Resetting of sympathetic rhythm by somatic afferents causes post-reflex coordination of sympathetic activity in rat

1. We have proposed previously that graded synchronous activity is produced by periodic inputs acting on weakly coupled or uncoupled oscillators influencing the discharges of a population of cutaneous vasoconstrictor sympathetic postganglionic neurones (PGNs) in anaesthetized rats. 2. Here we investigated the effects of somatic afferent (superficial radial nerve, RaN) stimulation, on the rhythmic discharges of this population. We recorded (1) at the population level from the ventral collector nerve and (2) from single PGNs focally from the caudal ventral artery of the tail. 3. Following RaN stimulation we observed an excitatory response followed by a period of reduced discharge and subsequent rhythmical discharges seemingly phase-locked to the stimulus. 4. We suggest that the rhythmical discharges following the initial excitatory response (conventional reflex) result from a resetting of sympathetic rhythm generators such that rhythmic PGN activity is synchronized transiently. We also demonstrate that a natural mechanical stimulus can produce a similar pattern of response. 5. Our results support the idea that in sympathetic control, resetting of multiple oscillators driving the rhythmic discharges of a population of PGNs may provide a mechanism for producing a sustained and coordinated response to somatic input.

Development of a novel in vitro assay (ALS assay) for evaluation of vaccine-induced antibody secretion from circulating mucosal lymphocytes

We describe here a novel method for measuring in vitro antibody secretion from the tissue culture of human B lymphocytes in peripheral blood mononuclear cells (PBMC) after oral vaccination with a killed cholera vaccine. Enzyme-linked immunosorbent assay (ELISA) titers of the antibody secreted in the cell supernatant were determined. The validation results demonstrated that human PBMC remained viable and continued to secrete antibodies (total immunoglobulin A [IgA] and IgG) for up to 4 days of incubation at 37 degrees C with 5% CO(2) in cell cultures. The secreted antibody concentration correlated positively with the PBMC concentration and incubation time in the tissue culture and correlated negatively with the storage time of the whole blood at room temperature. In vitro assay of secreting antibody in the lymphocyte supernatant (i.e., the ALS assay) is capable of the detecting specific antibody response after oral vaccination with a killed whole-cell-plus-B-subunit cholera vaccine (WC-B) in healthy adults in a phase I clinical trial. Postimmunization PBMC secreted antibodies to cholera toxin in the cell supernatants. Antibody production did not require any in vitro antigen stimulation. In the ALS assay, antigen-specific antibody titers of prevaccination samples were barely detectable, whereas serum antitoxin ELISA titers in background of prevaccine samples were significantly higher than the ALS titers. We conclude that, without any in vitro antigen stimulation after vaccination, PBMC secrete antibodies into the supernatants in the ALS assay. This assay can quantitatively measure the antigen-specific antibody production from the PBMC culture in postvaccination blood samples.

Orchestrated transcription of key pathways in Arabidopsis by the circadian clock

Like most organisms, plants have endogenous biological clocks that coordinate internal events with the external environment. We used high-density oligonucleotide microarrays to examine gene expression in Arabidopsis and found that 6% of the more than 8000 genes on the array exhibited circadian changes in steady-state messenger RNA levels. Clusters of circadian-regulated genes were found in pathways involved in plant responses to light and other key metabolic pathways. Computational analysis of cycling genes allowed the identification of a highly conserved promoter motif that we found to be required for circadian control of gene expression. Our study presents a comprehensive view of the temporal compartmentalization of physiological pathways by the circadian clock in a eukaryote.

Multicenter surveillance study for nosocomial infections in major hospitals in Korea. Nosocomial Infection Surveillance Committee of the Korean Society for Nosocomial Infection Control

BACKGROUND

The goals of a surveillance for nosocomial infections (NIs) are to observe the magnitude and characteristics of NIs and to plan and evaluate policies and guidelines of infection control. This study was designed to determine the rate and distribution of NIs and their causative pathogens in Korean hospitals.

METHODS

Prospective surveillance was performed at 15 acute care hospitals with more than 500 beds during a 3-month period from June to August 1996. The case-finding methods were laboratory-based surveillance for patients in the general wards and a direct review of medical charts done regularly for all the patients in the intensive care units.

RESULTS

A total of 3162 NIs were found among 85,547 discharged patients, with an overall nosocomial infection rate of 3.70 per 100 patients discharged. Urinary tract infections constituted 30.3% of all NIs. Other infections were pneumonias, 17.2%, surgical site infections, 15.5%, and primary bloodstream infections, 14.5%. The infection rate was the highest in neurosurgery (14.21), followed by neurology (8. 62) and ontology services (6.70). The infection rate in intensive care units was higher than it was in the general wards (10.74 vs 2. 57, P =.001). The commonly isolated organisms were Staphylococcus aureus (17.2%), Pseudomonas aeruginosa (13.8%), and Escherichia coli (12.3%).

CONCLUSIONS

This first multicenter surveillance study provided extensive information on the current status and trends of NIs in major hospitals in Korea. The results may contribute to the evaluation of infection control programs and the development of effective strategies in these hospitals.

The downregulation of Bcl-2 expression is necessary for theophylline-induced apoptosis of eosinophil

Apoptosis of eosinophils is of increasingly important value in modulating allergic inflammatory airway diseases, such as asthma, and is suppressed by interleukin-5 (IL-5) in in vitro culture. In this study, we examined the effects of theophylline on survival/apoptosis, intracellular cAMP concentration, and Bcl-2 protein expression. Treatment with theophylline protected eosinophils against IL-5-mediated inhibition of apoptosis with a simultaneous suppression of survival in a dose-dependent manner. Theophylline caused an increase in the intracellular cAMP levels of IL-5-stimulated eosinophils. Enhancement of eosinophil apoptosis was consistent with an increase in DNA fragmentation in eosinophils treated with theophylline. On the other hand, the Bcl-2 protein appeared to be expressed constitutively in freshly isolated eosinophils. Bcl-2 expression was augmented by IL-5 stimulation, yet it was considerably inhibited by theophylline treatment. These data suggest that intracellular cAMP levels and Bcl-2 expression are involved in the suppression of eosinophil survival by theophylline.

