Autoantibody profiles in intravenous immunoglobulin preparations: A possible cause of mistaken autoimmunity diagnosis

BACKGROUND

Intravenous immunoglobulins (IVIgs) derived from the pooled plasma of thousands of donors contain numerous types of IgG molecules, including autoantibodies commonly used to diagnose autoimmunity. While these autoantibodies can cause misinterpretation of serological tests for IVIg recipients, their profiles in IVIg preparations are not fully understood.

STUDY DESIGN AND METHODS

Using binding-capability based immune assays, we measured 18 varieties of clinically relevant autoantibodies in domestic blood donor-derived IVIg products. In addition, we analyzed an IVIg product from a US brand to evaluate the influence of regional and racial differences. Based on the determined autoantibody titers, pharmacokinetics of passively acquired autoantibodies and their possible detection period in serum were estimated.

RESULTS

Anti-thyroglobulin (Tg), anti-thyroidperoxidase (TPO), and anti-Sjögren's-syndrome-related antigen A (SS-A) antibodies were present in considerable amounts in IVIg products. Notably, these three autoantibodies can be detected in IVIg recipients' sera for up to 3 months after infusion.

DISCUSSION

To the best of our knowledge, this is the first study that analyzed multiple autoantibody profiles in both pooled plasma and IVIg products and that further evaluated their potential influences on diagnosis of autoimmunity. Clinicians should keep in mind that IVIgs contain several autoantibodies and that their infusion can produce false-positive serology results. To establish an accurate diagnosis, serological tests must be carefully interpreted and clinical symptoms should be more purposefully considered if patients are receiving IVIg therapy.

Radiofrequency Ablation Combined with Hepatic Artery Embolization Using a Tris-acryl Gelatin Microsphere for Colorectal Liver Metastases-Initial Experience

Purpose

We aim to evaluate retrospectively the feasibility, safety, and initial therapeutic outcomes of radiofrequency ablation combined with hepatic artery embolization using a tris-acryl gelatin microsphere for colorectal liver metastases.

Material and Methods

Six consecutive patients (4 men and 2 women) with median age of 68 years (range 57-78 years) underwent computed tomography fluoroscopy-guided radiofrequency ablation immediately after hepatic artery embolization using microspheres. This study evaluated tumor visibility on noncontrast-enhanced computed tomography immediately after hepatic artery embolization; analyzed local tumor progression; defined technical success as the coverage of the tumor by the ablative zone; and assessed adverse events based on Common Terminology Criteria for Adverse Events v5.0.

Results

Ten tumors with median maximum diameter of 9 mm (range 5-52 mm) were treated in nine sessions. Eight tumors (80%, 8/10 tumors) were detected as high-attenuation nodules. One tumor was treated in two sessions because follow-up computed tomography revealed an insufficient ablative margin. Therefore, the primary and secondary technical success was 90% (9/10 tumors) and 100% (10/10 tumors), respectively. Grade 2 pneumothorax was observed in one session (11%, 1/9 sessions). No grade 3 or higher adverse event was observed. The local tumor progression rate was 20% (2/10 tumors) during the median follow-up of 14 months.

Conclusions

Radiofrequency ablation following microsphere embolization may be a feasible, safe, and useful therapeutic option for controlling small colorectal liver metastases.

Efficacy of Percutaneous Direct Puncture Biopsy of Malignant Lung Tumors Contacting to the Pleura

BACKGROUND/AIM

This is a retrospective evaluation of whether percutaneous direct puncture biopsy of lung lesions contacting to the pleura is justified.

PATIENTS AND METHODS

Between August 2016 and July 2021, 163 consecutive patients (100 males, 63 females with a median age of 73 years) who had malignant lung tumors measuring 0.6-12.4 cm (median, 2.9 cm) that contacted to the pleura and underwent percutaneous lung biopsy under computed tomography fluoroscopic guidance using an 18-gauge end-cut needle were examined. The trajectory was direct puncture in 80 patients (49.1%, 80/163), and trans-lung in 83 patients (50.9%, 83/163). Diagnostic yield and major adverse event rates of direct and trans-lung puncture biopsies were compared.

RESULTS

No difference was found in diagnostic yield between direct puncture and trans-lung biopsies (93.8% vs. 98.8%, p=0.11). Major adverse events were major pneumothorax (n=13/163, 8.0%), pleural dissemination (n=18/163, 11.0%), and hemothorax requiring arterial embolization (n=1/163, 1.0%). Direct puncture caused major pneumothorax significantly less than trans-lung puncture did (0%, 0/80 vs. 15.7%, 13/83, p<0.001). No significant difference was found between the two biopsy methods regarding the incidence of pleural dissemination (11.0%, 11/80 vs. 8.4%, 7/83, p=0.32).

CONCLUSION

Direct puncture biopsy of malignant lung tumors contacting to the pleura is justified.

Clinical Utility of Bland Embolization Using Microspheres for Painful Malignant Musculoskeletal Tumors

BACKGROUND/AIM

To evaluate retrospectively whether bland embolization using microspheres is safe and useful for relieving pain in patients with painful malignant musculoskeletal (MSK) tumors.

PATIENTS AND METHODS

Bland embolization using microspheres was performed for 20 patients (11 women/9 men) with a median age of 69 years (range=40-89 years) who had 22 painful malignant MSK tumors. The maximum tumor diameters were 2.4-13.8 cm (median, 7.5 cm). Pain was evaluated using the visual analog scale. A decrease of this score by 2 or more after embolization was defined as clinically effective pain relief. Adverse events (AEs) were evaluated using CTCAE v5.0. Objective response, disease control rates, and overall survival were also evaluated.

RESULTS

Effective pain relief was achieved in 18 patients (90.0%, 18/20). Grade-3 AEs developed in four patients (20.0%, 4/20): skin ulcer (n=2), skin ulcer and pain (n=1), and muscle weakness with dysesthesia (n=1). No grade-4 or grade-5 AEs developed. Objective response and disease control rates were 26.7% (4/15) and 86.7% (13/15), respectively. The 1-year survival rate was 43.8%, with median survival of 9.2 months (range=0.5-41.0 months).

CONCLUSION

Although the survival benefit is equivocal, bland embolization is acceptably safe and useful for relieving pain by controlling tumor growth in patients with painful malignant MSK tumors.

