Sheep recombinant IGF-1 promotes organ-specific growth in fetal sheep

IGF-1 is a critical fetal growth-promoting hormone. Experimental infusion of an IGF-1 analog, human recombinant LR3 IGF-1, into late gestation fetal sheep increased fetal organ growth and skeletal muscle myoblast proliferation. However, LR3 IGF-1 has a low affinity for IGF binding proteins (IGFBP), thus reducing physiologic regulation of IGF-1 bioavailability. The peptide sequences for LR3 IGF-1 and sheep IGF-1 also differ. To overcome these limitations with LR3 IGF-1, we developed an ovine (sheep) specific recombinant IGF-1 (oIGF-1) and tested its effect on growth in fetal sheep. First, we measured in vitro myoblast proliferation in response to oIGF-1. Second, we examined anabolic signaling pathways from serial skeletal muscle biopsies in fetal sheep that received oIGF-1 or saline infusion for 2 hours. Finally, we measured the effect of fetal oIGF-1 infusion versus saline infusion (SAL) for 1 week on fetal body and organ growth, in vivo myoblast proliferation, skeletal muscle fractional protein synthetic rate, IGFBP expression in skeletal muscle and liver, and IGF-1 signaling pathways in skeletal muscle. Using this approach, we showed that oIGF-1 stimulated myoblast proliferation in vitro. When infused for 1 week, oIGF-1 increased organ growth of the heart, kidney, spleen, and adrenal glands and stimulated skeletal myoblast proliferation compared to SAL without increasing muscle fractional synthetic rate or hindlimb muscle mass. Hepatic and muscular gene expression of IGFBPs one to three was similar between oIGF-1 and SAL. We conclude that oIGF-1 promotes tissue and organ-specific growth in the normal sheep fetus.

Detection of Bartonella spp. and Rickettsia spp. in cat fleas (Ctenocephalides felis) collected from free-roaming domestic cats in southeastern Georgia, USA

The cat flea (Ctenocephalides felis) is a competent vector of numerous bacterial pathogens in the genera Bartonella and Rickettsia. In the United States, free-roaming domestic cats (Felis catus) increase the risk of exposure to C. felis for humans and their companion animals. In collaboration with a trap-neuter-return program, we collected fleas from 283 feral/stray cats in southeastern Georgia between May and July of 2020. A total of 3,643 flea specimens were collected, and C. felis was the only flea species recovered from all cats sampled. The mean number of fleas per cat host was highest in the month of June when compared to May and July, and higher in juvenile cats (< 1 year) than the adults (≥ 1 year). Real-time PCR assays were used to test a subset of the collected fleas (n = 468) for the presence of Bartonella spp. and Rickettsia spp. DNA. Among those flea pools tested, 35.2% were positive for genus-specific citrate synthase gene of Bartonella, 16.5% were positive for the genus-specific 17-kDa protein antigen gene of Rickettsia, and none were positive for the species-specific outer membrane protein B gene of Rickettsia typhi. The identification of potential flea-borne pathogens was more frequent from the subset of C. felis collected in May, and female cats had more Bartonella-positive fleas and less Rickettsia-positive fleas than male cats. Overall, the present study provides valuable insights into the frequency of C. felis from outdoor community cats in southeastern Georgia, and highlights the possible risk for human exposure to potential flea-borne pathogens.

Differences in body composition and growth persist postnatally in fetuses diagnosed with severe compared to mild fetal growth restriction

BACKGROUND

Fetal growth restriction (FGR) is most commonly diagnosed in pregnancy if the estimated fetal weight (EFW) is <  10th%. Those with abnormal Doppler velocimetry, indicating placental insufficiency and pathological FGR, demonstrate reduced fat and lean mass compared to both normally growing fetuses and FGR fetuses with normal Dopplers. The aim of this study was to determine how severity of FGR and abnormal Doppler velocimetry impacts neonatal body composition. Among a cohort of fetuses with an EFW <  10th%, we hypothesized that those with abnormal Dopplers and/or EFW <  3rd% would have persistent reductions in lean body mass and fat mass extending into the neonatal period compared to fetuses not meeting those criteria.

