Tissue-specific calibration of extracellular matrix material properties by transforming growth factor-β and Runx2 in bone is required for hearing

Physical cues, such as extracellular matrix stiffness, direct cell differentiation and support tissue-specific function. Perturbation of these cues underlies diverse pathologies, including osteoarthritis, cardiovascular disease and cancer. However, the molecular mechanisms that establish tissue-specific material properties and link them to healthy tissue function are unknown. We show that Runx2, a key lineage-specific transcription factor, regulates the material properties of bone matrix through the same transforming growth factor-β (TGFβ)-responsive pathway that controls osteoblast differentiation. Deregulated TGFβ or Runx2 function compromises the distinctly hard cochlear bone matrix and causes hearing loss, as seen in human cleidocranial dysplasia. In Runx2+/⁻ mice, inhibition of TGFβ signalling rescues both the material properties of the defective matrix, and hearing. This study elucidates the unknown cause of hearing loss in cleidocranial dysplasia, and demonstrates that a molecular pathway controlling cell differentiation also defines material properties of extracellular matrix. Furthermore, our results suggest that the careful regulation of these properties is essential for healthy tissue function.

Cycle-averaged dynamics of a periodically driven, closed-loop circulation model

Time-varying elastance models have been used extensively in the past to simulate the pulsatile nature of cardiovascular waveforms. Frequently, however, one is interested in dynamics that occur over longer time scales, in which case a detailed simulation of each cardiac contraction becomes computationally burdensome. In this paper, we apply circuit-averaging techniques to a periodically driven, closed-loop, three-compartment recirculation model. The resultant cycle-averaged model is linear and time invariant, and greatly reduces the computational burden. It is also amenable to systematic order reduction methods that lead to further efficiencies. Despite its simplicity, the averaged model captures the dynamics relevant to the representation of a range of cardiovascular reflex mechanisms.

A voxel-based morphometry study of patterns of brain atrophy in ALS and ALS/FTLD

OBJECTIVE

To investigate the patterns of MRI brain atrophy in patients with ALS with and without clinically evident frontotemporal lobar dementia (FTLD) using voxel-based morphometry (VBM).

METHODS

Voxel-based morphometry was used to compare T1-weighted MRI images obtained from ten ALS patients with FTLD, ten ALS patients who were cognitively and behaviorally normal, and 22 control subjects. Images from patients and controls were spatially pre-processed using a study-specific, customized template and a priori images. A statistical threshold of p < 0.05 corrected for multiple comparisons determined significance.

RESULTS

A common pattern of gray matter atrophy was seen in both ALS and ALS/FTLD patients when compared to controls that involved the bilateral motor/premotor cortices, the left middle and inferior frontal gyri, the anterior portion of the superior frontal gyri, the superior temporal gyri, the temporal poles and left posterior thalamus. Most of the frontal regions were significantly more atrophied in the ALS/FTLD group than in the ALS group. No significant differences were found in white matter volumes.

CONCLUSIONS

Patients with ALS and ALS associated with frontotemporal lobar degeneration exhibit widespread gray matter atrophy in frontotemporal regions. This finding supports the idea of a clinical and anatomic continuum between ALS and frontotemporal lobar degeneration.

Sequence variants and functional analysis of human papillomavirus type 16 E5 gene in clinical specimens

Previously, we found that the E5 protein can be expressed in HPV-16 infected precancerous lesions and cervical cancer. In this study, we investigated the presence of sequence variants of E5 in HPV-16 infected tissues. Toward this end, we amplified the E5 gene by polymerase chain reaction from 29 HPV-16 infected tissues including eight normal tissues, seven high grade neoplastic tissues (high grade squamous intraepithelial lesions (HSIL) and 14 cervical cancer tissues. Sequence analysis demonstrated that there were three mutational hot spots at positions 3979, 4042, and 4077 of the HPV-16 DNA; these and other mutations resulted in six variants in the E5 sequence. This resulted in four E5 protein mutants, named WTE5 [wild type E5 protein], 14E5, 21E5 and 56E5. Functional analysis of these four mutant proteins revealed that the transforming activities of 14E5, 21E5 and 56E5 were 0.95, 0.59, and 0.89 fold of WTE5, respectively. Although E5 was expressed in all of the HSIL and cervical cancer tissues, but in only one of the eight normal tissues tested, only WT E5 protein was found in HSIL while in cervical cancer tissues both WT and mutant E5 proteins were detected. Since these E5 proteins exhibited the same in vitro transforming activity, these data suggest that expression of E5 is important in development and progression toward malignancy but mutation of E5 does not affect the transformation process.

