Isolation and partial characterization of a 46-kd allergen of Bermuda grass pollen

Cyn d Bd46K, a 46-kD component of Bermuda grass (Cynodon dactylon) pollen, had been identified as an allergenic constituent. In the present study two-dimensional (2D) gel electrophoresis illustrated the presence of five acidic isoforms in Cyn d Bd46K, and this molecule was purified by monoclonal antibody (MAb) affinity chromatography for further characterization. Using a digoxigenin-labeled lectin-binding assay, the elucidating protein was disclosed to be a glycoprotein with terminal mannose. The involvement of a carbohydrate moiety in the allergenicity and antigenicity of the elucidated molecule was demonstrated with sodium-periodate-treated Cyn d Bd46K, which reduced binding to its specific MAb and human IgE. We were unable to identify the N-terminal amino acid sequences of Cyn d Bd46K, but some internal amino acid sequences were disclosed by microsequencing some fragments cleaved by Achromobacter protease I and fractionated by reversed-phase column chromatography. The amino acid sequences of 4 identified Cyn d Bd46K internal peptide fragments were found to be 25-71% identical with that of cytochrome c oxidase III from corn grass pollen. The present study provided important information for future experiments on the molecular cloning of the elucidated allergen.

Cataract formation after pars plana vitrectomy

To investigate the duration and pattern of cataract formation after pars plana vitrectomy, thirty-three eyes from 33 patients with complete data from March 1995 to January 2000 were collected in this study. The time and pattern of cataract formation was analyzed according to Lens Opacities Classification System III (LOCS III). The correlation between the mean cataract progression and follow-up time was determined by simple regression and correlation analysis. Diabetes mellitus and hypertension were the main causes of patients with vitreoretinopathy who underwent pars plana vitrectomy procedure. Twenty-one patients (63.6%) had diabetes mellitus and 11 patients (33.3%) had hypertension. Four eyes (13.8%) received intravitreal gas injection after pars plana vitrectomy. The correlation between cataract progression and follow-up time was clinically significant (p < 0.05). Thirty-one patients (94%) were nuclear cataract, the mean time of cataract formation being 9.1 months; 15 patients (46.9%) were cortical cataract, the mean time of formation being 8 months; and 24 patients (72.7%) were posterior subcapsular cataract, the mean time of formation being 13.3 months. Cataract formation after pars plana vitrectomy is not infrequent. Nuclear cataract is the most common type in this study. Vitreous microenvironmental changes, post-vitrectomy uveitis, intravitreal gas, and patient age may be the key points of cataract formation after surgery. The mechanism of longer-term effect of pars plana vitrectomy on lens status is still unknown and merits further study.

A second deciduous molar impacted in right maxillary sinus: a long-term follow-up

Primary tooth impaction is quite rare during the development of primary dentition. Various factors contribute to the impaction of a deciduous tooth, including malposition and malformation of the tooth bud, dentomaxillofacial disharmony, tumors, and cysts. This case was a 6-year-old female with complete left cleft lip/palate. A maxillary right second deciduous molar impacting at a high level approximate to the maxillary sinus was noted on the initial visit. To prevent surgical trauma to the surrounding tissue and succedaneous teeth, regular follow-up with radiographic examination was taken every 2 years. After a 7-year long-term follow-up, the impacted second primary molar in the right maxillary sinus had almost completely been resorbed with only about 10% of the original structure left. To the present, the resorption of the impacted deciduous molar seemed to have continued with no major pathological changes. Periodic radiographic examination is strongly advised until the total resorption process is completed.

Relationship between outcome of proliferative vitreoretinopathy and results of tissue culture of excised preretinal membranes

The purpose of this study was to explore the relationship between clinical post-surgery outcome of proliferative vitreoretinopathy (PVR) and the laboratory results of tissue culture, the specimens of which were excised of pre- or subretinal membranes from PVR patients. Surgically excised membranes from 25 PVR patients were microdissected into small pieces and plated into culture dishes with F12 medium supplemented with 30% fetal bovine serum. After primary culture became confluent, cells were passaged in subculture with F12 medium (10% fetal bovine serum). PVR patients were followed-up after surgery for an average of 21 months. The clinical outcome was compared, according to the growth pattern of the cells derived from the explanted membranes. In 25 PVR patients, 16 cases showed cell migration in the membrane, and cells grew rapidly to confluence in the primary culture in 7 cases. All active growing cells were identified as retinal pigment epithelial (RPE) cells by immunocytochemistry. In 7 cases with active cell growth, all had recurrent retinal detachment. In 18 cases without active cell growth, only 4 cases had the same outcomes. Statistical study showed that the difference between these two groups was significant (P < 0.01). These results indicate that the growth capacity of cultured RPE derived from excised membranes of PVR patients strongly influenced the prognosis for surgery.

Perfluorodecalin condensation on posterior surface of lens capsule and corneal endothelium during vitrectomy

BACKGROUND

High-density vitreous substitutes, including perfluorodecalin, are widely used in current vitreoretinal surgery. We report 4 cases of perfluorodecalin condensation on the posterior capsule of the lens or corneal endothelium during vitrectomy. To the best of our knowledge, no such phenomenon has ever been reported.

METHODS

This study consisted of 4 patients with retinal detachment and large retinal tears. All patients were men. All of the patients underwent pars plana vitrectomy, perfluorodecalin injection, endolaser retinopexy and air-fluid exchange. Two patients received additional surgery for scleral buckling.

RESULTS

Perfluorodecalin condensation was observed on the posterior surface of the lens capsule in one phakic patient and on the endothelium in three aphakic patients during vitrectomy. The condensation obscured the image of the fundus and made air-fluid exchange difficult. The condensation could be dissipated by first removing the perfluorodecalin as completely as possible, and then by lowering the intraocular pressure below the vapor pressure of perfluorodecalin.

CONCLUSIONS

Perfluorodecalin condensation may occur when perfluorodecalin is not properly used. To avoid forming condensation, high-density vitreous substitutes should never be injected into eyes that are completely air-filled, prolonged air-fluid exchanges should be avoided, and the intraocular pressure should always be kept at a higher level during air-fluid exchange.

