BACKGROUND: Crohn's colitis, frequently accompanied by stenosis or narrowing, can be difficult to assess through conventional methods. We evaluated the usefulness of virtual computed tomographic colonography (CTC) for the detection of colonic lesions due to Crohn's disease. METHODS: Forty-two lesions in 33 patients with Crohn's disease were examined by CTC and barium enema (BE). Twenty-two patients also were examined by colonoscopy (CS). The visualization ability of CTC was compared with those of the other two methods. RESULTS: In the visualization of elevated lesions, there was no significant difference between CTC and BE (18 of 20, p = 0.487) or between CTC and CS (15 of 16, p = 0.99); however, ulcerative lesions were less often visualized by CTC. However, CTC enabled identification of serious lesions in the colon proximal to the stenosis in nine patients and was superior to BE and CS in terms of its ability to visualize the proximal site of the stenosis (p = 0.003). CONCLUSION: CTC is clinically useful for the evaluation of Crohn's colitis, especially those with stenotic lesions.

Adult↗

PubMedDate not supplied

Mechanisms of depressant action of baclofen on the spinal reflex in the rat.

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Action Potentials↗

PubMedDate not supplied

Electron microscopic study on early decidualization of the endometrium of pregnant mice, with special reference to gap junctions.

Cytological changes in mouse decidual cells during the early stages from 4.5th to 11th day of pregnancy were examined by electron microscopy with special reference to gap junctions. The most noticeable feature of decidual cells was that there was an abundance of various-shaped gap junctions such as flat, undulated, omega-shaped, and annular-shaped gap junctions. Serial sectioning revealed that annular-shaped gap junctions were separated from the decidual cell plasma membrane. Intramembranous particles (IMPs) of the gap junctions as seen by freeze-fracture displayed a well-packed arrangement and a homogeneous size. Degenerative changes first appeared in decidual cells directly contiguous with trophoblasts on the 7th day, and spread to the deeper area as clearly seen on the 8th day. Along with degeneration of decidual cells, annular-shaped gap junctions were enfolded and gradually degraded by lysosomes. IMPs of such degenerative gap junctions were irregularly arranged and heterogenous in size. The decidual tissue became thin with elongated decidual cells as the placental disc grew on the 10th day. Extremely long undulated gap junctions were present in decidual cells, and a small number of annular-shaped gap junctions were also found in the cytoplasm. The presence of abundant gap junctions as demonstrated in the present study suggests that decidual cells will be able to develop as well as to function synchronously. In addition, it is suggested that redundant gap junctions become annular-shaped to be finally degraded by lysosomes.

Animals↗

PubMedDate not supplied

Comparisons between invasive and noninvasive determinations of embryonic heart rate in chickens.

The embryonic heart rate (HR) of chicken eggs was determined by ballistocardiography, electrocardiography, impedance-cardiography and acoustocardiography. The effects of these different methods on the HR were examined for young (12-day-old) and late (16- and 18-day-old) embryos. Ballistocardiography is a non-invasive method. Nevertheless, the mean HRs determined using this method at 5-hr intervals were significantly different in many embryos. This difference was caused by the natural variability of embryonic HR. The statistical analyses indicated that any of these four methods did not influence the HR measurement and can be used as a simple means for determination of the embryonic HR.

Acoustic Stimulation↗

PubMedDate not supplied

Serotonin 2A receptor gene polymorphism is not associated with completed suicide.

Several lines of evidence indicate that a serotonergic dysfunction is involved in the biological susceptibility to suicide. Recently, the A-1438G polymorphism of the serotonin 2A (5-HT2A) receptor gene has been suggested to be associated with suicide, but the results are inconsistent. We examined whether the A-1438G polymorphism of the 5-HT2A receptor gene was associated with suicide itself using 151 Japanese completed suicides. No significant difference in genotype distribution or allele frequencies of the polymorphism was found between the completed suicides and the comparison group. We conclude that the A-1438G polymorphism of the 5-HT2A receptor gene is not likely to have a major effect on the biological susceptibility of suicide.

Adult↗

PubMedDate not supplied

Effects of prenatal and postnatal exposure to styrene dimers and trimers on reproductive function in rats.

