Neural interactions within and beyond the critical band elicited by two simultaneously presented narrow band noises: a magnetoencephalographic study.

Neural activities elicited in the auditory system are systematically organized according to the frequency characteristics of corresponding sound inputs. This systematic frequency alignment, called 'tonotopy,' plays an important role in auditory perception. By means of magnetoencephalography (MEG) we investigated here interactions between neural groups activated by two simultaneously presented narrow-band noises (NBNs) within the human cortical tonotopic map. Auditory evoked fields indicated that the neural interactions activated by these NBNs depended on the frequency difference between them: the amplitude of the N1m-response systematically increased with increasing frequency difference between the NBNs until the critical bandwidth was reached. In contrast, the N1m decreased with frequency difference exceeding the critical bandwidth. The different N1m-response patterns within and beyond the critical band seem to result from the combination of inhibitory and excitatory neural processes in the auditory pathway and may contribute to the perception of complex sound patterns like speech and music.

Benfotiamine in diabetic polyneuropathy (BENDIP): results of a randomised, double blind, placebo-controlled clinical study.

AIM: Efficacy and safety of benfotiamine in treatment of diabetic polyneuropathy. METHODS: Double blind, placebo-controlled, phase-III-study. 181 patients were screened. 165 patients with symmetrical, distal diabetic polyneuropathy were randomised to one of three treatment groups entering the wash-out phase and 133/124 patients were analysed in the ITT/PP analysis: Benfotiamine 600 mg per day (n=47/43), benfotiamine 300 mg per day (n=45/42) or placebo (n=41/39). RESULTS: After 6 weeks of treatment, the primary outcome parameter NSS (Neuropathy Symptom Score) differed significantly between the treatment groups (p=0.033) in the PP (per protocol) population. In the ITT (intention to treat) population, the improvement of NSS was slightly above significance (p=0.055). The TSS (Total Symptom Score) showed no significant differences after 6 weeks of treatment. The improvement was more pronounced at the higher benfotiamine dose and increased with treatment duration. In the TSS, best results were obtained for the symptom "pain". Treatment was well tolerated in all groups. CONCLUSION: Benfotiamine may extend the treatment option for patients with diabetic polyneuropathy based on causal influence on impaired glucose metabolism. Further studies should confirm the positive experiences.

Growth hormone and bone mineral densitiy in HIV-1-infected male subjects.

The aim of this study was to characterize the GH-IGF-I axis of patients with HIV-1-infection without any symptoms of AIDS-associated wasting. A special emphasis was placed on determine bone mineral density (BMD) and biochemical markers of bone metabolism. Therefore 42 male fasting HIV-1-infected outpatients were included and estimation of serum GH, IGF-I, IGFBP-1 and 3, osteocalcin, TNF-alpha, 1,25dihydroxycholecalciferol, and endocrine markers of the gonad function by commercially available RIA's performed. DEXA-measurements of the lumbar spine and the Ward's triangle of the left hip were done. The GH, IGF-1, IGFBP-1 and 3 serum levels were within the normal range Performing Spearman-correlation test, we established significance between IGF-I serum levels and BMD lumbar spine and Ward's triangle (p < 0.01, p < 0.05), CD4 cell-count (p < 0.05), 1,25dihydroxycholecalciferol (p < 0.05), osteocalcin (p < 0.05), TNF-alpha (p < 0.05), body mass index (BMI) (p < 0.05) and total testosterone (p < 0.01). IGFBP-1 correlates both inversely significantly with CD4 cell-count (p < 0.05) and serum-calcium (p < 0.05). The IGFBP-3 correlates with BMI (p < 0.05) and serum osteocalcin (p < 0.05). Correlation both with markers of bone metabolism and vitamin D metabolites showed the important role of GH/IGF-I axis in modulating the availability of calcium in chronic conditions. This axis may be in a part responsible for the manifestation of the HIV-associated osteopenia.

Parathormone levels and Vitamin D metabolism in female patients with various grades of fecal elastase 1 deficiency.

