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Query: UMLS:C0011860 (type 2 diabetes)
 57,723 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Whereas functional, metabolic, neurotrophic, and morphological abnormalities of peripheral diabetic neuropathy (PDN) have been extensively explored in streptozotocin-induced diabetic rats and mice (models of type 1 diabetes), insufficient information is available on manifestations and pathogenetic mechanisms of PDN in type 2 diabetic models. The latter could constitute a problem for clinical trial design because the vast majority of subjects with diabetes have type 2 (non-insulin dependent) diabetes. This study was aimed at characterization of PDN in leptin-deficient (ob/ob) mice, a model of type 2 diabetes with relatively mild hyperglycemia and obesity. ob/ob mice ( approximately 11 weeks old) clearly developed manifest sciatic motor nerve conduction velocity (MNCV) and hind-limb digital sensory nerve conduction velocity (SNCV) deficits, thermal hypoalgesia, tactile allodynia, and a remarkable ( approximately 78%) loss of intraepidermal nerve fibers. They also had increased sorbitol pathway activity in the sciatic nerve and increased nitrotyrosine and poly(ADP-ribose) immunofluorescence in the sciatic nerve, spinal cord, and dorsal root ganglion (DRG). Aldose reductase inhibition with fidarestat (16 mg . kg(-1) . d(-1)), administered to ob/ob mice for 6 weeks starting from 5 weeks of age, was associated with preservation of normal MNCV and SNCV and alleviation of thermal hypoalgesia and intraepidermal nerve fiber loss but not tactile allodynia. Sciatic nerve nitrotyrosine immunofluorescence and the number of poly(ADP-ribose)-positive nuclei in sciatic nerve, spinal cord, and DRGs of fidarestat-treated ob/ob mice did not differ from those in nondiabetic controls. In conclusion, the leptin-deficient ob/ob mouse is a new animal model that develops both large motor and sensory fiber and small sensory fiber PDN and responds to pathogenetic treatment. The results support the role for increased aldose reductase activity in functional and structural changes of PDN in type 2 diabetes.
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PMID:The leptin-deficient (ob/ob) mouse: a new animal model of peripheral neuropathy of type 2 diabetes and obesity. 1713 Apr 77

This article examined the pattern of distribution of calcitonin gene-related peptide (CGRP) in the dorsal root ganglion (DRG) of normal and diabetic Wistar, Zucker lean, and Goto-Kakizaki (GK) rats to determine whether there are changes in the number and pattern of distribution of CGRP-positive neurons after the onset of latent or overt diabetes. Type 1 diabetes mellitus was induced in Wistar rats by a single dose of streptozotocin (STZ) given intraperitoneally (60 mg/kg body weight). Four weeks after the induction of diabetes mellitus, diabetic (n = 6) and normal (n = 6), Zucker lean (n = 6), and GK (n = 6) rats were anesthetized with chloral hydrate and their DRGs were removed and processed for immunohistochemistry. CGRP-positive neurons were observed in the DRG of normal and diabetic Wistar, Zucker lean (nondiabetic), and GK (animal model of type 2 diabetes) rats. CGRP was present in small-, medium-, and large-sized neurons of the DRG in these three animal models. Only a small percentage of large-sized neurons contains CGRP. The number of CGRP-positive neurons was significantly (P < 0.05) reduced in STZ-induced diabetic Wistar and GK rats compared to normal Wistar and Zucker lean rats. Moreover, the quantity of CGRP-containing varicose nerves was less in diabetic Wistar and GK rats compared to control Wistar and Zucker lean rats. The reduced number of CGRP-positive neurons in the DRG of GK rats indicated that subjects with latent diabetes may already have dysfunctional CGRP metabolism and thus diabetic neuropathy.
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PMID:Pattern of distribution of calcitonin gene-related Peptide in the dorsal root ganglion of animal models of diabetes mellitus. 1715 9

In diabetic patients, vascular disease and autonomic dysfunction might compromise cerebral autoregulation and contribute to orthostatic intolerance. The aim of our study was to determine whether impaired cerebral autoregulation contributes to orthostatic intolerance during lower body negative pressure in diabetic patients. Thirteen patients with early-stage type 2 diabetes were studied. We continuously recorded RR-interval, mean blood pressure and mean middle cerebral artery blood flow velocity at rest and during lower body negative pressure applied at -20 and -40 mm Hg. Spectral powers of RR-interval, blood pressure and cerebral blood flow velocity were analyzed in the sympathetically mediated low (LF: 0.04-0.15 Hz) and the high (HF: 0.15-0.5 Hz) frequency ranges. Cerebral autoregulation was assessed from the transfer function gain and phase shift between LF oscillations of blood pressure and cerebral blood flow velocity. In the diabetic patients, lower body negative pressure decreased the RR-interval, i.e. increased heart rate, while blood pressure and cerebral blood flow velocity decreased. Transfer function gain and phase shift remained stable. Lower body negative pressure did not induce the normal increase in sympathetically mediated LF-powers of blood pressure and cerebral blood flow velocity in our patients indicating sympathetic dysfunction. The stable phase shift, however, suggests intact cerebral autoregulation. The dying back pathology in diabetic neuropathy may explain an earlier and greater impairment of peripheral vasomotor than cerebrovascular control, thus maintaining cerebral blood flow constant and protecting patients from symptoms of presyncope.
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PMID:Cardiovascular and cerebrovascular responses to lower body negative pressure in type 2 diabetic patients. 1717 34

