The utility of molecular diagnostics to predict recurrence of head and neck carcinoma

BACKGROUND

Locoregional recurrence is the major cause of treatment failure after surgery for oral squamous cell carcinoma. Molecular diagnostics have the potential to improve on clinicopathological parameters to predict this recurrence and plan adjuvant treatment. The test most frequently applied is based on detecting TP53 mutations, but alternative methodology is required for cases that harbour the wild-type gene.

METHODS

One hundred and two cases with tumour-adjacent margins, considered to be clear margins by microscopy, were examined using carefully optimised molecular diagnostics based on detection of the TP53 and Ly-6D markers. The markers were also combined to provide a dual approach.

RESULTS

The dual molecular diagnostic identified cases with a significant increase in the probablility of developing locoregional recurrence when tumour-adjacent positive and clear margins were compared (P=0.0001). These tests were most useful when the clearance at the resection margins was 5 mm or less. The TP53-based diagnostic was a better predictor of locoregional recurrence than established clinicopathological parameters.

CONCLUSION

The optimised TP53-based diagnostic rapidly identifies an important subgroup of cases with close margins that will benefit from new treatment modalities to reduce the risk of recurrence.

New insights into BMP-7 mediated osteoblastic differentiation of primary human mesenchymal stem cells

Bone Morphogenetic Proteins (BMPs) are members of the TGF-beta superfamily of growth factors. Several BMPs exhibit osteoinductive bioactivities, and are critical for bone formation in both developing and mature skeletal systems. BMP-7 (OP-1) is currently used clinically in revision of posterolateral spine fusions and long bone non-unions. The current study characterizes BMP-7 induced gene expression during early osteoblastic differentiation of human mesenchymal stem cells (hMSC). Primary hMSC were treated with BMP-7 for 24 or 120 h and gene expression across the entire human genome was evaluated using Affymetrix HG-U133 Plus 2.0 Arrays. 955 probe sets representing 655 genes and 95 ESTs were identified as differentially expressed and were organized into three major expression profiles (Profiles A, B and C) by hierarchical clustering. Genes from each profile were classified according to biochemical pathway analyses. Profile A, representing genes upregulated by BMP-7, revealed strong enrichment for established osteogenic marker genes, as well as several genes with undefined roles in osteoblast function, including MFI2, HAS3, ADAMTS9, HEY1, DIO2 and FGFR3. A functional screen using siRNA suggested roles for MFI2, HEY1 and DIO2 in osteoblastic differentiation of hMSC. Profile B contained genes transiently downregulated by BMP-7, including numerous genes associated with cell cycle regulation. Follow-up studies confirmed that BMP-7 attenuates cell cycle progression and cell proliferation during early osteoblastic differentiation. Profile C, comprised of genes continuously downregulated by BMP-7, exhibited strong enrichment for genes associated with chemokine/cytokine activity. Inhibitory effects of BMP-7 on cytokine secretion were verified by analysis of enriched culture media. Potent downregulation of CHI3L1, a potential biomarker for numerous joint diseases, was also observed in Profile C. A focused evaluation of BMP, GDF and BMP inhibitor expression elucidated feedback loops modulating BMP-7 bioactivity. BMP-7 was found to induce BMP-2 and downregulate GDF5 expression. Transient knockdown of BMP-2 using siRNA demonstrated that osteoinductive properties associated with BMP-7 are independent of endogenous BMP-2 expression. Noggin was identified as the predominant inhibitor induced by BMP-7 treatment. Overall, this study provides new insight into key bioactivities characterizing early BMP-7 mediated osteoblastic differentiation.

BMP-2/4 and BMP-6/7 differentially utilize cell surface receptors to induce osteoblastic differentiation of human bone marrow-derived mesenchymal stem cells

Bone morphogenetic proteins (BMPs) are members of the transforming growth factor-beta superfamily of growth factors and are used clinically to induce new bone formation. The purpose of this study was to evaluate receptor utilization by BMP-2, BMP-4, BMP-6, and BMP-7 in primary human mesenchymal stem cells (hMSC), a physiologically relevant cell type that probably mediates the in vivo effects of BMPs. RNA interference-mediated gene knockdown revealed that osteoinductive BMP activities in hMSC are elicited through the type I receptors ACVR1A and BMPR1A and the type II receptors ACVR2A and BMPR2. BMPR1B and ACVR2B were expressed at low levels and were not found to play a significant role in signaling by any of the BMPs evaluated in this study. Type II receptor utilization differed significantly between BMP-2/4 and BMP-6/7. A greater reliance on BMPR2 was observed for BMP-2/4 relative to BMP-6/7, whereas ACVR2A was more critical to signaling by BMP-6/7 than BMP-2/4. Significant differences were also observed for the type I receptors. Although BMP-2/4 used predominantly BMPR1A for signaling, ACVR1A was the preferred type I receptor for BMP-6/7. Signaling by both BMP-2/4 and BMP-6/7 was mediated by homodimers of ACVR1A or BMPR1A. A portion of BMP-2/4 signaling also required concurrent BMPR1A and ACVR1A expression, suggesting that BMP-2/4 signal in part through ACVR1A/BMPR1A heterodimers. The capacity of ACVR1A and BMPR1A to form homodimers and heterodimers was confirmed by bioluminescence resonance energy transfer analyses. These results suggest different mechanisms for BMP-2/4- and BMP-6/7-induced osteoblastic differentiation in primary hMSC.

