Comparative studies by cell culture and in vivo implantation test on the toxicity of natural rubber latex materials

Colony assay using V79 cells, the agar diffusion assay with L929 cells, and the 7-day rabbit muscle implantation test were employed to evaluate the cytotoxicity and tissue toxicity of natural rubber latex (NRL) materials. The in vivo implantation test showed that, among 13 histological parameters, thickness of inflammatory layer was the most useful index to evaluate tissue responses quantitatively. A comparison of the in vivo and in vitro parameters revealed the following correlations between the thickness of the inflammatory layer and cytotoxicity indices: Colony assay of the extracts, IC50: r = 0.80; Agar diffusion assay, Zone index: r = 0.73; Lysis index: r = 0.61. From these results, it appears that the colony assay provides a more reliable prediction of the tissue response than the agar diffusion assay.

A synthetic study of methyl 3-deoxy-3-fluoro-alpha-D-glucopyranosides from methyl 2,3-anhydro-alpha-D-allopyranosides, and synthesis of 3'-deoxy-3'-fluorokanamycin A and 3'-chloro-3'-deoxykanamycin A

Reactions of 4,6-disubstituted 2,3-anhydro-alpha-D-allopyranosides with potassium hydrogenfluoride (KHF2) in ethane-1,2-diol gave, by oxirane-ring opening, the corresponding 2-deoxy-2-fluoro-alpha-D-altro- and 3-deoxy-3-fluoro-alpha-D-gluco-pyranosyl derivatives, with the latter always in preponderance. The influence of the substituents at C-4 and C-6 on the D-gluco-D-altro ratio (r) have been studied by molecular mechanics, and the discrepancy between the experimental and calculated r values has been positively utilized to measure the effects of solvation and hydrogen bonding relative to the C-4 and C-6 substituents. By application of this reaction, 3'-deoxy-3'-fluorokanamycin A has been prepared by treatment of a 2',3'-anhydro-3'-epikanamycin A derivative (35) with KHF2. 3'-Chloro-3'-deoxykanamycin A was also prepared.

Teratogenicity of arotinoids (retinoids) in the rat whole embryo culture

Structural modifications of the arotinoid molecule RO 13-7410 led to a difference in the teratogenic potencies of more than five orders of magnitude in mice in vivo and in micromass cultures of rat embryonic limb bud cells (Kistler et al. 1990). Five of these retinoids were selected and tested in rat whole embryo culture to determine the suitability of this in vitro test system for the identification of potentially non-teratogenic derivatives among this class of chemicals. The highest concentrations of the compounds with no effects (NOAEL) on general conceptus growth, on differentiation and on the frequency of dysmorphogenic embryos in vitro were compared with the lowest effective teratogenic doses in vivo (LOAEL) or with the concentrations leading to 50% inhibition of limb bud cell differentiation (IC50) in vitro. NOAEL's for the parameters of conceptus development ranged from 10(-5) micrograms/ml (0.03 nM) to 10 micrograms/ml (28.7 microM) for the compounds tested. These correlated very well with LOAEL and IC50 (R greater than 0.95). The types of dysmorphogenesis in vitro were those typical for retinoids, and for the most part resembled the malformations found in vivo. We conclude that the whole embryo culture system is a useful tool for the preliminary testing of retinoids.

Production and cytological studies of nine-paired barley (Hordeum vulgare)

Several barley plants with 2n = 18 chromosomes (9 II) were developed from crosses between two lines with 2n = 16 chromosomes (8 II). Cytological studies of the 18-chromosome plants showed nine bivalents at metaphase I and normal 9:9 segregation at anaphase I. Morphologically, these plants with 18 chromosomes were qualitatively similar to normal diploids (2n = 14), in spite of a duplication of a small proximal segment of the short arm of chromosome 3. However, the 18-chromosome plants were as vigorous as some normal diploid cultivars and more vigorous than 16-chromosome parental lines. If the duplicated segment carried beneficial gene(s), it might be useful for enhancement of germplasm in barley genetics and breeding. The significance of the establishment of this new 18-chromosome barley in karyotype evolution is discussed.Key words: nine-paired barley, aneuploid, trisomic, duplication, Hordeum.

