A prognostic index as diagnostic strategy in children suspected of mitochondriocytopathy

The aim of this study was to assess an optimal screening for paediatric patients suspected of mitochondriocytopathy to justify a muscle biopsy. Forty-five patients were included. Medical history, physical examination, cardiac and ophthalmologic evaluation, clinical chemical investigations, in vivo function tests, neuroimaging and a skeletal muscle biopsy were performed in all patients. The results of the biochemical muscle studies were compared with the results of the other investigations. First, parameters with a statistical relationship with the result in muscle, normal or deficient, were selected. Secondly, a prognostic index was constructed using these parameters. Five parameters were selected: age <4 years, elevated fasting lactate to pyruvate ratio, elevated thrombocyte count, elevated lactate, and elevated alanine. Each parameter was scored 0 (not present) or 1 (present). The chance of a normal biopsy with a given value of this index (sum of the scores) was calculated: logit (Pr) = alpha + beta x index; alpha: -0.8167 and beta: 0.8331. (Pr: probability of normal biopsy.) The chance of a normal biopsy with an index value of 5 is 0.03, 4 is 0.07, 3 is 0.16, 2 is 0.30, 1 is 0.50 and 0 is 0.69. This prognostic index is a valuable instrument in deciding whether the suspicion of mitochondriocytopathy is strong enough to merit a muscle biopsy.     

Rhythms of Consciousness: Binocular Rivalry Reveals Large-Scale Oscillatory Network Dynamics Mediating Visual Perception

Consciousness has been proposed to emerge from functionally integrated large-scale ensembles of gamma-synchronous neural populations that form and dissolve at a frequency in the theta band. We propose that discrete moments of perceptual experience are implemented by transient gamma-band synchronization of relevant cortical regions, and that disintegration and reintegration of these assemblies is time-locked to ongoing theta oscillations. In support of this hypothesis we provide evidence that (1) perceptual switching during binocular rivalry is time-locked to gamma-band synchronizations which recur at a theta rate, indicating that the onset of new conscious percepts coincides with the emergence of a new gamma-synchronous assembly that is locked to an ongoing theta rhythm; (2) localization of the generators of these gamma rhythms reveals recurrent prefrontal and parietal sources; (3) theta modulation of gamma-band synchronization is observed between and within the activated brain regions. These results suggest that ongoing theta-modulated-gamma mechanisms periodically reintegrate a large-scale prefrontal-parietal network critical for perceptual experience. Moreover, activation and network inclusion of inferior temporal cortex and motor cortex uniquely occurs on the cycle immediately preceding responses signaling perceptual switching. This suggests that the essential prefrontal-parietal oscillatory network is expanded to include additional cortical regions relevant to tasks and perceptions furnishing consciousness at that moment, in this case image processing and response initiation, and that these activations occur within a time frame consistent with the notion that conscious processes directly affect behaviour.     

Prospective study of 64 cases of Kawasaki's disease

We prospectively studied 64 children with Kawasaki disease. The well recognized signs were seen, but we also found hyperemia of the tympanic membrane in 27%, uveitis in 17%, syndrome of inappropriate secretion of anti-diuretic hormone in 9%, hydrops of the gallbladder in 8%, pulmonary infiltrations in 5% and one death. One patient presented with acute kidney failure, another one presented with stenosis of the renal artery, and 8 presented white blood cells (WBC) in the urinary sediment. Sedimentation was accelerated and there was an important decrease in hemoglobin blood level around the 5th day of illness. The WBC count rose around the 10th day; thereafter, all these results returned to normal while platelets counts rose. Albumin blood level was low, and all the following data were higher than normal: alpha-1-globulin, alpha-2-globulin, IgA, IgM, SGOT, SGPT, bilirubin and CRP. Viral studies were performed in 37 patients; 12 showed positive results.     

Treatment of infertile women with a deficient postcoital test with two antiestrogens: clomiphene and tamoxifen

Twenty-two infertile women with repeated deficient results in the postcoital test received clomiphene citrate or tamoxifen. The patterns of luteinizing hormone, follicle-stimulating hormone, prolactin, 17 beta-estradiol (E2), and progesterone were examined during the follicular and periovulatory phases of the menstrual cycle, as were the cervical mucus characteristics. Under clomiphene treatment, an overproduction of E2 was observed (P less than 0.01), which did not result in an improvement of the cervical mucus characteristics. The pH of the endocervical mucus was lower (P less than 0.01). Under tamoxifen treatment, the serum E2 levels were higher (P less than 0.05) and normalized. Higher spermatozoa penetration meter scores were observed during the preovulatory and periovulatory periods, whereas the pH of the endocervical mucus was not lowered. These data support that tamoxifen may be preferential to clomiphene in treating this kind of infertile woman.     

