Detecting parathyroid adenoma using technetium-99m tetrofosmin: comparison with P-glycoprotein and multidrug resistance related protein expression--a preliminary report

The aim of this study was to investigate the relationships among technetium-99m tetrofosmin (Tc-TF) accumulation in parathyroid adenoma and the expression of P-glycoprotein (Pgp) or multidrug resistance related protein (MRP). Before operation, 33 patients with parathyroid adenomas (larger than 1.5 gm) were studied with parathyroid scintigraphy 10 minutes and 2 hours after intravenous injection of Tc-TF before operation. Immunohistochemical analyses (IHA) were performed on multiple nonconsecutive sections of operative parathyroid specimens to detect Pgp or MRP expression. According to the results of IHA, the 33 parathyroid adenomas were separated into four groups: (1) 2 adenomas with both positive Pgp and positive MRP expression, (2) 1 adenomas with positive Pgp but negative MRP expression, (3) 2 adenomas with negative Pgp but positive MRP expression, and (4) 28 adenomas with both negative Pgp and negative MRP expression. All of 28 adenomas in the group 4 could be detected by Tc-TF parathyroid imaging. All of 5 adenomas in the groups 1 to 3 could not be detected by TcTF parathyroid imaging (p < 0.05). Not only the size of parathyroid adenomas, but also significant Pgp or MRP expression limited the sensitivity of Tc-TF parathyroid imaging to localize parathyroid adenomas before operation.

Electroporation for direct spinal gene transfer in rats

We investigated the feasibility of delivering exogenous genes into spinal cord using direct in vivo electrotransfection. Gene transfer to the spinal cord was accomplished via direct intrathecal injection of pE-GFP C1 vector, followed by five electric pulses for 50 ms at 200 V delivered intrathecally. The spinal cords were retrieved and analyzed with fluorescence microscopy, reverse transcription polymerase chain reaction (RT-PCR), and Western blotting. At day 1, 3 or 7 following electroporation a clear GFP expression in spinal cord tissue was detected. The most prominent transfection occurred in the meningeal cells and superficial layer of the spinal cord. Successful transfection was also confirmed with RT-PCR and Western blotting. The expression of GFP protein was peaked between 3 and 7 days after electroporation and significantly decreased at 14 days. No behavioral or spinal neurodegenerative changes were detected at any time point. This study demonstrates that direct in vivo electrotransfection represents an effective and simple method for spinal gene delivery and have a potential to be used clinically, especially, acute or chronic pain.

Development, survival and reproduction of black citrus aphid, Toxoptera aurantii (Hemiptera: Aphididae), as a function of temperature

The development, survival, and reproduction of the black citrus aphid Toxoptera aurantii (Boyer de Fonscolombe) were evaluated at ten constant temperatures (4, 7, 10, 15, 20, 25, 28, 30, 32 and 35 degrees C). Development was limited at 4 and 35 degrees C. Between 7 and 32 degrees C, developmental periods of immature stages varied from 44.2 days at 7 degrees C to 5.3 days at 28 degrees C. Overall immature development required 129.9 degree-days above 3.8 degrees C. The upper temperature thresholds of 32.3, 28.6, 29.3, 27.2, and 28.6 degrees C were determined from a non-linear biophysical model for the development of instars 1-4 and overall immature stages, respectively. Immature survivorship varied from 82.1 to 97.7% within the temperature range of 10-30 degrees C. However, immature survivorship was reduced to 26.3% at 7 degrees C and 33.1% at 32 degrees C. Mean adult longevity was the longest (44.2 days) at 15 degrees C and the shortest (6.2 days) at 32 degrees C. The predicted upper temperature limit for adult survivorship was at 32.3 degrees C. Total nymph production increased from 16.3 nymphs per female at 10 degrees C to 58.7 nymphs per female at 20 degrees C, declining to 6.1 nymphs per female at 32 degrees C. The estimation of lower and upper temperature limits for reproduction was at 8.2 and 32.5 degrees C, respectively. The population reared at 28 degrees C had the highest intrinsic rate of increase (0.394), the shortest population doubling time (1.8 days), and shortest mean generation time (9.5 days) compared with the populations reared at six other temperatures. The population reared at 20 degrees C had the highest net reproductive rate (54.6). The theoretical lower and upper temperature limits for population development, survival and reproduction were estimated at 9.4 and 30.4 degrees C, respectively. The biology of T. aurantii was also compared with three other citrus aphid species.

