bluuebunny/crossref_metadata_2025 huggingface dataset:
Creation of a genetic system for analysis of the phagocyte respiratory burst: high-level reconstitution of the NADPH oxidase in a nonhematopoietic system
Authors: Price Marianne O. , McPhail Linda C. , Lambeth J. David , Han Chang-Hoon , Knaus Ulla G. , Dinauer Mary C.
Published: October 2002

The phagocyte nicotinamide adenine dinucleotide phosphate (reduced form) (NADPH) oxidase was functionally reconstituted in monkey kidney COS-7 cells by transfection of essential subunits, gp91phox, p22phox, p47phox, and p67phox. COS-7 cells express the essential small guanosine 5′-triphosphatase, Rac1. Transgenic COS-phox cells were capable of arachidonic acid–induced NADPH oxidase activity up to 80% of that of human neutrophils, and of phorbol myristate acetate (PMA)–induced activity up to 20% of that of neutrophils. Expression of all 4 phox components was required for enzyme activity, and enzyme activation was associated with membrane translocation of p47phox, p67phox, and Rac1. Expression of p47phox Ser303Ala/Ser304Ala or Ser379Ala phosphorylation-deficient mutants resulted in significantly impaired NAPDH oxidase activity, compared with expression of wild-type p47phox or the p47phox Ser303Glu/Ser304Glu phosphorylation mimic, suggesting that p47phoxphosphorylation contributes to enzyme activity in the COS system, as is the case in neutrophils. Hence, COS-phox cells should be useful as a new whole-cell model that is both capable of high-level superoxide production and readily amenable to genetic manipulation for investigation of NADPH oxidase function. PMA-elicited superoxide production in COS-phox cells was regulated by activation of protein kinase C (PKC) and Rac. Although COS-7 cells differ from human neutrophils in PKC isoform expression, transient expression of major neutrophil isoforms in COS-phox cells did not increase PMA-induced superoxide production, suggesting that endogenous isoforms were not rate limiting. Val204 in p67phox, previously shown to be required for NADPH oxidase activity under cell-free conditions, was found to be essential for superoxide production by intact COS-phox cells, on the basis of transfection studies using a p67phox(Val204Ala) mutant.
Coronary no-reflow is caused by shedding of active tissue factor from dissected atherosclerotic plaque
Authors: Bonderman Diana , Teml Alexander , Jakowitsch Johannes , Adlbrecht Christopher , Gyöngyösi Mariann , Sperker Wolfgang , Lass Harald , Mosgoeller Wilhelm , Glogar Dietmar H. , Probst Peter , Maurer Gerald , Nemerson Yale , Lang Irene M.
Published: October 2002

Defined angiographically, no-reflow (NR) manifests as an acute reduction in coronary flow in the absence of epicardial vessel obstruction. One candidate protein to cause coronary NR is tissue factor (TF), which is abundant in atherosclerotic plaque and a cofactor for activated plasma coagulation factor VII. Scrapings from atherosclerotic carotid arteries contained TF activity (corresponding to 33.03 ± 13.00 pg/cm2 luminal plaque surface). Active TF was sedimented, indicating that TF was associated with membranes. Coronary blood was drawn from 6 patients undergoing coronary interventions with the distal protection device PercuSurge GuardWire (Traatek, Miami, FL). Fine particulate material that was recovered from coronary blood showed TF activity (corresponding to 91.1 ± 62.16 pg/mL authentic TF). To examine the role of TF in acute coronary NR, blood was drawn via a catheter from coronary vessels in 13 patients during NR and after restoration of flow. Mean TF antigen levels were elevated during NR (194.3 ± 142.8 pg/mL) as compared with levels after flow restoration (73.27 ± 31.90 pg/mL; P = .02). To dissect the effects of particulate material and purified TF on flow, selective intracoronary injection of atherosclerotic material or purified relipidated TF was performed in a porcine model. TF induced NR in the model, thus strengthening the concept that TF is causal, not just a bystander to atherosclerotic plaque material. The data suggest that active TF is released from dissected coronary atherosclerotic plaque and is one of the factors causing the NR phenomenon. Thus, blood-borne TF in the coronary circulation is a major determinant of flow.
Moyamoya syndrome in childhood sickle cell disease: a predictive factor for recurrent cerebrovascular events
Authors: Dobson Scott R. , Holden Kenton R. , Nietert Paul J. , Cure Joel K. , Laver Joseph H. , Disco Deborah , Abboud Miguel R.
Published: October 2002

