Dual crosslinking silk fibroin/pectin-based bioink development and the application on neural stem/progenitor cells spheroid laden 3D bioprinting

The human nervous system is an incredibly intricate physiological network, and neural cells lack the ability to repair and regenerate after a brain injury. 3-dimensional (3D) bioprinting technology offers a promising strategy for constructing biomimetic organ constructs and in vitro brain/disease models. The bioink serves as a pivotal component that emulates the microenvironment of biomimetic construct and exerts a profound influence on cellular behaviors. In this study, a series of mechanically adjustable and dual crosslinking bioinks were developed using photocrosslinkable methacrylated silk fibroin (SilMA) in combination with the ionic crosslinking material, pectin, or pectin methacryloyl (PecMA) with silk fibroin (SF) supplementation. SilMA/pectin exhibited superior properties, with SilMA providing biocompatibility and adjustable mechanical properties, while the addition of pectin enhanced printability. The porous structure supported neural cell growth, and 15 % SilMA/0.5 % pectin bioinks displayed excellent printability and shape fidelity. Neural stem/progenitor cells (NSPCs)-loaded bioinks were used to construct a 3D brain model, demonstrating sustained vitality and high neuronal differentiation without the need for growth factors. The SilMA/pectin bioinks demonstrated adjustable mechanical properties, favorable biocompatibility, and an environment highly conducive to neural induction, offering an alternative approach for neural tissue engineering applications or in vitro brain models.

An injectable, dual crosslinkable hybrid pectin methacrylate (PECMA)/gelatin methacryloyl (GelMA) hydrogel for skin hemostasis applications

Biomaterials for effective hemorrhage control are urgently needed in clinics as uncontrolled bleeding is associated with high mortality. Herein, we developed an injectable and in situ photo-crosslinkable hybrid hemostatic hydrogel by combining pectin methacrylate (PECMA) and gelatin methacryloyl (GelMA). This modular material system combines ionic- and photo-crosslinking chemistries to design interpenetrating networks (IPN) exhibiting tunable rheology, highly porous structure, and controllable swelling and mechanical properties. By simply changing the calcium (0-15 mM) and polymer (1.5-7%) content used for the sequential crosslinking of hydrogels via calcium gelation and UV-photopolymerization, it was possible to precisely modulate the injectability, degradation, and swelling ratio. Moreover, it is demonstrated that PECMA/GelMA hydrogels present good cytocompatibility and uniquely synergize the hemostatic properties of calcium ions on PECMA, the amine residues on GelMA, and the highly porous network toward rapid blood absorption and fast coagulation effect. An in vitro porcine skin bleeding model confirmed that the hydrogel could be directly injected into the wound and rapidly photo-crosslinked, circumventing the bleeding and decreasing the coagulation time by 39%. Importantly, the crosslinked hydrogel could be easily removed to prevent secondary wound injury. Overall, this injectable hybrid PECMA/GelMA hydrogel stands as a promising hemostatic material.

Dynamic Internet-Mediated Team-Based Case Management of High-Frequency Emergency Department Users

Introduction

We assessed whether a strategy using dynamic, internet-mediated, team-based case management could reduce the number of subsequent emergency department (ED) visits by frequent ED users.

Methods

Patients who attended the ED three or more times within 72 hours in June 2010 were identified. These cases were divided into the pain management or chronic disease group according to their chief complaint. Patients were assessed by expert panels, and initial care plans were developed and posted on an internal website. Thereafter, each emergency physician could follow or adjust the care plans dynamically via the internal website according to the patient's condition and use the website to communicate results. Care plans were revised by the team according to the patient's clinical situation as it changed. Patient ED visits over the subsequent six months were monitored.

Results

Fourteen cases were enrolled in the study, seven in each group. The mean number of visits per patient per month in the pain management and chronic disease groups decreased from 14.9 to 5.79 (p=0.031) and 6.1 to 2.9 (p<0.001) visits per month after the intervention, respectively. The overall mean number of visits per patient per month decreased from 10.5 to 4.36 (p=0.004), a decrease of 6.14 visits (58.27%).

Conclusions

Dynamic internet-mediated team-based case management may help to reduce subsequent visits in patients who frequently visit the ED. (Hong Kong j.emerg.med. 2014;21:161-166)

Integrative proteomic profiling of ovarian cancer cell lines reveals precursor cell associated proteins and functional status

A cell line representative of human high-grade serous ovarian cancer (HGSOC) should not only resemble its tumour of origin at the molecular level, but also demonstrate functional utility in pre-clinical investigations. Here, we report the integrated proteomic analysis of 26 ovarian cancer cell lines, HGSOC tumours, immortalized ovarian surface epithelial cells and fallopian tube epithelial cells via a single-run mass spectrometric workflow. The in-depth quantification of >10,000 proteins results in three distinct cell line categories: epithelial (group I), clear cell (group II) and mesenchymal (group III). We identify a 67-protein cell line signature, which separates our entire proteomic data set, as well as a confirmatory publicly available CPTAC/TCGA tumour proteome data set, into a predominantly epithelial and mesenchymal HGSOC tumour cluster. This proteomics-based epithelial/mesenchymal stratification of cell lines and human tumours indicates a possible origin of HGSOC either from the fallopian tube or from the ovarian surface epithelium.

High-grade serous ovarian cancer is the most common and aggressive ovarian cancer, with uncertain cell of origin. Here, the authors undertake a mass spectrometric analysis of 26 cancer cell lines and identify a protein signature that classifies ovarian cancer tissues into epithelial and mesenchymal groups.

Recurrence of bilateral atypical femoral fractures associated with the sequential use of teriparatide and denosumab: a case report

We report that a postmenopausal woman with osteoporosis developed bilateral incomplete atypical femoral fractures (AFFs) after seven years of bisphosphonate therapy. Cessation of the bisphosphonate and treatment with teriparatide was associated with near complete radiological resolution of the AFFs. After 12 months without treatment, denosumab was commenced to prevent structural deterioration. Six months later she developed recurrent bilateral AFFs. This case highlights the management dilemma in patients with ongoing bone loss but prone to stress fractures associated with antiresorptive therapy. Stopping the antiresorptive is recommended but structural decay will recur predisposing to fragility fractures. If the antiresorptive is continued, bone material composition will be further compromised predisposing to atypical fractures. Teriparatide may assist healing of stress fractures and improvement in bone matrix composition. Later antiresosrptive therapy to preserve bone microstructure may compromise material composition.

Abstract AS23: Microenvironment mediated downregulation of miR-193b promotes ovarian cancer metastasis

The cross-talk between ovarian cancer cells with the microenvironment of the site of metastasis is an essential determinant of successful metastatic colonization. microRNAs have been well established to play critical roles in various stages of cancer progression, including metastasis. However, the role of the signals from the microenvironment in regulating key microRNAs in metastasizing cancer cells has not been studied. Using a 3D culture model mimicking the human omentum, one of the principal sites of ovarian cancer metastasis, we have identified the microenvironment-induced downregulation of a tumor suppressor microRNA miR-193b in the metastasizing ovarian cancer cells. The direct interaction of the ovarian cancer cells with the mesothelial cells covering the surface of the omentum caused DNA methyltransferase 1 (DNMT1) mediated methylation and decreased expression of miR-193b. The reduction in miR-193b enabled the metastasizing cancer cells to invade and proliferate in the omentum both in vitro and in a mouse xenograft model of ovarian cancer metastasis. The functional effects of miR-193b were mediated at least partly through the concomitant increased expression of its target urokinase-type plasminogen activator (uPA). Our findings link paracrine signals from the microenvironment with the regulation of a key microRNA in cancer cells that is essential for the initial steps of ovarian cancer metastatic colonization. Targeting miR-193b would be a promising approach to treat ovarian cancer metastasis.

Citation Format: AK Mitra, CY Chiang, P Tiwari, ME Peter, E Lengyel. Microenvironment mediated downregulation of miR-193b promotes ovarian cancer metastasis [abstract]. In: Proceedings of the 10th Biennial Ovarian Cancer Research Symposium; Sep 8-9, 2014; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2015;21(16 Suppl):Abstract nr AS23.

Microenvironment-induced downregulation of miR-193b drives ovarian cancer metastasis

The cross-talk between ovarian cancer (OvCa) cells and the metastatic microenvironment is an essential determinant of successful colonization. Micro(mi)RNAs play several critical roles during metastasis; however, the role of microenvironmental cues in the regulation of miRNAs in metastasizing cancer cells has not been studied. Using a 3D culture model that mimics the human omentum, one of the principal sites of OvCa metastasis, we identified and characterized the microenvironment-induced downregulation of a tumor suppressor miRNA, miR-193b, in metastasizing OvCa cells. The direct interaction of the OvCa cells with mesothelial cells, which cover the surface of the omentum, caused a DNA methyltransferase 1 (DNMT1) mediated decrease in the expression of miR-193b. The reduction in miR-193b enabled the metastasizing cancer cells to invade and proliferate into human omental pieces ex vivo and into the omentum of a mouse xenograft model of OvCa metastasis. The functional effects of miR-193b were mediated, in large part, by the concomitant increased expression of its target, urokinase-type plasminogen activator (uPA), a known tumor-associated protease. These findings link paracrine signals from the microenvironment with the regulation of a key miRNA that is essential for the initial steps of OvCa metastatic colonization. Targeting miR-193b could prove effective in the treatment of OvCa metastasis.

