Detection of Bacillus piliformis by specific amplification of ribosomal sequences

In an effort to explore a sensitive species-specific detection system using the polymerase chain reaction (PCR) for B. piliformis, we sequenced 16S ribosomal DNA (rDNA) of the organism (MSK strain) isolated from the mouse and compared it with known rDNA sequences of the RJ strain isolated from the rat. Sequence homology between the MSK strain and the RJ strain was over 97%, but homology between the MSK strain and other bacterial species was less (70-83%). The results indicated that the sequences included B. piliformis species-specific regions. On the basis of the sequences, we designed a PCR primer set which amplifies B. piliformis rDNA specifically. The PCR with the primer set detected not only these two strains but also an HN strain of hamster origin, although it did not detect other organisms. Therefore, this primer set was considered to be specific for B. piliformis species. More than one organism (RJ strain) could be detected by the PCR method. Nine Jcl:Wistar rats were infected perorally with 2x10(4) RJ strain organisms, and three rats each were sacrificed on days 1, 3 and 5 postinoculation (p.i.) to investigate the presence of the organism in the liver, heart, cecum, spleen and mesenteric lymph nodes by PCR and the immunofluorescence test. On days 1 and 3 p.i., B. piliformis was not detected in any tissues of the six rats, but B. piliformis was detected in two of the three rats sacrificed on day 5 p.i. The presence of the pathogen was seen in both liver and heart (1/3), or in the cecum (1/3) by both methods.(ABSTRACT TRUNCATED AT 250 WORDS)

Determination of dephosphate bromofenofos in milk by liquid chromatography with electrochemical detection

A sensitive, specific method for the determination of dephosphate bromofenofos (DBFF) in milk by liquid chromatography (LC) with electrochemical detection is described. DBFF, the only metabolite of bromofenofos (BFF, a fasciolicide), was extracted from milk by liquid-liquid partition with acetone, acetonitrile, and dichloromethane and purified by using a C18 cartridge. The compound was separated from the matrix peaks by reversed-phase LC and detected by dual-electrode coulometric detection on a Kaseisorb LC ODS-300-5 (250 x 4.6 mm id, 5 microns) column. The mobile phase was acetonitrile-0.05M potassium dihydrogen phosphate (55 + 45, v/v) at pH 3.0. The flow rate was 1 mL/min at 40 degrees C. The applied potentials of detectors 1 and 2 were maintained at 0.30 and 0.45 V, respectively. Average recoveries (n = 5) of DBFF from milk spiked at 1 and 10 ng/mL were 73.1 and 82.7%, respectively; and coefficients of variation were 8.4 and 2.8%, respectively. The detection limit of DBFF in milk was 0.2 ng/mL. Fifty-nine raw and 181 commercial milks were analyzed. DBFF was detected in 4 raw milks (0.2-1.5 ng/mL; average, 0.6 ng/mL) and in 3 normal liquid commercial milks (0.3-0.7 ng/mL; average, 0.5 ng/mL). The identity of DBFF from milk was confirmed by gas chromatography/mass spectrometry.

Spinal cord protection: development of a paraplegia-preventive solution

We present a clinically available method to protect the spinal cord against ischemic or reperfusion injury and to prevent paraplegia after cross-clamping of the aorta. We separated 35 rabbits into five equal groups and clamped each animal's abdominal aorta distal to the left renal artery. We also occluded the aortas 2 cm above the iliac bifurcation for 45 minutes with inflated 5F balloon catheters. Through the catheter port distal to each balloon one of four different solutions was infused at 3 degrees C for 3 minutes at a rate of 5 mL/min (group I, uninfused control; group II, lactated Ringer's solution; group III, lactated Ringer's solution + 30 mg/kg of methylprednisolone; group IV, lactated Ringer's solution+methylprednisolone + 3 mL of 20% mannitol; group V, lactated Ringer's solution+methylprednisolone+mannitol + 10 mg/kg of vitamins E and C). We assessed the neurologic status of the hind limbs on the second postoperative day using Tarlov's criteria. The neurologic status in groups III, IV, and V was significantly superior to that of group I (p < 0.05, groups III versus I; p < 0.01, groups IV and V versus I). Spastic paraplegia occurred in 71% of group I, in 43% of group II, in 29% of group III, in 14% of group IV, and not at all in group V. The infusion of our specially blended solution with several spinal cord neuroprotective properties (hypothermia, methylprednisolone, mannitol, and vitamins E and C) achieved the best spinal cord protection against ischemic or reperfusion injury and prevented postoperative paraplegia.

