The convergence of regenerative medicine and rehabilitation: federal perspectives

Regenerative rehabilitation is the synergistic integration of principles and approaches from the regenerative medicine and rehabilitation fields, with the goal of optimizing form and function as well as patient independence. Regenerative medicine approaches for repairing or replacing damaged tissue or whole organs vary from utilizing cells (e.g., stem cells), to biologics (e.g., growth factors), to approaches using biomaterials and scaffolds, to any combination of these. While regenerative medicine offers tremendous clinical promise, regenerative rehabilitation offers the opportunity to positively influence regenerative medicine by inclusion of principles from rehabilitation sciences. Regenerative medicine by itself may not be sufficient to ensure successful translation into improving the function of those in the most need. Conversely, with a better understanding of regenerative medicine principals, rehabilitation researchers can better tailor rehabilitation efforts to accommodate and maximize the potential of regenerative approaches. Regenerative rehabilitative strategies can include activity-mediated plasticity, exercise dosing, electrical stimulation, and nutritional enhancers. Critical barriers in translating regenerative medicine techniques into humans may be difficult to overcome if preclinical studies do not consider outcomes that typically fall in the rehabilitation research domain, such as function, range of motion, sensation, and pain. The authors believe that encouraging clinicians and researchers from multiple disciplines to work collaboratively and synergistically will maximize restoration of function and quality of life for disabled and/or injured patients, including U.S. Veterans and Military Service Members (MSMs). Federal Government agencies have been investing in research and clinical care efforts focused on regenerative medicine (NIH, NSF, VA, and DoD), rehabilitation sciences (VA, NIH, NSF, DoD) and, more recently, regenerative rehabilitation (NIH and VA). As science advances and technology matures, researchers need to consider the integrative approach of regenerative rehabilitation to maximize the outcome to fully restore the function of patients.

Metastatic endometrial cancer of the paranasal sinuses

Endometrial carcinoma is the fourth most common cancer affecting women in the UK. Its most frequent sites of spread are to the pelvic and para-aortic lymph nodes, vagina and peritoneum. We report a case of a 63-year-old woman with known endometrial cancer who presented with left facial swelling and eye displacement. Investigations revealed an expansile soft-tissue density mass arising within the bone, centred on the left zygoma, with exophytic extension into the left maxillary antrum, infratemporal fossa and inferiorly into the orbit. Endoscopic biopsies were taken and histology confirmed metastatic deposits of endometrial cancer. Clinicians should be aware that distant spread of endometrial cancer is linked with advanced disseminated disease and palliative treatments should be considered.

Medication appropriateness tool for co-morbid health conditions in dementia: consensus recommendations from a multidisciplinary expert panel

Background

Medication management for people living with dementia is a complex task as it is unclear what constitutes optimal medication management in this population due to the shifting focus of health priorities and the balance between the benefits and harms of medications.

Aim

This study sought expert opinion to create a consensus list to define appropriate medication management of co‐morbidities for people with dementia.

Methods

This study used the Delphi technique. We invited multidisciplinary experts in geriatric therapeutics including pharmacists, doctors, nurse practitioners, a patient advocate and a psychologist to participate. Participants were asked to engage into three or more rounds of questioning. Round 1 was a questionnaire comprised of one question defining dementia and seven open‐ended questions about appropriate management of co‐morbidities in people with dementia. Two investigators qualitatively analysed the responses to questions from Round 1 using thematic analysis. The results of this analysis were provided to participants as statements in the Round 2 survey. The participants were asked to rate their agreement with each statement on a 5‐point Likert scale. The median and interquartile range (IQR) were calculated for the responses to each statement. Consensus was pre‐specified as an IQR less than or equal to 1. Statements where consensus was not achieved were presented to participants in Round 3. The Round 2 median and IQR values were provided and participants were again asked to rate their agreement with each statement on a 5‐point Likert scale. The statements where participants agreed or strongly agreed were included in the Medication Appropriateness Tool for Co‐morbid Health conditions in Dementia criteria.

Results

Fifty‐seven experts agreed to participate in the study, of whom 58% were pharmacists and 36% were medical practitioners. Fifty‐five participants completed the Round 1 (95% response rate). A total of 128 statements was included in the Round 2 survey. Consensus was reached on 93 statements in Round 2 (n = 48 responders, 84% response rate) and on 18 statements in Round 3 (n = 43 responders, 75% response rate). The participants reached consensus on 111 of 128 statements. Of these statements, 67 statements were included in the Medication Appropriateness Tool for Co‐morbid Health conditions in Dementia criteria. The statements were in the broad themes of preventative medication, symptom management, disease progression, psychoactive medication, treatment goals, principles of medication use, side‐effects and medication reviews.

Discussion

This research provides consensus‐based guidance for clinicians who manage co‐morbid health conditions in people with dementia.