Untangling a Knotted Angiographic Catheter Using a Balloon Catheter: A Case Report

When a 66-year-old man with hepatocellular carcinoma underwent an angiographic examination, a 4-Fr catheter was inserted from the right femoral artery. It became tightly knotted in the descending aorta. To untangle the knotted catheter, a noncompliant balloon catheter was delivered into the knotted loop from the contralateral femoral artery. After the balloon catheter was inflated from the inside of the knotted loop, the knot became loose. Finally, the knotted catheter was untangled. Subsequently, the remainder of the examination was performed as initially planned.

Radioprotective Effects of a Semicircular X-ray Shielding Device for Operators During CT Fluoroscopy-Guided Interventional Procedures: Experimental and Clinical Studies

PURPOSE

To evaluate, experimentally and clinically, the radioprotective effects of a semicircular X-ray shielding device for operators during CT fluoroscopy-guided IR procedures.

MATERIALS AND METHODS

During experimentation, the reduction rates of scattered radiation rates from CT fluoroscopy were evaluated using a humanoid phantom. Two shielding device positions were tested: "shielding close to the CT gantry" and "shielding close to the operator". The scattered radiation rate without shielding was also evaluated. The clinical study retrospectively evaluated the operator's radiation exposure during 314 CT-guided IR procedures. With a semicircular X-ray shielding device (with shielding group, n = 119) or without it (no shielding group, n = 195), CT fluoroscopy-guided IR procedures were performed. Radiation dose measurements were taken using a pocket dosimeter placed near the operator's eye. For shielding and no shielding groups, the procedure time, dose length product (DLP), and the operator's radiation exposures were compared.

RESULTS

Experimentation revealed the respective mean reduction rates of "shielding close to the CT gantry" and "shielding close to the operator" as 84.3% and 93.5% compared with the no-shielding setting. Although no significant differences were found in the procedure time and the DLP between "no shielding" and "with shielding" groups in the clinical study, the operators' radiation exposure in the "with shielding" group (0.03 ± 0.04 mSv) was significantly lower than in the "no shielding" group (0.14 ± 0.15 mSv; p < .001).

CONCLUSION

The semicircular X-ray shielding device provides valuable radioprotective effects for operators during CT fluoroscopy-guided IR.

Agaritine derived from Agaricus blazei Murrill induces apoptosis via mitochondrial membrane depolarization in hematological tumor cell lines

Objectives

Agaritine (AGT) is a hydrazine-containing compound derived from the mushroom Agaricus blazei Murill. We previously reported the antitumor effect of AGT on hematological tumor cell lines and suggested that AGT induces apoptosis in U937 cells via caspase activation. However, the antitumor mechanism of AGT has not been fully understood.

Methods

Four hematological tumor cell lines (K562, HL60, THP-1, H929) were used in this study. The cells were incubated in the presence of 50 μM AGT for 24 h and analyzed for cell viability, annexin V positivity, caspase-3/7 activity, mitochondrial membrane depolarization, cell cycle, DNA fragmentation, and the expression of mitochondrial membrane-associated proteins (Bax and cytochrome c).

Results

In HL60, K562, and H929 cells, AGT reduced cell viability and increased annexin V- and dead cell-positive rates; however, it did not affect THP-1 cells. In K562 and HL60 cells, caspase-3/7 activity, mitochondrial membrane depolarization, and expression of mitochondrial membrane proteins, Bax and cytochrome c, were all increased by AGT. Cell cycle analysis showed that only K562 exhibited an increase in the proportion of cells in G₂/M phase after the addition of AGT. DNA fragmentation was also observed after the addition of AGT.

Conclusions

These results indicate that AGT induces apoptosis in K562 and HL60 cells, like U937 reported previously, but showed no effect on THP-1 cells. It was suggested that AGT-induced apoptosis involves the expression of Bax and cytochrome c via mitochondrial membrane depolarization.

Clinical Experience of Percutaneous Radiofrequency Ablation Using an arfa RF ABLATION SYSTEMⓇ in Various Organs

PURPOSE

To evaluate the feasibility, safety, and efficacy of radiofrequency (RF) ablation using an ablation system (arfa RF ABLATION SYSTEM^Ⓡ; Japan Lifeline Co. Ltd.) for treating solid tumors in various organs.

MATERIAL AND METHODS

Between October 2019 and August 2021, 80 patients (29 women, 51 men; median age, 70.0 yr) underwent 107 RF ablation sessions using the ablation system to treat 151 tumors in the liver (n = 86), lung (n = 51), adrenal gland (n = 4), pleura (n = 4), bone (n = 3), lymph node (n = 2), and kidney (n = 1). The maximum tumor diameter was 2-40 mm (median, 11 mm). This study evaluated technical success (defined as the completion of planned RF ablation), technique efficacy (defined as the complete tumor ablation on follow-up images), and adverse events. Local tumor progression in 146 curatively treated malignant tumors was evaluated.

RESULTS

The technical success rate was 100% (107/107). Ablation zones in two tumors were insufficient. Therefore, the primary technique efficacy rate was 98.1% (105/107). Grade 3 hepatic infarction (1.6%, 1/64) and grade 4 pleuritis (3.4%, 1/29) occurred respectively after liver and lung RF ablation. During the median follow-up period of 10.2 months (Interquartile range, 4.2 and 16.4 months), local tumor progression developed in two tumors (1.4%, 2/146).

CONCLUSIONS

The arfa RF ABLATION SYSTEM^Ⓡ is a feasible, safe, and effective RF ablation device for managing solid tumors in various organs.

Andrographolide, isolated from Andrographis paniculata, induces apoptosis in monocytic leukemia and multiple myeloma cells via augmentation of reactive oxygen species production

Background: Andrographolide (Andro) is a diterpenoid component of the plant Andrographis paniculata that is known for its anti-tumor activity against a variety of cancer cells.  

Methods: We studied the effects of Andro on the viability of the human leukemia monocytic cell line THP-1 and the human multiple myeloma cell line H929. Andro was compared with cytosine arabinoside (Ara-C) and vincristine (VCR), which are well-established therapeutics against hematopoietic tumors. The importance of reactive oxygen species (ROS) production for the toxicity of each agent was investigated by using an inhibitor of ROS production, N-acetyl-L-cysteine (NAC).   

Results:  Andro reduced the viability of THP-1 and H929 in a concentration-dependent manner. H929 viability was highly susceptible to Andro, although only slightly susceptible to Ara-C. The agents Andro, Ara-C, and VCR each induced apoptosis, as shown by cellular shrinkage, DNA fragmentation, and increases in annexin V-binding, caspase-3/7 activity, ROS production, and mitochondrial membrane depolarization. Whereas Ara-C and VCR increased the percentages of cells in the G0/G1 and G2/M phases, respectively, Andro showed little or no detectable effect on cell cycle progression. The apoptotic activities of Andro were largely suppressed by NAC, an inhibitor of ROS production, whereas NAC hardly affected the apoptotic activities of Ara-C and VCR. 

