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Biomedical subjects

R Lobmann

Publications and source records attributed to R Lobmann.

16 recordsLinked to original sources
PubMed2005

[Hypoglycemia despite hyperglycemia. Is a cerebral glucose deficiency possible even with raised blood sugar levels?].

Hypoglycemia represents the most frequent endocrinologic emergency situation in prehospital patient care. As the patients are usually unconscious on arrival of emergency medical personnel, often the only way to establish a diagnosis is by determination of the blood glucose concentration. However, even normoglycemic or hyperglycemic levels cannot definitively exclude the diagnosis of a previous hypoglycemia as the cause of the acute cerebral deficiency. Therefore, and especially in the case of insulin-dependent diabetes mellitus, a differential diagnosis should be considered. We report a case of emergency treatment of a hypoglycemic episode in a female patient with prolonged neuroglycopenia together with cerebrovascular dementia and Alzheimer's disease.

Aged↗
PubMed2004

Antibiotic therapy for diabetic foot infections: comparison of cephalosporines with chinolones.

Diabetic foot complications are the most common cause of non-traumatic lower extremity amputations and uncontrolled infections represent a major risk factor. This open prospective, multicenter trial compared the efficacy of two antibiotic regimens for treatment of foot infections Wagner stage II or III in diabetic adults. Three hundred diabetic patients with severe, limb-threatening foot infection were consecutively enrolled in a prospective, observational, matched pairs controlled study to test two different antibiotic regimes (ceftriaxone vs chinolones) in addition to standard treatment of foot infection. After matching, 90 patients--each receiving ceftriaxone or chinolones--were analyzed. Our study demonstrated that treatment with a third generation cephalosporine is as effective as a treatment with chinolones. Response (reaching Wagner I or 0) was achieved in 58.0% in the ceftriaxone group and in 51.1% in the chinolone group (NS.). Fourteen days after initiation of treatment, the number of patients with microbiological isolates decreased in both groups (52 to 5 in the ceftriaxone group and 60 to 12 in the chinolone group). At hospital discharge, 66.0% of ceftriaxone and 64.4 of chinolone-treated diabetic ulcers were cured or improved. In summary, both substances proved to be effective in the primary antibiotic treatment of the diabetic foot; an early broad spectrum antibiotic treatment, that covers both gram-positive and gram negative bacteria as well as anerobes is undisputedly an imperative therapeutic intervention for the treatment of diabetic foot infection.

Adult↗
PubMed2004

Expression of cell surface antigens in diabetic patients and healthy controls after injury.

AIMS: Due to the systemic character of Type 2 diabetes, cellular disturbances paralleled by an altered expression of various growth factors constitute the basis for impaired wound healing. Cell-surface antigens are altered in chronic wounds and may also have an effect on the persistance of diabetic foot lesions. METHODS: We investigated blood samples of diabetic patients with diabetic foot ulcers (n=21) in comparison with those from healthy control patients subsequent to an injury (n=9). A blood sample (EDTA) was taken from each participant (in the trauma control group on the third day after injury) and examined by flow cytometry [fluorescence-activated cell sorter (FACS)]. Typical cell surface antigens involved in wound healing were studied [cluster of differentiation (CD)2, CD3, CD4, CD25 and human leukocyte antigen (HLA)-diabetic retinopathy (DR)]. RESULTS: known to adversely affect wound healing were elevated in diabetic patients (CD2 p<0.001; CD3 p=0.016, CD4 p=0.22, CD25 p<0.001). HLA-DR expression was also decreased in diabetic foot patients (p=0.023). CONCLUSIONS: Cell-surface antigens appear to be altered in diabetic patients when compared to healthy controls. Thus, due to the systemic character of Type 2 diabetes, cellular disturbances may well constitute the basis for impaired wound healing in diabetes.

Adult↗
PubMed2003

[Hypoglycemia, classification, therapy and preventable errors].

