[Clinical analysis of interventional embolization for 9 cases with frontal arteriovenous malformation]

PURPOSE

To investigate the efficacy and safety of interventional embolization in the treatment of frontal arteriovenous malformation (AVM).

METHODS

A retrospective study was used to analyze 9 patients with frontal AVM who were treated in Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine. The patients were treated with interventional embolization under the guidance of DSA. The scope of lesions was observed through DSA, and the injection dose of sclerosing agent was predicted so that the drug could be injected into the lesion cavity. The efficacy, adverse reactions and complications of all patients were observed and analyzed.

RESULTS

Among the 9 patients, there were 7 males(77.8%) and 2 females(22.2%), aged from 1.5-20 years old. Local swelling or mass was the main reported symptom(66.7%). The blood supply arteries of the cases involved in this study included superficial temporal artery and ophthalmic artery. All patients received interventional embolization treatment under general anesthesia, a total of 19 times (each patient received 1-6 times, average 2.1 times/person), and the average single dose of absolute ethanol was 9.0 mL. A total of 80 coils (4.2 coils/time on average) were used for 5 times (80 coils/19 times) with absolute ethanol embolization. In addition, bleomycin was used 3 times, pingyangmycin was used 2 times, and 3% polydocanol was used 1 time to assist embolization. Among the 9 cases included in this study, 4 cases were cured, 3 cases were basically cured, 2 cases were improved, and the effective rate of treatment was 100%. No local or systemic complications were reported in all patients.

CONCLUSIONS

In the treatment of frontal arteriovenous malformation, correct diagnosis according to clinical and imaging manifestations, and interventional embolization with anhydrous ethanol according to DSA angiography results can reduce trauma, improve symptoms, control lesions, and obtain relatively satisfactory treatment results. This scheme is safe and effective.

Ethanol Embolization of Chest Wall Arteriovenous Malformations: Four-Year Findings

OBJECTIVES

To summarize the clinical characteristics and investigate the efficacy of ethanol embolotherapy in the treatment of chest well arteriovenous malformation (AVM). Treatment-associated complications were also explored.

MATERIALS AND METHODS

Between March 2017 and August 2021, 32 consecutive patients (mean age, 23.7 years; age range, 5-54 years) who underwent ethanol embolotherapy for chest well AVMs under general anesthesia were included in this study. Embolization was performed through a direct puncture, transarterial catheterization, or a combination of the 2 procedures. The mean follow-up duration after the last treatment was 18.0 months (range, 3-42 months). The degree of devascularization on follow-up (assessed using angiography or computed tomography), and the clinical signs and symptoms of AVMs were evaluated as the therapeutic outcomes. The major and minor complications associated with the procedures were recorded.

RESULTS

A total of 103 embolization procedures (mean, 3.2; range, 2-7) comprising 101 ethanol embolization and 2 coil embolizations were performed on 32 patients with chest wall AVMs. The AVM nidus was accessed through the transarterial approach alone in 4 patients, by direct puncture in 11, and a combined procedure in 17 patients. Overall, more than 80% of the procedures were performed using the combined approach. Complete AVM devascularization was achieved in 12 (37.5%) patients. Moreover, 76% to 99% AVM was achieved in 18 patients (56.3%), and 50% to 75% in 2 patients (6.3%). Bleeding, pain, heart failure, and cosmetic deformities were the indications for treatment. For 3 patients (3/32, 9.4%) who had bleeding, the treatment stopped the hemorrhage. Complete pain relief was reported in 8 patients (8/32, 25.0%), whereas complete relief from congestive heart failure post-embolization was observed in 5 of the 6 patients with congestive heart failure (5/6, 83.3%). Complete correction of cosmesis deformities after embolization was achieved in 10 patients (10/32, 31.3%). Two patients who underwent surgery to correct persistent deformity after embolization only showed insignificant improvement. In addition, 6 (18.8%) patients developed 13 complications including blister, necrosis, hemothorax, transient hemoglobinuria, and transient pulmonary artery hypertension.

CONCLUSIONS

Ethanol embolotherapy is a safe and effective procedure for chest well AVMs. Surgery is required for some patients with residual cosmesis deformity.

CLINICAL IMPACT

Currently, there is no standard treatment for chest well AVMs due to their rarity and high heterogeneity. The present study shows that thanol embolotherapy is a safe and clinically effective treatment procedure for the chest well AVMs. Transarterial embolization in combination with direct puncture embolization can reach the AVM nidus. Ethanol embolotherapy can achieve complete obliteration of the AVM nidus in the majority of patients. Surgery may still be needed to correct cosmetic deformity after embolization. The present study provides valuable evidence to inform clinical decision-making.

Ethanol Embolization of Nasal Arteriovenous Malformations: A 10-Year, Single-Institution Experience

PURPOSE

To summarize a 10-year, single-institution experience with ethanol embolization of nasal arteriovenous malformations (NAVMs) in 52 patients.

PATIENTS AND METHODS

The present work was a retrospective study of 52 patients (aged between 1 and 67 years) with NAVMs who were treated with ethanol embolization between August 2009 and August 2019. The diagnosis of NAVMs was established based on clinical and imaging studies including ultrasound, computer tomography angiography, and digital subtract angiography. Embolization techniques used in the current study included transarterial, direct puncture, and a combination of both. The clinical and angiographic features, treatment methods, clinical outcomes, and complications were assessed within the mean period of 55.2 months (range, 1-119 months) after the last embolization.

RESULTS

The total number of embolization sessions (140 embolization procedures in 52 pts) included transarterial approach (1 pt), direct puncture (2 pt), and a combination of transarterial and direct puncture (49 pts). There was a positive correlation between nidus size and treatment sessions (r = 0.780, P = 0.0005) and the amount of ethanol injected (r = 0.840, P = 0.0004). Results of the current study showed that the therapeutic outcomes were complete response in two patients (3.8%) without recurrence throughout the follow-up period (range, 1-119 months; mean, 55.2 months), and partial response in 50 patients (96.2%). A total of seven patients (13.5%) experienced one or more complications, including skin necrosis in one patient (1.9%), transient hemoglobinuria in five patients (9.6%), and skin blister in five patients (9.6%).

CONCLUSION

The reported single-institution experience evidently indicated that ethanol embolotherapy has the potential to successfully devascularize NAVMs and also significantly improve symptoms and signs. Further, it was evident that the use of a combination of transarterial and direct puncture techniques has the potential to increase the rate of therapeutic response in patients with NAVMs.

