Innovative clinical scenario simulator for step-by-step microsurgical training

Background Microsurgical training should be implemented with consideration of operative difficulties that occur in actual clinical situations. We evaluated the effectiveness of a novel clinical scenario simulator for step-by-step microsurgical training that progressed from conventional training to escalated training with additional obstacles. Methods A training device was designed according to multiple and intricate clinical microsurgery scenarios. Twenty surgical residents with no experience in microsurgery were randomly assigned to either the control group (conventional training curricula, n = 10) or the experimental group (step-by-step training courses, n = 10). After 4 weeks of laboratory practice, the participants were scheduled to perform their first microvascular anastomoses on patients in an operating room. The Global Rating Scale (GRS) scores and operative duration were used to compare microsurgical skills between the two groups. Results There were no significant differences in the participants' baseline characteristics before microsurgical training between the groups with respect to age, sex, postgraduate year, surgical specialty, or mean GRS score (p < 0.05). There were also no significant differences in recipient sites between the two groups (p = 0.735). After training, the GRS scores in both groups were significantly improved (p = 0.000). However, in the actual microsurgical situations, the GRS scores were significantly higher in the experimental than control group (p < 0.05). There was no significant difference in the operative duration between the two groups (p < 0.13). Conclusion Compared with a traditional training program, this step-by-step microsurgical curriculum based on our clinical scenario simulator results in significant improvement in acquisition of microsurgical skills.

One stage reconstruction of mid-face fistulous defects after maxillary sinus carcinoma resection with chimeric perforator free flaps

BACKGROUND

The reconstruction of large fistulous defects following the radical ablation of maxillary sinus carcinoma remains challenging. The procedure requires not only the coverage of both intra-nasal lining and cheek skin but also sufficient obliteration of dead space between the two surfaces. In this report, we present our experience on the reconstruction of through-and-through defects in the mid-face with poly-foliated chimeric perforator flaps.

METHODS

Nine patients (five males and four females) who received a two-skin paddled and one muscle segment chimeric perforator flap reconstruction after maxillary sinus carcinoma ablation between March 2015 and December 2019 were retrospectively reviewed in authors' hospital. The mean age of the patients was 59.11. Six patients were diagnosed as squamous cell carcinoma, two as adenoid cystic carcinoma, and one as adenocarcinoma. Brown class IIIa defects were found in eight patients, and one patient had a Brown class IVa defect. The mean size of intra-nasal defect was 5.67 × 4.06 cm² , and the mean size of facial skin defect was 8.94 × 6.56 cm² . ALT flaps were used in five patients, LD flaps in four patients. The minor skin paddle was firstly inset to the mucosal defect site as the lining. Then, the muscle segment was inset to eliminate the dead cavity. Finally, the major skin paddle was inset to recover the cutaneous defect.

RESULTS

In ALT group, the mean size of the minor skin paddle was 5.7 × 4.7 cm² , and the mean size of the major skin paddle was 8.7 × 6.6 cm² . In LD group, the mean size of the minor skin paddle was 6.88 × 4.38 cm² , and the mean size of the major skin paddle was 11 × 7.75 cm² .All donor sites were closed primarily. All flaps survived and no partial flap loss was encountered. The mean follow-up time was 14.67 months, and there were no major postoperative complications.

CONCLUSION

The use of poly-foliated chimeric perforator free flaps can provide functional and aesthetic coverage for extensive through-and-through mid-face defects without significant donor-site morbidities.

[A prospective study on the development and application verification of the quantitative evaluation software for three-dimensional morphology of pathological scars based on photo modeling technology]