Tracking the assembly pathway of human immunodeficiency virus type 1 Gag deletion mutants by immunogold labeling

The Pr55gag gene product of human immunodeficiency virus type 1 (HIV-1) is sufficient to direct the formation of retrovirus-like particles (RVLPs). Recent biochemical evidence has indicated the presence of Gag intermediates in the cytoplasm; however, the Gag assembly process into RVLPs remains incompletely defined. The authors present here the subcellular localization of Gag mutant proteins in BSC40 and Jurkat cells by immunoelectron microscopy (IEM). The full Gag/Pol and Gag precursors, a C-terminal deletion mutant lacking a portion of nucleocapsid (NC), and all p6Gag gave rise to similar levels of RVLPs at the cell surface. A C-terminal deletion of all NC and p6Gag abrogated particle formation, whereas p24 was found in patches at the cell surface. Deletion of matrix (MA) sequences from Gag resulted in intracellular particles, and myristylation was not required for particle formation in the context of the MA deletion. Matrix expression was enhanced with Gag/Pol or Env coexpression as determined by semiquantitative IEM. p24 protein was targeted at vacuolar and mitochondrial membranes, but not at Golgi cisternae. In addition, aggregations of Gag intermediates and RVLPs in the cytoplasm, rough endoplasmic reticulum, cisternae, and mitochondria were noted. These results provide defined in situ evidence that HIV-1 particle assembly occurs in the cytosol in addition to budding at most intracellular membranes.

Left ventricular wave speed

Left ventricular (LV) wave speed (LVWS) was studied experimentally and confirmed in theory. Combining the definition of elastance (E) with the equations for the conservation of mass and momentum shows that LVWS is proportional to the square root of ELA, where L is long-axis length and A is the cross-sectional area, and the density of the blood. (We defined ELA = gamma, where gamma is compressibility.) We studied nine open chest, anesthetized dogs, three of which were studied during caval constriction when LV end-diastolic pressure was < or =0 mmHg. The hearts were paced at approximately 90 beats/min, and LV cross-sectional area was measured by using two pairs of ultrasonic crystals; E was calculated from the LV pressure-area loop. A pulse generator was connected to the LV apex, and LVWS was measured by using two pressure transducers: one near the apex and the other near the base. Their distance was measured roentgenographically and compared with the diameter of a reference ball. LVWS ranged from approximately 1 m/s during diastole to approximately 10 m/s during systole. The slope of the log c (where c is wave speed) vs. log gamma was 0.546, which is in agreement with theory (0.5). When gamma < or = 0, LVWS was approximately 1.5 m/s.

Induction of cytochrome P450-dependent monooxygenase in mouse liver and kidney by rutaecarpine, an alkaloid of the herbal drug Evodia rutaecarpa

Rutaecarpine is one of the main alkaloids of an herbal remedy, Evodia rutaecarpa, which has been used for the treatment of gastrointestinal disorder and headache. Effects of rutaecarpine on hepatic and renal cytochrome P450 (CYP)-dependent monooxygenase were studied in C57BL/6J mice. Treatment of mice with rutaecarpine by gastrogavage at 50 mg/kg/day for three days resulted in 57%, 41%, 6-, and 6-fold increases of hepatic microsomal benzo(a)pyrene hydroxylation, 7-ethoxycoumarin O-deethylation, 7-ethoxyresorufin O-deethylation, and 7-methoxyresorufin O-demethylation activities, respectively. However, the treatment had no effects on hepatic oxidation activities toward benzphetamine, N-nitrosodimethylamine, nifedipine, and erythromycin. In the kidney, rutaecarpine-treatment resulted in 2-fold and 42% increases of microsomal benzo(a)pyrene hydroxylation and 7-ethoxycoumarin O-deethylation activities, respectively. The treatment also increased renal 7-ethoxyresorufin O-deethylation activity to a detectable level. Immunoblot analysis of microsomal proteins showed that rutaecarpine-treatment increased the protein levels of CYP1A1 and CYP1A2 in the liver, whereas hepatic level of CYP3A-immunoreacted protein was not affected by rutaecarpine. These CYPs were not detectable in the immunoblot analyses of control and rutaecarpine-treated mouse kidney microsomes. These results indicated that rutaecarpine was a CYP1A inducer and showed potent inductive effects on both CYP1A1 and CYP1A2 in the liver.

