Activated T cells regulate bone loss and joint destruction in adjuvant arthritis through osteoprotegerin ligand

Bone remodelling and bone loss are controlled by a balance between the tumour necrosis factor family molecule osteoprotegerin ligand (OPGL) and its decoy receptor osteoprotegerin (OPG). In addition, OPGL regulates lymph node organogenesis, lymphocyte development and interactions between T cells and dendritic cells in the immune system. The OPGL receptor, RANK, is expressed on chondrocytes, osteoclast precursors and mature osteoclasts. OPGL expression in T cells is induced by antigen receptor engagement, which suggests that activated T cells may influence bone metabolism through OPGL and RANK. Here we report that activated T cells can directly trigger osteoclastogenesis through OPGL. Systemic activation of T cells in vivo leads to an OPGL-mediated increase in osteoclastogenesis and bone loss. In a T-cell-dependent model of rat adjuvant arthritis characterized by severe joint inflammation, bone and cartilage destruction and crippling, blocking of OPGL through osteoprotegerin treatment at the onset of disease prevents bone and cartilage destruction but not inflammation. These results show that both systemic and local T-cell activation can lead to OPGL production and subsequent bone loss, and they provide a novel paradigm for T cells as regulators of bone physiology.

Gating of CaMKII by cAMP-regulated protein phosphatase activity during LTP

Long-term potentiation (LTP) at the Schaffer collateral-CA1 synapse involves interacting signaling components, including calcium (Ca2+)/calmodulin-dependent protein kinase II (CaMKII) and cyclic adenosine monophosphate (cAMP) pathways. Postsynaptic injection of thiophosphorylated inhibitor-1 protein, a specific inhibitor of protein phosphatase-1 (PP1), substituted for cAMP pathway activation in LTP. Stimulation that induced LTP triggered cAMP-dependent phosphorylation of endogenous inhibitor-1 and a decrease in PP1 activity. This stimulation also increased phosphorylation of CaMKII at Thr286 and Ca2+-independent CaMKII activity in a cAMP-dependent manner. The blockade of LTP by a CaMKII inhibitor was not overcome by thiophosphorylated inhibitor-1. Thus, the cAMP pathway uses PP1 to gate CaMKII signaling in LTP.

Postsynaptic cAMP pathway gates early LTP in hippocampal CA1 region

The role of the cAMP pathway in LTP was studied in the CA1 region of hippocampus. Widely spaced trains of high frequency stimulation generated cAMP postsynaptically via NMDA receptors and calmodulin, consistent with the Ca2+/calmodulin-mediated stimulation of postsynaptic adenylyl cyclase. The early phase of LTP produced by the same pattern of high frequency stimulation was dependent on postsynaptic cAMP. However, synaptic transmission was not increased by postsynaptic application of cAMP. Early LTP became cAMP-independent when protein phosphatase inhibitors were injected postsynaptically. These observations indicate that in early LTP the cAMP signaling pathway, instead of transmitting signals for the generation of LTP, gates LTP through postsynaptic protein phosphatases.

Epidemiology and predictors of post-concussive syndrome after minor head injury in an emergency population

OBJECTIVE

To determine if clinical variables or neurobehavioural test (NBT) scores obtained in the ED within 24 hours of minor head injury (MHI) predict the development of postconcussive syndrome (PCS).

METHODS

Prospective, observational study of 71 MHI patients and 60 orthopaedic controls. MHI defined as loss of consciousness < 10 minutes or amnesia, GCS 15, no skull fracture or new neurologic focality on PE, and no brain injury on CT (if done). All patients received a seven part NBT battery in the ED. Telephone follow-up was done at 1, 3 and 6 months to determine if patients met the DSM IV definition of PCS.

ANALYSIS

Stepwise, multivariate, logistic regression.

RESULTS

Predictors of PCS at 1 month were female gender (OR = 7.8; 95% CI = 41.6, 1.98), presence of both retrograde and anterograde amnesia (OR = 0.055; CI = 0.002, 0.47), Digit Span Forward Scores (OR = 0.748; CI = 0.52, 1.03) and Hopkins Verbal Learning A scores (OR = 0.786; CI = 0.65, 0.91); at 3 months, presence of both retrograde and anterograde amnesia (OR = 0.13; CI = 0.0, 0.93), Digit Span Forward Scores (OR = 0.744; CI = 0.58, 0.94). No variables fit the model at 6 months. 92% of males scoring > 25 on Hopkins Verbal Learning A did not have PCS at 1 month, and 89% of females scoring < 9 on Digit Span Forward did have PCS at 1 month.

