Comparison of a mathematical model to predict 10-km performance from the Conconi test and ventilatory threshold measurements

The purpose of this study was to validate a mathematical model (MM) that evaluates the Conconi test and predicts 10-km race time. In addition, the relationship between ventilatory threshold (Tvent) determined from a laboratory test and heart rate deflection (HRd) from the Conconi test were examined. Seventeen trained runners performed the Conconi test, and performance times were predicted using a MM based on a logistics function. A correlational analysis indicated a highly significant relationship (r = .98, p < .01) between MM predicted time and actual time. Significant relationships were found between velocity at Tvent and HRd (r = .95, p < .01), and predicted times from each method (r = .96, p < .01). Heart rates from Tvent and HRd were also related (r = .79, p < .01). These results suggest that a MM of the Conconi test is a valid method of predicting 10-km performance and is closely related to traditional laboratory measures.

Primary bone marrow progenitors of both granulocytic and monocytic lineages are susceptible to infection with the agent of human granulocytic ehrlichiosis

Human granulocytic ehrlichiosis (HGE) is an emerging tickborne infection resulting in an acute febrile illness associated with cytopenias and characteristic intracellular organisms within peripheral blood granulocytes. The etiologic agent of HGE has recently been isolated and cultivated in the HL-60 promyelocytic leukemia cell line, but the spectrum of host cells that it naturally infects remains unknown. To determine if normal hematopoietic progenitors could be targets of infection, CD34+ primary human bone marrow cells, stimulated to differentiate along myelomonocytic lineages, were incubated with the HGE agent. Immature marrow progenitors and, remarkably, not only granulocytic but also CD14+ monocytic cells from these cultures supported replication of the HGE agent, suggesting that all are potential targets of infection in vivo. Infection of bone marrow progenitors may contribute to the hematologic manifestations of HGE. Furthermore, the ability of the agent to interact with monocytes has significant implications regarding disease pathogenesis and host response.

Incidence of iron-deficiency anaemia and depleted iron stores among nine-month-old infants in Vancouver, Canada

The iron status and feeding practices of 434 infants in Vancouver were determined at 39 +/- 1 week of age. Iron-deficiency anaemia (haemoglobin < or = 101 g/L, or < or = 110 g/L with two or three abnormal results from tests of serum ferritin, zinc erythrocyte protoporphyrin and total iron binding capacity) occurred in 7% of infants. Low iron stores (serum ferritin < 10 micrograms/l) occurred in about 24% of infants. Iron-deficiency anaemia was significantly associated (p < 0.001) with duration of breastfeeding. The prevalence of iron-deficiency anaemia among infants breastfed for 8 months was 15%. At 39 weeks (9 months) of age, about 5% and 13% of the infants were bottle-fed with cows milk or low iron infant formula, respectively, and this was also significantly associated (p < 0.02) with low iron stores. Iron-fortified infant cereals had been introduced to 95% of the infants by six months of age. This study shows iron-deficiency anaemia is a problem among a significant number of nine-month-old infants in Canada, and is not explained by failure to introduce iron-fortified infant cereals.

School-based wraparound planning: integrating services for students with emotional and behavioral needs

The wraparound process for planning unique and flexible services emerged from community-based human-service programs for children and youth exhibiting serious emotional disturbance. The application of wraparound in schools is described and illustrated via examples of local, statewide, and national initiatives. These experiences suggest strategies that can improve the school's effectiveness in serving students with, or at risk of, emotional and behavioral challenges.