We conducted a retrospective study to determine whether the presence of moyamoya collaterals influenced the risk of recurrence of cerebrovascular events (CVEs: stroke or transient ischemic attack) in patients with sickle cell disease placed on chronic transfusions after a stroke. Forty-three patients with homozygous sickle cell anemia (HbSS) and 1 with HbSOArab (16 females, 28 males) who had suffered strokes while under the age of 18 were studied. All patients had been on transfusions aimed at maintaining the sickle hemoglobin (HbS) level below 30%. They were followed for a mean of 6.6 years (2.2 to 20.4 years). The presence of collaterals was diagnosed based on either magnetic resonance angiography or conventional angiography. Eighteen (41%) of the 44 patients suffered recurrent CVEs. Nineteen (43%) (6 females, 13 males) patients had moyamoya collaterals. Eleven (58%) of these 19 experienced 21 total recurrent CVEs, including 4 strokes in 4 patients (21%). In comparison, 7 (28%) of 25 patients without moyamoya collaterals experienced 9 recurrent CVEs (P < .05) with only 1 recurrent stroke (4%). Moyamoya patients were also more likely to have 2 recurrent CVEs (42% vs 8%,P < .05) as well as poorer neuropsychological testing results. A proportional hazards regression analysis indicated that patients with moyamoya were more than twice as likely to incur a subsequent CVE (hazard ratio, 2.40; 95% confidence interval, 0.85, 6.75). We conclude that up to 41% of patients with sickle cell disease experience recurrent CVEs after an initial stroke despite chronic transfusions and that the risk of recurrence is significantly higher for those who have moyamoya collaterals.
Glycoprotein VI–mediated platelet fibrinogen receptor activation occurs through calcium-sensitive and PKC-sensitive pathways without a requirement for secreted ADP
Authors: Quinton Todd M. , Ozdener Fatih , Dangelmaier Carol , Daniel James L. , Kunapuli Satya P.
Published: October 2002

Collagen activates platelets by transducing signals through glycoprotein VI (GPVI). It is not clear whether collagen can directly activate fibrinogen receptors on the adherent platelets without a role for positive feedback agonists. We investigated the contribution of secondary G protein signaling to the mechanism of GPVI-stimulated platelet aggregation using the GPVI-selective agonists, convulxin and collagen-related peptide (CRP) as well as collagen. Adenosine diphosphate (ADP) scavengers or ADP receptor antagonists shifted the concentration-response curve slightly to the right at low concentrations of convulxin, whereas platelet aggregation at higher concentrations of convulxin was unaffected by these agents. ADP receptor antagonists shifted the concentration-response curve of collagen- or CRP-induced platelet aggregation to the right at all the concentrations. Protein kinase C inhibitor, Ro 31-8220, or a calcium chelator 5,5′-dimethyl-BAPTA shifted the concentration-response curve of convulxin-induced platelet aggregation to the right. In addition, pretreatment with both Ro 31-8220 and dimethyl-BAPTA resulted in total inhibition of convulxin-mediated aggregation. Blockade of either the calcium- or protein kinase C–regulated pathway leads to inhibition of fibrinogen receptor activation on platelets adherent to collagen, but inhibition of both pathways leads to abolished fibrinogen receptor activation. We conclude that collagen-induced activation of fibrinogen receptor on adherent platelets through GPVI signaling occurs without any significant role for secreted ADP or thromboxane A2. Furthermore, protein kinase C– and calcium-regulated pathways independently contribute to GPVI-mediated platelet aggregation.
Alanine-170 and proline-172 are critical determinants for extracellular CD20 epitopes; heterogeneity in the fine specificity of CD20 monoclonal antibodies is defined by additional requirements imposed by both amino acid sequence and quaternary structure
Authors: Polyak Maria J. , Deans Julie P.
Published: October 2002

In vivo ablation of malignant B cells can be achieved using antibodies directed against the CD20 antigen. Fine specificity differences among CD20 monoclonal antibodies (mAbs) are assumed not to be a factor in determining their efficacy because evidence from antibody-blocking studies indicates limited epitope diversity with only 2 overlapping extracellular CD20 epitopes. However, in this report a high degree of heterogeneity among antihuman CD20 mAbs is demonstrated. Mutation of alanine and proline at positions 170 and 172 (AxP) (single-letter amino acid codes; x indicates the identical amino acid at the same position in the murine and human CD20 sequences) in human CD20 abrogated the binding of all CD20 mAbs tested. Introduction of AxP into the equivalent positions in the murine sequence, which is not otherwise recognized by antihuman CD20 mAbs, fully reconstituted the epitope recognized by B1, the prototypic anti-CD20 mAb. 2H7, a mAb previously thought to recognize the same epitope as B1, did not recognize the murine AxP mutant. Reconstitution of the 2H7 epitope was achieved with additional mutations replacing VDxxD in the murine sequence for INxxN (positions 162-166 in the human sequence). The integrity of the 2H7 epitope, unlike that of B1, further depends on the maintenance of CD20 in an oligomeric complex. The majority of 16 antihuman CD20 mAbs tested, including rituximab, bound to murine CD20 containing the AxP mutations. Heterogeneity in the fine specificity of these antibodies was indicated by marked differences in their ability to induce homotypic cellular aggregation and translocation of CD20 to a detergent-insoluble membrane compartment previously identified as lipid rafts.
Humoral immune responses against Wilms tumor gene WT1product in patients with hematopoietic malignancies
Authors: Elisseeva Olga A. , Oka Yoshihiro , Tsuboi Akihiro , Ogata Kiyoyuki , Wu Fei , Kim Eui Ho , Soma Toshihiro , Tamaki Hiroya , Kawakami Manabu , Oji Yusuke , Hosen Naoki , Kubota Takeshi , Nakagawa Masashi , Yamagami Tamotsu , Hiraoka Akira , Tsukaguchi Machiko , Udaka Keiko , Ogawa Hiroyasu , Kishimoto Tadamitsu , Nomura Taisei , Sugiyama Haruo
Published: October 2002

