Search for a W' boson via the decay mode W'-->munumu in 1.8 TeV pp collisions

We report the results of a search for a W' boson produced in pp collisions at a center-of-mass energy of 1.8 TeV using a 107 pb-1 data sample recorded by the Collider Detector at Fermilab. We consider the decay channel W'-->&munumu and search for anomalous production of high transverse mass munumu lepton pairs. We observe no excess of events above background and set limits on the rate of W' boson production and decay relative to standard model W boson production and decay using a fit of the transverse mass distribution observed. If we assume standard model strength couplings of the W' boson to quark and lepton pairs, we exclude a W' boson with invariant mass less than 660 GeV/c2 at 95% confidence level.

Contact lens electroretinography in preterm infants from 32 weeks after conception: a development in current methodology

AIM

To assess the feasibility of using a contact lens electrode to record the electroretinogram (ERG) in preterm infants less than 35 weeks after conception.

METHODS

The ERG was recorded from seven very low birthweight preterm infants on a total of 14 occasions using an infant monkey contact lens electrode. Age at recording the first ERG ranged from 23 to 51 days (gestational age 32-34 weeks), and weight ranged upwards from 1100 g.

RESULTS

No complications were observed. With advancing age and maturity the dark adapted rod threshold decreased, indicating increased retinal sensitivity.

CONCLUSIONS

Contact lens recording of the ERG from extremely small immature preterm infants is a practicable and well tolerated procedure. This method of recording the ERG will enable further evaluation of retinal development in this vulnerable population.

Alexia for Braille following bilateral occipital stroke in an early blind woman

Recent functional imaging and neurophysiologic studies indicate that the occipital cortex may play a role in Braille reading in congenitally and early blind subjects. We report on a woman blind from birth who sustained bilateral occipital damage following an ischemic stroke. Prior to the stroke, the patient was a proficient Braille reader. Following the stroke, she was no longer able to read Braille yet her somatosensory perception appeared otherwise to be unchanged. This case supports the emerging evidence for the recruitment of striate and prestriate cortex for Braille reading in early blind subjects.

Development and characterization of expressed sequence tags for the turkey (Meleagris gallopavo) genome and comparative sequence analysis with other birds

Twenty-one randomly selected clones from a turkey (Meleagris gallopavo) pituitary complementary DNA (cDNA) library were sequenced to develop expressed sequence tags (ESTs) for this economically important avian species whose genome is among the least understood. Primers specific for the ESTs were used to produce amplicons from the genomic DNA of turkey, chicken (Gallus gallus), guinea fowl (Numidia meleagris), pigeon (Columba domestica), and quail (Corturnix japonica). The amplicons were sequenced and analyzed for sequence variation within- and similarity among-species and with GenBank database sequences. The proportion of shared bases between the turkey sequence and the consensus sequence from each of the other species ranged from 72% to 93% between turkey and pigeon and quail and between turkey and chicken, respectively. The total number of single nucleotide polymorphisms (SNPs) observed ranged from 3 in quail to 18 in chicken out of 4898 and 5265 bases analyzed, respectively. The most frequent nucleotide variation observed was a C-->T transition. Linkage analysis of one such SNP in the backcross progeny of the East Lansing reference DNA panel, localized TUS0005, the chicken sequence derived from primers specific for turkey TUT2E EST, to chromosome 4. The ESTs reported, as well as the SNPs may provide a useful resource for ongoing efforts to develop high utility genome maps for the turkey and chicken. The primers described can also be used as a tool in future investigations directed at further understanding the biology of the guinea fowl, pigeon and quail and their relatedness to the turkey.

An IBM PC-based system for the assessment of cardio-respiratory function using oscillating inert gas forcing signals

OBJECTIVE

An IBM PC-based real-time data acquisition, monitoring and analysis system was developed for the assessment of cardio-respiratory function, i.e. airway dead space, alveolar volume and pulmonary blood flow, using oscillating inert inspired gas forcing signals.

METHODS

The forcing gas mixture was generated by an in-house sinusoid gas delivery unit. The system interfaced with a mass spectrometer and an airway flow transducer, and performed real-time tracking of the breath-by-breath end-inspired, end-expired and mixed-expired concentrations. It calculated the cardiorespiratory parameters using two, i.e. continuous and tidal, in-house mathematical models of the lungs. The system's performance was evaluated using a mechanical bench lung, laboratory subjects and awake adults breathing spontaneously. Its predictive accuracy was compared with the measured volumes of the bench lung; single breath CO2 test for airway dead space and N2 washout for alveolar volume in laboratory subjects and awake adults; and thermal dilution technique for pulmonary blood flow in laboratory subjects.

RESULTS

Close agreements were found between the true and predicted airway dead space, i.e. mean differences of -12.39%, 14.47% and -17.49%, respectively, and that of alveolar volume, i.e. -8.03%, -3.62% and 7.22%, respectively, in the bench lung, laboratory subject and awake adult studies; and that of pulmonary blood flow (-23.81%) in the laboratory subjects using the continuous lung model. Even closer agreements were observed for airway dead space (-5.8%) and alveolar volume (-4.01%) of the bench lung and for pulmonary blood flow (-8.47%) in the laboratory subjects using the tidal lung model.

CONCLUSIONS

A system was developed to deliver, monitor and analyse on-line, and in real-time, output data from the sinusoid forcing technique. The technique was administered using the system in various subjects, and produced favourable predictions.