[A prospective cohort study on BMI levels and risk of acute pancreatitis]

Objective: To investigate the effects of body mass index (BMI) levels at different baseline on the risk of new-onset acute pancreatitis (AP). Methods: The subjects were from the Kailuan Study Cohort and divided into 3 groups according to baseline BMI levels: BMI<24 kg/m², normal weight; BMI 24-28 kg/m², overweight; BMI≥28 kg/m², obesity. The incidence of new-onset AP in these three groups was analyzed. The survival curve was plotted by Kaplan-Meier method, the cumulative incidence was calculated and tested by log-rank method. Multivariate Cox proportional hazards regression model was used to calculate HR of baseline BMI levels for AP. Results: A total of 123 841 subjects were included and followed up for (11.94±2.13) years, during which, 395 cases were found with AP. The incidence of AP was 2.67 per 10 000 person years in total population, and the incidences of AP were 2.20, 2.72 and 3.58 per 10 000 person-years in the normal, overweight and obesity groups, respectively. The cumulative incidences of AP was 0.32%, 0.40% and 0.49% in normal, overweight and obesity groups, respectively, which showed a significant inter-group difference by log-rank test (χ ²=13.17,P<0.01). The results of multivariable adjusted Cox proportional hazards regression model analysis indicated that obesity group (HR=1.45, 95%CI: 1.10-1.92) had a higher risk for AP compared with the normal BMI group. The subgroup analyses by age and sex showed that compared with the normal weight group,the HRs for AP in the obesity group was 1.58(95%CI:1.14-2.19) and 1.40(95%CI:1.03-1.90) among subjects younger than 60 years old and male subjects, respectively. After excluded onset AP within two years from baseline,with a control group from normal weight,the results of multivariate Cox proportional hazards regression model analysis indicated that the AP in the obesity group was 1.60 (95%CI: 1.18-2.15). Conclusion: Obesity may increase the risk of developing AP, particularly among young and middle-aged men.

Absolute Ethanol Embolization of Lip Arteriovenous Malformations: Observational Results from 10 Years of Experience

PURPOSE

To evaluate the safety and efficacy of ethanol embolization of lip arteriovenous malformations (AVMs).

MATERIALS AND METHODS

Seventy-six patients with lip AVMs were treated with 173 ethanol embolization procedures. Lip AVMs were treated with direct puncture alone in 21 patients (35 procedures, 20.2%), transarterial embolization alone in 13 patients (18 procedures, 10.4 %), and a combination of both in 60 patients (120 procedures, 69.3%). Adjunctive surgical resection was performed after embolization for cosmetic purposes based on the patient's request, including patient preference, functional impairment, and skin necrosis. The mean duration of follow-up was 30.9 months ± 27.6. The follow-up included clinic visits and telephonic questionnaires to evaluate the clinical signs and symptoms of AVMs as well as quality of life measures.

RESULTS

Of 76 patients, 51 showed 100% devascularization of AVMs, as determined using arteriography, followed by 23 with 76%-99% devascularization and 2 with 50%-75% devascularization. Of the 76 patients, 40 achieved complete symptom relief and 25 achieved major improvements in cosmetic deformity after embolization. Additionally, 54 patients achieved satisfactory function and aesthetic improvement with ethanol embolotherapy alone, whereas 22 achieved similar outcomes with a combination of ethanol embolotherapy and surgical intervention. Thirty-three adverse events (including 1 major) were documented.

CONCLUSIONS

Ethanol embolization of lip AVMs, as a mainstay, is efficacious in managing these lesions, with acceptable complications. Surgical resection after embolization may improve function and cosmesis in a subset of patients.

Effect of combined low-dose oral prednisone with beta-adrenergic receptor antagonists for refractory infantile hemangiomas: retrospective cohort study in 76 patients

Background

Beta-adrenergic receptor antagonists have been the first-line treatment for infantile hemangiomas (IHs); however, monotherapy may fail to achieve sufficient efficacy for certain patients, especially for refractory IHs. The aim of this study was to evaluate the efficacy and safety of the combination of prednisone and beta-adrenergic receptor antagonists for refractory IHs.

Methods

We studied 76 patients with refractory IHs. After more than one month of insufficient oral propranolol therapy, forty-four patients received additional treatment of prednisone, while thirty-two patients continued to receive beta-adrenergic receptor antagonists monotherapy. The response to treatment was assessed according to hemangioma score values.

Results

The outcomes of patients after combined treatment were significantly better than those with monotherapy of beta-adrenergic receptor antagonists. The age to initiate prednisone was significantly negatively correlated with the improvement in the combination treatment group. The age at initiate treatment showed significant correlation with score variation percentage in both groups. There was no significant difference in the treatment duration observed between the two groups. Multivariable logistic regression analysis for all patients showed prednisone administration was the most important factor to better overall outcomes.

Conclusions

Short-term addition of low-dose oral prednisone is an effective and safe adjunctive treatment for oral propranolol in contributing to refractory IH. Both early administration and long enough duration would be necessary.

Intraosseous Arteriovenous Malformations in the Extremities Managed with Coils and Absolute Ethanol Treatment

BACKGROUND

The extremity intraosseous arteriovenous malformations (AVMs) are rare high flow vascular lesions for which the treatment remains challenging. The aim of the study wasto assess treatment methods, interim results, and complications of coils and absolute ethanol in managing extremity intraosseous AVMs via direct puncture approach.

METHODS

From 2009 to 2017, 12 patients (mean age, 27.5 years; range, 3-54 years) with extremity intraosseous AVMs underwent staged coils and absolute ethanol treatment via the direct puncture approach. All patients were symptomatic before the procedure as per the Schobinger staging system. The mechanical detachable coils and undetachable coils were used first followed by the injection of absolute ethanol used as a sclerosant agent via a direct puncture approach. Follow-up evaluation (6 to 72 months; mean, 23.5 months), including imaging and symptoms and signs, was performed in all patients.

RESULTS

Twenty-seven absolute alcohol procedures were performed for patients with intravascular sclerosis (range: 1-3, mean: 2) with one procedure required per patient (n = 2), 2 per patient (n = 5), or 3 per patient (n = 5). The average stretched length of the total coils per patient was 843.33 cm. The amount of absolute ethanol used ranged from 10 mL to 45 mL (mean, 25.69 mL) in a single session. Nine of twelve patients (75%) exhibited complete responses, and 3 patients (25%) exhibited partial responses. One patient experienced minor complication of transient motor nerve injury and completely recovered half a month later. No major complications occurred.

CONCLUSIONS

The study provides strong evidence, suggesting that direct puncture and coils with absolute ethanol approach is an effective and safe treatment in patients with extremity intraosseous AVMs, yielding minor complications and good results.

An effective experimental method and apparatus for unsteady water vapor condensation investigation in high speed expansion flow

This paper presents an effective experimental method and system for mechanism study of unsteady water vapor condensation encountered in high speed expansion flow. We proposed an experimental method and designed a simplified expansion system to fulfill the study. Tunable diode laser absorption spectroscopy (TDLAS) and light sheet technique are integrated in the system to monitor the unsteady condensation process in a high speed expansion flow generated by the expansion system. Two near infrared water vapor absorption transitions (1395.0 nm and 1409.27 nm) and one near infrared methane absorption transition (1653.73 nm) are applied in the TDLAS measurement to measure the transient flow parameters during the condensation process. Using the experimental method, time dependent condensation processes are monitored with different expansion time scales. The light sheet results visually reveal the condensation phenomena during the expansion process, while TDLAS results quantitatively follow the condensation process. The experimental results are compared with computational fluid dynamics simulations and a good agreement between them is observed, which indicates that the presented experimental method and system is effective in investigating unsteady water vapor condensation in high speed expansion flow.

