Association of Lower Age and Cardiorespiratory Events during Intra-Arterial Chemotherapy for Retinoblastoma: A Prospective Observational Study.

BACKGROUND AND PURPOSE: Retinoblastoma is the most common primary intraocular tumor in childhood. Intra-arterial chemotherapy is becoming the standard of care for both first-line and rescue therapy, thus improving survival rates and decreasing the adverse effects of retinoblastoma treatment. Cardiorespiratory adverse events during general anesthesia for intra-arterial chemotherapy, including decreased lung compliance and bradycardia, have been described, but data regarding associated factors are still lacking. We aimed to assess the characteristics of patients and procedures associated with cardiorespiratory events during intra-arterial chemotherapy. MATERIALS AND METHODS: We performed a prospective monocenter observational study in children diagnosed with retinoblastoma undergoing intra-arterial chemotherapy under general anesthesia. The occurrence of cardiorespiratory events was registered. We also assessed clinical and procedural characteristics potentially associated with these events. RESULTS: A cardiorespiratory event was observed in 22 (12.5%) procedures, predominantly a decrease in tidal volume observed in 16 (9%) procedures. The median age was lower in the procedures with a cardiorespiratory event (20.43 [SD, 11.76] months versus 30.11 [SD, 24.17] months) (P < .05). Other variables such as bilateral disease or a previous intra-arterial chemotherapy treatment were not associated with the occurrence of a cardiorespiratory event. CONCLUSIONS: In children undergoing intra-arterial chemotherapy for retinoblastoma treatment, cardiorespiratory events were observed in 12.5% of procedures. Lower age was associated with this complication. Although predominantly mild, these events should have prompt diagnosis and treatment to prevent further deterioration and worse outcomes.

Hippocampal ether-à-go-go1 potassium channels blockade: effects in the startle reflex and prepulse inhibition.

Recently, our group described the ether-à-go-go1(Eag1) voltage-gated potassium (K(+)) channel (Kv10.1) expression in the dopaminergic cells indicating that these channels are part of the diversified group of ion channels related to dopaminergic neurons function. The increase of dopamine neurotransmission induces a reduction in the prepulse inhibition (PPI) of the acoustic startle reflex in rodents, which is a reliable index of sensorimotor gating deficits. The PPI response has been reported to be abnormally reduced in schizophrenia patients. The role of Eag1 K(+) channels in the PPI reaction had not been revealed until now, albeit the singular distribution of Eag1 in the dentate gyrus of the hippocampus and the hippocampal regulation of the startle reflex and PPI. The aim of this work was to investigate if Eag1 blockade on hippocampus modifies the PPI-disruptive effects of apomorphine in Wistar rats. Bilateral injection of anti-Eag1 single-chain antibody into the dentate gyrus of hippocampus did not modify apomorphine-disruptive effects in the PPI response. However, Eag1 antibody completely restored the startle amplitude decrease revealed after dentate gyrus surgery. These potentially biological important phenomenon merits further investigation regarding the role of Eag1 K(+) channels, mainly, on startle reflex modulation, since the physiological role of these channels remain obscure.

A simple inexpensive method for objective assessment of human sperm movement characteristics.

A simple, objective method is described for obtaining a well-defined and diversified set of human sperm movement characteristics. These data are suitable for comprehensive statistical comparisons of sperm suspensions. One-second time-exposure photomicrographs are taken with dark-field illumination of slides prepared from semen, cervical mucus, or artificial media. The negatives are projected as a filmstrip and are analyzed on a specially designed console. The filmstrips can be taken and developed in 15 minutes without darkroom facilities, and a complete analysis of the film requires an additional 15 to 20 minutes. Fifty spermatozoa are examined to determine percentage motility, and movement characteristics are recorded for 15 spermatozoa. With these data the swimming trajectories of individual spermatozoa can be reconstructed retrospectively. The sperm suspension as a whole is described in terms of percentage motility, mean swimming speed, percentage of progressive spermatozoa, mean swimming speed of progressive spermatozoa, percentage of straight-swimming spermatozoa, percentage of rolling spermatozoa, and percentage of yawing spermatozoa.

Detection of early retinal changes in diabetes by vitreous fluorophotometry.

A series of 77 patients with overt diabetes and with apparently normal fundi on ophthalmoscopy and fluorescein angiography was examined by vitreous fluorophotometry. Breakdown of the blood-retinal barrier, which appears to be the earliest clinically detectable change in the retina in diabetes, was a constant finding. Quantitative measurement by vitreous fluorophotometry of the breakdown of the blood-retinal barrier could be correlated with degree of metabolic control and previous duration of diabetic disease. Significantly higher vitreous fluorophotometry values, indicating a more marked breakdown of the blood-retinal barrier, were recorded in patients under poor metabolic control than in patients whose diabetes was under relatively better control. Similarly, patients who has had diabetes for longer periods of time showed higher vitreous fluorophotometry values than those recorded in patients with diabetes of shorter duration.