BACKGROUND: There are still too few conclusive reports about conspicuous parathormone (PTH) and Vitamin D metabolism in patients with fecal elastase 1 deficiency or any connection of the calcium metabolism to the severity of exocrine pancreas insufficiency. METHODS: Between March 1998 and September 2002, we investigated on 240 female patients with fecal elastase 1 deficiency at an average age of approx. 56.4 years and suffering from meteorism and weight loss as well as on age matched 80 healthy female controls. Serum levels of PTH, total calcium, D subset3-vitamins, calcitriol and calcefediol, as well as the concentration of fecal elastase 1 were determined in patients and controls. RESULTS: In 240 female patients with deficiency of fecal elastase 1 only two patients show milder cases of new diagnosed primary hyperparathyroidism. Calcitriol was markedly decreased (14.3 +/- 6.1 and 20.7 +/- 9.4 pg/ml) compared to controls (41.8 +/- 8.3 pg / ml) ( p < 0.01). Calcefediol was not significantly different within the various elastase-groups (p = 0.07). Nevertheless, vitamin D subset3 and fecal elastase 1 in patients correlated significantly (p < 0.01) and, compared to controls, both were extremely low (means in patients. Both D subset3-vitamins in patients were significantly lower when elastase 1 in feces was under 200 microg/g compared to the others (for calcitriol p < 0.05, for calcefediol p < 0.05). CONCLUSION: In female patients elastase 1 in feces confirm the grade of vitamin D supply, and thus show a vitamin D subset3-deficiency, depending on the loss of stool content. There seems to be a connection here between the loss of exocrine function and may be even the characteristic of sterol-binding of elastase 1 in the pancreas, which seems to be relevant for vitamin D-supply.

Fecal elastase 1 and vitamin D3 in patients with osteoporotic bone fractures.

BACKGROUND AND AIMS: The aim of the present study was to clarify if patients with osteoporotic bone fractures have exocrine pancreatic insufficiency, especially reduced fecal elastase 1, connected with lowered serum levels of vitamin D3 that could be relevant for predominant osteoporosis. METHODS: Between October 1999 and September 2001, we investigated on 167 patients with an average age of approx. 69 years suffering from typical osteoporotic bone fractures, as well as 20 healthy controls with an average age of 53 years. A standardized osteodensitometry via dual energy X-ray absorptiometry (DEXA) was performed in all participants. Levels of PTH, 1,25(OH)(2) Vitamin D(3), 25(OH) Vitamin D(3), calcium and phosphate in serum, elastase 1 in feces as well as the body mass index were determined in all patients and controls. RESULTS: In patients 25(OH)D3 was more than 60% and 1,25(OH)(2)D(3) was more than 53% decreased compared to controls. Fecal elastase 1 was lower than the lowest reference of 200 microg/g feces in more than 34% of the patients and it was more than 65% reduced in comparison to healthy controls (fecal elastase 1 patients: 240.7 +/- 96.3 microg/g; controls 694.9 +/- 138.6 microg/g). Separation of the patients in accordance with the elastase 1 contend in feces into four groups (below 100 microg/g, between 100 and 200 microg/g, between 201 and 300 microg/g and above 300 microg/g) resulted in significant variations for 25(OH)D(3), 1,25(OH)(2)D(3), calcium and PTH between these groups (p < 0.01). Furthermore 25(OH)D(3), 1,25(OH)(2)D(3), calcium and PTH correlated significantly with elastase 1 in feces (p < 0.01) the way, that lower fecal elastase 1 was connected with lower levels of the other parameters. BMI shows no relevant differences within the patients or between patients and controls. CONCLUSION: Exocrine pancreatic insufficiency, especially lowered fecal elastase 1, may be much more frequent in patients with osteoporotic bone fractures than suggested so far. Lowered exocrine pancreatic function with lowered fecal elastase 1 seems to be relevant as a reason for reduced levels of circulating vitamin D3 metabolites being an appropriate additional cause for predominant osteoporosis.

