Chiasmal apoplexy, an unusual complication of cerebral glioblastoma.
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Aged↗
Biomedical subjects
A Kamal
Publications and source records attributed to A Kamal.
Chiasmal apoplexy, an unusual complication of cerebral glioblastoma.
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Aged↗
Chemical LTD in the CA1 field of the hippocampus from young and mature rats.
Within the hippocampal formation, two forms of long-lasting synaptic plasticity, long-term potentiation (LTP) and long-term depression (LTD), can be induced which require the activation of NMDA receptors. Interestingly, it has been shown that both LTP and LTD are reduced in adult animals. Recently, a new chemical protocol has been described which elicits LTD in the CA1 field of the hippocampus. Application of 20 microM NMDA for 3 min results in a stable and long-lasting decrease in the evoked synaptic responses. We used this protocol to induce LTD in hippocampal slices from young and adult rats and show that this form of LTD is AP5-sensitive and can be blocked by the protein phosphatase inhibitor cyclosporin A in slices from adult animals. In contrast to electrical LTD (induced by prolonged low frequency stimulation), the extent of chemical LTD was not different between the young and adult rats. These findings indicate that the intracellular signal transduction cascades involved in long-lasting synaptic depression are still intact in adult animals.
2-Amino-5-phosphonovalerate↗
Difficulties in distinguishing between a mature spermatid and testicular spermatozoon.
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Female↗
Easily decapitated spermatozoa defect: a possible cause of unexplained infertility.
We report the first 16 cases of a new sperm abnormality which we call 'easily decapitated spermatozoa defect'. This was discovered during intracytoplasmic sperm injection (ICSI) in couples with unexplained infertility. Semen analysis was normal, but minimal micromanipulation for ICSI resulted in decapitation of the spermatozoon during immobilization. For some oocytes the head and tail were injected separately, in others the intact sperm was injected after minimal immobilization. A fertilization rate of 47.5% was obtained using ICSI. Conventional in-vitro fertilization (IVF) on sibling oocytes (three cases) or in a previous cycle (three cases) resulted in total failure of fertilization. All patients reached the embryo transfer stage and three pregnancies resulted. Findings on electron microscopy in four cases included spermatozoa with degeneration or absence of the basal plate, abnormalities of the proximal centriole and degeneration of the midpiece with a large cytoplasmic droplet. We conclude that an occult sperm abnormality presenting as easily decapitated spermatozoa during ICSI could be a cause of unexplained infertility, as it resulted in total failure of fertilization in conventional IVF. Further research is necessary to investigate this sperm abnormality.
Adult↗
Vigorous prostatic massage: a simple method to retrieve spermatozoa for intracytoplasmic sperm injection in psychogenic anejaculation: case report.
A simple, non-invasive method to retrieve spermatozoa from patients with anejaculation is described. Three patients with psychogenic primary anejaculation were referred for intracytoplasmic sperm injection (ICSI). On the day of oocyte retrieval, vigorous prostatic massage was done. Examination of the expressed prostatic secretion revealed a sufficient number of motile spermatozoa in cases 1 and 3. In case 1, only one poor quality oocyte was obtained and ICSI was unsuccessful. Spermatozoa were cryopreserved for future use. In case 2, no spermatozoa were retrieved by prostatic massage. A testicular biopsy was performed to retrieve spermatozoa for ICSI. Unfortunately no pregnancy resulted. In case 3, retrieved spermatozoa were successfully used for ICSI, and 19 ova were injected. Fertilization occurred in 10 of these; seven were cryopreserved and three embryos were transferred. Ultrasound scan has confirmed a singleton pregnancy, which is ongoing. We conclude that vigorous prostatic massage could be an effective method of sperm retrieval for assisted conception in selected patients with anejaculation.
Adult↗
Facile and improved synthesis of 4 beta-aminopodophyllotoxin congeners.
An efficient synthesis of 4 beta-aminopodophyllotoxin from 4 beta-bromopodophyllotoxin using ammonia, and also a facile synthesis of 4 beta-amino-4'-O-demethylpodophyllotoxin from 4 beta-azidopodophyllotoxin by simultaneous azido reduction and selective demethylation at 4'-position employing chlorotrimethylsilane and sodium iodide, has been described. These are potential precursors for the various 4 beta-amino analogs of podophyllotoxin possessing DNA topoisomerase II inhibition activity.
Antineoplastic Agents, Phytogenic↗
Annexin VI-mediated loss of spectrin during coated pit budding is coupled to delivery of LDL to lysosomes.
