Electron-microscopic study of gamma-aminobutyric acid immunoreactivity in the chief cells of the mouse carotid body

The present study shows gamma-aminobutyric acid (GABA) immunoreactivity in almost all chief cells of the mouse carotid body. GABA immunoreaction products were distributed diffusely in the cytoplasm as well as in the dense-cored granules. These findings suggest that GABA may be localized in the cytoplasm and granules, and may be released from the cells.

Direct monitoring of the microcirculation in experimental venous flaps with afferent arteriovenous fistulas

This study was conducted to determine the survival mechanism of tissue transfers which make use of an afferent arteriovenous fistula. The study was carried out using a rabbit ear chamber method. In the first experiment (n = 34), the rabbit ear was used to create a flap with a central afferent arteriovenous fistula with either dual (n = 28) or single (n = 6) drainage. In the second experiment (n = 6), a flap with a central arteriovenous fistula with single drainage was created as above. The central vein was then ligated in the flap to investigate the influence of the competent venous valve in the central vein. In both the first and second experiments, blood flow was noted in the capillaries and arterioles. This finding was interpreted as meaning that a flap with an afferent arteriovenous fistula is nourished through capillary circulation. It appears that the blood flow can circumvent the competent venous valve to perfuse the distal part of the ear.

Role of Coulomb energy in promoting collisionally activated dissociation of multiply charged peptides formed by electrospray ionization

Electrospray ionization tandem quadrupole mass spectrometry has been applied to a series of lysine-substituted octaalanines and some naturally occurring peptides containing more than two basic amino acid residues. Unusually high fragmentation efficiency along with site-specific cleavages at the outer side of and remote from basic residues were observed for collisionally activated dissociation spectra of multiply charged peptides (MCP) with basic residues in close proximity. It was suggested that Coulomb energy (CE) rather than Coulomb repulsion (CR) was responsible for promoting fragmentation of the MCP studied. A possible fragmentation mechanism of MCP is proposed, in which the conversion of CE into internal vibrational energy was brought about by intramolecular proton migration in the presence of CR between charged sites.

[LDL apheresis in the treatment of hyperlipoproteinemia]

In order to the reduce the LDL level of Familial hypercholesterolemia (FH), direct LDL removal techniques have been used in several laboratories. In Japan, selective LDL-apheresis by dextran sulfate cellulose column have been developed and is used in treatment of homo- and heterozygous FH patients. In this paper, I reviewed the effectiveness of LDL-apheresis treatment in FH patients with many evidences of regression of atherosclerosis and discussed the potential role of this technique in the future treatment for coronary heart disease. No significant side effect for long term treatment is not experienced.

Effect of calcium ions on hydroxyapatite formation from the hydrolysis of anhydrous dicalcium phosphate

Effects of solution calcium ions on hydroxyapatite (HAP) formation from the hydrolysis of dicalcium phosphate anhydrous (DCPA) were investigated under controlled solution conditions. The hydrolysis experiments (2.5 mmol DCPA/250 mL) were carried out at fixed pH in the absence or presence of CaCl2 (0-200 mmol/L) by standard pH stat techniques at 37 degrees C. The rate of hydrolysis was much faster, and the yield of HAP approximately doubled in the presence of CaCl2 when compared to no CaCl2, but no significant difference was observed over the range of Ca2+ concentrations examined (25-200 mmol/L). At equivalent conversion times, the crystallinity of the HAP formed was also greater in the presence of CaCl2. Calculations showed that much less DCPA dissolved to reach solution equilibrium with respect to HAP in the presence than in the absence of CaCl2. We conclude, therefore, that solution Ca2+ is an important factor in controlling HAP formation from the hydrolysis of acidic calcium phosphates such as DCPA.

