Interactions between growing thalamocortical afferent axons and the neocortical primordium in normal and reeler mutant mice

The interactions between growing thalamocortical afferent axons and the neocortical primordium were examined during neocortical development of the mouse cerebrum, by labeling the afferents with the carbocyanine fluorescent dye, DiI, which was introduced into the dorsal thalamus of the fixed brains of control and reeler mutant mice. In the neocortical primordium of the control mouse, the labeled afferents running tangentially in the intermediate zone formed a dense plexus in the subplate, the layer below the cortical plate, as early as the 16th gestational day (E16). Small numbers of the afferents invaded the lower cortical plate at E16 and increasing numbers of labeled growing axons extended into the cortical plate at E17. At the 4th postnatal day (P4), labeled afferents grew radially up to the upper cortical plate and terminal arborizations of the afferents were evident in the forming layer IV. In contrast, in the E16 cerebrum of the reeler mutant mouse, in which the cortical layers are inverted, the labeled afferents traversed the neocortical primordium directly towards the superplate, the superficial layer above the cortical plate and the equivalent of the subplate in the control mouse. Thick bundles of labeled axons reached the superplate and made contact with the superplate neurons. At P4 in the reeler neocortex, the afferent axons that had reached the superplate began to change their direction of growth and turned towards the deeper layer. Electron-microscopic observations at E16 revealed that immature synapses were formed on the somata of the subplate neurons in the control mouse, and similar immature synapses were also formed on the superplate neurons of the reeler mutant. At E16 in the control, NGF receptor immunoreactivity was expressed in the intermediate zone, subplate and lower cortical plate, and the mode of expression corresponded to the distribution of thalamocortical afferents. At the same stage of the reeler mutant, expression of NGF receptor immunoreactivity was confined to the afferent axons that had grown through the neocortical primordium towards the superplate. In the control at E17, highly polysialylated NCAM (NCAM-H), a homophilic cell adhesion molecule, was expressed in the subplate, marginal zone and afferent axons. In the reeler mutant at the same stage, this adhesion molecule was expressed in both the superplate and the bundles of the afferent axons. These findings suggest that the subplate and the superplate, which are composed of neurons generated at the earliest stage, attract growing thalamocortical afferent axons specifically by a chemotropic mechanism through the expression of NGF receptor.(ABSTRACT TRUNCATED AT 400 WORDS)

The development of noradrenaline-, acetylcholinesterase-, neuropeptide Y- and vasoactive intestinal polypeptide-containing nerves in human cerebral arteries

The development of cerebrovascular nerves containing noradrenaline (NA), acetylcholinesterase (AChE), neuropeptide Y (NPY) and vasoactive intestinal polypeptide (VIP) in the basilar artery was histochemically or immunohistochemically studied in human fetuses of various gestational ages. At the 12th week of gestation, nerve fibers containing NA and AChE appeared. Both types of nerve fibers consisted exclusively of the longitudinal nerve fibers (LNF) running along the basilar arteries. Subsequently, the circular nerve fibers (CNF) gradually increased and such development was then completed by the 20th week of gestation. NPY- and VIP-containing nerve fibers were detected in human fetal cerebral arteries in the 16th week of gestation, in the form of LNF. Subsequently, CNF gradually increased and development was completed by the 24th week of gestation. These results indicate that neuropeptide-containing nerve fibers, together with NA- and AChE-containing nerves, therefore contribute to the control of cerebral circulation in the later stages of embryogenesis in human cerebral arteries.

[Studies on the modified dimethylmethylene-blue (DMB) method for determining glycosaminoglycans (GAG) in urine]

The measurement of glycosaminoglycans (GAG) in urine is very important because GAG is an essential constituent of urinary diseases. Since previously reported methods of determination of GAG are quite complicated, dangerous or not stable, we developed a very simple and rapid method to estimate the content of GAG in urine using a microplate and microplate reader. An aliquot of diluted urine is mixed with a 1,9, dimethylmethylene blue (DMB) dye. The assay is based on the metachromatic shift in absorption maximum which occurs when sulfated glycosaminoglycans are added to the dye. The recovery of GAG is good. Other urinary compounds such as sugar, protein and blood did not influence the measurement of GAG. A good correlation was obtained between the modified DMB method and Blumenkrantz and Asboe-Hansen's method (r = 0.737, p < 0.001). The accuracy of this method makes it useful for screening urinary diseases.

