Towards grapevine root architectural models to adapt viticulture to drought

To sustainably adapt viticultural production to drought, the planting of rootstock genotypes adapted to a changing climate is a promising means. Rootstocks contribute to the regulation of scion vigor and water consumption, modulate scion phenological development and determine resource availability by root system architecture development. There is, however, a lack of knowledge on spatio-temporal root system development of rootstock genotypes and its interactions with environment and management that prevents efficient knowledge transfer into practice. Hence, winegrowers take only limited advantage of the large variability of existing rootstock genotypes. Models of vineyard water balance combined with root architectural models, using both static and dynamic representations of the root system, seem promising tools to match rootstock genotypes to frequently occurring future drought stress scenarios and address scientific knowledge gaps. In this perspective, we discuss how current developments in vineyard water balance modeling may provide the background for a better understanding of the interplay of rootstock genotypes, environment and management. We argue that root architecture traits are key drivers of this interplay, but our knowledge on rootstock architectures in the field remains limited both qualitatively and quantitatively. We propose phenotyping methods to help close current knowledge gaps and discuss approaches to integrate phenotyping data into different models to advance our understanding of rootstock x environment x management interactions and predict rootstock genotype performance in a changing climate. This could also provide a valuable basis for optimizing breeding efforts to develop new grapevine rootstock cultivars with optimal trait configurations for future growing conditions.

Implication of Row Orientation Changes on Fruit Parameters of Vitis vinifera L. cv. Riesling in Steep Slope Vineyards

Row orientation, among others, is a crucial factor in determining grapevine performance and health status, thus affecting berry components that form the basis of the later wine profile. However, the literature about the impact of changes in row orientation at steep slope sites on grapevine fruit composition as well as the differentiation between canopy sides hardly exists. Thus, the aim of this work was to gain knowledge about the impact of row orientation in steep slope vineyards on selected primary and secondary metabolites in berries of Vitis vinifera L. cv. Riesling. Samples were taken from both canopy sides of different row orientations of terraced and downslope vineyards in steep slopes. Free amino acids in the juice and flavonols in the berry skin had a positive correlation to sunlight exposure. Furthermore, grapevines showed adaptations to constantly higher light conditions, e.g., physiologically in reduction in chlorophyll content or protective mechanisms resulting in a lower susceptibility to sunburn damage. Thus, grapevine fruit parameters are affected by row orientation change in steep slopes.

Glycemic control with preprandial versus basal insulin in patients with type 2 diabetes mellitus poorly controlled by oral antidiabetes agents

OBJECTIVE

This study was designed to compare glycemic control (glycated hemoglobin [A1C] level) with either once-daily basal insulin (BI) (insulin glargine) or preprandial insulin (PPI) (Exubera) [insulin human (recombinant DNA origin)] inhalation powder, Pfizer Inc., New York, NY) in patients with type 2 diabetes mellitus (T2DM) poorly controlled on at least two oral antidiabetes agents (OADs).

METHODS

This was a 26-week, open-label, parallel-group, randomized study where 257 patients (mean A1C 8.6%) on OAD treatment for > or = 3 months were treated with either BI (n = 122) or PPI (n = 135). Based on self-monitored blood glucose levels, PPI dose was adjusted before each major meal, whereas BI dose was titrated in the morning or before bedtime. Prestudy OADs were continued, but doses could be modified.

RESULTS

At 26 weeks, change from baseline in A1C was greater with PPI (-1.7 vs. -1.4%, P = 0.0389). Numerically, more patients achieved A1C <6.5% (28% vs. 19%) and A1C <7.0% (63% vs. 55%) with PPI compared with BI. PPI had lower postmeal glucose increments, but higher prebreakfast glucose and weight gain (1.1kg), than BI. Mild or moderate hypoglycemic events were more frequent with PPI (6.2 vs. 2.9 events/months), but nocturnal hypoglycemic events were less frequent (22% vs. 30%).

CONCLUSIONS

PPI improved postprandial glucose and A1C levels significantly more than BI. More patients achieved A1C targets with PPI, at the expense of more hypoglycemia and body weight gain. These results illustrate the potential benefits and detriments of prandial insulin supplementation in patients with T2DM poorly controlled on OADs alone.

