Very early changes in circulating T3 and rT3 during development of metabolic derangement in diabetic patients

Alterations in circulating iodothyronines were studied in 15 juvenile type diabetic patients during the development of metabolic derangement after withdrawal of insulin. By means of measurements of circulating C peptide, one group of patients with and one without residual beta-cell function had been selected. In both groups there was a gradual decrease in serum T3 during the 12-hour period studied after withdrawal of insulin, while an increase in serum rT3 was observed after 4-6 hours. The alterations in serum T3 and the metabolic derangement were significantly more pronounced in patients without than with residual beta-cell function.

Dopamine transporter imaging and the effects of deep brain stimulation in patients with Parkinson’s disease

PURPOSE

Single-photon emission computed tomography (SPECT) with [123I]FP-CIT is a marker for loss of presynaptic dopamine transporters in the striatum in Parkinson's disease (PD). We used [123I]FP-CIT SPECT in order to evaluate binding to the dopamine transporter before and after neurosurgical treatment with bilateral stimulation in the subthalamic nucleus (STN).

METHODS

Thirty-five patients with levodopa-responsive PD were examined with [123I]FP-CIT SPECT pre-operatively (baseline scan: mean 3 months before surgery), and 3 and 12 months after surgery.

RESULTS

Pre-operatively, all patients already had substantial signs of severe nigrostriatal neuronal loss as determined from the [123I]FP-CIT SPECT scans. One year after surgery the specific [123I]FP-CIT binding to the striatum was significantly reduced by 10.3% compared with the pre-operative baseline scan. The mean time span from the baseline scan before surgery to the follow-up scan 1 year after surgery was 16.2 months. Hence, the rate of reduction equals a mean annual reduction of 7.7%. A comparable control group of patients with PD who did not undergo surgery was also examined longitudinally. In this group the specific binding of [123I]FP-CIT was reduced by 6.7% per year.

CONCLUSION

The specific binding of [123I]FP-CIT was reduced equally in the STN-stimulated patients and a group of non-operated PD patients with advanced disease. Our study does not support the notion that electrode implantation and STN stimulation exert a neuroprotective effect by themselves.

Imaging of dopamine transporters and D2 receptors in patients with Parkinson's disease and multiple system atrophy

PURPOSE

The aim of this study was to ascertain whether combined presynaptic and postsynaptic dopaminergic single-photon emission computed tomography (SPECT) scanning is useful for differentiation between patients with idiopathic Parkinson's disease (IPD), patients with multiple system atrophy of the striatonigral type (MSA) and healthy subjects.

METHODS

SPECT measurements of the dopamine transporter (DAT) were done with 123I-beta-CIT, while for determination of the dopamine D2-like receptors (D2), 123I-epidepride was used. Clinical evaluation and SPECT scans were carried out in 14 patients with IPD, eight patients with MSA and 11 healthy age-matched control subjects.

RESULTS

Putaminal DAT binding was reduced to 32% of control values in IPD and to 19% of control values in MSA . Significantly higher striatal asymmetry in DAT binding was found in MSA than in controls, but IPD patients had significantly higher asymmetry than MSA patients. Striatal D2 binding did not differ significantly between patients and healthy controls but the ratio between caudate DAT and D2 binding was significantly higher in patients with IPD than in those with MSA, even when disease severity was taken into account.

CONCLUSION

Patients with reduced striatal 123I-beta-CIT binding and a side-to-side difference greater than 15% are likely to suffer from IPD. Patients with reduced striatal 123I-beta-CIT binding and a side-to-side difference of between 5% and 15% are more likely to have MSA. 123I-epidepride SPECT measurements may add further diagnostic information, since the ratio between DAT and D2 receptor binding is significantly higher in IPD than in MSA.

No evidence for loss of hippocampal neurons in non-Alzheimer dementia patients

OBJECTIVE

To use stereological methods for estimating the total number of neurons in hippocampi of non-Alzheimer demented patients.

