Novel crystalloid structures in suprasellar paraganglioma

A-52-year-old woman was admitted to a hospital because of 2-year history of abnormal behavior and impaired visual acuity. Magnetic resonance imaging delineated a sizable mass at the suprasellar region. The partially removed tumor was arranged in irregular lobules composed of an admixture of clusters of cobblestone-like small cells and process-bearing cells with ovoid nuclei, surrounded by a fine, neuropil-like matrix. The Zellballen structure was inconspicuous, and mitosis was absent. Immunohistochemically, the tumor cells were positive for chromogranin A, synaptophysin, class III beta-tubulin and neurofilament, while negative for glial fibrillary acidic protein, cytokeratin and all 6 pituitary hormones. S100 protein expression was limited to cells adjacent to stroma. The MIB-1 labeling index was 0.5%. Histopathological diagnosis was paraganglioma of abortive architecture. Ultrastructurally, numerous dense-cored vesicles were found within the processes and cytoplasm. Synapse formation was not demonstrated. Interestingly, crystalloids up to 3 microm in size were frequently found. They had hexagonal or quadrilateral architecture without limiting membranes. The interval between periodically arranged fibrils was variable, ranging from approximately 20 - 50 nm. Retrospective examination by light microscopy failed to reveal corresponding structures. Crystalloids are rare manifestation of paragangliomas, yet undescribed in those of intracranial origin. Furthermore, the ultrastructure of the present case differs from those of previous cases.

[Liposarcoma of the pleural cavity; report of a case]

A 43-year-old-woman who had sever anterior chest pain visited our hospital on April 3, 2000. A well-defined abnormal shadow was seen in the middle and lower field of the right lung on chest X-ray. Computed tomography showed a large fat density mass in the right pleural cavity with a septum enhanced by contrast medium. Percutaneous needle biopsy revealed lipoma or liposarcoma. Complete resection could be done with combined resection of right lung, lpericardium, parietal pleura and diaphragm. Final histologic diagnosis was well differentiated liposarcoma. There are few reports of liposarcoma arising in the thoracic cavity, we present our case and review the 23 cases reported from the Japanese literatures.

Randomized study of dose or schedule modification of granulocyte colony-stimulating factor in platinum-based chemotherapy for elderly patients with lung cancer

It is generally believed that elderly patients are less able to tolerate aggressive cancer chemotherapy than their younger counterparts. Bone marrow cellularity diminishes with age and elderly patients may have decreased tolerance to myelosuppressive agents. Between November 1995 and October 1999, 68 chemotherapy-naive elderly (70 or more years old) patients with histologically or cytologically proven lung cancer who were to receive platinum-based chemotherapy were enrolled in this study. All patients had adequate cardiac, hematological, liver and renal function to receive chemotherapy. Patients were randomized into 3 groups. Patients in groups 1 and 2 received 2 microg/kg and 4 microg/kg granulocyte colony-stimulating factor (G-CSF, lenograstim), respectively, when grade 3 leukopenia (<2,000/microl) or neutropenia (<1,000/microl) appeared after chemotherapy. Patients in group 3 received 2 microg/kg G-CSF when grade 2 leukopenia (<3,000/microl) or neutropenia (<1,500/microl) appeared after chemotherapy. G-CSF was stopped in all groups when the leukocyte count increased to over 10,000/microl or the neutrophil count exceeded 5,000/microl. Full blood cell counts were examined 3 times a week after chemotherapy. All patients received platinum-based chemotherapy. Eighteen, 16 and 22 patients (78%, 73% and 96%) in groups 1, 2 and 3, respectively, received G-CSF when leukopenia or neutropenia appeared. The durations of G-CSF treatment required by groups 1 and 3 (5.7+/-3.6 and 6.6+/-3.2 days, respectively) did not differ significantly, but the duration of treatment required by group 2 (3.7+/-2.8 days) was significantly shorter than that of group 1 (p=0.048). The duration of grade 4 neutropenia in group 2 (0.7+/-1.1 days) was marginally shorter than that in group 1 (1.6+/-2.1 days, p=0.076). The neutrophil nadir of group 2 (949+/-757/microl) was marginally higher than that of group 1 (592+/-438/microl, p=0.058). No patients in group 2 experienced grade 4 neutropenia for 4 days or more or a neutrophil nadir less than 100/microl a significant difference from group 1, where 22% and 17% of patients experienced these events (p=0.02 and p=0.04, respectively). Similarly, no infections requiring antibiotics after chemotherapy occurred in patients in group 2, a significant difference from group 1 (26%, p=0.01). The rates of neutropenia and infection in groups 1 and 3 did not differ significantly. The peak plasma concentration of G-CSF in group 2 was significantly higher than in group 1 (p=0.0018), but did not differ significantly between groups 1 and 3. Doubling the dose of G-CSF could help to decrease neutropenia and prevent infection after chemotherapy in elderly patients with lung cancer.