Concentration of vascular endothelial growth factor in the subretinal fluid of retinal detachment

The purpose of this study was to investigate the release of vascular endothelial growth factor (VEGF) within the subretinal fluid in eyes with retinal detachment. Subretinal fluid was collected from patients with retinal detachment undergoing surgery for scleral buckling. Serum samples were also collected. The concentration of VEGF in the subretinal fluid and serum was investigated by enzyme-linked immunospecific assay. The average concentration of VEGF in serum samples was 168 +/- 153 pg/ml (mean +/- standard deviation). It was lower than the VEGF concentration in the subretinal fluid (485 +/- 570 pg/ml) in the same 18 patients with retinal detachment (p < 0.05). The average concentration of VEGF was 355 +/- 373 pg/ml in 31 samples of the subretinal fluid collected from simple rhegmatogenous retinal detachment. It was lower than the average concentration of 901 +/- 385 pg/ml in 8 samples of the subretinal fluid from retinal detachment with proliferative vitreoretinopathy (p < 0.05). The results suggest that the relative retinal ischemia in detached retina increases the release of VEGF into the subretinal space. Also, the concentration of VEGF within the subretinal fluid in proliferative vitreoretinopathy was higher than in simple rhegmatogenous retinal detachment.

Nitric oxide mediates depressor responses by activation of N-methyl-D-aspartate receptors in the nucleus tractus solitarius of cat

Nitric oxide (NO) is involved in cardiovascular regulation and sympathetic nerve activity of the central nervous system (CNS). The nucleus tractus solitarius (NTS) is important to cardiovascular regulation. However, the physiological role of NO in cardiovascular regulation effecting through the NTS remains unclear. The purpose of this study is to investigate the effect of NO measured by in vivo voltammetry on the cardiovascular responses in NTS induced by N-methyl-D-aspartate (NMDA) in anesthetized cats. Extracellular NO concentration was monitored through a Nafion- and porphyrin-coated carbon fiber electrode, which has previously been demonstrated sensitive and selective to NO responses. Microinjection of NMDA into NTS elicited a dose-dependent decrease in cardiovascular responses associated with NO release. Following the dose-response curve, a dose of 3 nmol of NMDA was selected. Microinjection of NMDA into NTS produced depressor responses and NO release. These responses in NTS to NMDA were attenuated by pretreatment with a competitive antagonist, 2-amino-5-phosphonopentanoat (AP-5, 1 nmol), and methylene blue (MB, 1 nmol), an inhibitor of guanylate cyclase. These results suggest that NO is formed from NMDA activation in NTS and that NO diffuses out of neurons into the nearby target neurons to produce depressor response and NO release through cyclic guanosine monophosphate (cGMP) formation. In conclusion, NO mediates depressor response consequent to activation of NMDA receptors in neurons of NTS.

Defatting of skin flaps using arthroscopic instruments--an effective alternative

Defatting is often required when skin flaps are transferred to the hand. We present three patients with skin flaps which were defatted using an arthroscopic shaver and a standard suction device. There were no complications and all three patients were satisfied with their outcomes. This method provided an effective treatment for our patients and did not require the purchase of specialised equipment.

Microbial keratitis--a late complication of penetrating keratoplasty

A retrospective review of 323 penetrating keratoplasties performed in Taiwan between January 1993 and December 1997 revealed that late microbial keratitis developed in 39 eyes of 36 patients (12.1%). All patients were operated on by the same surgeon, and all were followed for at least 1 year. The mean interval between the corneal transplantation and the onset of graft infection was 8.6 +/- 8.8 months (range 3 weeks-47 months). Predisposing risk factors for keratitis included chronic blepharitis with poor lid hygiene (43.6%), suture-related problems (38.5%), dry eyes (28.2%), epithelial defects (25.6%), and use of contact lenses (5.1%). Infectious keratitis was diagnosed within 6 months after keratoplasty in 59% of cases. Positive cultures were obtained in 100% of the ulcers; Pseudomonas aeruginosa and Staphylococcus aureus were the most common pathogens. In the final visual outcome assessment, 30.8% of cases had clear grafts, 20.5% had graft failures, and 10.3% had corneal perforations.

[Measurement and evaluation of visual index in VDT operators under Multi-user system]

OBJECTIVE

To evaluate the visual function of the visual display terminal (VDT) operators under the Multi-user system.

METHOD

Subjective symptoms of the VDT operators under the Multi-user system were measured before and after work in the field study. Visual indices were measured at 8:15, 9:15, 10:15, 11:15, or 12:15 a.m.

RESULT

No discomfort symptom was observed during the working time, and Longitudino-Kinetic visual acuity, and Critical flicker frequency didn't decrease. Refraction showed no significant decrease as compared with that at 8:15 except that of right eye measured at 12:15.

CONCLUSION

The Visual function of the VDT operators remained good in the Multi-user's system.

Surgical outcome of combined phacoemulsification and trabeculectomy

BACKGROUND

A retrospective study was undertaken to evaluate the results of phacoemulsification, intraocular lens implantation, and trabeculectomy in patients with cataracts coexisting with glaucoma.

METHODS

This study consisted of 20 eyes from 19 patients. Fifteen eyes had chronic angle-closure glaucoma and 5 eyes had primary open-angle glaucoma. All cases were followed for a minimum of 6 months (range, 6 to 16 months). The mean preoperative intraocular pressure (IOP) was 17.3 +/- 4.5 mmHg. The mean preoperative visual acuity was 0.05 +/- 0.19. The mean number of preoperative antiglaucoma medications per patient was 2.3.

