Assessment of middle-ear status during experimental otitis media using magnetic resonance imaging

Magnetic resonance imaging has proved to be a useful tool for in vivo imaging of a variety of tissues. In this study, magnetic resonance imaging was applied to the middle ear of experimental animals with otitis media. Results showed that the presence and distribution of effusion within the middle-ear space could be readily determined. Moreover, following injection of gadolinium-diethylenetriaminepentaacetic acid, a contrast agent, the inflamed middle-ear mucosa could be resolved. A comparison between magnetic resonance imaging and tympanometry with respect to the diagnosis of effusion showed that negative pressure tympanograms were equivocal (50% effusion) and that flat or normal tympanograms were in error in approximately 20% of the observations. These data document a role for magnetic resonance imaging in in vivo studies of the pathogenesis of otitis media with effusion.

Cerebral amyloid angiopathy and spontaneous intracerebral haemorrhage. Report of a sporadic case in a young Chinese

A 49-year-old Chinese male with spontaneous intracerebral haemorrhage due to cerebral amyloid angiopathy is presented. This is the first case reported in the Chinese population, and the youngest patient described without a family history or associated mental disorder.

Nasopharyngeal carcinoma and lymphoinfiltration

Originally referred to as 'lymphoepithelioma', undifferentiated and poorly differentiated nasopharyngeal carcinoma (NPC) tissues showed intense lymphoinfiltration. In a study of cryosections from 15 NPC tissues, we found that infiltrating lymphoid elements were comprised predominantly of lymphocytes, but plasma cells, follicular dendritic cells, and eosinophils were also commonly seen. Subpopulations of lymphocytes having the same phenotypes tend to aggregate, forming clusters or secondary follicles in stromatous tissues. The tumor areas were mainly infiltrated by T cells. Tumor cells and/or apparently normal epithelium in the paratumorous areas frequently expressed CD21, CD23, CD40 and a B lymphocytes carcinoma cross-reacting antigen (BLCa), all of which are involved in B cell activation and proliferation. CD21 and BLCa were strongly expressed near the surface of both squamous and columnar epithelium by those epithelial cells which are at advanced stage of differentiation, while CD40 was expressed by epithelial cells at earlier stages of differentiation located at or near the basement membrane. CD23 was mainly expressed by columnar cells and basal cells underlying squamous epithelium, but not, or weakly so, by flattened squamous cells or reserve cells underlying columnar epithelium. The large majority of tumor cells expressed CD40 and BLCa. A substantial proportion of them also expressed CD23, but the tumor cells were not reactive for CD21. Despite eosinophilic infiltration, IL-6 was not detected in tumor tissues. IL-1 was, however, detected in abundance in the cytoplasm of follicular dendritic-like cells and in the intercellular spaces in tumor areas and surrounding stromatous tissues. The immunobiology of NPC is discussed in the light of these observations.

Flumazenil as an antagonist for midazolam anesthesia in outpatient surgery

Rapid recovery is an essential component in the anesthesia of OPD surgery. In this study midazolam, the short-duration benzodiazepine, was used as an intravenous anesthetic in OPD surgery. At the end of the operation flumazenil, the specific antagonist of benzodiazepines, was given to reverse the effect of midazolam. Recovery of these patients was compared with those in the control group who received saline instead of flumazenil. In a randomized, placebo-controlled clinical study the antagonistic effect of flumazenil on midazolam was investigated in fifty ASA class I-II gynecologic outpatients subjected to D & C procedure under anesthesia induced with midazolam (0.3 mg/kg). They were divided into group A (flumazenil group) and group B (placebo group) with 25 patients in each. At the end of operation patients in group A were given 0.2 mg flumazenil intravenously to antagonize the residual effect of midazolam while patients in group B were given 2 ml normal saline intravenously as control. Our results showed that patients in group A exhibited a rapid and steady return of consciousness scaled by alertness, orientation of time and place and activity collaboration at 5, 30 and 60 min intervals following administration of flumazenil (p less than 0.005). There were no significant changes found in the hemodynamic or respiratory aspect between groups (p greater than 0.05). All the patients tolerated midazolam and flumazenil well. It is concluded that the use of flumazenil to antagonize the residual effect of midazolam is safe and effective as far as outpatient procedure is concerned.

The use of ketanserin for postoperative hypertension after abdominal surgery

Eighteen adult patients who developed hypertension (systolic blood pressure greater than 160 mmHg, diastolic blood pressure greater than 90 mmHg or both) at the early recovery period after major abdominal surgery were included in the study. Following intravenous injection of 10 mg ketanserin, eleven out of eighteen patients (61%) had their systolic or diastolic blood pressure fell below the target mark (160 mmHg and 90 mmHg), and the decrease was statistically significant (p less than 0.01 up to 120 min). There was no statistically significant change in heart rate. Four patients (22%) responded to 20 mg of ketanserin. Three patients (17%) did not have significant decrease of the blood pressure after 20 mg of ketanserin and they received other antihypertensives instead. No severe hypotensive episode was noted. We concluded that ketanserin is a moderate, rapid-onset and safe antihypertensive agent in treating postoperative hypertension following major abdominal surgery.