Role of cAMP-dependent pathway in eosinophil apoptosis and survival

The survival and apoptosis of eosinophils is of pivotal importance for controlling allergic diseases such as asthma and rhinitis. In this study we have investigated the role for cAMP in regulating eosinophil survival and apoptosis in the absence of eosinophil-active cytokines. The treatment with dibutyryl cyclic AMP (dbcAMP) increased eosinophil survival with a concomitant decrease of apoptosis in a dose-dependent manner. The pretreatment with a protein kinase A (PKA) inhibitor blocked the effects of dbcAMP on survival and apoptosis of eosinophils. The catalytic subunit of PKA was translocated to nucleus in parallel with a robust increase of intracellular cAMP levels upon exposure to dbcAMP but not IL-5, suggesting the separation of PKA activation from the IL-5-induced suppression of eosinophil apoptosis. When eosinophils were treated with pharmacological inhibitors of protein kinases prior to exposure to dbcAMP or IL-5, only the mitogen-activating protein kinase (MAPK) inhibitor, PD098059, was partly able to block dbcAMP-induced augmentation of eosinophil viability, whereas both Janus kinase 2 and MAPK inhibitors effectively interrupted the IL-5-induced prolongation of eosinophil survival. The effects of dbcAMP and these protein kinase inhibitors on eosinophil apoptosis were confirmed by morphologic analysis. We propose that a cAMP-dependent pathway may constitute an important component for regulating eosinophil survival/apoptosisand that cAMP may inhibit eosinophil apoptosis through the activation of PKA and of subsequent MAPK in part.

Physiological, pharmacological and neurohormonal assessment of autonomic function in progressive supranuclear palsy

The clinical features of progressive supranuclear palsy (PSP) overlap with other parkinsonian syndromes, including multiple system atrophy (MSA). Autonomic dysfunction is a characteristic of MSA, but has also been described in PSP. We therefore report results from a series of physiological studies of cardiovascular autonomic function in 35 PSP and 20 MSA subjects, and 26 age-matched healthy control subjects. The response to growth hormone-clonidine testing, a neuropharmacological assessment of central adrenoceptor function, was also assessed in 14 PSP and 10 MSA subjects, and compared with 10 controls. None was on medication which may have affected the results. Orthostatic hypotension did not occur in PSP subjects or controls, unlike MSA subjects. Overall there was no evidence of sympathetic vasoconstrictor failure in PSP subjects, unlike MSA subjects, although the pressor response to mental arithmetic was reduced. Cardiac parasympathetic function was affected in only a minority (three of 35) of PSP subjects and was abnormal in MSA subjects. After clonidine administration, growth hormone rose in PSP subjects (median increase 4.3; interquartile range 1.8-7.8 mU/l) and controls, unlike MSA subjects (0.9; 0.3-2.4 mU/l; P < 0.005, Mann-Whitney U-test). In conclusion, in PSP subjects, responses to both physiological and pharmacological tests provided evidence against widespread autonomic dysfunction; this differed markedly from MSA subjects. Thus, cardiovascular autonomic dysfunction should be an exclusionary feature in the diagnosis of PSP.

Multiple oscillators provide metastability in rhythm generation

Biological rhythms such as cardiac and circadian rhythms arise from activity of multiple oscillators with dispersed intrinsic frequencies. It has been proposed that a stable population rhythm, fundamental to normal physiological processes, can be achieved in these systems by synchronization, through mutual entrainment, of individual oscillators. Mutual entrainment, however, is unlikely to be the mechanism underlying the generation of a stable rhythm in a population of multiple weakly coupled or uncoupled oscillators. We have recently identified such a population that is involved in the sympathetic regulation of vascular tone in a thermoregulatory circulation. In this paper, we investigate the stability of the output rhythm of these sympathetic oscillators by subjecting the system to a periodic driving force (the lung inflation cycle-related activity). We show that a population rhythm coupled to the drive can remain stable over a much wider driving frequency range compared with that of any one of its constituent oscillators. This population rhythmicity still exists despite the fact that the dominant frequencies of individual oscillators are not necessarily 1:1 frequency-locked to the drive. We provide evidence to show that this population metastability is achieved through linear and nonlinear dynamic interactions between the driving force and single sympathetic oscillators. Our study suggests that the generation of a stable population rhythm can exist even in the absence of mutual entrainment of its constituents, and this allows the population to generate a stable and flexible patterned response.

Identification of genes expressed in the epithelium of porcine oviduct containing early embryos at various stages of development

As a first step toward elucidation of the action of factors secreted by the epithelium of oviduct, differential display reverse transcription-polymerase chain reaction (DDRT-PCR) was used in this study to identify transcripts of such oviductal factors in gilts carrying various stages of early embryo development post hormone-induced ovulation. A total of 13 differentially expressed transcripts were identified between 50 and 120 hr post-hCG injection (between 1- and 8-cell embryonic stages). Twelve of these transcripts were found to be initially expressed at 96 hr post-hCG injection (at 4-cell embryonic stage) and beyond. Three of such genes were shown by sequence analysis to be the porcine transforming growth factor-alpha, the porcine transforming growth factor-beta-binding protein II and a porcine astral natriuretic factor receptor-like transcript. Only one differentially expressed gene was detected between 50-60 and 85 hr post-hCG injection, and this gene turned out to be the porcine follicle-stimulating hormone receptor. The remaining eight transcripts detected by DDRT-PCR were novel. Moreover, most of these newly expressed genes were found to be turned on at a time coincidental with that of the 4-cell block of porcine embryos cultured in vitro. Our results demonstrate that DDRT-PCR is a feasible approach for rapid identification of genes that are differentially expressed in oviductal epithelium. Some of the genes thus identified may be important for unhindered development of embryos in the oviduct.

Adverse effects of limited hypotensive anesthesia on the outcome of patients with subarachnoid hemorrhage

OBJECT

This study was aimed at clarifying the effect of intraoperative hypotensive anesthesia on the outcome of early surgery in patients with subarachnoid hemorrhage (SAH) caused by saccular cerebral aneurysms. Other factors were also screened for possible effects on the outcome.

