The therapeutic value of vacuum external fixation in polytrauma patients with multiple ribs fracture

BACKGROUND

Multiple displaced rib fractures often result in a poor prognosis. Open reduction and internal fixation has been shown to provide benefits for patients with displaced rib fractures and flail chest. Nevertheless, for patients who are unwilling or unsuitable for surgery, the therapeutic options are limited. We developed a novel plastic vacuum device for rib fractures external stabilization. This study aims to compare the therapeutic efficacy of this device against a traditional chest strap in polytrauma patients with multiple rib fractures.

METHODS

A retrospective investigation was conducted on polytrauma patients with multiple rib fractures admitted to our trauma center between March 2020 and March 2023. Patients were categorized into two groups: vacuum external fixation and chest strap. Comparative analysis was conducted on baseline parameters, injury characteristics, and clinical outcomes between the two groups.

RESULTS

In this study, 54 patients were included, with 28 receiving chest strap and 26 undergoing vacuum external fixation. Results showed that, at 3 days and 7 days postintervention, the vacuum external fixation group had significantly lower visual analog scale scores during deep breathing and coughing (P < .05). Vacuum external fixation also reduced pleural drainage duration and volume, as well as lowered the risk of pneumonia and other complications (P < .05). Furthermore, the vacuum external fixation group demonstrated notable improvements in vital capacity, tidal volume, blood-gas test results, and a shorter hospital length of stay.

CONCLUSIONS

According to the study findings, vacuum external fixation appears to offer benefits to patients with multiple rib fractures, potentially reducing the risk of complications and improving overall clinical outcomes.

Pan-cancer characterization of cell-free immune-related miRNA identified as a robust biomarker for cancer diagnosis

Minimally invasive testing is essential for early cancer detection, impacting patient survival rates significantly. Our study aimed to establish a pioneering cell-free immune-related miRNAs (cf-IRmiRNAs) signature for early cancer detection. We analyzed circulating miRNA profiles from 15,832 participants, including individuals with 13 types of cancer and control. The data was randomly divided into training, validation, and test sets (7:2:1), with an additional external test set of 684 participants. In the discovery phase, we identified 100 differentially expressed cf-IRmiRNAs between the malignant and non-malignant, retaining 39 using the least absolute shrinkage and selection operator (LASSO) method. Five machine learning algorithms were adopted to construct cf-IRmiRNAs signature, and the diagnostic classifies based on XGBoost algorithm showed the excellent performance for cancer detection in the validation set (AUC: 0.984, CI: 0.980-0.989), determined through 5-fold cross-validation and grid search. Further evaluation in the test and external test sets confirmed the reliability and efficacy of the classifier (AUC: 0.980 to 1.000). The classifier successfully detected early-stage cancers, particularly lung, prostate, and gastric cancers. It also distinguished between benign and malignant tumors. This study represents the largest and most comprehensive pan-cancer analysis on cf-IRmiRNAs, offering a promising non-invasive diagnostic biomarker for early cancer detection and potential impact on clinical practice.

A comprehensive pan-cancer analysis of prognostic value and potential clinical implications of FTH1 in cancer immunotherapy

BACKGROUND

Numerous studies have highlighted the crucial value of the heavy chain of ferritin (FTH1) as a key regulator of iron metabolism and a suppressor of ferroptosis, intimately tied to the tumor immune microenvironment (TIME). Nevertheless, the precise impact of FTH1 on cancer immunotherapy remains vague. Our study aims to systematically explore the prognostic significance and immune role of FTH1 in pan-cancers immunotherapy.

METHODS

Our study delves into the potential of FTH1 as an immunotherapeutic target within the TIME of various solid cancers. The immune landscape and underlying mechanisms of FTH1 in the TIME were investigated by multiple algorithms and bioinformatics methods. Single-cell sequencing analysis and multiplex immunofluorescence staining techniques are applied to observe FTH1 co-expression on both tumor and immune cells.

RESULTS

FTH1 exhibited aberrant expression patterns across multiple cancers, which is strongly correlated with immunotherapy resistance. Patients with high FTH1 expression levels tended to derive less benefit from immunotherapies. Moreover, FTH1 demonstrated a significant correlation with TIME infiltration, immune checkpoint molecules, and immune-related pathways. Notably, FTH1 showed a positive association with macrophage infiltrations, its expression was particularly noteworthy in malignant cells and macrophages. Inhibiting FTH1-related signaling pathways appeared to be a potential strategy to counteract tumor immunotherapy resistance.

