Effect of liposome surface charge on the stability of technetium (99mTc) radiolabelled liposomes

Using liposomes radiolabelled by the 99mTechnetium-stannous chloride technique we have investigated the effect of surface charge on the stability of the isotope in vitro and in vivo. Dialysis of 99mTc-labelled positive, negative and neutral liposomes, which had been incubated in either saline or normal rat serum showed no significant loss of the isotope from the liposome surface with only 2 per cent of the isotope dialysed. A comparison of gel chromatography with dialysis confirmed that most of the isotope remained attached to the liposome surface, but it did reveal greater loss of the isotope, between 15 and 23 per cent. The liposome clearance rates obtained from 125I-egg phosphatidylcholine (EPC) and 99mTc dual-labelled positive or neutral liposomes were significantly different. The 99mTc marker was cleared five times faster from the positive liposomes and twice as fast from the neutral liposomes as the 125I-EPC integral membrane marker. The 99mTc attached to liposomes with a negative surface charge was stable in vivo and had the same clearance rate from the circulation as the 125I-EPC marker. These results indicate that the commonly used in vitro techniques for assessing liposome radiolabel stability are unsuitable for predicting the stability of the 99mTc in vivo.     

Melatonin and Sperm Motility/Melatonin und Spermatozoenmotilität

Several substances can interfere with microtubular function eg. colchicine. Melatonin, a hormone secreted by the pineal gland has similar effects as colchicine on microtubules. In this study melatonin levels were determined in both plasma and seminal plasma of patients with good or impaired motility and forward progression. There was no statistically significant difference between the mean plasma and seminal plasma values of patients with good or impaired motility and forward progression. There was no correlation between seminal plasma melatonin and impaired motility or any other semen parameter. There was also no correlation between plasma and seminal plasma concentrations of melatonin. High seminal plasma melatonin concentrations were not necessarily associated with impaired sperm motility. From these it is concluded that seminal plasma melatonin plays no important role in sperm motility.     

Changing glial organization relates to changing fiber order in the developing optic nerve of ferrets

The structures of the developing eye-stalk and the relationships of early retinofugal fibers as they pass through the stalk, chiasm, and tract have been studied by light and electron microscopical methods in fetal ferrets aged 23–27 days. The early eye-stalk can be divided into two parts: a narrow extracranial part has a narrow lumen and is lined by few cells, whereas a thicker intracranial part has a wider lumen and is lined by several rows of cells. At the earliest stages no axon bundles are recognizable in the stalk, but fibers of the supraoptic commissure are already beginning to cross the midline in the diencephalon. Subsequently, as retinofugal axons invade the stalk, the glia of the extracranial part of the stalk have an interfascicular distribution and axon bundles are separately encircled by glial cytoplasm. In the intracranial part, as in the chiasm and tract, the glial cells occupy a periventricular position and send slender radial cytoplasmic processes to the subpial surface; these pass between groups of axons that here lie immediately deep to the subpial glia. Whereas axonal growth cones have no evident preferred distribution in the extracranial stalk, they tend to accumulate near the pial surface intracranially. The boundary between the two types of organization shifts as development proceeds so that the interfascicular glial structure of the early extracranial stalk first encroaches upon the intracranial parts and later appears in the chiasm. The characteristic adult arrangement of fibers in an age-related order in the optic chiasm and tract, but not in the optic nerve, can be understood if axonal growth cones are guided toward the pial surface by radial glia but not by interfascicular glia. From the distribution of the growth cones, this is what appears to happen.     

Factors affecting the outcome in subdural empyema.

The case reports of 102 patients with subdural empyema, diagnosed in the years 1935-83, were reviewed to determine the factors affecting the outcome. Statistical analysis (likelihood ratio tests with chi square approximation and logistic regression) showed that year of diagnosis (p less than 0.01) and level of consciousness at the moment of diagnosis (p less than 0.01) had a significant bearing on the chance to survive and that these same two factors (each factor p less than 0.01) and extent of subdural pus accumulation at the moment of diagnosis (p less than 0.05) had a significant bearing on the chance of survival without severe disability. Among others the duration of the disease up to the moment of diagnosis and the mode of the first surgical procedure had no significant bearing on the outcome. These results together with those in the literature are discussed and it is concluded that diagnosis and treatment before the patient lapses into stupor or coma, increases the chance of survival and that with adequate management a mortality rate of 10% or lower is to be expected.     

Peripheral pulmonary artery aneurysm in a patient with limited respiratory reserve: controlled resection using cardiopulmonary bypass

Pulmonary artery aneurysms are rare lesions for which operative management is not frequently undertaken. When operation is indicated, central lesions involving the pulmonary trunk, right main pulmonary artery, or left main pulmonary artery are repaired using cardiopulmonary bypass. Peripheral aneurysms in segmental intrapulmonary arteries have been managed most frequently by lobectomy, but occasionally by aneurysmectomy and pulmonary arterial repair. We used cardiopulmonary bypass for peripheral pulmonary aneurysmectomy in a patient with limited respiratory reserve because he had undergone prior contralateral bilobectomy; this allowed controlled resection while preserving a maximal amount of pulmonary parenchyma.     

Characterization of human mammary normal and neoplastic cells grown in culture

The paper presented here describes cultivation and characterization of human mammary normal (NMC) and neoplastic (BO) cells. Characteristics: growth rate, colony growth in soft agar, nuclear overlaps, induction of multinucleation by Cytochalasin B and transplantation in vivo were compared between NMC- and BO-cells. Normal (NMC) cells are characterized by a slow growth rate (cell doubling time less than 70 hours), no growth in soft agar, no induction of uncontrolled nuclear division and no development of tumors after transplantation of cells in nude mice in vivo. The two cell types do not differ with respect to the nuclear overlapping ratio. In contrast, neoplastic (BO) cells showed a lower doubling time (less than 20 hours), colony growth in soft agar (greater than 20 colonies/30,000 cells), induction of multinucleation by Cytochalasin B (greater than or equal to 3 nuclei/cell), and tumors in nude mice were observed. Both cell types were recommended as an in-vitro model for screening antineoplastic agents.