Simultaneous magnetically directed drug convection and MR imaging

Superparamagnetic iron oxide nanoparticles (IO NPs) are of interest for their usefulness in biomedical applications. In this work, we have synthesized iron oxide nanocomposites surface-modified with different biocompatible polymers. Bovine serum albumin (BSA) was physisorbed onto these IO NPs along with an excipient during freeze-drying. The mass transport of the protein attached to the iron oxide core-shell nanoparticles (IO cs-NPs) under a gradient magnetic field of an MRI instrument was observed in vitro and in an egg as a model system for a biological fluid. From the in vitro experiments in agarose gels, it was observed that the protein gets separated from the core during mass transport for some cs-IO, but co-migration was observed for PEG-modified IO cs-NPs. These experiments demonstrated proof-of-concept for the use of IO cs-NPs in magnetically directed drug convection.

SPECIES-SPECIFIC SEQUENCE VARIATION OF PORCINE ISLET AMYLOID POLYPEPTIDE REDUCES ITS AMYLOIDOGENICITY AND MAY CONTRIBUTE TO IMPROVED FUNCTION AND SURVIVAL OF PIG ISLET XENOGRAFTS

Introduction: Long-term success of human islet transplants has been limited. Beta cell mass and function in transplanted islets progressively decline over time, resembling the progressive loss of insulin secretion in type2 diabetes. Transplanted islets, like those in type 2 diabetes, are subject to apoptotic beta cell death and the formation of toxic aggregates of the betacell peptide islet amyloid polypeptide (IAPP). Interestingly, porcine islets consistently maintain long-term normoglycemia when transplanted into immune-deficient, diabetic mice. We hypothesized that transplanted pig islets may not be subject to amyloid formation and amyloid-induced cell death, and that this may contribute to the success of porcine islet grafts. Methods & Results: Sequencing of porcine IAPP (pIAPP) from neonatal pig islet (NPI)-extracted RNA confirmed notabledifferences from human IAPP (hIAPP), including a proline substitution within the known amyloidogenic region and a glutamine-for-lysine at the N-terminalcleavage site of porcine proIAPP. Fibril formation was assessed by electron miscroscopy (EM) and Thioflavin T fluorescence. While synthetic hIAPP fibrillized within minutes, pIAPP required 6 weeks to form fibrils detectableby EM. Small peptide fragments of pIAPP failed to aggregate. By Thioflavin T fluorescence assay, hIAPP (40 µM) had an average lag time of 1 h and a 1,000-fold increase in fluorescence by 2 h while pIAPP showed little increase in fluorescence after 20 h. Small peptide fragments of pIAPP also failed to aggregate. hIAPP was significantly more toxic to INS-1 cells than pIAPP (20-200 µM), asassessed by TUNEL (16 h) and Alamar blue (24 h). We also failed to detect amyloid in any (0/9) NPI transplanted into streptozotocin diabetic murine recipients, while human islets had extensive amyloid deposition by 8 weeks post-transplant, associated with graft failure. Conclusion: Porcine IAPP, unlike human IAPP, is only weakly amyloidogenic and cytotoxic. We speculate that decreased fibrillogenicity of porcine compared to human IAPP may underlie the apparent enhanced survival andfunction of pig islet xenografts. KJP is supported by aChild & Family – Rx & D & CIHR – UBC MD PhD Studentship and a MichaelSmith Foundation for Health Research Junior Trainee Award.