Normalized pulse volume (NPV) derived photo-plethysmographically as a more valid measure of the finger vascular tone

Normalized pulse volume (NPV) was advocated as a more valid measure for the assessment of finger vascular tone. Based on the optical model in the finger tip expressed by Lambert--Beer's law, NPV is expressed as Delta I(a)/I. Here, Delta I(a) is the intensity of pulsatile component superimposed on the transmitted light (I). Theoretically, NPV seems to be superior to the conventional pulse volume (PV; corresponding to Delta I(a)). Firstly, NPV is in direct proportion to Delta V(a), which is the pulsatile component of the arterial blood volume, in a more exact manner. Relatedly, NPV can be processed as if it is an absolute value. Secondly, the sensitivity of NPV during stressful stimulations is expected to be higher. These expectations were supported experimentally using 13 male students. Firstly, the correlation between cutaneous vascular resistance in the finger tip (CVR) and NPV was higher than that between CVR and PV among all the subjects, although there was not much difference between these correlations within each subject. Secondly, NPV decreased much more than PV during mental stress. Some limitations of the present study were addressed, including the point that certain factors can violate the direct proportional relationship of NPV and PV to Delta V(a).

Diastolic flow velocity of the left pulmonary artery of patent ductus arteriosus in preterm infants

BACKGROUND

The usefulness of diastolic pulmonary flow velocity determined by echocardiography in the assessment of symptomatic patent ductus arteriosus (sPDA) in preterm infants has not been confirmed.

METHODS

Echocardiography was performed daily in infants ranging from 23 to 31 gestational weeks of age, and diastolic flow velocity of the left pulmonary artery (DFLPA) was measured. The DFLPA data before indomethacin administration for sPDA were compared with data obtained after indomethacin administration. The normal range of DFLPA was also determined from serial measurements performed in infants who did not develop sPDA during the first 7 days of life. Then, this range was compared with data from infants who did develop sPDA during this time.

RESULTS

In infants who underwent indomethacin treatment, DFLPA increased with the development of sPDA and decreased when the symptoms of sPDA disappeared. On the basis of results from serial DFLPA measurement, the sensitivity and specificity of DFLPA for assessing sPDA was found to be 0.82 and 0.83, respectively.

CONCLUSIONS

Measurement of DFLPA by echocardiography is a useful method for assessing sPDA in preterm infants.

Increased expression levels of p53 correlate with good response to cisplatin-based chemotherapy in non-small cell lung cancer

In order to determine whether expression of the tumor suppressor gene p53 in non-small cell lung cancer (NSCLC) correlates with chemotherapeutic response, resected tumors from 18 patients with recurrent lung cancer who had undergone complete resection and received chemotherapy after the initial tumor recurrence were subjected to p53 immunostaining. Histological examination of the resected tumors revealed 11 adenocarcinomas, 6 squamous cell carcinomas and one adenosquamous cell carcinoma. Group 1 was </=50% (n=9) and group 2 >50% (n=9) p53-immunopositive. All patients received cisplatin-based chemotherapy after recurrence. No patient in group 1 achieved response to chemotherapy whereas 2 and 3 in group 2 achieved complete and partial responses, respectively. The chemotherapy response rate of group 2 (56%) was significantly higher than that of group 1 (0%, p=0.009). The times to reoccurrence after tumor resection of group 2 was significantly better than that of group 1 (log-rank p=0.019, Wilcoxon p=0.042), and survival after chemotherapy of group 2 was also significantly better than that of group 1 (log-rank p=0.023, Wilcoxon p=0.034). It is suggested that high p53 expression levels in tumors correlate with both good response to cisplatin-based chemotherapy and good survival of patients with advanced NSCLC.

Role of infection in the development of acquired subglottic stenosis in neonates with prolonged intubation

OBJECTIVE

To examine whether clinically diagnosed infection correlates with subsequent development of subglottic stenosis in intubated neonates.

METHODS

Sixty-two neonatal infants intubated for more than 14 days were examined. Several risk factors for subglottic stenosis, including infection, duration of intubation, frequency of intubation, the size of the endotracheal tube etc., were evaluated by multiple logistic regression analysis.

