57 POTENTIALLY INAPPROPRIATE MEDICATION USE AND MORTALITY IN PATIENTS WITH COGNITIVE IMPAIRMENT

Background

Potentially inappropriate medications (PIMs are associated with falls, hospitalisation, and cognitive decline. Few studies have investigated the association between PIMs related to cognitive impairment (PIMCog) and mortality in dementia or mild cognitive impairment (MCI).

Methods

This was a retrospective observational study. Patients diagnosed with MCI or dementia (DSM-IV criteria) presenting to a tertiary-referral memory clinic from 2013–2019 were eligible. The primary outcome was all-cause death. Secondary outcomes were vascular death and non-vascular death defined according to formal certification. The primary exposure variable of interest was PIMCog, defined as any medication in the Beers 2015 or STOPP criteria, classified as potentially inappropriate for patients with cognitive impairment. Anticholinergic burden was measured using the anticholinergic cognitive burden (ACB) scale. Polypharmacy was defined as ≥5 medications. Cox proportional hazard models were used to calculate hazard ratios (HRs) and 95% confidence intervals (95% CIs).

Results

There were 418 patients included (n = 261 dementia, n = 157 MCI). The median age was 79 (interquartile range {IQR} 74–82) and median follow-up was 809 days (IQR 552–1,571). One or more PIMCog was prescribed in 141 patients (33.4%). PIMCog use was associated with all-cause mortality after adjustment for age, sex, dementia severity, Charlson Co-morbidity Index, chronic obstructive pulmonary disease, congestive cardiac failure, and peripheral vascular disease (HR 1.96, 95% CI 1.24–3.09). PIMCog use was associated with vascular death (HR 3.28, 95% CI 1.51–7.11) but not with non-vascular death (HR 1.40 95% CI: 0.78–2.52). Neither an ACB ≥3 (HR 0.87, 95% CI: 0.46–1.64) or polypharmacy (HR 1.87, 95% CI: 0.67–5.24) were associated with death.

Conclusion

The burden of PIMCog use in patients with cognitive impairment is high. PIMCog use is independently associated with all-cause mortality and vascular death. This is a potential modifiable risk factor for death in patients with neurocognitive disorders. Further research is required to independently validate this finding.

509 POTENTIALLY INAPPROPRIATE MEDICATION USE AND MORTALITY IN PATIENTS WITH COGNITIVE IMPAIRMENT

Introduction

Potentially inappropriate medications (PIMsare associated with falls, hospitalisation, and cognitive decline. Few studies have investigated the association between PIMsrelated to cognitive impairment (PIMCog) and mortality in dementia or mild cognitive impairment (MCI).

Methods

This was a retrospective observational study. Patients diagnosed with MCI or dementia (DSM-IV criteria) presenting to a tertiary-referral memory clinic from 2013–2019 were eligible. The primary outcome was all-cause death. Secondary outcomes were vascular death and non-vascular death defined according to formal certification. The primary exposure variable of interest was PIMCog, defined as any medication in the Beers 2015 or STOPP criteria, classified as potentially inappropriate for patients with cognitive impairment. Anticholinergic burden was measured using the anticholinergic cognitive burden (ACB) scale. Polypharmacy was defined as ≥5 medications. Cox proportional hazard models were used to calculate hazard ratios (HRs) and 95% confidence intervals (95% CIs).

Results

There were 418 patients included (n = 261 dementia, n = 157 MCI). The median age was 79 (interquartile range {IQR} 74–82) and median follow-up was 809 days (IQR 552–1,571). One or more PIMCog was prescribed in 141 patients (33.4%). PIMCog use was associated with all-cause mortality after adjustment for age, sex, dementia severity, Charlson Co-morbidity Index, chronic obstructive pulmonary disease, congestive cardiac failure, and peripheral vascular disease. (HR 1.96, 95% CI 1.24–3.09). PIMCog use was associated with vascular death (HR 3.28, 95% CI 1.51–7.11) but not with non-vascular death (HR 1.40 95% CI: 0.78–2.52). Neither an ACB ≥3 (HR 0.87, 95% CI: 0.46–1.64) or polypharmacy (HR 1.87, 95% CI: 0.67–5.24) were associated with death.

Conclusion

The burden of PIMCog use in patients with cognitive impairment is high. PIMCog use is independently associated with all-cause mortality and vascular death. This is a potential modifiable risk factor for death in patients with neurocognitive disorders. Further research is required to independently validate this finding.

