Type 1 diabetes and oral health: Findings from the Epidemiology of Diabetes Interventions and Complications (EDIC) study

OBJECTIVE

To describe long-term oral health outcomes and examine associations between sociodemographic factors, clinical characteristics, and markers of diabetes control on tooth loss in participants with type 1 diabetes enrolled in the Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications (DCCT/EDIC) study.

RESEARCH DESIGN AND METHODS

Oral health outcomes related to tooth loss were reported at annual visits during EDIC years 22-26 (2015-2019). Generalized estimating equation models were used to assess the association of individual risk factors and tooth loss, over repeated time points.

RESULTS

A total of 165 (17%) participants with type 1 diabetes reported 221 oral health outcomes related to tooth loss over a five-year period. After controlling for age and current tobacco use, the presence of diabetic peripheral neuropathy was significantly associated with an increased odds of tooth loss (OR = 1.88, 95% CI 1.24, 2.87) while higher mean HDL/LDL cholesterol ratio was significantly associated with a decreased odds of tooth loss (OR = 0.87, 95% CI = 0.79, 0.97).

CONCLUSIONS

These findings suggest that diabetes-related complications, either resulting from or independent of poor glycemia, may be directly associated with oral health conditions, and support the need for individuals with type 1 diabetes and providers to implement lifestyle and medical interventions to reduce oral health risks.

Utility of using electrocardiogram measures of heart rate variability as a measure of cardiovascular autonomic neuropathy in type 1 diabetes patients

AIMS/INTRODUCTION

Cardiovascular autonomic neuropathy (CAN) is a predictor of cardiovascular disease and mortality. Cardiovascular reflex tests (CARTs) are the gold standard for the diagnosis of CAN, but might not be feasible in large research cohorts or in clinical care. We investigated whether measures of heart rate variability obtained from standard electrocardiogram (ECG) recordings provide a reliable measure of CAN.

MATERIALS AND METHODS

Standardized CARTs (R-R response to paced breathing, Valsalva, postural changes) and digitized 12-lead resting ECGs were obtained concomitantly in Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications participants (n = 311). Standard deviation of normally conducted R-R intervals (SDNN) and the root mean square of successive differences between normal-to-normal R-R intervals (rMSSD) were measured from ECG. Sensitivity, specificity, probability of correct classification and Kappa statistics evaluated the agreement between ECG-derived CAN and CARTs-defined CAN.

RESULTS

Participants with CARTs-defined CAN had significantly lower SDNN and rMSSD compared with those without CAN (P < 0.001). The optimal cut-off points of ECG-derived CAN were <17.13 and <24.94 ms for SDNN and rMSSD, respectively. SDNN plays a dominant role in defining CAN, with an area under the curve of 0.73, indicating fair test performance. The Kappa statistic for SDNN was 0.41 (95% confidence interval 0.30-0.51) for the optimal cut-off point, showing fair agreement with CARTs-defined CAN. Combining SDNN and rMSSD optimal cut-off points does not provide additional predictive power for CAN.

CONCLUSIONS

These analyses are the first to show the agreement between indices of heart rate variability derived from ECGs and the gold standard CARTs, thus supporting potential use as a measure of CAN in clinical research and clinical care.

Comparison of central laboratory HbA1c measurements obtained from a capillary collection versus a standard venous whole blood collection in the GRADE and EDIC studies

BACKGROUND

We compared HbA1c values obtained from capillary blood collection kits versus venous whole blood collections in study participants with type 1 or type 2 diabetes.

METHODS

A total of 122 subjects, 64 with type 2 diabetes participating in the Glycemia Reduction Approaches in Diabetes: A Comparative Effectiveness (GRADE) Study and 58 with type 1 diabetes from the Epidemiology of Diabetes Interventions and Complications (EDIC) Study, participated in the validation study. Capillary tubes were filled by fingerstick by the participants on the same day as the collection of venous whole blood samples in EDTA-containing test tubes and were mailed to the central laboratory. HbA1c in all samples was measured with the same high-performance liquid chromatography. GRADE participants also completed a questionnaire on the ease of performing capillary collections.

RESULTS

Participants from 22 clinical centers (GRADE n = 5, EDIC n = 17) were between 35 and 86 years of age, with 52% male and diverse race/ethnicities. Venous HbA1c results ranged between 5.4-11.9% (35.5-106.6 mmol/mol) with corresponding capillary results ranging between 4.2-11.9% (22.4-106.6 mmol/mol). The venous and capillary results were highly correlated (R2 = 0.993) and 96.7% differed by ≤0.2% (2.2 mmol/mol). Of participants surveyed, 69% indicated that the instructions and collection were easy to follow and 97% felt the collection method would be easy to do at home.

CONCLUSIONS

The capillary blood HbA1c results compared well with the conventional venous whole blood results. The capillary kits can be employed in other studies to reduce interruption of critical data collection and potentially to augment clinical care when in-person visits are not possible.

Risk Factors for Kidney Disease in Type 1 Diabetes

OBJECTIVE

In type 1 diabetes (T1D), the course of microalbuminuria is unpredictable and timing of glomerular filtration rate (GFR) loss is uncertain. Thus, there is a need to identify the risk factors associated with the development of more advanced stages of kidney disease through large, long-term systematic analysis.