Local suture ligation-assisted percutaneous sclerotherapy for Kasabach-Merritt phenomenon-associated kaposiform haemangioendothelioma

Kaposiform haemangioendotheliomas (KHEs) complicated by the Kasabach-Merritt phenomenon (KMP) are rare and severe neoplastic lesions often associated with locally aggressive disease, consumption coagulopathy and high mortality rates. Current regimens have yet to achieve a satisfactory therapeutic effect. Thus, an effective and minimally invasive approach for treating complex KHE/KMP cases is necessary for clinical management. The present case series describes patients with KHE/KMP who underwent local suture ligation-assisted percutaneous sclerotherapy to minimise surgical trauma and ensure effective treatment. Between September 2015 and September 2017, 3 consecutive patients with KHE/KMP underwent staged local suture ligation-assisted percutaneous sclerotherapy. Of these patients, 2 presented with medical histories of corticosteroid treatment with unsatisfactory outcomes. The patients underwent a stepwise synthetic serial therapy programme consisting of percutaneous sclerotherapy and adjunctive pharmacotherapy accompanied by a suture ligation procedure. Clinical, radiological, pathological and laboratory data were analysed to evaluate the outcomes of the therapy. All patients were successfully managed with the proposed procedure. Significant relief of clinical symptoms and improvements in haematological indicators were achieved. No recurrence or complications were observed during regular follow-up (4, 19 and 28 months). In conclusion, local suture ligation-assisted percutaneous sclerotherapy was demonstrated to be a safe and effective treatment for KHE/KMP, being minimally invasive, involving simple manipulation and providing a clear treatment benefit in certain cases. Further studies involving larger sample sizes are required to thoroughly evaluate the procedure, which can potentially be used as a novel therapeutic option for KHE/KMP treatment.

A Novel Anisotropic Hydrogel with Integrated Self-Deformation and Controllable Shape Memory Effect

Although shape memory polymers have been highlighted widely and developed rapidly, it is still a challenging task to realize complex temporary shapes automatically in practical applications. Herein, a novel shape memory hydrogel with the ability of self-deformation is presented. Through constructing an anisotropic poly(acrylic acid)-polyacrylamide (PAAc-PAAm) structure, the obtained hydrogel exhibits stable self-deformation behavior in response to pH stimulus, and the shapes that formed automatically can be fixed by the coordination between carboxylic groups and Fe³⁺ ; therefore, self-deformation and shape memory behaviors are integrated in one system. Moreover, the magnitude of auto-deformation and shape memory could be adjusted with the concentration of corresponding ions, leading to programmable shape memory and shape recovery processes.

Occurrence and Genetic Diversity of Grapevine berry inner necrosis virus from Grapevines in China

To investigate the prevalence and genetic diversity of Grapevine berry inner necrosis virus (GINV) in China, 195 grapevine samples from 15 Chinese provinces and regions were tested using reverse-transcription polymerase chain reaction. The samples included symptomatic and asymptomatic cultivars, with 35.9% (70 of 195) of samples testing positive for GINV. Seventeen samples had obvious ring spot symptoms, and 94.1% (16 of 17) tested positive for GINV, suggesting that GINV may be highly associated with the ring spot symptom. The genetic diversity of GINV isolates was analyzed based on the partial nucleotide and amino acid sequences of the coat protein (CP) and movement protein (MP) genes. Phylogenetic analyses of the MP and CP gene sequences divided the GINV isolates into three groups. The majority of the Chinese isolates were in groups 1 and 2, and only one Chinese isolate, along with a previously reported Japanese isolate, was in group 3. This is the first report on the genetic diversity of GINV isolates and their prevalence and distribution in China.

[Chinese expert consensus on the use of topical timolol maleate treatment of infantile hemangiomas]

Non-selective β-blocker propranolol has been proved by FDA as the first-line agent for infantile hemangioma (IH) with dramatic response. To reduce the side effects caused by systemic administration of propranolol, timolol maleate treatment has been increasingly used as an alternative to systemic β-blockers and watchful waiting for many IH patients in recent years. However, the appropriate indications, drug dosage, dosing regimen, time for initiation, optimal duration, monitoring for side effects still remains controversial. To standardize the use of topical timolol in treating IH, avoid overtreatment or under-treatment, as well as minimize complications, a Chinese expert consensus on the use of topical timolol treatment of IH has been approved and written by a multidisciplinary experts group based on an up-to-date literature review and repeated discussion, which can be used to reduce inappropriate variations in clinical practice and to promote the delivery of high quality, evidence-based health care for IH patients.

[Chinese experts consensus on the use of oral propranolol for treatment of infantile hemangiomas]

Infantile hemangioma (IH) is one of the most common benign vascular tumors in children. A variety of treatment methods have been documented for the management of IH over the past years, including pharmacotherapy via oral administration or injection of corticosteroids, vincristine, alpha interferon and bleomycin; laser therapy, radionuclide therapy, cryotherapy and excisional surgery. The therapeutic efficacy of each treatment modality is variable, while adverse effects or complications are common and sometimes serious. Since the serendipitous discovery of propranolol, a nonselective beta-adrenergic receptor blocker, being very efficacious in treating IH in 2008, oral propranolol has earned a role as a first-line medical therapy for complicated IH. However, the appropriate drug dosage, dosing regimen, time for initiation, optimal duration, monitoring for side effects remains controversial. To standardize the use of propranolol in treating IH, avoid overtreatment or under-treatment, as well as minimize complications, a Chinese experts consensus on the use of oral propranolol for treatment of IH has been approved and written by a multidisciplinary experts group based on an up-to-date literature review and repeated discussion.

Intralesional injection of pingyangmycin is a safe and effective treatment for microcystic lymphatic malformations in the tongue

Objective

To evaluate the efficacy and safety of intralesional injection of pingyangmycin for the treatment of microcystic lymphatic malformations (LMs) in the tongue.

Methods

Eighteen patients with tongue microcystic LMs were treated with intralesional injection of pingyangmycin. The concentration of the drug was 1 mg/mL with an addition of dexamethasone. Repeated injections were performed at an interval of 3–4 weeks. The results were evaluated by clinical examinations and Doppler ultrasonography scan. The follow-up period was 12 months to eight years after the last treatment and the mean follow-up time was three years. All patients received 1–8 injections (mean, 3.0 injections) for the whole course of treatment. The total dose of pingyangmycin administered was 8–64 mg (mean, 24 mg).

Results

Fifteen patients had complete response with no cosmetic or functional problems. Three patients with macroglossia had a reduction of 50–90% in the lesion size and needed secondary surgery. No serious complications were encountered.

