Injectable Nanocomposite Implants Reduce ROS Accumulation and Improve Heart Function after Infarction

In a myocardial infarction, blood supply to the left ventricle is abrogated due to blockage of one of the coronary arteries, leading to ischemia, which further triggers the generation of reactive oxygen species (ROS). These sequential processes eventually lead to the death of contractile cells and affect the integrity of blood vessels, resulting in the formation of scar tissue. A new heart therapy comprised of cardiac implants encapsulated within an injectable extracellular matrix-gold nanoparticle composite hydrogel is reported. The particles on the collagenous fibers within the hydrogel promote fast transfer of electrical signal between cardiac cells, leading to the functional assembly of the cardiac implants. The composite hydrogel is shown to absorb reactive oxygen species in vitro and in vivo in mice ischemia reperfusion model. The reduction in ROS levels preserve cardiac tissue morphology and blood vessel integrity, reduce the scar size and the inflammatory response, and significantly prevent the deterioration of heart function.

Injectable Cardiac Cell Microdroplets for Tissue Regeneration

One of the strategies for heart regeneration includes cell delivery to the defected heart. However, most of the injected cells do not form quick cell-cell or cell-matrix interactions, therefore, their ability to engraft at the desired site and improve heart function is poor. Here, the use of a microfluidic system is reported for generating personalized hydrogel-based cellular microdroplets for cardiac cell delivery. To evaluate the system's limitations, a mathematical model of oxygen diffusion and consumption within the droplet is developed. Following, the microfluidic system's parameters are optimized and cardiac cells from neonatal rats or induced pluripotent stem cells are encapsulated. The morphology and cardiac specific markers are assessed and cell function within the droplets is analyzed. Finally, the cellular droplets are injected to mouse gastrocnemius muscle to validate cell retention, survival, and maturation within the host tissue. These results demonstrate the potential of this approach to generate personalized cellular microtissues, which can be injected to distinct regions in the body for treating damaged tissues.

3D Printing of Personalized Thick and Perfusable Cardiac Patches and Hearts

Generation of thick vascularized tissues that fully match the patient still remains an unmet challenge in cardiac tissue engineering. Here, a simple approach to 3D-print thick, vascularized, and perfusable cardiac patches that completely match the immunological, cellular, biochemical, and anatomical properties of the patient is reported. To this end, a biopsy of an omental tissue is taken from patients. While the cells are reprogrammed to become pluripotent stem cells, and differentiated to cardiomyocytes and endothelial cells, the extracellular matrix is processed into a personalized hydrogel. Following, the two cell types are separately combined with hydrogels to form bioinks for the parenchymal cardiac tissue and blood vessels. The ability to print functional vascularized patches according to the patient's anatomy is demonstrated. Blood vessel architecture is further improved by mathematical modeling of oxygen transfer. The structure and function of the patches are studied in vitro, and cardiac cell morphology is assessed after transplantation, revealing elongated cardiomyocytes with massive actinin striation. Finally, as a proof of concept, cellularized human hearts with a natural architecture are printed. These results demonstrate the potential of the approach for engineering personalized tissues and organs, or for drug screening in an appropriate anatomical structure and patient-specific biochemical microenvironment.

Personalized Hydrogels for Engineering Diverse Fully Autologous Tissue Implants

Despite incremental improvements in the field of tissue engineering, no technology is currently available for producing completely autologous implants where both the cells and the scaffolding material are generated from the patient, and thus do not provoke an immune response that may lead to implant rejection. Here, a new approach is introduced to efficiently engineer any tissue type, which its differentiation cues are known, from one small tissue biopsy. Pieces of omental tissues are extracted from patients and, while the cells are reprogrammed to become induced pluripotent stem cells, the extracellular matrix is processed into an immunologically matching, thermoresponsive hydrogel. Efficient cell differentiation within a large 3D hydrogel is reported, and, as a proof of concept, the generation of functional cardiac, cortical, spinal cord, and adipogenic tissue implants is demonstrated. This versatile bioengineering approach may assist to regenerate any tissue and organ with a minimal risk for immune rejection.

Engineered hybrid cardiac patches with multifunctional electronics for online monitoring and regulation of tissue function

In cardiac tissue engineering approaches to treat myocardial infarction, cardiac cells are seeded within three-dimensional porous scaffolds to create functional cardiac patches. However, current cardiac patches do not allow for online monitoring and reporting of engineered-tissue performance, and do not interfere to deliver signals for patch activation or to enable its integration with the host. Here, we report an engineered cardiac patch that integrates cardiac cells with flexible, freestanding electronics and a 3D nanocomposite scaffold. The patch exhibited robust electronic properties, enabling the recording of cellular electrical activities and the on-demand provision of electrical stimulation for synchronizing cell contraction. We also show that electroactive polymers containing biological factors can be deposited on designated electrodes to release drugs in the patch microenvironment on demand. We expect that the integration of complex electronics within cardiac patches will eventually provide therapeutic control and regulation of cardiac function.

Landmarks of the normal adult human trochlea based on axial MRI measurements: a cross-sectional study

PURPOSE

For deepening trochleoplasty, a procedure used worldwide to correct trochlear dysplasia, only few surgical steps are described precisely. Important surgical landmarks, such as optimal cartilaginous trochlear depth and percentages of the new lateral and medial facet, remain unanswered.