Conclusions: Andro induces ROS-dependent apoptosis in monocytic leukemia THP-1 and multiple myeloma H929 cells, underlining its potential as a therapeutic agent for treating hematopoietic tumors. The high toxicity for H929 cells, by a mechanism that is different from that of Ara-C and VCR, is encouraging for further studies on the use of Andro against multiple myeloma.

Lymphangiography as a Treatment for Refractory Congenital Chylothorax Due to RASopathies: A Report of Two Cases

In this study, we report two cases in which intranodal lymphangiography helped improve congenital chylothorax due to RASopathies. We performed lymphangiography after conservative treatments failed to improve chylothorax in an 8-year-old girl with cardiofaciocutaneous syndrome and a 2-month-old boy with Noonan syndrome. Inguinal lymph nodes were punctured with 25-gauge needles under ultrasonographic guidance, and 4 and 1 mL of iodized oil were injected, respectively, showing a backflow of iodized oil into the lungs. Chylothorax had improved in both patients after nodal lymphangiography. However, the second child experienced worsening of disease-associated extremity edema and died of sepsis 4 months later.

Use of Microballoon Catheter in Transarterial Ethanol Embolization of Renal Angiomyolipoma: A Retrospective Comparative Study with Historical Control?

Purpose:

To clarify the utility of microballoon catheter in renal arterial ethanol embolization of renal angiomyolipoma (AML).

Material and Methods:

A total of 20 patients (15 women, 5 men) with median age of 45 years (39-60 years) underwent embolization to treat 22 AMLs. A mixture of ethanol and iodized oil was injected into the feeding arteries of 13 tumors using balloon occlusion (the balloon embolization group) with a microballoon catheter and 9 tumors without using balloon occlusion (the non-balloon embolization group). Changes in the maximum tumor diameter, tumor volume, and adverse events were evaluated.

Result:

The median baseline maximum tumor diameters and volumes were 6.3 cm and 61.4 cm³ in the balloon embolization group, and 4.6 cm and 40.1 cm³ in the non-balloon embolization group, respectively. Tumor enhancement disappeared on postembolization angiography in all cases. All tumors shrunk after embolization. There were no statistically significant differences in the percent decrease in the maximum tumor diameter and volume at 10-12 month between balloon occlusion group (31.5% and 67.9%) and control group (34.8% and 62.6%). Fever was significantly more frequent when balloon occlusion was used: 38% vs. 0% (p = 0.03). No major complication was observed in either patient group.

Conclusions:

Balloon occlusion may not affect tumor shrinkage when embolizing AMLs with a mixture of ethanol and lipiodol.

Successful Embolization of Collaterals from the Round Ligament Artery during Uterine Artery Embolization for Traumatic Uterine Leiomyoma Rupture: A Case Report

We describe the case of a 48-year-old woman who presented with traumatic rupture of a giant leiomyoma and massive hemoperitoneum caused by slipping and falling in the bathroom. She was in shock on arrival, and resuscitation was performed. Contrast-enhanced computed tomography showed massive intra-abdominal hematoma and extravasation from the subserous leiomyoma. Uterine artery embolization was performed, but she went into shock again after 6 h. The second contrast-enhanced computed tomography revealed persistence of extravasation. During 2^nd UAE, an angiogram revealed extravasation originating from left round ligament artery. After the embolization of the left round ligament and bilateral uterine arteries, the patient recovered from shock. Total abdominal hysterectomy was performed on day 2 of admission to prevent re-bleeding and infection, then she discharged on day 19 of admission.

Internal Structures of the Globus Pallidus in Patients with Parkinson's Disease: Evaluation with Phase Difference-enhanced Imaging

Purpose:

The medial medullary lamina (MML) separates the medial globus pallidus (GPm) from the lateral. The aim of this study was to assess the changes in appearance of MML related to age using the phase difference-enhanced (PADRE) imaging and to determine whether PADRE can depict the MML in the patients with Parkinson’s disease (PD).

Materials and Methods:

We enrolled 20 patients with PD and 50 normal control subjects (NC). First, for the visualization of the MML in the NC, we compared the PADRE, susceptibility-weighted imaging (SWI)-like images and T₂weighted imaging (WI) by using multiple comparison. The grading methods are as follows: grade 1; MML was not delineated, grade 2; less than half of MML was delineated, grade 3; more than half of MML was delineated and grade 4; whole MML was clearly delineated. We determined grade 3 and 4 as good depiction, delineating the GPm. Then, we evaluated patients with PD using the same method.

Results:

In NC, the delineation of MML was good in 84% of cases on PADRE, but only 34% of cases showed a good depiction on SWI-like images (average grading score 3.31 vs 2.11, P < 0.05). No MML was delineated in all cases on T₂WI. Although younger subjects tended to show whole MML clearly, a part of MML tends to be obscured with age on PADRE. In patients with PD the depiction of MML on PADRE was also good in 90% of cases.

Conclusion:

The PADRE technique facilitates the depiction of the MML within globus pallidus (GP) on a broad range of age NC and patients with PD and it is superior to SWI-like images and T₂WI.

Identification of Heschl's gyrus on phase difference enhanced imaging

Background The white matter in the Heschl's gyrus (HG-WM) may appear differently to the other gyri on phase difference enhanced imaging (PADRE), which can enhance the myelin density. Purpose To evaluate the signal intensity (SI) of HG-WM using the PADRE technique and to compare the images with susceptibility-weighted imaging (SWI)-like images. Material and Methods The participants included 19 normal controls (38 HGs; mean age, 60.1 years; age range, 28-80 years). Coronal PADRE and SWI-like images were acquired using a 3T magnetic resonance (MR) system. The SI of the HG-WM was classified into three grades based on a comparison with the SI of the superior temporal gyrus: Grade 1, isointense; Grade 2, slightly hypointense, and Grade 3, markedly hypointense. Results In the assessment of the SI of the HG-WM, the HG-WM appeared hypointense in all 38 sites of the 19 participants; the hypointensity corresponded to Grade 2 in 13 (34%) images and Grade 3 in 25 (66%) images. On the other hand, the HG-WM was classified as Grade 1 (isointense) in all of the SWI-like images. Conclusion The HG-WM appears hypointense on PADRE, which probably reflects the higher myelin content. PADRE may be useful for identifying the HG through the assessment of the SI of the HG-WM.