Conclusion

The results suggested that intralesional injection of pingyangmycin is an effective and safe treatment for microcystic LMs in the tongue, and can be used as the first-line treatment protocol.

Anatomic relationship between impacted third mandibular molar and the mandibular canal as the risk factor of inferior alveolar nerve injury

Our aim was to explore the relation between the site of the mandibular canal and neurosensory impairment after extraction of impacted mandibular third molars. We organised a retrospective study of 537 extractions in 318 patients in which the affected tooth was intersected by the mandibular canal. This was verified by cone-beam computed tomography (CBCT), and we analysed the relation between the site of the canal and the likelihood of injury to the inferior alveolar nerve (IAN) after extraction of the third molar. The relation between the position of the root of the tooth and the mandibular canal was categorised into 4 groups: I=root above the canal; II=on the buccal side; III=on the lingual side; and IV=between the roots. The overall rate of neurosensory impairment after extraction was 6% (33/537). It occurred in 9/272 patients (3%) in group 1, 16/86 (19%) in group II, and in 8/172 (5%) in group III. There was no neurosensory impairment in group IV where the canal was between the roots. There were significant differences between group II and groups I and III (p<0.01), but not between groups I and III (p=0.32). The risk of damage to the inferior alveolar nerve is increased if third molars intersect with the mandibular canal, particularly on its buccal side.

Ethanol embolization of auricular arteriovenous malformations: preliminary results of 17 cases

BACKGROUND AND PURPOSE

Because of the relatively rare and extremely varied clinical presentations, arteriovenous malformations (AVMs) involving the auriculae are technically challenging clinical entities to diagnose and, ultimately, manage. The purpose of our study was to present our initial experience of ethanol embolization in a series of 17 patients with auricular AVMs and assess the interim therapeutic outcomes of this method.

MATERIALS AND METHODS

Our study group consisted of 17 patients. Transcatheter arterial embolization and/or direct percutaneous puncture embolization were performed. Pure or diluted ethanol was manually injected. Follow-up evaluation was obtained on the basis of physical examination and angiography at 3- to 4-month intervals and telephone questionnaire at 1-month intervals in all patients.

RESULTS

During the 29 ethanol embolization procedures, the amount of ethanol used ranged from 4 to 65 mL. The obliteration of ulceration, hemorrhage, pain, infection, pulsation, and bruit in most of the patients was obtained. The reduction of redness, swelling, and warmth was achieved in all of the patients, and 15 of the patients achieved downstaging of the Schobinger status. According to the angiographic findings, AVMs were devascularized 100% in 3 patients, 76% to 99% in 5 patients, 50% to 75% in 6 patients, and less than 50% in 3 patients. The most common complications were reversible necrosis and blister.

CONCLUSIONS

Ethanol embolization has proved efficacious and safe in the treatment of auricular AVMs and has the potential to be accepted as the primary mode of therapy in the management of these lesions.

Ethanol embolization of arteriovenous malformations of the mandible

BACKGROUND AND PURPOSE

Absolute ethanol was reported as an effective embolization of arteriovenous malformations (AVMs), but its use to treat AVMs in the mandible is not yet well established. Here, we present our clinical experience on treatment of mandibular AVMs with absolute ethanol.

MATERIALS AND METHODS

Eight consecutive patients with symptomatic AVMs of the mandible between August 2007 and September 2008 were enrolled in this study group. Among them, 6 patients underwent direct puncture embolization with absolute ethanol combined with coils, 1 patient underwent direct puncture embolization with absolute ethanol only, and the last patient had transarterial embolization with absolute ethanol alone. The use of coils decreased the flow and volume of the nidus, and then absolute ethanol embolization was directed against and obliterated the nidus completely. The procedure was performed with the patients under general anesthesia with nasal intubation, and the vital signs of the patients were constantly monitored during the injection of absolute ethanol. The total amount of absolute ethanol used per session was less than 1 mL/kg of body weight.

RESULTS

A total of 11 ethanol embolizations were performed on 8 patients, including 3 sessions with transarterial microcatheterization and 8 with direct puncture embolization. A venogram and control arteriogram performed immediately after the procedure were both obtained, which documented a significant thrombosis of the lesion in all patients. Follow-up examinations revealed that oral bleeding was controlled, the expansion of the external jugular vein in 5 cases was obliterated, and satisfactory shrinkage of the facial swelling was achieved. Follow-up angiography (mean, 4.2 months) was available in 4 patients, and there was no angiographic recurrence of the lesions. There were 3 cases with minor complications.

CONCLUSIONS

On the basis of our experience, treatment of AVMs in the mandible with absolute ethanol is a feasible, safe, and highly effective method.

[Non-involuting congenital hemangioma: a study for diagnosis and treatment]

OBJECTIVE

To study the history, clinical symptoms, imaging and histology of a rare distinct infantile hemangioma.

METHODS

12 patients (5 female, 7 male; aged 18 months - 26 years) diagnosed as non-involuting congenital hemangioma were retrospectively analyzed. The history, imaging, histologic examination and the treatment were collected.

RESULTS

Most of the patients had only one lesion which was round or ovoid, flat or plaque-like. The average size was about 5 cm x 6 cm. The overlying skin was usually had coarse telangiectasia with central or peripheral pallor. The skin has a high skin temperature. Magnetic resonance imaging, computed tomography angiography and digital subtraction angiography findings were similar to those of common infantile hemangioma. Histologic examination revealed lobular collections of small, thin-walled vessels with a large, often stellate, central vessel. "Hobnailed" endothelial cells lined along the intralobular vessels. Small arteries were observed "shunting" directly into lobular vessels or into abnormal extralobular veins. All lesions were easily excised without recurrence.

CONCLUSIONS

Non-involuting congenital hemangioma is a distinct infantile vascular tumor. It should be diagnose early and treated appropriately.

[Embolization of craniofacial arteriovenous malformations after the ligation of external carotid artery]

OBJECTIVE

To introduce the method of retrograde embolization through the superficial temporal artery (STA) after the ligation of external carotid artery (ECA) for the treatment of craniofacial arterio-venous malformations (AVM).

METHODS

Seven cases of craniofacial AVM were included in the study. After the ligation of ECA, the STA was surgically accessed and a 4F (1F = 0.333 mm) sheath introduced into the artery, and N-butyl-2-cyanoacrylate (NBCA) was selected as the permanent embolization material.

RESULTS

The angiogram was successfully carried out in these cases, which showed that some collateral branches from the ophthalmic artery of left internal carotid artery, vertebral artery and thyrocervical trunk provided the blood supply to the AVM nidus. The retrograde embolization with NBCA was completed.

CONCLUSIONS

The vascular architecture of craniofacial AVM after the ligated ECA was better demonstrated in angiogram of vertebral artery. The retrograde embolization through STA was an effective method for the treatment of craniofacial AVM.

