Involvement of Ca(2+)-calmodulin-dependent protein kinase II in the intestinal secretory action of Escherichia coli heat-stable enterotoxin II

Treating the mouse intestine with the calmodulin antagonist W-7 and KN-93, an inhibitor of Ca(2+)-calmodulin-dependent protein kinase II (CaMK II), reduced the sensitivity of the host to the action of Escherichia coli heat-stable enterotoxin II (STII). CaMK II activity in mouse intestinal cells increased after exposure to STII. These results indicate that CaMK II is involved in the mechanism of action of STII.

Effects of 6-chloro-2',3'-dideoxyguanosine (6-Cl-ddG) in surface lymph nodes of rhesus monkeys (Macaca mulatta) chronically infected with simian immunodeficiency virus (SIVmac239)

We studied the effects of 6-chloro-2',3'-dideoxyguanosine (6-Cl-ddG), an antiretroviral drug, in surface lymph nodes of rhesus monkeys (Macaca mulatta) chronically infected with simian immunodeficiency virus (SIV). The rhesus monkeys were treated with 25 mg/kg of 6-Cl-ddG every 8 hr for 2 weeks. We performed sequential biopsies of the surface lymph nodes three times: before, during, and after the drug treatment. The 6-Cl-ddG dramatically decreased the number of infectious virus (measured by limiting dilution assay) in lymph node mononuclear cells. This decrease was consistent with the decrease in the number of viral RNA-positive cells in lymph nodes (analyzed by in situ hybridization). Histopathological analysis revealed that hyperplastic lymphoid follicles were reduced in size, especially, enlarged areas of centroblasts in lymphoid follicles (the so-called dark areas of germinal centers) were declined. Our results demonstrated that 6-Cl-ddG decreased the viral burden concomitantly with reduced hyper-activation of germinal centers in lymphoid follicles of SIV-infected rhesus monkeys.

The effects of dexamethasone on antiemetics in female patients undergoing gynecologic surgery

This randomized, double-blind study compared the effects of dexamethasone plus either droperidol, metoclopramide, or granisetron with each antiemetic alone for preventing postoperative nausea and vomiting (PONV) in 270 female patients undergoing general anesthesia for major gynecological surgery. Patients were randomly assigned to receive either droperidol 1.25 mg (Group D1, n = 45), droperidol 1.25 mg plus dexamethasone 8 mg (Group D2, n = 45), metoclopramide 10 mg (Group M1, n = 45), metoclopramide 10 mg plus dexamethasone 8 mg (Group M2, n = 45), granisetron 40 micrograms/kg (Group G1, n = 45), or granisetron 40 micrograms/kg plus dexamethasone 8 mg (Group G2, n = 45) immediately before the induction of anesthesia. A standard general anesthetic technique and postoperative analgesia were used throughout the study. Complete response, defined as no PONV and no administration of rescue antiemetic medication during the first 24 h after anesthesia, was 49% in Group D1, 60% in Group D2 (P = 0.199 versus Group D1), 51% in Group M1, 62% in Group M2 (P = 0.198 versus Group M1), 80% in Group G1, and 96% in Group G2 (P = 0.025 versus Group G1). Our results suggest that dexamethasone enhances the antiemetic efficacy of granisetron but does not potentiate the other antiemetics-droperidol and metoclopramide-in female patients undergoing major gynecological surgery.

IMPLICATIONS

We compared the efficacy of dexamethasone plus three different antiemetics-droperidol, metoclopramide, and granisetron-for the prevention of nausea and vomiting after gynecologic surgery. The granisetron-dexamethasone combination was the most effective for preventing post-operative emetic symptoms.

Cardiovascular responses to tracheal extubation or LMA removal in normotensive and hypertensive patients

PURPOSE

This study was undertaken to evaluate the haemodynamic changes of tracheal extubation or removal of a laryngeal mask airway (LMA) in normotensive and hypertensive patients.

METHODS

In a randomized trial of normotensive and hypertensive patients (n = 40 of each), tracheal extubation or LMA removal was performed. Changes in heart rate (HR), mean arterial pressure (MAP) and rate-pressure product (RPP) were measured before and 1, 2, 3, 5, and 10 min after tracheal extubation or LMA removal.

