Poorly Controlled Congenital Hypothyroidism due to an Underlying Allgrove Syndrome.

BACKGROUND: Congenital hypothyroidism of thyroidal origin (CHT) is a common disorder in pediatric endocrinology practices, which can be difficult to manage. Elevated thyrotropin (TSH) concentrations are in the great majority of cases explained by poor compliance to levothyroxine therapy. METHODS: Case description. RESULTS: We present a boy with CHT, with 2 heterozygous mutations in the TSH receptor gene, who showed persistently elevated TSH concentrations and psychomotor retardation, initially misinterpreted as malcompliance. At the age of 4 years, he was diagnosed with adrenal insufficiency, wherefore a broad diagnostic search was initiated. After the start of glucocorticoid replacement therapy, his TSH normalized and the levothyroxine could be lowered. At the age of 6 years, his TSH increased again, this time caused by malabsorption of levothyroxine due to esophageal achalasia. In retrospect, alacrima was also present and the diagnosis of Allgrove syndrome was genetically confirmed. The CHT was considered a separate disease entity. CONCLUSIONS: In case of persistently elevated TSH levels in children with CHT, causes other than noncompliance must be considered. Second, in establishing the cause of adrenal insufficiency, specific symptoms, such as alacrima, are easily overlooked. Third, Allgrove syndrome is a rare disorder, in which diagnostic delay can lead to potentially life-threatening complications.

Pathogenesis of varroosis at the level of the honey bee (Apis mellifera) colony.

The parasitic mite Varroa destructor, in interaction with different viruses, is the main cause of honey bee colony mortality in most parts of the world. Here we studied how effects of individual-level parasitization are reflected by the bee colony as a whole. We measured disease progression in an apiary of 24 hives with differing degree of mite infestation, and investigated its relationship to 28 biometrical, physiological and biochemical indicators. In early summer, when the most heavily infested colonies already showed reduced growth, an elevated ratio of brood to bees, as well as a strong presence of phenoloxidase/prophenoloxidase in hive bees were found to be predictors of the time of colony collapse. One month later, the learning performance of worker bees as well as the activity of glucose oxidase measured from head extracts were significantly linked to the timing of colony collapse. Colonies at the brink of collapse were characterized by reduced weight of winter bees and a strong increase in their relative body water content. Our data confirm the importance of the immune system, known from studies of individually-infested bees, for the pathogenesis of varroosis at colony level. However, they also show that single-bee effects cannot always be extrapolated to the colony as a whole. This fact, together with the prominent role of colony-level factors like the ratio between brood and bees for disease progression, stress the importance of the superorganismal dimension of Varroa research.

High-dose GH treatment limited to the prepubertal period in young children with idiopathic short stature does not increase adult height.

OBJECTIVE: To assess the long-term effect of prepubertal high-dose GH treatment on growth in children with idiopathic short stature (ISS). DESIGN AND METHODS: Forty children with no signs of puberty, age at start 4-8 years (girls) or 4-10 years (boys), height SDS <-2.0 SDS, and birth length >-2.0 SDS, were randomly allocated to receive GH at a dose of 2 mg/m(2) per day (equivalent to 75 microg/kg per day at start and 64 microg/kg per day at stop) until the onset of puberty for at least 2 years (preceded by two 3-month periods of treatment with low or intermediate doses of GH separated by two washout periods of 3 months) or no treatment. In 28 cases, adult height (AH) was assessed at a mean (S.D.) age of 20.4 (2.3) years. RESULTS: GH-treated children (mean treatment period on high-dose GH 2.3 years (range 1.2-5.0 years)) showed an increased mean height SDS at discontinuation of the treatment compared with the controls (-1.3 (0.8) SDS versus -2.6 (0.8) SDS respectively). However, bone maturation was significantly accelerated in the GH-treated group compared with the controls (1.6 (0.4) versus 1.0 (0.2) years per year, respectively), and pubertal onset tended to advance. After an untreated interval of 3-12 years, AH was -2.1 (0.7) and -1.9 (0.6) in the GH-treated and control groups respectively. Age was a positive predictor of adult height gain. CONCLUSION: High-dose GH treatment restricted to the prepubertal period in young ISS children augments height gain during treatment, but accelerates bone maturation, resulting in a similar adult height compared with the untreated controls.