Low-dose dexamethasone effectively prevents postoperative nausea and vomiting after ambulatory laparoscopic surgery

PURPOSE

To evaluate the prophylactic effect of low-dose dexamethasone (5 mg) on postoperative nausea and vomiting (PONV) in women undergoing ambulatory laparoscopic surgery. Metoclopramide and saline served as controls.

METHODS

One hundred twenty women (n=40 in each of the three groups) undergoing ambulatory laparoscopic tubal ligation under general anesthesia were enrolled in this randomized, double-blinded, placebo-controlled study. After tracheal intubation, group I received i.v. dexamethasone 5 mg, whereas groups II and III received i.v. metoclopramide 10 mg and saline, respectively.

RESULTS

Patients in group I reported a lower incidence of PONV and requested less rescue antiemetics than those in group III during the first four postoperative hours (P <0.01). Patients in group I reported a lower incidence of PONV than those in groups II (P <0.05) and III (P <0.01) during the 24-hr postoperative period. Groups II and III did not differ from each other in the incidence of PONV and the proportion of patients who requested rescue antiemetics.

CONCLUSION

Prophylactic iv dexamethasone 5 mg significantly reduces the incidence of PONV in women undergoing ambulatory laparoscopic tubal ligation. At this dose, dexamethasone is more effective than metoclopramide 10 mg or placebo.

Murine renal allografts: spontaneous acceptance is associated with regulated T cell-mediated immunity

It was shown >20 yr ago that mice will spontaneously accept renal allografts in the absence of immunosuppression, but the mechanism responsible for this is not understood. We transplanted DBA/2 (H-2(d)) kidneys into nephrectomized C57BL/6 (H-2(b)) mice, and the allografts were spontaneously accepted for >60 days without immunosuppression. In contrast, nonimmunosuppressed cardiac and skin allografts in the same strain combination are rejected within approximately 10 days. The accepted renal allografts have a prominent leukocytic infiltrate, suggesting an ongoing, local immune response. At 60 days post-transplant, the recipients of accepted renal allografts display DBA/2-reactive alloantibodies. They also display DBA/2-reactive delayed-type hypersensitivity responses that are actively counter-regulated by DBA/2-induced TGF-beta production, but not by IL-10 production. These data suggest that a donor-reactive, cell-mediated immune mechanism involving TGF-beta is associated with the spontaneous acceptance of renal allografts in mice.

Comparison of the uptake and clearance of Tc-99m MIBI, Tl-201 and Ga-67 in drug-resistant lymphoma cell lines

Tc-99m sestamibi (MIBI) has been used as a tumor-seeking agent. However, its role in detecting lymphomas has not been widely investigated. The aim of the present study was to determine the uptake and clearance characteristics of Tc-99m MIBI in vincristine-resistant lymphoma cell lines. In addition, thallium-201 (Tl-201) and gallium-67 (Ga-67) uptake and clearance characteristics were evaluated for comparison with Tc-99m MIBI. Drug-resistant lymphoma cell lines (monocyte-like, histiocytic lymphoma, human; B-lymphoma cell line, American Burkitt lymphoma, lymphoblastoid, human; Hodgkin's disease, lymphoid, human) were selected by multistep vincristine treatment up to 50 nM. After incubation of the radiotracers, Tc-99m MIBI, Tl-201 and Ga-67, in medium for 0, 10, 20, 30, 60 or 120 min, the uptake and clearance of each radiotracer were measured in the drug-resistant lymphoma cell lines. In addition, P-glycoprotein expression was determined by immunohistochemical study. In a comparison of the three radiotracers, the uptake of Tc-99m MIBI was the greatest in the studied wild-type lymphoma cell lines. Tc-99m MIBI uptake was much lower in drug-resistant tumor cell lines than in non-resistant cell lines. On the other hand, the uptake characteristics of Tl-201 did not differ between drug-resistant and non-resistant cells. Immunohistochemistry analyses of Ab-1 or JSB indicated that tumor cells expressed MDR-1 protein in all three cell lines. Tc-99m MIBI is a good radiotracer for detecting drug resistance in lymphoma cell lines.

