 20-micrometer-thick plastic CH capsule filled with 4 atm of D3He fuel.

Use of active barriers to reduce eutrophication problems in urban lakes

Excessive concentration of phosphorus is one of the main causes of algal blooms and eutrophic conditions in lakes. In many urban lakes, it appears that a large proportion of the phosphorus in the water column comes from the sediments, particularly when these are anaerobic. Sub-aqueous capping is a relatively new method that has become an attractive option for isolating contaminated sediments from the environment, thus preventing or delaying the release of contaminants into surface waters. Active barrier materials (i.e. capping layers that consist of one or more reactive components) are gaining increasing attention for their greater efficiency in inactivating contaminants held in sediment layers. This paper reports laboratory bioreactor experiments to test the effectiveness of three forms of calcium carbonate (CaCO3) in reducing the release of phosphorus from anaerobic sediment from Lake Carramar, a small urban lake in Melbourne. Two of the CaCO3 active barrier materials tested proved to be quite effective, the most effective materials being the fine particle size, precipitated forms of CaCO3. Over the 20-day experimental period, a 2% layer of the German material SoCal reduced the amount of phosphorus released by almost 100 times over that occurring with no barrier. The Australian product ESCal, while not as effective as the SoCal, still reduced the phosphorus released by around 15 times that with no barrier. A finely ground Lilydale limestone was essentially ineffective in reducing phosphorus release from the sediments. A preliminary cost-benefit analysis suggests that SoCal is unlikely to be attractive for use in Australia, given the estimated application cost of around 3,800 dollars per tonne. However, although the ESCal is slightly less effective in retaining phosphorus, its potential application cost estimated at 2,000 dollars per tonne, makes it an attractive option. On the basis of these most promising preliminary results, we intend to further test the use of the ESCal. Further investigations will include: longer term laboratory studies using ESCal, optimisation of the barrier layer and methods for applying this material, mesocosms and full lake studies, and risk assessment studies to ensure there are no adverse ecological effects from its use.

The Living with Cancer Education Programme. I. Development of an Australian education and support programme for cancer patients and their family and friends

After a diagnosis of cancer, patients and their families and friends experience a significant need for information about the illness, treatment and prognosis, as well as support. Structured education and support group-based programmes play a major role in meeting these needs. Following a needs assessment in 1985, the Anti-Cancer Council of Victoria (ACCV), Australia, initiated development of the Living With Cancer Education Programme (LWCEP), a structured 8-week group programme providing education and support for people with cancer and their families and friends. This paper provides an historical overview of the LWCEP, as well as an outline of the programme aims, structure, content and delivery. Recent developments and future directions are also discussed. These include adaptation of the programme for individuals with advanced or recurrent cancer, modification of the programme structure and revision of the evaluation methodology.

The Living with Cancer Education Programme. II. Evaluation of an Australian education and support programme for cancer patients and their family and friends

A diagnosis of cancer can have major adverse physical, psychosocial and economic consequences for both the individual diagnosed with cancer and their family and friends. The provision of adequate information and support to individuals affected by cancer plays a key role in facilitating better adjustment and coping. Psychoeducational group programmes are an effective way of meeting this need. This paper reports on the results of an evaluation of an Australian education and support programme for individuals with cancer and their family and friends - the Living with Cancer Education Programme (LWCEP). Data are presented based on the evaluation of 152 programmes involving 1460 participants conducted between 1994 and 2000. Participant responses related to changes in self, general coping abilities and satisfaction with the programme are reported. Results showed high satisfaction with the programme and significant improvement in coping abilities, knowledge and communication and relationships with significant others and health professionals among both groups of participants. These findings highlight several important issues for professionals involved in the psychosocial care of cancer patients and their family and friends.

Platinum agents in the treatment of osteosarcoma: efficacy of cisplatin vs. carboplatin in human osteosarcoma cell lines

BACKGROUND

Cisplatin (cDDP), when used either alone or, more often, in combination with other agents, especially adriamycin, achieves a high response rate in osteosarcoma. Its use, however, is limited by severe nephro- and neuro-toxicity. Second generation platinum compounds, most notably carboplatin (CBDCA), have been developed in order to attempt to reduce these dose-limiting toxicities, and thus improve the therapeutic ratio. Studies evaluating the role of combination CT containing CBDCA vs. cDDP have demonstrated differing results depending on the tumor type tested and its role in the treatment of osteosarcoma has yet to be clarified.