Characteristics of the spermathecal contents of old and young honeybee queens.

Sperm are often stored, for a long time after mating, in females of various animal species. In case of the queen honeybee (Apis mellifera), sperm remain fertile for several years in the spermatheca. Little information is available regarding the effect of long-term storage of sperm on its fertility. To evaluate this, enzymes and/or sperm have been analysed from the spermatheca of 75 queens of various ages (0 year Y0, n=14; one year Y1, n=14; two years Y2, n=7; virgin queen VQ, n=40) and semen samples have been taken from 46 drones. The sperm from the spermatheca of older queens move more slowly (F=11.45, P < 0.0001) and show different movement patterns (Chi2=90.0, P < 0.0001) from those of the other groups. The spermatheca content of differently aged mated queens differ significantly with respect to the activities of lactate dehydrogenase (F=3.37, P < 0.05), citrate synthase (F=6.24, P < 0.005) and arginine kinase (F=9.44, P < 0.0006). Glyceraldehyde 3-phosphate dehydrogenase (F=0.10, P=0.91) does not differ significantly. The results suggest considerable changes in the energy metabolic profile of the spermatheca tissue, of the sperm or of both during sperm storage.

Regulatory properties of 6-phosphofructokinase and control of glycolysis in boar spermatozoa.

Glycolysis is crucial for sperm functions (motility and fertilization), but how this pathway is regulated in spermatozoa is not clear. This prompted to study the location and the regulatory properties of 6-phosphofructokinase (PFK, EC 2.7.1.11), the most important element for control of glycolytic flux. Unlike some other glycolytic enzymes, PFK showed no tight binding to sperm structures. It could readily be extracted from ejaculated boar spermatozoa by sonication and was then chromatographically purified. At physiological pH, the enzyme was allosterically inhibited by near-physiological concentrations of its co-substrate ATP, which induced co-operativity, i.e. reduced the affinity for the substrate fructose 6-phosphate. Inhibition by ATP was reinforced by citrate and H+. Above pH 8, PFK lost all its regulatory properties and showed maximum activity. However, in the physiological pH range, PFK activity was very sensitive to small changes in effectors. At near-physiological substrate concentrations, PFK activity requires activators (de-inhibitors) of which the combination of AMP and fructose 2,6-bisphosphate (F2,6P2) was most efficient as a result of synergistic effects. The kinetics of PFK suggest AMP, F2,6P2, H+, and citrate as allosteric effectors controlling PFK activity in boar spermatozoa. Using immunogold labeling, PFK was localized in the mid-piece and principal piece of the flagellum as well as in the acrosomal area at the top of the head and in the cytoplasmic droplets released from the mid-piece after ejaculation.

CSF biomarkers in frontotemporal lobar degeneration: relations with clinical characteristics, apolipoprotein E genotype, and neuroimaging.

In order to better understand the large variation in cerebrospinal fluid (CSF) tau and amyloid-beta(1-42) (Abeta42) in frontotemporal lobar degeneration (FTLD), relations between these biomarkers and clinical parameters, neuroimaging characteristics, and apolipoprotein E (ApoE) genotype were studied in 31 patients with FTLD, including 16 patients with the frontal variant and 15 with the temporal variant. CSF tau was highest in FTLD with predominant temporal involvement. In the frontal subgroup, CSF tau level was influenced by the number of ApoE epsilon3 alleles. In the temporal subgroup, CSF tau level was dependent on a combination of CSF Abeta42, age, disease duration, and disease severity. No relation with degree of atrophy or asymmetry on neuroimaging could be established. CSF Abeta42 variability remained unexplained. Future research could study the role of ApoE genotype and Abeta42 in FTLD, as well as establish measures for disease intensity.

Biomarker profiles and their relation to clinical variables in mild cognitive impairment.