Wilms tumor gene WT1 is expressed at high levels in hematopoietic malignancies, such as leukemias and myelodysplastic syndromes (MDS), and in various kinds of solid tumors, including lung cancer, and it exerts an oncogenic function in these malignancies. IgM and IgG WT1 antibodies were measured by means of dot blot assay in 73 patients with hematopoietic malignancies (16 acute myeloid leukemia [AML], 11 acute lymphoid leukemia [ALL], 13 chronic myeloid leukemia [CML], and 33 MDS) and 43 healthy volunteers. Immunoglobulin IgM, IgG, and IgM+IgG WT1 antibodies were detected in 40 (54.8%), 40 (54.8%), and 24 (32.8%), respectively, of the 73 patients with hematopoietic malignancies, whereas 7 (16.2%), 2 (4.7%), and none of the 43 healthy volunteers had IgM, IgG, or IgM+IgG WT1 antibodies, respectively. Furthermore, immunoglobulin isotype class switching of WT1 antibodies from IgM to IgG occurred in conjunction with disease progression from refractory anemia (RA) to RA with excess of blasts (RAEB), and further to RAEB in transformation (RAEB-t) in MDS patients. These results showed that humoral immune responses against the WT1 protein could be elicited in patients with WT1-expressing hematopoietic malignancies, and they suggested that the helper T-cell responses needed to induce humoral immune responses and immunoglobulin isotype class switching from IgM to IgG were also generated in these patients. Our findings may provide new insight into the rationale for elicitation of cytotoxic T-cell responses against the WT1 protein in cancer immunotherapy using the WT1 vaccine.
Changes in fatal and near-fatal asthma in an urban area of South Africa from 1980–1997
Authors: Zar H.J. , Stickells D. , Toerien A. , Wilson D. , Klein M. , Bateman E.D.
Published: October 2002

Over the past two decades, changes in the health services designed to improve access to and quality of asthma care have occurred in South Africa. The aim of this study was to investigate the incidence of fatal and near-fatal asthma (NFA) from 1980–1997 in an urban part of South Africa.

A retrospective analysis of fatal asthma and NFA in the Cape Town City Council area was performed. Mortality data were obtained from death notification records. Data on NFA were obtained from the records of patients admitted for asthma to intensive care units (ICUs) at major academic hospitals serving the area.

There were 1,506 deaths (mean age 56 yrs) from asthma reported; 39 and 3% occurred in people under 55 and 15 yrs, respectively. Average annual asthma mortality rate (8.1±1.9 per 100,000 population) was highest amongst people of mixed race (10.1±2.0), followed by Blacks (6.8±3.1) and Whites (5.0±1.9, p<0.001). Asthma mortality declined by 0.28 deaths per 100,000 population per year; rates decreased in all ethnic groups. Most deaths (72.3%) were outside a health facility and a higher number of deaths occurred on weekends (223 deaths·day−1) than weekdays (207 deaths·day−1, p=0.014). Paediatric asthma ICU admissions declined by 1.81 children·yr−1. The annual number of adults admitted to ICU for asthma, and the proportion requiring intermittent positive pressure ventilation did not change.

These results indicate that the incidence of fatal and near-fatal asthma in this area has declined over the period and this may reflect improved asthma management. However, the relatively high asthma mortality rate in people of mixed race and the predominance of deaths outside health facilities and on weekends suggest problems with access to care.
Pneumococcal vaccination: current and future issues
Authors: Örtqvist Å.
Published: October 2002

Infection withStreptococcus pneumoniaeremains a major global health burden meaning the development of effective vaccines is urgently needed. The current 23-valent polysaccharide vaccine has been shown to prevent pneumococcal pneumonia in immunocompetent young adults, but not in elderly persons.

However, in prevention of invasive pneumococcal disease, the vaccine is efficacious in the elderly and may also be effective in some groups of immunocompromised patients. The polysaccharide vaccine is, therefore, recommended in all older (≥55–65 yrs of age) adults and in young children (>2 yrs of age) who have a high risk for pneumococcal disease. Revaccination can be safely performed and is recommended 5 yrs after the first dose.

In children <2 yrs of age, the new polysaccharide-protein conjugate vaccines, including 7–11 serotypes, seem to be effective in the prevention of invasive disease, severe pneumonia and serotype-specific (and vaccine-related types) otitis media. The low serotype coverage, need for repeated doses, and high price, may decrease the usefulness of the new conjugates. However, the included serotypes correspond to those most often associated with penicillin resistance and vaccination is, therefore, a possible tool in limiting the spread of antibiotic-resistant pneumococci.
Initial risk class and length of hospital stay in community-acquired pneumonia
Authors: Menéndez R. , Ferrando D. , Vallés J.M. , Martínez E. , Perpiñá M.
Published: October 2002

The total medical costs of community-acquired pneumonia are directly related to the costs of hospital admission and length of stay. The aim of the present study was to evaluate the reasons for prolonged duration of stay in patients stratified in five risk classes for death, and to identify factors associated with prolonged stay.

The study population consisted of 295 patients. According to lower (classes I, II, III) or to higher (classes IV, V) risk, the target duration of hospitalization was set at 5 and 7 days, respectively. The causes of prolonged hospitalization were classified as pneumonia-related, complications, unstable comorbid diseases and nonclinical factors.

The overall percentage of patients with appropriate duration of hospitalization was 32%. Causes of prolonged hospitalization were related mainly to pneumonia (32%) from all risk classes. Morbid complications and instability of the underlying illness were greater in class V patients. Nonclinical factors were present in 29.5% of cases. Hypoxaemia, anaemia, hypoalbuminaemia, and complications appearing before 72 h were associated with prolonged hospitalization.