RESULTS

In normotensive patients, HR, MAP and RPP increased following tracheal extubation or LMA removal, and remained elevated for a maximum three minutes (P < 0.05). In hypertensive patients, the haemodynamic increases in response to extubation or LMA removal were observed for up to five minutes (P < 0.05). The immediate cardiovascular responses to extubation were greater than those related to LMA removal in both normotensive and hypertensive patients (normotensive: HR; 95 +/- 14 vs 81 +/- 11, MAP; 124 +/- 18 vs 106 +/- 10, RPP; 14,951 +/- 2720 vs 10,654 +/- 1898, hypertensive: HR 105 +/- 10 vs 87 +/- 13, MAP; 146 +/- 17 vs 119 +/- 12, RPP; 20,492 +/- 1674 vs 12,862 +/- 2115, mean +/- SD, P < 0.05). Following extubation or LMA removal, these haemodynamic variables increased more markedly in hypertensive patients than in normotensive patients (P < 0.05).

CONCLUSION

Removal of LMA is associated with less cardiovascular change than tracheal extubation in both normotensive and hypertensive patients.

Effective dose of granisetron in the reduction of nausea and vomiting after breast surgery

BACKGROUND

Prophylactic use of granisetron, a selective 5-hydroxytryptamine type 3 receptor antagonist, reduces the incidence of nausea and vomiting after breast surgery. This study was undertaken to determine the minimum effective dose of granisetron in the reduction of postoperative nausea and vomiting (PONV) in patients undergoing general anaesthesia for breast surgery.

METHODS

In a randomized, double-blind manner, 120 female patients aged 42-66 years were assigned to receive either placebo (saline) or granisetron in a dose of 20 micrograms.kg-1, 40 micrograms.kg-1 and 80 micrograms.kg-1 i.v. immediately before the induction of anaesthesia. A standard general anaesthetic technique was employed throughout. The PONV and safety assessments were performed continuously during the first 24 h after anaesthesia.

RESULTS

There were no significant differences among the groups with regard to patient demographics, surgical procedures, anaesthetics administered and analgesics given. The incidence of PONV was 47%, 43%, 17% and 17% after administration of placebo and granisetron 20 micrograms.kg-1, 40 micrograms.kg-1 and 80 micrograms.kg-1, respectively. Granisetron 40 micrograms.kg-1 was as effective as 80 micrograms.kg-1 and both resulted in significant reductions of the incidence of PONV compared with placebo and granisteron 20 micrograms.kg-1 (P < 0.05). No differences in the incidence of adverse events were observed among the groups.

CONCLUSION

Granisetron 40 micrograms.kg-1 appears to be the minimum effective dose for reducing PONV in patients undergoing general anaesthesia for breast surgery.

Concomitant cardiac and pulmonary operation. Pulmonary mechanics and outcome of phrenic nerve injury

OBJECTIVE

We describe the postoperative respiratory failure due to the phrenic nerve injury in the setting of concomitant cardiac and pulmonary operation.

EXPERIMENTAL STUDY

Prospective study.

SETTING

Department of Cardiac and Thoracic Surgery Osaka University Medical School.

PATIENTS AND INTERVENTIONS

From January 1984 to December 1993, 5 patients (1.4%) underwent the concomitant cardiac and pulmonary operation out of 359 patients who received surgical treatment for lung cancer at our institution.

MEASURES AND RESULTS

Three (60%) out of 5 patients required prolonged mechanical ventilation despite the absence of cardiac complication, lung edema or pneumonia. Diaphragm function and work of breathing were measured in two patients before and after weaning from mechanical ventilation. Phrenic nerve dysfunction was consistent with the result that trans-diaphragmatic pressure (delta Pdi) was low, a ratio of gastric to esophageal pressure swing (delta Pga/delta Pes) was abnormally negative, and work of breathing (WOB) was high. Phrenic nerve function restored associated with clinical improvement.

