Case of adolescent with Paget-Schroetter syndrome and underlying thrombophilia due to an elevated lipoprotein (A)

Upper extremity deep vein thrombosis (UEDVT) is a rare disorder in children and is most often associated with a central venous catheter (CVC), cancer, or an underlying thrombophilia. In adults, repetitive or strenuous upper extremity activity has been linked to mechanical compression of the thoracic outlet resulting in subclavian vein thrombosis, also known as Paget-Schroetter Syndrome (PSS). We present the case of a 14 year old female who was found to have an UEDVT consistent with PSS. On subsequent thrombophila screening, she was noted to have a significantly elevated lipoprotein (a) level of 83 (normal: <30 mg/dL). She underwent 3 months of anticoagulation therapy prior to her first rib resection and in follow-up was noted to have complete patency of her subclavian vein. This case illustrates the necessity for thrombophilia screening in the pediatric patient with UEDVT despite evidence of anatomic abnormality or mechanical venous compression.

The use of biomedical sensors to monitor capsule formation around soft tissue implants

Piezoelectric sensors have been shown to respond reproducibly to changes in tissue mechanical properties surrounding an implant over a 4-month period. The vibrational amplitude at a frequency corresponding to the radial resonance shows a statistically significant change over time. The initial period of inflammation is marked by a significant reduction in amplitude, which is indicative of an increase in viscous dissipation of the tissue. As collagen displaces the cellular response, the amplitude continues to decrease. Finally, as the tissue matures, the capsule becomes stiffer, and the viscous dissipation lessens. These results are consistent with qualitative assessments of explanted capsules. Strain gauges encased in a monolithic block of silicone exhibited a greater degree of variability, yet show similar trends over time. The strain increases in the initial 4-week period and remains relatively steady over the following 4 weeks. Beyond 8 weeks, the gauges begin to extrude from the animal or suffer a loss of electrical continuity. Steps are being taken to improve the strain sensor longevity in the animals.

Multiple meningiomas: differential involvement of the NF2 gene in children and adults

OBJECTIVE

To screen for NF2 mutations in people with meningiomas.

METHODS

Lymphocyte or tumour DNA was analysed from 46 individuals from 36 families who presented with a meningioma at age < or =15 years without vestibular schwannoma (VS), or who had multiple meningiomas in adulthood before the diagnosis of VS.

RESULTS

Eight of 13 people with meningioma and other features of neurofibromatosis 2 (NF2) had an identified constitutional NF2 mutation in blood DNA, but none of the other subjects had identified constitutional NF2 mutations.

CONCLUSIONS

Constitutional NF2 mutations are the most likely cause of meningioma in children and in people with a meningioma plus other non-VS features of NF2. Mosaic NF2 may be the cause of about 8% of multiple meningiomas in sporadic adult cases, but there are other causes in the majority of other such patients and in multiple meningioma in families.

Avoiding alar necrosis with post-nasal packs

Foley's catheter is used for post-nasal packing in severe epistaxis. Various methods have been described for securing the catheter in position, all of which can be associated with patient discomfort, risk of alar necrosis or unsightliness. We describe a new method to secure the Foley's catheter without these problems. The ribbon gauze used for anterior nasal packing is tied over the catheter in multiple knots to secure it in place. This has been successfully tried on over 50 patients.

Vildagliptin, a dipeptidyl peptidase-IV inhibitor, improves model-assessed beta-cell function in patients with type 2 diabetes

AIMS/HYPOTHESIS

The dipeptidyl peptidase IV inhibitor, vildagliptin, increases levels of intact glucagon-like peptide-1 (GLP-1) and improves glycemic control in patients with type 2 diabetes. Although GLP-1 is known to stimulate insulin secretion, vildagliptin does not affect plasma insulin levels in diabetic patients, suggesting that more sophisticated measures are necessary to ascertain the influence of vildagliptin on beta-cell function.

METHODS

This study examined the effects of 28-d treatment with vildagliptin (100 mg, twice daily; n = 9) vs. placebo (n = 11) on beta-cell function in diabetic patients using a mathematical model that describes the insulin secretory rate as a function of glucose levels (beta-cell dose response), the change in glucose with time (derivative component), and a potentiation factor, which is a function of time and may reflect the actions of nonglucose secretagogues and other factors.