METHODS

Hospital charts in 84 consecutive patients with SAH who underwent aneurysm clipping by Day 4 were examined. Possible factors affecting the outcome were analyzed using multiple logistic regression with the dichotomous Glasgow Outcome Scale score as the outcome variable. The relationship between the intraoperative hypotension and the occurrence and severity of vasospasm was studied using both single- and multivariate analyses.

CONCLUSIONS

Intraoperative hypotension had a significantly adverse effect on the outcome of SAH. Hypotension was also related to more frequent and severe manifestations of vasospasm. A long-lasting effect of brain retraction is possibly the cause of this phenomenon. The data contained in this study preclude the use of intraoperative hypotension even in a limited form.

Lumbar herniated disc presenting with cauda equina syndrome. Long-term follow-up of four cases

BACKGROUND

Cauda equina syndrome is a relatively rare presenting symptom of lumbar herniated discs. Early operative decompression is advocated, but it may not always restore the bladder function. In such cases, knowing the long-term outcome of bladder or sphincter disturbances is quite useful in planning the management of these patients.

METHODS

Hospital records of patients operated on for lumbar herniated discs were reviewed. Charts and imaging studies of those patients who presented with classic cauda equina syndrome were analyzed.

RESULTS

There were 4 patients (2.8%) of 144 consecutive surgical series of lumbar disc herniation, whose presenting symptom was classic cauda equina syndrome. Postoperatively, the patients had been followed at the clinic for a mean period of 6.4 years. Certain characteristic findings were noted on patients' neurological and radiological examinations. Although the recovery process of bladder function was very slow, taking months to years, all four patients achieved almost normal voiding with no major impairment of daily activities.

CONCLUSIONS

Even if short-term recovery of bladder function is poor after lumbar disc surgery for cauda equina syndrome, the long-term outcome is not necessarily so. We should follow up on these patients with such measures as intermittent self-catheterization and drug therapy, expecting slow but steady recovery of bladder and sphincter function.

Guillain-Barré syndrome presenting with severe pain: report of one case

Most neurologists are familiar with pain in Guillain-Barré syndrome but some pediatricians may still miss or underestimate it. We report a 10-year-old girl who presented with headache and numbness in lower extremities. On examination, she could walk and showed hyporeflexia, mild muscle weakness, prominent neck rigidity and right facial nerve palsy. Headache and pain in neck, low back and calves were so severe that she could not fall asleep and the response to analgesic was very poor. On 8th day of illness, she needed mechanical ventilation and suffered tetraplegia. Symptoms of autonomic dysfunction including hypertension and sinus tachycardia appeared thereafter and lasted for a week. After receiving a high dose of intravenous immunoglobulin (2 g/kg in 2 days), her condition improved gradually although joint pain persisted for about three weeks. She could walk unaided by day 40 and run by day 70, and recovered completely 6 months later. We emphasize that pain in GBS needs proper evaluation and management in children as well as in adults.

Current perception threshold testing in Fabry's disease

We investigated 16 patients with Fabry's disease (eight hemizygous men and eight heterozygous women) in one family. We used constant current perception threshold (CPT) testing, which evaluated three major sensory nerve fiber populations, to assess subjective complaints of pain and paresthesias. We also examined clinical and biochemical features and compared the values of CPTs and nerve conduction studies (NCS) in detecting the sensory neuropathy. Our results showed that CPT testing at low frequencies (5 and 250 Hz) was significantly more sensitive than at a higher frequency (2 kHz) and NCS in detecting sensory neuropathy in patients with Fabry's disease. However, there was no correlation between CPT testing and clinical symptom scores, duration of disease, creatinine clearance (Ccr) values or alpha-galactosidase A (AGA) activities in either hemizygous or heterozygous patients. Hemizygous patients clinically demonstrated more severe symptom scores, poorer renal function, and higher prevalence of hypohidrosis and corpora angiokeratomas than did heterozygous patients, which indicates that detailed clinical examinations can differentiate the clinical status of hemizygous men from heterozygous women. There were no associations between the biochemical levels of serum AGA activity and renal function (Ccr values) or the symptom scores (grading of acroparesthesia), indicating that biochemical parameters do not predict clinical severity.

Relation between erythrocyte reduced glutathione and glutamate concentrations in Korean Jindo dogs with erythrocytes possessing hereditary high activity of Na-K-ATPase and a high concentration of potassium

The concentrations of sodium, potassium, reduced glutathione (GSH) and free amino acids and Na-K-ATPase activity in erythrocytes were examined in 35 purebred Jindo dogs in Korea. The incidence of Jindo dogs with a high potassium concentration and high activity of Na-K-ATPase in erythrocytes (HK phenotype) was 25.7%. The erythrocyte GSH concentration in HK Jindo dogs varied widely, from 2.45 to 12.38 mmol/l of RBCs, and was positively correlated with the erythrocyte glutamate concentration. These results indicate that HK Jindo dogs have normal to very high levels of erythrocyte GSH, which might result from the varying quantity of Na-dependent glutamate influx in the erythrocytes.

Aplastic anemia in a petrochemical factory worker

A petrochemical worker with aplastic anemia was referred to our hospital. He worked in a petroleum resin-producing factory and had been exposed to low-level benzene while packaging the powder resin and pouring lime into a deactivation tank. According to the yearly environmental survey of the working area, the airborne benzene level was approximately 0.28 ppm. Exposure to benzene, a common chemical used widely in industry, may progressively lead to pancytopenia, aplastic anemia, and leukemia. The hematotoxicity of benzene is related to the amount and duration of exposure. Most risk predictions for benzene exposures have been based on rubber workers who were exposed to high concentrations. In the petroleum industry, the concentration of benzene is relatively low, and there are disputes over the toxicity of low-level benzene because of a lack of evidence. In this paper we report the case of aplastic anemia induced by low-level benzene exposure.