CONCLUSION

Our comprehensive analyses may offer valuable insights into the role of FTH1 in tumor immunotherapy. The observed correlations pave the way for further functional experiments, fostering an enhanced understanding that could shape future research endeavors.

Effect of omega-3 polyunsaturated fatty acids supplementation for patients with osteoarthritis: a meta-analysis

BACKGROUND

Omega-3 polyunsaturated fatty acids (n-3 PUFAs) confers anti-inflammatory efficacy, which has been suggested to be effective for patients with osteoarthritis (OA). However, previous studies evaluating the influence of n-3 PUFAs supplementation in patients with OA showed inconsistent results. We performed a systematic review and meta-analysis to comprehensively evaluate the influence of n-3 PUFAs on symptom and joint function of patients with OA.

METHODS

Relevant randomized controlled trials (RCTs) were obtained by searching PubMed, Embase, and Cochrane Library databases. A random-effects model was employed to combine the results.

RESULTS

Nine RCTs with 2070 patients with OA contributed to the meta-analysis. Pooled results showed that n-3 PUFAs supplementation could significantly relieve the arthritis pain as compared to placebo (standardized mean difference [SMD]: - 0.29, 95% confidence interval [CI] - 0.47 to - 0.11, p = 0.002, I² = 60%). Besides, supplementation with n-3 PUFAs was also associated with improved joint function (SMD: - 0.21, 95% CI - 0.34 to - 0.07, p = 0.002, I² = 27%). Subgroup analysis showed consistent results of studies with arthritis pain and joint function evaluated by the Western Ontario-McMaster University Osteoarthritis Index and other scales (p for subgroup difference = 0.33 and 0.34, respectively). No severe treatment-related adverse events (AEs) were observed in the included patients, and the incidence of overall AEs was similar between groups (odds ratio: 0.97, 95% CI 0.64-1.45, p = 0.86, I² = 0%).

CONCLUSIONS

Supplementation of n-3 PUFAs is effective to relieve pain and improve joint function in patients with OA.

Sacral osteotomy combined with triangular osteosynthesis in the treatment of malunion and nonunion of vertically displaced pelvic fractures

Background

Malunion and nonunion of vertically displaced pelvic fractures result in lower limb length discrepancies, claudication, and pain. There have been few previous reports of this type of corrective surgery for these old pelvic fractures. We present a surgical technique of sacral osteotomy combined with triangular osteosynthesis in the treatment of malunion and nonunion of vertically displaced pelvic fractures and report on its short-term clinical results.

Methods

We retrospectively reviewed nine patients (five males and four females) with malunion or nonunion of vertically displaced pelvic fractures treated with sacral osteotomy and triangular osteosynthesis from April 2015 to January 2020. The age ranged from 14 to 45 years (average, 30.7 years). The time from injury to deformity correction surgery ranged from 3 months to 5 years (average, 12.8 months). The vertical displacement of a unilateral hemipelvis was 3.0–4.5 cm (average, 3.80 cm). According to AO/OTA classification at the initial fracture, there are eight cases in type C1.3 and one case in type C3.3. Sacral osteotomy and triangular osteosynthesis were used in all nine patients. The degree of unilateral hemipelvic reduction was assessed postoperatively based on measurements from the anteroposterior (AP) X-ray. Majeed score and pain visual analog scale (VAS) were used to assess the therapeutic effect of the patients during follow-up.

Results

In all nine patients, postoperative AP X-ray showed correction displacement of 1.7–3.9 cm (average, 3.20 cm). All the patients were followed up for 6–36 months (average, 12.7 months). At the last follow-up, the Majeed score of pelvic fracture increased from an average of 53.9 points (30–84 points) preoperatively to 87.0 points (72–94 points), and the VAS score for pain decreased from an average of 6.0 points (4–8 points) preoperatively to 1.2 points (0–3 points). None had complications like infection, implant broken, screw loosening, iatrogenic nerve, and blood vessel injury.

Conclusion

Sacral osteotomy combined with triangular osteosynthesis for the treatment of pelvic malunion and nonunion caused by sacral fractures can correct significantly vertical displacement of a unilateral pelvis, prolong limb length, and reconstruct the stability of a pelvic ring, achieving good clinical results.

