[Validation study of the Chinese version of atopic dermatitis control tool]

To assess the reliability, validity and responsiveness of the Chinese version of the atopic dermatitis control tool (ADCT). After this study obtained authorization for the Chinese version of the ADCT scale. 114 patients with atopic dermatitis were enrolled from the Department of Dermatology, Peking University First Hospital using convenience sampling from October 2022. Patients were surveyed using the General Information Questionnaire, Chinese version of ADCT, patient-oriented eczema measure (POEM),peak pruritus numerical rating scale (PP-NRS),dermatology life quality index (DLQI) and the global patient self-assessment for disease severity. Mann-Whitney rank sum test and Spearman correlation analysis were used for item analysis; content validity was assessed using content validity index (CVI); exploratory factor analysis was used to assess structural validity; Cronbach' alpha coefficient was used to assess internal consistency; Spearman correlation analysis was used to assess the correlation of ADCT with other scales to assess external responsiveness. The results showed that all items were retained by item analysis. I-CVI was 0.9-1, and S-CVI/Average was 0.983; the scale extracted one common factor by factor analysis, the cumulative variance explanation rate was 77.927%; the Cronbach' alpha coefficient of the scale was 0.937; the correlation coefficients of the Chinese version of ADCT with POEM, PP-NRS, and DLQI were 0.805, 0.861, and 0.709 respectively. In conclusion, the Chinese version of the ADCT has adequate reliability, validity and responsiveness, and is suitable for measuring disease control in Chinese patients with atopic dermatitis.

The role of rectus muscle myectomy in the management of large-angle strabismus for Graves' ophthalmopathy

PurposeRetrospective noncomparative case series to investigate the role of rectus muscle myectomy for the treatment of large-angle strabismus in patients with Graves' ophthalmopathy.Patients and methodsData from 47 consecutive patients with Graves' ophthalmopathy who underwent complete myectomy for large-angle strabismus (strabismus greater than 25 prism diopters (PDs)) were collected retrospectively. Pre- and postoperative deviations in primary and reading position were measured in PDs. Postoperative deviation of <5 diopters in primary gaze and functional binocular vision in central 30° field were considered as successful surgical outcomes.ResultsPatients undergoing complete myectomy of the restricted muscles in large-angle strabismus achieved a 78.7% success rate after the first surgery. Reoperation performed on seven patients resulted in 85.7% success rate in reoperation group. The overall success rate was 91.5%. The mean efficacy of the isolated rectus muscle myectomy was 34.3±7.7 PDs.ConclusionsThe complete rectus muscle myectomy technique is effective and predictable in the treatment of large-angle strabismus in patients with Graves' ophthalmopathy.

Surgical coverage of exposed hydroxyapatite implant with retroauricular myoperiosteal graft

BACKGROUND

With the increasing use of hydroxyapatite orbital implants, the complication of exposure has become apparent to oculoplastic surgeons. Many kinds of patch grafts, such as sclera, dermis, and hard palate mucosa, have been used to cover exposed hydroxyapatite implants with inconsistent results. In this study, the authors use a newly developed technique, autogenous retroauricular myoperiosteal graft, and the results are reported.

METHODS

A piece of retroauricular muscle together with its underlying periosteum was carefully harvested. This myoperiosteal graft was patched to the debrided hydroxyapatite exposure area with the periosteal surface facing outward. The margin of periosteal surface was secured with conjunctiva and left uncovered for the surrounding conjunctiva to epithelialise.

RESULTS

Nine eyes with hydroxyapatite exposure more than 3 mm were managed with autogenous retroauricular myoperiosteal grafts. Seven cases were successfully treated with single graft surgery. The other two cases needed an additional graft surgery, and there was no re-exposure noted thereafter. Five patients received a successful insertion of the motility peg. All nine patients have been fitted with prosthesis with reasonable motility. There were no complication noted during more than 1 year of follow up.

CONCLUSION

The thick composite nature of the myoperiosteal graft provides a durable and vascularised coverage for exposed hydroxyapatite implants. This technique offers an encouraging alternative for the management of exposed hydroxyapatite implants.

Primary Placement of a Titanium Sleeve in Hydroxyapatite Orbital Implants

BACKGROUND

To study a new surgical option of primary placement of a titanium sleeve into hydroxyapatite implants during enucleation or evisceration.