RESEARCH DESIGN AND METHODS

Multivariable Cox proportional hazards models assessed the association of baseline and time-dependent glycemic and nonglycemic risk factors for incident macroalbuminuria and reduced estimated GFR (eGFR; defined as <60 mL/min/1.73 m²) over a mean of 27 years in the Diabetes Control and Complications Trial (DCCT) cohort.

RESULTS

Higher mean HbA_1c (hazard ratio [HR] 1.969 per 1% higher level [95% CI 1.671-2.319]) and male sex (HR 2.767 [95% CI 1.951-3.923]) were the most significant factors independently associated with incident macroalbuminuria, whereas higher mean triglycerides, higher pulse, higher systolic blood pressure (BP), longer diabetes duration, higher current HbA_1c, and lower mean weight had lower magnitude associations. For incident reduced eGFR, higher mean HbA_1c (HR 1.952 per 1% higher level [95% CI 1.714-2.223]) followed by higher mean triglycerides, older age, and higher systolic BP were the most significant factors.

CONCLUSIONS

Although several risk factors associated with macroalbuminuria and reduced eGFR were identified, higher mean glycemic exposure was the strongest determinant of kidney disease among the modifiable risk factors. These findings may inform targeted clinical strategies for the frequency of screening, prevention, and treatment of kidney disease in T1D.

Oxidative Stress and Cardiovascular Risk in Type 1 Diabetes Mellitus: Insights From the DCCT/EDIC Study

Background

Hyperglycemia leading to increased oxidative stress is implicated in the increased risk for the development of macrovascular and microvascular complications in patients with type 1 diabetes mellitus.

Methods and Results

A random subcohort of 349 participants was selected from the DCCT / EDIC (Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications) cohort. This included 320 controls and 29 cardiovascular disease cases that were augmented with 98 additional known cases to yield a case cohort of 447 participants (320 controls, 127 cases). Biosamples from DCCT baseline, year 1, and closeout of DCCT , and 1 to 2 years post‐ DCCT ( EDIC years 1 and 2) were measured for markers of oxidative stress, including plasma myeloperoxidase, paraoxonase activity, urinary F 2α isoprostanes, and its metabolite, 2,3 dinor‐8 iso prostaglandin F 2α . Following adjustment for glycated hemoblobin and weighting the observations inversely proportional to the sampling selection probabilities, higher paraoxonase activity, reflective of antioxidant activity, and 2,3 dinor‐8 iso prostaglandin F 2α , an oxidative marker, were significantly associated with lower risk of cardiovascular disease (−4.5% risk for 10% higher paraoxonase, P <0.003; −5.3% risk for 10% higher 2,3 dinor‐8 iso prostaglandin F 2α , P =0.0092). In contrast, the oxidative markers myeloperoxidase and F 2α isoprostanes were not significantly associated with cardiovascular disease after adjustment for glycated hemoblobin. There were no significant differences between DCCT intensive and conventional treatment groups in the change in all biomarkers across time segments.

Conclusions

Heightened antioxidant activity (rather than diminished oxidative stress markers) is associated with lower cardiovascular disease risk in type 1 diabetes mellitus, but these biomarkers did not change over time with intensification of glycemic control.

Clinical Trial Registration

URL : https://www.clinicaltrials.gov . Unique identifiers: NCT 00360815 and NCT 00360893.

Frequency of Evidence-Based Screening for Retinopathy in Type 1 Diabetes

BACKGROUND

In patients who have had type 1 diabetes for 5 years, current recommendations regarding screening for diabetic retinopathy include annual dilated retinal examinations to detect proliferative retinopathy or clinically significant macular edema, both of which require timely intervention to preserve vision. During 30 years of the Diabetes Control and Complications Trial (DCCT) and its longitudinal follow-up Epidemiology of Diabetes Interventions and Complications (EDIC) study, retinal photography was performed at intervals of 6 months to 4 years.

METHODS

We used retinal photographs from the DCCT/EDIC study to develop a rational screening frequency for retinopathy. Markov modeling was used to determine the likelihood of progression to proliferative diabetic retinopathy or clinically significant macular edema in patients with various initial retinopathy levels (no retinopathy or mild, moderate, or severe nonproliferative diabetic retinopathy). The models included recognized risk factors for progression of retinopathy.

RESULTS

Overall, the probability of progression to proliferative diabetic retinopathy or clinically significant macular edema was limited to approximately 5% between retinal screening examinations at 4 years among patients who had no retinopathy, 3 years among those with mild retinopathy, 6 months among those with moderate retinopathy, and 3 months among those with severe nonproliferative diabetic retinopathy. The risk of progression was also closely related to mean glycated hemoglobin levels. The risk of progression from no retinopathy to proliferative diabetic retinopathy or clinically significant macular edema was 1.0% over 5 years among patients with a glycated hemoglobin level of 6%, as compared with 4.3% over 3 years among patients with a glycated hemoglobin level of 10%. Over a 20-year period, the frequency of eye examinations was 58% lower with our practical, evidence-based schedule than with routine annual examinations, which resulted in substantial cost savings.

CONCLUSIONS

Our model for establishing an individualized schedule for retinopathy screening on the basis of the patient's current state of retinopathy and glycated hemoglobin level reduced the frequency of eye examinations without delaying the diagnosis of clinically significant disease. (Funded by the National Institute of Diabetes and Digestive and Kidney Diseases and others; DCCT/EDIC ClinicalTrials.gov numbers, NCT00360893 and NCT00360815 .).