CONCLUSIONS

Gender and two NBTs can help predict PCS after MHI.

Effects of wearing N95 and surgical facemasks on heart rate, thermal stress and subjective sensations

Aim: The study was aimed at investigating the effects of wearing N95 and surgical facemasks with and without nano-functional treatments on thermophysiological responses and the subjective perception of discomfort. Method: Five healthy male and five healthy female participants performed intermittent exercise on a treadmill while wearing the protective facemasks in a climate chamber controlled at an air temperature of 25°C and a relative humidity of 70%. Four types of facemasks, including N95 (3M 8210) and surgical facemasks, which were treated with nano-functional materials, were used in the study. Results: (1) The subjects had significantly lower average heart rates when wearing nano-treated and untreated surgical facemasks than when wearing nano-treated and untreated N95 facemasks. (2) The outer surface temperature of both surgical facemasks was significantly higher than that of both N95 facemasks. On the other hand, the microclimate and skin temperatures inside the facemask were significantly lower than those in both N95 facemasks. (3) Both surgical facemasks had significantly higher absolute humidity outside the surface than both N95 facemasks. The absolute humidity inside the surgical facemask was significantly lower than that inside both N95 facemasks. (4) Both surgical facemasks were rated significantly lower for perception of humidity, heat, breath resistance and overall discomfort than both N95 facemasks. The ratings for other sensations, including feeling unfit, tight, itchy, fatigued, odorous and salty, that were obtained while the subjects were wearing the surgical facemasks were significantly lower than when the subjects were wearing the N95 facemasks. (5) Subjective preference for the nano-treated surgical facemasks was the highest. There was significant differences in preference between the nano-treated and untreated surgical facemasks and between the surgical and N95 facemasks. Discussion: We discuss how N95 and surgical facemasks induce significantly different temperature and humidity in the microclimates of the facemasks, which have profound influences on heart rate and thermal stress and subjective perception of discomfort.

Defining the outcome of immunosuppression withdrawal after liver transplantation

Successful immunosuppression withdrawal should benefit the natural history of organ transplantation patients. To identify the clinical hazards of removing drug treatment and possible characteristics that predict a favorable outcome in long-term liver recipients, immunosuppression was withdrawn completely and the clinicopathological outcome documented in 18 liver recipients. Indication for transplantation, HLA matching, early rejection history, and presence of microchimerism were examined as predictors of outcome. Chimerism was determined by polymerase chain reaction-based examination for donor-specific HLA-DRB1 alleles and Y-gene-specific nucleotide sequences. At 3 years, 5 patients (28%) remained completely off immunosuppression; 12 patients (67%) experienced histological graft changes: acute rejection in 4, portal tract inflammation/hepatitis in 7, and necrosis in 1. Hepatitis B or C viral infections did not account for the nonrejection patterns. Unmasking of systemic disorders occurred. Chimerism, demonstrated in 7 patients (39%), with skin the optimal tissue, was not associated with tolerance. Parameters associated with successful drug withdrawal were transplantation for non-immune-mediated liver disorders, fewer donor-recipient HLA A, B, and DR mismatches, and a low incidence of early rejection. Immunosuppression withdrawal is a feasible option in a proportion of selected liver recipients, but identification of tolerant patients remains imprecise.

The role of fibroblasts in tissue engineering and regeneration

Fibroblasts are mesenchymal cells that can be readily cultured in the laboratory and play a significant role in epithelial-mesenchymal interactions, secreting various growth factors and cytokines that have a direct effect on epidermal proliferation, differentiation and formation of extracellular matrix. They have been incorporated into various tissue-engineered products such as Dermagraft (Advanced BioHealing, La Jolla, CA, U.S.A.) and Apligraf (Novartis, Basel, Switzerland) and used for a variety of clinical applications, including the treatment of burns, chronic venous ulcers and several other clinical applications in dermatology and plastic surgery. In this article we review the cell biology of dermal fibroblasts and discuss past and current experience of the clinical use of cultured fibroblasts.

