Infection and diabetes: the case for glucose control

Monitoring of polymorphonuclear leukocyte functions in diabetes mellitus--a comparative study of conventional radiometric function tests and low-light imaging systems

In this study neutrophil (PMN) phagocytic capacity was investigated using a conventional radiometric ingestion assay (IN) in comparison with PMN respiratory burst activity assessed by luminol-enhanced chemiluminescence (LCL) in response to phorbolesters and LCL induction during phagocytosis of opsonized Staphylococcus aureus (STLCL) in diabetes mellitus and healthy controls. PMN ingestion was measured with 3H-thymidine-labelled S. aureus in a kinetic radiometric assay. LCL and STLCL were assessed in a parallel detecting microtitre-plate luminometer (MTP-Reader). PMN of diabetic subjects showed a highly significant reduction of peak LCL in response to PMA as well as during phagocytosis of S. aureus (STLCL) compared to non-diabetic controls (p < 0.001 respectively). PMN ingestion in diabetic patients (51.8 +/- 4.6%) was significantly reduced compared to controls (78.3 +/- 6.2%) (p < 0.01). The in vitro data displayed impaired PMN oxidative burst activity at glucose concentrations > or = 13.8 mmol/L, whereas PMN IN was significantly reduced at glucose levels > or = 27.75 mmol/L. The control group showed a positive correlation of peak LCL response and IN (p < 0.05) but not of STCL and IN; in diabetic patients this was also true, but did not reach statistical significance. The data obtained in this study clearly demonstrated impaired PMN respiratory burst activity and markedly reduced phagocytic PMN functions in diabetic patients ex vivo and in vitro as measured by LCL and by ingestion of 3H-thymidine-labelled S. aureus suggesting inhibitory effects of elevated glucose concentrations on various PMN-functions, which might be of clinical importance concerning altered host defence.

Impaired immunoglobulin G Fc fragment function in diabetics is caused by a mechanism different from glycation

Glycation and fluorescence at 440 nm (excitation at 370 nm) were found to be increased in immunoglobulin G (IgG) from diabetics, strongly indicating the presence of IgG-linked advanced glycosylation end products. In contrast, levels of IgG-linked advanced glycosylation end products were low or undetectable in both normal and diabetic subjects when an advanced glycosylation end products specific antibody was employed for immunological determination of advanced glycosylation end products. Furthermore, no correlation exists between IgG glycation, fluorescence and immunoreactivity. In diabetics, the Fc fragment of IgG showed decreased protein A binding and decreased fixation of complement. This impairment of biological activity was not correlated with the immunologically determined level of advanced glycosylation end products, whereas IgG-linked fluorescence was inversely related to complement fixing activity. These results indicate that mechanisms different from glycation or browning are responsible for changes in the functional properties of IgG.

Hepatic abscesses associated with diabetes mellitus in two dogs

Two diabetic dogs were presented for anorexia, persistent fever, and poor control of hyperglycemia. Both had neutrophilia with left shift, hypoalbuminemia, and increased serum alkaline phosphatase (SAP) activity. Radiography indicated intrahepatic gas densities in 1 dog and a hepatic mass in the other. Abdominal sonography demonstrated multiple well-demarcated hypoechoic hepatic lesions consistent with abscesses. Both dogs were successfully treated by surgical resection of the abscessed liver lobes in conjunction with antibiotics and supportive therapy. Good control of hyperglycemia was achieved in both dogs after recovery. Intracellular and extracellular Gram-negative rod-shaped bacteria were abundant in the abscesses from both dogs. These cases suggest an association between diabetes mellitus and hepatic abscessation.

Thiobarbiturate and fructosamine assays: significance and interest of the borohydride blank

The acute-phase reaction (APR) induces the production by the liver of short-lived glycoproteins. The carbohydrate moiety of these proteins is thought to interfere with the thiobarbiturate (TBA) and nitroblue tetrazolium colorimetric tests which are used for assaying non-enzymatic glycosylation (NEG) of serum proteins. The aim of the present study was to assess the effect of the APR on the specificity of the colorimetric tests in non-diabetic and diabetic subjects. A positive correlation was found between C-reactive protein (CRP), an APR glycoprotein, and non-specific TBA reactivity as determined after borohydride reduction (BH4-resistant TBA, BR-TBA), both in non-diabetics (r = 0.61; P < 0.01) and diabetics (r = 0.68; P < 0.01). The BH4-sensitive specific TBA (SP-TBA) was not influenced by glycoproteins, and its increase in diabetics was correlated with the nitroblue tetrazolium assay (r = 0.89; P < 0.01). An independent effect of diabetes and APR on non-specific TBA was also demonstrated, suggesting an effect of hyperglycaemia on both protein glycation and glycosylation. TBA with borohydride reduction is an attractive tool for the study of complex glycoproteins in diabetes.

Obesity as a risk factor in major reconstructive vascular surgery

In a prospective analysis of 150 consecutive major vascular reconstructions, 104 patients were of normal weight (NW), 33 were overweight (OW) and 13 were obese (OB), as defined by body mass index calculations (BMI = kg/m2). Wound infections were more common in OW than NW patients (10/33 versus 10/104, p < 0.01) and in the OB compared to the NW group (4/13 versus 10/104, p < 0.05). Wound dehiscence was more common in the combined OW and OB groups than the NW patients (3/46 versus 0/104, p < 0.01). Chest infections were more common in OB (4/13) than NW (9/104) patients (p < 0.02). Median (interquartile range) in-patient stay was longer in OB patients [34 (15-41) days] compared to OW [14 (10-19) days, p < 0.001] and NW [11 (8-15) days; p < 0.001] patients. Nonetheless, there were no significant differences in the rates of more major complications or operative mortality between the three groups and early infrainguinal graft patency and limb salvage rates were not different. Only one prosthetic graft infection occurred in this series. In conclusion, despite the higher risk of infective complications, major vascular reconstruction can be performed safely in overweight and obese patients.