RESULTS

Infection that occurred within 14 days of intubation showed a positive correlation with subsequent subglottic stenosis. The duration of intubation, frequency of intubation and the size of the endotracheal tube did not affect the development of subglottic stenosis. The majority of infections were considered to be respiratory tract infections, including pneumonia.

CONCLUSIONS

Infection occurring within 14 days of intubation is considered to be a risk factor for acquired subglottic stenosis in neonates intubated for more than 14 days. Prevention of infection within 14 days of intubation may reduce the incidence of subglottic stenosis in neonates.

[A case of mixed connective tissue disease with lupus-like manifestations of the central nervous system, successfully treated with cyclophosphamide combined with prednisolone]

A 29-year-old woman experienced Raynaud's phenomenon, swelling of her fingers, eruptions on her face, and muscle weakness in 1990. She was diagnosed as having mixed connective tissue disease (MCTD) and was treated with prednisolone (PSL) for 3 years. Most of her complaints disappeared after the treatment. In March 1997, she experienced fever, erythema, and lymphadenopathy. Although she was treated with PSL (20 mg/day) again, muscle weakness, mental disturbance, and recto-urinary disturbance appeared. When she was re-admitted to our hospital, increased levels of muscle-derived enzymes and positivity of anti-RNP antibody were found. High signal areas in her cerebrum were shown by magnetic resonance imaging, and slow and spike pattern was shown by electroencephalography. Hypoperfusion of the cerebral blood flow was suggested on single photon emission computed tomography. The number of mononuclear cells, amount of protein and level of interleukin-6 were found to be elevated in her cerebrospinal fluid (CSF). Her neurological manifestations were diagnosed as being due to MCTD, and showed characteristics similar to those of systemic lupus erythematosus. She was treated with PSL (60 mg/day) followed by steroid pulse therapy. Because the response to this treatment was partial, oral administration of cyclophosphamide (CPM) (100 mg/day) was added. Muscle weakness and neurological abnormalities as well as abnormal laboratory findings gradually improved over the following two months. We conclude that the treatment with CPM combined with PSL may be useful, when neurological manifestations of MCTD are serious and resistant to conventional therapy.

Prophylactic administration of granulocyte colony-stimulating factor when monocytopenia appears lessens neutropenia caused by chemotherapy for lung cancer

In a retrospective study, we showed that a monocyte count of <150/microl on days 6 to 8 might be a predictor of grade III or IV neutropenia during cancer chemotherapy given at 3- or 4-week intervals. In the present study, we investigated whether the administration of granulocyte colony-stimulating factor (G-CSF) when monocytopenia appears lessens neutropenia during chemotherapy for lung cancer. Between June 1997 and August 1998, 60 patients who received chemotherapy at 3- or 4-week intervals for unresectable lung cancer were randomized to receive G-CSF (2 microg/kg or 50 microg/m2) when monocytopenia (<150/microl) appeared on days 6 to 8 after chemotherapy (group A) or when neutropenia (<1,000/microl) or leukopenia (<2,000/ microl) appeared after chemotherapy (group B). The administration of G-CSF was stopped when the leukocyte or neutrophil counts reached > 10,000/microl or 5,000/microl, respectively. The blood cells counts were examined three times a week and the degree, duration, and frequency of chemotherapy-induced neutropenia of the two groups were compared. One patient in group A was excluded because whole brain irradiation during chemotherapy was required. Twenty-nine and 30 patients in groups A and B, respectively, received platinum-based chemotherapy and their chemotherapy-induced hematologic toxicities were analyzed. The mean neutrophil count nadir of group A (1,558 +/- 1,771/microl) was significantly higher than that of group B (810 +/- 639/microl, p = 0.032). The duration of grade III neutropenia in group A (1.4 +/- 1.7 days) was significantly shorter than that in group B (2.9 +/- 1.9 days, p = 0.004), and the frequency of grade III neutropenia in group A (48%) was significantly lower than that in group B (83%, p = 0.002). Infectious episodes occurred in five and eight patients in groups A and B, respectively. The durations of G-CSF therapy required by group A and B patients (4.8 +/- 3.1 vs. 4.7 +/- 2.7 days) were not significantly different. Prophylactic administration of G-CSF did not exacerbate anemia or thrombocytopenia induced by chemotherapy. We conclude that the prophylactic administration of G-CSF when monocytopenia appears can lessen neutropenia caused by chemotherapy for lung cancer without increasing the total G-CSF dose.

