Symptomatic spinal intradural arachnoid cysts in the pediatric age group: description of three new cases and review of the literature

Spinal arachnoid cysts are a relatively uncommon lesion that may be either intra- or extradural, and intradural spinal arachnoid cysts are even less common. These cysts are usually asymptomatic but may produce symptoms by compressing the spinal cord or nerve roots suddenly or progressively. We present three cases in the pediatric age group with spinal intradural arachnoid cysts without a preceding history of trauma. Three patients with symptomatic intradural arachnoid cysts were investigated with conventional T1- and T2-weighted magnetic resonance imaging (MRI). The MRI scans demonstrated the intradural arachnoid cysts with slightly lower CSF signal intensity on the gradient echo images and slightly higher signal intensity on T1-weighted images. The first cyst was located at the level T12-L1 and compressed the conus medullaris, with neurogenic bladder and cauda equina syndrome for 2 months. The second was located at the level C5-T1 ventrally, with spastic gait and neurogenic bladder for 4 years. The other was located at T2-3 ventrally, with sudden onset of quadriplegia after jumping rope. The combined treatment of total resection and wide fenestration in our three patients produced an excellent return of neurologic function in each one, except for residual urinary disturbance in case 2. Intradural spinal arachnoid cysts appear to result from an alteration of the arachnoid trabeculae; some such cysts are ascribed anecdotally to previous trauma or arachnoiditis, whereas the majority are idiopathic and congenital. The majority of intradural spinal arachnoid cysts occur in the thoracic region and most are dorsal to the neural elements. Only 10 cases have been reported in which the intradural arachnoid cysts were located anterior to the cervical spinal cord, of which 8 were in the pediatric age group, like our case 2. Myelography, postcontrast CT myelography and MRI have been demonstrated as useful for the diagnosis of intradural arachnoid cysts. MRI is the imaging modality of choice, and the extent, size and nature of the lesion in our cases were well demonstrated by MRI. Surgical treatment is necessary if progressive neurological dysfunction appears in the course of spinal cord compression. Complete surgical excision of the cysts is the best choice of treatment, and wide fenestration and shunting of the cyst to the peritoneum, pleural cavity or right atrium were the modalities of choice. MRI offers a noninvasive and effective means to make the diagnosis of arachnoid cysts easier. Intradural arachnoid cysts may cause progressive myelopathy; however, the postoperative prognosis is good if the operation is performed prior to neurologic deficits.

Herpes simplex encephalitis: MRI findings in two cases confirmed by polymerase chain reaction assay

Herpes simplex virus (HSV) type I causes a fulminant necrotising meningoencephalitis distinguished from other encephalitides by its focal and often haemorrhagic nature. Specific antiviral therapy with acyclovir can significantly improve the prognosis. We present MRI findings of two cases of herpes simplex encephalitis (HSE) confirmed by PCR analysis, focusing on the serial changes after acyclovir therapy: gyral swelling, high signal intensity on T2-weighted images in the subfrontal region, temporal lobe and insula in the initial stage, then regional extension with enhancement and haemorrhage despite appropriate acyclovir therapy, and finally encephalomalacia and brain atrophy.

Effects of whole cell sonicates of Treponema lecithinolyticum on osteoclast differentiation

BACKGROUND

Alveolar bone destruction is a characteristic feature of periodontal diseases and multinucleated osteoclast cells derived from hemopoietic cells are responsible for bone resorption. Treponema lecithinolyticum is a novel oral spirochete isolated from the periodontal lesions.

METHODS

The effect of whole cell sonicates on the osteoclast differentiation was examined in a co-culture system of hemopoietic mouse bone marrow cells and calvaria derived-osteoblastic cells to clarify the role of T. lecithinolyticum in the alveolar bone destruction associated with periodontal diseases. The differentiated osteoclasts were confirmed by tartrate-resistant acid phosphatase (TRAP) staining.

RESULTS

Sonicates of this bacterium stimulated the osteoclast formation in the co-culture system in a dose-dependent manner. The sonicates-induced osteoclast formation was partially inhibited by the heat treatment of sonicates. Indomethacin, which is a prostaglandin inhibitor, decreased the osteoclast formation induced by the bacterial sonicates.

CONCLUSIONS

These findings suggest that T. lecithinolyticum induces osteoclast differentiation by a prostaglandin E2-dependent mechanism and that heat-labile components may be involved in this process.

