Lineage tree analysis of immunoglobulin variable-region gene mutations in autoimmune diseases: chronic activation, normal selection

Autoimmune diseases show high diversity in the affected organs, clinical manifestations and disease dynamics. Yet they all share common features, such as the ectopic germinal centers found in many affected tissues. Lineage trees depict the diversification, via somatic hypermutation (SHM), of immunoglobulin variable-region (IGV) genes. We previously developed an algorithm for quantifying the graphical properties of IGV gene lineage trees, allowing evaluation of the dynamical interplay between SHM and antigen-driven selection in different lymphoid tissues, species, and disease situations. Here, we apply this method to ectopic GC B cell clones from patients with Myasthenia Gravis, Rheumatoid Arthritis, and Sjögren's Syndrome, using data scaling to minimize the effects of the large variability due to methodological differences between groups. Autoimmune trees were found to be significantly larger relative to normal controls. In contrast, comparison of the measurements for tree branching indicated that similar selection pressure operates on autoimmune and normal control clones.

Anisotropic Poisson's ratio and compression modulus of cortical bone determined by speckle interferometry

Young's modulus and Poisson's ratios of 6mm-sized cubes of equine cortical bone were measured in compression using a micro-mechanical loading device. Surface displacements were determined by electronic speckle pattern-correlation interferometry. This method allows for non-destructive testing of very small samples in water. Analyses of standard materials showed that the method is accurate and precise for determining both Young's modulus and Poisson's ratio. Material properties were determined concurrently in three orthogonal anatomic directions (axial, radial and transverse). Young's modulus values were found to be anisotropic and consistent with values of equine cortical bone reported in the literature. Poisson's ratios were also found to be anisotropic, but lower than those previously reported. Poisson's ratios for the radial-transverse and transverse-radial directions were 0.15+/-0.02, for the axial-transverse and axial-radial directions 0.19+/-0.04, and for the transverse-axial and radial-axial direction 0.09+/-0.02 (mean+/-SD). Cubes located only millimetres apart had significantly different elastic properties, showing that significant spatial variation occurs in equine cortical bone.

Older age is risk for an international normalized ratio (INR) of 5 or more

The elderly have higher INR values, but this may be due to factors such as inter-current illnesses or drug changes. In the following case-controlled study we contacted 304 patients receiving warfarin treatment, one group with an INR of 5 or more, and three control groups (INR < 2, 2-3.9, 4-4.9). Variables that significantly predicted an INR of 5 or more in a logistic regression model included age, the use of antibiotics, stopping of a chronic drug, and the lack of knowledge of the target INR. After forcing in other variables associated with age (less valve disease, more use of multivitamins, and a lower dose of warfarin) the increased risk was 1.6 (1.12-2.28) per 10 years of age. We conclude that age is an independent risk factor for INR values of 5 or more.

Prolonged international normalized ratio correlates with a large intravascular fluid balance after major abdominal surgery

We performed a prospective randomized study of 32 patients who had undergone pancreaticoduodenectomy and did not receive blood during and after surgery. The patients were prospectively assigned to two groups related to fluid balance in the immediate postoperative period. Group 1 (14 patients) were maintained at a positive intravascular fluid balance of 0-1000 mL; Group 2 (18 patients) were maintained at a positive balance of 1000-2000 mL. Complete blood counts and coagulation tests (International Normalized Ratio) and activated partial thromboplastin time (aPTT) were performed at three time points: the day before surgery, on arrival at the postanesthesia care unit, and on leaving the postanesthesia care unit (16 h later). There were significant differences in International Normalized Ratio values between the groups with deterioration during the time they were in the postanesthesia care unit but not in aPTT values. Positive correlation was found between the amount of positive fluid balance and International Normalized Ratio prolongation, but not with aPTT, suggesting that restricted intravascular fluid balance is beneficial for preservation of coagulation after major abdominal surgery.

A Retrospective Study of the Incidence of Neurological Injury after Axillary Brachial Plexus Block

BACKGROUND

It has been suggested that performing a nerve block under general anesthesia, as customary in pediatric population, may predispose to nerve injury. However, few clinical data exist to either support or refute this assertion.

METHODS

We retrospectively reviewed data on all patients who received an axillary block for upper extremity surgery in our institution during an eight-year period. The blocks were performed under sedation or general anesthesia, without using a nerve stimulator. Perioperative records from the Hand Surgery Unit Clinic were reviewed for postoperative complaints and complications.

RESULTS

In the eight-year period of the review, 336 patients had axillary block. In total, 230 received the block with sedation and 106 during general anesthesia. All the sedated patients were older than 14 years (mean age 45.2), while of the general anesthesia patients 48 were older than 14 years (mean age 13.9 years). There were six cases of postoperative nerve injury in sedated patients (2.6%) vs. eight cases (7.5%) in the general anesthesia patients. Most patients recovered fully within several weeks. One patient had permanent nerve injury.