METHODS

A cross-sectional study (January 2011-August 2012) was carried out in adult patients (16-35 years) without trochlear dysplasia, who underwent magnetic resonance imaging (MRI). The main outcome was trochlear depth. The secondary outcome was the lateral/medial facet ratio. Measurements were made on the first axial cut from proximal with complete cartilage coverage of the trochlea. Differences between men and women were assessed.

RESULTS

Fifty-three patients (70% men) were included. Mean age was 24.6 years (SD±5.5). Overall mean trochlear depth was found to be as 4.0 mm (95% CI 3.6-4.3). Values differed significantly by gender (p=0.0271) with a mean of 3.4 mm (95% CI 3.0-3.8) for women and a mean of 4.2 mm (95% CI 3.8-4.7) for men. The mean ratio between the lateral and medial facet was 1.71 (95% CI 1.62-1.80), the lateral facet contributing 62.6% (95% CI 61.3-63.8) and the medial facet contributing 37.4% (95% CI 36.2-38.7) to the total cartilage length. For the facet ratio, there was no statistically significant gender difference (n.s.).

CONCLUSIONS

This study provides data on important landmarks for deepening trochleoplasty based on average MRI measurements in the general population. The difference between the MRI measurement and actual cartilage surface measurement is likely to be minimal, but is yet to be evaluated. Further evaluation of these landmarks by prospectively performing deepening trochleoplasty will determine the value of the clinical implication.

LEVEL OF EVIDENCE

II.

Evaluating the treatment of metastatic colorectal cancer with monoclonal antibodies

The ability to tailor biologic therapy based on the status of tumor biomarkers and monoclonal antibodies has become very important in the last years. The role of tumor biomarkers in treating colorectal cancer, specifically the K-RAS gene, was identified. K-RAS had a higher interest after Lievre and colleagues reported at the 2008 American Society of Clinical Oncology (ASCO) meeting, their analysis of K-RAS mutations in tumors from patients who did not appear to benefit from cetuximab therapy, providing additional data involving K-RAS mutant tumors and their lack of response to cetuximab, as part of first-line therapy for metastatic colorectal cancer. Furthermore, other trials evaluated the K-RAS status and the first-line treatment of metastatic colorectal cancer, the treatment of refractory metastatic cancer and dual-antibody therapy in the first-line treatment of colorectal cancer. Patients with mutant K-RAS colorectal tumors have no benefit from cetuximab, no matter the type of chemotherapy regimen.

3D representation of the surface topography of normal and dysplastic trochlea using MRI

The three-dimensional (3D) image of the articular surface topography of the normal and the dysplastic trochlea has not been defined. The aim of this study was to represent both the normal and dysplastic trochlear geometry in 3D using magnetic resonance imaging (MRI). Using the segmentation software program Amira (Mercury Computer Systems, Inc., Chelmsford, USA) we created 3D reconstructions of the distal femur bone and cartilage using MRI scans. Bone and cartilage of the distal femur were traced slice by slice in the acquisitioned dimension while the Amira program reconstructed the 3D model. This model was then transferred to the Rhinoceros 4.0 software (Robert McNeel & Associates, Seattle, USA) for measuring. Using this system a non-invasive 3D representation of the articular cartilage and bone of the normal trochlea and depiction of different types of trochlear dysplasia were possible. Potential advantages of these MRI measurements are assessment of the 3D articular cartilage of the whole trochlea and the bony contours on the same image, no imaging errors from joint malpositioning, no ionizing radiation, precise preoperative planning according to the documented pathomorphology, and comparison between the preoperative and the postoperative shapes. The disadvantages include higher costs compared to radiography or CT scans, and time consuming reconstruction, making them currently a research tool.

Promoting older adults' well-being through Internet training and use

The purpose of the current research was to test the psychological impact of learning how to use computers and the Internet in old age, hypothesizing that such activities would contribute to seniors' well-being and personal sense of empowerment. Employing a quasi-experimental research design, we offered a course, conducted in small groups, in computer operation and Internet browsing to 22 older adults (mean age of 80) who went to day-care centers for the elderly or resided in nursing homes. A comparison group of 26 participants (similar in all major respects) was engaged in other activities. Both groups were administered measures of physical functioning, life satisfaction, depression, loneliness and self-control at pre- and post-intervention four months later. Individual semi-structured interviews were conducted with participants who finished the computer course. ANCOVA was employed for controlling the effects of control variables and pre-intervention differences on participants who completed the activities. Results showed a significant improvement among participants in the intervention group in all measures except physical functioning, whereas deterioration in all measures was detected in the comparison group. Computer and Internet use seems to contribute to older adults' well-being and sense of empowerment by affecting their interpersonal interactions, promoting their cognitive functioning and contributing to their experience of control and independence.