Adhesins and ligands involved in the interaction of Candida spp. with epithelial and endothelial surfaces

Adhesion of candidal species to the epithelium of the gastrointestinal or genitourinary tract stands as a critical first step in the pathogenesis of candidal infection. After colonization and replication at mucosal surfaces, Candida albicans and other pathogenic species may penetrate the mucosal barrier, enter the vascular tree, and disseminate hematogenously. The consequences of this pathogenic cascade evoke considerable morbidity and mortality, especially among immunocompromised patients. Thus, interactions of C. albicans and other candidal species with epithelium and endothelium may lead to serious consequences for the human host. This review evaluates candidate candidal adhesions for epithelial and endothelial surfaces, with emphasis on the specificity of the interaction, the inhibitors that have been employed, and the ligands that have been identified on mammalian cells or matrices. Three types of interactions are described: protein-protein interactions, lectin-like interactions, and incompletely defined interactions in which the adhesive ligand is as yet unidentified. Special attention is given to the roles of integrin-like proteins. Differences in the mechanisms of candidal attachment to epithelium and endothelium are delineated. Last, on the basis of the available literature, avenues of potentially fruitful investigation are proposed.

Management dilemmas in the individual with cystic fibrosis and diabetes

As their life expectancy has improved, patients with cystic fibrosis (CF) have experienced an increasing incidence of diabetes. Hyperglycemia may adversely influence weight, pulmonary function, and development of microvascular complications. Strict control of blood glucose has not universally been sought, however. A program of multiple daily insulin injections and self-monitoring of blood glucose with an aim of normoglycemia is described in this article. The typical cystic fibrosis diet is variable in quantity and features a preponderance of simple carbohydrates; this is contrary to the usual diabetes meal plan. We describe the use of a flexible meal-planning system to establish individualized carbohydrate targets with specific insulin boluses titrated to each meal to control postprandial blood glucose excursions. Records of 22 patients followed for more than 1 year are reviewed. Mean (+/- standard error of the mean) glycosylated hemoglobin was reduced from 11.3 +/- 3.1% (at baseline) to 8.1 +/- 1.8% (at 1 year). Mean percent of ideal body weight also increased from 95.4 +/- 15.2 to 100 +/- 17.1. We conclude that strict metabolic control is an attainable goal in patients with cystic fibrosis and is associated with positive weight gain.

Glycation increases the vascular clearance rate of IgG in mice

As elevated levels of glycated IgG have been detected in the plasma of diabetics we have investigated whether glycation of IgG affects its vascular clearance rate, using a mouse model system. Polyclonal mouse IgG was aseptically incubated for 14-19 days with 0.5 M glucose in 0.1 M phosphate buffer (pH 7.4) at 37 degrees C. As control, IgG was incubated under identical conditions but with no added glucose. After incubation, both forms were labelled with 125I and injected intravenously into BALB/c mice. The rate of vascular clearance of the glycated IgG was found to be significantly higher than the control IgG in the periods 5-24 h (P < 0.001, n = 6) and 24-48 h (P < 0.01, n = 6) after injection. After 2-3 days the mice were killed and the major organs were harvested. With glycated IgG there was a significant increase in the 125I accumulated in the kidney (P < 0.02). In later experiments, dual labelling with 131I and 125I allowed mixtures of glycated and unglycated IgG to be injected into the same mouse so that the vascular clearance of both forms of IgG could be followed simultaneously. These experiments confirmed that glycation of the IgG significantly increases its vascular clearance rate.

The effects of 3-hydroxybutyrate and glucose on human T cell responses to Candida albicans

Diabetic patients are particularly susceptible to mucocutaneous candidosis. T lymphocytes are central to the induction of antigen-specific immune responses and may be sensitive to the biochemical abnormalities associated with poorly controlled diabetes; namely, hyperglycaemia and/or ketonemia. To examine this we have studied the effect of varying concentrations of glucose and 3-hydroxybutyrate (3-HB) in cultures of human T cells stimulated with Candida albicans antigen. Proliferation of T cells from six type 1 diabetic and six non-diabetic control subjects was significantly inhibited (both P < 0.05) in glucose-free medium, and at a glucose concentration of 80 mmol l-1 as compared with cultures containing glucose at physiological concentration (5 mmol l-1). 16 and 32 mmol l-1 3-HB also inhibited T cell proliferation in the presence of 5 mmol l-1 glucose (P < 0.05). The effect of glucose and 3-HB were not additive and the inhibition was not due to cell death. 32 mmol l-1 3-HB had less effect when present solely during antigen pulsing than during subsequent lymphocyte stimulation, and was effective even when added after 72 h of a six day culture. This suggests that ketosis affects T cell proliferation more than antigen processing and presentation. We conclude that human antigen-specific T cell proliferation is inhibited in vitro only by concentrations of 3-HB encountered in moderately severe diabetic ketoacidosis, and by glucose concentrations found in severe hyperosmolar non-ketotic coma. The impairment of T cell function under such extreme conditions could be implicated in the close association of diabetic ketoacidosis with deep fungal infections, particularly invasive mucormycosis.

Identifying and treating common and uncommon infections in the patient with diabetes

Patients with diabetes represent a unique group of individuals who appear more prone than others to developing infections. Several mechanisms have been proposed to explain the association between diabetes and infections. However, few conclusive studies exist and considerable debate continues regarding evidence for this predisposition. Despite this lack of documented proof, many health care practitioners acknowledge that a number of infections are overrepresented in patients with diabetes. Some of these infections appear to occur exclusively in patients with diabetes, especially patients who are poorly controlled. The presenting clinical features, causative organisms, and preferred treatment approaches will be discussed in this article for a variety of common and uncommon infections observed in patients with diabetes. In addition, the proposed predisposing factors will be addressed briefly.