The cause of prolonged hospitalization of patients with community-acquired pneumonia is multifactorial, depending mainly on pneumonia and comorbid conditions but there is a large number of unnecessary hospitalization days that could be reduced by improving the efficiency of hospital care.
Is overall asthma control being achieved? A hypothesis-generating study
Authors: Bateman E.D. , Bousquet J. , Braunstein G.L.
Published: October 2002

The efficacy of asthma therapy is traditionally measured using single  end-points. In contrast, the aim of therapy is to achieve overall control, defined by management guidelines as achieving a number of treatment goals. These goals reflect expert opinion, rather than being evidence based. The objective of this study was to determine whether guideline-defined asthma control is achievable.

Eight studies of salmeterol/fluticasone propionate combination therapy were analysed using three asthma control measures of varying stringency, derived from the guideline goals. For each measure, only patients meeting all goals were classified as controlled.

The analysis demonstrated that asthma control, as defined by management guidelines, can be achieved. For a given therapy, similar proportions of patients achieved control irrespective of disease severity, suggesting that outcome expectations should not be reduced for patients with more severe disease. Substantially more patients achieved the target values for individual goals than achieved overall control, indicating that reliance on individual end-points is likely to result in significant overestimation of true control.

The findings of this hypothesis-generating study should be prospectively tested. Future research will include a randomized controlled study designed to assess the proportion of patients able to achieve overall control of asthma when treatment is titrated appropriately.
Pulmonary gas exchange responses to histamine and methacholine challenges in mild asthma
Authors: Echazarreta A.L. , Gómez F.P. , Ribas J. , Sala E. , Barberà J.A. , Roca J. , Rodriguez-Roisin R.
Published: October 2002

Histamine (HIST) produces greater changes in bronchial and pulmonary vasculature, and so may produce more gas exchange abnormalities, than methacholine (MTH) after inhalational challenge. The goals of this study were to compare the effects of HIST and MTH challenge on pulmonary gas exchange in patients with mild asthma at an equivalent degree of bronchoconstriction.

Eleven patients were studied (mean±sem age, 22±1 yr; forced expiratory volume in one second (FEV1), 91±5% pred) using a randomized, double-blind cross-over design. Respiratory system resistance (Rrs), arterial blood gases, and ventilation-perfusion distributions were measured before and after HIST/MTH challenges when cumulative doses caused a 30% fall in FEV1.

Compared with baseline, HIST and MTH provoked similar moderate to severe increases inRrs(p<0.005 each), and mild to moderate decreases in arterial oxygen tension (Pa,O2) due to ventilation-perfusion abnormalities (dispersion of pulmonary blood flow -log SDQ-, 0.40±0.03–0.71±0.08 and 0.47±0.04–0.89±0.06; normal values <0.60–0.65), respectively, similar to those shown in mild to moderate acute asthma, without differences between them.

For the same degree of airflow obstruction, both histamine and methacholine bronchoprovocations induce, in patients with mild asthma, very similar disturbances in ventilation-perfusion distribution and respiratory system resistance, suggesting similar mechanisms of airway narrowing.
Pulmonary sarcoidosis in children: a follow-up study
Authors: Baculard A. , Blanc N. , Boulé M. , Fauroux B. , Chadelat K. , Boccon-Gibod L. , Tournier G. , Clement A.
Published: October 2002

Progression of pulmonary sarcoidosis in children remains poorly documented. The aim of this work was to gather follow-up information on pulmonary outcomes in children with sarcoidosis and to obtain data of relevance to a discussion of the optimal length and regimen of glucocorticoid therapy.

In the present study, the authors experience of pulmonary sarcoidosis in 21 children referred to the paediatric pulmonary department over a 10-yr period is reported with a documented follow-up of at least 4 yr. Evaluation of the disease during the follow-up included analysis of clinical manifestations, chest radiographs, pulmonary function tests with measurements of the vital capacity (VC), dynamic lung compliance (CL,dyn), lung transfer for CO (TL,CO), and arterial blood gases, as well as bronchoalveolar lavage (BAL) with determination of total and differential cell counts.

After initial evaluation the decision was a careful observation of four children without therapy. Corticosteroid treatment was initiated in 17 children. Analysis of results indicated that after 6–12 months of treatment most clinical manifestations of the disease and chest radiograph abnormalities disappeared, and beneficial effects on VC andTL,COwere apparent. After 18 months of steroids no benefit on pulmonary function tests could be noticed, with mainly persistence of alterations ofCL,dyn. Results of BAL studies documented the presence of an alveolitis with increased lymphocyte populations throughout the follow-up. Relapses were observed in four children during tapering of prednisone; they were not reported after discontinuation of steroid therapy.

Taken together data obtained in the presented population can lead to the following suggestions for the management of pulmonary sarcoidosis in children. BAL should be performed at the initial evaluation to document alveolitis; however, nothing seems to be gained from repeating this investigation during follow-up in the absence of specific reasons. Once the decision to initiate glucocorticoid therapy is made, 18 months may be a reasonable treatment duration. Discontinuation of therapy can be decided even if the pulmonary function tests remain abnormal, but the child should then be carefully monitored for a relapse.
The influence of fractional pulse pressure on the outcome of pulmonary thromboendarterectomy
Authors: Tanabe N. , Okada O. , Abe Y. , Masuda M. , Nakajima N. , Kuriyama T.
Published: October 2002

Although pulmonary thromboendarterectomy is an effective modality for the treatment of chronic thromboembolic pulmonary hypertension (CTEPH), the mortality in patients with severe haemodynamic disease is still high. Recently it was reported that fractional pulse pressure (pulmonary arterial pulse pressure/mean pulmonary arterial pressure) was higher in CTEPH than in primary pulmonary hypertension (PPH). It was hypothesized that fractional pulse pressure might be low in CTEPH with inaccessible distal thrombi and/or secondary pulmonary hypertensive change, resulting to the high operative mortality.