CONCLUSIONS

Diaphragm dysfunction and an increase in work of breathing may be potential causes of respiratory failure in patients after concomitant cardiac and pulmonary operation. This compromise in respiratory mechanics should not be overlooked in the postoperative care, which may lead to the best management in postoperative respiratory care.

Granisetron reduces the incidence of nausea and vomiting after middle ear surgery

We studied the efficacy of granisetron, a selective 5-hydroxytryptamine type-3 receptor antagonist, in preventing postoperative nausea and vomiting (PONV) after middle ear surgery. In a randomized, double-blind, placebo-controlled study, 60 ASA I patients received placebo (saline) or granisetron 40 micrograms kg-1 i.v. immediately before induction of anaesthesia (n = 30 in each group). A standard general anaesthetic technique was used. During the first 24 h after anaesthesia, the incidence of PONV in patients who had received granisetron was lower than in those who had received placebo (17% vs 63%; P < 0.05). There were no clinically important adverse effects in either group. We conclude that granisetron, given before anaesthesia, reduced the incidence of PONV after middle ear surgery.

Cloning and crystal structure of hematopoietic prostaglandin D synthase

Hematopoietic prostaglandin (PG) D synthase is the key enzyme for production of the D and J series of prostanoids in the immune system and mast cells. We isolated a cDNA for the rat enzyme, crystallized the recombinant enzyme, and determined the three-dimensional structure of the enzyme complexed with glutathione at 2.3 A resolution. The enzyme is the first member of the sigma class glutathione S-transferase (GST) from vertebrates and possesses a prominent cleft as the active site, which is never seen among other members of the GST family. The unique 3-D architecture of the cleft leads to the putative substrate binding mode and its catalytic mechanism, responsible for the specific isomerization from PGH2 to PGD2.

[Effects of calcium supplementation using AAACa or milk on nocturnal bone resorption in young women]

In order to study the effect of calcium supplementation on bone resorption, a randomized controlled crossover study was carried out on eight healthy 18-19 year old female volunteers using either AAACa heated oyster shell with vacuum-heated seaweed or milk. Regimen A consisted of an oral dose of 200 mg calcium in the form of AAACa. B 200 ml milk after breakfast and supper and at bedtime, and C control with no calcium supplement. Early morning fasting blood and urine sampling was carried out after 7 days of calcium supplementation. Serum calcium was higher in groups A and B than in C, and serum intact parathyroid hormone (PTH) was significantly lower in group A than in groups B and C, according to a paired t-test. Urinary excretion of crosslinked collagen degradation product, pyridinoline and deoxypyridinoline showed a similar decrease in groups A and B but not in C. The more effective suppression of PTH by AAACa than by milk may be due to its higher bioavailability and the absence of phosphate stimulating PTH secretion.

Phosphorylation of the Sendai virus M protein is not essential for virus replication either in vitro or in vivo

A large proportion of intracellular Sendai virus (SeV) M proteins is phosphorylated, but in mature virions the M protein is not phosphorylated or dephosphorylated. Phosphorylated M protein in cells is bound to the cytoskeletal components more firmly than unphosphorylated M protein. Thus it has been hypothesized that M protein phosphorylation plays an important role in the virus life cycle, especially in the step of maturation. Here, a transient expression-mutation experiment of the M gene demonstrated that a change of the Ser residue at the 70th position from the N-terminus to Ala (S70A) totally abolished M protein phosphorylation, strongly suggesting that this residue is phosphorylated. The mutated M gene was then placed in the corresponding region in the cDNA plasmid which generates a full-length antigenome SeV RNA, and a mutant SeV M-S70A was successfully recovered from the cDNA. This mutant virus was indeed defective in M protein phosphorylation but did not differ at all from the wild-type SeV recovered from the parental cDNA either in the replication kinetics and plaque morphology in cultured cells or in in vivo replication and pathogenicity for mice. We thus concluded that no phosphorylation of the M protein was required for SeV replication either in vitro or in vivo.

Experimental reconstruction of the mediastinal trachea with a wing-shaped reversed esophageal flap

BACKGROUND

In cases of extensive tracheal resection in which direct end-to-end anastomosis is impossible there is a need for reconstruction. Nevertheless, with the present lack of reliable artificial trachea, no reconstruction method is available to assure safe replacement of the mediastinal trachea.