Distribution of glutamate receptor subunit NMDAR1 in the hippocampus of normal elderly and patients with Alzheimer's disease

Immunocytochemical techniques were employed to study the distribution and cytological features of NMDAR1-immunoreactive elements in the human hippocampal formation. Subjects with Alzheimer's disease (AD), presenting with a wide range of neuropathology and classified into six Braak stage (I-VI), and nondemented age-matched controls were examined. In control cases, the most intense NMDAR1 immunoreactivity was observed within the soma and dendrites of granule cells in the dentate gyrus and pyramidal neurons in Ammon's horn. Whereas small variations in the pattern of immunoreactivity were noted in control cases, AD subjects were characterized with intersubject variability which in most instances correlated with neuropathologic severity. For example, AD cases, particularly those with mild/modest pathology (Braak I-III), were indistinguishable from controls in the overall pattern of immunolabeling. In contrast, in those more severe AD cases (Braak IV-VI) the intensity of immunolabeling within the CA fields was greater than observed in controls and those with mild AD pathology. In addition, in pathologically severe cases numerous NMDAR1-positive pyramidal neurons were characterized by unique morphologic features including long and often tortuous apical dendrites. These latter findings were most prevalent in the CA1 region and subiculum. In contrast to the marked increase in immunolabeling in the CA fields, in the dentate gyrus we observed a reduction in NMDAR1 labeling particularly within the outer molecular layer (i.e., termination zone of the perforant pathway). This latter region was also the site of a number of NMDAR1-labeled plaques. Notably, the overall pattern of NMDAR1 immunoreactivity is distinct from that observed with antibodies against AMPA receptor subunits and suggests a differential role of various inotropic glutamate receptors in hippocampal plasticity in AD.

Transorbital optic nerve sheath ultrasonography in normal children

AIM

Early diagnosis of acute intracranial hypertension is essential to enable prompt, optimal treatment. The optic nerve sheath diameter (ONSD) is increased in raised ICP and there has been recent interest in the use of ultrasound to diagnose and indirectly monitor raised ICP by ONSD measurement. The advantages of the technique include its non-invasiveness, wide availability, portability, low cost and the absence of ionizing radiation. This prospective study was designed to establish the range of normal values for ONSD in infants and children up to 15 years of age.

PATIENTS AND METHODS

One hundred and two children attending the hospital for other reasons were recruited to the study. Three measurements of the ONSD were taken for each eye, 3 mm behind the optic nerve head using a 7 MHz sector probe.

RESULTS

The range for ONSD was 2.1-4.3 mm, mean 3.08 (SD 0.36). There were no significant differences on ONSD measurement between boys and girls (P = 0.59) or between right and left eyes (P=0.66). When the data were grouped and analysed, a correlation between increasing age and increasing ONSD was seen (r2=0.48), with the greatest increase occurring in the first 2 months of life.

CONCLUSION

Using the technique described here, our results suggest that an ONSD of greater than 4 mm in infants less than 1 year, and 45 mm or greater in older children, should be regarded as abnormal.

Adenosine-induced atrial pro-arrhythmia in children

Adenosine has become the preferred acute treatment for common types of supraventricular tachycardia because of its efficacy and safety. There have been a few reports of serious proarrhythmic events associated with its use, including the induction of atrial fibrillation in adult patients. Three instances of adenosine-induced atrial proarrhythmia (two atrial fibrillation and one atrial flutter) have been observed in children with manifest or concealed Wolff-Parkinson-White syndrome at the Hospital for Sick Children, Toronto, Ontario since 1990, which indicates a previously unreported risk of atrial arrhythmia for children as well. Because adenosine may enhance antegrade bypass tract conduction, its use carries a risk of ventricular acceleration, including progression to ventricular fibrillation. Because of such rare and potentially life-threatening adverse effects, appropriate monitoring and precautions are required during the administration of the drug to children and adults.

Transcranial magnetic stimulation and neuroplasticity

We review past results and present novel data to illustrate different ways in which TMS can be used to study neural plasticity. Procedural learning during the serial reaction time task (SRTT) is used as a model of neural plasticity to illustrate the applications of TMS. These different applications of TMS represent principles of use that we believe are applicable to studies of cognitive neuroscience in general and exemplify the great potential of TMS in the study of brain and behavior. We review the use of TMS for (1) cortical output mapping using focal, single-pulse TMS; (2) identification of the mechanisms underlying neuroplasticity using paired-pulse TMS techniques; (3) enhancement of the information of other neuroimaging techniques by transient disruption of cortical function using repetitive TMS; and finally (4) modulation of cortical function with repetitive TMS to influence behavior and guide plasticity.

The population pharmacokinetics of long-term methotrexate in rheumatoid arthritis

AIMS

Methotrexate is considered by many practitioners to be the agent of choice in the treatment of rheumatoid arthritis. The pharmacokinetics of methotrexate have been reported to exhibit significant intersubject variability. Therefore, this study was undertaken to evaluate the population pharmacokinetics of methotrexate during long-term administration in adults with rheumatoid arthritis.

METHODS

Methotrexate pharmacokinetics were evaluated in a 36 month study of 62 adults with rheumatoid arthritis. Patients received oral or intramuscular doses of methotrexate weekly with pharmacokinetic studies performed every 6 months. Data were analyzed with nonlinear mixed effects modeling.

RESULTS

Three thousand two hundred and sixty post oral or intramuscular dose serum methotrexate concentrations comprising 425 individual concentration vs time profiles were modeled using NONMEM. Covariates that significantly (P < 0.005) influenced the disposition of methotrexate were age (AGE, years), body weight (BW, kg), creatinine clearance (CL(CR), 1 h(-1)), gender (GEN; 0 = male, 1 = female), dose (DOSE, micromol), and fed vs fasted state (FED; 0 = fasted, 1 = fed). The final model describing the biexponential disposition of methotrexate was clearance(CL, 1 h(-1)) = (0.0810*BW + 0.257*CL(CR))*(1-(0.167*GEN); central volume (Vc, 1) = 0.311*BW; peripheral volume (Vp, 1) = 0.469*BW-0.169*AGE; intercompartmental clearance (Q, 1 h(-1)) = 4.27*(1-0.355*GEN); oral absorption rate constant (ka(p.o.), h(-1)) = 4.70-0.0439*DOSE*(1-0.507*FED); intramuscular absorption rate constant (ka(i.m.), h(-1)) = 0.122*DOSE; relative bioavailability (F) = 93.4%; and oral absorption lag time (LAG(p.o.), min) = 13.5. Pharmacokinetic parameters (%CV) for a typical fasted male subject in this study were CL, 7.341 h(-1) (27%); Vc, 23.51 (28%); Vp, 25.31 (31%); Q, 4.25 1 h(-1) (41%); ka(p.o.), 3.67 h(-1) (77%); and ka(i.m.), 3.09 h(-1) (44%).

CONCLUSIONS

The population pharmacokinetics of methotrexate in adults with rheumatoid arthritis were well described by this investigation. Substantial interpatient variability was explained by incorporating patient specific data into regression equations predicting pharmacokinetic parameters.