To determine the influence of fractional pulse pressure to the outcome of surgery, 32 patients with CTEPH who had thromboendarterectomy between 1985 and 1998 were studied. Pulmonary haemodynamics and fractional pulse pressure were compared between survivors (n=26) and nonsurvivors (n=6) postoperatively. Those parameters in PPH (n=18) and large vessel pulmonary arteritis (n=6) were also analysed.

Fractional pulse pressure in CTEPH (1.23±0.21) was significantly higher than in PPH (0.93±0.22; p=0.0017) and lower than in pulmonary arteritis (1.69±0.32; p=0.03). Fractional pulse pressure in survivors (1.26±0.21) was significantly higher than in nonsurvivors (1.06±0.16; p=0.03). Fractional pulse pressure is a significant predictor for mortality in patients with high pulmonary vascular resistance >1100 dynes·sec·cm−5.

To conclude fractional pulse pressure in addition to pulmonary vascular resistance might be useful in predicting for the outcome of surgery, especially in patients with severe haemodynamic impairment.
Diaphragm fatigue during exercise at high altitude: the role of hypoxia and workload
Authors: Gudjonsdottir M. , Appendini L. , Baderna P. , Purro A. , Patessio A. , Vilianis G. , Pastorelli M. , Sigurdsson S.B. , Donner C.F.
Published: October 2002

The effect of high altitude (HA) on exercise-induced diaphragm fatigue in normal subjects was examined.

Eight normal subjects completed an incremental exercise test at sea level (SL) and at 3,325 m. Before (baseline), during, and after exercise (recovery), maximal transdiaphragm pressure (Pdi,sniff), breathing pattern, and diaphragmatic effort (PTPdi) were measured. Arterialized blood lactate was measured at baseline and during recovery.

At maximal exercise (WRmax)Pdi,snifffell to 72% and 61% of baseline at SL and HA respectively, recovering to baseline in 60 min at SL, and >60 min at HA. At the 5th min of recovery, circulating lactate was six-fold and seven-fold baseline at SL and HA, respectively. The time course of circulating lactate recovery was as forPdi,sniff. At WRmaxPTPdiwas 80.74±9.87 kPa·s−1at SL and 64.13±8.21 kPa·s−1at HA. HA WRmaxcompared to isowork rate, SL data showed a lowerPdi,sniff(8.90±0.68versus11.24±0.59 kPa) and higher minute ventilation (117±11versus91±13 L·min−1), PTPdibeing equal.

To conclude, in normal subjects hypoxia-related effects, and not an increase in diaphragm work, hastens exercise-induced diaphragm fatigue and delays its recovery at high altitude compared to sea level.
Elastic properties of the lung and the chest wall in young and adult healthy pigs
Authors: De Robertis E. , Liu J.M. , Blomquist S. , Dahm P.L. , Thörne J. , Jonson B.
Published: October 2002

Understanding of the elastic pressure/volume (Pel/V) curve is still limited in health and disease. The aim of the present study was to elucidate thePel/Vcurve and elastance of the respiratory system (ERS) lung (EL) and chest wall (ECW) in healthy pigs.

Six young (20.8 kg) and seven adult (58.9 kg), anaesthetized, paralysed and ventilated pigs were studied.Pel/Vcurves were recorded at zero end-expiratory pressure (ZEEP) and at positive end-expiratory pressure (PEEP) up to 40 cmH2O with a computer controlled ventilator during an insufflation at a low, constant flow.

Pel/Vcurves of the respiratory system showed a complex pattern in both young and adult pigs. During the insufflation,ERSdecreased, increased, fell, and increased again. A secondPel/Vcurve recorded immediately after the first one showed lower elastance and only one early fall inERS.ECWfell over the initial segment and was then nearly stable. Difference between 1st and 2nd curves reflected changes in ELcaused by recruitment during the 1st insufflation. At PEEP, such signs of collapse and recruitment were reduced.

A strong tendency to lung collapse contributes to a complex pattern of elastic pressure/volume curves. At low volumes and distending pressures the chest wall contributes significantly to changes in respiratory system elastance.
Surfactant protein A and other bronchoalveolar lavage fluid proteins are altered in cystic fibrosis
Authors: von Bredow C. , Birrer P. , Griese M.
Published: October 2002

Inflammation and proteolytic processes play an important role in the progression of cystic fibrosis (CF) lung disease. The goal of this study was to describe bronchoalveolar lavage fluid (BALF) protein pattern of CF patients in comparison to controls and to assess if there is proteolytic degradation of surfactant protein A (SP-A), an important innate host defence component of the lungs.

BALFs from 17 clinically stable CF patients and from eight healthy children were separated by two-dimensional gel electrophoresis. Silver staining was used to show BALF proteins and Western blotting to detect SP-A isoforms.

In CF, BALF proteins of a low molecular weight ≤20 kD were more abundant than in controls. Various proteins were seen in CF which were not present in controls andvice versa. Degradation of SP-A was present in 15 of 17 CF BALFs but in none of the controls, in contrast polymeric isoforms were seen in all controls and in four of 17 CF patients.