Purification, cloning, and expression of human plasma hyaluronidase

Hyaluronidase was purified from human plasma using Triton X-114 phase extractions and ion-exchange chromatography. Monoclonal antibodies generated against the purified protein by a novel screening assay were utilized to isolate homogeneous enzyme for microsequencing. The amino acid sequences obtained matched a cDNA in the Expressed Sequence Tag database which, with 5'-RACE-PCR, was used to clone the plasma hyaluronidase gene, termed Hyal-1. Hyal-1 codes for a protein of 435 amino acids that is over 40% identical to PH-20, a sperm-specific hyaluronidase. Unlike PH-20, which is only expressed in testis, transcripts of Hyal-1 were found in multiple tissues. Hyal-1 stably expressed in human embryonic kidney cells resulted in a 3,000 fold increase of secreted immunoreactive hyaluronidase activity that was biochemically indistinguishable from human plasma hyaluronidase. By immunological, molecular and biochemical criteria, we conclude that Hyal-1 is the predominant hyaluronidase found in human plasma.

Spontaneous entrapment of polynucleotides upon electrostatic interaction with ethanol-destabilized cationic liposomes

This study describes the effect of ethanol and the presence of poly(ethylene) glycol (PEG) lipids on the interaction of nucleotide-based polyelectrolytes with cationic liposomes. It is shown that preformed large unilamellar vesicles (LUVs) containing a cationic lipid and a PEG coating can be induced to entrap polynucleotides such as antisense oligonucleotides and plasmid DNA in the presence of ethanol. The interaction of the cationic liposomes with the polynucleotides leads to the formation of multilamellar liposomes ranging in size from 70 to 120 nm, only slightly bigger than the parent LUVs from which they originated. The degree of lamellarity as well as the size and polydispersity of the liposomes formed increases with increasing polynucleotide-to-lipid ratio. A direct correlation between the entrapment efficiency and the membrane-destabilizing effect of ethanol was observed. Although the morphology of the liposomes is still preserved at the ethanol concentrations used for entrapment (25-40%, v/v), entrapped low-molecular-weight solutes leak rapidly. In addition, lipids can flip-flop across the membrane and exchange rapidly between liposomes. Furthermore, there are indications that the interaction of the polynucleotides with the cationic liposomes in ethanol leads to formation of polynucleotide-cationic lipid domains, which act as adhesion points between liposomes. It is suggested that the spreading of this contact area leads to expulsion of PEG-ceramide and triggers processes that result in the formation of multilamellar systems with internalized polynucleotides. The high entrapment efficiencies achieved at high polyelectrolyte-to-lipid ratios and the small size and neutral character of these novel liposomal systems are of utility for liposomal delivery of macromolecular drugs.

High copy number of the pUC plasmid results from a Rom/Rop-suppressible point mutation in RNA II

The plasmids pUC18 and pUC19 are pBR322 derivatives that replicate at a copy number several fold higher than the parent during growth of Escherichia coli at 37 degrees C. We show here that the high copy number of pUC plasmids results from a single point mutation in the replication primer, RNA II, and that the phenotypic effects of this mutation can be suppressed by the Rom (RNA one modulator)/Rop protein or by lowering the growth temperature to 30 degrees C. The mutation's effects are enhanced by cell growth at 42 degrees C, at which copy number is further increased. During normal cell growth, the pUC mutation does not affect the length or function of RNA I, the antisense repressor of plasmid DNA replication, but may, as computer analysis suggests, alter the secondary structure of pUC RNA II. We suggest that the pUC mutation impedes interactions between the repressor and the primer by producing a temperature-dependent alteration of the RNA II conformation. The Rom/Rop protein may either promote normal folding of the mutated RNA II or, alternatively, may enable the interaction of sub-optimally folded RNA II with the repressor.

Immunization of breast cancer patients using a synthetic sialyl-Tn glycoconjugate plus Detox adjuvant

