In situ process monitoring in selective laser sintering using optical coherence tomography

Selective laser sintering (SLS) is an efficient process in additive manufacturing that enables rapid part production from computer-based designs. However, SLS is limited by its notable lack of in-situ process monitoring when compared to other manufacturing processes. We report the incorporation of optical coherence tomography into an SLS system in detail and demonstrate access to surface and sub-surface features. Video frame rate cross-sectional imaging reveals areas of sintering uniformity and areas of excessive heat error with high temporal resolution. We propose a set of image processing techniques for SLS process monitoring with OCT and report the limitations and obstacles for further OCT integration with SLS systems.

Antibody-mediated thyroid dysfunction during T-cell checkpoint blockade in patients with non-small-cell lung cancer

Background

Programmed cell death protein-1 (PD-1) blockade therapies have demonstrated durable responses and prolonged survival in a variety of malignancies. Treatment is generally well tolerated although immune-related adverse events (irAEs) can occur. Autoimmune thyroid dysfunction is among the most common irAE, but an assessment of the clinical, mechanistic, and immunologic features has not been previously described.

Patient and methods

Patients with advanced non-small-cell lung cancer (NSCLC) treated with pembrolizumab at Memorial Sloan Kettering Cancer Center (n = 51) as part of KEYNOTE-001 (NCT01295827) were included. Thyroid function test and anti-thyroid antibodies were assessed prospectively at each study visit, beginning before the first treatment. Frequency of development of thyroid dysfunction, association with anti-thyroid antibodies, clinical course, and relationship with progression-free survival and overall survival to treatment with pembrolizumab was evaluated.

Results

Of 51 patients treated, 3 were hypothyroid and 48 were not at baseline. Ten of 48 [21%, 95% confidence interval (CI) 10% to 35%] patients developed thyroid dysfunction requiring thyroid replacement. Anti-thyroid antibodies were present in 8 of 10 patients who developed thyroid dysfunction, compared with 3 of 38 who did not (80% versus 8%, P < 0.0001). Thyroid dysfunction occurred early (median, 42 days) in the pembrolizumab course, and a majority (6 of 10 patients) experienced brief, transient hyperthyroidism preceding the onset of hypothyroidism; no persistent hyperthyroidism occurred. Both hyperthyroidism and hypothyroidism were largely asymptomatic. Overall survival with pembrolizumab was significantly longer in subjects who developed thyroid dysfunction (hazard ratio, 0.29; 95% CI 0.09-0.94; P = 0.04).

Conclusions

Thyroid dysfunction during pembrolizumab treatment of NSCLC is common and is characterized by early-onset, frequently preceded by transient hyperthyroidism, closely associated with anti-thyroid antibodies, and may be associated with improved outcomes. The presence of antibody-mediated toxicity in T-cell-directed therapy suggests an under-recognized impact of PD-1 biology in modulating humoral immunity.

Necrotizing Enteritis and Hyperammonemic Encephalopathy Associated With Equine Coronavirus Infection in Equids

Equine coronavirus (ECoV) is a Betacoronavirus recently associated clinically and epidemiologically with emerging outbreaks of pyrogenic, enteric, and/or neurologic disease in horses in the United States, Japan, and Europe. We describe the pathologic, immunohistochemical, ultrastructural, and molecular findings in 2 horses and 1 donkey that succumbed to natural infection with ECoV. One horse and the donkey (case Nos. 1, 3) had severe diffuse necrotizing enteritis with marked villous attenuation, epithelial cell necrosis at the tips of the villi, neutrophilic and fibrinous extravasation into the small intestinal lumen (pseudomembrane formation), as well as crypt necrosis, microthrombosis, and hemorrhage. The other horse (case No. 2) had hyperammonemic encephalopathy with Alzheimer type II astrocytosis throughout the cerebral cortex. ECoV was detected by quantitative polymerase chain reaction in small intestinal tissue, contents, and/or feces, and coronavirus antigen was detected by immunohistochemistry in the small intestine in all cases. Coronavirus-like particles characterized by spherical, moderately electron lucent, enveloped virions with distinct peplomer-like structures projecting from the surface were detected by negatively stained transmission electron microscopy in small intestine in case No. 1, and transmission electron microscopy of fixed small intestinal tissue from the same case revealed similar 85- to 100-nm intracytoplasmic particles located in vacuoles and free in the cytoplasm of unidentified (presumably epithelial) cells. Sequence comparison showed 97.9% to 99.0% sequence identity with the ECoV-NC99 and Tokachi09 strains. All together, these results indicate that ECoV is associated with necrotizing enteritis and hyperammonemic encephalopathy in equids.