[Clinical study of a new injectable cephem, FK037, for acute bacterial prostatitis]

FK037, a new injectable cephem antibiotic, was administered in the treatment of 13 acute bacterial prostatitis (mean age 53.5, range 30-79), and its effectiveness and safety were evaluated. The human prostatic fluid (PF) concentration of FK037 on 7 specimens 1 hour after 1 g i.v.d., was in the range of 0.87-7.47 micrograms/ml (mean +/- SD, 3.43 +/- 2.23 micrograms/ml), whereas, the serum concentration averaged 45.3 +/- 2.88 micrograms/ml, the ratio of PF/serum consequently being 0.08 +/- 0.05. In the clinical study, 1g of FK037 was administered to 13 patients by i.v.d. twice a day for 7-9 days. Bacteriological eradication on expressed prostatic secretion (EPS) was obtained for all clinical isolates which included 11 strains of Escherichia coli (MIC < or = 0.05 microgram/ml), 2 of Enterococcus faecalis, and each one of Staphylococcus aureus and Morganella morganii. Symptomatical cure was 100% in all cases. As for safety profile, no side effects were noted. In laboratory values, slight elevation of transaminase were detected in 3 cases, but they were transient and returned to normal 1-2 weeks after completion of the therapy. We conclude that FK037 is highly effective in the treatment of acute bacterial prostatitis, and is well tolerated in comparison with other relative antimicrobials.

[Hilar type squamous cell carcinoma confined within the bronchial wall with hilar lymph node metastasis: a case report]

A 60-year-old male patient visited our hospital for evaluation of positive sputum cytology. A chest X-ray film revealed no abnormal shadows. Bronchofiberscopy showed a protruding lesion at the spur between left B8 and B9. Histological findings indicated squamous cell carcinoma. Left lower lobectomy with hilar and mediastinal lymph node dissection was performed. The tumor did not infiltrate beyond the bronchial cartilage on postoperative histologic examination. However, hilar lymph node (#12 l) metastasis was identified. Surgical resection with lymph node dissection is mandatory even in the hilar type lung cancer confined within the bronchial wall.

Analysis of gait in patients with peripheral vestibular disorders

Analysis of gait in patients with acute unilateral peripheral vestibular disorders was performed using foot switches and electromyography, with the aid of a telemetry system. Among the eight parameters set for the analysis, the occurrence rate of abnormality in the coefficient of variation (CV) was the highest (78%) for the time from heel strike to forefoot strike, followed by that of the location of maximum monophasic contraction of the gastrocnemius during stance, swing and stance. No significant laterality concerning the abnormally increased CV value in those parameters was found except for swing of the foot contralateral to the lesion side. The CV value of each parameter was significantly increased by removing visual cues, suggesting the importance of visual input for steady locomotion. No significant change in CV values of double support was obtained during the acute stage of vestibular neuronitis, indicating that weight transfer from one leg to the other could be smooth even though some difficulty was expected. Abnormal parameters at an acute stage returned to normal limits at recovery stage. The physiological background of the obtained results is discussed.

Dietary and hormonal regulation of aldolase B gene transcription in rat liver

In the liver of the fasted rat, the aldolase B (AldB) mRNA level decreased to about half of that of the control rat. When the control rat was refed the glucose-rich diet, the AldB mRNA level increased about six to seven times more than in the fasted rat. This increase was shown as the activation of the AldB gene transcription by a nuclear run-on assay. To understand the causal factor(s) for this activation, the relationship between the AldB mRNA level in the liver and the plasma concentrations of hormones, which are known as major regulators of carbohydrate metabolism during fasting and refeeding, was investigated. The plasma insulin level in the rat which was refed the glucose-rich diet increased in parallel to AldB mRNA level, while the plasma glucagon level decreased reciprocally to it. The relationship of the plasma corticosterone level to the AldB mRNA level was not obvious. To directly confirm the effects of these hormones on AldB gene transcription in the liver, the responses of AldB gene in the primary cultured hepatocytes to these hormones were examined. Insulin and dexamethasone were effective to activate AldB gene, while glucagon and thyroxine were suppressive. Thyroxine did not extinguish the effects of insulin and dexamethasone, but glucagon canceled them. Thus, it is probable that in vivo these hormones synergistically regulate the AldB gene transcription. In vitro transcription analysis of two AldB promoter constructs suggested that the proximal half of the AldB promoter (up to -92 bp from the transcription start site) is, at least in part, involved for this induction, and the distal half which contains liver-specific elements (-93 to -202 bp) is not involved. The possible explanation for the dietary regulation of aldolase B gene transcription in the liver is discussed.