Isolation and characterization of a highly hydrophobic new bacteriocin (gassericin A) from Lactobacillus gasseri LA39

A new bacteriocin, gassericin A, was purified from the culture fluid of Lactobacillus gasseri LA39 mainly by reverse-phase (RP) chromatography. The purification of gassericin A from a modified MRS broth, in which Tween 80 had been replaced by oleic acid, resulted in a 4500-fold increase in specific activity with a 6% recovery. Gassericin A was eluted as a single peak on the chromatogram from RP-HPLC and migrated by SDS-PAGE as a single band with a molecular weight of ca. 3.8 kDa. Gassericin A, a highly hydrophobic bacteriocin, was slightly soluble in water, but its solubility was increased by adding alcohol and acetonitrile. An amino acid analysis revealed that it was composed of 45.7% hydrophobic amino acids in the total residues of 35 amino acids. Gassericin A produced in the MRS broth associated strongly with Tween 80, although several further trials of dissociation were unsuccessful.

Nucleolar organizer regions in tongue carcinomas induced in rats: comparison with DNA cytofluorometric analysis

Eleven papillomas and 25 carcinomas were induced in rat tongues by oral administration of 0.001% 4-nitroquinoline 1-oxide (4NQO) in drinking water, and the biological characteristics and proliferative activity of the tumors were investigated by both DNA cytofluorometry and the argyrophilic nucleolar organizer region (AgNOR) staining method. The histopathological characteristics, the mean number of AgNORs per cell and DNA ploidy patterns were compared. The mean AgNOR number was lowest in normal epithelium (1.65 +/- 0.10), and highest in squamous cell carcinomas (2.97 +/- 0.70) and intermediate in papillomas (1.87 +/- 0.28). The differences were statistically significant. All normal epithelium and all papillomas showed a diploid pattern. Eighteen (72%) of 25 squamous cell carcinomas showed a diploid pattern, while 7 (28%) showed a diploid plus tetraploid pattern. There was a significant difference in the mean AgNOR number between the two ploidy groups of squamous cell carcinomas. These results suggest that the mean AgNOR number may reflect the histological grade in the process of carcinogenesis and polyploidization of carcinomas.

Different modes of interaction of two peptide fragments from subdomain 4 of rabbit skeletal muscle actin with actin promoters

Previously, we reported that the 2.6 kDa peptide fragment extending from Arg-177 to Tyr-198 in rabbit skeletal muscle actin bound to actin itself and inhibited its polymerization, while the 9.1 kDa peptide extending from Ser-199 to Tyr-279 in actin did not. The 2.6 kDa segment of actin was reported to contain one of the important actin-actin contacts (Hori, K. and Morita, F. (1992) J. Biochem. 112, 401-408). In this paper, we show additional evidence that the rate of salt-induced increase in the fluorescence of pyrene-labeled actin was decreased in the presence of the 2.6 kDa peptide. Conventional actin filaments were only scarcely observed in the presence of the 2.6 kDa peptide under an electron microscope with a steady state of fluorescence increase. Furthermore, the 2.6 kDa peptide was found to sever F-actin into short filament fragments. The 9.1 kDa peptide, on the other hand, neither inhibited the fluorescence increment of pyrene-actin nor severed actin filaments. However, the 9.1 kDa peptide was found to increase the viscosity and fluorescence intensity of pyrene-G-actin and to form short actin filaments in the absence of salts. Contact sites in the 9.1 kDa segment in actin may have a different mode of interaction with adjacent actin promoters in actin filaments from that of the 2.6 kDa segment.

New modification of a mammary artery retractor

A new accessory instrument to the self-retaining internal mammary artery retractor was developed. This instrument presses the chest wall inward, relieves the concavity of the inner surface of the chest wall, and provides good exposure of the internal mammary artery.