The aim of the study was to compare clinical variables between MCI patients at different risk for Alzheimer's disease (AD) according to their biomarker profile. Fifty-four percent out of 39 MCI patients had a low Abeta42 and high tau in cerebrospinal fluid (CSF) (high-risk), 26% either a low CSF Abeta32 or high CSF tau (intermediate-risk) and 20% a normal CSF Abeta42 and tau (low-risk). Both high-and intermediate-risk subjects differed from the low-risk group in episodic memory, executive functions and the preclinical AD scale (PAS),which combines a set of clinical parameters. Subjects at high risk did not differ from subjects with an intermediate risk. Abeta42 levels correlated with the MTA and PAS scores, tau levels with episodic memory. These correlations suggest that the biomarkers are not independent when compared to the other AD markers. Longitudinal studies are necessary to interpret the correlations between biomarkers, imaging, and neuropsychological markers.

Benefit of postponing normal puberty for improving final height.

Experiments of nature and clinical observations have provided indications that postponing puberty may increase final height in short children. In children with central precocious puberty, a GnRH analog (GnRHa) alone is efficacious in increasing final height, but in other conditions a combination of growth hormone (GH) and GnRHa is needed. In GH-deficient children with early onset of puberty and poor height prediction, the combination of GH and GnRHa increases final height by 1.0-1.3 s.d. In children with idiopathic short stature and persistent short stature after intrauterine growth retardation, the combination also appears to be beneficial. Potential side effects include weight gain, a negative effect on bone mineralization, and psychosocial consequences. More data on long-term safety have to be collected before the combination of GH and GnRHa in children with idiopathic short stature should be considered for clinical use outside clinical trials.

No major association of ApoE genotype with disease characteristics and MRI findings in multiple sclerosis.

BACKGROUND: Whereas a number of studies suggest that the ApoE polymorphism is not associated with disease susceptibility in multiple sclerosis (MS), results with regard to disease severity, however, are conflicting. Some studies suggest an unfavourable role of the epsilon4 allele. This study was performed to assess the association of the ApoE polymorphism with both disease susceptibility and disease course in a large group of MS patients using clinical and MRI measures. In addition the data were combined with available data from the literature. METHODS: In a group of 408 patients with clinically definite MS, genotype distribution was compared with that of 144 healthy controls. Combined analysis of published data on the association of ApoE polymorphism with MS was performed. Demographic and clinical findings were recorded and related to the ApoE genotype. In a subgroup, longitudinal MRI findings were available and related to the ApoE genotype. RESULTS: No significant differences were found in the distribution of genotypes between MS patients and controls. Combined analysis of published data showed a slightly increased susceptibility for MS in epsilon2-carriers. Disease characteristics (including age at onset and onset type), disease severity (progression index, time to reach EDSS 6) and MRI findings (lesion volumes and atrophy measures) were not associated with carriership o epsilon2 or epsilon4. CONCLUSIONS: In this cohort no association of the ApoE genotype with disease susceptibility nor clinical and MRI measures could be identified. However, combined analysis of published data could not definitely exclude the possibility of a minor role for epsilon2-carriership in MS.

Amyloid beta(1-42) and phosphorylated tau in CSF as markers for early-onset Alzheimer disease.

OBJECTIVE: To determine the diagnostic value of CSF amyloid beta(1-42) (Abeta42), CSF total tau, and CSF tau phosphorylated at threonine-181 (Ptau-181) in early-onset Alzheimer disease (EAD) vs frontotemporal lobar degeneration (FTLD). METHODS: Levels of Abeta42, total tau, and Ptau-181 in CSF were measured using commercially available ELISA in 47 EAD patients, 28 FTLD patients, and 21 nondemented control subjects. RESULTS: CSF Abeta42 was significantly lower and CSF total tau and CSF Ptau-181 significantly higher in EAD patients than FTLD patients and control subjects. There was an increase in diagnostic accuracy for CSF Ptau-181 vs CSF total tau (p = 0.067). Combining low CSF Abeta42 and high CSF Ptau-181 allowed EAD patients to be distinguished from FTLD patients with a sensitivity of 72% and a specificity of 93%. Logistic regression analysis with CSF Abeta42 and CSF Ptau-181 as independent continuous variables resulted in correct classification of 46 of 47 (98%) EAD patients and 23 of 28 (82%) FTLD patients. The diagnostic accuracy for EAD was independent of gender, disease duration, and disease severity. CONCLUSION: The combination of CSF Abeta42 and CSF Ptau-181 may help in differentiating EAD from FTLD.