Antibiotic susceptibility of the newly cultivated agent of human granulocytic ehrlichiosis: promising activity of quinolones and rifamycins

Human granulocytic ehrlichiosis (HGE) is a rapidly emerging tick-borne infection which presents as an acute febrile illness and is associated with hematologic abnormalities, elevated hepatic transaminase levels, and characteristic intracellular organisms in peripheral blood granulocytes. Although HGE has been successfully treated with tetracyclines, its susceptibility to other antibiotics remains unknown. No clear treatment alternative exist for young children, pregnant women, or allergic individuals, in whom tetracyclines are contra-indicated. We performed in vitro antibiotic susceptibility tests with this recently isolated agent grown in the human promyelocytic leukemia cell line HL-60. Doxycycline (MIC, 0.25 micrograms/ml), rifampin (MIC, 0.5 micrograms/ml), rifabutin (MIC, < or = 0.125 micrograms/ml), ciprofloxacin and ofloxacin (both with MICs of 2 micrograms/ml), and trovafloxacin (MIC, < or = 0.125 micrograms/ml) ciprofloxacin and ofloxacin (both with MICs of 2 micrograms/ml), and trovafloxacin (MIC, < or = 0.125 micrograms/ml) demonstrated significant activity against the HGE agent. These agents were also bactericidal. The HGE agent was resistant to clindamycin, trimethoprim-sulfamethoxazole, and imipenem-cilastatin, as well as to ampicillin, ceftriaxone, erythromycin, and azithromycin, antibiotics commonly used to treat Lyme disease. Both chloramphenicol and gentamicin had weak inhibitory activities but were not bactericidal. Our findings confirm the observed clinical efficacy of doxycycline and further suggest that the rifamycins and quinolones, particularly trovafloxacin, hold promise as alternative agents for treating this new infection.

Feeding formula without arachidonic acid and docosahexaenoic acid has no effect on preferential looking acuity or recognition memory in healthy full-term infants at 9 mo of age

Preferential looking acuity and novelty preference (a test of recognition memory) were determined by using Teller Acuity Cards and the Fagan Test of Infant Intelligence, respectively, for 399-433 healthy full-term infants at 39 +/- 1 wk of age. Duration of breast-feeding and age of infant at introduction and amount and type of formula were determined by questionnaire. Seventy-four infants (17%) were never breast-fed; another 92 infants (21%) were still receiving breast milk as the milk source at 39 wk of age. There were no differences in visual acuity or novelty preference among the infants when they were stratified by incidence or duration of breast-feeding. The formulas met current Canadian guidelines with > or = 0.7% of energy as linolenic acid, but had no docosahexaenoic or arachidonic acid. The studies indicate that formulas containing adequate linoleic and linolenic acids, without arachidonic or docosahexaenoic acid, impose no measurable deficits in performance in these visual and cognitive developmental tests at 9 mo of age in healthy full-term infants.

Dobutamine stress echocardiography: a new, noninvasive method for detecting ischemic heart disease

Pharmacologic induction of exercise with dobutamine hydrochloride, coupled with the technology of echocardiography, is an alternate method for evaluating ischemic heart disease. Dobutamine stress echocardiography involves obtaining echocardiographic images before, during, and after a titrated dobutamine infusion is administered. The study is positive if global or regional ventricular wall motion abnormalities develop. With our changing health care environment, this cost-effective, noninvasive diagnostic procedure is becoming a standard for determining the presence of coronary artery disease in those individuals who are unable or unwilling to undergo exercise stress testing.

Isolation of the equine granulocytic ehrlichiosis agent, Ehrlichia equi, in tick cell culture

The equine granulocytic ehrlichiosis agent, Ehrlichia equi, is closely related or identical to the human granulocytic ehrlichiosis (HGE) agent. Both are suspected of being transmitted by ticks. We have successfully isolated E. equi in a cell line, IDE8, derived from a putative vector, the tick Ixodes scapularis. Peripheral blood leukocytes from an experimentally infected horse were inoculated onto IDE8 monolayers. Cultures were incubated in a candle jar at 34 degrees C in tick cell culture medium with NaHCO3 and an organic buffer [3-(N-morpholino)-propanesulfonic acid] (MOPS). Within 2 weeks, infected cells were detected in Giemsa-stained culture samples, and the organisms subsequently spread to uninfected cells in the cultures. E. equi was passaged serially by transferring a portion of an infected culture to new cell layers every 2 to 3 weeks. The identity of the organisms was confirmed by PCR using oligonucleotide primers specific for E. equi and the HGE agent and by immunocytology. Homologous equine antibodies and human anti-HGE convalescent serum recognized E. equi grown in tick cell culture. Electron microscopy revealed electron-lucent and -dense ehrlichia-like forms developing within host cell endosomes. E. equi passaged twice in tick cell culture retained infectivity and pathogenicity for the equine host, as demonstrated by intravenous inoculation of a suspension of infected tick cells and subsequent reisolation from peripheral blood, in fulfillment of Koch's postulates. The horse developed severe clinical signs, i.e., fever, inappetence, thrombocytopenia, icterus, and limb edema, typical of granulocytic equine ehrlichiosis, within 1 week.