Effects of exogenously applied calponin on Ca(2+)-regulated force in skinned smooth muscle of the rabbit mesenteric artery

To help elucidate the physiological role of calponin (a thin-filament-linked regulatory protein) in smooth muscle contraction, the effects of its exogenous application were investigated on actin-activated MgAT-Pase activity in crude actomyosin from chicken gizzard, and on contraction induced by Ca(2+)-dependent and -independent means in arterial smooth muscle strips skinned by saponin or beta-escin. Calponin concentration dependently inhibited actin-activated MgATPase activity with a proportional increase in its binding to actomyosin and also attenuated Ca(2+)-induced contractions, in the presence or absence of calmodulin, in skinned arterial strips. Calponin, when phosphorylated by protein kinase C, reduced both its ability to bind to actomyosin and its inhibitory action on actomyosin MgATPase. The phosphorylated calponin also had no effect on the maximum Ca(2+)-induced contraction in skinned smooth muscle, suggesting that these actions of calponin are not nonspecific. Calponin attenuated the Ca(2+)-independent contraction observed in myosin light chain thio-phosphorylated strips, or on application of trypsin-treated myosin light chain kinase. However, calponin had no effect on maintained rigor contraction. These results suggest that in vascular smooth muscle, calponin may play a physiological role in the inhibition of Ca(2+)-regulated force, possibly through a direct action on active actin-myosin interactions.

Mechanisms of vasoconstriction induced by endothelin-1 in smooth muscle of rabbit mesenteric artery

1. The mechanism underlying the vasoconstriction induced by endothelin-1 (ET-1) was investigated by measuring the intracellular concentration of Ca2+ ([Ca2+]i), isometric force and phosphorylation of the myosin light chain (MLC) in endothelium-denuded unskinned and beta-escin-treated skinned smooth muscle from resistance vessels of the rabbit mesentery. The role of protein kinase C (PKC) in the action of ET-1 was studied in skinned smooth muscle using a synthetic peptide, PKC19-36, which corresponds to the autoinhibitory domain of PKC. 2. ET-1 (> 0.1 nM) induced slowly developing, maintained increases in [Ca2+]i and force. Nicardipine completely blocked the ET-1-induced increase in [Ca2+]i. BQ-123 (an inhibitor of the ETA receptor) blocked the ET-1-induced contraction but IRL 1620 (Suc-[Glu9,Ala11,15]-ET-1(8-21), an agonist of the ETB receptor) failed to induce contraction. 3. In ionomycin- and 70 mM K(+)-treated strips, ET-1 shifted the [Ca2+]i-force relationship to the left and enhanced the maximum amplitude of contraction induced by 2.6 mM Ca2+. In skinned smooth muscle treated with ionomycin, Ca2+ (0.1-3 microM) increased both force and MLC phosphorylation, in a concentration-dependent manner. ET-1 with GTP shifted both the Ca(2+)-force and Ca(2+)-MLC phosphorylation relationships to the left without significant changes in the maximum responses. ET-1 with GTP did not change the relationship between force and MLC phosphorylation. Similar effects were observed with phorbol 12,13-dibutyrate (PDBu, an activator of PKC). These results indicate that the sensitivity of MLC phosphorylation to Ca2+ is enhanced both by ET-1 with GTP and by PDBu. 4. PKC19-36 (an inhibitor of PKC) modified neither the contraction nor MLC phosphorylation induced by 0.3 microM Ca2+ but blocked the PDBu-induced enhancement of both these Ca(2+)-induced responses. However, PKC19-36 only partly inhibited the enhancement produced by ET-1 with GTP on the Ca(2+)-induced responses. PKC19-36 did not modify the relationship between force and MLC phosphorylation in the presence either of ET-1 with GTP or of PDBu. By contrast, BQ-123, neomycin and guanosine 5'-O-(2-thiodiphosphate) (GDP beta S) each abolished the ET-1-induced enhancement of the contraction induced by 0.3 microM Ca2+. 5. These results suggest that ET-1 acts on the ETA receptor and increases Ca2+ influxes through an activation of the dihydropyridine-sensitive Ca2+ channel, causing a long-lasting and maintained contraction in resistance vessels of the rabbit mesentery.(ABSTRACT TRUNCATED AT 400 WORDS)

Protection against spinal cord ischaemia: one-shot infusion of hypothermic solution