Silica-induced apoptosis in vitro and in vivo

Silica exposure results in an initially acute inflammatory response followed by chronic fibrotic change. The mechanism for the maintenance of silica-induced inflammation has not been understood yet. In silica-induced acute inflammation and chronic fibrosis, various mediators such as reactive oxygen species, cytokines and growth factors are released. And these substances are suggested to have the regulatory role for the inflammation and fibrosis by possessing the potential to influence apoptosis. To demonstrate the apoptosis as an underlying mechanism for the development of silicosis, in vitro and in vivo models were designed. In in vitro study, we evaluated that apoptotic cell fraction in silica (10, 50 microg/cm2)-treated A549 cells was significantly increased in comparison with control by FACS (fluorescein activated cell sorter). Also genomic DNA from silica (10, 50 microg/cm2)-treated A549 showed DNA ladder formation while control and 1 microg/cm2 groups didn't. In in vivo study, total cell numbers and apoptotic cell numbers of BAL (bronchoalveolar lavage) fluid from silica (10, 20, 40 mg/kg)-instilled rats were significantly higher than control group from 1 week. From these results, we concluded acute and chronic presence of apoptosis may contributes to silica-induced acute inflammation and chronic fibrosis.

Potential biomarker of coal workers' pneumoconiosis

It is well known that various cytokines and growth factors secreted from macrophages/monocytes play the key role in the pathogenesis of pneumoconiosis. These can act as biosensors for the prediction of pneumoconiosis. To evaluate which cytokines can be used as sensitive biomarkers in pneumoconiosis, we measured tumor necrosis factor-alpha (TNF-alpha), interleukin-8 (IL-8) and platelet-derived growth factor-AA (PDGF-AA) in supernatant of monocytes with or without coal dust (5 mg/ml) and serum in 42 coal miners with pneumoconiosis and ten healthy control. The coal-stimulated release of TNF-alpha and IL-8 from blood monocytes was significant increased in pneumoconiosis patients compared with controls. The level of TNF-alpha and IL-8 in blood serum was higher in subjects with pneumoconiosis than in controls.

Interleukin (IL)-5 downregulates tumor necrosis factor (TNF)-induced eotaxin messenger RNA (mRNA) expression in eosinophils. Induction of eotaxin mRNA by TNF and IL-5 in eosinophils

An eotaxin is a chemoattractant specific for eosinophils that are known to play a role in helminth infection and allergic responses. Although several cellular sources have been reported to produce eotaxin, it would be interesting to know whether eosinophils are able to produce their own eotaxin and participate in recruitment of themselves in response to inflammation. To this end, a cloned eotaxin complementary DNA was transcribed in vitro to use as a probe for detecting eotaxin messenger RNA (mRNA), and eotaxin protein levels were determined by enzyme-linked immunosorbent assay. Eotaxin mRNA was, as analyzed by in situ hybridization, rarely detectable in unstimulated eosinophils, but was strongly induced in eosinophils when stimulated with tumor necrosis factor (TNF). Interleukin (IL)-5, which is known to be a major factor of eosinophil survival in vivo and in vitro, was also able to induce a modest level of eotaxin mRNA but inhibited TNF-induced eotaxin mRNA expression in a dose-response manner. Dexamethasone inhibited TNF-induced eotaxin mRNA expression. This result was consistent with that from reverse transcription/polymerase chain reaction followed by Southern blot analysis. Unlike the little expression of eotaxin mRNA in the absence of stimuli, the measurement of eotaxin protein revealed that a considerable amount of eotaxin protein was constitutively produced in unstimulated eosinophils. Its expression was upregulated by TNF and IL-5 as well. However, the inhibitory effect of IL-5 on TNF-mediated eotaxin protein production was not as pronounced as that on eotaxin mRNA induction. Collectively, these data reflect the complex physiology of eosinophils in the expression of eotaxin gene upon the exposure to their survival and/or death factors.

Environmental measurements of total dust and fiber concentration in manufacturer and user of man-made mineral fibers

Man-made mineral fibers (MMMF), most of which are referred to as man-made vitreous fibers (MMVF), are mostly amorphous silicates manufactured from glass, rock, or other minerals. Analysis for MMMF have been restricted largely to the measurement of total airborne mass concentrations, but more recently to the determination of airborne fiber levels by phase contrast optical microscopy. In Korea, many small factories are related with manufacturing and using MMMF without any special evaluation of environmental measurements. Though MMMF are known as the substitute of asbestos and their toxicity are regarded as very low, MMMF do not totally excluded from the respiratory and/or skin diseases now. Therefore, we evaluated the environments of many workplaces with total dust and fiber concentration. Most dust and fiber concentrations were below threshold limit value (TLV) at various industries and working processes. However, these data showed a slight relationship between total dust and fiber concentration.

Sympathetic neuronal oscillators are capable of dynamic synchronization

In this paper we show that the discharges of sympathetic neurons innervating an identified peripheral target are driven by multiple oscillators that undergo dynamic synchronization when an entraining force, central respiratory drive (CRD), is increased. Activity was recorded from postganglionic sympathetic neurons (PGNs) innervating the caudal ventral artery of the rat tail: (1) at the population level from the ventral collector nerve (VCN); and (2) from pairs of single PGNs recorded simultaneously using a focal recording technique. Autospectral analysis of VCN activity revealed a more prominent rhythmical component in the presence of CRD than in its absence, suggesting that (1) multiple oscillators drive the discharges of PGNs and (2) these oscillators can be entrained and therefore synchronized by CRD. This interpretation was supported by analysis of the firing behavior of PGN pairs. Autocorrelation and cross-correlation analysis showed that pairs were not synchronized in the absence of CRD but showed significant synchronization when CRD was enhanced. Time-evolving spectral analysis and raster plots demonstrated that the temporal stability of PGN-to-PGN and CRD-to-PGN interactions at a given level of CRD were also dynamic in nature, with stable constant phase relationships predominating as CRD was increased. This is the first reported example of dynamic synchronization in populations of single postganglionic sympathetic neurons, and we suggest that, as in sensory processing and motor control, temporal pattern coding may also be an important feature of neuronal discharges in sympathetic pathways.

Theoretical comparison of surgery and radiosurgery in cerebral arteriovenous malformations

OBJECT

Management of patients with cerebral arteriovenous malformations (AVMs) is controversial. Excellent surgical results are obtained in patients with low Spetzler-Martin grades, whereas radiosurgery offers a good alternative with its high obliteration rate. In the absence of randomized studies, physicians must choose a treatment plan based on the currently available data. To support this decision-making process, a mathematical model designed to describe patient survival rates after each treatment option was developed.