Broadened ligand responsiveness of androgen receptor mutants obtained by random amino acid substitution of H874 and mutation hot spot T877 in prostate cancer

In a subset of endocrine therapy-resistant prostate cancers, amino acid substitutions H874Y, T877A and T877S, which broaden ligand specificity of the ligand binding domain (LBD) of the androgen receptor (AR), have been detected. To increase our knowledge of the role of amino acid substitutions at these specific positions in prostate cancer, codons 874 and 877 were subjected to random mutagenesis. AR mutants were screened in a yeast readout system for responsiveness to 5 alpha-dihydrotestosterone, progesterone and dehydroepiandrosterone. At position 874, only the histidine to tyrosine substitution could broaden AR ligand specificity. At position 877, 4 ligand specificity broadening substitutions were found: T877A, T877S, T877C and T877G. The latter 2 were not found in prostate cancer. The AR mutants were tested in mammalian (Hep3B) cells for responsiveness to 13 different ligands. All mutants displayed their own ligand specificity spectrum. Importantly, AR(H874Y) and AR(T877A) could be activated by cortisol. According to the 3-dimensional structure of the AR LBD, T877 interacts directly with the 17 beta-hydroxyl group of androgens. All amino acid substitutions identified at position 877 had smaller side chains than the threonine in the wild-type receptor, indicating that increased space in the ligand binding pocket is important in broadened ligand specificity. Because H874 does not interact directly with the ligand, its substitution by a tyrosine is expected to change the ligand binding pocket conformation indirectly. For T877C and T877G substitutions, 2-point mutations are required, and for H874Y, T877A and T877S substitutions, only a 1-point mutation is sufficient. This most likely explains that the latter 3 have been found in prostate cancer.     

Real-time PCR of host DNA in feces to study differential exfoliation of colonocytes between rats and humans

BACKGROUND: Colonic mucosa has a high turnover rate. At the end of their lifespan, colonocytes become senescent and die. Histological studies indicate that senescent colonocytes are shed (exfoliated) into the fecal stream in rats, but phagocytosed by mucosal macrophages in humans. We study whether quantification of host DNA in feces can be used as a non-invasive marker for this differential disposal of colonocytes. METHODS: Selective primers and probes for the rat and human beta-globin genes were designed and used in real-time PCR reactions. RESULTS: Host DNA was quantitatively extracted and detected in fecal samples of both species. Feces of rats fed a humanized diet contained approximately 100 microg rat DNA per g freeze-dried feces. In human feces, however, only 5 out of 12 samples contained detectable, though very low (less than 0.35 microg/g), levels of host DNA. This about 300-fold difference could not be attributed to differences in DNase activities in the fecal stream. CONCLUSION: Our results indicate that there is considerable luminal shedding of senescent colonocytes in rats, whereas mucosal phagocytosis is the main route of colonocyte disposal in humans. Thus, real-time PCR of host DNA in feces can be applied as a non-invasive method for studying the differential exfoliation of colonocytes.     

Multivitamin supplementation in oral contraceptive users.

The effects of oral contraceptives (OC) containing 30 micrograms of ethinyl oestradiol and of subsequent multivitamin and folic acid supplementation on vitamin A, total B2 [including its three individual constituents, i.e. riboflavine, RB; flavine-mono-nucleotide, FMN; and flavine-adenine-dinucleotide, FAD], B12, C and folate concentration in serum and red blood cells have been studied in a group of 59 non-pregnant female volunteers. The group taking OC comprised 28 women while 31 women were included in the group of non-OC users serving as the controls. The women were studied for four cycles. Blood samples were taken on days 3 and 23 of the first cycle to obtain baseline values of each analyte. Multivitamin and folic acid supplementation started on day 1 of the second cycle and this was continued daily throughout three consecutive cycles until the end of the study. Vitamin A levels were significantly higher and vitamin B12 levels were significantly lower in the group using OC. Comparison of the baseline values of vitamin total B2, FAD, C, serum and red blood cell folate as determined on days 3 and 23 of the first cycle of the two groups compared revealed no significant differences. Multivitamin and folic acid supplementation did not affect the concentrations of vitamin A and vitamin B12 with either group, whereas all other vitamins increased significantly in both groups. The consistency of each effect of multivitamin supplementation between the two groups was also tested. The degree of these effects was not statistically different between both groups. The results suggest that the vitamin status is indeed affected by OC treatment, but the effects of multivitamin supplementation are not different in OC and non-OC users. Supplementation during OC use or just after discontinuing treatment cannot be justified for healthy young women. However, in the case of women with a critical vitamin balance or higher folate needs, multivitamin supplementation may be considered.     

The significance of total creatine kinase activity and isozyme determinations in cerebrospinal fluid of neurological patients

Total CK activity is often increased in cerebrospinal fluid samples in neurological diseases (35%). These increased levels are frequently caused by CK M-chain activity and appear to have no diagnostic relevance. Furthermore, an obvious concentration gradient for total CK activity was often observed in two subsequent tubes from the same lumbar puncture. In this study, CK non-M activity is measured, being the sum of all CK activity not caused by the M-chain. A bioluminescence technique using anti-M-inhibiting antibodies was used for this purpose. In two subsequent tubes from the same lumbar puncture a difference of 8% in CK non-M activity was found. A similar gradient could be observed for total protein. Retrospectively, the correlation between CK non-M levels and the amount of brain tissue damage was studied in 81 neurological patients and in 19 healthy subjects. There was an obvious relation between the extent of brain tissue damage and the CSF CK non-M levels. The clinical results in this study are promising and justify a prospective study of the diagnostic relevance of this parameter in CSF in various patient groups.