Heparin induces amyloid formation in cultured human isletss

Background: Pancreatic islet transplantation offers improved glycemic control in type 1 diabetic patients above standard insulin therapy, ideally minimizing macro- and microvascular complications of diabetes mellitus. However success is limited thus far, with fewer than 10% of patients retaining insulin independence at two years post-transplantation. In addition to immune rejection, many non-immune factors may promote long-term graft secretory dysfunction and loss of viable graft mass. One such important non-immune factor may be the formation of islet amyloid, a pathologic lesion of the islet in type 2 diabetes that contributes to the progressive loss of b cells in that disease and that has been shown to form rapidly in human islets transplanted into NOD.scid mice. Amyloid deposits are composed primarily of the b cell secretory product islet amyloid polypeptide (IAPP), are cytotoxic, and develop in environments in which b cells are stressed. Heparin sulfate is used as an anti-coagulant in clinical islet transplantation and to prevent the instant blood-mediated inflammatory reaction (IBMIR), which occurs upon contact between islets and blood and may destroy a substantial proportion of the grafted islet mass. However, heparin is also known to stimulate amyloid fibril formation. Methods: To determine whether heparin may enhance amyloid formation in human islets and contribute to graft failure, we cultured isolated human islets in the presence or absence of heparin sulfate (42 and 420 units/ml) for 2 weeks in 11.1 mM glucose. Results: Histological assessment of sections of cultured islets for the presence of amyloid (by thioflavin S staining) revealed a marked, concentration-dependent increase in amyloid deposition following culture in the presence of heparin. Quantitative analysis of these sections showed that the proportion of islet area comprised of amyloid was increased approximately 2-fold (0.15%±0.12% vs 0.46%±0.15% of islet area) following culture in 42 units/ml heparin, and the proportion of islets in which amyloid was detectable (amyloid prevalence) was also increased (35%±24% vs 68%±10% of islets). At 420 units/ml heparin, the amyloid area was even greater (0.23%±0.15% vs 0.97%±0.42% of islet area) as was the amyloid prevalence (53%±29% vs 81%±14% of islets). To affirm that heparin can stimulate IAPP fibrillogenesis and enhance IAPP toxicity, we incubated synthetic human IAPP in the presence of heparin and measured amyloid formation in real time by thioflavin T fluorescence, and cell toxicity by Alamar blue viability assay in transformed rat (INS-1) ß-cell cultures. Heparin stimulated IAPP fibril formation and increased death of INS-1 cells exposed to IAPP (78.2%±10.9% vs 51.8%±12.2% of control viability), suggesting that heparin stimulates IAPP aggregation and toxicity. Remarkably, preliminary assessment of human islets cultured in heparin did not show increased islet cell death by TUNEL staining or loss of insulin immunostaining. Conclusion: In summary, heparin increases amyloid formation in cultured human islets. Although our preliminary data does not suggest that heparin-induced amyloid formation contributes to islet cell death, we speculate that heparin-induced amyloid formation may contribute to graft dysfunction and that caution should be used in the clinical application of this drug in islet transplantation.

Design and assessment of a tissue-engineered model of human phalanges and a small joint

OBJECTIVES

To develop models of human phalanges and small joints by suturing different cell-polymer constructs that are then implanted in athymic (nude) mice.

DESIGN

Models consisted of bovine periosteum, cartilage, and/or tendon cells seeded onto biodegradable polymer scaffolds of either polyglycolic acid (PGA) or copolymers of PGA and poly-L-lactic acid (PLLA) or poly-epsilon-caprolactone (PCL) and PLLA. Constructs were fabricated to produce a distal phalanx, middle phalanx, or distal interphalangeal joint.

SETTING AND SAMPLE POPULATION

Studies of more than 250 harvested implants were conducted at the Northeastern Ohio Universities College of Medicine.

EXPERIMENTAL VARIABLE

Polymer scaffold, cell type, and implantation time were examined.

OUTCOME MEASURE

Tissue-engineered specimens were characterized by histology, transmission electron microscopy, in situ hybridization, laser capture microdissection and qualitative and quantitative polymerase chain reaction analysis, magnetic resonance microscopy, and X-ray microtomography.

RESULTS

Over periods to 60 weeks of implantation, constructs developed through vascularity from host mice; formed new cartilage, bone, and/or tendon; expressed characteristic genes of bovine origin, including type I, II and X collagen, osteopontin, aggrecan, biglycan, and bone sialoprotein; secreted corresponding proteins; responded to applied mechanical stimuli; and maintained shapes of human phalanges with small joints.

CONCLUSION

Results give insight into construct processes of tissue regeneration and development and suggest more complete tissue-engineered cartilage, bone, and tendon models. These should have significant future scientific and clinical applications in medicine, including their use in plastic surgery, orthopaedics, craniofacial reconstruction, and teratology.

Radiosurgery planning supported by the GEMSS grid

GEMSS (Grid Enabled Medical Simulation Services IST-2001-37153) is an EU project funded to provide a test bed for Grid-enabled health applications. Its purpose is evaluation of Grid computing in the health sector. The health context imposes particular constraints on Grid infrastructure design, and it is this that has driven the feature set of the middleware. In addition to security, the time critical nature of health applications is accommodated by a Quality of Service component, and support for a well defined business model is also included. This paper documents experience of a GEMSS compliant radiosurgery application running within the Medical Physics department at the Royal Hallamshire Hospital in the UK. An outline of the Grid-enabled RAPT radiosurgery application is presented and preliminary experience of its use in the hospital environment is reported. The performance of the software is compared against GammaPlan (an industry standard) and advantages/disadvantages are highlighted. The RAPT software relies on features of the GEMSS middleware that are integral to the success of this application, and together they provide a glimpse of an enabling technology that can impact upon patient management in the 21st century.

Is ‘virtual histology’ the next step after the ‘virtual autopsy’? Magnetic resonance microscopy in forensic medicine

AIM

The study aimed to validate magnetic resonance microscopy (MRM) studies of forensic tissue specimens (skin samples with electric injury patterns) against the results from routine histology.