Clinical outcomes in elderly patients with advanced non-small cell lung cancer: results from ARIES, a bevacizumab observational cohort study

AIMS

Retrospective analyses from first-line clinical studies in advanced non-small cell lung cancer (NSCLC) have reported conflicting results on progression-free survival (PFS) and overall survival benefits with the addition of bevacizumab to chemotherapy in elderly patients. Here we report effectiveness and safety outcomes by age subgroup for patients with NSCLC in the ARIES observational cohort study.

MATERIALS AND METHODS

ARIES enrolled patients with advanced non-squamous NSCLC who received first-line bevacizumab-containing treatment per physician's choice. Kaplan-Meier estimates were used to calculate medians and 95% confidence intervals for PFS and overall survival for patients aged <65, ≥65, <75 and ≥75 years.

RESULTS

In total, 1967 patients receiving first-line treatment with bevacizumab and chemotherapy were enrolled. The median PFS and overall survival values were 6.4 (95% confidence interval = 6.0-6.8) and 14.2 (95% confidence interval = 12.7-15.2) months for patients aged <65 years, respectively, and 6.8 (95% confidence interval = 6.3-7.0) and 12.1 (95% confidence interval = 11.4-13.1) months for patients ≥65 years, respectively. For patients <75 years, the median PFS and overall survival values were 6.6 (95% confidence interval = 6.3-6.9) and 13.5 (95% confidence interval = 12.6-14.5) months, respectively, and 6.6 (95% confidence interval = 5.9-7.1) and 11.6 (95% confidence interval = 10.0-12.5) months, respectively, for patients ≥75 years. Incidence proportions of bevacizumab-associated adverse events were generally similar across all age groups.

CONCLUSIONS

Data from the ARIES study suggest that treatment with bevacizumab in combination with chemotherapy is a viable first-line treatment option for elderly bevacizumab-eligible patients with advanced non-squamous NSCLC.

Identification of a novel papillomavirus in a Northern Fulmar (Fulmarus glacialis) with viral production in cartilage

We report the identification of a novel papillomavirus, Fulmarus glacialis papillomavirus 1 (FgPV1), present within an interdigital foot mass of a Northern Fulmar (Fulmarus glacialis). The mass of interest was composed of normal stratified and keratinized epithelium and dense mesenchymal cells with central cartilaginous islands. Within the nuclei of many chondrocytes were loose aggregates or paracrystalline arrays of virions approximately 50 nm in size. Degenerate polymerase chain reaction was used to identify the virus as a putative papillomavirus, and the entire viral genome of 8132 base pairs was subsequently amplified and sequenced. Analysis revealed canonical papillomavirus architecture, including the early open reading frames E6, E7, E1, and E2 and the 2 late proteins L1 and L2. FgPV1 is most closely related to a cluster of avian and reptilian papillomaviruses as visualized by phylogenetic trees. This observation suggests that papillomavirus virion production can occur in mesenchymal cells.

Safety and effectiveness of bevacizumab treatment for metastatic colorectal cancer: final results from the Avastin(®) Registry - Investigation of Effectiveness and Safety (ARIES) observational cohort study

AIMS

The Avastin(®) Registry - Investigation of Effectiveness and Safety (ARIES) observational cohort study (OCS) was designed to prospectively examine outcomes associated with bevacizumab-containing treatment for metastatic colorectal cancer (mCRC) in a community-based setting, where patient populations are less restricted than those in randomised trials.

MATERIALS AND METHODS

Patients with mCRC who were eligible for bevacizumab in combination with chemotherapy in first- or second-line treatment were enrolled from November 2006 to September 2008. There were no protocol-specified treatment regimens; the dose and schedule of bevacizumab and chemotherapy were at the treating physician's discretion. The objectives in the ARIES OCS included analyses of progression-free survival (PFS), overall survival, treatment patterns and safety in each of the first- and second-line treatment cohorts.

RESULTS

ARIES enrolled 1550 patients with mCRC receiving first-line therapy with bevacizumab. The median follow-up time was 20.6 months. The median PFS in this cohort was 10.2 months (95% confidence interval 9.8-10.6) and the median overall survival was 23.2 months (95% confidence interval 21.2-24.8). In a separate cohort of 482 patients with second-line mCRC, the median follow-up time was 16.9 months, the median PFS and overall survival from the start of second-line treatment to the end of follow-up was 7.9 months (95% confidence interval 7.2-8.3) and 17.8 months (95% confidence interval 16.5-20.7), respectively. Incidences of known bevacizumab-associated adverse events in ARIES were generally consistent with those previously reported in OCSs and randomised trials.

CONCLUSION

Results from the prospective ARIES OCS add further evidence to support the effectiveness and safety of bevacizumab when added to first- and second-line treatment regimens for patients with mCRC in community treatment settings.