Alterations of vitamin D3 metabolism in young women with various grades of chronic pancreatitis.

BACKGROUND: There are still too few conclusive reports about conspicuous vitamin D-deficiency in young female patients with chronic pancreatitis, or any connection of the deficiency to the severity of the disease. Therefore the aim of this study was to examine marker of vitamin D3 metabolism in female patients with episode of biliary pancreatitis to determine if increased severity of the disease would correlate with impaired vitamin D3 metabolism. METHODS: Between 1996 and 2003, we investigated 53 premenopausal patients with an average age of approximately 33 years suffering from an episode of chronic pancreatitis, as well as 30 female healthy controls with an average age of 32.4 years. The severity of chronic pancreatitis in patients was determined via endoscopic retrograde cholangiopancreaticography (ERCP) and assigned to 1 of 3 grades based on the Cambridge classification. Additional parameter assessed were demographics, smoking, consumption of alcohol and CD-transferrin, fasting metabolic parameters, biochemical markers of vitamin D3 metabolism and fecal elastase 1. None of the patients received hormone replacement therapy, Vitamin D or Calcium-supplementation. RESULTS: The serum levels of 1,25-dihydroxyvitamin D [1,25(OH2)D] were significantly reduced compared to female healthy controls. Fecal elastase 1 correlated with this classification of severity of chronic pancreatitis (p < 0.01). Furthermore, fecal elastase 1 of patients correlated the same way with both D-vitamins (p <0.01). The level of both D3 vitamins in patients were significantly lowered when the content of fecal elastase 1 was under 200 microg/g compared to the others [for 1,25-(OH2)D3 p < 0.01; 25-OH- D3 p < 0.01]. CONCLUSION: Premenopausal patients with chronic pancreatitis are at risk of developing decreased levels of 1,25(OH2)D3. This fact may contribute to a negative calcium balance and alteration of bone metabolism. Therefore, ERCP and fecal elastase 1 verify the severity grade of a chronic pancreatitis, and thus show a vitamin D3 deficiency in young women, depending on the progress of disease.

Mexiletine in the treatment of diabetic neuropathy.

OBJECTIVE: To prove the efficacy of mexiletine in painful diabetic neuropathy. RESEARCH DESIGN AND METHODS: Treatment was provided in three dosages. For pain measurements, a VAS and McGill's verbal rating scale were chosen. Ninety-five patients were included in the study. RESULTS: A global assessment of the VAS among patients showed no differences between mexiletine treatment and placebo. The total evaluation (PRIT) of the McGill scale fell just below the level of significance. More specific exploratory evaluations of subclasses of the McGill scale, representing different degrees of pain, gave remarkable differences between mexiletine and placebo in sensory and miscellaneous items. In special subgroups, which were formed according to types and courses of complaints compiled at the beginning of this evaluation, the substantial advantages of the mexiletine treatment were shown with both the VAS and the McGill scale. CONCLUSIONS: Evidence strongly indicates that, in particular, those patients with stabbing or burning pain, heat sensations, or formication will benefit most by mexiletine therapy. Concerning the dosage, a medium regimen of 450 mg/day seems to be appropriate. With an increase in the antiarryhthmic dosage level, the efficacy does not rise proportionally. Mexiletine proved to be a safe therapy with negligible side effects at the medium dose range, even less than placebo; and remarkably, no cardiovascular side effects were noted. Further studies should avoid global assessments and pay more attention to the variety of complaints and quality of life.

Metabolic basis of high density lipoproteins and apolipoprotein A-I increase by HMG-CoA reductase inhibition in healthy subjects and a patient with coronary artery disease.