Hypoglycemia is a multifactorial problem that is caused by the interaction of numerous variables such as a individual pathophysiological response, treatment aspects and self control. In particular, the increasing use of intensified insulin therapy and thus the goal of normoglycemia has made hypoglycaemia to become a major hazard among the acute complications of diabetes mellitus. Early diagnosis and treatment is thus mandatory to reduce the increased morbidity and mortality of hypoglycaemia. Among the acute therapy of hypoglycaemia treatment includes a modification of diabetes therapy, patient education and a special training of hypoglycaemia awareness.

Diabetes Mellitus, Type 1↗
PubMed2002

Expression of matrix-metalloproteinases and their inhibitors in the wounds of diabetic and non-diabetic patients.

AIMS/HYPOTHESIS: The molecular factors that cause an acute wound in diabetic patients to become chronic have not yet been established. Wound healing is known to require a balance between the accumulation of collagenous and non-collagenous extracellular matrix components and their remodelling by matrix metalloproteinases (MMPs) and the tissue inhibitors of metalloproteinases (TIMPs). Our aim was to assess if the concentrations of MMPs and TIMPs were different between acute and chronic wounds in diabetic patients by analysing biopsy samples. METHODS: A 5 mm punch biopsy was taken from 20 diabetic foot ulcers of patients before initiating treatment and from traumatic wounds of 12 non-diabetic patients 2 days after injury. The concentrations of MMP-1, MMP-2(pro), MMP-2(active), MMP-8, MMP-9 and TIMP-2 were measured in detergent extracts of the biopsy homogenates using ELISAs and gelatin-zymography. RESULTS: The concentration of MMP-1 was increased 65-fold in biopsies of diabetic foot ulcers compared with the concentrations measured in biopsies of traumatic wounds. Similarly, MMP-2(pro) were increased threefold, sixfold for MMP-2(active), twofold for MMP-8 and 14-fold for MMP-9 compared to average concentrations in biopsies of traumatic wounds. Furthermore, the expression of TIMP-2 was reduced twofold in diabetic wounds compared with lesions of non-diabetic patients. CONCLUSION/INTERPRETATION: The combination of increased concentrations of MMPs with decreased concentrations of TIMP-2 in chronic diabetic foot ulcers compared with healing wounds in normal patients suggests that the increased proteolytic environment contributes to the failure of diabetic wounds to heal. New treatment strategies for healing chronic diabetic foot ulcers could be directed towards reducing concentrations of MMPs and increasing levels of TIMPs.

Biopsy↗
PubMed2002

[Strategies for control of diabetic foot syndrome. Amputation rate can be reduced!].

In two-thirds of the cases, wound healing can be achieved by good wound care, namely structured and stage-related management. Some 30% of the cases require extended and innovative therapeutic measures. In these complicated, poorly healing wounds, the supplementary use of special wound dressings or wound medication in the granulation phase can be considered. The application of such substances promoting wound healing (growth factors, cytokinin modulators, e.g. hyaluronic acid or protease inhibitors) may help to activate chronic lesions and thus initiate, and in particular abbreviate, healing. This aspect of reduced healing duration is of particular importance in the diabetic lesion, since it prevents or reduces secondary infection, the most common cause of major amputation.

Amputation, Surgical↗
PubMed2002

Association of increased plantar pressures with peripheral sensorimotor and peripheral autonomic neuropathy in Type 2 diabetic patients.