[Acute respiratory failure caused by tuberculosis requiring mechanical ventilation]

The patients with active tuberculosis in whom respiratory failure requiring mechanical ventilation developed were studied retrospectively. Nine patients (M 8, F 1) were identified at the National Tokyo Hospital during 5 years from January, 1993 to December, 1997. Seven of 9 patients were single men, and the duration of symptoms before admission was over 1 month in all patients, while the time from first visit to diagnosis was less than 7 days. All patients were identified as malnourished, and 7 patients suffered from another underlying diseases. The patients were classified into two groups. Six of 9 patients had pulmonary tuberculosis and the other three had miliary disease. The proportion of cases requiring mechanical ventilation was 0.3% and 8.6%, respectively, in pulmonary tuberculosis and miliary tuberculosis. At the start of mechanical ventilation, PaO2/FIO2 was lower than 200 in all 9 patients, and 6 patients were probably ARDS. Steroids (methylprednisolone 250-1000 mg/day) were used in all 9 patients. Despite the use of mechanical ventilation and antituberculous therapy, 8 out of 9 patients died. Only one patient with miliary tuberculosis survived. The establishment of the therapy for acute respiratory failure is needed so as to improve prognosis of such cases. At the same time, the delay in consulting a doctor led to acute respiratory failure in most cases, so it is also important to encourage tuberculosis patients to visit a doctor as soon as possible, after the appearance of symptoms.

Increased expression levels of cyclin-dependent kinase inhibitor p27 correlate with good responses to platinum-based chemotherapy in non-small cell lung cancer

In order to determine whether expression of the cyclin-dependent kinase inhibitor p27 in non-small cell lung cancer (NSCLC) correlates with chemotherapeutic response, resected tumors from 22 patients with recurrent lung cancer who had undergone complete resection and received chemotherapy after the initial tumor recurrence were subjected to p27 immunostaining. Histological examination of the resected tumors revealed 14 adenocarcinomas, 7 squamous cell carcinomas and one adenosquamous cell carcinoma. Fifty percent or less and over 50% of the cells in the resected tumors of 11 patients each (groups 1 and 2, respectively) were p27-immunopositive. All but one patient received platinum-based chemotherapy after recurrence. Only one in group 1 achieved a partial response (PR) in chemotherapy whereas 2 and 4 in group 2 achieved complete and PRs, respectively. The chemotherapy response rate of group 2 (54%) was significantly higher than that of group 1 (9%, p=0.022). The times to recurrence after tumor resection of the 2 groups did not differ significantly (log-rank p=0.23, Wilcoxon p=0. 32), but survival after chemotherapy of group 2 was significantly better than that of group 1 (log-rank p=0.045, Wilcoxon p=0.028). It is suggested that high p27 expression levels in tumors may predict the good responses to platinum-based chemotherapy for NSCLC.

N-[4-(3-ethoxy-2-hydropropoxy)phenyl] acrylamide selectively induces apoptosis of cerebellar granule cells in vivo and in vitro in rats

Oral administration of N-[4-(3-ethoxy-2-hydropropoxy)phenyl] acrylamide (EHA) induced selective granule cell destruction in the granular layer of the cerebellar cortex together with neurological signs, such as delayed righting reflex, gait or truncal ataxia, and convulsion. Neuropathologically, it caused multifocal granule cell destruction with nuclear pyknosis and spongiosis of the neuropile in the granular layer. Other neurons, including Purkinje cells, were spared. Ultrastructurally, damaged granule cells showed aggregation of nuclear chromatin and cytoplasmic edema, but cytoplasmic organelles were preserved. The brain uptake index of 14C-labeled EHA was similar to that of H2O. When EHA was added to rat cerebellar tissue cultures, only the granule cells showed nuclear pyknosis, aggregation of nuclear chromatin, and karyorrhexis with cytoplasmic swelling. These granule cells were positive for DNA fragmentation by the TUNEL method. These results suggest that EHA permeates the blood vessel wall and directly affects the cerebellar granule cells, resulting in selective granule cell apoptosis.

Beat-by-beat double-normalized pulse volume derived photoplethysmographically as a new quantitative index of finger vascular tone in humans

Near-infrared finger photoplethysmograms were recorded and double-normalized pulse volumes (DNPV = DeltaV(b)/V(b); V(b) = total blood volume in the fingertip, DeltaV(b) = pulsatile component of V(b)) were calculated in ten subjects during, immersion of the contralateral hand in water at three different temperatures (44 degrees C, 22 degrees C, 11 degrees C). The DNPV from the left finger was compared beat-by-beat with cutaneous vascular resistance (CVR) derived by dividing mean blood pressure of the left third finger by cutaneous blood flow of the left fourth finger. The correlations overall at the three temperatures between log DNPV(LF) and log CVR(LF) (LF, low frequency component of DNPV and CVR) ranged from -0.89 to -0.96 among the subjects. After adjusting for a maximal extension of the vascular wall (DNPV(max)), the correlations became stronger. It was concluded that DNPV was a reliable and valid indicator of vascular tone in the finger.