Risk factors for age-related maculopathy: the Visual Impairment Project

OBJECTIVE

To describe the risk factors and associated population attributable risk for age-related maculopathy (ARM) and age-related macular degeneration (AMD) in Australians aged 40 years and older.

METHODS

Residents were recruited from 9 randomly selected urban clusters and 4 randomly selected rural clusters in Victoria, Australia. At locally established test sites, the following information was collected: visual acuity, medical and health history, lifetime sunlight exposure, dietary intake, and fundus photographs. Age-related maculopathy and AMD were graded from the fundus photographs using an international classification and grading system. Backwards logistic regression was used to identify the independent risk factors for ARM and AMD.

RESULTS

The participation rate was 83% (n = 3271) among the urban residents and 92% (n = 1473) among the rural residents. Gradable fundus photographs of either eye were available for 4345 (92%) of the 4744 participants. There were 656 cases of ARM, giving a weighted prevalence of 15.1% (95% confidence limit [CL], 13.8, 16.4); and there were 30 cases of AMD, giving a weighted prevalence of 0.69% (95% CL, 0.33, 1.03). In multiple logistic regression, the risk factors for AMD were as follows: age (odds ratio [OR], 1.23; 95% CL, 1.17, 1.29), smoked cigarettes for longer than 40 years (OR, 2.39; 95% CL, 1.02, 5.57), and ever taken angiotensin-converting enzyme inhibitors (OR, 3.26; 95% CL, 1.33, 8.01). The magnitude of all of these risk factors was slightly less for ARM, and having ever taken blood cholesterol-lowering medications was also significant (OR, 1.67; 95% CL, 1.12, 2.47; P =.001).

CONCLUSION

Smoking is the only modifiable risk factor for ARM and AMD, among the many environmental and systemic factors that were assessed.

Toxic effects of six plant oils alone and in combination with controlled atmosphere on Liposcelis bostrychophila (Psocoptera: Liposcelididae)

Six plant essential oils alone as repellent and fumigant, and in combination with the controlled atmosphere against Liposcelis bostrychophila Badonnel were assessed in the laboratory. These essential oils were extracted from the leaves of six source plants: Citrus tangerina Tanaka, Citrus aurantium L., Citrus bergamia Risso et Poiteau, Pinus sylvestris L., Cupressus funebris End]., and Eucalyptus citriodora Hook. The repellency test indicated that L. bostrychophila adults were repelled by filter paper strips treated with six essential oils. Of these essential oils, the C. funebris oil was most effective followed by that of F. sylvestris, C. tangerina, C. bergamia, and E. citriodora. The average repellency of the C. aurantium oil against L. bostrychophila adults was significantly lower than other five test oils by day 14. These essential oils had a high level of toxicity in the fumigation assay against L. bostrychophila adults at both 10 and 20 ppm. When combined with two controlled atmosphere treatments (12% CO2 + 9% O2, and 10% CO2 + 5% O2, balanced N2), the toxicity of plant oils was enhanced significantly.

Predicting chemotherapy response and comparing with P-glycoprotein expression using technetium-99m tetrofosmin scan in untreated malignant lymphomas