Juxtacortical Lesions in Multiple Sclerosis: Assessment of Gray Matter Involvement Using Phase Difference-enhanced Imaging (PADRE)

Purpose:

In multiple sclerosis (MS), a juxtacortical lesion at the border between the gray matter (GM) and subcortical white matter (WM) may often involve the GM. A recently developed, phase-weighted magnetic resonance imaging (MRI) technique “phase difference enhanced imaging (PADRE)” can delineate the GM and WM clearly due to the difference in myelin concentration. We evaluated whether PADRE is useful for the detection of GM involvement in the juxtacortical MS lesions.

Methods:

One neuroradiologist reviewed the conventional MRI in 13 MS patients and selected 48 juxtacortical lesions. At the first reading session with the conventional MRI alone (T₂-weighted imaging, and two-dimensional and three-dimensional fluid-attenuated inversion recovery), two other neuroradiologists classified the lesions into three patterns according to their anatomical locations: (a) subcortical WM lesions involving the subcortical WM alone; (b) intracortical (IC) lesions involving the GM alone; (c) mixed GM/subcortical WM (mixed) lesions involving the both subcortical WM and GM. We defined the subcortical WM as a WM within a distance of 10 mm from inner edge of the GM. For the analyses, we excluded the white matter lesions further than 10 mm from inner edge of the GM. At the second reading session MRI and PADRE were available and the radiologists re-evaluated their prior classification.

Results:

At the first reading session, 27 lesions were classified as (a), 1 as (b), and 20 as (c). Therefore, a total of 21 lesions (44%) were judged to involve the GM. At the second reading session, the classification of 15 (31%) lesions changed; all 15 lesions were judged to involve the GM on the PADRE. Interobserver agreement (kappa value) was 0.84 for the first- and 0.95 for the second reading session.

Conclusion:

PADRE is useful for detecting GM involvement of the juxtacortical MS lesions.

Zebra sign of precentral gyri in amyotrophic lateral sclerosis: A novel finding using phase difference enhanced (PADRE) imaging-initial results

OBJECTIVE

We compared the precentral gyri (PG) on the PADRE of patients with amyotrophic lateral sclerosis (ALS) and healthy subjects (HSs) in order to determine whether it is possible to discriminate between ALS patients and HSs on an individual basis.

METHODS

First, two radiologists reviewed the appearance of the normal PG and that of ALS patients on PADRE in a non-blinded manner, and deviations from the appearance of the normal PG were recorded. Next, based on the presence of PG abnormalities on PADRE, we performed an observer performance study using 16 ALS patients and 16 HSs.

RESULTS

The radiologists were able to consensually define the PG as abnormal on PADRE when a low-signal-intensity layer was observed in the gray matter of the PG; a three- or four-layer organization (zebra sign) was characterized by the low-signal-intensity layer. The observer performance study demonstrated that the sensitivity, specificity, and accuracy of PG abnormalities on PADRE for discriminating ALS patients from HSs were 94 %, 94 %, and 94 %, respectively, for reviewers 1 and 2.

CONCLUSIONS

It was possible to discriminate between ALS patients and HSs based on the presence of PG abnormalities on PADRE, which may reflect upper motor neuron impairment in ALS.

KEY POINTS

• PADRE reveals low-signal-intensity layer in the PG of ALS • By PADRE findings on PG, we can discriminate ALS from HSs • PADRE may be a useful method for detecting UMN impairment in ALS.

Usefulness of quantitative susceptibility mapping for the diagnosis of Parkinson disease

BACKGROUND AND PURPOSE

Quantitative susceptibility mapping allows overcoming several nonlocal restrictions of susceptibility-weighted and phase imaging and enables quantification of magnetic susceptibility. We compared the diagnostic accuracy of quantitative susceptibility mapping and R2* (1/T2*) mapping to discriminate between patients with Parkinson disease and controls.

MATERIALS AND METHODS

For 21 patients with Parkinson disease and 21 age- and sex-matched controls, 2 radiologists measured the quantitative susceptibility mapping values and R2* values in 6 brain structures (the thalamus, putamen, caudate nucleus, pallidum, substantia nigra, and red nucleus).

RESULTS

The quantitative susceptibility mapping values and R2* values of the substantia nigra were significantly higher in patients with Parkinson disease (P < .01); measurements in other brain regions did not differ significantly between patients and controls. For the discrimination of patients with Parkinson disease from controls, receiver operating characteristic analysis suggested that the optimal cutoff values for the substantia nigra, based on the Youden Index, were >0.210 for quantitative susceptibility mapping and >28.8 for R2*. The sensitivity, specificity, and accuracy of quantitative susceptibility mapping were 90% (19 of 21), 86% (18 of 21), and 88% (37 of 42), respectively; for R2* mapping, they were 81% (17 of 21), 52% (11 of 21), and 67% (28 of 42). Pair-wise comparisons showed that the areas under the receiver operating characteristic curves were significantly larger for quantitative susceptibility mapping than for R2* mapping (0.91 versus 0.69, P < .05).

CONCLUSIONS

Quantitative susceptibility mapping showed higher diagnostic performance than R2* mapping for the discrimination between patients with Parkinson disease and controls.

Diagnosis of intracranial hemorrhagic lesions: comparison between 3D-SWAN (3D T2*-weighted imaging with multi-echo acquisition) and 2D-T2*-weighted imaging

BACKGROUND

3D-susceptibility-weighted angiography (SWAN) can produce high-resolution images that yield excellent susceptibility-weighted contrast at a relatively short acquisition time.

PURPOSE

To compare SWAN- and 2D-T2*-weighted gradient-echo images (T2*-WI) for their sensitivity in the depiction of cerebral hemorrhagic lesions.

MATERIAL AND METHODS

We subjected 75 patients with suspected cerebral hemorrhagic lesions to SWAN and T2*-WI at 3T. We first measured the contrast-to-noise ratio (CNR) using an agar phantom that contained different concentrations of superparamagnetic iron oxide (SPIO). The acquisition time for SWAN and T2*-WI was similar (182 vs. 196 s). Neuroradiologists compared the two imaging methods for lesion detectability and conspicuity.