Characterization and applications of auto-locked vacuum-sealed diode lasers for precision metrology

We demonstrate the performance characteristics of a new class of vacuum-sealed, autolocking diode laser systems and their applications to precision metrology. The laser is based on adaptations of a design that uses optical feedback from an interference filter and it includes a vacuum-sealed cavity, an interchangeable base-plate, and an autolocking digital controller. A change of the base-plate allows operation at desired wavelengths in the visible and near infrared spectral range, whereas the autolocking ability allows the laser to be tuned and frequency stabilized with respect to atomic, molecular, and solid-state resonances without human intervention using a variety of control algorithms programmed into the same controller. We characterize the frequency stability of this laser system based on the Allan deviation (ADEV) of the beat note and of the lock signal. We find that the ADEV floor of 2 × 10^-12 and short-term linewidth of ∼200 kHz are strongly influenced by current noise and vacuum sealing. Reducing the current noise and cavity pressure decreases the ADEV floor and increases the averaging time at which the floor occurs, which is a signature of long-term stability. We also show that evacuating the cavity to ∼1 Torr reduces the range of the correction signal of the feedback loop by approximately one order of magnitude, thereby increasing the lock range of the controller. The long-term stability allows the laser to be incorporated into a commercial gravimeter for accurate measurements of gravitational acceleration at the level of a few parts-per-billion, which are comparable to values obtained with an iodine-stabilized He-Ne laser. The autolocking and pattern-matching features of the controller allow the laser to be tuned and stabilized with respect to a temperature tunable transmission spectrum of a fiber-Bragg grating. This capability may be suitable for the development of a differential absorption LIDAR transmitter that can generate data at both on-line and off-line lock points using a single laser.

Protein and chemotherapy profiling of extracellular vesicles harvested from therapeutic induced senescent triple negative breast cancer cells

Triple negative breast cancer (TNBC) is an aggressive subtype with relatively poor clinical outcomes and limited treatment options. Chemotherapy, while killing cancer cells, can result in the generation of highly chemoresistant therapeutic induced senescent (TIS) cells that potentially form stem cell niches resulting in metastases. Intriguingly, senescent cells release significantly more extracellular vesicles (EVs) than non-senescent cells. Our aim was to profile EVs harvested from TIS TNBC cells compared with control cells to identify a potential mechanism by which TIS TNBC cells maintain survival in the face of chemotherapy. TIS was induced and confirmed in Cal51 TNBC cells using the chemotherapeutic paclitaxel (PTX) (Taxol). Mass spectrometry (MS) analysis of EVs harvested from TIS compared with control Cal51 cells was performed using Ingenuity Pathway Analysis and InnateDB programs. We demonstrate that TIS Cal51 cells treated with 75 nM PTX for 7 days became senescent (senescence-associated β-galactosidase (SA-β-Gal) positive, Ki67-negative, increased p21 and p16, G2/M cell cycle arrest) and released significantly more EVs (P=0.0002) and exosomes (P=0.0007) than non-senescent control cells. Moreover, TIS cells displayed an increased expression of the multidrug resistance protein 1/p-glycoprotein. MS analysis demonstrated that EVs derived from senescent Cal51 cells contained 142 proteins with a significant increased fold change compared with control EVs. Key proteins included ATPases, annexins, tubulins, integrins, Rabs and insoluble senescence-associated secretory phenotype (SASP) factors. A fluorescent analogue of PTX (Flutax-2) allowed appreciation of the removal of chemotherapy in EVs from senescent cells. Treatment of TIS cells with the exosome biogenesis inhibitor GW4869 resulted in reduced SA-β-Gal staining (P=0.04). In summary, this study demonstrates that TIS cells release significantly more EVs compared with control cells, containing chemotherapy and key proteins involved in cell proliferation, ATP depletion, apoptosis and the SASP. These findings may partially explain why cancer senescent cells remain viable despite chemotherapeutic challenge.