Both the conserved and the unique gene structure of stomach-specific calpains reveal processes of calpain gene evolution

The proteins nCL-2 and nCL-2' are members of the Ca2+-dependent cysteine protease (calpain) superfamily, with stomach-specific expression. Like other typical calpains, nCL-2 has three distinct domains, a protease, a C2-like, and a 5EF-hand Ca2+-binding domain, as well as the N-terminal propeptide region. On the other hand, nCL-2' lacks the C2-like and 5EF-hand domains but is otherwise identical to nCL-2, except for the three C-terminal residues. To examine the stomach-specific and presumed alternative expression mechanisms of nCL-2 and nCL-2', we have cloned and characterized the mouse gene for nCL-2 and nCL-2'. The mouse nCL-2 gene contains at least 23 exons, spanning more than 50 kb, and possesses an exon specific for nCL-2' in the middle. Therefore, nCL-2 and nCL-2' are generated by alternative splicing of the same gene, Capn8. Capn8 shows the highly conserved gene organization of the other typical calpain large subunit genes, CAPN1, CAPN2, CAPN3, CAPN9, CAPN11, and Capn12, except for the unique exon between exon 9 and exon 10 of Capn8, which encodes the 3' half of the nCL-2' transcript. No such exon in the corresponding regions was found in CAPN1, CAPN2, CAPN3, CAPN9, or CAPN11. Gene and cDNA structures of a presumed human orthologue of mouse nCL-2, CAPN8, were determined, revealing that it overlaps human CAPN2, the gene for the m-calpain large subunit, in head-to-head orientation at 1q32-41. These features of Capn8 and CAPN8 illustrate a process of calpain gene evolution, i.e., the protease, C2-like, and 5EF-hand domains presumably functioned as independent genes, and the calpain superfamily has evolved by ordered fusions of these ancestral gene units, with subsequent amplifications.

Impact of postprandial hypertriglyceridemia on vascular responses in patients with coronary artery disease: effects of ACE inhibitors and fibrates

We analyzed vascular responses (endothelial function, oxidant stress) to postprandial hypertriglyceridemia (PHTG) in patients with coronary artery disease (CAD) to reveal potential therapeutical effects of angiotensin converting enzyme inhibition (ACE-I) and of lipid lowering (fibrate). The study population (n=39, mean age: 60 years) consisted of four groups, all of which had angiographically documented CAD. A high fat group (n=9) consumed a high fat meal, a low fat group (n=9) a low fat meal, and ACE-I (n=10) or fibrate (n=11) groups consumed a high fat meal plus lisinopril or fenofibrate. Serum triglycerides (TG) increased significantly 2 h after eating a test meal in all groups with the exception of the low fat group. In the high and low fat groups changes of serum TG were positively correlated (r=0.664, P<0.005) with changes of phorbol ester-activated leukocyte superoxide anion radical (O(2-.)) formation and were negatively correlated (r=-0.488, P<0.05) with flow-mediated brachial artery dilation (FMD). There was a negative correlation (r=-0.419, P=0.094) between FMD and changes of O(2-.) formation in the high and low fat groups. In the ACE-I and fibrate groups, O(2-.) formation decreased 2 h after eating a test meal (from 5.34+/-1.01 to 3.81+/-1.15 nmol/10(6)cells per min, P<0.01, and from 4.66+/-0.91 to 4.26+/-0.97 nmol/10(6)cells per min, P=0.374, respectively). However, endothelial function did not show any significant changes 2 h after eating a test meal in all groups. PHTG increases oxidant stress and further deteriorates endothelial function, even in patients with CAD. Both ACE-I and fibrates have an antioxidant effect but no acute beneficial effects in terms of endothelial function under conditions of PHTG in CAD patients.

Adjustability of the circadian clock in the cockroaches: a comparative study of two closely related species, Blattella germanica and Blattella bisignata

A single 2h light pulse (250 lux) was given at various times to phase shift the locomotor circadian rhythm of two species of closely related cockroaches, Blattella bisignata and Blatella germanica. The phase-response curve (PRC) of both species showed a similar pattern. Phase delays and advances were induced by light pulse during the early and late subjective night, respectively, while no clear phase shifting was elicited during the subjective day. However, the magnitude of the phase delay (1.89h +/- 0.66h) and advance (0.69h +/- 0.36h) of B. bisignata was significantly larger than that of B. germanica (0.78h +/- 0.38h and 0.35h +/- 0.18h, respectively). This result indicates the superior adjustability of the circadian clock in B. bisignata. The period-response curve (PdRC) was also constructed for both species. Although both species did not show great flexibility in circadian period changes, the phase shifts were significantly correlated with the period changes in the advance zone of B. bisignata (r = 0.72, P < .1). This allowed the circadian clock of B. bisignata to display better entrainability since the phase advance adjustment was significantly more difficult than that of phase delay. The results indicate the overall adjustability of the circadian clock of B. germanica is inferior to that of B. bisignata. The significance of this finding is discussed from an ecological perspective.