The effect of the availability of inhaled insulin on glycaemic control in patients with Type 2 diabetes failing on oral therapy: the evaluation of Exubera as a therapeutic option on insulin initiation and improvement in glycaemic control in clinical practice (EXPERIENCE) trial

AIM

To examine the impact of inhaled human insulin (Exubera, EXU) on patient or physician willingness to adopt insulin after oral glucose-lowering agent failure.

METHODS

During a randomized controlled trial in primary, secondary and tertiary care in Europe and North America, 739 patients using >or= 2 oral glucose-lowering agents with glycated haemoglobin (HbA(1c)) >or= 8.0% were assigned to two treatment groups: Group 1 (standard care with the option of EXU) or Group 2 (standard care only). Standard care included adjusting oral therapy (optimizing current regimen or adding/omitting agents) and/or initiating subcutaneous (s.c.) insulin. The primary endpoint was difference in HbA(1c) between randomized groups at 26 weeks. Secondary outcomes included differences in the rate of uptake of insulin therapy, proportion achieving satisfactory glycaemic control, treatment satisfaction and safety outcomes.

RESULTS

At baseline, insulin was initiated by more [odds ratio 6.0; 95% confidence interval (CI) 4.2 to 8.8; P < 0.0001] patients in Group 1 (86.2%; 76.7% EXU plus 9.5% s.c.) than Group 2 (50.7%; s.c. insulin only). At 26 weeks, mean (sd) changes in HbA(1c) from baseline were -2.0% (1.2%) and -1.7% (1.3%) in Groups 1 and 2, respectively, a difference of -0.2% (95% CI: -0.1% to -0.4%; P = 0.004). In Group 1, 45% of patients achieved an HbA(1c)<or= 7.0% by 26 weeks compared with 39% in Group 2 (P = 0.02).

CONCLUSION

The availability of EXU may increase initiation of insulin, thereby contributing to improved overall glycaemic control in patients with Type 2 diabetes inadequately controlled on two or more oral glucose-lowering agents.

A comparative study of insulin lispro and human regular insulin in patients with type 2 diabetes mellitus and secondary failure of oral hypoglycemic agents

OBJECTIVE

To compare the effects of insulin lispro (LP) and human regular insulin (HR) when given twice daily with NPH insulin on glycemic control (HbA1c), daily blood glucose profiles and rates of hypoglycemia in patients with type 2 diabetes mellitus after failure to respond to sulfonylurea drugs.

RESEARCH DESIGN AND METHODS

A 5.5-month randomized, open-label, parallel study of 148 patients receiving either LP (n = 70) or HR (n = 78). Eight-point blood glucose profiles and HbA1c measurements were collected at baseline, 1.5, 3.5 and 5.5 months.

RESULTS

Two-hour post-breakfast and 2-hour post-supper blood glucose levels (means [and standard errors]) were significantly lower for LP than for HR at the end point (9.5 [0.4] mmol/L v. 10.9 [0.4] mmol/L and 8.4 [0.4] mmol/L v. 9.7 [0.4] mmol/L, respectively, p = 0.02 in both cases). HbA1c improved from 10.5% (0.2%) (LP) and 10.3% (0.2%) (HR) to 8.0% (0.1%). Hypoglycemia rates were similar during the day; however, there was an overnight trend to reduced rates with LP (0.08 [0.03] episodes/30 d v. 0.16 [0.04] episodes/30 d, p = 0.057). Quality-of life assessment showed significant improvement (p < 0.05) in the diabetes-related worry scale for LP subjects whereas HR subjects slightly worsened.

CONCLUSIONS

With traditional twice-daily insulin administration algorithms, LP improves 2-hour postprandial glucose levels, quality of life and overnight hypoglycemia rates while delivering an equivalent level of glycemic control (HbA1c) compared with HR to insulin-naïve patients with type 2 diabetes who require insulin.