RESULTS

Vildagliptin significantly increased the insulin secretory rate at 7 mmol/liter glucose (secretory tone), calculated from the dose response; the difference in least squares mean (deltaLSM) was 101 +/- 51 pmol.min(-1).m(-2) (P = 0.002). The slope of the beta-cell dose response, the derivative component, and the potentiation factor were not affected. Vildagliptin also significantly decreased mean prandial glucose (deltaLSM, -1.2 +/- 0.4 mmol/liter; P = 0.01) and glucagon (deltaLSM, -10.7 +/- 4.8 ng/liter; P = 0.03) levels and increased plasma levels of intact GLP-1 (deltaLSM, +10.8 +/- 1.6 pmol/liter; P < 0.0001) and gastric inhibitory polypeptide (deltaLSM, +43.4 +/- 9.4 pmol/liter; P < 0.0001) relative to placebo.

CONCLUSION

Vildagliptin is an incretin degradation inhibitor that improves beta-cell function in diabetic patients by increasing the insulin secretory tone.

Femoral neck fractures complicating metal-on-metal resurfaced hips: a report of 2 cases

Metal-on-metal hip resurfacing arthroplasty is increasingly popular for younger patients with advanced hip disease. Intra-operative or immediate postoperative femoral neck fracture after metal-on-metal hip resurfacing is a well-described technical complication, ranging from 0% to 1.5%. We report 2 cases of late femoral neck fracture occurring 8 and 15 months following the index operation, with a review of the literature. We recommend that patient selection should be of prime importance before embarking on metal-on-metal surface hip replacement to avoid such complications.

Evaluation of transgenic cotton varieties and a glyphosate application on seedling disease incidence

A study was conducted to determine whether stand densities of transgenic cotton (Gossypium hirsutum) varieties, with or without glyphosate, were similar to conventional varieties of the same lineage group in Georgia and Mississippi. Transgenic and conventional cotton varieties were placed into five lineage groups of related varieties and seedling disease was evaluated in three greenhouse tests and a field trial using Rhizoctonia solani AG-4. Seed vigor was determined by standard germination studies were conducted evaluating conventional and transgenic varieties of similar lineage. Results showed that no interactions occurred for the heights and dry weight data across treatments within the lineage groups in any of the experiments. No interactions were shown between stand densities at different inoculum rates and inoculated versus uninoculated pots (plots). Across all greenhouse studies, stand counts of PM 1220 were similar to the transgenic varieties PM 1220 RR and PM 1220 B/RR with or without a glyphosate application. In the field trial, PM 1220 B/RR + glyphosate had significantly lower stands than all other treatments expect PM 1220 RR (no glyphosate treatment) prior to and after glyphosate application. Stand densities for varieties within the lineage group DPL 5415 were also inconsistent when compared between the greenhouse and field trials with no apparent trends occurring. However, the Coker 312 varieties containing glyphosate tolerance had consistently lower stand counts compared to the conventional variety of Coker 312 but only during the greenhouse studies. Seed germination of Coker 312 could not be correlated with either the greenhouse or field trial data. In general, the commercially available varieties such as PM 1220, DPL 5690, DPL 5415, and DPL 50 with glyphosate tolerance had similar stand count, height, and dry weight data when compared to the conventional varieties from the same lineage group regardless of a glyphosate application. When differences did occur, no consistent trends could be determined within these four lineage groups.

Ethnic differences in stage of presentation of adults newly diagnosed with HIV-1 infection in south London

OBJECTIVES

To establish whether there were ethnic differences in demographic characteristics, the stage at HIV diagnosis and reasons for and location of HIV testing between 1998 and 2000 in a large ethnically diverse HIV-1-infected clinic population in south London in the era of highly active antiretroviral therapy.

METHODS

A retrospective review was carried out of all persons >18 years old attending King's College Hospital with a first positive HIV-1 test between 1 January 1998 and 31 October 2000, and of a random sample of patients attending St Thomas' hospital with a first positive HIV-1 test in the same period. Demographic data, details of reasons for and site of HIV test, clinical stage, CD4 lymphocyte count and HIV-1 viral load at HIV diagnosis were abstracted from the local database and medical records. Comparisons were made according to ethnic group (white, black African and black Caribbean) and over time (1998, 1999 and 2000).