ATM haplotypes and breast cancer risk in Jewish high-risk women

While genetic factors clearly play a role in conferring breast cancer risk, the contribution of ATM gene mutations to breast cancer is still unsettled. To shed light on this issue, ATM haplotypes were constructed using eight SNPs spanning the ATM gene region (142 kb) in ethnically diverse non-Ashkenazi Jewish controls (n=118) and high-risk (n=142) women. Of the 28 haplotypes noted, four were encountered in frequencies of 5% or more and accounted for 85% of all haplotypes. Subsequently, ATM haplotyping of high-risk, non-Ashkenazi Jews was performed on 66 women with breast cancer and 76 asymptomatic. One SNP (rs228589) was significantly more prevalent among breast cancer cases compared with controls (P=4 x 10(-9)), and one discriminative ATM haplotype was significantly more prevalent among breast cancer cases (33.3%) compared with controls (3.8%), (P< or =10(-10)). There was no significant difference in the SNP and haplotype distribution between asymptomatic high-risk and symptomatic women as a function of disease status. We conclude that a specific ATM SNP and a specific haplotype are associated with increased breast cancer risk in high-risk non-Ashkenazi Jews.

[Results of laparoscopic repair of abdominal wall hernias using an ePTFE-polypropylene composite mesh]

BACKGROUND

The standard technique for laparoscopic ventral hernioplasty (peritoneal onlay) reduces the recurrence rate and the rate of other complications, in particular the risk of infections. However, the procedure requires a special mesh to mitigate the risk of visceral adhesions. For this purpose an ePTFE mesh is generally used. There are limited reported clinical data regarding the long-term results and benefits of other biomaterials.

STUDY DESIGN

Bard Composix mesh was used for laparoscopic ventral hernia repair. This biomaterial combines two different clinically proven materials--polypropylene with a thin layer of ePTFE--to maximize ingrowth of surrounding tissue, while mitigating the risk of visceral adhesions. Demographic, operative and postoperative data were collected and analyzed. Follow-up clinical evaluations were conducted 6-10 days, 4 weeks, and every 6 (th) month after surgery in all patients.

RESULTS

Fifteen patients were involved in the study. The mean operating time was 101.2 min (64-190 min). There were no intraoperative complications or conversion to open procedure. Postoperative complications were 1 seroma, 4 cases of prolonged ileus, one tacks-site pain requiring second-look laparoscopy. Hospital discharge occurred on average 6 days (3-10 days) after surgery. The mean follow-up was 12.4 months (range 5-29 months). No late complications or hernia recurrence were observed.

CONCLUSIONS

Laparoscopic prosthetic ventral hernioplasty using the composite polypropylene/ePTFE mesh offers short hospital stay and acceptable complications for primary and recurrent ventral hernias. Disadvantage of the composite mesh is the difficulty to roll this product into a sufficiently small size to permit its easy introduction into the abdominal cavity.

Laparoscopic resection of a bleeding meckel s diverticulum: a case report and review of the literature

The preoperative diagnosis of Meckel's diverticulum in adults is uncommon, and even more infrequent is the presentation of a bleeding Meckel's diverticulum after childhood. The case of a 22-year old, otherwise healthy male is presented here. The diagnosis was made by barium examination of small bowel and confirmed by diagnostic laparoscopy, followed by complete laparoscopic resection using an Endo-GIA Stapler (United States Surgical Corp., Norwalk, Conn.]. Histopathological examination of the specimen showed inflammed ileal mucosa with hemorrhages in several foci. The literature of Meckel's diverticula and its complications are reviewed here. Based on data from the reviewed literature and our own experience, we suggest that laparoscopic resection is the treatment of choice for Meckel's diverticulum, if it is diagnosed preoperatively or during diagnostic laparoscopy. The procedure allows for a smooth postoperative course, early discharge from the hospital, and arapid return to normal activity.

Case series: coexistence of Sjögren's syndrome and sarcoidosis

OBJECTIVE

To present cases of coexisting sarcoidosis and Sjogren's syndrome (SS).

METHODS

We analyzed the clinical data of our 464 patients with SS with a clinical picture suggesting coexisting SS and sarcoidosis. We followed them for several years.

RESULTS

We found 5 patients with coexisting SS and sarcoidosis. In 3 patients, pure sarcoidosis could mimic SS.

CONCLUSION

In our experience, the frequency of sarcoidosis in SS is much higher than in the general population. One of the European criteria is that before the diagnosis of SS is made, the presence of sarcoidosis must be excluded. From our experience of 5 cases we determined that the 2 diseases can coexist, which indicates the value of these criteria.

Synovitis, acne, pustulosis, hyperostosis, osteitis (SAPHO) syndrome in childhood: a report of ten cases and review of the literature

Chronic recurrent multifocal osteomyelitis is a rare chronic inflammatory musculoskeletal process observed in children and young adults. Recently, the acronym SAPHO syndrome (for synovitis, acne, pustulosis, hyperostosis, osteitis) was coined to emphasise the association between osteo-articular inflammations and different skin abnormalities which are aseptic and filled with neutrophils. In adults, chronic recurrent multifocal osteomyelitis is now a classical manifestation of SAPHO syndrome. Chronic skin disorders were seen in eight of ten children on follow-up at the University Children's Hospitals in Bern and Zurich and in 61 of 260 paediatric cases reported in the literature. The different skin lesions were palmoplantar pustulosis (n = 40), non-palmoplantar pustulosis (n = 6), psoriasis vulgaris (n = 16) or severe acne (n = 4). More rarely Sweet syndrome (n = 2) or pyoderma gangrenosum (n = 1) were reported.

CONCLUSION

The synovitis, acne, pustulosis, hyperostosis, osteitis syndrome is pertinent even in paediatrics since skin involvement is frequent.