Lumbopelvic fixation with S2 alar-iliac screws for U-shaped sacral fractures

OBJECTIVE

To investigate the surgical methods and clinical effects of lumbopelvic fixation (LPF) with S2 alar-iliac (S2AI) screws for U-shaped sacral fractures.

METHODS

From December 2019 to August 2020, 14 patients with U-shaped sacral fractures were treated with LPF using S2AI screws. Demographics, fracture classification, mechanism of injury, surgical treatment, complications and clinical results were assessed. All patients had a LPF with or without nerve decompression. The reduction quality was evaluated according to the Matta criteria. Neurological function was evaluated according to the Gibbons grading. The activities of daily life were evaluated according to the Majeed scoring system at the last follow-up.

RESULTS

Among 14 consecutive patients with U-shaped sacral fractures, the age at injury ranged from 13 to 72 years (average 30.3 ± 17.5 years). There were 4 males and 10 females. All patients were followed up for 6-15 months (average 7.8 ± 2.7 months). Thirteen patients were fixed with bilateral S2AI screws, and one patient was fixed only unilaterally due to unilateral spinopelvic dissociation. The excellent and good rate of postoperative pelvic reduction quality was 92% (excellent 10, good 3, fair 1). At the latest follow-up, the excellent and good rate of pelvic function was 100% (excellent 9, good 5) and all patients achieved different extents of neurological recovery. One patient had a postoperative superficial surgical site infection, which healed after debridement. Radiological examination at 3-6 months after operation showed that all fractures had healed. No complications were found in any patients during follow-up, such as implant fracture, loss of reduction, deep wound infection, wound dehiscence and screw protrusion discomfort.

CONCLUSION

LPF with S2AI screws for the treatment of U-shaped sacral fractures has exhibited distinct advantages, including firm fixation, a low rate of surgical site complications and satisfactory clinical efficacy. This approach provides sufficient stability to accelerate the commencement of postoperative rehabilitation.

Chemogenetic modulation reveals distinct roles of the subthalamic nucleus and its afferents in the regulation of locomotor sensitization to amphetamine in rats

The subthalamic nucleus (STN) is a key node in cortico-basal-ganglia thalamic circuits, guiding behavioral output through its position as an excitatory relay of the striatal indirect pathway and its direct connections with the cortex. There have been conflicting results regarding the role of the STN in addiction-related behavior to psychostimulants, and little is known with respect to the role of STN afferents. To address this, we used viral vectors to express DREADDs (Designer Receptors Exclusively Activated by Designer Drugs) in the STN of rats in order to bidirectionally manipulate STN activity during the induction of amphetamine sensitization. In addition, we used a Cre-recombinase dependent G_i/o-coupled DREADD approach to transiently inhibit afferents from ventral pallidum (a subcomponent of the striatal indirect pathway) or the prelimbic cortex (a subcomponent of the cortico-STN hyperdirect pathway). Despite inducing mild hyperactivity in non-drug controls, stimulation of STN neurons with G_q-DREADDs blocked the development and persistence of amphetamine sensitization as well as conditioned responding. In contrast, inhibition of STN neurons with G_i/o-DREADDs enhanced the induction of sensitization without altering its persistence or conditioned responding. Chemogenetic inhibition of afferents from ventral pallidum had no effect on amphetamine sensitization but blocked conditioned responding whereas chemogenetic inhibition of afferents from prelimbic cortex attenuated the persistence of sensitization as well as conditioned responding. These results suggest the STN and its afferents play complex roles in the regulation of amphetamine sensitization and highlight the need for further characterization of how integration of inputs within STN guide behavior.

Analysis of therapeutic potential of monocytic myeloid-derived suppressor cells in cardiac allotransplantation

BACKGROUND

Myeloid-derived suppressor cells (MDSCs) and regulatory T cells (Tregs) are attractive immune cells to induce immune tolerance. To explore a strategy for improving the efficacy of MDSC therapies, we examined the impact of adoptive transfer of several types of MDSCs on graft rejection in a murine heart transplantation model.

METHODS

We analyzed the effects of induced syngeneic and allogeneic bone marrow-derived MDSCs (BM-MDSCs) on graft survival and suppressive capacity. We also compared the ability of syngeneic monocytic MDSCs (Mo-MDSCs) and polymorphonuclear MDSCs (PMN-MDSCs) to inhibit graft rejection and investigated the suppression mechanisms.