AIM: Diabetic polyneuropathy plays a highly significant role in the pathogenesis of the diabetic foot syndrome. It was the objective of this study to investigate the association of different forms of neuropathy (cardiac autonomic, sensorimotor and peripheral autonomic) with elevated plantar pressures in diabetic patients. METHODS: A total of 103 Type 2 diabetic patients was investigated. High plantar pressure was diagnosed when the total peak pressure was greater than 500 N/m2. Thirty-three participants were identified as patients with high-risk pressure and 70 patients had a mean peak pressure lower than 500 N/m2. All patients underwent a complete medical examination including determination of neuropathy, vascular status and foot pressures. RESULTS: Peripheral sensomotoric (p<0.012) and peripheral autonomic neuropathy (p<0.05) were significantly found more often in patients with high plantar pressures. There was no apparent association between autonomic cardial neuropathy and enhanced foot pressure (p=0.175). CONCLUSIONS: Our data clearly point to a correlation of diabetic neuropathy and higher plantar pressures. Interestingly, while there was a strong association between peripheral measures of neuropathy, no higher incidence of cardiac neuropathy in patients with increased foot pressure profiles was found. We strongly recommend that patients with clinical signs and indices of peripheral neuropathy be monitored by pedobarography for early detection and prophylactic shoe care for preventing the development of a diabetic foot ulcer.

Aged↗
PubMed2001

Relation between homocysteinaemia and diabetic neuropathy in patients with Type 2 diabetes mellitus.

AIMS: Limited data are available on determinants of diabetic neuropathy as its pathogenesis is multifactorial. Since homocysteine exhibits toxic effects on vascular endothelial cells, the association between homocysteine and the prevalence of neuropathy in Type 2 diabetes mellitus was investigated. METHODS: A total of 65 Type 2 diabetic patients were consecutively enrolled into the study. Neuropathy was diagnosed according to clinical symptoms, clinical examination, electrophysiological sensory testing and autonomic function testing. With regard to homocysteine-related parameters, plasma homocysteine, folate, vitamin B12, vitamin B6 and renal function (creatinine, ceratinine clearance, cystatin C) were measured, and the C677T polymorphism of the methylenetetrahydrofolate reductase gene was determined. RESULTS: Forty-three of the Type 2 diabetic patients were classified as suffering from neuropathy. Both patient groups were comparable with regard to demographic data, blood pressure, glucose metabolism, renal function and homocysteine-related vitamins. In contrast, homocysteine levels (P = 0.04) and the frequency of hyperhomocysteinemia (>or= 15 micromol/l) (P = 0.01) were significantly increased in neuropathic patients. In a logistic regression model with neuropathy as dependent variable, homocysteine (adjusted for creatinine, homocysteine-related vitamins, HbA1c and duration of diabetes) was the only significant variable associated with the prevalence of neuropathy (odds ratio for homocysteine per 5 micromol/l increase: 2.60 (95% confidence interval 1.07-6.33)). CONCLUSION: The data indicate that homocysteine is independently associated with the prevalence of diabetic neuropathy in a collective of Type 2 diabetic patients. A larger, prospective study would be desirable to clarify the role of homocysteine in the pathogenesis of diabetic neuropathy.

Adult↗
PubMed2001

Effects of preventative footwear on foot pressure as determined by pedobarography in diabetic patients: a prospective study.

AIMS: This study analysed the effects of specially manufactured insoles on foot pressures in diabetic patients during a 1-year prospective observation period. METHODS: We studied 81 type 2 diabetic patients without foot lesions. Using pedobarography three different regions of interest were examined: maximum peak pressure (MPP) of the total foot area, heel region and head of metatarsal bone I-III. Eighteen patients with high risk pressure (MPP of total foot 474 +/- 183 kPa; heel region 278 +/- 147 kPa, metatarsal 389 +/- 222 kPa) received optimal insole support. Sixty-three patients as a control group (MMP of total foot 367.7 +/- 157 kPa; heel 263.1 +/- 127 kPa, metatarsal 339.9 +/- 171 kPa) received conventional footwear. RESULTS: After insole support a 30% pressure reduction of total foot MMP (474 +/- 183 kPa vs. 290 +/- 106 kPa) was achieved in the treatment group. After 6 months (324 +/- 127 kPa) and 1 year (380 +/- 190 kPa) a pressure reduction was found. Between the 6- and 12-month controls plantar pressures again increased. In the control group a significant increase of all peak pressures occurred. CONCLUSIONS: Early insole support is successful in reducing plantar pressure. A repeated adjustment should be performed every 6 months to prevent foot pressure increases. The comparison of foot pressure development between the two groups showed constant levels in the treatment group. In the control group a marked increase of the pressure values was found. Identification and subsequent support of patients with high ulceration risk may help to reduce the high amputation rate.