The expression of HPV-16 E5 protein in squamous neoplastic changes in the uterine cervix

To investigate the expression of human papillomavirus type 16 (HPV-16) E5 protein in squamous neoplastic changes in the uterine cervix, the specific E5 antibody was generated and used to identify the expression of E5 protein in 40 cases of HPV-16-positive tissues and 5 previously identified HPV-negative normal cervical tissues. The results revealed that E5 protein was primarily expressed in the lower third of the epithelium in low-grade squamous intraepithelial lesions (SILs) and throughout the whole epithelium in high-grade SILs. In invasive squamous carcinoma, 60% of HPV-16-infected cancers which contained the episomal viral genome had the E5 gene, and could express E5 protein which was located throughout the whole epithelium. Previously, we documented the expression of type I growth factor receptors [ERBB1/EGFR (epidermal growth factor receptor), ERBB2, ERBB3 and ERBB4] in the full range of cervical neoplasias by immunohistochemistry assay. Hence, in this study, we extensively analyzed the correlation between the expression of E5 protein and the expression of type I growth factor receptors. Among 40 HPV-16- infected cervical neoplasias, we found that the expression of E5 protein was significantly correlated with either the expression of the ERBB1 or the ERBB4 receptor.

The impact of simulated distal interphalangeal joint fusion on grip strength

This study assessed the impact of distal interphalangeal (DIP) joint fusion on grip strength and how this may be related to a profundus quadriga. Nineteen adults (12 men and 7 women) with an average age of 32.6 years (range: 24-61 years) underwent a series of grip strength measurements with simulation of DIP arthrodesis to the index, long, and index and long (index-long) fingers. The nondominant hand served as a control for the testing. All participants were tested in the same manner: baseline dominant and nondominant hands without DIP block followed by blocking of DIP flexion on the dominant hand only for index, index-long, and long finger alone. Nondominant hands also were tested each time, but without blocking to serve as a control for normal changes in grip strength with repeated testing. Grip strength values were compared to baseline for each trial using the Student's t test. Significant decreases in grip strength were seen for all DIP blocking compared with baseline, but no significant differences were noted in the equivalent trial in the nondominant, nonblocked hand. These findings may have clinical relevance when performing DIP arthrodesis.

Adenovirus-mediated p21((WAF1/SDII/CIP1)) gene transfer induces apoptosis of human cervical cancer cell lines

p21((WAF1/SDII/CIP1)) (p21) arrests cell growth by inhibiting cyclin-depend kinases. To explore the potential of using p21 for the gene therapy of cervical cancer, we infected human papillomavirus (HPV)-positive cervical cancer cells (HeLa, SiHa, and Z172) and HPV-negative cervical cancer cells (C33A) with recombinant adenovirus encoding p21 cDNA. The results revealed that effective inhibition of cell growth could be achieved by sense p21 adenovirus but not antisense p21 adenovirus infection and occurred through apoptosis as measured by DNA fragmentation and chromatin condensation. Apoptosis was also observed in xenografts of human cervical cancer cells infected with sense p21 adenovirus, as confirmed by in situ terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling (TUNEL). The apoptosis was not prevented by overexpression of the bcl-2 transgene. To sum up, the apoptotic effect suggests that p21 should be a tumoricidal agent instead of a tumoristatic agent in preventing cervical cancers. In addition, our report substantiates the combination of the high efficiency of adenovirus vector-mediated gene delivery and the apoptotic effect of p21.

The expression of type I growth factor receptors in the squamous neoplastic changes of uterine cervix

AIM

The type I family of growth factor receptors includes ErbB1, ErbB2, ErbB3, and ErbB4 which are frequently overexpressed in various human cancer cells. In this study, we systematically investigated the frequency and distribution of these four receptors in relation to neoplastic changes and tumor behaviors in the uterine cervix.

MATERIALS

A total 84 of cases including 12 cases of normal cervical tissues, 6 cases of low grade squamous intraepithelial lesion, 10 cases of high grade squamous intraepithelial lesion, and 56 cases of squamous cells carcinoma were examined.