Immunohistochemical and histochemical evidence for the presence of noradrenaline, serotonin and gamma-aminobutyric acid in chief cells of the mouse carotid body

The immunohistochemical study revealed tyrosine hydroxylase (TH), dopamine beta-hydroxylase (DBH), phenylethanolamine N-methyltransferase (PNMT), serotonin, glutamate decarboxylase (GAD) and gamma-aminobutyric acid (GABA) immunoreactivities in the mouse carotid body. TH and DBH immunoreactivities were found in almost all chief cells and a few ganglion cells, and in relatively numerous varicose nerve fibers of the carotid body. The histofluorescence microscopy showed catecholamine fluorescence in almost all chief cells. However, no PNMT immunoreactivity was observed in the carotid body. Serotonin, GAD and GABA immunoreactivities were also seen in almost all chief cells of the carotid body. From combined immunohistochemistry and fluorescence histochemistry, catecholamine and serotonin or catecholamine and GABA were colocalized in almost all chief cells. Thus, these findings suggest that noradrenaline, serotonin and GABA may be synthesized and co-exist in almost all chief cells of the mouse carotid body and may play roles in chemoreceptive functions.

Long-term outcome for 120 Japanese patients with Takayasu's disease. Clinical and statistical analyses of related prognostic factors

BACKGROUND

Patients with Takayasu's disease, a chronic inflammatory arteriopathy of unknown cause, have variable clinical courses, and predictors of the long-term outcome are not well understood. We studied prognostic factors of this disease, based on follow-up results, and a new prognostic classification was proposed.

METHODS AND RESULTS

Life-table methods and Cox regression analyses were applied to clinical data on 120 patients who had been prospectively followed for a median of 13 years (range, 1 month to 34 years). The overall survival rate at 15 years after the diagnosis was 82.9% and remained the same for the remainder of the follow-up period. Univariate Cox analyses revealed that of the six dichotomous variables evaluated at diagnosis, four were statistically significant predictors, including complications (Takayasu's retinopathy, hypertension, aortic regurgitation, and aneurysm), pattern of the past clinical course, age of the patient, and calendar year of diagnosis. Thus, the 15-year survival was 66.3% versus 96.4% for patients with and without a major complication, 67.9% versus 92.9% for patients with and without a progressive course, 58.3% versus 92.7% for age > 35 years and < or = 35 years, and 79.9% versus 96.5% for patients diagnosed in 1957 through 1975 and in 1976 through 1990, respectively. The delay in diagnosis and the erythrocyte sedimentation rate (ESR) were of marginal significance. The multivariate Cox analysis showed that only two of the above variables were statistically independent predictors, ie, the major complication and the progressive course. In addition to these two factors, ESR was the third predictor, if the Cox stepwise elimination procedure was performed. These three predictors used in various combinations made a total of 1822 classifications theoretically feasible. Of these, a three-stage classification was selected as the best one, based on the Akaike information criterion. The presence of both major complication and progressive course (stage 3) was the worst prognostic indicator (43% survival at 15 years). In contrast, no patient died who had neither of these manifestations or who had a progressive course but an elevated ESR as well (stage 1).

CONCLUSIONS

The long-term outcome for patients with Takayasu's disease seems best predicted by two major prognostic factors, ie, complications and the pattern of the past clinical course, as well as by ESR. Aggressive medical and surgical treatment may be considered for patients with a major complication and a progressive course (stage 3).

Synergistic inhibition by BQ-123 and BQ-788 of endothelin-1-induced contractions of the rabbit pulmonary artery

In the rabbit isolated pulmonary artery, neither the ETA receptor antagonist, BQ-123 (10 microM), nor the ETB receptor antagonist, BQ-788 (10 microM), inhibited the contractions induced by 1 nM endothelin-1 (ET-1). However, the combination of BQ-123 and BQ-788 completely inhibited the ET-1-induced contraction. In contrast, the ETB-selective agonist, sarafotoxin S6c (1 nM)-induced contraction was completely inhibited by BQ-788 but not by BQ-123. In receptor binding assays, [125I]-ET-1 specific binding to pulmonary arterial membranes was inhibited by BQ-123 (1 microM) by approximately 20% and additive treatment with BQ-788 (1 microM) completely inhibited the BQ-123-resistant component of [125I]-ET-1 specific binding. The present study demonstrates synergistic inhibition by BQ-123 and BQ-788 of ET-1-induced contraction of the rabbit pulmonary artery and the coexistence of ETA and ETB receptors, suggesting that the activation of either only ETA or only ETB receptors may be sufficient to cause complete vasoconstriction. Therefore, blockade of both receptor subtypes would be necessary for the inhibition of some ETA/ETB composite types of responses.