[Surgical ligation and occlusion of the feeding artery should not be used in management of arteriovenous malformations (AVMs) of the craniofacial regions]

Arteriovenous malformations (AVMs) are congenital vascular anomalies, which seldom occur in the craniofacial regions. The rarity of these lesions compounds their extreme management difficulty. The clinical manifestation, vascular architecture, natural progress history and therapeutic strategy on AVMs in the craniofacial regions were reviewed in this paper. It is concluded that surgical ligation or occlusion of feeding arteries proves totally futile as the phenomenon of neovascular recruitment reconstituted arterial inflow to the AVM nidus. The procedure should be prohibited to do because of the ineffectiveness and hindering further endovascular treatment.

Carotid artery resection and reconstruction: clinical experience of 28 consecutive cases

The aim of this study was to analyse the experience at a single institution in carotid artery resection with or without reconstruction performed as part of an oncological procedure or emergency haemostasis. A total of 28 patients were included in this retrospective study; 17 underwent ligation or resection of the carotid artery, and 11 underwent reconstruction of the carotid artery. The perioperative complications and surgical outcomes were recorded and analysed. Of the 17 patients with ligation or resection of the carotid artery, 4 developed neurologic deficit within 2 weeks postoperatively. Three patients with malignant tumours died 1 month (1) and 4 months (2) postoperatively. Of the 11 patients undergoing carotid reconstruction, no major cerebral complications were noted after operation. Colour Doppler showed patent vascular graft 1 year postoperatively in nine patients. Due to the higher complication rates both in short and long term with ligation or resection of the carotid artery, resection and revascularization of the carotid artery is advocated for patients with carotid artery involvement when possible.

Plain Film Arthrography Applied to the Diagnosis of Intra-Articular Adhesions of the Temporomandibular Joint

PURPOSE

To evaluate the diagnostic accuracy of plain film arthrography (PFA) on the presence of intra-articular adhesions of the temporomandibular joint (TMJ).

PATIENTS AND METHODS

The study population included 105 consecutive patients (105 TMJs) and data collected in our department. All patients were examined by PFA and arthroscopy. The findings of interpreting PFA were recorded as positive, suspicious, or negative according to the PFA radiographic criteria. After comparing the findings of PFA with those of arthroscopy, the comparison data were assessed by generating receiver operating characteristic curve (ROC curve) and analyzing the area (A(z)) under the curves with SPSS 11.0 (SPSS, Inc, Chicago, IL), and the area under the ROC curve was calculated. According to the area, the diagnostic value of PFA was evaluated. Meanwhile, the causes of misdiagnosis and underdiagnosis of intra-articular adhesions were analyzed.

RESULTS

Arthroscopic surgery results confirmed that 56 TMJs in 105 patients had adhesions. The area under ROC curve was 0.73 (confidence interval, 0.64, 0.82; P < .05). The adhesions located in the medial groove could hardly be detected through PFA, while those located in the lateral two thirds of upper joint compartment could easily be detected.

CONCLUSION

Although the diagnostic accuracy of PFA was fair, it was a simple and effective modality to diagnose intra-articular adhesions of the TMJ. The causes of misdiagnosis and underdiagnosis were related to the size and location of the intra-articular adhesions.

Magnetic resonance arthrography applied to the diagnosis of intraarticular adhesions of the temporomandibular joint

The purpose of this study is to investigate the diagnostic accuracy of magnetic resonance arthrography (MRAr) on the diagnosis of intraarticular adhesions of the temporomandibular joint (TMJ). Twenty-four patients (31 joints) diagnosed as internal disorders of TMJ were examined to establish the presence, suspicion or absence of intraarticular adhesions through MRAr according to the MRAr radiographic criteria in a blind fashion, subsequent arthroscopy were performed on all 31 joints. The findings were compared to MRAr with those of arthroscopy. The comparison data were assessed by generating receiver operating characteristic curve (ROC curve) and analyzing the area (Az) under the curve with SPSS11.0 software. The area under the ROC curve was 0.91 (0.86, 0.95), P<0.05. MRAr proves to be an excellent modality to diagnose intraarticular adhesions of TMJ.

[Magnetic resonance arthrography for the diagnosis of intraarticular adhesions of TMJ adhesions]

PURPOSE

To evaluate the value of magnetic resonance arthrography (MRAr) on the diagnosis of intraarticular adhesions of the temporomandibular joint(TMJ).

METHODS

30 consecutive patients (31 TMJs) diagnosed as internal derangement of TMJ were examined by MRAr and arthroscopy. The findings of interpreting MRAr were recorded as positive, suspicious and negative according to the MRAr radiographic criteria. After comparing the findings of MRAr with those of arthroscopy, the numbers of true positive, true negative,false positive and false negative were obtained. Through SPSS11.0, receiver operator characteristic curve(ROC curve) was made, and the area under the ROC curve was calculated. According to the area, the diagnostic accuracy of MRAr was evaluated.

RESULTS

Surgery results confirmed that 22 TMJs in 31 TMJs had adhesions. According to the above criteria, we found 20 TMJs were positive, 3 TMJs were suspicious, and 8 TMJs were negative. After comparing the findings of MRI with those of arthroscopy, true positive in 19 TMJs and false positive in 1 TMJs were detected among 20 positive TMJs, adhesion in 2 TMJs and no adhesion in 1 TMJs were detected among 3 suspicious TMJs, and true negative in 7 TMJs and false negative in 1 TMJs were detected among 8 negative TMJs. The area under ROC curve was 0.91(0.86,0.95), P<0.05.

CONCLUSION

It is concluded that: (1)The diagnostic accuracy of MRAr is excellent, much better than that of PFA and MRI. (2) MRAr is an ideal method to diagnose intraarticular adhesions of TMJ.

[The DSA features of AVM of jaws]

OBJECTIVE

To evaluate the vascular architecture of AVM of jaws on DSA.

METHODS

12 cases of AVM of jaws comprised this study group, and 5 cases in maxilla and 7 cases in mandible, respectively. Seldinger technique was applied to carry out carotid angiography under the guidance of DSA machine (PHILIPS V3000).

RESULTS

The DSA features of AVM of jaws included varix into the posterior area of jaws. The varix of the maxilla was supplied by the posterior superior alveolar artery and transversal facial artery when the soft tissue was involved, and the varix of the mandible was supplied by the inferior alveolar artery, maxillary and facial artery.

CONCLUSION

Angiography is considered necessary for the diagnosis and embolization of AVM of jaws, and the varix is the center of lesion.

[Embolization of AVM of jaws]

OBJECTIVE

To report our experience to embolize the AVM of jaws by direct percutaneous puncture. in conjunction with endovascular therapy.

METHODS

3 cases of AVM of mandible and 3 cases of AVM of maxilla comprised this study group. The patients were embolized with fibered coils, PVA and NBCA. The coils were placed directly into the center of the intraosseous lesion. The procedure was under the guidance of DSA machine (PHILIPS V3000).