Delayed Gastric Emptying Is Associated With Early and Long-term Hyperglycemia in Type 1 Diabetes Mellitus

BACKGROUND & AIMS

After the Diabetes Control and Complications Trial (DCCT), the Epidemiology of Diabetes Interventions and Complications (EDIC) study continued to show persistent benefit of prior intensive therapy on neuropathy, retinopathy, and nephropathy in type 1 diabetes mellitus (DM). The relationship between control of glycemia and gastric emptying (GE) is unclear.

METHODS

We assessed GE with a (13)C-spirulina breath test and symptoms in 78 participants with type 1 diabetes at year 20 of EDIC. The relationship between delayed GE and glycated hemoglobin (HbA1c), complications of DM, and gastrointestinal symptoms were evaluated.

RESULTS

GE was normal (37 participants; 50%), delayed (35 participants; 47%), or rapid (2 participants; 3%). The latest mean HbA1c was 7.7%. In univariate analyses, delayed GE was associated with greater DCCT baseline HbA1c and duration of DM before DCCT (P ≤ .04), greater mean HbA1c over an average of 27 years of follow-up evaluation (during DCCT-EDIC, P = .01), lower R-R variability during deep breathing (P = .03) and severe nephropathy (P = .05), and a greater composite upper gastrointestinal symptom score (P < .05). In multivariate models, retinopathy was the only complication of DM associated with delayed GE. Separately, DCCT baseline HbA1c (odds ratio [OR], 1.6; 95% confidence interval [CI], 1.1-2.3) and duration of DM (OR, 1.2; 95% CI, 1.01-1.3) before DCCT entry and mean HbA1c during DCCT-EDIC (OR, 2.2; 95% CI, 1.04-4.5) were associated independently with delayed GE.

CONCLUSIONS

In the DCCT/EDIC study, delayed GE was remarkably common and associated with gastrointestinal symptoms and with measures of early and long-term hyperglycemia. ClinicalTrials.gov numbers NCT00360815 and NCT00360893.

Musculoskeletal complications in type 1 diabetes

OBJECTIVE

The development of periarticular thickening of skin on the hands and limited joint mobility (cheiroarthropathy) is associated with diabetes and can lead to significant disability. The objective of this study was to describe the prevalence of cheiroarthropathy in the well-characterized Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications (DCCT/EDIC) cohort and examine associated risk factors, microvascular complications, and the effect of former DCCT therapy (intensive [INT] vs. conventional [CONV]) on its development.

RESEARCH DESIGN AND METHODS

This cross-sectional analysis was performed in 1,217 participants (95% of the active cohort) in EDIC years 18/19 after an average of 24 years of follow-up. Cheiroarthropathy-defined as the presence of any one of the following: adhesive capsulitis, carpal tunnel syndrome, flexor tenosynovitis, Dupuytren's contracture, or a positive prayer sign-was assessed using a targeted medical history and standardized physical examination. A self-administered questionnaire (Disabilities of the Arm, Shoulder and Hand [DASH]) assessed functional disability.

RESULTS

Cheiroarthropathy was present in 66% of subjects (64% of the INT group and 68% of the CONV group; P = 0.1640) and was associated with age, sex, diabetes duration, skin intrinsic fluorescence, HbA1c, neuropathy, and retinopathy (P < 0.005 for each). DASH functional disability scores were worse among subjects with cheiroarthropathy (P < 0.0001).

CONCLUSIONS

Cheiroarthropathy is common in people with type 1 diabetes of long duration (∼30 years) and is related to longer duration and higher levels of glycemia. Clinicians should include cheiroarthropathy in their routine history and physical examination of patients with type 1 diabetes because it causes clinically significant functional disability.

Evaluating the role of epigenetic histone modifications in the metabolic memory of type 1 diabetes

We assessed whether epigenetic histone posttranslational modifications are associated with the prolonged beneficial effects (metabolic memory) of intensive versus conventional therapy during the Diabetes Control and Complications Trial (DCCT) on the progression of microvascular outcomes in the long-term Epidemiology of Diabetes Interventions and Complications (EDIC) study. We performed chromatin immunoprecipitation linked to promoter tiling arrays to profile H3 lysine-9 acetylation (H3K9Ac), H3 lysine-4 trimethylation (H3K4Me3), and H3K9Me2 in blood monocytes and lymphocytes obtained from 30 DCCT conventional treatment group subjects (case subjects: mean DCCT HbA1c level >9.1% [76 mmol/mol] and progression of retinopathy or nephropathy by EDIC year 10 of follow-up) versus 30 DCCT intensive treatment subjects (control subjects: mean DCCT HbA1c level <7.3% [56 mmol/mol] and without progression of retinopathy or nephropathy). Monocytes from case subjects had statistically greater numbers of promoter regions with enrichment in H3K9Ac (active chromatin mark) compared with control subjects (P = 0.0096). Among the patients in the two groups combined, monocyte H3K9Ac was significantly associated with the mean HbA1c level during the DCCT and EDIC (each P < 2.2E-16). Of note, the top 38 case hyperacetylated promoters (P < 0.05) included >15 genes related to the nuclear factor-κB inflammatory pathway and were enriched in genes related to diabetes complications. These results suggest an association between HbA1c level and H3K9Ac, and a possible epigenetic explanation for metabolic memory in humans.

