Human plasma phospholipid transfer protein activity is decreased by acute hyperglycaemia: studies without and with hyperinsulinaemia in Type 1 diabetes mellitus

AIMS

Little is known about the regulation of phospholipid transfer protein (PLTP), that plays a key role in lipoprotein metabolism. PLTP secretion may be up-regulated by glucose in vitro, whereas plasma PLTP activity is decreased by exogenous hyperinsulinaemia and glucose-induced hyperinsulinaemia in vivo. In the present study, we evaluated the separate effects of hyperglycaemia and hyperinsulinaemia in C-peptide-negative Type 1 diabetic patients.

METHODS

The protocol was carried out in 16 patients (eight females). In each individual, plasma PLTP mass and activity (measured by enzyme-linked immuno-sorbent assay and liposome-high density lipoprotein system, respectively) as well as plasma cholesteryl ester transfer protein (CETP) activity, lipids and apolipoprotein levels were determined at the end of four different glucose clamps, each lasting 210 min: standard insulin (30 mU/kg/h) and standard glucose (glucose 5.0 mmol/l) (SI-SG), standard insulin and high glucose (glucose 12 mmol/l) (SI-HG), high insulin (150 mU/kg/h) and standard glucose (HI-SG), and high insulin and high glucose (HI-HG).

RESULTS

Plasma lipids and (apo)lipoproteins, measured at the end of the SI-HG, HI-SG and HI-HG clamps, were not significantly different compared with the levels obtained at the end of the SI-SG clamp. Median plasma PLTP mass and activity at the end of the SI-SG clamp were 12.8 mg/l and 13.2 micromol/ml/h, respectively. Median plasma PLTP mass decreased by 9.1% at the end of the HI-HG clamp (P < 0.01), whereas the changes at the end of the SI-HG and HI-SG clamps were not significant. Median plasma PLTP activity decreased by 5.7, 4.6 and 8.6% at the end of the SI-HG, HI-SG and HI-HG clamps, respectively (all P < 0.05). Median plasma CETP activity was 177 nmol/ml/h at the end of the SI-SG clamp, and decreased by 4.9% (P < 0.05) and by 8.3% (P < 0.05) at the end of the HI-SG and the HI-HG clamps, respectively. Plasma CETP activity did not change significantly at the end of the SI-HG clamp.

CONCLUSIONS

The present study demonstrates that plasma PLTP activity is independently decreased by acute hyperglycaemia and hyperinsulinaemia in humans in vivo. These data do not support a direct role of short-term hyperglycaemia in up-regulating plasma PLTP levels.

Gabexate mesilate hastens recovery from vecuronium-induced neuromuscular blockade

BACKGROUND AND OBJECTIVE

To test the hypothesis that gabexate mesilate, a protease inihibitor, hastens recovery from neuromuscular blockade, we examined the effect of gabexate mesilate on the recovery of vecuronium-induced neuromuscular blockade in anaesthetized patients in a double-blind, randomized fashion.

METHODS

Thirty adult patients were divided into two groups of 15. In the gabexate mesilate group, immediately after administration of vecuronium 0.1 mg kg(-1), a continuous infusion of gabexate mesilate was started at a speed of 1.5 mg kg(-1) h(-1). In the control group, normal saline was administered instead of gabexate mesilate. Times to the return of T1, T2, T3 or T4 (first, second, third and fourth response of train-of-four (TOF)), times to the recovery of T1/control to 0.25 (T25) or 0.5 (T50), recovery of T1/control or TOF ratio (T4/T1) were compared between the two groups.

RESULTS

Times to the returns of T1, T2, T3 and T4 in the gabexate mesilate group were significantly shorter than in the control group (19.4 +/- 6.8 vs. 25.7 +/- 7.2 min for T1; mean +/- SD, P = 0.020). Times to T25 and T50 were significantly shorter in the gabexate mesilate group than in the control group (34.0 +/- 9.9 vs. 51.3 +/- 10.2 min for T25, P < 0.001). T1/control and TOF ratio in the gabexate mesilate group were significantly higher than in the control group 40-80 min and 40-120 min after administration of vecuronium, respectively (P < 0.05).