RESULTS

Of the 494 patients with new HIV-1 diagnoses between January 1998 and December 2000, 179 (36.2%) were white, 270 (54.7%) were black African and 45 (9.1%) were black Caribbean. There were significant differences across the ethnic groups in HIV risk group, reasons for and site of HIV testing, and clinical and CD4 stage at diagnosis. Among whites, 72.6% were men who had sex with men, 3.4% injecting drug users and 21.2% heterosexuals, compared to 2.2%, 0.4% and 93.3% among black Africans, and 28.9%, 0% and 68.9% among black Caribbeans (P<0.001). Black Africans were more likely to present with an AIDS diagnosis (21.3%) and a lower CD4 cell count [223 cells/microL; interquartile range (IQR) 88-348] compared to both whites (9.9%; 358 cells/microL; IQR 151-508) and black Caribbeans (17.9%; 294 cells/microL; IQR 113-380), who were intermediate between whites and black Africans in their stage of presentation. There was a statistically nonsignificant trend with time, between 1998 and 2000, towards earlier diagnosis based on the CD4 cell count in whites (323 and 403 cells/microL) and black Caribbeans (232 and 333 cells/microL), but a later diagnosis in black Africans (233 and 175 cells/microL). The majority of black Africans were HIV-tested as a result of suggestive symptoms or antenatal screening (58.4%) rather than because of perceived risk (40.5%), in contrast to the situation in whites (24.1% vs. 71.7%, respectively) or black Caribbeans (34.5% vs. 65.5%, respectively) (P<0.001). We found no significant differences across ethnic groups in age, HIV-1 viral load or year of HIV diagnosis.

CONCLUSIONS

Black Africans continue to present with more advanced HIV disease than whites or black Caribbeans, with no evidence of any trend towards earlier diagnosis. Future educational campaigns designed to promote the uptake of HIV testing among black Africans and black Caribbeans will need to address the multiple barriers to testing, including misperception of risk, stigma and ready access to testing.

Evaluation of transgenic cotton varieties and a glyphosate application on seedling disease incidence

A study was conducted to determine whether stand densities of transgenic cotton (Gossypium hirsutum) varieties, with or without glyphosate, were similar to conventional varieties of the same lineage group in Georgia and Mississippi. Transgenic and conventional cotton varieties were placed into five lineage groups of related varieties and seedling disease was evaluated in three greenhouse tests and a field trial using Rhizoctonia solani AG-4. Seed vigor was determined by standard germination studies were conducted evaluating conventional and transgenic varieties of similar lineage. Results showed that no interactions occurred for the heights and dry weight data across treatments within the lineage groups in any of the experiments. No interactions were shown between stand densities at different inoculum rates and inoculated versus uninoculated pots (plots). Across all greenhouse studies, stand counts of PM 1220 were similar to the transgenic varieties PM 1220 RR and PM 1220 B/RR with or without a glyphosate application. In the field trial, PM 1220 B/RR + glyphosate had significantly lower stands than all other treatments expect PM 1220 RR (no glyphosate treatment) prior to and after glyphosate application. Stand densities for varieties within the lineage group DPL 5415 were also inconsistent when compared between the greenhouse and field trials with no apparent trends occurring. However, the Coker 312 varieties containing glyphosate tolerance had consistently lower stand counts compared to the conventional variety of Coker 312 but only during the greenhouse studies. Seed germination of Coker 312 could not be correlated with either the greenhouse or field trial data. In general, the commercially available varieties such as PM 1220, DPL 5690, DPL 5415, and DPL 50 with glyphosate tolerance had similar stand count, height, and dry weight data when compared to the conventional varieties from the same lineage group regardless of a glyphosate application. When differences did occur, no consistent trends could be determined within these four lineage groups.