Energy metabolism and intracellular pH in boar spermatozoa.

The effect of energy metabolism on intracellular pH was studied in boar spermatozoa using nuclear magnetic resonance (NMR) spectroscopy and confocal microscopy with the pH-sensitive dye seminaphthorhodafluor (SNARF-1). Freshly ejaculated spermatozoa had a high adenylate energy charge (AEC=0.8), which decreased to 0.6 under aerobic conditions and to 0.2 under anaerobic conditions. Correspondingly, no ATP resonances but high AMP resonance were visible in (31)P-NMR-spectra of the spermatozoa. When an artificial oxygen buffer (Fluosol) and a purpose-built air supply system were used during (31)P-NMR data acquisition, ATP resonances reappeared whereas the AMP resonance disappeared. Boar spermatozoa kept under aerobic conditions have intracellular compartments that differ markedly in pH, as demonstrated by both (31)P-NMR spectroscopy and confocal microscopy. Using confocal microscopy, the midpiece of the flagellum in which all mitochondria are located was identified as an acidic compartment (pH(i-mp) 6.7). The intracellular pH of both the head (pH(i-h)) and the long principal piece of the flagellum (pH(i-pp)) were 7.2 and, thus, only slightly below the extracellular pH (pH(e) 7.3). Storage of spermatozoa in a glucose-free medium at 15 degrees C when they are immotile slowly shifted the pH(i-mp) from 6.7 to 6.9 within 20 h, whereas pH(i-h) and pH(i-pp) remained unchanged (pH 7.1-7.2). When glucose was present in the medium, all visible compartments of the spermatozoa as well as the medium were acidified to pH 6.2 within 20 h. Under these conditions a resonance at 4.8 mg kg(-1) appeared representing glycerol 3-phosphate.

Decreased lysophosphatidylcholine/phosphatidylcholine ratio in cerebrospinal fluid in Alzheimer's disease.

Choline containing phospholipids are essential for the integrity of the'cell'membrane. Minor changes in the lysophosphatidylcholine (lyso-PC)/phosphatidylcholine (PC) ratio may lead to neuronal damage and cell loss. Several studies have shown protein and lipid oxidation in Alzheimer's disease (AD) affected brain regions. Amyloid-beta peptides may induce free-radical oxidative stress which normally is counteracted by anti-oxidant defense mechanisms. We hypothesize that oxidation may lead to changed concentrations of choline containing phospholipids in cerebrospinal fluid (CSF) of AD patients, because of the susceptibility of the unsaturated acyl-chains of PC for oxidation. PC and lyso-PC were determined in CSF of AD patients (n=19) and subjects with subjective memory complaints without dementia (n=19) by tandem mass spectrometry. No differences in total PC concentrations were observed between both study groups. Furthermore, we could not demonstrate different concentrations of PC species containing linoleic acid and PC species containing arachidonic acid. Interestingly, lyso-PC concentrations tended to be lower while the lyso-PC/PC ratio was significantly decreased in CSF of AD patients compared to controls (0.36% versus 0.54%; P=0.017). A comparable decrease was found for the lyso-PC/PC ratio for PC containing linoleic acid (P=0.022) or arachidonic acid (P=0.010), respectively. The lower lyso-PC/PC ratio in CSF of patients with AD may reflect alterations in the metabolism of choline-containing phospholipids in the brain in AD, and suggests that PC species containing linoleic acid or arachidonic acid are equally involved.

Experimental approaches to study vascularization in tissue engineering and biomaterial applications.

The success of tissue engineering and biomaterial applications is not only dependent on the growth and functioning of the organ- or tissue-specific cells on the biomaterial but is entirely dependent in most cases on a successful vascularization after implantation. The process of vascularization involves angiogenesis; the formation of new blood vessels which spread into the implant material and supply the existing cells with the nutrients to survive. We have established in vitro methods using human microvascular endothelial cells to evaluate novel biomaterials for endothelial cell attachment, cytotoxicity, growth, angiogenesis and the effects on gene regulation. These in vitro studies can be used to rapidly evaluate the potential success of a new biomaterial and for the development of matrix scaffolds which will promote a physiological vascularization response.