RESULTS

Postoperatively, all patients except for one no longer required antiglaucoma medication. The mean IOP was 10.7 +/- 3.7 mmHg one month postoperatively and 13.7 +/- 4.3 mmHg at the final follow-up visit. Vision improved in 80% of the patients and remained unchanged in 20%. The failure to achieve improvement was due to advanced optic atrophy. The mean level of surgically induced astigmatism at the final visit was 0.98 +/- 0.91 diopters as calculated by vector analysis. Various extents of fibrin exudate was found in 10 eyes (50%). The most serious postoperative complication, occurring in one eye (5%), was temporary hypotony with moderate choroidal effusion, which later resolved spontaneously.

CONCLUSION

Combined phacoemulsification and trabeculectomy is an effective and safe approach for obtaining good visual rehabilitation and glaucoma control.

Management of severe proliferative vitreo-retinopathy with perfluorocarbon liquids and silicone oil

12 patients of retinal detachment with advanced proliferative vitreoretinopathy were managed with intraoperative perfluoro-N-octane and postoperative silicone oil injection from March 1994 to June 1996 in Kaohsiung Medical University Hospital. The combined intraoprative procedures included posterior vitrectomy (12 eyes), membrane peeling (12 eyes), lower peripheral iridectomy (8 eyes), endo-photocoagulation (8 eyes), retinotomy (8 eyes), and retinal fixation with tack (1 eye). After a minimum of 10 months of follow up, the retina was successfully reattached in 10 (84%) of the 12 eyes, 5 of these eyes had stable tractional detachments on the anterior part of the scleral buckle. Seven patients (58.3%) regained vision of 5/200 or better. The rate of improvement by listing best corrected visual acuity after operation was 75%. We think that the ability to readily remove additional pre-retinal fibrous tissue after the retina was flattened with perfluorocarbon liquids allowed the surgeon to perform a further complete membrane dissection. It can therefore improve the success rate of surgery and hence decrease the rate of complications that was previously thought to be caused by sillicone oil.

Recurrent herpetic keratitis induced by laser iridectomy: case report

The mechanism for herpetic keratitis reactivation remains unclear. When observed clinically, the reactivation may be associated with a variety of endogenous and exogenous stimuli, such as strong sunlight, fever, menstruation, and psychiatric disturbances. In experimental studies, most methods of inducing recurrence have involved some degree of corneal trauma, inflammation, neuronal stimulation, or damage to the nerves that innervate the cornea. Although corneal damage after laser iridectomy (LI) is well documented, recurrent herpetic keratitis induced by LI has never been reported. Here we present an unusual case of recurrent herpetic keratitis induced by LI. The location of the bullous keratopathy was strongly correlated to the site of laser iridectomy. Clinical findings as well as the dramatic response to antiviral treatment supported the diagnosis. Although the energy for laser iridectomy is relatively safe for most circumstances, the possibility of inducing herpetic keratitis cannot be ignored. Therefore it is important for clinicians to beware of this potential complication.

The experience to use a modified en bloc excision technique in vitrectomy for diabetic traction retinal detachment

Modified en bloc excision is a technique in which all posterior hyaloid is excised except the portions essential for membrane dissection. Then, bimanual dissection techniques allow excision of retained fibrovascular membrane "en bloc" with hyaloid. In a consecutive series of 16 eyes with diabetic traction retinal detachment treated with this technique, visual acuity of 5/200 or better was obtained in 11 (69%) of the cases, and complete macula reattachment was noted in 14 (87%) of 16 eyes. The final visual acuity was improved in 12 (75%) cases. While this surgical technique allows a higher rate of anatomic success and less postoperative morbidity, visual results remain limited by irreversible alteration in retinal function.

Association of HLA-DR and -DQ alleles with idiopathic achalasia

BACKGROUND & AIMS

Idiopathic achalasia is a motility disorder of the esophagus characterized by incomplete relaxation of the lower esophageal sphincter and a loss of normal peristaltic activity in the body of the esophagus. The loss of inhibitory neurons in the distal esophagus, as well as abnormalities in the vagus nerve, dorsal motor nucleus of the vagus nerve, and autonomic nervous system, have been described in achalasia. Although the underlying cause of idiopathic achalasia is unknown, the diffuse neuronal effects found suggest a possible viral or neurodegenerative mechanism. By use of serological methods, a significant association between the HLA-DQ1 phenotype and idiopathic achalasia has been found, suggesting a possible immunogenetic mechanism. To further define immunogenetics in the pathogenesis of idiopathic achalasia, we performed tissue typing in patients with achalasia to determine their specific HLA phenotypes.

METHODS

We prospectively studied 32 patients (23 white and 9 black) with idiopathic achalasia. Peripheral blood was collected, and HLA-DR and -DQ typing by polymerase chain reaction with sequence-specific primers was performed. Results were compared with those from 268 racially matched local controls.

RESULTS

Idiopathic achalasia and the broad HLA-DQ1 allele were not significantly associated in either population, although a trend was found in white subjects (odds ratio [OR], 2.16; chi2 = 5.36, P corrected [Pc] = 0.0824). Further subtyping in white subjects revealed a significant association between idiopathic achalasia and the DQB1*0602 allele (OR, 3.10; chi2 = 7.32, Pc = 0.0408). A strong trend was also found with the DRB1*15 allele (OR, 2.83; chi2 = 8.11, Pc = 0.0572). In the black population, there was no association between idiopathic achalasia and DQB1*0602 or DRB1*15, but a trend was found with DRB1*12 (OR, 6. 19; chi2 = 5.19, P = 0.0227 uncorrected, Pc = 0.295).

CONCLUSIONS

Idiopathic achalasia is associated with HLA alleles in a race-specific manner. These results support an immunogenetic mechanism in the pathogenesis of idiopathic achalasia.

Fusion of the lumbar spine with a free vascularized fibular bone graft: case report

Spinal fusion with either non-vascularized or vascularized bone grafts has been well documented for inflammatory, degenerative, post-oncological and post-traumatic reconstruction Vascularized bone graft has been proven to have more rapid healing and better clinical results. A few reports have indicated that free vascularized fibular bone grafts have been used for reconstruction of the cervical and thoracic spine with good clinical results. We report a case of a third lumbar vertebra burst fracture successfully treated with a free vascularized fibula graft after failure of an initial conventional bone graft. The neurological symptoms improved significantly. The strong and straight bone quality makes the vascularized fibula an ideal choice for reconstruction of the spine. Vascularized fibula bone graft is an option in cases with failed nonvascularized bone grafts, in cases where an iliac bone is not suitable for reconstruction, or in cases where a poor recipient bed makes having well-vascularized bone necessary. This report describes our surgical approach and demonstrates the versatility of the free fibular osteoseptocutaneous flap for reconstruction of any portion of the spine.