Previously we reported that annexin VI is required for the budding of clathrin-coated pits from human fibroblast plasma membranes in vitro. Here we show that annexin VI bound to the NH2-terminal 28-kD portion of membrane spectrin is as effective as cytosolic annexin VI in supporting coated pit budding. Annexin VI-dependent budding is accompanied by the loss of approximately 50% of the spectrin from the membrane and is blocked by the cysteine protease inhibitor N-acetyl-leucyl-leucyl-norleucinal (ALLN). Incubation of fibroblasts in the presence of ALLN initially blocks the uptake of low density lipoprotein (LDL), but the cells recover after 1 h and internalize LDL with normal kinetics. The LDL internalized under these conditions, however, fails to migrate to the center of the cell and is not degraded. ALLN-treated cells have twice as many coated pits and twofold more membrane clathrin, suggesting that new coated pits have assembled. Annexin VI is not required for the budding of these new coated pits and ALLN does not inhibit. Finally, microinjection of a truncated annexin VI that inhibits budding in vitro has the same effect on LDL internalization as ALLN. These findings suggest that fibroblasts are able to make at least two types of coated pits, one of which requires the annexin VI-dependent activation of a cysteine protease to disconnect the clathrin lattice from the spectrin membrane cytoskeleton during the final stages of budding.
Annexin A6↗
Water maze learning and hippocampal synaptic plasticity in streptozotocin-diabetic rats: effects of insulin treatment.
Streptozotocin-diabetic rats express deficits in water maze learning and hippocampal synaptic plasticity. The present study examined whether these deficits could be prevented and/or reversed with insulin treatment. In addition, the water maze learning deficit in diabetic rats was further characterized. Insulin treatment was commenced at the onset of diabetes in a prevention experiment, and 10 weeks after diabetes induction in a reversal experiment. After 10 weeks of treatment, insulin-treated diabetic rats, untreated diabetic rats and non-diabetic controls were tested in a spatial version of the Morris water maze. Next, hippocampal long-term potentiation (LTP) was measured in vitro. To further characterize the effects of diabetes on water maze learning, a separate group of rats was pre-trained in a non-spatial version of the maze, prior to exposure to the spatial version. Both water maze learning and hippocampal LTP were impaired in diabetic rats. Insulin treatment commenced at the onset of diabetes prevented these impairments. In the reversal experiment, insulin treatment failed to reverse established deficits in maze learning and restored LTP only partially. Non-spatial pre-training abolished the performance deficit of diabetic rats in the spatial version of the maze. It is concluded that insulin treatment may prevent but not reverse deficits in water maze learning and LTP in streptozotocin-diabetic rats. The pre-training experiment suggests that the performance deficit of diabetic rats in the spatial version of the water maze is related to difficulties in learning the procedures of the maze rather than to impairments of spatial learning.
Animals↗
Increasing age reduces expression of long-term depression and dynamic range of transmission plasticity in CA1 field of the rat hippocampus.
Long-term depression, depotentiation and long-term potentiation of field excitatory postsynaptic potentials in the CA1 field of the hippocampus were studied in slices from two-, 12-, 24- and 36-week-old rats. Long-term potentiation was induced by stimulating afferent fibres for 1 s at 100 Hz. Long-term depression was induced either by stimulating the afferent pathways twice for 15 min at 1 Hz (protocol 1), giving in total 1800 pulses, or by stimulating the fibres at 5 min intervals twice at 1 Hz for 5 min followed by 5 min stimulation at 5 Hz (protocol 2), giving in total 2100 pulses. We found significant long-term depression in slices of all groups stimulated with protocol 1; however, the magnitude of long-term depression in slices from 24- and 36-week-old rats was significantly lower than that in slices from two- and 12-week old rats, although there was no such difference in the magnitude of long-term potentiation between slices. Stimulation protocol 2 induced long-term depression only in slices from two- and 12-week-old rats. Comparison of the dynamic range of transmission plasticity in slices from two- and 36-week-old rats, calculated as the difference between the nearly saturated long-term potentiation and nearly saturated depotentiation, revealed a significantly smaller dynamic range in slices from 36-week-old rats in comparison with slices from two-week-old animals. The decrease in the dynamic range in slices from 36-week-old rats was due to a diminished capacity to depotentiate the nearly saturated long-term potentiation and not due to a decreased long-term potentiation expression in these slices. In contrast to long-term depression, in which the slope of the field excitatory postsynaptic potentials consistently and significantly decreased below the baseline level, the nearly saturated depotentiation did not decrease below the original, pre-long potentiation baseline level. The results demonstrate that increasing age reduces expression of long-term depression and the dynamic range of transmission plasticity.
Aging↗
Sustained release intravitreal ganciclovir implant as salvage treatment in AIDS related cytomegalovirus retinitis.
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AIDS-Related Opportunistic Infections↗
Intravitreal sustained-release ganciclovir implantation to control cytomegalovirus retinitis in AIDS.