Clinical application of infrared thermography in diagnosis and therapeutic assessment of vascular ischemic pain

Temperature is a very important and useful manifestation of various disease entities. The importance of body temperature as an indicator of disease has been known for centuries but in recent years attention has also been paid to how to conveniently and effectively make use of skin temperature as a diagnostic tool. Skin temperature can be measured with thermocouples, electronic thermistor-thermometers, electronic integrators, liquid crystal thermography, and infrared thermography. The temperature of extremities is largely dependent on the blood flow through peripheral vessels, and in the study of vascular diseases thermography has been, therefore, found to be useful. Blood flow can be assessed by many methods including washout techniques or laser Doppler flowmetry. Of these, infrared thermography has the advantages of being noninvasive, remote from the patient when in use, and capable of producing multiple recordings at short time intervals. Here we present a case of vascular ischemic pain which was diagnosed and therapeutically assessed by thermography.

Production and characterization of murine monoclonal antibodies specific for serogroups E1 and E4 Salmonella

Two anti-Salmonella serogroup E-specific monoclonal antibodies (MAbs) are described. Neither antibody reacted with any of the 58 strains of serogroups A-D Salmonella tested by enzyme immunoassays nor did they react with any of the 21 other species of enterobacteria, 15 species of other Gram-negative bacteria, and 6 species of Gram-positive bacteria. In contrast, all 14 strains of serogroups E1 and E4 Salmonella reacted with both antibodies. Ascitic fluids of these two antibodies agglutinated all 42 strains of serogroups E1 and E4 Salmonella tested by slide agglutination method but did not agglutinate any of the 107 strains of other serogroups of Salmonella. Lysogenic conversion of serogroup E1 Salmonella strains by phages epsilon 15 and epsilon 34 resulted in loss of reactivities of these strains with the MAbs.

An unusual complication of silastic dural substitute: case report

A case is presented in which a patient developed an unusual complication after the use of Silastic dural substitute. In 1983, the patient underwent removal of a meningioma with the involved dura. Five years later, he developed around the graft material a very thick connective tissue capsule, which simulated a recurrent meningioma clinically and radiologically.

Early detection of cerebral dysfunction by quantitative EEG during cardiopulmonary-bypass period for open-heart surgery

Neuropsychiatric complications are well known risks of open heart surgery. In this regard cerebral damage is caused either by microembolism or insult from low perfusion pressure as a consequence of extracorporeal circulation. It seems probable that monitoring of the quantitative electroencephalography (QEEG) during the surgical procedure can help minimize the incidence of neurological sequelae through early detection. Moreover, it seems important to establish whether the pre-operative EEG has a predictive value for the possible neurological outcome and whether the post-operative EEG has conclusive value for the neurological outcome and, above all to ascertain whether the peri-operative QEEG contains information valuable on the diagnosis of final neurological outcome. To elucidate the feasibility of QEEG as a means to monitor the cerebral function a study was thus undertaken. Twenty-five ASA II-IV patients with age ranging from 25-79 y/o undergoing cardiac surgery under extracorporeal circulation were enrolled for study. The types of surgery varied from coronary artery by-pass graft (CABG), valvular replacement, and excision and grafting for aortic dissecting aneurysm. 16-channel EEGs were recorded with a Cadwell Spectrum 32 in accordance with the international 10-20 system. 48 epochs (1 epoch = 2.5 seconds) of EEG recordings of pre-bypass and post-bypass periods were measured and quantitatively analyzed. Pre- & post-operatively, psychoneurological assessments were performed and correlated with the QEEG. The parameters employed in the study were absolute power, relative power, power asymmetry, and coherence. All the results of two-session comparisons were transformed into z score values. Our preliminary study revealed that there exists a specific multivariate profile of QEEG for specific disease entity. And all the patients with z score less than or equal to 3.0 turned out to be free from any significant sequelate.

The significance of skull fracture in acute traumatic intracranial hematomas in adolescents: a prospective study

A prospective study was conducted to validate the retrospective finding that adolescents (11 to 15 years old) with skull fractures were prone to develop acute traumatic intracranial hematoma (ICH). Over a 4-year period, 1178 consecutive adolescents attended the emergency room directly, of whom 760 were discharged well and 418 were admitted. All underwent skull x-ray studies. Immediate computerized tomography (CT) scans were performed in patients with Glasgow Coma Scale (GCS) scores of less than 15, in those with radiological and/or clinical evidence of skull fracture, and whenever clinically indicated. Of the 418 admitted patients, only 26 had skull fractures; 13 of these developed ICH. Four patients without skull fracture developed diffuse brain swelling. The remaining 401 patients were discharged after observation periods of up to 48 hours. Of the 13 patients with ICH, 10 had admission GCS scores of 15; however, four deteriorated rapidly and required urgent operation, and four remained stable but were operated on due to their large ICH. Two required conservative treatment only and both made good recovery. Three patients were in coma (GCS score less than or equal to 8) on admission. One patient had an epidural hematoma and made good recovery after surgery. Two developed delayed ICH after operations for associated systemic injuries despite initial CT showing diffuse brain swelling only, and both died despite evacuation of the ICH. Multivariate analysis showed that skull fracture was the only independent significant risk factor in predicting ICH in adolescents (sensitivity of 100% and specificity of 97%). A routine skull x-ray study is therefore mandatory in all head-injured adolescents and, if a skull fracture is detected, immediate CT may be performed for early detection of ICH.