We have synthesized various formulations that have potential for active specific immunotherapy (ASI) of human cancers. Sialyl-Tn (STn) is a potentially important target structure for ASI because its expression on mucins is a strong, independent predictor of poor prognosis, suggesting that it may have functional significance in the metastatic process. In this first pilot study of synthetic sialyl-Tn hapten conjugated to keyhole limpet hemocyanin (STn-KLH), with Detox adjuvant, toxicity and humoral immunogenicity were assessed in 12 patients with metastatic breast cancer. Toxicity was minimal, restricted to local cutaneous reactions (apart from transient nausea and vomiting following single low-dose cyclophosphamide treatment). Using STn-conjugated human serum albumin in a solid-phase enzyme-linked immunosorbent assay, it was shown that all patients developed IgM and IgG specific for the synthetic STn hapten. Following immunization, most patients were shown to develop increased titres of complement-mediated cytotoxic antibodies, partially inhibited by synthetic STn hapten, but not by the related TF hapten. We also detected IgM and IgG antibodies reactive with natural STn determinants expressed on ovine submaxillary mucin, the STn specificity of this reactivity being confirmed by hapten inhibition. Evaluation of clinical efficacy in a small pilot study is difficult. Five patients are alive 12 or more months after entry, and another 4 patients are alive 6 or more months after entry into the study. All 3 patients with known widespread bulky disease progressed despite ASI, 2 having died from widespread cancer. Two patients had partial responses, each lasting 6 months. While several patients had disease stability for 3-10 months, 1 patient with pulmonary metastases remains stable 15 months after entry into the program.

Normative values and inter-observer agreement for liquid and solid bolus swallows in upright and supine positions as assessed by esophageal high-resolution manometry

BACKGROUND

High-resolution manometry (HRM) with spatiotemporal representation of pressure data is a recent advance in esophageal measurement. At present, normal values are available for 5mL water swallows in the supine position. This study provides reference values for liquid and solid bolus swallows in the upright seated and supine positions.

METHODS

A total of 23 asymptomatic volunteers (11M:12F, age 20-56) underwent HRM (Manoscan 360; Sierra Scientific Instruments) with 5mL water and 1cm3 bread swallows in the upright and supine positions. Normal values for primary parameters associated with effective bolus transport [proximal transition zone length (PTZ, assesses peristaltic coordination], contraction front velocity (CFV), distal contractile index (DCI) and integrated relaxation pressure (IRP)] are presented. For each parameter, median values along with the 5-95th percentile range are reported. Inter-observer agreement between independent observers is reported using the intra-class correlation coefficient.

KEY RESULTS

A higher proportion of swallows were peristaltic for liquids than solids in both the upright and supine positions (both P<0.05). As workload increases with solid bolus and on moving from the upright to the supine position the esophageal contractile response resulted in a shorter PTZ, a slower CFV, and a more vigorous DCI. Also IRP increased during solid bolus transit (all P<0.01). There was significant agreement between independent observers for HRM parameters.

CONCLUSIONS & INFERENCES

Normative values for esophageal function for solids as well as liquids and in the 'physiologic', upright position will optimize the utility of HRM studies. The high level of inter-observer agreement indicates that these can be applied as reference values in clinical practice.

Severe infective keratitis leading to hospital admission in New Zealand

AIM

To identify key risk factors and the management and outcome of severe infective keratitis leading to public hospital admission in New Zealand.

METHODS

Over a 2 year period, all admissions of presumed infective keratitis to Auckland Hospital were identified. The clinical records of all 103 cases were retrospectively reviewed with respect to clinical features, risk factors, management, and outcomes.

RESULTS

The mean time from first symptoms or signs and presentation to hospital was 8.9 (SD 15.5) days. The majority of subjects, 88%, had at least one of the risk factors commonly associated with infective keratitis including previous ocular surgery (30%), contact lens wear (26%), topical corticosteroid use (25%), and ocular trauma (24%). Corneal scraping was performed in 92% and of a total of 105 scrapes, 71% were positive. Bacteria were isolated in all these cases, the majority being Gram positive organisms (72%). The most common isolates identified were coagulase negative Staphylococcus (16%), Propionibacterium acnes (14%), Staphylococcus epidermidis (11%), and Streptococcus pneumoniae (9%). In addition, yeasts were isolated in 5%, fungi in 4%, virus in 2%, and chlamydia in 1%. Importantly, polymicrobial infection accounted for 33% of culture positive cases. Antimicrobial treatment was changed on the basis of culture results in 17 cases (16.5%). Median initial visual and final best corrected visual acuity was 6/36-6/48 (logMAR 0.86) (IQR 0.39-2.00) and 6/12-6/15 (logMAR 0.360) (IQR 0.15-1.70), respectively. Previous ocular surgery and topical corticosteroid use were significantly associated with poorer visual acuity. The mean hospital stay was 5.8 days and the median 4.0 (IQR 2.0-8.0) days. Longer duration of stay was associated with the presence of hypopyon, larger ulcers, previous ocular surgery, and poor visual acuity.