High-sensitivity two-dimensional thermal- and mechanical-stress-induced birefringence measurements in a Nd:YAG rod

A novel polarimeter for measuring the two-dimensional (2D) thermal- and mechanical-stress-induced birefringence in solid-state laser materials such as Nd:YAG is proposed. Using this device, we could sensitively measure the direction of the principal birefringence axis as well as the phase shift δ with sign when δ < π/4. The 2D thermal- and mechanical-stress-induced birefringence in a laser-diode-pumped Nd:YAG rod was successfully measured with the proposed polarimeter. We also found an active quarter-wave Nd:YAG phase retarder.

[A long-survival case of unresectable liver metastasis of colon cancer by hepatic arterial intermittent multidrug infusion chemotherapy]

We experienced a long-survival case with unresectable liver metastasis of sigmoid cancer by hepatic arterial intermittent multidrug infusion chemotherapy. The patient was a 65-year-old man. A movable tumor was palpable at the left lower abdomen. The serum CEA value was 15.6 ng/ml. Abdominal CT scan showed a 3 cm-sized low-density area near the root of the right and middle hepatic vein in segment 4. He had undergone sigmoidectomy, cholecystectomy and cannulation into the proper hepatic artery. Chemotherapy was performed by using 5-FU (250 mg), Adriacin (5 mg) and mitomycin C (4 mg) every second week from 4 months after surgery as an outpatient. In the CT scan image, the low-density area completely disappeared at 10 months after treatment, and the CR interval was 14 months. The patient has been alive for 5 years after surgery.

Clinical implications of isolated T wave inversion in adults: electrocardiographic differentiation of the underlying causes of this phenomenon

OBJECTIVES

This study aimed to assess the causes and clinical implications of isolated T wave inversion in adults and to evaluate electrocardiographic (ECG) differentiation of these causes.

BACKGROUND

There are few previous reports on isolated T wave inversion in adults, which is a paradoxic observation in normal adults and in those with severe coronary artery disease.

METHODS

We used echocardiography, stress thallium-201 scintigraphy and coronary angiography to determine the underlying causes and then used conventional electrocardiography and precordial ECG mapping to differentiate them. Eighty-six consecutive patients with isolated T wave inversion were classified as follows: group A included 23 asymptomatic patients; group B included 63 patients with chest pain.

RESULTS

In group A, isolated T wave inversion was found as a normal variant in 20 patients and was due to hypertrophic cardiomyopathy in 3. In group B, the cause was hypertrophic cardiomyopathy in 3 patients, pericarditis in 2, coronary artery disease (lesions of the proximal left anterior descending coronary artery) in 39 and a normal variant in 19. The causes of isolated T wave inversion were difficult to determine from 12-lead ECG findings alone. However, when the inverted T wave region extended into the upper part of the precordium, precordial ECG mapping demonstrated excellent detection of coronary artery disease, with a sensitivity, specificity and overall accuracy of 88%, 93% and 91%, respectively.

CONCLUSIONS

Isolated T wave inversion in asymptomatic adults is usually a normal variant. In patients with chest pain, isolated T wave inversions can develop in two different situations: a normal variant and severe coronary artery disease; these can be easily differentiated by precordial ECG mapping using conventional electrocardiography.

Endothelin ETB receptors couple to two distinct signaling pathways in porcine kidney epithelial LLC-PK1 cells

We characterized the endothelin (ET) receptor subtypes responsible for signal transduction in cultured porcine kidney epithelial LLC-PK1 cells. Both ET-1 (IC50, 43 pM) and ET-3 (IC50, 46 pM) inhibited the binding of [125I]ET-1 to LLC-PK1 cells to a similar extent. The binding affinity of LLC-PK1 cells was about 10,000 times higher for the ETB antagonist BQ-788 [N-cis-2,6-dimethyl-piperidinocarbonyl-L-tau-metylleucyl-D-+ ++Nin- methoxycarbonyltryptophanyl-D-norleucine] (IC50, 1.3 nM) than for the ETA antagonist BQ-123 [cyclo-(D-Trp-D-Asp-Pro-D-Val-Leu)] (IC50, 14 microM). ET-1 enhanced cyclic GMP (cGMP) production, but reduced vasopressin- and forskolin-stimulated cyclic AMP (cAMP) production. Both effects of ET-1 were antagonized by BQ-788, but not by BQ-123. The cAMP decrease, but not the cGMP increase, in response to ET-1 was inhibited by pertussis toxin, suggesting that the former response is mediated by pertussis toxin-sensitive Gi, whereas the latter is mediated by a pertussis toxin-insensitive G-protein. Therefore, the ETB receptors in LLC-PK1 cells couple to the two types of signal transduction cascades to reduce cAMP production and stimulate cGMP production via distinct G-proteins. ET-1 and probably also ET-3 may play a role in the regulation of renal epithelial transport by decreasing cAMP and increasing cGMP.