RESULTS

Both syngeneic and allogeneic donor- or allogeneic third-party-derived BM-MDSCs prolonged graft survival, although syngeneic BM-MDSCs inhibited anti-donor immune responses most effectively in vitro. Syngeneic Mo-MDSCs, rather than PMN-MDSCs, were responsible for immune suppression through downregulating inducible nitric oxide synthase (iNOS) and expanded naturally occurring thymic originated Treg (nTreg) in vitro. Adoptive transfer of Mo-MDSCs, but not PMN-MDSCs, prolonged graft survival and increased Treg infiltration into the graft heart.

CONCLUSION

Recipient-derived Mo-MDSCs are most effective in prolonging graft survival via inhibiting T cell response and nTreg infiltration.

More Hippocampal Weight and Cells in Cardiac Allograft Transplanted Mice

The hippocampus is a brain structure that plays a fundamental role in memory and learning. Many animal studies have demonstrated that the structure of the hippocampus has evolved through exercise and play. However, little is known on the relationship between the brain and immunological reaction. In this study, we investigated the correlation between the weight of the hippocampus and transplant immunology in a murine heart transplant model. Fully vascularized heterotopic hearts from CBA (H2^k, allogeneic group) or C57BL/6 (H2^b, syngeneic group) donors were transplanted into C57BL/6 recipients by using microsurgical techniques. The weights of the whole brain and hippocampus from syngeneic and allogeneic groups were recorded 1, 2, and 4 weeks after grafting, and histologic assessments were performed. The syngeneic group maintained beating cardiac grafts for over 30 days, but the allogeneic group rejected CBA cardiac allografts acutely within 8 days. The average weight of whole brain from syngeneic and allogeneic group 1, 2, and 4 weeks had no significant differences. However, the average weight of hippocampus at 2 and 4 weeks was considerably increased in the allogeneic group compared with the syngeneic group. Histologic assessments with hematoxylin-eosin and Kluver-Barrera staining of hippocampus from allogeneic group 1 week after grafting demonstrated a greater number of granule and pyramidal cells in the hippocampus. Alloimmune responses in our model increase the weight of hippocampus.

Graft Protective Effect of HMG-CoA Reductase Inhibitor Pravastatin in Murine Cardiac Allograft Transplantation

The HMG-CoA reductase inhibitor (statin), which reduces serum cholesterol, has been demonstrated in the control of immune responses and may potentially play an important role in the regulation of acute and chronic rejection in organ transplantations. We investigated the graft-protective effect of a kind of statin, pravastatin, in the survival of fully major histocompatibility complex--mismatched murine cardiac allograft transplantation. Fully vascularized heterotopic hearts from C57BL/6 donors were transplanted into CBA recipients through microsurgical techniques. CBA recipients transplanted with a C57BL/6 heart received oral administration of 40, 120, or 400 μg/kg/day of pravastatin from the day of transplantation to 7 days afterward. Immunohistochemical staining studies were performed to determine whether intimal formation of coronary arteries in the transplanted cardiac allografts was preserved and also to conduct morphometric analysis. Untreated CBA recipients rejected C57BL/6 cardiac grafts acutely (median survival time [MST] 7 days). CBA recipients exposed with 40 and 120 μg/kg/day of pravastatin had a small prolonged allograft survival (MSTs of 10 and 9 days, respectively). However, the MST of CBA recipients exposed to 400 μg/kg/day of pravastatin was significantly effective for allograft survival (MST 50 days). Immunohistochemical staining assessments on 4 weeks after grafting showed suppression of intimal hyperplasia in allograft coronary arteries. Pravastatin could induce the prolongation of fully major histocompatibility complex--mismatched cardiac allograft through the protection of the coronary artery.