MATERIAL AND METHODS

Hippocampi from six women with severely impaired memory but without Alzheimer pathology were compared with six mentally intact age-matched female controls. The total number of neurons was estimated in the granule cell layer of the dentate gyrus, the hilus of the dentate gyrus, the pyramidal cell layer of CA3 and CA2, the pyramidal cell layer of CA1 and the cellular layer of subiculum using the optical fractionator.

RESULTS

The total neuron number was the same in the dementia cases, 22.4 x 106, compared with 22.7 x 106 in the controls (P = 0.85). No region-specific group differences or side difference were found. Two cases without clinical signs of dementia but with abundant plaques and tangles in hippocampus and neocortex had total neuron numbers within normal limits.

CONCLUSION

Our results indicate that severely impaired memory can occur in the presence of intact numbers of hippocampal neurons in non-Alzheimer dementia and that nerve cell loss in the hippocampus might be characteristic for Alzheimer's disease, and perhaps other forms of primary cortical dementia.

Size of neocortical neurons in control subjects and in Alzheimer's disease

The aim of the present study was to estimate mean neuronal volume and absolute size distributions of the neocortical neurons in brains from controls and AD patients using stereological methods based on unbiased principles to determine whether changes in absolute cell size are part of the neuropathological pattern of Alzheimer's disease. The neocortex of 8 patients with Alzheimer's disease (AD), mean age 81.1 (68-94) y was compared with 9 nondemented controls, mean age 80.9 (65-101) y. The brains came from Johns Hopkins University Hospital (JHUH) in Baltimore, USA, the Netherlands Brain Bank (NBB), and from a large brain repository in Denmark. The rotator method was used to obtain an estimate of cell volumes providing absolute size distributions of the volume of both cell perikaryon and cell nuclei. The geometric mean volume of cell nuclei in neocortical neurons was 328 microm3 (interindividual CV = 0.15) in the Alzheimer group compared with 277 microm3 (interindividual CV = 0.17) in controls which was a statistically significant increase (P = 0.049). The perikaryal volume was 1117 microm3 in the Alzheimer group compared with 999 microm3 in controls which was a nonsignificant difference (P = 0.20). There was a highly significant correlation between the nuclear and perikaryal volumes in all individuals. The average slope of the regression lines was significantly higher in the Alzheimer patients than in the controls, illustrating that nuclear hypertrophy was more pronounced in the largest neurons.

Increasing loss of brain tissue with increasing dementia: a stereological study of post-mortem brains from elderly females

Neocortical volumes, cortical thickness and volumes of archicortex, the ventricular system, the central grey matter and white matter were estimated using stereological methods on the brains from 28 elderly females (mean age 81.8 years) with increasing degree of senile dementia and brains from 13 (mean age 82.7 years) female controls who did not suffer from dementia. The estimator of pial surface area, as opposed to the other stereological techniques used in this study, was not strictly unbiased. Brains from patients with dementia (14 Alzheimer cases and 14 non-Alzheimer cases) had decreased cortex volume, and neocortical thickness was significantly reduced in the patients with dementia, with the highest degree of reduction in those whose dementia was most severe, as were the volumes of archicortex. No statistically significant difference was found in the volumes of cortex, white matter, central grey structures, ventricular volume or archicortex between the cases with Alzheimer's dementia (N = 14) compared with those with non-Alzheimer dementia (N = 14). The ventricular volume increased with increasing degree of dementia, but did not reach statistical significance in the dementia group compared with the control group. Surface area did not change in those patients with dementia, and no significant reductions were found in the volumes of white matter or central grey structures in the patients with dementia compared with controls.

Long-term botulinum toxin treatment of cervical dystonia--EMG changes in injected and noninjected muscles

OBJECTIVE

To evaluate changes in quantitative EMG of injected and noninjected sternocleidomastoid muscles following long-term unilateral botulinum toxin treatment of cervical dystonia.