HMG-CoA reductase inhibitors, such as pravastatin, are widely used as lipid lowering drugs in hypercholesterolemia. Pravastatin does not only reduce the atherogenic low density lipoprotein (LDL)-cholesterol, but is also increasing high density lipoprotein (HDL)-cholesterol. However, the mechanism leading to an increase of HDL are unclear. Therefore, the effects of pravastatin on the in vivo kinetics of apolipoprotein (apo) A-I were studied in six normolipidemic subjects and in a patient with coronary artery disease (CAD) utilizing stable isotope tracer techniques. Two turnover studies were performed. The first turnover study was carried out before any drug treatment, the second study after 6 weeks of 40 mg pravastatin/day. Three times deuterium labeled L-leucine (3D-leucine) was given as a primed bolus constant infusion (bolus: 1340 microg/kg; infusion: 22 microg/kg per h), and tracer uptake into HDL apoA-I was determined by gas chromatography (GC)-mass-spectrometry (MS). In the healthy subjects HDL-cholesterol increased by 13% and apoA-I increased by 12% under pravastatin treatment. The HDL in the CAD patient decreased by 3% and apoA-I increased by 2%. Prior to drug treatment the mean apoA-I fractional synthetic rate (FSR) was 0.194 per day (S.D. +/- 0.02) and apoA-I production rate (PR) was 10.8 mg/kg per day (S.D. +/- 2.1). The CAD patient had a FSR of 0.219 per day and a PR of 10.6 mg/kg per day. After treatment with pravastatin the mean apoA-I FSR was 0.204 per day (S.D. +/- 0.02) and apoA-I PR was 12.5 mg/kg per day (S.D. +/- 1.5) in the healthy subjects. Despite only minor changes of HDL and apoA-I in the CAD patient, there were significant changes of FSR (0.267 per day) and PR (13.1 mg/kg per day) with pravastatin treatment. The in vivo kinetic data demonstrate an increased FSR of apoA-I. The increase in apoA-I is due to an increased PR of apoA-I. This study demonstrates increased production of HDL apoA-I as the metabolic cause of the increase in HDL and apoA-I levels under inhibition of HMG-CoA reductase in man.

Alterations of bone mineral density and bone metabolism in patients with various grades of chronic pancreatitis.

The aim of this study was to examine bone mineral density (BMD) and bone metabolism in patients with chronic pancreatitis to determine if increased severity of the disease would correlate with increased bone loss. Between October 1999 and September 2000, we investigated 42 patients with an average age of approximately 53 years suffering from chronic pancreatitis, as well as 20 healthy male controls with an average age of 49 years. Dual energy x-ray absorptiometry (DEXA) was performed on patients and controls, and serum levels of parathyroid hormone (PTH), osteocalcin (OC), carboxy-terminal propeptide of type I procollagen (CICP), bone-specific alkaline phosphatase (BAP), 1,25(OH)(2) vitamin D(3) and 25(OH) vitamin D(3), as well as fecal elastase 1 were also determined. The severity of chronic pancreatitis in patients was determined via endoscopic retrograde cholangiopancreatography (ERCP) and assigned to 1 of 3 grades based on the Cambridge classification. BMD of patients with chronic pancreatitis was markedly decreased compared to controls (means in patients: DEXA lumbar vertebra anterior/posterior (LV ap) 96.8% +/- 4.2%, DEXA Ward's triangle (WARD) 92.2% +/- 5.2%; controls: DEXA LV ap 98.7% +/- 3.7%, DEXA WARD 97.1% +/- 3.1%; P <.05 and P <.0001) and correlated with the various Cambridge-grades (DEXA LV ap and DEXA WARD, P <.01). Fecal elastase 1 showed sensitivities of 14%, 87%, and 95% for the Cambridge-grades I, II, and III, respectively, and correlated with this classification of severity of chronic pancreatitis (P <.01). Furthermore, fecal elastase 1 of patients correlated the same way with both D(3)-vitamins (P <.01), as well as with parameters of BMD (P <.01). If fecal elastase 1 in patients was below 200 micro g/g, then the BMD and vitamin D(3) values were also significantly decreased compared to those with fecal elastase 1 above 200 micro g/g. In patients with Cambridge grades II and III 1,25(OH)(2)D(3) was markedly decreased (26.7 +/- 7.7 pg/mL and 27.6 +/- 9.0 pg/mL) compared to those with Cambridge grade I (38.0 +/- 10.5 pg/mL; between I and II, P =.027; between I and III, P =.033). 25(OH)D(3) was not significantly different within the various Cambridge groups (P =.07). Compared to controls, both D(3) vitamins, as well as fecal elastase 1, were extremely low (means in patients: fecal elastase 1, 140.7 +/- 75.7 micro g/g; 1,25(OH)(2)D(3), 29.9 +/- 9.5 pg/mL; 25(OH)D(3), 26.7 +/- 9.7 nmol/L; controls: fecal elastase 1, 694.9 +/- 138.6 micro g/g; 1,25(OH)(2)D(3), 67.5 +/- 4.3 pg/mL; 25(OH)D(3), 69.5 +/- 13.5 nmol/L). A significant correlation was observed between increased severity of chronic pancreatitis based on both endoscopic retrograde cholangiopancreatography and levels of fecal elastase 1, with decreased circulating levels of vitmain D(3) and decreased BMD. This supports a connection between the inflammatory destruction of the pancreas (Cambridge classification), exocrine pancreatic insufficiency (fecal elastase 1), altered levels of vitamin D metabolites, and loss of skeletal mass.