LU103793 (NSC D-669356): a synthetic peptide that interacts with microtubules and inhibits mitosis

LU103793 (NSC D-669356) is a new synthetic derivative of Dolastatin 15, an antiproliferative compound which was isolated from the mollusk Dolabella auricularia. Like Dolastatin 15, LU103793 is highly cytotoxic in vitro (IC50 = 0.1 nM). To investigate the mechanism of action of LU103793, we used a combination of biochemical and cellular methods. Turbidity assays with bovine brain microtubules demonstrated that LU103793 inhibits microtubule polymerization in a concentration-dependent manner (IC50 = 7 microM). Treatment with this compound also induced depolymerization of preassembled microtubules. Cell cycle analysis of tumor cell lines treated with LU103793 indicated a block in the G2-M phase. At the cellular level, it induced depolymerization of microtubules in interphase cells and development of abnormal spindles and chromosome distribution in mitotic cells. Although these effects are very similar to the cellular alterations caused by vinblastine, LU103793 does not inhibit vinblastine binding to unpolymerized tubulin in vitro. Our results suggest that LU103793 exerts its cytotoxic activity primarily through disruption of microtubule organization.

Impact of physician awareness on hospital charges for radical retropubic prostatectomy

PURPOSE

We determine if physician awareness of hospital costs for radical retropubic prostatectomy affects physician practice patterns.

MATERIALS AND METHODS

We reviewed 256 consecutive radical retropubic prostatectomies performed by 14 urologists during 4 years at a community hospital. After 2 years the physicians were provided information on factors that may decrease charges.

RESULTS

Charges decreased significantly following intervention, from +f417,134 within the initial 2 years to +f413,826 within the last 2 years (p < 0.005). Significant decreases were noted for length of stay, need for intensive care, operating time and blood loss.

CONCLUSIONS

Traditional methods of physician education can impact practice patterns to decrease hospital charges for radical retropubic prostatectomy.

The role of the physician in effecting change in hospital charge for radical prostatectomy

BACKGROUND

Continuing effort is being made to provide the best medical care in a cost-effective manner, requiring an evaluation of factors that control charges. The number of cases of carcinoma of the prostate gland and the number of radical retropubic prostatectomies performed have increased in recent years, with an estimate of several hundred million dollars being spent annually on this procedure in the United States of America. Because physicians are reported to effect the majority of charges for a hospitalization, this study examines the influence of notification of the physician of hospital charges on the overall hospital charges for radical retropubic prostatectomy.

STUDY DESIGN

Total hospital charge and duration per hospitalization were determined for all patients having radical prostatectomies performed at five community hospitals in Richmond, VA, between January 1991 and December 1993. Patients included 625 males diagnosed with carcinoma of the prostate gland undergoing radical prostatectomy by one of 20 urologists from several different private practice groups. Halfway into the time period studied, physicians were notified of data collection and of factors that seemed to have a role in hospital charges. Total hospital charges before and after physician notification were measured to determine whether or not physicians could effect hospital charges.

RESULTS

Overall, hospital charges decreased significantly after notification of physicians in the study. The decline in total charges continued throughout the follow-up period. Duration of hospitalization decreased throughout the entire study period, while total charge per hospital day increased.

CONCLUSIONS

Physician awareness of hospital charges for operative procedures and accompanying hospitalizations may influence the overall decrease in charges.