Involvement of ATP in noxious stimulus-evoked release of glutamate in rat medullary dorsal horn: a microdialysis study

Our electrophysiological studies have shown that both purinergic and glutamatergic receptors are involved in central sensitization of nociceptive neurons in the medullary dorsal horn (MDH). Here we assessed the effects of intrathecal administration of apyrase (a nucleotide degrading enzyme of endogenous adenosine 5-triphosphate [ATP]), a combination of apyrase and 1,3-dipropyl-8-cyclopentylxanthine (DPCPX, an adenosine A1 receptor antagonist), or 2,3-O-2,4,6-trinitrophenyl-adenosine triphosphate (TNP-ATP, a P2X1, P2X3, P2X2/3 receptor antagonist) on the release of glutamate in the rat MDH evoked by application of mustard oil (MO) to the molar tooth pulp. In vivo microdialysis was used to dialyse the MDH every 5 min, and included 3 basal samples, 6 samples after drug treatment and 12 samples following application of MO. Tooth pulp application of MO induced a significant increase in glutamate release in the MDH. Superfusion of apyrase or TNP-ATP alone significantly reduced the MO-induced glutamate release in the MDH, as compared to vehicle. Furthermore, the suppressive effects of apyrase on glutamate release were reduced by combining it with DPCPX. This study demonstrates that application of an inflammatory irritant to the tooth pulp induces glutamate release in the rat MDH in vivo that may be reduced by processes involving endogenous ATP and adenosine.

Systemic pregabalin attenuates sensorimotor responses and medullary glutamate release in inflammatory tooth pain model

Our previous studies have demonstrated that application of inflammatory irritant mustard oil (MO) to the tooth pulp induces medullary glutamate release and central sensitization in the rat medullary dorsal horn (MDH), as well as nociceptive sensorimotor responses in craniofacial muscles in rats. There is recent evidence that anticonvulsant drugs such as pregabalin that influence glutamatergic neurotransmission are effective in several pain states. The aim of this study was to examine whether systemic administration of pregabalin attenuated glutamate release in the medulla as well as these nociceptive effects reflected in increased electromyographic (EMG) activity induced by MO application to the tooth pulp. Male adult rats were anesthetized with isofluorane (1.0-1.2%), and jaw and tongue muscle EMG activities were recorded by needle electrodes inserted bilaterally into masseter and anterior digastric muscles and into the genioglossus muscle, and also the medullary release of glutamate was assessed by in vivo microdialysis. Pregabalin or vehicle control (isotonic saline) was administered 30 min before the pulpal application of MO or vehicle control (mineral oil). Application of mineral oil to the maxillary first molar tooth pulp produced no change in baseline EMG activity and glutamate release. However, application of MO to the pulp significantly increased both the medullary release of glutamate and EMG activity in the jaw and tongue muscles for several minutes. In contrast, pre-medication with pregabalin, but not vehicle control, significantly and dose-dependently attenuated the medullary glutamate release and EMG activity in these muscles after MO application to the tooth pulp (analysis of variance (ANOVA), p<0.05). These results suggest that pregabalin may attenuate the medullary release of glutamate and associated nociceptive sensorimotor responses in this acute inflammatory pulpal pain model, and that it may prove useful for the treatment of orofacial inflammatory pain states.

Effect of cyclosporine-A on orthodontic tooth movement in rats

OBJECTIVE

The objective of this study is to examine the effect of cyclosporine-A (CsA) on the rate of orthodontic tooth movement in rats.

SETTING AND SAMPLE POPULATION

This is a randomized controlled trial with a split-mouth design in Sprague-Dawley rats.

MATERIAL AND METHODS

Eighteen rats, divided at random in two groups, were fed with 8 mg/kg CsA (experiment) or mineral oil (control) daily after initial healing of bilateral maxillary second molar removal. All rats received orthodontic coil springs (10 cN) secured to the maxillary incisors and first molars at the rights side, while no springs were placed at the left. Distances between first and third molars were measured on days 0, 3, 6, and 12. After sacrificing on day 12, the alveolar ridges of the maxillae were sectioned and blood samples were collected for serum tartrate-resistant acid phosphatase (TRAP)-5b level detection and for histology, respectively.

RESULTS

Significantly larger changes in intermolar distances were found after orthodontic force application in the CsA group at days 3 and 12 when compared with the control group. The inter-radicular dental alveolus of CSA-fed rats was osteopenic. Significantly increased TRAP-5b serum level was noted in the CsA group when compared with the control group.

CONCLUSIONS

We suggest that CsA enhanced the rate of orthodontic tooth movement. The osteopenia and the increased osteoclastic activity could be the underlying factors.

Modulation of astroglial glutamine synthetase activity affects nociceptive behaviour and central sensitization of medullary dorsal horn nociceptive neurons in a rat model of chronic pulpitis

Previous studies indicate that the astroglial glutamate-glutamine shuttle may be involved in acute pulpal inflammatory pain by influencing central sensitization induced in nociceptive neurons in the trigeminal subnucleus caudalis [the medullary dorsal horn (MDH)] by application of an inflammatory irritant to the rat tooth pulp. The aim of this study was to test if intrathecal application to the rat medulla of the astroglial glutamine synthetase inhibitor methionine sulfoximine (MSO) can influence the central sensitization of MDH nociceptive neurons and the animal's associated behaviour that are manifested in a model of chronic pulpitis pain induced by exposure of a mandibular molar pulp. This model was found to be associated with nocifensive behaviour and enhanced reflex activity evoked by mechanical stimulation of the rat's facial skin and with immunocytochemical evidence of astroglial activation in the MDH. These features were apparent for up to 28 days post-operatively. During this post-operative period, the nocifensive behaviour and enhanced reflex activity were significantly attenuated by intrathecal application of MSO (5 μL, 10 mM) but not by vehicle application. In electrophysiological recordings of nociceptive neuronal activity in the MDH, central sensitization was also evident in pulp-exposed rats but not in intact rats and could be significantly attenuated by MSO application but not by vehicle application. These behavioural and neuronal findings suggest that the astroglial glutamate-glutamine shuttle is responsible for the maintenance of inflammation-induced nocifensive behavioural changes and the accompanying central sensitization in MDH nociceptive neurons in this chronic pulpitis pain model.

Prolonged fecal shedding of CTX-M-15-producing Escherichia coli and recurrent sepsis in a patient after cord blood stem-cell transplantation

An extended-spectrum beta-lactamase (CTX-M-15 type)-producing Escherichia coli persisted in the intestinal tract for >5 months in a pediatric patient after cord blood stem-cell transplantation and caused 2 episodes of sepsis. The bla(CTX-M-15) is carried by a large plasmid of approximately 130 kb in size. The prolonged shedding of the highly resistant E. coli posed a great challenge to infection control and public health.

Involvement of glia in central sensitization in trigeminal subnucleus caudalis (medullary dorsal horn)

Central sensitization is a crucial mechanism underlying the increased excitability of nociceptive pathways following peripheral tissue injury and inflammation. We have previously demonstrated that the small-fiber excitant and inflammatory irritant mustard oil (MO) applied to the tooth pulp produces glutamatergic- and purinergic-dependent central sensitization in brainstem nociceptive neurons of trigeminal subnucleus caudalis (Vc). Recent studies have implicated both astrocytes and microglia in spinal nociceptive mechanisms, showing, for example, that inhibition of spinal astroglial metabolism or spinal microglial p38MAPK activation can attenuate hyperalgesia in inflammatory pain models but have not tested effects of glial inhibitors on central sensitization in functionally identified spinal nociceptive neurons. The aim of the present study was to determine whether glial cells are involved in the MO-induced central sensitization in Vc nociceptive neurons, by examining the effects of intrathecally applied SB203580 (SB), an inhibitor of p38MAPK, and fluoroacetate (FA), an inhibitor of the astroglial metabolic enzyme aconitase. During continuous superfusion of phosphate-buffered saline over Vc, MO application to the pulp-induced central sensitization in Vc nociceptive neurons reflected in significant increases in cutaneous mechanoreceptive field (RF) size and responses to noxious mechanical stimuli and a decrease in mechanical activation threshold. The i.t. application of SB or FA markedly attenuated the MO-induced increases in pinch RF size and responses to noxious stimuli and the decrease in activation threshold. Neither SB nor FA application significantly affected the baseline (i.e., pre-MO application) RF and response properties. These results suggest that glial metabolic processes are important in the development of Vc central sensitization.