Styrene dimers and trimers (SDT) were evaluated for reproductive toxicity in Sprague-Dawley rats. SDT was administered orally to rats at doses of 0, 0.04, 0.2, and 1.0 mg/kg from day 6 of gestation through day 21 after delivery. Clinical signs, including pregnancy and lactation, and changes in body weight and food consumption were assessed. All dams underwent a gross necropsy examination. The brain, liver, kidney, ovary, uterus, thyroid gland, and pituitary were weighed. Offspring were evaluated for the effects of the test compound on viability, growth, anogenital distance, preputial separation and vaginal opening, behavioral function, estrous cycling, mating, and fertility. There were no test compound-related clinical signs or effects on body weight or food consumption in dams during any phase of the study. In addition, no abnormalities in delivery or lactation, including gestation length, were noted in any dam. No dose-dependent changes were observed in pup viability or growth. There were no adverse effects of SDT on any developmental landmark, learning, memory, or estrous cycling in offspring. The number of days to inseminations in the 0.2 mg/kg group was significantly greater than that in the control group, but was independent of dose. No test compound-related necropsy findings were seen in either the dams or the offspring. No compound-related histopathologic findings were noted in the reproductive tissues of either the male or female offspring. No compound-related alterations in sperm motion or density were detected in the offspring. Thyroid stimulating hormone levels in the male offspring of the 0.2 mg/kg and 1.0 mg/kg groups were significantly higher than those in the controls, whereas thyroid hormone (T(3), T(4)) levels in these groups were comparable to the controls. In addition, the thyroid glands of males in all groups were similar histologically. These results indicate that SDT administered at doses as high as 1.0 mg/kg (1000 times the estimated human daily intake) did not produce reproductive toxicity in dams or offspring.

Animals↗

PubMedDate not supplied

Effect of butyl benzyl phthalate in Sprague-Dawley rats after gavage administration: a two-generation reproductive study.

Butyl benzyl phthalate (BBP), a plasticizer, has been shown in in vitro studies to be weakly estrogenic, and in in vivo studies to possess testicular toxicity and teratogenicity, but few experimental data on BBP multigeneration effects on reproduction in mammals are available. The present two-generation reproductive study was conducted in male and female Sprague-Dawley rats using oral doses of 0, 20, 100, and 500 mg/kg/day BBP. Endpoints were chosen in order to evaluate both subchronic and reproductive toxicity. In the parent animals (F(0)), a decrease in body weight gain was observed in males in the 500 mg/kg/day group, although no significant decrease in food consumption was found. No dose-related changes were observed in estrous cyclicity, fertility, or lactation. A dose-dependent increase in kidney weight in rats of both sexes, an increase in liver weight in males, and a decrease in the weight of the ovaries in females were observed. No macroscopic or microscopic changes were found in the reproductive system of males or females. Oral administration of BBP caused a decrease in the serum concentration of testosterone, and an increase in FSH. In the next generation (F(1)), the body weight of male and female offspring at birth in the 100 and 500 mg/kg groups was significantly decreased, and the body weight in the 500 mg/kg group was lower throughout the study, while viability was not affected. Anogenital distance (AGD) at birth was decreased in male pups and was increased in female pups of the 500 mg/kg/day group. Preputial separation for male offspring in the 500 mg/kg/day group was delayed, while vaginal opening for female offspring in this group was not affected. BBP did not affect reproductive ability, including delivery and lactation, at any dose whereas macroscopic and microscopic changes of the testis, and decreased serum concentrations of testosterone were observed in male offspring of the 500 mg/kg/day group after puberty. From these data, it would appear that 20 mg/kg BBP is a no observed adverse effect level (NOAEL) for reproductive effects on parent animals and the next generation.

Administration, Oral↗

PubMedDate not supplied

Reproductive effects of nonylphenol in rats after gavage administration: a two-generation study.

The potential reproductive toxicity of nonylphenol (NP) was assessed in a two-generation reproductive toxicity study. Groups of 25 male and female Crj:CD (SD) IGS rats were given NP by gavage at levels of 2, 10, or 50 mg/kg, and 25 males and females were given corn oil as controls. No adverse changes in clinical signs were observed in any rats throughout the study. Significant increases in the liver, kidney and pituitary gland weights in males, and decreases in thymus weight in males and in ovary weight in females were observed in the 50 mg/kg group. NP did not affect sperm characteristics or the estrous cycle at any dose administered. A significant increase in the TSH level was observed in males in the 50 mg/kg group. No adverse effects of NP on reproduction were found. At necropsy, no treatment-related alterations were observed in any organs including the reproductive tissues in any group. Histopathologic changes were found in the liver of male and female rats and kidneys of males in the 50 mg/kg group. The viability of offspring from postnatal day 0 to 4 in the 50 mg/kg group was reduced as compared with that in the controls, although growth was not affected by NP administration. On postnatal day 22, an increase in the serum FSH level and decrease in T(3) level for males, and decreases in LH and TSH levels and an increase in T(3) levels for females were observed in the 50 mg/kg group. NP did not affect the timing of preputial separation, while vaginal opening was accelerated in the 50 mg/kg group. No adverse changes were found in behavior or learning in the offspring of NP-treated groups. There were no treatment-related changes in any reproductive parameter, including estrous cycle, mating, fertility, delivery, and lactation, except for significant decreases in the numbers of implantation sites and live pups, and a significant decrease in ovary weight in the 50 mg/kg group. Kidney and liver weight were increased in males in the 50 mg/kg group. Histopathologic examination revealed changes in the liver of males and females of the 50 mg/kg group. No treatment-related changes were observed in the sperm characteristics. Hormone data should be interpreted cautiously until the findings are repeated and confirmed by further studies. These results of NP suggested that the no observed adverse effect level (NOAEL) on reproductive capacity is 50 mg/kg/day or greater in parent animals, and 10 mg/kg/day in the next generation under the present experimental condition.

