Metagenomic shotgun sequencing reveals the enrichment of Salmonella and Mycobacterium in larynx due to prolonged ethanol exposure

The exposure of ethanol increases the risk of head and neck inflammation and tumor progression. However, limited studies have investigated the composition and functionality of laryngeal microbiota under ethanol exposure. We established an ethanol-exposed mouse model to investigate the changes in composition and function of laryngeal microbiota using Metagenomic shotgun sequencing. In the middle and late stages of the experiment, the laryngeal microbiota of mice exposed to ethanol exhibited obvious distinguished from that of the control group on principal-coordinate analysis (PCoA) plots. Among the highly abundant species, Salmonella enterica and Mycobacterium marinum were likely to be most impacted. Our findings indicated that the exposure to ethanol significantly increased their abundance in larynxes in mice of the same age, which has been confirmed through FISH experiments. Among the species-related functions and genes, metabolism is most severely affected by ethanol. The difference was most obvious in the second month of the experiment, which may be alleviated later because the animal established tolerance. Notable enrichments concerning energy, amino acid, and carbohydrate metabolic pathways occurred during the second month under ethanol exposure. Finally, based on the correlation between species and functional variations, a network was established to investigate relationships among microbiota, functional pathways, and related genes affected by ethanol. Our data first demonstrated the continuous changes of abundance, function and their interrelationship of laryngeal microbiota under ethanol exposure by Metagenomic shotgun sequencing.

Importance

Ethanol may participate in the inflammation and tumor progression by affecting the composition of the laryngeal microbiota. Here, we applied the metagenomic shotgun sequencing instead of 16 S rRNA sequencing method to identify the laryngeal microbiota under ethanol exposure. Salmonella enterica and Mycobacterium marinum are two dominant species that may play a role in the reconstruction of the laryngeal microenvironment, as their local abundance increases following exposure to ethanol. The metabolic function is most evidently impacted, and several potential metabolic pathways could be associated with alterations in microbiota composition. These findings could help us better understand the impact of prolonged ethanol exposure on the microbial composition and functionality in the larynx.

Integrative methylome and transcriptome analysis reveals epigenetic regulation of Fusobacterium nucleatum in laryngeal cancer

The aetiological mechanisms of Fusobacterium nucleatum in laryngeal cancer remain unclear. This study aimed to reveal the epigenetic signature induced by F. nucleatum in laryngeal squamous cell carcinoma (LSCC). Combined analysis of methylome and transcriptome data was performed to address the functional role of F. nucleatum in laryngeal cancer. Twenty-nine differentially expressed methylation-driven genes were identified by mapping the methylation levels of significant differential methylation sites to the expression levels of related genes. The combined analysis revealed that F. nucleatum promoted Janus kinase 3 (JAK3) gene expression in LSCC. Further validation found decreased methylation and elevated expression of JAK3 in the F. nucleatum-treated LSCC cell group; F. nucleatum abundance and JAK3 gene expression had a positive correlation in tumour tissues. This analysis provides a novel understanding of the impact of F. nucleatum in the methylome and transcriptome of laryngeal cancer. Identification of these epigenetic regulatory mechanisms opens up new avenues for mechanistic studies to explore novel therapeutic strategies.

Fusobacterium nucleatum facilitates proliferation and autophagy by activating miR-361-3p/NUDT1 axis through oxidative stress in hypopharyngeal squamous cell carcinoma

BACKGROUND

To investigate how Fusobacterium nucleatum (Fn) promotes oxidative stress and mediates proliferation and autophagy in hypopharyngeal squamous cell carcinoma (HPSCC).

METHODS

The prognosis for 82 HPSCC cases was retrospectively analyzed. HPSCC cell line FaDu was co-cultured with Fn. Knockdown of NUDT1 (shNUDT1 group) was done after observing DNA damage response. CCK8 and tumorigenesis assays for proliferation observation, mitochondria ROS (MitoROS) measurement to examine intracellular oxidative stress, and ELISA to analyze concentration of 8-oxo-2'-deoxyguanosine (8-oxo-dG) in cells. Dual-luciferase reporter assays clarified miR-361-3p connection with NUDT1. Autophagy flow was observed using electron microscopy and related proteins.