Objective: To develop a quantitative evaluation software for three-dimensional morphology of pathological scars based on photo modeling technology, and to verify its accuracy and feasibility in clinical application. Methods: The method of prospective observational study was adopted. From April 2019 to January 2022, 59 patients with pathological scars (totally 107 scars) who met the inclusion criteria were admitted to the First Medical Center of Chinese PLA General Hospital, including 27 males and 32 females, aged 33 (26, 44) years. Based on photo modeling technology, a software for measuring three-dimensional morphological parameters of pathological scars was developed with functions of collecting patients' basic information, and scar photography, three-dimensional reconstruction, browsing the models, and generating reports. This software and the clinical routine methods (vernier calipers, color Doppler ultrasonic diagnostic equipment, and elastomeric impression water injection method measurement) were used to measure the longest length, maximum thickness, and volume of scars, respectively. For scars with successful modelling, the number, distribution of scars, number of patients, and the longest length, maximum thickness, and volume of scars measured by both the software and clinical routine methods were collected. For scars with failed modelling, the number, distribution, type of scars, and the number of patients were collected. The correlation and consistency of the software and clinical routine methods in measuring the longest length, maximum thickness, and volume of scars were analyzed by unital linear regression analysis and the Bland-Altman method, respectively, and the intraclass correlation coefficients (ICCs), mean absolute error (MAE), and mean absolute percentage error (MAPE) were calculated. Results: A total of 102 scars from 54 patients were successfully modeled, which located in the chest (43 scars), in the shoulder and back (27 scars), in the limb (12 scars), in the face and neck (9 scars), in the auricle (6 scars), and in the abdomen (5 scars). The longest length, maximum thickness, and volume measured by the software and clinical routine methods were 3.61 (2.13, 5.19) and 3.53 (2.02, 5.11) cm, 0.45 (0.28, 0.70) and 0.43 (0.24, 0.72) cm, 1.17 (0.43, 3.57) and 0.96 (0.36, 3.26) mL. The 5 hypertrophic scars and auricular keloids from 5 patients were unsuccessfully modeled. The longest length, maximum thickness, and volume measured by the software and clinical routine methods showed obvious linear correlation (with r values of 0.985, 0.917, and 0.998, P<0.05). The ICCs of the longest length, maximum thickness, and volume of scars measured by the software and clinical routine methods were 0.993, 0.958, and 0.999 (with 95% confidence intervals of 0.989-0.995, 0.938-0.971, and 0.998-0.999, respectively). The longest length, maximum thickness, and volume of scars measured by the software and clinical routine methods had good consistency. The Bland-Altman method showed that 3.92% (4/102), 7.84% (8/102), and 8.82% (9/102) of the scars with the longest length, maximum thickness, and volume respectively were outside the 95% consistency limit. Within the 95% consistency limit, 2.04% (2/98) scars had the longest length error of more than 0.5 cm, 1.06% (1/94) scars had the maximum thickness error of more than 0.2 cm, and 2.15% (2/93) scars had the volume error of more than 0.5 mL. The MAE and MAPE of the longest length, maximum thickness, and volume of scars measured by the software and clinical routine methods were 0.21 cm, 0.10 cm, 0.24 mL, and 5.75%, 21.21%, 24.80%, respectively. Conclusions: The quantitative evaluation software for three-dimensional morphology of pathological scars based on photo modeling technology can realize the three-dimensional modeling and measurement of morphological parameters of most pathological scars. Its measurement results were in good consistency with those of clinical routine methods, and the errors were acceptable in clinic. This software can be used as an auxiliary method for clinical diagnosis and treatment of pathological scars.

Time-Resolved Extracellular Matrix Atlas of the Developing Human Skin Dermis

Skin aging is a physiological issue that is still relatively poorly understood. Studies have demonstrated that the dermal extracellular matrix (ECM) plays important roles in skin aging. However, the roles of the changes in ECM characteristics and the molecules that are secreted to the extracellular space and are involved in the formation of the dermal matrix from birth to old age remain unclear. To explore the way in which the ECM microenvironment supports the functions of skin development across different age groups is also poorly understood, we used a decellularization method and matrisome analysis to compare the composition, expression, and function of the dermal ECM in toddler, teenager, adult, and elderly skin. We found that the collagens, glycoproteins, proteoglycans, and regulatory factors that support skin development and interact with these core ECM proteins were differentially expressed at different ages. ECM expression markers occurring during the process of skin development were identified. In addition, our results elucidated the characteristics of ECM synthesis, response to skin development, and the features of the ECM that support epidermal stem cell growth via the basement membrane during skin aging.

The use of free myocutaneous flap and implant reinsertion for staged cranial reconstruction in patients with titanium mesh exposure and large skull defects with soft tissue infection after cranioplasty: Report of 19 cases

BACKGROUND

Management of cranial defects following failed cranioplasty due to titanium mesh exposure and infection is challenging. The purpose of this report is to describe a modified technique using a free myocutaneous flap transfer for primary soft tissue reconstruction, and titanium mesh reinsertion for cranioplasty revision.

METHODS

Nineteen patients with titanium mesh exposure and infection following cranioplasty were treated from January 2012 to January 2019. The average patient age was 41.89 years and the average size of the cranial defect was 7.74 × 13.92 cm. The reasons for craniotomy were craniocerebral trauma (n = 17), cerebrovascular disease (n = 1), and brain tumor (n = 1). The mean duration between implant exposure and current procedure was 7.16 months. Implant was removed and a free myocutaneous flap was designed to cover both scalp and cranium defects. After a mean duration of 12.32 months, implants were re-inserted in a vascularized pocket at the second stage by elevating a plane between the previously transferred fascia layer and muscle layer.

RESULTS

The average sizes of the muscle flaps and skin paddles were 7.74 × 13.92 cm and 4.97 × 8.97 cm. The average size of the implants was 8.24 × 14.42 cm. All flaps survived completely with no complication. After an average follow-up of 48.16 months there were no cranioplasty failures. Functional coverage of craniectomy defect sites with normalized head contour was achieved.

CONCLUSIONS

The use of free myocutaneous flap and implant reinsertion achieved durable cranial and scalp defect reconstruction and aesthetic outcomes. The myocutaneous flap increases blood supply to the scalp, which may reduce the chances of infection and implant re-exposure.