Problems and pitfalls of sulphonylurea therapy in older patients

The prevalence of non-insulin-dependent diabetes mellitus (type II) increases with age, so that approximately half of all known patients in English-speaking countries are over 65 years of age. There is no reason to believe that the criteria for blood glucose control should be any less stringent for elderly patients unless they have a limited life expectancy. Sulphonylurea drugs remain an effective means of achieving blood glucose control after failure of dietary therapy alone in older patients. However, changes in normal metabolism of drugs with age and the development of other pathologies in elderly patients make it important that these drugs are prescribed with care. Severe symptomatic hypoglycaemia is the most serious adverse effect of sulphonylurea drugs and this becomes progressively more likely with increasing age, depending primarily on the substantial reduction of renal function with normal aging. Other adverse effects are much less commonly of clinical importance. To minimise the risk of hypoglycaemia, it is important that patients receive closely supervised dietary management with education about their disease for at least 3 months before sulphonylurea drugs are prescribed. In elderly patients a short-acting agent with no active metabolites should be used. As patients become older, those receiving long-acting agents can be changed to short-acting agents before problems arise. If blood glucose control appears satisfactory on treatment, then symptoms of hypoglycaemia should be sought. If control is poor, then the criteria for introduction of insulin, with appropriate education, do not differ from those in younger patients.

Distinct mechanisms of epithelial adhesion for Candida albicans and Candida tropicalis. Identification of the participating ligands and development of inhibitory peptides

The yeast Candida albicans is the leading cause of disseminated fungal infection in neonates, immunocompromised hosts, diabetics, and postoperative patients; Candida tropicalis is the second most frequent isolate. Because the integrin analogue in C. albicans shares antigenic, structural, and functional homologies with the beta 2-integrin subunits alpha M and alpha X, we investigated the role of integrin analogues in epithelial adhesion of C. albicans and C. tropicalis. On flow cytometry with the monoclonal antibody (mAb) OKM1, surface fluorescence was highest for C. albicans and significantly reduced for C. tropicalis (P < 0.001). However, adhesion to the human epithelial cell line HeLa S3 did not differ for these two candidal species: specific adhesion was highest for C. albicans at 44.0 +/- 1.8%, and only slightly lower for C. tropicalis at 38.8 +/- 3.6% (P = NS). The disparity between expression of the integrin analogue and epithelial adhesion suggested distinct mechanisms for this process in C. albicans versus C. tropicalis. Preincubation of C. albicans with anti-alpha M mAbs, with purified iC3b (the RGD ligand for the integrin analogue), or with 9-15-mer RGD peptides from iC3b all inhibited epithelial adhesion significantly (P < 0.001-0.04). Purified fibronectin or fibronectin-RGD peptides failed to block C. albicans adhesion. In contrast, epithelial adhesion of C. tropicalis was significantly inhibited by purified fibronectin and its RGD peptides (P < or = 0.021), but not by iC3b nor the iC3b-RGD peptides. Both iC3b and fibronectin were identified on the surface of epithelial cells after growth in serum-free medium. A polyclonal antibody to C3 inhibited C. albicans adhesion while a control antibody to fibronectin was ineffective; the converse was true for C. tropicalis. These results indicate that the pathogenic yeasts C. albicans and C. tropicalis recognize distinct RGD ligands present at the surface of the epithelial cell and that these interactions can be differentially inhibited by defined RGD peptides containing appropriate flanking sequences.

Poor glycemic control and antepartum obstetric complications in women with insulin-dependent diabetes

OBJECTIVE

The purpose of this study was to test the hypothesis that the rate of complications of pregnancy in women with insulin-dependent diabetes is higher than in nondiabetic women and is associated with poor glycemic control and microvascular disease.

METHOD

Women who enrolled in a multidisciplinary program of diabetes in pregnancy prior to 20 weeks' gestation were included in the study and matched 1:2 by age, race and parity to a control group of nondiabetic women. Complications of pregnancy were retrospectively analyzed and compared between groups. The association of complications with glycemic control and microvascular disease was analyzed within the diabetic group.

RESULT

Women with diabetes had significantly higher rates of pregnancy-induced hypertension (PIH), polyhydramnios, pyelonephritis, preterm delivery and meconium-stained amniotic fluid. Poor glycemic control, particularly during the first and second trimesters of pregnancy, was associated with all complications, except pyelonephritis. Microvascular disease was associated with PIH and preterm delivery prior to 34 weeks.

CONCLUSION

Women with insulin-dependent diabetes are at high risk for complications of pregnancy. Glycemic control during the first and second trimesters may affect events later in pregnancy.

Bacteriuria, bacterial virulence and host factors in diabetic patients

The prevalence of bacteriuria as well as bacterial virulence and host factors were studied in 514 diabetic outpatients and 405 nondiabetic controls. The prevalence of bacteriuria was not significantly higher in diabetic women (15/239, 6.3%) than in age-matched nondiabetic women (8/236, 3.4%). In diabetic and nondiabetic men, the prevalence was also similar but lower than in women. E. coli was found in 55% of urine cultures with significant growth from diabetic patients, while in 91% of positive cultures from nondiabetic controls. Most E. coli strains lacked ability of P-fimbriae-mediated adhesion and aerobactin-mediated iron uptake, indicating low bacterial virulence. Long-term metabolic control (HbA1c), prevalence of retinopathy, neuropathy and previous foot ulcers were similar in bacteriuric and nonbacteriuric diabetic patients, matched according to gender, age, and duration of diabetes. Renal function was also similar, though the frequency of proteinuria and elevated blood pressure tended to be higher in the bacteriuric than in the noninfected group. Eight-three percent of the bacteriuric patients reported previous urinary tract infections but only 61% of nonbacteriuric patients (p = 0.07). As compared to non-diabetic women, diabetic women reported significantly more previous urinary tract infections (p < 0.01). In conclusion, the prevalence of bacteriuria in diabetic outpatients was not significantly higher than in non-diabetic outpatients or healthy volunteers. No studied host factor was clearly associated with bacteriuria in diabetic patients, although proteinuria and hypertension tended to be more common. The infecting E. coli strains were of low virulence.