RESULTS

Fn was highly associated with NUDT1. The shNUDT1 group experienced lower proliferation compared with normal FaDu (NC group) in vivo and in vitro. The shNUDT1 group showed 8-oxo-dG and γH2AX to be elevated. Intracellular ROS decreased in shNUDT1Fn group when compared to Fn group. Upregulating miR-361-3p could suppress NUDT1 expression and downstream proliferation and autophagy. Fn modulated miR-361-3p via OH-, which could be proven by H2O2 assay and N-acetylcysteine.

CONCLUSIONS

Higher Fn in HPSCC patients suggests poorer prognosis. NUDT1 might affect cell proliferation and autophagy and modulate DNA damage response. The oxidative stress induced miR-361-3p/NUDT1 axis is first introduced in microbiome-carcinoma research.

Fusobacterium nucleatum impairs DNA mismatch repair and stability in patients with squamous cell carcinoma of the head and neck

BACKGROUND

Dysbiosis of the laryngeal microbiota has been demonstrated to the development of head and neck squamous cell carcinoma (HNSCC), but the association of Fusobacterium and Fusobacterium nucleatum (F. nucleatum) with DNA mismatch repair (MMR) and microsatellite instability (MSI) has not been investigated.

METHODS

The abundance of Fusobacterium and F. nucleatum, the status of deficient MMR (dMMR) and MSI, and MMR-related gene expression were analyzed in 171 HNSCC tissues, 61 paired para-tumor tissues, and 60 vocal cord polyp tissues. The molecular mechanism of F. nucleatum and MMR-related gene expression were investigated in two human HNSCC cell lines (Tu 686 and FD-LSC-1).

RESULTS

Our results demonstrated that a high Fusobacterium abundance was detected in the HNSCC tissues and was exaggerated in the recurrent patients. We further found that a high Fusobacterium abundance was detected in the HNSCC tissues with dMMR and MSI. The Fusobacterium abundance was negatively correlated with the expression of MLH1, MSH2, and MSH6 in the HNSCC tissues. The Fusobacterium abundance was closely associated with the F. nucleatum abundance in the HNSCC tissues. F. nucleatum increased miR-205-5p expression to suppress MLH1, MSH2, and MSH6 expression via the TLR4- and MYD88-dependent innate immune signaling pathway, resulting in dMMR, DNA damage, and cell proliferation in HNSCC.

CONCLUSIONS

F. nucleatum impacts HNSCC epigenetic changes in tissues with dMMR to promote DNA damage and cell proliferation by suppressing MMR-related gene expression via the TLR4/MYD88/miR-205-5p signaling pathway, which is valuable in the development of efficient strategies for HNSCC prevention and treatment.

LAY SUMMARY

This study clearly indicates that Fusobacterium induced head and neck squamous cell carcinoma (HNSCC) aggressiveness to affect poor prognosis in HNSCC patients by epigenetic alteration of DNA mismatch repair (MMR) and microsatellite instability. Moreover, the research has shown that Fusobacterium nucleatum ( F. nucleatum ) impacts HNSCC epigenetic changes in tissues with deficient MMR to promote DNA damage and cell proliferation by suppressing MMRrelated gene expression via the TLR4/MYD88/miR-205-5p signaling pathway.

The Prognostic Capacity of Systemic Inflammation Response Index, Neutrophil-to-Lymphocyte Ratio, Lymphocyte-to-Monocyte Ratio, and Platelet-to-Lymphocyte Ratio in Patients with Hypopharyngeal Squamous Cell Carcinoma

INTRODUCTION

Systemic inflammation response index (SIRI), neutrophil-to-lymphocyte ratio (NLR), and platelet-to-lymphocyte ratio (PLR) have been proposed as peripheral blood biomarkers. We compared these blood biomarkers to identify the best predictor in patients with hypopharyngeal squamous cell carcinoma (HPSCC).

METHODS

We conducted a retrospective study on 304 patients with HPSCC. SIRI was divided into three groups using X-tile version 3.6.1. The optimal cut-off points for NLR, LMR, and PLR were selected through RStudio. We compared the prognostic capacity of SIRI with that of NLR, LMR, and PLR using receiver operating characteristic curves.

RESULTS

Smoking, cancer in the postcricoid region, lymph node metastasis (N+), extracapsular invasion, SIRI in the highest tertile (>2.80), and LMR in the lowest tertile (<5.0) may cause poor 5-year overall survival (OS) in patients with HPSCC. Local and distant recurrences may occur earlier in those with lymph node metastasis and a tumor invading beyond the mucosa layer.