METHODS

A standard enucleation or cornea preserved evisceration was performed, followed by preplacement of a titanium sleeve into the hydroxyapatite implant by a hand drill sleeve driver. Care must be taken to ensure that the titanium sleeve is positioned centrally when the implant is put inside the orbital socket or eviscerated shell. The Tenon capsule and conjunctiva were meticulously closed with minimal tension. Complications such as sleeve exposure, coralline exposure, and infection of the titanium sleeve were closely observed.

RESULTS

In all, 30 patients were treated in the above fashion with 10 enucleation and 20 evisceration procedures. The follow-up period ranged from 9 to 24 months. Three of the sleeves were found to have exposed spontaneously at 5 and 7 weeks following original surgery. They had no further complication except one sleeve loosening. The remaining 27 sleeves that did not spontaneously expose pursued secondary exposure of the titanium sleeve and peg insertion by conjunctival cutdown procedure 3 months after original surgery. Two sleeves were found to be oblique positioned after the conjunctival cutdown procedure. Fortunately, all the 30 patients were successfully fit with a peg-coupled prosthesis with good motility.

CONCLUSION

Primary placement of a titanium sleeve into hydroxyapatite implants has several advantages, including high patient acceptance, technical simplicity, and office-based conjunctival cutdown pegging procedure. By avoiding the expense of postoperative imaging study and additional prosthetic modification, a more rapid and efficient rehabilitation is possible.

Manganese stimulates stellation of cultured rat cortical astrocytes

We investigated the effect of manganese on the morphology of cultured rat cortical astrocytes. Astrocytes exhibited flattened, polygonal morphology in the absence of stimulation, and differentiated into process-bearing stellate cells following exposure to MnCl(2). MnCl(2)-induced stellation was a reversible process, which depended on the presence of extracellular free manganese. MnCl(2)-induced stellation did not stop with the introduction of pertussis toxin, PD98059, SB203580, phorbol 12-myristat 13-acetate, SQ22536, or LY83583. Alternatively, MnCl(2)-induced stellation did stop when exposed to colchicine and sodium orthovanadate, suggesting the involvement of the cytoskeletal elements and orthovanadate-sensitive protein tyrosine phosphatase. MnCl(2) might function as a factor regulating astrocyte morphology.

Tyrosine kinase signaling involved in glutamate-induced astrocyte proliferation

Proliferation of astrocytes is a common response of the CNS to injury and disease. The mechanisms controlling the proliferation of astrocytes are of great interest. In this paper, the signaling pathways underlying glutamate-induced astrocyte proliferation are investigated. Glutamate stimulates the proliferation of non-synchronized, subconfluent cultures of rat cortical astrocytes. Glutamate-induced cell proliferation is not prevented by inhibitors of G protein, protein kinase A, protein kinase C, phosphatidylinositol 3 kinase, extracellular signal-regulated kinase, or phospholipase A2. However, the tyrosine kinase inhibitors Genistein and Herbimycin A inhibit the glutamate-induced proliferation. Moreover, this proliferation is mediated by the activation of glutamate metabotropic receptors. These results suggest that glutamate induces astrocyte proliferation through a tyrosine kinase pathway.

Hypoxemia inducing endothelin-1 secretion in meconium aspiration in piglets

According to our previous study, the secretion of endothelin-1 (ET-1) was induced after meconium aspiration in piglets. In order to determine the role of hypoxemia in the ET-1 secretion during meconium aspiration, 12 piglets were randomly assigned into 2 groups: the hyperoxia and the hypoxia group (6 animals/group). Instillation of meconium (20% in normal saline) was achieved via the endotracheal tube (3 mL/kg) in all these animals. The hyperoxia group was ventilated with 100% oxygen, whereas the hypoxia group was ventilated with only 40% of oxygen. The plasma ET-1 levels, arterial blood gases and hemodynamics were measured at the baseline, 60, 120, 180, and 240 minutes after meconium instillation. The result showed plasma ET-1 levels to be significantly higher in the hypoxia group than the hyperoxia group at 180 and 240 min, respectively (p <0.05 andp <0.01). Besides, the pulmonary arterial pressures were significantly higher in the hypoxia group after 60 min (p <0.05 at 60 min and p <0.01 after 120 min). These results suggested that hypoxemia may be the major factor for inducing ET-1 secretion in meconium aspiration syndrome.