Topical anesthesia: Proxymetacaine versus Amethocaine for clear corneal phacoemulsification

PURPOSE

To evaluate the use of proparacaine (Proxymetacaine) versus tetracaine (Amethocaine) as the topical anesthetic agent for phacoemulsification cataract surgery using a 3.5 mm clear corneal sutureless incision.

SETTING

Harold Wood Hospital, Romford, Essex, United Kingdom.

METHODS

This prospective study comprised 40 randomly selected patients. Twenty were given Proxymetacaine and 20, Amethocaine. The level of discomfort experienced during delivery of the topical anesthetic agent and during and immediately after surgery was measured using a pain score. During surgery, topical anesthesia was supplemented by intracameral lignocaine 1%.

RESULTS

Patients given Proxymetacaine experienced no stinging sensation during its administration; those given Amethocaine reported varying degrees of discomfort. The difference between groups was statistically significant (P < .01). There was no difference between groups in the amount of discomfort experienced intraoperatively or postoperatively.

CONCLUSION

Proxymetacaine is the topical analgesic of choice for phacoemulsification because it produced no discomfort on administration yet had the same analgesic properties as Amethocaine.

A real-time algorithm to improve the response time of a clinical multigas analyser

OBJECTIVE

An algorithm to improve the response time of a clinical respiratory multigas analyser is presented.

METHODS

The algorithm involves the application of a second order differential equation to the analyser gas output signals in real-time. The adjusted analyser output signals are compared with those of a quadrupole respiratory mass spectrometer sampling and analysing simultaneously.

RESULTS

Our results show a close correlation between the adjusted clinical gas analyser and the mass spectrometer signals. Lung volumes derived from a non-invasive sinusoidal inert gas forcing technique, in a model test lung, using the adjusted clinical gas analyser and the mass spectrometer signals demonstrated comparable results.

CONCLUSIONS

The algorithm provides an improvement on the relatively slow response times of the clinical gas analyser for breath-by-breath time-dependent applications. The same algorithm can also be applied to other instruments which have slow response times.

Synthesis and proteinase inhibitory properties of diphenyl phosphonate analogues of aspartic and glutamic acids

The synthesis of diphenyl phosphonate analogues of aspartic and glutamic acid, and their inhibitory activity against S. aureus V8 protease and granzyme B, is described. The study has revealed difficulties with protecting group compatibility in the synthesis of these analogues. Two analogues, Acetyl. AspP (OPh)2 and Acetyl.GluP (OPh)2 were found to function as irreversible inactivators of V8 proteinase, yet exhibit no activity against granzyme B.

Complication of ventricular demand pacing after orthotopic heart transplantation: unusual case of pacemaker syndrome in an infant

BACKGROUND

Sinus node dysfunction is the most common indication for antibradycardiac permanent pacing after heart transplantation. Lack of atrioventricular synchrony during pacing can result in symptoms ranging from mild chest discomfort to severe manifestations such as dyspnea, hypotension, and cardiovascular collapse, all of which are ascribed to pacemaker syndrome. In infants pacemaker syndrome is often only recognized in the face of marked hemodynamic compromise.

RESULTS

This report details an unusual account of pacemaker syndrome in an infant after orthotopic heart transplantation.

CONCLUSIONS

Careful assessment of atrioventricular synchrony is important after infant transplantation.

Efficient gene transfer into primary and immortalized human fetal glial cells using adeno-associated virus vectors: establishment of a glial cell line with a functional CD4 receptor

Adeno associated virus (AAV) is a non-pathogenic dependent parvovirus with a broad host range, capable of high levels of transduction and stable integration into the host cell genome. We have investigated the potential for using AAV as a vector for gene transfer into glial cells of the human fetal nervous system. Recombinant AAV vectors expression either the reporter gene beta-galactosidase or a human CD4 receptor were able to transduce both primary glial cells of the human fetal nervous system and an SV40 immortalized human fetal glial cell line (SVG). No difference in transduction efficiency was observed between the primary cells and the cell line which in both cases was as high as 95%. Stable transfectants of the glial cell line expressing the CD4 receptor were selected. An SVG/CD4 expressing line was then established. The presence of the CD4 receptor was confirmed by immunohistochemistry, Westerm immuno-blotting and flow cytometric analysis. The CD4 receptor was shown to be functional by infection of the SVG/CD4 cell line with the human immunodeficiency virus (HIV). Upon infection, the SVG/CD4 cells produced 20-fold higher levels of the HIV intracellular core antigen P24 than the CD4 negative parental cells and in addition formed syncytia. The use of AAV vectors should prove useful in biological investigations of human glial cells and offers promise as a means of ex vivo and in vivo gene delivery.

Nasal provocation with allergen induces a secondary serum IgE antibody response

The study of the IgE response to seasonal antigen exposure is limited by its occurrence once a year and by the variability of patient exposure to pollens. To overcome these problems, we investigated whether nasal challenge with antigen causes an increase in serum anti-ragweed IgE levels. We challenged individuals with ragweed allergy intranasally with nanogram quantities of ragweed antigen extract and measured their serum anti-ragweed IgE levels before and at weekly intervals after challenge. In a series of studies we found that there was a reproducible rise in antigen-specific serum IgE levels beginning the first week after challenge that plateaued at about 180% of baseline levels during the fourth week and remained elevated for 8 weeks. Not all individuals showed this response. The magnitude of the allergen-specific IgE response to nasal challenge appeared to be greater than the response to seasonal exposure. Treatment with intranasal beclomethasone before challenge did not affect the response. The results demonstrate a human in vivo model for the study of the antigen-specific secondary IgE response to allergen.