[Vascular thrombosis and pulmonary thrombo-embolism due to harness suspension]

BACKGROUND

In many sports (such as rock-climbing and caving) and working activities (e.g., construction and maintenance of buildings, pruning of lung-trunked trees, abseiling in wells) people run the risk of falling from a height. To prevent the effects of any potential fall, personalprotection devices consisting of at least a body holding device (i.e. a harness of some type), a lanyard and a reliable anchor are used.

OBJECTIVES

Reporting on the occurrence of vascular thrombosis in subjects undergoing prolonged hanging in a harness, either for work or recreation.

METHODS

We investigated patients treated for vascular thrombosis in our hospital in the last 5 years to identify subjects with frequent use of a harness.

RESULTS

We identified a 36-year-old rock-climber who developed pulmonary thrombo-embolism and infarction 5 days after he had been wearing a harness for 12 hours consecutively, and a 32 year-old worker who often used a harness to fix wire-nettings to prevent rocks falling from steep places and suffered thrombosis of the left superficial femoral artery. A feature of both cases was the considerable length of time spent hanging in the harness and the absence of alternative risk factors for thrombosis.

CONCLUSIONS

Prolonged hanging in a harness can be dangerous in itself because it can produce vascular thrombosis. Reduction of intravascular blood flow (stasis) and compression of the femoral veins by harness groin straps were the likely pathogenetic mechanisms of the described diseases. The importance is stressed of prevention, which must be based on planned regular breaks in the hanging position, checking on the fit and comfort level of the harness before it is first used, as well as medical surveillance of the subjects who spend prolonged periods in a harness for work or recreation.

Pramlintide as an adjunct to insulin in patients with type 2 diabetes in a clinical practice setting reduced A1C, postprandial glucose excursions, and weight

OBJECTIVE

This study was designed to assess the safety and efficacy of pramlintide therapy in patients with type 2 diabetes in a clinical practice setting.

METHODS

In this open-label study, 166 insulin-treated patients with type 2 diabetes added pramlintide therapy (120 microg) during an initiation period in which mealtime insulin was reduced by 30-50%. Insulin doses were subsequently adjusted to optimize glycemic control. Endpoints included safety, as well as change in A1C, postprandial glucose, weight, insulin dose, and patient satisfaction following 6 months of pramlintide treatment.

RESULTS

At 6 months, the change in A1C from baseline (8.3%) was -0.56% (P < 0.05; n = 59). Pramlintide treatment significantly reduced mean postprandial glucose excursions (P < 0.05) and weight (-2.8 kg; P < 0.05; n = 125). Glycemic benefits were achieved with lower mealtime insulin doses (-10.3%; P < 0.05; n = 104). Nausea, primarily mild to moderate, was reported by 29.5% of patients (severe nausea in 2.4%). Rates of severe hypoglycemia were low (0.04 events/patient-year).

CONCLUSIONS

In this uncontrolled, open-label setting, pramlintide initiation while reducing mealtime insulin, followed by insulin dose optimization, resulted in improvements in postprandial glucose excursions and A1C. These improvements in glycemic control were accompanied by weight loss.

Gravitational effects on mammalian cells

In this paper we present first the results of our most recent investigations on gravitational effects on the activation of human lymphocytes: by immunoenzymatic staining and by using concanavalin A (Con A) coated to red blood cells (RBC) we demonstrate that the increase of activation measured at 10xg is due to a simultaneous activation of T- and B-lymphocytes whereas at 1xg only T-cells are stimulated. Conversely, activation of T-cells by chemical modification of the membrane with sodium periodate is depressed at 10xg. Secondly, experiments performed in the centrifuge as well as in the clinostat with Friend, K-562, and hybridoma cells show that each cell line develops its own adaptation reaction to gravitational stress.

Actin filaments responsible for the location of the nucleus in the lentil statocyte are sensitive to gravity

The location of the nucleus in statocytes or lentil roots grown: 1), at 1 g on the ground, 2), on a 1 g centrifuge in space, 3), in simulated microgravity on a slowly rotating clinostat (0.9 rmp) 4), in microgravity in space was investigated and statistically evaluated. In cells differentiated at 1 g on the ground, the nuclear membrane was almost in contact with the plasmalemma lining the proximal cell wall, whereas in statocytes of roots crown on the clinostat there was a distance of 0.47 micrometers (horizontal clinorotation) and or 0.76 micrometers (vertical clinorotation) between these membranes. However, in microgravity the nucleus was the most displaced, 0.87 micrometers from the proximal cell wall. Centrifugation of vertically grown roots in the root-tip direction showed that the threshold of centrifugal force to detach all nuclei from the proximal cell wall was about 40 g. In statocytes developed in the presence of cytochalasin B at 1 g the nuclei were sedimented on the amyloplasts at the distal cell pole, demonstrating that the location of the nucleus depends on actin filaments. The results obtained are in agreement with the hypothesis that gravity causes a tension of actin filaments and that this part of the cytoskeleton undergoes a relaxation in microgravity.