Changes in calciotropic hormones and biochemical markers of bone metabolism in patients with human immunodeficiency virus infection.

Data on the bone metabolism of human immunodeficiency virus (HIV)-infected patients are still extremely rare. To investigate the influence of HIV infection on the calciotropic hormones and markers of bone metabolism, we therefore performed a cross-sectional study on 100 patients (65 males and 35 females) with proven HIV infection. The following criteria were used for exclusion from the study: age less than 20/more than 50 years, confinement to bed, wasting symptoms, treatment with agents containing ketoconazole, renal or hepatic insufficiency, clinical or echographic signs of liver cirrhosis, endocrine diseases, or treatment with medications known to influence bone metabolism. Bone mineral content (BMC) was determined by single-photon absorptiometry on the left forearm. Reduced BMC was found among the male and female HIV-infected patients. Additional long-term use of heroin resulted in a severe loss of mineralization in the respective females. The markers of bone metabolism were determined in urine and serum samples. Significantly lower osteocalcin concentrations were found, indicating a reduced bone formation rate whose severity showed a significant correlation with the progressive loss of CD4 helper cells and was independent of low vitamin D3 levels (1,25-dihydroxycholecalciferol) and alterations of protein metabolism. Increased urinary excretion of cross-links as an expression of enhanced bone resorption was likewise significantly correlated with the loss of CD4 helper cells and independent of the vitamin D concentration and protein metabolism. It is therefore concluded that the changes in bone metabolism are mainly due to mechanisms of the impaired immune defense of HIV-infected patients.

Diabetes mellitus-associated decrease in nerve growth factor levels is reversed by allogeneic pancreatic islet transplantation.

After an untreated 5-month duration of streptozotocin (STZ)-induced diabetes mellitus (DM), nerve growth factor (NGF) levels in BDE rats were decreased to 45-65% of control in the sympathetically innervated target organs iris and submandibular gland, in the superior cervical ganglion (containing NGF-dependent sympathetic perikarya projecting to the cranial targets), and in the NGF-transporting sciatic nerve. Successful allogeneic pancreatic islet transplantation (providing a physiological glucose homeostasis without immunosuppression) after 3-4 weeks of DM reversed the DM-related decrease in NGF levels 4 months after transplantation as compared with untreated diabetic rats. By contrast, NGF levels in the treated vas deferens (innervated by short postganglionic sympathetic neurons) remained increased as in the untreated diabetic rats (175% of control). Thus, DM-associated changes in endogenous NGF levels seem to be reversible by institution of metabolic control, at least at an early stage of DM when NGF-responsive neurons have not been deprived of NGF for a long time.

Vitamin D receptor genotypes are not associated with rheumatoid arthritis or biochemical parameters of bone turnover in German RA patients.