METHODS

A prospective cohort of FGR fetuses with an estimated fetal weight (EFW) <  10th% was categorized as severe (EFW <  3rd% and/or abnormal Dopplers; FGR-S) versus mild (EFW 3-10th% ; FGR-M). Air Displacement Plethysmography and anthropometrics were performed at birth and/or within the first 6-8 weeks of life.

RESULTS

FGR-S versus FGR-M were born one week earlier (P = 0.0024), were shorter (P = 0.0033), lighter (P = 0.0001) with smaller weight-for-age Z-scores (P = 0.0004), had smaller head circumference (P = 0.0004) and lower fat mass (P = 0.01) at birth. At approximately 6-8 weeks postmenstrual age, weight, head circumference, and fat mass were similar but FGR-S neonates were shorter (P = 0.0049) with lower lean mass (P = 0.0258).

CONCLUSION

Doppler velocimetry abnormalities in fetuses with an EFW <  10th% identified neonates who were smaller at birth and demonstrated catch-up growth by 6-8 weeks of life that favored fat mass accretion over lean mass and linear growth.

Reactive oxygen species-mediated immunity against bacterial infection in the gut of cat fleas (Ctenocephalides felis)

Fleas (Order Siphonaptera) transmit numerous bacterial pathogens that cause severe human diseases (e.g., cat scratch disease, flea-borne spotted fever, murine typhus, plague). Because initial entry of these infectious agents occurs while blood feeding, the immune response in the flea gut is considered to be the first line of defense against invading microbes. However, relatively few studies have identified the flea immune molecules that effectively resist or limit infection in the gut. In other hematophagous insects, an immediate immune response to imbibed pathogens is the generation of reactive oxygen species (ROS). In this study, we utilized cat fleas (Ctenocephalides felis) to investigate whether oral infection with a well-known insect bacterial pathogen (Serratia marcescens) induces ROS synthesis in the flea gut, and whether production of ROS provides a defense mechanism against microbial colonization. Specifically, we treated fleas with an antioxidant to limit the number of free radicals in the digestive tract prior to infection, and then measured the following: S. marcescens infection loads, hydrogen peroxide (ROS) levels, and mRNA abundance of ROS signaling pathway genes. Overall, our data shows that ROS levels increase in response to infection in the flea gut, and that this increase helps to strengthen the flea immune response through the microbicidal activity of ROS.

Fleas (Siphonaptera) Parasitizing Peridomestic and Indigenous Mammals in Panamá and Screening of Selected Fleas for Vector-Borne Bacterial Pathogens

In total, 341 fleas belonging to 16 species were collected from 78 host mammals belonging to 10 species in Panamá from 2010 to 2016. The cat flea, Ctenocephalides felis (Bouché) predominated on domestic dogs and was also recorded from domestic cats, the raccoon, Procyon lotor (Linnaeus) and the common opossum, Didelphis marsupialis Linnaeus. The largest number of flea species (7) was recorded from D. marsupialis and the most common flea on that host was the ctenophthalmid, Adoratopsylla intermedia copha Jordan. One Oriental rat flea, Xenopsylla cheopis (Rothschild), was collected from D. marsupialis. Native rodents were parasitized by indigenous ceratophyllid, rhopalopsyllid, and stephanocircid fleas. The Mexican deermouse, Peromyscus mexicanus (Saussure), was parasitized by six species of ceratophyllids belonging to the mostly Central American genera, Baculomeris, Jellisonia, Kohlsia and Plusaetis. The long-tailed singing mouse, Scotinomys xerampelinus (Bangs), was parasitized by Plocopsylla scotinomi Tipton and Méndez, the only species of stephanocircid flea known from Central America. Twenty-six pools of extracted flea DNA representing 5 flea species (C. felis, Pulex echidnophagoides (Wagner), Pulex simulans Baker, A. intermedia copha, and P. scotinomi) and 79 individual fleas were all real-time polymerase chain reaction negative for Rickettsia felis, Rickettsia typhi, and Bartonella henselae.