The UL45 gene product is required for herpes simplex virus type 1 glycoprotein B-induced fusion

Herpes simplex virus type 1 (HSV-1) syncytial (syn) mutants cause formation of giant polykaryocytes and have been utilized to identify genes promoting or suppressing cell fusion. We previously described an HSV-1 recombinant, F1 (J.L. Goodman, M. L. Cook, F. Sederati, K. Izumi, and J. G. Stevens, J. Virol. 63:1153-1161, 1989), which has unique virulence properties and a syn mutation in the carboxy terminus of glycoprotein B (gB). We attempted to replace this single-base-pair syn mutation through cotransfection with a 379-bp PCR-generated fragment of wild-type gB. The nonsyncytial viruses isolated were shown by DNA sequencing not to have acquired the expected wild-type gB sequence. Instead, they had lost their cell-cell fusion properties because of alterations mapping to the UL45 gene. The mutant UL45 gene is one nonsyncytial derivative of F1, A4B, was found to have a deletion of a C at UL45 nucleotide 230, resulting in a predicted frame shift and termination at 92 rather than 172 amino acids. Northern (RNA) analysis showed that the mutant UL45 gene was normally transcribed. However, Western immunoblotting showed no detectable UL45 gene product from A4B or from another similarly isolated nonsyncytial F1 derivative, A61B, while another such virus, 1ACSS, expressed reduced amounts of UL45. When A4B was cotransfected with the wild-type UL45 gene, restoration of UL45 expression correlated with restoration of syncytium formation. Conversely, cloned DNA fragments containing the mutant A4B UL45 gene transferred the loss of cell-cell fusion to other gB syn mutants, rendering them UL45 negative and nonsyncytial. We conclude that normal UL45 expression is required to allow cell fusion induced by gB syn mutants and that the nonessential UL45 protein may play an important role as a mediator of fusion events during HSV-1 infection.

Development of visual acuity in relation to plasma and erythrocyte omega-6 and omega-3 fatty acids in healthy term gestation infants

The development of preferential looking acuity was studied prospectively to 3 mo of age in exclusively breast-fed and formula-fed term gestation infants. The formula contained (% of total fatty acids) 17.9% linoleic acid (18:2 omega-6) and 2.1% alpha-linolenic acid (18:3 omega-3) but no docosahexaenoic acid (22:6 omega-3) or arachidonic acid (20:4 omega-6). The breast milk contained (mean +/- SEM) 13.4 +/- 0.8% 18:2 omega-6, 1.5 +/- 0.1% 18:3 omega-3, 0.51 +/- 0.03% 20:4 omega-6, and 0.22 +/- 0.02% 22:6 omega-3. Preferential looking acuity, assessed by the acuity-card procedure, and plasma phospholipid and erythrocyte phosphatidylcholine and phosphatidylethanolamine fatty acids were determined at 14 d and 3 mo of age. There were no significant differences in acuity at 14 d or 3 mo, despite substantial differences in erythrocyte and plasma lipid 22:6 omega-3. Visual acuity was [mean (cycles/degree) +/- SD (octaves)] 3.93 +/- 0.54 and 4.77 +/- 0.48 and erythrocyte phosphatidylethanolamine %22:6 omega-3 was (mean +/- SE) 7.6 +/- 0.5 and 4.0 +/- 0.2 in the 3-mo-old breast-fed and formula-fed infants, respectively. These studies show that feeding formula containing 2.1% 18:3 omega-3 (approximately 1.0% energy) results in development of visual acuity similar to breast-feeding in term infants to > or = 3 mo of age.