CONCLUSION

Gabexate mesilate hastens recovery from neuromuscular block in anaesthetized patients receiving vecuronium.

Nasal exposure to Staphylococcal enterotoxin enhances the development of allergic rhinitis in mice

BACKGROUND

Staphylococcal enterotoxins (SEs) appear to play a role in the pathogenesis of allergic disease. However, little is known whether the nasal exposure to SE affects the development of allergic rhinitis (AR).

OBJECTIVE

We sought to determine the in vivo effect of nasal exposure to SE on the development of AR using mouse model.

METHODS

BALB/c mice were intranasally sensitized with Schistosoma mansoni egg antigen (SmEA) in the presence or absence of staphylococcal enterotoxin B (SEB). Control mice were intranasally sensitized with either SEB or SmEA alone. The production of antigen-specific antibodies including IgE, nasal eosinoplilia and cytokines by nasal mononuclear cells was compared among mice that had or had not received SEB treatment.

RESULTS

Nasal exposure to SEB enhanced the development of AR in SmEA-sensitized mice, as manifested by SmEA-specific IgE production, nasal eosinophilia, and IL-4 and IL-5 production by nasal mononuclear cells after Ag challenge. This treatment also elicited IFN-gamma production by SmEA-primed cells. In addition, these mice produced SEB-specific IgE whereas mice treated with SEB without SmEA sensitization did not produce SEB-specific IgE or demonstrate nasal eosinophilia.

CONCLUSION

These results suggest that the nasal exposure to SEB enhances susceptibility to AR although the exposure to SE solely does not induce AR.

Type 2 diabetes mellitus is associated with differential effects on plasma cholesteryl ester transfer protein and phospholipid transfer protein activities and concentrations

BACKGROUND

Human plasma contains two lipid transfer proteins, cholesteryl ester transfer protein (CETP) and phospholipid transfer protein (PLTP), which are crucial in reverse cholesterol transport.

METHODS

Plasma CETP and PLTP activity levels and concentrations in 16 type 2 diabetic patients and 16 matched healthy subjects were determined, and these data were correlated to clinical variables, including insulin sensitivity and lipid levels.

RESULTS

Plasma triglycerides were higher (p<0.02) and high-density lipoprotein (HDL) cholesterol (p<0.02) was lower in diabetic patients. Plasma CETP activity and concentrations were not significantly different between diabetic and healthy subjects, but CETP specific activity was lower in diabetic patients (p<0.001). Multiple regression analysis showed that plasma CETP activity was positively related to CETP concentration (p=0.0001) and negatively to the diabetic state (p<0.002) or to HbA1c (p<0.02). PLTP activity (p<0.05) and specific activity were higher (p<0.05), whereas there was no difference in PLTP concentration between the two groups. There was no significant bivariate correlation between PLTP concentration and activity, in either healthy or diabetic subjects. Multiple regression analysis did disclose positive relationships of PLTP activity with PLTP concentration (p=0.0001), plasma triglycerides (p=0.0001) and waist/hip ratio (p=0.0001), but not with the diabetic state or HbA1c.

CONCLUSIONS

Neither CETP nor PLTP activity was independently associated with insulin sensitivity. Specific CETP activity is decreased in type 2 diabetes mellitus. In contrast, specific PLTP activity is higher in diabetes, as a result of the association of plasma PLTP activity with plasma triglycerides and obesity. Measurement of both plasma lipid transfer protein activity and mass levels may thus provide extra information in diabetes mellitus.