OBJECTIVE: Vitamin D is known to exert immunomodulatory effects. An overrepresentation of the b allele of the vitamin D receptor (VDR) has been detected in autoimmune diseases as type-1-diabetes and multiple sclerosis. VDR polymorphisms have been shown to influence bone metabolism and bone density. The aim of the present study was to examine the distribution of VDR alleles in German rheumatoid arthritis (RA) patients and their relation to bone turnover parameters. METHODS: 62 German RA patients were included and compared to 40 controls. Three VDR alleles were examined (Bsm I, Taq I and Fok I). In addition, serum intact osteocalcin (OC), parathyroid hormone, bone specific alkaline phosphatase (B-ALP), the carboxyterminal extension peptide of type I procollagen, 25-OH-vitamin D and urinary deoxypyridinoline (DPD) excretion were measured. Furthermore, C-reactive protein, erythrocyte sedimentation rate and rheumatoid factor were measured. RESULTS: We found a slightly higher frequency of the bB and tT-genotype in RA patients compared to controls, which was not statistically significant. OC and B-ALP were found to be significantly higher in RA patients with positive correlations between bone formation and resorption parameters indicating higher bone turnover in RA patients with maintained coupling. CRP in RA patients correlated with DPD and inversely with PTH. VDR genotype showed no association with bone turnover, family history or the presence of rheumatoid factor. CONCLUSIONS: Our results suggest that VDR polymorphisms do not play a major role in RA predisposition in Germans.

A benfotiamine-vitamin B combination in treatment of diabetic polyneuropathy.

In a double-blind, randomized, controlled study, the effectiveness of treatment with a combination of Benfotiamine (an Allithiamine, a lipid-soluble derivative of vitamin B1 with high bioavailability) plus vitamin B6/B12 on objective parameters of neuropathy was studied over a period of 12 weeks on 24 diabetic patients with diabetic polyneuropathy. The results showed a significant improvement (p = 0.006) of nerve conduction velocity in the peroneal nerve and a statistical trend toward improvement of the vibration perception threshold. Long-term observation of 9 patients with verum over a period of 9 months support the results. Therapy-specific adverse effects were not seen. The results of this double-blind investigation, of the long-term observation and of the reports in the literature support the contention that the neurotropic benfotiamine-vitamin B combination represents a starting point in the treatment of diabetic polyneuropathy.

Efficacy of benfotiamine versus thiamine on function and glycation products of peripheral nerves in diabetic rats.

In rats with streptozotocin (STZ) induced diabetes the effect of (watersoluble) thiamine nitrate and of (lipidsoluble) benfotiamine on peripheral nerve function (motor nerve conduction velocity) as well as on the formation of advanced glycation end-products in peripheral nerve tissue was studied. In one group of animals drug administration was started immediately after diabetes induction (prevention study) and in another group two months after diabetes induction (treatment study). Motor nerve conduction velocity (NCV) dropped by 10.5% in diabetic animals, carboxymethyl-lysine (CML) rose to a 3.5fold concentration, deoxyglucosone (3DG)-type AGE formation was increased 5.1fold compared with controls. After three months preventive administration of both vitamin B(1) preparations NCV had increased substantially compared with results in diabetic controls. It was nearly normal after six months with benfotiamine, while the administration of thiamine nitrate resulted in no further amelioration. NCV was nearly normalized after six months of benfotiamine application but not with thiamine. Furthermore, benfotiamine induced a major inhibition of neural imidazole-type AGE formation and completely prevented diabetes induced glycoxidation products (CML). Treatment with thiamine did not significantly affect AGE or cmL levels. Unlike treatment with water-soluble thiamine nitrate timely administration of liposoluble prodrug benfotiamine was effective in the prevention of functional damage and of AGE and cmL formation in nerves of diabetic rats.

Multiple endocrine neoplasia (MEN)--an overview and case report--patient with sporadic bilateral pheochromocytoma, hyperparathyroidism and marfanoid habitus.