METHODS

The theoretical survival curve in patients undergoing conventional surgery, radiosurgery, or observation was calculated. Theoretical life expectancies in patients with AVMs who presented at various initial ages were calculated for each treatment strategy. A systematic method was also developed to compare the estimated risks of various treatment combinations.

CONCLUSIONS

Conventional surgery and radiosurgery definitely produced better survival rates than observation. In the comparison of surgery with radiosurgery, radiosurgery was equivalent to surgery with a combined morbidity and mortality rate of approximately 7% for a 20-year-old patient with an unruptured cerebral AVM. Data for other patient ages and treatment combinations are tabulated for use in determining the best treatment strategy. The authors believe that their analysis will provide logical support for the decision-making process involved in the treatment of patients with cerebral AVMs.

The effect of orthodontic treatment on salivary flow, pH, buffer capacity, and levels of mutans streptococci and lactobacilli

Fixed orthodontic treatment has been shown to cause an increased incidence of enamel demineralisation. The purpose of this study was to investigate the changes in stimulated salivary flow rate, pH, buffer capacity, and the levels of mutans streptococci (MS) and lactobacilli in patients undergoing therapy with fixed orthodontic appliances. Saliva samples, plaque index scores and dietary histories were taken from 21 sequential patients before the start of treatment, and one month and three months after placement of brackets and bands. There was a statistically significant increase in stimulated salivary flow rate, pH, buffer capacity, plaque index scores, and in the levels of MS and lactobacilli after three months of active treatment. It is postulated that the balance between the cariogenic challenge posed by high levels of MS and lactobacilli, and the reparative effects of concurrent increases in salivary flow rate, pH and buffer capacity, determines the likelihood of mineral loss or gain over time. A failure to follow basic preventive measures may increase the risk for some patients of enamel decalcification during orthodontic treatment with fixed appliances.

Cysteine carboxyl O-methylation of human placental 23 kDa protein

C-Terminal carboxyl methylation of a human placental 23 kDa protein catalyzed by membrane-associated methyltransferase has been investigated. The 23 kDa protein substrate methylated was partially purified by DEAE-Sephacel, hydroxyapatite and Sephadex G-100 gel filtration chromatographies. The substrate protein was eluted on Sephadex G-100 gel filtration chromatography as a protein of about 29 kDa. In the absence of Mg2+, the methylation was stimulated by guanine nucleotides (GTP, GDP and GTPgammaS), but in the presence of Mg2+, only GTPgammaS stimulated the methylation which was similar to the effect on the G25K/rhoGDI complex. AFC, an inhibitor of C-terminal carboxyl methylation, inhibited the methylation of human placental 23 kDa protein. These results suggests that the substrate is a small G protein different from the G25K and is methylated on C-terminal isoprenylated cysteine residue. This was also confirmed by vapor phase analysis. The methylated substrate protein was redistributed to membrane after in vitro methylation, suggesting that the methylation of this protein is important for the redistribution of the 23 kDa small G protein for its putative role in intracellular signaling.

Thoracic disc herniation mimicking acute lumbar disc disease

STUDY DESIGN

Case report of a 49-year-old woman with a lower thoracic disc herniation mimicking acute lumbosacral radiculopathy.

OBJECTIVE

To describe an unusual case of thoracic disc herniation mimicking acute lumbar disc disease.

SUMMARY OF BACKGROUND DATA

Symptomatic thoracic disc herniation is rare and its clinical manifestations differ widely from those of cervical and lumbar disc herniations. Midline back pain and signs of spinal cord compression progressing over months or years are the predominant clinical features. Acute and subacute thoracic disc herniation occurs in less than 10% of patients, and isolated root pain is unusual.

METHODS

A 49-year-old woman had acute low back pain radiation into the left buttock and the lateral aspect of the left leg and left foot. Magnetic resonance imaging study showed a bulging disc and posterior osteophytes at T11-T12.

RESULTS

Surgical removal of the herniated disc and osteophytes rapidly relieved her symptoms and neurologic deficits. A follow-up neurologic examination 3 years later showed normal motor and sensory functions, although low back soreness was noted occasionally.

CONCLUSION

A case of thoracic disc herniation mimicking an acute lumbosacral radiculopathy is presented. Compression of the lumbosacral spinal nerve roots at the lower thoracic level after exit from the lumbar enlargement may be the mechanism for this unusual presentation.

Treatment of extracranial internal carotid artery aneurysm with resection and external carotid artery bypass

The authors report a case of extracranial internal carotid artery aneurysm with resection of aneurysm and bridging a defect by using the external carotid artery after ligation of its distal end. This technique proposes to prevent neointimal hyperplasia and anastomotic stenosis.

Sclerotherapy with OK-432 for recurrent cystic thyroid nodule

We have adopted OK-432 as a sclerosing agent in the treatment of cystic predominant thyroid nodules and have analyzed our findings to assess the efficacy of intralesional instillation of OK-432. From 1992 through 1993, 48 patients with recurrent or progressive cystic thyroid nodules after 2 or 3 aspirations alone, and whom were cytologically negative for malignancy, were used for this study. The OK-432 solution was prepared by dissolving 0.1 mg of OK-432 in 2 ml of physiologic saline and it was instilled in the amount of 1/10-to-1/5 of the aspirated cystic fluid. A repeated course of therapy was given up to 3 times when sufficient resolution was not obtained 4-to-6 weeks after treatment. The mean number of treatment sessions per patient was 1.5. Throughout the follow-up period from 30-to-45 months (mean, 38 months), 32 (66.7%) patients experienced an almost complete disappearance (< 0.05 cm in diameter) of the cystic lesion, and 12 (25%) patients responded partially by having it decrease by more than half (> 0.5 cm in diameter) of the initial cyst size, and none of these patients required further treatment. The remaining 4 (8.3%) patients showed insufficient resolution despite 3 courses of therapy and 2 of these patients underwent thyroidectomy, in which the lesion proved benign in both cases. All of the patients tolerated the sclerotherapy well. No significant local complications attributed to this treatment were observed. However, a low-grade fever was observed in 26 (54.2%) patients for 2 to 5 days after instillation, which subsided with symptomatic treatment. On the basis of our experience, OK-432 sclerotherapy appears to be safe, simple and effective, and can be a useful alternative treatment for cystic thyroid nodules.