Immunity of fleas (Order Siphonaptera)

The immune response of arthropod vectors plays a key role in the spread and transmission of vector-borne diseases. Although fleas transmit several human pathogens (e.g., Bartonella henselae, Rickettsia felis, R. typhi, and Yersinia pestis), few studies have examined how these vectors respond to infection. In hematophagous arthropods, imbibed pathogens must survive the hostile environment of blood meal digestion, which includes proteolytic digestive enzymes, protease inhibitors and expression of genes associated with protection of epithelial linings. Additionally, insect epithelial cells exhibit local immune defense against ingested pathogens by producing antimicrobial peptides and reactive oxygen species. This review details these and other aspects of insect immunity as it relates to fleas, with an emphasis on the gut immune response to two blood-borne pathogens, R. typhi and Y. pestis.

Transstadial immune activation in a mosquito: Adults that emerge from infected larvae have stronger antibacterial activity in their hemocoel yet increased susceptibility to malaria infection

Larval and adult mosquitoes mount immune responses against pathogens that invade their hemocoel. Although it has been suggested that a correlation exists between immune processes across insect life stages, the influence that an infection in the hemocoel of a larva has on the immune system of the eclosed adult remains unknown. Here, we used Anopheles gambiae to test whether a larval infection influences the adult response to a subsequent bacterial or malaria parasite infection. We found that for both female and male mosquitoes, a larval infection enhances the efficiency of bacterial clearance following a secondary infection in the hemocoel of adults. The adults that emerge from infected larvae have more hemocytes than adults that emerge from naive or injured larvae, and individual hemocytes have greater phagocytic activity. Furthermore, mRNA abundance of immune genes-such as cecropin A, Lysozyme C1, Stat-A, and Tep1-is higher in adults that emerge from infected larvae. A larval infection, however, does not have a meaningful effect on the probability that female adults will survive a systemic bacterial infection, and increases the susceptibility of females to Plasmodium yoelii, as measured by oocyst prevalence and intensity in the midgut. Finally, immune proficiency varies by sex; females exhibit increased bacterial killing, have twice as many hemocytes, and more highly express immune genes. Together, these results show that a larval hemocoelic infection induces transstadial immune activation-possibly via transstadial immune priming-but that it confers both costs and benefits to the emerged adults.

Transstadial transmission of larval hemocoelic infection negatively affects development and adult female longevity in the mosquito Anopheles gambiae

During all life stages, mosquitoes are exposed to pathogens, and employ an immune system to resist or limit infection. Although much attention has been paid to how adult mosquitoes fight infection, little is known about how an infection during the larval stage affects the biology of the resultant adult. In this study, we investigated whether a bacterial infection in the hemocoel of the African malaria mosquito, Anopheles gambiae, is transstadially transmitted from larvae to adults (both females and males), and whether immune stimulation in the hemocoel as a larva alters development or biological traits of the adult. Specifically, larvae were injected in the hemocoel with either fluorescent microspheres or Escherichia coli, and the following traits were examined: transstadial transmission, larval development to adulthood, adult survival, and adult body size. Our results show that transstadial transmission of hemocoel contents occurs from larvae to pupae and from pupae to adults, but that bacterial prevalence and intensity varies with age. Injury, immune stimulation or infection decreases the proportion of larvae that undergo pupation and eclosion, infection decreases the longevity of adult females, and treatment has complex effects on the body size of the resultant adults. The present study adds larval hemocoelic infection to the known non-genetic factors that reduce overall fitness by negatively affecting development and adult biological traits that influence mosquito vector competence.