RESULTS

The CNR of the phantom was higher on SWAN images. Of the 75 patients, 50 were found to have a total of 278 cerebral hemorrhagic lesions (microbleeds, n = 229 [82.4%]; intracerebral hemorrhage, n = 18 [6.5%]; superficial siderosis, n = 13 [4.7%]; axonal injuries, n = 8 [2.9%]; subarachnoid hemorrhage [SAH] or brain contusion, n = 3 each [1.0%]; subdural hematoma, n = 2 [0.7%]; cavernous hemangioma or dural arterteriovenous fistula, n = 1 each [0.4%]). In none of the lesions was the SWAN sequence inferior to T2*-WI with respect to lesion detectability and conspicuity. In fact, SWAN yielded better lesion conspicuity in patients with superficial siderosis and SAH: it detected significantly more lesions than T2*-WI (P < 0.01) and it was particularly useful for the detection of microbleeds and lesions near the skull base.

CONCLUSION

SWAN is equal or superior to standard T2*-WI for the diagnosis of various cerebral hemorrhagic lesions. Because its acquisition time is reasonable it may replace T2*-WI.

Intervertebral disc degeneration associated with lumbosacral transitional vertebrae

We studied 52 patients, each with a lumbosacral transitional vertebra. Using MRI we found that the lumbar discs immediately above the transitional vertebra were significantly more degenerative and those between the transitional vertebrae and the sacrum were significantly less degenerative compared with discs at other levels. We also performed an anatomical study using 70 cadavers. We found that the iliolumbar ligament at the level immediately above the transitional vertebra was thinner and weaker than it was in cadavers without a lumbosacral transitional vertebra.

Instability of the vertebral segment above the transitional vertebra because of a weak iliolumbar ligament could lead to subsequent disc degeneration which may occur earlier than at other disc levels. Some stability between the transitional vertebra and the sacrum could be preserved by the formation of either an articulation or by bony union between the vertebra and the sacrum through its transverse process. This may protect the disc from further degeneration in the long term.

Yersinia pseudotuberculosis infection in breeding monkeys: detection and analysis of strain diversity by PCR

In the last three decades, several monkeys reared in outdoor/indoor-outdoor breeding colonies and cages of the Primate Research Institute, Kyoto University, died of yersiniosis caused by Yersinia pseudotuberculosis, necessitating introduction of a method to detect the bacteria rapidly and thus allow preventive measures to be undertaken. A rapid nested polymerase chain reaction (PCR) method for identification of Y. pseudotuberculosis in fecal samples and a random amplified polymorphic DNA (RAPD)-PCR approach for distinguishing between bacterial strains were therefore developed. Yersinia pseudotuberculosis isolates from monkey specimens were found to be classifiable into several types. To determine the source of infection, hundreds of fecal samples of wild rats, pigeons, and sparrows were collected from around the breeding colonies and cages, and subjected to PCR analyses. Yersinia pseudotuberculosis was detected in 1.7% of the fecal samples of wild rats. The DNA fingerprints of the bacteria revealed by RAPD-PCR were the same as that of one strain isolated from macaques, suggesting the wild rat to be a possible source of infection.

Spatial and temporal gene expression for fibroblast growth factor type I receptor (FGFR1) during fracture healing in the rat

Recent experiments have shown that exogenous basic fibroblast growth factor (bFGF) enlarges fracture callus and accelerates the healing of osteotomized long bones. The actions of bFGF are mediated by four different transmembrane receptors (FGFR1-4). Among them, FGFR1 has a high affinity for bFGF, and gain-of-function mutations of the FGFR1 gene cause craniosynostosis in humans. Gene expression for FGFR1 has been analyzed in embryogenesis; however, in skeletal repair, detailed expression of FGFR1 has not been fully established. In the present study, a rat model of closed femoral fracture healing was used to quantify mRNA encoding the FGFR1 and to characterize cells expressing FGFR1 by in situ hybridization. Gene expression for FGFR1 was rapidly upregulated after fracture; its mRNA level on day 1 was 3.4-fold higher than that of unfractured femora. At this stage, a moderate signal for FGFR1 was detected in periosteal osteoprogenitor cells, inflammatory cells near fracture sites, and cells among muscle layers. FGFR1 mRNA reached peak expression when callus remodeling actively progressed (6.8-fold on day 14), and remained elevated even in the later stages of healing (6.3-fold on day 28). During the intermediate stage of fracture healing, a strong signal for FGFR1 was diffusely distributed in mature osteoblasts in the hard callus, and mature osteoclasts also expressed a weak signal for FGFR1. These results suggest that FGF/FGFR1 signaling has multifunctional roles during fracture healing and may regulate both osteoblasts and osteoclasts, contributing to bone formation and callus remodeling.

Spatial and temporal gene expression in chondrogenesis during fracture healing and the effects of basic fibroblast growth factor

Chondrogenesis is an essential component of endochondral fracture healing, though the molecular and cellular events by which it is regulated have not been fully elucidated. In this study, we used a rat model of closed fracture healing to determine the spatial and temporal expression of genes for cartilage-specific collagens. Furthermore, to determine the effects of basic fibroblast growth factor (bFGF) on chondrogenesis in fracture healing, we injected 100 microg recombinant human bFGF into the fracture site immediately after fracture. In normal calluses, pro-alpha1(II) collagen mRNA (COL2A1) was detected in proliferative chondrocytes beginning on day 4 after the fracture, and pro-alpha1(X) collagen mRNA (COL10A1) in hypertrophic chondrocytes beginning on day 7. In FGF-injected calluses, the cartilage enlarged in size significantly. On day 14, both COL2A1- and COL10A1-expressing cells were more widely distributed, and the amounts of COL2A1 and COL10A1 mRNAs were both approximately 2-fold increased when compared with uninjected fractures. Temporal patterns of expression for these genes were, however, identical to those found in normal calluses. The number of proliferating cell nuclear antigen-positive cells was increased in the non-cartilaginous area in the bFGF-injected calluses by day 4. The present molecular analyses demonstrate that a single injection of bFGF enhances the proliferation of chondroprogenitor cells in fracture callus, and thus contributes to the formation of a larger cartilage. However, maturation of chondrocytes and replacement of the cartilage by osseous tissue are not enhanced by exogenous bFGF, and this results in the prolonged cartilaginous callus phase. We conclude that, in the healing of closed fractures of long bones, exogenous bFGF has a capacity to enlarge the cartilaginous calluses, but not to induce more rapid healing.

[Antiangiogenic and antimetastatic effects of toremifene citrate]

In this study, we demonstrated that toremifene citrate (TOR) inhibited the tube formation and migration of human umbilical vein endothelial cells (HUVEC) in vitro. Moreover, TOR suppressed angiogenesis in rabbit cornea and lung metastasis of human fibrosarcoma HT-1080 cells in nude mice. The antiangiogenic activity in vitro was apparent at the concentration of 5 microM which is clinically achievable by oral administration of 120 mg/kg of TOR. These results suggest that clinical treatment with 120 mg/day of TOR might be expected to exhibit antiangiogenesis and antimetastasis effects, in addition to inhibition of estrogen-dependent tumor cell growth.