Association of immune responses and ischemic brain infarction in rat

Inflammation plays an important role in the pathogenesis of neurodegenerative diseases including ischemia. Occlusion of common carotid artery and middle cerebral artery has been used to produce focal ischemic lesions in the rat. Here, we examined the associations between immune reactions and postischemic brain infarction. Ischemia/reperfusion time-dependently caused brain infarction. The kinetics of inflammatory reactions in rat brain including inflammatory cell infiltration, edema formation, cytokines/chemokines and adhesion molecules production and matrix metalloproteinase activation were relevant to the progression of ischemic infarction. Differential induction profile after ischemia suggests that this activation might contribute to secondary brain damage in ischemic tissues. On the other hand, another possibility of this response is to trigger processes that mediate the neural regeneration after ischemic injury.

Cerebral ischemia/reperfusion injury in rat brain: effects of naloxone

The pathogenesis of cerebral ischemia/reperfusion (I/R) involves cytokine/chemokine production, inflammatory cell influx, astrogliosis, cytoskeletal protein degradation and breakdown of the blood-brain barrier. (-)-Naloxone is able to reduce infarct volume and has been used as a therapeutic agent for cerebral I/R injuries. However, its effects on the mentioned pathophysiologic changes have scarcely been addressed. Cerebral I/R was produced by occluding and opening bilateral common carotid artery and unilateral middle cerebral artery in Sprague-Dawley rats. After cerebral I/R, the degradation of neuronal microtubule-associated protein-2 (MAP-2) was strongly associated with astrogliosis, inflammatory cell infiltration, cytokine/chemokine overproduction, and matrix metalloproteinase-9 activation. (-)-Naloxone pretreatment suppresses post-ischemic activation and preserves more MAP-2 protein. Therefore, (-)-naloxone administration might be an effective therapeutic intervention for reducing ischemic injuries.

Effect of hypocapnia in the first three days of life on the subsequent development of periventricular leukomalacia in premature infants

Several etiologies for causing periventricular leukomalacia (PVL) in preterm infants have been investigated worldwidely. The aim of this study is to investigate whether hypocapnia plays a role in the pathogenesis of the subsequent development of PVL. From Jan. 1997 to June 1998, 91 premature infants (mean gestational age 28.8 +/- 2.5 weeks and birth body weight 1169 +/- 385 g) born in Chung Gung Children's Hospital requiring mechanical ventilation in the first 72 hrs were enrolled in our study. Serial neuorosonogram were followed on day 1, 3, 7 and then at least every 2 to 3 weeks until discharge. These infants were divided into two groups defined as the PVL group and non-PVL group. Variables comprising perinatal data were analyzed and compared between these two groups to screen out possible risk factors related to the development of PVL. There was no difference noted. As for the effect of PaCO2, we found the infants with PVL to have mean lower PaCO2 during the first 72 hours of life. (P = 0.004). Logistic regression model revealed that the incidence for PVL increased significantly when mean PaCO2 is lowered to less than 25 mmHg. Hypocapnia during the first three days of life seems to be an important etiological factor associated with the development of periventricular leukomalacia. Therefore, the ventilatory strategy in the care of the premature neonates should not only provide adequate ventilation but also careful avoidance of hypocapnia.

Differential effects of cytokines and redox potential on glutamate uptake in rat cortical glial cultures

Perturbation of glutamate uptake may contribute to the pathogenesis of neuronal damage in the central nervous system. Cytokine overproduction, oxidative stress, energy failure, and metabolic impairment are commonly concomitant or resultant consequences of brain injury, which might synergistically exacerbate neuronal damage. In this study, we elucidate the effects of these events on glutamate uptake. Rat cortical glial cultures lowered the concentration of extracellular glutamate via glutamate transporters. Disturbance of ionic gradients, energy depletion, and reduced metabolic function impaired glutamate transporter activity. Tumor necrosis factor-alpha and interleukin (lL)-1beta potentiated glutamate-mediated oxidative stress and finally resulted in decrease in glutamate transporter activity. However, IL-4 and IL-10 exhibited no significant effects on both events. These results suggest that oxidative stress has a potential neurotoxicity by means of impairing glutamate transport into astrocytes.

Effect of carbon dioxide tension in the first three days of life on the development of retinopathy of prematurity

BACKGROUND

This study focuses on the effect of carbon dioxide tension in the first 3 days of life on the development of retinopathy of prematurity (ROP) in mechanically ventilated premature infants.