CONCLUSIONS

SIRI was a better predictor of OS than LMR, PLR, and NLR in HPSCC patients. SIRI in the highest tertile (>2.80) and LMR in the lowest tertile (<5.0) may cause poor 5-year OS.

Cross-comparison of microbiota in the oropharynx, hypopharyngeal squamous cell carcinoma and their adjacent tissues through quantitative microbiome profiling

Aims

To clarify the absolute abundance of microbial communities on hypopharyngeal squamous cell carcinoma and their correlation to those in the oropharynx.

Methods

Clinical data, swabs, and tissue samples from 27 HPSCC patients were collected in this study and divided into three sampling groups: 19 oropharyngeal mucosa (OPM), 27 hypopharyngeal carcinomas tissues (HC), and 26 corresponding adjacent tissues (AT). Relative microbiome profiling (RMP), and quantitative microbiome profiling (QMP) of 16S rRNA amplicon sequencing were used for analysis.

Results

Beta-diversity showed that abundance and phylogenetic tree in OPM group were less when compared to either HC and AT. Although HC and AT were found to have similar microbiota, Bray-Curtis based beta-diversity still highlighted differences. Fusobacterium, Porphyromonas, Haemophilus, and Peptostreptococcus at the genus level in OPM were positively correlated with HC. After categorizing HC through TNM staging, the abundance of genera Fusobacterium, Parvimonas, and Dialister were found to be enhanced in higher T classifications (T3-4) and advanced stages (Ⅳ).

Conclusions

QMP yielded more comprehensive results than RMP. Dysbiosis was found in OPM groups and could be used to narrow down differential microbiome for the HC group. Genera of Parvimonas, Fusobacterium, and Dialister were deemed asrisk factors of advanced HPSCC.

Dual inhibition of autophagy and PI3K/mTOR pathway as a potential therapeutic strategy against laryngeal squamous cell carcinoma

Background

New and effective chemotherapy or targeted therapy strategies are needed against laryngeal squamous cell carcinoma (LSCC). We aimed to explore the antitumor effect of dual PI3K/mTOR inhibitor combined with autophagy suppression on LSCC and its underlying mechanism.

Methods

Hep-2 and AMC-HN-8 cell lines were treated with the Akt inhibitor LY294002, mTOR inhibitor rapamycin, and dual inhibitor NVP-BEZ235 separately. The biological characteristics of in vitro proliferation, cell cycle, apoptosis, migration, invasion, and autophagy were analyzed, and the expression levels of PI3K/Akt/mTOR pathway-related proteins were also measured. The in vivo effects of NVP-BEZ235 combined with inhibition of autophagy using pharmacological inhibitor was further assessed.

Results

Compared with Akt or mTOR inhibitor, NVP-BEZ235 had the most significant biological effects on LSCC cells. When combined with various autophagy inhibitors, along with siRNA against ATG7, NVP-BEZ235 showed a synergic antitumor effect in LSCC through increasing cell apoptosis and death both in vitro and vivo.

Conclusions

NVP-BEZ235 exerted potent antitumor effects on LSCC, especially when combined with the autophagy inhibitor both in vitro and vivo, providing convincing experimental data for new molecular targeted therapy for LSCC.

Association Between Alcohol Dehydrogenase Polymorphisms and the Recurrence of Laryngeal Carcinoma

OBJECTIVES

Alcohol consumption is closely associated with prognosis for laryngeal squamous cell carcinoma (LSCC) patients. As key enzymes in ethanol metabolism, proteins in the alcohol dehydrogenase (ADH) family make for valuable targets to establish a novel predictive nomogram model. This study attempts to do so by focusing on the single nucleotide polymorphisms (SNPs) of ADH1B and ADH1C in LSCC.

METHODS

Sixty eight LSCC patients that were followed up for more than 10 years were retrospectively analyzed. Endpoints of the current study included disease-free survival and overall survival. Survival analyses were performed using the Kaplan-Meier method and evaluated by log-rank test. The prognostic value of eight ADH1B SNPs and three ADH1C SNPs were evaluated using univariate and multivariate Cox regression analyses. A nomogram model for disease-free survival was established and evaluated using the receiver operating characteristic curve, the C-index, and a calibration plot.