Bovine and human NPH insulins as T cell immunogens

The aim of this study was to assess the immunocompetence of T cells from patients with poorly controlled diabetes with respect to Candida albicans antigen and to compare the relative immunogenicity of human insulin, bovine insulin and protamine at the T-cell level during 6 months treatment with human or bovine NPH insulins. T-cell proliferation was measured in vitro in response to C. albicans, bovine and human insulin, bovine and human NPH and protamine in 17 patients with newly-diagnosed type 1 (insulin-dependent) and 12 with poorly-controlled type 2 (non-insulin-dependent diabetes) before and after 0.5, 1, 3 and 6 months of treatment with either bovine or human NPH insulin. The following results were found: Baseline responses to C. albicans (as a recall antigen) were similar for patients and controls despite marked hyperglycaemia in the patients. No patient had a response greater than mean + 2 S.D. of controls to human or bovine insulin before starting treatment, or had insulin autoantibodies. Treatment with human NPH insulin did not induce T-cell responses to human or bovine insulin, but 3/13 (23%) patients treated with bovine NPH responded to bovine and human insulin after 6 months, of whom one responded exclusively to human. In contrast, 6 (46%) bovine and 3 (19%) human NPH-treated patients responded to protamine. It was concluded that there is no evidence of T-cell immunosuppression in poorly-controlled diabetes or of T-cell autoimmunity to insulin in newly-diagnosed type 1 diabetes. Treatment with bovine NPH insulin immunizes T cells to insulin, but human NPH does not.(ABSTRACT TRUNCATED AT 250 WORDS)

Prevalence of diabetes mellitus in odontogenic infections and oral candidiasis: an analysis of neutrophil suppression

The prevalence of diabetes mellitus (DM) in odontogenic infections and oral candidiasis was examined, and influences of DM on the clinical manifestations of the infections and neutrophil functions were investigated. Among 21 severe and 221 mild odontogenic infections, DM was detected in 5 cases in each group. Of 64 cases of symptomatic oral candidiasis, 8 cases were complicated with DM which was detected by blood examination during treatment. During the period of infection, the mean fasting blood sugar level was 16.0 +/- 4.4 and 9.8 +/- 1.2 mmol/l in the DM-complicated odontogenic infections and candidiasis, respectively. All white blood counts, C-reactive protein levels and erythrocyte sedimentation rates were more elevated in DM(+) odontogenic infection cases than in DM(-) ones. In DM(+) candidiasis, hyposalivation (0.79 +/- 0.54 ml/10 min) was observed. The polymorphonuclear leukocytes from diabetic patients, especially those with candidiasis, produced less free oxygen radicals and exhibited reduced phagocytosis and intracellular killing of Candida cells associated with this reduced O2- generation during the infection. These suppressed neutrophil functions increased after treatment but did not reach control levels. These results indicate that DM is a predisposing condition for odontogenic infections and oral candidiasis, that DM-complicated infections become severe because of neutrophil suppression, and that examination of blood sugar level should be essential for patients with oral infections.

Evidence of ex vivo and in vitro impaired neutrophil oxidative burst and phagocytic capacity in type 1 diabetes mellitus

In this study neutrophil (PMN) oxidative burst activity was investigated ex vivo and in vitro in comparison to the PMN-phagocytic functions ingestion and bacterial killing in poorly-controlled type 1 diabetic patients. Luminol enhanced chemiluminescence in response to phorbolesters as a measure of oxidative burst was assessed in a parallel detecting microtiterplate luminometer in 40 poorly-controlled type 1 diabetic subjects. PMN ingestion was measured with [3H]thymidine-labelled Staphylococcus aureus in a kinetic radiometric assay. Microbicidal activity was determined by pure plate counting of surviving bacteria (colony forming units, cfu) after defined pmn challenge. PMNs of type 1 diabetic subjects showed a highly significant reduction of peak CL response in response to PMA compared to nondiabetic controls (P < 0.001) and PMN ingestion (51.8 +/- 4.6%) and bacterial killing (28.6 +/- 3.2%) were reduced as well (78.2 +/- 5.2% (IN) and 18.4 +/- 4.1% (BK), P < 0.01, respectively). The in vitro data displayed impaired PMN oxidative burst activity at glucose concentrations > or = 13.8 mmol/l whereas PMN IN and BK were significantly reduced at glucose levels > or = 27.75 mmol/l. In the control group there was a positive correlation of peak CL response and IN as well as BK (P < 0.05); in type 1 diabetic patients this was also true, but did not reach statistical significance. The data obtained in this study clearly demonstrated impaired PMN oxidative burst activity and markedly reduced ingestion and bacterial killing in type 1 diabetic patients ex vivo and in vitro.(ABSTRACT TRUNCATED AT 250 WORDS)

Hypertonic glucose inhibits the production of oxygen-derived free radicals by rat neutrophils

We studied the influence of graded degrees of hypertonic glucose or sucrose on the generation of oxygen-derived free radicals by rat neutrophils. Hypertonic glucose and sucrose exerted dose- and time-dependent inhibition of chemiluminescence amplified by luciferin analog (CLA-DCL) and luminol (L-DCL) in response to fMLP. Hypertonic glucose was more effective to this chemiluminescence inhibition than hypertonic sucrose was. This inhibition of hypertonicity was more effective in CLA-DCL than in L-DCL. Although the production of superoxide anion measured by the reduction of ferricytochrome c was more inhibited by hypertonic glucose than by hypertonic sucrose, the myeloperoxidase activity was not affected by either glucose or sucrose hyperosmolarity. These data suggest that hyperosmotic state by itself and an additional direct glucose-toxicity may contribute to the impaired neutrophil function in the diabetic state.