METHODS AND RESULTS

Computed tomography and magnetic resonance imaging are fast becoming important tools in clinical and forensic pathology. This study is the first forensic application of MRM to the analysis of electric injury patterns in human skin. Three-dimensional high-resolution MRM images of fixed skin specimens provided a complete 3D view of the damaged tissues at the site of an electric injury as well as in neighboring tissues, consistent with histologic findings. The image intensity of the dermal layer in T2-weighted MRM images was reduced in the central zone due to carbonization or coagulation necrosis and increased in the intermediate zone because of dermal edema. A subjacent blood vessel with an intravascular occlusion supports the hypothesis that current traveled through the vascular system before arcing to ground.

CONCLUSION

High-resolution imaging offers a noninvasive alternative to conventional histology in forensic wound analysis and can be used to perform 3D virtual histology.

Pictorial review: MRI of chronic spinal cord injury

Patients who have suffered a spinal cord injury and who demonstrate new or changing clinical features such as increasing myelopathy, ascending neurological level, pain or increasing muscle spasms may have developed a late complication such as post-traumatic syrinx. MRI is the investigation of choice for assessment of chronic spinal cord injury. The aim of this pictorial review is to illustrate the various late appearances of the injured spinal cord.

Cartilage calcification studied by proton nuclear magnetic resonance microscopy

A three-dimensional (3D) mineralizing culture system using hollow fiber bioreactors has been developed to study the early stages of endochondral ossification by proton nuclear magnetic resonance (NMR) microscopy. Chondrocytes harvested from the cephalic half of the sterna from 17-day-old chick embryos were terminally differentiated with 33 nM of retinoic acid for 1 week and mineralization was initiated by the addition of 1% beta-glycerophosphate to the culture medium. Histological sections taken after 6 weeks of development in culture confirmed calcification of the cartilage matrix formed in bioreactors. Calcium to phosphorus ratios (1.62-1.68) from X-ray microanalysis supported electron diffraction of thin tissue sections showing the presence of a poorly crystalline hydroxyapatite mineral phase in the cultures. After 4 weeks of culture, quantitative proton NMR images showed water proton magnetization transfer rate constants (km) were higher in premineralized cartilage compared with uncalcified cartilage, a result suggesting collagen enrichment of the matrix. Notably after 5 weeks mineral deposits formed in bioreactors principally in the collagen-enriched zones of the cartilage with increased km values. This caused marked reductions in water proton longitudinal (T1) and transverse (T2) relaxation times and water diffusion coefficients (D). These results support the hypothesis that mineralization proceeds in association with a collagen template. After 6 weeks of culture development, the water proton T2 values decreased by 13% and D increased by 7% in uncalcified areas, compared with the same regions of tissue examined 1 week earlier. These changes could be attributed to the formation of small mineral inclusions in the cartilage, possibly mediated by matrix vesicles, which may play an important role in cartilage calcification. In summary, NMR images acquired before and after the onset of mineralization of the same tissue provide unique insights into the matrix events leading to endochondral mineral formation.

Histomorphometry of the embryonic avian growth plate by proton nuclear magnetic resonance microscopy

Quantitative nuclear magnetic resonance (NMR) microscopy was used to characterize the biochemical and morphological properties of the different zones within the growth plate of an embryonic chick femur. For precalcified tissue, water proton transverse relaxation times (T2) and magnetization transfer values (MT) were directly and inversely dependent, respectively, on tissue cellularity, defined as the intracellular area per unit area on histological sections. T2 values extrapolated for intra- and extracellular water were 96 ms and 46 ms, respectively. The extracellular T2 was comparable with that measured for mature cartilage. The MT values extrapolated for intra- and extracellular compartments were 0.32 and 0.85, respectively. These values were comparable with those values reported in the literature for cell pellets and for mature cartilage tissue. Thus, cellularity dominated the NMR properties of this immature cartilage tissue. Mineral deposits within calcified cartilage and periosteal bone invoked NMR relaxation processes that were dependent on the inorganic mineral phase. Additionally, collagen molecules present in mineralized zones gave rise to a significant MT effect. These results show the utility of water proton NMR microscopy for assessing both the organic and inorganic phases within mineralized tissues.

Imaging of collagen and proteoglycan in cartilage sections using Fourier transform infrared spectral imaging

OBJECTIVE

To test the hypothesis that Fourier transform infrared (FTIR) spectral imaging, coupled with multivariate data processing techniques, can image the spatial distribution of matrix constituents in native and engineered cartilage samples.

METHODS

Tissue sections from native and trypsin-digested bovine nasal cartilage (BNC) and from engineered cartilage, generated by chick sternal chondrocytes grown in a hollow fiber bioreactor, were placed either on calcium fluoride windows for FTIR analysis or gelatinized microscope slides for histologic analysis. Based on the assumption that cartilage is predominantly chondroitin sulfate (CS) and type II collagen, chemical images were extracted from FTIR spectral imaging data sets using 2 multivariate methods: the Euclidean distance algorithm and a least-squares approach.