PROCEDURE

In this study, we compared the in vitro anti-tumor activity of cDDP and CBDCA in a panel of three human osteosarcoma cell lines (HOS, MG63, and U2OS).

RESULTS

cDDP and CBDCA (0-20 micromol) showed marked variation in cytotoxicity among the three cell lines. EC(50) values for CBDCA in HOS and MG63 cells were approximately two-fold higher than for cDDP and the ratio of AUC(CBDCA) to AUC(cDDP) varied from 1.8 in the HOS cell line to 2.3 in the MG63 cell line. Exposure of MG63 and HOS cells to either cDDP or CBDCA (1.67 and 13.5 micromol) caused a G2/M cell cycle arrest by 24 hr. Also evident was a sub G1 peak indicative of cell death by apoptosis. U2OS cells were relatively resistant to the cytotoxic effects of both drugs, although a cell cycle arrest in response to DNA damage was observed. This suggests that unlike MG63 and HOS cells, U2OS cells have either a more efficient repair pathway for platinum-induced DNA damage or are able to evade apoptosis. Examination of apoptotic events and cellular recovery demonstrated that both an 8-16-fold higher concentration and longer treatment period for CBDCA compared with cDDP was required to produce equivalent cell death and a loss of the ability of single cell clones to form colonies in both the HOS and MG63, but not the U2OS cell line.

CONCLUSIONS

Our findings suggest that CBDCA at a two- to four-fold higher concentration than cDDP has potential therapeutic activity in platinum sensitive osteosarcomas, particularly when cDDP cytotoxicity compromises therapeutic efficacy.

Positive and negative thought disorder and psychopathology in childhood among subjects with adulthood schizophrenia

The New York High-Risk Project (NYHRP) is a longitudinal study of offspring of parents with schizophrenia or affective disorder and normal controls. Neuropsychological deficits had been observed at about age 9 in subjects with adulthood schizophrenia. We explored whether in these subjects, early signs of clinical schizophrenia-related symptoms, such as thought disorder or behavioral abnormalities, could also be observed.

METHODS

We rated thought disorder and symptoms from videotaped interviews at age 9, using the Scale for the Assessment of Thought, Language and Communication (TLC), and the Mental Health Assessment Form (MHAF). With factor analyses we examined the structure of the ratings, and from interpretable factors, scales were assembled. MANOVAs were used to examine the effect of parental risk and adulthood psychiatric diagnosis (schizophrenia-related psychosis (SRP), major affective disorder (MAD), no disorder/other (NoDx/other)) as independent variables (IV) on thought disorder and symptoms as dependent variables.

RESULTS

Global, positive and negative thought disorder, and negative symptoms were significantly higher in subjects with adulthood schizophrenia-related psychosis than both comparison groups. A significant interaction between the two IVs was effective with respect to positive thought disorder. This scale was particularly elevated among subjects with adulthood schizophrenia-related psychosis at parental risk for affective disorder (all of whom had adulthood schizoaffective disorder).

CONCLUSIONS

We were able to show that global, negative and positive thought disorder and negative symptoms were present in subjects with adulthood schizophrenia already at mid-childhood, years before onset of psychosis. Further, we found a particularly high propensity to positive symptoms in subjects with adulthood schizophrenia who have also an affective component in their symptoms. This association, previously reported in acute schizophrenia, was here observed years before the first psychotic episode.