Administration of Thrombomodulin (CD141) Could Improve Cardiac Allograft Survival in Mice

Thrombomodulin (TM) is a promising natural anti-coagulant therapeutic protein that is effective in the treatment of disseminated intravascular coagulation. However, the mechanisms by which TM on micro-vessels enable the regulation of intimal hyperplasia remain elusive. We investigated the graft-protective effects of TM in a fully major histocompatibility complex-mismatched murine cardiac allograft transplantation model. CBA recipients transplanted with a C57BL/6 heart received intraperitoneal administration of 0.2, 2.0, and 20.0 μg/day of TM for 8 days. Histological staining was conducted to assess the degree of inflammation and infiltration in the transplanted cardiac grafts. Untreated CBA recipients rejected C57BL/6 cardiac grafts acutely (median survival time [MST] was 7 days). CBA recipients exposed to the above dosages had significantly prolonged allograft survival (MSTs were 16, 21, and 37.5 days, respectively). Histologic assessments from TM-exposed recipients 2 weeks after grafting showed that the myocardium and vessel structure in their allografts were clearly preserved, and that the infiltration of inflammatory cells around coronary arteries was suppressed. TM can induce the prolongation of fully major histocompatibility complex-mismatched cardiac allograft by exerting graft protective effects within the myocardium and coronary arteries.

Graft protective effect and induction of CD4+Foxp3+ cell by Thrombomodulin on allograft arteriosclerosis in mice

Background

Thrombomodulin (TM) is a promising therapeutic natural anti-coagulant, which exerts the effects to control disseminated intravascular coagulation. However, little is known whether TM on micro-vessels could play an important role in the regulation of intimal hyperplasia. We investigated the vessel-protective effect of TM in the survival of fully major histocompatibility complex (MHC)-mismatched murine cardiac allograft transplantation.

Methods

CBA recipients transplanted with a C57BL/6 heart received intraperitoneal administration of normal saline or 0.2, 2.0, and 20.0 μg/day of TM for 7 days (n = 5, 7, 11, and 11, respectively). Immunohistochemical and fluorescent staining studies were performed to determine whether CD4⁺Foxp3⁺ regulatory T cell were generated at 2 and 4 weeks after grafting. Morphometric analysis for neointimal formation in the coronary arteries of the transplanted allograft was conducted at 2 and 4 weeks after grafting.

Results

Untreated CBA recipients rejected C57BL/6 cardiac grafts acutely (median survival time [MST], 7 days). CBA recipients exposed with the above doses had significantly prolonged allograft survival (MSTs, 17, 24 and 50 days, respectively). Morphometric assessment showed that intimal hyperplasia was clearly suppressed in the left and right coronary arteries or allografts from TM-exposed recipients 2 and 4 weeks. Immunohistochemical studies at 2 weeks showed more CD4⁺Foxp3⁺ cells and lower myocardial damage in the allografts from TM-exposed recipients. Notably, fluorescent staining studies demonstrated that TM-exposed recipients 4 weeks post-engraftment had strong aggregation of CD4⁺Foxp3⁺ cells in the intima of the coronary arteries of the cardiac allografts.

Conclusions

TM may prolong the survival of fully MHC-mismatched cardiac allografts through suppressing intimal hyperplasia and inducing the accumulation of regulatory CD4⁺Foxp3⁺ cells within coronary arteries.

Induction of Regulatory CD4+ Cells and Prolongation of Fully Major Histocompatibility Complex Mismatched Murine Cardiac Allograft by Shigyakusan

Shigyakusan (also known as Tsumura Japan [TJ]-35) is composed of peony, bitter orange, licorice, and Bupleuri radix is used for cholecystitis and gastritis as an anti-inflammatory agent. We investigated the effect of TJ-35 on alloimmune response in a murine heart transplantation model. CBA mice that underwent transplantation of a C57BL/6 (B6) heart were assigned to four groups: no treatment, TJ-35-exposed, each component-exposed, or each component missing-exposed. The four groups above each received oral administration of TJ-35, each component, or TJ-35 with each component missing from the day of transplantation until 7 days, respectively. Untreated CBA recipients rejected B6 cardiac grafts acutely (median survival time [MST], 7 days). TJ-35-exposed CBA recipients had significantly prolonged B6 allograft survival (MST, 20.5 days). However, MSTs of CBA recipients that had been administered each component and TJ-35 with each component missing did not reach that of TJ-35-exposed recipients. Adoptive transfer of CD4⁺ splenocytes from TJ-35-exposed primary allograft recipients resulted in significant prolonged allograft survival in naïve secondary recipients (MST, 63 days). Flow cytometry studies showed that the percentage of CD4⁺CD25⁺Foxp3⁺ cell population was increased in TJ-35-exposed CBA recipients. In conclusion, TJ-35-induced prolongation of fully allogeneic cardiac allografts and may generate regulatory CD4⁺CD25⁺Foxp3⁺ cells in our model. The effect seemed to require all components of TJ-35.