CONCLUSIONS

Infectious keratitis is an important cause of ocular morbidity. A significant proportion of cases have potentially modifiable risk factors. Previous ocular surgery and topical corticosteroid use, in particular, were associated with poorer visual outcomes. Many cases of severe keratitis might be avoided, or their severity reduced, by appropriate education of patients and ophthalmologists.

Serum cardiac enzymes in stroke

Serum cardiac enzyme levels (CK, LDH, SGOT) were estimated and the ECG recorded for 4 days following admission of 288 patients (Group I) to a stroke intensive care unit. Sixty-four of these patients, subsequently found not to have strokes, served as controls. Mean serum levels of all 3 cardiac enzymes were elevated in 8% of the 224 patients with stroke. The mean serum enzyme levels in patients with transient ischemic attacks (TIA) did not differ from controls. In a second group of 230 patients with stroke (Group II) serum CK levels were measured and the isoenzyems were fractionated to determine the tissue source of the enzymes. One hundred and one patients had raised total CK values and 25 of these (11%) had raised CK-MB (heart) iso-enzyme, the remainder having CK-MM (skeletal muscle) fraction. No serum CK-BB (brain) iso-enzyme was detected in any patient. Patients with positive serum levels of CK-MB has more evidence of acute myocardial ischemia on ECG (p less than 0.05), and more cardiac arrhythmias (p less than 0.001) than those with normal CK levels. Scattered areas of myocytolysis were found in the myocardium at autopsy in one patient. The acute rise in serum cardiac enzymes which we have recorded in the initial stages of stroke suggest that acute myocardial involvement is a commoner complication than is generally recognized. Also, since the CK-MB rises were modest and progressive, it is more likely that this acute myocardial dysfunction is a consequence, rather than a cause, of the acute cerebrovascular lesion.

Sexual network analysis of a gonorrhoea outbreak

OBJECTIVES

Sexual partnerships can be viewed as networks in order to study disease transmission. We examined the transmission of Neisseria gonorrhoeae in a localised outbreak in Alberta, Canada, using measures of network centrality to determine the association between risk of infection of network members and their position within the sexual network. We also compared risk in smaller disconnected components with a large network centred on a social venue.

METHODS

During the investigation of the outbreak, epidemiological data were collected on gonorrhoea cases and their sexual contacts from STI surveillance records. In addition to traditional contact tracing information, subjects were interviewed about social venues they attended in the past year where casual sexual partnering may have occurred. Sexual networks were constructed by linking together named partners. Univariate comparisons of individual network member characteristics and algebraic measures of network centrality were completed.

RESULTS

The sexual networks consisted of 182 individuals, of whom 107 were index cases with laboratory confirmed gonorrhoea and 75 partners of index cases. People who had significantly higher information centrality within each of their local networks were found to have patronised a popular motel bar in the main town in the region (p = 0.05). When the social interaction through the bar was considered, a large network of 89 individuals was constructed that joined all eight of the largest local networks. Moreover, several networks from different communities were linked by individuals who served as bridge populations as a result of their sexual partnering.

CONCLUSION

Asking clients about particular social venues emphasised the importance of location in disease transmission. Network measures of centrality, particularly information centrality, allowed the identification of key individuals through whom infection could be channelled into local networks. Such individuals would be ideal targets for increased interventions.

Intrachain disulfide bond in the core hinge region of human IgG4

IgG is a tetrameric protein composed of two copies each of the light and heavy chains. The four-chain structure is maintained by strong noncovalent interactions between the amino-terminal half of pairs of heavy-light chains and between the carboxyl-terminal regions of the two heavy chains. In addition, interchain disulfide bonds link each heavy-light chain and also link the paired heavy chains. An engineered human IgG4 specific for human tumor necrosis factor-alpha (CDP571) is similar to human myeloma IgG4 in that it is secreted as both disulfide bonded tetramers (approximately 75% of the total amount of IgG) and as tetramers composed of nondisulfide bonded half-IgG4 (heavy chain disulfide bonded to light chain) molecules. However, when CDP571 was genetically engineered with a proline at residue 229 of the core hinge region rather than serine, CDP571 (S229P), or with an IgG1 rather than IgG4 hinge region, CDP571(gamma 1), only trace amounts of nondisulfide bonded half-IgG tetramers were observed. Trypsin digest reversephase HPLC peptide mapping studies of CDP571 and CDP571(gamma 1) with on-line electrospray ionization mass spectroscopy supplemented with Edman sequencing identified the chemical factor preventing inter-heavy chain disulfide bond formation between half-IgG molecules: the two cysteines in the IgG4 and IgG1 core hinge region (CPSCP and CPPCP, respectively) are capable of forming an intrachain disulfide bond. Conformational modeling studies on cyclic disulfide bonded CPSCP and CPPCP peptides yielded energy ranges for the low-energy conformations of 31-33 kcal/mol and 40-42 kcal/mol, respectively. In addition, higher torsion and angle bending energies were observed for the CPPCP peptide due to backbone constraints caused by the extra proline. These modeling results suggest a reason why a larger fraction of intrachain bonds are observed in IgG4 rather than IgG1 molecules: the serine in the core hinge region of IgG4 allows more hinge region flexibility than the proline of IgG1 and thus may permit formation of a stable intrachain disulfide bond more readily.