The protective effect of a one-short infusion of a range of low-temperature hypothermic solutions against spinal cord ischaemia was investigated. Forty rabbits were allocated into five groups each of eight animals. The abdominal aorta of each rabbit was clamped distal to the left renal artery, and also occluded for 30 min above the iliac bifurcation with an inflated 50-gauge French balloon catheter. Ringer's solution with lactate was infused through the catheter port distal to the balloon, at various temperatures (group I, uninfused control; group II, 33 degrees C; group III, 23 degrees C; group IV, 13 degrees C; and group V, 3 degrees C). The neurological status of the hind limbs was assessed on the second postoperative day using the criteria of Tarlov. A further eight rabbits underwent laminectomy at L2 or L3. Temperature probes were inserted into the spinal cord and the cord temperature monitored continuously during infusion in four rabbits from each of groups I and V. Spastic paraplegia occurred in five rabbits in group I, three in group II, and two in group III. Four rabbits in groups II and III, seven in group IV and all eight in group V showed complete recovery of neurological function. The infusion of 3 degrees C solution achieved significantly lower spinal cord temperatures in group V after aortic clamping, compared with the temperatures in group I (P < 0.001-0.005). It was concluded that protection against spinal cord ischaemia and prevention of postoperative paraplegia are promoted as the temperature of the hypothermic infusion solution is lowered.

Endoscopic ligation of gastric varices using a detachable snare

A new technique of endoscopic treatment for gastric varices is presented here, which was applied in 10 patients, either electively (n = 9) or as emergency therapy for bleeding (n = 9) or as emergency therapy for bleeding (n = 1). A detachable snare is placed endoscopically, tightened around the varix, and then detached using a similar principle to that of band ligation. Following one or two treatment sessions (one snare applied in seven cases, two snares applied in three cases), eradication of gastric varices was observed in all patients. No significant complications were encountered, and nine of 13 snares passed spontaneously, the remaining ones being removed when found during follow-up endoscopy. Short-term follow-up (4-12 months, mean: 7.2 months) did not show either reappearance of varices or rebleeding in any of the patients. Angiography and endoscopic ultrasonography performed in four patients before and after treatment showed regression or disappearance of intramural vessels. Further studies will show the relative value of this new technique compared to other treatment modalities such as banding or cyanoacrylate injection.

Superficial-type adenomas and adenocarcinomas of the colon and rectum: a comparative morphological study

BACKGROUND/AIMS

It has been uncertain whether colorectal carcinomas preferentially arise on preexisting adenomas or de novo. However, from a morphological viewpoint, it seems unlikely that pedunculated or exophytic malignant polyps progress to the deeply ulcerated advanced carcinomas usually found clinically.

METHODS

The morphological features of 26 nonpolypoid, superficial-type colorectal tumors (17 adenomas and 9 adenocarcinomas) were compared to clarify the developmental route of colorectal carcinomas.

RESULTS

The adenomas and adenocarcinomas were very similar in size and gross appearance; however, examination of the surface appearances of unsectioned tumors by dissecting microscopy was helpful for distinguishing the two. Histologically, no adenomatous tissue was found in any case of superficial-type adenocarcinoma. Five of the nine adenocarcinomas, even including those of small size, invaded the submucosal layer, and two showed lymph node metastasis.

CONCLUSIONS

These findings suggest that superficial-type adenocarcinomas show rapid growth and aggressive behavior. We suggest that this type of carcinoma may not progress by the adenoma-to-carcinoma pathway but that it may arise from a very small superficial-type adenoma.

Effects of sex steroids on the proliferation of thymic epithelial cells in a culture model: a role of protein kinase C

Using a rat thymic epithelial cell line (TEC; IT-45R1), the present study attempted to elucidate the mechanism of action of sex steroid hormones (SH) on the proliferation of TEC. The findings were as follows: (a) the proliferation of TEC in response to SH was mediated through protein kinase C activity introduced as a result of interaction between SH and plasma-borne inhibitors; (b) the strong inhibitory effect of SH on TEC proliferation might be mediated through the SH receptor pathway because the proliferative response was triggered by progesterone (P) and androgen (A), whereas the inhibitory response was triggered by P, A and oestrogen. These results clearly suggest that the control of TEC proliferation is a 'shut-off' mechanism triggered by high plasma levels of SH. This further refers to the speculation that the development of the normal thymus may be due to a lack of this 'shut-off' mechanism so that development occurs at the adequate plasma SH levels that are often observed before puberty. However, this development is inhibited at the high plasma SH levels after puberty and/or during pregnancy.