RESULTS

The acute arterial bleeding in 4 patients was controllable. The other two cases with oozing bleeding and a warm soft mass on the left face with a palpable pulse respectively, their symptoms and signs got improved a lot. The pericoronal oozing of blood in all patients disappeared during a 3 to 24 months follow-up and new bone formation was found in the follow-up radiography.

CONCLUSION

The embolization of the AVM of jaws by direct percutaneous puncture in conjunction with endovascular therapy is effective and safe, however the longer follow-up is expected.

[The diagnostic value of CT for arteriovenous malformations of jaws]

OBJECTIVE

To evaluate the diagnostic value of CT for arteriovenous malformations (AVM) of jaws.

METHODS

12 cases of central vascular malformations of jaws comprised this study group, 5 cases in maxilla and 7cases in mandible, respectively. The X-ray projection included panoramic radiography, Water's position and posterioanterior and lateral oblique view of mandible. The CT scans were obtained on Somatom ART and the axial and coronal scanning modalities were applied.

RESULTS

Radiographically different signs of the AVM of jaws were demonstrated, X plain film has no pathognomic features. The CT features included lytic expansion of bone, expanded space of marrow, obliteration of trabeculae and intact cortex of jaws. These signs were demonstrated very well in bone window setting. There were three forms of demonstrations of AVM of jaws as following: (1) local unilocular, (2) diffused unilocular, (3) multilocular.

CONCLUSION

CT is helpful for early diagnosis of AVM of jaws, and can provide the guidance for the direct puncture embolization.

[Embolization in arteriovenous malformations of maxillofacial region with PVA]

OBJECTIVE

To evaluate the embolization of arteriovenous malformations of the maxillofacial region with PVA.

METHODS

8 cases (male:3, female:5) of arteriovenous malformations of the maxillofacial region comprised this study group. The embolic material used was PVA (Polyvinyl Alcohol Foam) particles (250-500 microm) injected using 4.0 to 3.0 French-size catheters, catheterized selectively in the feeding pedicles of the AVM under the guidance of DSA machine (PHILIPS V3000).

RESULTS

Five patients were embolized an a single session, and three patients needed two sessions. Immediate angiographical results showed total disappearance of the AVMs in all patients. Swelling, pulsation, and bruit were disappeared after embolization. Pericoronal oozing of blood and acute arterial bleeding was controllable. Local pain, swelling,and low-grade fever usually lasted from 3 to 7 days after embolization.

CONCLUSION

The embolization of arteriovenous malformations of the maxillofacial region with PVA is effective and safe, and the longer follow-up is expected.

Substantia nigra pars reticulata lesion facilitates kainic acid-induced seizures

The administration of subconvulsive doses of kainic acid (5 mg/kg, intraperitoneally) to rats, with lesion of the substantia nigra pars reticulata (1 week), produced high frequency wet dog shakes and severe convulsive behavior (observed in 60% of the rats). The behavior was not observed in rats treated with kainic acid but without reticulata lesion. The results show that rats with unilateral lesion of the substantia nigra pars reticulata are more vulnerable to seizure stimuli.

Substantia nigra pars reticulata lesion induces preconvulsive behavior and changes in glutamate receptor gene expression in the rat brain

The substantia nigra pars reticulata (SNpr) has been proposed to play an important role in the control of the propagation and/or the generation of epileptic seizures. Earlier studies have shown differential effects of the lesion of the SNpr on seizure genesis that demonstrated a regional difference in the anterior and posterior parts of the SNpr in preconvulsive behavior induced by unilateral reticulata injection of dopamine (DA). This study was aimed to investigate some of the underlying mechanisms of the preconvulsive behavior elicited by unilateral SNpr DA injection by the study of changes in the gene expression of glutamate receptor subunits (GluR1, GluR2 and NMDAR1) and of changes in animal behavior following coinfusion of DA and a DA D1 antagonist SCH 23390 into the SNpr. Unilateral injection of exogenous DA into the anterior region of the SNpr induced rapid and short lasting preconvulsive behavior up to wet dog shakes stage and a significant reduction of gene expression for GluR1, GluR2 and NMDAR1 subunits in rat hippocampal subfields including CA1 through CA4 and dentate gyrus (DG) at 1 day after nigral DA injection. The effect was long lasting and persisted for at least 3 weeks. Both preconvulsive behavior and downregulation of glutamate receptor subunit genes were completely blocked by simultaneous coinfusion of DA and SCH 23390. The results suggest, for the first time, that DA D1 receptor in the SNpr may mediate the nigral-involved seizure development. Glutamate desensitization, and/or selective early neuronal damage might be responsible for the downregulation of glutamate receptor subunits by transient preconvulsive activity.

Lesion of the substantia nigra pars compacta downregulates striatal glutamate receptor subunit mRNA expression

This is a study of the effect of the unilateral administration of dopamine (DA) in the pars compacta of the substantia nigra (SN) of the rat on striatal glutamate receptor subunit (GluR1, GluR2 and NMDAR1) gene expression determined by in situ hybridization. The location of the nigral lesion was determined by tyrosine hydroxylase (TH) immunohistochemistry and its extent by the striatal DA and 3,4-dihydroxyphenylacetic acid (DOPAC) concentrations. The DA-induced lesions produce significant bilateral reductions in the expression of GluR1 and NMDAR1 subunit mRNA in the medio-lateral striatum, whereas the expression of striatal GluR2 receptors was not changed. The reduction in GluR1 and NMDAR1 subunit mRNA may be the consequence of glutamatergic hyperactivity developed in the presence of a damaged nigro-striatal system and these may be associated with the genesis of some neurodegenerative diseases.

[The Value of CT Scanning in the Diagnosis of Temporomandibular Joint Dysfunction]

OBJECTIVE:To evaluate the role of CT in the diagnosis of temporomandibular joint dysfunction MATERIAL: 48 temporomandibular joints of 26 patients suspecting osseous changes were examined by CT, with 1mm of layer thickness. All patients had Sch llers position projection as comparison. RESULTS:CT is more sensitive to detect the osseous changes of TMJ than Sch llers position projection, but not well demonstrating sclerosis of TMJ. The Sch llers position projection can only shows the lesion of lateral 1/3 of condyle, but CT including total condyle. CONCLUSION: CT is an important and sensitive tool in detecting osseous changes of temporomandibular joint.

[Clinical Application of CT assisted Double Contrast Arthrography of Temporomandibular Joint]

OBJECTIVE:To introduce double-contrast arthrography of TMJ with reformatted sagittal and coronal CT imaging and to evaluate the value of its application in the diagnosis of temporomandibular joint dysfunction. METHODS: 14 patients in whom diagnosis can not be established with conventional arthrography were examined by double contrast arthrography with reformatted sagittal and coronal CT imaging. RESULTS: In double-contrast arthrography with CT imaging, 1 case was normal;1 case had anterior displacement with reduction;2 cases were anterior displacement without reduction, and 8 cases were with disk adhesion. CONCLUSION:The double contrast arthrography with reformatted sagittal and coronal CT imaging was a very important alternative to conventional arthrography, and has special value to demonstrate adhesion of TMJ.