The Analysis of Phenylbutazone and Its Active Metabolite, Oxyphenbutazone, in Equine Tissues (Muscle, Kidney, and Liver), Urine, and Serum by LC-MS/MS

This study reports the use of two validated LC with tandem MS (MS/MS) methods to study the residue depletion profile of phenylbutazone (PBZ) and its metabolite oxyphenbutazone (OXPBZ) from equine serum, urine, and muscle, kidney, and liver tissues. One LC-MS/MS method, with an LOQ of 1.0 ng/mL for PBZ and 2.0 ng/mL for OXPBZ, was used for the analysis of the two drugs in the biological fluids (equine urine and serum); the other LC-MS/MS method, with an LOQ of 0.5 ng/g for PBZ and OXPBZ, was used for the analysis of the drugs in the equine tissue samples. PBZ was administered intravenously to two horses dosed with 8.8 mg/kg PBZ once daily for 4 days and sacrificed humanely at a slaughter plant 7 days after the last drug administration. Urine, serum, and kidney, liver, and muscle tissues were collected from the two horses and shipped on ice to the laboratory and stored at -20°C until analysis. The concentrations of PBZ and OXPBZ residues in the biological fluid and tissue samples collected at slaughter were measured with the two validated LC-MS/MS methods using deuterated internal standards. The results demonstrate that the validated methods are fit for studying the depletion kinetics of PBZ residues in equine tissues and biological fluids.

Dopamine D(3) receptor deficiency sensitizes mice to iron deficiency-related deficits in motor learning

Iron deficiency is a widespread form of malnutrition and is known to interfere with cognitive performance and development. To elucidate the role of dopamine D3 and iron deficiency (ID) in inducing cognitive deficits, we studied wildtype and D3 knockout mice on normal or iron-deficient diets subjected to a running wheel-based motor skill sequence. Surprisingly, ID alone had no effect on motor learning in this study, whereas combined ID and dopamine D(3) receptor (D3R)-deficiency significantly interfered with the acquisition of motor skills. Reduced D3R function may serve as a predisposing factor towards ID-related effects on motor learning.

MiRNA-29a regulates the expression of numerous proteins and reduces the invasiveness and proliferation of human carcinoma cell lines

In this study we have identified a functional role for miR-29a in cancer cell invasion and proliferation. MiRNA expression profiling of human NSCLC cell lines indicated that miR-29a levels were reduced in more invasive cell lines. Exogenous overexpression of miR-29a in both lung and pancreatic cancer cell lines resulted in a significant reduction in the invasion phenotype, as well as in proliferation. 2D DIGE proteomic profiling of cells transfected with pre-miR-29a or anti-miR-29a resulted in the identification of over 100 differentially regulated proteins. The fold change of protein expression was generally modest--in the range 1.2-1.7-fold. Only 14 were predicted computationally to have miR-29a seed sequences in their 3' UTR region. Subsequent studies using siRNA to knock down several candidate proteins from the 2D DIGE experiment identified RAN (a member of the RAS oncogene family) which significantly reduced the invasive capability of a model lung cancer cell line. We conclude that miR-29a has a significant anti-invasive and anti-proliferative effect on lung cancer cells in vitro and functions as an anti-oncomir. This function is likely mediated through the post-transcriptional fine tuning of the cellular levels of several proteins, both directly and indirectly, and in particular we provide some evidence that RAN represents one of these.

Equine protozoal myeloencephalitis caused by Neospora hughesi in an adult horse in Saskatchewan

A protozoal parasite identified as Neospora hughesi was found in inflammatory lesions in the central nervous system of a Canadian-born adult horse presented with neurological signs. This is believed to be the first case of equine protozoal myeloencephalitis (EPM) caused by Neospora hughesi in a horse outside of the United States.

Purification and identification of a 7.6-kDa protein in media conditioned by superinvasive cancer cells

BACKGROUND

Selection of the human drug sensitive and invasive cell line (MDA-MB-435S-F) with the chemotherapeutic agent paclitaxel, resulted in the development of drug resistant cell lines displaying enhanced invasion-related characteristics.

MATERIALS AND METHODS

Serum-free conditioned media from the human cancer drug-sensitive and invasive cell line (MDA-MB-435S-F) and its paclitaxel-resistant superinvasive variant (MDA-MB-435S-F/Taxol10p4pSI) were analyzed using Surface enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF MS).

RESULTS

A differentially expressed protein was observed at 7.6 kDa, which was 4-fold up-regulated in MDA-MB-435S-F/Taxol10p4pSI. The differentially expressed protein was identified using matrix-assisted laser desorption ionization tandem time-of-flight mass spectrometry (MALDI-TOF/TOF MS), as a fragment of bovine transferrin. The transferrin receptor was also found to be overexpressed in the superinvasive cell line.