RESULTS

Significant association was exhibited between rs17033 (p < 0.001) and rs1229984 (p = 0.002) with an increase in LSCC recurrence rate on Kaplan-Meier curves. Multivariate logistic regression analysis revealed that the rs17033 polymorphism of ADH1B was independently associated with an increased risk of LSCC recurrence (HR = 3.325, 95% CI = 1.684-6.566, p = 0.001). Based on these findings, a prognostic nomogram of LSCC patients involving ADH1B rs17033 was constructed.

CONCLUSION

This study has demonstrated an independent association between ADH1B gene variants and the recurrence of LSCC. A nomogram model based on rs17033 of ADH1B, age, T, and N stages were successfully developed for the first time to predict the probability of recurrence in LSCC patients.

LEVEL OF EVIDENCE

III Retrospective cohort study Laryngoscope, 2022.

A positive feed-forward loop between Fusobacterium nucleatum and ethanol metabolism reprogramming drives laryngeal cancer progression and metastasis

Alcohol consumption, which affects the structure and composition of the laryngeal microbiota, is one of the most important risk factors for laryngeal squamous cell cancer (LSCC). Our results demonstrated that high enrichment of Fusobacterium nucleatum (F. nucleatum) in LSCC was associated with poor prognosis. F. nucleatum increased miR-155-5p and miR-205-5p expression to suppress alcohol dehydrogenase 1B (ADH1B) and transforming growth factor β receptor 2 (TGFBR2) expression by activating innate immune signaling, resulting in ethanol metabolism reprogramming to allow F. nucleatum accumulation and PI3K/AKT signaling pathway activation to promote epithelial-mesenchymal transition, further exacerbating the uncontrolled progression and metastasis of LSCC. Therefore, the positive feed-forward loop between F. nucleatum and ethanol metabolism reprogramming promotes cell proliferation, migration, and invasion to affect LSCC patient prognosis. The amount of F. nucleatum is a potential prognostic biomarker, which yields valuable insight into clinical management that may improve the oncologic outcome of patients with LSCC.

Oropharynx microbiota transitions in hypopharyngeal carcinoma treatment of induced chemotherapy followed by surgery

AIMS

To analyze changes in oropharynx microbiota composition after receiving induced chemotherapy followed by surgery for hypopharyngeal squamous cell carcinoma (HPSCC) patients.

METHODS

Clinical data and swab samples of 38 HPSCC patients (HPSCC group) and 30 patients with benign disease (control group, CG) were enrolled in the study. HPSCC group was stratified into two groups: induced chemotherapy group (IC) of 10 patients and non-induced chemotherapy group (nIC) of 28 patients. The microbiota from oropharyngeal membrane was analyzed through 16S rRNA sequencing.

RESULTS

Alpha-diversity (Shannon and Ace indexes) and weighted UniFrac based beta-diversity severely decreased in the HPSCC group when compared with CG. In pre-operative comparisons, PCoA and NMDS analyses showed microbial structures in the IC group were more similar to CG than nIC. Both IC group and nIC group yielded significantly diverse post-operative communities in contrast to their pre-operative counterparts, evident by the decrease in genera Veillonella and Fusobacterium and increase in genera Streptococcus and Gemella. Given that post-operative oropharynx microbiota showed no difference between IC and nIC groups, the IC group showed less accumulation in anaerobic communities. The abundance of genera Fusobacterium, Parvimonas, Actinomyces were enhanced in the advanced stages (III/IV).

CONCLUSIONS

Oropharynx microbiota in the HPSCC group presents dysbiosis with low diversity and abundance. Induced chemotherapy is beneficial in adjusting the oropharynx microbial environment leading to fewer amounts of anaerobe accumulation after operation. Higher amounts of Fusobacterium in advanced stages (III/IV) may influence the progression of HPSCC.

Glycolysis related gene expression signature in predicting prognosis of laryngeal squamous cell carcinoma

Researches have suggested that aerobic glycolysis can reflect the development and progression of most carcinomas. We aimed to investigate whether glycolysis-related genes (GRGs) are associated with overall survival in laryngeal squamous cell carcinoma (LSCC). Here, we identified differentially expressed GRGs in TCGA dataset and microarray sample of GSE27020 from GEO database. A set of two glycolytic gene signatures, including DDIT4 and PLOD2 was screened through Cox and Lasso regression. The risk score was calculated using the gene expression of the two GRGs. The high-risk group presented a poor prognosis through Kaplan–Meier method. The ROC curve indicated good prediction performance in survival based on the validation of four cohorts. Univariate and multivariate Cox regression analyses suggested that two-gene signature could be an independent risk factor in LSCC. A total of 17 LSCC patients were enrolled to clarify the genetic expression through using reverse transcription-polymerase chain reaction (RT-PCR). A visualized nomogram was then constructed to predict 1-, 3-, and 5-year overall survival. Taken together, two novel glycolytic gene signatures were discovered and validated, providing a potential therapeutic and overall survival (OS)-prediction biomarker for LSCC.