Transdifferentiation of pigmented multipotent epithelium during morphallactic development of budding tunicates

In the budding tunicate, Polyandrocarpa misakiensis, the atrial epithelium is the major formative tissue giving rise to the pharynx, digestive tract, brain and endostyle of a bud. We show here that this multipotent epithelium carries several differentiation markers that are lost in the process of bud development. In both adult animals and growing buds, the atrial epithelium contained orange-pigmented granules in the cytoplasm. In developing buds, on the other hand, the cells committed to organ primordia have lost the granules, taken a cuboidal shape and have a large nucleus with a prominent nucleolus, like undifferentiated cells. The atrial epithelium was also characterized by ALP expressed on the apical surface of the cell. During budding the enzyme activity disappeared from the atrial epithelium and reappeared in the primordial digestive tract. Immunohistochemical studies suggested strongly that during gut formation, ALP antigens has been switched from the epithelial isoform to the intestinal isoform. These results have shown that in P. misakiensis budding involves transdifferentiation of multipotent, but differentiated epithelium, confirming our previous results (Fujiwara and Kawamura, Dev. Growth Differ. 34:463-472, 1992).

Lichen sclerosis et atrophicus with prominent telangiectasia

Lichen sclerosis et atrophicus is characterized by the development of well demarcated, depigmented macules with epidermal atrophy. Hemorrhage occurs occasionally; however, telangiectasia is seldom remarkable. We studied a case of lichen sclerosis et atrophicus with striking telangiectasia which involved a 62-year-old male who was suffering from this disorder on his upper back. An initial lesion had been excised 15 years earlier. Thirteen years after the original surgery, he noticed a similar skin eruption accompanied by telangiectasia that had recurred around the surgical scar. We present here a detailed description of this case and provide a short review of the literature.

Canine Lyme disease: clinical and serological evaluations in 21 dogs in Japan

Of 21 dogs from Sapporo, Hokkaido that had been recognised as having been bitten by ticks, 16 were seropositive to Borrelia burgdorferi by ELISA. Thirteen of the seropositive dogs showed signs such as fever, astasia, convulsions, anorexia, fatigue, abnormal gait, nervous signs, diarrhoea, corneal opacity and conjunctivitis. These signs subsided as a result of antibiotic treatment within five days. The plasma concentrations of creatinine in the 21 dogs were higher than in control dogs. Seven ticks that were removed from seven of the dogs were Ixodes persulcatus, and B burgdorferi was isolated from the midgut of two of the ticks.

Isolation and partial characterization of crystal matrix protein as a potent inhibitor of calcium oxalate crystal aggregation: evidence of activation peptide of human prothrombin

In order to clarify the characteristics of crystal matrix protein (CMP), which exhibits a remarkable affinity for calcium oxalate crystals and may be important in stone pathogenesis, we have isolated CMP from macromolecular matrix substances of newly-formed calcium oxalate crystals. Purification of CMP consisted of calcium oxalate crystal formation, dissolution of crystals, electrodialysis, anion exchange chromatography and high-performance liquid chromatography. CMP showed the protein band of 31 kDa in sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The N-terminal amino acid sequence of CMP was identical to that of human prothrombin. Both anti-CMP polyclonal antibody and anti-human prothrombin antibody cross-reacted well with human prothrombin and CMP in Western blotting. Its amino acid composition and its molecular weight of 31 kDa strongly suggest that CMP is the activation peptide of human prothrombin.