Characterization of allergen-specific monocyte-derived dendritic cells generated from monocytes by a single-step procedure: effect on naïve and memory T cells

BACKGROUND

Dendritic cells are one of the most potent antigen-presenting cells and when pulsed with allergen can modulate allergen-specific T-cell responses. We sought to establish a single-step method by which to generate allergen-specific monocyte-derived dendritic cells (MoDCs).

METHODS

Dermatophagoides farinae (Df)-prepulsed MoDCs were generated from monocytes by culturing with Df in the presence interleukin (IL)-4, granulocyte-macrophage colony-stimulating factor (GM-CSF) and tumour necrosis factor (TNF)-alpha simultaneously. Df-prepulsed MoDC were incubated with autologous naive and memory T cells in the absence of recall antigen, then proliferation and cytokine production by T cells was determined.

RESULTS

Generation of allergen-prepulsed MoDCs was confirmed by examining expression of surface molecules. Df-prepulsed MoDC selectively induced proliferation of Df-specific T cells in the absence of recall antigen. Under these conditions, Df-prepulsed MoDCs augmented but did not alter the cytokine production profile. In addition, Df-prepulsed MoDCs activated naive T cells leading to proliferation and selective production of IFN-gamma in allergic patients but not in healthy subjects.

CONCLUSIONS

These results suggest that Df-prepulsed MoDC generated from monocytes by a simple single-step manipulation can induce Df-specific cellular responses from both naive and memory T cells in the absence of recall antigen, and these cells potentially can be utilized as immune adjuvants in allergen-specific immunotherapy.

Retracted : Reversal of vecuronium with neostigmine in patients with diabetes mellitus

Reversal of vecuronium-induced neuromuscular blockade with neostigmine was compared in two groups of 16 subjects: patients with Type 2 diabetes mellitus and normal controls. When the first twitch of the train-of-four had returned to 25% of the control value, neostigmine 40 microg x kg(-1) and atropine 20 microg x kg(-1) were given to reverse the neuromuscular blockade. The train-of-four ratio was lower at 3 min, 6 min, 9 min, 12 min and 15 min after reversal in the diabetic group than in the control group but the differences did not reach statistical significance. Fifteen minutes after reversal, the number of patients in whom recovery from neuromuscular blockade was judged insufficient to guarantee good respiratory function (train-of-four ratio < 0.74) did not differ between the groups. However, 15 min after reversal, the number of patients with a train-of-four ratio < 0.9 was significantly higher in the Diabetic Group than in the Control Group (15 vs. 10, p = 0.033).

High prevalence of haemosiderin accumulation in the cytoplasm of gastric glands in patients with liver cirrhosis

AIMS

To investigate the presence of iron in biopsy and resection specimens from the stomach of patients with hepatic cirrhosis of various aetiologies.

METHODS

Among 753 patients who had been admitted to the hospital with liver cirrhosis from 1984 to 2002, and 723 patients who underwent liver biopsy or liver resection from 1990 to 2003, 426 patients with concomitant gastric biopsy or gastrectomy were selected for study. Formalin fixed, paraffin wax embedded tissues of the stomach and the liver (when available) were retrieved from the pathology files of Kariya General Hospital, Japan. Haematoxylin and eosin staining and Perls' stain were performed for all the available tissues and haemosiderin and its localisation were examined.

RESULTS

In total, 78 patients-72 of those with cirrhosis (26%) and six without cirrhosis (4%)-showed accumulation of haemosiderin. Regardless of aetiology, patients with clinical varices showed more frequent haemosiderin accumulation (40%) than patients without varices (19%). For patients with cirrhosis, there were no significant differences in the positive rate between those with (28%) or without (23%) hepatocellular carcinoma.

CONCLUSION

The significant increase in haemosiderin deposition in the gastric glands of patients with cirrhosis suggests that the assessment of iron deposition in gastric biopsy specimens may have predictive value in controlling patients with cirrhosis.

