Vascular phenotype in angiogenic and non-angiogenic lung non-small cell carcinomas

We have previously described a group of non-small cell lung carcinomas without morphological evidence of neo-angiogenesis. In these tumours neoplastic cells fill up the alveoli and the only vessels present appear to belong to the trapped alveolar septa. In the present study we have characterised the phenotype of the vessels present in these non-angiogenic tumours, in normal lung and in angiogenic non-small cell lung carcinomas. The vessels, identified by the expression of CD31, were scored as mature when expressing the epitope LH39 in the basal membrane and as newly formed when expressing alphaVbeta3 on the endothelial cells and/or lacking LH39 expression. In the nine putative non-angiogenic cases examined, the vascular phenotype of all the vessels was the same as that of alveolar vessels in normal lung: LH39 positive and alphaVbeta3 variable or negative. Instead in 104 angiogenic tumours examined, only a minority of vessels (mean 13.1%; range 0--60%) expressed LH39, while alphaVbeta3 (in 45 cases) was strongly expressed on many vessels (mean 55.5%; range 5--90%). We conclude that in putative non-angiogenic tumours the vascular phenotype is that of normal vessels and there is no neo-angiogenesis. This type of cancer may be resistant to some anti-angiogenic therapy and different strategies need to be developed.

Cancer: impact of nutrition intervention outcome--nutrition issues for patients

OBJECTIVE

We examined nutritional issues, assessment, and intervention strategies for patients with cancer.

METHODS

Reviews of practice guidelines and published reports were used to identify nutritional issues and strategies that can benefit patients with cancer.

RESULTS

Assessment tools such as the Patient-Generated Subjective Global Assessment are useful in terms of identifying patients with nutrition issues and guiding intervention. However, quality of life and other measures should also be considered. There is a need for early and ongoing nutrition interventions.

CONCLUSIONS

Encourage patients to try a new food or supplement on days when they are not receiving chemotherapy or radiation therapy because it may result in better tolerance. Screen patients to determine their nutritional status. Closely monitor changes in weight, food intake, and symptoms such as nausea and vomiting. Refer to a registered dietitian for a complete nutrition assessment and individualized counseling.

Radiofrequency tissue volume reduction: multilesion vs single-lesion treatments for snoring

OBJECTIVE

To compare the safety and efficacy of single-lesion and multilesion radiofrequency tissue reduction (RFTR) of the soft palate for the treatment of snoring.

DESIGN

Prospective, nonrandomized clinical trial.

SETTING

University hospital outpatient clinic.

PATIENTS

Nonrandomized patients undergoing RFTR to treat socially unacceptable snoring. Of 47 patients, 16 received single-lesion treatments and 31 received multilesion treatments.

INTERVENTION

Soft-palate RFTR was performed using a radiofrequency generator. Patients required 1 to 3 treatments based on improvement or withdrawal from the study, and each received 1, 3, or 4 lesions per treatment. Patients who received single-lesion therapy did not cross over into the multilesion group; however, 5 patients in the multilesion group received 4-lesion therapy after a treatment with 3 lesions.

MAIN OUTCOME MEASURES

Outcome measures were determined using visual analog scale questionnaires assessing level of snoring (snoring index) and level of pain (pain index) associated with the procedure. Adverse events and complications during treatment were cataloged. Data were collected before the procedure, 6 weeks after each treatment, and an average of 16 months after the last procedure.

RESULTS

Single-lesion and multilesion groups showed significant improvement in snoring after RFTR treatments (P<.01 for both). However, compared with the single-lesion group, the multilesion group required fewer treatments (1.94 vs 2.38; P =.05) and was more than twice as likely to be cured after 2 treatments (61% vs 25%; P =.02). A trend toward improved clinical outcomes with increased number of lesions and total energy per treatment was observed when patients treated with 1, 3, or 4 lesions were compared. The 4-lesion group had the most pronounced improvement in snoring index score per treatment, the lowest number of treatments required for cure, and the greatest percentage of patients cured after 2 treatment sessions. Follow-up demonstrated minimal relapse of snoring in the multilesion group at a mean of 16 months. Although there was a statistically significant increase in pain in the multilesion group vs the single-lesion group, this increase did not increase narcotic use or time off work and was considered minimal by reporting patients.