Spike responses of sympathetic vertebral nerve activities during stimulation of the pressor dorsomedial and rostral ventrolateral medulla differ in cats

In this study, we developed a differential integrator unit containing a window discriminator (WPI-121) and three integrators (sample/hold, Gould) to characterize the difference in spikes involved in sympathetic vertebral nerve activity (VNA) and integrated VNA (Int. VNA) during stimulation of the dorsomedial (DM) and rostral ventrolateral (RVLM) medullar. The upper level (UL) in the window discriminator was set at a value, 80% of the VNA amplitude above the zero. The low level (LL) was set at a value 10% above the zero. The number of VNA spikes above the UL in the window discriminator was defined as Fa, while the number of VNA spikes within the UL and LL as Fw. In 26 cats anesthetized with urethane and alpha-chloralose, results showed that electrical stimulation and microinjections of glutamate (Glu, 0.25 M, 50 nl) or glycine (Gly, 1.0 M, 50 nl) at the same point in DM or RVLM increased both systemic arterial pressure (SAP) and Int. VNA. However, the increase of Int.VNA on DM stimulation was contributed by increases of both Fa and Fw, while on RVLM stimulation the increase of Int.VNA was mainly contributed by the increase of Fa, against a decrease of Fw. As compared to Glu, stimulation of DM by Gly produced more increase in Fw, while stimulation of RVLM by Gly produced more decrease in Fw. During RVLM stimulation the VNA was usually transferred to a huge synchronized oscillation. These findings suggest that although stimulations of the sympathetic-pressor neurons in DM and RVLM produce similar increases in SAP and VNA, the nature of these neurons is different.

Concomitant tuberculosis and pyogenic infection of the cervical spine. A case report

STUDY DESIGN

This case report describes a middle-aged woman with concomitant tuberculosis and pyogenic infection of the cervical spine.

OBJECTIVE

To describe an unusual case of concomitant tuberculosis and pyogenic infection of the cervical spine.

SUMMARY OF BACKGROUND DATA

Neither tuberculosis nor pyogenic spondylitis of the cervical spine is a common disorder. This case report describes a concomitant infection of C3-C4 in an otherwise healthy patient. To the authors' knowledge, such a case has never been reported.

METHODS

This 52-year-old woman had spontaneous neck pain and myelopathy. Radiologic examination revealed the presence of an epidural abscess with destruction of C3-C4 vertebral bodies.

RESULTS

Anterior decompression and fusion were performed, followed by therapy with antituberculosis drugs and antibiotics. The patient completely recovered. A follow-up radiograph revealed that solid fusion had been achieved.

CONCLUSION

A case of concomitant tuberculosis and pyogenic infection of the cervical spine is presented. The possibility of this differential diagnosis should be considered, especially in areas of endemic tuberculosis. Examination of biopsy samples for histologic and bacteriologic findings is important to confirm this diagnosis. Radical debridement and combination therapy are strongly recommended to treat patients with this combination of infections.

Glycine increases arterial pressure and augments NMDA-induced pressor responses in the dorsomedial and ventrolateral medulla of cats

The present study is designed to determine and characterize two neurobiological events. Firstly, we investigated whether increases of systemic arterial pressure (SAP) and sympathetic vertebral nerve activity (VNA) produced by microinjection of glycine (Gly) in the dorsomedial (DM) or rostral ventrolateral medulla (RVLM) are mediated by pressor neurons in DM or RVLM. Secondly, we assessed whether simultaneous microinjections of Gly and N-methyl-D-aspartate (NMDA) in DM or RVLM potentiate the NMDA-pressor effects. Changes in SAP and VNA were recorded in 33 cats under alpha-chloralose and urethane anesthesia. Microinjection of sodium glutamate (Glu, 0.25 M, 30 nl) or Gly (1.0 M, 30 nl) into the DM or RVLM increased SAP and VNA in similar magnitude. Latencies of changes in SAP and VNA induced by Gly, however, were longer (3 s) than those induced by Glu. Prior microinjection of the following antagonists blocked the Gly-induced pressor responses: 2-amino-5-phosphonopentanoate (AP-5, 25 mM, 30 nl), a specific NMDA receptor antagonist; or glutamate diethyl ester (GDEE, 0.5 M, 30 nl), a quisqualate receptor antagonist; or kynurenic acid (KYN, 10 mM, 30 nl), a broad spectrum competitive Glu antagonist. Prior treatment with strychnine (3 mM, 30 nl), a specific Gly antagonist, also blocked the Gly-induced pressor responses. Since Gly is believed to be an inhibitory neurotransmitter, these data suggest that Gly may produce pressor actions via an inhibition on specific inhibitory neurons synapsing with the pressor neurons. NMDA (0.1 M, 30 nl) and Gly (1.0 M, 30 nl) microinjected simultaneously in DM or RVLM produced a greater pressor action than NMDA alone. This potentiation was blocked by KYN, another known antagonist for such potentiation, but was only partially blocked by strychnine.

Reversed arterial flow in free flap surgery for leg reconstruction

A lower leg open fracture with an accompanying extensive soft-tissue defect may require free flap transfer to resurface the wound. In open-leg fracture injuries the major arteries are frequently damaged during the injurious event. When the antegrade arterial blood flow is not available for arterial inflow to the free flap, end-to-side arterial anastomoses or a venous graft from a proximal healthy artery is an appropriate solution. Reversed arterial flow is another technique that may be used to provide arterial inflow to the free flap. We report 5 patients with open tibial fracture injuries that were successfully covered using latissimus dorsi muscle free flaps with reverse arterial inflow and either antegrade venous outflow (4 patients) or retrograde outflow (1 patient). This technique is indicated when (1) the defect is not located at the site adjacent to the residual antegrade artery, (2) a long vein graft might pass through severely scarred soft tissue, or (3) after failure in end-to-side anastomosis with accompanying insufficient antegrade proximal arterial flow but good distal arterial reflux.