CSF markers related to pathogenetic mechanisms in Alzheimer's disease.

Serum amyloid P component (SAP) and complement C1q are found highly co-localized with extracellular fibrillar amyloidbeta (Abeta) deposits in Alzheimer's disease (AD) brain. Conflicting data were reported earlier about the cerebrospinal fluid (CSF) levels of SAP and C1q in AD compared to controls. The objective of the present study was to compare the levels of Abeta(1-42), tau, C1q and SAP in CSF of a well characterized group of AD patients and controls, and to assess the association with dementia severity. Significantly decreased CSF levels of Abeta(1-42) were observed in the AD group (480 +/- 104 ng/L) as compared to controls (1,040 +/- 213 ng/L), whereas tau levels were significantly higher in patients with AD (618 +/- 292 ng/L) than in controls (277 +/- 136 ng/L). Combining the results of Abeta(1-42) and tau measurements resulted in a clear separation between the AD group and the controls. No significant differences in CSF levels of SAP and C1q were observed between the well characterized AD patients and non demented control group. Furthermore, we could not demonstrate a correlation between SAP and C1q CSF levels and the severity of the disease, expressed in Mini-Mental State Examination (MMSE) scores. Therefore, in our opinion these factors can be excluded from the list of potentially interesting biomarkers for AD diagnosis and progression.

Molecular evidence for putative tumour suppressor genes on chromosome 13q specific to BRCA1 related ovarian and fallopian tube cancer.

BACKGROUND/AIMS: Loss of heterozygosity (LOH) on chromosome 13q has been reported to occur frequently in human ovarian cancer, and indications have been found that chromosome 13 may also play a specific role in the inherited form of ovarian cancer. The aim of this study was to define regions on chromosome 13 that may harbour additional tumour suppressor genes involved in the tumorigenesis of BRCA1 related ovarian and fallopian tube cancer. MATERIALS/METHODS: DNA extracted from paraffin wax blocks of 36 BRCA1 associated ovarian and fallopian tube carcinomas was analysed by LOH polymerase chain reaction using seven highly polymorphic microsatellite markers spanning chromosome 13q. RESULTS: High LOH frequencies were found on loci 13q11, 13q14, 13q21, 13q22-31, 13q32, and 13q32-4, suggesting the presence of putative tumour suppressor genes on the long arm of chromosome 13 that may play a role in the pathogenesis of BRCA1 related ovarian and fallopian tube cancer. LOH patterns appeared to be independent of the type of BRCA1 mutation, stage, and grade. Although in some cases there were indications for loss of larger parts of chromosome 13, in most cases losses were fairly randomly distributed over chromosome 13 with retained parts in between lost parts. Microsatellite instability was found in six cases. CONCLUSION: Several loci on chromosome 13q show high frequencies of LOH in BRCA1 related ovarian and fallopian tube cancer, and may therefore harbour putative tumour suppressor genes involved in the carcinogenesis of this particular type of hereditary cancer.

Effects of gender and age on the association of apolipoprotein E epsilon4 with bone mineral density, bone turnover and the risk of fractures in older people.

The aim of this study was to examine whether the presence of apolipoprotein E epsilon4 (ApoE epsilon4) is associated with a lower bone mineral density (BMD), lower quantitative ultrasound (QUS) measurements, higher bone turnover and fracture risk, and whether these relations are modified by gender and age. A total of 1406 elderly men and women (> or =65 years) of the Longitudinal Aging Study Amsterdam (LASA) participated in this study. In all participants, QUS measurements were assessed, as well as serum osteocalcin (OC) and urine deoxypyridinolin (DPD/Cr urine). Follow-up of fractures was done each three months. In a subsample ( n = 604), total body bone mineral content (BMC) and BMD of the hip and lumbar spine were measured. In addition, prevalent vertebral deformities were identified on radiographs. In women, the presence of ApoE epsilon4 was associated with significantly lower femoral neck BMD (g/cm(2); mean +/- SEM; epsilon4+, 0.64 +/- 0.01 vs. epsilon4-, 0.67 +/- 0.01; p = 0.04), lower trochanter BMD (g/cm(2); mean +/- SEM; epsilon4+, 0.58 +/- 0.01 vs. epsilon4-, 0.61 +/- 0.01; p = 0.01) and lower total body BMC (g; mean +/- SEM; epsilon4+, 1787 +/- 40.0 vs. epsilon4-, 1863 +/- 23.8; p = 0.04). Women with ApoE epsilon4 also had a higher risk of severe vertebral deformities (OR=2.78; 95%CI: 1.21-6.34). In men, the associations between ApoE status and both hip BMD and QUS depended on age. Only among the younger men (65-69 years) was the presence of ApoE epsilon4 associated with lower BMD values. Bone markers and fractures were not associated with ApoE epsilon4 in either women, or men. In conclusion, this large community-based study confirms the importance of ApoE epsilon4 as a possible genetic risk factor related to BMD and vertebral deformities and demonstrates that its effect is gender related, and depends on age in men only.