METHODS

From January 1997 to June 1998, 91 premature infants (gestational age 28.8 +/- 2.5 weeks, birth weight 1169 +/- 385 g) born in Chung Gung Children's Hospital requiring mechanical ventilation in the first 72 hours were enrolled in our study. Ophthalmic examination was performed initially at 4-6 weeks of age and then every week if ROP was found and every other week if the result was normal until discharge. These infants were divided into 2 groups: those with and without ROP. Medical records of the highest and lowest blood gas measurements were recorded during the first 3 days of life. To screen for possible risk factors related to the development of ROP within these 2 groups, variables comprising perinatal data were compared.

RESULTS

The perinatal factors were compared, whish showed that infants with ROP had a lower mean gestational age (p < 0.001), mean birth body weight (p < 0.001), and a longer duration under mechanical ventilation (p < 0.001). The severity and incidence of ROP were not affected by either hypercapnia or hypocapnia; even with the superimposed effect of hyperoxia, the effect was minimal.

CONCLUSION

Hypercarbia or hypocarbia in the first 3 days of mechanically ventilated preterm neonates does not affect the subsequent development of retinopathy of prematurity. However, a lower gestational age and birth weight as well as longer-duration mechanical ventilation might be independent predictors for the occurrence of ROP. The role of PaCO2 in the pathophysiology of retinopathy of prematurity remains undetermined, and further investigation in the future is warranted.

Gliotoxic action of glutamate on cultured astrocytes

Because of the well-documented importance of glutamate clearance by astrocytes in protecting neurons against excitotoxicity, it was interesting to examine whether L-glutamate exerts a toxic action on cultured astrocytes. Cell damage was evaluated by measuring activity of lactate dehydrogenase (LDH) released into the culture medium. Exposure of astrocyte cultures of the neonatal rat cerebral cortex to L-glutamate resulted in a concentration- and time-dependent increase in the release of LDH. L-Glutamate-induced gliotoxicity appeared to be mediated predominantly by the increase of oxidative stress because the reduced glutathione content and its effects were almost completely blocked by vitamin E and pyrrolidinedithiocarbamate. To support this notion further, the supplementation or depletion of intracellular reduced glutathione content attenuated or worsened L-glutamate toxicity, respectively. Activation of the glutamate transporter mimicked the action of L-glutamate on astrocytes. In addition, degrees of cell damage were not directly correlated to the levels of glutamate uptake. Moreover, the mechanism of this toxicity required energy and macromolecular synthesis. Taken together, brief exposure to L-glutamate resulted in glutamate uptake and cell swelling, whereas sustained exposure injured astrocytes via oxidative stress instead of the excitatory mechanism.

Non-infectious epiglottitis in children: two cases report

Two young children who suffered from thermal injuries to the epiglottis after swallowing corrosive agent and hot water respectively. Findings, clinically and radiologically, in both children were similar to acute infectious epiglottitis. Both recovered quickly with close observation and parenteral antibiotics. Although Haemophilus influenzae type b (Hib) is the major pathogen of epiglottitis, in areas with low incidence of Hib infection and high vaccination rates, non-infectious epiglottic swelling should be considered first.

Results of intraoperative mitomycin C application in dacryocystorhinostomy

AIMS

To evaluate the long term results of intraoperative mitomycin C application in dacryocystorhinostomy (DCR) surgery compared with results of the conventional procedure.

METHODS

In this prospective randomised controlled study, a total of 88 eyes diagnosed with acquired nasolacrimal duct obstruction were randomly divided into a conventional DCR group and a mitomycin C group in which mitomycin C was used during DCR surgery. The surgical procedures in both groups were exactly the same, except that in the patients in the mitomycin C group, a piece of neurosurgical cottonoid soaked with 0.2 mg/ml mitomycin C was applied to the osteotomy site for 30 minutes. The results of the DCR surgeries were evaluated by objective findings such as irrigation and the height of tear meniscus and subjective symptoms by asking patients the condition of tearing improvement.

RESULTS

Among the 44 eyes in the mitomycin C group, 95.5% of patients remained totally symptom free after 10 months of follow up; while in the conventional group, 70.5% of patients were reported to be symptom free and 18% of patients to have an improvement in their symptoms. There was a significant difference between these two groups. As far as objective findings were concerned, there were 41 eyes in the mitomycin C group classified as having a normal and one eye with moderate tear meniscus level, compared with 32 eyes and seven eyes, respectively, in the conventional group. There was also a significant difference between these two groups. The non-patency rate in the mitomycin C group is 4.5% compared with 11.4% in the conventional group. There were no complications such as abnormal nasal bleeding, mucosal necrosis, or infection except one patient with delayed wound healing.