CONCLUSION

Multilesion RFTR using higher energy levels per treatment is safe and has increased efficacy without increased complications relative to single-lesion therapy.

Temporal gene regulation during HIV-1 infection of human CD4+ T cells

CD4(+) T-cell depletion is a characteristic of human immunodeficiency virus type 1 (HIV-1) infection. In this study, modulation of mRNA expression of 6800 genes was monitored simultaneously at eight time points in a CD4(+) T-cell line (CEM-GFP) during HIV infection. The responses to infection included: (1) >30% decrease at 72 h after infection in overall host-cell production of monitored mRNA synthesis, with the replacement of host-cell mRNA by viral mRNA, (2) suppression of the expression of selected mitochondrial and DNA repair gene transcripts, (3) increased expression of the proapoptotic gene and its gene p53-induced product Bax, and (4) activation of caspases 2, 3, and 9. The intense HIV-1 transcription resulted in the repression of much cellular RNA expression and was associated with the induction of apoptosis of infected cells but not bystander cells. This choreographed host gene response indicated that the subversion of the cell transcriptional machinery for the purpose of HIV-1 replication is akin to genotoxic stress and represents a major factor leading to HIV-induced apoptosis.

National Institute for Biological Standards and Control/UK Blood Transfusion Service working standards for HBsAg, anti-HCV and anti-HIV-1 ('go/no-go' controls)

BACKGROUND AND OBJECTIVES

The positive controls supplied with the commercial kits used in the testing of blood donations for markers of viral infection are usually of high reactivity and do not give users a reliable indication of optimal performance of the kit on a day-to-day basis.

MATERIALS AND METHODS

The National Institute for Biological Standards and Control has developed working standards for hepatitis B surface antigen (HBsAg), anti-hepatitis C virus (anti-HCV) and anti-human immunodeficiency virus type 1 (anti-HIV-1) for the UK Blood Transfusion Services for daily use in every test.

RESULTS

Data from the use of these reagents are collated and quarterly reports are issued.

CONCLUSIONS

The centralized collation, analysis and reporting of the results from users of working standards facilitate the continual assessment of the responses obtained by individual laboratories, comparisons of the interlaboratory performance and the performance of different manufacturers' kits at a national level. This information complements the data on infection surveillance and initial/repeat reactivities using the same kits.

A UK survey of virological testing of cadaver tissue donors. Microbiology Working Group of the NIBSC steering group on Tissue/Cell Banking and Engineering

OBJECTIVES

To analyse information about virological testing of cadaveric tissue donors, including the kits used and the rates of test reactivity.

MATERIALS AND METHODS

Retrospective data were collected using a standardised questionnaire sent to 16 tissue banks in the UK. The rates of repeat reactive screen tests and confirmed positive results for the markers HBsAg, anti-HCV, anti-HIV were analysed in 1,833 cadaver tissue donors tested at 12 tissue banks over one year up to March 1998.

RESULTS

There was a wide range of kits in use for virological screen testing of cadaver donors. The rates of repeat reactivity in the screen tests varied from 0 to 42%.

CONCLUSION

The findings have implications for policies based on discard of tissues from donors with repeat reactive results, and raise important safety issues with regards to cadaveric virological testing, as the test systems in use have not been validated for cadaver blood samples.

Biological implications of a discrete mathematical model for collagen deposition and alignment in dermal wound repair

We develop a novel mathematical model for collagen deposition and alignment during dermal wound healing. We focus on the interactions between fibroblasts, modelled as discrete entities, and a continuous extracellular matrix composed of collagen and a fibrin based blood clot. There are four basic interactions assumed in the model: fibroblasts orient the collagen matrix, fibroblasts produce and degrade collagen and fibrin and the matrix directs the fibroblasts and determines the speed of the cells. Several factors which influence the alignment of collagen are examined and related to current anti-scarring therapies using transforming growth factor beta. The most influential of these factors are cell speed and, more importantly for wound healing, the influx of fibroblasts from surrounding tissue.

Malnutrition: role of the TwoCal HN Med Pass program

Malnutrition is common in older adults and is associated with poor outcomes. The causes and outcomes of malnutrition are discussed, and the TwoCal HN Med Pass program, designed to overcome poor dietary intake, is described. Benefits of the program, role of the pharmacist, identification of candidates for the TwoCal HN Med Pass program, and health care team roles and responsibilities are reviewed.