Natural history of individuals with asymptomatic disc abnormalities in magnetic resonance imaging: predictors of low back pain-related medical consultation and work incapacity

STUDY DESIGN

Prospective study on individuals with asymptomatic lumbar disc abnormalities detected in magnetic resonance imaging.

OBJECTIVES

To determine the natural history of asymptomatic disc abnormalities in magnetic resonance imaging and to identify predictors of future low back pain-related medical consultation and work incapacity.

SUMMARY OF BACKGROUND DATA

The natural history of individuals with asymptomatic disc herniations has not been well established, but the high rate of lumbar disc alterations recently detected in asymptomatic individuals by magnetic resonance imaging demands reconsideration of a pathomorphology-based explanation of low back pain and sciatica.

METHODS

Forty-six asymptomatic individuals who had a high rate of disc herniations (73%) were observed for an average of 5 years (range, 54-72 months). Four classes of variables (medical data including magnetic resonance imaging-identified disc abnormalities, general psychological factors, physical job characteristics, and psychosocial aspects of work) were assessed at baseline and follow-up.

RESULTS

Disc herniations and neural compromise did not significantly worsen at follow-up, whereas disc degeneration progressed in 17 individuals (41.5%). Minor episodes of low back pain occurred in 19 individuals (41.3%), 6 of whom had to seek medical treatment and 5 of whom had to stop work temporarily. The requirement for low back pain-related medical consultation was predicted with high accuracy by listlessness, job satisfaction, and working in shifts (P < 0.001). Work incapacity was best predicted by physical job characteristics, job disaffection, and working in shifts (P < 0.01).

CONCLUSION

Physical job characteristics and psychological aspects of work were more powerful than magnetic resonance imaging-identified disc abnormalities in predicting the need for low back pain-related medical consultation and the resultant work incapacity. However,the conclusions are still preliminary, and replication of the findings in larger and more representative study samples is needed.

A new operating room concept for minimal invasive surgery

Since 1990 new developments have found their way into almost every area of minimally invasive surgery (MIS), and nowadays, 90% of all gynecological operations and 80% of all abdominal operations can be performed by this approach. In contrast to surgical development, operating room (OR) design has not progressed much over the past half century. While a number of surgical suites have been designed for specific specialties, more commonplace is the flexible OR concept.

The role of routine pelvic lymph node sampling in patients with stage I endometrial carcinoma: second thoughts

BACKGROUND AND METHODS

The cases of 245 patients diagnosed during 1980-1989 with stage I endometrial carcinoma were retrospectively reviewed in order to assess the contribution of lymph node sampling (LNS) to both course of treatment and outcome. The 183 women treated by gyneco-oncologic surgeons had undergone the standard surgical procedure of total abdominal hysterectomy (TAH), bilateral salpingo-oophorectomy (BSO) and pelvic lymph node sampling (LNS). Sixty-two other women, treated by gynecologists, received only TAH and BSO. Of women who had received TAH+BSO+LNS, 105 (57.4%) were referred for adjuvant radiotherapy on the basis of one or any combination of high grade histology (G2 or G3), myometrial invasion to a depth of 50% or more and LNS positivity. Of the group who had not had LNS, 37 (59.7%) likewise received adjuvant radiotherapy but on the bases of histology and/or depth of invasion.

RESULTS AND CONCLUSIONS

Recurrence and survival over a mean follow-up period of 7.5 years (range 5-15 years) showed no significant differences between the patients who underwent LNS and those who did not. Of 43 recurrences, six were among 'low risk' women (those with both minimal invasion and low grade histology), suggesting a special need among this group for the additional staging information which LNS may provide.

Opposing effects of tyrosine kinase inhibitors on mineralization of normal and tumor bone cells

Induction of matrix maturation and mineralization in calcified tissues is important for patients with primary bone tumors and other bone deficiencies, e.g., osteoporosis. For the former it signifies a better prognosis in osteosarcoma, and for the latter it might improve bone remodeling. In the present study we exposed osteosarcoma cells (Saos2), normal bone cells, and marrow stroma to two different tyrosine kinase (TK) inhibitors: AG-555 and AG-1478. These tyrphostins differ in their effect on signal transduction downstream to the TK receptor (RTK): AG-1478 inhibits src family TKs whereas AG-555 inhibits nuclear TKs. We found that both tyrphostins at 50 microM increased specific alkaline phosphatase (ALP) activity in Saos2 cells. AG-555 abrogated mineralization whereas AG-1478 increased it. Similarly, in human bone-derived cell cultures the same dose of tyrphostins had an opposing effect on mineralization but, in contrast to AG-555, AG-1478 positively selected cells with ALP activity. These tyrphostins also differed in their effect on rat marrow stromal cells. AG-555 decreased cell counts unselectively, whereas the decreased cell counts by AG-1478 resulted in selection of osteoprogenitor cells as indicated by a concordant increase in specific ALP activity. The effect of a lower dose of AG-1478, 5 microM, on the increase in mineralization exceeded its own efficiency in selecting cells with specific ALP activity. Our results indicate that AG-1478 selects and preserves the osteoblastic phenotype, at doses moderately higher than those required to induce mineralization, and substantially higher than the doses required for RTK inhibition. Identification of downstream molecular targets for AG-1478, in marrow stromal cells, might prove useful in designing more selective drugs, capable of separating proliferative from differentiation-inducing activities.