CONCLUSION

Cleavage of serum proteins such as transferrin could provide a valuable source of markers for malignant tumours and could also play a role in aspects of cancer pathogenesis, such as tumour cachexia.

The effects of ageing on the distribution of vesicular acetylcholine transporter immunoreactive inputs to pelvic motoneurons of male Wistar rats

Age-related changes in the number and size of large cholinergic terminals immunoreactive for vesicular acetylcholine transporter (VAChT), were documented for the dorsolateral nucleus (DLN), retrodorsolateral nucleus (RDLN) and spinal nucleus of the bulbospongiosus (SNB) of the lumbosacral spinal cord of male rats. The most significant changes were a large increase in the number and size of cholinergic terminals within the DLN of aged animals, together with a small decrease in terminal number within the RDLN. No significant age-associated differences in VAChT labeling were seen within the SNB. In both age groups, SNB motoneurons projecting to the levator ani muscle received about 9 to 10 contacts from large cholinergic terminals. Ultrastructural examination of the terminals revealed structures likely to be postsynaptic subsurface cisterns that are characteristic of type C terminal boutons. Since both the DLN and SNB contain motoneurons innervating pelvic muscles and sphincters, these findings provide further evidence for a central cholinergic influence on micturition and sexual reflexes and suggest that this may remain robust in the face of ageing.

Effects of monotherapy with (R)-9-(2-phosphonylmethoxypropyl)adenine (PMPA) on the evolution of a primary Simian immunodeficiency virus (SIV) isolate

Determining the impact of antiretroviral therapy on virus evolution could advance the development of improved therapeutics/vaccines against HIV. Toward this goal, we analyzed virus burden, quasispecies complexity, and T cell responses in SIV/DeltaB670-infected rhesus macaques+/-treatment for 7 months with PMPA (2-30 weeks postinfection). Treatment divided the animals into two groups: poor responders (a reduction of < or =1 log) and responders (> or =2 log reduction) in virus burden. Virus evolution in poor responders and untreated controls was characterized by expression of a complex quasispecies that evolved as the disease progressed. This included the universal loss of a viral genotype selected against by in vitro passage in monkey cells and selected for by propagation in human cells. In contrast, a good response to PMPA was characterized by infection with a less complex quasispecies that evolved more slowly. Interestingly, in 2 of the best responders, the human-preferred genotype persisted until the study was discontinued (89 weeks p.i.). Neither virus burden nor the magnitude of the T cell response at 2 weeks postinfection predicted PMPA responsiveness. However, responders expressed a less complex quasispecies than nonresponders prior to treatment. These data suggest a role for intrinsic host factors in treatment responsiveness, and lend support for therapeutic vaccination as an adjunct to effective therapy.

Pharmacokinetics of florfenicol in North American elk (Cervus elaphus)

Florfenicol pharmacokinetics after administration of a single subcutaneous (s.c.) dose of 40 mg/kg of body weight in adult elk (Cervus elaphus) was investigated. Serum florfenicol concentrations were determined by a sensitive high-performance liquid chromatographic method with limit of quantification of 0.03 microg/mL. Florfenicol pharmacokinetic parameters in elk were estimated using a noncompartmental approach. After a single s.c. injection, florfenicol concentrations remained above 1 microg/mL for approximately 36 h and above 0.5 microg/mL for approximately 72 h. Following s.c. injection, florfenicol was absorbed rapidly with a mean maximum concentration (C(max)) of 3.7 microg/mL achieved at 4.2 h (T(max)). The C(max) value in elk is similar to values reported in cattle at the same dose, suggesting that the 40 mg/kg s.c. dose achieves therapeutic concentrations in elk. A mean elimination half-life (t(1/2)) of 44 h is shorter than that reported in cattle. The more rapid elimination half-life in elk suggests that elk may require a multiple dose regimen for therapeutic success with s.c. Nuflor. We recommend s.c. Nuflor be administered subcutaneously to elk every 24 h at a dose level of 40 mg/kg.