Cutaneous injection of RANTES causes eosinophil recruitment: comparison of nonallergic and allergic human subjects

RANTES, a member of the C-C chemokine family, is a potent chemoattractant for T lymphocytes and eosinophils, but not neutrophils. To determine the effect of RANTES on cell recruitment in vivo, we injected up to 4 microg of RANTES intradermally into both allergic and nonallergic subjects and obtained biopsies 30 min, 6 h, and 24 h later. A dose- and time-dependent recruitment of eosinophils, CD45RO+ cells, and CD3+ cells was observed, with no effect seen on polymononuclear, cutaneous lymphocyte Ag+, CD68+, or tryptase+ cells. Eosinophil recruitment occurred more rapidly in allergic subjects than in nonallergic subjects. No eosinophil infiltrate was observed in nonallergic biopsies at 30 min and 6 h, whereas significant eosinophil recruitment was observed in allergic subjects by 30 min, reaching near-maximum levels by 6 h. The peak responses at 24 h were similar in both groups (nonallergic, 110 +/- 24 eosinophils/mm2; allergic, 113 +/- 38 eosinophils/mm2). The two groups had comparable numbers of circulating eosinophils. Major basic protein staining demonstrated eosinophil degranulation in both allergic and nonallergic groups. RANTES injection resulted in activation of endothelial E-selectin expression at 24 h. Incubation of cultured HUVECs with RANTES had no effect on adhesion molecule expression, suggesting that the in vivo effect may have been indirect. Our studies demonstrate that RANTES is a potent chemoattractant for eosinophils, CD3+ cells, and CD45RO+ cells in human skin. The accelerated eosinophil recruitment in allergic subjects provides support for the hypothesis that eosinophils from these subjects are primed in vivo.

Cutaneous injection of RANTES causes eosinophil recruitment: comparison of nonallergic and allergic human subjects

RANTES, a member of the C-C chemokine family, is a potent chemoattractant for T lymphocytes and eosinophils, but not neutrophils. To determine the effect of RANTES on cell recruitment in vivo, we injected up to 4 microg of RANTES intradermally into both allergic and nonallergic subjects and obtained biopsies 30 min, 6 h, and 24 h later. A dose- and time-dependent recruitment of eosinophils, CD45RO+ cells, and CD3+ cells was observed, with no effect seen on polymononuclear, cutaneous lymphocyte Ag+, CD68+, or tryptase+ cells. Eosinophil recruitment occurred more rapidly in allergic subjects than in nonallergic subjects. No eosinophil infiltrate was observed in nonallergic biopsies at 30 min and 6 h, whereas significant eosinophil recruitment was observed in allergic subjects by 30 min, reaching near-maximum levels by 6 h. The peak responses at 24 h were similar in both groups (nonallergic, 110 +/- 24 eosinophils/mm2; allergic, 113 +/- 38 eosinophils/mm2). The two groups had comparable numbers of circulating eosinophils. Major basic protein staining demonstrated eosinophil degranulation in both allergic and nonallergic groups. RANTES injection resulted in activation of endothelial E-selectin expression at 24 h. Incubation of cultured HUVECs with RANTES had no effect on adhesion molecule expression, suggesting that the in vivo effect may have been indirect. Our studies demonstrate that RANTES is a potent chemoattractant for eosinophils, CD3+ cells, and CD45RO+ cells in human skin. The accelerated eosinophil recruitment in allergic subjects provides support for the hypothesis that eosinophils from these subjects are primed in vivo.

The loss of GluR2(3) immunoreactivity precedes neurofibrillary tangle formation in the entorhinal cortex and hippocampus of Alzheimer brains

Double-immunolabeling techniques were employed to examine the distribution of GluR2(3) subunits and markers of early cytoskeletal changes (mab MC1) within the entorhinal cortex (EC) and hippocampus of cases with varying degrees of Alzheimer disease (AD) pathology (stages I-VI by Braak and Braak). In addition near-adjacent tissue sections were double-immunolabeled using antibodies against GluR2(3) and a marker of normal neuronal cytoskeleton (MAP2). In those cases classified as stages I-II, most layer II neurons of the EC and pyramidal neurons in the CA1/subiculum were double-labeled with GluR2(3) and MAP2. An occasional MC1-labeled cell was observed, yet in no instance were these neurons double-labeled with GluR2(3). In cases with moderate AD pathology (stages III-IV), layer II of the EC and CA1/subiculum were characterized by a substantial loss of GluR2(3)-labeled neurons, while many were still immunoreactive to MAP2. Notably, the loss of GluR2(3) immunolabeling was accompanied by an increasing number of MC1-positive neurons. In no instance were GluR2(3) and MC1 co-localized within the same neuron. In cases with severe AD pathology (stages V-VI), the EC and CA1/subiculum were almost completely devoid of GluR2(3)-positive neurons. MAP2-labeled neurons also were reduced in number. In contrast, both regions contained an abundance of MC1-positive cells. That GluR2(3) and MC1 are not observed in the same neuron, together with the observation that the number of GluR2(3)-labeled neurons decreases as the number of MC1-positive cells increases, suggest that a loss of GluR2(3) immunolabeling precedes the appearance of MC1 immunolabeling.

Autologous hapten-modified melanoma vaccine as postsurgical adjuvant treatment after resection of nodal metastases

PURPOSE

To determine whether treatment with an autologous whole-cell vaccine modified with the hapten dinitrophenyl (DNP vaccine) is an effective postsurgical adjuvant treatment for melanoma patients with clinically evident nodal metastases.

PATIENTS AND METHODS

Eligible patients had regional nodal metastases that were large enough (> or = 3 cm diameter) to prepare vaccine. Following standard lymphadenectomy, patients were treated with DNP vaccine on a monthly or weekly schedule.

RESULTS

Of 62 patients with metastasis in a single lymph node bed (stage III), 36 are alive after a median follow-up time of 55 months (range, 29 to 76); the projected 5-year relapse-free and overall survival rates are 45% and 58%, respectively. Of 15 patients with metastases in two nodal sites, five are alive with a median follow-up time of 73 months. An unexpected finding was the significantly better survival of older patients; the projected 5-year survival of patients greater than 50 versus < or = 50 years was 71% and 47%, respectively (P = .011, log-rank test). The development of a positive delayed-type hypersensitivity (DTH) response to unmodified autologous melanoma cells was associated with significantly longer 5-year survival (71% v 49%; P = .031). Finally, the median survival time from date of first recurrence was significantly longer for patients whose subcutaneous recurrence exhibited an inflammatory response (> 19.4 v 5.9 months; P < .001).