RESULTS

Our results show significant difference with increasing grades of dysplasia in terms of these four receptor expressions. No association was found between these four receptors and cell keratinization/differentiation of squamous cell carcinoma of the cervix. Of the four receptors studied, only the expression of erbB2/neu gene was significantly associated with lymph nodal metastasis. Moreover, we find that the coexpression of ErbB1 and ErbB4 was significant in cervical carcinoma.

CONCLUSIONS

The coexpression of ErbB1 and ErbB4 in cervical carcinoma suggests that they may be involved in receptor heterodimerization leading to the activation of signaling pathway in the cervical carcinoma.

Characterization of 14 different putative protein kinase cDNA clones of the C4 plant Sorghum bicolor

C4 photosynthesis is functionally dependent on metabolic interactions between mesophyll- and bundle-sheath cells. Although the C4 cycle is biochemically well understood, many aspects of the regulation of enzyme activities, gene expression and cell differentiation are elusive. Protein kinases are likely involved in these regulatory processes, providing links to hormonal, metabolic and developmental signal-transduction pathways. Here we describe the cloning and characterization of 14 different putative protein kinase leaf cDNA clones from the C4 plant Sorghum bicolor. These genes belong to three different protein kinase subfamilies: ribosomal protein S6 kinases, SNF1-like protein kinases, and receptor-like protein kinases. We report the partial cDNA sequences, mesophyll/bundle-sheath steady-state mRNA ratios, mesophyll/etiolated leaf steady-state mRNA ratios, and the positions of 14 protein kinase genes on the genetic map of S. bicolor. Only three of the protein kinase genes described here are expressed preferentially in mesophyll cells as compared with the bundle-sheath.

The induction of apoptosis by SV40 T antigen correlates with c-jun overexpression

Simian virus (SV40) T antigen shares many characteristics with adenovirus E1A which is known to induce apoptosis. To verify the potential of SV40 T antigen-mediated apoptosis, we stably expressed T antigen in immortalized human epithelial cells (Z172 and HaCaT). We found that SV40 T antigen could directly cause apoptosis in 22-27% of these cells under normal growth condition as measured by chromatin condensation and nucleosomal fragmentation. The apoptosis of HaCaT cells which contain mutant p53 suggests the p53-independent nature of T antigen-mediated apoptosis. T antigen-induced apoptosis was associated with increased expression of c-Jun protein. Moreover, the overexpression of c-jun alone in these cells also induced apoptosis, indicating that c-jun might play an important role in T antigen-induced apoptosis.

A second type of rod opsin cDNA from the common carp (Cyprinus carpio)

A second type of rhodopsin cDNA from carp (cRh-II) shared 97.2% polynucleotide identity with the previously reported cRh-I. The deduced amino acid sequences of cRh-I and cRh-II exhibited 98.6% identity. The key difference between these two types of cRh is that valine at position 169 of cRh-I was replaced by glutamic acid in cRh-II. Southern blot analysis of genomic DNA showed that there were two types of cRh gene. These two rod opsin genes were proven to be expressed in carp retinas by using RT-PCR with type-specific primers.

Carp cDNA sequence encoding a putative diazepam-binding inhibitor/endozepine/acyl-CoA-binding protein

A full-length cDNA coding for common carp diazepam-binding inhibitor (DBI)/endozepine (EP)/acyl-CoA-binding protein (ACBP) was isolated and sequenced. The deduced DBI/EP/ACBP is comprised of 87 amino acids (including initiating methionine) without possessing a signal peptide. Common carp DBI/EP/ACBP displays 77%, 78%, 70%, 63%, 61% and 45% identity with human, bovine, rat, frog, duck and yeast DBI/EP/ACBP, respectively.

Acute fracture bipartite patella: case report and literature review

Disorders of the patella are the most common cause of anterior knee pain. The etiologies of anterior knee pain are reviewed. A case report of an acute displaced patella fracture in a bipartite union is presented. Bipartite patellar development, incidence, radiographic findings, and clinical symptoms follow. Treatment of excision of displaced fragment provides an excellent result.