CONCLUSIONS

Intraoperative mitomycin C application is effective in increasing the success rate of DCR surgery in standard nasolacrimal duct obstruction, and no significant complications resulted from its use.

Late-gestation tracheal occlusion in the fetal lamb causes rapid lung growth with type II cell preservation

BACKGROUND

Fetal tracheal occlusion (TO) results in varying degrees of lung growth. This study examines whether gestational age influences lung growth response following TO.

MATERIALS AND METHODS

Fetal lambs (term = 145 days) underwent TO early (108 days, n = 6) or late (122 days, n = 6) in gestation. Aspirated lung fluid volume (LFV) and intratracheal pressure (ITP) were recorded daily. Two weeks after TO, the fetuses were sacrificed. Lung growth was assessed by lung weight and stereologic volumetry. Type II cellular density was assessed by computer-assisted morphometry using antisurfactant protein B antibody.

RESULTS

After early TO, ITP remained below 2 mm Hg for all but one of the first 5 days. In late TO, ITP rose to 4.8 +/- 1.7 mm Hg by Day 1 and remained elevated. LFV remained lower after early than after late TO (P < 0.05) for 8 days. Thereafter, pressure and volume reached similar levels in both TO groups; both were significantly higher than their respective controls (P < 0.05). Parenchymal fraction (1 - air-space fraction) was significantly smaller after late TO (22.8 +/- 1.2%) than after early TO (31.3 +/- 0.5%). Type II density was 38.0 +/- 12.4 x 10(6)/mL after early TO and 84.0 +/- 24.3 x 10(6)/mL in control (P < 0.05); the difference between late TO and control was not significant.

CONCLUSIONS

Late tracheal occlusion in fetal lambs caused more rapid lung growth than earlier TO, although ultimate lung size was similar in both groups. Late TO also resulted in greater air-space fraction and better preservation of the type II cell population than early TO. Late-gestation tracheal occlusion may therefore be preferable to prolonged occlusion initiated earlier.

Astrocytic alteration induced by Japanese encephalitis virus infection

The neurotropism of Japanese encephalitis virus (EV) has not been well characterized. Astrocytes are parts of the blood-brain barrier, a major source of chemokines, and critical effectors of central inflammation. Thus, astrocytes might play some role as JEV travels from the peripheral to the CNS and/or the resultant encephalitis. Using rat cortical cultures, we found that JEV can cause cellular and/or functional changes in astrocytes as indicated by increased expression of interleukin-6 (IL-6), regulated by activation, normal T cell expressed and secreted (RANTES), and monocyte chemotactic protein 1 (MCP-1), increased lactate release and glucose uptake, and attenuation of glutamate toxicity. These modulations occur needed by the cells for compensation and may affect neuron and/or astrocyte function.

Effects of naloxone on lactate, pyruvate metabolism and antioxidant enzyme activity in rat cerebral ischemia/reperfusion

Whether naloxone may modulate energy metabolism and endogenous antioxidant enzyme activities in ischemic cortex was studied. Cerebral ischemia/reperfusion (I/R) was produced by occluding two common carotid arteries and the right middle cerebral artery for 90 min followed by reperfusion in anesthetized Sprague-Dawley rats. Both pre-treatment (0.03 or 0.3 mg) and post-treatment (0.3 mg) of naloxone by intracerebroventricular infusion significantly reduced cortical infarct volumes. Pre-treatment with 0.03 mg reduced ischemia-induced suppression of extracellular pyruvate level and enhancement of lactate/pyruvate ratio as well as cerebral I/R-induced increases of endogenous catalase, glutathione peroxidase, and manganese superoxide dismutase activities. In conclusion, neuroprotective effects of naloxone in terms of reducing brain infarction involve attenuation of the disturbance of cellular functions following cerebral I/R via restoration of mitochondrial activities or energy metabolism.