Evidence that palmitic acid is absorbed as sn-2 monoacylglycerol from human milk by breast-fed infants

Milk fatty acids consist of about 20-25% palmitic acid (16:0), with about 70% of 16:0 esterified to the sn-2 position of the milk triacylglycerols. Hydrolysis of dietary triacylglycerols by endogeneous lipases produces sn-2 monoacylglycerols and free fatty acids, which are absorbed, reesterified, and then secreted into plasma. Unesterified 16:0 is not well absorbed and readily forms soaps with calcium in the intestine. The positioning of 16:0 at the sn-2 position of milk triacylglycerols could explain the high coefficient of absorption of milk fat. However, the milk lipase, bile salt-stimulated lipase, has been suggested to complete the hydrolysis of milk fat to free fatty acids and glycerol. These studies determined whether 16:0 is absorbed from human milk as sn-2 monopalmitin by comparison of the plasma triacylglycerol total and sn-2 position fatty acid composition between breast-fed and formula-fed term gestation infants. The human milk and formula had 21.0 and 22.3% of 16:0, respectively, with 54.2 and 4.8% 16:0 in the fatty acids esterified to the 2 position. The plasma triacylglycerol total fatty acids had 26.0 +/- 0.6 and 26.2 +/- 0.6% of 16:0, and the sn-2 position fatty acids had 23.3 +/- 3.3 and 7.4 +/- 0.7% of 16:0 in the three-month-old exclusively breast-fed (n = 17) and formula-fed (n = 18) infants, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Biochemical and functional approaches to study of fatty acid requirements for very premature infants

Plasma and RBC omega-6 and omega-3 fatty acids reflect the composition of these fatty acids in the diet, and their analyses seem unlikely to add little more to studies on infant fatty acid requirements than evidence that the milk or formula diet was adhered to. Tests of visual function, cognitive, and motor skill development, however, are sufficiently sensitive to demonstrate significant differences between groups of infants fed diets that differ only in fatty acid composition. These functional tests offer the potential for future research with modified formulas or expressed milk to determine not only fatty acid requirements but also to further fundamental understanding of the role of specific omega-6 and omega-3 fatty acids in CNS development and function.

Direct Observation of ClO from Chlorine Nitrate Photolysis

Chlorine nitrate photolysis has been investigated with the use of a molecular beam technique. Excitation at both 248 and 193 nanometers led to photodissociation by two pathways, CIONO(2) --> CIO + NO()2 and CIONO(2) --> Cl + NO3, with comparable yields. This experiment provides a direct measurement of the CIO product channel and consequently raises the possibility of an analogous channel in CIO dimer photolysis. Photodissociation of the CIO dimer is a critical step in the catalytic cycle that is presumed to dominate polar stratospheric ozone destruction. A substantial yield of CIO would reduce the efficiency of this cycle.

High-pressure, high-temperature bioreactor for comparing effects of hyperbaric and hydrostatic pressure on bacterial growth

We describe a high-pressure reactor system suitable for simultaneous hyperbaric and hydrostatic pressurization of bacterial cultures at elevated temperatures. For the deep-sea thermophile ES4, the growth rate at 500 atm (1 atm = 101.29 kPa) and 95 degrees C under hydrostatic pressure was ca. three times the growth rate under hyperbaric pressure and ca. 40% higher than the growth rate at 35 atm.

A combination of human cytomegalovirus (HCMV)-specific murine monoclonal antibodies exhibits synergistic antiviral activity in vitro

A combination of HCMV-specific monoclonal antibodies (MAbs) reactive with glycoproteins in gcI complexes which exhibit synergistic antiviral activity in vitro is described. MAbs directed against different structural and biological properties of HCMV have been selected to increase the antiviral activity against all possible strains, and to reduce the likelihood that resistant strains will emerge with prolonged exposure. Furthermore, in vitro analysis demonstrates that certain of the MAbs in the combination augment the virus-neutralizing activity of other component antibodies, thereby decreasing the amount of total antibody protein required to inhibit HCMV infection. Certain MAbs have been selected to inactivate extracellular virus during the early phase of HCMV infection, whereas others have been selected to prevent its spread once cells have been infected. These data suggest that a MAb cocktail may be useful for prophylaxis and treatment of patients at risk of life-threatening HCMV infections.