Osteoid osteoma of the os calcis in a teenage athlete

Osteoid osteomas are small, benign bone tumors most commonly located in the proximal femur or tibia. The classic presentation is localized pain increasing in severity at night, and relieved by the use of anti-inflammatory medications. In a young athlete complaining of foot pain, many conditions should be included in the differential diagnosis. A case of osteoid osteoma of the os calcis in a teenage basketball player is presented.

Cyclization of disulfide-containing peptides in solid-phase synthesis

Disulfide-containing peptides may be obtained in good yields and purities when oxidations are carried out on peptide chains anchored to polymeric supports used for solid-phase synthesis. Such approaches take advantage of the pseudo-dilution phenomenon which favors intramolecular processes. A variety of procedures have been demonstrated using the related model peptides Ac-Cys-Pro-D Val-Cys-NH2 and Ac-Pen-Pro-D Val-Cys-NH2 (which both readily assume a type II beta-turn conformation that becomes stabilized by a 14-membered disulfide-containing intramolecular ring), and oxytocin (conformationally mobile 20-membered disulfide ring). Both Boc and Fmoc were used for N alpha-amino protection, the beta-thiols of cysteine or penicillamine were blocked by S-acetamidomethyl (Acm), S-9-fluorenylmethyl (Fm), or S-trityl (Trt), and compatible anchoring linkages included HF-labile 4-methylbenzhydrylamide (MBHA), TFA-labile tris (alkoxy)benzylamide (PAL), and photolabile o-nitrobenzylamide (Nonb). Assemblies of linear sequences proceeded smoothly, and polymer-supported oxidations were carried out in a variety of ways either directly or after deblocking to the resin-bound dithiol. Chains were released from the support without substantial damage to the disulfide bridges, and overall yields were as high as 60-90%.

[Primary small cell carcinoma of the kidney: report of a case]

Primary small cell carcinoma (SCC) of the kidney is an extremely rare neoplasm. The morphological, immunohistological and ultrastructural features are closely akin to primary SCC of the lung. The case of a 38-year-old married male, nonsmoker, with primary small cell carcinoma of the kidney and associated multiple bony metastases is reported. Roentgenographic studies exhibited a tumor mass 3 cm in diameter over the middle portion of the left kidney. A CT scan of the cervical and thoracic spines, and a whole body bone scan displayed multiple osteolytic lesions suggesting multiple bony metastatic lesions. A chest X ray and CT scan of the nasopharynx demonstrated no significant lesions. A complete workup was performed followed by a left nephrectomy. Histologically, the tumor revealed SCC of the kidney. Immunohistochemically, the tumor cells demonstrated immunoreactivity to cytokeratin (CK), neuron-specific enolase (NSE) and produced negative stains to argentaffin, argyrophil, S-100 and chromogranin A. Ultrastructurally, these neoplastic small cells revealed a few cytoplasmic dense-core neuroendocrine-type differentiated secretory granules, measuring 110 to 115 nm in size. Thus, adjuvant therapy, supplemented with chemotherapy and radiotherapy, was employed. The patient was alive and well 6 months after surgery. To the best of our knowledge, there are four documented cases of primary SCC of the kidney. In this article, the light microscopic, immunohistochemical and ultrastructural studies of renal SCC are presented and suggest a renal pelvic epithelial origin of renal SCC. Cognitively renal SCC appears to be an aggressive tumor, regardless of the degree of neuroendocrine differentiation.

Characterization and partial purification of the cockroach antigen in relation to housedust and housedust mite (D.f.) antigens

Allergens in crude cockroach antigens (CRa) have not been well defined. In order to characterize the CRa, the authors partially purified CRa by gel filtration (G-75) and analyzed it by polyacrylamide electrophoresis (PAGE) and allergy skin testing (AST). Hyperimmune serum was produced against CRa in rabbit (R anti-CRa) and used for immunoelectrophoresis (IEP), double immunodiffusion (DID), crossed immunoelectrophoresis (CIE), and crossed radio immunoelectrophoresis (CRIE) to further characterize the CRa. The crude CRa contained 9 and 15 precipitating arcs by IEP and CIE, respectively. Indirect CRIE revealed that CRa contained nine to 15 different allergens. There were no lines of identity between the CRa and housedust mite (D.f.) or between the CRa and commercial housedust by DID or IEP. Autologous housedust of cockroach asthmatic subjects showed lines of identity with the CRa. Fractionation of CRa on a Sephadex G-75 column chromatography showed two distinct peaks (B1 and B2) separated by a broad valley. The high molecular fraction B1 was most allergenic (100%) and contained three antigens of high molecular weight. These three antigens were identifiable by the techniques of IE, CIE, and DID. B2, the low molecular fraction (molecular weight less than 13,000 dalton) contained minor allergen(s). B2 elicited positive AST in 55% of cockroach-sensitive individuals, but it was not detected by IEP, CIE, nor by DID.