High dose radiation delivered by intensity modulated conformal radiotherapy improves the outcome of localized prostate cancer

PURPOSE

We present the long-term outcome and tolerance of 3-dimensional (D) conformal and intensity modulated radiation therapy for localized prostate cancer.

MATERIALS AND METHODS

Between October 1988 and December 1998, 1,100 patients with clinical stages T1c-T3 prostate cancer were treated with 3-D conformal or intensity modulated radiation therapy. Patients were categorized into prognostic risk groups based on pretreatment prostate specific antigen (PSA), Gleason score and clinical stage. Sextant biopsies were performed 2.5 years or greater after treatment to assess local control. PSA relapse was defined according to the consensus guidelines of the American Society for Therapeutic Radiation Oncology. Late toxicity was classified according to the Radiation Therapy Oncology Group morbidity grading scale. Median followup was 60 months.

RESULTS

At 5 years the PSA relapse-free survival rate in patients at favorable, intermediate and unfavorable risk was 85% (95% confidence interval [CI] +/- 4), 58% (95% CI +/- 6) and 38% (95% CI +/- 6), respectively (p <0.001). Radiation dose was the most powerful variable impacting PSA relapse-free survival in each prognostic risk group. The 5-year actuarial PSA relapse-free survival rate for patients at favorable risk who received 64.8 to 70.2 Gy. was 77% (95% CI +/- 8) compared to 90% (95% CI +/- 8) for those treated with 75.6 to 86.4 Gy. (p = 0.04) [corrected]. The corresponding rates were 50% (95% CI +/- 8) versus 70% (95% CI +/- 6) in intermediate risk cases (p = 0.001), and 21% (95% CI +/- 8) versus 47% (95% CI +/- 6) in unfavorable risk cases (p = 0.008) [corrected]. Only 4 of 41 patients (10%) who received 81 Gy. had a positive biopsy 2.5 years or greater after treatment compared with 27 of 119 (23%) after 75.6, 23 of 68 (34%) after 70.2 and 13 of 24 (54%) after 64.8 Gy. The incidence of toxicity after 3-D conformal radiation therapy was dose dependent. The 5-year actuarial rate of grade 2 rectal toxicity in patients who received 75.6 Gy. or greater was 14% (95% CI +/- 2) compared with 5% (95% CI +/- 2) in those treated at lower dose levels (p <0.001). Treatment with intensity modulated radiation therapy significantly decreased the incidence of late grade 2 rectal toxicity since the 3-year actuarial incidence in 189 cases managed by 81 Gy. was 2% (95% CI +/- 2) compared with 14% (95% CI +/- 2) in 61 managed by the same dose of 3-D conformal radiation therapy (p = 0.005). The 5-year actuarial rate of grade 2 urinary toxicity in patients who received 75.6 Gy. or greater 3-D conformal radiation therapy was 13% compared with 4% in those treated up to lower doses (p <0.001). Intensity modulated radiation therapy did not affect the incidence of urinary toxicity.

CONCLUSIONS

Sophisticated conformal radiotherapy techniques with high dose 3-D conformal and intensity modulated radiation therapy improve the biochemical outcome in patients with favorable, intermediate and unfavorable risk prostate cancer. Intensity modulated radiation therapy is associated with minimal rectal and bladder toxicity, and, hence, represents the treatment delivery approach with the most favorable risk-to-benefit ratio.

Lagophthalmos surgery in leprosy: findings from a population-based survey in Korea

Lagophthalmos continues to be a serious problem in cured leprosy patients. We conducted a population-based survey of lagophthalmos surgical coverage (LSC), barriers to lagophthalmos surgery and outcome of lagophthalmos surgery in leprosy patients in South Korea. In our survey, there were 60 patients with lagophthalmos who had needed surgery (> 5 mm gap), 34 of whom had received surgery, resulting in a lagophthalmos surgery coverage of 57%. Among the 34 patients who had received lagophthalmos surgery, 18 needed further surgery. Among those who had never had surgery, none of the demographic indicators predicted surgical uptake; the primary reason given for failure to have surgery was lack of knowledge about it. Outcome of surgery (by eye) showed that 29% of eyes still had a gap of 5 mm or more. The frequency of symptoms (tearing, blurring of vision, pain, etc.) was high. Even in settings with a good eye care infrastructure, such as Korea, uptake of surgery can still be low and results may not be satisfactory to patients. There is a need for practical guidelines for leprosy control programmes in the areas of (a) patient recognition, (b) patient education, (c) monitoring the uptake of surgery, and (d) monitoring the outcome of surgery to ensure the best possible outcome.

