Preliminary time-of-flight neutron diffraction study of human deoxyhemoglobin

Human hemoglobin (HbA) is an intricate system that has evolved to efficiently transport oxygen molecules (O(2)) from lung to tissue. Its quaternary structure can fluctuate between two conformations, T (tense or deoxy) and R (relaxed or oxy), which have low and high affinity for O(2), respectively. The binding of O(2) to the heme sites of HbA is regulated by protons and by inorganic anions. In order to investigate the role of the protonation states of protein residues in O(2) binding, large crystals of deoxy HbA (approximately 20 mm(3)) were grown in D(2)O under anaerobic conditions for neutron diffraction studies. A time-of-flight neutron data set was collected to 1.8 A resolution on the Protein Crystallography Station (PCS) at the spallation source run by Los Alamos Neutron Science Center (LANSCE). The HbA tetramer (64.6 kDa; 574 residues excluding the four heme groups) occupies the largest asymmetric unit (space group P2(1)) from which a high-resolution neutron data set has been collected to date.

Intraoperative surgical clearance confirmation of tongue carcinomas using ultrasound

OBJECTIVES

The existence of tumour cells on the surgical margin can be shown in frozen sections. However, there has been no method to obtain information about surgical clearance intraoperatively. We propose a simple method to confirm the surgical clearance of tongue carcinomas during surgery.

METHODS

Just after the resection of a tumour in a conventional manner, the resected fresh specimen was immersed in a gelatine solution, maintaining its original shape and orientation, and refrigerated for solidification of the gelatine. Then ultrasound observation of the gelatine-embedded specimen was performed from the surface of the gelatine.

RESULTS

Very fine images could be obtained easily and without any specialist skills.

CONCLUSIONS

With this method, the operator can easily obtain information about surgical clearance during the operation.

Effects of propofol and halothane on long-term potentiation in the rat hippocampus after transient cerebral ischaemia

BACKGROUND

Propofol is reported to have protective effects on cerebral ischaemia-induced neuronal death. The aim of this study was to explore whether propofol and halothane can protect hippocampal neuronal function from ischaemic injury during general anaesthesia in rats.

METHODS

Rats were divided into 2-vessel occlusion (incomplete cerebral ischaemia) and 4-vessel occlusion (complete cerebral ischaemia) groups consisting of three subgroups each (sham-operated, propofol and halothane groups). One hour after starting propofol 1 mg kg(-1) min(-1) with 30% O2 and N2 or halothane 0.8% in 30% O2 and N2 rats with or without bilateral vertebral artery occlusion had bilateral common carotid arteries occluded by vessel clips for 10 min. Anaesthesia was maintained for another 1 h. Seven days after ischaemia-reperfusion, hippocampal long-term potentiation in the perforant path-dentate gyrus synapse was determined as an index of cerebral outcome.

RESULTS

In the propofol groups, the formation of long-term potentiation was significantly impaired in the 2-vessel and 4-vessel occlusion groups compared to the respective sham-operated groups (P < 0.01 and P < 0.05, respectively). Impaired formation of long-term potentiation in propofol groups was comparable to that in halothane groups. The formation of long-team potentiation in the propofol and halothane 2-vessel group was not significantly different from that in the awake 2-vessel group.

CONCLUSIONS

Propofol and halothane administered during ischaemia do not possess protective effects against hippocampal neuronal dysfunction induced by cerebral ischaemia-reperfusion as evaluated by our transient ischaemic rat models.

Biopersistence of inhaled nickel oxide nanoparticles in rat lung

In order to investigate whether or not airborne nanoparticles with a minimum agglomeration could be used for exposure tests on animals, we developed a nanoparticle generation system and examined the biological effects of the particles in an inhalation study. The generation system was composed of an ultrasonic nebulizer and diffusion dryers, and 30 Wistar male rats were exposed to nickel oxide (NiO) nanoparticles for 4 wk (6 h/day). The geometric mean diameter of the particles and the daily average exposure concentration determined by a combination of a differential mobility analyzer and a condensation nucleus counter in the exposure chamber were 139 +/- 12 nm and 1.0 +/- 0.5 x 10(5) particles/cm3, respectively. At 4 days and 1 and 3 mo after the inhalation, each group of 10 rats were sacrificed and NiO nanoparticles deposited in the lung were determined by chemical analysis and the biopersistence (biological half time) was calculated. The deposited amount of NiO nanoparticles in the rat lungs at 4 days after the inhalation was 29 +/- 4 microg. The retained particle amount in the rat lungs after the inhalation exponentially decreased and the calculated biological half time was 62 days. The histopathological change was not severe just after the inhalation nor throughout the observation time. We concluded that nanoparticles with a minimum agglomeration were dispersed stably in the chamber and exposed to rats for 4 wk and that deposited amounts in the rat lungs and the biopersistence of the particles and the biological response in lung were detected.

[A case of unresectable gastric cancer complicated by serious pyloric stenosis in which S-1 administration after gastrojejunostomy proved effective]

We report a patient with unresectable gastric cancer who was effectively treated with S-1 after gastrojejunostomy. A 64-year-old man was referred to our hospital for anorexia and epigastric palpable mass. Upper gastrointestinal endoscopy revealed an ulcerous tumor in the antrum of the stomach, and gastric roentgenography showed pyloric stenosis. CT showed simultaneous multiple liver metastases. We performed gastrojejunostomy to allow oral intake. He was treated with daily oral administration of 120-80 mg S-1 for two weeks followed by one week rest as one course. The treatment was repeated for 19 courses until remission was observed. Weekly paclitaxel therapy (80 mg/m(2)/week) was then chosen as second-line chemotherapy. Administration was continued for three weeks with one-week rest. The treatment course was repeated for 6 courses. Bi-weekly administration of CPT-11 (80 mg) and CDDP (30 mg) was chosen as third-line chemotherapy. He died of progressive disease 2 years and 2 months after surgery. During chemotherapy, he maintained a performance status of 0 to 1, and maintained quality of life. This case suggested that the gastrojejunostomy was a useful method for treating unresectable gastric cancer, allowing the possibility of oral intake, and the use of S-1.