[Indications and limitations of endovascular surgery in carotid revascularization]

PURPOSE

Today percutaneous transluminal angioplasty is seldom utilized to treat carotid artery stenosis and the indications and results of this procedure are discordant between the few authors that do it. This leads to caution in selecting PTA as the first choice. Analysing the literature and their own experience, authors describe optimal indications and technique for this procedure.

METHODS

Eight patients with stenosis of the common carotid artery and five patients with stenosis of the internal carotid artery were treated with PTA. In the first group five cases were performed in association with a surgical distal revascularization, to obtain a good run-in. In six cases symptomatic restenosis due to intimal hyperplasia were treated. The two remaining cases were relative to complex clinical situations and high operative risk.

RESULTS

In eleven patients out of thirteen a good clinical and hemodynamic result was obtained; in one case the carotid artery occluded and in another case a new restenosis occurred.

DISCUSSION

PTA has some advantages: low operative trauma, cerebral ischemia short time, possibility to treat inaccessible or hardly accessible lesions. The eventuality of complications is high and for this reason the procedure must be utilised only in selected cases, with prudence and with a team well trained in peripheral angioplasty.

CONCLUSION

PTA for carotid artery stenosis today is still an experimental procedure; its value in comparison with carotid endarterectomy has to be proven with well designed clinical randomized trials.

Special considerations concerning regulatory requirements and drug development for peptides and biotech products in the EU

The marketing authorization for a new medicinal product is based on the scientific assessment of its quality, safety and efficacy. The marketing authorization application (MAA) which covers all the relevant documentation can be filed in the EU via different application procedures. For peptides and biological products special issues have to be taken into consideration during drug development. Due to special production procedures and the complexity of the active substance itself, peptides and biotech products are subject to specific regulatory requirements. This leads to the necessity to discuss the development program of a new peptide or biotech product with the health authorities on a case by case basis. This article will focus on the special regulatory requirements for peptides and biotech products including the registration procedures as well as technical, preclinical and clinical issues.

Nasal mucus clearance in rats: differences with sex and phase of the oestrous cycle

We studied the changes in airway mucus rheology and clearability, as well as in morphometric indices, between male rats and females in either the oestrous or dioestrous phases of the oestrous cycle. Three-month-old Wistar rats were studied and the phases of the oestrous cycle were determined based on analysis of vaginal smears stained by a modified Shorr's procedure. Nasal mucus samples were analysed by means of magnetic rheometry and determination of in vitro transport rate in the frog palate preparation. In situ clearance on the exposed nasal septum was also determined. The mucociliary velocity in situ was significantly affected by both sex and the oestrous cycle phase. In female rats, dioestrous phase clearance was significantly slower than the oestrous phase one. Clearance in male rats was faster than that of both the phases studied in females. Mucus rigidity of females in the oestrous phase was more rigid than that of females in the dioestrous phase and that of males. Mucus viscosity/elasticity ratio for deformations performed at high frequencies was greater for females in comparison with males. Cough clearability computed on the basis of rheological parameters was predicted to be more favourable in females. There were no significant differences between the three groups in mucociliary clearance in vitro. Morphometric studies of the nasal epithelium showed that epithelial and glandular volumes did not exhibit sex- or oestrous-phase-related differences, but the amount of epithelial acidic glycoproteins was lower in females in the oestrous phase in comparison with males and those in the dioestrous phase, the same trend being observed in the glands of the lamina propria.(ABSTRACT TRUNCATED AT 250 WORDS)

Development of a miniature bioreactor for continuous culture in a space laboratory

A new type of miniature bioreactor for continuous culture of yeast cells in space laboratories has been developed. Silicon microtechnology has permitted the integration of numerous functions and systems in a volume of 87 x 63 x 63 mm3 and a weight of 610 g. The 100 ml of fresh medium can be delivered at variable flow rates to the cultivation chamber (volume 3 ml) by means of a micropump. The culture is agitated by a magnetic stirrer. Microsensors monitor pH, temperature and redox potential. The decrease of pH occurring during the cultivation of Saccharomyces cerevisiae is compensated electrochemically. A window allows the inspection of the culture status. Samples of up to 1 ml can be drawn through a silicone rubber septum. The data measured by the sensors are transmitted on-line to the ground station during operations in space. The bioreactor had to fulfil several requirements related to the safety regulation of the space agencies. In particular, new materials had to be selected and tested for their biocompatibility. The instrument has now passed all space and biological qualification tests and will be used in an experiment selected by ESA for the International Microgravity Laboratory-2 Mission in Spacelab in July 1994. This paper gives the results of the functional and biological tests and a detailed description of the instrument.