A meta-analysis review of the effects of recombinant bovine somatotropin. 1. Methodology and effects on production

This manuscript presents the results of a review of the effects of recombinant bovine somatotropin (rBST) on milk production, milk composition, dry matter intake, and body condition score that was carried out by an expert panel established by the Canadian Veterinary Medical Association (CVMA). The panel was established by the CVMA in response to a request from Health Canada in 1998 and their report was made public in 1999. A series of meta-analyses was used to combine data on production and nutrition related parameters that were extracted from all randomized clinical trials, which had been published in peer-reviewed journals or which were provided by Health Canada, from the submission by Monsanto for registration of rBST in Canada. A companion paper will present the results of the effects of the drug on measures of health, reproductive performance, and culling parameters. Recombinant bovine somatotropin was found to increase milk production by 11.3% in primiparous cows and 15.6% in multiparous cows; although there was considerable variation from study to study. While some statistically significant effects on milk composition (% butterfat, protein, and lactose) were found, they were all very small. Treatment increased dry matter intake by an average 1.5 kg/day during the treatment period and dry matter intake remained elevated on into the first 60 days of the subsequent lactation. Despite the increase in dry matter intake, treated animals had lower body condition scores at the end of the treatment period, and the reduced scores persisted through until the start of the subsequent lactation.

A meta-analysis review of the effects of recombinant bovine somatotropin. 2. Effects on animal health, reproductive performance, and culling

This manuscript presents the results of a review of the effects of recombinant bovine somatotropin (rBST) on dairy cattle health, reproductive performance, and culling, that was carried out by an expert panel established by the Canadian Veterinary Medical Association (CVMA). The panel was established by the CVMA in response to a request from Health Canada in 1998 and their report was made public in 1999. A series of meta-analyses was used to combine data on health-related parameters that were extracted from all randomized clinical trials that had been published in peer-reviewed journals or which were provided by Health Canada from the submission by Monsanto for registration of rBST in Canada. A companion paper (1) presents the estimates of the effect of the drug on production parameters. Recombinant bovine somatotropin was found to increase the risk of clinical mastitis by approximately 25% during the treatment period but there was insufficient data to draw firm conclusions about the effects of the drug on the prevalence of subclinical intra-mammary infections. Use of rBST increased the risk of a cow failing to conceive by approximately 40%. For cows which did conceive, there was no effect on services per conception and only a small increase in average days open (5 days). Use of the drug had no effect on gestation length, but the information about a possible effect on the risk of twinning was equivocal. Cows treated with rBST had an estimated 55% increase in the risk of developing clinical signs of lameness. Few studies reported data on culling, but based on those that did, there appeared to be an increase risk of culling evident in multiparous cows. Use of the drug in 1 lactation period appeared to reduce the risk of metabolic diseases (particularly ketosis) in the early period of the subsequent lactation.

An economic analysis of sown pasture trends on the tablelands of south-eastern New South Wales

The latter part of the 20th century has seen a persistent decline in the productivity of some types of sown pastures on the central and southern tablelands of New South Wales. Currently, much research effort is directed to stabilising the perennial grass component of these pastures. This paper evaluates the economic justification of that emphasis. It is argued that trends in livestock production can usefully represent increases or decreases in the stocks of three broad categories of sown pastures that are defined as being those pastures sown to introduced perennial grasses and legumes (perennial grasses), introduced legumes only (legumes), and the total of both these categories. Regression methods were used to determine the changes that have occurred in the livestock production from these pastures that could be explained by changes in a range of economic and other variables. The estimated models were then used to forecast wool, beef and lamb production from each pasture type. The results indicate that changes in prices and costs have influenced the trends in animal production from these pastures and that the structures of these influences have changed over time. Production from perennial grass-legume pastures has remained high relative to production from legume pastures despite adverse cost-price trends. The forecasts indicated a continuation of present levels of perennial grass-legume pasture areas but a decline in production from the legume pastures. The results support the concerns about the continued deterioration in the legume only pastures and the thrust of R&D programs that promote the benefits of perennial grass-legume pastures. The use and analysis of public data to improve understanding of the economic factors that influence the long-term stability of intensively grazed rangelands is highlighted.