Treatment of Severe Postburn Contracture of the Elbow via Distraction With External Circular Frame in Pediatric Patient

BACKGROUND

Although external circular frame (ECF) has been widely used for the correction of knee and ankle deformities, few studies reported the use of ECF for the treatment of severe postburn elbow contracture and stiffness (SPECS). The purpose of this retrospective study was to investigate the effectiveness and safety of the distraction using ECF in treating SPECS.

METHODS

After institutional review board approval, we implemented a retrospective single-center case series study composed of consecutive patients treated for SPECS at Chinese PLA General Hospital between January 2010 and January 2018. After scar release and skin grafting, distraction with ECF was performed for 4 to 6 weeks, and the frame was retained for 2 more weeks before removal. Four weeks of splinting and at least 1 year of rehabilitation were recommended. Patient demographics, active and passive range of motion (ROM) of the elbow at different time points (preoperative, postdistraction, and final follow-up), and complications were collected from the electronic medical record. The primary outcome was the long-term improvement of the ROM. Other outcomes included complications and recurrence.

RESULTS

The ECF was used to treat SPECS in 6 patients (3 males and 3 females, average age of 11.7 ± 2.6 years). Scar release and distraction with ECF significantly increased both active (from 3° preoperative to 38.7° postdistraction) and passive (from 3.5° preoperative to 48.3° postdistraction) ROM over an average distraction duration of 5.2 weeks. The long-term improvement of active and passive ROM was 38° ± 13.4° and 46° ± 14.7°, respectively, over a median follow-up of 4.1 years. Pin-tract infection occurred in 2 patients and were treated with local wound care and oral antibiotics. A tendon readhesion developed in 1 of the 6 patients because of noncompliance with splinting and physiotherapy, and was treated with revision surgery.

CONCLUSIONS

The 3C strategy (i.e., contracture release, coverage of the defect with skin grafting, and correction of articular angle with gradual distraction using the ECF) is able to increase the ROM with minor complications. We recommend distraction with ECF as part of the treatment arsenal, particularly for severe contractures in which 1-stage correction is unfeasible because of considerable soft tissue shortening.

The "Matrisome" reveals the characterization of skin keloid microenvironment

Keloids are fibroproliferative dermal tumors of unknown origin that are characterized by the overabundant accumulation of extracellular matrix (ECM) components. The mechanism of keloid formation has remained unclear because of a poor understanding of its molecular basis. In this study, the dermal ECM components of keloids were identified and the pathological features of keloid formation were characterized using large-scale quantitative proteomic analyses of decellularized keloid biomatrix scaffolds. We identified a total of 267 dermal core ECM and ECM-associated proteins that were differentially expressed between patients with keloids and healthy controls. Skin mechanical properties and biological processes including protease activity, wound healing, and adhesion were disordered in keloids. The integrated network analysis of the upregulated ECM proteins revealed multiple signaling pathways involved in these processes that may lead to keloid formation. Our findings may improve the scientific basis of keloid treatment and provide new ideas for the establishment of keloid models.

Matrisome Provides a Supportive Microenvironment for Skin Functions of Diverse Species

A biomaterial scaffold is a promising tool employed to drive tissue regeneration. This technology has been successfully applied in human tissue rebuilding, particularly for the skin. Meanwhile, there is still room for further improvement, such as maintaining sufficient functionality of a biomaterial scaffold. Here, we developed a new decellularization method to generate a complete anatomical skin biomatrix scaffold with a preserved extracellular matrix (ECM) architecture. We performed proteomic and bioinformatic analyses of the skin scaffold maps of humans, pigs, and rats and systematically analyzed the interaction between ECM proteins and different cell types in the skin microenvironment. These interactions served to quantify the structure and function of the skin's Matrisome comprising core ECM components and ECM-associated soluble signaling molecules required for the regulation of epidermal development. We primarily found that the properties of the skin ECM were species-specific. For example, the composition and function of the ECM of the human skin were more similar to those of pigs compared with those of rats. However, the skin ECM of the pig was significantly deficient in its enzyme systems and immune regulatory factors compared with that of humans. These findings provide a new understanding of the role of the skin ECM niche as well as an attractive strategy that can apply tissue engineering principles to skin biomatrix scaffold materials, which promises to accelerate and enhance tissue regeneration.

Adipose extracellular matrix promotes skin wound healing by inducing the differentiation of adipose‑derived stem cells into fibroblasts

