Comprehensive assessment of the photomutagenicity, photogenotoxicity and photo(cyto)toxicity of azulene.

The polycyclic aromatic hydrocarbon azulene and its naturally occurring derivative guaiazulene (1,4-dimethyl-7-isopropylazulene) are known to absorb light in the UV-vis region of the spectrum. Both compounds were reported to be mutagenic in the Salmonella typhimurium bacterial mutagenicity assay (Ames test) in strain TA102, and to cause DNA damage in the comet assay in vitro upon exposure to UVA light. In contrast, another study reported a photoprotective effect in vitro of guaiazulene. We present here a comprehensive assessment of the photo(cyto)toxicity (3T3 fibroblast Neutral Red uptake test), the photomutagenicity (Ames test) and photogenotoxicity (comet assay and micronucleus test in L5178Y cells in vitro) of azulene. In the Ames test, the mutagenicity of azulene was assessed in the presence and absence of UV light by use of the Salmonella strains TA102, TA104, TA2638 and E. coli WP2. Azulene was irradiated before being plated with bacteria (pre-irradiation), or concomitantly with the bacteria either after plating or while in suspension. Guaiazulene was included in some of the experiments. Neither in the photo-Ames test nor in the other photogenotoxicity tests, azulene or guaiazulene showed any photomutagenic or photogenotoxic activity. Weak photo(cyto)toxicity (estimate of PIF≥1.67) was observed with azulene in the 3T3 NRU test, the Alamar Blue test and the relative cell count, which may be due to the generation of reactive oxygen species, as reported recently.

[Radiological and clinical functional examinations 36 months after anterior cruciate ligament repair by a patellar tendon graft]. / Radiologische und klinisch funktionelle Untersuchung 36 Monate nach vorderer Kreuzbandplastik mittels Patellarsehnentransplantat.

AIM: The aim of this study was to examine radiological and functional outcome measurements after anterior cruciate ligament (ACL) reconstruction with a bone-tendon-bone (BTB) graft. Investigations included assessment of bony integration conditions regarding the use of bioabsorbable cross pins or a lateral screw for femoral graft fixation. A description of radiological parameters in contrast with IKDC findings is also given. METHOD: After ACL injuries, 45 patients underwent an ACL repair. For tibial tunnel placement the tibial guide was used in full knee extension. A size-specific femoral aimer was placed by using the transtibial technique in the "over the top" position and the tunnel was reamed with the acorn reamer to 30 mm depth. In 15 patients the BTB graft was fixed with a titanium blunt nose screw from the lateral aspect. The cross-pin technique with bioabsorbable RIGIDFIX implants was used in 30 patients. All patients underwent a follow-up study 36 month postoperatively. Geometric tests of digitised X-rays were performed. For clinical and functional outcome studies of ACL repairs the IKDC score is widely accepted. The score was modified into numeric parameters for 15 selected groups of the IKDC score. All 15 categories were rated from 1 to 4 points (Category A = 4, B = 3, C = 2, D = 1). Clinical and radiological results were statistically analysed. RESULTS: According to the literature, tunnel placement tibial was physiological in 91% and femoral in 93% of the cases. The femoral tunnel was completely invisible in all patients. No necrosis or pathological findings in former pin holes were seen. In 24 patients the medial compartment space was smaller, but less than 50 % compared to intraoperative X-rays. Even if the mean of tibial tunnel widening was 2.65 mm it was statistically not connected to the results of the IKDC score or X-ray findings of the femoral tunnel. Results in the IKDC groups and categories were seen to be in accord with overall very good and good outcomes. The modified IKDC score showed a mean of 55 points with a range from 46 as lowest (1 patient) and 60 in 4 patients (9%) as highest numeric score. CONCLUSION: Lateral femoral fixation with screws or bioabsorbable cross-pins shows a biological bony incorporation of a BTB graft. Tibial tunnel widening was seen but without any functional effects. Overall radiological and functional outcomes based on the IKDC score demonstrate results in favour of ACL reconstruction with BTB grafts. Due to the narrowing of the medial compartment space, more radiological outcome studies with a special emphasis on degenerative aspects have to be done.

Role of protein synthesis in the development of a transcriptionally permissive state in one-cell stage mouse embryos.

The time of onset of gene transcription in the mouse embryo is temporally regulated. A prominent feature of this regulation is a change during the one-cell stage from a transcriptionally nonpermissive state to a transcriptionally permissive state. During the early one-cell stage, the cytoplasm is either inadequate or suppressive for nuclear gene transcription, but by the late one-cell stage, the cytoplasm acquires the ability to support gene transcription either in endogenous nuclei or exogenous nuclei introduced microsurgically. We have investigated the role of protein synthesis in this cytoplasmic transition. Nuclei from two-cell stage embryos treated with alpha-amanitin were used to evaluate the transcriptional permissiveness of late one-cell stage cytoplasm, as indicated by the production of transcripts from four genes that are specifically transcribed at elevated rates during the two-cell stage. Two of these genes were transcribed following nuclear transfer to late one-cell stage cytoplasm, and two were not transcribed. Treatment of the recipient cytoplasm with cycloheximide to inhibit protein synthesis from the early to the late one-cell stage inhibited the transcription of the two genes that were transcribed in the untreated, late one-cell stage recipients. These results indicate that acquisition of the transcriptionally permissive state during the one-cell stage is facilitated by protein synthesis, and that the transcriptional permissiveness in the late one-cell stage cytoplasm is limited to certain genes.