Evaluation of a practical technique for determining insulin requirements in diabetic patients receiving total parenteral nutrition

A practical technique to provide central parenteral nutrition to insulin-taking diabetic patients based on prehospitalization insulin requirements and insulin placed in the central parenteral nutrition was originally presented based on retrospective review. The present article confirms the safety and applicability of this method after a multiyear period of application. Particularly noteworthy are the absence of hypoglycemic episodes, the attainment of reasonable blood glucose control, and the relatively consistent relationship of insulin required in central parenteral nutrition to prehospitalization insulin requirements.

Selective decontamination of the digestive tract in intensive care

Nosocomial infection in intensive care unit (ICU) practice is a common problem and is associated with abnormal carriage of Gram-negative aerobic bacilli in the gastrointestinal tract, resulting in endogenous infections. Selective decontamination of the digestive tract (SDD) is a regimen aimed at preventing or eradicating this abnormal carriage. A large number of trials examining SDD in ICU practice have been published, the vast majority showing a significant reduction in the incidence of nosocomial, Gram-negative infection. However, the impact on morbidity and mortality is much less certain. A recent meta-analysis has suggested a 10-20% reduction in mortality (3-6% absolute difference) with SDD. A discussion of these results is presented together with potential criticisms of SDD.

Infection and immune response in the elderly

A number of immunologic functions have been shown to decline in an age-related fashion, particularly cell-mediated immunity and antibody response to an immunogen. Underlying degenerative diseases and medications further contribute to the immunologic abnormalities noted in the elderly. The elderly in hospitals and nursing homes are a particularly vulnerable subset, with a high incidence of institutionally acquired infection. Aspects of disease prevention in the elderly are discussed.

Increases in plasma lysosomal enzymes in type 1 (insulin-dependent) diabetes mellitus: relationship to diabetic complications and glycaemic control

Lysosomal enzymes degrade membrane glycoconjugates, and increased circulating enzyme activity may be an important mechanism in the pathogenesis of diabetic microangiopathy. We have assayed a profile of seven lysosomal enzyme activities (nmol.h-1.ml-1) in platelet-free plasma from 54 Type 1 (insulin-dependent) diabetic subjects (median age 31 years) and 42 matched normal control subjects. A significant increase in median (interquartile range) enzyme activity was measured in diabetic compared to control subjects for beta-D-glucuronidase, 121 (97.7-171) vs 88.8 (62.8-113), p less than 0.001; beta-D-Nacetylglucosaminidase, 693 (568-799) vs 568 (462-686), p less than 0.001; alpha-D-mannosidase, 23.8 (16.7-28.9) vs 14.5 (10.1-20.0), p less than 0.001; and beta-D-galactosidase, 6.94 (6.11-9.99) vs 6.66 (4.78-8.33), p less than 0.04. In contrast, alpha-L-fucosidase, alpha-D-galactosidase and beta-D-mannosidase activities were similar in diabetic and control subjects. None of the enzyme activities differed significantly (p less than 0.05) between 24 diabetic patients with clinical complications and 30 complication-free diabetic patients with similar glycaemic control which does not support the hypothesis that enzyme increases in diabetes arise simply by leakage from damaged tissues. In the diabetic subjects HbA1, median (interquartile range) 9.10 (7.40-10.60), was significantly related to beta-D-glucuronidase (rs = 0.56, p less than 0.001) and beta-D-Nacetylglucosaminidase (rs = 0.55, p less than 0.001). We have therefore demonstrated in diabetic subjects an increase in certain lysosomal glycosidases, that correlates with glycaemic control.(ABSTRACT TRUNCATED AT 250 WORDS)

Oral disorders associated with diabetes mellitus

The protean manifestations of diabetes include various associated oral disorders such as sialosis, xerostomia, impairment of taste, and localized infections of which oral candidosis is the most commonly observed. The association of specific oral diseases and diabetes is of importance both in the detection of undiagnosed diabetes and in the elucidation of the pathogenesis of various oro-facial diseases. The clinical features and possible causes of oral disorders recognized to be associated with diabetes are reviewed with emphasis on good oral hygiene in the diabetic patient.

Intracellular hydrogen peroxide production by peripheral phagocytes from diabetic patients. Dissociation between polymorphonuclear leucocytes and monocytes

Although the standard assays for reactive oxygen species have been based on the measurement of those released into the extracellular environment, the microbicidal capacity to the engulfed microorganisms is mainly dependent on those released into the intracellular environment, such as phagosomes. We studied intracellular oxidative activities of individual phagocytes by dichlorofluorescein (DCFH) oxidation assay to investigate the relationship between the reactive oxygen species released intracellularly and the impaired microbicidal capacity in diabetic patients. Time courses of intracellular production of hydrogen peroxide by polymorphonuclear leucocytes (PMNL) and monocytes were observed at the resting condition and after the stimulation with phorbol myristate acetate (PMA; 160 nM) by flow cytometry. Thirty-four patients with non-insulin-dependent diabetes mellitus (NIDDM) and 23 age-matched healthy volunteers were subjected to the studies. PMNL from patients with NIDDM showed a significantly decreased capacity to produce hydrogen peroxide after the stimulation (P less than 0.05 at 15 min, P less than 0.01 at 30 and 45 min). By contrast, intracellular hydrogen peroxide production by monocytes at the resting condition and an early stimulatory phase (8 min after the stimulation) was significantly (P less than 0.01) enhanced in patients with NIDDM compared with that in controls. Both the changes of intracellular hydrogen peroxide production observed in PMNL and monocytes from patients with NIDDM were in association with an increased haemoglobin Alc level in erythrocytes, but did not relate to total cholesterol and triglyceride levels in the serum. The possible mechanisms of these dissociated changes in hydrogen peroxide producing capacity of phagocytes from patients with NIDDM are discussed.