CONCLUSION

Postsurgical adjuvant therapy with autologous DNP-modified vaccine appears to produce survival rates that are markedly higher than have been reported with surgery alone. Moreover, this approach has some intriguing immunobiologic features that might provide insights into the human tumor-host relationship.

Melanoma of unknown primary site: presentation, treatment, and prognosis--a single institution study. University of Pennsylvania Pigmented Lesion Study Group

BACKGROUND

A retrospective analysis of 40 patients diagnosed with melanoma of unknown primary site (MUP) was undertaken to analyze the etiology and clinical behavior of this presentation.

METHODS

The patient records were located by a computer search of the Pigmented Lesion Clinic data base at the University of Pennsylvania. With the Cox proportional hazards model, the survival of the MUP patients with lymph node presentation was compared with that of patients with lymph node disease and a known concurrent primary melanoma.

RESULTS

Sixty-five percent of the patients presented with lymph node metastasis only, 28% presented with visceral lesions, and 8% presented with subcutaneous nodules. The prevalence of dysplastic nevi was 22.5%. The overall 4-year survival rate for the 40 MUP patients was 55% +/- 9%. The 4-year survival (57% +/- 12%) of patients with lymph node presentation was compared with that of patients presenting with lymph node disease and a known concurrent primary melanoma (19 +/- 6%). Survival was significantly different between the groups (P = 0.008). This survival difference remained significant (P = 0.02) even after adjustments for number of positive lymph nodes, year of diagnosis, and age at diagnosis.

CONCLUSIONS

This analysis revealed that MUP patients with lymph node metastasis survived significantly longer than patients diagnosed with lymph node metastasis concurrent with a known cutaneous primary melanoma. The prevalence of dysplastic nevi in the MUP patient series was intermediate between that reported among primary melanoma patients and that reported among population controls, suggesting the likelihood of a primary cutaneous origin for the metastatic melanoma.

Oxygen transport with oscillations of inspired oxygen concentration

A theoretical model predicts that forced inspiratory oxygen concentration oscillations can be used to recover cardiorespiratory data and elicit information about the oxygen transport system (Hahn, 1996). The effects of hypoxia on the penetration of these generated oxygen oscillations into arterial and venous blood were explored in dogs exposed to a graded severity of hypoxia. Continuously recorded sinusoidal oxygen oscillations in the respired partial pressure, blood tension and mixed-venous saturation show that the transmission of forced oxygen oscillations from the lungs to the arterial blood depends on the mean arterial saturation. When mean inspired oxygen is high enough to fully saturate arterial haemoglobin, an inspired oscillation can only be transmitted in the blood as an oscillation in oxygen tension. However, in the presence of arterial hypoxaemia, oscillations in both the oxygen saturation and partial pressure of arterial blood are observed. Under these conditions, the oxygen saturation and partial pressure oscillations are also transmitted to mixed-venous blood. Our data illustrates that the link between the arterial and mixed-venous oscillations is non-linear and dependent on the sigmoidal binding relationship between oxygen and haemoglobin.

Extraordinary conservation of cysteines among homologous Chironomus silk proteins sp185 and sp220

Aquatic larvae of the midge, Chironomus tentans, synthesize a 185-kDa silk protein (sp185) with the cysteine-containing motif Cys-X-Cys-X-Cys (where X is any residue) every 20-28 residues. We report here the cloning and full-length sequence of cDNAs encoding homologous silk proteins from Chironomus pallidivittatus (sp185) and Chironomus thummi (sp220). Deduced amino acid sequences reveal proteins of nearly identical mass composed of 72 blocks of 20-28 residues, 61% of which can be described by the motif X5-8-Cys-X5-(Trp/Phe/Tyr)-X4-Cys-X-Cys-X-Cys. Spatial arrangement of these residues is preserved more than surrounding sequences. cDNA clones enabled us to map the genes on polytene chromosomes and identify for the first time the homolog of the Camptochironomus Balbiani ring 3 locus in Chironomus thummi. The apparent molecular weight difference between these proteins (185 vs 220 kDa) is not attributable to primary structure and may be due to differential N-linked glycosylation. DNA distances and codon substitutions indicate that the C. tentans and C. pallidivittatus genes are more related to each other than either is to C. thummi; however, substitution rates for the 5'- and 3'-halves of these genes are different. Blockwise sequence comparisons suggest intragenic variation in that some regions evolved slower or faster than the mean and may have been subjected to different selective pressures.

Controlled pilot study of rapid amphotericin B infusions

This pilot study compared the toxicity of a one hour with a four hour amphotericin B infusion in children. There were more severe chills in the former group on the first day of infusion, and more hypotension in the latter group over the study duration.

Measurement of respiratory parameters by using inspired oxygen sinusoidal forcing signals

A companion paper (C. E. W. Hahn. J. Appl. Physiol 81: 985-997, 1996) described a continuous-flow gas-exchange mathematical model, which predicted that forced inspired oxygen sinusoids could be used to measure respiratory parameters rapidly, in place of the inert gas argon. We therefore made simultaneous measurements of dead space volume (VD) and alveolar volume (VA) in an animal model, using argon and oxygen inspired gas concentration sinusoid forcing signals, and then compared the results. Our data confirmed the model prediction that the attenuations of the oxygen and argon sinusoid perturbations are identical in the alveolar gas space, even though there is a net uptake of oxygen by the body. Our results show that the calculated values of VD and VA, obtained by using inspired oxygen forcing signals, were independent of both the mean fractional inspired oxygen concentration (FIO2; range 0.18-0.80% vol/vol) and the oxygen forcing signal amplitude (range +/- 2-6% vol/vol). In these studies, oxygen forcing signals, with forcing periods between 1 and 2 min, were able to measure controlled changes in instrument dead space to within 16 ml and also measure positive end-expiratory pressure-induced changes in VA. Under hyperoxic conditions, intravascular oxygen sensors confirmed that the sinusoidal PO2 signal passed into the arterial blood but not into the mixed-venous blood. However, the sinusoid perturbation PO2 signal did pass into the mixed-venous blood when the mean FIO2 was mildly hypoxic (FIO2 = 0.18% vol/vol). These data show that oxygen can be used instead of argon to measure airways dead space and VA.