Administration, Oral↗

PubMedDate not supplied

Reproductive effects in male and female rats of neonatal exposure to genistein.

Sprague-Dawley rats were administered genistein orally at doses of 12.5, 25, 50, or 100 mg/kg on postnatal days 1 through 5 to examine its effects on reproductive function after puberty. In addition, preputial separation and vaginal opening as endpoints of sexual maturation, estrous cycling, sperm count, serum testosterone concentration, and histopathologic changes of reproductive organs of male and female rats were examined. Body weights of male and female rats exposed to genistein at any dose level examined were lower than those of controls. Timing of preputial separation in males and timing of vaginal opening were not affected by genistein treatment. The number of females showing estrous cycle irregularities was increased by genistein treatment. The fertility of female rats exposed neonatally to genistein at 100 mg/kg was disrupted, while neonatal exposure to genistein did not affect male fertility. Neither sperm counts nor serum testosterone concentration were changed by neonatal exposure to genistein. Female rats exposed neonatally to genistein at 100 mg/kg showed histopathologic changes in the ovaries and uterus, while male rats showed no histopathologic alterations in the gonads. The results of this study indicate that early neonatal exposure to genistein caused dysfunction of postpubertal reproductive performance as well as abnormal development of gonads in female but not in male rats.

Administration, Oral↗

PubMedDate not supplied

Reproductive effects in male and female rats from neonatal exposure to p-octylphenol.

A number of alkylphenolic compounds are used in a variety of commercial products and have been shown in in vitro studies to be weakly estrogenic, but in vivo data are not available addressing this issue in mammals. Human exposure to alkylphenols may occur not only from these environmental contaminants but also through contact with manufactured and metabolic breakdown products. In this study, Sprague-Dawley rats were exposed to octylphenol by oral gavage at doses of 0 (vehicle: corn oil), 12.5, 25, 50, or 100 mg/kg once daily on postnatal days 1 through 5 to examine its effects on male and female reproductive function after puberty. In addition, preputial separation and vaginal opening as endpoints of sexual maturation, estrous cycling, sperm count, serum testosterone concentration, and histopathologic changes of the reproductive organs of male and female rats were examined. Male reproductive organs were weighed at necropsy. Body weights of male and female rats exposed to octylphenol at 50 and 100 mg/kg throughout the study after the administration period, those of both sexes at 7 and 9 weeks of age in the 25 mg/kg group, and that of females at 9 weeks of age in the 12.5 mg/kg group were lower than those of controls. Significant delays in acquisition of puberty in males and females exposed to octylphenol at 50 and 100 mg/kg were observed. Estrous cycle, copulation and fertility, sperm count, and serum testosterone concentration were not affected by neonatal exposure to octylphenol. Significant decrease in absolute and relative prostate weight in the 12.5, 25, 50, and 100 mg/kg groups, and absolute epididymal weight in the 100 mg/kg group, increase in relative testes weight in the 100 mg/kg group, and relative seminal vesicle weights in the 50 and 100 mg/kg groups were found. Histopathologic analyses of reproductive organs in male and female rats exposed neonatally to octylphenol revealed no marked alterations. The results of this study indicate that early neonatal exposure to octylphenol by oral gavage did not cause dysfunction of reproductive performance (mating and fertility) in male or female rats, and no disruption of development of the reproductive tract was observed in male or female rats, while significant decreases in body weights in the 25 mg/kg and more groups, delays of sexual maturation in the 50 mg/kg and greater groups, and decrease in ventral prostate weights in all octylphenol-treated groups were found. Therefore, it is concluded that NOAEL (no-observed adverse effect level) for systemic toxicity was < or =12.5 mg/kg/day and that for reproductive toxicity was 100 mg/kg/day under the present experimental condition.

Administration, Oral↗

PubMedDate not supplied

Binding of a non-beta-lactam antibiotic to penicillin-binding proteins.

In the search for new beta-lactam antibiotics of natural origin, the discoveries of cephamycins and sulfazecins (monobactams) were important turning points in that they accelerated many screening efforts aimed at other new compounds. In our target-directed screening for beta-lactam antibiotics using beta-lactam hypersensitive mutants, we have examined Gram-negative bacteria isolated from natural habitats and have recently reported several types of beta-lactam antibiotics such as cephabacins and formadicins. Here we report a novel antibiotic, lactivicin, found using this system. Although lactivicin has various biological activities commonly observed in beta-lactam antibiotics, it does not possess a beta-lactam ring in its molecule, but has the unique structure of a dicyclic dipeptide.

Anti-Bacterial Agents↗