Alzheimer's disease is not associated with altered concentrations of the nitric oxide synthase inhibitor asymmetric dimethylarginine in cerebrospinal fluid.

Nitric oxide (NO) may play a role in the pathophysiology of Alzheimer's disease (AD). Asymmetric dimethylarginine (ADMA), an endogenous inhibitor of NO synthase, is involved in regulation of NO production. Recently it has been reported that dimethylarginine dimethylaminohydrolase, an enzyme that hydrolyses ADMA into citrulline and dimethylamine, is specifically elevated in neurons displaying cytoskeletal abnormalities and oxidative stress in AD. We hypothesized that this could lead to altered CSF concentrations of ADMA in AD. Measurement of ADMA and dimethylamine in CSF revealed no significant differences between AD patients (n = 20) and age-matched control subjects (n = 20). Our results suggest that in early stages of AD overall regulation of NO production by ADMA is not aberrant.

Biochemical markers of growth hormone (GH) sensitivity in children with idiopathic short stature: individual capacity of IGF-I generation after high-dose GH treatment determines the growth response to GH.

OBJECTIVE AND PATIENTS: To assess multiple dose-response relationships between three GH doses (1.5, 3.0 and 6.0 IU/m2) and nine different biochemical markers of GH sensitivity in a well-defined group of 17 children with idiopathic short stature (ISS). DESIGN AND MEASUREMENTS: Serum levels of IGF-I, IGF-II and IGFBP-3, and peripheral markers leptin, C-terminal propeptide of type I collagen (PICP) and N-terminal propeptide of type III collagen (PIIINP), alkaline phosphatase (AP) and osteocalcin (OC) were measured at the start and after 2 and 12 weeks of periods of no treatment, GH 1.5 IU/m2 and GH 3.0 IU/m2. Twelve-week washout periods were applied between the 12-week GH-treatment periods. High-dose GH treatment was given during the second year of study and all serum markers were measured at start, after 2 and 12 weeks and 1 year of GH 6.0 IU/m2. In 18 non-GH-treated children with ISS the same parameters were measured yearly. The bone resorption marker urinary deoxypyridinoline (DPD) was measured during 12-h day and night periods at start and after 2 weeks GH 1.5, 3.0 and 6.0 IU/m2. RESULTS: All markers were GH dependent, but the timing of maximal response varied among different markers. Height SDS at start, age at start and IGF-II at baseline were inversely related to the first-year growth response (r = -0.73, P = 0.001; r = -0.53, P = 0.03; and r = -0.53, P = 0.03, respectively). Some statistically significant correlations between biochemical responses on low GH doses (1.5 or 3.0 IU/m2) and second-year growth response were found, but these showed no consistent pattern. However, all changes in IGF-I SDS after GH 6.0 IU/m2 measured either after 2 or 12 weeks or 1 year correlated significantly with the second-year growth response (r = 0.55, P = 0.02; r = 0.81, P = 0.001; and r = 0.86, P < 0.001, respectively). Baseline or GH-stimulated levels of peripheral markers did not correlate with the growth response. CONCLUSION: The individual capacity of IGF-I generation after high-dose GH treatment (6.0 IU/m2) determines the growth response on high-dose GH treatment. Peripheral markers do not seem to play a role in growth prediction of children with ISS.