Prognostic values of preoperative platelet-to-lymphocyte ratio and platelet-related indices in advanced hypopharyngeal squamous cell carcinoma

OBJECTIVES

To investigate the prognostic values of preoperative platelet-to-lymphocyte ratio (PLR) and platelet-related indices in advanced hypopharyngeal squamous cell carcinoma (HPSCC).

METHODS

The data of 247 eligible advanced HPSCC patients were reviewed retrospectively. Pretreatment haematological parameters were categorised into two groups based on the result of X-tile, and several variates were assessed using chi-square test, Kaplan-Meier method, Cox univariate and multivariate analysis.

RESULTS

The optimal cut-off points of 171.4 for PLR, 260 × 10⁹ /L for platelet, 10.4 fL for mean platelet volume (MPV) and 16.5% for platelet distribution width were defined. The haematological parameters PLR and MPV, postoperative metastasis and internal jugular vein invasion were statistically significant in OS and DFS analyses (P < .05). The high PLR (>171.4) or high MPV (>10.4 fL) was significantly associated with worse OS and DFS (P < .05).

CONCLUSIONS

The preoperative levels of PLR and MPV could be considered as independent prognostic predictors in patients with advanced HPSCC.

Pretreatment Level of Red Cell Distribution Width as a Prognostic Indicator for Survival in a Large Cohort Study of Male Laryngeal Squamous Carcinoma

Objective: High levels of red cell distribution width (RDW) may be associated with adverse outcomes in patients with cancer. The purpose of the present study was to investigate the prognostic impact of pretreatment RDW levels on overall survival (OS), cancer-specific survival (CSS), and disease-free survival (DFS) in a large cohort of male laryngeal squamous cell cancer (LSCC) patients.

Methods: A total of 809 LSCC patients who were treated between 2007 and 2011 at the Eye & ENT Hospital of Fudan University were enrolled and evaluated retrospectively. OS, CSS, and DFS were analyzed using the Kaplan–Meier method. To evaluate the prognostic significance of RDW levels, univariate, and multivariate Cox analyses were applied.

Results: Higher pretreatment RDW levels were significantly associated with high death events, red blood cell count, hemoglobin, radiotherapy, operation therapy, and advanced tumor stage (p < 0.05). From the univariate analysis, we observed that the higher (13.2–13.5%) and the highest (>13.5%) quartiles of RDW level were consistent factors for poor OS, CSS, and DFS in LSCC patients. In the multivariate analysis, after adjusting for confounding factors, the higher and highest quartiles of RDW levels were identified as independent prognostic factors in male LSCC patients.

Conclusion: Higher pretreatment RDW levels were demonstrated to be associated with poor clinical outcome in male LSCC patients and might be novel markers for patient stratification in LSCC management.

Willed action and attention to the selection of action

Actions are said to be 'willed' if we consciously pay attention to their selection. It has been suggested that they are associated with activations in the dorsal prefrontal cortex (area 46). However, because previous experiments typically used a 'free selection' paradigm to examine this hypothesis, it is unclear whether the results reflected the attention to the selection of action or the freedom of choice allowed by the tasks. In this experiment, we minimized the difference of working memory demand across task conditions by using novel stimuli in each trial. We found that activation in the dorsal prefrontal cortex on a free selection task was not significantly different from that induced by another task that required attention to the selection of action, although the responses were externally specified. This suggests that the dorsal prefrontal cortex is in fact associated with attention to the selection of action, but does not play a unique role in the generation of internally initiated actions. However, the presupplementary motor area (pre-SMA) may subserve this function as activity in this region was found to be tightly associated with the free selection of responses.