METHODS

After tubular resection of the mediastinal trachea in mongrel dogs, the trachea was reconstructed using a wing-shaped reversed esophageal flap. A silicone tube was used as an internal stent.

RESULTS

In group I (16 animals), three tracheal rings were resected; in group II (4 animals), six tracheal rings; in group III (6 animals), eight tracheal rings; and in group IV (5 animals), eight tracheal rings and the lining of the greater omentum. Safe reconstruction was accomplished in all cases in groups I and II, 2 of 6 cases in group III, and 2 of 5 cases in group IV. The omentopexy failed to prevent incomplete closure, yet served to minimize inflammation in the mediastinum.

CONCLUSIONS

A reversed esophageal autograft can be considered as a tracheal replacement.

Prevention of PONV with granisetron, droperidol and metoclopramide in female patients with history of motion sickness

PURPOSE

Motion sickness is one of the patient-related factors associated with postoperative nausea and vomiting (PONV). This study was undertaken to assess the efficacy of granisetron, droperidol and metoclopramide for preventing PONV in female patients with a history of motion sickness undergoing major gynaecological surgery.

METHODS

In a prospective, randomized, placebo-controlled, double-blind study, 120 patients received either 1.25 mg droperidol, 10 mg metoclopramide, 40 micrograms.kg-1 granisetron or placebo (saline) iv immediately before induction of anaesthesia. A standardized anaesthetic technique and postoperative analgesia were used in all patients. During the first 24 hr after anaesthesia, the incidence of PONV and adverse events were recorded by nursing-staff.

RESULTS

The treatment groups were similar for patient demographics, types of surgery, anaesthetics administered and opioid given. The incidence of PONV was 70%, 50%, 57% and 23% in the placebo, droperidol, metoclopramide and granisetron groups, respectively (P < 0.05; overall chi 2 test). No difference in the incidence of adverse events was observed in either group.

CONCLUSION

Granisetron is a better prophylactic antiemetic than droperidol or metoclopramide in female patients with a history of motion sickness undergoing major gynaecological surgery.

Epithelioid angiosarcoma of bone

Angiosarcoma of bone is a rare, high-grade sarcoma of vascular origin. This article describes an epithelioid angiosarcoma in the humerus of a 48-year-old man. A multilocular osteolytic lesion with undefined margins and destroyed cortical and medullary bone, associated with a large soft tissue mass was demonstrated radiologically in the proximal metaphysis of the right humerus. The tumor, resected by amputation, was composed mostly of proliferating malignant cells with an epithelioid morphology. It had a predominantly sheet-like growth pattern, and an occasional pseudoglandular or alveolar arrangement, mimicking an adenocarcinoma. The dilated anastomotic vascular spaces lined by epithelioid endothelial cells and the intracytoplasmic lumina/vacuoles that sometimes contained erythrocytes suggested focal endothelial differentiation. On immunohistochemical investigation, many neoplastic cells expressed cytokeratin and endothelial markers: factor-VIII related antigen, CD31, and UEA-I. The ultrastructure of the tumor was consistent with that of an angiosarcoma. Our patient died of disease shortly after the diagnosis, implying an aggressive clinical course. Awareness of the existence of skeletal epithelioid angiosarcoma, combined with the identification of intracytoplasmic lumina, or at least small vasoformative foci, and immunohistochemical positivity for endothelial markers provide the best guide for distinguishing this tumor from metastatic carcinomas.

Use of a fusion protein to obtain crystals suitable for X-ray analysis: crystallization of a GST-fused protein containing the DNA-binding domain of DNA replication-related element-binding factor, DREF

Crystals of glutathione-S-transferase (GST)-fused protein containing the DNA-binding domain of DNA replication-related element-binding factor, DREF, were obtained under crystallization conditions similar to those for GST. Preliminary X-ray crystallographic analysis revealed that crystals of the GST-fused protein belong to space group P6(1)22 or P6(5)22 with unit cell dimensions a = b = 140.4 A, c = 93.5 A and gamma = 120 degrees, having one molecule in the crystallographic asymmetric unit. The crystals diffract to 2.5 A resolution. The cell dimensions are related to those of GST crystals thus far reported. Crystallization of the DNA-binding domain that was cleaved from the fused protein by thrombin was also carried out using several methods under numerous conditions, but efforts to produce well-ordered large crystals were unsuccessful. A possible application of GST-fusion proteins for small target proteins or domains to obtain crystals suitable for X-ray structure determination is proposed.