Nursing competencies: personal characteristics contributing to effective nursing performance

AIMS OF THE STUDY

Core competencies are important in enabling an individual to adapt to new environments and perform superior professional practice. This study was to identify the underlying competencies which contributed to effective nursing performance.

BACKGROUND

Most of the previous competencies are either derived from researchers' conceptual analysis or based on practitioners' direct report. Competencies derived from these methods either are subject to bias or are unable to identify the essential elements for effective nursing care.

METHOD

Following the McBer method, 50 experienced nurses in China were asked to report 82 valid critical incidents in their jobs. Two individuals coded the scripts and decided the presence of each competency according to a pre-established coding system.

RESULTS

Ten competencies including interpersonal understanding, commitment, information gathering, etc. were identified. Each competency was illustrated by behavioural indicators.

CONCLUSIONS

Skills, traits, motives and attitudes all contribute to effective nursing performance. The findings assist in the delineation and development of nursing competencies and thus provide realistic working behaviours for nursing education and management.

In vivo protective performance of N95 respirator and surgical facemask

BACKGROUND

The SARS outbreak in 2003 has spawned a major controversy concerning protective performance facemasks for healthcare workers. This study reports a study on in-vivo protective performance of surgical masks and N95 respirators.

METHODS

Typical surgical masks and N95 respirators used in Hong Kong hospitals were tested in comparison with those treated with nano-functional materials (called nano-masks) on various physical properties and in-vivo wear filtration efficiency, as well as usability test in hospitals for surgical masks.

RESULTS

Tests on physical properties showed that N95 respirators had significantly lower air permeability and water vapor permeability than surgical masks. The in-vivo filtration tests illustrated that N95 respirators filtered out 97% of potassium chloride (KCl) solution, while surgical masks filtered out 95% of KCl solution. Nano-masks show stronger water repellency and antibacterial activities, but no difference in usability, comparing with normal N95 and surgical masks.

CONCLUSIONS

Surgical masks can provide in-vivo filtration protection of 95% filtration efficiency. N95 respirators provide higher in-vivo filtration efficiency of 97% with significant reduction of air permeability and water vapor permeability. Compared to normal surgical masks/respirators, the nano-masks can provide additional protective functions in stopping capillary diffusion and antibacterial activities.

Active immunization of human ovarian cancer patients against a common carcinoma (Thomsen-Friedenreich) determinant using a synthetic carbohydrate antigen