Inductions of oxidative DNA damage and mesothelioma by crocidolite, with special reference to the presence of iron inside and outside of asbestos fiber

Inductions of oxidative DNA damage (oh8dG) in vitro and peritoneal mesothelioma in rats (F344, female) were compared between crocidolite (CR) and de-ironized crocidolite [DCR, washed by HCl and ethylenediamine tetraacetic acid (EDTA)] to verify the hypothesis that reactive oxygen species contribute to carcinogenesis, focusing on the role of iron present inside or outside of the CR. The yield of oh8dG was 14.6 oh8dG/10(5)dG in CR and 30.2 in DCR under simple incubation with DNA. In the incubation systems added several chemicals and H2O2, DCR induced higher levels of oh8dG than CR. Especially, the addition of Fe2O3 and H2O2 to DCR increased oh8dG in DNA depending on the Fe2O3 concentration, however, this tendency was not observed in the same system of CR. Surprisingly, 7 out of 10 rats died within 2 days after the injection of 10 mg of Fe2O3 following the DCR injection (5 mg/rat), showing necroses of hepatocytes from the surface of each lobe where CR and Fe2O3 particles had been deposited together. There was no death in other groups of rats. One year after the i.p. injection of CR (5 mg/rat, single injection), mesotheliomas were found in all rats administered DCR and Fe2O3 (2 mg/rat, once a week, for 35 weeks), in 4 rats of DCR alone (n = 10), in 5 rats of CR alone (n = 10) and in none of the rats administered Fe2O3 alone (n = 10). Therefore, present results indicate that the induction of oxidative DNA damage changed even when the same type of asbestos was washed by chemical treatment, and Fe2O3 promoted the development of mesothelioma which was induced by DCR.

Suppression of retroviral tumors in hosts immune to viral oncogene product

Feline sarcoma virus of Snyder-Theilen strain (ST-FeSV) induces sarcomas in Wistar/Ma rats following neonatal virus injection. Induced tumors express the viral oncogene product (P85) and elicit in hosts the specific serum anti-P85 antibody detectable by Western blot analysis. Syngeneic adult female rats were immunized with an ST-FeSV induced sarcoma that was 100% transplantable to syngeneic adult rats. Newborns from immunized rats (vaccinated rats) were found to carry anti-P85 in their sera at birth. Following neonatal injection of the virus to vaccinated and non-vaccinated control rats, tumor incidence was found to be lower and survival time significantly longer in vaccinated rats than in controls (p < 0.01). A nonapeptide known to be thymic hormone (FTS) showed suppressive effects on tumor development. These results indicate that tumors caused by perinatal retrovirus infection may be suppressed by efficient elicitation of cell-mediated immune response against the product of oncogene of the causative virus.

Genetic instability of human cells with DNA related to human retrovirus

To elucidate the role of HTLV-I in human neoplasia, DNA was extracted from tumor tissues, cultured cells, and/or sera from 20 HTLV-I seropositive and from 10 seronegative cancer patients, subjected to PCR-PAGE, and analyzed by Southern hybridization. HTLV-I related sequences were detected in tumors of the seropositives with different types of cancer. In the seronegatives, gag related sequences were detected in some tumors, whereas LTR related sequences were detected in only uterus carcinoma and tax related sequences in none of tumors examined. These sequences were detected in tumor cells as well as lymphoid cells by in situ hybridization. Some of these sequences were also detected in cultured fibroblasts derived from ATL patients. Cultured normal human lymphocytes grew continuously in conditioned media following HTLV-I infection, and transformed on exposure to carcinogens. Chromosome changes in transformed cells appeared clustering to chromosomes abnormalized on HTLV-I infection. The frequency of abnormal chromosomes in lymphocytes was significantly higher in the seropositives and in their family members than in seronegative normal donors. The frequency increased with advancement of host age in the seropositives but not in the seronegatives. These findings indicate that some individuals carry HTLV-I related sequences that may be derepressed by host aging and resulted in increasing genetic instability of host cells rendering them increasingly susceptible to carcinogens.