Role of bypass, endarterectomy, extra-anatomic bypass and endovascular surgery in unilateral iliac occlusive disease: a review of 1257 cases

Some 1257 patients who had undergone revascularization procedures for unilateral iliac occlusions were reviewed retrospectively. A total of 824 patients were operated upon using conventional operations, 165 patients had femorofemoral bypass and 268 were treated using endovascular surgery techniques. Revascularization was performed through an extraperitoneal approach by means of iliac thromboendarterectomy (560) or iliac femoral bypass (264) if there was a total occlusion of either the common or external iliac artery (group 1). A femorofemoral crossover bypass was inserted when the operative risk was considered to be high (group 2). Endovascular procedures (percutaneous transluminal angioplasty 234, laser percutaneous transluminal angioplasty 11, stenting 22, atherectomy one) were used in recent years to treat stenoses or occlusions of 3 cm or less (group 3). The indications for operation were severe claudication in 79.7% in group 1 and 92.6% in group 3, whereas in group 2 66.7% of patients presented with symptoms of more advanced ischaemia. The immediate patency rate was 97.0% after extraperitoneal reconstructive surgery, 96.9% in the femorofemoral group and 92.1% in patients having an endovascular procedure. The operative mortality rate was 0.7, 4.2, and 0.3% for groups 1-3, respectively. The 5-year patency rate, analysed by the life-table method, was 77.9% in group 1, 75.3% in group 2 and 73.7% in group 3 (P = n.s., log rank test). The different revascularization techniques were chosen on the basis of the type of disease present and the patient's general condition. All procedures appeared to be effective when correctly selected.

Intraoperative transluminal angioplasty of recurrent carotid stenosis

A 61-year-old female presented with symptomatic recurrent left internal carotid stenosis. A method of intraoperative balloon dilatation under protective clamping of the common carotid artery is described.

Cultivation of hamster kidney cells in a dynamic cell culture system in space (Spacelab IML-1 Mission)

Cell proliferation, tissue plasminogen activator (t-PA) production and metabolic changes of Hamster Kidney cells (HaK) grown on microcarriers in an automatic Dynamic Cell Culture System (DCCS) were determined on the first International Microgravity Mission (IML-1) Spacelab (22-30 January 1992). The DCCS was designed for two cell culture chambers (volume: 200 microliters each), one operating as a hatch system, the other as a perfusion system. Medium exchange was achieved with an osmotic pump (flow rate 1 microliter h-1). Two major items were investigated: the biological performance of the DCCS in space and the effect of microgravity on HaK cells. The results obtained demonstrated that (1) the DCCS can be used for biological experiments on long term Spacelab missions. In fact, higher cell densities and higher concentration of glucose but lower concentration of lactate in the perfusion chambers than in the batch chambers were measured. The concentration of t-PA, glutamine and ammonia was similar in all chambers. (2) Microgravity had no effect on cell growth and metabolism of HaK cells.

Correlation between rheologic properties and in vitro ciliary transport of rat nasal mucus

The relationship between mucus rheologic variables and in vitro ciliary transport was investigated in mucus samples collected from the upper airways of 30 Wistar rats. In vitro mucus transportability was determined by means of the frog palate preparation. Rheologic evaluation was done by measuring the rigidity modulus (log G*, representing the vectorial sum of viscosity and elasticity) and the loss tangent (tan delta, i.e. the ratio between viscosity and elasticity) at 1 and 100 radian/s using a magnetic microrheometer. The correlation between the rheologic variables and in vitro mucus transportability was made by stepwise multiple linear regression analysis, with frog palate transport rate considered as the dependent variable. A significant relationship was obtained between the rheologic parameters (log G* and tan delta) measured at 1 radian/s and the frog palate transport ratio. The relative speed of mucus samples was related to rheology according to the following relationship: rat/frog speed ratio = 1.666-0.434 log G*-0.331 tan delta, for G* and delta determined at 1 radian/s (multiple r = 0.666, p < 0.001). Transport rates predicted from the above formula gave a satisfactory fit to those observed in a second set of 30 rats. The present results indicate that the overall mucus impedance, as well as the ratio between viscosity and elasticity, are important in determining the efficiency of clearance. In addition, it was shown that measurements performed by applying relatively low frequency deformations are preferable for predicting ciliary transport.

PTA and laser assisted PTA combined with simultaneous surgical revascularization

In this study we investigated the efficacy of percutaneous transluminal angioplasty (PTA) and laser percutaneous transluminal angioplasty (LPTA) as an adjunct to surgery in patients with peripheral vascular disease. We report 84 cases of the simultaneous association of direct arterial surgery and angioradiological procedures to treat 82 patients with arterial occlusive disease of the lower limbs. Sixty-five patients (79.2%) were affected by severe claudication and 14 (19.6%) presented with rest pain or gangrene. One patient (1.2%) had signs of acute ischemia. PTA or LPTA were utilized as an inflow procedure in 41 cases (48.8%), as an outflow procedure in 24 (28.6%) and in 19 cases (22.6%) to recanalize an arterial occlusion in the contralateral limb opposite to surgical interventions. Immediate postoperative patency was achieved in 79 cases (94.0%), while in 5 cases (6.0%) it was impossible to perform a satisfactory balloon dilatation. The complication rate was 16.6%: 10 perioperative thromboses, 1 plaque dissection, 1 peripheral embolus, 1 haemorrhage and 1 femoral nerve lesion. No perioperative mortality occurred in this group of patients. Long term patency, analyzed with the life-table method (mean follow-up: 28 months) was respectively 78.0%, 76.3% and 78.9% at 5 years. These data indicate that the combined revascularization technique should always be recommended in properly selected patients because it is less invasive, the surgical risk and operative time are reduced and associated with early and long term cumulative patency rates comparable to those of extensive surgery.