METHODS

We investigated 27 patients with cervical dystonia, who received repeated unilateral botulinum toxin injections of the sternocleidomastoid muscle, with quantitative EMG at rest and at maximal voluntary contraction. The patients had on the average 7.1 botulinum toxin treatments and the follow-up period was on the average 31 months (SD 16).

RESULTS

After the first treatment, the injected sternocleidomastoid muscles showed a significant decrease in turns/s (mean 45%) and amplitude (mean 52%) at rest, and in amplitude at maximal flexion (mean 24%) and rotation (mean 39%). Except for a reduction in turns/s at rotation (mean 19%) no further reductions in EMG parameters were seen after long-term treatment. The contralateral noninjected sternocleidomastoid muscles showed no significant change in EMG activity after the first BT treatment, but after long-term treatment a significant reduction in turns/s and amplitude at both maximal flexion (turns: mean 28%; amplitude: mean 25%) and rotation (turns/s: mean 32%; amplitude: mean 25%) were seen as compared to pretreatment values.

CONCLUSION

The results indicate that there seems to be no cumulative chemodenervation by repeated botulinum toxin injections of sternocleidomastoid muscles measured by quantitative EMG. Contralateral noninjected sternocleidomastoid muscles however, seem to be affected following long-term treatment. The mechanism behind this finding is unknown.

A clinical trial of dextromethorphan in amyotrophic lateral sclerosis

INTRODUCTION

Although the cause of amyotrophic lateral sclerosis (ALS) is unknown, excitotoxicity mediated by glutamate has been implicated. Dextromethorphan is a NMDA-glutamate receptor antagonist with neuroprotective properties.

MATERIAL AND METHODS

The effect of treatment with dextromethorphan (150 mg daily) in ALS patients was evaluated in a randomized, double-blind, placebo-controlled study. Forty-five patients were included in the analysis.

RESULTS

At the end of the treatment period, 12 months after randomization, 15 patients (65%) in the placebo group and 12 patients (55 %) in the dextromethorphan group were still alive (log rank test, P=0.49). Rates of disease progression, as expressed by rates of decline in pulmonary function and in functional disability, were similar in both groups except for a significantly less pronounced rate of decline in the ability scores for the lower extremities in the dextromethorphan group.

CONCLUSION

Treatment with a relatively low dose of dextromethorphan did not result in an improvement in 12-month survival in ALS.

No global neocortical nerve cell loss in brains from patients with senile dementia of Alzheimer's type

Precise estimates of total neuron numbers in neocortices of 11 women, mean age 82.6 years (range 79-88) with severe senile dementia of the Alzheimer's type (SDAT) were compared with similar estimates in 10 cognitively normal women of comparable mean age (84.1 years; range 74-92). The total mean nerve cell number in the SDAT group was 16.9 x 10(9) with a coefficient of variation (CV = SD/mean) = 0.14, whereas mean total neuron number in the control group was 18.1 x 10(9), CV = 0.18. In a material of this size the reduction of 6% in neocortical cell number in the SDATs is neither statistically nor biologically significant. Nevertheless, all patients with SDAT were severely demented, having a mean score of 5.6 on a 1-7-scale of dementia. This contrasts with the nondemented individuals who had lived an independent life at home until shortly before death. The SDAT patients showed a rather consistent reduction in cortical volume by 14%, an atrophy that was solely due to a reduced cortical thickness. In addition, all had multiple neocortical plaques (Bielschowsky silver stain).

Clinical evaluation and pharmacological treatment of Gilles de la Tourette's syndrome and other hyperkinesias

The clinical evaluation and pharmacological treatment of Gilles de la Tourette's syndrome (TS) and other hyperkinesias in Hvidovre Hospital is reviewed. Pimozide still seems to be the most effective single drug in the treatment of Tourette symptoms. Anticholinergics most often in combination with one or two other drugs are still the most effective drug in the treatment of dystonia. Clozapine is an effective alternative in the treatment of tremor.