[Cytofluorometric DNA analysis in different histological patterns of thyroid papillary carcinoma]

Some papillary carcinomas of thyroid glands contain not only typical papillary structures but also various histological features in the same tumor. To investigate how areas with variable histological features differ in proliferative activity and how these differences influence the biological behavior of the whole tumor, we measured DNA contents by cytofluorometry in six papillary carcinomas with different histological features in the same tumor. DNA ploidy patterns were determined and the percentage of S plus G2M phase cells (S + G2M fraction) was calculated only in diploid tumors to assess the proliferative activity. The following conclusions were drawn. 1) It was demonstrated that there were differences in proliferative activity among areas with variable histological features in 4 of six tumors. 2) In the tumors which invaded adjacent tissues, the proliferative activity of the invasive area tended to be higher than that of the original area of the tumor. Therefore, the possibility exists that more precise evaluation of the biological behavior of the tumor can be obtained by measuring DNA contents of the tumor cells in invasive areas. 3) There was the gap in S + G2M fractions among some tumors with the same histological differentiation. Accordingly, DNA analysis of tumors would be of value in estimating proliferative activity.

Mitogen-activated protein kinase and its activator are regulated by hypertonic stress in Madin-Darby canine kidney cells

Madin-Darby canine kidney cells behave like the renal medulla and accumulate small organic solutes (osmolytes) in a hypertonic environment. The accumulation of osmolytes is primarily dependent on changes in gene expression of enzymes that synthesize osmolytes (sorbitol) or transporters that uptake them (myo-inositol, betaine, and taurine). The mechanism by which hypertonicity increases the transcription of these genes, however, remains unclear. Recently, it has been reported that yeast mitogen-activated protein (MAP) kinase and its activator, MAP kinase-kinase, are involved in osmosensing signal transduction and that mutants in these kinases fail to accumulate glycerol, a yeast osmolyte. No information is available in mammals regarding the role of MAP kinase in the cellular response to hypertonicity. We have examined whether MAP kinase and MAP kinase-kinase are regulated by extracellular osmolarity in Madin-Darby canine kidney cells. Both kinases were activated by hypertonic stress in a time- and osmolarity-dependent manner and reached their maximal activity within 10 min. Additionally, it was suggested that MAP kinase was activated in a protein kinase C-dependent manner. These results indicate that MAP kinase and MAP kinase-kinase(s) are regulated by extracellular osmolarity.

[Rheumatoid arthritis terminating in multiple myeloma]

A 65-year-old woman with a 25-year history of rheumatoid arthritis (RA) was admitted because of acute pneumonia in January, 1991. Then she was pointed out M proteinemia (IgG 3,220 mg/dl, IgA 139 mg/dl, IgM 216 mg/dl) for the first time. Serum IL-6 was below 4.0 pg/ml. She was followed up because of lack of bone change. Plasma cell count in bone marrow were 14.6%. She was re-admitted because of development of bone lesions March, 1992. There was no joint pains, and serum IgG, IgA and IgM were 5,148 mg/dl, 114 mg/dl and 106 mg/dl, respectively. CRP was negative. Serological tests of rheumatoid factor and antinuclear antibody were both positive. Serum IL-6 was elevated to 14.8 pg/ml. Bone marrow aspiration disclosed 30.6% myeloma cells. Serum IgG, A, and M were 5,148 mg/dl, 114 mg/dl and 106 mg/dl, respectively. Serum immunoelectrophoresis showed monoclonal IgG with kappa type light chain. X-ray findings revealed radiolucent myelomatous foci. From these findings, IgG kappa-type multiple myeloma with RA was diagnosed.

Scanning electron microscopic observations of the vascular structure of vertebral end-plates in rabbits

We used scanning electron microscopy to examine the microcirculation in the vertebral end-plates of rabbits. The arteriola arborizes and swells at the end-plate and then coils to make a microvessel loop. This loop is the structure we refer to as a vascular bud. We suggest that these loop structures of the capillaries play a major role in the nutrition of the intervertebral discs.

[Effect of dopamine and prostaglandin E1 on portal venous oxygenation]

We evaluated the effects of dopamine (DA) and PGE1 on portal venous oxygenation in patients undergoing gastrectomy. Thirty-two patients studied were anesthetized with isoflurane and nitrous oxide in oxygen. They were divided into three groups: DA was infused at a rate of 3 micrograms.kg-1.min-1 in 10 patients (DA group), PGE1 was infused at a rate of 0.02 microgram.kg-1.min-1 in 10 patients (PGE1 group), and the remainders did not receive DA nor PGE1 (control group). There were no significant differences in PaO2 and SaO2 among three groups. However, portal venous PO2 and SaO2 in DA and PGE1 group were significantly higher than those in the control group. These results suggest that DA and PGE1 elevate the portal venous PO2 and SO2 by increasing splanchnic blood flow more than its oxygen uptake or without increasing splanchnic oxygen uptake, and increase the oxygen supply to the liver.