A staged laryngotracheal reconstruction using alloplast (Proplast) in the canine model

Standard laryngotracheal reconstructive procedures are constrained by the availability of grafting materials and the ability to repair large defects. Reconstruction utilizing alloplasts may be ideal, but previous results have generally been poor. We present a two-stage procedure using Proplast to reconstruct large laryngotracheal defects in 6 dogs. A custom-made Proplast implant was inserted into a strap muscle pocket and buccal mucosa was placed in the adjacent peritracheal tissue. The muscle-Proplast composite graft was rotated to repair a large defect (3.25 cm by 2.25 cm). All 6 dogs survived. Endoscopic and histologic studies over 12 months showed continued stabilization and maturation of the implant. We feel that Proplast may be used as an alternative to autograft for reconstructing large laryngotracheal defects when the procedure is staged to allow maximal fibrous ingrowth and the implant is protected from infection.

The hemodynamics and clinical effects of labetalol in hypotensive anesthesia

Labetalol is a relatively new and unique hypotensive agent that has both alpha- and beta-adrenoceptor blocking properties. 12 patients in fit physical condition who underwent elective oral surgery were subject to hypotensive anesthesia with labetalol to assess the hemodynamic aspects and clinical effects of the drug. All of them had their anesthesia maintained with halothane and N2O in 50% O2 supplemented by fentanyl and vecuronium. Initiation of deliberate hypotension was made with intravenous bolus of labetalol at 0.5 mg/kg and the ideal level of mean arterial pressure at 55 +/- 5 mm Hg was maintained with adjustment of the concentration of halothane. At the termination of deliberate hypotension, the blood pressure was recuperated to the baseline level by lowering the concentration of halothane and administration of 0.5-0.6 mg intravenous atropine. Our results showed that the total dose of labetalol used was 44 +/- 13 mg and blood loss amounted to 354 +/- 136 ml. Important changes of hemodynamic parameters before and after labetalol included the fall of mean BP, HR, mean PAP, CI, LVSWI, SVRI, PVRI and O2 delivery and the increasing of O2 extraction. As to CVP, PCWP, SVI, O2 consumption and shunting the alterations were minimal. Blood gas analysis showed that, save a slight fall of pH indicating mild metabolic acidosis, the PaO2 and PaCO2 remained unchanged following the use of labetalol. Labetalol-induced hypotension could be effectively reversed by using of atropine as shown in our study and all the patients recovered uneventfully from hypotensive anesthesia. They were entirely free from any complication or sequela relevant to the deliberate hypotension after one year's follow-up.(ABSTRACT TRUNCATED AT 250 WORDS)

The risk of intracranial complications in pediatric head injury. Results of multivariate analysis

Retrospective analysis of 12,072 pediatric head injury cases admitted to hospital revealed 159 patients with intracranial complications: 132 had intracranial hematoma and 27 had diffuse brain swelling. Multivariate analysis revealed two risk factors that could be recognized easily by primary-care physicians. They were found to be significant in predicting the development of intracranial complications. These risk factors were impairment of consciousness at the time of admission and clinical and/or radiological skull fracture. Analysis revealed that the combination of impaired consciousness and skull fracture carried the highest risk of complication (75%); however, the presence of impaired consciousness alone had an intermediate level of risk (19%). The presence of skull fracture alone carried a small overall risk (2%); however, this was highly dependent on age. The absence of all the risk factors considered carried a negligible risk of intracranial complications, provided proper skull X-rays were taken and correctly interpreted.

[Oral tramadol for extracorporeal shock wave lithotripsy]

Two hundred patients undergoing shock wave lithotripsy for renal calculi with the improved version of Dornier HM3 lithotripter system were randomly divided into group A and group B with 100 patients in each. Patients in group A were orally given tramadol 100 mg and lorazepam 1 mg and those in group B flunitrazepam 1 mg was given. Those in group A, who did not need supplemental medication during ESWL were subdivided in group A while those who needed an adjuvant of 100 micrograms intravenous fentanyl were subdivided in group A2. Like group A, those in group B, who did not need supplemental drug and those who needed 100 micrograms intravenous fentanyl were respectively subcategorized into groups B1 and B2. Drugs were given with 15 mL water 30 min prior to ESWL. Pre-operatively, an intravenous line and monitoring system which included noninvasive blood pressure and pulse oximeter were established. The entire course was divided into 5 stages i.e. stage I (prior to oral medication), stage II (10 min after medication), stage III (10 min following ESWL), stage IV (5 min following 100 micrograms intravenous fentanyl) and stage V (10 min after ESWL). The mean blood pressure, heart rate and SpO2, pain scale, sedation scale and side effects were recorded in various stages. The results showed that in group A 68 patients passed the ESWL smoothly (A1) and 32 patients needed supplemental fentanyl (A2). In group B 70 patients successfully underwent the ESWL (B1) while 30 patients needed supplemental fentanyl (B2). Ther were no significant changes in both groups in various stages regarding heart rate.(ABSTRACT TRUNCATED AT 250 WORDS)