Immunohistochemical staining of fixed tissue using antigen retrieval and a thermal cycler

The use of monoclonal antibodies to identify antigens in perfused fixed tissue is currently very challenging. Recently, many antigen retrieval methods have been described that require heating the tissue on slides using a microwave oven. Here, we describe a protocol for antigen retrieval that uses a commercially available solution called Citra and a DNA thermal cycler to heat the tissue sections. This method (i) allows for precise control of the temperature and time (unlike the microwave oven), (ii) uses very small quantities of the antigen retrieval solution, (iii) stains either free-floating sections or sections mounted on slides and (iv) achieves uniform staining throughout the tissue. In the paraformaldehyde-perfused fixed rat cerebellum, the monoclonal antibody glial fibrillary acidic protein conveys the clarity of the Bergmann and stellate glia in the strata. Scanning confocal images through the center of the tissue demonstrates the depth of antibody penetration achieved using this method. Finally, using a monoclonal antibody against the simian virus 40 (SV40) T antigen allowed positive, unequivocal identification of a grafted cell line, immortalized using SV40 T protein, thus demonstrating the true value of this method in an experimental paradigm.

Expression of tyrosine hydroxylase in an immortalized human fetal astrocyte cell line; in vitro characterization and engraftment into the rodent striatum

The use of primary human fetal tissue in the treatment of neurodegenerative disorders, while promising, faces several difficult technical and ethical issues. An alternative approach that would obviate these problems would be to use immortalized cell lines of human fetal central nervous system origin. An immortalized human fetal astrocyte cell line (SVG) has been established (45) and herein we describe the in vitro and in vivo characteristics of this cell line which suggest that it may be a useful vehicle for neural transplantation. The SVG cell line is vimentin, GFAP, Thy 1.1 and MHC class I positive, and negative for neurofilament and neuron specific enolase, consistent with its glial origin. To determine whether the cell line could be used as a drug delivery system, a cDNA expression vector for tyrosine hydroxylase was constructed (phTH/Neo) and stably expressed in the SVG cells for over 18 months as demonstrated by immunohistochemistry and Western blotting of the stable transfectants. HPLC analysis of the supernatant from these cells, termed SVG-TH, consistently found 4-6 pmol/ml/min of l-dopa produced with the addition of BH4 to the media. Furthermore, in cocultivation experiments with hNT neurons, PC-12 cells and primary rat fetal mesencephalic tissue, both the SVG and SVG-TH cells demonstrated neurotrophic potential, suggesting that they constituitively express factors with neuroregenerative potential. To determine the viability of these cells in vivo, SVG-TH cells were grafted into the striatum of Sprague-Dawley rats and followed over time. A panel of antibodies was used to unequivocally differentiate the engrafted cells from the host parenchyma, including antibodies to: SV40 large T antigen (expressed in the SVG-TH cells), human and rat MHC class 1, vimentin, GFAP, and tyrosine hydroxylase. While the graft was easily identified with the first week, over the course of a four week period of time the engrafted cells decreased in number. Concomittantly, rat CD4 and CD8 expression in the vicinity of the graft increased, consistent with xenograft rejection. When the SVG-TH cells were grafted to the lesioned striatum of a 6-hydroxydopamine lesioned rats, rotational behavior of the rat decreased as much as 80% initially, then slowly returned to baseline over the next four weeks, parallelling graft rejection. Thus, the SVG-TH cells can induce a functional recovery in an animal model of Parkinson's disease, however as a xenograft, the SVG cells are recognized by the immune system.

Expression of Tyrosine Hydroxylase in an Immortalized Human Fetal Astrocyte Cell Line; in Vitro Characterization and Engraftment into the Rodent Striatum

The use of primary human fetal tissue in the treatment of neurodegenerative disorders, while promising, faces several difficult technical and ethical issues. An alternative approach that would obviate these problems would be to use immortalized cell lines of human fetal central nervous system origin. An immortalized human fetal astrocyte cell line (SVG) has been established (45) and herein we describe the in vitro and in vivo characteristics of this cell line which suggest that it may be a useful vehicle for neural transplantation. The SVG cell line is vimentin, GFAP, Thy 1.1 and MHC class I positive, and negative for neurofilament and neuron specific enolase, consistent with its glial origin. To determine whether the cell line could be used as a drug delivery system, a cDNA expression vector for tyrosine hydroxylase was constructed (phTH/Neo) and stably expressed in the SVG cells for over 18 months as demonstrated by immunohistochemistry and Western blotting of the stable transfectants. HPLC analysis of the supernatant from these cells, termed SVG-TH, consistently found 4-6 pmol/ml/min of 1-dopa produced with the addition of BH4to the media. Furthermore, in cocultivation experiments with hNT neurons, PC-12 cells and primary rat fetal mesencephalic tissue, both the SVG and SVG-TH cells demonstrated neurotrophic potential, suggesting that they constituitively express factors with neuroregenerative potential. To determine the viability of these cells in vivo, SVG-TH cells were grafted into the striatum of Sprague-Dawley rats and followed over time. A panel of antibodies was used to unequivocally differentiate the engrafted cells from the host parenchyma, including antibodies to: SV40 large T antigen (expressed in the SVG-TH cells), human and rat MHC class 1, vimentin, GFAP, and tyrosine hydroxylase. While the graft was easily identified with the first week, over the course of a four week period of time the engrafted cells decreased in number. Concomittantly, rat CD4 and CD8 expression in the vicinity of the graft increased, consistent with xenograft rejection. When the SVG-TH cells were grafted to the lesioned striatum of a 6-hydroxydopamine lesioned rats, rotational behavior of the rat decreased as much as 80% initially, then slowly returned to baseline over the next four weeks, parallelling graft rejection. Thus, the SVG-TH cells can induce a functional recovery in an animal model of Parkinson's disease, however as a xenograft, the SVG cells are recognized by the immune system.

A unique case of long-term survival in a male patient with malignant melanoma of the distal urethra

Primary malignant melanoma of the urethra in male patients is a rare entity, noted to have a dismal prognosis in recent reviews. No case of long-term disease-free survival in patients with primary malignant melanoma has been previously reported. We report the first such case, and review briefly the factors that could have contributed to our patient's long-term survival. We also illustrate the precursor lesion present six years prior to diagnosis.