Severe defects in the formation of epaxial musculature in open brain (opb) mutant mouse embryos.

The differentiation of somite derivatives is dependent on signals from neighboring axial structures. While ventral signals have been described extensively, little is known about dorsal influences, especially those from the dorsal half of the neural tube. Here, we describe severe phenotypic alterations in dorsal somite derivatives of homozygous open brain (opb) mutant mouse embryos which suggest crucial interactions between dorsal neural tube and dorsal somite regions. At Theiler stage 17 (day 10.5 post coitum) of development, strongly altered expression patterns of Pax3 and Myf5 were observed in dorsal somite regions indicating that the dorsal myotome and dermomyotome were not differentiating properly. These abnormalities were later followed by the absence of epaxial (dorsal) musculature; whereas, body wall and limb musculature formed normally. Analysis of Mox1 and Pax1 expression in opb embryos revealed additional defects in the differentiation of the dorsal sclerotome. The observed abnormalities coincided with defects in differentiation of dorsal neural tube regions. The implications of our findings for interactions between dorsal neural tube, surface ectoderm and dorsomedial somite regions in specifying epaxial musculature are discussed.

Open brain, a new mouse mutant with severe neural tube defects, shows altered gene expression patterns in the developing spinal cord.

We describe a new mouse mutation, designated open brain (opb), which results in severe defects in the developing neural tube. Homozygous opb embryos exhibited an exencephalic malformation involving the forebrain, midbrain and hindbrain regions. The primary defect of the exencephaly could be traced back to a failure to initiate neural tube closure at the midbrain-forebrain boundary. Severe malformations in the spinal cord and dorsal root ganglia were observed in the thoracic region. The spinal cord of opb mutant embryos exhibited an abnormal circular to oval shape and showed defects in both ventral and dorsal regions. In severely affected spinal cord regions, a dorsalmost region of cells negative for Wnt-3a, Msx-2, Pax-3 and Pax-6 gene expression was detected and dorsal expression of Pax-6 was increased. In ventral regions, the area of Shh and HNF-3 beta expression was enlarged and the future motor neuron horns appeared to be reduced in size. These observations indicate that opb embryos exhibit defects in the specification of cells along the dorsoventral axis of the developing spinal cord. Although small dorsal root ganglia were formed in opb mutants, their metameric organization was lost. In addition, defects in eye development and malformations in the axial skeleton and developing limbs were observed. The implications of these findings are discussed in the context of dorsoventral patterning of the developing neural tube and compared with known mouse mutants exhibiting similar defects.

Effect of dronabinol on nutritional status in HIV infection.

OBJECTIVE: To examine the effect of dronabinol (delta-9-tetrahydrocannabinol) on appetite and nutritional status in patients with symptomatic HIV infection and weight loss. DESIGN: Double-blind, randomized, placebo-controlled, crossover trial with two five-week treatment periods separated by a two-week washout period. Patients received dronabinol 5 mg twice daily before meals or placebo. SETTING: A university-based HIV/AIDS clinic and a large infectious disease private practice largely devoted to care of patients with HIV. PARTICIPANTS: Twelve HIV-infected patients who had had at least a 2.25-kg weight loss participated in the study. Five patients completed the protocol, and seven withdrew (two because of drug intolerance, two because of disease progression, two because of noncompliance, and one because of experimental antiretroviral therapy). MAIN OUTCOME MEASURES: Main outcome measures included caloric intake, weight, percent body fat, serum prealbumin, and symptom distress. RESULTS: During dronabinol treatment, subjects experienced increased percent body fat (one percent, p = 0.04); decreased symptom distress (p = 0.04); and trends toward weight gain (0.5 kg, p = 0.13), increased prealbumin (29.0 mg/L, p = 0.11), and improved appetite score (p = 0.14). CONCLUSIONS: In a selected group of HIV-infected patients with weight loss, short-term treatment with dronabinol may result in improvement in nutritional status and symptom distress.

'Synaptic' bodies in the pineal glands of the cow, sheep and pig.

The present results show that 'synaptic' bodies (SB) are a heterogeneous group of organelles in the pineal glands of Artiodactyla. Basically, rod-like (ribbons) and sphere-like (spherules) SB can be distinguished. In the pig small numbers of both 'synaptic' ribbons (SR) and 'synaptic' spherules (SS) are found. In bovine and ovine pineal glands few SS but no SR were seen. The same results were obtained from animals of the same species but from different continents. This suggests that the numbers of SB are species specific rather than influenced by the different lighting conditions in Europe and in equatorial Africa.