Proteolytic damage to surfactant protein A and significant changes of normal bronchoalveolar lavage fluid proteins occur in lungs of cystic fibrosis patients. Identification of altered bronchoalveolar lavage fluid proteins may give new insights into pathogenic mechanisms and provide new targets for therapy.
THE ORGANIZATION OF AN EFFECTIVE EXPLORATION DEPARTMENT
Authors: Weatherby B. B.
Published: October 2002

The author reviews the functions of a Land, Lease and Exploration Department in a large oil company, and describes in detail the integral parts. Criteria are furnished for the background of men suitable for the various positions, and a detailed organization chart is submitted which also shows the flow of information secured from the various field methods. Much stress is placed upon the need for detailed, routine reports. The part played by contracting geophysical exploration companies is also described, and the extent of the service which they should render is shown.
“Shearing Phenomena at High Pressures of Possible Importance for Geology.” Journal of Geology, Vol. XLIV, pp. 653–669, 1936. By P. W. Bridgman.
Authors: Boos C. Maynard
Published: October 2002

Contributions from Bridgman’s high‐pressure laboratory at Harvard are always of interest. In the present article he discusses flow, and the shearing stresses necessary to produce flow under high pressure for a wide variety of substances. Rigidity, or the resistance to shearing stress, is one of the fundamental constants of the seismologist, and Bridgman here deals with shearing stresses under conditions of great pressure comparable to those under which seismic data are obtained. The experiments were made at room temperatures, but at pressures as high as [Formula: see text] corresponding to those prevailing at depths of 166 km. Few rocks now available for examination at the surface of the earth are likely to have been buried so deep.
GRAVIMETER PROSPECTING FOR CHROMITE IN CUBA
Authors: Hammer Sigmund , Nettleton L. L. , Hastings W. K.
Published: October 2002

As a contribution to the War Production Board’s program of exploration for strategic minerals and under an arrangement with the Bethlehem Steel Company, Gulf Research & Development Company, in early 1942, made gravimeter surveys in the chromite bearing Camaguey District, Cuba. One large chromite deposit, under and between two adjacent gravity anomalies, which has been outlined to date by core drilling based on the results of this work, constitutes a substantial addition to the chrome ore reserves of the district. Chrome ore bodies occur in or are associated with igneous rocks. Extensive density determinations of selected rock samples revealed that the chrome ore has a positive density contrast of about 1.5 with respect to the serpentine rock in which it occurs, but also that local occurrences of various other types of igneous rocks, as well as weathered surface material, cause appreciable density contrasts. The technical aspects of the gravimeter field work are discussed. Many gravity anomalies were found; subsequent geological field work and a systematic program of test drilling proves the anomalies to arise from a variety of causes. Typical examples of gravity anomalies due to chromite deposits and to various igneous rock masses are presented. The paper concludes with brief comments on the economic significance of the work.
THE ANALYSIS OF OBLIQUE REFLECTION DATA
Authors: Horton C. W.
Published: October 2002

In regions where the reflecting layers have large dips it is difficult to interpret reflection data if the shot‐point and the instrument‐spread do not coincide. In this paper rigorous methods of locating the reflection‐point and of determining the magnitude and direction of the dip are given. Two approximate solutions are discussed in detail and by means of theoretical considerations and numerical examples it is shown that the errors introduced by the approximations are adequately small.
EFFECT OF SURFACE TOPOGRAPHY ON SEISMIC MAPPING
Authors: Widess M. B.
Published: October 2002

The presence of rough surface topography in a prospect frequently constitutes a source of error in seismic mapping and poses the question of what computational methods can be applied by which seismic maps may be freed of the effect of surface relief. Various aspects of the problem are described. The use of a plane datum‐horizon is generally adequate as a solution of the problem. For greater refinement, the structural map may be modified to account for the overburden effect, the approximate magnitude of which is considered. Further modification may be required when lateral variations in subweathering velocity occur. Statistical analysis for determining the degree of conformity between surface topography and mapped structure at depth is useful in gathering data on the influence of surface topography.
DIMENSIONS AND UNITS OF ELECTROMAGNETIC QUANTITIES
Authors: Baker Glenn J.
Published: October 2002

A brief history is given of the confusion in the literature in regard to c.g.s. electromagnetic units and some inconsistencies are pointed out. It is contended that most geomagnetic measurements are of the flux density B rather than of H, and that the gamma is correctly regarded as equivalent to [Formula: see text] gausses. Dimensions of the important electromagnetic quantities and the numerical relations between m.k.s. units and electromagnetic and electrostatic c.g.s. units are set forth. The adoption of m.k.s. units is urged as they are particularly advantageous to engineers.
ELECTRIC FIELD OF AN OSCILLATING DIPOLE ON THE SURFACE OF A TWO LAYER EARTH
Authors: Wolf Alfred
Published: October 2002

The electric field of a low frequency oscillator placed on the surface of a two layer earth is determined in two special cases, namely, the case in which the conductivities of the two layers are nearly equal, and the case in which the lower layer is a perfect insulator; in the latter case, only terms of zero and first order in frequency are considered. It is shown that, when the upper layer is sufficiently thin or is very thick, the mutual inductance of two wire elements on the surface of a two layer earth has the same value as for a homogeneous earth. In the case of an insulated layer, it is shown that the maximum departure of the value of mutual inductance of two collinear wire elements from the corresponding value on a homogeneous earth is 35%.
AMBIGUITY IN GRAVITY INTERPRETATION
Authors: Skeels D. C.
Published: October 2002

