Oscillations of electrical potential along a root of a higher plant

Higher plants exhibit an oscillation of electrical potential near the surface along the root. The oscillation was studied with the aid of both the usual intracellular microelectrode technique and the extracellular multielectrode technique, the latter making it possible to measure simultaneously electrical potentials along the root. It was found that the oscillation of extracellular surface potential showed the largest amplitude in the elongation region, and the phase of the oscillation in this region differed by 180 degrees from that in the mature region, where the oscillation appeared coherent. The measurement of the intracellular electrical potential suggested the existence of oscillatory components localized to the parenchyma/xylem interface in the elongation region. A theoretical analysis based on an electrical circuit network described the above-mentioned behavior. It was shown that the oscillation was propagated along the root over several centimeters without substantial decay in the mature region.

[Evaluation of irinotecan hydrochloride (CPT-11) and trastuzumab combination therapy as salvage treatment in patients with HER2 overexpressing metastatic breast cancer]

BACKGROUND

Though irinotecan hydrochloride(CPT-11)was approved in Japan in 1994, there have been few reports since that evaluated the efficacy of CPT-11. The position of this agent in the treatment of patients with metastatic breast cancer(MBC)is not definite. In addition, no report has been published to date about CPT-11 and trastuzumab combination therapy.

PURPOSE

To evaluate retrospectively the efficacy of CPT-11 and trastuzumab combination therapy as salvage treatment in patients with human epidermal growth factor receptor 2 (HER2)overexpressing MBC.

PATIENTS AND METHOD

We examined ten cases who received this therapy against MBC since February 2002 till March 2007 in our hospital. Overall response rate, change of tumor markers, time to treatment failure (TTF), time to progression( TTP), overall survival (OS)after start of CPT-11 and adverse events were examined for efficacy and tolerability.

RESULTS

Median age was 57 (40-67)and median number of prior chemotherapies was 5(2-9). Though the overall response rate was 20%, some tumor reduction was observed totally in seven cases. CEA and CA15-3 were decreased in 78%(7/9)and 63%(5/8) of cases, respectively. Median TTF, TTP and OS were 3, 4, and 6 months, respectively. Adverse events included three cases of severe neutropenia, one of whom died of treatment-related sepsis. Slight diarrhea occurred in seven and severe nausea occurred in two cases. Dose modification of CPT-11 was necessary in 5 cases, and three discontinued CPT-11 administration, mainly due to easy fatigability, nausea and neutropenia. During the therapy, four cases were all inpatients, and 6 eventually became outpatients.

DISCUSSION

This therapy for patients with HER2 overexpressing metastatic cancer resistant to multi-agents demonstrated a good result in terms of antitumor effect. But high tolerability could not be documented by our experience with this therapy. It was supposed that the risk management with prediction of adverse events and preparation of better supportive therapy could make for the higher tolerability of this therapy for more effective clinical use.

Effects of Neonatally Administered High-dose Diethylstilbestrol on the Induction of Mammary Tumors Induced by 7,12-Dimethylbenz[a]anthracene in Female Rats

The aim of this study was to investigate the effects of neonatal administration of a relatively high dose of diethylstilbestrol (DES) on the induction of mammary carcinomas (MCs) and benign proliferative lesions (PLs) induced by 7,12-dimethylbenz[a]anthracene (DMBA) in female rats. Three different terms of daily administration of DES (10 μg) were used: 0–14, 0–5, and 6–14 days after birth. Control animals were administered solvent (oil) alone once daily from 0 to 14 days after birth. Rats were given DMBA (10 mg) at 50 days after birth. All rats administered DES showed persistent estrus and anovulatory ovaries. In rats administered DES from 0 to 14 and 0 to 5 days after birth there was protection from development of MCs and PLs, and serum levels of both estrogen and progesterone were significantly lower than in the control animals at 100 days after birth. In rats administered DES from 6 to 14 days after birth, the incidence of MCs was equal to that of the control animals (100%), and the number of PLs was significantly higher than in the control animals. The critical period for exposure to endocrine disruptors, such as DES, affecting the induction of MCs and PLs may be from 0 to 5 days after birth.