[Toxicity studies of paclitaxel. (II)--One-month intermittent intravenous toxicity in rats]

Paclitaxel, an antineoplastic agent, was intravenously given to Crj:CD (SD) rats of both sexes at 0 (saline), 0 (vehicle), 1.0 (low dose), 3.3 (intermediate dose) and 10.0 (high dose) mg/kg at five-day interval over one-month period (6 times in total) to investigate its repeated dose toxicity and the reversibility of toxic effects. The results obtained are summarized as follows: 1. Decreased activity with prone position was observed for high dose and vehicle groups, and alopecia was seen for many high dose rats. Body weight gain and food intake were suppressed for high and intermediate dose groups. No deaths occurred. 2. Red blood cell count, hemoglobin, hematocrit, white blood cell count, relative neutrophil count, platelet count and reticulocyte count were decreased for high dose groups. Red blood cells count was also decreased for intermediate dose groups. 3. Thymic atrophy, splenic hematopoiesis, bone marrow hypoplasia, testicular atrophy with suppression of spermatogenesis and tubular atrophy, and epididymal atrophy were observed for high dose rats. 4. Above-described changes excluding the findings on the testis and epididymis for high dose rats were shown to be generally reversible. Based on these results, the no-toxic effect dose of paclitaxel was estimated to be 1.0 mg/kg in rats under this study condition.

[Reproductive and developmental toxicity studies of paclitaxel. (I)--Intravenous administration to rats prior to and in the early stages of pregnancy]

Paclitaxel, an antineoplastic agent, was administered intravenously to Crj: CD (SD) rats daily at dose levels of 0 (saline and vehicle), 0.1, 0.3 and 1.0 mg/kg for 63 days prior to mating and during the mating period in males, and for 14 days prior to mating and during the mating period as well as day 0 to day 7 of gestation in females. Results were as follows: 1. Body weight gains were shown a tendency to hasten in vehicle-treated male rats associated with the increased food consumption. However, the vehicle-treated group had no effect in the other parameters that were measured in this study when compared to the saline-treated group. 2. 1.0 mg/kg paclitaxel caused suppression of the body weight gains accompanied by the decreased food consumption in either male or female rats. 3. Adrenal and ovarian weights were decreased in 1.0 mg/kg dams at term. 4. The fertility indices in both sexes of 1.0 mg/kg were lower than the saline-treated group. However, the copulation indices in both sexes in 1.0 mg/kg rats were comparable to those of the saline-treated group. 5. Decreases in the number of corpora lutea, implantations and live fetuses or increases in the number of empty implantation sites and total embryo-fetal deaths were observed in 1.0 mg/kg dams. However, the fetal weights, crown-rump distances and tail lengths in live fetuses were not affected by paclitaxel treatment. Based on the reproductive and developmental indices, the no toxic-effect dose level of paclitaxel is 0.3 mg/kg/day for parent animals and their fetuses.

Spontaneous vascular mineralization in the brains of cows

The frequency of occurrence and the characteristics of vascular mineralization in the brains of cows were studied. Mineralized lesions were found in the pallidal arteries in eight of 13 cows. They appeared as basophilic deposits in the arterial walls, were sheath-like or tubular in shape, and were accompanied by intimal oedema or fibrous thickening. The deposits were positive for periodic acid-Schiff, von Kossa's, alizarin red and Berlin blue stains. Elemental analysis revealed the presence of large amounts of phosphorus, calcium and zinc, as well as small amounts of iron, copper and sodium.