Optimizing sampling designs for volume measurements of components of human brain using a stereological method

Measurements of the cerebral cortical volume used to be very laborious, due to the 3-D complexity of the gyral pattern. Using stereological methods, which allow the quantification of 3-D structures from measurements on 2-D cross-sections, the difficulties have been overcome. In thirty formalin-fixed normal human brains the total volumes were measured by saline displacement. The brains were serially sliced in coronal sections and the fractional areas of the cortex, white matter, central grey structures and ventricles were determined by point-counting. Using Cavaliéri's principle the volumes of these structures were calculated. The average cortical fixed volume was 549 ml (SD +/- 107) corresponding to 54% of the total volume of the hemispheres. The coefficient of error of the cortical volume determinations was 2.6%. The efficiency of the design and the possibilities for optimizing the design are discussed. This point-counting method was preferred to the use of an automatic image analyser, being precise, easy to handle and not interfering with further tissue processing for histological preparation.

Clinical features and long-term treatment with pimozide in 65 patients with Gilles de la Tourette's syndrome

During the last seven years 65 patients with Gilles de la Tourette's syndrome have been treated. Pimozide was used as the preferred drug because of our experience of treating other hyperkinesias which indicated fewer side-effects than with haloperidol. Of the 65 patients with Gilles de la Tourette's syndrome, 59 were treated with pimozide alone or in combination with tetrabenazine or clonidine. The dose ranges of pimozide were 0.5-9 mg per day. Eighty-one percent experienced a good clinical response without side-effects. The side-effects seen in our patients were sedation, gain in weight, depression, pseudoparkinsonism and akathisia; acute dystonic reactions, blurred vision, slurred speech and xerostomia did not occur. No cases of tardive dyskinesia were seen.

The effect of insulin deprivation on fasting levels of 5000 dalton gastric inhibitory polypeptide in type 1 (insulin-dependent) diabetics

To investigate whether metabolic decompensation has an effect on gastric inhibitory polypeptide (GIP), 8 fasting male type 1 diabetics were deprived of insulin for 12 h. An overnight insulin infusion aiming at normoglycaemia was stopped at 08.00 h. During the following 12 h blood glucose increased from 7.0 +/- 0.4 to 14.9 +/- 1.0 mmol/l, P less than 0.01, 3-hydroxy-butyrate from 0.18 +/- 0.07 to 4.00 +/- 0.74 nmol/1, P less than 0.01, and immunoreactive GIP (IR-GIP) from 16.7 +/- 2.6 to 21.9 +/- 2.9 pmol/1, P less than 0.05. The antiserum employed, R65, only measures 5000 dalton IR-GIP. The final IR-GIP concentrations were not significantly different from fasting IR-GIP concentrations in 13 normal male subjects (17.4 +/- 1.5 pmol/1). Short term insulin deprivation therefore is associated with a slight increase in fasting IR-GIP concentrations. Whether this modest increase in IR-GIP significantly enhances insulin secretion is unknown.

Relation of immunoreactive gastric inhibitory polypeptide to changes in glycaemic control and B cell function in type 1 (insulin-dependent) diabetes mellitus

The effect of strict glycaemic control on plasma immunoreactive gastric inhibitory polypeptide (IR-GIP) concentrations and pancreatic B cell function as estimated by plasma C-peptide was evaluated in 14 Type 1 (insulin-dependent) diabetics. The effect was estimated by giving a test meal before (test 1) and after (test 2) 1 week with near normal blood glucose control (mean blood glucose 6.7 +/- 0.2 mmol/l) and again 3 weeks later (test 3) in the outpatient clinic. The glycaemic control was significantly improved at test 2 and test 3 compared with that of test 1. The IR-GIP concentrations before and after the meals were similar at all three tests and not different from those found in 21 normal controls. In 8 patients with a significant B cell response at test 1, B cell function was significantly improved both at test 2 and test 3 but no change in fasting or post-prandial IR-GIP concentrations was found and no correlation between B cell function and IR-GIP existed. We conclude that strict glycaemic control improves B cell function but does not modulate plasma IR-GIP concentrations. Factors other than GIP seem to be of greater importance in determining the magnitude of B cell function in Type 1 diabetes.