Self-management in bronchiectasis: the patients' perspective

Self-management programmes for chronic disease are a high priority for healthcare providers. The content and method of delivery of self-management should give consideration to the specific requirements of the disease population. The aims of the present study were to assess the physical and psychosocial impact of bronchiectasis, to determine whether patients with bronchiectasis are receptive to self-management and to identify any obstacles or sources of support for a disease-specific self-management programme. A total of 32 patients with a diagnosis of bronchiectasis attended four focus groups. Each focus group was videotaped and subjected to qualitative analysis using the grounded theory approach. Bronchiectasis had an impact on patients' physical and psychosocial well-being. Patients demonstrated the potential to self-manage with strategies including self-regulation of medication and airway clearance. Perceived obstacles to self-management included lack of information and confidence. Patients suggested that self-management could be promoted through disease-specific information and appropriate healthcare procedures. In summary, patients with bronchiectasis have their lives disrupted by this chronic condition, but are receptive to self-management. The present study has provided information from the patients' perspective of elements which need to be included in a successful disease-specific self-management programme.

Expression of haptoglobin mRNA in the liver and oviduct during the oestrous cycle of cows (Bos taurus)

Recent evidence supports involvement of the acute phase protein haptoglobin in numerous events of mammalian reproduction. The objective of this study was to determine whether haptoglobin mRNA was expressed in the bovine ovary and oviduct, and to evaluate whether expression of haptoglobin mRNA in reproductive tissues and liver was associated with a specific phase of the bovine oestrous cycle. Oestrus was synchronized in Holstein cows by prostaglandin injection and tissues were collected during the luteal and peri-oestrous stages of the oestrous cycle. Total RNA was isolated and reverse-transcription polymerase chain reaction (RT-PCR) was performed using primers designed against regions of similarity in human, rat and mouse haptoglobin sequences. Haptoglobin mRNA expression was detected in oviductal cells and liver, during both stages of the oestrous cycle, but not in ovarian follicular cells. The 302 bp PCR product was determined to share 82-83% identity with reported primate haptoglobin sequences. Analysis by Northern blotting revealed 1.2 and 1.4 kb haptoglobin mRNA transcripts in the oviduct and liver, and indicated that hepatic haptoglobin mRNA expression was elevated above basal levels in a greater proportion of peri-oestrous cows (4/4) than luteal cows (1/5). Haptoglobin cDNA was cloned and in vitro transcribed to generate probes for in situ hybridization. Haptoglobin mRNA was detected in the liver, but not in the ovary or oviduct. We conclude that haptoglobin mRNA expression in the bovine liver is up-regulated during the peri-oestrous phase of the oestrous cycle, and that the bovine oviduct expresses a low level of haptoglobin mRNA constitutively. This temporal pattern of haptoglobin mRNA expression would expose reproductive tissues to elevated concentrations of serum haptoglobin during the peri-oestrous stage, and suggests that haptoglobin may be important in reproductive events occurring during this time period.

Identification and immunohistochemical localization of a haptoglobin-like protein in the tissues and fluids of the bovine (Bos taurus) ovary and oviduct

The objective of this study was to establish the identity of a 40 kDa bovine oviductal fluid protein as a haptoglobin-like protein and to evaluate the association of the haptoglobin-like protein with ovarian and oviductal tissues and fluids. An oviductal fluid protein band corresponding to a molecular mass of 40 kDa was excised and electroeluted from SDS-PAGE gels. Sequence analysis revealed an N-terminal region sharing 81% identity with the beta-subunit of bovine haptoglobin. The 40 kDa oviductal fluid protein crossreacted on immunoblots with antiserum against rabbit endometrial haptoglobin and with an anti-human haptoglobin polyclonal antibody. Two-dimensional PAGE revealed four protein variants ranging in pI from 7.7 to 8.6, which appeared identical, with respect to molecular weight, number of isoforms and pI, to bovine haptoglobin in acute phase serum. The haptoglobin-like protein was localized using immunohistochemistry to the lumina of blood vessels and to the extracellular matrix of ovarian and oviductal tissues. Immunostaining for the haptoglobin-like protein was also detected in the oviductal lumen, in the mucosa of the ampullary oviduct but not the isthmic oviduct, and in intermittent ampullary epithelial cells. Within the ovary, the haptoglobin-like protein was localized to the avascular granulosa cells and follicular fluid of antral follicles, but not in the theca cells or in preantral follicles of any developmental stage. It was concluded that the haptoglobin-like protein is a normal constituent of bovine ovarian and oviductal tissues and fluids, and it was hypothesized that the haptoglobin-like protein contributes to ovarian follicular development and oviductal function.