The status of diabetes mellitus in primary care institution and restructured hospitals in Singapore

The Diabcare-Asia Singapore 1998 project was carried out using data from 22 centres collected on paper forms to provide an overview of diabetes management and metabolic control status in 1697 diabetic patients from both primary health care clinic (PHC) (67%) and restructured hospital (RH) (33%) settings. PHC patients were on average older than RH patients (61.3 +/- 11.2 years vs 51.5 +/- 17.7 years), and had a shorter duration of diagnosed diabetes (9.2 +/- 6.8 years vs 12.0 +/- 8.5 years). The mean body mass index (BMI) for PHC patients was 25.5 +/- 4.4 kg/m2 vs 24.5 +/- 4.2 kg/m2 for RH patients. Proportionately more PHC than RH patients were overweight (BMI >25 kg/m2) (49% vs 42%). Patients with type I diabetes constituted 3.5% of PHC vs 18.1% of the RH cohort. HbA1c information was available for 92.5% of RH vs 69% of PHC patients. HbA1c measurements were <1% above ULN in 50% of PHC vs 37% of RH patients, while FBG was >7.8 mmol/l in >61% of all patients. Proteinuria (>500 mg/24 hrs) was reported in 13% of PHC vs 26% of RH patients tested. Microalbuminuria (20-300 mg/l) was noted in 36% of 171 RH patients tested. Oral hypoglycaemic agents were used as sole therapy in 83.5% of PHC vs 43% of RH patients. Eye, feet, renal and severe late complications were more commonly reported by RH than PHC patients. There is a variation in the patient profiles and care between PHC and RH patients.

A window on the current status of diabetes mellitus in Singapore--the Diabcare-Singapore 1998 study

The Diabcare-Singapore project was carried out in 22 clinics (general hospitals, GH and primary healthcare centres, PHC) to provide an overview of diabetes management and metabolic control status. Data from 1697 diabetic patients were collected on paper forms and analysed centrally. Type 2 diabetes mellitus patients constituted 91.4% and type I patients constituted 8.1% of population. The proportion of type I patients was greater in GH (18.1%) vs PHC (3.4%). The mean age (+/- SD) was 58.1 +/- 14.4 years and mean duration of diabetes was 10.1 +/- 7.5 years. Mean body mass index (BMI) was 25.1 +/- 4.4 kg/m2 and more than half (53%) of patients were overweight (BMI >25 kg/m2). Mean HbA1c and FBG levels were 8.0 (1.9% and 9.1 +/- 3.1 mmol/l. A total of 51% of patients had HbA1c (1% above the Upper Limits of Normal (ULN). Fasting blood glucose (FBG) was >7.8 mmol/l in 61% of patients. The majority (70%) had satisfactory levels of fasting lipids (triglycerides, total cholesterol and HDL-cholesterol). Only 19.7% practised home blood glucose self-monitoring, while 99% reported receiving some diabetes education. Sixteen percent of patients had abnormal levels of protein (>500 mg/24 h) in the urine, 3% had elevated serum creatinine levels and 36% had microalbuminuria. Retinopathy (12%), cataract (16%) and neuropathy (12%) were commonly reported diabetic complications. The data revealed suboptimal glycaemic control in about half of patients studied.

Changes in activation of alcohol expectancies in memory in relation to changes in alcohol use after participation in an expectancy challenge program

Memory model-based expectancy studies have shed light on the process by which expectancies may influence drinking but have not related changes in expectancy activation to drinking changes. In the present study, 38 undergraduates completed a drinking measure and factor-based and memory model-based expectancy measures, before and after an expectancy challenge intervention designed to alter expectancies. Expectancies were mapped into memory network format with individual differences scaling and likely paths of activation were modeled with preference mapping. Results indicated that exposure to the expectancy challenge led to a change in likely activation of expectancies for men, but not for women. In the 30 days after the intervention, alcohol use among men decreased significantly but did not change among women. Therefore, changes in likely activation corresponded to changes in drinking. These findings support a memory model conceptualization of expectancy influence on drinking.

Dermal fibroblasts do not enhance the graft take rate of autologous, cultured keratinocyte suspension on full-thickness wounds in rats

Dermal fibroblasts are known to play an important role in wound healing. In this study, cultured autologous keratinocyte suspension was applied with fibrin glue to the full-thickness wounds in rats (N = 20). Histological analysis on day 14 showed regenerated epithelium in 10 wounds (50%). Keratinocytes were also premixed with allogeneic dermal fibroblasts in a ratio of 3:1 and 5:1 before application to other full-thickness wounds (N = 20) with fibrin glue. Regeneration of epithelium was observed in 10 (50%) and 9 (45%) wounds respectively. Acute inflammatory reaction and mild to moderate proliferation of fibroblasts in the subepithelial layer of the allogeneic fibroblasts were noted. The addition of dermal fibroblasts to keratinocytes/fibrin glue does not enhance the take rate of the cultured keratinocyte suspension.