Diminished immunoreactive gastric inhibitory polypeptide response to a meal in newly diagnosed type I (insulin-dependent) diabetics

The release of immunoreactive gastric inhibitory polypeptide (IR-GIP) in response to a standard meal was examined in 10 normal subjects and 15 type I (insulin-dependent) diabetics 7 days (test I), 14 days (test II), and 3 months (test III) after time of diagnosis. During all three tests, the diabetics had significantly lower plasma IR-GIP concentrations than the controls from 15-90 min after the standard meal. The IR-GIP response in the diabetics measured as the integrated area under the response curve corresponded to 70% of that of normal subjects. beta-cell function evaluated from the C-peptide response to the meal increased significantly from test I to test III whereas the IR-GIP response was similar during all three tests. As GIP is known to potentiate glucose-induced insulin secretion and possibly the biosynthesis of insulin, the low IR-GIP responses in subjects with type I diabetes may significantly influence insulin levels and hyperglycemia.

The transient effect of strict glycaemic control on B cell function in newly diagnosed type 1 (insulin-dependent) diabetic patients

Within 24h of diagnosis, 15 consecutive Type 1 (insulin-dependent) diabetic patients were allocated at random to one of two treatment groups: group A (n = 9, mean age: 28 years, range: 17-35 years) was treated conventionally with one or two daily doses of insulin; group B (n = 6, mean age: 27 years, range: 21-37 years) was treated with nine daily injections of fast-acting insulin for ten days and there-after conventionally as for group A. The mean diurnal blood glucose concentration during the initial ten days of insulin treatment was 11.7 +/- 0.5 mmol/l (mean +/- SEM) in group A and 6.4 +/- 0.3 mmol/l in group B (p less than 0.01). Pancreatic B cell function was evaluated 1, 7, 14, 90, and 180 days after the start of insulin treatment from the C-peptide response to a standard meal. At one and seven days after diagnosis, no difference was found in B cell function between the two groups. After 14 days, the amount of C-peptide secreted during the test meal was 18.0 +/- 2.6 nmol (mean +/- SEM) in group A compared with 29.0 +/- 3.6 nmol in group B (p less than 0.05). After 90 and 180 days, no difference was demonstrated in B cell function. The maximal B cell function observed was similar in the two groups, but occurred earlier in group B (at 14 days) than in group A (at 90 days) (p less than 0.05). This study indicates that strict initial glycaemic control may lead to an earlier improvement in B cell function, but that this improvement is of short duration.

Insulin secretory reserve in insulin dependent patients at time of diagnosis and the first 180 days of insulin treatment

Eleven newly diagnosed insulin dependent patients were studied before and during the first 16 h after start of insulin treatment. All the patients were found to have significant amounts of C-peptide in plasma indicating residual insulin secretion. The fall in blood glucose after start of insulin therapy was followed by a parallel decrease in C-peptide (R = 0.99, P < 0.01) suggesting that the beta-cells may respond to variation in blood glucose. Eight of the patients were studied 1, 4, 7, 14, 90 and 180 days after start of insulin therapy. During the first 90 days of treatment an increasing maximal C-peptide concentration was found after a standard breakfast test meal. Two thirds of this improvement i beta-cell function was found after the initial 14 days with an average increase in maximal C-peptide of 260 per cent. The sensitivity to glucose improved.