Immunocytochemical study of dystrophin localization in cone cells of mouse retinas

PURPOSE

Previously, the authors reported that dystrophin was observed under the rod cell membranes in rat retinas. However, it was not determined whether dystrophin is located in cone cells. In the current study, the authors clarify dystrophin localization in cone cells of mouse retinas.

METHODS

Immunoblotting, confocal laser scanning microscopy, and immunoelectron microscopy were used to investigate retinal dystrophin with a monoclonal antibody raised against the human dystrophin C-terminus.

RESULTS

Immunoblotting analysis showed some immunoreactive bands from retinal extracts. Confocal images indicated two different immunostaining patterns: One was a tiny dot, and the other was a larger, aggregated dot. Immunoelectron microscopy revealed that retinal dystrophin was localized in cone cells as well as in rod cells.

CONCLUSIONS

Retinal dystrophin is a common component of cone and rod cells and probably is related to the physiological function of photoreceptor cells.

Antidromic burst activity of locus coeruleus neurons during cortical spreading depression

The electrical activity of locus coeruleus neurons was investigated during cortical spreading depression in urethane-anaesthetized rats. Cortical spreading depression was induced by a direct application of 1-3 M KCl solution to the surface of the cerebral cortex. The occurrence of cortical spreading depression was assessed by recording negative d.c. shifts and in some experiments by monitoring the extracellular potassium concentrations. The mean spontaneous firing rate of locus coeruleus neurons was significantly reduced during cortical spreading depression. Approximately 60% of locus coeruleus neurons recorded during cortical spreading depression revealed anomalous burst activity consisting of multiple initial segment spikes as well as full initial segment-somatodendritic spikes with a marked initial segment-somatodendritic break. Each spike of the cortical spreading depression-related burst activity occurred at intervals ranging from 15.0 ms to 90.1 ms (34.9 +/- 0.5 ms). The burst activity appeared unpredictably at variable intervals in a phasic or tonic manner during cortical spreading depression. The cortical spreading depression-related burst activity of locus coeruleus neurons mimicked antidromic spikes induced by train stimulation of the cerebral cortex at short interspike intervals during iontophoretic application of GABA to locus coeruleus neurons, whereas it was totally different from synaptically-activated burst activity induced by tail pinch. The full spikes and initial segment spikes in the cortical spreading depression-related burst activity failed to collide with cortically elicited antidromic spikes, even when they appeared within the collision interval. The proportion of initial segment spikes in the cortical spreading depression-related burst activity was reduced following an increase in membrane excitability by iontophoretic application of glutamate, and increased during a decreased membrane excitability by GABA application. The antidromic burst activity of locus coeruleus neurons also appeared for a short time during cortical spreading depression prior to the occurrence of seizure waves induced by GABA antagonists, while the burst activity could not be observed during seizure activity. These results indicate that the cortical spreading depression-related burst activity was of antidromic origin and that the marked initial segment-somatodendritic break in spontaneous spikes of locus coeruleus neurons during cortical spreading depression was due to reduced excitability of the somatodendritic membrane. The cortical spreading depression-related burst activity may cause release of a large amount of noradrenaline in vast regions of locus coeruleus terminal fields through the numerous axon collaterals, thereby playing a role in functional changes of brain neurons related to cortical spreading depression.