Associations between tobacco and tuberculosis

The association between smoking and tuberculosis (TB) has been investigated since 1918. Both passive and active exposure to tobacco smoke have been shown to be associated with tuberculous infection and with the transition from being infected to developing TB disease. The association between smoking and developing TB disease (without separating the risk of transition from being exposed to being infected and that from being infected to developing TB disease) has been reported substantially. Smoking affects the clinical manifestations of TB. It has been shown that ever smokers are more likely to have cough, dyspnoea, chest radiograph appearances of upper zone involvement, cavity and miliary appearance, and positive sputum culture, but are less likely to have isolated extra-pulmonary involvement than non-smokers. Smoking has been found to be associated with both relapse of TB and TB mortality. There appears to be enough evidence to conclude that smoking is causally associated with TB disease. Patients with TB need and should receive counselling and assistance in stopping smoking.

Central sensitization in thalamic nociceptive neurons induced by mustard oil application to rat molar tooth pulp

We have recently demonstrated that application of mustard oil (MO), a small-fiber excitant and inflammatory irritant, to the rat maxillary molar tooth pulp induces central sensitization that is reflected in changes in spontaneous activity, mechanoreceptive field (RF) size, mechanical activation threshold, and responses to graded mechanical stimuli applied to the neuronal RF in trigeminal brainstem subnucleus caudalis and subnucleus oralis. The aim of this study was to test whether central sensitization can be induced in nociceptive neurons of the posterior thalamus by MO application to the pulp. Single unit neuronal activity was recorded in the ventroposterior medial nucleus (VPM) or posterior nuclear group (PO) of the thalamus in anesthetized rats, and nociceptive neurons were classified as wide dynamic range (WDR) or nociceptive-specific (NS). MO application to the pulp was studied in 47 thalamic nociceptive neurons and found to excite over 50% of the 35 VPM neurons tested and to produce significant long-lasting (over 40 min) increases in spontaneous activity, cutaneous pinch RF size and responses to graded mechanical stimuli, and a decrease in threshold in the 29 NS neurons tested; a smaller but statistically significant increase in mean spontaneous firing rate and decrease in activation threshold occurred following MO in the six WDR neurons tested. Vehicle application to the pulp did not produce any significant changes in six VPM NS neurons tested. MO application to the pulp produced pronounced increases in spontaneous activity, pinch RF size, and responses to mechanical stimuli, and a decrease in threshold in three of the six PO neurons. In conclusion, application of the inflammatory irritant MO to the tooth pulp results in central sensitization of thalamic nociceptive neurons and this neuronal hyperexcitability likely contributes to the behavioral consequences of peripheral inflammation manifesting as pain referral, hyperalgesia and allodynia.

Patient and health system delays in the diagnosis and treatment of tuberculosis in Southern Taiwan

SETTING

Tainan city, Tainan county and 13 townships of Kaohsiung county, Southern Taiwan.

OBJECTIVE

To measure delays in the diagnosis and treatment of sputum-positive tuberculosis (TB) and to determine factors associated with delays in seeking health care (patient delay) and in starting anti-tuberculosis treatment (health system delay).

DESIGN

A population-based patient interview study.

RESULTS

Median patient delay was 7 days (range 0-730). Median health system delay was 23 days (range 0-489), 13 for smear-positive patients and 37 for smear-negative patients (P < 0.005). Median total delay was 44 days (range 0-730). Age <65 years was associated with longer patient delay. Negative smear, absence of haemoptysis, not having a chest radiograph at the first medical consultation and visiting clinics for first consultation were associated with a longer health system delay. Age <65 years, negative smear and cough as the only presenting symptom were associated with longer total delay.

CONCLUSION

Patient delay was substantially shorter than health system delay. To reduce health system delay, clinics need to be involved and the referral mechanism must be strengthened. Physicians should maintain high alert for TB and perform prompt sputum smear examinations.

Endogenous ATP involvement in mustard-oil-induced central sensitization in trigeminal subnucleus caudalis (medullary dorsal horn)

Central sensitization represents a sustained hypersensitive state of dorsal horn nociceptive neurons that can be evoked by peripheral inflammation or injury to nerves and tissues. It reflects neuroplastic changes such as increases in neuronal spontaneous activity, receptive field size, and responses to suprathreshold stimuli and a decrease in activation threshold. We recently demonstrated that purinergic receptor mechanisms in trigeminal subnucleus caudalis (Vc; medullary dorsal horn) are also involved in the initiation and maintenance of central sensitization in brain stem nociceptive neurons of trigeminal subnucleus oralis. The aim of the present study was to investigate whether endogenous ATP is involved in the development of central sensitization in Vc itself. The experiments were carried out on urethan/alpha-chloralose anesthetized and immobilized rats. Single neurons were recorded and identified as nociceptive-specific (NS) in the deep laminae of Vc. During continuous saline superfusion (0.6 ml/h it) over the caudal medulla, Vc neuronal central sensitization was readily induced by mustard oil application to the tooth pulp. However, this mustard-oil-induced central sensitization could be completely blocked by continuous intrathecal superfusion of the wide-spectrum P2X receptor antagonist pyridoxal-phosphate-6-azophenyl-2, 4-disulphonic acid tetra-sodium (33-100 microM) and by apyrase (an ectonucleotidase enzyme, 30 units/ml). Superfusion of the selective P2X1, P2X3 and P2X(2/3) receptor antagonist 2',3'-O-(2,4,6-trinitrophenyl) adenosine 5'-triphosphate (6-638 microM) partially blocked the Vc central sensitization. The two P2X receptor antagonists did not significantly affect the baseline nociceptive properties of the Vc neurons. These findings implicate endogenous ATP as an important mediator contributing to the development of central sensitization in nociceptive neurons of the deep laminae of the dorsal horn.

A method to determine the utility of the third diagnostic and the second follow-up sputum smear examinations to diagnose tuberculosis cases and failures

SETTING

Forty-two laboratories in four countries.

OBJECTIVE

To determine the number of sputum smear examinations required to identify one additional case of tuberculosis from a third serial diagnostic smear or one additional treatment failure from a second serial follow-up smear.

MATERIAL AND METHODS

Country-specific prevalence of new cases and failures among 59 665 examinees were determined, as well as the incremental yield from serial smears. The reciprocal value of the product of the prevalence of cases or failures and the respective incremental yield from the last serial smear provided the number of slides that have to be examined to identify one additional case or failure.

RESULTS

The expected prevalence of cases among suspects ranged from 5.4% to 32.8%; the incremental yield from a third serial smear ranged from 0.7% to 7.2%. Between 122.7 and 796.3 smears were required to identify one additional case with the third serial smear. The prevalence of failures among follow-up examinees ranged from 1.0% to 2.5%; the incremental yield from the second follow-up serial smear ranged from 4.5% to 26.9%. Between 164.8 and 2133.4 slides were required to identify one additional failure with the second serial smear.

CONCLUSION

The utility of serial smears can be rationally determined by careful review of program data.

The impact of national health insurance on the notification of tuberculosis in Taiwan

SETTING

General notification of tuberculosis in Taiwan.

OBJECTIVES

To ensure the completeness of notification of tuberculosis (TB) in Taiwan, the Bureau of National Health Insurance (NHI) introduced two policies in 1997: 1) the no-notification-no-reimbursement (NNNR) policy, and 2) the notification-fee (NF) policy. The goals of this study were to investigate the impact of the NNNR and NF policies on notification of TB.

DESIGN

Review of all cases notified to the National TB Register from 1995 to 1999 to determine calendar trend, type of case and source of notification.

RESULTS

There were 11,453 and 13,612 reported cases in 1995 and 1996, respectively. Following the implementation of the NHI policies, there was a 47% increase in 1997, with 20 021 reported cases. Quarterly reporting of cases reached a historic peak in the third quarter of 1997. The increase in reported cases was mainly from general hospitals/clinics. Since 1998, the number of reported cases has declined steadily, at a rate of 7% and 3% in 1998 and 1999, respectively.

CONCLUSIONS

The NNNR and NF policies had a significant impact on notification of TB in Taiwan. These policies substantially improved completeness of reporting, an observation with implications for surveillance of other reported diseases.

Inflammatory pseudotumor of the lung in a coal miner with pneumoconiosis

Inflammatory pseudotumors of the lung are uncommon and etiologically diverse lesions that often present as solitary masses in the lung. It may be difficult to distinguish these lesions from more commonly encountered lung neoplasms. Inflammatory pseudotumors can also occur in other organs, but the lung is most commonly involved. We describe a 63-year-old male coal miner with a 40-year history of dust exposure, who had a large right middle lobe mass on chest roentgenograms, with slow growth over the 7 years prior to admission. Repeated transthoracic echo-guided biopsies of the mass were indicative of an inflammatory and reactive process. The radiographic, histologic, and clinical findings indicated a diagnosis of inflammatory pseudotumor. The patient refused surgical intervention and was regularly followed at our outpatient clinic. Follow-up chest roentgenograms for 1 year revealed that the tumor size was stable. This case suggested that inflammatory pseudotumor, although uncommon, should be included in the differential diagnosis in a patient with pneumoconiosis and a solitary mass in the lung.

On the direct products of measurement structures

This paper considers the direct products of relational systems of the same type and scales defined thereon, as well as the invariance properties of functions on such product structures. The results will be applied to a theory of multidimensional scale types.