Effect of milrinone on vecuronium-induced neuromuscular block

We examined the effect of milrinone, a phosphodiesterase III inhibitor, on neuromuscular block induced by vecuronium. Thirty adult patients were randomly assigned to one of two equal groups: the milrinone group and the control group. Subjects in the milrinone group received an intravenous loading dose of milrinone 5 microg x kg-1x min-1 for 10 min, followed by an infusion at a rate of 0.5 microg x kg-1x min-1. Subjects in the control group received normal saline at a rate of 0.1 ml x kg-1 x h-1. Thirty minutes after the beginning of the infusion of milrinone, anaesthesia was induced with intravenous thiopental 4 mg x kg-1 and fentanyl 2 microg x kg-1, and was maintained with isoflurane in oxygen and nitrous oxide. Neuromuscular blockade was monitored electromyographically at the adductor pollicis muscle. The times from the administration of vecuronium 0.1 mg.kg-1 to the onset of neuromuscular block and the return of the first, second, third, and fourth response of the train-of-four were compared between the two groups. Times to the recovery of the ratio of the first twitch to the control twitch to 25%, 50% and 75%, and times to the recovery of train-of-four ratio to 25%, 50% and 75% were also compared between the two groups. The onset of neuromuscular block in the milrinone group was significantly slower than in the control group. The times to the returns of the four twitches of the train-of-four, times to recovery of the ratio of the first twitch to the control twitch to 25% and 50%, and the times to the recovery of the train-of-four ratio to 25% and 50% were significantly shorter in the milrinone group than in the control group. We conclude that milrinone delays the onset of neuromuscular blockade but hastens its recovery in anaesthetised patients receiving vecuronium.

Activation of caspase-12 by endoplasmic reticulum stress induced by transient middle cerebral artery occlusion in mice

We sought to clarify the involvement of caspase-12, a representative molecule related to endoplasmic reticulum (ER) stress-induced cell-death signaling pathways, in neuronal death resulting from ischemia/reperfusion in mice. Transient focal cerebral ischemia (1 h) was produced by intraluminal occlusion of the middle cerebral artery (MCA). We assessed the expression patterns of caspase-12, Bip/GRP78, an ER-resident molecular chaperone whose expression serves as a good marker of ER stress, and caspase-7 by Western blotting and/or immunohistochemistry. Double-fluorescent staining of caspase-12 immunohistochemistry and the terminal deoxynucleotidyl transferase-mediated DNA nick-end labeling (TUNEL) method was performed to clarify the involvement of caspase-12 in cell death. We confirmed that ER stress was induced during reperfusion in our model, as witnessed by up-regulated Bip/GRP78 expression in the MCA territory. Western blot analysis revealed that caspase-12 activation occurred at 5-23 h of reperfusion, and immunoreactivity for caspase-12 was enhanced mainly in striatal neurons on the ischemic side at the same time points. We found the co-localization of caspase-12 immunoreactivity and DNA fragmentation detectable by the TUNEL method. We did not detect the presence of caspase-7 in the ER fraction at the period of caspase-12 cleavage. Our results imply that cerebral ischemia/reperfusion induces ER stress and that caspase-12 activation concurred with ER stress. Caspase-12 seems to be involved in neuronal death induced by ischemia/reperfusion. Caspase-7 is not likely to contribute to the cleavage of caspase-12 in our experimental model.

Tissue engineering of the intervertebral disc with cultured annulus fibrosus cells using atelocollagen honeycomb-shaped scaffold with a membrane seal (ACHMS scaffold)