Safety and ocular hypotensive efficacy of a single dose of metoclopramide or droperidol in healthy subjects

The purpose of this study was to evaluate the IOP lowering effect of two topical dopamine antagonists, metoclopramide or droperidol, in healthy subjects. Forty healthy volunteers were randomly assigned to receive, in double-masked fashion, topical administration of a single drop of 0.5% metoclopramide or 0.25% droperidol, with the fellow eye receiving isotonic saline as placebo. IOP was measured before and 1, 3, 5, and 7 hours after instillation of drugs. Ocular irritation and conjunctival congestion were also recorded at the time of each measurement. In the metoclopramide group, the maximal mean percentage change in IOP was -14.4% in tested eyes as compared with -10.8% in placebo-treated eyes 3 hours after instillation. All the changes were not significantly different between the metoclopramide-treated and the placebo-treated eyes at all time points. In the droperidol group, the maximal mean percentage change in IOP was -19.6% in tested eyes as compared with -17.7% in placebo-treated eyes at 3 hours after instillation. There was also no significant difference between the droperidol-treated and the placebo-treated eyes. None of the volunteers reported ocular irritation or conjunctival congestion after instillation of the drugs. In conclusion, while topical droperidol or metoclopramide tended to lower IOP in healthy subjects, the decrease in IOP did not differ significantly from that in placebo-treated eyes. Both drugs appear to be safe. Further studies with larger numbers of subjects at higher doses in glaucomatous subjects are needed before definite conclusions on drug efficacy can be drawn.

Oncocytic adenomatous hyperplasia of the lacrimal sac: a case report and review of the literature

Oncocytic tumors of the lacrimal sac are very rare, with only 21 cases documented in the world literature. The authors report a 75-year-old woman who sought treatment for recurrent dacryocystitis and a palpable mass in the left medial canthal area. The patient underwent surgery for removal of a suspected lacrimal sac cancer, but pathologic findings indicated benign oncocytic adenomatous hyperplasia. Complete removal of the tumor and long-term follow-up are necessary in patients with lacrimal sac oncocytic lesions. The authors discuss the characteristic features of ocular adnexal oncocytic lesions and review the literature.

The impact of a clinical pathway for transurethral resection of the prostate on costs and clinical outcomes

The purpose of this study was to evaluate the effects of implementing a clinical pathway for transurethral resection of the prostate on hospital costs and procedures, outcomes, and complications. Consecutive patients who underwent transurethral resection of the prostate for benign prostate hyperplasia in our hospital before (February-August 1996) and after (October 1996-March 1997) implementation of the clinical pathway were included. Statistical analyses included Student's t-test to test the impact of the clinical pathway on resource consumption and medical care processes, and multiple linear regression to control for patient characteristics such as age, severity of disease, and comorbidity. The major findings of this study were that implementation of the clinical pathway 1) decreased resource consumption and controlled medical care expenditure; 2) influenced physicians' patterns of practice and decreased the number of procedures performed; and 3) did not affect clinical outcomes or complication rates. In conclusion, our results support the hypothesis that the clinical pathway is an effective medical management tool to contain costs, which does not adversely affect quality of care. We suggest health policy makers promote clinical pathways in more hospitals to encourage appropriate resource consumption.

[A clinical and pathologic analysis of 13 cases of adult respiratory distress syndrome]

The autopsy findings and clinical features of 13 cases of adult respiratory distress syndrome (ARDS) were analysed. The underlying causes consisted of malignant tumor of the hematopoietic tissue, severe infections, surgical wounds and water drowning. Although tachypnoea and dyspnoea are the chief symptoms of ARDS., we noticed, however, that at the beginning of the episode or when complicated by other factors (such as fracture of cervical vertebra with transverse paralysis), the pulmonary symptoms may be not very obvious. Histological examination showed hyperplasia and fibrosis of the alveolar epithelium in those cases with a course of more than 5 days. Such findings rendered classification of ARDS into acute and chronic types reasonable.

Wikstroemia indica promotes development of nasopharyngeal carcinoma in rats initiated by dinitrosopiperazine

Nasopharyngeal carcinoma was induced in an initiation/promotion model in rats by s.c. injection of dinitrosopiperazine in the nasopharyngeal cavity. This was followed by repeated 10-cal administration of an extract of roots of the Chinese medicinal herb WI (botanical family: Thymelaeaceae). Three groups of rats were used: group-1 received DNP followed by repeated WI; group-2 received DNP once; group-3 received WI repeatedly. At 180-205 days after DNP + WI administration 26% of the rats in that group exhibited NPC (two were carcinomas in situ and four were early infiltrating carcinomas). In the other two groups no carcinomas were found. In the group which received DNP followed by WI, other pathological changes, such as hyperplasia of nasopharyngeal epithelium, squamous metaplasia, and papillary hyperplasia, were also more frequent than that in the other two groups.