A comparison of four patient immobilization devices in the treatment of prostate cancer patients with three dimensional conformal radiotherapy

PURPOSE

To determine the variability of patient positioning during three-dimensional conformal radiotherapy (3D-CRT) for prostate cancer treated with no immobilization or one of four immunobilization devices, and to determine the effects of patient body habitus and pelvic circumference on patient movement with each individual inmobilization technique.

METHODS AND MATERIALS

To see whether our immobilization techniques have improved day-to-day patient movement, a retrospective analysis was carried out. A total of 62 patients treated at one facility on a single machine with 3D-CRT via a four-field box technique (anterior-posterior and opposed laterals) in the supine position with either no immobilization or one of four immobilization devices. Five groups of patients were compared: (a) group 1-no immobilization; (b) group 2-alpha cradle from the waist to upper thigh; (c) group 3-alpha cradle from waist to below the knees; (d) group 4-styrofoam leg immobilizer (below knees); and (e) group 5-aquaplast cast encompassing the entire abdomen and pelvis to midthigh with alpha cradle immobilization to their lower legs and feet. Prior to starting radiotherapy, portal films of all four treatment fields were obtained 1 day before treatment. Subsequently, portal films were then obtained at least once a week. Portal films were compared with the simulation films and appropriate changes were made and verified on the next day prior to treatment. A deviation of greater than 0.5 cm or greater was considered to be clincally significant in our analysis. We studied the difference among the types of immobilization and no immobilization by looking at the frequency of movements (overall, and on each of the three axes) that a patient had during the course of his treatment. Using a logistic regression model, the probability of overall and individual directional movement for each group was obtained. In addition, the effects of patient body habitus and pelvic circumference on movement were analyzed.

RESULTS

The maximum deviation was 2 cm and the median deviation was 1.2 cm. For each patient, the probability of movement ranged from 0 to 76%, with a mean of 39%. There was no significant difference seen in overall movement with any of the immobilzation devices compared to no immobilization, but there was less vertical (9 vs. 18%; p = 0.03) and AP (6 vs. 15%; p = 0.14) movement with the aquaplast than any other group. However, when examining the lateral direction, the aquaplast had significantly more movement (32 vs. 9%; p < 0.001). When accounting for body habitus and pelvic circumference, no immobilization device was effective in reducing movement in obese patients or in patients with pelvic circumference greater than 105 cm. The aquaplast group had a significantly increased amount of lateral movement with obesity (42 vs. 23%; p < 0.05), and with pelvic circumference >105 cm (33 vs. 29%; p < 0.05).

CONCLUSIONS

There was no significant reduction in overall patient movement noted with any of the immobilization devices compared to no immobilization. The aquaplast group had reduced vertical and AP movement of greater than 0.5 cm. There was significantly more lateral movement with aquaplast appreciated in obese patients or patients with pelvic circumferences greater than 105 cm. The aquaplast immobilization appears to be useful in reducing movement in two very clinicaly important dimensions (AP and vertical). Despite our findings, other immobilization may still be useful especially in the treatment of nonobese patients. It is clear that the optimal immobilization technique and patient positioning are yet to be determined.

Identification of human brain regions underlying responses to resistive inspiratory loading with functional magnetic resonance imaging

Compensatory ventilatory responses to increased inspiratory loading are essential for adequate breathing regulation in a number of pulmonary diseases; however, the human brain sites mediating such responses are unknown. Midsagittal and axial images were acquired in 11 healthy volunteers during unloaded and loaded (30 cmH2O; 1 cmH2O = 98 Pa) inspiratory breathing, by using functional magnetic resonance imaging (fMRI) strategies (1.5-tesla MR; repetition time, 72 msec; echo time, 45 msec; flip angle, 30 degrees; field of view, 26 cm; slice thickness, 5 mm; number of excitations, 1; matrix, 128 x 256). Digital image subtractions and region of interest analyses revealed significantly increased fMRI signal intensity in discrete areas of the ventral and dorsal pons, interpeduncular nucleus, basal forebrain, putamen, and cerebellar regions. Upon load withdrawal, certain regions displayed a rapid fMRI signal off-transient, while in others, a slower fMRI signal decay emerged. Sustained loading elicited slow decreases in fMRI signal across activated regions, while second application of an identical load resulted in smaller signal increases compared to initial signal responses (P < 0.001). A moderate inspiratory load is associated with consistent regional activation of discrete brain locations; certain of these regions have been implicated in mediation of loaded breathing in animal models. We speculate that temporal changes in fMRI signal may indicate respiratory after-discharge and/or habituation phenomena.

Autoantibody response to the Ro/La particle may predict outcome in neonatal lupus erythematosus

This study was undertaken to determine the role of antibodies against both recombinant Ro (r-Ro) and La (r-La) proteins and polypeptides derived from the recombinant La protein in predicting fetal and neonatal outcome in children at risk to develop neonatal lupus erythematosus (NLE). All sera were obtained in the perinatal period and quantitative ELISA assays were used. We collected 41 maternal sera within 2 months of delivery of a child with NLE (21 with congenital heart disease block (CHB) and 20 with dermatologic NLE) and 19 sera from anti-Ro and/or anti-La antibody-positive mothers with systemic lupus erythematosus (SLE) who delivered a child without NLE. All sera were tested for anti-r-La and anti-r-Ro antibodies by ELISA, and most sera were tested for antibodies directed against La polypeptides by immunoblot. We found significantly higher anti-r-La antibody levels in the sera from mothers of children with NLE compared with sera from mothers of unaffected children (0.67 +/- 0.43 versus 0.14 +/- 0.30; P < 0.0001). There was a statistically significant difference in the mean anti-r-La levels between the sera of mothers of children with CHB compared with dermatologic NLE (0.51 +/- 0.45 versus 0.83 +/- 0.37 respectively; P = 0.0091). When we examined antibodies directed against the recombinant 52-kD Ro protein, there was a statistically significant elevation of titres in the sera of mothers of NLE children (0.77 +/- 0.35) compared with non-NLE mothers (0.29 +/- 0.39; P < 0.0001). There was no difference in the r-Ro levels between mothers of children with dermatologic NLE compared with CHB (0.82 +/- 0.37 versus 0.71 +/- 0.74; P = 0.32). When we examined polypeptides derived from the recombinant La protein, the mean number of polypeptides recognized by sera from mothers of children with NLE was significantly higher than the mean number of polypeptides recognized by sera from mothers of unaffected children (5.1 +/- 0.54 versus 2.3 +/- 0.54 respectively; P < 0.001). More importantly, when we examined the individual polypeptides, we found that only sera from mothers of children with NLE and not from mothers of unaffected children recognized a polypeptide designated DD (30% versus 0%, respectively). These studies indicate that the autoantibody response to the Ro/La particle can differentiate sera from mothers of children with NLE and sera from mothers of unaffected children. Furthermore, there was a difference in the anti-La autoantibody response between mothers of children with CHB and dermatologic NLE.(ABSTRACT TRUNCATED AT 400 WORDS)

