The role of growth/differentiation factor 5 (GDF5) in the induction and survival of midbrain dopaminergic neurones: relevance to Parkinson's disease treatment

Growth/differentiation factor-5 (GDF5) is a member of the transforming growth factor-beta superfamily which has potent effects on dopaminergic neurones in vitro and in vivo. GDF5 is under investigation as a potential therapeutic agent for Parkinson's disease (PD), which is caused by the progressive degeneration of dopaminergic neurones projecting from the substantia nigra (SN) to the striatum. In the rat ventral mesencephalon (VM; the developing SN), GDF5 expression peaks at embryonic day 14, the time at which dopaminergic neurones undergo terminal differentiation. Addition of GDF5 protein to cultures of embryonic rat VM increases the survival and improves the morphology of dopaminergic neurones in these cultures. GDF5 treatment also increases the number of cells which adopt a dopaminergic phenotype in cultures of VM progenitor cells. Intracerebral administration of GDF5 has potent neuroprotective and restorative effects on the nigrostriatal pathway in animal models of PD. Furthermore, addition of GDF5 protein to embryonic rat dopaminergic neuronal transplants improves their survival and function in a rat model of PD. Thus, GDF5 has potential applications to PD therapy as a dopaminergic neuroprotective agent and as a factor that may induce a dopaminergic neuronal fate in unrestricted progenitor cells.     

Efficacy and safety of galantamine (reminyl) for dementia in patients with Parkinson's disease (an open controlled trial)

An open controlled trial of the use of galantamine at a maximum dose of 16 mg/day included 41 patients with Parkinson's disease with dementia randomized to a galantamine treatment group (21 patients) and a control group (20 patients). Cognitive, neuropsychiatric, and motor symptoms were assessed clinically before the trial and at 4, 12, and 24 weeks, using the Mini Mental State Examination (MMSE), the cognitive Alzheimer's Disease Assessment Scale (ADAS-cog), the clock drawing test, the Frontal Assessment Battery (FAB), and the Neuropsychiatric Inventory (NPI) with assessment of distress in relatives. Patients treated with galantamine had better scores on the MMSE (p < 0.05),ADAS-cog (p < 0.05), the clock drawing test (p < 0.05), and the FAB (p < 0.01) at the end of the study period as compared with the control group. Changes in total point scores on the NPI-12 at the ends of weeks 12 and 24, as compared with the beginning of the trial, were in favor of the group treated with galantamine, with significant changes in the hallucinations (p = 0.0002), anxiety (p = 0.04), sleep disturbance (p = 0.04), and apathy (p = 0.006) sections. Galantamine treatment was accompanied by decreases in the level of distress in patients' relatives (p = 0.007) and improvements in daily activity (p = 0.003). Improvements in gait and decreases in freezing and falls were seen in the galantamine treatment group. However, two patients of this group showed minor increases in tremor. Side effects (drooling, postural hypotension, nausea, dysuria) occurred in seven patients (30%). __________ Translated from Zhurnal Nevrologii i Psikhiatrii imeni S. S. Korsakova, Vol. 107, No. 12, pp. 25–33, December, 2007.     

A prospective, randomized, double-blind clinical trial to study the efficacy and efficiency of a fixed dose of recombinant follicle stimulating hormone (Puregon) in women undergoing ovarian stimulation

A prospective, randomized, double-blind, multicentre (n = 5) study was conducted to compare the influence of either a 100 or 200 IU daily fixed-dose regimen of recombinant follicle stimulating hormone (FSH) on the number of oocytes retrieved and the total dose used in down-regulated women undergoing ovarian stimulation. Fertilization was done by intracytoplasmic sperm injection or conventional in-vitro fertilization. A total of 199 women were treated with FSH, 101 subjects with 100 IU and 98 subjects with 200 IU. In subjects of the 200 IU treatment group, significantly more oocytes were retrieved compared to the 100 IU group (10.6 versus 6.2 oocytes, P < 0.001). The total dose needed to develop at least three follicles with a diameter of > or = 17 mm was significantly lower in the 100 IU treatment group (1114 IU versus 1931 IU, P < 0.001). In the low-dose group, significantly lower serum concentrations of oestradiol, progesterone and FSH were observed at the day of human chorionic gonadotrophin administration. Although more cycle cancellations due to low response were seen in the 100 IU group (n = 24 versus n = 3), the clinical pregnancy rate per started cycle was similar (24.7% in the 100 IU group versus 23.3% in the 200 IU group). In the high-dose group, more side-effects, in particular more cases of ovarian hyperstimulation syndrome, were noted. It is concluded that compared to 200 IU, the use of a 100 IU fixed dose is less efficacious in terms of the number of oocytes retrieved, but more efficient as indicated by a lower total dose.