Basal cell carcinoma arising in pemphigus vulgaris of the lower eyelid

A 59-year-old woman on continuous treatment with corticosteroids and immunosuppressive drugs for pemphigus vulgaris of 14 year's duration presented with an enlarging nodular lesion on the right lower eyelid. The neoplasm, diagnosed as basal cell carcinoma, was excised conserving the lid margin, and eyelid reconstruction was done with a rotated cheek flap. Wound healing proceeded without complications in spite of immunosuppressive treatment, and the final cosmetic and functional result was satisfactory.

Thrombectomy for late graft limb occlusion: our experience in 182 consecutive cases

Late occlusion of an aortofemoral bypass graft is usually caused by fibrointimal hyperplasia or progressive atherosclerosis. Several surgical approaches have been advocated in order to minimize the operative risk, to correct the impaired inflow and to provide a satisfactory outflow. In the last 16 years, in the Institute of Vascular Surgery and Angiology of the University of Milan, we have operated upon 182 consecutive thrombosed grafts. Inflow was restored by performing a graft limb thrombectomy using a Fogarty balloon catheter and simultaneously employing an endarterectomy ring stripper to dislodge tenaciously adherent fibrinous material and thrombotic plug. As the superficial femoral artery was generally occluded, usually a good outflow was achieved by profundaplasty in 101 cases (55.5%) or direct bypass (interposition graft), to a more distal segment of the profunda femoris artery in 55 cases (30.2%). Concomitant popliteal or tibial revascularization was done in the remaining 26 cases (14.3%) when pre-operative or intra-operative findings suggested an inadequate collateral network through the profunda femoris artery. Early re-occlusion, which occurred in 14 cases (7.6%), generally due to insufficient outflow, was corrected by additional intervention in 7 cases (3.8%), while 7 legs were amputated for extensive atherosclerotic disease. Six patients died giving a mortality rate of 3.3%. This low rate in a high risk population is probably related to our policy of operating under loco-regional anaesthesia. Long term results, with a patency rate of 62.0% at 3 years and 60.2% at 5 years (life table method), prove that this operation is a durable procedure for correction of graft limb thrombosis.

Femoral noninfected anastomotic aneurysms. A report of 56 cases

Fifty-six femoral non infected anastomotic false aneurysms (FAAs) were observed in 49 patients admitted to the Institute of Vascular Surgery, University of Milan, from 1975 to 1988; in 6 patients they were bilateral. These aneurysms developed after primary revascularization procedures at a mean interval of 66 months (range 12 to 156 months); one recurred after reparative surgery. Forty-four FAAs (78.6%) were asymptomatic, whereas 3 (5.3%) were complicated by acute expansion and 9 (16.1%) by thrombosis. Host vessel degeneration was the cause of aneurysm formation in most cases. A history of hypertension was present in 30% of the patients. All anastomotic aneurysms were operated upon except for one small aneurysm that was asymptomatic. In 5 patients aneurysm resection was carried out on both sides. The surgical technique was endoaneurysmectomy in all the cases with insertion of an interposition graft in 48 cases, a fabric patch in 2 cases and prosthesis re-anastomosis in 5 cases. One case of peripheral embolization occurring in the early postoperative period was successfully treated and there was no operative mortality. In our opinion elective repair of these aneurysms should be recommended whenever possible because of their propensity to develop serious complications and the operative morbidity is low.

Effect of long-term physical exercise on lymphocyte reactivity: similarity to spaceflight reactions

The response of critical immunological parameters in seven athletes to the sustained physical stress of marathon running was assessed. Variables analysed were the responsiveness of lymphocytes (measured as mitogenic response to concanavalin A), the numbers of lymphocytes, their subsets, and leukocyte numbers. In addition, blood levels of cortisol, epinephrine, and norepinephrine were determined. After the run, lymphocyte responsiveness was severely depressed to 1-70% of the resting values, even though the lymphocyte counts did not change. Leukocyte counts were elevated 2.8-fold. No dramatic changes were found within the lymphocyte subsets, although an increase in pan T-cells and the helper/inducer subset 2 d after the run was significant. In addition, the numbers of B-cells decreased significantly. No change was observed within the suppressor/cytotoxic subset. Cortisol increased 2.1-fold, epinephrine 3.2-fold and norepinephrine 2.7-fold. All these parameters returned to baseline values within 2 d. These data were compared with data obtained during and after spaceflight. We conclude that prolonged physical stress of marathon running induces changes in immunological responsiveness that are strikingly similar to those arising from the stress of spaceflight.

Pharmacokinetics of enteric-coated aspirin and inhibition of platelet thromboxane A2 and vascular prostacyclin generation in humans

We evaluated whether an enteric-coated aspirin formulation showed a "presystemic" component in its antiplatelet effect and if so would spare vascular cyclooxygenase. In six healthy volunteers, 30 to 45 minutes after ingestion of 325 mg enteric-coated aspirin, platelet thromboxane A2 generation was inhibited by about 20% before any drug could be detected in the peripheral venous blood. A further decline in thromboxane A2 generation occurred with appearance of aspirin in blood between 60 and 240 minutes. No presystemic component could be detected after 325 mg aspirin tablets. Ten patients undergoing saphenectomy received 325 mg of either aspirin tablet or enteric-coated aspirin; 12 hours later platelet thromboxane A2 and peripheral vascular prostacyclin generation were significantly reduced by 98% and 58%, respectively. The effects of the two aspirin formulations were not different. Aspirin formulations with "presystemic" component in their antiplatelet effect may not necessarily result in sparing of peripheral vascular cyclooxygenase.