[Features of filamentous cytoskeletons in acquired multidrug-resistance of HL-60 human leukemia cell line]

Acquired resistance to chemotherapeutic drugs by tumor cells is an important obstacle to effective therapy of human malignancy. These resistance cell lines originated from human or rodent have been characterized by increased expression of MDR (Multidrug-resistance) gene and P-glycoprotein which plays as efflux pump of drugs from cells. These multidrug-resistance sublines also have been reported increased activities of protein kinases and glutathione S-transferase-pi. Although there have been extensive biophysical and biochemical characterization of the differences between parental lines and MDR tumor cell sublines, morphologic observations have been limited. In this study, filamentous cytoskeletons which involve many biological phenomena such as maintenance of cell morphology, mitosis, cellular movement, transport, and adhesion, were observed by confocal laser microscopy. To compare the expression of each cytoskeletons, fluorescent intensities of cells stained for each cytoskeletons were measured by confocal laser microscopic system. Utilizing this methodology, higher microtubular expression was observed in HL-60/ADR and K562/ADR than in their parental lines, but no significant differences of actin and vimentin were observed. Phosphorylation by protein kinases has been established as a key factor in the regulation of cytoskeletal function. But little is known about the role of protein phosphorylation in cytoskeletal function. Since increased activities of PKC and PTK were detected in HL-60/ADR, the effect of PKC inhibitor, staurosporine (STR), or PTK inhibitor, genistein (GNS), on cell growth was detected. STR and GNS reduced the resistance to Adriamycin in HL-60/ADR. Furthermore, STR and GNS disrupted the filamentous structure of microtubules in HL-60/ADR, and suppressed the expression of microtubules to 37%, and 49%, respectively. In contrast, PKC activator, phorbol ester (TPA), caused stronger microtubular assembling in HL-60/ADR, and increased the expression of microtubules to 134%. Resulting from this study, it is likely that acquired MDR of HL-60 and K562 was associated with increased expression of microtubules, and microtubular assembling or disassembling was considered to be regulated in part by PKC and PTK.

Effect of herbimycin A, an inhibitor of tyrosine kinase, on protein tyrosine kinase activity and phosphotyrosyl proteins of Ph1-positive leukemia cells

Herbimycin A, a benzoquinonoid anasamycin antibiotic, preferentially inhibited the in vitro growth of Ph1-positive leukemia cell lines. On the other hand, genistein, which was developed as an inhibitor of receptor-type tyrosine kinase, and other protein kinase inhibitors showed no selective inhibition of Ph1-positive leukemia cell growth. Herbimycin A also displayed an abrogative effect on the transformation of murine hematopoietic cells by transfection with a bcr/abl oncoprotein-expressing retroviral vector. The antitumor action of herbimycin A on Ph1-positive leukemia cells is related to an inhibition of activity of bcr/abl protein tyrosine kinase and a subsequent reduction of the constitutive phosphotyrosyl proteins, however, the antibiotic has no effect on the expression of bcr/abl mRNA and oncoprotein. Therefore, herbimycin A may provide an important insight into the oncogenic action of bcr/abl oncoprotein and the future development of oncoprotein-targeted therapeutic agents.

The favourable effect of cyclophosphamide pulse therapy in the treatment of massive pulmonary haemorrhage in systemic lupus erythematosus

Pulmonary haemorrhage (PH) is a rare but very serious complication of systemic lupus erythematosus (SLE) and the treatment is still controversial. Some authors showed the effectiveness of methylprednisolone pulse therapy for PH, although its effect was often transient. A 12-year-old Japanese girl with lupus nephritis and recurrent massive PH in SLE was treated with methylprednisolone pulse therapy. The effect on PH was transient and she needed three cycles within a month and side-effects developed. Pulse therapy with cyclophosphamide, synchronized with plasmapheresis, was tried. Thereafter she did not experience PH for 7 months, whereas lupus nephritis did not improve. Pulse cyclophosphamide would be effective for life threatening massive PH in SLE patients.