Fibroblasts are the major effector cells of skin wound healing. Adipose-derived stem cells can differentiate into fibroblasts under certain conditions. In the present study, it was hypothesized that adipose-derived stem cells (ADSCs) could be induced by the adipose extracellular matrix (ECM) to differentiate into fibroblasts in order to promote skin wound healing. First, flow cytometry was used to detect the ratio of fibroblasts and relative expression of the fibroblast markers cytokeratin 19 (CK19) and vimentin in ADSCs. Then, the effect of the adipose ECM during the differentiation of ADSCs into fibroblasts was investigated by detecting the total amount of collagen fibers and degree of fibrosis, and the proliferation and cell cycle of differentiated fibroblasts, using the MTT assay and flow cytometry analysis respectively. Finally, a mouse skin wound model was established and treated with PBS, ADSC suspension or ECM + ADSCs to compare wound healing rate and expression of collagen I and collagen III by immunohistochemistry. Following induction of ADSCs with the adipose ECM, more fibroblasts were found, expression of CK19 and vimentin increased, and a greater degree of fibrosis occurred, which revealed the positive effect of the adipose ECM on the differentiation of ADSCs into fibroblasts. In addition, the induced fibroblasts had enhanced proliferation activity, with more cells in the S phase and fewer in the G2/M phase. The in vivo experiment indicated that the ECM produced by the ADSCs had a faster wound healing rate and increased expression of collagen I and collagen III compared with mice injected with PBS or ADSCs alone, which verified that ADSCs induced by the adipose ECM had a positive effect on skin wound healing. The present study demonstrated that the adipose ECM in combination with ADSCs may be a novel therapeutic target for the repair of skin injury, due to the ability of the adipose ECM to induce the differentiation of ADSCs into fibroblasts and to facilitate the wound healing process.

Effect of tobacco smoke on hydrogen sulfide-induced rat thoracic aorta relaxation

Levels of hydrogen sulfide (H₂S), a gaseous signaling molecule, are reduced in the serum of individuals who smoke. We hypothesized that tobacco smoke influenced smooth muscle relaxation by decreasing H₂S levels and this effect could also influence expression of cystathionine γ-lyase (CSE) and sulfonylurea receptor-2 (SUR-2). The aim of this study was to explore the effect of tobacco smoke on H₂S-mediated rat thoracic aorta relaxation and its possible mechanism. Thirty-two Sprague-Dawley rats were divided into four groups: control (C) group, short-term smoker (SS) group, mid-term smoker (MS) group, and long-term smoker (LS) group. H₂S concentrations in serum, action of H₂S on rat aortic vascular relaxation, and expression of CSE and SUR-2 in thoracic aortic smooth muscle were measured. Although there was no significant difference in H₂S between the C and the SS groups, concentration of H₂S was significantly reduced in both the LS and MS groups compared to control (P<0.01). Furthermore, H₂S was significantly lower in the LS than in the MS group (P<0.05). Rat aortic vascular relaxation was lower in all three treatment groups compared to the control, with the most significant decrease observed in the LS group (P<0.05 compared to the MS group). Expression of CSE and SUR-2 was reduced in the LS and MS groups compared to control (P<0.05), with the lowest levels observed in the LS group (P<0.05). Therefore, tobacco smoke reduced expression of CSE and SUR-2 in rat thoracic aorta, which may inhibit H₂S production and vascular dilation.

First Report of Tomato chlorosis virus in China

In October 2012, a severe yellowing disease was found on greenhouse and plastic house tomato (Solanum lycopersicum) plants in Beijing, China. The disease incidence varied from 5 to 80% in each of six fields across Haidian and Daxing districts. The lower leaves showed symptoms of interveinal chlorosis, leaf brittleness, and limited brown necrotic flecks, similar to symptoms induced by Tomato chlorosis virus (ToCV) and Tomato infectious chlorosis virus (TICV) (two members of genus Crinivirus, family Closteroviridae) (4). A large number of whiteflies (Bemisia tabaci) were also observed. Leaf samples were taken from eight symptomatic and two asymptomatic tomato plants in two plastic houses in the Haidian district and total RNA was isolated from the 10 samples using TRIzol reagent (Tiangen, Beijing, China). Nested reverse transcription (RT)-PCR was performed to test the presence of ToCV and TICV with degenerate primers HS-11 and HS-12 and specific primers ToC-5/ToC-6 or TIC-3/TIC-4 for ToCV or TICV, respectively (1). With ToCV primers, a 463-bp specific fragment was amplified from eight symptomatic samples but not from two asymptomatic samples, and there was no amplification with TICV primers from any sample. Sequence analysis of the amplified fragment showed 99% nucleotide sequence identity with the heat shock protein 70 homolog (HSP70h) gene of ToCV isolates from Japan (GenBank Accession No. AB513442), Spain (DQ136146), Florida (AY903448), and Greece (EU284744). The presence of ToCV was confirmed by amplification of a 848-bp fragment covering the coat protein (CP) gene of ToCV with primers CP-F (5'-GAATCTTTTAGAAGCTTTGGTTTAAGG-3') and CP-R (5'-GATCCTCTTGATCCTCATAGATTTC-3') (3). The CP had 97 to 99% amino acid sequence identity to the above-mentioned four ToCV isolates. A sequence of the CP gene obtained from one isolate was deposited at GenBank (KC311375). Additionally, virions were isolated from 25 g of symptomatic samples followed Klaassen's method (2) and their lengths were estimated to be about 800 to 850 nm by transmission electronic microscopy To our knowledge, this is the first report of ToCV on tomato in mainland China. Tomato is one of the most widely cultivated crops in China and the spread of ToCV in China may cause significant economic losses. Further information on the prevalence and incidence of ToCV is required to assess the potential impact of this virus. References: (1) C. I. Dovas et al. Plant Dis. 86:1345, 2002. (2) V. A. Klaassen et al. J. Gen. Virol. 75:1525, 1994. (3) H. Tomoki et al. J. Gen. Plant Pathol. 76:168, 2010. (4) G. C. Wisler et al. Phytopathology 88:402, 1998.