Balanced fluid exchange by volume homeostatic fluid-fluid exchanger--a new solution to postvitrectomy vitreous hemorrhage

We introduce a new device and a new technique that facilitate the clearance of postvitrectomy vitreous hemorrhage. We have developed a volume homeostatic fluid-fluid exchanger--Chen's Infusion/Aspiration (Chen's I/A) device. Due to reciprocal synchronized hydraulic action, Chen's I/A provides simultaneous infusion and aspiration of fluid of equal amounts. Therefore, it can be used to perform vitreous cavity lavage through smaller caliber needles and at the same time maintain a constant intraocular pressure. This improved vitreous cavity lavage technique is named Balanced Fluid Exchange. Performing Balanced Fluid Exchange with Chen's I/A can reduce trauma to the eyeball and decrease complications resulting from unstable intraocular pressure. Thus, it increases both the intra-operative and post-operative clearance rates of postvitrectomy vitreous hemorrhage, and is a promising method for the management of postvitrectomy vitreous hemorrhage.

Diagnostic criteria for pseudomalignant osteoblastoma

AIMS

Osteoblastoma is a rare bone tumour and differentiation from osteosarcoma is occasionally a diagnostic problem. The difficulty is further compounded when such a lesion microscopically shows cytological or architectural atypia.

METHODS AND RESULTS

A case of pseudomalignant osteoblastoma occurring in the left iliac crest of a 34-year-old Chinese woman is presented. Radiographic findings were non-diagnostic, but favoured a benign yet locally aggressive lesion. Histologically the diagnosis was based on the findings of classical osteoblastoma areas harbouring pseudomalignant osteoblasts in the absence of mitoses, but there were co-existing atypical architectural features also.

CONCLUSION

The significance and pathogenesis of the 'permeative pattern' are discussed. Difficulties in differentiating borderline lesions are emphasized.

Propofol inhibits medullary pressor mechanisms in cats

PURPOSE

Propofol may cause hypotension and the mechanism is complex. The present study was designed to determine the direct actions of propofol in medulla of cats.

METHODS

Mean systematic arterial pressure (MSAP), heart rate (HR) and cardiac contractility (dp/dt) were compared before and after administration of propofol the femoral vein (2, 3, or 4 mg.kg-1), vertebral artery (1 mg.kg-1) or the lateral cerebral ventricle (0.5 mg.kg-1) in eight anaesthetized cats. To study the direct effect of propofol in medulla, pressor areas of the dorsomedial medulla (DM) and rostral ventrolateral medulla (RVLM), or the depressor area of the caudal ventrolateral medulla (CVLM) were first identified with electrical stimuli and then confirmed by pressure microinjection of glutamate (Glu, 0.25M, 30 nl) via a multibarrel-micropipette in 28 cats. One hour later, propofol (0.001%, 50 nl) was microinjected at the same site. Electrical stimulation and Glu were applied again to compare changes of SAP, HR and dp/dt with that of the control.

RESULTS

Propofol dose-dependently decreased SAP, HR and cardiac contractility. The percent increase of MSAP induced by Glu were reduced by propofol in DM (59 +/- 3% vs 13 +/- 2%, n = 11, P < 0.01) or in RVLM (56 +/- 4% vs 18 +/- 2%, n = 9, P < 0.01). In CVLM, propofol slightly but not significantly increased depressor responses elicited by Glu (-27 +/- 2% vs -33 +/- 3%, n = 5, P > 0.05).

CONCLUSION

Our results show that propofol principally inhibits the vasomotor mechanism in the dorsomedial and ventrolateral medulla to effect its hypotensive actions.

Attenuation of cardiovascular reactions of vocalized and non-vocalized defence areas of periaqueductal grey following lesions in dorsomedial or ventrolateral medulla of cats

In the pretentorial periaqueductal grey (PAG), the region producing pressor responses, vocalization and other somatic and visceral signs (VPR) of the defence reaction and another region producing pressor responses (PR) were localized by electrical stimulation in adult cats, anesthetized with intraperitoneal chloralose (40 mg/kg) and urethane (400 mg/kg). The pressor responses included increases of systemic arterial pressure (SAP) and heart rate, increases of blood flow in the common carotid and femoral arteries and a decrease of blood flow in the superior mesenteric artery. The VPR was found in a relatively restricted region of the dorsolateral PAG, while PR was found scattered within the dorsal and ventral portions of the lateral PAG. The increase of SAP and the changes of blood flow in the sampled arteries were slightly greater during VPR than PR stimulation. Mild vocalization with a slight increase of SAP but marked increases of carotid and femoral blood flow (vasodilation) could be induced by microinjection of N-methyl D-aspartate (0.2 M, 200 nl) into the VPR and the blood flow increase, particularly that of the femoral artery, was greatly attenuated by atropine (1 mg/kg, i.v.). In order to ascertain the contribution of the medullary pressor areas to the VPR- and PR-induced responses, extensive lesions were made in the dorsomedial (DM) or vetrolateral medulla (VLM) by microinjections of kainic acid (KA, 0.024 M) in 27 of the 42 cats. The resting SAP and blood flow of the three arteries were reduced by lesioning of the VLM more than that of the DM. Responses of SAP and blood flow from activation of the PR and VPR, particularly the latter, were affected more after DM compared to VLM lesioning. These data suggest that, while the pretentorial PAG constitutes the 'defence area,' vocalization is confined exclusively to its dorsolateral region and that both the VLM and DM contribute to the cardiovascular components of defence reactions. The DM appears to have a greater contribution compared to the VLM.