Hepatitis A immunoglobulin: an international collaborative study to establish the second international standard

A collaborative study was carried out to assess the suitability of a candidate replacement material for the International Standard for hepatitis A immunoglobulin, which was found to be reactive for HCV RNA, and to calibrate it in International Units. The candidate standard, coded 97/646, was derived from a bulk of 16% immunoglobulin supplied by the Central Laboratory of the Netherlands Red Cross, Amsterdam, and diluted 1 in 2 in H2O resulting in a final immunoglobulin concentration of 8%. Sixteen laboratories from 11 countries participated in the study and contributed data from 64 assays performed using six commercial assay kits and four in-house methods. All assays were analysed as parallel line bioassays comparing assay response with log concentration. The overall mean potency of the candidate replacement immunoglobulin standard, 97/646, relative to the International Standard for hepatitis A immunoglobulin, was 98.6 IU/ml. A freeze-dried serum preparation, 97/648, was also calibrated in this study and had a potency of 22.64 IU/ml. The Second International Standard for hepatitis A immunoglobulin, human, was established by the World Health Organisation Expert Committee on Biological Standardisation in 1998 with a potency of 49 IU per ampoule when reconstituted in 0.5 ml.

Pressure ulcer management: the importance of nutrition

Nutrition plays an important role in pressure ulcer prevention and treatment. Nutrition assessment techniques and nutritional interventions for patients at risk for developing a pressure ulcer or who currently have pressure ulcers are essential components of quality patient care.

Heart rate variability in obese children: relations to total body and visceral adiposity, and changes with physical training and detraining

OBJECTIVE

Heart rate variability provides non-invasive information about cardiac parasympathetic activity (PSA). We determined in obese children: (1) relations of baseline PSA to body composition and hemodynamics; (2) effects of physical training (PT) and cessation of PT; and (3) which factors explained individual differences in responsivity of PSA to the PT.

RESEARCH METHODS AND PROCEDURES

The root mean square of successive differences (RMSSD) was the index of PSA. Obese children (n = 79) were randomly assigned to groups that participated in PT during the first or second 4-month periods of the study.

RESULTS

Baseline RMSSD was significantly (p<0.05) associated with lower levels of: fat mass, fat-free mass, subcutaneous abdominal adipose tissue, resting heart rate (HR), resting systolic blood pressure, and exercise HR. Stepwise multiple regression produced a final model (R2 = 0.36) that included only resting HR. The analysis of changes over the three time points of the study found a significant (p = 0.026) time by group interaction, such that RMSSD increased during periods of PT and decreased following cessation of PT. Greater individual increases in response to the PT (p<0.05) were seen in those who had lower pre-PT RMSSD levels, showed the greatest decreases in resting HR, and increased most in vigorous physical activity. The final regression model retained only the change in resting HR as a significant predictor of the changes in the RMSSD (R2 = 0.23).

DISCUSSION

Regular exercise that improved fitness and body composition had a favorable effect on PSA in obese children.

A hepatitis B virus variant found in the sera of immunised children induces a conformational change in the HBsAg "a" determinant

The emergence of variants in the outer envelope proteins of hepatitis B virus (HBV) are found among individuals vaccinated against HBV and asymptomatic carriers of the infection. For example, children in The Gambia vaccinated against hepatitis B may show serological evidence of breakthrough infections, particularly if anti-HBs antibodies induced by the vaccine are low in titre. A single-point mutation at nucleotide 421 of the S gene is associated with such breakthrough infections. In the present study, the antigenicity of variant HBV S protein expressed as HBsAg particles in a vaccinia virus expression system has been characterised using a panel of monoclonal antibodies directed against linear and conformational determinations of the S protein. A cellular ELISA procedure using expressed antigen in Vero cells revealed differences in reactivity using four of the six antibodies that had been raised against the adw subtype of HBV and recognise conformational epitopes in the a determinant. In two instances, an enhanced reactivity for the variant antigen was found, confirming that point mutations in the a determinant of the S protein between residues 139 and 147 may result in significant changes in conformation. These findings also demonstrate that there are distinct antigenic differences between the vaccine strains of HBsAg/ adw subtype and the predominant HBsAg subtype circulating in West Africa. The implications of this work are that serodiagnosis of HBV infections may be unreliable in populations where there is a possibility of variant HBV infections emerging in the face of increasing herd immunity to HBV as a result of vaccination, particularly using monoclonal antibody-based diagnostic tests. Such variants may play a role in the maintenance of HBV infections in endemic regions.