Effect of clarithromycin on Pseudomonas aeruginosa biofilms

Using an experimental in vitro culture system, we investigated the effect of clarithromycin on biofilm formation by a leucine-requiring Pseudomonas aeruginosa mutant strain (HU1). Biofilm formation on celldesks in a chemically defined medium was assessed by viable cell count as well as by measurement of glycocalyx production and scanning electron-microscopic observation. Cells proliferated exponentially until day 3 and remained stationary afterwards. The amount of glycocalyx, simultaneously semiquantified, showed a linear increase from day 1 to day 12. Scanning electron microscopy revealed firm biofilms on day 5. Three different concentrations of Clarithromycin (CAM) (minimum inhibitory concentration MIC 64 microg/ml) were added continuously at the early and late phases of biofilm formation, and the antibiofilm effect of CAM was evaluated by the changes in cell count and glycocalyx production. CAM was effective on biofilms at 100 microg/ml but neither at 1 nor at 10 microg/ml. It is suggested that glycocalyx production started following bacterial multiplication and continued even after the cells had entered the stationary phase to form mature biofilms. No antibiofilm effect of CAM was observed at sub-MIC.

Spatial and temporal variation of secondary flow during oscillatory flow in model human central airways

Axial and secondary velocity profiles were measured in a model human central airway to clarify the oscillatory flow structure during high-frequency oscillation. We used a rigid model of human airways consisting of asymmetrical bifurcations up to third generation. Velocities in each branch of the bifurcations were measured by two-color laser-Doppler velocimeter. The secondary velocity magnitudes and the deflection of axial velocity were dependent not only on the branching angle and curvature ratio of each bifurcation, but also strongly depended on the shape of the path generated by the cascade of branches. Secondary flow velocities were higher in the left bronchus than in the right bronchus. This spatial variation of secondary flow was well correlated with differing gas transport rates between the left and right main bronchus.

[Active pulmonary tuberculosis in patients with lung cancer]

To clarify the features of the coexistence of active pulmonary tuberculosis in patients with lung cancer, we analyzed clinical data on 25 cases with coexisting lung cancer and active pulmonary tuberculosis encountered at Tokyo National Chest Hospital during the period from 1991 to 1998. There were 23 men and 2 women, with a mean age of 70 years. The incidence of lung cancer among patients with active pulmonary tuberculosis at our hospital was 0.7 per cent, while the incidence of active pulmonary tuberculosis in untreated lung cancer patients at our hospital was 1.9 per cent. We classified the 25 cases into 2 groups as follows: (1) tuberculosis sequential to lung cancer (11 cases) and (2) tuberculosis concurrently detected with lung cancer (14 cases). All patients in the former group were transferred from other hospitals after diagnosing the coexistence of pulmonary tuberculosis during the management of lung cancer. Histological types of lung cancer were squamous cell carcinoma in 12, adenocarcinoma in 9, and small cell carcinoma in 4, and as to the disease stage, stages III to IV were predominant. Analysis on relationship of chest X-ray findings between lung cancer and pulmonary tuberculosis revealed that in general, the location of lung cancer and tuberculosis seemed to be independent. Tuberculosis in the sequential group was more extensive and severer than in the concurrent group. In the concurrent group, treatment for tuberculosis was successful except for one case, and coexisting tuberculosis did not seem to affect the course of lung cancer among this group. However, in the sequential group, 5 patients died within 3 months, 2 of them died of tuberculosis. We consider that in the management of lung cancer, physicians should consider the possibility of coexistent active pulmonary tuberculosis and should not make delay in the diagnosis of active pulmonary tuberculosis.

Detection of K-ras mutations of bronchoalveolar lavage fluid cells aids the diagnosis of lung cancer in small pulmonary lesions