Orthopaedic ice-skating injuries in a regional hospital in Hong Kong

Ice-skating is a popular sport in Hong Kong. Since the opening of our hospital, we have observed a special pattern of injury related to ice-skating. Individuals have had a wide range of injuries including fractures and deep tissue lacerations, many of which have needed operative intervention. Public awareness of the risks remains low. The pattern and mechanisms of injury, management modalities, and contributing factors to the injuries are discussed. Preventive measures and socioeconomic implications are also discussed.

Daily omeprazole surpasses intermittent dosing in preventing relapse of oesophagitis: a US multi-centre double-blind study

INTRODUCTION

Relapse of erosive oesophagitis occurs in almost all patients if treatment is stopped after initial healing.

AIM

To assess the potential of different therapeutic regimens of omeprazole to prevent relapse of erosive reflux oesophagitis after initial healing with omeprazole.

PATIENTS AND METHODS

Patients whose active erosive reflux oesophagitis (grade > or = 2) had healed (grade 0 or 1) after 4-8 weeks of open-label omeprazole 40 mg daily (phase I) were eligible to join a multi-centre, 6-month double-blind, placebo-controlled maintenance study (phase II), which included endoscopy, symptom assessments, serum gastrin measurements, and gastric fundic biopsies. During phase I, endoscopy was performed at weeks 0, 4, and 8. At the end of phase I, 429 of 472 patients (91%) were healed, and there were significant reductions in heartburn, dysphagia and acid regurgitation. Of the 429 patients who healed, 406 joined phase II and were randomized to one of three groups: 20 mg omeprazole daily (n = 138), 20 mg omeprazole for 3 consecutive days each week (n = 137), or placebo (n = 131). During phase II, endoscopy was performed at months 1, 3, and 6 or at symptomatic relapse.

RESULTS

The percentages of patients still in endoscopic remission at 6 months were 11% for placebo, 34% for omeprazole 3-days-a-week, and 70% for omeprazole daily. Both omeprazole regimens were superior to placebo in preventing recurrence of symptoms (P < 0.001); however, omeprazole 20 mg daily was superior to omeprazole 20 mg 3-days-a-week (P < 0.001). Compared to baseline, omeprazole therapy resulted in no significant differences among treatment groups in the distribution of gastric endocrine cells.

CONCLUSIONS

These results show that after healing of erosive oesophagitis with 4-8 weeks of omeprazole, relapse of oesophagitis and recurrence of reflux symptoms can be prevented in 70% of patients with a maintenance regimen of 20 mg daily, but that intermittent dosing comprising 3 consecutive days each week significantly compromises efficacy.

Evidence of a direct projection from the cardiovascular-reactive dorsal medulla to the intermediolateral cell column of the spinal cord in cats as revealed by light and electron microscopy

To ascertain whether the dorsal medulla, a well-established vasopressor structure, would project directly to the sympathetic intermediolateral cell column of the spinal cord, we have carried out both anterograde and retrograde tracing studies in cats. For anterograde tracing, biotin-dextran was iontophoretically delivered into the cardiovascular-reactive dorsal medulla following its functional identification by electrical stimulation. The anterogradely transported biotin-dextran was then visualized using the avidin-biotin-horseradish peroxidase complex method. By light microscopy, dextran-labelled varicose axons were observed bilaterally in the intermediolateral nucleus extending from segments T1 to L3, but concentrated in segments T1-T5, notably at levels T2-T4. Electron microscopic examination revealed the localization of biotin-dextran reaction product in some small myelinated axons and axon terminals in the intermediolateral cell column. The majority of tracer-labelled axonal boutons contained spherical synaptic vesicles and made asymmetric synaptic contacts primarily with small dendrites. A few boutons contained polymorphic synaptic vesicles and tended to form symmetric axodendritic synapses. Spinally projecting neurons of the dorsal medulla were identified using the retrograde transport of horseradish peroxidase injected into the electrically cardiovascular-reactive intermediolateral nucleus. The labelled neurons were localized in the medullary dorsomedial reticular formation ventromedial to the nucleus of the solitary tract, approximately 0.5-5 mm rostral to the obex. The projection was bilateral, but was relatively denser in the rostral portion of the contralateral dorsal medulla. The present findings support the hypothesis that the dorsal medulla, through its direct pathway innervating the intermediolateral nucleus, may serve as a sympathetic premotor structure for regulation of arterial pressure.

Use of dynamic capillaroscopy for studying cutaneous microcirculation in patients with diabetes mellitus

To investigate the relationship between cutaneous microcirculation and retinopathy in diabetes mellitus, we studied by dynamic capillaroscopy 35 diabetes mellitus patients, including 10 patients without retinopathy, 10 patients with background retinopathy, and 15 patients with proliferative retinopathy. We found that (1) cutaneous and retinal microcirculation in diabetes mellitus in long-term diabetes mellitus, regressional rather than proliferational changes occurred in skin vasculature as compared to that in retina; (2) functional impairments of cutaneous microcirculation, that is, decreased resting capillary blood cell velocity, peak blood cell velocity, and prolonged time to peak capillary blood cell velocity by dynamic capillaroscopy, could be detected in diabetes mellitus patients without retinopathy; (3) the degree of tortouosity of capillaries, impairment in peak capillary blood cell velocity, and time to peak capillary blood cell velocity of cutaneous microcirculation were significantly correlated with the gravity of retinopathy in diabetes mellitus patients; (4) abnormal leakage of fluorescence in cutaneous microcirculation appeared in diabetes mellitus patients with or without abnormal fluorescein angiography in retina. In conclusion, dynamic capillaroscopy used in concert with ophthalmoscopy and fluorescein angiography can facilitate a comprehensive examination of vasculopathy in diabetes mellitus.