The objective of the study was to investigate the regeneration of intervertebral discs after laser discectomy using tissue engineering procedures. Annulus fibrosus (AF) cells from the intervertebral discs of Japanese white rabbits were cultured in an atelocollagen honeycomb-shaped scaffold with a membrane seal (ACHMS scaffold), to produce a high-density, three-dimensional culture for up to 3 weeks. Although the DNA content in the scaffold increased at a lower rate than that in the monolayer culture, expression of type II collagen and glycosaminoglycan accumulation in the scaffold were at higher levels than in the monolayer. The AF cells that had been cultured in the scaffold for 7 days were allografted into the lacunae of intervertebral discs of recipients (40 rabbits, 14-16 weeks old; average weight, 3.2 kg), whose nucleus pulposus (NP) had been vaporised with an ICG dye-enhanced laser. The allografted cultured AF cells survived and produced hyaline-like cartilage. Furthermore, the narrowing of the intervertebral disc space of the cell-containing scaffold insertion groups was significantly inhibited after 12 post-operative weeks.

Monitoring of neuromuscular block after administration of vecuronium in patients with diabetes mellitus

BACKGROUND

We studied the supramaximal current for ulnar nerve stimulation during electromyographic monitoring of onset and recovery of neuromuscular block using a neuromuscular transmission module (M-NMT Module, Datex-Ohmeda) in patients with Type 2 diabetes undergoing anaesthesia with nitrous oxide, oxygen, isoflurane and fentanyl.

METHODS

Thirty-six diabetic patients were randomly assigned to a post-tetanic count (PTC) group (n=17) or train-of-four (TOF) group (n=19). In addition, 30 non-diabetic patients were divided into control PTC (n=15) and TOF groups (n=15).

RESULTS

In the diabetic patients (diabetes PTC and diabetes TOF groups), the mean supramaximal stimulating current was significantly higher than in the non-diabetic patients (control PTC and TOF groups) (50.5 (SD 14.1) vs 33.4 (6.1) mA, P<0.01). Onset of neuromuscular block (time to disappearance of T1) after vecuronium 0.1 mg kg(-1) in the diabetic patients did not differ significantly from that in the non-diabetic patients (276 (77) vs 244 (44) s, P=0.055). Time to return of PTC1 did not differ significantly between the diabetes and control PTC groups (21.0 (12.1) vs 15.7 (5.0) min, P=0.126). Times to return of T1 and T4 in the diabetes TOF group were significantly longer than in the control TOF group (T1: 37.5 (15.2) vs 25.7 (7.6) min, P=0.01; T4: 61.4 (23.7) vs 43.5 (11.4) min, P=0.01). During recovery, PTC and T4/T1 in the diabetes PTC and TOF groups were similar to those in the control PTC and TOF groups, respectively. T1/T0 in the diabetes TOF group was significantly less than in the control TOF group, 80-120 min after vecuronium (P<0.05).

CONCLUSIONS

In diabetic patients, supramaximal current is higher than in non-diabetic patients. After vecuronium, onset of neuromuscular block and recovery of PTC or T4/T1 are not altered, but time to return of T1 or T4, and recovery of T1/T0 are delayed in diabetic patients.

Nodular sclerotic change in dermatofibrosarcoma protuberans: a potential diagnostic problem

Nodular sclerotic change in dermatofibrosarcoma protuberans (DFSP) is not a well-recognized event. Sclerotic change is reported in three patients with DFSP: a 33-year-old woman with a left subclavian mass, a 29-year-old woman with a mass on the left crus and a 31-year-old man with a mass on the left cheek. Histologically, lesions consisted of two types of feature, one type being typical of DFSP and the other being rich in collagen. In the first patient, each type formed a distinct compartment, each of which contained scattered cells containing melanin pigment. In the second patient, foci with typical DFSP histology were distributed within the collagen-rich area and also formed a substantial compartment in the periphery of the lesion, with pigmented cells being distributed mainly in and around the cellular area. In the third patient, the collagenous area occupied about half of the lesion. There was no pigmentation. In all three cases the collagen-rich area contained sparsely distributed fibroblast-like cells that stained positive with CD34. Sclerotic change in DFSP could cause substantial difficulty in diagnosis if the biopsy material were partial and small. The clinical history and knowledge about the existence of this kind of histological variation in DFSP are important.