Cyclosporin-induced gingival overgrowth at the newly formed edentulous ridge in rats: a morphological and histometric evaluation

BACKGROUND

Since cyclosporin A (CsA)-induced overgrowth seldom occurs at sites distant from teeth, the periodontal ligament has been considered significant. The aim of this study was to examine overgrowth occurrence at the edentulous ridge--the sites without the ligament--after CsA therapy in rats.

METHODS

After extracting all right maxillary molars, 16 Sprague-Dawley rats underwent a 2-week healing period. The animals were separated into CsA and control groups. CsA rats received 15 mg/kg of CsA by gastric feeding for 4 weeks, while the control group received only mineral oil. At the end of study, all animals were sacrificed and stone models were immediately obtained by rubber-based impressions. The edentulous ridge morphology, including the bucco-lingual width and the vertical height, was measured on the models. For histometry, 10 sections were selected from the edentulous ridge of each animal after undecalcified tissue preparation. The soft tissue areas of the edentulous ridge and the trabecular bone morphology of the dental alveolus were measured.

RESULTS

CsA therapy produced a significant increase of the ridge width and height, measured from the stone models, when compared to the control group. Under histometry, CsA resulted in a significant increase of the epithelium, connective tissue, and total soft tissue areas. The measured trabecular bone volume was affected by both examining factors: the drug therapy and the location of the dental alveolus. CsA therapy produced a significant loss of bone volume but a significant increase of the bone-specific surface area. Although the mean osteoid volume was similar between CsA and control groups, a significant decrease of the fractional formation surface in the CsA group was revealed.

CONCLUSIONS

An enlarged edentulous ridge and an altered dental alveolar bone morphology were observed in CsA-treated animals at the end of the study; therefore, we suggest that CsA may induce not only a soft tissue overgrowth but also an alveolar bone alteration at the edentulous ridge. The hypothesis that tooth or periodontal ligament is an essential component for the overgrowth development is questioned.

Complete atrio-ventricular block as a major clinical presentation of the primary cardiac lymphoma: a case report

It is uncommon for malignant lymphomas to present primarily with cardiac invasion as the main clinical feature. What we are interested in is not only where the disease is, but also those symptoms that it may induce. Sudden onset of complete atrio-ventricular block is one of the most common clinical presentations. Cardiac tamponade is another common disease entity which, if it locates over outlets of great vessels, may also exert symptoms of obstructive vessels. Diagnosis can be made by needle aspiration under the guidance of transcutaneous or transesophageal echocardiography. Both CT scan and MRI play positive roles in the diagnosis of cardiac lymphomas, and the latter can even provide much more image information than the former. We report a 70-year-old male with primary cardiac lymphoma with initial clinical pictures of sudden onset of complete atrio-ventricular block. Chemotherapy was utilized with cyclophosphamide, vincristine and prednisolone (COP) initially for four courses and followed by adding doxorubicin (CHOP) for another three courses. The patient was still in remission status after treatment for 2 years.

Neuroplasticity Induced by Tooth Pulp Stimulation in Trigeminal Subnucleus Oralis Involves NMDA Receptor Mechanisms

We have recently demonstrated that application of the mustard oil (MO), a small-fiber excitant and inflammatory irritant, to the rat maxillary molar tooth pulp induces significant increases in jaw muscle electromyographic (EMG) activity and neuroplastic changes in trigeminal (V) subnucleus caudalis. Since subnucleus oralis (Vo) as well as caudalis receives projections from molar pulp afferents and is also an integral brain stem relay of afferent input from orofacial structures, we tested whether MO application to the exposed pulp induces neuroplastic changes in oralis neurons and whether microinjection of MK-801, a noncompetitive NMDA antagonist, into the Vo influences the pulp/MO-induced neuroplastic changes in chloralose/urethan-anesthetized rats. Single neuronal activity was recorded in Vo, and neurons classified as low-threshold mechanoreceptive (LTM), wide dynamic range (WDR), nociceptive-specific (NS), deep (D), or skin/mucosa and deep (S + D). The spontaneous activity, mechanoreceptive field (RF) size, mechanical threshold, and response to suprathreshold mechanical stimuli applied to the neuronal RF were assessed prior to and throughout a 40- to 60-min period after MO application to the maxillary molar pulp. In animals pretreated with saline microinjection (0.3 μl) into the Vo, MO application to the pulp produced a significant increase in spontaneous activity, expansion of the pinch or deep RF, decrease in the mechanical threshold, and increase in response to suprathreshold mechanical stimuli of the nociceptive (WDR, NS, and S + D) neurons except for those nociceptive neurons having their RF only in the intraoral region. The pulpal application of MO did not produce any significant neuroplastic changes in LTM neurons. Furthermore, in animals pretreated with MK-801 microinjection (3 μg/0.3 μl) into the Vo, MO application to the pulp did not produce any significant changes in the RF and response properties of nociceptive neurons. In other animals pretreated with saline (0.3 μl) or MK-801 (3 μg/0.3 μl) microinjected into the Vo, mineral oil application to the pulp did not produce any significant changes in RF and response properties of nociceptive neurons. These findings indicate that the application of MO to the tooth pulp can induce significant neuroplastic changes in oralis nociceptive neurons and that central NMDA receptor mechanisms may be involved in these neuroplastic changes.

Does nifedipine aggravate cyclosporin--induced gingival overgrowth? An experiment in rats

BACKGROUND

Nifedipine (NIF) may aggravate cyclosporin A (CsA)-induced gingival overgrowth because the potentiated gingival overgrowth has been observed in the patients treated with CsA and NIF. The purpose of this study was to evaluate whether NIF could aggravate the CsA-induced gingival overgrowth in a rat model.

METHODS

Ninety male Sprague-Dawley rats were divided into 6 groups: the first group received 8 mg/kg of CsA daily by gastric feeding for 6 weeks; the second and third groups received NIF daily at a dosage of 10 or 50 mg/kg; the fourth and fifth groups received CsA (8 mg/kg) and NIF (10 or 50 mg/kg); and the sixth group received solvents as a negative control. Gingival dimensions (including bucco-lingual depth, mesio-distal width, and vertical height) were assessed bi-weekly from impressed stone models of the mandibular incisal region. At the end of the experiment, the animals were sacrificed. Following histopathological procedures, serial horizontal sections were obtained at the base of the central incisal papilla. Two tissue levels were selected for histometric analysis. Level 1 was defined as the point where the lingual gingiva embraced the bucco-lingual midpoint of the roots and the level 2 as the point where the lingual gingiva at the enamel-dentinal junction approximated the bucco-proximal angle of the roots. The bucco-lingual depth and the mesio-distal width of the papilla were recorded on 5 consecutive sections at the 2 levels, respectively.

RESULTS

At the 6-week observations, the gingival dimensions (including the depth, width, and height) significantly increased after CsA therapy and the increasing treatment duration; however, only the mesio-distal width increased after NIF therapy. For NIF therapy alone, a positive linear relation was noted by increased NIF treatment dosages in all gingival dimensions at week 6. But, this relationship was not found in the combined therapies. By histometry, tissue dimensions increased following single drug therapy, either CsA or NIF, at both levels. In animals with the combined therapies, the tissue dimensions decreased if the animals received 10 mg NIF, while they rebounded to control levels with the 50 mg dosage. A dose-dependent positive pattern by NIF was noted in tissue dimensions, but the pattern did not occur in animals that received combined therapy.

CONCLUSIONS

The gingival dimensions increased after CsA or NIF therapy, although they were more prevalent with CsA. But the augmenting pattern in gingival morphology observed with CsA therapy decreased when the animals received additional NIF. Therefore, we question whether NIF is a critical factor in aggravating the CsA-induced gingival overgrowth.

Phytoremediation of MTBE from a groundwater plume

The feasibility of phytoremediation to both remediate and hydraulically contain a methyl tert-butyl ether (MTBE)-contaminated groundwater plume was investigated in a three-phase study that included the following elements: (i) a laboratory bioreactor study that examined the fate and transport of 14C-radiolabeled MTBE in hybrid poplar trees, (ii) a novel approach for a mathematical modeling study that investigated the influence of deep-rooted trees on unsaturated and saturated groundwater flow, and (iii) a field study at a Houston site with MTBE-contaminated groundwater where hybrid poplar trees were planted. In the laboratory study, the predominant fate pathway was uptake and evapotranspiration of [14C]-MTBE from leaves and stems of poplar cuttings rooted in hydroponic solution. The modeling study demonstrates that phytohydraulic containment of MTBE in groundwater by deep-rooted trees can be achieved. The field study demonstrated significant groundwater uptake of groundwater by deep-rooted trees via direct measurement in the first three seasons. The use of vegetation may provide a cost-effective in-situ alternative for containment and remediation of MTBE-contaminated groundwater plumes.

Pulmonary resection in the treatment of patients with pulmonary multidrug-resistant tuberculosis in Taiwan

SETTING

Chronic Disease Control Bureau, Department of Health, Taiwan.

OBJECTIVE

To evaluate the role of pulmonary resection in the treatment of pulmonary tuberculosis resistant to isoniazid and rifampin (MDR-TB).