It is shown that contrary to what is stated and implied in much of the literature, gravity data cannot, of themselves, be interpreted uniquely. It is shown by means of a two‐dimensional example that for a given anomaly and a given density contrast a wide range of possible interpretations can be made, at various depths, and that whereas there is a maximum depth for the solution the minimum depth is zero. Other examples are given to show that depth rules based upon the assumption of geometrical shapes may give results very much in error when applied to actual anomalies. Nor does the method of interpretation by vertical gradients allow us to make an unique interpretation, or to distinguish deep from shallow anomalies as has been claimed. It is shown that we do not escape the ambiguity by using second derivative quantities such as gradient and curvature, and that, in fact, gravity and its derivatives are related by a corollary of Green’s theorem. This theorem provides an analytical proof of ambiguity not only for the case of gravity data but for magnetic data as well.
STUDIES ON SEISMIC WAVES: III. PROPAGATION OF ELASTIC WAVES IN THE NEIGHBORHOOD OF A FREE BOUNDARY
Authors: Fu C. Y.
Published: October 2002

Continuous and spherical harmonic waves are generated at an internal point of the medium. By use of the classical method of Sommerfeld, the different modes of propagation near a free surface after the arrival of the waves are examined. From the approximate evaluations of the integrals, it is found that in addition to the ordinary types of body and surface waves, there are also inhomogeneous waves and surface waves which are not of the Rayleigh type. The amplitude factors of these latter waves vary inversely as the square instead of as the square root of the epicentral distance. Altogether, there are not less than five different types of waves and they are obtained from integrations in the neighborhood of the singularities of the integrals.
GEOPHYSICAL HISTORY OF RAISIN CITY FIELD, CALIFORNIA
Authors: Sloat John
Published: October 2002

The discovery history of Raisin City Field is presented because it demonstrates the ability of the seismograph to locate low relief structures, where closure is present only in certain zones, even in areas where records are of mediocre quality. The seismic map which led to leasing is shown, along with detail maps made several years later. Gravimeter maps and maps from well points are also presented.
GRADING SYSTEM FOR SEISMIC REFLECTIONS AND CORRELATIONS
Authors: Gaby Phil P.
Published: October 2002

The modern reflection seismograph places progressively more emphasis on continuous profiling. The use of the continuous profile method automatically makes possible the computation of dip and the plotting of dip cross sections. Fundamentally the accuracy of a dip computed on such a continuous‐profile symmetrical record is of the same order as the accuracy of a “correlation” between adjacent records because the dip consists of a continuous‐profile correlation over the same length of subsurface base line as that obtained by “correlation” of adjacent, continuous profiles. Dip computation is the fundamental procedure in areas of discontinuous correlation. Further, the use of dip and of correlation provides two essentially independent approaches to the determination of subsurface structure. The combination of the two is used to provide more uniformly accurate results than can be had through the use of either one alone. We require a practical method for sorting and grading the accuracy of dip indications and of correlation, which system should be based on substantially the same fundamentals in each case and should be as free as possible from the vagaries of personal judgment. A system is outlined which is adapted to both purposes. In evaluating dip attitudes, the grade indicates: (a) The certainty with which the event may be identified as a true reflection, and (b) The accuracy of the indicated dip. Similarly, in evaluating correlation, the grade indicates: (a) The certainty with which the events being correlated are known to be correlatives, and (b) The accuracy of the indicated correlation drop. These grades, placed on the cross section, serve as a guide in sorting out any conflicting information at the time the interpretation (and map) is being made. The use of such grades allows the concentration of all pertinent information in one place where any conflicting evidence can be weighed in terms of relative merit.
DISCUSSION OF MULTIPLE REFLECTIONS
Authors: Lester O. C.
Published: October 2002

A field experiment designed for the purpose of recording and identifying sound reflections from the surface of the earth is described. Shot and recording points at varying depths in adjacent deep holes were used. This experiment was performed at several locations in the Mid‐Continent and Gulf Coast areas. No evidence of reflections from the ground‐air contact was observed.
AIRBORNE MAGNETIC PROFILE ABOVE 40TH PARALLEL, EASTERN COLORADO TO WESTERN INDIANA
Authors: Jensen Homer
Published: October 2002

On the return trip from the Geophysical Meetings in Denver in the spring of 1948, the Gulf magnetometer in the Aero Service Corporation DC‐3 magnetometer survey plane was operated continuously from a point near Adena, Colorado, to the vicinity of Indianapolis, Indiana, as part of a program of running long lines in the course of routine transfer of survey airplanes.
A SUMMARY OF EXTENSION COURSES SUITABLE FOR FIELD‐CREW TRAINING
Authors: Leonard James H.
Published: October 2002

A summary is made of all university and college extension courses which may be utilized in field training of geophysical crews.
BAHAMAS AIRBORNE MAGNETOMETER SURVEY
Authors: Bemrose J. , Heggblom J. C. , Holt T. C. , Richards T. C. , Watson R. J.
Published: October 2002

This paper presents some of the background prior to the actual survey, the functioning of the “Technical Committee” and its relationship to the contractors. A brief outline is also presented covering the various technical phases of the operation together with some of the inherent hazards of the area and how they were handled. A summary of recommended changes in equipment and procedure arising from the experience of this survey is given.
SEISMIC WAVE PROPAGATION
Authors: Clewell D. H. , Simon R. F.
Published: October 2002