Platinum(IV) complexes with dipeptide. X-ray crystal structure, 195Pt NMR spectra, and their inhibitory glucose metabolism activity in Candida albicans

Three dipeptide complexes of the form K[Pt(IV)(dipep)Cl3] and two complexes of the form K[Pt(IV)(Hdipep)Cl4] were newly prepared and isolated. The platinum(IV) complexes containing the dipeptide were obtained directly by adding KI to H2[PtCl6] solution. The reaction using KI was rapidly completed and provided analytically pure yellow products in the form of K[Pt(dipeptide)Cl3] for H2digly, H2gly(alpha)-ala, H2alpha-alagly and H2di(alpha)-ala. The K[Pt(IV)(digly)Cl3] complex crystallizes in the monoclinic space group P2(1)/c with unit cell dimensions a = 10.540(3) A, b = 13.835(3) A, c = 8.123(3) A, beta = 97.01(2) degrees, Z = 4. The crystal data represented the first report of a Pt(IV) complex with a deprotonated peptide, and this complex has the rare iminol type diglycine(2-) coordinating to Pt(IV) with the bond lengths of the C2-N1 (amide) bond (1.285(13) A). The 195Pt NMR peaks of the K[Pt(IV)(dipep)Cl3] and the K[Pt(IV)(Hdipep)Cl4] complexes appeared at about 270 ppm and at about -130 ppm, respectively, and were predicted for a given set of ligand atoms. While the K[Pt(IV)(x-gly)Cl3] complexes, where x denotes the glycine or alpha-alanine moieties, were easily reduced to the corresponding platinum(II) complexes, the K[Pt(IV)(x-alpha-ala)Cl3] complexes were not reduced, but the Cl- ion was substituted for OH- ion in the reaction solution. The K[Pt(digly)Cl3] and K[Pt(gly-L-alpha-ala)Cl3] complexes inhibited the growth of Candida albicans, and the antifungal activities were 3- to 4-fold higher than those of cisplatin. The metabolism of glucose in C. albicans was strongly inhibited by K[Pt(digly)Cl3] and K[Pt(gly-L-alpha-ala)Cl3] but not by the antifungal agent fluconazole.

Fluid shear stress-induced cyclooxygenase-2 expression is mediated by C/EBP beta, cAMP-response element-binding protein, and AP-1 in osteoblastic MC3T3-E1 cells

Mechanical loading is crucial for maintenance of bone integrity and architecture, and prostaglandins are an important mediator of mechanosensing. Cyclooxygenase-2 (COX-2), an inducible isoform of prostaglandin G/H synthase, is induced by mechanical loading-derived fluid shear stress in bone-forming cells such as osteoblasts and osteocytes. In this study, we investigated transcription factor and transcriptional regulatory elements responsible for the shear stress-induced COX-2 expression in osteoblastic MC3T3-E1 cells. When the cells were transfected with luciferase-reporter plasmids including the 5'-flanking region of the murine cox-2 gene, the fluid shear stress increased the luciferase activities, consistent with the induction of COX-2 mRNA and protein expression. Deletion analysis of the promoter region revealed that the shear stress-induced luciferase responses were regulated by two regions, -172 to -100 base pair (bp) and -79 to -46 bp, of the cox-2 promoter, in which putative cis-elements of C/EBP beta, AP-1, cAMP-response element-binding protein (CREB), and E box are included. Mutation of sites of C/EBP beta, AP-1, and/or cAMP-response element decreased the shear stress-induced luciferase activities, whereas mutation of the E box did not affect the responses. In an electrophoretic mobility shift assay, shear stress enhanced nuclear extract binding to double-stranded oligonucleotide probes containing C/EBP beta and AP-1-binding motifs, and the bands of the complexes were supershifted by the addition of antibody specific for each regulator. Although the binding activity of CREB toward its probe was unaffected by shear stress, the phosphorylation of CREB was enhanced by the stress. These data suggest that C/EBP beta, AP-1, and CREB play crucial roles in the shear stress-induced cox-2 expression in osteoblasts.

Effects of early angiotensin-converting enzyme inhibition on cardiac gene expression after acute myocardial infarction

BACKGROUND

ACE inhibition after myocardial infarction (MI) has been shown to have beneficial effects on cardiac anatomy and function. The purpose of this study was to examine the effects of ACE inhibition on cardiac gene expression after MI.

METHODS AND RESULTS

Rats were randomized to receive captopril or no treatment 1 day after MI. Eight weeks later, cardiac function and hemodynamics were measured by use of indwelling catheters and perivascular flow probes. Myocardial gene expression was assessed with DNA microarrays and real-time reverse transcription-polymerase chain reaction. The ratios of heart and left ventricular weights to body weight were significantly increased by MI and normalized by captopril. Cardiac index and stroke volume index were lower in the untreated MI group than in sham controls but were normal in the MI+captopril group. Thirty-seven genes were found to be differentially expressed between the untreated MI group and sham controls; 31 were induced and 6 repressed. Captopril partially or completely inhibited changes in 10 of the genes. The 37 genes clustered into 11 functional groups, and 6 had >/=1 genes whose expression was modified by ACE inhibition.

CONCLUSIONS

ACE inhibition after MI inhibits cardiac hypertrophy, preserves cardiac function, and attenuates changes in myocardial gene expression. Gene expression profiling reveals, however, that some elements of the pathophysiology may be unaffected by the treatment and be targets for new therapies.

Endogenous production of TGF-beta is essential for osteoclastogenesis induced by a combination of receptor activator of NF-kappa B ligand and macrophage-colony-stimulating factor

Differentiation of osteoclasts, the cells primarily responsible for bone resorption, is controlled by a variety of osteotropic hormones and cytokines. Of these factors, receptor activator of NF-kappaB (RANK) ligand (RANKL) has been recently cloned as an essential inducer of osteoclastogenesis in the presence of M-CSF. Here, we isolated a stroma-free population of monocyte/macrophage (M/Mphi)-like hemopoietic cells from mouse unfractionated bone cells that were capable of differentiating into mature osteoclasts by treatment with soluble RANKL (sRANKL) and M-CSF. However, the efficiency of osteoclast formation was low, suggesting the requirement for additional factors. The isolated M/Mphi-like hemopoietic cells expressed TGF-beta and type I and II receptors of TGF-beta. Therefore, we examined the effect of TGF-beta on osteoclastogenesis. TGF-beta with a combination of sRANKL and M-CSF promoted the differentiation of nearly all M/Mphi-like hemopoietic cells into cells of the osteoclast lineage. Neutralizing anti-TGF-beta Ab abrogated the osteoclast generation. These TGF-beta effects were also observed in cultures of unfractionated bone cells, and anti-TGF-beta blocked the stimulatory effect of 1, 25-dihydroxyvitamin D(3). Translocation of NF-kappaB into nuclei induced by sRANKL in TGF-beta-pretreated M/Mphi-like hemopoietic cells was greater than that in untreated cells, whereas TGF-beta did not up-regulate the expression of RANK, the receptor of RANKL. Our findings suggest that TGF-beta is an essential autocrine factor for osteoclastogenesis.