Effects of basic fibroblast growth factor on irradiated porcine skin flaps

OBJECTIVE

To determine the vascular and collagen effects of supplemental basic fibroblast growth factor (bFGF) in irradiated porcine skin flaps.

INTERVENTION

Animals were subjected to 2 fractions of 650 cGy orthovoltage radiation. Following this, the skin flaps were administered bFGF intracuticularly for 6 days before and after surgery. The animals were sacrificed 3 weeks after the start of bFGF administration. Tissues were analyzed for vascularity, collagen content, wound-breaking strength, and histopathological analysis.

RESULTS

The bFGF-treated flaps showed a 62% increase in vascularity compared with controls (10.4%+/-2.4% vs 6.43%+/-2.27%; P<.05). The bFGF flaps had a significantly lower collagen concentration compared with control flaps when measured by hydroxyproline content (0.0619+/-0.0211 nm/microg vs 0.0784+/-0.0150 nm/microg). Wound-breaking strength was not significantly different, although the bFGF flaps had a trend toward lower breaking strength. Histologically, the bFGF-treated flaps showed increased cellularity, fibroblasts, and extracellular mucopolysaccharides compared with controls.

CONCLUSIONS

This study provides evidence that supplemental bFGF can increase vascularity to skin flaps in previously irradiated porcine skin tissue. Histologically, radiation did not prevent the angiogenic effect of bFGF.

Myasthenia gravis and Charcot-Marie-Tooth disease type 1A: an unusual combination of diseases

Concurrence of myasthenia gravis (MG) and Charcot-Marie-Tooth type 1 (CMT1A) neuropathy is rare. We describe a 60-year-old woman with MG and genetically proved CMT1A. The fluctuating ocular symptoms and proximal limb weakness were markedly improved by pyridostigmine treatment. Recognition of the possible association of MG and CMT1A in the same patient is important because the therapeutic result is rewarding.

Enamel demineralization during orthodontic treatment. Aetiology and prevention

The aetiology of enamel demineralization during fixed orthodontic treatment and its sequelae are discussed. A summary is given of the various methods available to assess the risk of demineralization prior to active treatment. The best preventive strategy would appear to be an assessment of risk factors prior to banding, coupled with fluoride rinses, regular reinforcement of oral hygiene, and dietary advice throughout the course of treatment.

Local application of anti-NGF blocks the collateral sprouting in rats following chronic constriction injury of the sciatic nerve

Systemic administration of anti-nerve growth factor (NGF) antibodies can block nociceptive fiber sprouting into denervated adult rat skin. However, the effect of local application of anti-NGF on collateral sprouting in rats caused by chronic constriction injury (CCI) has not been well studied. We investigated the influence of local anti-NGF on collateral sprouting caused by CCI of the rat's sciatic nerve. Using a dye-labeled plasma extravasation technique, we can easily evaluate the extent of collateral sprouting by the clearly defined blue coloration area. Our results showed that local application of anti-NGF either in a high or low dose significantly prevented the spread of collateral sprouting from the saphenous nerve into the sciatic innervation territory. In contrast, distilled water did not show a significant block of the saphenous nerve collateral sprouting. Our study suggests that collateral sprouting is dependent on the local availability of NGF by the nearby intact cutaneous nerve fibers.

Detection of CSF flow in the ventriculo-Peritoneal shunt using MRI

OBJECTIVE

A noninvasive test for shunt function would be beneficial in the management of patients with CSF shunting. We present our method to diagnose shunt function using MRI.

MATERIALS AND METHODS

We performed two experiments. In the first we simultaneously performed MRI of two tubes, one with water flowing inside at various flow speeds and the other with static water inside, and compared the signal intensity inside each lumen. In the second we took four MR images of the actual shunt tubes in three patients at different states of shunt function, each having a tube containing static water pasted side by side with the actual subcutaneous shunt tube.

RESULTS

In the first experiment we could detect the enhancement effect of slow flow. The minimal detectable flow speed using this method was approximately 1.7 ml/h. The result obtained in actual patients matched the clinical status of the shunt function.

CONCLUSION

This method would be useful as a qualitative test for shunt function.

Positive elements in the laminin gamma 1 gene synergize to activate high level transcription during cellular differentiation

Transcription of the murine laminin gamma 1 gene is activated during retinoic acid/cAMP induced differentiation of F9 embryonal carcinoma cells. Positive transcription control elements associated with two DNase I hypersensitive regions in the large first intron of the gene have been identified which confer a differentiation response on the laminin gamma 1 promoter. However, the kinetics of transcriptional activation suggest each DNA region interacts with transcription factors appearing at different times during differentiation. Synergy between the two regions in cis causes high level activation.

Tuberculous meningitis in patients with nasopharyngeal carcinoma

Mycobacterial infection has been recognized as a complication in patients with malignancy. Tuberculous (TB) meningitis has not been reported in patients with nasopharyngeal carcinoma (NPC); it may have been overlooked or confused with the underlying malignancy or meningitis caused by other microorganisms. We describe the occurrence of culture-proven TB meningitis in 2 NPC patients. The time lag between the diagnosis of NPC and the occurrence of TB meningitis was 4 years in 1 patient and 6 years in the other. In both patients, the diagnosis of TB meningitis was delayed; they were initially treated for bacterial meningitis. Subsequent antituberculous chemotherapy was successful in 1 patient but failed in the other. Recognition of the infection is important for early diagnosis and proper treatment of this potentially fatal condition in patients with NPC.

Cervical central cord syndrome involving the spinal trigeminal nucleus: a case report

BACKGROUND

Central cord syndrome is a commonly encountered disease entity. Its underlying pathophysiology, however, is not well understood.

METHODS

A 20-year-old patient with cervical injury with an atypical symptom of burning sensation in the face and neck area is reported.

RESULTS

The initial burning sensation in the face retreated from the center towards the periphery according to the "onionskin" segmentation of facial dermatomes, which suggested some pathologic condition residing in the spinal trigeminal nucleus.

CONCLUSIONS

The findings of this case suggest that the main locus of pathologic process of the central cord syndrome is in the gray matter rather than the white matter.