TR4 orphan receptor represses the human steroid 21-hydroxylase gene expression through the monomeric AGGTCA motif

The human TR4 orphan receptor (TR4) is a member of the nuclear receptor superfamily. It functions as a transcriptional factor which regulates and controls many important physiological functions. It has been documented that TR4 may bind as a homodimer to a DNA response element containing two direct repeats of the AGGTCA consensus motif. Surprisingly, our data reveal that the expression of the human steroid 21-hydroxylase (21-OHase) gene could be repressed by TR4 via the monomeric AGGTCA motif (-228TR4RE) at its 5' flanking region (nucleotide numbers 1431-1444, 5'-GGAAAAAGGTCAGG-3'). Electrophoretic mobility shift assay showed specific binding with a dissociation constant of 0.4 nM between TR4 and the monomeric -288TR4RE motif. However, TR4 does not form heterodimers with either retinoid X receptor alpha or SHP (short heterodimer partner) orphan receptor. Additionally, both dual-luciferase and chloramphenicol acetyltransferase assays demonstrated that TR4 can function as a repressor via the -228TR4RE of the 21-OHase gene. In conclusion, our data suggest that TR4 may bind to a monomeric DNA response element and play an important role in the suppression of the 21-OHase gene expression.

Immobilization of poly(ethylene glycol) or its sulfonate onto polymer surfaces by ozone oxidation

A novel surface modification method has been developed to improve biocompatibility of polymeric biomaterials. This approach involves ozonation and then followed by graft polymerization with acrylates containing PEG, sulfonated PEG or by coupling of PEG derivatives. All the reactions were confirmed by ATR FT-IR and ESCA. The degree of ozonation measured by the iodide method was dependent on the ozone permeability of the polymers used. Surface hydrophilicity was investigated by measuring the contact angles. Ozonation itself yielded a slight increase in hydrophilicity and a decrease in platelet adhesion, but PEG immobilization showed a significant effect on surface hydrophilicity and platelet adhesion to confirm well-known PEG's passivity which minimize the adhesion of blood components on polymer surfaces. Both graft polymerization and coupling were effective for PU. In contrast, only grafting gave enough yields for PMMA and silicone. Platelet adhesion results demonstrated that all PEG modified surfaces adsorbed lower platelet adhesion than untreated or ozonated ones. Polymers coupled with sulfonated PEG exhibited the lowest platelet adhesion when compared with control and PEG coupled ones by virtue of the synergistic effect of non-adhesive PEG and negatively charged SO3 groups. This PEG or sulfonated PEG immobilization technology using ozonation is relatively simple for introducing uniform surface modification and therefore very useful for practical application of blood contacting medical devices.

Typing and antimicrobial susceptibilities of methicillin resistant Staphylococcus aureus (MRSA) strains isolated in a hospital in Korea

Methicillin-resistant Staphylococcus aureus (MRSA) strains may cause serious nosocomial infections, including pneumonia and septicemia. The rate of methicillin-resistance among S. aureus isolates in Korea is over 50%. In this study, 90 MRSA isolates from Kyung Hee University Hospital were characterized employing bacteriophage typing, pulsed-field gel electrophoresis (PFGE), and antimicrobial susceptibility testing. Eighty percent of the strains could be phage-typed. The largest group or 40% of the strains belonged to lyso group III, followed by 32% of the isolates which produced a reaction with regional additional phages. Phage type 83A was most frequently encountered, followed by phage type D11. PFGE patterns confirmed the presence of two major clusters, which comprise the isolates belonging to lyso group III and the strains that were typable with regional additional phages. The latter group also contained a number of strains that were nontypable with bacteriophages. The resistance rates to ciprofloxacin, erythromycin, tetracycline, gentamicin and clindamycin were over 94%. Strains with intermediate resistance to vancomycin strains or resistance to mupirocin were not found. In conclusion, this study demonstrates that the results of phage typing are confirmed and supplemented by PFGE data.

Evaluation of survival rate after follicular unit transplantation using the KNU implanter

BACKGROUND

Many hair transplant surgeons have advocated the use of micrograft megasessions for the purpose of a more natural looking end result, especially in the Oriental with higher skin/hair color contrast and darker, coarse, straight hairs. But it also has some fundamental limitations. Most important are a low graft yield and a low density after transplantation. There are several reports about the survival rate of micrografts in Caucasians, though the results are variable, but few reports about the survival rate and fate of micrografts in Orientals.

OBJECTIVE

To compare the survival rate of one-hair follicular units with that of two-hair follicular units using the KNU implanter, to ascertain the average survival rate of micrografts (one- and two-hair follicular units), and to evaluate the fate of grafted hair according to time.

METHODS

Two templates of 1.5 cm2 were made by tattooing on both sides of the frontoparietal recess areas in 11 patients with male pattern baldness (beyond Norwood type IIIa). The authors planted one-hair unit micrografts in the left template and two-hair unit micrografts in the right template, which were prepared by the concept of follicular unit, and counted the surviving number of follicular units at 1 and 3 months and total hairs at 6 and 12 months after transplantation.