In a phase I study, ten ovarian cancer patients with extensive metastatic disease despite chemotherapy were immunized three to eight times subcutaneously with the synthetic form of the immunodominant disaccharide (beta Gal1----3 alpha GalNAc) of the Thomsen-Friedenreich antigen conjugated to KLH (TF alpha-KLH) plus DETOX adjuvant. Six patients were given a "low" dose of TF alpha-KLH (100 micrograms/injection) and four patients were given a "high" dose (500 micrograms/injection). All patients received a single low-dose cyclophosphamide treatment (200 mg/m2 i.v.) 3 days prior to commencement of the series of immunizations. Immunizations were 2 weeks apart. Little or no toxicity was noted. As expected, all patients (prior to immunization) had naturally occurring IgM antibodies against the synthetic TF alpha hapten. None of the patients had detectable pre-existing IgG or IgA antibodies against synthetic TF alpha hapten. Nine of the ten ovarian cancer patients showed a significant increase in IgM titer above pre-existing levels following immunizations with TF alpha-KLH plus DETOX adjuvant. These same patients also produced IgG anti-TF alpha and eight of these also produced IgA anti-TF alpha, although the IgA responses were weaker. Most of the IgG responses followed the IgM responses by 2-4 weeks. Two patients produced a vigorous IgG response after their first TF alpha-KLH injection, suggesting a recall response. Both direct ELISAs on various solid-phase synthetic carbohydrate antigens and hapten inhibition experiments confirmed the TF alpha hapten specificity of the antibodies. IgM and IgG anti-TF alpha-specific antibodies reacted with natural TF antigen, by ELISA and FACS analysis, although the titers were generally lower than the titers against the immunizing TF alpha hapten. Increased levels of cytotoxic antibodies against TF-expressing tumor cell targets were detected in eight of the ten patients following immunization. One patient who had no detectable cytotoxic antibodies prior to immunization developed increasingly strong cytotoxic antibodies as a function of the number of immunizations. The low antigen dose patients showed as good or better humoral immune responses than the high antigen dose patients. All four high-dose and four of six low-dose patients developed moderate to strong DTH reactions at the vaccination sites. Our results demonstrate that KLH is an acceptable carrier for carbohydrate haptens in humans and that DETOX is an appropriate nontoxic adjuvant for the generation of high-titer specific anti-carbohydrate responses in human cancer patients.(ABSTRACT TRUNCATED AT 400 WORDS)

Immunogenicity of synthetic peptides related to the core peptide sequence encoded by the human MUC1 mucin gene: effect of immunization on the growth of murine mammary adenocarcinoma cells transfected with the human MUC1 gene

The immune response of CAF1 mice to various synthetic peptides (SP) related to the amino acid sequence (PDTRPAPGSTAPPAHGVTSA) of the tandem repeat of the MUC1 human breast mucin core peptide was evaluated. The most immunogenic preparations of the synthetic peptides were those conjugated to keyhole limpet hemocyanin (KLH) or clustered in a dendritic multiple antigenic peptide (MAP-4) configuration. The mice were immunized subcutaneously with synthetic peptides emulsified in RIBI adjuvant, employing various immunization protocols. Equivalently high IgG responses were induced using SP-KLH conjugates (GVTSAPDTRPAPGSTA-KLH) or an SP--MAP-4 chimeric configuration (SP1-6), which also included a universal malarial CST-3 T-helper epitope (SP1-6 = SAPDTRPAEKKIAKMEKASSVFNVVNS--MAP-4). These IgG antibodies bound both the appropriate MUC1 synthetic peptides and the cell surface expressed MUC1 mucin on murine mammary cells that had been transfected with the human MUC1 gene and a human breast cancer cell line that expresses cell-surface MUC1. A MAP-4 molecule, which included the entire 20-amino-acid sequence of the MUC1 tandem repeat (SP1-5 = PDTRPAPGSTAPPAHGVTSA-MAP-4) induced a poor IgG response. In contrast, all three types of molecule: SP-KLH, SP1-6 and SP1-5, were found to be good immunogens for the induction of specific delayed-type hypersensitivity (DTH) reactions measured using either synthetic peptides or MUC1-transfected cells. In addition, immunization with irradiated MUC1-transfected cells induced strong DTH reactions measured using synthetic peptides that expressed the PDTRP sequence, which has been shown to be, or to overlap, a T cell epitope in humans and a B cell epitope in mice. Finally, it was demonstrated that synthetic MUC1 peptide "vaccines" could be used both prophylactically and therapeutically to inhibit the growth of MUC1-transfected tumor cells and prolong the survival of tumor-bearing mice.

Atypical teratoid/rhabdoid tumor of the central nervous system: a comparative study with primitive neuroectodermal tumor/medulloblastoma

Eleven atypical teratoid/rhabdoid tumors (AT/RT) and 121 primitive neuroectodermal tumors/medulloblastomas (PNET/MB) were included in this study for evaluation of the histopathological features of AT/RT and comparison between AT/RT and PNET/MB. Histopathological studies of AT/RT showed that in addition to the commonly recognized components, i.e., rhabdoid cells, small (PNET/MB) cells, spindle cells and epithelial components, there was a previously unrecognized component, sickle-shaped embracing cells, which were present in all cases and could be useful as a histological marker of this tumor. Immunohistochemical studies showed divergent differentiation of the tumor cells and among the 16 antibodies studied, vimentin, neuron-specific enolase, epithelial membrane antigen and glial fibrillary acidic protein were most commonly reactive. The frequency of AT/RT expressed as a ratio of AT/RT to PNET/MB was 1:11 in general and increased to 1:3.8 among patients younger than 3 years old. The AT/RT patients were younger than those with PNET/MB and had a female predominance. The MIB-1 labeling index of AT/RT was significantly higher than that of PNET/MB (mean 63.9 vs 40.1), which correlated with a shorter survival in patients with AT/RT than those with PNET/MB (median survival time 15.4 months vs 156.4 months).