[Continuous thoracic epidural fentanyl in postoperative pain control--a comparison of two different dosages]

We evaluate the postoperative pain relief using continuous epidural fentanyl infusion in two different dosages for thoracic and upper abdominal surgeries. A total of 21 ASA class III patients were studied. A thoracic epidural catheter was placed before surgery but pain control was begun when the patients became fully awake and complained of pain in the recovery room. Patients were divided into group A (n = 9) and group B (n = 12). Those in group A were given fentanyl 1.5 micrograms/kg in saline solution as initial dose followed by continuous infusion at a rate of 1 microgram/kg/h for 23 hours. In group B the initial dose and the maintenance dose were respectively 1.0 microgram/kg and 0.5 micrograms/kg/h. Following the initial dose, the intensity of pain was assessed hourly for a total of 24 hours using a visual analogue pain scale with scores from 0 to 10. In group A, the pain scale fell from the baseline level of 7.7 +/- 2.6 to 2.3 +/- 2.0 at the first hour while in group B it fell from 8.9 +/- 1.4 to 4.3 +/- 2.1. The pain scores following continuous infusion in groups A and B were respectively 1.3 +/- 1.5 and 2.9 +/- 1.7. Although the analgesic effect appeared to be better in group A, pain relief was satisfactory in both groups (p less than 0.01). Regarding respiratory depression, there was a greater degree of rise in PaCO2 in group A and some of the patients even had a PaCO2 value above 50 mmHg.(ABSTRACT TRUNCATED AT 250 WORDS)

Factors influencing the development of gastrointestinal complications after neurosurgery: results of multivariate analysis

A retrospective review of 526 patients who underwent neurosurgery for nontraumatic conditions over a 5-year period revealed 36 (6.8%) patients with endoscopically and or surgically documented postoperative gastrointestinal (GI) complications. Two patients had GI bleeding and perforation, and the remaining patients had bleeding only. Multivariate analysis indicated 5 factors that were of independent significance in predicting the development of postoperative GI complications. These factors included 1) inappropriate secretion of antidiuretic hormone, 2) preoperative coma (Glasgow Coma Score less than 9), 3) the presence of postoperative complications, 4) age greater than or equal to 60 years, and 5) pyogenic infection of the central nervous system. Further analysis of the 36 patients with GI complications revealed that they could be divided into three groups with different clinical courses. In Group I (n = 10), all patients died as a result of their neurological conditions; GI complications were just preterminal events and did not require treatment. In Groups II (n = 11) and III (n = 15), GI complications were symptomatic and life-threatening events, respectively. Eleven patients from Group III died as a direct result of the GI complications. Separate multivariate analyses based on the patients in Groups II and III revealed that preoperative coma was the only significant factor that predicted the occurrence of life-threatening complications. Patients who are at high risk of developing postoperative GI complications can thus be identified, and intensive prophylaxis may be instituted.

Fatigue of acrylic bone cement--effect of frequency and environment

This study was conducted to investigate some fundamental fatigue testing variables as they apply to the response characteristics of acrylic bone cement. Cyclic loading under load control was conducted at frequencies of 1, 2, 5, 10, and 20 Hz in air at room temperature. At a tensile stress range of 0.3-20.0 MPa the fatigue life increased linearly with logarithmic frequency. The effect of conditioning and testing in saline at both room temperature and 37 degrees C at similar stress levels and a frequency of 10 Hz were also examined. When compared to dry testing at room temperature, testing in saline at 37 degrees C resulted in a reduction in fatigue life while testing in saline at room temperature produced an increase in fatigue life. Of a number of statistical distributions considered, the Weibull was found to be the most appropriate in documenting the findings of this investigation. A companion fractographic investigation of the failure surfaces demonstrated distinct regions of crack growth and fast fracture.