DESIGN

In a retrospective cohort study, 27 MDR-TB patients who underwent pulmonary resection between December 1990 and March 1999 were reviewed. Individually-tailored treatment regimens were selected at a once-weekly staff conference following review of the patient's case history and drug susceptibility results. Surgery was performed for selected patients, essentially those: 1) whose medical treatment had failed, or for whom treatment failure seemed highly likely, or for whom post-treatment relapse seemed likely, 2) with predominantly localised disease, 3) with adequate cardiopulmonary reserve, and 4) whose treatment regimen had been composed of at least two effective drugs to diminish the mycobacterial burden.

RESULTS

There was no surgical mortality apart from one peri-operative death (4%). Three patients (11%) developed complications, and 24 (92%) patients demonstrated sputum conversion and/or remained negative after surgery. Twenty-three patients have already completed treatment, and during a mean of 42 +/- 18 follow-up months (range 15-80 months), one patient relapsed. This patient was disease-free after another course of treatment.

CONCLUSION

For selected patients, pulmonary resection may improve the outcome of pulmonary MDR-TB.

Heterobimetallics of nickel-iron dinitrosyl: electronic control by chelate and diatomic ligands

Reaction of [PPN][Fe(NO)2(SePh)2] (1) with dimeric [Ni(mu-SCH2CH2SCH2CH2S)]2 in the presence of additional NO2- produced the neutral heterobimetallic [(ON)Ni[(mu-SCH2CH2)2S]Fe(NO)2] complex (2). The X-ray crystal structures of 1 and 2 show distorted tetrahedral iron dinitrosyl groups, assigned according to the Feltham-Enemark notation as [Fe(NO)2]9 The Fe-NO bonds are off linearity by an average of approximately equals 10 degrees for compounds 1 and 2, while a more linear Ni-NO coordination with a Ni-NO distance of 1.644(2) A was found in 2. The v(NO) value of complex 2 is consistent with an assignment for [Ni(NO)]9 of Ni0(NO)+ as is known for analogous phosphine derivatives, P3Ni0(NO)+. EPR signals of g values = 2.02-2.03 confirmed the existence of the odd electron in the chalcogenated [Fe(NO)2]9 compounds. Two [Fe(NO)2]10 complexes coordinated by the nickel(II) dithiolate, (bismercaptoethanediazacyclooctane)nickel(II), (Ni-1), (Ni-1)Fe(CO)(NO)2 and (Ni-1)Fe(NO)2, were prepared for comparison to the Ni0(NO)+ derivative and other monomeric and homodimetallic derivatives of the Fe(NO)2 fragment. While the oxidation level of Fe(NO)2 is the primary determinant of v(NO) values, they are also highly sensitive to ancillary ligands and, thereby, the distal metal influence through the bridging thiolate donor.

Effects of GABA receptor antagonist on trigeminal caudalis nociceptive neurons in normal and neonatally capsaicin-treated rats

We have recently demonstrated that significant increases in cutaneous mechanoreceptive field (RF) size and spontaneous activity occur in nociceptive neurons of trigeminal subnucleus caudalis (Vc, the medullary dorsal horn) of adult rats depleted of C-fiber afferents by neonatal treatment with capsaicin. These neuronal changes in capsaicin-treated (CAP) rats are suggestive of central neuroplasticity and involve N-methyl-D-aspartic acid (NMDA) receptor mechanisms. The present study examined whether the GABA(A) receptor antagonist bicuculline (BIC) or the GABA(B) receptor antagonist 2-hydroxysaclofen (SAC) can influence the RF properties and activity of Vc nociceptive neurons classified as either nociceptive-specific or wide-dynamic range in CAP adult rats or in neonatally vehicle-treated (CON) rats. C-fiber depletion was confirmed in the CAP rats by a significant decrease in plasma extravasation of Evans blue dye in a skin area receiving topical application of mustard oil, a small-fiber excitant and inflammatory irritant. As previously reported, marked increases in cutaneous RF size and spontaneous activity occurred in Vc nociceptive neurons of adult CAP rats, compared with CON rats. GABA(A) receptor blockade by BIC (i.t.) in CON rats produced a significant increase in spontaneous activity and in pinch RF size and tactile RF size (or appearance of a tactile area in the RF of nociceptive-specific neurons), as well as a significant lowering of the mechanical threshold and a significant enhancement of responses to pinch stimuli applied to the RF. In CAP rats, GABA(A) receptor blockade also produced significant changes similar to those documented in CON rats, except for a paradoxical and significant decrease in pinch RF size and no noticeable changes in responses to pinch stimuli. GABA(B) receptor blockade by SAC (i.t. ) did not produce any significant changes in Vc nociceptive neurons in either CON or CAP rats. These results suggest that GABA(A) receptor-mediated inhibition may be involved in maintaining the functional expression of Vc nociceptive neuronal properties in normal conditions, and that in animals depleted of their C-fiber afferents, some features of this GABA(A) receptor-mediated modulation may be disrupted such that a GABA(A) receptor-mediated excitation is manifested.

Interleukin-1 and tumor necrosis factor activities partially account for calvarial bone resorption induced by local injection of lipopolysaccharide

The present study was undertaken to test the hypothesis that tumor necrosis factor (TNF) and/or interleukin-1 (IL-1) activity mediates lipopolysaccharide (LPS)-induced bone resorption in vivo. To test this hypothesis, Escherichia coli LPS or Porphyromonas gingivalis LPS was injected into the subcutaneous tissues overlying mouse calvariae. Histological sections, prepared from the center of the lesion, were stained for tartrate-resistant acid phosphatase, and histomorphometric analysis was performed to quantify the osteoclast number and the area of bone resorption. In time course experiments using normal mice, a peak of bone resorption occurred 5 days after endotoxin stimulation. In dose-response experiments, IL-1 receptor type 1 deletion (IL-1R(-/-)), TNF double-receptor p55/p75 deletion (TNF p55(-/-)/p75(-/-)), combined TNF p55 and IL-1 receptor type 1 deletion (TNF p55(-/-)/IL-1R(-/-)), and IL-1beta-converting enzyme-deficient (ICE(-/-)) mice and the respective wild-type mice were injected with 500, 100, or 20 micrograms of P. gingivalis LPS and sacrificed 5 days after LPS injection. At the highest dose (500 micrograms), significant decreases in osteoclast number occurred in mutant mice compared to wild-type mice: (i) a 64% reduction for the TNF p55(-/-)/IL-1R(-/-) mice, (ii) a 57% reduction for the IL-1R(-/-) mice, (iii) a 41% reduction for the TNF p55(-/-)/p75(-/-) mice, and (iv) a 38% reduction for the ICE(-/-) mice. At the two lower doses, bone resorption was apparent but no significant differences between mutant and wild-type animals were observed. The present data indicate that at higher doses, LPS-induced bone resorption is substantially mediated by IL-1 and TNF receptor signaling. Furthermore, IL-1 receptor signaling appears to be slightly more important than TNF receptor signaling. At lower LPS doses, other pathways leading to osteoclast activity that are independent of TNF and IL-1 are involved.

Involvement of trigeminal subnucleus caudalis (medullary dorsal horn) in craniofacial nociceptive reflex activity

We have previously shown that an increase in electromyographic (EMG) activity of digastric (DIG) and masseter (MASS) muscles can be reflexly evoked by injection into the rat's temporomandibular joint (TMJ) region of the small-fibre excitant and inflammatory irritant mustard oil (MO). Since the trigeminal (V) subnucleus caudalis (Vc, i.e. medullary dorsal horn) has traditionally been viewed as an essential brainstem relay site of nociceptive information from craniofacial tissues, an EMG study was carried out in 45 anaesthetized rats to determine if Vc is involved in the MO-evoked increases in jaw muscle EMG activity. The effects of histologically confirmed surgical or chemical lesions of Vc on this evoked EMG activity were tested in different groups of rats. MO injection into the left TMJ region of intact rats evoked bilateral increases in EMG activity of DIG and MASS which could be significantly reduced by surgical transection of the left caudal brainstem at the obex level; MO injection into the right TMJ region in these same rats still readily evoked increases in EMG activity. A sagittal section medial to Vc or transection at the level of the second cervical spinal segment did not produce any significant reduction in the reflexly evoked EMG activity. Neurones in Vc, as opposed to fibres of passage, appear to be important for the MO-evoked EMG activity, since injection into Vc of the neurotoxic chemical ibotenic acid significantly reduced the mustard oil-evoked EMG activity. The Vc also appears to play a role in the activation of contralateral V motoneurons, as evidenced by the activation of the contralateral DIG and MASS muscles by the injection of MO into the left TMJ region of intact rats and by the reduction of this evoked EMG activity in the contralateral DIG and MASS of rats with a surgical transection or ibotenic acid lesion of the left Vc. These findings suggest that Vc may be a critical element in the neural pathways underlying the reflex responses evoked bilaterally in DIG and MASS muscles by noxious stimulation of the TMJ region.