Management of diabetes in surgery: a survey of current practice by anaesthetists

A questionnaire survey of anaesthetists, based at the three main hospitals in Bristol, was undertaken to determine what methods are currently being used by anaesthetists to manage diabetes in patients for surgery. Replies were received from 56 of the 90 anaesthetists (62%). Surgical procedures were defined as minor, moderate, and major. Two areas were identified where considerable differences in management between anaesthetists occurred, namely insulin-treated patients requiring minor surgery, and non-insulin-treated patients requiring moderate surgery. In addition, no consensus view was apparent for the preferred intra-operative blood glucose range or for the threshold blood glucose level at which to postpone an operation. It was apparent that anaesthetists preferred to administer intravenous insulin by a syringe pump rather than by a drip bag containing insulin, potassium, and glucose, particularly if more severe metabolic upset was anticipated. No difference in management was apparent between different hospital grades or between the three hospitals.

Effects of anaesthesia and surgery on the immune response

Alterations have been found to occur in every component of immune response during anaesthesia and surgery. These alterations represent the body's general physiological responses and are mainly dependent on the extent of surgery, as well as other factors such as the patient's age and health status, medication and blood transfusion. Anaesthetic and operative complications have profound effects on these responses. Basically, the immune response to anaesthesia and surgery is a beneficial reaction, needed in local host defences and wound healing and in preventing the body from making autoantibodies against its own tissues. The responses may, however, contribute to the development of postoperative infections and spread of malignant disease. During uncomplicated conventional surgery, the immune response usually passes clinically unnoticed without any harmful effects. Absent responses and excessively high responses, on the other hand, harm the patient. Our understanding of immunological phenomena and our possibilities of controlling mediator activation are now lagging behind the technical advances made in operative treatment. If we want to decrease operative morbidity and mortality to below their present levels, more attention should be directed to immune responses to major surgery, injuries and operative complications with massive mediator release which place the surgical patient at risk. Experimental evidence suggests that results of treatment in injured and operated patients can in the future be improved by controlling immune responses and their mediator systems. Our current level of knowledge of immune responses is already helping us to avoid many immune-mediated complications. However, routine interference with these responses is not indicated.

Urinary tract infections in patients with diabetes mellitus

We have endeavoured to determine whether there is any difference in the bacteriological pattern of UTI and the antibiotic sensitivity patterns of the pathogens concerned between diabetic and non-diabetic patients. Over a period of 1 year, a total of 287 diabetic patients (221 females and 66 males) with community-acquired and nosocomial urinary tract infections were studied. There were 265 patients (228 females and 37 males) without any predisposition to urinary tract infections (UTI) and who served as controls. Although Escherichia coli was the predominant organism in community-acquired UTI in diabetic patients, it was found significantly less than in the non-diabetic population (P less than 0.005). The percentage of Klebsiella species causing community-acquired UTI in diabetic patients was significantly higher than in non-diabetics (P less than 0.005). The antibiotic sensitivity patterns of the organisms in the two groups, however, were not significantly different. The organisms isolated from nosocomial UTI in diabetics showed a significantly greater preponderance of Klebsiella spp. and a significantly lower percentage of E. coli when compared to community-acquired UTI in diabetics (P less than 0.005). Klebsiella spp. in nosocomial UTI of diabetics showed an overall increase in resistance to antibiotics. At least a quarter of the isolates of Klebsiella spp. in nosocomial UTI were resistant to third-generation cephalosporins. Patients with diabetes mellitus appear to have an increased incidence of Klebsiella spp. as the pathogen in both community-acquired and nosocomial UTI. Antibiotic resistance in the organisms isolated from nosocomial UTI is greater than that related to community-acquired UTI in diabetic patients.

The influence of aldose reductase on the oxidative burst in diabetic neutrophils

Lucigenin-enhanced chemiluminescence was examined as an index of neutrophil superoxide production in four groups of 20 subjects: controls with/without infection and type 1 diabetics with/without infection. At 5 mM glucose there was no significant difference in chemiluminescence output between neutrophils from the four groups (P greater than 0.01). Increasing the in vitro glucose concentration from 5 to 20 mM produced an 8.75% reduction in superoxide in the combined control groups, compared with a 21.45% reduction in the diabetic subjects (P less than 0.01). With the addition of an aldose reductase inhibitor (Statil, ICI) to neutrophils from diabetic subjects, the suppression caused by an increase in glucose concentration to 20 mM was reduced to 4.5%. This value was similar to the controls (P greater than 0.01). Neutrophil aldose reductase activity, measured in 28 diabetic subjects was 0.024 +/- 0.003 U/10(8) cells (mean +/- SE). There was a significant correlation between aldose reductase activity and superoxide suppression (P less than 0.01, r = 0.64). These results suggest that aldose reductase is responsible for reduced superoxide production in diabetic patients and the addition of an aldose reductase inhibitor to the diabetic neutrophil restores superoxide output to control values.

Aldose reductase inhibitors and diabetic complications

Aldose reductase inhibitors impede flux of glucose through the sorbitol pathway in diabetes mellitus. They therefore reduce the accumulation of the pathway metabolites, sorbitol and fructose, reduce the impact of the flux on the cofactors used by the pathway and reduce other derived phenomena, such as osmotic stress and myo-inositol depletion. As drugs, their targets are the chronic complications of diabetes--neuropathy, retinopathy, nephropathy and vasculopathy. In experimental models there is proof of activity against biochemical, functional and structural defects in all of the involved tissues, but we await full clinical verification of this potential.

Frequent hospital admissions for bacterial infections among aboriginal people with diabetes in central Australia

OBJECTIVE

To determine hospital-based morbidity and mortality from bacterial infections among Aboriginal people with diabetes in central Australia.

DESIGN

Examination of medical records on diabetic inpatients between January 1984 and December 1986.

SETTING

Alice Springs Hospital in central Australia, covering an Aboriginal population of about 12,500 people.

PATIENTS

Subjects admitted with a bacterial infection (n = 165) were selected from the database of all Aboriginal people known to have diabetes in the region (n = 374; all had non-insulin dependent diabetes).