Ulcerative Umbrellar Lesions in Captive Moon Jelly (Aurelia aurita) Medusae

Over a period of 6 months, dozens of moon jelly ( Aurelia aurita) medusae from a single-species exhibit at the California Science Center (CSC) developed exumbrellar ulcers. Ulcers were progressive, causing umbrellar creases that expanded radially to the bell rim and occasional adoral erosions that extended into gastrovascular cavities. Husbandry interventions, including addition of ultraviolet light sterilizers, repopulation with fresh cultures, and enclosure disinfection, did not arrest the recurrence of lesions. Biopsies or whole specimens representing 17 medusae (15 affected and 2 grossly unaffected) from CSC and 2 control medusae from Aquarium of the Pacific were submitted to a private diagnostic laboratory and processed for light and electron microscopy. Microscopic lesions were present in all CSC medusae and were not observed or negligible in control medusae. Lesions included ulceration, necrosis, and hyperplasia in all umbrellar layers, with most severe lesions in the exumbrella and amoebocyte infiltration in the underlying mesoglea. Special stains, electron microscopy, and fungal culture did not associate microorganisms with the lesions. Bacterial cultures from the CSC population consistently grew Shewanella and Vibrio spp, both of which were considered commensal. Trauma and environmental stress are proposed as possible causes for the ulcers.

Suspicious cervical lymph nodes detected after thyroidectomy for papillary thyroid cancer usually remain stable over years in properly selected patients

CONTEXT

The risk of loco-regional recurrence in papillary thyroid cancer (PTC) patients ranges from 15-30%. However, the clinical significance of small-volume loco-regional recurrence detected by highly sensitive ultrasonography is unclear.

OBJECTIVE

Our objective was to describe the natural history of abnormal cervical lymph nodes (LN) diagnosed after initial treatment.

DESIGN

We conducted a retrospective cohort study.

PATIENTS

166 PTC with patients who had at least one abnormal LN outside the thyroid be on ultrasound and selected for active surveillance were included.

MAIN OUTCOME MEASURE

LN growth during a period of active surveillance was the primary outcome.

RESULTS

Most patients had classical PTC (85%) and an intermediate risk of recurrence (77%). The median LN size at the start of the observation period was 1.3 cm (range, 0.5-2.7 cm) in largest diameter, with all nodes having at least one abnormal sonographic characteristic (70% of patients had LN with at least two abnormal features). In almost all patients, the LN were in the lateral neck, primarily in levels 3 (43%) and 4 (58%). After a median follow-up of 3.5 yr, only 20% (33 of 166) grew at least 3 mm, 9% (15 of 166) grew at least 5 mm, and 14% (23 of 166) resolved. None of the clinical or sonographic features were predictive of LN growth (positive predictive value range = 0.21-0.57). There were no local complications (nerve damage or local invasion) related to the abnormal nodes and no disease-related mortality.

CONCLUSIONS

Suspicious cervical LN in the lateral neck usually remain stable for long periods of time in properly selected PTC patients and can be safely followed with serial ultrasounds.

Initial therapy with either thyroid lobectomy or total thyroidectomy without radioactive iodine remnant ablation is associated with very low rates of structural disease recurrence in properly selected patients with differentiated thyroid cancer

OBJECTIVE

To describe the risk of structural disease recurrence in a cohort of patients with differentiated thyroid cancer selected for treatment with either thyroid lobectomy or total thyroidectomy without radioactive iodine remnant ablation (RRA).

DESIGN

Retrospective review.

PATIENTS

A total of 289 patients were selected for either thyroid lobectomy (n = 72) or total thyroidectomy (n = 217) without RRA and followed with modern disease detection tools in a tertiary referral centre. Most patients had papillary thyroid cancer (89%) without clinically evident lymph node metastases (91%). However, 55% (156/289) of patients had primary tumours that were >1 cm and 10% (28/289) had minor extrathyroidal extension.

MEASUREMENTS

The primary endpoint was detection of recurrent/persistent structural disease.

RESULTS

After a 5-year median follow-up, structural disease recurrence was detected in 2·3% (5/217) of patients treated with total thyroidectomy without RRA, and in 4·2% (3/72) of patients treated with thyroid lobectomy. Size of the primary tumour, the presence of cervical lymph node metastases and American Thyroid Association risk category were all statistically significant predictors of recurrence. Changes in serum thyroglobulin were not helpful in identifying the presence of persistent/recurrent structural disease. Importantly, 88% (7/8) of the patients that had recurrent disease were rendered clinically disease free with additional therapies.

CONCLUSIONS

Initial risk stratification is able to identify a cohort of patients with differentiated thyroid cancer with a very low risk of structural disease recurrence following treatment with either thyroid lobectomy or total thyroidectomy without RRA. Our data strongly support a selective approach to the initial management of thyroid cancer.