Tuberculous empyema

The clinical courses of 35 tuberculous empyema patients were investigated retrospectively from November 1990 through November 1995. Most patients had nonspecific symptoms and signs but with far-advanced pulmonary parenchymal lesions in their chest roentgenographs. The effusions showed neutrophilic leukocytosis with a 60% positive culture rate for Mycobacterium tuberculosis. Multidrug resistant strains were found in 7 out of 18 cultures. All patients received chemotherapy and eight of them underwent additional surgical management. Twenty-two (62.9%) patients had been treated successfully and one patient is still under treatment. The remaining 12 patients either died during treatment or defaulted; and four (11.4%) of them had died of tuberculosis. We conclude that the treatment outcome of tuberculous empyema is less satisfactory than that of pulmonary tuberculosis, however, modern multidrug chemotherapy with repeated drainage and opportune surgical interventions could be in prospect of successful treatment of tuberculous empyema.

NMDA receptor mechanisms contribute to neuroplasticity induced in caudalis nociceptive neurons by tooth pulp stimulation

We recently demonstrated that application of mustard oil (MO), a small-fiber excitant and inflammatory irritant, to the rat maxillary molar tooth pulp induces significant and prolonged increases in jaw muscle electromyographic (EMG) activity that are suggestive of central neuroplasticity. Because small-fiber afferents, including pulp afferents, access nociceptive neurons in trigeminal (V) subnucleus caudalis, this study examined whether pulpal application of MO induces neuroplastic changes in caudalis nociceptive neurons (wide dynamic range and nociceptive specific) and whether central N-methyl--aspartate (NMDA) receptor mechanisms are involved in these MO-induced neuroplastic changes. After pretreatment with vehicle (saline, 10 microliter i.t.) to the surface of the medulla, the pulpal application of MO to the maxillary molar tooth pulp produced a significant increase in neuronal spontaneous activity, a significant expansion of the pinch and/or tactile mechanoreceptive field (RF), a significant decrease in mechanical threshold, and significant increases in neuronal responses to graded pinch stimuli. Compared with vehicle-treated rats, pretreatment with the NMDA receptor antagonist MK-801 (10 microgram/10 microliter i.t.) followed by MO application to the pulp in another group of rats significantly reduced or abolished these MO-induced neuroplastic changes in nociceptive neurons. In another group of rats pretreated with saline (intrathecally), mineral oil application to the pulp did not show any significant changes in spontaneous activity or RF properties over the 40-min observation period. The pulpal application of MO in other rats (pretreated with saline, intrathecally) did not produce any significant neuroplastic changes in caudalis low-threshold mechanoreceptive neurons. These results indicate that the MO-induced activation of molar pulpal afferents can produce profound NMDA receptor-related neuroplastic changes in caudalis nociceptive neurons. Such neuroplastic changes may contribute to the hyperalgesia and spread of pain that can be associated with pulpal inflammation.

Short-course chemotherapy for isoniazid-resistant pulmonary tuberculosis

Standard short-course chemotherapy including isoniazid, rifampicin, pyrazinamide, and ethambutol has been the recommended treatment for tuberculosis in Taiwan since November 1990. The effectiveness of this treatment was evaluated retrospectively in 108 patients with isolates resistant to isoniazid alone and 115 patients with drug-susceptible pulmonary tuberculosis diagnosed and treated at the Taiwan Provincial Chronic Disease Control Bureau from November 1990 through December 1995. The success rate of treatment was 94.4% in patients with isoniazid-resistant Mycobacterium tuberculosis strains, which was not significantly different from the 97.4% rate in patients with susceptible strains. Of the patients treated successfully, no bacteriologic relapse was found in 97 patients with isoniazid-resistant strains or 103 patients with drug-susceptible strains 12 months after the end of chemotherapy. No significant advantage in treatment outcome was found in patients infected with isoniazid-resistant strains who received chemotherapy for more than 6 months (successful treatment rate, 95.0% vs 92.8%), but the failure rate was higher in patients with a previous history of antituberculosis therapy (17.6% vs 3.3%). We conclude that short-course chemotherapy is effective for isoniazid-resistant pulmonary tuberculosis and that there is no significant difference in treatment outcome between patients with or without isoniazid-resistant disease.

Screening of human immunodeficiency virus infection in pulmonary tuberculosis patients in Taiwan

To disclose the impact of human immunodeficiency virus (HIV) infection on the tuberculosis epidemic in Taiwan, we prospectively screened for HIV infection in patients with active pulmonary tuberculosis. A total of 378 patients who were admitted to the Taiwan Provincial Chronic Disease Control Bureau from January through December 1996 were enrolled. HIV serologic testing was performed by enzyme-linked immunosorbent assay (ELISA). A positive ELISA test was confirmed by Western blot analysis. One patient was infected with HIV. We conclude that the impact of HIV infection on the epidemic of tuberculosis in Taiwan is not significant at present.

Initial drug resistance of Mycobacterium tuberculosis in Taiwan

The prevalence and mortality rate of pulmonary tuberculosis in adults are high in Taiwan. Because the emergence of drug-resistant tuberculosis is one of the major causes of this sustained high tuberculosis mortality, surveillance of initial drug resistance is important. We tested Mycobacterium tuberculosis isolates from 1,935 newly diagnosed tuberculosis patients from January 1990 through December 1995 at the Taiwan Provincial Chronic Disease Control Bureau. The overall initial drug resistance rate was 12.3%; 8.7% of isolates were resistant to only one drug, 2.6% to two drugs, 0.7% to three drugs, and 0.3% to four drugs. The resistance rates to individual drugs were: streptomycin, 5.7%; isoniazid, 9.2%; ethambutol, 0.7%; and rifampin, 1.5%. The frequency of multidrug-resistant M. tuberculosis (resistant to at least isoniazid and rifampin) was 1.2%. In view of the high initial isoniazid resistance rate and low initial ethambutol resistance rate, ethambutol should be added to the regimen for the initial treatment of tuberculosis in Taiwan. The emergence of multidrug-resistant M. tuberculosis is ominous and should be considered when treating patients in Taiwan.

NMDA receptor involvement in neuroplastic changes induced by neonatal capsaicin treatment in trigeminal nociceptive neurons

NMDA receptor involvement in neuroplastic changes induced by neonatal capsaicin treatment in trigeminal nociceptive neurons. J. Neurophysiol. 78: 2799-2803, 1997. This study examines whether 1) the neonatal loss of C-fiber afferents results in neuroplastic changes in the mechanoreceptive field (RF) properties and spontaneous activity of nociceptive neurons in trigeminal subnucleus caudalis (medullary dorsal horn) of adult rats, and that 2) N-methyl--aspartic acid (NMDA) receptor mechanisms are involved in these neuroplastic changes. Compared with vehicle-treated (i.e., control, CON) rats, capsaicin-treated (CAP) rats showed a marked increase in neuronal spontaneous activity and RF size per se, but these neuroplastic changes could be significantly reduced by MK-801 (1 mg/kg, iv), a noncompetitive NMDA receptor antagonist; RF size and spontaneous activity remained unchanged in CON rats after MK-801 administration and in CAP rats after vehicle (saline, iv). Administration of 7-chlorokynurenic acid intrathecally (5 microgram/10 microliter), an antagonist of strychnine-insensitive glycine bindin sites on the NMDA receptor, also significantly reduced neuronal RF size and spontaneous activity in CAP rats, but not in CON rats. These data provide evidence that C-fiber afferents play a role in shaping the properties of nociceptive neurons and that the neuroplastic changes involve NMDA receptor mechanisms.

Hepatitis B vaccine in hemodialysis patients with hepatitis C viral infection

Patients on hemodialysis therapy are at a relatively high risk of exposure to hepatitis B virus (HBV) infection. The prevalence of hepatitis C virus (HCV) infection is even higher and was reported as 33.2% in Taiwan. Although the efficacy of hepatitis B vaccine was well documented, the vaccination schedule in hemodialysis patients is not clearly defined. And under such a high prevalence of HCV infection, little is known about the influence of HCV imposing on HBV vaccination. We studied 50 chronic hemodialysis patients who were serologically negative for the hepatitis B surface antigen (HBsAg), the antibody to the hepatitis B surface antigen (anti-HBs) and the antibody to the hepatitis B core antigen (anti-HBc); 26 of them were positive for the antibody to hepatitis C virus (anti-HCV) test. Recombinant hepatitis B vaccine (Engerix-B) 40 micrograms per dose was administered by the intramuscular route at deltoid region at 0, 1, 2, 6 and 12 months respectively to all the patients. Forty-six patients had completed the study. The effective seroconversion rate (serum anti-HBs titer > 10 mIU ml-1) at 1 month after the final vaccine was 76.1% (35/46). The effective conversion rates of the anti-HCV(+) group to the anti-HCV(-) were 75% versus 77.3% (P = 0.857). Geometric mean anti-HBs titers were 177.67 mIU ml-1 versus 189.28 mIU ml-1 (P = 0.867). Our results showed that five-dose injections of HBV vaccine do not present a superior outcome to the four-dose regimen comparing to published data. The status of positivity of anti-HCV do not pose an suboptimal effect on HBV vaccination of hemodialysis patients.