MAIN OUTCOME MEASURES

Number of admissions, type and site of infections, causative organisms, duration of hospital stay and cause of death.

RESULTS

The 281 admissions for infections accounted for 4.6% of adult Aboriginal admissions to hospital. Thirteen patients died. Eleven patients required amputation of a digit or limb. In 1986, 13/200 patients admitted with diabetes had bacteraemia compared with 14/1885 patients who did not have diabetes. One patient had Fournier's gangrene, one had malignant otitis externa, one community acquired Acinetobacter pneumonia, one pneumonia with Succinivibrio spp. found in blood cultures, and one meningitis and transverse myelopathy with Streptococcus milleri found in blood cultures.

CONCLUSIONS

The frequency, type and severity of infections in the relatively young patients result in high personal costs to the community and financial costs to the health care system. Standard preventive measures must be implemented to control severe bacterial infections among subjects with diabetes in this socially and economically marginalised population group.

Fournier's gangrene of scrotum in a patient with AIDS

Fournier's gangrene of the scrotum, a form of necrotising fasciitis, is a rare but potentially fatal disorder. Predisposing conditions include chronic alcoholism and diabetes mellitus, possibly as a result of impaired immunity. Fournier's syndrome, occurring in a patient with AIDS, is described.

Mixed acid fermentation of glucose as a mechanism of emphysematous urinary tract infection

Emphysematous pyelonephritis is a severe necrotizing infection that usually occurs in patients with diabetes mellitus or obstructive uropathy. Although glucose fermentation has been considered as the main cause of gas production the actual mechanism remains controversial. Compositions of gas samples from 2 patients with emphysematous pyelonephritis recently encountered were analyzed, and showed 15% hydrogen, 4.8% carbon dioxide, 60% nitrogen, 6.7% oxygen and some unknown gases in case 1, and 3.4% hydrogen, 22% carbon dioxide, 66% nitrogen and 9.8% oxygen in case 2. These results tend to implicate mixed acid fermentation of glucose as the pathway by which emphysematous urinary tract infections develop.

Molecular mimicry in Candida albicans. Role of an integrin analogue in adhesion of the yeast to human endothelium

Hematogenous infection with the yeast Candida albicans now occurs with increasing frequency in the neonate, the immunocompromised patient, and the hyperglycemic or hyperalimented host. Yeast-phase C. albicans expresses a protein that is antigenically and structurally related to CD11b/CD18, a member of the beta 2 integrins and a well-characterized adhesin for mammalian neutrophils. Both the neutrophil protein and its analogue in C. albicans have an identical affinity for the C3 ligand iC3b, and both proteins are significantly increased in expression at 37 degrees C. Given these several similarities, we therefore studied the role of the integrin analogue on C. albicans in the adhesion of the yeast to human umbilical vein endothelium (HUVE). After growth of C. albicans in 20 mM D-glucose, as opposed to 20 mM L-glutamate, flow cytometric analysis with monoclonal antibodies recognizing the alpha-subunit of CD11b/CD18 demonstrated a 25.0% increase in mean channel fluorescence (range 18.4-31.8%), as well as an increased percentage of yeasts fluorescing (P less than 0.02). This increased intensity of fluorescence, which corresponds to increased expression of the integrin analogue, also correlated with a significant increase of 30-80% in adhesion of glucose-grown C. albicans to HUVE (P less than 0.02). Blockade of the integrin analogue on C. albicans by monoclonal antibodies recognizing adhesive epitopes on neutrophil CD11b/CD18 inhibited glucose-enhanced adhesion of C. albicans to HUVE. Incubation of glucose-grown C. albicans with saturating concentrations of purified human iC3b, the ligand for CD11b/CD18, reduced adhesion of the yeast to HUVE by 49.7%, whereas BSA in equimolar concentration had no effect (P less than 0.001). These results identify a glucose-responsive integrin analogue on C. albicans as one of possibly several cellular structures that mediate adhesion of the yeast to human endothelium.

Alterations in monocyte receptor function in type 1 diabetic patients with ketoacidosis

The level of expression of three monocyte cell surface receptors was studied in seven patients with Type 1 (insulin-dependent) diabetes admitted to hospital with ketoacidosis. After recovery of metabolic control the monocyte carbohydrate-binding ('lectin-like') receptors that recognize bacterial cell wall sugars and receptors for complement components were reduced in the patients compared with normal control subjects. This was in contrast to the expression of the receptor for the Fc portion of immunoglobulin which remained unaltered. Compared with the control subjects the level of 'lectin-like' receptors was reduced by 22.8 +/- 6.5% (p less than 0.05) on admission to hospital and 12.1 +/- 1.7% (p less than 0.001) 6 weeks later when metabolic control had been established. The expression of complement receptors was 33.8 +/- 8.1% (p less than 0.01) lower than normal subjects when the diabetic patients suffered from ketoacidosis and 8.6 +/- 1.6% (p less than 0.01) lower than control subjects when patients had recovered metabolic control. The increased susceptibility to infection seen in diabetic patients, and the high incidence of infection in patients with ketoacidosis, may be partially the result of these changes in monocyte recognition mechanisms.

Effect of epidemic influenza on ketoacidosis, pneumonia and death in diabetes mellitus: a hospital register survey of 1976-1979 in The Netherlands

The influence of epidemic influenza on hospitalizations because of influenza, pneumonia and diabetic acidosis in patients with diabetes mellitus was investigated. Data on the weekly incidence of influenza-like illness were obtained from the Continuous Morbidity Registration and the cumulative data on hospitalizations in short-stay hospitals were obtained from the National Medical Registration. Patients with duodenal ulcer were used as a control population. Epidemic elevations of influenza infections were observed in 1976 and 1978. The estimated relative risk for hospitalization because of influenza infection was 1.1 and 1.0 for the two non-epidemic years 1977 and 1979, respectively. For the epidemic years 1976 and 1978 this risk was calculated to be 5.7 and 6.2, respectively. An increased relative risk was also noted for pneumonia; being 25.6 for both epidemic years. The estimated relative risk of dying during hospitalization rose from 30.9 in 1977 to 91.8 in 1978. The number of hospitalizations for ketoacidosis was 50% higher in 1978 than in the other three years. During the epidemic years, 25.7% of patients hospitalized for pneumonia died, while this percentage was 14.6% in the non-epidemic years (P less than 0.05). Differences in mortality due to diabetic acidosis were similar: 25.4% in epidemic and 14.7% in non-epidemic years (P less than 0.01). During the 1978 epidemic, one out of every 1300 patients with diabetes mellitus was hospitalized because of pneumonia. It is estimated that 1 of every 260 patients with IDDM was hospitalized for diabetic acidosis. It is concluded that patients with diabetes mellitus have indeed a very high influenza-associated morbidity.