Neuropsychological predictors of functional outcome in Cognitive Behavioral Social Skills Training for older people with schizophrenia

Cognitive Behavioral Social Skills Training (CBSST) is a 24-session weekly group therapy intervention to improve functioning in people with schizophrenia. In our prior randomized clinical trial comparing treatment as usual (TAU) with TAU plus group CBSST (Granholm, E., McQuaid, J.R., McClure, F.S., Auslander, L., Perivoliotis, D., Pedrelli, P., Patterson, T., Jeste, D.V., 2005. A randomized controlled trial of cognitive behavioral social skills training for middle-aged and older outpatients with chronic schizophrenia. Am. J. Psychiatry 162, 520-529.), participants with schizophrenia in CBSST showed significantly better functional outcome than participants in TAU. The present study was a secondary analysis of neuropsychological predictors of functional outcome in our prior CBSST trial. We examined (1) whether neuropsychological impairment at baseline moderated functional outcome in CBSST relative to TAU, and (2) whether improvement in neuropsychological abilities mediated improvement in functional outcome in CBSST. Attention, verbal learning/memory, speed of processing, and executive functions were assessed at baseline, end of treatment, and 12-month follow-up. Greater severity of neuropsychological impairment at baseline predicted poorer functional outcome for both treatment groups (nonspecific predictor), but the interaction between severity of neuropsychological impairment and treatment group was not significant (no moderation). Effect sizes for the difference between treatment groups on functional outcome measures at 12-month follow-up were similar for participants with relatively mild (d=.44-.64) and severe (d=.29-.60) neuropsychological impairment. Results also did not support the hypothesis that improvement in neuropsychological abilities mediated improvement in functioning in CBSST. Adding CBSST to standard pharmacologic care, therefore, improved functioning relative to standard care alone, even for participants with severe neuropsychological impairment, and this improvement in functioning was not related to improvement in neuropsychological abilities in CBSST.

The tylosin-biosynthetic genes of Streptomyces fradiae

The tylosin-biosynthetic (tyl) gene cluster occupies about 1% of the genome of Streptomycesfradiae and includes at least 43 open reading frames. In addition to structural genes required for tylosin production, the tyl cluster contains three resistance determinants and several regulatory genes. Tylosin production is evidently controlled by pathway-specific and pleiotropic regulators with the likely involvement of y-butyrolactone signalling factors. Accumulation of the polyketide aglycone is controlled by glycosylated macrolides and optimal performance of the complex polyketide synthase enzyme requires the activity of an editing thioesterase.

Human parathyroid hormone 1-34 reverses bone loss in ovariectomized mice

The experimental work characterizing the anabolic effect of parathyroid hormone (PTH) in bone has been performed in nonmurine ovariectomized (OVX) animals, mainly rats. A major drawback of these animal models is their inaccessibility to genetic manipulations such as gene knockout and overexpression. Therefore, this study on PTH anabolic activity was carried out in OVX mice that can be manipulated genetically in future studies. Adult Swiss-Webster mice were OVX, and after the fifth postoperative week were treated intermittently with human PTH(1-34) [hPTH(1-34)] or vehicle for 4 weeks. Femoral bones were evaluated by microcomputed tomography (microCT) followed by histomorphometry. A tight correlation was observed between trabecular density (BV/TV) determinations made by both methods. The BV/TV showed >60% loss in the distal metaphysis in 5-week and 9-week post-OVX, non-PTH-treated animals. PTH induced a approximately 35% recovery of this loss and a approximately 40% reversal of the associated decreases in trabecular number (Tb.N) and connectivity. PTH also caused a shift from single to double calcein-labeled trabecular surfaces, a significant enhancement in the mineralizing perimeter and a respective 2- and 3-fold stimulation of the mineral appositional rate (MAR) and bone formation rate (BFR). Diaphyseal endosteal cortical MAR and thickness also were increased with a high correlation between these parameters. These data show that OVX osteoporotic mice respond to PTH by increased osteoblast activity and the consequent restoration of trabecular network. The Swiss-Webster mouse model will be useful in future studies investigating molecular mechanisms involved in the pathogenesis and treatment of osteoporosis, including the mechanisms of action of known and future bone antiresorptive and anabolic agents.

Outcome of treatment for limb and limb girdle sarcomas at the Royal Marsden Hospital

AIMS

In this study we aimed to determine local recurrence, mortality an d amputation rates in patients presenting with limb and limb girdle soft tissue sarcomas.

METHOD

A review of all 439 patients presenting with p rimary or recurrent soft tissue sarcomas of limb and limb girdle to the Royal Marsden Hospital between 1989 and 1995 was carried out.

RESULTS

The local recurrence rate was 15.5% and the mortality rate was 30%, with a median follow up of 3.2 years and an overall amputation rate of 4.8%.

CONCLUSION

The outcome of limb and limb girdle sarcomas in this study i s comparable to those reported elsewhere.