Improved glycaemic control with the use of self-prepared mixtures of insulin lispro and insulin lispro protamine suspension in patients with types 1 and 2 diabetes

A total of 166 patients (102 type 1, 64 type 2) were randomised to insulin lispro (LP) combined with insulin lispro protamine suspension (NPL), an intermediate-acting formulation of LP, or to regular human insulin (HR) combined with human NPH insulin (NPH) in this open-label, parallel study. Insulin doses were similar at endpoint. Blood glucose (BG) measurements (before and two hours after meals, bedtime, 3 a.m.)(mmol/l) were lower with LP/NPL two hours after breakfast (8.84 +/- 0.32 vs 10.29 +/- 0.41, p < 0.001), before lunch (6.21 +/- 0.20 vs 7.10 +/- 0.31, p = 0.016), two hours after the evening meal (10.18 +/- 0.36 vs 7.86 +/- 0.28, p < 0.0.001), and at bedtime (7.85 +/- 0.28 vs 9.43 +/- 0.40, p = 001). HbA1c was lower for LP/NPL at endpoint (7.54 +/- 0.11% vs 7.92 +/- 0.10%, p = 0.019). There was no difference in hypoglycaemia or insulin antibody levels. LP/NPL resulted in better glycaemic control than HR/NPH without increasing the risk of hypoglycaemia.

Effectiveness of human ultralente versus NPH insulin in providing basal insulin replacement for an insulin lispro multiple daily injection regimen. A double-blind randomized prospective trial. The Canadian Lispro Study Group

OBJECTIVE

To compare human ultralente (UL) insulin with human NPH insulin as basal insulin replacement in patients who use insulin lispro before meals.

RESEARCH DESIGN AND METHODS

There were 178 patients with type 1 diabetes who were randomized to receive either human NPH or UL insulin once daily at bedtime in a 1-year double-blind clinical study. Eight-point blood glucose profiles were collected once monthly in the first 4 months, then every 2 months for the remainder of the study. Patients were also asked to perform premeal blood glucose measurements every day throughout the study. If before-supper blood glucose levels consistently exceeded 8 mmol/l despite optimal postprandial control with the lunch dose of insulin lispro, a second dose of basal insulin before breakfast was administered.

RESULTS

For the group as a whole, insulin doses before meals and basal insulin doses were similar at baseline. At study's end, meal doses remained the same (30 +/- 1 U/day for UL., 29 +/- 1 U/day for NPH), while basal requirements were somewhat higher for the UL group than the NPH group: 30 +/- 1 U/day vs. 26 +/- 1 U/day, respectively (P < 0.05). The rates of severe hypoglycemia were similar for patients on NPH (0.05 +/- 0.03 per patient every 30 days) and for UL (0.07 +/- 0.04 per patient every 30 days) insulin. There was no significant difference for glycemic control between the NPH and UL groups overall (HbAlc at the end of the study: 7.6 +/- 0.1 vs. 7.7 +/- 0.1%, respectively), and by study's end a similar number of patients in the NPH and the UL groups needed to be switched to twice daily basal insulin (21 and 24%, respectively). Patients requiring twice-daily injections of basal insulin had a longer duration of diabetes (17.8 +/- 1.5 vs. 14.0 +/- 0.8 years, P < 0.05) and a highest baseline HbAlc (8.6 +/- 0.1 vs. 8.0 +/- 0.1%, P < 0.002) and were significantly older (38 +/- 2 vs. 34 +/- 1 years, P < 0.007). Patients who were switched to twice-daily NPH insulin had lower HbAlc levels at study's end compared with those switched to twice-daily UL insulin (7.7 +/- 0.2 vs. 8.2 +/- 0.3%), but this difference was not statistically significant. Distribution of hypoglycemia across the day was also similar in both groups.

CONCLUSIONS

UL or NPH insulin, when used as the basal insulin for multiple injection regimens, results in similar glycemic control in patients using insulin lispro before meals. However, in patients who require a second injection of basal insulin, NPH insulin appears to provide lower prebreakfast and prelunch glucose levels compared with UL insulin.