[A Comparative Study of MRI and CT Double-Contrast Arthrography in Diagnosis of Disc Adhesion of TMJ]

OBJECTIVE:To compare the results of CT-assisted double-contrast arthrography and MRI in the diagnosis of adhesion of TMJ. MATERIAL:18 patients with adhesion of TMJ were examined by CT-assisted double-contrast arthrography and MRI, and their results were analysed including position, degree and with or without osseous changes. RESULTS:18 cases of adhesion were demonstrated on CT-assisted double-contrast arthrography, and that only 6 cases of them were diagnosed on MRI.CONCLUSION: CT-assisted double-contrast arthrography is more sensitive and accurate than MRI in demonstrating the disk adhesion of TMJ.

Development of a CD28 receptor binding-based screen and identification of a biologically active inhibitor

CD28 is a T-cell costimulatory receptor which plays a pivotal role in antigen-induced T-cell response. We have developed a cell-free and scintillation-proximity assay-based screen to search for molecules that inhibit ligand binding to CD28. The assay was shown to be versatile and adaptable to automation for high-throughput screening. Using this assay, we identified an inhibitor of CD28, NP2214. The inhibitor was shown to be active in vitro by suppressing IL-2 synthesis and proliferation of peripheral blood mononuclear cells in response to CD28 costimulation. We also demonstrated the additive effects of NP2214 and cyclosporine A which act mechanistically distinctly in inhibiting costimulation-induced IL-2 synthesis.

Induction of preconvulsive behavior and Fos expression by dopamine-induced nigral lesion in the rat

The substantia nigra pars reticulata (SNpr) has been proposed to play an important role in controlling the propagation and/or the generation of limbic seizures. Earlier work has shown that SN lesions have differential effects on seizure activity, suggesting that at least two discrete topographical regions mediate anticonvulsant or proconvulsant effects. The present investigation showed that exogenous dopamine (DA; 1.5-2.0 mumol) unilaterally injected into the anterior SNpr induced preconvulsive behavior (starting, immobilization, facial and mouth movements and wet-dog shakes). In addition, these rats showed Fos oncoprotein expression in the limbic system. These effects were observed in 90% of the rats with anterior SNpr DA injection. Rats with posterior SNpr injection did not show preconvulsive behavior nor Fos expression. These results show for the first time that unilateral DA lesion of the anterior portion of SNpr elicits Fos expression and preconvulsive behavior. In addition, the results suggest that lesion of the anterior and posterior regions of SNpr appear to exert different influences in the generation of preconvulsive behavior. The time course of behavior changes and Fos expression was also studied.

[Function of lymphocyte beta-adrenergic receptor in depression]

Lymphocyte beta-adrenergic receptor function of 20 depressed patients and 18 healthy volunteers were measured using radioligand binding technique. It was found that the affinity and sensitivity of this receptor were significantly higher in endogenous depressed patients than those in normal controls. After the electro-acupuncture-treatment (EAT), lymphocyte beta-receptor function decreased in patients who responded well to EAT, but still not reached normal level.

A major T cell antigen of Mycobacterium leprae is a 10-kD heat-shock cognate protein

Several mycobacterial antigens, identified by monoclonal antibodies and patient sera, have been found to be homologous to stress or heat-shock proteins (hsp) defined in Escherichia coli and yeast. A major antigen recognized by most Mycobacterium leprae-reactive human T cell lines and cell wall-reactive T cell clones is a 10-kD protein that has now been cloned and sequenced. The predicted amino acid sequence of this protein is 44% homologous to the hsp 10 (GroES) of E. coli. The purified native and recombinant 10-kD protein was found to be a stronger stimulator of peripheral blood T cell proliferation than other native and recombinant M. leprae proteins tested. The degree of reactivity paralleled the response to intact M. leprae throughout the spectrum of leprosy. Limiting-dilution analysis of peripheral blood lymphocytes from a patient contact and a tuberculoid patient indicated that approximately one third of M. leprae-reactive T cell precursors responded to the 10-kD antigen. T cell lines derived from lepromin skin tests were strongly responsive to the 10-kD protein. T cell clones reactive to both the purified native and recombinant 10-kD antigens recognized M. leprae-specific epitopes as well as epitopes crossreactive with the cognate antigen of M. tuberculosis. Further, the purified hsp 10 elicited strong delayed-type hypersensitivity reactions in guinea pigs sensitized to M. leprae. The strong T cell responses against the M. leprae 10-kD protein suggest a role for this heat-shock cognate protein in the protective/resistant responses to infection.

Rhombohedral Twin Structure in Hematite (α-Fe2O3)

Electron optical imaging of the structure of haematite ( α-Fe2O3) in two projections has allowed the microscopic twinning elements of rhombohedral twins to be determined. A systematic analysis of alternative structural models, using computer-simulation and image-matching considerations, as well as crystallochemical arguments, is presented. The twin has a screw operation consisting of a pure rotation of 180� about [0111], the twinning direction, combined with a parallel translation of (1/22) [0111]. The twinning plane (0112) forms a coherent interface, consisting of face-and edge-shared octahedra , with no change in the normal nearest-neighbour coordination.

Lipoarabinomannan, a possible virulence factor involved in persistence of Mycobacterium tuberculosis within macrophages

Mycobacterium tuberculosis and Mycobacterium leprae, the causative agents of tuberculosis and leprosy, respectively, produce large quantities of lipoarabinomannan (LAM), a highly immunogenic, cell wall-associated glycolipid. This molecule has been previously reported to be a potent inhibitor of gamma interferon-mediated activation of murine macrophages. Studies of the mechanism by which this mycobacterial glycolipid down-regulates macrophage effector functions provide evidence that LAM acts at several levels and that it can (i) scavenge potentially cytotoxic oxygen free radicals, (ii) inhibit protein kinase C activity, and (iii) block the transcriptional activation of gamma interferon-inducible genes in human macrophage-like cell lines. These results suggest that LAM can inhibit macrophage activation and triggering and cytocidal activity and that it may represent a chemically defined virulence factor contributing to the persistence of mycobacteria within mononuclear phagocytes.