The purposes of this study were to predict the chemotherapy response of untreated malignant lymphomas (ML) using a technetium-99m tetrofosmin (Tc-TF) scan and to compare Tc-TF results with P-glycoprotein (Pgp) expression. Before undergoing chemotherapy, 25 patients with ML were enrolled in this study. Tc-TF scan was performed 10 min after intravenous injection of Tc-TF. Immunohistochemical analyses were performed on multiple sections of ML specimens to evaluate Pgp expression. The chemotherapy response was evaluated in the first 1-2 years after the completion of treatment. The mean tumor-to-background ratio of the 15 patients with good responses (3.23+/-0.56) was significantly higher than that of the ten patients with poor responses (1.18+/-0.11). All of the 15 patients with good responses had positive Tc-TF scan results, but negative Pgp expression. Among the ten patients with poor responses, all had negative Tc-TF scan results, but six had positive Pgp expression and four had negative Pgp expression. Significant differences in the incidences of good and poor responses were found between patients with positive Tc-TF scan results and patients with negative Tc-TF scan results and between patients with positive Pgp expression and patients with negative Pgp expression. No significant differences in the incidences of good and poor responses were found between Hodgkin's disease patients and non-Hodgkin's lymphoma patients, stage I-II patients and III-IV patients, patients aged >40 and patients aged < or =40 years, and patients with and without B symptoms. Compared with other prognostic factors, Tc-TF scan results and Pgp expression more accurately predict the chemotherapy response in patients with ML.

[Detection of serum free insulin-like growth factor 1 in patients with chronic viral hepatitis]

OBJECTIVE

To evaluate the serum free insulin-like growth factor 1 (IGF-1) level and its relation with the severity and prognosis in patients with chronic viral hepatitis, liver cirrhosis and severe chronic hepatitis.

METHODS

Serum free IGF-1 was detected by ELISA in 43 patients with chronic viral hepatitis, 20 with liver cirrhosis and 12 with chronic severe hepatitis.

RESULTS

Serum free IGF-1 was significantly decreased in patients with liver cirrhosis and severe chronic hepatitis. Five patients with chronic severe hepatitis whose serum free IGF-1 was lower than 0.2 ng/l died during follow-up. Four patients whose serum free IGF-1 above 0.3 ng/l survived. Serum free IGF-1 was significantly reduced in patients with albumin lower than 30 g/l.

CONCLUSIONS

Serum free IGF-1 is decreased in patients with liver cirrhosis and severe chronic hepatitis and it can predict the prognosis of patients with severe chronic hepatitis.

[Prevalence of mutants in the determinant region of hepatitis B surface antigen among Chinese carriers after receiving only active postexposure immunoprophylaxis]

OBJECTIVE

To determine the frequency of hepatitis B surface antigen (HBsAg) mutations in the alpha determinant region among children who developed chronic hepatitis B virus (HBV) infection after receiving only active postexposure immunoprophylaxis.

METHODS

HBsAg mutations were determined by PCR-directed nucleotide sequencing and sequence-specific solid-phase PCR analysis(SS-SPPCR) for 97 Chinese carrier cases after hepatitis B vaccination, for 88 children born aged women controls, and for 95 population based children controls.

RESULTS

Prevalence of amino acid substitutions as detected by direct sequencing among carrier cases, women controls, and children controls were 30.9%, 10.2%, and 5.3%, respectively. The most frequent amino acid substitutions observed were at residues 145, 126, and 133. However, there was no difference in the prevalence of 145 and 126 amino acid mutants as detected by a sensitive SS-SPPCR method between carrier cases and controls. The prevalence of 145 Arg and 145 Ala mutants that were detected by SS-SPPCR was 39.2%, 33.0% and 32.6% among carrier cases, women controls, and children controls, respectively. The total odds ratio was 5.41 for mutants detected by direct sequencing. Odds ratio were 34.55 and 33.39 among adw2 subtype and genotype B subjects for mutants detected by direct sequencing, respectively.

CONCLUSIONS

The results show that hepatitis B virus mutants in the determinant are fairly consistent observed but without immune selective pressures; HBV variant strains may pre-existent as minor quasispecies. The prevalence of mutants is related to HBV subtypes and genotypes.