Effects of hypergravity on "whole-blood" cultures of human lymphocytes

The purpose of this paper is to present a detailed description of the effects of hypergravity on the mitogenic response of human lymphocytes to concanavalin A. The effect on cultures of lymphocytes isolated from peripheral blood are compared with those on whole-blood cultures obtained by diluting fresh blood with culture medium 1:10. Whole-blood cultures of lymphocytes from crew members will be investigated inflight on the Spacelab missions D-1 in 1985 and SLS-1 in 1987. In hypergravity there is an increase in lymphocyte activation of up to 500%. A similar increase can be induced by pre-incubating the cultures in hypergravity prior to exposure to concanavalin A at 1 G. The effect is less evident in cultures of isolated lymphocytes. The influence of autologous plasma and erythrocytes has also been investigated. Plasma and hypergravity have a synergistic and positive effect on lymphocyte activation, i.e. cultures of separated lymphocytes show the highest activation when incubated at 10 G and supplemented with autologous plasma. Conversely, erythrocytes depress lymphocyte activation.

Surgical treatment for aggressive giant keratoacanthoma of the face

A case of aggressive giant keratoacanthoma on the right temple region is described. Histopathologic examination was not definitive for keratoacanthoma, so that clinical considerations were helpful for diagnosis. The neoplasm was treated successfully with surgical excision and immediate repair with skin graft, in spite of one narrow peripheral area of residual disease on the wound surface after resection.

Differential salicylate-aspirin interaction on vascular prostacyclin and platelet thromboxane synthesis in patients undergoing saphenectomy

We studied the ability of salicylate to counteract the effect of aspirin on platelet thromboxane synthesis and prostacyclin formation in venous tissue in patients undergoing saphenectomy. A single intravenous dose of 40 mg aspirin completely blocked thromboxane formation and reduced prostacyclin to about 43% of the control values. When salicylate (1000 mg po) corresponding in anesthetized subjects to blood levels of 25.9 +/- 5 micrograms/ml was administered before aspirin, vascular prostacyclin was no longer inhibited, whereas platelet thromboxane was still significantly blocked. These results suggest that the combination of salicylate with aspirin at an appropriate dose ratio may result in almost complete dissociation of the drug's effect on platelets and vessels in man.

Treatment of peripheral congenital arterio-venous fistulas

The authors describe their experience in the treatment of peripheral congenital A-V fistulas in 64 cases. Different surgical procedures (skeletation, "en bloc resection") have been performed in 19 patients, embolization in 15 patients. The need for a more radical and definitive procedure has induced the authors, in a recent series of 6 patients, to associate embolization and surgical therapy in the same operative session. The results are encouraging. The technique is reported.

Rupture of gastroduodenal artery aneurysm into the portal vein

Aneurysms of the gastroduodenal artery are very rarely observed. Rupture occurs in about 60% of cases and is usually associated with gastroduodenal bleeding. A case of rupture into the portal vein and secondary portal hypertension is presented. The combined use of computed tomography (CT scan) and selective visceral angiography was very useful for the diagnosis.

[New trends in the treatment of trophic sequelae post-phlebitic syndrome]

Authors analyses most recent concepts on pathogenesis of trophic changes in post-phlebitic syndrome: particularly they consider the role of extravascular fibrin deposition, in patients with depressed plasmatic fibrinolytic activity. In this patients, according to recent reports, it seems useful a fibrinolytic therapy to improve trophic conditions of the post-phlebitic limb, particularly in respect to dermatoliposclerosis. Authors refer their experience on a double blind study with stanozolol an anabolizing steroid with fibrinolytic activity: in all treated patients good clinical results were obtained; however no enhancement of plasmatic fibrinolytic activity was demonstrated.

[Epidemiological evaluation of thromboembolic risk. Critical review of the prospects offered by determination of antithrombin III]

Authors review the epidemiology of deep venous thrombosis and the prothrombotic state in high risk patients; particularly antithrombin III role in blood clotting is considered. A fall in antithrombin III concentration and/or activity can induce hypercoagulability and thrombosis. Moreover authors stress the need to evaluate antithrombin III as anti-Xa activity, to detect high risk patients for deep venous thrombosis.

Tissues concentration and excretion of deslanatoside C-3H in newborn and growing rabbits

Deslanatoside C-3H was injected (i.p. 50 microgram/kg) into rabbits of 1, 4, 10, 20 days and more than 1 year old. The rabbits were sacrificed 2 and 6 h after dosing. Levels in all tissues were higher in newborn rabbits, decreased in the older animals and then in most tissues increased in adults to different degrees, showing the highest values in kidneys. Biliary excretion and above all urinary excretion increased with age. Levels in atria, ventricles, aorta and liver in rabbits 1 and 4 days old were consistently higher at the 6th h than those at the 2nd h, these tissues showing a particularly marked avidity with Deslanatoside C; in the older animals this behaviour was reversed. These data and those of other Authors working on other glycosides (incleding Digoxin) and other species (including newborn children) lead to the conclusion that digitalis glycosides in new born species are excreted at a lower rate and incorporated in the body tissues at a higher rate than in adults. They may also in part explain the large dosages employed in human infants in comparison with adults, as the higher distribtuion volume retains a large amount of the injected glycoside.