Speculations are made regarding the significance of the well‐known observation that seismic reflection energy is usually in the frequency range of from 20 to 100 cycles per second. The general absence of reflected energy below 20 cps is attributed to the fact that the wavelengths of seismic waves in this frequency range are becoming large compared to the thicknesses of reflecting beds; accordingly, the reflection coefficients are low with the results that the geologic section appears more or less homogeneous, the low frequency energy is unweakened by reflections, is transmitted efficiently, and can only return to the surface by refraction. As the frequency is increased the wavelengths become comparable to the vertical discontinuities represented by stratification and more efficient reflection takes place with the result that reflected energy is returned and detected at the surface. At still higher frequencies the wavelengths become comparable to small inhomogeneities distributed at random throughout the geologic section and the energy is therefore diffused and scattered to such an extent that transmission into the earth is limited. This weakening of the main wave front by scattering, plus the weakening by absorption processes involving viscous and solid friction, constitute an effective cutting off of high frequency transmission. The high frequency scattered energy diffuses back to the surface and appears on the seismogram as “hash,” unless eliminated by filters, or is absorbed before it reaches the surface. Such a speculative picture of seismic energy propagation accounts qualitatively for (1) the continuous reception of random energy that is always superimposed upon the reflection energy, (2) the tendency for deep reflections to be of lower frequency than shallow reflections, and (3) the fact that theoretical considerations of absorption do not always account for known attenuation of high frequency seismic energy.
SOME CONSIDERATIONS OF THE MECHANISM OF THE GENERATION OF SEISMIC WAVES BY EXPLOSIVES
Authors: Morris George
Published: October 2002

The mechanism whereby an elastic pulse is generated in the ground due to the detonation of an explosive charge is discussed. Initially the pressure in the borehole is very high, of the order of several hundred tons per square inch. The sudden impact of this on the walls of the borehole causes a shock wave in the ground, the intensity of which is very much greater than the ground can bear, so that the wave rapidly loses energy in fracturing the ground, and degenerates into an elastic pulse at a distance defined as the critical radius. This elastic pulse is transmitted sensibly unchanged through the ground. The ground vibration detected by a geophone is the synthesis of this pulse modified by reflections and refractions at the interfaces of the geological formation of the site, spread out in time according to the paths along which the components have travelled. Although adequate quantitative information is lacking, an attempt is made to evaluate such a pulse at various stages of its career in order that the physical magnitudes involved may be appreciated.
NOTE ON THE ANALYSIS OF OBLIQUE REFLECTION DATA
Authors: Hazebroek P.
Published: October 2002

A rigorous geometrical solution is given of the problem of determining the location and orientation of a layer from observations at a cross spread, assuming a linear velocity distribution.
RADIOACTIVITY AND MINERALIZATION IN RHYOLITE PORPHYRY
Authors: Damon Paul E.
Published: October 2002

Measurements of the hard gamma radiation from the pre‐Cambrian rhyolite porphyry of the Bourbon, Missouri, well core show a direct relationship between mineralization and radioactive content. Low activities are, in general, associated with high mineral density, whereas the mineral density is a function of the magnetite content. The low activities are most probably due to a leaching out of the potassium content. This indicates that gamma‐ray well logs should be capable of accurately measuring the location of mineral deposits in potassium rich rock. Potassium analysis of the core is planned by the Missouri Geological Survey.
THE POULTER SEISMIC METHOD OF GEOPHYSICAL EXPLORATION
Authors: Poulter Thos. C.
Published: October 2002

The Poulter seismic method is outlined and an analysis is made of the frequency distribution of seismic energy from different sources. The effect of different sources upon the directivity of the energy in the ground and the improvement that can be obtained in signal‐to‐noise ratio is discussed. Three different methods are described for controlling the frequency of the seismic impulses being introduced into the ground and the resulting improvement in the quality of records is illustrated. The almost complete elimination of multiple reflections by the method is indicated.
CRYSTAL SHAKETABLE FOR GEOPHONE STUDIES
Authors: Bardeen Thomas
Published: October 2002

A comparison is made between shaketables driven by piezoelectric crystals and those of conventional design. The general construction of crystal shaketables and the auxiliary equipment necessary for geophone studies are discussed. The theory of geophone motion shows that a measurement of phase shift between the geophone output and the crystal shaketable driving voltage can be used to determine the nature frequency and damping of the moving mass of the geophone. The crystal shaketable gives a simple method for routine testing of geophones both in the laboratory and the field.
GEOPHYSICAL RADIO FIELD INTENSITY MEASUREMENTS
Authors: Sorge Bart W. , Woods John P. , Kerr V. Robert , Silverman Daniel , Brewer Richard , Rust W. M. , Wyckoff R. D.
Published: October 2002

Part 11 of the Federal Communications Commission’s Rules and Regulations—Rules Governing Industrial Radio Services, effective July 1, 1949, now governs the use of radio in connection with geophysical prospecting. Paragraph 11.57e specifies that an application for authority to operate on one of the frequencies in the range 1.6–6.0 mc must be fully justified and accompanied by a showing that it is impossible to use a higher order of frequencies for accomplishment of the same purposes. This applies to the traditional medium frequencies 1602 to 1700 kc used in geophysical prospecting communications.