Direct stimulation of osteoclastic bone resorption by bone morphogenetic protein (BMP)-2 and expression of BMP receptors in mature osteoclasts

Bone morphogenetic proteins (BMPs) play an important role in various kinds of pattern formation and organogenesis during vertebrate development. In the skeleton, BMPs induce the differentiation of cells of chondrocytic and osteoblastic cell lineage and enhance their function. However, the action of BMPs on osteoclastic bone resorption, a process essential for pathophysiological bone development and regeneration, is still controversial. In this study, we examine the direct effect of BMPs on osteoclastic bone-resorbing activity in a culture of highly purified rabbit mature osteoclasts. BMP-2 caused a dose- and time-dependent increase in bone resorption pits excavated by the isolated osteoclasts. BMP-4 also stimulated osteoclastic bone resorption. The increase in osteoclastic bone resorption induced by BMP-2 was abolished by the simultaneous addition of follistatin, a BMP/activin binding protein that negates their biological activity. Just as it increased bone resorption, BMP-2 also elevated the messenger RNA expressions of cathepsin K and carbonic anhydrase II, which are key enzymes for the degradation of organic and inorganic bone matrices, respectively. Type IA and II BMP receptors (BMPRs), and their downstream signal transduction molecules, Smad1 and Smad5, were expressed in isolated osteoclasts as well as in osteoblastic cells, whereas type IB BMPR was undetectable. BMPs directly stimulate mature osteoclast function probably mediated by BMPR-IA and BMPR-II and their downstream molecules expressed in osteoclasts. The results presented here expand our understanding of the multifunctional roles of BMPs in bone development.

[Recent progress in studies on osteocytes--osteocytes and mechanical stress]

Although osteocytes are of the most abundant cells in bone, our knowledge about the role of osteocytes in bone metabolism is still poor compared with that about osteoblasts and osteoclasts, both being on the surface of bone. Osteocytes are terminally differentiated bone-forming cells. During bone formation, some of the osteoblasts lining the surface of bone are incorporated into the newly formed osteoid matrix and become osteocytes, while the other osteoblasts remain on the surface as lining cells. During this transition from osteoblasts to osteocytes, the cells lose numerous osteoblastic phenotypes and acquire osteocytic characteristics such as high expression of osteocalcin and particularly their specific morphology. Osteocytes are connected with each other in bone and with osteoblasts on the bone surface through canaliculi, forming cellular networks; and gap-junctions present at the contact sites mediate their intercellular communication. Several roles of osteocytes in bone have been proposed so far. Of them, based on the morphological characteristics of osteocytes, sensation of mechanical stress loaded onto bone is suspected to be one of their functions. One of the mechanical stresses on bone is fluid shear stress. Between the osteocyte's plasma membrane and the bone matrix is the periosteocytic space. This space exists both in the lacunae and in the canaliculi, and it is filled with extracellular fluid (ECF). Application of mechanical stress to bone locally deforms the tissue. This periodical deformation subsequently causes an increase in the flow of ECF in the periosteocytic space, resulting in shear stress on the surface of the osteocytes. Experimental studies demonstrated that bone cells were equivalently or more sensitive to the fluid shear stress than epithelial cells. Osteocytic cells cultured enhanced expression of prostaglandin (PG) G/H synthase-2 (COX-2) mRNA in response to shear stress. PGE2 is a potent regulator of proliferation and function of osteoblasts and osteoclasts. Therefore, a metabolic response by osteoblasts and osteoclasts lining the bone surface may be caused by PGE2 produced by osteocytes in response to shear stress when the prostanoid reaches the surface through the canaliculi. In conclusion, osteocytes play an important role in sensing extracellular mechanical stress, and the mechanical signals mediated by osteocytes may regulate the overall metabolism of cells in bone tissue.

Anti-Candida activity of a new platinum derivative

A new platinum derivative of the form H[Pt(IV)(Hdigly)Cl(2)(OH)(2)] (Hdigly==glycylglycine) damaged the Candida albicans cell membrane and inhibited the growth of the cells. The cytotoxic activity of H[Pt(IV)(Hdigly)Cl(2)(OH)(2)] on mammalian cells was 10-fold lower than that of cis-diammine-dichloroplatinum (cisplatin). Substitution of platinum for peptides is effective for enhancement of antifungal activity and reduction of the toxicity to mammalian cells.

[Estimation of age from teeth using the racemization of aspartic acid (racemization method)]

We report a method for estimation of age from teeth using the racemization of amino acids (racemization method). This method is based on the characteristics of the constant age-related increase in the amount of D-aspartic acid in dentin. We estimated age by measuring the ratio of D-aspartic acid to L-aspartic acid, i.e. the ratio of racemization ¿ratio of D/L, ln[(1 + D/L)/(1 - D/L)]¿. Because different D/L ratios have been obtained from different teeth in the same individuals and from different sites of dentin in the same tooth, we usually prepare bucco-lingual longitudinal sections at the central part of each tooth, and prepare samples of powdered whole dentin. This powder is then mixed and used to measure the D/L ratio in the dentin. To accurately estimate age from forensic specimens, we simultaneously measured the D/L ratios in more than four control teeth of the same type obtained from subjects of known age. Use of control teeth is necessary because it is sometimes difficult to maintain constant running conditions for gas chromatography to obtain reproducible values in different runs. Therefore, for every measurement, we determined an equation for calculating age from the D/L ratios of control teeth, and estimated the age of the specimen tooth by substituting in its D/L ratio. The most reliable results were obtained using samples of lower incisors or premolars, which are single-rooted teeth with a relatively small volume of dentin. Thus sampling of the dentin is easier than for other teeth. It is better to keep control teeth desiccated because racemization does not proceed readily under such conditions. The deviation from the actual age in the cases we examined was less than 3 years. Thus, racemization of amino acids can be used for accurate estimation of age from teeth.