RESULTS

Least-squares analysis of the FTIR data of native BNC yielded a collagen content of 54 +/- 13% and a CS content of 37 +/- 16% (mean +/- SD). Euclidean distance analysis of measurements made on trypsin-digested BNC demonstrated only trace amounts of CS. For engineered cartilage, the CS content was significantly lower (15 +/- 5%), while the collagen content (73 +/- 6%) was significantly higher than biochemically determined values (CS 34%, collagen 5%, protein 61%). These differences are due to the fact that the dimethylmethylene blue assay overestimated the CS content of the tissue because it is not specific for CS, while the FTIR spectral imaging technique overestimated the collagen content because it lacks specificity for different proteins.

CONCLUSION

FTIR spectral imaging combines histology-like spatial localization with the quantitative capability of bulk chemical analysis. For molecules with a unique spectral signature, such as CS, the FTIR technique coupled with multivariate analysis can define a unique spatial distribution. However, for some applications, the lack of specificity of this technique for different types of proteins may be a limitation.

The mental and physical health of female sex workers: a comparative study

OBJECTIVES

The objective of this study was to compare the mental and physical health, adult abuse experiences and social networks of female sex workers with data previously collected from two large community samples of age-matched women.

METHOD

A convenience sample of sex workers were interviewed and completed two well-established questionnaires, the General Health Questionnaire (GHQ-28) and the Intimate Bond Measure (IBM). Sex workers were invited to reflect on their experiences of their work.

RESULTS

There were no differences in mental health on the GHQ-28 or in self-esteem (measured by an item on the Present State Examination) between the two groups. Neither were there any differences in their assessment of their physical health or the quality of their social networks. Sex workers were less likely to be married and had been exposed to more adult physical and sexual abuse than the comparison group. They were more likely to smoke and to drink heavily when they drank. One-third said that their general practitioner was not aware of their work. A subgroup not working with regular clients or in a massage parlour had higher GHQ-28 scores and may be an at-risk group. Narrative information about the work, particularly its intermittent nature, is presented.

CONCLUSIONS

No evidence was found that sex work and increased adult psychiatric morbidity are inevitably associated, although there may be subgroups of workers with particular problems. The illegal and stigmatized nature of sex work are likely to make usual public health strategies more difficult to apply, considerations which should give concern from a preventive health standpoint.

Response of engineered cartilage tissue to biochemical agents as studied by proton magnetic resonance microscopy

OBJECTIVE

To test the hypothesis that magnetic resonance imaging (MRI) results correlate with the biochemical composition of cartilage matrix and can therefore be used to evaluate natural tissue development and the effects of biologic interventions.

METHODS

Chondrocytes harvested from day-16 chick embryo sterna were inoculated into an MRI-compatible hollow-fiber bioreactor. The tissue that formed over a period of 2-4 weeks was studied biochemically, histologically, and with MRI. Besides natural development, the response of the tissue to administration of retinoic acid, interleukin-1beta (IL-1beta), and daily dosing with ascorbic acid was studied.

RESULTS

Tissue wet and dry weight, glycosaminoglycan (GAG) content, and collagen content all increased with development time, while tissue hydration decreased. The administration of retinoic acid resulted in a significant reduction in tissue wet weight, proteoglycan content, and cell number and an increase in hydration as compared with controls. Daily dosing with ascorbic acid increased tissue collagen content significantly compared with controls, while the administration of IL-1beta resulted in increased proteoglycan content. The water proton longitudinal and transverse relaxation rates correlated well with GAG and collagen concentrations of the matrix as well as with tissue hydration. In contrast, the magnetization transfer value for the tissue correlated only with total collagen. Finally, the self-diffusion coefficient of water correlated with tissue hydration.

CONCLUSION

Parameters derived from MR images obtained noninvasively can be used to quantitatively assess the composition of cartilage tissue generated in a bioreactor. We conclude that MRI is a promising modality for the assessment of certain biochemical properties of cartilage in a wide variety of settings.

Evaluation of potential sources of bias in a genetic epidemiologic study of breast cancer