A new technique to resurface wounds with composite biocompatible epidermal graft and artificial skin

BACKGROUND

The incorporation of cultured epidermal autograft on the neodermis of artificial skin (Integra, Integra LifeSciences, Plainsboro, NJ) has been met with some difficulties. A new engraftment technique to resurface the wounds with Integra and composite biocompatible epidermal graft (CBEG) has been successfully applied on three patients for elective reconstructive procedures.

METHODS

A small skin biopsy was taken from the normal edge of the lesion for keratinocytes and dermal fibroblast cultures 2 weeks before surgery. When sufficient cells were grown, the patient was admitted for the excision of the lesions or scars. The wounds of the patients, ranging from 125 to 250 cm2, were covered with Integra. When the neodermis of the Integra was fully vascularized, the silicone membrane of the Integra was removed and replaced with the CBEG, which consisted of autologous keratinocytes cultivated on a hyaluronate-derived membrane (Laserskin; Fidia Advanced Biopolymers, Abano Terme, Italy)) using human dermal fibroblasts as a feeder layer.

RESULTS

Clinically, there was good initial "take" of the CBEGs in these three patients, ranging from 50% to 100%. Biopsy specimens of the grafted wounds were taken 1 to 3 weeks after the application of the CBEGs. Epithelialization was noted in all patients.

CONCLUSION

This engraftment technique has several advantages. The CBEG is much easier to handle than the conventional cultured epidermal autograft. It eliminates the invasive second procedure for skin harvesting, with resulting pain and scarring. The application of the CBEG can be easily performed at the bedside.

Changes in activation of alcohol expectancies in memory in relation to changes in alcohol use after participation in an expectancy challenge program

Memory model-based expectancy studies have shed light on the process by which expectancies may influence drinking but have not related changes in expectancy activation to drinking changes. In the present study, 38 undergraduates completed a drinking measure and factor-based and memory model-based expectancy measures, before and after an expectancy challenge intervention designed to alter expectancies. Expectancies were mapped into memory network format with individual differences scaling and likely paths of activation were modeled with preference mapping. Results indicated that exposure to the expectancy challenge led to a change in likely activation of expectancies for men, but not for women. In the 30 days after the intervention, alcohol use among men decreased significantly but did not change among women. Therefore, changes in likely activation corresponded to changes in drinking. These findings support a memory model conceptualization of expectancy influence on drinking.

A new system for the cultivation of keratinocytes on acellular human dermis with the use of fibrin glue and 3T3 feeder cells

The growth of human keratinocytes on human acellular dermis in 4 different culture systems was compared. Epidermis was completely separated and removed from dermis after skin samples had been soaked in 0.1% trypsin at 4 degrees C for 1 week. Forty pieces of saline-washed dermis, 1 cm2 each, were randomized into 4 groups: in group A, human keratinocytes that had undergone 2 to 3 cell passages were seeded (30 x 10(4) cell/cm2) onto the dermis and sprayed with a thin layer of fibrin glue and proliferative 3T3 feeder cells that had been growing separately on the culture dish; in group B, the dermis was only sprayed with fibrin glue; in group C, the dermis was treated with 3T3 cells only; and in group D, the dermis was not sprayed with anything. The dermis samples in all groups were raised on a grid to provide an air-liquid culture system. Histology results of the composite grafts at 2 weeks were assessed as having either scanty colonies of keratinocytes (SCK), continuous stratified epithelium (CSE), or no observable keratinocyte growth. Eight out of the ten dermis samples (80%) in group A demonstrated CSE, and 30% of the samples in group B showed SCK. There were 10% SCK and 20% CSE in group C, and in group D, 30% SCK and 10% CSE were found. The good results in group A indicated that the fibrin glue facilitated the seeding efficiency of the keratinocytes on the dermis and that the vital factors released from the 3T3 feeder cells enhanced the growth and differentiation of the keratinocytes. This model provides an optimal system for the cultivation of keratinocytes on acellular dermis.