Quantification of operative benefit for unruptured cerebral aneurysms: a theoretical approach

The indications for surgery on unruptured asymptomatic cerebral aneurysms are still unclear. In this report, the authors use mathematical methods to attempt to quantify the benefit of surgery for unruptured aneurysms. Theoretical survival curves for either operative or conservative treatment were obtained by solving differential equations on the survival rate of a patient harboring an unruptured aneurysm. Patients' life expectancies were calculated as areas under these curves, and operative benefit was quantified as a gain in average life expectancy. To analyze morbidity, two concepts were introduced: premorbid survival rate and average premorbid survival period, and the operative gain of average premorbid survival period was calculated under certain assumptions. Larger operative benefit was observed in younger patients, with increasingly less benefit in the elderly. The operative gain of average life expectancy was 3.9 years for a 40-year-old patient, 2.4 years for 50, 1.3 years for 60, and 0.6 years for a 70-year-old. Quantified operative benefit is presented in a table for various patient ages, yearly rupture rates, and expected operative morbidity and mortality. This mathematical method would be useful to both surgeons and patients in making their decisions on surgery.

Fabry's disease: report of a case

Fabry's disease is a rare hereditary disorder of glycosphingolipid metabolism. Its clinical features have not been adequately described in Taiwan. This paper reports on a 32-year-old man who had painful acroparesthesia, disseminated skin angiokeratomas, whorled corneal opacity, mitral valve prolapse and renal insufficiency. There was also involvement of the central motor pathways and the autonomic nervous system. A sural nerve biopsy showed loss of small myelinated and unmyelinated fibers. A reduced serum activity of alpha-galactosidase A and a large amount of urinary globotriaosylceramide confirmed the diagnosis of Fabry's disease.

Preoperative chemoradiotherapy for locoregional esophageal cancer: preliminary report

Conventional treatment of esophageal cancer with surgery or radiation alone has afforded few long-term survivors. In order to improve outcome and determine the efficacy of a combined modality approach, this prospective study was performed. Between May 1993 and August 1994, 27 patients with loco-regional squamous cell carcinoma of the esophagus were treated with 2 courses of combined fluorouracil(1000mg per square meter of body-surface area daily for 5 days) and cisplatin(60mg per square meter on the first day)(D1 and D29) plus 48Gy of radiation therapy(RT) over 4 weeks. A transhiatal esophagectomy was planned 3-4 weeks after chemoradiotherapy. Twenty-seven patients completed a full course of therapy. Clinical response was evaluable in 26 patients: 22 patients showed improvement and relief from dysphagia, 2 patients stable disease, and 2 patients progression. One patient died of sepsis 1 week after completion of chemoradiotherapy and was excluded from the analysis. Ten patients underwent operation after chemoradiation. Of them, 5 showed complete histologic response. One of the complete responders died of recurred disease 8.5months after operation, the other 2 patients died of sudden death, and sepsis from wound deheiscence 7 days after operation, respectively. Nine patients refused operation because of excellent relief of their dysphagia and 6 patients were denied because of disease progression(2), fear of operations(2), old age and family member's disapprovement(1), and underlying liver cirrhosis(1). The last one patient was awaiting for operation. Of 13 patients who refused or denied operation, 6 patients finished further chemotherapy and radiatherapy(external radiation 1200 cGy+intracavitary radiation 900 cGy, 2 cycles of 5FU+cisplatin). This intensive preoperative chemoradiotherapy is feasible, and allows for a high rate of resectability and a high rate of complete pathologic response in a locoregional esophageal cancer. Toxicity is considerable but manageable. This study warrants further investigation.

Differential effects of 3,4,5,3',4',5'-hexachlorobiphenyl (HCB) on interrenal steroidogenesis in male and female rainbow trout Oncorhynchus mykiss

1. The conversion of progesterone to 17 alpha-hydroxyprogesterone (17 alpha-OHP), 11-deoxycortisol (11-DOCR) and deoxycorticosterone (DOC) was significantly higher in female rainbow trout than in male trout; in contrast, the interrenal production of cortisol (CR) plus cortisone (CN) was higher in males than in females. 2. Following treatment with 1 mg/kg of HCB, the interrenal conversion of progesterone to 17 alpha-OHP and 11-DOCR was significantly increased in male and female trout but at 20 mg/kg of HCB, the production of these metabolites was increased in males and decreased in females; CR+CN production was unchanged after HCB treatment in both sexes.

Chlorination of cellulose with N-chlorosuccinimide-triphenylphosphine under homogeneous conditions in lithium chloride-N,N-dimethylacetamide

Microcrystalline cellulose was chlorinated with N-chlorosuccinimide-triphenylphosphine under homogeneous conditions in LiCl-N,N-dimethylacetamide. At the early stage of the reaction only replacement of the 6-hydroxyl groups with chlorine was observed, and 3-hydroxyl groups were replaced at a lower rate with Walden inversion. The effects of reaction conditions on the extent of chlorination were studied in detail. More than two equivalents of chlorination reagents per glucose residue were necessary to attain a high degree of substitution (ds) by chlorine, and the maximum ds attained was 1.86. Chlorinated disaccharides were found in the hydrolyzates of chlorodeoxycelluloses hydrolyzed under mild conditions, and their structures were studied by mass spectrometry.

Long-term cultured mouse mast cells: ultrastructure, histamine and leukotriene levels

Interleukin 3 (IL3), dependent cells were obtained from bone marrow (9/10 experiments) and spleen cells (4/5 experiments), but not from the thymus. These cells were similar to mucosal mast cell toluidine blue staining and electron microscopy. They had heterogenous metachromatic granules, and some had large scroll-like structures. They also contained histamine (200-800 ng/10(6) cells) for the first 2-5 weeks, whose level diminished to less than 30 ng/10(6) cells by 10 weeks of culture. They also generated leukotriene (LT) C4/D4 (10-40 ng/10(6) cells) and LTB4 (2-5 ng/10(6) cells) for over 100 days of culture. In one experiment, bone marrow-derived mast cells after 150 days of culture began to produce an IL3-like substance and proliferated exponentially without exogenous IL3.