Cyclosporin A and its non-immunosuppressive derivative exhibit a differential effect on cell-mediated mineralization in culture

Chronic immunosuppressive treatment with cyclosporin A (CsA) is associated with decreased bone density. However, in culture, CsA inhibits osteoclast differentiation and bone resorption. This raises the question as to whether CsA also affects osteoblast function. Immunophilin, one of the CsA-binding cyclophilins that is implicated in the immunosuppressive action of CsA via calcineurin, is a peptidyl prolyl cis-trans isomerase (PPl). CsA also binds a mitochondrial membrane PPl which is implicated in controlling permeability transition pores. Therefore, in the present study we tested the effect of CsA on cell mediated mineralization in parallel with mitochondrial rhodamine retention as an indicator of mitochondrial membrane potential Rat marrow stromal cells were grown in dexamethasone (DEX) medium to stimulate mineralization in culture, and CsA was added to various cultures using different treatment schedules. Low dose (0.1 microM) CsA inhibited mineralization, compared to controls, when present in the cultures during days 3-11 of DEX stimulation. Contrarily, high dose CsA (1.0 microM) resisted the inhibitory effect of the low dose. SDZ 220-384 (SDZ), a non-immunosuppressive derivative of CsA which is known, like CsA, to bind to mitochondrial cyclophilin but does not inhibit calcineurin, was also tested. Both high and low doses of SDZ decreased mineralization when present in the cultures from day 3 or from day 0. The similar effect of the low CsA dose and SDZ on mineralization is in accord with their ability to block permeability transition pores. The differential effect, on day 21 mineralization, between high CsA dose and SDZ took place in parallel to their opposing effects on mitochondrial membrane potential. On days 4-8, mitochondrial rhodamine retention was higher under CsA than under SDZ. Under these conditions there was no significant difference between the effects of these drugs on cell proliferation measured on day 11; there was a minor decrease in specific alkaline phosphatase activity by SDZ, too small to explain the extent of mineralization inhibition by SDZ. These results suggest that permeability transition pores might be involved in controlling mineralization. Unlike SDZ, CsA exhibits an additional effect on the mitochondrial membrane potential and on mineralization when applied at a high dose on day 3. Therefore identifying the additional activity of high dose CsA, which is missing in SDZ, may be beneficial. Such activity is expected to resist changes in rhodamine retention and decreased mineralization induced by SDZ, and yet enable preservation of immunosuppressive activity of CsA.

Cell-mediated mineralization in culture at low temperature associated with subtle thermogenic response

In both the growth plate and in marrow stromal cell cultures cell-mediated mineralization is preceded by characteristics of anaerobic and low efficiency energy metabolism. Reagents that increase mineralization like malonate and dexamethasone (DEX) also increase the mitochondrial membrane potential (MtMP) especially 1 week after DEX stimulation. Contrarily, levamisole, which decreases mineralization, also decreases MtMP. Modulation of MtMP and energy metabolism could be linked to regulation of mineralization by the uncoupling of oxidative phosphorylation. This uncoupling should be associated with thermogenesis in cells that induce mineralization. We examined whether cold temperature affects mineralization, and whether cellular thermogenesis takes place at cold temperature in parallel to changes in MtMP. Osteoprogenitor cells (OPC) induced, in DEX stimulated rat marrow stroma, higher mineralization at 33 degrees C than at 37 degrees C. Increased mineralization by cold temperature required long incubation since incubation in the cold during short intervals, 3-4 days, did not increase mineralization relative to (37 degrees C) controls. Marrow stromal cells in the presence of valinomycin responded to incubation at 33 degrees C by retaining all the vital dye after 4 h, unlike the cells at 37 degrees C; however, after 24 h the level of dye retention at 33 degrees C was the same as at 37 degrees C. The delayed response of the temperature-dependent (> 37 degrees C) K+ ionophor to incubation in the cold indicated that certain cells may respond to low temperature by local intracellular heating, and by heat conduction to the plasma membrane. DEX-stimulated stromal cells, unlike unstimulated cells, showed increased mitochondrial rhodamine 123 retention in the presence of valinomycin after 24 h in the cold, which corresponds to day 4 of OPC induction. This is consistent with the concept that valinomycin-induced cell damage is mediated by (cold-induced) local heating. The mechanism of this cell damage should selectively prefer nonthermogenic (rhodamine retaining) over thermogenic (rhodamine leaking) cells such as OPC. At cold temperature DEX-stimulated stromal cells showed the best anti-OPC selection under exposure to valinomycine between days 3-7, concurrent with the period of rhodamine leakage from the mitochondria. These results indicate that thermogenesis is enhanced during the period of low MtMP in mineralizing cells, and prolonged exposure to cold increases mineralization also due to induction of subtle thermogenesis.

Blunt hepatic trauma in adults: correlation of CT injury grading with outcome

PURPOSE

To correlate injury grading with computed tomography (CT) to treatment outcome.

MATERIALS AND METHODS

Forty-eight patients with proved blunt hepatic injuries underwent dynamic CT with contrast material before treatment. The injuries were classified with a five-point CT-based grading system. The CT injury grades and the amount of hemoperitoneum seen on CT scans were compared with the clinical and surgical findings, radiologic follow-up, and outcome.