Urinary tract infection in the impaired host

In general, defects in phagocytosis and in humoral or cellular immunity do not appear to predispose to the acquisition of UTI but do influence the clinical manifestations and the severity, microbiology, and complications of infection once it is established. The incidence of UTI in immunosuppressed patients other than diabetics or renal transplant recipients is not higher than the incidence in nonimmunosuppressed individuals. The higher frequencies of infection seen in diabetics and in renal transplant recipients correlate best with the duration of bladder instrumentation rather than with glycosuria or immunosuppressive regimen. Neutropenia blunts the clinical manifestations of UTI and predisposes to bacteremia. Use of broad spectrum antibiotics results in alterations in indigenous flora, promotes urinary infections with resistant nosocomial pathogens, and predisposes to fungemia with hematogenous seeding of the urinary tract. Routine screening for detection of asymptomatic bacteriuria and prompt institution of antimicrobial therapy is indicated only in renal transplant recipients within 3 months of their surgery and not in any of the other diseases discussed.

Insulin therapy in maturity-onset diabetes

A prime target of insulin action in patients with maturity onset diabetes is suppression of hepatic glucose production in both the fasting and postprandial states. In patients who fail to respond to oral treatment insulin improves glycaemic control, has an antiatherogenic effect on the serum lipoprotein pattern, and increases well being. The beneficial long-term effects of insulin therapy on morbidity and mortality are, however, still unproved. The regimens of insulin therapy are not established. In patients with normal or increased basal serum C-peptide concentration treatment may start with intermediate or long-acting insulin at bedtime together with oral medication, or in the morning with or without oral medication. If this fails two injections of intermediate-acting insulin or multiple injections of short-acting insulin should be started. Hypoglycaemia is uncommon in maturity onset diabetes treated with insulin, but moderate weight gain usually occurs. The possible role of hyperinsulinemia as a predisposing factor for atherogenesis remains unresolved. Despite controversies over treatment, any patient with maturity onset diabetes not responding to oral agents should be regarded as a candidate for insulin therapy.

Protein glycation and oxidative stress in diabetes mellitus and ageing

Hyperglycemia is increasingly regarded as the cause of the diabetic complications, in particular via the ability of glucose to glycate proteins and generate Maillard browning products which cross-link proteins and render them brown and fluorescent in vitro. Similar changes occur in vivo to long-lived proteins in diabetes mellitus as well as in ageing. The evidence supporting this route of glucose toxicity is discussed in the context of the ability of glucose to oxidize in vitro (catalyzed by trace amounts of transition metal) generating hydrogen peroxide, highly reactive oxidants, and protein-reactive ketoaldehyde compounds. It is suggested that protein browning in vivo may not result from the reactions of glucose with protein but from the transition metal-catalyzed reactions of other small autoxidisable substrates, such as ascorbate, with protein. Overall, studies of glycation and protein browning suggest a critical role for oxidative processes perhaps involving decompartmentalized transition metals and a variety of low molecular weight reducing agents in diabetes mellitus and ageing.

Impairment by glycation of immunoglobulin G Fc fragment function

Incubation of human immunoglobulin G (IgG) with glucose in vitro leads to the formation of glycated IgG concomitant with marked changes in functional properties of the Fc fragment. After 22 days of incubation in the absence and presence of 13.9, 27.7 and 55.5 mmol/l glucose, respectively, protein A binding was reduced by 42, 66 and 83%, depending on the glucose concentration employed. Binding of complement by IgG was abolished after incubation of the immunoglobulins for 13 days at 13.9 mmol/l glucose. In contrast, functional properties of the Fab region were unaffected upon glycation, as revealed by determination of antigen-binding capacity, antibody affinity and antibody concentration. The functional changes of the Fc fragment were observed at glycation levels comparable to those found in diabetics.

The relation of diabetic control to in vivo pH of soft tissue abscesses

It has been shown that induced soft tissue abscesses have a lower intra-abscess pH in the uncontrolled diabetic host than in the nondiabetic control. These differences were felt to be secondary to alterations in white cell metabolism. The current study compares the intra-abscess pH in three groups of mice: (I) nondiabetic, (II) untreated diabetic, and (III) insulin-treated diabetic. Diabetes was induced with streptozotocin in male white mice. The bacteria used to induce the abscesses were a combination of B. fragilis and Enterococcus. The blood glucose values of groups I, II, and III were 189 mg% (+/- 20.3), 256 mg% (+/- 121.9), and 712.8 mg% (+/- 169.7), respectively. None of the animals were ketotic, and peritoneal pH (reflecting systemic pH) showed no significant differences between groups. There were no significant differences in colony counts between any groups. The intra-abscess pH values of groups I, II, and III were 6.97 (+/- 0.26), 6.85 (+/- 0.41), and 6.08 (+/- 0.70). The differences in intra-abscess pH and blood glucose levels were all significantly different from each other when all three groups were compared. The insulin-treated mice tended to return to normality but had the widest spread of values. Since a decrease in intra-abscess pH has been felt to be a reflection of white cell activity, our studies may be the first to demonstrate an in vivo effect of insulin on white cell activity.