RESULTS

The mean survival rate by the number of follicular units was 47.3 and 57.4% at 1 and 3 months after transplantation, respectively. The mean survival rate by the total number of hairs was 92.0 and 90.4% at 6 and 12 months after transplantation, respectively.

CONCLUSION

About 50% of the transplanted hairs fell out in 1 month, but at 6 months the survival rate of follicular unit transplantation using the KNU implanter showed a good result (92%), and there were no significant differences in the mean survival rate of follicular unit and total hairs between one-hair and two-hair units at 1, 3, 6, and 12 months after transplantation.

Amygdala is critical for stress-induced modulation of hippocampal long-term potentiation and learning

Stress is a biologically significant factor shown to influence synaptic plasticity and memory functioning in the hippocampus. This study examined the role of the amygdala, a brain structure implicated in coordinating stress behaviors and modulating memory consolidation, in mediating stress effects on hippocampal long-term potentiation (LTP) and memory in rats. Electrolytic lesions of the amygdala effectively blocked the adverse physiological and behavioral effects of restraint and tailshock stress, without impeding the increase in corticosterone secretion to stress. Physiologically, hippocampal slices from stressed animals exhibited impaired LTP relative to slices from unstressed control animals, whereas hippocampal slices from stressed animals with amygdalar lesions exhibited normal LTP. Behaviorally, stressed animals were impaired in retention of a hippocampal-dependent hidden platform version of the Morris water maze task, and this impairment was blocked by amygdalar lesions. In a fixed location-visible platform water maze task that can be acquired by independent hippocampal and nonhippocampal memory systems, stress enhanced the use of nonhippocampal-based memory to acquire the task. These results indicate that an intact amygdala is necessary for the expression of the modulatory effects of stress on hippocampal LTP and memory.

Hepatic hemangiomas with arterioportal shunt: findings at two-phase CT

PURPOSE

To determine the prevalence of arterioportal shunt associated with hepatic hemangiomas, describe the two-phase spiral computed tomographic (CT) findings, and correlate the presence of arterioportal shunt with the size and rapidity of enhancement of hemangiomas.

MATERIALS AND METHODS

The study group consisted of 109 hepatic hemangiomas in 69 patients who underwent two-phase spiral CT during 1 year. CT scans were obtained during the hepatic arterial (30-second delay) and portal venous (65-second delay) phases after injection of 120 mL of contrast material (3 mL/sec). Arterioportal shunts were diagnosed when hepatic arterial phase CT scans showed a wedge-shaped or irregularly shaped homogeneous enhancement in the liver parenchyma adjacent to the tumor and when portal venous phase CT scans showed isoattenuation or slight hyperattenuation, compared with normal liver in that area, and when there was no demonstrable cause of these attenuation differences. The presence of arterioportal shunt in hemangioma was correlated with the size of the tumor and the rapidity of intratumoral enhancement.

RESULTS

Arterioportal shunt was found in 28 (25.7%) of 109 hemangiomas. There was no statistically significant relationship between lesion size and presence of the arterioportal shunt (P =.653). Arterioportal shunt was more frequently found in hemangiomas with rapid enhancement (P <.01).

CONCLUSION

Arterioportal shunts are not uncommonly seen in hepatic hemangiomas at two-phase spiral CT. Hemangiomas with arterioportal shunts tend to show rapid enhancement.

Cataract in leprosy patients: cataract surgical coverage, barriers to acceptance of surgery, and outcome of surgery in a population based survey in Korea

BACKGROUND/AIMS

Cataract is the leading cause of blindness in leprosy patients. There is no population based information on the cataract surgical coverage, barriers to use of surgical services, and outcome of surgery in these patients. We sought to determine these measures of cataract programme effectiveness in a cured leprosy population in South Korea.

METHODS

The population consisted of residents of six leprosy resettlement villages in central South Korea. All residents were invited to participate in a study of eye disease and interviewed regarding use of surgical services and reasons for not using these services.

RESULTS

The cataract surgical coverage in this population was 55.4% when <6/18 was used as the cut off and increased to 78.3% when the cut off was <6/60. Barriers reported by patients included being told by the doctor that the cataract was not mature and a perception by the patient that there was no need for surgery. Among patients who had aphakic surgery, 71% were still blind in the operative eye while among patients who had pseudophakic surgery, 14% were still blind (presenting vision). Blindness in pseudophakic patients could be reduced to 3% with spectacle correction.

CONCLUSION

Cataract prevalence in leprosy patients will increase as life expectancy continues to increase. Leprosy control programmes will need to develop activities aimed at reducing the burden of cataract. Recommendations include establishing collaborative agreements with ophthalmological services to provide high quality IOL surgery to these patients, training of health staff to identify and refer patients in need of surgery, monitoring the uptake of cataract surgery among patients needing services, and monitoring the outcome of surgery to improve refractive outcome.