Preoperative cardiac risk assessment for patients having peripheral vascular surgery

PURPOSE

To review the methods used for preoperative cardiac risk stratification of patients having peripheral vascular surgery.

DATA SOURCES

Relevant studies published before August 1991 were identified using a MEDLINE search of the English-language literature, followed by a manual search of the references of all identified articles.

STUDY SELECTION

All clinical studies evaluating methods used for preoperative cardiac risk stratification of patients having peripheral vascular surgery.

DATA EXTRACTION

The key data extracted from each article included the inclusion and exclusion criteria of the study patients, the techniques used for testing and the corresponding definitions of positive test results, and the clinical outcomes of the tested patients. Data were analyzed using a Bayesian conceptual framework, and pretest probabilities were converted to post-test probabilities using calculation of likelihood ratios.

RESULTS

Patients with high scores on clinical cardiac risk indexes (Goldman index greater than 12 or Detsky index greater than 15), or more than three of the criteria identified by Eagle (age greater than 70 years, diabetes, angina, Q waves on electrocardiogram, or ventricular arrhythmias) are likely to be at higher risk for cardiac death and myocardial infarction after vascular surgery. Those with both low scores and none of Eagle's criteria may be at lower risk, but this result has not been reproduced by independent studies. Neither group of patients would benefit from further investigation for cardiac risk stratification. Patients with one or two of these criteria may be at intermediate risk and would benefit most from further testing for the purposes of risk stratification. Most of the published evidence shows that the absence of redistribution on dipyridamole-thallium scanning identifies a low risk for postoperative cardiac complications, whereas the presence of redistribution predicts a high risk. Preliminary reports suggest that preoperative monitoring for silent myocardial ischemia may also be useful in identifying a high-risk subset of patients.

CONCLUSIONS

Patients identified clinically to be at either very low or high risk for cardiac complications after peripheral vascular surgery are unlikely to benefit from further risk stratification. Dipyridamole-thallium scanning is the test of choice for further evaluation of patients at intermediate clinical risk because studies have shown that it is sensitive enough to rule out a high-risk status for patients who do not have redistribution.

Modulation of wound healing after glaucoma surgery

The healing process after glaucoma filtration is the main determinant of surgical failure and, even more important, the final intraocular pressure. The ability to fully control wound healing may ultimately give us the ability to set the intraocular pressure in the low teens for all patients undergoing glaucoma filtration surgery. The authors review the changes in how to use antimetabolites to improve safety, and many of the exciting new areas of progress, including growth factor neutralization and future molecular therapies to control wound healing.

X-ray surface dose measurements using TLD extrapolation

Surface dose measurements in therapeutic x-ray beams are of importance in determining the dose to the skin of patients undergoing radiotherapy. Measurements were performed in the 6-MV beam of a medical linear accelerator with LiF thermoluminescence dosimeters (TLD) using a solid water phantom. TLD chips (surface area 3.17 x 3.17 cm2) of three different thicknesses (0.230, 0.099, and 0.038 g/cm2) were used to extrapolate dose readings to an infinitesimally thin layer of LiF. This surface dose was measured for field sizes ranging from 1 x 1 cm2 to 40 x 40 cm2. The surface dose relative to maximum dose was found to be 10.0% for a field size of 5 x 5 cm2, 16.3% for 10 x 10 cm2, and 26.9% for 20 x 20 cm2. Using a 6-mm Perspex block tray in the beam increased the surface dose in these fields to 10.7%, 17.7%, and 34.2% respectively. Due to the small size of the TLD chips, TLD extrapolation is applicable also for intracavity and exit dose determinations. The technique used for in vivo dosimetry could provide clinicians information about the build up of dose up to 1-mm depth in addition to an extrapolated surface dose measurement.