Aged↗
PubMed2000

Impairment and recovery of elementary cognitive function induced by hypoglycemia in type-1 diabetic patients and healthy controls.

Although neuroendocrine changes after induction of hypoglycemia, in patients with diabetes and healthy persons, are thoroughly investigated, cognitive adaptation processes are still insufficiently understood. Changes in cognitive functions are mainly investigated by psychometric tests, which represent a summation of different cognitive processes. We aimed at dissecting cognitive adaptation into single components, i.e. stimulus selection, response choice, and reaction speed during a hyperinsulinemic hypoglycemic clamp in patients with type-1 diabetes and matched healthy controls. Using novel neurophysiological analyses, the event-related potentials of early stimulus selection (selection negativity) and response selection (lateralized readiness potential) were studied, in addition to reaction time (RT). A total of 12 diabetic patients and 12 normal volunteers were studied while receiving a hyperinsulinemic hypoglycemic clamp. RTs and the event-related potentials related to stimulus selection and response selection were significantly delayed during hypoglycemia in both groups, whereas early evoked potentials (P100) were unaltered. This suggests that hypoglycemia delays stimulus selection, with the consequence that also central and motor processing are delayed. In addition, patients with diabetes showed an earlier negative shift over the frontal cortex, which, when compared with the controls, reveals better adaptation to hypoglycemia in frontal cortical brain regions. After restoration of euglycemia stimulus selection, response selection and RT returned to baseline level in the type-1 group. In the control group, however, response selection and RTs were still delayed. This suggests that type-1 patients, possibly because of the past occurrence of hypoglycemic events, might be able to better cope with the hypoglycemic state than healthy volunteers who lack such a history. In summary, our data demonstrate, for the first time, that cognitive adaptation processes to an experimental hypoglycemic episode can clearly be dissected into their single components.

Adrenocorticotropic Hormone↗
PubMed1999

Analysis of the Gly40Ser polymorphism in the glucagon receptor gene in a German non-insulin-dependent diabetes mellitus population.

A heterozygous polymorphism changing GGT40 (Gly) to AGT40 (Ser) in the glucagon receptor gene (GCG-R) was reported to be associated with non-insulin-dependent diabetes mellitus (NIDDM). A possible involvement of this polymorphism in impaired glucose tolerance was also suggested in a French population. However, the prevalence of this polymorphism differs markedly among different ethnic groups, whereby the results in German populations were found to be contradictory. We thus investigated the association of this mutation with NIDDM and healthy subjects in 508 German subjects (196 NIDDM, and 312 controls). None of the control subjects, but one of the NIDDM patients demonstrated the Gly40Ser polymorphism. Since no first-degree relative of the index patient had this genetic variance, a de novo mutation is suggested. Although the frequency of the Gly40Ser polymorphism in NIDDM observed in France is not confirmed in our population, this genetic variance is also evident in Germany.

Adult↗
PubMed1997

Differentiation of hypoglycaemia induced cognitive impairments. An electrophysiological approach.