Changes in temporomandibular disc position during growth in young Japanese

PURPOSE

To detect the initial changes in temporomandibular disc position during growth with MRI examination in a prospective longitudinal study of a young Japanese population.

METHODS

Forty-four temporomandibular joints in 22 healthy asymptomatic volunteers, mean age 11.8 years, age range 9-16 years, were examined by MRI. They were re-examined 2-3 years later. The mean age and age range at the second examination were 14.5 years and 12-19 years, respectively. The discs were assessed at three different locations by oblique sagittal planes at the lateral, central and medial parts, and the displacement was evaluated as a partial anterior or total anterior position.

RESULTS

Six joints already had a partial anterior position of the disc at the initial examination and no developmental change in disc position was observed during the examination period. Nine joints developed partial disc displacement during the examination period. Every partial displacement was observed at the lateral part of the disc. One joint developed a total anterior position from the lateral to the medial images.

CONCLUSIONS

Initial changes in the disc position are likely to start from the lateral part of the joint in the early teenage years and are often asymptomatic.

Surgical strategy for advanced gastric cancer with a concomitant thoracoabdominal aortic aneurysm requiring arterial reconstruction of the visceral branches

A 70-year-old man who presented with hematemesis was found to have advanced gastric cancer concomitant with a thoracoabdominal aortic aneurysm (TAAA), which involved all branches of the visceral arteries. The patient underwent the following staged operations: first, radical resection of the advanced gastric cancer with simultaneous reconstruction of the visceral branches, followed 1 month later by endovascular aortic replacement of the TAAA. He recovered uneventfully and was discharged without any paralytic complications or sign of graft infection.

Functional evaluations of the parotid and submandibular glands using dynamic magnetic resonance sialography

PURPOSE

To evaluate the functional differences between the parotid and submandibular glands using dynamic MR sialography.

METHODS

In 30 volunteers, the time-dependent changes (dynamic changes) in the maximum area of the detectable parotid and submandibular gland ducts on dynamic MR sialographic images were analysed.

RESULTS

Dynamic changes in the parotid gland ducts were detectable on MR sialographic images in all volunteers, but images of the submandibular gland ducts were detectable in only 23 volunteers. In addition, the dynamic changes in the submandibular gland ducts in these 23 subjects were less than those seen in the parotid gland ducts. A relationship was found between the changing ratio of parotid (Pearson r=0.448, P=0.013) or submandibular gland ducts (Pearson r=0.418, P=0.047) and the salivary flow rate during the stimulation period.

CONCLUSIONS

Dynamic MR sialography allows evaluation of rest and stimulated functioning and morphological evaluation of the parotid and submandibular glands. This technique appears to have many possible applications in the dental, medical and biological fields.

Gender difference in unstimulated whole saliva flow rate and salivary gland sizes

OBJECTIVE

A gender difference in the unstimulated whole saliva flow rate (UWSFR) may be due to a difference in the sizes of the salivary glands. In this study, we investigated the relationships among the UWSFR, gland sizes and body sizes of healthy young adult males and females.

DESIGN

Unstimulated whole saliva was collected for 5 min by the spitting method in 50 healthy young adults, and the flow rate of the saliva was measured. Heights and weights were measured, and body mass indices (BMI) were calculated. The sizes of the salivary glands were measured by use of a magnetic resonance imaging technique.

RESULTS

Parotid and submandibular gland sizes and flow rates in females were significantly smaller than those in males, as were also the weights, heights and BMI. In both males and females, there were significant positive correlations between gland sizes and the flow rates, weights and BMI. The variations of the flow rates were reduced by standardizing them with gland sizes, weights and BMI.

CONCLUSIONS

These results suggest that the lower UWSFR in females as compared with males is due to the smaller gland sizes due to the smaller body sizes.

Successful delivery after the transfer of twice-vitrified embryos derived from in vitro matured oocytes: a case report

We report here the first case of successful pregnancy and delivery after the blastocyst transfer of twice-vitrified embryos produced following in vitro maturation (IVM) and ICSI. The patient received 5000 IU hCG on day 12 of the treatment cycle, and oocyte retrieval was carried out 36 h after hCG injection. A total of 22 immature oocytes were obtained. Following incubation for 26 h in IVM medium, 15 oocytes (68.2%) reached metaphase II stage. In total, 13 oocytes (86.7%) were fertilized after ICSI with the husband's sperm, and 11 embryos at the pronuclear stage and two cleaved embryos on day 2 were vitrified because of thin endometrial thickness. Eight cryopreserved embryos at the pronuclear stage were warmed and cultured until the day 3 stage. Three embryos were transferred, and three embryos were twice vitrified. Unfortunately, these transferred embryos did not implant. Three twice-vitrified embryos were rewarmed and cultured until the day 5 stage, and two embryos were transferred. The second transfer attempt of twice-vitrified embryos resulted in the full-term delivery of a healthy infant. This case report demonstrates that twice-vitrified embryos, developed using an IVM protocol, retain the developmental competence for full-term, healthy infants.