Increased susceptibility to oxidative DNA damage in regenerating liver

Spontaneous and hepatocarcinogen (2-nitropropane, 2-NP)-induced levels of 8-hydroxy-2'-deoxyguanosine (oh8dG) in the nuclear DNA of regenerating liver [24, 48, 72 h and 7 days after partial hepatectomy (PH)] of male Sprague-Dawley rats were analysed for the verification of a hypothesis that the high susceptibility of proliferating hepatocytes to DNA damage is related to the well-known high susceptibility to carcinogens after PH. Interestingly, the spontaneous level of nuclear oh8dG in regenerating liver was significantly decreased (P < 0.01) at 48 h after PH (1.05 +/- 0.31 oh8dG/10(5)dG) compared with the level in normal rats (1.90 +/- 0.41). 2-NP induced an oh8dG level of 4.49 +/- 0.86 in nuclear DNA of rat liver without PH. However, in rats administered 2-NP (injections were performed 6 h before each sacrifice) after PH, the oh8dG level was significantly higher at 24 h (5.45 +/- 1.41, P < 0.05), 48 h (5.85 +/- 0.88, P < 0.01) and 72 h (5.67 +/- 1.07, P < 0.05) after PH than those with 2-NP exposure alone. Therefore, it is suggested that nuclear DNA in proliferating hepatocytes is in a stage susceptible to exogenous attack by 2-NP, and consequently this phenomenon might be related to the induction of hepatocarcinogenesis after PH.

The effect of pravastatin on prevention of restenosis after successful percutaneous transluminal coronary angioplasty

Numerous attempts have been made to prevent late restenosis after successful percutaneous transluminal coronary angioplasty (PTCA), but there is still no effective treatment. This report describes the effect of an oral lipid-lowering agent, pravastatin, on restenosis after successful PTCA. Sixty-six patients who underwent successful elective PTCA were assigned to a pravastatin-treated group (Group 1, n = 29) or an untreated group (Group 2, n = 37) in a prospective and randomized fashion. Pravastatin (5 mg or 10 mg twice a day) was given to Group 1 patients from day 3 after the procedure. Selective coronary angiography was repeated 3 to 5 months later, or sooner if the patient developed angina pectoris. The serum cholesterol level was decreased significantly in Group 1 (from 215.7 +/- 44.3 mg/dl to 181.2 +/- 30.3 mg/dl, p < 0.001), but not in Group 2 (from 191.9 +/- 30.8 mg/dl to 191.8 +/- 33.3 mg/dl, p = ns), at the time of repeat coronary angiography. However, there were no differences between the groups with regard to the recurrence of angina, the need for repeat PTCA, or restenosis, as assessed by quantitative analysis of coronary cineangiograms. These results suggest that oral pravastatin therapy does not effectively prevent late restenosis after successful PTCA by this mode of administration.

Left ventricular function of the heart regressed by nifedipine in spontaneously hypertensive rats

Left ventricular (LV) performance of the pharmacologically regressed heart in hypertension is still unclear. We compared LV function of the heart regressed by nifedipine with that of the hypertrophied heart in spontaneously hypertensive rats (SHR). Nifedipine (30 mg/kg/day in food) was given to 15-week-old male SHR for 20 weeks (n = 12). Age- and sex-matched SHR served as controls (n = 12). LV catheterization was performed using a micromanometer and cardiac output was determined by the thermodilution method. Hemodynamic studies were performed after washout of nifedipine (24 h), when blood pressure had returned to the untreated level. Peak pumping ability was assessed during acute volume loading with saline. Nifedipine significantly decreased blood pressure in conscious animals (222 +/- 11 to 201 +/- 12 mmHg, p < 0.01) and reduced LV weight (1.20 +/- 0.07 to 1.07 +/- 0.05g, p < 0.01). After washout of nifedipine, LV systolic and end-diastolic pressures, dp/dtmax and cardiac output determined under pentobarbital anesthesia were similar in the treated and untreated groups. Peak pumping ability during acute preload elevation was also similar in the 2 groups. Plasma norepinephrine was unaltered, and plasma renin activity was significantly lower in the treated rats (p < 0.05). These results indicate that nifedipine regressed LVH with a minimal reduction of blood pressure and without evidence of neurohumoral activation or volume retention. In conclusion, LV function of the heart regressed by nifedipine was preserved after a spontaneous rise in blood pressure and during acute preload elevation.