A novel form of therapy, the intravitreal ganciclovir implant (Vitrasert), was used to treat cytomegalovirus (CMV) retinitis in AIDS, when it was not possible to continue systemic therapy or disease progression was evident despite conventional intravenous treatment. A review of the ophthalmic and general health data, operative records and fundus photographs of 9 individuals who had Vitrasert implantation surgery in Edinburgh. Two patients received bilateral replacement implant procedures. Visual acuity, concomitant anti-CMV therapy, complications of implantation and control of retinitis were documented until final follow-up. Control of CMV retinitis was achieved in all individuals at one month postoperatively and remained controlled for a mean period of 5.8 months. Postoperative complications were mild and transient in all but 2 eyes of 2 patients who developed non-progressive macula oedema. Blinding complications as a result of surgery were not encountered and retinal detachment was not observed in this series. Vitrasert implantation is an acceptable and well tolerated treatment for CMV retinitis when systemic therapy fails to control disease progression.
AIDS-Related Opportunistic Infections↗
Fertilization and pregnancy rates after intracytoplasmic sperm injection using ejaculate semen and surgically retrieved sperm.
OBJECTIVE: To compare the fertilization rates and pregnancy rates (PRs) in intracytoplasmic sperm injection (ICSI) using sperm from ejaculates of normal and abnormal semen, epididymal sperm, and testicular sperm of obstructive and nonobstructive azoospermic patients. DESIGN: Retrospective study. SETTING: The Egyptian IVF-ET Center. PATIENT(S): Three hundred fifty patients underwent 366 ICSI cycles. INTERVENTION(S): ICSI, epididymal sperm aspiration, and testicular biopsy. MAIN OUTCOME MEASURE(S): Fertilization rates and PRs. RESULT(S): Patients were divided into five groups according to the quality and source of sperm. Patients in group 1 underwent 102 cycles of ICSI using ejaculated abnormal semen, group 2 underwent 44 cycles using epididymal sperm, group 3 underwent 82 cycles using testicular sperm from obstructive azoospermia, group 4 underwent 80 cycles using testicular sperm from nonobstructive azoospermia, and group 5 underwent 58 cycles using normal semen. There was no significant difference in the fertilization rates and PRs among groups 1, 2, and 3. In group 4, the fertilization rate and PR were significantly lower than in all other groups. In group 5, the fertilization rate was significantly higher than in all other groups. CONCLUSION(S): The fertilizing ability of sperm in ICSI is highest with normal semen and lowest with sperm extracted from a testicular biopsy in nonobstructive azoospermia. There was no significant difference in fertilization rates and PRs between ejaculated sperm of different parameters and surgically retrieved sperm in obstructive azoospermia.
Adult↗
Intracytoplasmic sperm injection using surgically retrieved epididymal and testicular spermatozoa in cases of obstructive and non-obstructive azoospermia.
This was a retrospective study of 115 patients who underwent 124 cycles of ICSI using surgically retrieved spermatozoa. The objective was to compare the results of ICSI in patients with obstructive azoospermia using epididymal spermatozoa (36 cycles) or testicular spermatozoa (58 cycles) with ICSI in patients with non-obstructive azoospermia using testicular spermatozoa (30 cycles). When epididymal spermatozoa were used for ICSI, the fertilization rate per injected metaphase-II oocyte and the clinical pregnancy rate per ICSI cycle were 60.4 and 25%, respectively. When testicular spermatozoa were used in obstructive cases, the fertilization rate and pregnancy rate were 57.9 and 34.5%. In non-obstructive cases the fertilization and pregnancy rates were 41.2 and 16.6%. When patients with obstructive azoospermia were regrouped according to the cause of obstruction, the fertilization and pregnancy rates were 59.1 and 35.1% in acquired obstruction and 58.7 and 24.3% in congenital obstruction. The fertilization and pregnancy rates were not statistically different (p > 0.05) when testicular or epididymal spermatozoa were used in obstructive cases; neither was statistically different (p > 0.05) when compared in patients with congenital and acquired obstruction. On the other hand, the fertilization and pregnancy rates in cases with non-obstructive azoospermia were significantly lower (p < 0.05) than in obstructive cases.
Adult↗
Intracytoplasmic sperm injection in obstructive and non-obstructive azoospermia.
We compared the results of intracytoplasmic sperm injection (ICSI) in: (i) obstructive versus non-obstructive azoospermia, (ii) obstructive azoospermia using epididymal versus testicular spermatozoa and (iii) acquired versus congenital obstructive azoospermia due to congenital absence of the vas deferens (CAVD). A retrospective analysis was done of 241 consecutive ICSI cycles done in 103 patients with non-obstructive azoospermia and 119 patients with obstructive azoospermia. In the obstructive group, 135 ICSI cycles were performed. Epididymal spermatozoa were used in 44 cycles and testicular spermatozoa in 91 cycles. In the non-obstructive group, 106 cycles were performed. The fertilization and pregnancy per cycle rates were 59.5 and 27.3% respectively using epididymal spermatozoa, 54.4 and 31.9% respectively using testicular spermatozoa in obstructive cases, and 39 and 11.3% respectively in non-obstructive cases. The fertilization and pregnancy per cycle rates were 56.6 and 37% respectively in acquired obstructive cases, and 55.2 and 20.4% respectively in CAVD. In conclusion, ICSI using spermatozoa from patients with acquired obstructive azoospermia resulted in significantly higher fertilization and pregnancy rates as compared to CAVD and non-obstructive cases.