CONCLUSIONS

Definitive conclusions cannot be drawn because of disparities in patient group demographics (majority of pediatric patients were in the general anesthesia group) and the retrospective nature of this study. Nevertheless, the findings suggest that the conduct of axillary block under general anesthesia in pediatric patients holds a greater potential for nerve injury than when the block is performed under sedation in adults.

ACC/AHA guidelines for preoperative cardiovascular evaluation for noncardiac surgery: a critical point of view

This review examines the issue of preoperative cardiac evaluation from a critical point of view, based on recent medical literature. We reviewed the history of that field and focused on the American College of Cardiology and American Heart Association guidelines, which are a cornerstone in the field of cardiac patients undergoing noncardiac surgery. These guidelines synthesized the data into a comprehensive format and established the concept of integrating the patient's risk with the surgical risk. Nevertheless, there are some weaknesses in the guidelines. We believe that a better understanding of the guideline limitations will allow an improved and more educated practice of its recommendations.

Quantitative analysis of clonal bone marrow CD19+ B cells: use of B cell lineage trees to delineate their role in the pathogenesis of light chain amyloidosis

Light chain amyloidosis (AL) is a bone marrow (BM) plasma cell neoplasia with systemic deposition of Ig light chain amyloid fibrils. Here, we report the identification of clonal CD19 B cells in the BM and the use of a novel mathematical algorithm to generate B cell lineage trees of the clonal CD19 B cells and CD138 plasma cells from the BM of AL patients to delineate the relationship between these two clonal populations. The CD19+ clonal B cells in the BM of AL patients related to the clonal plasma cells represent a pre-plasma cell precursor population. The B cell lineage trees from AL patients also show significant differences in clonal diversification and antigenic selection compared to clones from normal, healthy controls. These data provide a robust example of the use of graphical quantification methods in delineating the role of neoplastic precursors in the pathogenesis of hematopoietic malignancies.

Parathyroid hormone response to tracheal intubation in hyperparathyroid patients and normal subjects

The stress of direct laryngoscopy and passing an endotracheal tube through the vocal cords elicits haemodynamic, metabolic and hormonal changes such as raising blood catecholamine levels. Catecholamines are known stimulants of PTH secretion. The effect of tracheal intubation on plasma parathyroid hormone levels has not yet been investigated. We monitored changes in plasma parathyroid hormone levels before and after tracheal intubation in 72 hyperparathyroid patients undergoing elective parathyroidectomy for primary and secondary hyperparathyroidism. These findings were compared to data collected from 20 subjects who underwent elective surgery (thyroidectomy or laparoscopic cholecystectomy) under general anesthesia. In the control group, tracheal intubation significantly increased plasma parathyroid hormone levels from 59 +/- 31 pg/ml to 91 +/- 40 pg/ml (mean +/- SD) (p<0.0003). In primary hyperparathyroid patients, the identical procedure increased plasma parathyroid hormone levels from 206 +/- 104 pg/ml to 217 +/- 113 pg/ml (p = 0.12) and from 898 +/- 495 pg/ml to 1162 +/- 613 pg/ml (p = 0.07) in secondary hyperparathyroidism patients. We concluded that tracheal intubation raises plasma parathyroid hormone levels. The mechanism underlying this response requires further investigation.

Microbubbles

Gas embolism is a known complication of various invasive procedures, and its management is well established. The consequence of gas microemboli, microbubbles, is underrecognized and usually overlooked in daily practice. We present the current data regarding the pathophysiology of microemboli and their clinical consequences. Microbubbles originate mainly in extracorporeal lines and devices, such as cardiopulmonary bypass and dialysis machines, but may be endogenous in cases of decompression sickness or mechanical heart valves. Circulating in the blood stream, microbubbles lodge in the capillary bed of various organs, mainly the lungs. The microbubble obstructs blood flow in the capillary, thus causing tissue ischemia, followed by inflammatory response and complement activation. Aggregation of platelets and clot formation occurs as well, leading to further obstruction of microcirculation and tissue damage. In this review, we present evidence of the biological and clinical detrimental effects of microbubbles as demonstrated by studies in animal models and humans, and discuss management of the microbubble problem with regard to detection, prevention, and treatment.