Mass screening for diabetic retinopathy--a report on diabetic retinal screening in primary care clinics in Singapore

INTRODUCTION

Mass screening for diabetic retinopathy is expensive and inaccessible if done by institutional ophthalmalogists. Most diabetics are seen in primary care. Hence it is logical to provide mass screening in primary care clinics. In Singapore, government polyclinics are ideal centres of screening as they are well organised and accessible to the community. SCREENING METHOD: An effective mass screening strategy must provide wide coverage, be low cost and have the ability to assess diabetic eyes accurately and quickly. Non-mydriatic fundal photography was used as the screening method. Mass coverage was achieved by rotating two cameras around six government polyclinics. Cost was reduced by training existing staff and organising the programme to provide a high turnover of screenees. The photographs were read by ophthalmologists in a government-owned hospital. Patients that required referral were referred to specialist eye clinics.

RESULTS

A total of 13,296 patients were screened or rescreened during a period of 2 years (25 months). 2,911 patients or 21.8% of the total screened were found to have diabetic retinopathy. About half of these (10.8%) had sight threatening retinopathy. The most common sight threatening retinopathy was maculopathy (8.0%). Twenty-two percent of cases screened were referred. These include referral for other ocular conditions detected during the screening.

CONCLUSION

Non-mydriatic fundal photography has proven to be both accessible and effective in screening diabetic eyes in urban Singapore and can be recommended for mass screening of diabetic eyes in the community.

Wound care in the elderly patient

Wound care in the elderly population requires careful attention to the medical status of the patient. The patient's underlying medical condition can often dictate what reconstructive options are appropriate. Many reconstructive techniques are available to repair a wide variety of wounds.

Results of surgical treatment of talipes equinovarus congenita

A series of 153 feet in 103 patients were surgically treated for idiopathic clubfeet (mean follow-up period of 10.3 years). Thirty-four percent had prior surgery before referral to the authors' institution. Functional results were excellent in 28.7%, good in 37.9%, fair in 13.1%, and unsatisfactory in 20.3%. The complication rate was 7.4%. Serious complications included translocation of os calcis, avascular necrosis of the talus, and injuries to neurovascular structures. Pain after strenuous activities was noted in 11.3% of the feet. In 9.8% of feet, limitation of activities was noted by the patients. Translocation of the hindfoot was associated with extensive subtalar release and often resulted in poor function. At operation, extensive subtalar release should only be performed with caution after failure of correction from release of other medial and posterior structures.

Body weight and depot fat changes as influenced by exercise and dietary fat sources in adult BHE rats

Adult male BHE rats were fed diets containing 15% of either corn oil (CO) or medium chain triglycerides (MCT) as the dietary source of fat. Further, rats were allowed to remain sedentary or were forced to exercise by swimming for 1 hour daily, for 3 weeks, followed by swimming for 2 hours daily for 3 weeks. The exercise for 3 weeks caused significant reductions in average body weight gains. After 6 weeks of exercise the lipid content of the adipose cells was reduced by about 50%. Fat cell numbers were not changed by either fat source or exercise, but fat cell size was significantly reduced after swimming daily for 6 weeks.

Prenatal development of acid beta-glycosidases in the rat liver, effect of triiodothyronine or cortisone administered to pregnant rats

We have found that acid beta-galactosidase, beta-glucuronidase and N-acetyl-beta-glucosaminidase in the rat fetal liver increase during the last week of pregnancy. These enzyme activities were influenced by treatment of pregnant rats (daily from day 16) with L-tri-iodothyronine (20 or 50 microgram/100 gm b.w.) or cortisone acetate (10 or 50 mg/100 gm b.w.) as studied in their fetuses obtained on day 22 by caesarian section.

Effect of cortisone or triiodothyronine administration to pregnant rats on lysosomal hydrolases in fetal forebrain and cerebellum

Triiodothyronine injected daily to pregnant rats for the last week of gestation (50 microgram/100 g b.wt) increased the specific activities of 5 acid glycosidases in the fetal forebrain and cerebellum. Cortisone (50 mg/100 g b.wt) administered in the same period had no effect on cerebellum acid hydrolases, but decreased their activity in the forebrain.

Comparison of postnatal development of several acid glycosidases in the rat forebrain and cerebellum

Changes of activity of several glycosidases (beta-galactosidase, beta-glucuronidase, N-acetyl-beta-D-glucosaminidase, alpha-D-mannosidase and alpha-L-fucosidase) were compared in the forebrain and cerebellum during postnatal development of the rat. Detailed analysis of the data showed similarities, but also substantial differences in their development in both organs. This is interpreted as an indication of the presence of common regulatory mechanisms, as well as of other factors which differently influence development of the glycosidases studied in both CNS parts.