Effect of continuous subcutaneous insulin infusion with lispro on hepatic responsiveness to glucagon in type 1 diabetes

OBJECTIVE

People with type 1 diabetes frequently develop a blunted counterregulatory hormone response to hypoglycemia coupled with a decreased hepatic response to glucagon, and consequently, they have an increased risk of severe hypoglycemia. We have evaluated the effect of insulin lispro (Humalog) versus regular human insulin (Humulin R) on the hepatic glucose production (HGP) response to glucagon in type 1 diabetic patients on intensive insulin therapy with continuous subcutaneous insulin infusion (CSII).

RESEARCH DESIGN AND METHODS

Ten subjects on CSII were treated for 3 months with lispro and 3 months with regular insulin in a double-blind randomized crossover study After 3 months of treatment with each insulin, hepatic sensitivity to glucagon was measured in each subject. The test consisted of a 4-h simultaneous infusion of somatostatin (450 microg/h) to suppress endogenous glucagon, regular insulin (0.15 mU x kg(-1) x min(-1)), glucose at a variable rate to maintain plasma glucose near 5 mmol/l, and D-[6,6-2H2]glucose to measure HGP During the last 2 h, glucagon was infused at 1.5 ng x kg(-1) x min(-1). Eight nondiabetic people served as control subjects.

RESULTS

During the glucagon infusion period, free plasma insulin levels in the diabetic subjects were 71.7+/-1.6 vs. 74.8+/-0.5 pmol/l after lispro and regular insulin treatment, with plasma glucagon levels of 88.3+/-1.8 and 83.7+/-1.5 ng/l for insulin:glucagon ratios of 2.8 and 3.0. respectively (NS). However, plasma glucose increased to 9.2+/-1.1 mmo/l after lispro insulin compared with 7.1+/-0.9 mmol/l after regular insulin (P < 0.01), and the rise in HGP was 5.7 +/-2.8 micromol x kg(-1) x min(-1) after lispro insulin versus 3.1+/-2.9 micromol x kg(-1) x min(-1) after regular insulin treatment (P=0.02). In the control subjects, HGP increased by 10.7+/-4.2 micromol x kg(-1) x min(-1) under glucagon infusion.

CONCLUSIONS

Insulin lispro treatment by CSII was associated with a heightened response in HGP to glucagon compared with regular human insulin. This suggests that insulin lispro increases the sensitivity of the liver to glucagon and could potentially decrease the risk of severe hypoglycemia.

Counterregulatory hormone responses after long-term continuous subcutaneous insulin infusion with lispro insulin

OBJECTIVE

To determine whether the long-term use of insulin lispro (LP) affects the counterregulatory hormone response to hypoglycemia.

RESEARCH DESIGN AND METHODS

Ten patients (age range 26-51 years; ratio of men to women 9:1; BMI 24.9 +/- 0.48; mean HbA1c 7.84 +/- 0.25%) with IDDM, treated with continuous subcutaneous insulin infusion (CSII; Disetronic H-TRON V100) were studied using a double-blind, crossover design. Patients were randomized to LP or human regular insulin (HR) for 3 months and then crossed over to the other insulin for an additional 3 months. All meal boluses were given 0-5 min before breakfast, lunch, and dinner. Counterregulatory hormone responses to a stepped hypoglycemic clamp (consecutive glucose levels in mmol/l: 4.2; 3.5; 2.8, each for 1 h) were evaluated at the end of each treatment period.

RESULTS

HbA1c was significantly lower with LP versus HR (7.47 +/- 0.28% vs. 7.9 +/- 0.26%, P = 0.04). The incidence of hypoglycemia per 30 days (capillary blood glucose < 3.0 mmol/l and/or symptoms) during the last month of the study was significantly lower with LP versus HR (8.7 +/- 2.9 vs. 11.8 +/- 2.9, P = 0.03). The total daily insulin dosage was not different in the two treatment periods. There was no episode of severe hypoglycemia or diabetic ketoacidosis. The peak growth hormone, cortisol, glucagon, and epinephrine responses during the same period of hypoglycemia were not different for each treatment period.

CONCLUSIONS

The use of LP in CSII results in improved glycemic control and a decrease in the frequency of hypoglycemia without adversely affecting counterregulatory hormone response to hypoglycemia.