RESULTS

Hepatic injuries were classified as CT grade 1 in two patients, grade 2 in 15 patients, grade 3 in 21 patients, and grade 4 in 10 patients. Conservative treatment was performed in 38 patients, including 15 patients with grade 3 and 10 patients with grade 4 injuries; 10 of these patients also had major hemoperitoneum (> 500 mL). Conservative treatment was successful in 37 patients but was complicated in two patients by development of an arteriovenous fistula or a biloma and failed in one patient because of delayed hepatic rupture. Exploratory laparotomy was performed in 10 patients but revealed marked active hepatic bleeding in only one patient.

CONCLUSION

Injury grading with CT may reflect the degree of hepatic parenchymal damage but does not indicate patients in whom complications may develop or surgery is necessary. Monitoring of conservative treatment with CT allows detection of resultant complications.

Opposing effects on mitochondrial membrane potential by malonate and levamisole, whose effect on cell-mediated mineralization is antagonistic

The act of chondrocyte preparation for primary, enchondral, mineralization is associated with a decline in mitochondrial respiration toward the end of the proliferative zone and the hypertrophic zone in the growth plate. Dexamethasone (Dex)-stimulated cultures of rat marrow stroma constitute a differentiation model simulating, in its energy metabolism, chondrocyte mineralization. In this model, early inhibition of succinate dehydrogenase (SDH) enriches the culture with mineralizing cells, whereas levamisole inhibits mineralization. Dex also increases mitochondrial membrane potential in stromal cells, especially on days 7-8 of stimulation. In the present study, suicide inhibition of SDH, by nitropropionic acid (NPA), in Dex-stimulated cells showed a dose-dependent increase in day 21 mineralization; the maximal effect was induced on days 2-4 of stimulation. Mineralization under 2-day-long exposure to NPA showed a similar trend to the previously studied effect of continuous exposure to malonate applied between days 3-11. Unlike malonate, the effect of NPA required its presence in the cultures for only 2 days and resulted in higher mineralization than that seen under 8 days of malonate. NPA delineated a period, days 2/4 to 7/9, in which inhibition of succinate oxidation is necessary to augment mineralization. During this period, NPA also exhibited OPC selection capacity. Early application of levamisole, under conditions previously shown to decrease day 21 mineralization, maintained mitochondrial membrane potential at the beginning of Dex stimulation but decreased or had little effect on it during days 5-10. By contrast, malonate previously found to increase day 21 mineralization decreased the membrane potential at the beginning of Dex stimulation but increased it later on day 7, or during days 5-10. These results indicate that during osteoprogenitor differentiation, before the mineralization stage, a surge in mitochondrial inner membrane potential during late matrix maturation may be a marker that heralds the extracellular matrix mineralization.

Analysis of cell-mediated mineralization in culture of bone-derived embryonic cells with neurofibromatosis

von Recklinghausen neurofibromatosis (NF1) is an autosomal dominant genetic disorder associated with congenital pseudoarthrosis and with short stature. To examine whether the NF1 phenotype includes functional osteogenic defects, embryonic bone-derived cells affected with NF1 were tested in culture for specific alkaline phosphatase (ALP) activity and cell-mediated mineralization and compared with other embryonic bone derived cells. NF1 showed a relatively higher specific ALP activity, which has further increased in response to dexamethasone + beta-glycerophosphate (beta GP) (Dex medium) coordinately with a decrease in cell proliferation. In In the control group, two samples showed increased ALP activity, one showed decreased activity and the forth one did not show any change in ALP. NF1 cells were distinguished from other cells regarding day 21 mineralization, they did not mineralize when cultured with ascorbate alone in the absence of Dex medium, whereas control cells did mineralize. Adding beta GP resulted in mineralization by NF1 cells but less than in other cells. In addition, NF1 cells responded to dexamethasone by increasing the beta GP-induced mineralization, as opposed to cells from other embryonic bones, which either did not respond or have even decreased mineralization under dexamethasone. Upon cis-hydroxyproline exposure, Dex medium has also distinguished NF1 cell ALP activity from that of other cell origins. Inhibition of respiratory complex II by malonate showed that most embryonic bone-derived cells of 12 weeks gestation are malonate resistant; thus, malonate selection was ineffective. This is in contrast to rat marrow stromal cells previously shown to undergo mineralizing cell enrichment in response to malonate. Exposure to levamisole, of Dex-treated cells, at days 0-11 has inhibited day 21 mineralization in all tested cultures in spite of the increase in day 11-specific ALP activity. Both malonate and levamisole did not distinguish NF1 cells from the osteogenic phenotype of other cells. Essentially embryonic bone-derived cells from 12 weeks gestation, cultured in the absence of beta GP, retained their mineralization capacity, which does not increase under dexamethasone, as distinguished from NF1 cells which require beta GP for mineralization and positively respond to dexamethasone. Therefore, bone-derived NF1 cells may be useful for studying the regulation of the mineralization process.