[Clinicobacteriological study of Pasteurella multocida as a zoonosis (1). Condition of dog and cat carriers of Pasteurella, and the influence for human carrier rate by kiss with the pets]

Pasteurella multocida is a gram-negative short rod-shaped bacteria, which is a part of the indigenous flora of the oral cavity of many animals other than man. The number of reports on cases of infections with this bacterium due to animal bites and/or scratches, bacterial infections of the respiratory tract, sepsis due to this organism and death caused by the bacteria have been increasing in recent years. We investigated P. multocida in the hair and oral cavity of 3 dogs and 29 cats according to the classification of Mutters et al.. We also studied the relationship between the carrier rate for Pasteurella in the oral cavity and kissing of pets in 24 pet owners (3 dogs and 11 cats). No P. multocida was isolated from the hair of neither dogs nor cats. One strain of P. multocida subsp. multocida and two strains of P. stomatis, were isolated from the oral cavity of dogs, and 35 strains of Pasteurella were isolated from the oral cavity of cats. Two strains of P. multocida subsp. multocida, whose biochemical properties were different, were detected in the oral cavity of one cat. In three cats, Pasteurella other than P. multocida subsp. multocida was isolated from the same oral cavity. No Pasteurella was detected in the oral cavity of 19 pet owners who had not kissed their cats, whereas P. stomatis was isolated from the oral cavity of one of 2 pet owners who had kissed their cats and in 2 of 3 pet owners who had kissed their dogs (the same bacteria was isolated from a dog that was being kept by some of these positive pet owners).(ABSTRACT TRUNCATED AT 250 WORDS)

[The first report of human chronic sinusitis by Pasteurella multocida subsp. multocida in Japan]

A 53-year-old male visited our hospital due to nasal obstruction persisting for 6 months and constant rhinorrhea. Pasteurella multocida subsp. multocida was isolated from his nasal discharge and lavage fluid of the maxillary sinus, and also from the oral cavity of the dog he kept. The bacterial strains isolated from the patient and dog were identical in terms of biochemical properties, and drug sensitivity. Although serotype was different, the strain from the patient showed (A:6) and that from his dog showed (A:5). The microorganism is not present in the general environment. The patient had contact with his dog such as he kissed it frequently, gave it food with his chopsticks et al.. From the mouth of the people who kiss one's dog, we detected Pasteurella of the same character of bacteria as from the mouth of the dog. We detected two Pasteurella multocida of different character from only one mouth of a cat. Pasteurella multocida was checked in only one colony for sero type. Sero type A is the popular type for dogs and cats. The above suggest that their was a high possibility that the Pasteurella multocida subsp. multocida found in the patient was from his dog. In Japan, the incidence of Pasteurella multocida subsp. multocida infection has been increasing. In 1969, the Japanese Ministry of Health and Welfare officially communicated this infection as a zoonosis to related institutions. At both medical and surgical departments, wither the patient keeps a pet should be confirmed during interview, and guidance of pet keeping methods is important in some cases from the aspect of clinical bacteriology.(ABSTRACT TRUNCATED AT 250 WORDS)