Hemagglutination activity of Lactobacillus acidophilus group lactic acid bacteria

The cells of 28 strains of the Lactobacillus acidophilus group were evaluated for hemagglutination (HA) activity. The activity was found in the surface layer (SL) protein fraction extracted by 2 M guanidine hydrochloride. The most SL proteins from the A group strains (L. acidophilus (A1), L. crispatus (A2), L. amylovorus (A3), and L. gallinarum (A4)) showed HA activity, but the proteins from the B group strains (L. gasseri (B1) and L. johnsonii (B2)) showed no activity. The SL proteins from the A group strains were composed in common of a main component having molecular mass of about 40-45 kDa on SDS-PAGE. The SL proteins from JCM 1034 strain that showed the highest HA activity was fractionated by CM-Toyopearl ion-exchange chromatography. The highest HA activity was detected in the major protein of 41 kDa. This protein was purified and shown to be composed of about 50% of hydrophobic amino acids. The HA activity of the protein (1034 lectin) was specifically inhibited by fetuin and bovine lactoferrin at the concentrations of 80 and 160 micrograms/ml, respectively. The removal of N-acetylneuraminic acid from fetuin significantly decreased the inhibitory activity.

[Ventricular septal perforation following acute myocardial infarction in an 85-year-old woman]

An 85-year-old woman who experienced sudden severe chest and back pains was admitted to our hospital. On admission a pansystolic murmur was audible and the ECG showed an acute antero-septal myocardial infarction. Right heart catheterization revealed increased oxygen from the right atrium to the right ventricle, leading to the diagnosis of ventricular septal perforation (VSP). Hemodynamics of the patient were stabilized using only a low dosage of dopamine. However the heart weakened progressively, an operation was performed on the 13th day after the onset of the perforation. The post-operative course was uneventful. She is the oldest patient with VSP which has been successfully operated in Japan.

A new UV-sensitive syndrome not belonging to any complementation groups of xeroderma pigmentosum or Cockayne syndrome: siblings showing biochemical characteristics of Cockayne syndrome without typical clinical manifestations

We report here on two siblings who show no clinical manifestations except for slight cutaneous photosensitivity and cutaneous pigmentation but have biochemical characteristics of Cockayne syndrome (CS). Fibroblasts derived from the patients (Kps2 and Kps3) were 3-4 times more sensitive to UV than normal cells. Although unscheduled DNA synthesis (UDS) in these cells was at a normal level, recovery of RNA synthesis (RRS) after UV irradiation was severely depressed. Microinjection of bacteriophage T4 endonuclease V into the cells corrected RRS after UV irradiation to a level near normal. These results indicate that DNA repair of cyclobutane-type pyrimidine dimers is impaired in the cells and the biochemical characteristics are similar to those of CS cells. However, cell fusion complementation tests with CS group A and B cells resulted in correction of RRS after UV irradiation. Cell fusion with XP group A, B, D, F and G cells also corrected RRS after UV irradiation, and microinjection of cell extracts prepared from Kps3 cells corrected UDS in XP group C and E cells, indicating that the patients do not belong to any complementation group of XP or CS. These results suggest that the patients have a new UV-sensitive syndrome with a biochemical phenotype of CS.

Assessment of the pathological grade of astrocytic gliomas using an MRI score

To evaluate the usefulness of an MRI score for identifying tumour tissue characteristics, 41 histologically verified supratentorial astrocytic gliomas, including 13 low-grade astrocytomas (LGA) 14 anaplastic astrocytomas (AA) and 14 glioblastoma multiformes (GBM), were examined with a 0.5T superconductive MR imager. Nine MRI criteria were used: heterogeneity (HET), cyst formation or necrosis (CN), haemorrhage (HEM), crossing the midline (CM), oedema or mass effect (EM), border definition (BD), flow void (FV), degree (CE-D) and heterogeneity (CE-HET) of contrast enhancement; Gd-enhanced T1-weighted images were obtained in 32 cases (10 LGA, 10 AA, and 12 GBM). Each of the criteria was scored and analysed statistically. The mean values of LGA, AA and GBM were 0.45 +/- 0.31, 1.18 +/- 0.20, and 1.47 +/- 0.22, respectively. The MRI score increased with the pathological grades (P < 0.01-0.001). LGA had significantly lower values than AA in five (HET, CN, EM, BD, CE-D) of the nine criteria (55.6%) and lower values than GBM in all except HEM (88.9%). Three criteria (33.3%): HET, CN, and FV were significantly higher in GBM than AA. CE-D, HET, EM, CN, and CE-HET proved to be related to the pathological grade by a multiple regression analysis (P < 0.001).