Preservation of high regional blood flow at epicardial rim after coronary occlusion in dogs

A thin myocardial layer adjacent to the epicardium (epicardial rim) often survives after transmural myocardial infarction. Regional myocardial blood flow (Qm) at this rim may be high enough to maintain myocardial viability during coronary occlusion. To test this hypothesis, we measured Qm in 12 anesthetized dogs during left anterior descending coronary artery occlusion using nonradioactive colored microspheres. Myocardium in the region supplied by the occluded artery was sliced into sections approximately 0.5 mm thick from the epicardial surface to the endocardium, and the Qm in each section was determined. During occlusion, the Qm of myocardium within 0.5 mm of the epicardial surface remained at 74.8 +/- 8.8% of the preocclusion level. Maintenance of this high Qm during occlusion was abolished when an epicardial incision approximately 1 mm deep was made around the occluded area. These findings suggest that Qm is maintained at a surprisingly high level at the epicardial rim after coronary occlusion through epicardial arterial communications, which may be sufficient to maintain myocardial viability.

Organ-specific and hormone-dependent expression of genes for serine carboxypeptidases during development and following germination of rice grains

Several cDNA clones encoding either serine carboxypeptidases or related proteins of Oryza sativa L. were identified, and the abundance of the corresponding mRNA in immature and germinated grains was examined. The deduced amino acid sequence of each cDNA included key sequences, such as a pentapeptide (G-X-S-X-G/A) that is conserved among many serine carboxypeptidases, and the putative protein products were classified as two general and one novel type of cereal serine carboxypeptidases. Two general types exhibited considerable homology to type I and type III carboxypeptidases of cereal plants. The novel type encoded a serine carboxypeptidase-like protein that was very similar to type III carboxypeptidases of barley and wheat but had slight differences in both the N- and the C-terminal sequences. The mRNAs of each of these carboxypeptidases were observed in immature grains, and they decreased during maturation. The abundance of mRNA for each class of carboxypeptidase increased again following germination with the same time course and in a tissue-specific manner. The mRNAs for type I and type III-like carboxypeptidases were abundant in germinated embryos composed of leaf, root, and scutellum, whereas the mRNA for type III carboxypeptidase was conspicuous in endosperm that contained the aleurone layer. Altered amounts of mRNA in deembryonated half-grains in response to phytohormones, such as gibberellic acid and abscisic acid, were only detectable in the case of type III carboxypeptidase. Southern blot analysis using rice genomic DNA revealed the simple organization of each gene for these three classes of carboxypeptidases.

[Toxicity studies of paclitaxel. (I)--Single dose intravenous toxicity in rats]

Paclitaxel, an antineoplastic agent, was given to Crj: CD (SD) rats of both sexes at 38, 50, 65 and 85 mg/kg by single intravenous administration to investigate its acute toxicity. The results obtained are summarized as follows: 1. Tachypnea and decreased activity with prone position were noted for vehicle and all paclitaxel groups, and alopecia for all paclitaxel groups. 2. Deaths occurred for one out of 5 males and 2 out of 5 females at 85 mg/kg. One female died of respiratory insufficiency induced by vehicle on Day 0. One female and one male died of the systemic toxicity of paclitaxel such as hypoplasia of the bone marrow and lymphoid depletion of lymphatic organs on Days 6 and 12, respectively. 3. On Days 4 and 5, all paclitaxel groups showed decreases of reticulocyte and white blood cell counts, as well as decrease of differential count of neutrophils. These changes were generally recovered by a week after dosing. 4. Histopathological examinations revealed atrophy of the thymic medulla, hypoplasia of the bone marrow and lymphoid depletion of the spleen for a few males at 85 mg/kg, and hypospermatogenesis and tubular atrophy of the testes for all paclitaxel groups. Based on these results, 85 mg/kg of paclitaxel was lethal to rats, and hematopoietic, lymphoid and male reproductive systems were primarily affected under this condition.

[Antigenicity study of paclitaxel]