Effect of monovalent measles and trivalent measles-mumps-rubella vaccines at various ages and concurrent administration with hepatitis B vaccine

To determine the most suitable vaccination schedule in developing countries, a study was conducted to reevaluate the immunogenicity of monovalent measles vaccine and trivalent measles-mumps-rubella vaccine at different ages. The success rate of measles vaccination was 84% at 9 months, 88% at 12 months and 100% at 15 months of age. Vaccination with measles vaccines at 9 and 15 months of age was also 96% immunogenic. Most vaccinees (16 of 17) not responding to the first measles vaccine before 1 year of age developed measles antibody with another shot of vaccine after 15 months of age. Trivalent measles-mumps-rubella vaccine worked well in children ages 14 to 18 months. Administering trivalent vaccine and hepatitis B vaccine concurrently at 1 year of age, rubella and mumps antibodies developed in more than 95% of vaccinees, while measles antibody was detected in 88%. Responses to hepatitis B vaccine in this situation were good; 89% of vaccinees developed antibody against hepatitis B surface antigen (greater than or equal to 10 mIU/ml) and the geometric mean titer was 362.49 mIU/ml. In summary vaccination twice at 9 and 15 months is effective and is a useful regimen in developing countries where measles is still endemic. Trivalent vaccine and hepatitis B vaccine will not interfere with each other when given together at 1 year of age.

Diagnostic value of arterial hematocrits in neonatal polycythemia

In order to study the correlation among arterial, capillary and venous hematocrits, sixty newborn babies delivered in our hospital were chosen after receiving their parents' consents for hematocrits study within their first eight hours of life. The venous hematocrits of them (59.77 +/- 14.15%) correlate with arterial hematocrits (57.84 +/- 14.36%) very well (r = 0.95, p less than 0.001). Whereas, the venous and arterial hematocrits correlate with capillary hematocrits (66.63 +/- 15.56%) also significantly (r = 0.72, p less than 0.001 for both). Arterial hematocrits of more than 62% is proportionate to venous hematocrits of 64% and above. The relationship between arterial and venous hematocrits does not change even after we divide the subjects into those venous hematocrits above 64% and those below 64%. Furthermore, the capillary hematocrits of above 70% can be used as the criteria of polycythemia in the neonatal screening. If the capillary hematocrit is above 70%, then venous hematocrit should be checked for the confirmation of polycythemia.

Decreases in excitatory synaptic transmission and increases in recurrent inhibition in the rat dentate gyrus after transient cerebral ischemia

Excitatory transmission along the perforant path from the entorhinal cortex to the granule cells of the dentate gyrus was evaluated two days after 10 min of transient cerebral ischemia in the rat. The amplitude of the population spike, and the amplitude and the initial slope of the population excitatory postsynaptic potential (EPSP) evoked by the perforant path stimulation were measured across a range of stimulus intensities, and were compared with control values. Inhibitory interactions were evaluated using the paradigm of paired pulse stimulation, comparing the amplitude of the population spike evoked by the second pulse of a pair to the initial spike. The maximal values of the initial slope of the population EPSP and the population spike were reduced in the ischemic group. Also, the extent of paired pulse inhibition was greater in the ischemic group. These results suggest that: (1) excitatory synaptic transmission along the perforant path is impaired in the postischemic period, (2) inhibition of the dentate granule cells is enhanced in this period. These results are not consistent with the hypothesis that there is a hyperactivation of the tri-synaptic circuit in the chronic postischemic period that accounts for the excitotoxic death of CA1 neurons.

Hippocampal unit activity after transient cerebral ischemia in rats

Single unit activity of CA1 and CA3 neurons in the hippocampus was recorded in rats 1, 2, or 3 days after 10 minutes of transient cerebral ischemia induced by the clamping of both carotid arteries combined with hypotension. In addition, paired pulse inhibition/facilitation of the CA1 population spike was examined on Day 2 using two successive stimuli of the contralateral CA3 region delivered at various intervals. On Day 1, the mean +/- SEM firing rate in the CA1 region was 0.91 +/- 0.42/sec (n = 5), which was not significantly different from the control value of 0.98 +/- 0.26/sec (n = 5). Firing rate increased on Days 2 and 3 to 3.96 +/- 0.69/sec (n = 5), and 6.49 +/- 0.89/sec (n = 5), respectively. In the CA3 region, the mean +/- SEM firing rate of 1.18 +/- 0.27/sec in the five control rats sharply dropped to 0.14 +/- 0.11/sec in the five Day 1 rats and gradually increased to 0.45 +/- 0.11/sec in the five Day 3 rats. Histologic examination of these rats revealed ischemic changes restricted to CA1 neurons on Days 2 and 3. The paired-pulse experiment showed no significant difference between six control and six Day 2 rats in the inhibition of the second population spike with interstimulus intervals of less than 400 msec. At interstimulus intervals of greater than 500 msec there was facilitation of the second spike, which lasted 5 seconds in Day 2 rats. This facilitation was not observed in control rats. Because CA3 neurons constitute the main input to CA1 pyramidal cells, decreased activity of CA3 neurons indicates less excitatory input to CA1 neurons.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical analysis of infants of diabetic mothers

The clinical spectra of 82 infants of diabetic mothers (IDMs) encountered in the past 15 years are presented. The perinatal mortality rate was 6.1%, The observed morbidities of the 78 live-born IDMs were: large for gestational age, 35.9%; prematurity, 12.8%; small for gestational age, 12.8%; respiratory distress, 17.9%; low Apgar score, 6.4%; nerve injury, 2.6%; hypoglycemia, 10.3%; hyperbilirubinemia, 28.2%; polycythemia, 12.8%; hypocalcemia, 5.1%; hypertrophic cardiomyopathy, 3.8%. Furthermore, 15.9% (13/82) of these infants suffered from congenital malformation, a rate nearly 10 times higher than that of the general neonatal population born in this hospital. In comparing sugar control during organogenesis, the mothers who had malformed infants had significantly higher fasting plasma glucose level than the mothers who had normal infants (P less than 0.05). Since tight control of maternal diabetes is mandatory to reduce the prevalence of mortality and malformation of the IDMs, we suggest that there is an urgent need to improve health education and supervision before and during pregnancy in all diabetic women.