The combined use of flaps based on the subscapular vascular system for limb reconstruction

The combined use of flaps based on the subscapular vascular system for limb reconstructions has been infrequently reported. Such combinations have mainly been used for mandibular and facial reconstructions. We have used these flaps as free flaps for lower limb reconstructions in 7 patients, in 6 cases after trauma and in one after infection. A latissimus dorsi muscle or musculocutaneous flap and serratus anterior muscle flap were used together in 4 cases, and a latissimus dorsi muscle flap and parascapular flap in 3 cases. All cases healed satisfactorily. The indications for the combined use of these flaps are to resurface two separate defects simultaneously or to resurface very large defects. The anatomy of the subscapular vascular system allows the combined use of two or more flaps. It has the advantage of requiring anastomosis of one vascular pedicle only. Such combined flaps are particularly suitable for resurfacing defects wider than their length in relation to the long axis of the limb.

Involvement of non-NMDA and NMDA receptors in glutamate-induced pressor or depressor responses of the pons and medulla

1. Fifty-five intact and six baroreceptor denervated and vagotomized cats of either sex were anaesthetized intraperitoneally with urethane (400 mg/kg) and alpha-chloralose (40 mg/kg). Responses of the systemic arterial pressure (SAP), mean SAP (MSAP) and sympathetic vertebral nerve (VNA) and renal nerve activities (RNA) were recorded. 2. In intact animals, monosodium L-glutamate (Glu, 0.1 mol/L, 50 nL) was microinjected into pressor areas of the locus coeruleus (LC), gigantocellular tegmental field (GTF), rostral ventrolateral medulla (RVLM) and dorsomedial medulla (DM), and the depressor areas of caudal ventrolateral medulla (CVLM). The induced actions were compared before and after microinjection of either glutamate antagonists, glutamate diethylester (GDEE, 0.5 mol/L, 50-100 nL), a competitive AMPA receptor blocker, or 2-amino-5-phosphonovaleric acid (D-AP5, 0.025 mol/L, 50-100 nL), a competitive N-methyl-D-aspartate (NMDA) receptor blocker. GDEE completely blocked the increases of SAP and VNA elicited from all pressor areas. D-AP5 only partially blocked the pressor but slightly blocked VNA and RNA responses from LC, GTF and DM, particularly those from RVLM. Neither GDEE nor D-AP5 blocked the depressor responses of SAP and two nerve activities elicited from CVLM. 3. In baroreceptor denervated animals, NMDA (2 mmol/L, 50-100 nL) and AMPA (0.2 mmol/L, 50-100 nL) were micro-injected into the same pressor areas of GTF, RVLM and DM and the depressor area of CVLM responsive to Glu activation (0.1 mol/L, 30 nL). In RVLM, DM and CVLM, the results of either NMDA or AMPA were similar to those induced by Glu. However, in GTF, microinjection of either NMDA or AMPA did not induce similar responses to Glu. This suggests that the nature of GTF may differ from RVLM and DM. 4. The above results suggest that the Glu-induced pressor responses from LC, GTF, DM and especially RVLM, are primarily mediated through AMPA receptors. The Glu-induced depressor responses from CVLM may not be predominantly mediated by either AMPA or NMDA receptors. 5. In both baroreceptor-intact and -denervated cats stimulation of the pressor areas often produced an increase of VNA and a decrease of RNA, while in the depressor CVLM decreased both VNA and RNA. The VNA, but not RNA were positively correlated with the pressor responses, while both VNA and RNA were positively correlated with the depressor responses. This may suggest that neurons of the sympathetic vertebral and renal nerves are topographically organized in the brain.

Nipple reduction with a modified circumcision technique

Several methods of reduction of the hypertrophic nipple have been reported. All of them have some drawbacks. We propose a technique that can be easily performed and can produce excellent aesthetic as well as good functional results.

Reversible esophageal motility disorder in a patient with sarcoidosis

We report the case of a patient who presented with new onset of dysphagia for solids and liquids. Her condition was subsequently diagnosed as sarcoidosis on the basis of granulomatous inflammation in tissue obtained from transbronchial fine needle aspiration, noncaseating granulomas in a full-thickness lip biopsy, mild uveitis on slit lamp examination, and serum angiotensin-converting enzyme activity of 120 U/L. Esophageal manometry revealed a nonspecific esophageal motility disorder with 60% nontransmitted contractions and a lower esophageal sphincter that failed to relax with wet swallows. The patient was treated with 40 mg prednisone per day, and within 2 wk her dysphagia had markedly improved. Prednisone was continued with a slow taper, and after 1 month ber dysphagia had resolved and her esophageal manometry was normal. To our knowledge, this is the first case of sarcoidosis presenting with dysphagia and documented esophageal dysmotility in which symptoms and manometric abnormalities normalized after therapy with systemic corticosteroids.

Glycine produced pressor responses when microinjected in the pressor areas of pons and medulla in cats

In 24 cats under chloralose/urethane anesthesia changes of systemic arterial pressure (SAP) and sympathetic vertebral nerve activities (VNA) were induced by microinjection of glycine (Gly, 1.0 M, 50 nl) into the pressor areas of the rostral pons, i.e., locus coeruleus-parabrachial nucleus (LC-PBN), nucleus of gigantocellular tegmental field-lateral tegmental field (FTG-FTL), and dorsomedial (DM) and ventrolateral (VLM) medulla. The effects were compared with those induced by microinjection of sodium glutamate (Glu, 0.25 M, 50 nl) into the same sites. In about 60% of the injections Gly produced increases in SAP and VNA similar to that of Glu. The increase in SAP was greater in VLM, while the increase in VNA was more marked in DM. In the rest of microinjections Gly and Glu produced changes of SAP and VNA in different combinations. The latency of Gly-induced increases in SAP and VNA was 1 to 3 s longer than that induced by Glu. Our findings show that although Gly is classified as an inhibitory transmitter, it often produced excitation of the pressor neurons in the pons and medulla similar to that of Glu. Whether Gly acts through the same cardiovascular neurons that respond to Glu or through activation of different kinds of neurons remains to be elucidated.