The antigenic property of paclitaxel was examined using its protein mixtures (paclitaxel + OVA, paclitaxel + GSA, paclitaxel + RSA) in guinea pigs and mice in comparison with ovalbumin (OVA) and the protein conjugate of 4-aminoantipriyne (AAP). The following results were obtained: 1. When guinea pigs were sensitized with paclitaxel or paclitaxel + OVA emulsified with Freund's complete adjuvant, none of active systemic anaphylaxis (ASA), passive cutaneous anaphylaxis (PCA) and Schultz-Dale reaction were induced by challenge with paclitaxel or paclitaxel + GSA (guinea pig serum albumin). In the observation of active cutaneous anaphylaxis (ACA), no changes were observed in animals treated with paclitaxel alone as a sensitizing and/or a challenging antigen under the condition where slight delayed type hypersensitivity was elicited in animals sensitized with paclitaxel + OVA and challenged with paclitaxel + GSA. 2. When mice were sensitized with paclitaxel or paclitaxel + OVA adsorbed to alum. sera of these animals revealed a negative reaction in PCA using rats by challenge with paclitaxel or paclitaxel + RSA (rat serum albumin). 3. Protein bindings of paclitaxel with the above albumins were more than 40%. As shown above, paclitaxel was considered not to possess antigenic property under the experimental condition. In addition, the dose levels of paclitaxel employed in the present experiment were confirmed not to suppress the immune response to OVA.

[Toxicity studies of paclitaxel. (III)--Six-month intermittent intravenous toxicity in rats]

Paclitaxel, an antineoplastic agent, was intravenously given to Crj:CD (SD) rats of both sexes at 0 (saline), 0 (vehicle), 0.3 (low dose), 1.0 (intermediate dose) and 3.3 (high dose) mg/kg at seven-day interval over a six-month period (total of 27 doses) to investigate its repeated dose toxicity. The results obtained are summarized as follows: 1. No deaths occurred in this study. Vehicle-related salivation was seen for some high dose and vehicle control rats. Soiling of the perigenital region was observed for some high dose females. 2. Red blood cell count, hemoglobin, hematocrit and white blood cell count were decreased for high dose rats. Reticulocyte count was increased and relative neutrophil count was decreased for high dose males. 3. Relative erythroid and myeloid cell count were decreased for high dose rats in bone marrow smear examinations. 4. Bone marrow hypoplasia and splenic hemosiderosis were observed for high dose rats, and thymic atrophy and lymphoid depletion were seen for some high dose males. Based on the these results, the no-toxic effect dose of paclitaxel was estimated to be 1.0 mg/kg in rats under this study condition.

[Reproductive and developmental toxicity studies of paclitaxel. (III)--Intravenous administration to rats during the perinatal and lactation periods]

Paclitaxel, an antineoplastic agent, was administered intravenously to pregnant Crj: CD (SD) rats daily at dose levels of 0 (saline and vehicle), 0.1, 0.3 and 1.0 mg/kg from day 17 of gestation to postpartum day 21. Results were as follows: 1. The vehicle-treated group had no effect in any of the parameters that were measured in this study when compared to the saline-treated group. 2. 1.0 mg/kg paclitaxel caused suppression of the body weight gains associated with the decreased food consumption in F0 dams during the lactation period. 3. Thymic, heart and uterine weights were reduced in 1.0 mg/kg F0 dams at completion of the lactation period. In addition, thymic atrophy was observed for 1.0 mg/kg F0 dams macroscopically. 4. Paclitaxel did not alter the delivery status of F0 dams or birth, viability and weaning indices in F1 pups. 5. The days required for presence of hair, incisor eruption and testicular descent were statistically delayed in 1.0 mg/kg F1 rats. 6. The latency time for olfactory orientation was prolonged in 1.0 mg/kg F1 rats on postnatal day 15. Further, the positive response rates for air righting were reduced in 1.0 mg/kg F1 rats from postnatal day 17 to day 20. 7. 1.0 mg/kg paclitaxel caused suppression of the body weight gains in male F1 rats from postnatal week 1 to week 12. Though body weight gains were decreased in 1.0 mg/kg female F1 rats from postnatal week 1 to week 7, there were no significant differences between dosed animals and saline-treated animals regarding the body weight gains and food consumption during the gestation period. 8. Paclitaxel did not affect the learning ability and memory, spontaneous motor activity or emotionality in F1 rats. 9. The reproductive performance in both male and female F1 rats were not affected by paclitaxel. 10. Splenic weights were reduced in 1.0 mg/kg male and female F1 rats at weaning. Furthermore, liver weights were decreased in 1.0 mg/kg male F1 rats after mating. 11. No influence on prenatal development was observed for F2 fetuses even at the highest dose level of paclitaxel. Based on the reproductive and developmental indices, the no toxic-effect dose level of paclitaxel is 1.0 mg/kg/day and 0.3 mg/kg/day for dams (F0) and their offspring (F1), respectively.