In vitro activity of newer quinolones on Streptococcus pneumoniae isolated from outpatients

The case of a newborn with asymptomatic chylous ascites operated on because of voluminous inguino-scrotal hernia is reported and a review of the recent literature about aetiology, diagnosis and treatment of neonatal chylous ascites is made.     

In vitro biosynthesis of rabbit blastokinin

Changes of the height of retinal detachments up to 0.1 mm can be visualized by A-scan-ultrasonography; such small changes cannot be ascertained by means of ophthalmoscopy. Based on echooculometric measurements of the maximal height of retinal detachments during the first hours and days after surgery without subretinal drainage, the final success (24 cases) or failure (2 cases) could be predicted 24 hours at latest. Thus in cases of retarded resorption of the subretinal fluid it can be decided by means of echography, wether a reattachment of the retina can be expected or a failure, the cause of which needs early detection.     

In vitro cytotoxicity of paclitaxel-transferrin conjugate on H69 cells

Transferrin is a serum glycoprotein involved in iron transport. Transferrin acts also in cell growth regulation through membrane receptors. The number of transferrin receptors is increased in tumor and other rapidly dividing cells. This renders transferrin suitable for use in cytotoxic drugs targetting tumor cells. Paclitaxel was derivatized on 2' carbon and coupled with trasferrin using glutaraldehyde. The cytotoxicity of the conjugate was evaluated on small cell carcinoma of the lung cell line (H69). As compared to paclitaxel, the conjugate exhibited a slight decrease in cytotoxicity.     

In vitro induction of F1 hybrid anti-parent cell-mediated cytotoxicity

Spleen cells from normal (C57BL/6 X DBA/2)F1 mice were sensitized in vitro for 5 days with irradiated C57BL/6 or DBA/2 parental stimulating cells. Effector cells were generated which specifically lysed 51Cr-labeled targets (leukemia or mitogen-stimulated lymphoid cells) H-2-matched with the parental genotype used for sensitization. The response of F1 spleen cells to the C57BL/6 parent was stronger and more reproducible than that to the DBA/2 parent. The kinetics of generation of effector cells were similar for the F1 anti-parent and an F1 anti-allogeneic response. However, the magnitude of the F1 anti-C57BL/6 cytotoxic response was considerably lower than the F1 response to allogeneic cells. The ratio of responder to stimulator cells in the cultures was more critical for the former than for the latter response. Several lots of fetal bovine serum were found to be adequate for supplementing the medium in the induction of J1 hybrid anti-parent and anti-allogeneic cytotoxic effector cells. Based on these and other studies, it would appear that the F1 hybrid anti-parent cytotoxic response provides an in vitro model of murine hemopoietic graft rejection in vivo. This response may be elicited by a mechanism distinct from T cell-mediated cytotoxicity and involve different subpopulations of spleen cells.     

In vitro evaluation of the cytotoxicity of two glass-ionomer root canal sealers

The cytotoxicity of two glass-ionomer root canal sealers (Ketac-Endo and Endion) was tested by using an established cell line, BHK21/C13. Under aseptic conditions, the sealers were prepared according to the manufacturers' directions, and 0.1 ml of each material was placed in petri dishes. After setting for 6 h, the sealers were covered with 20 x 10(4) cells per dish. The cultures were incubated at 37 degrees C for 24 h, 48 h, and 72 h. Cytotoxicity was assessed by a quantitative technique at three observation periods. Endion was highly cytotoxic, causing a significant decrease in cell density. Ketac-Endo proved to be a very biocompatible material.     