Extracellular secretion of Escherichia coli heat-stable enterotoxin I across the outer membrane

Escherichia coli heat-stable enterotoxin Ip (STIp) is an extracellular toxin consisting of 18 amino acid residues that is synthesized as a precursor of pre (amino acid residues 1 to 19), pro (amino acid residues 20 to 54), and mature (amino acid residues 55 to 72) regions. The precursor synthesized in the cytoplasm is translocated across the inner membrane by the general export pathway consisting of Sec proteins. The pre region functions as a leader peptide and is cleaved during translocation. However, it remains unknown how the resulting peptide (pro-mature peptide) translocates across the outer membrane. In this study, we investigated the structure of the STIp that passes through the outer membrane to determine how it translocates through the outer membrane. The results showed that the pro region is cleaved in the periplasmic space. The generated peptide becomes the mature form of STIp, which happens to have disulfide bonds, which then passes through the outer membrane. We also showed that STIp with a carboxy-terminal peptide consisting of 3 amino acid residues passes through the outer membrane, whereas STIp with a peptide composed of 37 residues does not. Amino acid analysis of mutant STIp purified from culture supernatant revealed that the peptide composed of 37 amino acid residues was cleaved into fragments of 5 amino acid residues. In addition, analyses of STIps with a mutation at the cysteine residue and the dsbA mutant strain revealed that the formation of an intramolecular disulfide bond within STIp is not absolutely required for the mature region of STIp to pass through the outer membrane.

RETRACTED ARTICLE: Nicardipine inhibits amrinone-enhanced contractility in fatigued diaphragm

The purpose of this study was to examine the effect of amrinone, a bipyridine derivative, with and without nicardipine, a calcium channel blocker, on the contractility of fatigued diaphragm in dogs. Twenty dogs were divided into two groups of ten each: amrinone group (group A) and combined amrinone and nicardipine group (group AN). Diaphragmatic fatigue was induced by intermittent supramaximal bilateral electrophrenic stimulation at a frequency of 20 Hz applied for 30 min. Diaphragmatic contractility was assessed from changes in transdiaphragmatic pressure (Pdi). In group A, after producing fatigue, amrinone (0.75 mg·kg(-1) loading dose plus 10 μg·kg(-1)·min(-1) maintenance dose) was administered iv. In group AN, nicardipine 5 μg·kg(-1)·min(-1) was infused iv simultaneously with amrinone during this period. After diaphragmatic fatigue, Pdi at low-frequency (10-30 Hz) stimulation decreased compared with the prefatigue values (P<0.05), whereas no change in Pdi was observed at high-frequency (50-100 Hz), stimulation. The Pdi at each stimulus were increased compared with the fatigued values (P<0.05) by administering amrinone, and returned to these values after this agent was discontinued. The Pdi values at any frequency of stimulation did not change when amrinone was administered with nicardipine. Our results suggest that amirinone may enhance contractility in fatigued diaphragm via its effect on transmembrane calcium movement.

Experimental bronchiolitis obliterans induced by in vivo HVJ-liposome-mediated endothelin-1 gene transfer

BACKGROUND

Bronchiolitis obliterans (OB) is a lesion that results when injury to small conducting airways is repaired by a proliferation of fibrous granulation tissue. Bronchiolitis obliterans has emerged as a main cause of morbidity and mortality in the setting of lung and heart-lung transplantation. Endothelin-1 (ET-1), initially discovered as a vasoconstrictive peptide, has a mitogenic activity on vascular smooth cells and airway epithelial cells. Overproduction of endothelin has been reported in patients with OB or chronic rejection after lung transplantation. It is still undetermined whether locally overexpressed ET-1 has a potential impact in the pathogenesis of OB.

METHODS

We locally overexpressed ET-1 using ultraviolet irradiation-inactivated hemagglutinating virus of Japan (HVJ)-liposome-mediated in vivo gene transfer. Plasmid DNA of prepro-ET-1 and high mobility group 1 protein were coencapsulated in liposomes, and were introduced into airway epithelial cells by HVJ-mediated membrane fusion. Control animals received instillation of HVJ-liposome with an empty expression cassette. To confirm the efficiency of transfection, HVJ liposome with beta-galactosidase gene was introduced. The expression of ET-1 and beta-galactosidase was assessed by immunohistochemistry.