Membrane topology of the melibiose carrier of Escherichia coli

The minimum structural information necessary to formulate and assess mechanistic models of integral membrane protein function is that of membrane topology. This paper characterizes the topological structure of the melibiose carrier of Escherichia coli based on constraints provided by genetic fusions to the compartment-specific reporter protein alkaline phosphatase. Twenty-eight unique chimeras exhibiting either low alkaline phosphatase activity (cytoplasmic location of the fusion joint) or high alkaline phosphatase activity (periplasmic location of the fusion joint) were characterized and used in conjunction with Goldman-Engelman-Steitz hydropathy analysis to model topological structure. The melibiose carrier is predicted to have a cytoplasmic amino terminus, two sets of six transmembrane domains separated by an unusually large cytoplasmic loop ("six-loop-six" arrangement), and a 45-residue cytoplasmic carboxyl tail. Remarkably, the identical six-loop-six arrangement is predicted from the hydrophobicity plots of the H(+)-coupled lactose, arabinose, xylose, and citrate cotransporters of E. coli, the glucose transporter from rat brain, the family of glucose transporters isolated from various human tissues and cell lines, and the human, mouse, and hamster multidrug resistance transporters (Henderson, P.J.F. (1990) Res. Microbiol. 141, 316-328; Maloney, P.C. (1990) Res. Microbiol. 141, 374-383). Such a broad degree of conservation (or convergence) suggests a distinct structural and/or mechanistic advantage associated with the six-loop-six motif. The nature of this advantage is as yet unknown.

In vitro reconstitution of an erythropoietin gene transcription system using its 5'-flanking sequence and a nuclear extract from anemic kidney

We have developed an in vitro transcription system for the erythropoietin (Epo) gene. This system uses a plasmid carrying 0.2 kb of 5'-flanking sequence from the human Epo gene, rNTPs and a nuclear extract from mouse kidney. The transcribed RNA was assayed by primer extension with an end-labeled primer complementary to the sequence of the plasmid, dNTPs and reverse transcriptase. The primer extension product corresponding to the transcript was detected on a sequencing gel. The in vitro promoter activity of the Epo 5'-flanking sequence was observed with a nuclear extract from anemic kidney but not with that from normal kidney.

Somatic afferent regulation of plasma luteinizing hormone and testosterone in anesthetized rats

The effects of cutaneous stimulation on plasma luteinizing hormone (LH) and testosterone were examined in adult male Wistar rats anesthetized with pentobarbital. Under the resting condition without somatic sensory stimulation, plasma LH and testosterone measured every 30 min between 1400 and 1730 h revealed no significant fluctuations. Nociceptive mechanical stimulation of bilateral hindpaws by pinching for 10 min significantly increased plasma LH and testosterone. Plasma LH was increased 30 and 60 min after stimulation, while plasma testosterone was increased 60-150 min after stimulation. However, innocuous mechanical stimulation of bilateral hindlimbs by brushing for 10 min did not significantly change either plasma LH or testosterone. These results indicate that, when emotional factors were eliminated by anesthetization, cutaneous nociceptive information led to the increased secretion of LH from the anterior pituitary, resulting in an increase in testosterone secretion from the testes into the plasma.

Effects of olfactory stimulation with jasmin and its component chemicals on the duration of pentobarbital-induced sleep in mice

The effect of olfactory stimulation with jasmin and its component chemicals on pentobarbital sleep time was investigated using mice. In the present study we sought to determine which component of jasmin influences pentobarbital sleep time via olfactory stimulation. Sleep time was defined as the time elapsed between intraperitoneal pentobarbital administration and the first time that the animal was able to spontaneously right itself. Sleep time was significantly decreased by olfactory stimulation with jasmin, and also by one of the fractions obtained by fractional distillation at 150 degrees C and 0.1 mmHg. The fraction which influenced the sleep time was found to consist of benzyl benzoate, isophytol, geranyl linalool, phytol and phytyl acetate, which were identified using gas chromatography with mass and infrared spectrometry. In experiments using authentic samples of these components, phytol significantly shortened the pentobarbital sleep time, while the others had no effect. We conclude that phytol is the component of jasmin which reduces the duration of pentobarbital-induced sleep.