Systematic errors, or bias, can arise at several stages of a study, including selection of subjects, measurement of exposure and disease, and data analysis. Little attention appears to have been paid to potential sources of bias in genetic epidemiologic studies, despite the fact that the study of units (families) and members (relatives) within those units produces unique opportunities for bias to be introduced. The ability to evaluate whether selection bias has occurred is rare. In 1944, a case-control family study of breast cancer was initiated at the Dight Institute for Human Genetics at the University of Minnesota. A follow-up study of these 544 families is currently being conducted on sisters, daughters, nieces, and granddaughters of the probands, and a control group of women who are spouses of male first- and second-degree relatives. Updated data are collected on females who are 18 years or older through telephone interviews and questionnaires. The availability of detailed family history information on these families at baseline provided an opportunity to evaluate several potential sources of bias. Analyses were performed to determine if families lost to follow-up differed from those who were successfully located or excluded (ineligible), and whether participation rates within a family differed by relationship to proband, age, and family history of cancer. The latter participation rates for individuals were examined with respect to a telephone interview, a mailed questionnaire, and screening mammography. There were no statistically significant differences in the cancer histories of families that were excluded, those that were lost to follow-up, and those that participated. Within families, degree of relationship to the breast cancer proband was significantly associated with age-adjusted participation rates on mailed questionnaires (P < 0.005) and mammography (P < 0.005), but not telephone interviews (P = 0.29). After adjustment for age, marry-ins with a family history of breast cancer were not significantly more likely than marry-ins without a family history to undergo mammography (P = 0.11) or return mailed questionnaires (P = 0.74). Although non-participation is a potentially serious source of bias to a genetic epidemiologic study and the effect of variable participation rates should be explored when investigating the genetic component of a disease, it does not appear to be a problem for this particular study.

Early developmental experiences of female sex workers: a comparative study

OBJECTIVE

The aim of this paper is to explore the early family environment of a sample of female sex workers and compare the findings with a large community data set of similarly aged women.

METHOD

Sex workers recruited by a snowball method were given a semi-structured interview, which included the Parental Bonding Instrument. These results were compared to those from the Otago Women's Child Sexual Abuse (OWCSA) study.

RESULTS

The sex workers' families were of lower socioeconomic status and had experienced more parental separation than had the OWCSA families. The mothers of sex workers were more frequently the family's main wage earner. Sex workers described both parents as less caring than did the OWCSA women. They were significantly more likely than the OWCSA women to report childhood sexual abuse. The sex workers were more likely to have left home early, to have become pregnant before the age of 19 years and to not have completed tertiary study.

CONCLUSIONS

The sex workers studied came from families with more interpersonal difficulties during childhood and adolescence than did a control community sample of similarly aged women. The relevance and generalisability of this conclusion to the wider sex worker population is difficult to determine, given the non-random selection of this sex worker sample.

Vascular surgical society of great britain and ireland: review of out-of-hours vascular procedures in a tertiary vascular unit

BACKGROUND: The aim of this study was to review out-of-hours vascular procedures in a tertiary vascular unit. METHODS: The vascular emergencies that presented outside normal working hours (17. 00 to 08.00 hours) in a vascular unit between January and June 1998 were reviewed. Only cases considered to be life or limb threatening and requiring urgent surgical or radiological intervention were assessed. RESULTS: The Table shows that a significant number of vascular emergencies was performed out of hours in one unit. This was, in part, due to an increase in the number of tertiary referrals, which represented 57 per cent of all emergency procedures. Reasons for the tertiary referrals were: no consultant vascular surgeon on call (33 per cent), no consultant interventional radiologist on call (26 per cent), lack of intensive care beds (30 per cent) and complex procedure (11 per cent). The overall mortality rate of patients referred in this period was 15 per cent. The unit has three consultant vascular surgeons, two consultant interventional radio- logists and one vascular specialist registrar. CONCLUSION: The significant increase in out-of-hours vascular emergencies, both surgical and radiological, has placed an enormous demand on senior members of the team. In addition, it has had a significant impact on the unit's elective admissions and waiting lists, in particular those for routine general surgery. To support the growth in complex emergency referrals, senior vascular fellows in both vascular surgery and radiology have been appointed and proposals are underway to restructure local vascular services.

Cartilage formation in a hollow fiber bioreactor studied by proton magnetic resonance microscopy

The ideal in vitro system for investigating the regulation of cartilage formation and maintenance would allow for three-dimensional tissue growth, a wide range of biochemical interventions, and non-destructive evaluation. We have developed a hollow fiber bioreactor (HFBR) system which meets these criteria. After injection with embryonic chick sternal chondrocytes, neocartilage is elaborated around the hollow fibers, reaching a thickness of up to a millimeter after four weeks of growth. This process was monitored over time with nuclear magnetic resonance (NMR) microimaging and correlative biochemical and histologic analyses. Tissue volume and cellularity increased greatly during development. This was accompanied by changes in magnetic resonance properties consistent with increased macromolecular content. Further, tissue heterogeneity, observed as regional variations in cell size in histologic sections, was also observed in quantitative NMR images.

Cutaneous mast cell tumors in cats: 32 cases (1991-1994)

Case records of 32 cats with cutaneous mast cell tumors (CMCTs) were reviewed. Using the Patnaik system for grading canine mast cell tumors, the relationships between histopathological grade and patient survival time and tumor recurrence were examined. Tumor histopathological grade had no prognostic significance. One-, two-, and three-year tumor recurrence rates following surgical excision were 16%, 19%, and 13%, respectively. Incomplete excision was not associated with a higher rate of tumor recurrence.