The multiple endocrine neoplasia syndromes are divided into two categories: MEN type I and MEN type II. The MEN type II syndrome is further divided into MEN IIa and MEN IIb. The syndromes are characterized by benign and malignant changes in two or more endocrine organs, as well as incidental changes in nervous, muscular and connective tissue. Two main forms can be distinguished: the MEN-I syndrome with hyperplasia of the parathyroid gland, accompanied by islet cell tumor and pituitary adenoma; the MEN-II syndrome with medullary thyroid carcinoma in combination with bilateral pheochromocytoma and hyperplasia of the parathyroid gland (MEN IIa), while type IIb is characterized by the additional appearance of neurocutaneous manifestations without primary hyperparathyroidism. Characteristics shared by these syndromes include the involved cell type, most of the tumors are composed of one or more specific polypeptide- and biogenic amine-producing cell types (APUD--amine precursor uptake and decarboxylation). The second characteristic is the increased incidence in certain families. The hereditary component is autosomal dominant with variable expression but high penetrance. Mechanisms of tumorigenesis differ in these syndromes. While MEN I is caused by an inherited mutation of a tumor suppressor gene, menin, located on the long arm of chromosome 11, MEN II is caused by activation of the RET proto-oncogene. We have reported the case of a young man exhibiting bilateral pheochromocytoma. In addition, the patient showed mild primary hyperparathyroidism and marfanoid habitus, all these stigmata usually being part of the MEN-II syndrome. Although this described patient showed a phenotypic mixture of the MEN-IIa and MEN-IIb syndrome, the genetic analysis for MEN II and von-Hippel-Lindau gene did not reveal any pathologic mutations, the endocrine disorders described here are not related to multiple endocrine neoplasia syndromes.

Osteoporosis and bone metabolic parameters in dependence upon calcium intake through milk and milk products.

The bone mineral content of young adults as well as of osteoporotic patients and age-matched controls without bone disease was measured by single-photon absorptiometry. A retrospective nutrition survey was additionally made to study the relationship between bone mineral content and calcium intake in different periods of life. The bone mineral content and bone mineral density of young adults is directly related to the calcium intake through milk and dairy products. The osteoporotics had a significantly lower bone mineral content than the controls. Calcium intake through milk and milk products in childhood and adolescence had been significantly lower in the patients than in the controls, whereas in the later periods of life (20-30 years prior to the study and at the time of the study) there were no significant differences between the calcium intakes of the two groups. It was also found that an adequate intake of calcium protected against increased bone resorption, as evidenced in particular by the reduced levels of serum osteocalcin, a parameter of bone turnover. In conclusion it can be stated that the data support the hypothesis that adequate calcium intake through milk and milk products in childhood and adolescence is a decisive marker for obtaining a maximum bone mass (peak adult bone mass) and for the prevention of osteoporosis. Furthermore, it can be stated that increased calcium intake in the later years may not reduce the accelerated risk of osteoporosis resulting from inadequate calcium intake during childhood and adolescence.

Osteopenia in HIV-infected women prior to highly active antiretroviral therapy.