Treadmill exercise induces murine cardiac allograft survival and generates regulatory T cell

Exercise therapy has been associated with improvement in functional capacity and quality of life. The role of exercise therapy in heart transplant recipients is of great interest for the transplant society, although concerning the effect of exercise therapy, there is little knowledge at present. We analyzed the effects of exercise on alloimmune responses in murine cardiac allograft transplantation. CBA mice (H2^k) underwent transplantation of C57Bl/6 (H2^b) hearts and exercised on a treadmill. Untreated CBA recipients rejected C57Bl/6 cardiac grafts acutely (median survival time [MST], 7 days). CBA recipients treated with treadmill for 1 week after transplantation, and for 1 week both before and after transplantation prolonged allograft survivals (MSTs, 35 and 18 days, respectively). However, treadmill exercise recipients for 1 week before transplantation were not effective to allograft survival (MST, 8 days). Adoptive transfer of whole splenocytes and CD4⁺ cells from treadmill exercise recipients significantly prolonged allograft survival in naive secondary recipients (MSTs, 30 and 52 days, respectively), suggesting that regulatory cells was generated after treadmill exercise. Moreover, flow cytometry studies showed that CD4⁺CD25⁺Foxp3⁺ cell population increased in treadmill exercise recipients. Therefore, postoperative but not pre-operative exercise could induce prolongation of survival of fully allogeneic cardiac allografts and generate CD4⁺CD25⁺Foxp3⁺ regulatory T cells.

Depressive disorders among children in the transforming China: an epidemiological survey of prevalence, correlates, and service use

BACKGROUND

To date, no one-phase survey of childhood depression has been performed in China that involves both urban and rural community children. The objective of this study was to determine the prevalence, correlates, and mental health service utilization of depressive disorders (DDs) in a community-based sample of 6-14-year-old children in south-central China.

METHODS

Children (3,582) were approached through multistage sampling and interviewed using a Chinese version of the Mini International Neuropsychiatric Interview for Children and Adolescents 5.0, which is a structured interview that is administered by trained psychiatrists to obtain information from children and their guardians.

RESULTS

The overall prevalence of all current DDs was found to be 2.8% (95%CI: 1.5-3.9). The risk factors for depression included being 9-14-year old, not attending school, having unmarried parents, living in a non-nuclear family (single parent or parentless family), being taken care of by people other than two parents (single parent, grandparent(s), other relatives, or others) during the past year, and not being breastfed prior to 1 year of age. Only 5.8% of the depressed children had received professional help prior to the interview.

CONCLUSIONS

The prevalence of DDs among children in this part of China is relatively high compared with most figures reported in other countries. Depression in this age group has been a major public health concern, but it is often underrecognized. There is an urgent need to develop efficacious interventions aimed at the prevention and early recognition of childhood depression.

Gene expression changes in mouse brain after exposure to low-dose ionizing radiation

PURPOSE

To characterize the cellular functions associated with the altered transcript profiles of mouse brain exposed to low-dose in vivo gamma-irradiation.

MATERIALS AND METHODS

Cerebral RNA was isolated at 30 min and 4 h after whole-body irradiation at 0.1 or 2 Gy, hybridized to random oligonucleotide arrays, and evaluated for time and dose-response patterns by multifactorial analyses.

RESULTS

Brain irradiation modulated the expression patterns of 1574 genes, of which 855 showed more than 1.5-fold variation. about 30% of genes showed dose-dependent variations, including genes exclusively affected by 0.1 Gy. About 60% of genes showed time-dependent variation with more genes affected at 30 min than at 4 h. Early changes involved signal transduction, ion regulation and synaptic signalling. Later changes involved metabolic functions including myelin and protein synthesis. Low-dose radiation also modulated the expression of genes involved in stress response, cell-cycle control and DNA synthesis/repair.

CONCLUSIONS

Doses of 0.1 Gy induced changes in gene expression that were qualitatively different from those at 2 Gy. The findings suggest that low-dose irradiation of the brain induces the expression of genes involved in protective and reparative functions, while down-modulating genes involved in neural signalling activity.

Radio-frequency matched filtering by photorefractive optical holography

Matched filtering of megahertz-bandwidth signals by use of holograms recorded in a photorefractive crystal is demonstrated. Holographic recording of rapidly varying signals has heretofore been hampered by the relatively slow response of photorefractive crystals. For the first time, to our knowledge, synchronization between waveforms and short optical sampling pulses is used with acousto-optic electrical-to-optical conversion to build up static holograms of rf waveforms in a SBN crystal. Readout with a continuous input signal yields a time-resolved correlation with stored waveforms.