Torsion angle based design of peptidomimetics: a dipeptidic template adopting beta-I turn (Ac-Aib-AzGly--NH(2))

We have attempted to design a model dipeptide (acetyl dipeptide amide, Ac-CA1-CA2--NH(2)) that can adopt specifically typical torsion angles of the beta-I turn (phi(i+1), psi(i+1), phi(i+2), psi(i+2)=-60 degrees, -30 degrees, -90 degrees, 0 degrees ). The key of the design is the combination of constrained amino acids that prefer to adopt the desired torsion angles. We chose Aib (aminoisobutyric acid) as the first residue of which phi and psi angles must be -60 degrees and -30 degrees, respectively. Then, we selected an azaamino acid as the second residue since previous studies have indicated that they prefer to adopt +/-90 degrees of phi angle and 0 degrees or 180 degrees of psi angle. The conformational preference of the resulting Ac-Aib-AzGly--NH(2) is investigated using ab initio methods. The conformations implying beta-I and beta-I' turns are energetically most favorable, as we expected. Thus, we synthesized the designed molecule on the solid phase considering the future generation of combinatorial libraries using an automatic peptide synthesizer. Then, NMR spectroscopy was carried out to confirm their conformational preference in solution was carried out. The results indicated that the Ac-Aib-AzGly--NH(2) adopt beta-I or beta-I' turns in solution forming an intramolecular hydrogen bonding between Ac--C(O) and terminal NH(2). We believe that such a small peptidomimetic template is highly useful for the design of drug candidates and molecular devices.

Long-term intake of Korean red ginseng in HIV-1-infected patients: development of resistance mutation to zidovudine is delayed

We have observed that CD4+ T cell counts in human immunodeficiency virus (HIV)-1-infected patients treated with only Korean red ginseng (KRG) are maintained or even increased for a prolonged period. In the present study, we investigated whether the development of resistance mutations in reverse transcriptase (RT) to zidovudine (ZDV) is delayed by combined therapy with KRG and ZDV. Nested polymerase chain reaction (PCR) and direct sequencing methods were used to define RT codons 41, 67, 70, 210, 215 and 219 of the HIV-1 pol gene in DNA from peripheral blood mononuclear cells (PBMC) samples from 18 patients. Nine of these eighteen patients were in the KRG group and had been treated with KRG for 60 +/- 15 months (range: 38-82) and ZDV, and nine were in the control group and had been treated with ZDV only. The patients in the KRG group had been treated with ZDV for 75 +/- 24 months, and CD4+ T cell counts were maintained from 239 +/- 85 to 234 +/- 187 microliters-1 (P > 0.05) during the study period, whereas the patients in the control group had been treated with ZDV for 51 +/- 31 months, and their CD4+ T cell counts decreased from 272 +/- 97 to 146 +/- 154 microliters-1 (P < 0.01). In samples within 24 months of ZDV therapy, the overall incidence of 6 resistance mutations to ZDV was 4.2% and 47% in the KRG and control group (P < 0.01), respectively. In samples after 24 months of therapy, the incidence was 21.7% and 56.3% in the KRG and control group (P < 0.01), respectively. These data suggest that the maintenance of CD4+ T cell counts by ZDV and KRG-intake for a prolonged period might be indirectly associated with delayed development of resistance to ZDV by KRG-intake.

The outcome of the nonoperated contralateral hand in carpal tunnel syndrome

It is not well known how the nonoperated contralateral hand behaves in bilateral carpal tunnel syndrome (CTS). The postoperative clinical course of the nonoperated contralateral hand in unilateral CTS is not well documented either. Of 324 CTS patients, the authors studied 37 who had carpal tunnel release on one hand only to evaluate the postoperative outcome of the nonoperated contralateral hand. The other 287 patients had operations on both hands. Seven patients were excluded because of missing data or because they could not be contacted. All 324 patients were subject to clinical and electrodiagnostic studies on both hands. The patients were divided into three groups. Group I was composed of patients who had bilateral CTS, diagnosed clinically and electrophysiologically, but who had surgery done only on the hand with the most pronounced symptoms. The patients in group II showed symptoms of CTS in one hand only. However, the opposite hand was diagnosed with subclinical CTS: Electrodiagnostic studies showed involvement of the median nerve, but without symptoms. Group III was composed of true unilateral CTS patients, diagnosed by symptoms and electrodiagnostic study. The results of the electrodiagnosis were categorized according to the severity of median nerve damage (mild, moderate, severe). The outcome and postoperative clinical course of the nonoperated contralateral hand were evaluated by electromyography and telephone survey. This method of survey was used because of the vast spread of patients throughout the country. Within 1 year, all 30 operated hands showed significant improvement, 20 of which belonged to group I. Regarding progress of the nonoperated contralateral hand, 10 patients showed improvement of one grade whereas 5 patients showed three grades of improvement. In another 5 patients there was no change whatsoever. In addition, from groups II and III there were 5 patients who showed no change in the nonoperated hand. The postoperative electromyographic findings of the nonoperated contralateral hand was not commensurate with the symptoms. However, regardless of electromyographic results, the nonoperated contralateral hand showed significant improvement (p < 0.0001). Patients with unilateral CTS did not experience any symptom development in the nonoperated contralateral hand.