Assessment of the "scholarly project" requirement for emergency medicine residents: report of the SAEM Research Directors' workshop. SAEM Research Directors' Interest Group

OBJECTIVES

Differences in interpretation of the residency review committee (RRC) directive concerning resident scholarly activity have resulted in inconsistencies in the practical fulfillment of this responsibility among the various training programs in emergency medicine. During a workshop organized by the SAEM Research Directors' Interest Group (RDIG), a consensus statement was developed regarding the scope, definition, and purpose of the scholarly project requirement.

METHODS

During the workshop, the NIH model of consensus building was used to develop statements pertaining to specific questions of the goals, definition, and endpoints of the scholarly project. The program consisted of an overview of the history and issues related to the scholarly project and presentations of varying viewpoints from interested parties. A final consensus of answers to the defined questions was then developed by the workshop participants during roundtable discussions and further refined through interactive debate using the RDIG e-mail list server.

RESULTS

By consensus it was agreed that the primary role of the scholarly project is to instruct residents in the process of scientific inquiry, to teach problem-solving skills, and to expose the resident to the mechanics of research. To realize these goals, the project should include the general elements of hypothesis formulation, data collection, analytic thinking, and interpretation of results. It was also thought that these elements should be documented in some written form with a literature review.

CONCLUSIONS

While each residency program must implement the RRC residency requirements in a manner that best suits the needs and culture of its individual environment, a concurrence of definition and approach to satisfying the scholarly project requirement would provide better consistency in resident training. Guidelines developed by consensus during the SAEM RDIG workshop may serve as a general recipe that can be used to fulfill the goals of the scholarly project and the spirit of the RRC directive.

Cocaine absorption after application of a viscous cocaine-containing TAC solution

STUDY OBJECTIVES

We sought to measure plasma cocaine and benzoylecgonine levels in children after application of a solution of a topical anesthetic containing tetracaine 0.5%, epinephrine 1:2, 000, and viscous cocaine 5.9% (TAC) to lacerations requiring suture repair. Previous reports demonstrating cocaine absorption used aqueous cocaine. The purpose of this study is to determine whether systemic absorption occurs with viscous cocaine.

METHODS

We used a convenience sample of children in a pediatric emergency department during the summer months of 1994 and 1995. Participants were pediatric patients less than 15 years of age with simple lacerations requiring suturing.

RESULTS

Twenty-five patients were enrolled in the study. The mean age of the patients was 8.5 years (range, 3 to 13 years). Lacerations tended to be small, with a mean length of 2.2 cm (range, 1 to 8 cm). Plasma cocaine and benzoylecgonine levels were measured by means of high-performance liquid chromatography. The mean time for obtaining the plasma sample for cocaine analysis was 67.2+/-23.9 minutes (range, 28 to 130 minutes) after application of the viscous cocaine-containing TAC solution. Qualitative assay results, which were accurate to 50 ng/mL, were negative in all 25 patients for both plasma cocaine and benzoylecgonine. No child demonstrated any signs or symptoms suggestive of cocaine toxicity.

CONCLUSION

In our study, application of viscous cocaine-containing TAC solutions to small lacerations did not produce clinically important cocaine absorption.

The macrolide-lincosamide-streptogramin B resistance phenotypes characterized by using a specifically deleted, antibiotic-sensitive strain of Streptomyces lividans

Genes conferring resistance to macrolide, lincosamide, and streptogramin B (MLS) antibiotics via ribosomal modification are widespread in bacteria, including clinical isolates and MLS-producing actinomycetes. Such erm-type genes encode enzymes that mono- or dimethylate residue A-2058 of 23S rRNA. The different phenotypes resulting from monomethylation (MLS-I phenotype, conferred by erm type I genes) or dimethylation (MLS-II phenotype due to erm type II genes) have been characterized by introducing tlrD or ermE, respectively, into an MLS-sensitive derivative of Streptomyces lividans TK21. This strain (designated OS456) was generated by specific replacement of the endogenous resistance genes lrm and mgt. The MLS-I phenotype is characterized by high-level resistance to lincomycin with only marginal resistance to macrolides such as chalcomycin or tylosin, whereas the MLS-II phenotype involves high-level resistance to all MLS drugs. Mono- and dimethylated ribosomes were introduced into a cell-free protein-synthesizing system prepared from S. lividans and compared with unmodified particles in their response to antibiotics. There was no simple correlation between the relative potencies of MLS drugs at the level of the target site (i.e., the ribosome) and their antibacterial activities expressed as MICs.