Inflammatory pseudotumor of the spleen--case report and literature review

Inflammatory pseudotumor (IPT) of the spleen is an extremely rare benign lesion. We herein report an additional case of a 64-year-old man with IPT of spleen to compare with seven cases previously reported in the literature. However, the immunohistochemical studies has demonstrated to polyclonality of plasma cells which was comparable to these seven previously reported cases. The clinical and pathological findings, as well as the possibilities of etiology and pathogenesis are also described.

The role of immunotherapy in cockroach asthma

To evaluate the preventive role of immunotherapy in severe perennial asthma, we investigated cockroach asthma as a model. Twenty-eight subjects with bronchial asthma due to cockroach hypersensitivity (BACR) were divided into two groups in alternating order: 15 were started with cockroach antigen immunotherapy (CRa-IT) and 13 were given control immunotherapy. Eleven in the former group and two in the latter group completed the study after 5 years. The changes in symptoms and medication scores were assessed; blocking antibody factor in the paired pre- and postimmune serum of the two groups was measured and compared. Cellular sensitivity (HR50) was measured using the basophil-rich leukocytes (BRLs) obtained from the two treated asthma groups, and the result was compared with that of the untreated cockroach asthmatic cells. The average symptom score changed from 7.2 +/- 2.7 to 1.2 +/- 0.4 in the CRa-IT group. The control-IT group showed no change. The medication score changed from 11.4 +/- 1.6 to 5.2 +/- 1.4 in the CRa-IT group only (p less than 0.01). The mean blocking antibody factor in the immune serum of the CRa-IT group showed a 2.5 x 10(2)-fold increase [1.3 +/- 0.3 x 10(-1) in postimmune serum/5.2 +/- 2.0 +/- 10(-4) in preimmune serum (p less than 0.001)]. No difference was noted in the HR50 of the BRLs in the post- and preimmune serum of the control-IT group. Antihuman IgG absorption of the post-CRa-IT serum reduced the blocking antibody to 1/1000-fold; no difference in the HR50 of the BRLs was noted between the post-control-IT and the pre-CRa-IT serum (p greater than 0.2). The BRLs of the CRa-IT asthmatics, however, showed blunted sensitivity not affected by the serum factor (5.8 +/- 1.5 x 10(-2) micrograms/ml in post-CRa-IT serum and 5.6 +/- 1.3 x 10(-2) micrograms/ml in pre-CRa-IT serum) (p greater than 0.2). The BRLs of the control-IT group retained their cell sensitivity as well as the blocking effect of the CRa-immune serum. This study thus demonstrated that CRa-IT reduces symptom and medication scores clinically in cockroach-asthmatic subjects, and the CRa-IT produces the CRa-specific blocking antibody of the IgG type. It also reduces anaphylactic leukocyte sensitivity, which is not affected by humoral factor.

Nonflammable endotracheal device for CO2 laser ablation of benign laryngeal and proximal tracheal tumors

A Holinger aspirating tube may be utilized as a nonflammable endotracheal device during CO2 laser ablation of benign laryngeal and proximal tracheal tumors. Adequate jet ventilation may be performed through this small diameter (3.0 mm), metallic device while providing an unobstructed view of the surgical lesion. This technique was well-accepted by surgeons during the clinical trials. Because the 3.0 mm outside diameter was significantly smaller than the smallest flexible, uncuffed metal endotracheal tube currently available (6.9 mm), the rigid structure facilitated atraumatic insertion past the surgical lesion. Both the use of this device and the required anesthetic technique are described in three CO2 laser ablative procedures. The authors consider that this device increases safety during this potentially hazardous procedure by eliminating the flammable polyvinyl chloride endotracheal tube and cottonoid packings most frequently used during this procedure.