The human antibody response to streptococcal C5a peptidase

An ELISA was developed to measure antibody, both IgG and IgA, against the streptococcal C5a peptidase (SCP), in human sera and saliva. Generally, sera and saliva from young, uninfected children lacked antibody to SCP. In contrast, most sera and saliva specimens from healthy adults had measurable levels of anti-SCP IgG and SCP-specific secretory IgA (anti-SCP sIgA). Paired acute and convalescent sera from patients with streptococcal pharyngitis possessed significantly higher levels of anti-SCP IgG than did sera from healthy individuals. Sera containing high concentrations of anti-SCP immunoglobulin were capable of neutralizing SCP activity. A survey of healthy adults and children also showed that the latter were significantly less likely to have anti-SCP sIgA in their saliva. Detection of this antibody in greater than 90% of the saliva specimens obtained from children who had recently experienced streptococcal pharyngitis demonstrated that children can produce a secretory response. This is thought to be the first report of a secretory IgA response in humans to a somatic antigen of Streptococcus pyogenes.

Management of benign ureteral structures: open surgical repair or endoscopic dilation?

We reviewed 20 cases of ureteral strictures, 15 of which were secondary to ureteral trauma. Of the patients 6 were managed initially by open repair and 14 underwent endoscopic manipulation. All 6 open repairs were successful, compared to 9 of the 14 patients who underwent endoscopic dilation of the ureteral stricture. Of the 5 failures 3 were due to the inability to cannulate the strictured ureter with a guide wire and 2 failed to respond to balloon dilation. Of these 5 patients 4 were treated successfully by an open operation. There were no serious intraoperative or postoperative complications. The average hospitalization was less for the endoscopic group (2.1 days) compared to the open surgical group (8.3 days). Followup ranged from 6 to 48 months.

Pressure and Temperature Effects on Growth and Methane Production of the Extreme Thermophile Methanococcus jannaschii

The marine archaebacterium Methanococcus jannaschii was studied at high temperatures and hyperbaric pressures of helium to investigate the effect of pressure on the behavior of a deep-sea thermophile. Methanogenesis and growth (as measured by protein production) at both 86 and 90°C were accelerated by pressure up to 750 atm (1 atm = 101.29kPa), but growth was not observed above 90°C at either 7.8 or 250 atm. However, growth and methanogenesis were uncoupled above 90°C, and the high-temperature limit for methanogenesis was increased by pressure. Substantial methane formation was evident at 98°C and 250 atm, whereas no methane formation was observed at 94°C and 7.8 atm. In contrast, when argon was substituted for helium as the pressurizing gas at 250 atm, no methane was produced at 86°C. Methanogenesis was also suppressed at 86°C and 250 atm when the culture was pressurized with a 4:1 mix of H 2 and CO 2 , although limited methanogenesis did occur when the culture was pressurized with H 2 .

Antibody inhibition of HeLa cell invasion by Yersinia enterocolitica

Antisera were prepared in rabbits against formalized and heat-killed bacteria of Yersinia enterocolitica serotype O:5,27 and against formalized bacteria of serotype O:8. Both strains used for immunization demonstrated adhesion to and invasion of HeLa cells. Coating of the bacteria with antibody did not greatly alter adhesion (i.e., extracellular attachment) to HeLa cells; however, antibody against formalized bacteria of both serotypes inhibited HeLa cell invasion by the homologous and heterologous strains. The Fab fragments from purified immunoglobulins also demonstrated cross-reacting inhibition of HeLa cell invasion. Antibody against heat-killed bacteria of serotype O:5,27 had no inhibitory activity. Adsorption of the antiserum against formalized bacteria of serotype O:5,27 with lipopolysaccharide from the homologous strain removed anti-lipopolysaccharide antibody but did not remove the inhibitory activity. The antiserum against formalized bacteria of serotype O:8 showed no antibody against lipopolysaccharide from serotype O:5,27 and no agglutinins against heat-killed bacteria of this strain. From these results, it is tentatively suggested that protein structures are important in mediating epithelial cell invasion by Y. enterocolitica.

Obsidian Dating and East African Archeology

New experimental procedures have made it possible to establish specific hydration rates for the numerous compositional types of obsidian to be found at archeological sites in Kenya. Two rates are applied to artifacts from the Prospect Farm site, revealing a history of occupation extending back 120,000 years.