Malignant epithelial parotid tumours: a rational treatment policy

Formal parotidectomy was undertaken in 271 patients by one surgeon over 11 years. Forty patients were treated for malignant salivary tumours (nine were recurrent). Low-grade tumours (45 per cent) were treated by surgery alone, untreated high-grade tumours (55 per cent) by surgery and radiotherapy, before or after operation, depending on clinical findings. The aims of surgery were to obtain tumour clearance, to preserve the facial nerve if possible, and to perform radical neck dissection for palpable malignant lymphadenopathy proven cytologically and for high-grade tumours when intraoperative jugulodigastric lymph node biopsy confirmed metastasis. Four patients sustained facial weakness as a result of surgery. At a median of 46 months follow-up two patients had developed local recurrence. Eleven patients with high-grade but none with low-grade tumours died from metastases. Patients with high-grade lesions with facial weakness from malignant infiltration and those with lymphatic metastasis have a significantly worse prognosis than those without. Locoregional control of parotid cancers can be achieved by formal parotidectomy and selective irradiation without routine sacrifice of the facial nerve.

Extracellular matrix of the synovial intimal cell layer

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Development of GM-CSF antagonist peptides

Granulocyte/macrophage colony stimulating factor (GM-CSF) is both a hematopoietic growth factor and a cytokine implicated in inflammatory disease. The development of GM-CSF antagonist peptides corresponding to the GM-CSF native sequence should allow their modification into higher affinity analogs, but this is hampered by the low affinity of linear peptides. To adequately evaluate such low affinity peptides, the use of several independent assays should allow specific versus nonspecific inhibitors to be distinguished. In this study, inhibition of GM-CSF-dependent cell growth, inhibition of GM-CSF binding and immunologic cross-reactivity between GM-CSF-derived peptides and native protein by neutralizing antibodies have been used to evaluate peptide analogs with potential bioactivity. The GM-CSF sequence was divided into 6 peptides ranging in size from 15-24 amino acids. Antisera were raised to these peptides in mice and assayed for immunologic cross-reactivity. 4/6 anti-peptide antisera bound GM-CSF on ELISA and 3/6 on immunoprecipitation. Antisera to two of the peptides (corresponding to residues 17-31 and 96-112) inhibited GM-CSF-dependent cellular proliferation in two cell lines, with one peptide derived from residues 17-31 demonstrating inhibition of GM-CSF binding and direct biological inhibitory activity. A peptide that did not elicit native GM-CSF reactive antibodies, corresponding to residues 54-78, was recognized by two neutralizing monoclonal antibodies. It exhibited inhibition of GM-CSF binding and direct biological antagonist activity. These studies implicate two sites in mediating GM-CSF biological activity, and indicate that biological antagonists can be developed based on these sites.

Management of soft tissue sarcoma

A total of 485 patients with a proven or suspected diagnosis of soft tissue sarcoma were referred over a 3-year period. Of these, 61 were referred for opinion only and 424 for definitive treatment. Overall there were 223 patients with primary soft tissue sarcoma and 84 with recurrent sarcoma, 84 with benign soft tissue tumours and 22 with non-soft tissue sarcoma malignancy; 11 patients were referred with known metastatic disease. The commonest benign tumours mimicking soft tissue sarcoma were fibromatosis and benign intermuscular or intramuscular lipoma. The malignant tumours suspected clinically of being soft tissue sarcoma were bone tumours, lymphoma and metastatic carcinoma. Of the 172 patients with primary soft tissue sarcoma referred with a proven diagnosis this had been established by excision biopsy in 94 and open incision biopsy in 48. By contrast, of those undiagnosed at referral, 44 of 51 patients with soft tissue sarcoma had the diagnosis made by Tru-cut core biopsy. Amputation was performed in four of 165 patients with primary extremity soft tissue sarcoma and in five of 54 with recurrent extremity sarcoma, giving an overall amputation rate of 4 per cent. It is proposed that the amputation rate for extremity soft tissue sarcoma can be reduced by the use of reconstructive procedures, particularly myocutaneous flaps to the proximal limbs and limb girdles, and free vascularized flaps to sites distal to the midthigh and midarm.

Superficial parotidectomy in the treatment of cutaneous melanoma of the head and neck

The preauricular lymph nodes are frequently the first site of metastatic disease from primary malignant melanoma of the upper two-thirds of the face or the anterior scalp. For these patients, or those with adjacent metastatic nodal disease, the prognosis is poor. The median survival of 13 such patients presented was 2 years, with two long-term survivors at 4 and 6 years. Palliative surgery can, however, prevent uncontrolled locoregional disease. Patients with palpable preauricular and cervical node disease should be treated by facial nerve-preserving parotidectomy and radical neck dissection. When no cervical nodes are palpable in patients with preauricular node metastasis, peroperative jugulodigastric node biopsy and frozen-section histopathological examination are useful to select patients for radical neck dissection.

