| 1. |
- Jakobsson, Gunnar
(författare)
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On Complications to Cataract Surgery
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Cataract surgery, meaning exchange of the opaque lens in the eye with an artificial lens, is nowadays one of the most successful surgical procedures ever known. It is also the most frequent surgery performed in the Western world. In Sweden alone, more than 100,000 cataract operations are performed annually. Severe complications are rare, occurring only in a few percent of the patients, but owing to the large number of surgeries even infrequent complications amount to a substantial number of patients. The aim of this thesis was to study two different complications – retinal detachment (RD) and late artificial intraocular lens (IOL) dislocation – and to analyze inflammatory mediators in the vitreous of phakic (no previous cataract surgery) and pseudophakic (previous cataract surgery with IOL) eyes. Methods: Paper I is a multicenter case-control study evaluating the incidence and outcome of RD in eyes experiencing a perioperative complication with rupture of the lens capsule. Paper II and III are studies on patients with late IOL dislocation with a retrospective and a prospective observational design respectively. In paper IV the level of inflammatory immune mediators was measured in vitreous from phakic and pseudophakic patients. Results: The risk of developing RD after cataract surgery with a capsular rupture increased more than ten fold during the three-year follow-up period. Multivariate analyzes showed an odds ratio (OR) of 14.8 for RD. Additional risk factors were male sex (OR = 8.5) and lens remnants in the vitreous (OR = 14.4). The majority (62%) of eyes experiencing RD had a poor visual outcome of 0.1 or less. In patients with late IOL dislocation the median time to repositioning surgery was 6.5 years. This interval was significantly shorter in older patients and in eyes with perioperative complications (3.2 years). Pseudoexfoliations (PXF) were present in 60% of the patients and 36% had glaucoma. The annual incidence of late IOL dislocation in the pseudophakic population was calculated to 0.05%. Repositioning of the dislocated IOL with scleral sutures and a high frequency of pars plana vitrectomy procedures resulted in few complications and 59% of the patients obtained a visual acuity of ≥0.5. In patients with IOL dislocation and glaucoma, improved intraocular pressure (IOP) control was observed. Vitreous samples revealed significantly higher and sustained levels of immune mediators in pseudophakic eyes compared to phakic eyes. Conclusions: RD following capsule rupture results in profound visual loss in the majority of patients. Late IOL dislocation requiring reconstructive surgery occurs annually in 1/2000 pseudophakic patients. Risk factors are initially complicated cataract surgery, PXF and old age. The prognosis after repositioning surgery is good and IOP control in glaucoma patients is improved. Cataract surgery and pseudophakia induce elevated and sustained levels of inflammatory immune mediators in the vitreous.
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| 2. |
- Ahmad, Tashfeen
(författare)
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Diabetic osteopathy : a study in the rat
- 2003
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The present study on non-obese Goto-Kakizaki (GK) rats with type-2 diabetes and neuropathy was an attempt to describe and define pertinent features of diabetic osteopathy. Altogether, the study included 33 GK rats aged 12 and 20 months, and 36 age-matched Wistar rats as controls. All underwent test of glucose tolerance and nerve (sciatic) conduction velocity (NCV) showing that the diabetic rats had significantly higher blood glucose levels and lower NCV confirming the presence of diabetes and neuropathy. Skeletal features: Radiologic analysis of bone entailed X-ray, Dual Energy X-ray Absorptiometry (DEXA) and peripheral Quantitative Computed Tomography (pQCT). In diabetic rats, the length of humerus and height of vertebrae was reduced by 8%. The long bones exhibited endosteal erosion of the diaphyses up to 18% and periosteal expansion up to 8%. The vertebrae and metaphyses of long bones showed a decrease up to 24% in areal bone mineral density (BMD), whereas no decrease was seen in the diaphyses. Cross-sectional measurements by pQCT showed a decrease in volumetric BMD ranging from 33 to 62%, which exclusively pertained to trabecular bone (vertebrae, metaphyses), whereas volumetric BMD of the cortical bone of diaphyses was only marginally affected. The results indicate that juxta-articular bone in diabetes is substantially weaker, whereas diaphyseal cortical bone may be even stronger. Over all, the observations suggest that the diabetic skeleton is characterized by regional changes, which cannot be explained by systemic factors like calcium regulating hormones. Local bone turn-over is regulated by complex mechanisms involving cytokines, prostaglandins, growth factors and, also neuropeptides. Further analysis focused on the insulin-like growth factor (IGF) system and neuronal mediators in bone. IGF system: Immunoassays