Complete two-handed laparoscopic appendectomy: report of 100 cases

A complete two-handed technique for laparoscopic appendectomy is described. From April 1992 to July 1994, 100 patients with suspected acute appendicitis were selected to undergo this approach. This technique allows the surgeon to manipulate instruments with both hands for dissecting, transecting and removing the appendix. The appropriate placement of three cannulas in the lower abdominal midline makes this technique possible. Monopolar cautery is used to dissect the mesoappendix and to cauterize the appendicular vessels. Two ligatures are placed at the junction of the appendix with the cecum. The appendix is clamped at its base by ratchet forceps and is extracted along with the forceps immediately after transection. None of the patients selected for this procedure required conversion to open appendectomy. Postoperative complications occurred in four patients, two with umbilical wound infections and two with intra-abdominal abscesses; 12 patients had perforated appendicitis. The results of this study suggest that a complete two-handed laparoscopic appendectomy can be safely and successfully accomplished in patients with suspected acute appendicitis.

Achalasia associated with esophageal diverticula. Prevalence and potential implications

Although esophageal diverticula have been rarely reported in patients with achalasia, their prevalence and the potential implications of the relationship are not well known. We reviewed the medical records and the manometric and radiographic examinations in 120 patients with achalasia to determine the prevalence of esophageal diverticula and to evaluate their importance in this motility disorder. Esophageal diverticula were found in only 6 (5%) of 120 patients, and all were located in the lower half of the esophagus. Sex distribution and the prevalence of dysphagia and regurgitation, which affected all patients with diverticula and 88% of those with achalasia only, were not different significantly. Patients with esophageal diverticula were significantly older (72 vs. 52 years) than those without diverticula. In 5 of 6 patients with diverticula, mean lower esophageal sphincter (LES) pressure was 44.5 mm Hg compared to 39.1 mm Hg in 86 of 114 patients with achalasia only. Treatment by pneumatic dilatation was done in 4 patients with esophageal diverticula and in 105 patients without diverticula. Five esophageal perforations occurred, all in patients without esophageal diverticula.

Correlation of lower esophageal mucosal ring and lower esophageal sphincter pressure

We assessed the relationship of lower esophageal sphincter pressure (LESP) to presence and absence of lower esophageal mucosal ring (LEMR) in 66 patients to determine if the LEMR was more likely related to prolonged sphincter hypotension. This potential relationship is of interest because LEMR may be due to reflux esophagitis. Each patient had radiographic and manometric studies, and both examinations were done within one week of each other. The mean LESP in patients with LEMR was 23.8 mm Hg (range 4.2-64 mm Hg) compared to 28.7 mm Hg (range 8-59 mm Hg) in patients without LEMR; the difference was not statistically significant. Patients with LEMR were also divided into three subgroups according to the diameter of the rings (< or = 13 mm, 14-19 mm, > or = 20 mm). There was no significant relationship between the caliber of LEMR and LESP (P > 0.05). Presence of LEMR did not affect the amplitude or duration of primary esophageal peristalsis. These results do not support a relationship between LEMR and prolonged LESP hypotension or abnormal esophageal motility. However, other pathogenetic mechanisms involved in producing reflux esophagitis not related to prolonged sphincter hypotension were not studied.

The changes of ocular axial length and corneal curvatures after scleral buckling for retinal detachment

As myopia plays an important role in the pathogenesis of retinal detachment, alterations of refractive components after scleral buckling procedures for retinal detachment may be an important factor for retinal redetachment. To find out the refractive change following retinal detachment surgery, we prospectively followed up the alterations of corneal curvature, and axial components (axial length, anterior chamber depth, lens thickness, and vitreous length) of 44 eyes of rhegmatogenous retinal detachment before and after operations. The procedures consisted of encircling scleral buckling (12 eyes) and segmental scleral buckling (32 eyes). All patients were followed for 6 months postoperatively. The corneal curvatures were measured with a keratometer, the axial length and axial components were measured with an A-scan ultrasonography. The methods and materials used in operation were recorded in detail to correlate with the refractive changes. The corneal curvature showed a trend to flatten early after operation (the 1st week), and gradually reversed to steepening. But, the difference was statistically significant only at the K2 (vertical meridian) in the 1st postoperative week and the K1 (horizontal meridian) in the 4th postoperative week. Lengthening of eyeballs were noted in the encircling group (12 eyes), but only the elongation in the 1st postoperative week was statistically significant. While in segmental buckling group, the axial length of the eyeballs was transiently shortened. The shortening was significant in the 2nd, 4th, and 6th week after operation. The reduction of eyeball's axial length was related to the shortening of vitreous length and shallowing of anterior chamber.(ABSTRACT TRUNCATED AT 250 WORDS)

Activation of neurons in cardiovascular areas of cat brain stem affects spinal reflexes

In 65 cats anesthetized with chloralose (40 mg/kg) and urethane (400 mg/kg), the effects of electrical stimulation and microinjection of sodium glutamate (0.25 M, 100-200 nl) in the pressor areas in the rostral brain stem on the evoked L5 ventral root response (EVRR) due to intermittent stimulation of sciatic afferents were compared to stimulating the dorsomedial (DM) and ventrolateral (VLM) medulla. In general, stimulating these rostral brain stem pressor areas including the diencephalon (DIC) and rostral pons (RP) produced increases in systemic arterial pressure (SAP). In most of the cases (85%) there were associated changes in the EVRR, predominantly a decrease in EVRR (72%). Stimulation of the midbrain (MB, principally in the periaqueductal grey) produced decreases in SAP and EVRR. Decreases in EVRR was observed in 91% of the DM and VLM stimulations in which an increase in SAP was produced. This EVRR inhibition was essentially unaltered after acute midcollicular decerebration. Increases in EVRR were also observed and occurred more often in the rostral brain stem than in the medulla. Since changes of both EVRR and SAP could be reproduced by microinjection of Glu into the cardiovascular-reactive areas of the brain stem, this suggests that neuronal perikarya in these areas are responsible for both actions. On some occasions, Glu induced changes in EVRR but not in SAP. This effect occurred more frequently in the rostral brain stem than in the medulla. The present data suggest that separate neuron population exist in the brain stem for the integration of SAP and spinal reflexes.(ABSTRACT TRUNCATED AT 250 WORDS)