An investigation into the use of restriction endonuclease analysis for the study of transmission of mutans streptococci

Restriction endonuclease analysis (REA) was performed on the total cellular DNA from each of 396 strains of mutans streptococci (1) to determine its potential usefulness for the study of transmission of the organism and (2) to document the proportions and variety of strains harbored by members of a small group of families. The DNA was digested with restriction enzyme EcoRI and/or HindIII, electrophoresed on agarose gels, and the resulting patterns compared. The strains examined included fresh isolates from 58 subjects, including 19 strains from each member of five families. The sensitivity and reproducibility of REA patterns from the mutans streptococci seemed ideal for studies of their epidemiology and transmission. The pattern of each isolate from humans was unique, except for isolates from the same individual or from the same family. REA types from subjects from different families were always heterogeneous. A high frequency of multiple REA types (up to 5) was observed in many subjects. While evidence for intra-familial transmission was obtained, including transmission between spouses, there was also strong evidence of frequent sources of infection outside of the family. Mutations of strains to streptomycin resistance or to lactate dehydrogenase deficiency caused no detectable change in the REA patterns. The lack of plasmids in any of the 57 fresh isolates that were examined for them suggested that they may have contributed little to the heterogeneity of the patterns seen.

The significance of thrombocytopenia in the development of postoperative intracranial hematoma

A group of 35 patients undergoing intracranial surgery who exhibited perioperative thrombocytopenia (platelet count less than 150,000/microliters) was studied retrospectively. Of the 35 patients, 14 (40%) developed postoperative intracranial hematomas requiring reoperation and seven (20%) died within 2 weeks after the operation. Analysis revealed that a perioperative platelet count below 100,000/microliters in a patient who failed to respond to platelet transfusions was associated with a higher risk of postoperative hematoma formation. All six patients with this profile developed postoperative hematomas. If the platelet count rose promptly from below 100,000/microliters to a normal level after platelet transfusions, the incidence of hematoma formation decreased dramatically. None of the three patients with this response developed postoperative hematoma. In patients in whom an acute drop in platelet count from the normal range to between 100,000 and 124,000/microliters occurred in the immediate perioperative period, there was a significantly higher change of hematoma formation; this finding has not hitherto been described. Of the 14 patients with this clinical course, eight developed postoperative hematoma after craniotomy for tumors and vascular lesions. This latter observation was substantiated by the fact that thrombocytopenic patients with postoperative hematomas had a greater reduction in platelet count than thrombocytopenic patients with no postoperative hematomas (p = 0.0004).

Neurosurgical aspects of cerebral cryptococcosis

Eleven patients with raised intracranial pressure caused by cerebral cryptococcosis developed complications requiring neurosurgical operations. Two patients were fully conscious on admission, and 9 had impaired consciousness, four of whom were comatose. Seven patients were found to have hydrocephalus only. Two patients had cerebral edema initially, and 2 had cystic lesions. One of the latter developed subdural effusion. All patients eventually developed progressive hydrocephalus requiring placement of a ventriculoperitoneal shunt. Four patients were initially treated by external ventricular drainage. When external ventricular drainage was used initially, there were no associated complications; however, there was a high incidence of complications (4 of 7 patients) when a ventriculoperitoneal shunt was placed as the initial treatment. Of the 11 patients, 10 (91%) survived; of these 9 (82%) made an excellent recovery and 7 (64%) returned to their original work. The patient who died had been receiving steroid therapy for hypopituitarism.

Spinal meningioma arising from a lumbar nerve root. Case report

A case is reported of cauda equina compression from an intradural meningioma arising from the L-5 nerve root in a young man.

Lack of efficacy of middle-ear inflation: treatment of otitis media with effusion in children

A randomized controlled trial was conducted to evaluate the efficacy of autoinflation of the middle ear in the treatment of otitis media with effusion. Forty-one children with middle ear effusion not responsive to antimicrobial therapy enrolled in the study. Of these subjects, 75 percent had effusion duration over 3 months. A system consisting of a disposable anesthesia mask attached to a flowmeter was used to teach children to perform autoinflation based on a modified Valsalva technique. Subjects were stratified according to their ability to achieve tubal opening as assessed by tympanometry and tubosonometry. Subjects were randomly assigned to either treatment or observation group and were followed weekly for 2 weeks; subjects in the treatment group attempted inflation three times each day for 2 weeks. Of the 19 subjects who were in the autoinflation group, only one (5.3 percent) was effusion-free at the two-week endpoint and of the 21 subjects in the control, only two (9.5 percent) were without middle-ear effusion. Autoinflation was ineffective for treatment of children with otitis media with effusion in our study.

Failure of cimetidine prophylaxis in neurosurgery

Three hundred and eight-one patients who underwent major neurosurgical procedures were given cimetidine prophylaxis against stress ulceration. Nine patients (2.4%) developed acute gastrointestinal complications; two patients had perforation and bleeding from gastroduodenal ulcers, and seven patients had bleeding alone. Six of these patients, all above the age of 70 years, died as a consequence of the complication. Univariate analysis showed that four variables--state of consciousness, syndrome of inappropriate secretion of antidiuretic hormone, nature of surgery, and age--were significant factors in predicting cimetidine failure. Multivariate analysis revealed that a patient's pre-operative state of consciousness and the presence of inappropriate secretion of antidiuretic hormone were of independent significance in predicting cimetidine failure. The risk was 52% and 0.07%, respectively, when both factors were either present or absent.