Effect of Rickettsia felis Strain Variation on Infection, Transmission, and Fitness in the Cat Flea (Siphonaptera: Pulicidae)

Rickettsia felis is a human pathogen transmitted by the cat flea, Ctenocephalides felis (Bouché) (str. LSU), as well as an obligate symbiont of the parthenogenic booklouse Liposcelis bostrychophila (Badonnel) (str. LSU-Lb). The influence of genetic variability in these two strains of R. felis on host specialization and fitness and possible resulting differences on infection and transmission kinetics in C. felis is unknown. Utilizing an artificial host system, cat fleas were exposed to a R. felis str. LSU-Lb-infected bloodmeal and monitored for infection at 7-d intervals for 28 d. Quantitative real-time PCR was used to determine rickettsial load and infection density in newly exposed cat fleas, and transmission frequency between cat fleas. The effect of persistent R. felis infection on cat flea F1 progeny was also assessed. At 7 d postexposure 76.7% of the cat fleas successfully acquired R. felis str. LSU-Lb. In R. felis str. LSU-Lb-exposed cat fleas, the mean infection load (6.15 × 106), infection density (0.76), and infection prevalence (91/114) were significantly greater than R. felis str. LSU infection load (3.09 × 106), infection density (0.68), and infection prevalence (76/113). A persistent R. felis str. LSU-Lb infection was detected for 28 d in adult cat fleas but neither female:male ratio distortion nor vertical transmission was observed in F1 progeny. While infection kinetics differed, with higher intensity associated with R. felis str. LSU-Lb, no distinct phenotype was observed in the F1 progeny.

Neonatal outcomes after introduction of a national intrapartum fetal surveillance education program: a retrospective cohort study

OBJECTIVE

To determine the impact of a multidisciplinary fetal surveillance education program (FSEP) on term neonatal outcomes.

METHODS

A retrospective cohort study of term neonatal outcomes before (1998-2004) and after (2005-2010) introduction of a FSEP. Clinical data was collected for all term infants admitted to a neonatal intensive care unit (NICU) in Australia between 1998 and 2010. Infants with congenital abnormalities were excluded. Neonatal mortality and severe neonatal morbidity (admission to a NICU, respiratory support, hypoxic encephalopathy) were compared before and after the FSEP was introduced. The rates of operative delivery during this time were assessed.

RESULTS

There were 3 512 596 live term births between 1998 and 2010. The intrapartum hypoxic death rate at term decreased from 2.02 to 1.07 per 10 000 total births. More neonates were admitted to NICU after 2005 (10.6 versus 14.6 per 10 000 live births), however fewer babies admitted to the neonatal unit had Apgar scores < 5 at five minutes (55.1-45.5%, RR 0.82, 95% CI 0.7-0.87); and rates of hypoxic ischemic encephalopathy fell from 36% to 30% (RR 0.83, 95% CI 0.76-0.90). There was no increase in rates of emergency in labour caesarean sections (11.7% pre versus 11.1% post, RR 0.95, 95% CI 0.95-0.96).

CONCLUSIONS

Introduction of a national FSEP was associated with increased neonatal admissions but a reduction in intrapartum hypoxia, without increasing emergency caesarean section rates.

Transmission mechanisms of an emerging insect-borne rickettsial pathogen

BACKGROUND

Vector-borne pathogens must overcome arthropod infection and escape barriers (e.g. midgut and salivary glands) during the extrinsic incubation period (EIP) before subsequent transmission to another host. This particular timespan is undetermined for the etiological agent of flea-borne spotted fever (Rickettsia felis). Artificial acquisition of R. felis by blood-feeding cat fleas revealed dissemination to the salivary glands after seven days; however, this length of time is inconsistent with co-feeding studies that produced infectious cat fleas within 24 h of infection. In the current study, we demonstrated that an alternative mechanism is responsible for the early-phase transmission that typifies flea-borne R. felis spread.

METHODS

Co-feeding transmission bioassays were constructed to assess temporal dynamics of R. felis amongst cat fleas, including exposure time to produce infectious fleas and association time to transmit infection to naïve fleas. Additional experiments examined the proportion of R. felis-exposed cat fleas with contaminated mouthparts, as well as the likelihood for cat fleas to release R. felis from their mouthparts following exposure to an infectious bloodmeal. The potential for mechanical transmission of R. felis by co-feeding cat fleas was further examined using fluorescent latex beads, as opposed to a live pathogen, which would not require a biological mechanism to achieve transmission.