Spatial and temporal distribution of CD44 and osteopontin in fracture callus

The multifunctional adhesion molecule CD44 is a major cell-surface receptor for hyaluronic acid (HUA). Recent data suggest that it may also bind the ubiquitous bone-matrix protein, osteopontin (OPN). Because OPN has been shown to be a potentially important protein in bone remodelling, we investigated the hypothesis that OPN interactions with the CD44 receptor on bone cells participate in the regulation of the healing of fractures. We examined the spatial and temporal patterns of expression of OPN and CD44 in healing fractures of rat femora by in situ hybridisation and immunohistochemistry. We also localised HUA in the fracture callus using biotinylated HUA-binding protein.

OPN was expressed in remodelling areas of the hard callus and was found in osteocytes, osteoclasts and osteoprogenitor cells, but not in cuboidal osteoblasts which were otherwise shown to express osteocalcin. The OPN signal in osteocytes was not uniformly distributed, but was restricted to specific regions near sites where OPN mRNA-positive osteoclasts were attached to bone surfaces. In the remodelling callus, intense immunostaining for CD44 was detected in osteocyte lacunae, along canaliculi, and on the basolateral plasma membrane of osteoclasts, but not in the cuboidal osteoblasts. HUA staining was detected in fibrous tissues but little was observed in areas of hard callus where bone remodelling was progressing.

Our findings suggest that OPN, rather than HUA, is the major ligand for CD44 on bone cells in the remodelling phase of healing of fractures. They also raise the possibility that such interactions may be involved in the communication of osteocytes with each other and with osteoclasts on bone surfaces. The interactions between CD44 and OPN may have important clinical implications in the repair of skeletal tissues.

Spatial and temporal distribution of CD44 and osteopontin in fracture callus

The multifunctional adhesion molecule CD44 is a major cell-surface receptor for hyaluronic acid (HUA). Recent data suggest that it may also bind the ubiquitous bone-matrix protein, osteopontin (OPN). Because OPN has been shown to be a potentially important protein in bone remodelling, we investigated the hypothesis that OPN interactions with the CD44 receptor on bone cells participate in the regulation of the healing of fractures. We examined the spatial and temporal patterns of expression of OPN and CD44 in healing fractures of rat femora by in situ hybridisation and immunohistochemistry. We also localised HUA in the fracture callus using biotinylated HUA-binding protein. OPN was expressed in remodelling areas of the hard callus and was found in osteocytes, osteoclasts and osteoprogenitor cells, but not in cuboidal osteoblasts which were otherwise shown to express osteocalcin. The OPN signal in osteocytes was not uniformly distributed, but was restricted to specific regions near sites where OPN mRNA-positive osteoclasts were attached to bone surfaces. In the remodelling callus, intense immunostaining for CD44 was detected in osteocyte lacunae, along canaliculi, and on the basolateral plasma membrane of osteoclasts, but not in the cuboidal osteoblasts. HUA staining was detected in fibrous tissues but little was observed in areas of hard callus where bone remodelling was progressing. Our findings suggest that OPN, rather than HUA, is the major ligand for CD44 on bone cells in the remodelling phase of healing of fractures. They also raise the possibility that such interactions may be involved in the communication of osteocytes with each other and with osteoclasts on bone surfaces. The interactions between CD44 and OPN may have important clinical implications in the repair of skeletal tissues.

Tumor necrosis factor-alpha production-inhibiting activity of phthalimide analogues on human leukemia THP-1 cells and a structure-activity relationship study

N-Substituted phthalimides (2-substituted 1H-isoindole-1,3-diones) were prepared and their inhibitory effects on tumor necrosis factor-alpha (TNF-alpha) production by human leukemia cell line THP-1 stimulated with 12-O-tetradecanoylphorbol 13-acetate (TPA) or okadaic acid (OA) were examined. A structure-activity relationship study of these phthalimide analogues revealed that their inhibitory effects on TPA- and OA-induced TNF-alpha production by THP-1 cells are well correlated to each other, i.e. they may involve the same target molecule(s). An analysis by the use of phthalimide analogue-immobilized affinity gels indicated the existence of several phthalimide-binding proteins in THP-1 cell extract.

Novel biological response modifiers: phthalimides with tumor necrosis factor-alpha production-regulating activity

Novel N-substituted phthalimides (2-substituted 1H-isoindole-1,3-diones) were prepared, and their effects on tumor necrosis factor-alpha (TNF-alpha) production by human leukemia cell line HL-60 stimulated with 12-O-tetradecanoylphorbol 13-acetate (TPA) or okadaic acid (OA) were examined. A structure-activity relationship study of the N-phenylphthalimides and N-benzylphthalimides revealed that their enhancing effect on TPA-induced TNF-alpha production by HL-60 cells and their inhibiting effect on OA-induced TNF-alpha production by HL-60 cells are only partially correlated.

Estimation of age from teeth by amino acid racemization: influence of fixative

To determine the age of a subject from teeth accurately utilizing the racemization rates of amino acids, standard samples of the same tooth species from the same jaw are necessary as controls, as well as data for identification. However, standard teeth are generally stored in fixatives such as ethanol and formalin. We investigated and compared the degree of progression of racemization of dentinal aspartic acid in teeth stored in 95% ethanol, 10% formalin, or 10% neutral formalin fixatives. The racemization rate of dentinal aspartic acid in teeth stored in 10% neutral formalin was the highest, followed by that for teeth stored in 10% formalin then that for teeth stored in 95% ethanol. Teeth stored in these fixatives at 15 degrees C showed almost no progression of racemization. The racemization ratio (D/L ratio) in teeth extracted 10 years previously was almost unchanged from that at the time of extraction, and allowed an accurate evaluation of the subjects age at tooth extraction.

Cromakalim suppresses hypertonic saline-induced renal vasoconstriction in anaesthetized dogs

1. Intrarenal arterial infusion of hypertonic saline (HS) transiently increased and then gradually reduced renal blood flow (RBF) in anaesthetized dogs. Glomerular filtration rate (GFR) but not filtration fraction decreased at the end of the infusion. 2. In the presence of a potassium channel opener cromakalim (0.3 microgram/kg per min), HS infusion failed to reduce RBF; the initial increase in RBF was maintained throughout the infusion. Since cromakalim also prevented the decrease in GFR, HS infusion lowered filtration fraction. 3. The results suggest that cromakalim inhibits both pre-and postglomerular vasoconstriction induced by HS infusion.