Phacoemulsification conditions resulting in thermal wound injury

PURPOSE

To determine and model the relationships between phacoemulsification conditions and viscoelastic agents that result in thermal wound injury.

SETTING

Animal laboratory, Irvine, California, USA.

METHODS

Mechanical and animal models, various wound sizes, phacoemulsification tips, and dispersive and cohesive viscoelastic agents were evaluated. Settings for phaco power, vacuum, and irrigation levels were controlled within a surgically relevant range. In the mechanical and animal models, incision temperature was assessed as a function of phacoemulsification parameters and time. In the animal model, wound damage was evaluated at the time of surgery.

RESULTS

Induced time delays from the onset of phaco power to the onset of irrigation flow caused a thermal rise at the incision site. In these experiments, lack of irrigation and aspiration resulted in the greatest thermal rise and caused wound damage. Both the cohesive and dispersive viscoelastic agents were associated with a delay in the start of irrigation and aspiration, which resulted in similar maximum temperatures. Mathematical models were developed to estimate the maximum incision temperature from the phacoemulsification power, the duration (seconds) of occlusion, the tip gauge and type, and other phacoemulsification parameters. The models predict that under comparable conditions, occlusion with a viscoelastic agent will result in higher incision temperatures than occlusion with a balanced salt solution.

CONCLUSION

Under comparable phacoemulsification conditions, both the cohesive and dispersive viscoelastic agents were associated with elevated temperatures that would be preventable by ensuring irrigation and aspiration flow before the onset of phacoemulsification power.

Is there a difference in incision healing based on location?

PURPOSE

To determine whether there is a difference in the healing process between incisions that begin in avascular region and those that begin in vascular region.

SETTING

Wills Eye Hospital, Philadelphia, Pennsylvania, and Kresge Eye Institute, Detroit, Michigan USA.

METHODS/MATERIALS

Feline evaluations were conducted at two sites (one evaluation at each site). Eyes in both evaluations were grouped by incision location: avascular (clear corneal) incisions or vascular (limbal) incisions. A series of postoperative examinations were conducted in each group of both evaluations that included slitlamp examination, measurements of external pressure and incision stability, and histological analysis.

RESULTS

All limbal incisions were stable 7 days after surgery. Histological analyses in both evaluations showed a difference in tissue response between clear corneal and limbal incisions; the limbal incisions had an early fibroblastic response and the clear corneal, a delayed response.

CONCLUSION

The predominant factors in incision healing and stability were incision geometry, architecture, and location. Endothelial pump action was effective in removing fluid but was not effective in incision stability. Histological analyses confirmed that starting incisions in the vascular region (limbus) resulted in a fibroblastic response that enhanced incision stability and allowed rapid incision healing within 7 days postoperatively compared with the 60 days healing time required for incisions started in the avascular region (cornea).

Histopathology of argon laser peripheral iridoplasty

We report the light and electron microscopic findings from two eyes treated with argon laser peripheral iridoplasty (ALPI) for bilateral angle-closure glaucoma. The patient, a 45-year-old man, died from complications of acquired immunodeficiency syndrome 16 days following ALPI. Ocular pathologic findings included contraction furrow formation and proliferation of fibroblast-like cells, accompanied by collagen deposition on the iris surface, denaturation of stromal collagen, and coagulative necrosis of blood vessels within the anterior two thirds of the iris stroma. These findings suggest that heat shrinkage of collagen may be responsible for the short-term response to ALPI, and that contraction of the fibroblastic membrane may be responsible for its long-term effects. Additionally, the presence of coagulative necrosis of iris blood vessels suggests that overt treatment may result in iris necrosis. To our knowledge this is the first report of the histopathology of ALPI.

Serum selenium and gastric cancer in two regions of Norfolk

Selenium concentrations were measured in the serum of 244 patients attending the Norfolk and Norwich Hospital, and 246 attending the James Paget Hospital in Gorleston, Norfolk. Both the mean and the median serum selenium concentration was lower in Gorleston than in Norwich, the difference being much greater in women than in men. Whereas the selenium concentrations were normally distributed about the mean for the Norwich area, there was a skewed distribution for the Gorleston area. The results are discussed in relation to the previously observed high risk of intestinal type gastric cancer in the Gorleston area.