of IGF-I were done on serum, ankle samples and cortical preparations. In addition, the inhibitory IGF-I binding proteins, IGFBP-1 and -4 were analysed in serum. In diabetic rats, serum IGF-I was reduced by 18%, while IGFBP-1 and IGFBP-4 were increased by 89 and 20%, respectively. This complies with the lower BMD in the diabetic rats. In cortical bone, IGF-I was reduced by 38%, whereas no change was seen in ankles. The loss of IGF-I in cortical bone represents a novel finding. Given the cortical expansion observed in diabetic rats, the opposite was expected. Conceivably, loss of IGF-I results in endosteal erosion, which is compensated by periosteal expansion. Neuropeptides: The analyses focused on two sensory mediators, i.e. substance P (SP) and calcitonin gene- related peptide (CGRP), and one autonomic, i.e. neuropeptide Y (NPY). Immunohistochemistry was applied to ankles and tibial diaphyses, whereas radioimmunoassay (RIA) was used for separate preparations of periosteum, cortex and bone marrow from femur and tibia, whole ankles, dorsal root ganglia (DRG) and lumbar spinal cord. The morphological analysis showed SP, CGRP and NPY positive nerve fibers in bone and joints, which mostly were blood vessel related, although free terminals were also seen. In addition, NPY-positive hematopoietic cells were observed in the bone marrow. RIA revealed a significant decrease of CGRP, albeit not of SP, in DRG (-26%) and spinal cord (-29%) in the diabetic rats. As for bone, only NPY was significantly reduced, most evidently in bone marrow (-66%), but also in cortical bone (-36%) and ankles (-29%). Given the bone anabolic effects of CGRP and NPY, loss of these neuropeptides may prove, at least partly, to underlie the trabecular osteopenia and endocortical erosion observed in diabetic rats. Conclusion: The skeleton of diabetic rats with type-2 diabetes and neuropathy is characterized by regional changes of size, form, mineral content and density and concomitantly with regional abnormalities of the IGF- system and neuropeptides suggesting that also local factors beyond systemic play an important role in the development of diabetic osteopathy.
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| 3. |
- Ahmad, T., et al.
(författare)
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Frequency and outcomes of undiagnosed diabetes mellitus in patients presenting with acute myocardial infarction
- 2020
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Ingår i: Medical Forum Monthly. - : Medical Forum Monthly. - 1029-385X. ; 31:12, s. 3-7
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To find out frequency and outcomes of undiagnosed diabetes mellitus in patients presenting with acute ST elevation myocardial infarction (STEMI). Study Design: Descriptive / Cross-Sectional Study Place and Duration of study: This study was conducted at the Cardiology Department, Lady Reading Hospital, Peshawar from November 2018 to May 2019. Materials and Methods: Patient of either gender having age ranging between 30-75 years old with acute STEMI who present within 12 hours of symptoms and with no past history of documented diabetes mellitus were included in the study. Venous blood samples for laboratory data, including random blood sugar, two fasting blood sugar and HBA1c using hitachi modular evo p800 machine was done. Results: A total of 158 patients having acute STEMI were studied. Males were 68.4% (n=108).The mean age was 59.65 ±10.80 years. Frequency of undiagnosed diabetes mellitus was 31.64 % (n = 50). In non-diabetics stress hyperglycemia was found in 51.85 % (n=56) patients. Among various types of STEMI, anterior STEMI was more common presentation 34.1 % (n=54. p= 0.85). Mean HBA1C was 6.19 ± 1.87%. Frequency of Ventricular tachycardia (VT) was 22.2 % in which undiagnosed diabetics were n=18 (p=0.004).Ventricular fibrillation was present in 13.3 % patients with undiagnosed diabetics were n=14 (p=0.001). Frequency of AF was 13.9% (n=22) with undiagnosed diabetics having AF in n=13 (p=0.003). SVT was present in 5.7% (n=9) patients with not significant difference between two groups (p=0.017). Among various mechanical complications VSR was present in 10 % (n=16) of patients (p=0.001), cardiogenic shock in 11.1 % (n=18) patients (p=0.004), acute LVF was present in 15.8 % patients (p=0.017). Conclusion: In our study we concluded that one third of patients having acute ST elevation myocardial infarction have undiagnosed diabetes mellitus (31.64 %, n = 50). The most common complication was ventricular tachycardia among electrical complication and LVF among mechanical complication.
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| 4. |
- Ahmad, Tauseef, 1986, et al.
(författare)
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Methodology for Power-Aware Coherent Receiver Design
- 2013
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Ingår i: Optics InfoBase Conference Papers. - 2162-2701. ; , s. SPT4D.4-
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Konferensbidrag (refereegranskat)abstract
- We describe a methodology to design and evaluate DSP hardware for a coherent receiver. Important parameters that can be assessed include DSP power consumption and chip area.