Tibial implant mineralization in rats is inversely related to serum osteogenic capacity

In this study, the correlation between the mineralization of healing bone defects and the osteogenic capacity of the serum was tested in rats. The purpose of the study was to test the hypothesis that during callus formation, some serum factors are consumed. The bone defects in the tibia contained two different implant types, and all sustained juxta-implant fractures. One implant type was the coral Porites and the other was its recrystallized version (Interpore-200), which exhibit different mineralization rates during fracture healing. Use of these two implant types permitted generation of an expanded mineralization spectrum suitable for regression analysis. Mineralization was assessed by measuring the mineral content change (MCC) using dual-energy X-ray absorptiometry. Osteogenic capacity of sera of the implanted rats was assessed by its ability to increase specific alkaline phosphatase (ALP) activity in stromal cell cultures. The MCC was followed for 5 weeks in the Porites and Interpore-200 implants, and it was found that the MCC in Interpore-200 implants exceeded that of the Porites implants. Thus, the two implant types generated a wide mineralization spectrum. Induction of ALP in stromal cell culture was lower for sera derived from rats implanted with Interpore-200 than for sera derived from rats implanted with Porites. Two weeks after implantation, the change in serum ALP induction correlated inversely with the MCC of bone defects. This indicates that during callus formation, the mineralization rate is reciprocally related to the serum osteogenic capacity. The decreased serum osteogenic capacity may be interpreted by the hypothesis that callus formation consumes certain serum osteogenic factors.

Long-term follow-up of the Günther basket inferior vena cava filter: does mechanical instability cause complications?

PURPOSE

The Günther basket inferior vena cava filter (GBF) has been withdrawn from the market because of its mechanical instability, but a number of patients still live with the device.

METHODS

In a two-center study, we evaluated the long-term follow-up of the GBF, based on clinical data in 78 patients, and on imaging studies including plain radiographs, Doppler ultrasound, angiography, or computed tomography (CT) in 50 patients.

RESULTS

In a mean period of 3 years, pulmonary embolism was diagnosed in five patients (6.4%), with an overall rate of 0.02 embolic episodes per patient per year. None of these patients required hospitalization, and there were no deaths due to pulmonary embolism. Inferior vena cava thrombosis was documented in three patients (3.9%), and occlusive venous thrombosis at the access site in seven patients (9%). Spontaneous migration was documented in 43% of the examined filters and spontaneous disruption in 77%. Dislocated filter fragments were localized by CT in the adjacent retroperitoneum in 11%, in the aortic lumen in 2%, and in a peripheral pulmonary artery in 7%. None of the patients had symptoms attributable to filter migration or disruption.

CONCLUSION

Our results indicate that the rate of clinically relevant complications with the GBF is no higher than with other vena cava filters. Because mechanical instability of the GBF had no clinical consequences, we conclude that patients who live with this device may be observed and treated in a manner similar to patients with other vena cava filters.

Marrow stromal cell commitment to mineralization under the effect of a prolyl hydroxylase inhibitor

Mitochondrial response to the effect of a hydroxylase (PH) inhibitor was tested in marrow stromal cells during stimulation of osteoprogenitor cell (OPC) differentiation. The rationale for this was to explore pathways of regulatory interactions between procollagen synthesis and mitochondrial respiration that could be linked to the commitment of OPCs to mineralization. Stimulated OPCs exposed to the PH inhibitor cis-hydroxyproline (cis-HP), compared to the noninhibiting isomer trans-HP, for 11 days showed a dose-dependent decrease in cell proliferation, the surviving cells showed increased alkaline phosphatase activity. Trans-HP did not influence the cis-HP effect on ALP and on proliferation arrest. Short time exposures, 2-3 days, to cis-HP at different periods suggested that Days 0-3 and 3-5 were critical for the commitment to Day 21 mineralization of OPCs. On Days 0-3 cells were most sensitive to cis-HP, since on Day 11, 8 days after removal of cis-HP, they were too scarce to be counted by the staining method. However, the presence of 5.0 mM cis-HP in the cultures during Days 3-5 has induced on Day 21 close to 24-fold more mineralization/cell than controls, compared to the trans-HP effect, which was only close to 3-fold. The presence of cis-HP in the cultures on Days 0-3 has augmented the mitochondrial Day 3 retention of rhodamine 123 (Rho) in the stromal cells, relative to controls, compared to the presence of trans-HP. However, the presence of cis-HP during Days 3-5 or 3-6 resulted in lower Day 5 Rho retention, relative to controls, which was not significantly different from the retention that resulted from trans-HP. Since Rho retention is related to the final result of aerobic respiration level, these results are interpreted as a cis-HP inhibitory effect on procollagen peptidyl-proline hydroxylation, which may in turn release oxygen surpluses, to be available for mitochondrial consumption. The fall in Rho retention responses to cis-HP between Days 0-3 and 3-5 is suggesting either abrupt decrease in proline hydroxylation or poor mitochondrial sensitivity to oxygen in Day 3-5 cultures.

Induction of osteoprogenitor cell differentiation in rat marrow stroma increases mitochondrial retention of rhodamine 123 in stromal cells

Bone marrow stromal cells contain colony forming cells with the potential to differentiate into osteoprogenitor (OPC) cells. OPC-stimulation medium, containing dexamethasone, ascorbate, and beta-glycerophosphate is widely used to recruit OPCs in culture. Cultures were incubated 24 h with rhodamine 123 (Rho), on different days, to examine the effect of the OPC-stimulation medium on the mitochondrial membrane potential of stromal cells. Cultures grown in both ordinary medium (DMEM with 15% FCS) and OPC-stimulation medium showed 2 Rho retention peaks on days 3-4 and 10-11. Between days 5 and 10 there was a drop in Rho retention/cell. OPC-stimulation medium increased Rho retention by at least twice the amount relative to ordinary medium, and has quadrupled it on day 7. Incubation with Rho concentrations above 5.0 micrograms/ml inhibited the portion of increased Rho retention which was contributed by the OPC-stimulation medium. Prolonged exposure to 0.1, 1.0, and 10.0 micrograms/ml Rho for 12 days only slightly increased day 12 ALP activity/cell, had no effect on day-21 mineralization and only the high dose, 10.0 micrograms/ml, doubled stromal cell proliferation. Under 24 h incubation Rho concentrations of 1.0 microgram/ml and below can serve as a marker for mitochondrial membrane potential in differentiating stromal cells. The results indicate that under both culture conditions stromal cell mitochondria undergo cycles of high and low membrane potential states and that the OPC-stimulation medium constantly maintains an elevated membrane potential relative to ordinary medium.