[A case of paclitaxel and trastuzumab-resistant recurrent breast cancer with liver metastasis responding to S-1]

We experienced a case of paclitaxel- and trastuzumab-resistant recurrent breast cancer with liver metastases showing significant improvement by S-1. A 76-year-old woman was diagnosed with left breast cancer (T2N1M0, Stage II B). She received total mastectomy and CEF (cyclophosphamide 500 mg/m(2), epirubicin 60 mg/m(2), 5-FU 750 mg/m(2)) as adjuvant chemotherapy in March 2004. But twelve months later, she was referred to our clinic for management of lung and left supraclavicular lymph node metastases. Then weekly paclitaxel (80 mg/m(2)) and trastuzumab were started. After 2 cycles of weekly paclitaxel and trastuzumab treatment, lung and lymph node metastases were reduced and the patient showed a clinical response (CR), so she was treated by trastuzumab only. But seven months later, she was diagnosed as a recurrence of liver metastases. She was treated by combined paclitaxel and trastuzumab again, but liver metastases and tumor marker were progressive. S-1 was administered orally 100 mg/day every day for 4 weeks, followed by a 2-week rest interval as 1 cycle, and trastuzumab was injected at 2 mg/kg/week for every weeks. After 2 courses of the treatment, the level of tumor marker and tumor size of liver metastases were reduced. Only rash (grade 1) was observed during treatment. The treatment of S-1 is thought to be effective for taxane-resistant recurrent breast cancer.

Renal adenocarcinoma in a ferret

A spontaneous case of renal tumor was observed in a 7-year-old ovariectomized female pet ferret (Mustela putorius furo). Clinical signs included exhaustion, emaciation, anorexia, and stooping position. At necropsy, a solid and cystic mass replaced the left kidney and adrenal gland. The tumor was composed of pleomorphic epithelial cells with a large number of giant cells. Metastases were recognized in the lung, liver, greater omentum, right renal pelvis, and systemic lymph nodes. Immunohistochemical stains revealed that the tumor cells were positive for CD10, cytokeratin (CAM 5.2), and Ki-67 (MIB-1). On the basis of morphologic and immunohistochemical features, the tumor was diagnosed as a pleomorphic renal adenocarcinoma. This type of neoplasm is very rare in all species and has never been reported in a ferret.

Transient expression of M-CSF is important for osteoclast-like cell differentiation in a monocytic leukemia cell line

Cells of U937, a human monocytic leukemia cell line, differentiate into macrophages by treatment with 12-o-tetradecanoylphorbol-13-acetate (TPA), whereas cells treated with 1 alpha, 25-dihydroxyvitamin D3 [1,25-(OH)2D3] continue to grow without undergoing differentiation. When U937 cells were successively treated with TPA and 1,25-(OH)2D3, tartrate-resistant acid phosphatase-positive multinucleated cells appeared at 5 days after the treatment. These osteoclast-like cells released a soluble form of 45Ca from 45Ca-labeled bone particles. These cells were not formed when the order of treatment with TPA and 1,25-(OH)2D3 was reversed. Use of either dexamethasone or interferon-gamma (IFN-gamma) was effective in inhibiting the formation of these osteoclast-like cells. The expression of c-src, c-fms, and macrophage colony stimulating factor (M-CSF) was induced by TPA treatment; however, TPA-induced M-CSF gene transcription was attenuated by the subsequent addition of 1,25-(OH)2D3. Furthermore, both dexamethasone and IFN-gamma impaired the attenuation of M-CSF expression, suggesting that the transient expression of M-CSF may be important for the formation of osteoclast-like cells.

Relationship between Growth and Electric Oscillations in Bean Roots

Extracellular and intracellular electric potentials in bean roots are known to show electric oscillations along the longitudinal axis with a period of several minutes. The relationship between growth and the electric oscillations was studied using roots of adzuki (Phaseolus chrysanthos). We measured surface electric potentials with a multielectrode apparatus while simultaneously measuring elongation using a CCD camera and monitor. Roots having an electric oscillation grew faster than roots with no oscillation. Furthermore, elongation rate was higher in roots with higher oscillation frequency. Oscillation frequency had a strong dependence on temperature; i.e. Q(10) was estimated at 1.7. These results suggest a correlation between electric oscillation and elongation.

CT demonstration of spinal epidural emphysema after strenuous exercise

We report a case of spinal epidural emphysema after strenuous exercise. The emphysema was without clinical signs and disappeared after 2 weeks.