Somatic afferent stimulation-plasma corticosterone, luteinizing hormone (LH), and testosterone responses in aged male rats under anesthetization

Our previous studies have demonstrated that somatic sensory stimulation can produce increases in secretions of corticosterone, luteinizing hormone (LH), and testosterone in young male Wistar rats of 13-22 weeks old even after emotional factors are eliminated by pentobarbital-anesthetizing of the subjects. In the present study, we examined the effects of somatic sensory stimulation on plasma corticosterone, LH, and testosterone using aged male Wistar rats (24-27 months old) under the same anesthetizing condition as employed in our previous studies. We compared the reflex responses in aged rats with those previously measured in young rats. Nociceptive mechanical stimulation of both hindpaws by pinching for 10 min significantly increased plasma corticosterone levels in aged rats. The magnitude and time-course of this response were equivalent to those in young rats. On the other hand, neither plasma LH nor testosterone levels were changed by nociceptive mechanical stimulation of the hindpaws of aged rats. This is in sharp contrast to the increase in both plasma LH and testosterone caused by the stimulation of young rats. These results indicate a functional dissociation induced by aging between the secretory responses of the anterior pituitary, testes on the one hand and the adrenal cortex on the other hand, to nociceptive somatic sensory stimulation. Aging does not alter corticosterone release from the adrenal cortex to nociceptive somatic sensory stimulation; however, LH secretion from the anterior pituitary and testosterone secretion from the testes to nociceptive somatic sensory stimulation are subject to dysfunction with aging.

Sequential change of hemodynamic reserve in patients with major cerebral artery occlusion or severe stenosis

To identify regional vasodilatory capacity and its sequential change, we evaluated prospectively a total of 78 acetazolamide tests in 51 patients with occlusion or greater than 75% stenosis of the carotid or middle cerebral arteries. The relative distribution of cerebral blood flow was determined by single photon emission computed tomography using N-isopropyl-p-[123I]-iodoamphetamine before and after intravenous injection of acetazolamide. Reduced vasodilatory capacity was demonstrated in 20 patients (38%), including 5 patients with hemodynamic transient ischemic attacks or infarction. Follow-up acetazolamide tests revealed asymptomatic progression of the arterial lesion (from stenosis to occlusion) in 1 patient and almost complete improvement of vasodilatory capacity in 5 patients, including 3 without surgical intervention. During an average follow-up period of 18.5 months, 4 patients died from cardiac causes or neoplasm; no neurovascular events occurred. Much larger numbers of patients with longer observation periods will be necessary to clarify the contribution of chronic hemodynamic failure to subsequent stroke. However, the present data indicate that the acetazolamide test is useful for assessing the course of high grade stenosis or occlusion of major cerebral arteries.

Autolytic transition of mu-calpain upon activation as resolved by antibodies distinguishing between the pre- and post-autolysis forms

A novel method to observe the autolytic activation of a mammalian cytoplasmic calcium protease, mu-calpain, was developed using a set of antipeptidic antibodies capable of distinguishing between the pre- and post-autolysis forms of the enzyme. Antibodies raised against synthetic peptides designed to match the N-terminal sequences of the pre- and post-autolysis forms of the mu-calpain large subunit reacted specifically with the corresponding form of calpain and not with the other. The antibodies were specific and sensitive enough to detect the antigens in crude cell lysates. The relevance of the immunochemical detection of calpain activation was confirmed by the observation that proteolysis of a substrate protein by purified mu-calpain paralleled autolysis at various pCa as probed by these antibodies and that autolysis preceded substrate proteolysis. We also observed calcium-dependent autolysis of calpain accompanying subsequent proteolysis of substrate in intact cells using the antibodies. The method will provide a novel approach to assess the physiological targets of the enzyme by determining the local intracellular sites of calpain activation.

Evaluation of biocompatibility, based on quantitative determination of the vascular response induced by material implantation

The biocompatibility of nine different materials, including positive and negative references, 4 polyurethane based and 3 latex based materials was investigated by (1) cytotoxic assay using V79 chinese hamster cells, (2) the thickness of inflammatory layer at 3 and 7 days after intramuscular implantation test, and (3) the course of the blood flow in tissue reaction around subcutaneously implanted materials using Laser Doppler Flowmetry (LDF) over 14 days following implantation. In addition, for some materials, different modes of sterilization were compared. Although the three methods explore different reactive systems, the material ranking obtained was highly similar for the three methods, suggesting a relative accuracy between them. For one latex however, an absence of cytotoxic effect in culture and a highly intense response by LDF investigation of the same order of magnitude as for the positive reference implant suggest that bioincompatibility may result from the material itself and cannot be exclusively investigated by the leaching of toxic components.