[Preliminary clinical observations on autologous cultured skin fibroblasts transplantation to treat the facial soft tissue deficiencies]

OBJECTIVE

To observe the effect and safety of autologous cultured skin fibroblasts transplantation for treating depressed facial skin defects.

METHODS

A total of 19 patients were treated from Jan, 2010 to Oct, 2010. Autologous skin fibroblasts were separated from postauricular skin biopsy or resected skin tissue in other surgeries such as blepharoplasty. They were cultured and expanded with exclusive method. Cells (2 x 10(7)/ml) within three passages were injected intradermally at the site of skin depression three times at one-month interval. Adverse events were observed and recorded. Clinical effects were evaluated and graded by two unrelated physicians before and 6 months after the first injection.

RESULTS

Cells from 16 patients were successfully cultured at the first time. The other 3 patients underwent a second harvest. A total amount of 6 x 10(8) cells could be reached within three passages in 45 days. 16 out of 19 patients accomplished the whole course of this study. Minor adverse events were observed in two patients including small ulcer caused by over injection in one patient and slightly redness and swelling in the other. The redness disappeared after a week without any treatment. No serious complications were observed. Significant difference was noticed between the scores obtained before and after the treatment.

CONCLUSIONS

From this study, neither serious complications nor excessive cell proliferation or scar formation was found after cell injection. The effect of using autologous fibroblast transplantation was obvious and long-lasting, which provides a new choice for the treatment of depressed facial skin defects.

Preclinical safety studies on autologous cultured human skin fibroblast transplantation

Recently, FDA approved the clinical use of autologous fibroblasts (LAVIV™) for the improvement of nasolabial fold wrinkles in adults. The use of autologous fibroblasts for the augmentation of dermal and subcutaneous defects represents a potentially exciting natural alternative to the use of other filler materials for its long-term corrective ability and absence of allergic adverse effects proved by clinical application. However, compared to the clinical evidence, preclinical studies are far from enough. In this study, human skin-derived fibroblasts were cultured and expanded for both in vitro and in vivo observations. In vitro, the subcultured fibroblasts were divided into two groups. One set of cells underwent cell cycle and karyotype analysis at passages 5 and 10. The second group of cells was cocultured in medium with different concentrations of human skin extract D for the measurement of collagen concentration and cell count. In vivo, the subcultured fibroblasts were injected into nude mice subcutaneously. Biopsies were taken for morphology observation and specific collagen staining at 1, 2, and 3 months after injection. The results in vitro showed no significant differences in cell cycle distribution between passages 5 and 10. Cell proliferation and secretion were inhibited as the concentration of extract D increased. In vivo, the fibroblasts were remarkably denser on the experimental side with no dysplastic cells. Mitotic cells were easily observed at the end of the first month but were rare at the end of the third month. Type III collagen was detected at the end of the first month, while collagen type I was positive at the end of the second month. The content of both collagens increased as time passed. The above results indicated that the use of the autologous fibroblasts was safe, providing a basic support for clinical use of fibroblasts.

Different types of panic attacks-three case reports

Case report/ Introduction

A panic attack is an explosion of high anxiety. It is strongly associated with a sense of losing control or predicting that the very worst will happen. It is not a mental disorder, more than one in five people experience one or more panic attacks in their lifetime, but few go on to develop panic disorder or agoraphobia. There are different types of panic attacks: Cued Panic Attacks, Situational Predisposed Panic Attacks and Spontaneous Panic Attacks.

Objectives

To discuss three case reports with one year follow-up, each one of a different type of panic attack.

Case report

1 Female, 25-years-old. First panic attack at age 20, since there several spontaneous episodes with a mean of 4 a week, not related to any specific situation, event, or place, without any warning.

Case report

2 Male, 28-years-old. Has always been afraid of airplanes but it was only 3 years ago that riding on an airplane has started to trigger panic attack. He don’t experience panic attacks in any other situation.

Case report

3 Male, 31-years-old. First episode 4 years ago while driving alone and since there driving, traveling alone, enclosed spaces and crowds are more likely to trigger a panic attack but not always. They don’t have a specific fear or phobia tied to that situation or place; they simply tend to experience panic attacks when there.

Conclusion

Understanding the different types of panic attacks can help you and your doctor determine the cause of your attacks and the best way to go about treating them.

Computer-aided applications of nanoscale smart materials for biomedical applications

Nanotechnology has the potential to impact the treatment of many diseases that currently plague society: cancer, AIDS, dementia of various kinds and so on. Nanoscale smart materials, such as carbon nanotubes, C60, dendrimers and cyclodextrins, hold great promise for use in the development of better diagnostics, drug delivery and the alteration of biological function. Although experimentation is being used to explore the potential offered by these materials, it is by its very nature expensive in terms of time, resources and expertise. Insight with respect to the behavior of these materials in the presence of biological entities can be obtained much more rapidly by molecular dynamics simulation. Furthermore, the results of simulation may be used to guide experimentation so that it is much more productive than it might be in the absence of such information. The interactions of several nanoscale structures with biological macromolecules can already be probed effectively using molecular dynamics simulation. The results obtained should form the basis for significant new developments in the treatment of disease.