The protective role of HSP90 against 3-hydroxykynurenine-induced neuronal apoptosis

3-hydroxykynurenine (3HK), an endogenous metabolite of tryptophan in the kynurenine pathway, is a potential neurotoxin in several neurodegenerative disorders. Stabilizing protein structure, heat shock proteins (HSPs) have diverse roles as molecular chaperones to mediate stress tolerance. In the present study, we investigated the possible protective role of HSPs against 3HK induced neuronal cell death. Here we report that 3HK induced in a dose- and time-dependent manner neuronal cell death in neuroblastoma SK-N-SH cells. The cell death showed characteristic apoptotic features such as cell shrinkage, plasma membrane blebbing, chromatin condensation, and nuclear condensation and fragmentation. Furthermore, SK-N-SN cells were protected from 3HK induced cytotoxicity by prior elevation of HSPs expression. Our results show that the protective effect was abolished by HSP90 anti-sense oligonucleotides while not by HSP27 and HSP70 anti-sense oligonucleotides. Also, our result shows that HSP90 effectively inhibits caspases activities leading to the apoptosis. These results suggest that 3HK induces apoptosis in neuroblastoma SK-N-SN cells and that HSP90 is major contributing protein component of protection against 3HK induced apoptosis.

Metabolic regulation of brain Abeta by neprilysin

Amyloid beta peptide (Abeta), the pathogenic agent of Alzheimer's disease (AD), is a physiological metabolite in the brain. We examined the role of neprilysin, a candidate Abeta-degrading peptidase, in the metabolism using neprilysin gene-disrupted mice. Neprilysin deficiency resulted in defects both in the degradation of exogenously administered Abeta and in the metabolic suppression of the endogenous Abeta levels in a gene dose-dependent manner. The regional levels of Abeta in the neprilysin-deficient mouse brain were in the distinct order of hippocampus, cortex, thalamus/striatum, and cerebellum, where hippocampus has the highest level and cerebellum the lowest, correlating with the vulnerability to Abeta deposition in brains of humans with AD. Our observations suggest that even partial down-regulation of neprilysin activity, which could be caused by aging, can contribute to AD development by promoting Abeta accumulation.

Effect of Nd:YAG laser irradiation on the apical leakage of obturated root canals: an electrochemical study

AIM

The purpose of this laboratory study was to evaluate the effect of Nd:YAG laser irradiation on the apical leakage of obturated root canals using an electrochemical method.

METHODOLOGY

Forty extracted single-rooted teeth were selected and the anatomic crown of each tooth was removed. The specimens were randomly divided into four groups. In group 1, the root canals were prepared with K-files and irradiated with Nd:YAG laser (5 W, 20 Hz) via a 300 microns optical fibre. Then the root canals were obturated with laterally condensed gutta-percha and Pulp Canal Sealer EWT. In group 2, the root canals were treated with the same method as those of group 1 but without laser irradiation. In group 3, the root canals were prepared with ProFiles, laser irradiated and then obturated with vertically condensed gutta-percha and Pulp Canal Sealer EWT. In group 4, the root canals were treated with the same method as those of group 3 but without laser irradiation. The electric resistance between standard and experimental electrodes in the canals was measured over a period of 10 days.

RESULTS

At 2 h, groups 1 and 3 irradiated with laser had significantly less apical leakage than group 2 (P < 0.05). After 10 days, group 4 had the highest leakage, followed by groups 2, 1 and 3; the differences between the groups was statistically significant (P < 0.05).

CONCLUSIONS

Laser irradiation following root canal preparation reduced apical leakage following root canal obturation.