An increased prevalence of K-ras oncogene mutation in lung adenocarcinoma has been shown by PCR-primer-introduced restriction with enrichment for mutation alleles (PCR-PIREMA) experiments. In the present study we investigated whether this method is useful for the diagnosis of lung cancer in small pulmonary lesions, which are difficult to diagnose cytologically as lung cancer by bronchoscopic examination. We examined bronchoalveolar lavage fluid (BALF) cells from 33 patients with single nodular pulmonary lesions of less than 2 cm in diameter (measured on chest computed tomography scans) for K-ras (codon 12) mutation, by PCR-PIREMA. Transbronchial fiberscopic examinations had not revealed lung cancer cytologically in any of the patients. The final diagnoses for the 33 lesions were 20 adenocarcinomas, 5 cases of focal fibrosis, 5 cases of pneumonia, 1 case of tuberculosis, 1 hamartoma, and 1 case of lymph node swelling. BALF cell lysates were amplified and digested with a restriction enzyme to detect the K-ras oncogene. Only the normal K-ras was observed after the first amplification and digestion for each of the 33 patients. Three amplifications and digestions were performed for each sample. We detected mutation of K-ras in BALF cells from 15 (75%) of 20 lung cancer patients and in cells from only 4 (31%) of 13 patients with nonmalignant lesions. The detection rate of the K-ras mutation in lung cancer was significantly greater than that in nonmalignant lesions (P = 0.012). Our results indicate that the detection of the codon 12 K-ras mutation in BALF cells by PCR-PIREMA aids the diagnosis of lung cancer in patients with small pulmonary lesions with negative cytological findings.

Effect of the growth rate of Pseudomonas aeruginosa biofilms on the susceptibility to antimicrobial agents: beta-lactams and fluoroquinolones

The growth rate of biofilm bacteria of a leucine-requiring mutant Pseudomonas aeruginosa HU1 was regulated by the leucine concentration in a chemically-defined medium. The semiquantitative measurement of glycocalyx and scanning electron microscopy revealed that the kinetics of HU1-biofilm formation were dependent on the incubation time and the leucine concentration in the medium. The effect of the growth rate of biofilm cells on their susceptibility to antimicrobial agents, three beta-lactams and four fluoroquinolones, was evaluated. beta-Lactams showed weak bactericidal activity to biofilm cells; the activity was greater in younger biofilm cells growing in high concentrations of leucine. Fluoroquinolones revealed strong bactericidal activity to biofilm bacteria regardless of the growth rate. The following is suggested: the bactericidal action of beta-lactams against biofilm cells is affected by the cell growth rate, while that of fluoroquinolones is considerably greater and independent on the growth rate.

Augmentation of axial dispersion by intermittent oscillatory flow

The efficiency of axial gas dispersion during ventilation with high-frequency oscillation (HFO) is improved by manipulating the oscillatory flow waveform such that intermittent oscillatory flow occurs. We therefore measured the velocity profiles and effective axial gas diffusivity during intermittent oscillatory flow in a straight tube to verify the intermittency augmentation effect on axial gas transfer. The effective diffusivity was dependent on the flow patterns and significantly increased with an increase in the duration of the stationary phase. It was also found that the ratio of effective diffusivity to molecular diffusivity is two times greater than that in sinusoidal oscillatory flow. Moreover, turbulence during deceleration or at the beginning of the stationary phase further augments axial dispersion, with the effective diffusivity being over three times as large, thereby proving that the use of intermittent oscillatory flow effectively augments axial dispersion for ventilation with HFO.

Permeation of antimicrobial agents through Pseudomonas aeruginosa biofilms: a simple method

In this study, we evaluated the permeation of piperacillin (PIPC), imipenem (IPM), amikacin (AKM), gentamicin (GM), ofloxacin (OFLX), levofloxacin (LVFX), ciprofloxacin (CPFX) and sparfloxacin (SPFX) through Pseudomonas aeruginosa biofilm with a simple new method. Bacteria used were a leucine-requiring mucoid mutant. Bacteria were grown on the membrane of a cell culture insert in chemically defined medium and incubated at 37 degrees C for 5 days. At days 0, 1, 3 and 5, the penetration rates through the biofilms were measured. PIPC and IPM demonstrated relatively high permeation both with penetration rates at day 5 of 50%, whereas AMK and GM, which are aminoglycosides, showed low permeation both with penetration rates after day 1 of less than 25%. Among the 4 fluoroquinolones, LVFX and SPFX demonstrated excellent permeation with penetration rates that reached 100% from day 0 to 5, while OFLX and CPFX showed almost the same permeation as IPM. This method of measuring penetration rates of antimicrobial agents through biofilm is very simple and useful for the evaluation of antibiotics against biofilm-forming bacteria.