In most Western countries, diabetic nephropathy (DN) has become the single most common condition found in patients with end-stage renal disease (ESRD). This is to some extent due to better survival of diabetic patients with renal failure, but mostly due to the dramatic increase in the prevalence of type 2 diabetes. The majority of type 2 diabetic patients with renal failure suffer from nodular glomerulosclerosis (Kimmelstiel-Wilson); but ischemic nephropathy, irreversible acute renal failure (mostly acute on chronic) and diabetes co-existing with primary renal diseases are common as well. Classical DN evolves in a sequence of stages. After a period of glomerular hyperfiltration, increased urinary albumin excretion [microalbuminuria (MA)] i.e. 30-300 mg/day or 20 - 200 microg/minute indicates the onset of overt DN. Risk factors for development of DN are positive family history, hyperglycemia in the mother during pregnancy, high blood pressure, obesity and insulin resistance. Poor glycemic control (HbAlc) and elevated systolic blood pressure (> 135 mm Hg) interact in enhancing the risk of DN. Proteinuria and smoking are major promoters of progression. The risk of onset of microalbuminuria can be reduced by lowering of blood pressure and specifically by blockade of the renin angiotensin system (RAS). In patients with established DN, the target systolic blood pressure should be <130 mm Hg and RAS blockade is obligatory. Treating all cardiovascular risk factors is a high priority. Antihypertensive management is rendered difficult by extreme volume sensitivity, pronounced activation of the RAS and autonomic neuropathy. Cardiac events are excessively frequent, glycemic control becomes difficult and autonomic diabetic neuropathy with gastroparesis and diabetic foot are additional problems. Hemodialysis or continuous ambulatory peritoneal dialysis should be started relatively early. In the absence of contraindications, transplantation (renal transplantation, combined kidney/pancreas transplantation or pancreas after kidney transplantation) is the treatment of choice.
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PMID:Diabetic nephropathy. 1718 81

Several systems are used for the diagnosis of diabeticpolyneuropathy (DPN). We analyzed the isolated use of vibration perception thresholds (VPTs) or monofilament (MF) for the diagnosis of DPN. A group of 400 patients who had type 2 diabetes was selected from the North Catalonia Study Group. A clinical neurologic evaluation was performed based on three categories of the San Antonio Consensus. Neurothesiometer and quantitative tuning fork explored VPT, and MF was assessed by Olmos and Michigan Diabetic Neuropathy Score (MDNS) criteria. The use of VPT and MF showed a high specificity and low sensitivity. MF, by MDNS criteria, was more sensitive and specific, and showed more accurate positive and negative predictive values. The predicted probability of DPN diagnosis was higher with a tuning fork evaluation.
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PMID:Isolated use of vibration perception thresholds and semmes-weinstein monofilament in diagnosing diabetic polyneuropathy: "the North Catalonia diabetes study". 1727 May 90

Diabetic neuropathy (DN) is a common severe complication of type 2 diabetes. The symptoms of chronic pain, tingling, and numbness are generally attributed to small fiber dysfunction. However, little is known about the pathology among innervation to distal extremities, where symptoms start earliest and are most severe, and where the innervation density is the highest and includes a wide variety of large fiber sensory endings. Our study assessed the immunochemistry, morphology, and density of the nonvascular innervation in glabrous skin from the hands of aged nondiabetic rhesus monkeys and from age-matched monkeys that had different durations of spontaneously occurring type 2 diabetes. Age-related reductions occurred among all types of innervation, with epidermal C-fiber endings preferentially diminishing earlier than presumptive Adelta-fiber endings. In diabetic monkeys epidermal innervation density diminished faster, became more unevenly distributed, and lost immunodetectable expression of calcitonin gene-related peptide and capsaicin receptors, TrpV1. Pacinian corpuscles also deteriorated. However, during the first few years of hyperglycemia, a surprising hypertrophy occurred among terminal arbors of remaining epidermal endings. Hypertrophy also occurred among Meissner corpuscles and Merkel endings supplied by Abeta fibers. After longer-term hyperglycemia, Meissner corpuscle hypertrophy declined but the number of corpuscles remained higher than in age-matched nondiabetics. However, the diabetic Meissner corpuscles had an abnormal structure and immunochemistry. In contrast, the expanded Merkel innervation was reduced to age-matched nondiabetic levels. These results indicate that transient phases of substantial innervation remodeling occur during the progression of diabetes, with differential increases and decreases occurring among the varieties of innervation.
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PMID:Differential hypertrophy and atrophy among all types of cutaneous innervation in the glabrous skin of the monkey hand during aging and naturally occurring type 2 diabetes. 1727 31