Proliferating oligodendrocytes are present in both active and chronic inactive multiple sclerosis plaques

The proliferation marker Ki-67 labels cell nuclei in the G(1), S, M, and G(2) phases of the cell cycle. We used Ki-67 immunohistochemistry to quantify proliferating glial cells in brain tissue sections from twenty-four patients, comprised of multiple sclerosis, normal brains, and other neurological disease controls. Glial proliferation was greatly increased in MS lesions when compared with control brain white matter. Both actively demyelinating/early remyelinating plaques and chronic inactive plaques of long standing often displayed large numbers of glial cells in the proliferative cycle. The bulk of these proliferating cells were of oligodendroglial lineage in the MS plaques. Ki-67 positive macrophage/microglial lineage cells were largely restricted to acute lesions. The finding of increased numbers of proliferating oligodendroglia in most MS plaques, regardless of disease duration or activity state, indicates that the MS brain is capable of recruiting unexpectedly large numbers of new oligodendrocytes over long periods of time. The factors within the MS plaque microenvironment that provoke new oligodendrocyte generation and their subsequent loss still need to be identified.

Platelet-derived growth factor-alpha receptor-positive oligodendroglia are frequent in multiple sclerosis lesions

Platelet-derived growth factor (PDGF) ligand is a potent glial cell mitogen. When its cognate receptor (PDGF-alphaR) is expressed on oligodendroglial lineage cells, such cells are considered capable of division, and the receptor thus serves as a phenotypic marker for oligodendrocyte precursor cells. Here we identify using immunohistochemistry a considerably enlarged, PDGF-alphaR-expressing oligodendrocyte cell population within multiple sclerosis (MS) white matter lesions compared to control brains. Numerous PDGF-alphaR-positive oligodendroglia also colabel heavily with the nuclear cell proliferation marker antibody Ki-67. Our finding of large numbers of proliferating oligodendroglia in MS brains expressing up-regulated PDGF-alphaR suggests that these progenitor-like cells represent an important source of regenerating cells for the healing MS lesion.

Latino physician supply in California: sources, locations, and projections

PURPOSE

To determine the number of Latino physicians in California, identify the schools and countries where they were educated, determine the percentage located in Latino areas, and project the supply of Latino physicians to 2020.

METHOD

From a 1999 list of 74,345 licensed physicians, the authors identified Latino U.S. medical graduates (USMGs) by "heavily Hispanic" surnames and Latino international medical graduates (IMGs) by country and school of graduation. The 1999 license addresses of all physicians in Los Angeles County were analyzed against 1998 Latino-population data by zip code. A baseline projection of the supply of Latino physicians was based on the ten-year (1986 to 1995) average annual production of Latino physicians educated in California, out of state, and in Latin America. A worst-case projection assumed the continuation of recent trends: a 32% decrease in California-educated Latino USMGs, a 19% decrease in out-of-state Latino USMGs, and a reduction of Latino IMGs to five per year.

RESULTS

In 1999, 3,578 Latino physicians comprised 4.8% of all Californian physicians. In contrast, Latinos made up 30.4% of the state's population. Latino physicians were more likely than non-Latinos to have addresses in a heavily Latino zip code. In the baseline projection, while the overall supply of Latino physicians will increase by nearly 30% by 2020, that growth will be dwarfed by the 74% growth in the Latino population over the same time. In the worst-case projection, the actual number of Latino physicians will decrease from the 1999 figure of 3,578 to 3,448 by 2020, while the Latino population continues to grow.

CONCLUSIONS

(1) The Latino USMG supply must be markedly increased in the number of first-year matriculants in both California and out-of-state schools. (2) The issue of Latino IMGs requires special attention, and may provide a temporary solution to the Latino physician shortfall. (3) Non-Latino physicians need to be prepared to be culturally effective with a large and growing Latino patient population.

Up-regulated p75NTR neurotrophin receptor on glial cells in MS plaques

OBJECTIVE

To investigate the expression of the neurotrophin receptor p75NTR on glial cells within MS plaques.

BACKGROUND

In recent studies on the pathogenesis of MS white matter plaques, we found large populations of inflammatory and resident glial cells, including oligodendrocytes undergoing cell death, and identified increased expression of Fas receptor and ligand death pathway signaling molecules on the same glial cell types. In another study, the p75NTR was shown to induce apoptotic death of maturing oligodendrocytes when exposed to NGF in vitro.

METHODS

We used immunohistochemistry and in situ reverse-transcription PCR to detect p75NTR expression on inflammatory and resident glial cells in MS plaques and used TUNEL staining for fragmented DNA to detect cell death.