Mycosis fungoides in a horse

A 17-year-old Quarter Horse mare was examined to determine the cause of a vulvar mass. Differential diagnoses for the swollen, ulcerated tissue included hypersensitivity reaction to insect stings or bites and cutaneous neoplasia. During the next 4 months, the mass enlarged involving the skin of the perineum and ventral aspect of the abdomen with secondary dependent edema of both hind limbs. Histologic examination of biopsy and necropsy specimens revealed changes consistent with a diagnosis of mycosis fungoides (cutaneous T-cell lymphoma). Diagnostic features included invasion of neoplastic lymphocytes into the epidermis and detection of T-cell lineage of neoplastic cells. Location of lesions at a mucocutaneous junction, association with epidermal ulcers, and progressive skin involvement mimic the condition in human beings and other species. Prognosis is poor when the condition is at the tumor stage (invasion of deep tissues).

Somatic hypermutation introduces insertions and deletions into immunoglobulin V genes

During a germinal center reaction, random mutations are introduced into immunoglobulin V genes to increase the affinity of antibody molecules and to further diversify the B cell repertoire. Antigen-directed selection of B cell clones that generate high affinity surface Ig results in the affinity maturation of the antibody response. The mutations of Ig genes are typically basepair substitutions, although DNA insertions and deletions have been reported to occur at a low frequency. In this study, we describe five insertion and four deletion events in otherwise somatically mutated VH gene cDNA molecules. Two of these insertions and all four deletions were obtained through the sequencing of 395 cDNA clones (approximately 110,000 nucleotides) from CD38+IgD- germinal center, and CD38-IgD- memory B cell populations from a single human tonsil. No germline genes that could have encoded these six cDNA clones were found after an extensive characterization of the genomic VH4 repertoire of the tonsil donor. These six insertions or deletions and three additional insertion events isolated from other sources occurred as triplets or multiples thereof, leaving the transcripts in frame. Additionally, 8 of 9 of these events occurred in the CDR1 or CDR2, following a pattern consistent with selection, and making it unlikely that these events were artifacts of the experimental system. The lack of similar instances in unmutated IgD+CD38- follicular mantle cDNA clones statistically associates these events to the somatic hypermutation process (P = 0.014). Close scrutiny of the 9 insertion/deletion events reported here, and of 25 additional insertions or deletions collected from the literature, suggest that secondary structural elements in the DNA sequences capable of producing loop intermediates may be a prerequisite in most instances. Furthermore, these events most frequently involve sequence motifs resembling known intrinsic hotspots of somatic hypermutation. These insertion/deletion events are consistent with models of somatic hypermutation involving an unstable polymerase enzyme complex lacking proofreading capabilities, and suggest a downregulation or alteration of DNA repair at the V locus during the hypermutation process.

Magnetic resonance microscopy studies of cation diffusion in cartilage

The diffusion of copper ions in bovine nasal cartilage (BNC), a dense connective tissue, was investigated to further the understanding of ion transport in charged biopolymer systems. Using an inversion-recovery null-point imaging technique, it was found that the diffusion rate of divalent copper ions into cartilage was significantly lower in normal BNC than in BNC in which the matrix fixed charges had been reduced by enzymatic digestion or acid neutralization. In normal cartilage, counterion diffusion was not well described by a simple Fickian process, likely owing to the high charge density of the constituent molecules. In contrast, in both digested and acid neutralized BNC, counterion diffusion appeared Fickian. Features of the ion transport process were modeled using a diffusion equation which included a linear sorption term to account for cation binding. The diffusion coefficient of copper in cartilage increased with decreasing matrix fixed charge and was constant for reservoir concentrations up to 30 mM. The activation energy for the diffusion of copper into BNC was determined to be 34.5 kJ/mol.

Assay for bacteria in porous media by diffusion-weighted NMR

In this work, an NMR technique capable of detecting bacterial cells and measuring the cell density in suspension and in porous media has been developed. It is based on the pulsed-field-gradient technique and relies on the fact that extracellular water diffuses freely while intracellular water is completely restricted by the relatively impermeable cell wall of the bacterium. At high wave vectors, the signal from extracellular water is completely suppressed while the signal from intracellular water is comparatively unaffected. This technique has been applied to the mapping of bacterial distributions in porous media. This method is presented as a non-destructive, real-time technique for biomass characterization within laboratory column and flow cell experiments, and possibly for monitoring in situ bioremediation.