Immunoglobulin variable-region gene mutational lineage tree analysis: application to autoimmune diseases

Lineage trees have frequently been drawn to illustrate diversification, via somatic hypermutation (SHM), of immunoglobulin variable-region (IGV) genes. In order to extract more information from IGV sequences, we developed a novel mathematical method for analyzing the graphical properties of IgV gene lineage trees, allowing quantification of the differences between the dynamics of SHM and antigen-driven selection in different lymphoid tissues, species, and disease situations. Here, we investigated trees generated from published IGV sequence data from B cell clones participating in autoimmune responses in patients with Myasthenia Gravis (MG), Rheumatoid Arthritis (RA), and Sjögren's Syndrome (SS). At present, as no standards exist for cell sampling and sequence extraction methods, data obtained by different research groups from two studies of the same disease often vary considerably. Nevertheless, based on comparisons of data groups within individual studies, we show here that lineage trees from different individual patients are often similar and can be grouped together, as can trees from two different tissues in the same patient, and even from IgG- and IgA-expressing B cell clones. Additionally, lineage trees from most studies reflect the chronic character of autoimmune diseases.

Minimally invasive surgery for treatment of hyperparathyroidism

BACKGROUND

Minimal invasive surgery for parathyroidectomy has been introduced in the treatment of hyperparathyroidism.

OBJECTIVE

To evaluate the contribution of the sestamibi-SPECT (MIBI) localization, cervical ultrasonography, and intraoperative rapid turbo intact parathormone assay in minimal invasive parathyroidectomy.

METHODS

Between August 1999 and March 2004, 146 consecutive hyperthyroid patients were treated using the MIBI and ultrasound for preoperative localization and iPTH measurements for intraoperative assessment.

RESULTS

Parathyroid adenoma was detected in 106 patients, primary hyperplasia in 16, secondary hyperplasia in 16, tertiary hyperplasia in 5, and parathyroid carcinoma in 1 patient. Minimal invasive exploration of the neck was performed in 84 of the 106 patients (79.2%) with an adenoma, and in 17 of them this procedure was performed under local cervical block anesthesia in awake patients. Adenoma was correctly diagnosed by MIBI scan in 74% of the patients, and by ultrasound in 61%. The addition of ultrasonography to MIBI increased the accuracy of adenoma detection to 83%. In 2 of the 146 patients (1.4%) iPTH could not be significantly reduced during the initial surgical procedure. Minimal invasive surgery with minimal morbidity, and avoiding bilateral neck exploration, was achieved in 79.2% of patients with a primary solitary adenoma.

CONCLUSIONS

Preoperative localizationof the parathyroid gland by MIBI and ultrasound together with intraoperative iPTH measurements resulted in an overall cure rate of 98.6% for the entire series, The addition of ultrasound to the MIBI scan increased the accuracy of adenoma detection.

Fluid administration during abdominal surgery influences on coagulation in the postoperative period

OBJECTIVE

Postoperative coagulopathy is an important concern for patients after major surgery. Our objective was to define the factors that correlate with postoperative deterioration in coagulation.

DESIGN

Retrospective clinical case study.

SETTING

University hospital.

PARTICIPANTS

Adult patients (n = 150), who underwent major abdominal surgery, were randomly chosen to participate in the study. For each patient, demographic and medical data, anesthetic information, type and duration of surgery, hemodynamic variables, fluid administration, as well as preoperative and postoperative prothrombin time and partial thromboplastin time were collected. Statistical analysis was used to determine which factors correlated with deterioration of coagulation tests.

RESULTS

We found statistically significant correlation between deteriorating coagulation functions and administration of more than 3 l of crystalloids during abdominal surgery. There was also correlation between administration of more than 500 ml of colloid administration and elongation of protrombin time. The remainder of the above studied factors did not correlate with deteriorating coagulation.

CONCLUSIONS

Administration of more than 3-l crystalloids or 500-ml colloids during abdominal surgery correlates with postoperative coagulopathy.

Thoracic epidural local anesthetics are ineffective in alleviating post-thoracotomy ipsilateral shoulder pain

OBJECTIVE

This study was conducted to estimate the incidence and clinical predictors of post-thoracotomy shoulder pain and to determine the effectiveness of thoracic epidural block in alleviating this pain.

DESIGN

A prospective clinical trial.

SETTING

University teaching hospital.

PARTICIPANTS AND INTERVENTIONS

Thirty-two adult patients undergoing elective thoracic surgery consented to participate in the study. All operations were open thoracotomies done by the same team of surgeons and anesthesiologists. A thoracic (T6) epidural catheter was placed before induction of general anesthesia. Each patient received 7 mL of lidocaine 2% epidurally and repeated doses of 5 mL of lidocaine 2% every half hour during the operation. Postoperatively, the occurrence of incision or ipsilateral shoulder pain was observed and treated with a maximal dose of 5 mL of lidocaine 2%. If ineffective, indomethacin suppository (nonsteroidal anti-inflammatory drug [NSAID]) was given. Variables such as patient's age, sex, American Society of Anesthesiologists physical status, type, site and duration of surgery, duration of anesthesia, the resection of main bronchus, and the use of thoracostomy tubes were recorded.