Purification and characterization of an enzyme involved in oxidative carbon-carbon bond cleavage reactions in the methionine salvage pathway of Klebsiella pneumoniae

The 5-methylthio-D-ribose moiety of 5'-(methylthio)-adenosine is converted to methionine in a wide variety of organisms. 2,3-Diketo-5-methylthio-1-phosphopentane is an advanced intermediate in the methionine recycling pathway present in the Gram-negative bacterium Klebsiella pneumoniae. This unusual metabolite is oxidatively cleaved to yield formate (from C-1), 2-keto-4-methylthiobutyrate (the transamination product of methionine), and 3-methylthiopropionate. To further characterize this oxidative conversion, the desthio analog of the naturally occurring diketone, namely 2,3-diketo-1-phosphohexane I, was synthesized. If the metabolism of I is analogous to that of 2,3-diketo-5-methylthio-1-phosphopentane it should be converted to formate, 2-ketopentanoate, and butyrate. An enzyme (E-1), which mediates the oxidative conversion of I to formate and 2-ketopentanoate, was isolated from extracts of K. pneumoniae. E-1 was purified 100-fold to homogeneity in 10% yield. The native enzyme is a monomeric protein of M(r) 27,000. The activity of E-1 requires magnesium ion as a cofactor. No other prosthetic groups were detected. Incubation of the enzyme with I, under anaerobic conditions, led to the discovery of two intermediates. These species have been identified by 1H and 13C NMR, UV-visible spectroscopy, and model chemistry studies as 2-hydroxy-3-keto-1-phospho-1-hexene II, generated by enolization of I; and 1,2-dihydroxy-3-keto-1-hexene III, generated by enzymatic dephosphorylation of II. Intermediates II and III are released from the active site of the enzyme; III accumulates under anaerobic conditions. Under aerobic conditions, III is non-enzymically oxidized to 2-ketopentanoate, formate, and other products. Compound II was also generated by heating I at pH 7.5 for 7 min. Action of alkaline phosphatase on II produces III.

Radical axillary dissection in the staging and treatment of breast cancer

The results of 237 radical axillary dissections undertaken by one surgeon in patients with breast cancer were reviewed to evaluate the role of this procedure in staging and treatment. The accuracy of physical examination in detecting axillary metastases was 68%. With a policy of enforced shoulder immobilisation for 10 days postoperatively, the incidence of postoperative wound complications was 8%. There have been three axillary recurrences during a median follow-up period of 44 months (range 6-97 months). Late complications were assessed in 50 patients followed up for greater than 12 months. While eight patients complained of constant swelling of the arm, only three had a difference in arm circumference of greater than 3 cm and only one had persistent limitation of shoulder abduction. Radical axillary dissection ensures accurate clinical staging and provides excellent local control with few complications and without the need for axillary irradiation.

Resuscitation fluid for a patient with head injury and hypovolemic shock

The resuscitation of a patient with severe closed head injury and hypovolemic shock is a commonly encountered clinical scenario. The optimal resuscitation formula remains controversial. Aggressive use of crystalloid solutions may worsen brain injury. Early use of mannitol or hypertonic agents may worsen hemorrhage and shock. The optimal approach to the resuscitation of a patient with head trauma and hypovolemic shock is reviewed and discussed. Recent experimental evidence suggests that the early inclusion of an agent such as mannitol in the resuscitation formula may be appropriate despite the evidence of shock. However, the controversy remains unresolved.

Regulation of the immune response to peptide antigens: differential induction of immediate-type hypersensitivity and T cell proliferation due to changes in either peptide structure or major histocompatibility complex haplotype

The immunodominant CD4 T cell epitope of the bacteriophage lambda cI repressor protein in several inbred mouse strains can be represented by a peptide encompassing amino acids 12-26. Here, we show that this peptide, and a variety of its sequence variants, can induce immediate-type hypersensitivity in mice. 12-26 variants that differ by as little as single amino acid residues deviate greatly in their ability to induce hypersensitivity. Further, differences in major histocompatibility complex class II alleles appear to be as influential as changes in peptide structure in determining whether hypersensitivity is developed. The ability of a given peptide-class II combination to induce hypersensitivity correlates with production of peptide-specific antibody, but not with ability or inability to induce a T cell proliferative response. Administration of anti-interleukin 4 (IL-4) mAb prevents the development of hypersensitivity, and analysis of cytokine production by T cell hybridomas derived from peptide-immunized mice suggests that whether a given peptide-class II combination can induce hypersensitivity depends on its ability to induce IL-4 production. The data demonstrate that changes in the nature of the epitope(s) recognized by the CD4 T cell population can result in qualitative differences in the response elicited in this population, ultimately leading to dramatic quantitative and qualitative variations in the effector phase of the immune response.