New technique for time series analysis combining the maximum entropy method and non-linear least squares method: its value in heart rate variability analysis

A new technique for time series analysis, which is a combination of the maximum entropy method (MEM) for spectral analysis and the non-linear least squares method (LSM) for fitting analysis, is described. In this technique, the MEM power spectral density (MEMPSD) is calculated using a very large lag that could diminish the lag dependence of dominant periods estimated by the MEM analysis. The validity of this large lag is confirmed by the LSM, given that the ten dominant MEM periods are known quantities. To validate the MEM plus LSM technique, it is compared with autoregressive (AR) modelling, by analysing heart rate variability under pharmacological interventions (phenylephrine and trinitroglycerine), using 16 young males. The results indicate that the MEMPSD, when compared with the ARPSD, has numerous periods that could reproduce the original time series much more accurately, as revealed by the LSM analysis. However, both the low- and high-frequency powers with MEMPSD and ARPSDs shift in the expected directions in accordance with the pharmacological effects on the cardiovascular system. The implications of these results are discussed from the theoretical and practical standpoints of the MEM plus LSM technique, compared with AR modelling.

[An oral repeated dose toxicity study of a new antineoplastic agent S-1 in dogs. I. A 13-week repeated dose toxicity study. II. An ophthalmologic toxicity recovery study]

S-1, an antineoplastic formulation of a fluorinated pyrimidine derivative containing tegafur (FT), CDHP, and potassium oxonate (Oxo) in a molar ratio of 1:0.4:1, was recently developed by Taiho Pharmaceutical Co., Ltd., with the aim of prolonging the effective plasma concentration of 5-fluorouracil (5-FU) over that producted by FT alone and reducing its dose-limiting gastrointestinal toxicity. As a part of the S-1 toxicity study, a 13-week repeated dose toxicity study and a recovery study of opthalmologic effects were conducted in dogs. The following results were obtained. All S-1 doses are expressed in terms of their FT content. 1. Concerning the general condition, dark brown pigment was deposited on the sclera of the eye in all S-1 treated groups starting at the second week of treatment, and clouding of the cornea was noted in the 3 mg/kg/day group starting after 3-4 weeks of treatment. In the 3 and 6 mg/kg/day groups, general signs such as salivation, reduction in spontaneous movements, and sedation appeared, and 1 male and 2 females of the 3 mg/kg/day group died or were moribund 4-5 weeks after treatment began. All animals of the 6 mg/kg/day died or were sacrificed within 2 weeks of the start of the study. 2. Food consumption and body weight were reduced in the groups administered 1 mg/kg/day or more S-1. 3. No apparent drug-induced changes were observed on electrocardiography, urinalysis, fecal occult blood test, hematological examination, liver and kidney function tests, or ocular mucosa infection tests. 4. Blood biochemical examinations showed decreases in creatinine and chloride levels in males, an increase in LDH activity, and decreases in the albumin level and A/G ratio in females of the 3 mg/kg/day group. 5. Organ weighing showed that the relative weight of the kidney was increased in males and females of the 3 mg/kg/day group. 6. Histopathological examination revealed melanin deposition in the conjunctiva or cornea and atrophy inflammation, neutrophil infiltration, and neovascularization in the corneal epithelium. Atrophy of lymphatic tissues, such as the thymus, spleen and various lymph nodes, and changes in the reproductive system such as aspermatogenesis and uterine atrophy, which are commonly observed side effects of anticancer drugs, were also noted. 7. In the group administered FT, vacuolation of the cerebral fornix and commissura anterior was observed in 1 animal, but no changes were observed in other examinations. 8. The toxic effects of S-1 appeared primarily in the eyes, lymphatic tissues, and reproductive organs, and deaths were ascribed to weakening due to exacerbation of the general effects accompanied by disorders of immunological function. The NOAEL of S-1 in this study was estimated to be the dose that delivered less than 0.5 mg/kg/day in both males and females. 9. Changes in the eye observed after S-1 administration are such as pigmentation of the sclera and white turbidity of the cornea. Though it may be produced vision decreased, these changes are considered to be unaccompanied by functional disorders and to be reversible.

[A 13-week oral repeated dose toxicity study of a new antineoplastic agent S-1 in rats]