A hepatitis B virus variant found in the sera of immunised children induces a conformational change in the HBsAg "a" determinant

The emergence of variants in the outer envelope proteins of hepatitis B virus (HBV) are found among individuals vaccinated against HBV and asymptomatic carriers of the infection. For example, children in The Gambia vaccinated against hepatitis B may show serological evidence of breakthrough infections, particularly if anti-HBs antibodies induced by the vaccine are low in titre. A single-point mutation at nucleotide 421 of the S gene is associated with such breakthrough infections. In the present study, the antigenicity of variant HBV S protein expressed as HBsAg particles in a vaccinia virus expression system has been characterised using a panel of monoclonal antibodies directed against linear and conformational determinations of the S protein. A cellular ELISA procedure using expressed antigen in Vero cells revealed differences in reactivity using four of the six antibodies that had been raised against the adw subtype of HBV and recognise conformational epitopes in the a determinant. In two instances, an enhanced reactivity for the variant antigen was found, confirming that point mutations in the a determinant of the S protein between residues 139 and 147 may result in significant changes in conformation. These findings also demonstrate that there are distinct antigenic differences between the vaccine strains of HBsAg/ adw subtype and the predominant HBsAg subtype circulating in West Africa. The implications of this work are that serodiagnosis of HBV infections may be unreliable in populations where there is a possibility of variant HBV infections emerging in the face of increasing herd immunity to HBV as a result of vaccination, particularly using monoclonal antibody-based diagnostic tests. Such variants may play a role in the maintenance of HBV infections in endemic regions.

Increased mast cell degranulation within thalamus in early pre-lesion stages of an experimental model of Wernicke's encephalopathy

A large increase in the number and percentage of degranulating mast cells was observed within thalamus of rats after 6-7 days of thiamine deficiency (TD). No mast cells were detected in the inferior olivary and lateral vestibular nuclei, which are also severely damaged by TD. After 11-12 days of TD, the number of ED2 immunopositive macrophages increased in thalamus. In the brainstem nuclei, an increase in the number of macrophages occurred much earlier in treatment (i.e. day 6). An increase in GFAP-positive astrocytes within thalamus occurred after the changes in mast cells and prior to the increase in macrophages. In brainstem, reactive astrocytes appeared along with the increase in macrophages. These data suggest that mast cell degranulation is a very early response induced by TD, and the resultant release of cytokines and other chemical mediators may play critical roles in both the early vascular damage and eventual tissue destruction within thalamus, but not within brainstem. These results also suggest that macrophages and reactive astrocytes may play more direct roles in the pathogenesis of brainstem lesions.

Development of a valid and reliable malnutrition screening tool for adult acute hospital patients

Nutrition screening identifies individuals who are malnourished or at risk of becoming malnourished and who may benefit from nutrition support. The aim of this study was to develop a simple, reliable and valid malnutrition screening tool that could be used at hospital admission to identify adult acute patients at risk of malnutrition. The sample population included 408 patients admitted to an Australian hospital, excluding pediatric, maternity, and psychiatric patients. The ability of various nutrition screening questions to predict subjective global assessment (SGA) were examined in contingency tables. The combination of nutrition screening questions with the highest sensitivity and specificity at predicting SGA was termed the malnutrition screening tool (MST), and consisted of two questions regarding appetite and recent unintentional weight loss. Subjects who were at risk of malnutrition according to the MST had significantly lower mean values for the objective nutrition parameters (except immunologic parameters) and longer length of stays than subjects who were not at risk of malnutrition. Therefore convergent and predictive validity of the MST was established. The interrater reliability of the malnutrition screening tool was high (93-97%). The MST is a simple, quick, valid, and reliable tool which can be used to identify patients at risk of malnutrition.