Epididymis↗
Prospective controlled randomized study of in vitro fertilization versus intracytoplasmic sperm injection in the treatment of tubal factor infertility with normal semen parameters.
OBJECTIVE: To compare the results of IVF and intracytoplasmic sperm injection (ICSI) in tubal factor infertility with normal semen parameters. DESIGN: A prospective randomized study. SETTING: The Egyptian IVF-ET Center. PARTICIPANTS: One hundred sixteen patients infertile due to tubal factor were divided randomly into two groups. Group A(n = 58) was treated with IVF and group B(m = 58) was treated with ICSI. INTERVENTION: In vitro fertilization and ICSI. MAIN OUTCOME MEASURE: Pregnancy rate. RESULTS: In group A, 736 oocytes were retrieved and normal (two pronuclear [2pN] fertilization occurred in 477 oocytes (64.8%). In group B, 748 oocytes were retrieved, 572 metaphase II oocytes were injected, and 2PN fertilization occurred in 400 oocytes (70% per injected oocyte and 53.5% per retrieved oocyte). Clinical pregnancy was diagnosed in 18 patients in group A (31%) and 19 patients in group B (32.8%). There was no significant difference in the pregnancy rate between the two groups. The fertilization rate per retrieved oocytes was significantly higher in group A. CONCLUSIONS: Intracytoplasmic sperm injection does not offer a higher pregnancy rate as compared with IVF in the treatment of tubal factor infertility with normal semen.
Chorionic Gonadotropin↗
Place learning and hippocampal synaptic plasticity in streptozotocin-induced diabetic rats.
Moderate impairment of learning and memory has been recognized as a complication of diabetes. The present study examined behavioral and electrophysiological measures of cerebral function in streptozotocin (STZ)-induced diabetic rats. Behavioral testing consisted of a spatial learning task in a water maze. Electrophysiological testing consisted of in vitro assessment of hippocampal long-term potentiation (LTP), an activity-dependent form of synaptic plasticity, which is believed to be related to the cellular mechanisms of learning and memory. Two experiments were performed: the first with severely hyperglycemic rats and the second with moderately hyperglycemic rats. Rats were tested in the water maze 11 weeks after induction of diabetes. Next, LTP was measured in vitro in trained animals. Both spatial learning and LTP expression in the CA1 field of the hippocampus were impaired in severely hyperglycemic rats as compared with nondiabetic controls. In contrast, spatial learning and hippocampal LTP were unaffected in moderately hyperglycemic rats. The association of alterations in hippocampal LTP with specific learning impairments has previously been reported in conditions other than diabetes. Our findings suggest that changes in LTP-like forms of synaptic plasticity in the hippocampus, and possibly in other cerebral structures, are involved in learning deficits in STZ-induced diabetes. The beneficial effect of moderate glycemic control on both place learning and hippocampal LTP supports the significance of the relation between these two parameters and indicates that the development of the observed deficits may be related to the level of glycemic control.
Animals↗
Assessment of autonomic function using complex demodulation and posture entrainment techniques: an application to normal subjects and diabetic patients.
The assessment of autonomic nervous systems (sympathetic and parasympathetic) using the method of complex demodulation and posture entrainment are presented. The heart rate variability signals were derived from the ECG of normal subjects and diabetic patients in both supine and standing positions. The method of complex demodulation is employed on the heart rate variability data for both groups. Two significant bands in the heart rate variability spectrum were investigated by this technique. The amplitude of the high frequency band (0.181-0.4 Hz) showed the parasympathetic changes in normal subjects and, to a lesser extent, in the diabetic patients. The amplitude of the low frequency band (0.03-0.15 Hz) showed the influence of sympathetic changes in both groups. The complex demodulation method indicated the effect of high frequency and low frequency bands on both divisions of autonomic function in regulating the heart rate variability in both normal subjects and diabetic patients. In the supine position, the parasympathetic and sympathetic were balanced. On standing (posture entrainment), the high frequency band showed a decrease in amplitude due to decreased parasympathetic activity, while the low frequency band showed an increase in amplitude, which indicated an increase in sympathetic activity. These patterns were repeated in both normal subjects and diabetic patients. It seems that the use of posture entrainment combined with the complex demodulation method is significant to characterize, assess and quantify the autonomic function in health and disease.
Adult↗