Computerised tomography guided preoperative localisation of small intracranial lesions

A simple method for preoperative localisation of small intracerebral lesions is described. Small cortical and subcortical lesions around the motor area were precisely located with computerised tomography in nine patients and these lesions were then excised through a three centimetre craniotomy.

Reactivity of a new Pan-B monoclonal antibody (MA6) against human leukaemias

The reactivity of a new Pan-B monoclonal antibody, MA6, against 69 cases of ALL, three plasmacytoma, 10 AML and five CML was evaluated. The antibody reacted positively against five of the 11 cases of U-ALL, 15 of the 26 C-ALL and all the cases of Pre B-ALL (one), B-ALL (one), B-CLL (12) and HCL (two). The MA6 did not react against the 16 cases of T-ALL, three plasmacytoma, 10 AML and five CML. The antibody has a broader spectrum of B-cell reactivity than CD9 and CD20 but is similar to the Pan-B antibody, CD19. MA6 appears to react against some of the very immature B cells and is therefore potentially useful, in conjunction with other antibodies such as CD9 and CD19, to confirm the B-lineage of some cases of U-ALL. The difference in the spectrum of reactivity against B-cell malignancies between MA6 and the other CDw40 antibody, G28-5, confirms their difference in antigenic specificity.

In situ detection of Epstein-Barr virus markers in nasopharyngeal carcinoma patients

Cryosections of nasopharyngeal tissue from 9 patients suspected of having nasopharyngeal carcinoma (NPC) were examined for the presence of Epstein-Barr virus (EBV) markers in situ to assess virus infection in the nasopharynx. Viral DNA, EB nuclear antigen, and/or early antigens (EA.D and EA.R) were detected in 5 NPC specimens. EBV infection was not confined to the tumor areas of the biopsy specimens. Lymphoid cells and nontumor areas of these specimens contained EBV markers. In addition, nasopharyngeal tissues obtained from 3 of 4 patients in clinical remission for the disease showed evidence of EBV infection.

Efficacy of a new macrolide (azithromycin). For acute otitis media in the chinchilla model

The efficacy of an investigational macrolide, azithromycin, in the treatment of acute otitis media consequent to an infection by a strain of beta-lactamase-producing Haemophilus influenzae, was evaluated using the chinchilla animal model. The results indicate that the azithromycin high-dosage (30 mg/kg/d) group has a significantly higher rate for effusion sterilization and resolution as compared with the other treatment groups. Unique pharmacokinetic properties of this investigational antimicrobial were demonstrated. Clinical trials using azithromycin for the treatment of upper respiratory tract infections, including otitis media, are warranted.

The effect of postoperative collateral ligament laxity in total knee arthroplasty

Forty-seven patients who had been treated by 63 total knee arthroplasties were assessed at 12-84 months after the operation. The data were analyzed to determine if collateral ligament laxity had a detrimental effect on the clinical outcome. The Hospital for Special Surgery (HSS) score was used to make the clinical assessment and a modified HSS score, which excluded points awarded for laxity, was also used. Unidirectional (varus or valgus) and total (varus and valgus) laxity were used as a basis of analysis. None of the examined parameters produced results suggesting that lax knees were worse than stable knees. Indeed, knees with increasing laxity through the categories of mild and moderate showed better statistically significant results in HSS score and pain than those with lesser degrees of laxity. Seventy-five percent of the knees with unidirectional laxity were classified as excellent; only 38.5% of the stable knees were graded as excellent (p less than 0.01). Only 9% of the lax knees had complaints of pain; 38% of the stable knees were painful (p less than 0.05). No significant difference in functional score and walking ability was noted between the lax and the stable knees. Seventy-eight percent of the lax knees had a range of motion over 100 degrees; 62.5% of the stable knees achieved this range.

Prolonged therapeutic external ventricular drainage: a prospective study

Over a 2 1/2-year period, 34 patients underwent therapeutic external ventricular drainage with a valve-regulated system. The mean duration of drainage was 16 days. There was no incidence of ventricular infection, nor was there blockage of the ventricular catheter requiring revision. Eventually, 13 patients required ventriculoperitoneal shunts. All survivors remained free from complications after more than 6 months of follow-up. The system proved safe and reliable in patients requiring prolonged ventricular drainage.

Characterisation and application of a murine monoclonal antibody specific for the serogroup C2 Salmonella

An IgG3 murine monoclonal antibody (designated MO8) specific for the serogroup C2 Salmonella lipopolysaccharide (LPS) was generated by fusing mouse myeloma cells NS1 with spleen cells of BALB/c mice immunised with heat-killed S. manhattan. MO8 reacted with purified LPS prepared from serogroup C2 Salmonella but did not react with that prepared from other O serogroups, and its reactivity was also specifically absorbed by serogroup C2 Salmonella only. Polyacrylamide gel electrophoresis of the serogroup C2 LPS and subsequent immunoblotting with MO8 yielded multiple reactive bands giving a characteristic ladder pattern. The specificity of MO8 was further demonstrated in the slide agglutination test with 223 bacteria, of which only 25 belonging to serogroup C2 Salmonella reacted with the MO8 ascitic fluid. The specificity of MO8 makes it useful not only for the serological identification of Salmonella but also for the epitope analysis of the serogroup C2 LPS.