[Evaluation for serum apolipoproteins in patients with diabetes mellitus]

Six fractions of serum apolipoproteins (apolipoprotein A-I, A-II, B, C-II, C-III and E) obtained from 100 patients with diabetes mellitus not administered any antihyperlipidemic drugs were measured to clarify the relationship between diabetes mellitus and the abnormal lipidosis. The serum concentrations of apolipoprotein B, C-II and C-III were significantly higher in these diabetics than in the controls (p < 0.05), and that of apolipoprotein E was significantly lower (p < 0.01). The serum concentrations of apolipoprotein C-II, C-III and E (p < 0.05) as well as HbA1C and FRA (p < 0.001) were significantly higher in the insufficient control group (FPG > or = 140 mg/dl) of diabetes mellitus. The serum concentrations of apolipoprotein C-II, C-III and E were significantly higher in the treated groups (p < 0.05). The serum concentrations of apolipoprotein B, C-II, C-III and E were significantly higher (p < 0.01) in the high cholesterol group (> 220mg/dl) and the high triglyceride group (> 150mg/dl) among the diabetic groups, but no significant differences were observed in the concentrations of apolipoprotein A-I and A-II.

The peritoneal equilibration test variables in pediatric CAPD patients

The peritoneal equilibration test (PET) is generally accepted as a valuable tool in individualizing continuous ambulatory peritoneal dialysis (CAPD) treatment schedules in adults. However, the classification of peritoneal permeability as described by Twardowski is not available for children due to differences in peritoneal transport abilities. In this paper, we report the results of the PET for 20 patients aged from 1.5 to 24 years (mean 10.3 years), who started CAPD therapy at age 0-15 years, using Twardowski's standardized technique. D/P creatinine (dialysate to plasma ratio of creatinine at 4 h), D/D0 glucose (the ratio of dialysate glucose at 4 h dwell time to dialysate glucose at 0 dwell time), and the residual volume (RV) in the abdominal cavity were calculated. The mean and standard deviation values for D/P creatinine and D/D0 glucose were of a higher permeability level than those reported in Twardowski's data. Furthermore, a significant correlation of creatinine and glucose with fluid drainage ability of the peritoneum were observed. A large amount of RV (425 +/- 125 mL/m2) was detected in the patients' peritoneal cavity and this had a significant correlation with dialysate leak occurrences. The authors suggest that the RV would be an indicator for leaks and especially latent leaks. The cause of a large RV is unknown, but there is a probability that drainage volume and transport rates of metabolites decrease because the concentration of the instilled dialysate is immediately diluted by a large RV within the peritoneum.

Converting enzyme inhibition improves congestion and survival in hypertensive rats with high-output heart failure

The effects of angiotensin-converting enzyme (ACE) inhibitors in high-output heart failure have not yet been well established. We evaluated the effects of lisinopril (3 mg/kg/day) on hemodynamics, neurohormones, and survival in 10-week-old spontaneously hypertensive rats (SHR) with aortocaval fistula. Sham-operated treated and untreated SHR served as controls. Cardiac output (CO) was determined by thermodilution method, and renal blood flow (RBF) was assessed by laser-Doppler flowmetry. In sham-operated SHR, 2-week treatment with lisinopril decreased blood pressure (BP), left ventricular (LV) weight, and total peripheral resistance (TPR) (p < 0.01 each) and increased RBF and plasma renin activity (PRA) (both p < 0.05); CO and LV end-diastolic pressure (LVEDP) were unchanged. Fistula creation induced biventricular hypertrophy and high-output heart failure [increased LVEDP, CO, pulse pressure, and plasma norepinephrine (NE) and decreased RBF] with congestive signs (ascites, tachypnea). Lisinopril decreased LVEDP (p < 0.01), increased RBF, prolonged survival (both p < 0.05), and prevented ascites (0 vs. 46%) and increased PRA (p < 0.05) and attenuated the increase in plasma NE. Heart weight, BP, and CO were not affected by lisinopril. Thus, lisinopril ameliorated congestion and improved survival in SHR with fistula without compromising cardiorenal hemodynamics. Venous and renal dilatation and attenuation of vasoconstrictive systems may have contributed to the beneficial effects.