Improved lentiviral transduction of human mesenchymal stem cells for therapeutic intervention in pancreatic cancer

Genetic modification of human bone marrow mesenchymal stem cells (MSC) is highly valuable for their exploitation in basic science and therapeutic applications, for example in cancer. We present here a new, fast and easy-to-use method to enrich a functional population of lentiviral (LV)-transduced MSC expressing enhanced green fluorescent protein (eGFP). We replaced the eGFP gene by a fusion gene of puromycin acetyltransferase and eGFP. Upon LV gene transfer and puromycin selection, we quickly obtained a pure transduced MSC population, in which growth, differentiation capacity and migration preferences were not compromised. Furthermore, we are the first to report the migration velocity of MSC among which 30% were moving and velocity of about 15 mum h(-1) was not altered by LV transduction. Manipulated MSC underwent senescence one passage earlier than non-transduced cells, suggesting the use for therapeutic intervention in early passage numbers. Upon tail vein application in nude mice, the majority of LV-transduced MSC could be detected in human orthotopic pancreatic tumor xenografts and to a minor extent in mouse liver, kidney and lung. Together, LV transduction of genes to MSC followed by puromycin selection is a powerful tool for basic research and improves the therapeutic prospects of MSC as vehicles in gene therapy.

Childhood sexual abuse among outpatients attending adult psychiatric outpatient clinics: a case-control study

Only a few studies have focussed on the importance of routine investigation of childhood sexual abuse in outpatients attending adult psychiatric outpatient clinics. The aim of this study is to explore the association between having a history of childhood sexual abuse (CSA) and attending adult Psychiatric Outpatient Clinics in Trinidad.

METHODS

This was a case-control study conducted in twelve psychiatric outpatient clinics located throughout Trinidad A questionnaire covering demographic, social, and sexual abuse components was administered by semi-structured interview to 566 participants, of whom 242 were cases, 239 were controls and 85 had incomplete questionnaires. The cases were 242 patients attending psychiatric outpatient clinics in Trinidad and the controls were 239 non-physician staffmembers at the clinics. Results were analyzed using the Stastistical Package for the Social Sciences (SPSS) version 10.

RESULTS

Chi-square analyses revealed several significant differences between the cases and control group. Sixty-three (26%) cases and 29 (12.1%) controls experienced CSA (p < 0.000). Twenty-five (39.7%) of the CSA cases had their experiences between the ages of 4 to 8 years and 13 (44.8%) of the CSA controls had their experiences between the ages of 9 to 12 (p < 0.01). Twenty-six (41.3%) of the cases and 3 (10.3%) of the controls had been abused at least 5 times (p < 0.000). Seventeen (58.6%) abused CSA controls reported having been sexually abused as a child only once. CSA with both force and manipulation was reported by 30 (47.6%) CSA cases while 6 (20.7%) CSA controls experienced CSA with force and manipulation (p < 0. 025). The abused CSA cases reported having a smaller social network of 2 persons compared to the abused CSA controls who had a social network of more than 4 persons (p < 0. 05). Of the 92 abused participants, 73.9% were women, and only 52.2% had told someone about the CSA. For the majority of CSA cases and CSA controls, the abuse involved one abuser.

CONCLUSION

A positive correlation was established between earlier onset of CSA, repeated abuse (occurring more than 5 times), a limited social network in patients who had CSA and attending adult psychiatric outpatient clinics. Identifying CSA in psychiatric outpatients may lead to early intervention and aid patient management.

Biology of the schistosome lung-stage schistosomulum

Past and more recent research has examined the ultrastructure, metabolism, cell biology, genomics and post-genomics of schistosome schistosomula. These areas are considered and discussed in this review with particular emphasis on (1) the early migration phases through the host, (2) interaction of the host immune response with the parasite surface, (3) glucose uptake mechanisms, and (4) defining the transcriptional profiles of lung-stage schistosomula compared with other developmental stages using microarrays. The microarray profiling studies suggest caution is required when considering the use of schistosomes obtained by in vitro means for molecular or biochemical studies.

Transcriptome profiling of lung schistosomula,in vitro cultured schistosomula and adult Schistosoma japonicum

The schistosomulum is the main target of vaccine-induced protective immunity; however, most studies have utilized schistosomula produced by mechanical transformation of infective larvae followed by in vitro culture rather than larvae isolated directly from the lungs of infected mammals. Using transmission electron microscopy, we demonstrated that there was little difference in the ultrastructure of Schistosoma japonicum schistosomula obtained by the two methods. However, significant differences in gene expression profiles were apparent when we used an oligonucleotide microarray to compare the gene expression profiles of schistosomula obtained in vivo from lung tissue with those maintained in vitro, and with adult worms of S. japonicum. It is likely that host environmental factors, which cannot be reliably reproduced in vitro, do influence the growth, development and overall biology of schistosomes. Thus caution is urged when using in vitro-cultured schistosomes and mechanically transformed/cultured schistosomula in molecular, biochemical and immunological studies.

