708 Examining the Management of Acute Lower GI Bleeds in Order to Improve Policies and Reflect Safe and Updated Guidance

Introduction

Acute lower gastrointestinal bleeding (LGIB) tends to occur in elderly patients with complex comorbidities. At North Middlesex University Hospital (NMUH), LGIB patients are primarily managed by the surgical department. We amended local policies by integrating aspects of new guidelines published by the British Society of Gastroenterology (BSG).

Method

Handover documentation between November 2019 and January 2020 established patients admitted with LGIB (n = 45). Further data regarding the management of these patients was collated from clinical software and compared to standards set from BSG guidelines.

Results

We found NMUH to be efficient in ruling out upper GI bleeds via 24-hour OGDs and had low surgical intervention rates (0.02%). 40% of patients were transfused with an admission haemoglobin above suggested NICE thresholds, accounting for cardiovascular comorbidities. 56% of patients were discharged without a documented anticoagulation plan. Over 50% of patients did not have BSG recommended inpatient investigations.

Conclusions

Updated Trust guidelines aim to uphold areas that NMUH were shown to excel in, while reiterating NICE transfusion thresholds and include guidance regarding anticoagulant and antiplatelet medications. The Oakland score and shock index have been integrated into local protocols and will aid clinicians in making safe decisions in the management of LGIB patients.

Connective tissue growth factor is involved in structural retinal vascular changes in long-term experimental diabetes

Early retinal vascular changes in the development of diabetic retinopathy (DR) include capillary basal lamina (BL) thickening, pericyte loss and the development of acellular capillaries. Expression of the CCN (connective tissue growth factor/cysteine-rich 61/nephroblastoma overexpressed) family member CCN2 or connective tissue growth factor (CTGF), a potent inducer of the expression of BL components, is upregulated early in diabetes. Diabetic mice lacking one functional CTGF allele (CTGF⁺/⁻) do not show this BL thickening. As early events in DR may be interrelated, we hypothesized that CTGF plays a role in the pathological changes of retinal capillaries other than BL thickening. We studied the effects of long-term (6-8 months) streptozotocin-induced diabetes on retinal capillary BL thickness, numbers of pericytes and the development of acellular capillaries in wild type and CTGF⁺/⁻ mice. Our results show that an absence of BL thickening of retinal capillaries in long-term diabetic CTGF⁺/⁻ mice is associated with reduced pericyte dropout and reduced formation of acellular capillaries. We conclude that CTGF is involved in structural retinal vascular changes in diabetic rodents. Inhibition of CTGF in the eye may therefore be protective against the development of DR.

Walking ability of children with a hexapod external ring fixator (TSF®) and foot plate mounting at the lower leg

Wearing an external fixator for several months can be expected to profoundly affect the ability to walk, but, in principle, full weight-bearing is possible during corrective procedures with the Taylor Spatial Frame (TSF). The present prospective cohort study was conducted to assess whether patients are able to walk with or without crutches during treatment with a TSF on the lower leg. Twenty-four patients (10 girls, 14 boys; average age 11 years, range 6-17) scheduled for fixator surgery with osteotomies in the lower leg and foot mounting were included. Dynamic foot loading during free walking was measured with plantar pressure measurements. The contact area, contact time and contact pressure on the foot plate were recorded and normalized to body weight. In the first postoperative week, all patients needed crutches and 67% showed partial weight-bearing. At the second measurement, about 6 weeks after surgery, 21% of the patients could walk without crutches and 58% were partially weight-bearing with crutches. On the day before fixator removal, 50% of the patients were fully weight-bearing without crutches and 38% were partially weight-bearing, but 12% could not bear any weight or were unable to walk. When a ring fixator is used to correct lower leg deformity and prevent equinus, there is minimal risk of complete dependence and abasia. This study shows that up to 88% of the pediatric patients are able to walk while wearing the fixator. Already a few days after surgery, two-thirds of the patients were partially weight-bearing with crutches, and only 12% needed a wheelchair and were not able to walk with the fixator.