Insulin lispro in CSII: results of a double-blind crossover study

Insulin lispro is a human insulin analog that dissociates more rapidly than human regular insulin after subcutaneous injection, resulting in higher insulin levels at an earlier point in time and a shorter duration of action. The aim of the study was to evaluate if this pharmacokinetic difference would translate into better postprandial and overall control in 30 IDDM patients (age, 35.1 +/- 1.5 years; male-female ratio, 17:13; BMI, 24.8 +/- 0.5 kg/m2; HbA1c, 8.03 +/- 0.13% at baseline) treated with continuous subcutaneous insulin infusion (CSII; Disetronic H-TRON V100) in a double-blind crossover clinical study. Patients were randomized to insulin lispro or human regular insulin for 3 months before crossing over to the other insulin for another 3 months. All meal boluses were given immediately before breakfast, lunch, and supper. An eight-point blood glucose profile was measured once weekly, and HbA1c levels were measured monthly. At the end of the 3-month treatment period, HbA1c levels were significantly lower with insulin lispro, compared with human regular insulin: 7.66 +/- 0.13 vs. 8.00 +/- 0.16% (P = 0.0041). While preprandial, bedtime, and 2:00 A.M. values for blood glucose were not significantly different, 1-h postprandial blood glucose was significantly improved after breakfast, lunch, and dinner with insulin lispro, compared with human regular insulin: 8.35 vs. 9.79 mmol/l (P = 0.006), 7.58 vs. 8.74 mmol/l (P = 0.049), and 7.85 vs. 9.01 mmol/l (P = 0.03). The incidence of hypoglycemia per 30 days (blood glucose levels, <3.0 mmol/l) was 8.4 +/- 1.3 before randomization, decreasing to 6.0 +/- 0.9 for insulin lispro and to 7.6 +/- 1.3 for regular insulin during the last month of the study. Two patients in each group reported insulin precipitation. We conclude that insulin lispro improves glycemic control in CSII without increasing the risk of hypoglycemia.

Final results of the Canadian phase I dose escalation trial of gemcitabine and cisplatin for advanced non-small cell lung cancer

When given at doses of > or = 1,250 mg2 weekly x 3 with a 1-week break, single-agent gemcitabine induces responses in more than 20% of previously untreated patients with non-small cell lung cancer (NSCLC). This study was undertaken to determine the maximum tolerated doses for a 4-week cycle of gemcitabine and cisplatin given in combination weekly x 3 with a 1-week rest. Patients younger than 75 years were eligible if they had stage III/IV NSCLC, life expectancy > or = 12 weeks, hemoglobin > or = 10 g/dL, absolute granulocyte count > or = 2 x 10(9)/L, platelets > or = 100 x 10(9)/L, hepatic enzymes < or = 3 times the upper limit of normal, and serum creatinine < or = 130 mumol/L. The starting doses for gemcitabine and cisplatin were 1,000 mg/m2 and 25 mg/m2 per week x 3, respectively. At dose level 2 cisplatin was increased to 30 mg/m2/week x 3. Thereafter only the gemcitabine was increased, by 250 mg/m2/wk at each dose level, to a maximum of 2,250 mg/m2/wk at dose level 7. The median nadir granulocyte and platelet counts decreased with each dose level, but dose-limiting toxicity in two or more patients was not encountered in the first treatment cycle, even at dose level 7. Cumulative bone marrow toxicity was seen at all dose levels, and this resulted in frequent dose reductions or omissions. Dose delivery was well maintained over time only at dose level 1. Grade 3-4 nonhematologic toxicity was infrequent and rarely dose limiting. An assessment of all toxicities seen during the treatment cycles was undertaken using continual reassessment methodology. This model suggested that dose level 4 (cisplatin 30 mg/m2/wk and gemcitabine 1,500 mg/m2/wk) would be the maximum dose at which grade 4 toxicity would be expected in up to 33% of patients at any time over four treatment cycles. Of 47 patients evaluable for response, partial remission was seen in 14, with an overall response rate of 30% (confidence interval, 17% to 43%). The median duration of response was 16 weeks and the median survival time was 24 weeks (range, 3.5 to 64+ weeks). A phase II trial is planned in which dose level 4 will be evaluated in a larger cohort of patients with NSCLC.