RESULTS

Up-regulated p75NTR messenger RNA and protein were demonstrated in both oligodendrocytes and microglia/macrophages in MS plaques but not in control white matter. However, only a fraction of p75NTR expressing oligodendrocytes was also stained by TUNEL.

CONCLUSIONS

Glial cell expression of p75NTR receptor is up-regulated during MS plaque formation. The exact role of this receptor in glial cell death and/or survival in MS remains to be elucidated.

Simultaneous occurrence of two supernumerary autosomal ring chromosomes r(1) and r(16) in twins

Ring chromosomes are estimated to occur in 3/10000 newborns and the simultaneous occurrence of two autosomal rings must be a very rare event. Recently, the characterisation of these markers using fluorescence in situ hybridisation (FISH) has greatly enhanced cytogenetic-phenotypic correlations in patients with these marker chromosomes. This kind of analysis enabled us to clarify a unique karyotype containing a r(1) and a r(16) in identical twins born after a 26 week gestation with minimal somatic abnormalities. The origin of the rings was identified using a satellite and whole chromosome painting probes. FISH analysis showed the same abnormal female karyotype in both twins, 48,XX,+r(1)(p13q21),+r(16)(p11q11).ish r(1) (D1Z5+,wcpl+), r(16)(D16Z2+,wcp16+) in about two thirds of the cells. Each also had minor clones with a normal female karyotype or with one or the other supernumerary ring. Half of the r(1) contained CBG band negative material and the r(16) appeared to be totally CBG band positive. These twins represent the second report of the simultaneous occurrence of multiple autosomal rings. Their description may help to delineate a new chromosome disorder and shows the usefulness of FISH analysis.

Deletion of the pseudoautosomal region in a male with a unique Y;13 translocation and short stature

Short stature is a common finding in patients with Ullrich-Turner syndrome. Structural abnormalities involving the terminal short arms of the X and Y chromosomes have been shown to lead to short stature. A putative locus affecting height called PHOG/SHOX has been localized to a 170-kb critical region within the pseudoautosomal region (PAR). It contains a homeodomain and functions as a transcription factor. We have studied a 10-year-old boy with idiopathic short stature who was found to have a unique Y;13 translocation. Southern blot analysis using cDNA probes indicated that most of the PAR, including PHOG/SHOX, was lost as a result of this translocation. We conclude that haploinsufficiency for this gene is responsible for the growth failure in our patient. Treatment with recombinant growth hormone has resulted in greatly improved growth velocity.

The effect of total lymphoid irradiation and low-dose steroids on T lymphocyte populations in multiple sclerosis: correlation with clinical and MRI status

We have monitored the cell surface phenotypic changes occurring in T, B and NK cells of chronic progressive multiple sclerosis (MS) patients after total lymphoid irradiation (TLI) plus low-dose prednisone (TLI-LDP) therapy in comparison to sham TLI-LDP. TLI-LDP resulted in a marked reduction in the relative and absolute number of total CD3+ T cells, CD4+ helper T cells, CD4+ CD45RA+ naive T cells and CD19+ B cells for at least 1 year after treatment. No change occurred in the percent CD8+ T cells although the number of these cells declined after radiotherapy. The CD4/CD8 T cell ratio was also decreased. The relative percent of CD16+ NK cells increased steadily after TLI-LDP while the number of NK cells transiently declined but returned to baseline values 1 year later. An increase in the percent of CD2+ CD3- cells and a decrease in their number after therapy was also observed. In contrast, no significant changes in the number of T, B or NK cells were seen in the MS patients receiving sham TLI-LDP. These results provide further evidence that radiotherapy causes a reduction of immunocompetent T and B cells and that a population of possibly NK cells and/or immature T cells appears to be repopulating the circulation after TLI. In addition, a correlation was observed between alterations in lymphocyte populations and the presence or absence of contrast enhancing or new T2 lesions on brain magnetic resonance imaging (MRI) in the TLI-LDP treated MS patients. Patients devoid of contrast enhancing or new T2 lesions had a decreased percentage of CD3+ and CD4+ T cells prior to therapy and at six months following TLI-LDP compared to patients with such lesions. An association was also observed between stability in disease activity as determined on the Expanded Disability Status Scale and relative values of CD3 T cells.