Evidence-based esthetic dentistry

Evidence-based clinical practice integrates the best available evidence with clinical expertise. This article presents a clinical case scenario and, using a four-step, evidence-based approach, demonstrates how to (1) ask an evidence-based question; (2) search MEDLINE for the best evidence; (3) critically appraise the evidence; and (4) apply the evidence to the patient. The procedure is demonstrated with the sample question, Does bleaching of bonded porcelain veneers increase marginal leakage? A MEDLINE search strategy was developed for synonyms of the key words that best identify the problem, the intervention, and the outcome. The synonyms were combined using the Boolean operator "or" to identify a "sensitive" (i.e., inclusive) universe of 140,000 journal articles. These categories were then combined using the Boolean operator "and" to identify the most "specific" (i.e., exclusive) four articles from among the 140,000. Finally, to find the best evidence, the articles were limited to "humans" and "randomized controlled trials." This identified one article. Critical appraisal of the limited data in this one article indicates that the methods are valid and statistically significant, but because of the methods employed, may not be clinically important. Evidence-based methods take one to the edge of the available information universe in about 15 minutes. The results can be both exhilarating and sobering. They can indicate the depth or limits of available information and suggest gaps in the knowledge-base that require further study. Most importantly, however, the results allow practitioners to communicate incisively and truthfully with patients and to make more informed clinical choices.

Role of elevated plasma transforming growth factor-beta1 levels in wound healing

Transforming growth factor (TGF)-beta1 plays a central role in wound healing. Wounds treated with neutralizing antibody to TGF-beta1 have a lower inflammatory response, reduced early extracellular matrix deposition, and reduced later cutaneous scarring, indicating the importance of local tissue TGF-beta1. By contrast, increasing the local, tissue levels of TGF-beta1 increases the early extracellular matrix deposition but does not alter scar formation. Increased levels of plasma TGF-beta1 correlate with increased fibrogenesis in the lung, kidneys, and liver. The aim of the present study was to investigate the role of elevated systemic levels of TGF-beta1 on wound healing. We used transgenic mice that express high levels of active TGF-beta1 and have elevated plasma levels of TGF-beta1 and wild-type mice of the same strain as controls. Incisional wounds and subcutaneously implanted polyvinyl alcohol (PVA) sponges were analyzed. Surprisingly, cutaneous wounds in transgenic, TGF-beta1-overexpressing mice healed with reduced scarring accompanied by an increase in the immunostaining for TGF-beta3 and TGF-beta-receptor RII and a decrease in immunostaining for TGF-beta1 compared with wounds in control mice. By contrast, the PVA sponges showed the opposite response, with PVA sponges from transgenic mice demonstrating an enhanced rate of cellular influx and matrix deposition into the sponges accompanied by an increase in the immunostaining for all three TGF-beta isoforms and their receptors compared with PVA sponges from control mice. Together, the data demonstrate that increased circulating levels of TGF-beta1 do not always result in increased expression or activity in selected target tissues such as the skin. The two wound models, subcutaneously implanted PVA sponges and cutaneous incisional wounds, differ significantly in terms of host response patterns. Finally, the data reinforce our previous observations that the relative ratios of the three TGF-beta isoforms is critical for control of scarring.

Plasma leptin concentrations in obese children: changes during 4-mo periods with and without physical training

BACKGROUND

Little is known about the effects of physical training on plasma leptin concentrations in children.

OBJECTIVE

We sought to determine the effects of 4-mo periods with and without physical training on leptin in obese children and to explore the determinants of leptin at baseline and in response to physical training.

DESIGN

Participants were 34 obese 7-11-y-old children randomly assigned to engage in physical training during either the first or second 4 mo of the 8-mo study.

RESULTS

Total body composition, visceral adiposity, and insulin were all positively correlated with leptin at baseline (P < or = 0.05); however, only fat mass was retained in the final stepwise regression (P = 0.0001, R2 = 0.57). Leptin decreased during the 4-mo periods of physical training and increased in the 4 mo after cessation of physical training (P < 0.001 for the time by group interaction). Decreases in leptin were greatest in children with higher pretraining leptin concentrations, those whose total mass increased least, and those whose insulin concentrations decreased most (P < or = 0.05); only pretraining leptin concentration (P = 0.009) and change in total mass (P = 0.0002) were retained in the final regression (R2 = 0.53).

CONCLUSIONS

In obese children, leptin concentration decreased during 4 mo of physical training and increased during a subsequent 4-mo period without physical training, fat mass was highly correlated with baseline leptin, and greater reductions in leptin during 4 mo of physical training were seen in children with higher pretraining leptin and in those whose total mass increased least.