Excellent prognosis of Japanese patients with chest pain and normal or nearly normal coronary arteries--2- to 13-year follow-up of 274 patients after coronary cineangiography

Although the prognosis of patients with chest pain and normal coronary arteries is reportedly good in the Western literature, it is unclear in Japan. The purpose of this study was to examine the natural history of 274 consecutive patients with chest pain and normal or nearly normal coronary arteries, and to determine whether the possibility of minor coronary artery disease has clinical implications as a prodromal factor of other heart diseases. Six of the patients died during the mean observation period of 6 years (74.5 +/- 35.4 months): 2 cancer, 3 cerebro-vascular accident, and 1 renal failure death. Three additional patients suffered from nonfatal cerebro-vascular accidents. Eleven patients were readmitted for evaluation of chest pain, and 4 of these were diagnosed as having vasospastic angina. Progression of significant coronary artery disease was not detected in these 11 patients with repeated coronary angiography. None of the patients in this study developed fatal or nonfatal myocardial infarction. A small number of patients (36/240, 15.0%) continued to suffer from chest pain. None of the patients developed cardiomyopathies or valvular heart diseases. Our observations indicate that the prognosis of chest pain with normal or nearly normal coronary arteries is better than that presented in the Western reports.

Influence of RF capacitive heating on the alpha 1-adrenergic receptors of rat prostates

The aim of this study was to find out the influence of radiofrequency (RF) capacitive heating on the alpha 1-adrenergic receptor of rat prostates. The prostates of 30-week-old Wistar rats were submitted to a 1-hour single session of RF capacitive heating at 45 degrees C. The ventral prostates that were submitted to heating were compared to those of other rats that were not submitted to heating. In order to determine the density of alpha 1-adrenergic receptors in rat ventral prostates, binding assays for alpha 1-adrenergic receptor were performed with [3H]prazosin in membrane preparations. The receptor density in the control group was 27.07 +/- 3.75 fmol/mg protein. The alpha 1-adrenergic receptor density (Bmax) in the thermotherapy group was 17.91 +/- 5.15 fmol/mg protein. A remarkable decrease in the density of alpha 1-adrenergic receptors was observed in the rat prostates of the thermotherapy group. In conclusion, the present results demonstrate that heating the rat prostate by RF capacitive heating damages the alpha 1-adrenergic receptors.

Predominant induction of kinetochore-containing micronuclei by extracts of diesel exhaust particulates in cultured human lymphocytes

The aneuploidy-inducing activity of extracts of diesel exhaust particulates from light duty (LD) and heavy duty (HD) engines was investigated in cultured peripheral blood lymphocytes of 8 healthy donors using the cytokinesis-block micronucleus test with the kinetochore labelling modification. A majority of the subjects tested showed a significant kinetochore-positive micronucleus induction after treatment with the highest dose (150 micrograms/ml) of LD extract, although some subjects also showed induction of kinetochore-negative micronuclei. Only one subject had significantly increased numbers of kinetochore-positive micronuclei at a dose of 400 micrograms/ml of HD extract. These results suggest that diesel extract, at least LD extract, possesses the ability to induce whole chromosome loss (aneuploidy) preferentially, although there are also chromosome breaks.