Treatment of multidrug-resistant tuberculosis in Taiwan

Eighty-seven patients with multidrug-resistant tuberculosis (MDR-TB) diagnosed between 1988 and 1990 were treated with isoniazid and at least three other effective second-line drugs based on in vitro susceptibility tests. Of these patients, 10% failed to adhere to the regimen and 43% remained sputum positive after 6 months of treatment. Only 47% showed sputum conversion within 6 months of treatment and 12% of them relapsed during the first year of follow-up. From September 1987 to July 1989, 36 patients with MDR-TB were treated with a regimen containing rifabutin, isoniazid and at least three other susceptible drugs. Only 47% achieved a sustained sputum conversion. Four died during treatment due to disease progression. From March 1992 to July 1993, 17 cases of MDR-TB were treated with an ofloxacin-containing anti-TB regimen for 12-24 months. Two failed to adhere to the regimen for more than 1 month during the first 6 months of therapy. Among the remaining 15, 26% failed to achieve sputum conversion, 73% achieved bacterial conversion, 9 within 1 month and the other 2 within 2 months. No significant adverse effect was associated with ofloxacin use. We concluded that ofloxacin is a better choice among the more toxic and less potent second-line drugs, and should be used along with other anti-TB drugs in treating patients with MDR-TB.

Comparison of lansoprazole and omeprazole in the short-term management of duodenal ulcers in Taiwan

Lansoprazole is a novel H+/K+-ATPase inhibitor which exhibits a very potent and long-acting suppression of acid secretion. The object of this randomized, controlled trial was to compare duodenal ulcer healing rates after 4 weeks of treatment with a once-daily regimen of either 30 mg lansoprazole or 20 mg omeprazole. Of a total of 111 patients 57 received lansoprazole, whereas 54 received omeprazole. In intention-to-treat analysis at 4 weeks, 89.5% patients showed ulcer healing following treatment with lansoprazole compared with 83.3% of patients treated with omeprazole. Per protocol analysis indicated that 96.1% of patients treated with lansoprazole showed ulcer healing, compared with 93.6% of patients treated with omeprazole (NS). Age, smoking or ulcer size did not affect the ulcer healing rate. Both agents could effectively and quickly resolve ulcer symptoms. The Helicobacter pylori clearance was seen in 36 (73.5%) patients in the lansoprazole group and in 40 (80%) patients in the omeprazole group after four weeks of treatment (NS). In addition, both agents led to hypergastrinaemia, by approximately 1.6 fold. Adverse side effects included a few occurrences of reversible skin rash and constipation. It is concluded that lansoprazole elicits an adequate healing response and resolves symptoms of duodenal ulcer as well as omeprazole. Furthermore, lansoprazole is well tolerated with a few adverse side effects.

Recurrent hypertensive intracerebral hemorrhage

Hypertensive intracerebral hemorrhage has been considered as a one-time event with rare recurrence. This observation is quite different from our experience in Taiwan. We, therefore, conducted a systematic review of our series of consecutive patients with recurrent bleeding. During a 2-year period, we encountered 47 patients with recurrent hypertensive intracerebral hemorrhage from a total of 892 consecutive patients with hypertensive hemorrhage (5.3%). There were 25 men and 22 women with a mean age of 59 +/- 10 (range: 36-78) years at the onset of the first hemorrhage and 62 +/- 9 (range: 39-80) years at the second hemorrhage. The median interval between 2 hemorrhages was 2 years and 4 months (range: 1 month to 8.5 years). All except one recurrent hemorrhages occurred at a site different from the previous one. Of the 38 patients admitted to our hospital for both hemorrhages only 5 were regularly treated with antihypertensive therapy. The outcome for the recurrent bleeding was grave: 26% died and 51% became totally dependent or vegetative. Recurrent hypertensive hemorrhage is not as rare as previously thought; it comprises 5.3% of our patients with hypertensive intracerebral hemorrhage. The recurrent hemorrhage, however, rarely occurs at the same location as the previous one. Uncontrolled hypertension appears to be an important risk factor for the recurrence. Control of blood pressure after the first bleeding should be attempted to prevent recurrent hemorrhage.

Parabrachial area and nucleus raphe magnus-induced modulation of nociceptive and nonnociceptive trigeminal subnucleus caudalis neurons activated by cutaneous or deep inputs

1. The aim of this study was to test whether parabrachial area (PBA) stimulation exerts inhibitory influences on the spontaneous activity and responses evoked by skin and deep afferent inputs in trigeminal subnucleus caudalis (Vc) neurons, and to compare these effects with those of nucleus raphe magnus (NRM) stimulation. A total of 92 nonnociceptive and nociceptive Vc neurons was recorded in urethan/alpha-chloralose-anesthetized rats. Each neuron was functionally classified as low-threshold mechanoceptive (LTM), wide dynamic range (WDR), nociceptive-specific (NS), nociceptive convergent with both skin and deep inputs (S+D), or deep nociceptive (D); the LTM neurons could be subdivided as rapidly adapting (RA) or slowly adapting (SA). Conditioning stimulation was applied to histologically verified sites in PBA and NRM. 2. The spontaneous or evoked activity of all classes of neurons could be inhibited by PBA as well as by NRM stimulation, but generally the incidence and magnitude of inhibition were lower for the LTM neurons. Occasionally, facilitation of neuronal activity was also produced by PBA and NRM stimulation. 3. The spontaneous activity of 11 LTM neurons (6 RA, 5 SA), 13 nociceptive neurons (6 WDR, 7 NS), and 5 D neurons was tested with stimulation of PBA or NRM or both. LTM spontaneous activity was more significantly inhibited by NRM stimulation than by PBA stimulation, whereas both NRM and PBA stimulation had similar and significant inhibitory effects on NS, WDR, and D neurons. 4. The evoked nonnociceptive responses of 28 LTM neurons (16 RA, 12 SA) and of 6 WDR neurons were also tested with stimulation of PBA or NRM or both. The magnitudes of inhibition of the responses produced by PBA conditioning stimulation were statistically significantly less than those induced by NRM conditioning stimulation. 5. The cutaneous and deep nociceptive responses of cutaneous nociceptive neurons (9 NS, 19 WDR) and seven D neurons, respectively, were also tested with PBA and NRM stimulation. There was a significant difference in potency between PBA- and NRM-induced inhibition, but no difference in the magnitude of inhibitory effects among NS, WDR, and D neurons. For both PBA and NRM conditioning stimulation, graded increases in intensities of stimulation produced linear increases in inhibitory effects on nociceptive responses; an increase in stimulation frequency from 5 to 400 Hz also produced increases in inhibition of the nociceptive responses. 6. In five S+D nociceptive convergent neurons, the responses elicited by deep inputs were more powerfully inhibited by PBA stimulation than those elicited by cutaneous inputs.(ABSTRACT TRUNCATED AT 400 WORDS)

Responses of neurons in the rat thalamic nucleus submedius to cutaneous, muscle and visceral nociceptive stimuli

The findings of recent studies have suggested that nucleus submedius (Sm) may be an important thalamic relay for nociceptive information. The aim of the present electrophysiological study was to examine in greater detail the activity and response properties of neurons in the rat Sm in order to further evaluate this hypothesis. Single unit extracellular recordings from neurons histologically verified to be in Sm were obtained in urethane/chloralose-anesthetized rats. Noxious but not innocuous mechanical stimulation elicited responses in 75% of the 204 neurons studied. Most (85%) of these neurons were excited, 10% were inhibited and a few neurons (5%) were excited by stimulation at some sites on the body and inhibited from other sites. The receptive fields were usually very large and bilateral. No marked differences were observed in the incidence, response type, or spontaneous activity of neurons located in dorsal, ventral, rostral or caudal parts of Sm. Most of these neurons (99 of 108, 92%) also responded to noxious heating and had a mean threshold of 47 degrees C. The majority of the neurons (19 of 21, 90%) also responded to subcutaneous, intramuscular or intraperitoneal injections of noxious chemicals (formalin or hypertonic saline). The responses elicited by pinching skin or squeezing muscle were frequently facilitated by the subcutaneous or intramuscular injections of formalin. Single electrical stimuli delivered to the cutaneous receptive field rarely produced responses. However, short trains (15-25 msec trains of 200 Hz, 3 msec pulses at 5-10 mA) delivered repetitively elicited responses in 90% (n = 73) of the neurons. These responses appearing after repetitive stimulation frequently resembled the 'wind-up' pattern observed in spinal cord dorsal horn. The conduction velocities of the primary afferents which elicited the Sm neuronal responses as estimated from the latency differences of responses elicited by stimulation at two points along the tail, were indicative of recruitment of A delta and C fibers. These findings provide further support for the proposed role of Sm in thalamic nociceptive mechanisms.