Different epitope structures select distinct mutant forms of an antibody variable region for expression during the immune response

Antibody variable (V) regions that initially differ from one another by only single amino acid residues at VH-D and D-JH segment junctions (termed canonical V regions) can be elicited in strain A/J mice by three different haptens. Among such V regions an amino acid substitution due to somatic mutation is recurrently observed at VH CDR2 position 58, regardless of which of these haptens is used for immunization. This substitution confers upon a canonical V region a generic increase in affinity for all the haptens. Conversely, the type of amino acid substitution at VH position 59 resulting from somatic mutation that is recurrently observed among such V regions changes with the eliciting hapten, in a manner that correlates directly with the cognate affinity increases (or decreases) for hapten conferred by the observed substitutions. This small subregion of VH CDR2 therefore plays a major role in determining both affinity and specificity for antigen. The data confirm that affinity for antigen is of pivotal importance in determining the degree of selection of different mutant forms of a V region. Moreover, during an immune response a sufficiently diverse mutant repertoire can be generated from a single canonical V region to allow adaptation to increase affinity for three different epitopes.

Serious poisonings among older adults: a study of hospitalization and mortality rates in Massachusetts 1983-85

We analyzed poisoning-related hospitalization and mortality rates among older adults living in Massachusetts during 1983-85. While poisoning-related hospitalization rates of individuals greater than or equal to 60 years were near the state average, death rates for men greater than or equal to 70 years and for women over 60 were higher than those of younger individuals. Medications and carbon monoxide were commonly implicated agents in these poisoning deaths. Older adults are more vulnerable to death from a poisoning than are younger age groups.

Molecular analysis of original antigenic sin. I. Clonal selection, somatic mutation, and isotype switching during a memory B cell response

To determine how the memory B cell population elicited to one epitope might be used in immune responses to other, structurally related epitopes, we explored the phenomenon of original antigenic sin. Strain A/J mice reproducibly respond to immunization with p-azophenylarsonate (Ars) by production of anti-Ars antibodies encoded predominantly by a single VH gene segment (VHIdCR). The structural analogue of Ars p-azophenylsulfonate (Sulf) fails alone to elicit such V regions, but can do so in A/J mice previously immunized with Ars, providing a means to specifically examine B cells capable of responding secondarily to a crossreactive antigen (i.e., memory cells). VHIdCR-expressing hybridomas were derived from the Ars-primed, Sulf-boosted original antigenic sin response of A/J mice at various times after Ars priming, and the properties of the antibodies they express and the structure of the genes encoding these antibodies were characterized. The data obtained support the following conclusions: (a) The Ars-induced memory B cell population capable of being crossreactively stimulated by Sulf is largely formed from a small fraction of all B cells participating in the anti-Ars primary response that express somatically mutated V regions; (b) the antibody repertoire and clonal composition of this population are stable over long periods of time; (c) memory B cells are capable of clonal expansion in the absence of a high rate of V gene somatic mutation; (d) the activation requirements for clonal selection of memory, versus naive B cells appear to differ; and (e) a major fraction of Ars-induced memory B cells express either IgM or IgG3 prior to and during the initial stages of the sin response.

An endogenous peptide that induces long-term blood pressure elevation

A peptide was recently isolated from the blood of spontaneously hypertensive (SH) rats that stimulated an increase of calcium uptake by vascular tissue in vitro. In the present study normotensive rats were given nanomolar amounts of this peptide by intravenous or picomolar amounts by intracerebral injection and the effect on blood pressure was recorded. Injection of the peptide into the circulation had no significant effect on the elevation of blood pressure. By comparison, the injection of the compound into the third ventricle of the brain resulted in the elevation of blood pressure to hypertensive levels. The blood pressure response was characterized by a prolonged period of onset with maximal elevation observed several days after the beginning of treatment. Subsequently, the increase in blood pressure was well maintained with significant elevation noted days following the cessation of treatment.

Influence of the macromolecular form of a B cell epitope on the expression of antibody variable and constant region structure

We investigated the influence of the macromolecular form of an epitope on the structure of antibody variable and constant regions expressed by the B cell population participating in an immune response to that epitope. Hybridomas were constructed from strain A/J mice undergoing either primary or secondary immune responses to p-azophenylarsonate conjugated to Brucella abortus (Ars-Bruc). We determined the sequences of the V genes expressed by hybridomas selected on the basis of expression of a single VH gene segment known to encode a large family of anti-Ars antibodies. These sequences were compared with the sequences of V genes expressed by a previously characterized panel of hybridomas isolated in the same way during the primary and secondary responses of A/J mice to Ars-KLH. The repertoire of Ars-specific V domains expressed among primary and secondary hybridomas elicited with these two forms of Ars were similar, as were the differences between primary and secondary V region somatic mutational alteration and affinity for Ars. In contrast, predominant expression of IgG2 anti-Ars antibodies was elicited in the secondary Ars-Bruc response, whereas secondary anti-Ars antibodies elicited with Ars-KLH are predominantly IgG1. Thus, differences in the macromolecular form of Ars clearly influence the isotypic profile of the anti-Ars response, but the expression, diversification, and selection of V domains elicited with this hapten are not greatly affected by such differences. Our results suggest that while isotype regulation is highly perceptive of the macromolecular form of a B cell epitope, V region regulation is primarily influenced by the molecular structure of that epitope.