Population pharmacokinetic meta-analysis with efavirenz

A population-based pharmacokinetic (PK) model has been developed for efavirenz based on 16 phase I studies. The combined data set consisted of 334 healthy volunteers, 2,907 efavirenz dose administrations and 9,342 measured plasma concentrations across a range of doses from 100-600 mg. The pharmacokinetic structural model was a 2-compartment model with first-order absorption with differentiation between single- and multiple-dose exposure to account for known hepatic cytochrome P450 induction of efavirenz metabolism. Model-building was performed on the index data set (66% of the total database), as a data-splitting technique was used to validate the final model using NONMEM. The final model confirmed the appropriateness of separate clearance terms for single and multiple dose administration (2.65 versus 10.2 l/h, respectively). Clearance increased with dose and frequency of administration. A lower clearance was predicted in Asians and Blacks relative to Caucasians. A slightly lower clearance was observed in females relative to males (9.08 compared to 10.2 l/h in males) and interactions on clearance due to co-administration of fluconazole, ritonavir, rifampin, indinavir and azithromycin were identified. The magnitudes of these effects were small and did not suggest dose adjustment in the various subpopulations. With little exception, these results agree with the findings from the non-compartmental analyses. The residual variability was 21% CV and the intersubject variation in CL/F and V/F was 48 and 85%, respectively. The phase I meta-analysis was able to substantiate the pharmacokinetic characteristics of efavirenz derived from the composite of individual well-defined studies. The model was deemed adequate for subsequent evaluation in HIV-infected patients. Covariates and outlier classes identified in this phase I meta-analysis were similarly identified in subsequent analyses of patient data.

Structure and conformation of DAB dendrimers in solution via multidimensional NMR techniques

NOESY-HSQC 3D-NMR and NOESY 2D-NMR techniques have been used on a 750 MHz spectrometer to study the chain conformations of different generation DAB dendrimers (poly[propylene imine] dendrimers) in chloroform and benzene solutions. The high-field multidimensional NMR techniques provided the chemical shift dispersion needed to resolve all of the unique resonances in the dendrimers. By studying the NOE interactions among dendritic chain protons, information about through space interactions between protons on different parts of the dendrimer chain is obtained, which is directly related to the conformation of the dendrimer. These experiments also give further proof of the chemical shift assignments obtained from the HMQC-TOCSY 2D and 3D NMR experiments. The concentration effects on chemical shifts have also been observed, revealing information about the interactions between solvent and different parts of dendrimer molecules. These studies clearly show for DAB dendrimers, that folded chain conformations can occur in nonpolar solvents such as benzene and extended chain conformations are predominant in polar solvents such as chloroform.

Inhibition of actin-myosin subfragment 1 ATPase activity by troponin I and IC: relationship to the thin filament states of muscle

Troponin I (TnI) is the component of the troponin complex that inhibits actomyosin ATPase activity, and Ca(2+) binding to the troponin C (TnC) component reverses the inhibition. Effects of the binding of TnI and the TnI-TnC (TnIC) complex to actin-tropomyosin (actinTm) on ATPase and on the binding kinetics of myosin subfragment 1 (S1) were studied to clarify the mechanism of the inhibition. TnI and TnIC in the absence of Ca(2+) bind to actinTm and inhibit ATPase to similar levels with a stoichiometry of one TnI or one TnIC per one Tm and seven actin subunits. TnI also binds to actinTmTn in the presence of Ca(2+) with a stoichiometry and inhibition constant similar to those for the binding to actinTm of TnI and Tn in the absence of Ca(2+). Thus, in the presence of Ca(2+), the intrinsic TnI which is released from its binding site on actinTm does not interfere with the binding of an extra molecule of TnI to actinTmTn. The rate of S1 binding to actinTmTnI and to actinTmTnTnI in the presence of Ca(2+) was inhibited to the same extent as upon removal of Ca(2+) from actinTmTn. These studies show that TnI inhibits ATPase by the same mechanism as Tn in the absence of Ca(2+), by shifting the thin filament equilibria from the open state to the closed and blocked states.

Posttranscriptional destabilization of the bradykinin B1 receptor messenger RNA: cloning and functional characterization of the 3'-untranslated region

We showed previously that the inducible bradykinin B1 receptor (BKB1R) gene expression is regulated, in part, through mRNA stabilization. Here we clone the 3'-untranslated region (3'-UTR) of the BKB1R. This region proves to be very short, containing only 14 bases with an alternative polyadenylation signal (AUUAAA) which overlaps with the stop codon. Reverse transcription confirms the presence of this alternative polyadenylation signal. Northern blot shows a single species of BKB1R mRNA of approximately 1.4 kb in agreement with its calculated length. The BKB1R mRNA induced by TNFalpha, phorbol ester, bradykinin, and desArg10-kallidin contain the same 3'-UTR species. To test the role of this region in the regulation of mRNA stability, we generated a chimeric luciferase construct containing the BKB1R 3'-UTR. The mRNA transcribed from the wild-type luciferase gene displayed a half-life of approximately 6 h. The mRNA transcribed from the chimeric construct displayed a half-life of only 1 h. This decrease was also reflected at the level of enzyme activity. Luciferase activity from cells transfected with the chimeric construct was 10 times less than from cells transfected with wild-type luciferase. The data presented provide compelling evidence that the 3'-UTR is participating in the regulation of BKB1R mRNA stability and its ultimate expression.