RESULTS

Bronchial epithelium alveolar cells and alveolar macrophage were stained blue (X-Gal) 1 week after in vivo gene transfer of beta-galactosidase gene, indicating beta-gal activity. In animals 1 to 2 weeks after in vivo transfection of prepro-ET-1 gene, hyperplastic connective tissue plaque was seen in the alveolar duct and small conducting airway, indicating histologically distinctive bronchiolitis obliterans. Strong ET-1-like immunoactivities were seen in the airway epithelial, hyperplastic connective tissue, and alveolar cells. No histopathologic changes were seen in the control animals.

CONCLUSIONS

These results suggested that ET-1 may play an important role in the pathogenesis of OB. The effective pharmacologic antagonist or inhibitor may possibly control the progression of disease in patients of OB.

Springtime peaks of trace metals in Antarctic snow

Drifting snow samples were collected at Asuka Station (71 degrees 32'S, 24 degrees 08'E, 930 m above sea level) over a period from July to December 1991; 36 elements (including Na, Mg, K, Ca, Fe, Al, Li, V, Cr, Mn, Co, Ni, Cu, Zn, Ga, Se, Rb, Sr, Cd, Pb, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Th) in snow were analyzed by inductively coupled plasma-mass spectrometry (ICP-MS) by direct sample introduction. Concentrations of Cl-, NO3-, and SO(4)2- in the snow were also determined by ion chromatography. In late September to early October, there was a pronounced peak concentration of most of the elements together with non-sea salt sulfate. Enrichment factor analyses suggest that Na, Mg, Ca, K, and Sr are of marine origin and Al, Fe, Mn, Rb, Cr, Ni, Ga, V, and all the rare earth elements are of crustal origins. Volcanic eruption of Mt. Pinatubo (June 1991) and Mt. Hudson (August 1991) could be the reason for the precipitation of Pb, Cd, Cu, Zn, and Se together with non-sea salt sulfates in the austral spring at Asuka Station.

A simple method for recovering the motile spermatozoa from extremely low quality sperm samples

Recovery of motile spermatozoa from extremely low quality samples for use in the intracytoplasmic sperm injection (ICSI) procedure is difficult. To solve this problem we developed a simple method to recover the motile spermatozoa using a 3% polyvinylpyrrolidone (PVP) droplet. After depositing a sperm pellet into this slightly viscous droplet, motile spermatozoa readily swam out to the clear area while immotile spermatozoa dispersed to a lesser extent, so that motile and immotile cells became clearly separated from each other. A total of 36 ICSI cycles using spermatozoa with extremely low quality characteristics were performed. We recovered the motile spermatozoa from all sperm samples from two sources of poor quality spermatozoa. Thirty-one cycles of ICSI with ejaculate resulted in fertilization and pregnancy rates of 54 and 29% respectively. Five cycles of ICSI with frozen-thawed epididymal spermatozoa resulted in fertilization and pregnancy rates of 70 and 60% respectively. The 3% PVP droplet method is very simple and easy to perform, so it may be useful for recovering the motile spermatozoa from extremely low quality sperm samples used for ICSI.

Granisetron reduces incidence of nausea and vomiting after breast surgery

BACKGROUND

Postoperative nausea and vomiting (PONV) remains a troublesome problem. The study was performed to evaluate the antiemetic efficacy of prophylactic granisetron, a selective 5-hydroxytryptamine type 3 receptor antagonist, on the incidence of PONV in patients undergoing general anaesthesia for breast surgery.

METHODS

In a randomized, placebo-controlled, double-blind study, 50 female patients, 45-68 years, were given a single dose of either placebo (saline, n = 25) or granisetron (40 micrograms.kg-1, n = 25) intravenously over 2-5 min immediately before the induction of anaesthesia. Postoperatively, during the first 24 hours after anaesthesia, the incidence of PONV and adverse events was recorded.

RESULTS

The treatment groups were similar for patient demographics, types of surgery, anaesthetic and postoperative management. Postoperatively, the incidence of PONV was 48% and 16% after administration of placebo and granisetron, respectively (P < 0.05). No differences in the incidence of other adverse events were observed between the two groups.

CONCLUSION

Granisetron is an effective antiemetic for preventing PONV in patients undergoing general anaesthesia for breast surgery.