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| 5. |
- Callaghan, Terry V., et al.
(författare)
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A new climate era in the sub-Arctic : Accelerating climate changes and multiple impacts
- 2010
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Ingår i: Geophysical Research Letters. - 0094-8276 .- 1944-8007. ; 37:14, s. L14705-
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Tidskriftsartikel (refereegranskat)abstract
- Climate warming in the Swedish sub-Arctic since 2000 has reached a level at which statistical analysis shows for the first time that current warming has exceeded that in the late 1930' s and early 1940' s, and has significantly crossed the 0 degrees C mean annual temperature threshold which causes many cryospheric and ecological impacts. The accelerating temperature increase trend has driven similar trends in the century-long increase in snow thickness, loss of lake ice, increases in active layer thickness, lake water TOC (total organic carbon) concentrations and the assemblages of diatoms, and changes in tree-line location and plant community structure. Some of these impacts were not evident in the first warm period of the 20th Century. Changes in climate are associated with reduced temperature variability, particularly loss of cold winters and cool summers, and an increase in extreme precipitation events that cause mountain slope instability and infrastructure failure. The long term records of multiple, local environmental factors compiled here for the first time provide detailed information for adaptation strategy development while dramatic changes in an environment particularly vulnerable to climate change highlight the need to adopt global mitigation strategies.
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| 8. |
- Aberg, KA, et al.
(författare)
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MBD-seq as a cost-effective approach for methylome-wide association studies: demonstration in 1500 case--control samples
- 2012
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Ingår i: Epigenomics. - : Future Medicine Ltd. - 1750-192X .- 1750-1911. ; 4:6, s. 605-621
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Tidskriftsartikel (refereegranskat)abstract
- Aim: We studied the use of methyl-CpG binding domain (MBD) protein-enriched genome sequencing (MBD-seq) as a cost-effective screening tool for methylome-wide association studies (MWAS). Materials & methods: Because MBD-seq has not yet been applied on a large scale, we first developed and tested a pipeline for data processing using 1500 schizophrenia cases and controls plus 75 technical replicates with an average of 68 million reads per sample. This involved the use of technical replicates to optimize quality control for multi- and duplicate-reads, an in silico experiment to identify CpGs in loci with alignment problems, CpG coverage calculations based on multiparametric estimates of the fragment size distribution, a two-stage adaptive algorithm to combine data from correlated adjacent CpG sites, principal component analyses to control for confounders and new software tailored to handle the large data set. Results: We replicated MWAS findings in independent samples using a different technology that provided single base resolution. In an MWAS of age-related methylation changes, one of our top findings was a previously reported robust association involving GRIA2. Our results also suggested that owing to the many confounding effects, a considerable challenge in MWAS is to identify those effects that are informative about disease processes. Conclusion: This study showed the potential of MBD-seq as a cost-effective tool in large-scale disease studies.
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| 9. |
- Aune, Solveig, 1957, et al.
(författare)
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Characteristics of patients who die in hospital with no attempt at resuscitation
- 2005
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Ingår i: Resuscitation. - : Elsevier BV. - 0300-9572 .- 1873-1570. ; 65:3, s. 291-9
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To describe the characteristics, cause of hospitalisation and symptoms prior to death in patients dying in hospital without resuscitation being started and the extent to which these decisions were documented. MATERIALS AND METHODS: All patients who died at Sahlgrenska University Hospital in Goteborg, Sweden, in whom cardiopulmonary resuscitation (CPR) was not attempted during a period of one year. RESULTS: Among 674 patients, 71% suffered respiratory insufficiency, 43% were unconscious and 32% had congestive heart failure during the 24h before death. In the vast majority of patients, the diagnosis on admission to hospital was the same as the primary cause of death. The cause of death was life-threatening organ failure, including malignancy (44%), cerebral lesion (10%) and acute coronary syndrome (10%). The prior decision of 'do not attempt resuscitation' (DNAR) was documented in the medical notes in 82%. In the remaining 119 patients (18%), only 16 died unexpectedly. In all these 16 cases, it was regarded retrospectively as ethically justifiable not to start CPR. CONCLUSION: In patients who died at a Swedish University Hospital, we did not find a single case in which it was regarded as unethical not to start CPR. The patient group studied here had a poor prognosis due to a severe deterioration in their condition. To support this, we also found a high degree of documentation of DNAR. The low rate of CPR attempts after in-hospital cardiac arrest appears to be justified.
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| 10. |
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