Effect of exercise on cation transport in human red cells

To test the hypothesis that environmental as well as genetic factors are important determinants of monovalent cation transport systems in humans, and to explore potential basic mechanisms of the alleged antihypertensive effects of habitual exercise, we studied the effects of a 12-week exercise program (45 minutes, 3-5 times per week) upon several membrane transport parameters in erythrocytes from a population of 63 adult men (30 normotensive subjects and 33 essential hypertensive patients). Subjects were randomly assigned into either an exercise group or a sedentary control group, and clinical and membrane transport parameters were measured at baseline and after 3 months. Exercising subjects demonstrated increases in maximal treadmill work capacity (p less than 0.001) and high-density lipoprotein cholesterol levels (p = 0.009) as well as decreases in heart rate at a fixed submaximal workload (p less than 0.05) and body weight (p less than 0.001) relative to the sedentary group. In conjunction with these well-described effects of exercise conditioning, the exercise group demonstrated a significant decrease in Na+-Li+ countertransport (p = 0.002), without significant changes in any other transport parameters measured. Blood pressure was not significantly altered in either group. We conclude that powerful environmental influences such as exercise training may act in concert with genetic factors to influence monovalent cation transport in humans and must be considered in further investigations of the pathophysiological linkage between altered monovalent cation transport and essential hypertension.

Is running an analogue of anorexia nervosa? An empirical study of obligatory running and anorexia nervosa

A recent report suggested that compulsive runners share a common set of psychological traits and behavioral dispositions with patients with anorexia nervosa. In an effort to objectively assess the similarity between anorexia nervosa and obligatory running, 43 runners and 24 patients with anorexia nervosa completed the Minnesota Multiphasic Personality Inventory (MMPI). Results indicated that the obligatory runners generally scored within the normal range, while the anorectic patients did not. The anorectic patients obtained more pathological scores than the runners on eight of the ten clinical subscales of the MMPI. Fifty percent of the anorectic patients obtained elevations on three or more of the MMPI subscales, while no runners obtained more than two scale elevations. Depression (scale 2) and psychopathy (scale 4) were particularly prevalent in the anorectic group. We conclude that obligatory runners do not suffer from the same degree of psychopathology as do patients with anorexia nervosa.

Enflurane-induced grand mal seizures during otic microsurgery

Abnormal electroencephalographic seizure-like activity and myoclonic movements have been recognized during enflurane anesthesia. This is most commonly seen in the presence of respiratory alkalosis and high concentrations of enflurane. Immediate and delayed postoperative generalized tonic-clonic convulsions have also been reported after enflurane anesthesia. Experimental studies have shown that auditory stimuli could facilitate seizure activity during deep enflurane anesthesia. Here we report a case of intraoperative generalized tonic-clonic convulsion during low concentrations of enflurane without evidence of hyperventilation and the presence of auditory stimulation.

Characterization of the B-chain of human plasma alpha 2HS-glycoprotein. The complete amino acid sequence and primary structure of its heteroglycan

alpha 2HS-Glycoprotein, a normal human plasma protein, was recently shown to consist of two polypeptide chains. In the present study, we have separated these two chains from one another and have elucidated the complete primary structure of the B-chain. Employing automated Edman degradation, the polypeptide moiety of this chain was shown to consist of 27 amino acid residues with an unequal distribution of the neutral and charged amino acid residues. The first 20 residues are uncharged, whereas the carboxyl-terminal heptapeptide contains all charged residues. Utilizing 500-MHz 1H-NMR spectroscopy, the carbohydrate unit proved to be a trisaccharide consisting of sialic acid, galactose, and N-acetylgalactosamine O-glycosidically linked to serine (residue 6). The structure of the B-chain was found to be as follows. (formula; see text) Thus, the molecular weight of the B-chain is 3386. Evaluation of the polypeptide chain by the procedure of Chou and Fasman (Chou, P.Y., and Fasman, G.D. (1979) Adv. Enzymol. 47, 45-148) predicts that the B-chain has two beta-turns. Thereby, the carbohydrate unit which is linked to the Ser residue located in the first beta-turn appears to be directed away from the protein. The second beta-turn probably includes the Cys residue which links the B- to the A-chain. In agreement with the CD analysis, the B-chain lacks beta-conformation but possesses a short alpha-helical region.