Resection of aortic aneurysms without aortic clamp technique with the aid of hypothermic total body retrograde perfusion

Aneurysms involving either the aortic arch or the proximal descending thoracic aorta in five patients were resected with the aid of profound hypothermic total body retrograde perfusion. Traditional surgical management of the aortic arch and the descending thoracic aorta necessitates clamping of the aorta. However, this technique may be associated with rupture or atheroembolism. Rupture occurring at the clamping site may be difficult to repair. Atheroembolism to the brain compromises the neurologic system, and multiple organ embolism is associated with disseminated intravascular coagulopathy. Atheroembolism in cardiovascular surgery has become increasingly prevalent. It is necessary to prevent clamp injuries and to preserve the function of the vital organs, such as the brain, heart, and liver, during aortic reconstruction. We applied a total body retrograde perfusion technique to operations for aortic aneurysms. Total body retrograde perfusion consists of cerebral protection by continuous perfusion through the superior vena cava, intermittent retrograde coronary perfusion through the coronary sinus, and continuous abdominal visceral perfusion through the inferior vena cava. It can yield a relatively bloodless operating field without the need for aortic clamping. We believe this new adjunct offers excellent results in the surgical treatment of aneurysms of the aortic arch or adjacent structures.

Protection against ischemic spinal cord injury: one-shot perfusion cooling and percutaneous topical cooling

PURPOSE

We investigated the protective effect of two methods of hypothermia against ischemic spinal cord injury: one-shot perfusion cooling and percutaneous topical cooling.

METHODS

Twenty-five rabbits were divided into five equal groups. The abdominal aorta was isolated proximally by a vascular clamp and distally by an inflated balloon catheter for 60 minutes. Group I served as control. In groups II (2.5 ml/min) and III (5.0 ml/min), hypothermic lactated Ringer's solution was infused for 3 minutes from the distal end of the catheter. Ice blocks were placed behind the backs of rabbits 30 minutes before ischemia in group IV. Group V underwent the procedures combined with those in groups II and IV (infusion of hypothermic solution plus placement of ice blocks). Another 15 rabbits underwent laminectomy at the L2 or L3 level. A temperature probe was inserted into the spinal cord to monitor cord temperature continuously during the procedures in all five groups (three rabbits per group).

RESULTS

Neurologic status on the second postoperative day in groups IV and V was significantly superior to that in group I (p < 0.01), but the neurologic status of groups II and III did not differ significantly from the neurologic status of group I. The spinal cord temperature in groups II and III dropped rapidly with the infusion, but it rose again quickly. In contrast, the spinal cord was kept sufficiently hypothermic during ischemia in groups IV and V.

CONCLUSIONS

We concluded that the percutaneous cooling method can keep the spinal cord sufficiently hypothermic during ischemia to lead to a significantly superior neurologic outcome.

Assessment of bromodeoxyuridine-labeled S-phase cells in experimentally induced precancerous lesions in the rat's tongue

Precancerous lesions and early invasive carcinomas were produced in the tongues of rats by oral administration of 0.001% 4-nitroquinoline 1-oxide in drinking water. The distribution and densities of S-phase cells were then studied in an attempt to clarify the mechanism of carcinogenesis from the viewpoint of cell cycle. Bromodeoxyuridine (BrdU)-labeled S-phase cells were demonstrated by an indirect peroxidase method, using anti-BrdU monoclonal antibody, and their percentage was determined as the labeling index (LI). The average BrdU LI was significantly higher in the precancerous lesions than in the normal epithelium. There was a wide range of LI found in cells showing such changes as hyperplasia, hyperparakeratosis, dysplasia and papilloma, but the differences among them were not significant. These findings also showed that there could be considerable differences in proliferative activity among lesions of the same grade, while the difference in histology did not mean a difference in proliferative activity. Additionally, many BrdU-labeled cells were seen in a few layers over the basement membranes of non-cancerous lesions immediately adjacent to early invasive carcinoma, suggesting that these layers had a higher possibility for advancing to early invasive carcinoma.