Diabetic and alcoholic neuropathies are heterogeneous groups with variable lesions of axons or myelin. Their pathogenesis is complex and involves multiple pathways. To elucidate the impact of immunological factors in development of these neuropathies the expression of some cytokines in serum was studied: tumour necrosis factor a (TNF-a), monocyte chemotactic protein-1 (MCP-1) and growth-regulated oncogene alpha (GRO-alpha; CXCL1). 29 patients with type 2 diabetes, 31 with chronic alcohol abuse and 20 healthy controls were included in the study. The type of neuropathy (involvement of axon or myelin) was evaluated by electrophysiological methods (EMG and nerve conduction velocity). The cytokine level was determined by ELISA method. For statistical comparison the nonparametric Mann-Whitney test was used. The evaluated material was divided according to clinical duration of neuropathy and electrophysiological pattern. Expression of TNF-alpha in both types of neuropathy does not differ from the control material. Expression of MCP-1 was higher, but insignificantly, in patients with alcoholic neuropathy. The same concerns the demyelinating form versus axonal diabetic neuropathy. Serum level of GRO-alpha; was significantly higher in patients with alcoholic neuropathy and in cases with demyelinating form of diabetic neuropathy than in control subjects. GRO-alpha; is a potent neutrophil chemoattractant playing an important role in various primary and secondary inflammatory processes. The results suggest that GRO-alpha; may contribute to the mechanism of alcoholic neuropathy and in demyelinating form of diabetic neuropathy.
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PMID:Impact of cytokines on the pathomechanism of diabetic and alcoholic neuropathies. 1759 98

A 57-year-old man with type 2 diabetes mellitus for 10 years showed progressive loss of muscle strength in both legs, pain and muscle atrophy in the femoral region and significant weight loss. On admission, he could not stand alone and used a wheelchair. He also complained of severe pain in the lower extremities. He was diagnosed with proximal diabetic neuropathy (PDN) by characteristic clinical and electrophysiological features. Intravenous immunoglobulin therapy (IVIg 0.4 g/kg x 5 days) markedly reduced the severe pain and muscle weakness in the legs. Eventually, pain assessed by the Visual Analogue Scale was relieved by 80% and muscle strength was also well recovered, thereby enabling the patient to walk with a cane. The present case suggests that IVIg therapy may be effective for the relief of pain in PDN.
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PMID:Intravenous immunoglobulin therapy markedly ameliorates muscle weakness and severe pain in proximal diabetic neuropathy. 1763 82

The repeatedly expressed doubts about the value of an effective therapy for diabetic neuropathies are no longer acceptable. Today a number of excellent longitudinal and cross-sectional studies, i.e. DCCT, Steno 2, DCCT/EDIC, European Diabetes Prospective Complications Study, are available. The attending physician should make every effort to diagnose diabetic neuropathies as soon as possible with all their multivarious manifestations. Treatment must be promptly, aggressively and multifactorially as described in evidence-based guidelines. In principle, the same risk factors apply to neuropathy in type 1 and type 2 diabetes as for macro-angiopathy and microangiopathy. Therapy focuses on establishing near-normal diabetes and blood pressure control, lipid management, intensive patient education, avoidance of exogenous noxae such as alcohol and nicotine and if necessary, an effective therapy of neuropathic pain. The objective of all diagnostic and preventive efforts must be always to avoid the development of the diabetic neuropathic foot syndrome, which is the most important end stage of somatic and autonomic diabetic neuropathy.
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PMID:[Diabetic neuropathy: therapeutic nihilism is no longer acceptable]. 1772 63

Diabetic neuropathy (DN) is a debilitating complication of type 1 and type 2 diabetes. Rodent models of DN do not fully replicate the pathology observed in human patients. We examined DN in streptozotocin (STZ)-induced [B6] and spontaneous type 1 diabetes [B6Ins2(Akita)] and spontaneous type 2 diabetes [B6-db/db, BKS-db/db]. Despite persistent hyperglycemia, the STZ-treated B6 and B6Ins2(Akita) mice were resistant to the development of DN. In contrast, DN developed in both type 2 diabetes models: the B6-db/db and BKS-db/db mice. The persistence of hyperglycemia and development of DN in the B6-db/db mice required an increased fat diet while the BKS-db/db mice developed severe DN and remained hyperglycemic on standard mouse chow. Our data support the hypothesis that genetic background and diet influence the development of DN and should be considered when developing new models of DN.
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PMID:Mouse models of diabetic neuropathy. 1780 49


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