The afferent and efferent connections of the nucleus submedius in the rat

The afferent and efferent connections of the nucleus submedius (Sm) in the medial thalamus of the rat were examined. Injections of wheat-germ agglutinin conjugated horseradish peroxidase (WGA-HRP) into the Sm resulted in dense terminal labeling in the middle layers of the ipsilateral ventrolateral orbital cortex (VLO). Less dense labeling was also observed in the superficial and deep layers of VLO and in the medial part of the lateral orbital cortex (LO) and in the contralateral VLO. Retrogradely labeled neurons were observed primarily in the deep layers of VLO and the dorsal peduncular cortex (DP). Labeled neurons were also observed bilaterally, in the nucleus of the horizontal limb of the diagonal band, the lateral hypothalamus, the thalamic reticular nucleus (Rt), medial parabrachial nucleus (MPB), and the laterodorsal tegmental nucleus (LDT). Many labeled neurons were also observed in the trigeminal brain-stem complex. Injections of Fluoro-Gold (FG) into Sm resulted in a very similar distribution of retrogradely labeled neurons. Injections of WGA-HRP and FG in the orbital cortex confirmed the ipsilateral Sm projection to VLO and suggested that the middle and deep layers of VLO receive a specific ipsilateral projection from the dorsal Sm and that the superficial layers receive a projection primarily from the ventral Sm. Injections of WGA-HRP into the lateral hypothalamus, LDT, and MPB confirmed the retrograde labeling findings; the lateral hypothalamus was found to send a projection to the medial Sm, the LDT region to the ventromedial Sm and the MPB to the medial and dorsal Sm. These findings confirm and extend the results of previous studies in cat and rat indicating that Sm has a major and specific reciprocal connection with VLO. This finding, in conjunction with previous studies showing direct spinal and trigeminal inputs and the existence of nociceptive neurons in Sm and VLO, provides further support for a role of Sm in nociception.

Trigeminal and dorsal column nuclei projections to the anterior pretectal nucleus in the rat

The projections of the trigeminal (V) sensory nuclei (VSN) and the dorsal column nuclei (DCN) to the anterior pretectal nucleus (APT) of the rat were investigated by the use of anterograde and retrograde transport of wheat-germ agglutinin-conjugated horseradish peroxidase (WGA-HRP). Injections of WGA-HRP into the APT retrogradely labeled neurons in the contralateral VSN and DCN. The labeled neurons in the VSN were most concentrated in the rostral V subnucleus interpolaris (Vi), but were also found in caudal V subnucleus oralis (Vo). No labeled neurons were seen in V subnucleus caudalis. In the DCN, retrogradely labeled neurons were observed in rostral portions of both the cuneate (Cu) and gracile (Gr) nuclei. Injections of WGA-HRP into the rostral Vi or caudal Vo resulted in dense anterograde terminal labeling in the ventral two-thirds of the APT; the labeling was maximal in the ventromedial part of the caudal half of the APT and did not extend into its most rostral portion. Labeling resulting from injections of tracer into Cu or Gr was located primarily in the ventral half of the APT, was maximal in the mid-levels of the nucleus and extended into its rostral portions. These results indicate the existence of prominent somatosensory projections to the APT and are consistent with recent findings suggesting a role for the APT in sensorimotor integration.

Anterior pretectal nucleus-induced modulatory effects on trigeminal brainstem somatosensory neurons

This study examined the effects of anterior pretectal nucleus (APT) conditioning stimulation on the activity of 92 functionally identified somatosensory brainstem neurons in the trigeminal (V) subnuclei oralis, interpolaris and caudalis of anesthetized rats. Conditioning stimulation inhibited most of the nociceptive neurons and some of the non-nociceptive neurons; facilitation was observed only in some non-nociceptive neurons. These data indicate that the ATP has modulatory effects on both nociceptive and non-nociceptive V somatosensory neurons.

Trigeminal projections to the nucleus submedius of the thalamus in the rat

Methods involving the anterograde and retrograde transport of wheat-germ agglutinin conjugated horseradish peroxidase and the retrograde transport of Fluoro-Gold were used in rats to examine the distribution within the spinal trigeminal nucleus of trigeminal neurons projecting to the nucleus submedius (Sm) of the thalamus, as well as the distribution of axon terminals within the Sm. Following injections into the trigeminal nucleus, axon terminals were seen in the dorsal part of the anterior Sm; the terminals occurred bilaterally but had an obvious contralateral dominance. To help determine the precise location of the Sm-petal neurons, the border between trigeminal subnuclei interpolaris and caudalis was examined by the use of immunohistochemical procedures for calcitonin gene-related peptide (CGRP). The Sm-petal neurons that were labeled retrogradely occurred only at the caudal interpolaris and rostral caudalis levels; the number of labeled neurons on the contralateral side was approximately six times that on the ipsilateral side. Most of these neurons were located in the ventral part of the caudal interpolaris and rostral caudalis and spinal trigeminal tract; in caudalis, the neurons were almost exclusively localized to its superficial layers. There were approximately three times more labeled neurons in interpolaris than in caudalis. In the experiments combined with immunohistochemistry for CGRP, many neurons (34%) were seen in proximity to CGRP-like immunopositive fibers. These results suggest that the Sm of the rat receives its orofacial afferent inputs from brainstem neurons that are localized to the caudal interpolaris and rostral caudalis. In view of previous studies that have implicated these three structures in somatosensory function, and in particular nociception, our data point to a role for this direct projection from interpolaris and caudalis to Sm in the central processing of pain.

Periaqueductal gray matter and nucleus raphe magnus involvement in anterior pretectal nucleus-induced inhibition of jaw-opening reflex in rats

In previous studies we have shown that electrical stimulation of the cortex or anterior pretectal nucleus (APT) inhibits the jaw-opening reflex (JOR). In the present study we investigated whether these effects are mediated by a relay in the periaqueductal gray matter (PAG) or rostroventromedial medulla (RVM). Experiments were performed on chloralose-urethane anesthetized rats. The JOR which was elicited by electrical stimulation of the mandibular incisor tooth was monitored by recording the evoked digastric muscle activity. Conditioning stimulation (20 ms train of 0.2 ms pulses at 400 Hz) was delivered to the facial area of the sensorimotor cortex, APT, PAG or nucleus raphe magnus (NRM) 50 ms prior to the test stimulus to the tooth that evoked the JOR. In addition, the effects of microinjections of glutamate into APT, PAG and NRM on the tooth-evoked JOR were also evaluated. The inhibition of the JOR by electrical and glutamate conditioning stimulation was found to be most potent for activation of the NRM and least potent for the APT. Local anesthetic (2% lidocaine, 0.3-0.6 microliters) block of the PAG could partially, significantly (P less than 0.05) and reversibly reduce both the APT and cortical-induced depression of the JOR. Lidocaine block of the ventromedial pons reversibly reduced the PAG, APT and cortical-induced inhibition of the JOR (P less than 0.05). Lidocaine block of the lateral RVM had powerfully (P less than 0.01) and reversibly reduced the PAG-induced inhibition, but had only a small effect (P less than 0.05) on the APT-induced inhibition and no significant effect on the cortical-induced inhibition.(ABSTRACT TRUNCATED AT 250 WORDS)

Physicochemical properties of carbovir, a potential anti-HIV agent

(+-)-Carbovir [(+-)-9-[4 alpha-(hydroxymethyl)-cyclopent-2-ene-1 alpha-yl]guanine; NSC 614846] is a novel carbocyclic nucleoside analogue which has been shown to be a potent and selective inhibitor of HIV in vitro. As part of an effort to develop a parenteral formulation for subsequent clinical and toxicological evaluation of this compound, the aqueous solution stability of carbovir as a function of pH and temperature and various physicochemical properties of carbovir including its pKa, solubility versus pH and solvent composition, and octanol-water partition coefficient have been examined. Ultraviolet spectrophotometry indicated that carbovir has pKa values of 3.15 and 9.68, respectively, at 25 degrees C and 0.01 ionic strength. The aqueous solubility of carbovir over the pH range 7-10.5 was consistent with that expected of a weak acid with a pKa of 9.65 and an intrinsic solubility of 1.24 mg/mL. Due to the limited solubility of carbovir at physiological pH, methods for solubilizing carbovir in aqueous solution were explored, including propylene glycol-water cosolvents and complexation with hydroxypropyl-beta-cyclodextrin. As expected for carbovir, a semipolar compound with an octanol-water partition coefficient of 0.29, propylene glycol:water cosolvents were not highly effective in enhancing solubility. Complex formation between carbovir and 2-hydroxypropyl-beta-cyclodextrin was found to be more effective, with a K1:1 of 105 M-1 for the complexation. The pH profiles generated at 50, 70, and 90 degrees C were accounted for by acid-catalyzed degradation at low pH leading to the formation of guanine and a neutral degradation pathway which dominates above pH 4. Prototype lyophilized formulations containing (after reconstitution) 10 mg/mL of carbovir at a pH of 10.6 were developed and evaluated.

Effect of unilateral vagotomy on capsaicin-induced neurogenic inflammation in the trachea of rats

This study reports the effect of unilateral vagotomy on neurogenic inflammation in the trachea. Neurogenic inflammation was produced in the trachea of vagotomized rats by a venous injection of capsaicin, the pungent ingredient of red pepper. Monastral blue was used as tracer dye to label the affected blood vessels. Vagus nerves and tracheal tissues were processed for light and electron microscopy. The damaged right vagus nerve was found to have degenerated. However, unilateral vagotomy did not completely block neurogenic inflammation in the trachea ipsilaterally and contralaterally, as shown in the whole mount preparations. Microscopic observations of tracheal tissue sections showed that neurogenic inflammation did not evenly occur on both sides of the trachea. The possible reason for this is discussed.