Effects of hypoglycaemia on distinct cognitive processes were assessed with event-related brain-potential (ERP) measures and reaction times in a hybrid selective-attention/response-choice task. One group of subjects received a euglycaemia-hypoglycaemia-euglycaemia treatment order and a second group a euglycaemia-placebo(euglycaemia)-euglycaemia sequence of treatments. During hypoglycaemia, ERP measures of selective attention (selection negativity), response choice (lateralized readiness potential) and reaction time were delayed compared with baseline performance. After restoration of euglycaemia, the onset of the selection negativity returned to baseline, whereas the lateralized readiness potential was still delayed, and error frequencies remained elevated. These results suggest that hypoglycaemia delays both the stimulus selection and the motor-response selection. They further suggest that the stimulus-selection process recovers quickly after restoration of euglycaemia, but that the response-selection process does not. Slow shifts in cortical potentials with a broad frontal distribution that occurred during hypoglycaemia, are discussed in relation to frontal lobe mechanisms involved in the control of subordinate, modality-specific selection mechanisms.

Adult↗
PubMed1995

Association between diabetic-autonomic-C-fibre-neuropathy and medial wall calcification and the significance in the outcome of trophic foot lesions.

The role of peripheral autonomic nerve failure in the development of medial arterial calcification is discussed controversially in the literature. In addition, the influence of medial wall calcification in the development of trophic foot lesions is still not fully understood. We have compared 28 diabetic patients with cardiac autonomic failure and/or decreased acetylcholine-induced sweat response with 22 diabetic patients without evidence of diabetic neuropathy and 27 healthy control subjects. A strong association was found between medial wall calcification and diminished heart rate variation (p.001) or diminished peripheral sweat response (p < 0.001). Only one subject in the control group exhibited a calcification of the tunica media in the lower limb. Medial calcinosis was accompanied by a significant rise of systolic ankle blood pressure (p < 0.05). In addition, there was a strong relationship between medial wall calcification and trophic foot lesions (p < 0.0001). Our results demonstrate a strong association between sympathetic C-fibre neuropathy and the development of medial wall calcification, as well as between calcification of the tunica media and trophic foot ulceration. Further investigation is necessary to determine whether there is a causal connection between medial arterial sclerosis and diabetic foot ulceration, or whether both are independent consequences of diabetic neuropathy.

Acetylcholine↗
PubMed1995

Peripheral osteopenia in adult patients with insulin-dependent diabetes mellitus.

Alterations in bone metabolism in diabetes mellitus is a topic of special interest. Bone blood flow is increased in the distal limb of diabetic patients, which is believed to increase osteoclastic activity. We measure bone mineral density using dual-photon absorptiometry in the distal lower limb, the femoral neck, and the lumbar spine in 41 IDDM patients and in 30 control persons. In the diabetic group there was a 10% reduction of bone mineral density in the femoral neck (p < 0.01) and a 12% reduction in the distal limb (p < 0.001) compared with the control group. No significant difference was found in the lumbar spine (p = 0.22). Our data yield incidence for peripheral osteopenia in IDDM-patients, independent of any systemic bone disease such as osteoporosis. A link between decreased bone mineral density and diabetic neuropathy has been observed for the femoral neck (p < 0.001), but not for the distal limb or axial skeleton. Whether there is a common aetiological link or a casual connection between diabetic neuropathy and bone mineral density has still to be determined.

Absorptiometry, Photon↗
PubMed1994

Association between "diabetic thick skin syndrome" and neurological disorders in diabetes mellitus.

Skin thickness on the extremities of patients with diabetes mellitus has been described controversially. Using high resolution ultrasonography, we were able to show a significant increase in skin thickness at the forearm (P < 0.05), thigh (P < 0.001) and lower limb (P < 0.05) of diabetic patients, most prominent at the thigh. No difference in skin thickness was found at the dorsum of the foot. In addition, skin thickness was not related to the duration of diabetes, age or HbA1. A close association was found between diabetic neuropathy and increasing skin thickness. Diabetic patients with neurological disorders had a significant increase in skin thickness versus diabetic patients without neuropathy. The present findings suggest that diabetic neuropathy and abnormalities of connective tissue have a common etiological link in their development or that both are time-dependent processes. Whether changes in capillary blood flow, increase of nonenzymatic glycosylation, polyol accumulation or other metabolic disorders are responsible for these findings remains still to be established.

Adult↗