Disc morphology in health and disease

The morphology of the intervertebral disc is dependent on the type of components present and the manner in which they are assembled. This, in turn, will determine how the tissue carries out its primary physiological functions of load bearing and allowing movement in all directions of the otherwise rigid spine. The disc starts its life in an ordered fashion, with the outer annulus fibrosus consisting of a series of regular concentric bundles of collagen fibres around the central gelatinous nucleus pulposus. With advancing age there is increased complexity of lamellae, with more bifurcations, interdigitations and irregularity in number and size of lamellar bands, probably as a result of the disc cells' synthetic response to variations in incident loads. This change in organization itself will lead to altered load bearing, hence possibly establishing a self-perpetuating cycle of disruption to disc morphology, which, once started, may be irreversible. There are also alterations to cell organization with disease and degeneration. There may be increased cell number, with clusters of cells forming by cell proliferation, or increased cell death, whether by necrosis or apoptosis, in degenerate or deformed discs such as are found in spinal deformities; for example, scoliosis. Any change in cell number is likely to alter the nutritive requirements and concentration gradients of both nutrients and metabolites. The normally avascular disc in the healthy adult can become increasingly vascularized and innervated with degeneration and disease. This may lead to an increased supply of oxygen and nutrients to the disc, but can also introduce other cells types and molecules such as cytokines and growth factors.

Effects of fuel-shell mix upon direct-drive, spherical implosions on OMEGA

Fuel-shell mix and implosion performance are studied for many capsule types in direct-drive experiments at OMEGA. The amount of mixing and the size of the mix region are inferred from charged-particle spectrometry data and confirmed with an experimentally constrained model. Measured yields and convergence ratios CR fall short of one-dimensional predictions, especially for low capsule fill pressures. CR is approximately 11 for pressures from 3 to 15 atm, in contrast to predictions of approximately 25 for 3 atm and approximately 12 for 15 atm. The performance shortfalls are likely to be caused by fuel-shell mix.

Binge eating disorder in extreme obesity

OBJECTIVE

To determine whether extremely obese binge eating disorder (BED) subjects (BED defined by the Eating Disorder Examination) differ from their extremely obese non-BED counterparts in terms of their eating disturbances, psychiatric morbidity and health status.

DESIGN

Prospective clinical comparison of BED and non-BED subjects undergoing gastric bypass surgery (GBP).

SUBJECTS

Thirty seven extremely obese (defined as BMI > or = 40 kg/m(2)) subjects (31 women, six men), aged 22-58 y.

MEASUREMENTS

Eating Disorder Examination 12th Edition (EDE), Three Factor Eating Questionnaire (TFEQ), Structured Clinical Interview for the Diagnostic and Statistical Manual-IV (SCID-IV), Short-Form Health Status Survey (SF-36), and 24 h Feeding Paradigm.

RESULTS

Twenty-five percent of subjects were classified as BED (11% met full and 14% partial BED criteria) and 75% of subjects were classified as non-BED. BED (full and partial) subjects had higher eating disturbance in terms of eating concern and shape concern (as found by the EDE), higher disinhibition (as found by the TFEQ), and they consumed more liquid meal during the 24 h feeding paradigm. No difference was found in psychiatric morbidity between BED and non-BED in terms of DSM-IV Axis I diagnosis. The health status scores of both BED and non-BED subjects were significantly lower than US norms on all subscales of the SF-36, particularly the BED group.

CONCLUSION

Our findings support the validity of the category of BED within a population of extremely obese individuals before undergoing GBP. BED subjects differed from their non-BED counterparts in that they had a greater disturbance in eating attitudes and behavior, a poorer physical and mental health status, and a suggestion of impaired hunger/satiety control. However, in this population of extremely obese subjects, the stability of BED warrants further study.

Cell cluster formation in degenerate lumbar intervertebral discs is associated with increased disc cell proliferation

Healthy human intervertebral discs contain relatively few cells and these are sparsely distributed. A characteristic feature of disc degeneration, however, is the appearance of cell clusters, particularly in damaged areas. How these clusters form is currently unknown. We have examined excised pathological human discs for evidence of cell proliferation. Disc sections were immunostained for the proliferating cell nuclear antigen (PCNA) and the proliferation-associated Ki-67 antigen. PCNA immunopositive cells were observed within degenerate discs, commonly though not exclusively, in cell clusters. Cells immunopositive for the Ki-67 antigen were less prevalent than those for PCNA, but similarly were observed frequently within clusters in degenerate discs. In contrast, immunopositivity for these markers was not common in less degenerate discs or in areas of the disc where cell clusters were not observed. These observations suggest that disc cell proliferation is associated with disc degeneration and is the likely cause of cell cluster formation.