Mimicking proteasomal release of polyglutamine peptides initiates aggregation and toxicity

Several neurodegenerative disorders, including Huntington's disease, are caused by expansion of the polyglutamine (polyQ) tract over 40 glutamines in the disease-related protein. Fragments of these proteins containing the expanded polyQ tract are thought to initiate aggregation and represent the toxic species. Although it is not clear how these toxic fragments are generated, in vitro data suggest that proteasomes are unable to digest polyQ tracts. To examine whether the resulting polyQ peptides could initiate aggregation in living cells, we mimicked proteasomal release of monomeric polyQ peptides. These peptides lack the commonly used starting methionine residue or any additional tag. Only expanded polyQ peptides seem to be peptidase resistant, and their accumulation initiated the aggregation process. As observed in polyQ disorders, these aggregates subsequently sequestered proteasomes, ubiquitin and polyQ proteins, and recruited Hsp70. The generated expanded polyQ peptides were toxic to neuronal cells. Our approach mimics proteasomal release of pure polyQ peptides in living cells, and represents a valuable tool to screen for proteins and compounds that affect aggregation and toxicity.

Evaluation of the toxicological properties of ground- and surface-water samples from the Aral Sea Basin

In order to determine whether there is a potential health risk associated with the water supply in the Aral Sea Basin, ground- and surface-water samples were collected in and around Aralsk and from the Aral Sea in 2002. Water samples from Akchi, a small town close to Almaty, served as controls. Bioassays with different toxicological endpoints were employed to assess the general toxicological status. Additionally, the samples were analysed for microbial contamination. The samples were tested in the primary hepatocyte assay for their potential to induce micronuclei and chromosomal aberrations as cumulative indicators for genotoxicity. In parallel, the effects on cell proliferation evidenced by mitotic index and cytotoxicity such as the appearance of necrotic and apoptotic cells, were determined. Furthermore, samples were examined using the Microtox assay for general toxicity. Chemical analysis according to European regulations was performed and soil and water samples were analysed for DDT and DDE. The results obtained indicated no increased cyto- or genotoxic potential of the water samples, nor levels of DDT or DDE exceeding the thresholds levels suggested by WHO. Our data therefore do not support the hypothesis that the contamination of the drinking water in and around Aralsk is responsible for the health effects previously described such as increased rates of liver disease and in particular liver cancer. Microbiological analysis, however, revealed the presence of contamination in most samples analysed.

Changes in the acinar distribution of some enzymes involved in carbohydrate metabolism in rat liver parenchyma after experimentally induced cholestasis

Extrahepatic cholestasis induced by ligation and transsection of the common bile duct caused a change in the parenchyma/stroma relationship in rat liver. Two weeks after ligation, the periportal zones of the parenchyma were progressively invaded by expanding bile ductules with surrounding connective tissue diverging from the portal areas. Parenchymal disarray developed and small clumps of hepatocytes or isolated hepatocytes were scattered within the expanded portal areas. These cells showed normal activity of lactate, succinate and glutamate dehydrogenase and may, therefore, be considered to be functionally active. After cholestasis the remainder of the liver parenchyma showed adaptational changes with respect to glucose homeostasis, as demonstrated by histochemical means. Glycogen stores disappeared completely whereas glycogen phosphorylase activity increased about ten fold. The increased glycogen phosphorylase activity and glycogen depletion indicate a greater glycogenolytic capacity in liver parenchyma after bile duct ligation to maintain as far as possible a normal plasma glucose concentration. The parenchymal distribution pattern of glucose-6-phosphatase activity did not change significantly after bile duct ligation. The isolated hepatocytes within the expanded portal tracts showed a high activity of this enzyme whereas the pericentral parenchyma was only moderately active. The distribution patterns of glucose-6-phosphate dehydrogenase and lactate dehydrogenase activity in the liver parenchyma were also largely unchanged after bile duct ligation, but the histochemical reaction for glucose-6-phosphate dehydrogenase activity demonstrated infiltration of the remainder of the parenchyma by non-parenchymal cells, possibly Küpffer cells and leucocytes as part of an inflammatory reaction. Under normal conditions the mitochondrial enzymes succinate and glutamate dehydrogenase show an opposite heterogenous distribution pattern in liver parenchyma. Following cholestasis both enzymes became uniformly distributed. The underlying regulatory mechanism for these different changes in distribution patterns of enzyme activities is not yet understood.