Pharmacokinetics of intravesical doxorubicin in superficial bladder cancer patients

The urine and plasma pharmacokinetics of intravesical doxorubicin were studied in 8 patients with a history of superficial bladder cancer. Patients received 6 weekly treatments of 40 mg. doxorubicin in 20 ml. physiological saline. Doxorubicin was detectable (0.2 ng./ml. or more) in plasma from 6 of 8 patients during the initial treatment. The maximal concentrations ranged from 0.5 to 4.5 ng./ml. (mean 1.4). Doxorubicin was not detected in plasma from 7 of 8 patients during treatment 2 and not detected in any patient during treatment 4. The doxorubicin concentrations in urine decreased to approximately 50% at 5 minutes after dosing due to dilution by post-catheterization residual urine, and decreased by a further 6-fold by the end of the 2-hour treatment due to urine production. The recovery of doxorubicin at the end of treatment averaged 88.3%, with an additional recovery of 3.7% during the subsequent 4 hours. Urinary pH (range 5.5 to 8.5) did not affect the stability nor the systemic absorption of doxorubicin. In conclusion, we found that for intravesical doxorubicin therapy there was insignificant systemic exposure to doxorubicin, the highest systemic absorption from the bladder occurred shortly after surgery, there was high target site (bladder tissue) specificity, insignificant metabolism and/or degradation of doxorubicin, and dilution of urinary doxorubicin concentrations and, therefore, decreased tumor exposure to the drug due to residual urine and urine production.

Prophylactic oral naltrexone with intrathecal morphine for cesarean section: effects on adverse reactions and analgesia

The influence of two different doses of oral naltrexone on the adverse effects and the analgesia associated with intrathecal morphine was compared in a double-blind, placebo-controlled study. Thirty-five patients undergoing cesarean section were provided postoperative analgesia by 0.25 mg intrathecal morphine. Sixty minutes later they were given 6 mg naltrexone, 3 mg naltrexone, or placebo as an oral solution. Pain relief was assessed by the Visual Analog Scale. Requirements for additional analgesics and side effects were recorded. Duration of analgesia was shorter in the 3- and 6-mg naltrexone groups than in the placebo group, 10.0 +/- 2.6, 12.4 +/- 2.6, and 19.2 +/- 4.5 h (mean +/- SEM), respectively, but values did not reach statistical significance. The incidence of pruritus and vomiting was significantly less in the 6-mg naltrexone group than in the other two groups (P less than 0.05). Somnolence was significantly less in the 3- and 6-mg naltrexone groups than in the placebo group (P less than 0.05). Naltrexone (6 mg) is an effective oral prophylactic against the pruritus and vomiting associated with intrathecal morphine for analgesia after cesarean section, but it is associated with shorter duration of analgesia.

The preparation of polyamide-oligonucleotide probes containing multiple non-radioactive labels

Oligonucleotide probes containing multiple non-radioactive labels have been prepared by utilising and extending the methods used to prepare polyamide-oligonucleotide conjugates. The probes were prepared by incorporating suitable amino acid residues, such as lysines, in the polyamide, which were then used as sites for the attachment of the non-radioactive labels. The procedures developed give control over the distance of the label from the oligonucleotide, and also the inter-label distance. The labels can be conveniently introduced while the substrate is still on the solid support. Even though fluorescent oligonucleotide probes prepared in this way carrying multiple carboxyfluorescein labels gave low levels of fluorescence due to quenching, the probes containing ten biotin labels gave a detection sensitivity of approximately 5 attomole (3 million molecules).

Preparation of base-modified nucleosides suitable for non-radioactive label attachment and their incorporation into synthetic oligodeoxyribonucleotides

A very mild and efficient procedure has been developed for the preparation of C-5 substituted deoxyuridines. The substituent carries a masked primary aliphatic amino group. These compounds are readily converted into their phosphoramidites and can be used to prepare oligonucleotides carrying one or more aliphatic amino groups. Fluorescein isothiocyanate coupled to these compounds gives oligonucleotide probes carrying multiple fluorescein labels. These compounds have a free 5'-hydroxy group enabling additional 5'- end radioactive labelling for evaluation of their hybridization characteristics. It was found that oligonucleotides carrying a long (11 atom) linker arm to the fluorescein hybridize more efficiently to mRNA than those carrying a short (4 atom) arm. The long linker arm derivatives are comparable to underivatized oligonucleotides in hybridizing to mRNA.