To predict chemotherapy response using technetium-99m tetrofosmin and compare with p-glycoprotein and multidrug resistance related protein-1 expression in patients with untreated small cell lung cancer

The aim of this study was to investigate the relationships among technetium-99m tetrofosmin (Tc-TF) accumulation in untreated small cell lung cancer (SCLC), the expression of P-glycoprotein (Pgp) and multidrug resistance related protein-1 (MRP1), and the response to chemotherapy in patients with untreated SCLC. Thirty patients with SCLC were studied with chest scintigraphy 15 to 30 min after intravenous injection of Tc-TF before chemotherapeutic induction. Tc-TF chest scans were interpreted both visually and quantitatively. The response to chemotherapy was evaluated upon completion of chemotherapy. Immunohistochemical analyses were performed on multiple non-consecutive sections of biopsy specimens to detect Pgp and MRP1 expression. Fifteen patients with good response to chemotherapy had a significantly higher incidence (100.0%) of positive Tc-TF chest single photon emission computed tomography (SPECT) findings and negative Pgp or MPR expression than 15 patients with poor response (20%) (P<0.05). The tumor/background (T/B) ratios were 1.8+/-0.3 and 1.2+/-0.3 for patients with good response and poor response, respectively (P<0.05). However, other prognostic factors (performance status, tumor size and stage) were not significantly related to Tc-TF chest scan findings and response to chemotherapy. Tc-TF chest scintigraphy correlated well with Pgp or MRP1 expression and accurately predicted the response to chemotherapy in patients with SCLC.

Caspase activation in response to cytotoxic Rana catesbeiana ribonuclease in MCF-7 cells

Rana catesbeiana ribonuclease (RC-RNase) and onconase were proven to own anti-tumor activity. While molecular determinants of onconase-induced cell death have become more explicit, the RC-RNase-induced death pathway remains presently unknown. Here we demonstrated that RC-RNase-induced molecular cascades in caspase-3-deficient MCF-7 cells did not include activation of initiation caspase-8 and -9. Cleavage timing suggested that procaspase-2 and -6 might be processed by active caspase-7 in MCF-7 cells. Caspase-7 was also responsible for cleavage of the poly(ADP-ribose) polymerase. Furthermore, we reported that overexpression of Bcl-X(L) could raise the survival rates of MCF-7 cells treated with RC-RNase and onconase.

Visual impairment, age-related cataract, and mortality

OBJECTIVE

To explore associations between visual impairment, cataract, and mortality in older persons after adjusting for other factors associated with mortality.

METHODS

A population cohort of 3654 persons aged 49 years or older (82.4% of eligible residents in the Blue Mountains region, west of Sydney, Australia), were examined at the Blue Mountains Eye Study baseline period (1992-1994) and followed up 5 years later (1997-1999). Australian National Death Index data were used to confirm persons who had died since baseline. Associations between mortality and presence of visual impairment and cataract at baseline were assessed using the Cox proportional hazards regression model, controlling for age, sex, demographic and socioeconomic status, medical history, and health risk behaviors.

RESULTS

By June 30, 1999, 604 participants (16.5%) had died. The age- and sex-standardized 7-year cumulative mortality rate was 26% among persons with any visual impairment and 16% in persons without visual impairment. After adjusting for factors found significantly associated with mortality, including age, male sex, low self-rated health, low socioeconomic status, systemic medical conditions, and negative health risk behaviors, the presence at baseline of any visual impairment was independently associated with increased mortality risk (risk ratio [RR], 1.7; 95% confidence interval, 1.2-2.3). The presence of age-related cataract, either nuclear (RR, 1.5), cortical (RR, 1.3), or posterior subcapsular cataract (RR, 1.5), was also significantly associated with increased mortality risk. These associations remained statistically significant when visual impairment and each type of cataract were included simultaneously in the multivariate Cox model.

CONCLUSION

Visual impairment and age-related cataract may be independent risk factors for increased mortality in older persons.

Negative wave reflections in pulmonary arteries

The pulmonary arterial branching pattern suggests that the early systolic forward-going compression wave (FCW) might be reflected as a backward-going expansion wave (BEW). Accordingly, in 11 open-chest anesthetized dogs we measured proximal pulmonary arterial pressure and flow (velocity) and evaluated wave reflection using wave-intensity analysis under low-volume, high-volume, high-volume + 20 cmH2O positive end-expiratory pressure (PEEP), and hypoxic conditions. We defined the reflection coefficient R as the ratio of the energy of the reflected wave (BEW [-]; backward-going compression wave, BCW [+]) to that of the incident wave (FCW [+]). We found that R = -0.07 +/- 0.02 under low-volume conditions, which increased in absolute magnitude to -0.20 +/- 0.04 (P < 0.01) under high-volume conditions. The addition of PEEP increased R further to -0.26 +/- 0.02 (P < 0.01). All of these BEWs were reflected from a site ~3 cm downstream. During hypoxia, the BEW was maintained and a BCW appeared (R = +0.09 +/- 0.03) from a closed-end site ~9 cm downstream. The normal pulmonary arterial circulation in the open-chest dog is characterized by negative wave reflection tending to facilitate right ventricular ejection; this reflection increases with increasing blood volume and PEEP.