Phase I dose-escalation trial of gemcitabine and cisplatin for advanced non-small-cell lung cancer: usefulness of mathematic modeling to determine maximum-tolerable dose

PURPOSE

This study was undertaken to determine the maximum-tolerated doses of gemcitabine and cisplatin, each given weekly for 3 weeks with a 1-week rest.

PATIENTS AND METHODS

Patients less than 75 years of age were eligible if they had stage III/IV non-small-cell lung cancer (NSCLC), life expectancy > or = 12 weeks, hemoglobin level > or = 10 g/dL, granulocyte count > or = 2 x 10(9)/L, platelet count > or = 100 x 10(9)/L, hepatic enzymes < or = three times the upper limit of normal, and creatinine concentration < or = 130 mumoles/L. The starting doses for gemcitabine and cisplatin were 1,000 mg/m2 and 25 mg/m2 per week for 3 weeks. At dose level 2, cisplatin was increased to 30 mg/m2/wk for 3 weeks, and thereafter only gemcitabine was increased by 250 mg/m2/wk at each dose level to a maximum of 2,250 mg/m2/wk.

RESULTS

There were 33 men and 17 women, with a median age of 62 years. Pathology included adenocarcinoma in 35 patients, squamous in eight, large cell in six, and mixed histology in one. Sixteen patients had stage III and 34 had stage IV tumors. The median nadir granulocyte and platelet counts decreased with each dose level, but cycle 1 dose-limiting toxicity (DLT) in > or = two patients was not encountered in cycle 1, even at the highest dose level. Cumulative marrow toxicity was seen at all levels, which resulted in frequent dose reductions or omissions. A mathematic model of all toxicities over time suggested that dose level 4 (cisplatin 30 mg/m2/wk and gemcitabine 1,500 mg/m2/wk) would be the maximum dose at which grade 4 toxicity would be expected in < or = 33% of patients over four cycles. Of 47 assessable patients, 14 achieved a partial response (30%; confidence interval, 17% to 43%). The median duration was 16 weeks and the median survival time was 24 weeks (range, 3.5-64+).

CONCLUSION

Weekly gemcitabine and cisplatin are active against NSCLC, and the recommended phase II doses are 30 and 1,500 mg/m2/wk for 3 weeks, respectively.

Phase I trial of gemcitabine and cisplatin in advanced non-small cell lung cancer: a preliminary report

A phase I trial was performed to investigate the tolerability and efficacy of the novel nucleoside analogue gemcitabine in combination with cisplatin in the treatment of advanced non-small cell lung cancer. Both cisplatin and gemcitabine were administered as 30 min infusions weekly x 3 with a week of rest. There was one dose escalation of cisplatin from 25 mg/m2 (dose level 1) to 30 mg/m2 (in subsequent dose levels 2-5), such that the mean dose intensity for the weekly x 3 q 4 week cycle was 22.5 mg/m2/week which is close to that achieved with 100 mg/m2 bolus monthly. Gemcitabine was initiated at 1000 mg/m2 (dose levels 1 and 2) then escalated by 250 mg/m2/week to 1750 mg/m2 (dose level 5). Of 32 chemotherapy-naive patients entered (22 males, 10 females; median age 61 years, range 29-74 years), 11 had localized tumours (2 stage IIIa, 9 IIIb) and 21 had stage IV tumours with haematogenous metastases and a poor prognosis. Twenty-one patients had adenocarcinoma, 4 squamous cell carcinoma, 6 large cell undifferentiated tumors, and one had mixed squamous and adenocarcinoma. Dose-limiting toxicity was not seen in more than one patient in cycle 1 at any dose level. Grade 4 granulocytopenia and thrombocytopenia occurred more frequently with repeated dosing, necessitating dose reductions except at the lowest dose level (cisplatin 25 mg/m2, gemcitabine 1000 mg/m2). Non-haematological toxicity was mild and rapidly reversible. Cisplatin administration led to a higher frequency of nausea and vomiting than that seen with gemcitabine alone, but this was easily controlled with antiemetics. In the 28 patients evaluable, to date responses have been seen at most dose levels, with an overall response rate 35.7%. This phase I trial is ongoing and further dose escalation is intended to determine the MTD of gemcitabine.