Monte Carlo simulations on marker grouping and ordering

Four global algorithms, maximum likelihood (ML), sum of adjacent LOD score (SALOD), sum of adjacent recombinant fractions (SARF) and product of adjacent recombinant fraction (PARF), and one approximation algorithm, seriation (SER), were used to compare the marker ordering efficiencies for correctly given linkage groups based on doubled haploid (DH) populations. The Monte Carlo simulation results indicated the marker ordering powers for the five methods were almost identical. High correlation coefficients were greater than 0.99 between grouping power and ordering power, indicating that all these methods for marker ordering were reliable. Therefore, the main problem for linkage analysis was how to improve the grouping power. Since the SER approach provided the advantage of speed without losing ordering power, this approach was used for detailed simulations. For more generality, multiple linkage groups were employed, and population size, linkage cutoff criterion, marker spacing pattern (even or uneven), and marker spacing distance (close or loose) were considered for obtaining acceptable grouping powers. Simulation results indicated that the grouping power was related to population size, marker spacing distance, and cutoff criterion. Generally, a large population size provided higher grouping power than small population size, and closely linked markers provided higher grouping power than loosely linked markers. The cutoff criterion range for achieving acceptable grouping power and ordering power differed for varying cases; however, combining all situations in this study, a cutoff criterion ranging from 50 cM to 60 cM was recommended for achieving acceptable grouping power and ordering power for different cases.

Phytoremediation of heavy metal-contaminated land by trees--a review

This paper reviews the potential for using trees for the phytoremediation of heavy metal-contaminated land. It considers the following aspects: metal tolerance in trees, heavy metal uptake by trees grown on contaminated substrates, heavy metal compartmentalisation within trees, phytoremediation using trees and the phytoremediation potential of willow (Salix spp.).

Adult small intestinal transplantation in England and Wales

BACKGROUND

In 1996 two transplantation centres in the UK were commissioned by the National Specialist Commissioning Advisory Group for England and Wales to assess small intestinal transplantation in adults. The joint experience of the two centres is presented.

METHODS

Patients with irreversible small intestinal failure and complications of parenteral nutrition, and those with abdominal disease requiring extensive visceral resection, were assessed as candidates and where appropriate listed for surgery.

RESULTS

Thirty-six patients were assessed for small intestinal transplantation and, of these, 14 underwent surgery. Twelve patients survived the transplantation procedure. Of these, seven patients were alive at 1 year, five at 3 years and three at 5 years. Three patients remain alive. Patient and graft survival improved with experience; the 1-year survival rate improved in the last 4 years of this experience from 43 to 57 per cent, and the 3-year survival rate from 29 to 43 per cent.

CONCLUSION

Small intestinal transplantation is associated with a high mortality rate but may benefit carefully selected patients in whom conservative management is likely to carry a greater mortality rate.

Screening of willow species for resistance to heavy metals: comparison of performance in a hydroponics system and field trials

The aim of this study was to ascertain whether metal resistance in willow (Salix) clones grown in a hydroponics screening test correlated with data from the same clones grown independently in a field trial. If so, results from a short-term, glasshouse-based system could be extrapolated to the field, allowing rapid identification of willows suitable for planting in metal-contaminated substrates without necessitating longterm field trials. Principal Components Analysis was used to show groups of clones and to assess the relative importance of the parameters measured in both the hydroponics system and the field; including plant response factors such as increase in stem height, as well as metal concentrations in plant tissues. The clones tested fell into two distinct groups. Salix viminalis clones and the basket willow Black Maul (S. triandra) were less resistant to elevated concentrations of heavy metals than a group of hardier clones, including S. burjatica 'Germany,' S.x dasyclados, S. candida and S. spaethii. The more resistant clones produced more biomass in the glasshouse and field, and had higher metal concentrations in the wood. The less resistant clones had greater concentrations of Cu and Ni in the bark, and produced less biomass in the glasshouse and field. Significant relationships were found between the response of the same clones grown the in short-term glasshouse hydroponics system and in the field.

Development of a hydroponic screening technique to assess heavy metal resistance in willow (Salix)

A nutrient thin film hydroponic system has been developed which allows rapid screening of willow (Salix) clones for their resistance to heavy metals, and hence their use in phytoremediation. Two clones known to be different in their resistance to heavy metals (Salix burjatica (Germany) and S. triandra x viminalis (Q83)), could be distinguished on the basis of leaf biomass, root biomass and stem height after 6 weeks. There were also differences in the uptake of heavy metals between the two clones.