In vitro cytotoxicity test for estimating non-ocular irritation dose of ophthalmic solutions

The in vitro cytotoxicity test for estimating the non-ocular irritation dose of ophthalmic solutions was investigated. In the in vitro test, normal human epidermal keratinocytes (NHEK) in a confluent monolayer were incubated for 48 hr in a medium with test compounds. The concentration of a test compound which causes a 50% reduction in NHEK viability was determined as IC50 by MTT colorimetric assay. For comparison, the in vivo rabbit ocular irritation tests were carried out by the standard Draize method. The maximum concentration, which did not show any ocular irritation, was determined as DS0. The results showed the correlation coefficient between the IC50 values and the DS0 values for 19 test compounds to be 0.82. However, the correlation coefficients for 10 compounds, which have IC50 values of less than 300 micrograms/ml, and for 7 alcohols were 0.99. The IC50-DS0 correlation curves obtained could be utilized as the critical concentrations for ocular irritation. These results suggest that our in vitro/in vivo test can estimate non-ocular irritation dose of the ophthalmic preparations in advance of the in vivo tests.     

In vitro fertilization, culture, and transfer of rabbit ova

Ovulated rabbit oocytes were fertilized in vitro in chemically defined media supplemented with bovine serum albumin and either cultured up to the expanding blastocyst stage or transferred to recipients after varying periods of culture. Embryos transferred after up to 72 hours of in vitro culture were born as viable young. Oocytes from young virgin does were superior to oocytes from nonvirgin does for the purpose of in vitro fertilization (54% versus 26% fertilized, P less than 0.01). Capacitated sperm from artificially inseminated capacitators resulted in fertilization rates slightly lower than those from naturally mated does (46% versus 57% fertilized, P less than 0.025). Removal of cumulus and corona cells from oocytes with hyaluronidase and repeated aspiration through a fine pipette resulted in lowered fertilization rates (51% versus 73%, P less than 0.025). Linbro Disposo Tray wells were as good as glass tissue-culture dishes for the in vitro mixing of gametes and were more convenient to use. Modified Ham's F10 medium was used to culture the in vitro-fertilized embryos. However, when a modified Brackett's medium was used instead of modified Ham's F10 for the initial 4-hour period after mixing gametes, more oocytes were fertilized (52% versus 28%, P less than 0.01).     

In vitro cytotoxicity of guanylhydrazones (MGBG and PGBG) on cultured Chinese hamster ovary cells

Periosteum was obtained within 10 days of injury from the site of 17 adult tibial diaphyseal fractures during internal fixation. Osteogenic cells, non-osteogenic cells and vascular elements were identified in situ using a variety of techniques. In all cases, the periosteum was thickened with randomly distributed plaques of cartilage and bone. Cells covering newly formed bone trabeculae expressed osteocalcin. Lectin-binding revealed high vascularity. Few mast cells were observed. Macrophages and acid phosphatase positive cells, some multinucleate, were observed in abundance. These findings suggest that the repair of the adult human diaphyseal fracture is similar to that of experimental fractures in rapidity of onset, high vascularity and in bone and cartilage formation. They differ in the fact that chondrogenesis and osteogenesis appear to be simultaneous in human fractures but sequential in experimental fractures. The paucity of mast cells suggests that they probably play no significant role in the repair of the human fractures.     

In vitro cytotoxicity and teratogenicity of norethisterone and levonorgestrel released from hollow nylon monofilaments

We investigate the effect of the neuron characteristics on the behavior of a recurrent excitatory neural network model. First, we present the different types of dynamics obtained with simulations of a network of coupled excitatory spike-response neuron models placed under the influence of noise. Then, we derive a discrete map describing the dynamics of large fully connected networks. By studying the bifurcation structure of this map, we can determine for which ranges of the neuron model parameters the network will display collective oscillations or other types of dynamics.     

Comparative in vitro activities of new quinolones against coryneform bacteria

The in vitro activities of eight quinolones against 115 coryneform bacteria (20 Corynebacterium jeikeium, 15 Corynebacterium minutissimum, 15 Corynebacterium striatum, 25 Corynebacterium urealyticum, 10 Corynebacterium xerosis, 10 Corynebacterium group ANF-1, 10 Corynebacterium group 12, and 10 Listeria monocytogenes) were determined. The MICs of ciprofloxacin, ofloxacin, and sparfloxacin for 90% of C. jeikeium, C. urealyticum, and C. xerosis isolates tested were > 16 micrograms/ml. Those of BAY Y 3118 and clinafloxacin against these species were 0.5 and 1 to 2 micrograms/ml, respectively. The MICs for 90% of all 115 strains tested were 0.5 microgram/ml for BAY Y 3118, 1 microgram/ml for clinafloxacin, 2 micrograms/ml for E-5068, 4 micrograms/ml for E-5065, and > 16 micrograms/ml for ciprofloxacin, ofloxacin, sparfloxacin, and E-4868.     