RESULTS

Analyses revealed that R. felis-infected cat fleas were infectious to naïve fleas less than 24 h after exposure to the pathogen, but showed no rickettsial dissemination to the salivary glands during this early-phase transmission. Additionally, the current study revealed that R. felis-infected cat fleas must co-feed with naïve fleas for more than 12 h in order for early-phase transmission to occur. Further evidence supported that contaminated flea mouthparts may be the source of the bacteria transmitted early, and demonstrated that R. felis is released from the mouthparts during brief probing events. Moreover, the use of fluorescent latex beads supports the notion that early-phase transmission of R. felis is a mechanical mechanism.

CONCLUSIONS

Determination of the transmission mechanisms utilized by R. felis is essential to fully understand the vulnerability of susceptible vertebrate hosts, including humans, to this pathogen.

Rickettsia felis, an Emerging Flea-Borne Rickettsiosis

Rickettsia felis is an emerging insect-borne rickettsial pathogen and the causative agent of flea-borne spotted fever. First described as a human pathogen from the USA in 1991, R. felis is now identified throughout the world and considered a common cause of fever in Africa. The cosmopolitan distribution of this pathogen is credited to the equally widespread occurrence of cat fleas (Ctenocephalides felis), the primary vector and reservoir of R. felis. Although R. felis is a relatively new member of the pathogenic Rickettsia, limited knowledge of basic R. felis biology continues to hinder research progression of this unique bacterium. This is a comprehensive review examining what is known and unknown relative to R. felis transmission biology, epidemiology of the disease, and genetics, with an insight into areas of needed investigation.

Cofeeding intra- and interspecific transmission of an emerging insect-borne rickettsial pathogen

Cat fleas (Ctenocephalides felis) are known as the primary vector and reservoir of Rickettsia felis, the causative agent of flea-borne spotted fever; however, field surveys regularly report molecular detection of this infectious agent from other blood-feeding arthropods. The presence of R. felis in additional arthropods may be the result of chance consumption of an infectious bloodmeal, but isolation of viable rickettsiae circulating in the blood of suspected vertebrate reservoirs has not been demonstrated. Successful transmission of pathogens between actively blood-feeding arthropods in the absence of a disseminated vertebrate infection has been verified, referred to as cofeeding transmission. Therefore, the principal route from systemically infected vertebrates to uninfected arthropods may not be applicable to the R. felis transmission cycle. Here, we show both intra- and interspecific transmission of R. felis between cofeeding arthropods on a vertebrate host. Analyses revealed that infected cat fleas transmitted R. felis to naïve cat fleas and rat fleas (Xenopsylla cheopis) via fleabite on a nonrickettsemic vertebrate host. Also, cat fleas infected by cofeeding were infectious to newly emerged uninfected cat fleas in an artificial system. Furthermore, we utilized a stochastic model to demonstrate that cofeeding is sufficient to explain the enzootic spread of R. felis amongst populations of the biological vector. Our results implicate cat fleas in the spread of R. felis amongst different vectors, and the demonstration of cofeeding transmission of R. felis through a vertebrate host represents a novel transmission paradigm for insect-borne Rickettsia and furthers our understanding of this emerging rickettsiosis.

Oil sands naphthenic acids: a review of properties, measurement, and treatment

The Alberta oil sands contain one of the world's largest reserves of oil - over 169 billion barrels of bitumen are economically recoverable with current extraction technologies. Surface mining and subsequent hot water extraction of bitumen from the ore generates about nine cubic meters of raw tailings per cubic meter of oil. Oil sands facilities are required to operate under a policy of zero water discharge, resulting in ponds containing more than one billion cubic meters of tailings, a mixture of sand, fines and process-affected water. Process-affected water contains numerous organic compounds, including naphthenic acids (NAs), which have been identified as the primary source of acute toxicity of process-affected water. Developments in analytical techniques, aerobic biodegradability, and treatment via chemical oxidation (ozone) of NAs are reviewed. The field continues to be challenged by the lack of a cost-effective, accurate analytical technique for NAs or an understanding of all the organic constituents in process-affected water that may be contributing to observed toxicity and thus requiring treatment.