Ion transport studies in calcium alginate gels by magnetic resonance microscopy

Polyelectrolyte biopolymers such as calcium alginate are becoming increasingly important for the recovery of heavy metals from aqueous solutions. To understand the mechanism of ion transport in these biopolymer systems, the transport of copper ions into calcium alginate gels was investigated using proton nuclear magnetic resonance (NMR) microscopy. Copper ion transport was imaged using an inversion recovery technique which utilizes the paramagnetic effect of copper on water proton relaxation times. Diffusion experiments were performed in a diffusion cell designed to approximate a semi-infinite slab geometry at temperatures between 278 and 313 K using copper reservoir concentrations between 10 and 60 mM. The diffusion coefficient of copper in these gels was calculated from the NMR data to fit a combined diffusion-reaction model involving a diffusion term (D) and a kinetic binding term (k). At 23 degrees C, the diffusion coefficients in 1, 2, and 3% (w/v) gels were 3.1 x 10(10), 2.0 x 10(10), and 1.4 x 10(10) m2/s, respectively. The activation energy for diffusion in the 2% (w/v) gel was 28 kJ/mol.

Magnetic resonance imaging (MRI) of calcium alginate gels

The spatial heterogeneity of calcium alginate gels has been visualised by the variation of image intensity across the gel by one-, two-, and three-dimensional MRI. From the linear dependence of (T2)-1 on alginate concentration it is now possible to use MRI to map alginate concentration gradients within calcium alginate gels noninvasively. Since the concentration of alginate determines the pore size of the gel matrix, those alginate concentration maps will be useful in determining the pore size distribution within the gel, which is important in controlled release applications.

Clinical and pathologic features of endometrial hyperplasia, pyometra, and endometritis in cats: 79 cases (1980-1985)

Records of 79 cats determined to have endometrial hyperplasia (EH) with or without pyometra or endometritis were studied. Forty-eight cats (61%) were spayed or died because of complications relating to reproductive tract disease. All other cats were free of clinical signs of disease, and lesions were found incidentally during routine ovariohysterectomy or at necropsy. Prevalence of uterine lesions was greater in cats greater than or equal to 5 years old. Breeding, age at first breeding, and queening could not be correlated with clinical or pathologic signs of disease. Seventy-one percent (34/48) of cats with clinical signs referable to the reproductive tract had histologic evidence of pyometra or endometritis, whereas only 19% (6/31) of cats without clinical signs had histologic evidence of either disease. Only 23% (9/39) of cats without pyometra or endometritis had corpora lutea (CL) in at least one ovary, whereas 40% (16/40) of cats with either pyometra or endometritis had CL. We concluded that the prevalence of EH in cats increases with age in sexually intact female cats, and that most cases of pyometra or endometritis, but not EH, in cats are associated with retained CL.

A review of eosinophil chemotaxis and function in Taenia taeniaeformis infections in the laboratory rat

The eosinophil has long been associated with diseases of acute hypersensitivity and with parasite infections, but its exact role in the pathogenesis of these conditions remains uncertain. Characterization of factors associated with migration of eosinophils into tissues has helped to elucidate eosinophil function. Eosinophil chemotactic factors associated with acute hypersensitivity reactions include the eosinophil chemotactic factors of anaphylaxis, histamine, and arachidonic acid metabolites, all of which are released from mast cells, and the lymphokine eosinophil stimulation promoter (ESP). Eosinophilotaxins associated with parasitic diseases include the lymphokine ESP and the low molecular weight factor ECF-G, both associated with schistosome infection in mice. In addition, in several parasite infections parasite-derived protein eosinophil chemotactic factors have been identified and characterized. The proteins associated with Ascaris, Anisakis, and Schistosoma infections appear to be distinct from one another. We have recently partially characterized a protein from Taenia taeniaeformis larvae which has marked chemotactic activity for eosinophils. In addition we have demonstrated eosinophil chemotactic activity associated with metabolism of arachidonic acid by T. taeniaeformis metacestodes. The results of studies in taeniasis and other parasite infections, therefore, indicate that parasite-derived factors may directly influence migration of eosinophils.

Cholangiocarcinoma in a yellow-faced Amazon parrot (Amazona xanthops)

A cholangiocarcinoma in a 3 1/2-year-old yellow-faced Amazon parrot (Amazona xanthops) is reported. The parrot presented with a prolapsed cloaca and died after a 6-week clinical course of progressive weight loss. The tumor replaced much of the normal hepatic architecture but apparently did not metastasize. Cholangiocarcinomas have been reported rarely in several species of domestic and captive wild birds, but this appears to be the first reported case in a large psitticiform bird.

The adjunct consumer group

Little by little, the community is becoming aware of the Weber Mental Health Center and PAAG. A recent study shows that the community approach leads to high visibility; PAAG activities were known by 37% of 1,000 people recently interviewed. This compares to 5%, 7%, and 15% having knowledge of other more traditional medical centers in Utah. It is felt that this approach is an important part in putting the community mental health center in proper perspective in the community. It is felt that the adjunct consumer group provides almost infinite flexibility to meet human needs. As a result, the Northern Utah Unit of the State Hospital will remain closed, largely because PAAG is serving the community.