In vitro study of the mechanical effects of shock-wave lithotripsy

Impulsive stress in repeated shock waves administered during extracorporeal shock-wave lithotripsy (ESWL) causes injury to kidney tissue. In a study of the mechanical input of ESWL, the effects of focused shock waves on thin planar polymeric membranes immersed in a variety of tissue-mimicking fluids have been examined. A direct mechanism of failure by shock compression and an indirect mechanism by bubble collapse have been observed. Thin membranes are easily damaged by bubble collapse. After propagating through cavitation-free acoustically heterogeneous media (liquids mixed with hollow glass spheres, and tissue) shock waves cause membranes to fail in fatigue by a shearing mechanism. As is characteristic of dynamic fatigue, the failure stress increases with strain rate, determined by the amplitude and rise time of the attenuated shock wave. Shocks with large amplitude and short rise time (i.e., in uniform media) cause no damage. Thus the inhomogeneity of tissue is likely to contribute to injury in ESWL. A definition of dose is proposed which yields a criterion for damage based on measurable shock wave properties.     

In vitro experimental study of adriamycin-loaded chitosan drug delivery system

Tumors of the epididymis are very rare. They are benign tumors in 75 per cent of the cases. Papillary cystadenoma represents 4-9 per cent of epididymal benign tumors. Often associated with the syndrome of von Hippel Lindau and infertility, histologically it can be confused with metastatic renal cell carcinoma. We report two cases of papillary cystadenoma located in the head of the right epididymis, with no concomitance with the syndrome of von Hippel Lindau, cured by the removal of the neoplastic nodule. There was no recidivation, in confirmation of the neoplastic benignity.     

In vitro dissolution and urinary excretion study of metoclopramide tablets

Changes in cardiac troponin I (cTnI) in Kawasaki disease before and after treatment with intravenous gamma-globulins (i.v.GG) were investigated in 42 cases in order to confirm the usefulness of cTnI as a serological test for the early onset of acute myocarditis and the effectiveness of i.v.GG as treatment for it. The level of cTnI before i.v.GG treatment was increased in 42.9% (18/42), but 89% (16/18) were in the normal range after treatment as shown by improved clinical symptoms and signs; 9.5% (4/42) were treated twice with i.v.GG because of recurrent high fever, with a positive level of cTnI in the second test. Despite the improved clinical symptoms and signs after retreatment with i.v.GG, 4.7% (2/42) continued to have an increased level of cTnI in follow-up studies. In conclusion, the measurement of cTnI is a useful serologic test for the early diagnosis of myocarditis or myocardial cell injury and for confirming the effectiveness of i.v.GG therapy for the cure and prevention of cardiovascular abnormalities in KD patients.     

Effect of low fluoride dentifrices on microhardness of sound enamel. In vitro study

The present study was undertaken to evaluate the effect of dentifrices containing low fluoride concentrations on microhardness of sound enamel in 50 healthy young premolar teeth. They were divided into five different groups according to the concentrations of fluoride in dentifrice used. The Vickers hardness of enamel was measured using a Zwick microhardness tester under 1000 g load and a Vickers indenter before and after the application of fluoride dentifrices. The results of the present study suggest that low fluoride concentration dentifrices are as effective as the higher concentrations in increasing the hardness of enamel.     