The effect of electrical stimulation on the trunk control in young children with spastic diplegic cerebral palsy

This study was designed to determine the effectiveness of electrical stimulation over the trunk in improving sitting balance in young children with spastic diplegic cerebral palsy who displayed poor trunk control. The subjects ranged in age from 8 to 16 months and were randomly assigned to two groups. Both group had physical therapy for 6 weeks. Electrical stimulation (ES) group had additional electrical stimulation over the abdomen and posterior back muscles. Radiographic studies were carried out on the whole spine while they were sitting before and after treatment. Kyphotic angle, Cobb's angle and lumbo-sacral angle were measured. Additionally, sitting score-Gross Motor Function Measure (GMFM) was also evaluated. There was no difference of these values at initial evaluation between the two groups. Following 6 weeks of intensive therapy, the changes of kyphotic angle and sitting score-GMFM were significantly higher in ES group statistically when compared with those of the control group. The Cobb's angle following treatment was improved in ES group, but not statistically compared with that of control group. This study suggests that electrical stimulation over the trunk become a beneficial therapeutic technique in improving the sitting posture and trunk control in young children with spastic diplegic cerebral palsy.

Clinical Features and Prognosis of Lung Cancer with Brain Metastasis

PURPOSE

Brain metastasis is estimated to occur in 20~40% of solid tumor patients and the most common primary tumor is lung cancer. Even though the prognosis of brain metastasis is grave and the 1-year survival rate is only 15%, symptom palliations are made with whole brain radiation therapy. We retrospectively evaluated the clinical features and prognostic factors of lung cancer with brain metastasis.

MATERIALS AND METHODS

From January 1987 to October 1999, 50 lung cancer patients with brain metastasis underwent whole brain radiation therapy. We reviewed the improvement in neurologic symptoms and survival according to the following parameters; performance status, histological type, presence of brain metastasis at the initial diagnosis of lung cancer, presence of extracranial metastasis, multiplicity of brain lesion, presence of primary lung symptom and treatment modalities.

RESULTS

The most frequent symptom with brain metastasis was a headache (50%). Palliation of the headache and other symptoms was achieved in 81% of the patients. Median overall survival after brain metastasis was 21 weeks and the 1 year survival rate was 15%. Patients without extracranial metastasis had a longer median survival than those with, 38 weeks versus 15 weeks, respectively (p=0.01).

CONCLUSION

In lung cancer with brain metastasis, neurologic symptoms can be palliated with whole brain radiation therapy, and in this study among such patients, absence of extracranial metastasis can be a good prognostic factor.

His-His-Leu, an angiotensin I converting enzyme inhibitory peptide derived from Korean soybean paste, exerts antihypertensive activity in vivo

It has been reported that soybean peptide fractions isolated from Korean fermented soybean paste exert angiotensin I converting enzyme (ACE) inhibitory activity in vitro. In this study, further purification and identification of the most active fraction inhibiting ACE activity were performed, and its antihypertensive activity in vivo was confirmed. Subsequently, a novel ACE inhibitory peptide was isolated by preparative HPLC. The amino acid sequence of the isolated peptide was identified as His-His-Leu (HHL) by Edman degradation. The IC(50) value of the HHL for ACE activity was 2.2 microg/mL in vitro. Moreover, the synthetic tripeptide HHL (spHHL) resulted in a significant decrease of ACE activity in the aorta and led to lowered systolic blood pressure (SBP) in spontaneously hypertensive (SH) rats compared to control. Triple injections of spHHL, 5 mg/kg of body weight/injection resulted in a significant decrease of SBP by 61 mmHg (p < 0.01) after the third injection. These results demonstrated that the ACE inhibitory peptide HHL derived from Korean fermented soybean paste exerted antihypertensive activity in vivo.

Factors Influencing Visualization of Vertebral Metastases on MR Imaging Versus Bone Scintigraphy

OBJECTIVE

The purpose of this study was to investigate whether the location and size of vertebral body metastases influence the difference in detection rates between MR imaging and bone scintigraphy.

MATERIALS AND METHODS

We retrospectively evaluated the vertebral body lesions detected on MR imaging in 74 patients with known widely disseminated metastatic disease. Three radiologists independently reviewed the MR images and bone scintigraphs. MR imaging findings included lesion size and its spatial relationship to the bony cortex (intramedullary, subcortical, and transcortical) and results were correlated with those of planar technetium 99m bone scintigraphy.

RESULTS

Findings on bone scans were negative for all intramedullary lesions without cortical involvement shown on MR imaging, regardless of their size. Findings on bone scans (71.3% for transcortical and 33.8% for subcortical) were frequently positive for lesions with cortical involvement (trans- or subcortical), and the probability of positive findings on bone scans was also influenced by the lesion size. Statistical analysis showed a positive correlation among cortical involvement, lesion size, and positive findings on bone scintigraphy (p < 0.0001).

CONCLUSION

Location (the presence of cortical bone involvement on MR imaging) and size of the vertebral body metastases appear to be important contributing factors to the difference in detection rates between MR imaging and bone scintigraphy. Cortical involvement is likely the cause of positive findings on bone scans. Early vertebral metastases tend to be small and located in the medullary cavity without cortical involvement, and therefore, findings may be positive on MR images but negative on bone scans.