Divergent activities of protein kinases in IL-6-induced differentiation of a human B cell line

Lymphokines including IL-2, IL-4, and IL-6 are involved in the induction of Ig production by activated B cells. We have investigated the role of protein kinases in IL-6-induced IgM secretion by SKW6.4 cells, an IL-6 responsive B cell line. IL-6-stimulated IgM production was inhibited by elevated intracellular cAMP induced either by the addition of dibutyryl cAMP or cholera toxin. The inhibitory effect of elevated intracellular cAMP was blocked by n-(2-(Methylamino)ethyl)-5-isoquinolinesulfonic dihydrochloride (H8), an inhibitor of protein kinase A. H8 did not affect IgM secretion induced by IL-6. In contrast, the addition of 1-(5-isoquinolinesulfonyl)-2-methylpiperizine dihydrochloride (H7), an inhibitor of protein kinase C activity, markedly inhibited IL-6-stimulated IgM production by SKW6.4 cells. H7 and elevated intracellular cAMP inhibited IgM mRNA expression and subsequent IgM synthesis by SKW6.4 cells. SKW6.4 proliferation, as determined by [3H]thymidine incorporation, was not markedly affected by IL-6, dibutyryl cAMP, cholera toxin, H7 or H8. PMA, an activator of protein kinase C, directly stimulated significant IgM secretion by SKW6.4 cells. When added to PMA-stimulated SKW6.4 cells, IL-6 stimulated additional IgM production. This observation suggested that IL-6 could stimulate differentiation without activating protein kinase C. This was confirmed by demonstrating that IL-6 did not stimulate production of diacylglycerol, did not induce the translocation of protein kinase C from the cytosolic compartment to the plasma membrane and could induce SKW6.4 cells to produce IgM after depletion of their cellular protein kinase C by PMA. Taken together these results suggests that IL-6-stimulated IgM production requires utilization of an H7-inhibitable protein kinase that can be inhibited by a protein kinase A-dependent pathway. Despite the fact that PMA can stimulate IgM production in SKW6.4 cells, IL-6 appears to use a protein kinase pathway other than protein kinase C to induce IgM production.

Divergent activities of protein kinases in IL-6-induced differentiation of a human B cell line

Lymphokines including IL-2, IL-4, and IL-6 are involved in the induction of Ig production by activated B cells. We have investigated the role of protein kinases in IL-6-induced IgM secretion by SKW6.4 cells, an IL-6 responsive B cell line. IL-6-stimulated IgM production was inhibited by elevated intracellular cAMP induced either by the addition of dibutyryl cAMP or cholera toxin. The inhibitory effect of elevated intracellular cAMP was blocked by n-(2-(Methylamino)ethyl)-5-isoquinolinesulfonic dihydrochloride (H8), an inhibitor of protein kinase A. H8 did not affect IgM secretion induced by IL-6. In contrast, the addition of 1-(5-isoquinolinesulfonyl)-2-methylpiperizine dihydrochloride (H7), an inhibitor of protein kinase C activity, markedly inhibited IL-6-stimulated IgM production by SKW6.4 cells. H7 and elevated intracellular cAMP inhibited IgM mRNA expression and subsequent IgM synthesis by SKW6.4 cells. SKW6.4 proliferation, as determined by [3H]thymidine incorporation, was not markedly affected by IL-6, dibutyryl cAMP, cholera toxin, H7 or H8. PMA, an activator of protein kinase C, directly stimulated significant IgM secretion by SKW6.4 cells. When added to PMA-stimulated SKW6.4 cells, IL-6 stimulated additional IgM production. This observation suggested that IL-6 could stimulate differentiation without activating protein kinase C. This was confirmed by demonstrating that IL-6 did not stimulate production of diacylglycerol, did not induce the translocation of protein kinase C from the cytosolic compartment to the plasma membrane and could induce SKW6.4 cells to produce IgM after depletion of their cellular protein kinase C by PMA. Taken together these results suggests that IL-6-stimulated IgM production requires utilization of an H7-inhibitable protein kinase that can be inhibited by a protein kinase A-dependent pathway. Despite the fact that PMA can stimulate IgM production in SKW6.4 cells, IL-6 appears to use a protein kinase pathway other than protein kinase C to induce IgM production.

Molecular cloning of a gene selectively induced by gamma interferon from human macrophage cell line U937

A cDNA clone encoding a gamma interferon (IFN-gamma)-inducible mRNA in human cells of the macrophage lineage was isolated and characterized. The corresponding gene, gamma.1, was selectively induced by IFN-gamma, responding a hundredfold better to IFN-gamma than to IFN-alpha. The induction was rapid and transient, with maximal mRNA accumulation at about 3 h and decline to the basal level after 48 h. Transcriptional activation could be detected as early as 5 min after IFN-gamma stimulation and accounted entirely for the mRNA accumulation. The induction of gamma.1 by IFN-gamma was cell-type restricted, being seen only in macrophages and endothelial cells. In addition, phorbol ester-induced differentiation of promyelocytic HL-60 cells and promonocytic THP-1 cells rendered the gamma.1 gene inducible by IFN-gamma. The 1.0-kilobase gamma.1 cDNA sequence encoded a small predicted polypeptide of 38 amino acids and had a conserved sequence associated with rapidly turning over mRNAs. In vitro translation of the gamma.1 transcript yielded a 4,000-dalton polypeptide.

Interferon-gamma-induced transcriptional activation is mediated by protein kinase C

Interferon-gamma (IFN-gamma) regulates a variety of biological functions and is the principal lymphokine known to activate macrophages. In studies of the molecular mechanisms by which these cells are regulated by IFN-gamma, the transcriptional activation of an IFN-gamma-inducible gene, gamma.1, in human macrophage-like cell lines was examined. Transcription of this gene is rapidly induced by 0.1-1 unit of IFN-gamma. In addition, gamma.1 transcription is efficiently induced by phorbol 12-myristate 13-acetate, which is known to activate protein kinase C (PKC). Both stimulators of gamma.1 transcription induce the translocation of PKC from the cytosol of a membrane fraction. Two selective inhibitors of PKC, H7 and sphingosine, suppressed not only the induction of gamma.1 mRNA but transcription of HLA-DR by IFN-gamma as well. These findings establish that PKC plays a significant role in the signal transduction pathway leading to transcriptional activation of some IFN-gamma-regulated genes of cells of the mononuclear phagocyte lineage.

Genetically restricted suppressor T-cell clones derived from lepromatous leprosy lesions

Leprosy is a spectral disease in which immune responses to Mycobacterium leprae correlate with the clinical, bacteriological and histopathological manifestations of disease, so study of its pathology provides insights into immunoregulatory mechanisms in man. At the tuberculoid pole, patients have few lesions in the skin which contain rare organisms and are able to mount strong cell-mediated immune responses to M. leprae antigens. In contrast, at the lepromatous pole, patients have disseminated skin lesions containing large numbers of acid-fast bacilli and are selectively unresponsive to antigens of M. leprae. M. leprae-induced suppressor cells derived from peripheral blood have been reported to be active in vitro, yet their in vivo significance has remained unclear. Because the focal point of the immune response to M. leprae is the skin lesion consisting of lymphocytes and macrophages, we have recently developed methods for isolating lymphocytes from skin biopsies of leprosy patients. We report here that two T8 clones derived from lepromatous leprosy skin biopsies, in the presence of lepromin, suppress concanavalin A (Con-A) responses both of peripheral blood mononuclear cells and of T4 clones in an HLA-D (HLA, histocompatibility locus antigen)-restricted manner. Moreover, these T8 clones suppressed responses of HLA-D-matched, but not HLA-D-mismatched antigen-responsive T4 clones to M. leprae antigens, indicating that T-cell suppression is major histocompatibility complex (MHC)-restricted at some level in man.