Role of residual insulin secretion in protecting against ketoacidosis in insulin-dependent diabetes

The role of preserved beta-cell function in preventing ketoacidosis in type I insulin-dependent diabetes was assessed in eight patients with and seven patients without residual beta-cell function as determined from C-peptide concentrations. After 12 hours of insulin fatty-acid, and glycerol concentrations were all significantly higher in patients without beta-cell function than in those with residual secretion. Mean blood glucose concentrations reached 17.2 +/- SE of mean 1.3 mmol/l (310 +/- 23 mg/100 ml) in the first group compared with 8.8 +/- 1.4 mmol/l (159 +/- 25 mg/100 ml) in the second (P less than 0.01), while 3-hydroxybutyrate concentrations rose to 5.5 +/- mmol/l (57 +/- 5 mg/100 ml) and 1.4 +/- 0.3 mmol/l (15 +/- 3 mg/100 ml) in the two groups respectively (P less than 0.01). Individual mean C-peptide concentrations showed a significant inverse correlation with the final blood glucose values (r = -0.91; P less than 0.02). These findings strongly suggest that even minimal residual insulin secretion is important for metabolic wellbeing in diabetes and may prevent the development of severe ketoacidosis when insulin delivery is inadequate.

Plasma C-peptide in uraemic patients

The kidney has been suggested as the main organ for the degradation of C-peptide. This hypothesis was tested in subjects with normal fasting blood glucose concentration and varying degrees of renal failure. Forty-nine subjects with endogenous creatinine clearance ranging from 0--25 ml/min were studied. The basal steady state concentrations of C-peptide (CP) and the immunoreactivity of insulin (IRI) were determined in plasma from fasting patients. The average IRI was similar to that found in normal subjects while a higher CP was found in all patients but two. The average CP in the nephrectomized patients was six times higher than the mean CP in normal subjects (0.35 pmol/ml). There was a significant inverse correlation between clearance and CP (r = 0.51, P less than 0.001) with the highest CP in nephrectomized patients. It is concluded that the increased CP in renal failure, and especially the markedly increased CP in the nephrectomized group supports the hypothesis of the kidney being the organ mainly responsible for the degradation of C-peptide also in man.

Pharmacokinetics of amikacin during hemodialysis and peritoneal dialysis

The pharmacokinetics of amikacin were examined in six bilaterally nephrectomized patients undergoing hemodialysis and in four patients with a minimal residual renal function undergoing peritoneal dialysis. The mean elimination half-life before the dialysis was 86.5 h in the anephric patients and 44.3 h in the patients with minimal residual kidney function. The results from the anephric patients suggest that some extrarenal elimination of amikacin may occur. The mean volume of distribution was about 25% of the total body weight. This is in accordance with values reported from subjects with normal renal function. During hemodialysis the half-life decreased to less than 10% (5.6 h) of the pretreatment value. The effectiveness of peritoneal dialysis was less as the half-life decreased to only about 30% (17.9 h) of the pretreatment value. During the dialyses a significant correlation between the half-life of amikacin and the decrease in blood urea and serum creatinine was demonstrated. The pharmacokinetic data were used to make dosage regimen recommendations for the treatment of patients undergoing intermittent hemodialysis or peritoneal dialysis.

Plasma aldosterone during extracellular fluid volume expansion in patients on regular haemodialysis

The influence of extracellular fluid volume expansion on the plasma aldosterone concentration (PAC) was investigated in five anephric and six non-nephrectomized patients on regular haemodialysis, and compared to a control group of four anephric and four non-nephrectomized patients. Plasma-renin activity, cortisol, Na+, and K+ were measured together with the PAC during the investigation. In anephric patients the PAC remained constant during the control period as well as during extracellular fluid volume expansion by infusion of 350 mmol of 20% mannitol. In the non-nephrectomized patients PAC diminished after mannitol infusion. The decline in PAC was correlated with the basal levels of PAC and the plasma renin activity. It is concluded that 5% extracellular fluid volume expansion has no direct influence on the regulation of PAC in patients without the renal renin-angiotensin system and that the regulation of PAC in anephric patients in the present investigation is probably mediated by changes in potassium and ACTH.