[Selective blood sampling from the sinus petrosus inferior: a comparison of CRF and TRH stimulation]

In 10 patients with hypophyseal Cushing microadenomas, selective bilateral sampling from the inferior petrosal sinuses was performed and the effect of stimulation by iv TRH and CRF was compared. On the side of the microadenoma. ACTH concentration rose from 650 +/- 242 pg/ml to 2712 +/- 843 pg/ml following injection of CRF and 2025 +/- 242 pg/ml after TRH. Contralateral values were 165 +/- 79 pg/ml, 490 +/- 200 pg/ml and 165 +/- 72 pg/ml respectively. Prolactin concentration on the side of the adenoma was 98 +/- 49 ng/ml before stimulation, 236 +/- 62 ng/ml after CRF and 747 +/- 168 ng/ml after TRH. Contralateral concentration was 22 +/- 10 ng/ml, 64 +/- 19 ng/ml respectively. Sampling localised all adenomas correctly, whereas contrast-enhanced MRT diagnosed only four adenomas.

[Computer-assisted diabetes therapy--a challenge for modern medicine]

By the use of computers in the therapy of diabetes new diagnostic and therapeutic possibilities are brought about. The computers open the possibility for a comprehensive data seizing, evaluation of the stored material and possibilities of various abilities for demonstration. Moreover, it becomes possible to regulate the therapy more subtly with the help of self-adapting programs and in its consequence to render it more effective than the own management of therapy is able to do it. This manifests itself significantly in badly or only moderately stabilised diabetics. In very well educated and trained diabetics even the superiority of the management of the computer becomes visible. Here this can no more be shown in the improvement of the stabilisation of diabetes which can no more be improved without risks for the patient. In these patients it is the reduction of the frequency of hyperglycaemia, by means of which can be shown that the stabilisation of diabetes in diabetics who were well stabilised already before can still be improved by the computer therapy. In addition to this the computer seems to cause further positive effects on the learning behaviour of the diabetics.

[Osteoporosis: a case report]

A 56-year-old female patient was admitted to our hospital because she was suffering from severe osteoporosis. The patient had experienced repeated spontaneous fractures for 1.5 years such as serial rib fractures, fractures of the sternum and most recently fracture of the neck of the femur after a minimal trauma. Histology revealed a low-turnover-osteoporosis. Subsequent radiologic examination showed extreme osteoporosis of the skeleton with numerous compression fractures of the vertebral bodies as the most outstanding finding. The bone histology and the relatively short history of spontaneous fractures led us to investigate endogenous hypercortisolism as a possible cause although clinical signs were absent. An attenuated diurnal variation of cortisol levels and lack of suppressibility of cortisol was found. Furthermore, magnetic resonance tomography showed a microadenoma of the pituitary gland. Computerized tomography of the adrenals was normal. Transsphenoidal surgery confirmed the tentative diagnosis and histological examination revealed a bilateral adenoma of the pituitary gland.

Compliance in microcomputer-assisted conventional insulin therapy: computer simulation study results

Compliance in diabetes self-management is a complex issue. It involves the interdependent daily actions of self-measurement of blood glucose and adherence to a prescribed schedule of daily activities. This impacts strongly on lifestyle because it necessitates precise meal timing as well as control of size and carbohydrate content. We sought to identify how strongly relaxing the lifestyle constraints per se would impact the ability to achieve improved metabolic control. To isolate these effects from those that result from poor measurement compliance, we used a computer simulator called OMNI et al. Furthermore, to standardize the "clinical" therapy, a second microprocessor device called an "Insulin Dosage Computer" was used to adjust insulin doses based on the usual clinical practice of four times a day precibal blood glucose measurements. Ten type 1 diabetic patients were stimulated and each followed for 120 simulated days. In each such subject, the simulation was repeated three times to include three different levels of lifestyle compliance ranging from excellent to poor. In all three protocols, starting from a level of poor control of diabetes, mean blood glucose values were significantly improved without significant differences after 120 days of computer-simulated treatment. Only the standard deviations, expressing the fluctuations of blood glucose and hence its stability, increased with decreasing lifestyle compliance. This computer simulation predicts that consistent self-monitoring of four blood glucose values per day is the cornerstone of diabetic self-control and that the use of these data according to a standardized therapeutic algorithm for insulin adjustment may successfully stabilize even patients with poor lifestyle compliance. Clinical studies must follow.