MEASUREMENTS AND MAIN RESULTS

Postoperatively, 10 patients (31%) had shoulder pain, 4 patients (12.5%) complained of incision pain, and 2 (6.3%) complained of both incision and shoulder pain. A bolus of 5 mL of lidocaine 2% in the epidural catheter relieved incision pain in all the patients, but was ineffective for shoulder pain. Indomethacin suppository was effective in these patients. No correlation was found between any variable and the occurrence of shoulder pain.

CONCLUSIONS

It is concluded that post-thoracotomy shoulder pain is a common problem, and the previously mentioned variables did not predict its appearance. Thoracic epidural block is effective in the treatment of incision but not shoulder pain. The NSAID indomethacin suppository was found to be effective for that problem.

Monochromatic light stimuli during embryogenesis enhance embryo development and posthatch growth

Photostimulation with green light accelerated BW and muscle development of broilers. In experiment 1, temperature sensors were inserted into 50 broiler eggs. The eggs were placed under 5 green light-emitting diode (LED) lamps at an intensity of 0.1 W/m2 at eggshell level for 5, 10, 15, 20, and 25 min (n = 10). Egg temperatures were recorded continuously. A high correlation was found between lighting period and egg temperature elevation, and an intermittent light regimen of 15 min on and 15 min off was found to eliminate light-induced egg overheating. In experiment 2, the effect of in ovo green light photostimulation on embryonic development was studied. Five hundred fertile eggs were divided into 2 groups: the first was photostimulated with green light from 5 d of incubation until hatch (0.1 W/m2 intensity) and the second was incubated in the dark. In ovo green light photostimulation caused a significant elevation in BW and breast muscle weight during embryo development and posthatch until 6 d of age. In experiment 3, 240 fertile broiler eggs were divided into 2 groups as described in experiment 2. At hatch, chicks from each in ovo light treatment were divided into 2 subgroups: the first was reared under green light and the second under white light. In ovo photostimulation with green light enhanced BW and breast muscle weight. However, rearing under green light did not have any synergistic effect on BW. Collectively, the results suggest that stimulation with green light enhances development and growth in chicks and that the best effect is achieved when this stimulus is provided during incubation.

Unilateral negative-pressure pulmonary edema in an infant during bronchoscopy

We report here a case of a 3-week-old infant with a lung disease of unknown origin who underwent diagnostic fiber-optic bronchoscopy. During the procedure, she developed unilateral pulmonary edema. Factors that contributed to this complication are discussed along with means to reduce its occurrence.

Cardiorespiratory parameters during conventional or gasless gynecological laparoscopy under general or regional anesthesia

BACKGROUND

Conventional laparoscopy is aided by CO2 insufflation, which may impair the cardiorespiratory system and have life-threatening implications. This procedure is conducted under general anesthesia (GA). Gasless laparoscopy supposedly eliminates most of those disadvantages, but is technically more difficult to perform. In the present study, we compared cardiorespiratory parameters of conventional abdominal laparoscopy under GA to gasless laparoscopy under general or epidural anesthesia.

MATERIAL/METHODS

This is a prospective study. Twenty four healthy female patients undergoing gynecological laparoscopies lasting <90 min were randomly assigned to one of three groups: group 1, conventional laparoscopy under GA; group 2, gasless laparoscopy under GA; and group 3, gasless laparoscopy under epidural anesthesia. Cardiorespiratory parameters and length of operative, postanesthesia care unit (PACU), and hospitalization periods as well as analgesic requirements in the PACU and complications in the operative and postoperative periods were recorded.

RESULTS

No significant differences were detected between groups throughout the operative and postoperative periods, except for a rise in CO2 in group 1 and a lower analgesic requirement in the PACU in group 3.

CONCLUSIONS

General and regional anesthesia may be employed in gasless laparoscopy for gynecological surgery.

Retroperitoneal Hematoma After Spinal Anesthesia with the Paramedian Approach

We present a case of a patient who developed a retroperitoneal bleeding after spinal anesthesia using 22-gauge Quincke needle, with the paramedian approach. Two attempts were needed to accomplish the block. Four hours later the patient complained of back pain radiating to her left calf, with weakness of the quadriceps muscle. Computed tomography revealed a large retroperitoneal hematoma from bleeding lumbar artery. Angiography failed to demonstrate the vessel. The patient was transfused with packed red blood cells and recovered gradually. She had normal coagulation tests throughout the event.

IMPLICATIONS

We describe a case of a large retroperitoneal hematoma after the placement of an uneventful spinal block. The patient required four units of packed red blood cells despite having normal coagulation profiles throughout the event. The diagnosis and treatment of retroperitoneal hematoma are discussed.