A follow-up study by vitreous fluorophotometry of early retinal involvement in diabetes.

A series of 25 diabetic patients who showed apparently normal fundi on ophthalmoscopy and fundus fluorescein angiography were observed by using vitreous fluorophotometry for 30 months. The results showed that the alteration of the blood-retinal barrier increased generally during the follow-up period, particularly in the diabetic patients who were under poor metabolic control. The degree of breakdown of the blood-retinal barrier was significantly associated with the duration of the diabetic disease.

Vitreous fluorophotometry and retinal blood flow studies in proliferative retinopathy.

The permeability of the blood-retinal barrier and retinal blood flow were evaluated by two new fluorophotometric methods in a series of patients with proliferative retinopathy, due either to retinal vein occlusion or to diabetes. A breakdown of the blood-retinal barrier and a decrease in retinal blood flow were observed in these patients. The breakdown of the blood-retinal barrier could be quantitated by vitreous fluorophotometry, which revealed very high concentrations of fluorescein in the vitreous after intravenous administration. The decrease in retinal blood flow appeared to be due mainly to appreciable narrowing of the retinal arteriolar vessels.

Studies on retinal blood flow. II. Diabetic retinopathy.

Diabetic patients grouped according to the evolutive stages of their retinal involvement were examined by a direct method for estimation of segmental retinal blood flow by slit-lamp fluorophotometry. Initial stages of retinal involvement in diabetes, in which the only alteration is a breakdown of the blood-retinal barrier, show values of segmental blood flow that are within normal limits. Patients with a minimal background retinopathy show a slight increase in retinal blood flow, whereas an highly significant increase of segmental blood flow is observed in the more advanced stages of background retinopathy with maculopathy. In general, a good correlation is apparent between the progressions of diabetic background retinopathy and increase in retinal blood flow. On the other hand, patients with proliferative retinopathy show lower values of retinal blood flow, which are attributable to a marked decrease in arterial diameter.

Cinemicrographic analysis of cytoplasmic and nuclear events associated with germinal vesicle breakdown in rat oocytes exposed to LH in vitro.

Cinemicrography, with Nomarski differential interference optics, was used to study the motion of cytoplasmic organelles and events leading to germinal vesicle breakdown (GVB) in rat oocytes perfused with a defined medium with or without LH. Initially, cytoplasmic organelles, 0-3--1-5 micrometer diam., appeared to move randomly and were uniformly distributed. A gradually increasing vigour of organellar movement, saltatory translocation of organelles and discontinuous convergent flow of groups of organelles around the nucleus were observed. Ultimately, most of the organelles, which possessed several properties indicative of lysosomes, accumulated around the nucleus. In the presence of 5--6 micrograms LH/ml perfusate, GVB was usually complete by 80 min, whereas in the absence of hormone, or in the presence of LH + antiserum to LH, GVB took up to 130 min. A sudden slight decrease in nuclear size, undulating activity in the nuclear envelope, and the appearance of intranuclear filaments indicated imminent GVB. The appearance of spherical bodies at the nucleolar surface, and the subsequent mobilization and collapse of the nucleolus in the nucleoplasm, were advanced events in the nuclear response. It is suggested that LH promotes GVB trought activation of lysosomes.

The mechanism of the nephridial apparatus of Paramecium multimicronucleatum. I. Expulsion of water from the vesicle.

Recent analysis of the mechanism of the nephridial apparatus of Paramecium multimicronucleatum by high-speed cinematography (300 fps at x 250) confirms the observations by electron microscopy (Schneider, 1960) that once the pore is opened, the vesicle is invaginated by adjacent cytoplasm and is emptied by collapsing under pressure from that cytoplasm, aided perhaps by pressure of the fibrils which anchor the ampullae to the excretory canal. There is no indication of active contraction of the vesicle or its membrane. There is no permanent pore to the vesicle. The vesicle is closed by a sealing of the ruptured membrane where it is in contact with the pellicular excretory canal. At onset of expulsion of vesicular fluid the membrane across the basal opening of the excretory canal is ripped along one semicircular portion of the excretory pore and is driven up against the opposite wall as a flap while the water rushes out. A constriction of the vesicular and cell membranes at the base of the excretory canal reseals the opening.