Oocyte morphology predicts outcome of intracytoplasmic sperm injection

To examine the influence of cytoplasmic morphology on the success rate of intracytoplasmic sperm injection (ICSI), the morphology of 837 metaphase II oocytes was assessed after cumulus stripping. The main abnormalities detected were excessive granularity, cytoplasmic inclusions such as vacuoles, smooth endoplasmic reticulum clustering and refractile bodies. Microinjection was performed in 538 oocytes with normal cytoplasm, 142 out of 161 with excessive granularity and 112 out of 138 with cytoplasmic inclusions. Very poor oocytes were not injected. No difference was found in fertilization rate. The embryos achieved cleaved normally and a similar number of good quality embryos among the three groups was noted. The outcome of transfer of embryos derived solely from normal oocytes (group A: 72 patients, 183 embryos) was compared with those from oocytes with cytoplasmic abnormalities (group B: 34 patients, 85 embryos). In group A, 17 clinical pregnancies (24% per patient, implantation rate 10%) were established. In group B, only one clinical pregnancy (3% per patient, implantation rate 1%) was established, from the transfer of embryos derived from oocytes with homogeneous granularity of the cytoplasm. No pregnancy resulted following the transfer of embryos from eggs with cytoplasmic inclusions. The difference was statistically significant. The outcome of ICSI is dependent on the quality of the oocytes retrieved. Normal fertilization and early embryo development were achieved in oocytes with abnormal cytoplasm morphology, but the resulting embryos failed to demonstrate the same implantation potential as those derived from oocytes with normal cytoplasm.      

Effects of lorazepam on short latency afferent inhibition and short latency intracortical inhibition in humans

Experimental studies have demonstrated that the GABAergic system modulates acetylcholine release and, through GABA_A receptors, tonically inhibits cholinergic activity. Little is known about the effects of GABA on the cholinergic activity in the human central nervous system. In vivo evaluation of some cholinergic circuits of the human brain has recently been introduced using a transcranial magnetic stimulation (TMS) protocol based on coupling peripheral nerve stimulation with TMS of the motor cortex. Peripheral nerve inputs have an inhibitory effect on motor cortex excitability at short intervals (short latency afferent inhibition, SAI). We investigated whether GABA_A activity enhancement by lorazepam modifies SAI. We also evaluated the effects produced by lorazepam on a different TMS protocol of cortical inhibition, the short interval intracortical inhibition (SICI), which is believed to be directly related to GABA_A activity. In 10 healthy volunteers, the effects of lorazepam were compared with those produced by quetiapine, a psychotropic drug with sedative effects with no appreciable affinity at cholinergic muscarinic and benzodiazepine receptors, and with those of a placebo using a randomized double-blind study design. Administration of lorazepam produced a significant increase in SICI  ( F _3,9= 3.19, P = 0.039)  . In contrast to SICI, SAI was significantly reduced by lorazepam  ( F _3,9= 9.39, P = 0.0002)  . Our findings demonstrate that GABA_A activity enhancement determines a suppression of SAI and an increase of SICI.     

Formation of RNA and protein in cells infected with standard and defective Sindbis virus

Our studies on the formation of Sindbis virus proteins have established that: 1. one of the two envelope proteins (E2) accumulates in infected cells as a higher molecular weight precursor that is slowly converted to the virion protein; 2. the large protein (mol. wt 130000 daltons), that accumulates in cells infected with a temperature-sensitive mutant of Sindbis virus contains sequences of the three virion proteins; and 3. the protein (mol. wt. 100000 daltons) isolated from BHK cells infected with Sindbis virus is related in sequence to the two envelope proteins.We have investigated the formation of defective-interfering (DI) particles of Sindbis virus and their ability to inhibit the replication of standard virus. BHK cells infected with passages of Sindbis virus containing DI particles accumulate a species of RNA (20S) that is about half the molecular weight of the 26S RNA. We have demonstrated by competitive hybridization experiments that 20S RNA contains half the sequences of 26S RNA. We also present evidence that in contrast to 26S RNA, 20S does not bind to polysomesin vivo and is not translatedin vitro.Presented on the Meeting on Studies on Virus Replication of the Commission of the European Communities in Brüssel, May 1974.     

Simultaneous evaluation of basal FSH and oestradiol response to GnRH analogue (F-G-test) allows effective drug regimen selection for IVF

To determine whether preliminary assessment of ovarian reserve by simultaneous evaluation of basal follicle-stimulating hormone (FSH) and oestradiol response to gonadotrophin releasing hormone (GnRH) analogue (F-G-test) can be used to tailor individually the drug regimen for ovarian stimulation, the in-vitro fertilization (IVF) results of 238 patients were retrospectively analysed. Sixty-two women with abnormal response to the test (DeltaE2 <180 pmol/l and/or FSH >9.5 mIU/ml) had commenced buserelin nasal spray in the mid-luteal phase and discontinued it on cycle day 1. Ovarian stimulation was started on cycle day 3 with 375 IU/day of gonadotrophin. Fifty-three patients completed the treatment cycle (group A). A total of 176 women with normal response to the test (DeltaE2 >180 pmol/l and FSH <9.5 mIU/ml) had continued the GnRH analogue throughout the stimulation cycle and a starting dose of 225 IU/day of gonadotrophin was used from cycle day 3. A total of 158 patients completed the treatment cycle (group B). Group A had significantly higher age (34.9 +/- 4.2 versus 33.2 +/- 4.2) (P < 0.05) and basal FSH (9.2 +/- 3.8 versus 7.0 +/- 2.2) (P < 0.05) and required a higher total dose of gonadotrophin. The numbers of oocytes retrieved and embryos transferred were significantly lower. However, fertilization, clinical pregnancies, and implantation rates were similar in both groups. It was concluded that simultaneous evaluation of basal FSH and oestradiol response to GnRH analogue can be useful in identifying subcategories of women with reduced ovarian reserve who may benefit from reduced GnRH analogue administration and a higher starting dose of gonadotrophin.     

Bone Marrow Stromal Cells (BMSCs) in Bone Engineering: Limitations and Recent Advances

Bone marrow stromal cells (BMSCs) have been isolated for the first time by Friedenstein et al. and since then have been considered the progenitor cells for the skeletal tissues. Indeed BMSCs are clonogenic, fibroblastic in shape, and can differentiate along multiple lineages such as osteoblasts, chondrocytes, adipocytes, and hematopoiesis-supportive stroma. When implanted in vivo on a three-dimensional bioceramic scaffold into immunocompromised mice, BMSCs form bone and hematopoiesis-supportive stroma. The ease of harvest from a donor bone marrow together with the ability to form bone in vivo make BMSCs ideal for clinical applications. Thus, ex vivo expanded BMSCs have been employed, first in large animal models, then in human clinical trials, to repair large bone segmental defects. Further investigation of the expanded BMSC population led to the observation that in vitro expansion appears a limiting passage: cells tend to senesce and lose their multidifferentiation potential with time in culture. To overcome these limitations, two approaches have been proposed: (1) identification of the appropriate culture conditions to prevent senescence by possibly selecting a subpopulation with stem cell characteristics, and (2) engineering of the cells by transfection with the telomerase gene to prevent cells from telomere shortening and consequent aging.