S-1, an antineoplastic formulation of a fluorinated pyrimidine derivative containing tegafur (FT), CDHP, and potassium oxonate (Oxo) in a molar ratio of 1:0.4:1, was recently developed by Taiho Pharmaceutical Co., Ltd., with the aim of prolonging the effective plasma concentration of 5-fluorouracil (5-FU) over that produced by FT alone and reducing its dose-limiting gastrointestinal toxicity. As a part of the S-1 toxicity study, a 13-week oral repeated dose toxicity study and a recovery study using male and female rats was conducted. Doses of S-1 were adjusted to deliver 1.5, 5, and 15 mg/kg/day as doses of FT, and FT was given at 15 mg/kg/day. The following results were obtained. 1. In clinical observation, edema of the limbs and face or swelling of the auricle of the ear and an anemic appearance were observed in both sexes in the 15 mg/kg/day group as dose of FT. Subsequently, males in this group developed severe anemia, decreased spontaneous motor activity, emaciation, and subnormal skin temperature, and many males died. In the survivors, keratosis of the palm, sole, or tail was observed, with necrosis and loss of the tail tip in the severe cases. 2. Body weight gain was suppressed from about week 2 of treatment in both sexes in the 15 mg/kg/day group as dose of FT, and there was almost no weight gain after week 4-5. Food consumption was consistently less than the control value for males in the 15 mg/kg/day group as dose of FT throughout the treatment period. 3. No marked changes were observed in water intake and on opthalmologic examination. 4. In the fecal test for occult blood, a positive tendency was observed in both sexes in the 15 mg/kg/day group as dose of FT. 5. Urinalysis disclosed a slight increase in protein and decrease in sodium, potassium, and chloride in males, and an increase in protein in females in the 15 mg/kg/day group as dose of FT. 6. Hematologically, both sexes in the 15 mg/kg/day group as dose of FT showed decreases in red blood cell count, hemoglobin, and hematocrit, and increases in platelet count and fibrinogen, with a slight decrease in white blood cell count in males. 7. In the blood biochemical test, abnormal findings included increases in total cholesterol and free cholesterol, and decreases in non-esterified fatty acid and albumin in both sexes in the 15 mg/kg/day group as dose of FT. 8. In organ weight measurement, abnormal changes included a decrease in thymus weight in both sexes in the 5 mg/kg/day or higher dosage groups and a decrease in the testis weight in males and an increase in the liver weight in females in the 15 mg/kg/day group as dose of FT. 9. Histopathologically, both sexes in the 15 mg/kg/day group as dose of FT showed a decrease in the red pulp of the bone marrow, atrophy of the thymus, white pulp of the spleen, and testes. degeneration of the renal tubules, and ulcerative changes of the skin or oral mucosa. 10. The findings were unremarkable in the FT group. 11. During the recovery study, all the toxic effects tended to reverse. 12. The NOAEL of S-1 was estimated to be 1.5 mg/kg/day as dose of FT for both sexes.

[Oral single-dose toxicity study of a new antineoplastic agent S-1, and its components, CDHP, and Oxo]

S-1, an antineoplastic formulation of a fluorinated pyrimidine derivative containing tegafur (FT), CDHP, and potassium oxonate (Oxo) in a molar ratio of 1:0.4:1, was recently developed by Taiho Pharmaceutical Co., Ltd., with the aim of prolonging the effective plasma concentration of 5-fluorouracil (5-FU) over that produced by FT alone and reducing its dose-limiting gastrointestinal toxicity. As a part of the S-1 toxicity study, the single-dose toxicity of S-1 as well as that of its components, CDHP and Oxo, was investigated in mice, rats, and dogs. The following results were obtained. 1. In mice and rats, excretion of diarrheal stools, salivation, and alopecia were observed after S-1 administration. In severe cases, the animals subsequently showed emaciation due to weight loss or suppressed weight gain, decreased spontaneous motor activity, an anemic appearance, bradypnea, prone position, and death. In the CDHP and Oxo treatment groups of rats, the only toxic signs were soft or diarrheal stools on the dosing day. 2. In dogs, vomiting and excretion of diarrheal, mucous, or soft stools was observed after S-1 administration. In the CDHP and Oxo treatment groups, excretion of soft and diarrheal stools and vomiting were observed relatively frequently from the dosing day until day 1. 3. In the pathological examination of the animals given S-1, mice and rats showed pulmonary congestion/edema, dark red discoloration of the mesenteric lymph nodes, atrophy of lymphatic tissues such as the thymus and lymph nodes, decreases of lymphocytes in the splenic white pulp and mesenteric lymph nodes, a decrease in bone marrow cells, congestion of the glandular stomach, and aggregates of bacteria in the lung, liver, or spleen. In dogs, abnormal changes were observed mainly in the lymphatic organs such as the thymus and lymph nodes. 4. The LD50 values of S-1 in terms of the amount FT they contained were estimated to be 549 mg/kg for mice(male), 441-551 mg/kg for rats (both sexes) and about 53 mg/kg for dogs (male). The LD50 values of CDHP and Oxo were 2000 mg/kg or higher for both rats (both sexes) and dogs (male). 5. Hematopoietic and lymphatic impairments, immunosuppression associated with respiratory were considered to be the cause of death from S-1. The toxicity of S-1 reflects the toxicity of 5-FU and was not found the different toxicity by the addition of CDHP and Oxo.