Effects of dexamethasone on emesis in cats sedated with xylazine hydrochloride

OBJECTIVE

To determine antiemetic efficacy of prophylactic administration of dexamethasone and its influence on sedation in cats sedated with xylazine hydrochloride.

ANIMALS

6 healthy adult cats (3 males and 3 females).

PROCEDURE

The prophylactic antiemetic effect of 4 doses of dexamethasone (1, 2, 4, and 8 mg/kg of body weight, IM) or saline (0.9% NaCl) solution (0.066 ml/kg, IM) administered 1 hour before administration of xylazine (0.66 mg/kg, IM) was evaluated. Cats initially were given saline treatment (day 0) and were given sequentially increasing doses of xylazine on days 7, 14, 21, and 28. After xylazine injection, all cats were observed for 30 minutes to allow assessment of frequency of emesis and time until onset of the first emetic episode. The influence of dexamethasone on xylazine-induced sedation in these cats also was evaluated.

RESULTS

Prior treatment with 4 or 8 mg/kg of dexamethasone significantly reduced the frequency of emetic episodes and also significantly prolonged the time until onset of the first emetic episode after xylazine injection. Time until onset of the first emetic episode also was significantly prolonged for dexamethasone at a dose of 2 mg/kg. Time until onset of sedation after administration of xylazine was not altered by administration of dexamethasone.

CONCLUSIONS AND CLINICAL RELEVANCE

Dexamethasone (4 or 8 mg/kg, IM) significantly decreased the frequency of emetic episodes induced by xylazine without compromising sedative effects in cats. Dexamethasone may be used prophylactically as an antiemetic in cats treated with xylazine.

[Effects of corticosterone on the activity of the neurons in the rostral ventrolateral medulla of rats]

Spontaneous discharges of the rostral ventrolateral medulla (RVLM) neurons were extracellularly recorded by multi-barrelled microelectrodes in urethane-anesthetized rats. A total of 145 neurons were recorded: 33 were cardiovascular, 31 were nociceptive modulating, and 81 were unknown functional. The cardiovascular neurons were electrophysiologically identified through activating baroreceptor reflex by electrical stimulation of the aortic nerve and by intravenous injection of phenylephrine. Of the 33 cardiovascular neurons, 25 (76%) increased in firing rate after iontophoretical application of corticosterone sulfate (CORT), and 8 (24%) failed to respond. Of the 31 nociceptive modulating neurons excited by noxious stimulation, the firing rate decreased in 19 (64%), increased in 2 (6%), and did not respond in 10 (30%) after iontophoresis of CORT. Of the remaining 81 unknown functional neurons, 32 (40%) were excited, 5 (6%) inhibited, and 44 (54%) were not affected by CORT. These results demonstrate that CORT may modulate the activities of the neurons in RVLM through fast non-genomical effect, suggesting that the mechanism of the fast actions of CORT may play an important role in integration of the cardiovascular, nociceptive modulating activity under some conditions such as stress.

Evaluation of chemotherapy response using technetium-99M-sestamibi scintigraphy in untreated adult malignant lymphomas and comparison with other prognosis factors: a preliminary report

The purpose of this study was to predict chemotherapy response using technetium-99m methoxyisobutylisonitrile (Tc-MIBI) scintigraphy in untreated adult malignant lymphomas (ML) and compare the response with other prognosis factors. Before chemotherapy, 25 adult patients with ML were enrolled in this study. Tc-MIBI scintigraphy was performed 10 min after intravenous injection of Tc-MIBI to calculate tumor-to-background (T/B) uptake ratio and interpret the results visually. Chemotherapy response was evaluated in the first 1 to 2 years after completion of treatment by clinical and radiological methods. The mean T/B uptake ratio of the 15 patients with good response (3.3 +/- 0.6) was significantly higher than that of the 10 patients with poor response (1.2 +/- 0.1). All of the 15 patients with good response had positive Tc-MIBI scintigraphic results. All of the 10 patients with poor response had negative Tc-MIBI scintigraphic results. However, there were no significant differences in the incidences of good and poor responses for other prognosis factors. In our preliminary study, when compared with other prognosis factors, Tc-MIBI scintigraphy was the best tool to predict chemotherapy response in adult patients with ML.