Modified total lymphoid irradiation and low dose corticosteroids in progressive multiple sclerosis

In a double-blind prospective randomized trial, we assessed the efficacy and safety of modified total lymphoid irradiation (TLI) plus low dose prednisone (TLI-LDP) as compared to sham TLI plus identical prednisone therapy (sham TLI-LDP) in 46 patients with progressive forms of multiple sclerosis (MS). No significant difference existed between groups at study entry in patient age, sex, duration of MS, or disability status. However, following treatment, significantly fewer TLI patients showed a sustained one point decline in the Expanded Disability Status Scale, the primary study endpoint, as compared to the sham TLI group using the Kaplan-Meier Product-limit survival analysis, (P<0.005). Risk for relapse requiring treatment with intravenous methylprednisolone was reduced by 54% in the TLI-treated group (P<0.05). Significantly fewer TLI-LDP patients had gadolinium enhancing plus new T2-weighted lesions (P=0.018) when compared to the sham group post-treatment. There was also a substantial and significant decrease in blood lymphocytes in the TLI-LDP group when compared to either pretreatment values or to sham TLI-LDP through at least 12 months post-therapy. Side effects secondary to TLI were generally mild and well-tolerated. These results further support the hypothesis that TLI and systemic immunosuppression have a beneficial effect in progressive forms of MS.

Cell death and birth in multiple sclerosis brain

The hallmark of the brain pathology in multiple sclerosis is the white matter plaque, characterized by myelin destruction and oligodendrocyte loss. To examine the role that cell death plays in the development of MS lesions, we used the in situ TUNEL technique, a method that sensitively detects DNA fragmentation associated with death at the single cell level. We found that patchy areas within acute MS lesions have massive numbers of inflammatory and glial cells undergoing cell death. The punched out areas of some long-standing chronic lesions also had labeled glial cells showing that the attack was not a single event. Immunocytochemical identification of the dying cells with glial specific marker co-labeling showed that 14-40% were the myelin-sustaining oligodendroglial cell. Confocal microscopic evaluation of fluorescein-labeled TUNEL positive cells revealed nuclei with morphologic characteristics of apoptosis, and electrophoresed MS brain DNA produced a ladder characteristic of apoptotic DNA cleavage confirming that substantial numbers of labeled cells, but not necessarily all, were dying by apoptotic mechanisms rather than cell necrosis. Companion studies using a marker for cell proliferation on MS lesions revealed that unexpectedly large populations of perivascular inflammatory cells and parenchymal glial cells had entered the cell proliferation cycle. These findings establish that two opposing glial cell responses - relentless cell death and coincident brisk cellular proliferation - are important features of MS pathology. In the end, however, glial cell loss prevails, and we suspect apoptosis may be the critical death mechanism responsible for the depletion of myelin observed in this condition.

Involvement of the CD95 (APO-1/Fas) receptor/ligand system in multiple sclerosis brain

Immunohistochemical methods were used to search for Fas receptor/Fas ligand system involvement in multiple sclerosis (MS) white matter brain lesions. We found large numbers of Fas ligand (Fas-L)-bearing cells present in two acute lesions and 12 of 16 chronic MS lesions, and very few positive cells in non-inflammatory controls. Four of six brains from non-MS neuropathologic conditions associated with inflammation and white matter disease were, however, also positive for Fas-L. Double staining with cell-specific markers revealed that the pattern of ligand-positive cells in chronic MS lesions was complex and composed of several different cell types which were primarily resident glial cells with a small overlay of macrophages. Fas/APO 1 (CD95) receptor expression in MS tissue was also evaluated and marked upregulation of the receptor was found. In addition, Fas receptor was induced, but to a lesser extent, in numerous control brains. The observations that TUNEL-positive dying cells were present in MS lesions and showed excellent co-localization with Fas-L, indicate that the Fas death system may contribute to plaque pathogenesis and could lead to the development of a new category of therapeutic agents for MS.

Cranio-facial fibro-osseous dysplasia. A case report and overview of the management of the condition

Fibro-osseous dysplasia is a developmental non familial, benign anomaly of bone development occurring in single or multiple bones, characterised by the replacement of normal bone by fibro-osseous tissue. We describe the case of a fourteen year old boy, which illustrates many of the difficulties confronting surgeons dealing with this uncommon condition. Complete surgical excision was required, before a definitive histological diagnosis could be established. We report the clinical, radiological and pathological features of this unusual case. We review the pathology of the condition and discuss the approaches to surgical management.