A comparative study of amoxicillin-clavulanate and amoxicillin. Treatment of otitis media with effusion

A double-blind randomized clinical trial was conducted at two sites comparing amoxicillin-clavulanate potassium (Augmentin) and amoxicillin trihydrate for the treatment of otitis media with effusion ("secretory otitis media"). One hundred eight subjects were randomly assigned to receive a ten-day course of either drug regimen. Clinical response was assessed at ten days and four weeks after entry. For those without middle ear effusion at four weeks, recurrence rates were measured at 8, 12, and 16 weeks after entry. At ten days following entry, 29 (51.8%) of 56 subjects in the amoxicillin-clavulanate-treated group were effusion free compared with 16 (32.0%) of 50 subjects in the amoxicillin-treated group (P = .06). At four weeks following entry, 26 (50.0%) of 50 subjects in the amoxicillin-clavulanate-treated group were effusion free compared with 23 (51.1%) of 45 subjects in the group given amoxicillin. By the 16-week visit, eight (36.4%) of 22 subjects in the amoxicillin-clavulanate-treated group who were effusion free at four weeks had recurrence of effusion, compared with 12 (63.2%) of 19 subjects in the amoxicillin-treated group. This study suggests that there was a favorable clinical response immediately following treatment in the amoxicillin-clavulanate--treated subjects as compared with those treated with amoxicillin, but this benefit was not sustained at the four-week end point.

Intraventricular haematoma: management of comatose patients with valve regulated external ventricular drainage

Over a 2-year period, 22 consecutive comatose patients (Glasgow Coma Score of less than or equal to 8) with intraventricular haematomas were managed with prolonged external ventricular drainage via an external one-way valve regulated system. The mean duration of drainage was 12 days. The overall mortality was 23%. According to the Glasgow Outcome Scale, 36% had severe to moderate disability and 41% made good recovery. Mortality and morbidity were closely related to the type of intraventricular haematoma and patients' preoperative clinical state. Drainage related complications: infection, and ventricular catheter blockage requiring revision, were not observed as a result of this technique. Of the survivors, nine eventually required ventriculoperitoneal shunts. Sump and valve regulated external ventricular drainage is, therefore, a useful procedure in the management of patients with extensive intraventricular haematoma.

A preliminary report of long-term elimination of detectable mutans streptococci in man

Application of an antimicrobial varnish to the teeth of 33 adult volunteers resulted in the elimination of detectable mutans streptococci from the saliva of 21 of them for a mean period of 34.6 weeks (range, 4 to 89 weeks) without additional treatment. The mean number of applications of varnish required for elimination was 3.14 (range, 1 to 5). Extensive examination of 10 subjects made free of mutans streptococci on the basis of saliva examination revealed no detectable mutans streptococci in their dental plaque. In 14 of the subjects in whom mutans streptococci were eliminated, they subsequently re-appeared after a mean period of 22.7 weeks (range, 4 to 71 weeks). Four out of the five recurrences that were treated were eliminated with only one additional varnish application. The treatment failed to provide long-term elimination of detectable mutans streptococci in 12 of the 33 treated subjects. No serious adverse reactions were observed in any of the treated subjects. The results indicate that it is possible to eliminate mutans streptococci from man in a safe and effective manner.

Strong association between the major histocompatibility complex and systemic lupus erythematosus in southern Chinese

The distribution of HLA-A, B, and DR alleles has been studied in 100 Chinese patients with systemic lupus erythematosus and in 100 healthy Chinese controls. Complement components factor B, C4A and C4B were studied in 72 patients and 61 controls. There was no significant difference between patients and controls in the distribution of HLA-A, HLA-B, factor B and C4B alleles, but there was a significant excess of HLA-DR2 and C4A null in the patients. An unusual variant of C4B was found in 6 patients and 1 control. The possible role of haplotypes is considered in interpreting these results and relating them to previous findings in Chinese.

An instrument using variation of resistance to aid in needle tip insertion in epidural block in monkeys

A new method is proposed to detect the entrance of a needle into the epidural space. Measuring the changes in electric resistance during the insertion of the needle through different tissues in the interspinal space can help anesthesiologists judge whether and when the needle has entered the epidural space. This preliminary, animal study showed that the proposed method performed quite satisfactorily. The electric resistance of the tissues in the interspinal space varied from 1.57 +/- 1.22 k omega to 2.93 +/- 1.14 k omega, and the resistance of the epidural space varied from 9.00 +/- 1.12 k omega to 14.64 +/- 1.25 k omega. The difference was statistically significant (p less than 0.001). This difference in the resistance can be used to verify placement of the tip of the needle in the epidural space and help anesthesiologists administer epidural anesthesia.