Comparing 18-fluoro-2-deoxyglucose positron emission tomography with a combination of technetium 99m tetrofosmin single photon emission computed tomography and computed tomography to detect recurrent or persistent nasopharyngeal carcinomas after radiotherapy

BACKGROUND

The diagnostic accuracy of combined computed tomography (CT) and technetium 99m tetrofosmin (Tc-TF) single photon emission computed tomography (SPECT) of head and neck to differentiate recurrent or residual nasopharyngeal carcinomas (NPCs) from benign lesions after radiotherapy was evaluated and compared with positron emission tomography (PET) with 18-fluoro-2-deoxyglucose (FDG).

METHODS

Four months after radiotherapy, 36 patients with NPC underwent Tc-TF SPECT and CT of head and neck to differentiate recurrent or residual NPC from benign lesions. Histopathologic examinations were performed on nasopharyngeal biopsies of all 36 patients.

RESULTS

Based on the biopsy results, the sensitivity, specificity, and accuracy of Tc-TF SPECT were 64%, 96%, and 86%, respectively, for differentiation of recurrent or persistent NPC from benign lesions. For CT and FDG-PET, the sensitivity, specificity, and accuracy were 73%, 88%, and 83% and 100%, 96%, 97%, respectively. For the 27 patients with NPC whose Tc-TF SPECT and CT results were congruent, the combination of Tc-TF SPECT and CT had the same sensitivity, specificity, and accuracy (100%, 96%, and 96%) as FDG-PET. For the nine patients with NPC with incongruent Tc-TF SPECT and CT results, FDG-PET correctly differentiated two benign lesions from seven recurrent/residual NPCs.

CONCLUSIONS

Although, FDG-PET is the best tool for detecting recurrent or residual NPC, combined congruent Tc-TF SPECT and CT results achieved the same accuracy as FDG-PET. Therefore, we concluded that FDG-PET could be considered only when Tc-TF SPECT and CT give incongruent results.

Use of dexamethasone on the prophylaxis of nausea and vomiting after tympanomastoid surgery

OBJECTIVE

The aim of this study was to evaluate the prophylactic effect of dexamethasone on postoperative nausea and vomiting (PONV) in patients undergoing tympanomastoid surgery.

STUDY DESIGN

Eighty patients (n = 40 in each of two groups) undergoing tympanomastoid surgery under general anesthesia were enrolled in this randomized, double-blind, placebo-controlled study.

METHODS

After tracheal intubation, group 1 received 10 mg dexamethasone intravenously, whereas group 2 received saline intravenously. Several parameters concerning with the occurrence of PONV were evaluated.

RESULTS

We found that dexamethasone reduced the total incidence of nausea and vomiting by 45%, with a 95% confidence interval of 26% to 64% (P <.001). Furthermore, dexamethasone reduced the incidence of vomiting episodes >4 times and the incidence of patients requiring rescue antiemetics (P <.05).

CONCLUSION

Dexamethasone at a dosage of 10 mg administered intravenously is effective in preventing PONV in patients undergoing tympanomastoid surgery.

[Studies on asymmetric synthesis of R-phenylethanolamine by whole cells of Arachnia sp. P163]

Effects of various factors on asymmetric synthesis of R-phenylaminoethanol from aminoacetophenone by the whole cells of Arachnia sp. P163 producing alcohol dehydrogenase for phenylethanol amine was investigated. It found that, although the reduction was inhibited by the substrate and the product, but it has the very high stereoselectivity. The reduction was normaly carried out with 2% glucose for reproduction of coenzyme in the reaction system without oxygen. The conversion yield and ee value of the product achieved 65% and 100%, respectively.