Comparative effectiveness of hypothermia rewarming techniques: radio frequency energy vs. warm water

The purpose of this study was to compare the rewarming effectiveness of a radio frequency coil (13.56 MHz) at a specific absorption rate (SAR) of 2.5 W/kg (RF) with warm water immersion (40 degrees C) (WW) and an insulated mummy-type insulating sack (IS) under simulated field conditions. Four male subjects, ages 24-35, were immersed in 10 degrees C water for up to 90 min or until their rectal temperatures (Tre) decreased to 35 degrees C. Each subject had 3 trials in which they were immersed. After each immersion, rewarming was accomplished with either RF, WW, or IS, so that each subject was rewarmed once with each method. Comparisons of the 3 rewarming methods were based on the rate of increase of Tre during rewarming (Tre/t), Tre 60 min after the start of rewarming (Tre60), the time-interval measured from extraction from the water to the end of afterdrop (tad), and the magnitude of any observed Tre afterdrop (Tad). WW had significantly greater Tre/t and Tre60 than either RF or IS (P < 0.03) and a smaller tad than IS (P < 0.05). IS had significantly greater Tad than either WW or RF (P < 0.05). No significant differences in Tre/t, Tre60, or tad were observed between IS and RF. The results of this study indicate that for mildly hypothermic individuals, active rewarming with RF at a SAR of 2.5 W/kg is less effective than WW and roughly equivalent to passive rewarming with IS.

Assessment of the terminal 40-millisecond QRS vector in children with a history of tricyclic antidepressant ingestion

Tricyclic antidepressant (TCA) ingestions remain a serious and not uncommon overdose in children. In adults, a terminal 40 millisecond QRS vector (T40-ms) between 120 and 270 degrees has been proposed as a marker for TCA overdose; however, the normal rightward deviation and high incidence of incomplete right bundle branch block noted in the electrocardiograms (ECGs) of young children may limit the usefulness of this criterion in this population. A retrospective chart review of pediatric patients less than 11 years of age admitted to the Hospital for Sick Children with birth dates after 1971 identified by International Classification of Diseases, Ninth Edition, coding for TCA ingestion was undertaken, and data related to complications were collected and reviewed. The ECGs of 35 children presenting with TCA ingestion were examined by two blinded cardiologists and the T40-ms as well as QRS, QTc, and PR intervals were calculated and compared to those of 35 healthy age-matched controls undergoing routine ECGs. In the 35 children (aged 48 +/- 39 months [mean +/- SD]) with a history of TCA ingestion, symptoms were categorized as significant in 18 (51%), mild in 12 (34%), and none in five (14%). Seizures were present in 13 (37%), hypotension in three (9%), and arrhythmias in five (14%). The mean T40-ms axes in the TCA and control groups were 111 +/- 66 degrees and 97 +/- 71 degrees, respectively. A T40-ms between 120 and 270 degrees had a sensitivity of 38% and a specificity of 74%. A marked variability in the T40-ms was noted in both the exposed and control groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Ex vivo human placental transfer of human immunodeficiency virus-1 p24 antigen

OBJECTIVE

Our purpose was to determine whether human immunodeficiency virus-1 p24 antigen crosses the human placenta and, if so, to determine its clearance index relative to antipyrine.

STUDY DESIGN

Eight term human placentas from uncomplicated vaginal or cesarean section deliveries were studied by ex vivo placental perfusion to determine the incidence and concentration required to obtain passage of p24 antigen into the fetal circulation. The concentration of p24 antigen was determined by antigen-capture enzyme immunoassay.

RESULTS

The passage of p24 antigen into the fetal circulation was observed in three of five placentas studied when the p24 antigen concentration in the maternal circulation was 2942.8 +/- 401 pg/ml. When the p24 concentration in the maternal circulation was raised approximately fourfold to 14506 +/- 4124 pg/ml, p24 antigen passed to the fetal circulation in two of three placentas and in three of three placentas in the closed perfusion system.

CONCLUSIONS

p24 antigen crossed the human placenta to the fetal circulation in what appears to be a concentration-dependent manner.

Acute basal ganglia infarction in propionic acidemia

An 8-year-old girl with propionic acidemia had acute and rapidly fatal symmetric necrosis of the caudate, globus pallidus, and putamen. Clinical presentation was with acute aphasia, generalized hypotonia, and muscle weakness. There was no evidence of metabolic decompensation, and analysis of the organic acids of the urine indicated good metabolic control. Organic acids in the cerebrospinal fluid were unremarkable. These observations indicate that the pathophysiology of "metabolic stroke" is more complicated than previously thought.

Clinical and histopathologic study of varicella zoster virus retinitis in patients with the acquired immunodeficiency syndrome

Varicella zoster virus retinitis in patients with the acquired immunodeficiency syndrome is known to be a devastating disease. We studied a series of six consecutive patients that sheds new light on the clinical manifestations and treatment options of this disorder. All patients had episodes of cutaneous zoster, long-term exposure to oral acyclovir, and CD4+ T lymphocyte counts less than 50 cells/mm3. Two of the six patients had simultaneous radiographically demonstrable and histologically proven varicella zoster virus encephalitis; this is an important association. Histologic examination of autopsy specimens disclosed that the retinal infection by varicella zoster virus involves the retinal pigment epithelium more heavily than the inner retina, which is consistent with the characteristic clinical impression of an outer retinal necrosis.