Molecular histology in skin appendage morphogenesis

Classical histological studies have demonstrated the cellular organization of skin appendages and helped us appreciate the intricate structures and function of skin appendages. At this juncture, questions can be directed to determine how these cellular organizations are achieved. How do cells rearrange themselves to form the complex cyto-architecture of skin appendages? What are the molecular bases of the morphogenesis and histogenesis of skin appendages? Recently, many new molecules expressed in a spatial and temporal specific manner during the formation of skin appendages were identified by molecular biological approaches. In this review, novel molecular techniques that are useful in skin appendage research are discussed. The distribution of exemplary molecules from different categories including growth factors, intracellular signaling molecules, homeobox genes, adhesion molecules, and extracellular matrix molecules are summarized in a diagram using feather and hair as models. We hope that these results will serve as the ground work for completing the molecular mapping of skin appendages which will refine and re-define our understanding of the developmental process beyond relying on morphological criteria. We also hope that the listed protocols will help those who are interested in this venture. This new molecular histology of skin appendages is the foundation for forming new hypotheses on how molecules are mechanistically involved in skin appendage development and for designing experiments to test them. This may also lead to the modulation of healing and regeneration processes in future treatment modalities.

Orthogonal photorefractive grating storage

Using multiple signal beams and controlling their relative phases, we demonstrate angular multiplexing of phase-sensitive holographic gratings in a photorefractive crystal. Interference between diffracted signal beams determines total diffracted intensities as a function of the relative phases between input signals compared with those between gratings. Complete constructive and destructive interference produce maximum and near-zero diffraction, respectively, from orthogonal gratings.

cDCC (chicken homologue to a gene deleted in colorectal carcinoma) is an epithelial adhesion molecule expressed in the basal cells and involved in epithelial-mesenchymal interaction

Cloning of human DCC (deleted in colorectal carcinoma, Fearon et al., 1990) showed that it is an immunoglobulin superfamily member homologous to neural cell adhesion molecules (N-CAM). To explore the normal function of this molecule, we have cloned a chicken homologue to DCC (cDCC) and raised an antibody to DCC. cDCC is a protein of 160 kDa with an expression pattern distinct from those of other immunoglobulin family members including N-CAM and Ng-CAM. Transgene expression of cDCC in fibroblasts led to increased cell-cell adhesion. Localization studies in chicken and mouse embryos showed that DCC is expressed in the epithelia of skin, gut, lung, and bladder. In adult, the expression of DCC is limited to the basal layer of stratified epithelium in skin, crypt regions of intestinal villi, and stem cells in mammary duct. Cell aggregation assay using embryonic chicken skin epithelial cells and antibody to DCC showed it is a Ca2+ independent cell adhesion molecule. In epithelial-mesenchymal interactions during feather morphogenesis, antibody to DCC suppressed the formation of dermal condensations and the polarized localization of N-CAM and fibronectin. These results implied that DCC is an epithelial cell adhesion molecule required for mediating critical functions in epithelial-epithelial and epithelial-mesenchymal interactions.

Loss of heterozygosity on chromosome 13 is common only in the biologically more aggressive subtypes of ovarian epithelial tumors and is associated with normal retinoblastoma gene expression

We examined the frequencies of loss of heterozygosity on chromosome 13 in 77 primary ovarian epithelial tumors subdivided into cystadenomas, tumors of low malignant potential, low grade carcinomas, and high grade carcinomas. Such losses were found in approximately 50% of high grade carcinomas but were not detected in any of the other tumor subtypes (P < 0.0001), suggesting a strong association between these abnormalities and the high grade carcinoma phenotype. The tumors were also examined for abnormalities in expression of the retinoblastoma susceptibility gene (RB). This was assessed by immunohistochemical staining of archival tumor sections with a polyclonal antibody directed against both the phosphorylated and the underphosphorylated forms of the RB protein. Most of the tumors, including those with allelic deletions on chromosome 13, showed normal RB nuclear protein staining patterns. We conclude that loss of RB expression is not a frequent event in primary ovarian carcinomas and that this gene is probably not the target of the frequent allelic deletions on chromosome 13 found in high grade ovarian carcinomas.