In vitro study on the integrity of a hydroxylapatite coating when challenged with staphylococci

An in vitro study was performed to evaluate the effect of Staphylococcus aureus and Staphylococcus epidermidis on the integrity of a hydroxylapatite coating. The coating plasma-sprayed on poly(L-lactide), showed dissolution during a 24 h incubation period. This was indicated by an increase in pH and calcium release in the buffer solution. After 4 h of incubation, calcium levels decreased due to the precipitation of calcium phosphate complexes on the coating. The bacteria digested or dissolved the coating, creating irregularly shaped holes. Although the integrity of the hydroxylapatite coating was focally damaged within 2-4 h of incubation with staphylococci, the extent of the damage was only marginal. Due to the formation of a layer of CaP precipitates though, bacteria could not be counted accurately after 4-8 h of incubation. This model could reveal part of the failure mechanism of infected hydroxylapatite coated implants.     

In vitro study of pesticide hematotoxicity in human and rat progenitors

Some pesticides are hematotoxic and cause aplastic anemia, agranulocytosis, neutropenia, and thrombopenia. In order to evaluate hematopoietic progenitor cultures in the exploration of pesticide hematotoxicity, human and rat colony-forming unit-granulocyte and macrophage (CFU-GM) were cultured in the presence of different concentrations of pesticides, known to be either hematotoxic or innocuous for blood cells. The results were compared to the control culture of the same sample. Four insecticides (lindane, azinphos, mevinphos, parathion methyl), three herbicides, (2,4,5, T, bromacil, MCPA), and two fungicides (fosethyl-aluminum, DNOC) were tested and exhibited the following data: 1) Pesticides, known to be hematotoxic, inhibited the development of progenitors. Different phenomena were observed and suggested different mechanisms: cell destruction, block in mitosis, decrease or delay in mitosis. 2) Difference in sensitivity to molecules between human and rat progenitors was observed. Human progenitors were more sensitive to pesticides, except for 2,4,5 T.     

In vitro crystallisation systems for the study of urinary stone formation

Hydroxyapatite orbital implants undergo early ingrowth of fibrovascular tissue after enucleation. This animal study determined whether control and osteogenin-impregnated hydroxyapatite orbital implants vary in their osteogenic response at 6 and 52 weeks. Rabbits underwent enucleation with implantation of control or osteogenin-impregnated hydroxyapatite spheres. Light microscopy determined fibrovascular ingrowth, and histomorphometry quantitated the amount of bone produced. Osteogenin implants vascularized at a faster rate and contained bony foci by 6 weeks that became confluent at 1 year. Spontaneous osteogenesis was not seen in control animals at 6 weeks. After 1 year they contained bone, although less than in the osteogenin implants. Mixed cell inflammation was observed at the hydroxyapatite-tissue interface in both groups. No inflammation was noted at the interface of hydroxyapatite and bone. These are the first controlled observations that bone-specific differentiation occurs in the pores of spherical hydroxyapatite implants within the soft tissues of the socket. This vascularized process can be enhanced with osteogenin to occur earlier and more uniformly in the implants at one year.     

In vitro determination of cytotoxic drug response in ovarian carcinoma using the fluorometric microculture cytotoxicity assay (FMCA)

The fluorometric microculture cytotoxicity assay (FMCA), a short-term in vitro assay based on the concept of total tumor cell kill, was used for testing the cytotoxic drug sensitivity of tumor cells from patients with ovarian carcinoma. A total of 125 fresh specimens was obtained, 98 (78%) of which were analyzed successfully. Data from 45 patients were available for clinical correlations. The FMCA appeared to yield clinically relevant cytotoxic drug sensitivity data for ovarian carcinoma as indicated by a comparison with tumor samples obtained from patients with non-Hodgkin's lymphoma or kidney carcinoma. Considering the most active single agent in vitro actually given in vivo, and using the median drug activity among all ovarian carcinoma samples as a cut-off, the sensitivity of the assay and its specificity were 75 and 52%, respectively. Cross-resistance in vitro was frequently observed between standard drugs but not between standard drugs and Taxol. Ten percent of the specimens showed an extreme resistance for at least 4 of 6 of the drugs investigated.