Effects of pulsing electromagnetic fields on cultured cartilage cells

In order to evaluate the effects of pulsing electromagnetic fields (PEMFs) on cell proliferation and glycosaminoglycan (GAG) synthesis and to study the action site of PEMF stimulation in the cells, we performed a series of experiments on rabbit costal growth cartilage cells and human articular cartilage cells in culture. A PEMF stimulator was made using a Helmholz coil. Repetitive pulse burst electric currents with a burst width of 76 ms, a pulse width of 230 microseconds and 6.4 Hz were passed through this coil. The magnetic field strength reached 0.4 mT (tesla) on the average. The syntheses of DNA and GAG were measured by 3H-thymidine and 35S-sulfuric acid incorporations. The effects on the cells treated with lidocaine, adriamycin and irradiation were also measured using a colony forming assay. The PEMF stimulation for the duration of 5 days promoted both cell proliferation and GAG synthesis in growth cartilage cells and intermittent stimulation on and off alternatively every 12 h increased them most significantly, while, in articular cartilage cells, the stimulation promoted cell proliferation, but did not enhance GAG synthesis. PEMF stimulation promoted cells treated with lidocaine more significantly than with other agents. These results present evidence that intermittent PEMF stimulation is more effective on both cell proliferation and GAG synthesis of cartilage cells than continuous stimulation, and that the stimulation could exert effects not by nucleus directly, but by the cellular membrane-dependent mechanism. This study provides further basic data to encourage the clinical application of PEMF stimulation on bone and cartilage disorders.

[Post-operative respiratory management of patients with ventricular septal defect with pulmonary hypertension (VSD+PH)]

Post-operative respiratory management was evaluated in patients with VSD+PH. Comparison was made between Group I (6 patients under 6 months) and Group II (10 patients 6 months or above). Oxygenation after surgical operation in Gp I was poor and the patients needed longer period of mechanical ventilation (MV), while Gp II patients required shorter duration of MV. In Gp I, the duration of MV after the cardiac surgery correlated with the length of cardiopulmonary bypass. In conclusion, cardiopulmonary bypass may influence the post-operative pulmonary function and patients who require longer period of MV are younger infants or newborns whose pulmonary function is immature and PH is severe.

[Clinical observation of hemodynamic changes during anaphylactic reaction]

Four cases of anaphylactic shock are reported. In two patients who underwent A-C bypass operation, we evaluated hemodynamic changes systemically when the anaphylactic reaction occurred. At that time it was observed that arterial pressure, central venus pressure, left atrial pressure and systemic vascular resistance decreased and that cardiac index increased. In other two patients it was not possible to evaluate hemodynamic changes during reaction. But one of these two patients developed coronary spasm accompanied with anaphylactic shock and the other patient who had depressed cardiac function and had developed cardiogenic shock, died of cardiac failure after 47 days. It is suggested that hemodynamic changes in anaphylactic reaction varies depending on different general conditions of the patient.

Eosinophilia caused by administration of L-tryptophan to animals with adrenal dysfunction

We have investigated an animal model of eosinophilia-myalgia syndrome (EMS), a disease that occurred in various parts of the United States in 1989, with a view to determining its cause. We speculated that adrenal dysfunction might have potentially contributed to the occurrence of EMS and studied the effects of adrenal dysfunction on the eosinophil count in peripheral blood by using rats and mice whose adrenals had been excised or that had been metyrapone-treated, and giving them L-tryptophan. As a result, a significant increase in the eosinophil count was observed in both animal species. The results suggest that EMS may have been caused, not by L-tryptophan alone, but by the combined effects of adrenal dysfunction and L-tryptophan ingestion.