Selective in situ pancreatic perfusion via chronic in vivo celiac artery catheterization

A new technique to catheterize the celiac artery has been developed. This has opened the possibility for direct in vivo, in situ study of pancreatic endocrine cell function in a conscious experimental animal. The catheter is small, soft and placed without arterial ligation so that celiac artery, hepatic, splenic, and pancreatic blood flows were essentially not compromised. Arterial vessel integrity, absence of inflammation, and thrombosis as well as catheter patency were achieved for periods exceeding eight months. Metabolically and hormonally, the presence of the catheter had no effect on the fasting status. However, we found somewhat lower glucose levels and higher insulin levels in the response to oral glucose challenges after catheterization, but these differences were statistically not significant. Glucose loads of 50 mg/kg (0.75 g) administered directly to the pancreas via the celiac artery produced peak insulin levels similar to peripheral glucose loads some tenfold larger. We suggest that this technique may be useful to selectively study the first-pass pancreatic response to a variety of hormones, drugs or metabolic substrates.

[Selective blood sampling from the inferior petrosal sinus using digital subtraction angiography]

Simultaneous bilateral venous sampling of blood from the inferior petrosal sinuses helps in the differentiation between peripheral and central ACTH hypersecretion. One can also locate the site of a hormonally active hypophyseal micro-adenoma that cannot be demonstrated by other methods. The authors have experience with fifteen patients and discuss the indications, technique and problems as well as the advantages of using digital subtraction angiography.

Developmental and application of insulin infusion profiles for therapy of type-I diabetics with portable insulin infusion systems

We studied the insulin requirements of seven insulin-dependent diabetics applying a glucose controlled insulin infusion system. The data were transformed into individually programmed and rectangular profiles. The MAGE, a measure of blood sugar fluctuations, was significantly lower when individually programmed step profiles were used (P less than 0.005) than it was when rectangular profiles were applied: 57.7 +/- 24.8 mg/dl vs 89.0 +/- 42.9 mg/dl. The average of measured blood glucose levels was significantly lower in individually programmed infusion profiles (P less than 0.025). The combination of individually programmed profiles and preprandial insulin bolus significantly reduced the postprandial blood glucose level and increase (P less than 0.001). Our investigations suggest that individually programmed insulin infusion profiles are able to smooth blood glucose fluctuations. When combined with an initial insulin bolus they may lead to a reduced insulin consumption after meals.

Development of individual insulin infusion profiles for open loop infusion systems

A computer controlled syringe-type insulin infusion pump storing up to 254 different infusion rates, eight different meal programs and two different basal rates automatically changeable during 24 h in EPROM was used for insulin infusion applying a wavy step profile. This profile approaching the physiological postprandial insulin secretion of the B-cell was calculated by an algorithm following the biphasic insulin secretion model proposed by E. Cerasi . The computer program for the open loop infusion device simulated the feed-back structure of a closed loop insulin secretion control by an algorithm based upon a theoretical postprandial blood sugar profile. Fifteen unstable juvenile onset insulin requiring diabetics could be well controlled after two to three days of an intravenous open loop insulin infusion program. The programs consisted of two constant basal rates and superimposed wavy step profile programs activated at the beginning of each meal. The preabsorptive bolus or cephalic phase was an additional tool both for improved postprandial blood sugar control and further reduction of insulin consumption. The programmable insulin infusion device proved as a valuable tool for the study of a sophisticated insulin infusion profile suitable as well for open loop as for closed loop insulin infusion systems.