Severe thrombocytopenia due to combined cimetidine and phenytoin therapy

Combined use of cimetidine and phenytoin among 1512 neurosurgical patients has led to severe thrombocytopenia in 4 patients. One died, and 1 became vegetative. We propose that cimetidine and phenytoin act synergistically to depress the megakaryocyte at the bone marrow. Because thrombocytopenia and inadequate hemostasis are hazardous in neurosurgery, we recommend discontinuation of the cimetidine and phenytoin combination.

Autoinflation of eustachian tube in young children

Inflation of the middle ear has long been thought to be beneficial in the treatment of otitis media. We describe a new system of autoinflation based on a modified Valsalva technique consisting of an anesthesia mask and a flowmeter which can be used successfully by children. An objective method to record eustachian tube opening during autoinflation using frequency spectrum analysis of the ear canal sounds is also presented. Tubal opening results of this method were compared to the traditional method using preinflation and postinflation tympanometry. Study subjects included 20 adults with normal otologic findings and 35 children with middle-ear effusion; all together 107 ears of children and adults with and without effusion were tested. Using the frequency spectrum analysis, tubal opening was recorded in 75% of adult ears and 56% of children's ears. Also, in both groups, a sound pressure peak with the same characteristic frequency around 2 kHz was associated with tubal openings. The methods described are incorporated into a clinical trial being conducted at the Children's Hospital of Pittsburgh.

Paraplegia due to extramedullary hematopoiesis in thalassemia. Case report

Surgical excision followed by radiotherapy has been the recommended treatment for paraplegia due to extramedullary hematopoiesis in patients with beta-thalassemia. The authors report the successful treatment of such a case by partial excision and repeated blood transfusions.

Characterization of a human B-lymphocyte carcinoma cross-reacting antigen (BLCa) in B lymphocytes identified by two murine monoclonal antibodies

The murine monoclonal antibody (MAb) MA6 is selectively reactive against a large variety of human B lymphocytes including those in early stages of B-cell differentiation such as committed progenitors of B lymphocytes, pre-B lymphocytes, Burkitt lymphoma cells, and those at later stages of differentiation such as peripheral blood B lymphocytes and myeloma cells. The major antigen identified by this antibody on such B lymphocytes (BLCa) is a 55-kDa glycoprotein or a group of similar glycoproteins, with the MA6-reactive determinant localized on the carbohydrate moiety. On isoelectric focusing, this antigen exhibits a degree of charge microheterogeneity, migrating as a diffused band with an average isoelectric point at pH 5.7. BLCa was also identified by another murine MAb, MA5. The antigenic determinant recognized by this antibody is also localized on the carbohydrate moiety of the molecule, but, unlike the MA6-reactive determinant, it is shared by other glycoproteins from different types of cells.

Characterization of a murine monoclonal-antibody-defined B-lymphocyte carcinoma cross-reacting antigen (BLCa) from nasopharyngeal carcinoma tissues

Biopsies were obtained from 12 patients suspected of having nasopharyngeal carcinoma (NPC). A portion of the tissue was submitted for histopathology and another for Western blotting using a murine monoclonal antibody (MAb), MA6. Touch smears of the tissues were also prepared immediately prior to extraction and Western blotting for immunoenzymic staining. The results showed that a B-lymphocyte carcinoma cross-reacting antigen (BLCa), or an antigen similar to it, was the major antigen in the tumor tissue recognized by MA6. The antigen was detected in tissues from 8 patients, of whom 7 had confirmed NPC and one had eskimoma, but not in tissue from the remaining 4 patients who did not have histologically confirmed malignancy. Immunocytology showed that tumour cells were present in the touch smears from all but one of the tumour patients but not in the other patients, and that the tumour cells comprised the large majority of the MA6-reactive cell population. The other MA6-reactive cell types present included certain weakly reactive epithelial cells and occasional lymphoid cells, presumably B lymphocytes. However, these cell types were similarly distributed between the tissues obtained from patients with or without malignant diseases. It was concluded, therefore, that the tumour cells in these tissues are the principal source of BLCa and, as such, the antigen may constitute an objective and reliable marker of NPC.

Evaluation of monoclonal antibodies for the detection of exfoliative nasopharyngeal carcinoma cells

Exfoliative cells were aspirated from 15 patients suspected of having nasopharyngeal carcinoma (NPC) and showing the presence of lesions or other abnormalities in the nasopharynx. They were tested for binding with a 125I monoclonal antibody (MAb) (MA6) which is selectively reactive against human B lymphocytes and a variety of carcinomas. A positive result was obtained from 6/9 patients with, and from 0/5 patients without, histologically confirmed disease. One patient with eskimoma also gave a negative binding result. Cytology was specific but less sensitive, tumour cells being detected in 3 of the patients with confirmed disease. Immunocytology using MA6 was limited, like cytology, by poor recovery of the tumour cells and the results were in complete concordance with cytology. The other MAbs used were raised against carcinoembryonic antigen (CEA) and a carcinoma cell line (Ca2), respectively. The latter was not reactive against the NPC tumour cells while the CEA antibody was not sufficiently selective to be useful.