Studies of the levamisole inhibitory effect on rat stromal-cell commitment to mineralization

The ability of Levamisole to decrease mineralization in skeletal tissue is usually related to its effect on alkaline phosphatase (ALP). However, Levamisole is also suspected to diminish mineralization by an additional mechanism which is unrelated to the ALP control of apatite crystal growth. To delineate the time in differentiation during which Levamisole inhibits mineralization, a tissue culture model system of bone marrow stromal cells was used. Secondary cultures of stromal cells were propagated in osteoprogenitor cell (OPC) induction medium for three weeks, followed by measurement of calcium precipitation. In situ ALP assays at pH 7.6 were also performed. When cells were cultured with 0.2 mM Levamisole for three weeks, Day 20 values of calcium precipitates were lower than in controls, but Day 20 ALP values were paradoxically higher. The correlation between calcium and ALP within each group was low. The correlation slightly improved, in uninhibited cultures, when Day 21 calcium values were matched with earlier Day 12 ALP values. This suggested the existence of a Levamisole-sensitive mechanism for mineralization inhibition effective prior to the culture's mineralization stage. To focus on this early effect on mineralization Levamisole was added to stromal cultures on different days and removed on Day 12. Levamisole decreased Day 21 mineralization when added on Days 0, 3, 5, and 7, but not when added on Day 9. The Levamisole-induced inhibition of mineralization was accompanied by an increase in Day 12 ALP specific activity, compared to controls, when added from Day 5 and thereafter. The results indicate that part of the ability of stromal cells to mineralize is determined during the first week of culture.(ABSTRACT TRUNCATED AT 250 WORDS)

Selection of malonate-resistant stromal cell-derived osteoprogenitor cells in vitro

Bone marrow stromal cells give rise to osteoprogenitor cell (OPC) colonies, with characteristic mineralized bone nodules in vitro. During differentiation, OPCs in the culture are surrounded by heterogeneous populations of various cell lineages and by different OPC differentiation stages. In the present study, attempts were made to increase the homogeneity of OPCs in culture. The reliance on energy metabolism restricted to glycolysis, which is specific to the premineralizing skeletal cells, was tested as a selectable marker for cells in this stage. Day 12 alkaline phosphatase (ALP) and day 20-21 calcium precipitates were used as early and late OPC differentiation markers. Malonate, a competitive inhibitor of succinate dehydrogenase, was added to the OPC stimulation medium, to interfere with the Krebs cycle-dependent energy metabolism operating in most of the stromal cells. OPCs that entered the stage of energy metabolism restricted to glycolysis were expected to become malonate resistant. Malonate showed dose and time dependence, 10 mM malonate added on day 3, decreased day 12 ALP activity/well to the lowest level. Variations in time and length of exposure to malonate used during the first 12 days of differentiation showed an inverse correlation between specific ALP activity and cell yield. Malonate-treated variations of specific ALP and of cell yield indices were up to 30- to 40-fold larger than variations within day 21 calcium precipitates. Thus, calcifying cells were almost unchanged relatively to noncalcifying cells. These results indicate that malonate-resistant cells are mostly selected, rather than induced, to differentiate by malonate. The results also show that stromal derived OPCs undergo a similar biochemical stage as in chondrocytes.

Vitamin A concentration in amniotic fluid and maternal serum related to neural-tube defects

The vitamin A concentration of amniotic fluid and maternal serum was measured during the second trimester of pregnancy in 106 women, 12 of whom had a baby with a neural-tube defect. In these 12 pregnancies the amniotic fluid vitamin A concentration was significantly higher than in 94 normal pregnancies. There was a highly significant correlation between amniotic fluid vitamin A and both zinc and alpha-fetoprotein (AFP) levels. The maternal serum vitamin A levels were also significantly related to serum zinc levels. Women with a raised serum AFP level, but a normal baby, had significantly higher amniotic fluid vitamin A levels and significantly lower serum vitamin A levels compared with those in women with normal serum AFP levels.

The effect of palliative surgery on the survival of central nervous system malformations

Patients suffering from hydrocephalus alone or in combination with spinal defect were investigated in this retrospective study. The cases were grouped to those who did not have any treatment to relieve the symptoms of hydrocephalus and to those who receive certain palliative therapy. Comparisons were made between the groups regarding the life-span and the incidence of secondary complications. The life-span showed a close agreement within the groups, but the occurrence and the severity of secondary complications were found to be less in the treated group. While the reasons are acceptable which are given to select the patients for the initial closure of the spinal defect there seems to be no justification in with-holding palliative surgery for the treatment of hydrocephalus.