Jet ventilation for operative laryngoscopy

High pressure oxygen jet ventilation via a small bore endotracheal tube has been found to be a very effective method for operative laryngoscopy and bronchoscopy under general anesthesia. Advantages of this technique include easily visualization of the larynx and good access for surgical manipulations and bronchoscopic procedures while maintaining excellent patient oxygenation and ventilation. There are few contra-indications for this procedure. Over the past 7 years we have done several thousand operative laryngoscopies using high pressure oxygen jet ventilation with few complications and excellent anesthetic and surgical results.

Inadvertent endobronchial intubation with nasogastric tube. Occurrence after head and neck surgery

Inadvertent endobronchial intubation with nasogastric tubes is hazardous. Massive aspiration can be fatal after nasogastric feeding. In this study, methods of blind nasogastric tube insertion and conventional techniques of confirming the site of the tube are discussed. We stress that direct laryngoscopy either during or immediately after placement or a chest roentgenogram should be considered in the case of nasogastric feeding after major head and neck surgery.

An alpha2-macroglobulin associated factor produced by T lymphocytes which provides polyclonal stimulation of B lymphocytes to maintain the turnover of their surface Ig

The supernatant of 'crowded' but not 'spread' rabbit spleen cell cultures contains a macroglobulin factor which behaves in an Ig-turnover assay as any T-independent antigen or polyclonal B-cell activator (PBA). In the supernatants of crowded rabbit lymphoid cell cultures prepared in serum free medium, the factor was found to be associated entirely with the alpha-macroglobulin (alpha M) fraction (alpha 1 + alpha 2). This alpha M was most probably actively secreted by the lymphocytes because: (i) sequential supernatants obtained in serum free medium of crowded cultures contained equal amounts of alpha M as well as equal PBA activity; (ii) the alpha M became labelled when the cells were grown in medium containing a radioactive amino acid. Macrophages were not required for the production of PBA. PBA was not produced when either crowded B or T cells were cultured alone but only when they were cultured together. Purified T cells were not triggered by any plant lectin to produce PBA. By use of anti-alpha 2M allotype antibodies and B and T cells from different rabbits, the PBA was shown to have the allotype of the T-cell donor. The PBA was associated with rabbit alpha 2M but not alpha 1M. We concluded that upon close contact, B cells stimulate T cells to produce a PBA associated with alpha 2M.

Postoperative venous air embolism after removal of neck drains

Venous air embolism has been known to be a major hazard during diagnostic, therapeutic, and surgical procedures. An acute massive venous air embolism can cause obstruction of the pulmonary outflow tract and subsequently result in cardiac standstill. Sudden cardiopulmonary instability occurred in a patient after removal of neck drains. Various methods of diagnosis and treatment can be used to manage this complication. An awareness of this potential complication and early diagnosis with prompt management are critical.

Stress-strain relationship and neurological sequelae of uniaxial elongation of the spinal cord of cats

An in vivo experimental method was developed to measure the mechanical or rheological properties of the spinal cord of anesthetized cats. This novel approach resulted in measurements of the tensile force in the cord and the modulus of the spinal cord tissue under longitudinal elongation. Both sensory and motor function of the cats recovered within a week after a spinal cord segment had been stretched by a 50% elongation.

Polyclonal B cell activator associated with alpha-2-macroglobulin in the serum of patients with rheumatoid arthritis

We investigated whether patients with rheumatoid arthritis have a polyclonal B cell activator (PBA) in their serum by using three methods: (1) the ability of any PBA to maintain the surface Ig of rabbit or human B cells in vitro; (2) the induction of blast transformation in human B lymphocyte cultures, and (3) stimulation of nude mouse spleen cells in vitro. All three methods indicated that a PBA is present in the serum of patients with rheumatoid arthritis but not in normal individuals or in patients with arthritis in which autoimmune phenomena have not been demonstrated. The entire PBA activity in rheumatoid arthritis patient serum was found associated with the macroglobulin fraction obtained by Sephadex G-200 chromatography and was precipitated by rabbit anti-human alpha 2-macroglobulin, but not by rabbit anti-Ig antibody. When alpha 2-macroglobulin was purified from patient serum the entire PBA activity was recovered in this fraction. Normal alpha 2-macroglobulin prepared by the same procedure had no PBA activity. Thus, the existence of a PBA associated with alpha 2-macroglobulin was demonstrated in serum of patients with rheumatoid arthritis.