BACKGROUND AND OBJECTIVES: Multiple endocrine and metabolic consequences of human immunodeficiency (HIV) infection exist that alter bone metabolism in patients with acquired immune deficiency syndrome (AIDS). Osteopenia in AIDS patients has been associated with antiretroviral therapy particularly with protease inhibitors. However, there is very little data on bone metabolism in female subjects with AIDS prior to highly active antiretroviral therapy. METHODS: Bone mineral density (BMD) was assessed by dual-energy X-ray absorptiometry (DEXA) in 50 HIV-infected female outpatients (mean age 37 years) both in the lumbar spine and the Ward's triangle of the left hip. Additional parameter assessed were demographics, smoking, CD4 counts, fasting metabolic parameters and biochemical markers of bone metabolism. None of the patients received reverse transcriptase inhibitors or protease inhibitors, vitamin D or calcium-supplementation. RESULTS: The serum levels of parathyroid hormone and 1,25-dihydroxyvitamin D (1,25(OH2)D) were significantly reduced compared to 50 age-matched female healthy controls. Urinary calcium and pyridinium crosslinks-excretion corrected for creatinine excretion were elevated (P<0.01) and were likewise significantly correlated with the loss of CD4 cells (P<0.05). Serum osteocalcin was significantly lowered (P<0.01). Reduced BMD of the lumbar spine (t -score <-2.5 SD below normal) was found in seven patients (14%) and osteopenia (t -score -1.0 to -2.5 SD below normal) was diagnosed in 31 (62%). No patient had a fracture since being infected with HIV. The BMD was reduced both in lumbar spine and the hip measured in the left Ward's triangle. There were significant positive correlation between the CD4 counts and 1,25(OH2)D (P<0.05). Neither the CD4 counts nor the duration of disease correlated with BMD. The reduced bone formation rate was linked to progressive loss of CD4-cell count. CONCLUSION: Osteopenia in HIV-infected female subjects is commonly manifested both in lumbar spine and Ward's triangle of the hip. There is a dissociation between lowered markers of bone formation rate and the increased bone resorption expressed as elevated urinary crosslinks and calcium excretion. Furthermore, the decreased levels of 1,25(OH2)D may contribute to a negative calcium balance and inhibition of bone formation. Our results suggest that further research is necessary to determine, whether low levels of 1,25(OH2)D lead to an accelerated inflammatory process in AIDS, since 1,25(OH)2D is known as an endogenous immune modulator suppressing formation of activated T cells and cell proliferation.

Treatment of prolactinomas and growth hormone-producing adenomas with an injectable bromocriptine retard preparation and a somatostatin analogue delivered by an implantable pump.

Among 14 patients with prolactinomas a single injection of 50 mg bromocriptine in a retard preparation resulted in a decrease of the initially elevated serum prolactin levels (to 4-62% of the initial value) in 12 cases and in a tumor shrinkage in 9 patients. In 3 out of 4 acromegalics injection and/or infusion of the somatostatin analogue SMS 201-995 (in 2 patients with an implanted Infusaid pump) led to a normalization of growth hormone and somatomedin-C levels.

Studies on the influence of selective adenomectomy on hormone secretion from normal anterior pituitary gland.

In 70 patients with pituitary adenomas combined stimulation tests using releasing factors were performed before and 10 to 20 days after pituitary surgery. Qualitatively, the dynamics of hormone secretion were mostly unaltered after surgery. Quantitatively, the mean amounts of secreted hormones were found lowered after surgery. In some individual patients, however, a postoperative improvement was also observed. Pituitary testing early after surgery proved to be helpful for assessing the definite need for a hormonal replacement therapy.

Correlation between plasma TNF-alpha, IGF-1, biochemical markers of bone metabolism, markers of inflammation/disease activity, and clinical manifestations in ankylosing spondylitis.

In patients with established ankylosing spondylitis (AS) and a healthy control group, plasma levels of IGF-1 and TNF-alpha as well as possible connections with biochemical markers of the bone metabolism, humoral inflammatory activity (ESR, CRP), clinical manifestations, and an established clinical activity score (Bath Ankylosing Spondylitis Activity Index = BASDAI) were examined. In AS-patients (men and women) significantly increased TNF-alpha levels were found. Moreover, patients with enthesopathy showed a significantly more frequent increase of CRP and TNF-alpha levels besides an increased urinary pyridinium cross-link excretion. In addition, a significant positive correlation between TNF-alpha, CRP, BASDAI, and urinary pyridinium cross-link excretion was proved, besides a significant negative correlation of IGF-I to urinary pyridinium cross-links and TNF-alpha levels. Summing up, it may be said that TNF-alpha seems to be a reliable surrogate marker in enthesitis. This was proved so far for IgA and endothelium stimulating angiogenic factor only. Besides, the present results argue against a stimulation of osteogenesis. The catabolic situation under high TNF-alpha and low IGF-1 levels may play an important role in the pathogenesis of osteoporosis in AS.