Indigenous microbes survive in situ ozonation improving biodegradation of dissolved organic matter in aged oil sands process-affected waters

The oil sands industry faces significant challenges in developing effective remediation technologies for process-affected water stored in tailings ponds. Naphthenic acids, a complex mixture of cycloaliphatic carboxylic acids, have been of particular concern because they concentrate in tailings ponds and are a component of the acutely toxic fraction of process water. Ozone treatment has been demonstrated as an effective means of rapidly degrading naphthenic acids, reducing process water toxicity, and increasing its biodegradability following seeding with the endogenous process water bacteria. This study is the first to examine subsequent in situ biodegradation following ozone pretreatment. Two aged oil sands process-affected waters from experimental reclamation tailings ponds were ozonated to reduce the dissolved organic carbon, to which naphthenic acids contributed minimally (<1mgL(-1)). Treatment with an ozone dose of 50mgL(-1) improved the 84d biodegradability of remaining dissolved organic carbon during subsequent aerobic incubation (11-13mgL(-1) removed from aged process-affected waters versus 5mgL(-1) when not pretreated with ozone). The ozone-treated indigenous microbial communities were as capable of degrading organic matter as the same community not exposed to ozone. This supports ozonation coupled with biodegradation as an effective and feasible treatment option.

Turtle ectoparasites from the Pacific coastal region of Colombia

This study provides an update on the ectoparasites (ticks and leeches) associated with Rhinoclemmys annulata and provides new accounts on the ectoparasites associated with R. nasuta, R. melanosterna andKinosternon leucostomum from the Pacific coast of Colombia. The presence ofAmblyomma sabanerae on R. nasuta and R. melanosterna provided two new host records for the tick species. Also, the documentation ofA. sabanerae from the Department of Valle del Cauca represents a new department record for the species in Colombia. Placobdella ringueleti was identified fromR. nasuta and K. leucostomum, which represents a new host record for the leech species, as well as a significant extension of the known range.

Roles of the calcineurin and CaMK signaling pathways in fast-to-slow fiber type transformation of cultured adult mouse skeletal muscle fibers

Two Ca2+-dependent signaling pathways, mediated by the Ca2+-activated phosphatase calcineurin and by the Ca2+-activated kinase Ca2+/calmodulin-dependent kinase (CaMK), are both believed to function in fast-to-slow skeletal muscle fiber type transformation, but questions about the relative importance of the two pathways still remain. Here, the differential gene expression during fast-to-slow fiber type transformation was studied using cultured adult flexor digitorum brevis (FDB) fibers and a custom minimicroarray system containing 21 fiber type-specific marker genes. After 3 days of culture, unstimulated fibers showed a generally slower gene expression profile; 3 days of electric field stimulation of cultured FDB fibers with a slow fiber-type pattern transformed the fibers to an even slower gene expression profile. Unstimulated FDB fibers overexpressing constitutively active calcineurin featured a slower gene expression profile, except four genes, indicating that transformation occurred, but was incomplete with activation of the calcineurin pathway alone. In both unstimulated FDB fibers and slow-type electrically stimulated FDB fibers, blocking of CaMK pathway with KN93 generated a faster gene expression profile compared with the negative control KN92, indicating that CaMK pathway functions during the transformation induced by both unstimulated culturing and slow fiber-type electrical stimulation. Moreover, neither the calcineurin nor the CaMK pathway alone could maximally activate the transformation, and coordination of the two pathways is required to accomplish a complete fast-to-slow fiber type transformation.

Ca2+ sparks and T tubule reorganization in dedifferentiating adult mouse skeletal muscle fibers

Ca(+) sparks are rare in healthy adult mammalian skeletal muscle but may appear when adult fiber integrity is compromised, and occur in embryonic muscle but decline as the animal develops. Here we used cultured adult mouse flexor digitorum brevis muscle fibers to monitor occurrence of Ca(2+) sparks during maintenance of adult fiber morphology and during eventual fiber morphological dedifferentiation after various times in culture. Fibers cultured for up to 3 days retain normal morphology and striated appearance. Ca(2+) sparks were rare in these fibers. At 5-7 days in culture, many of the original muscle fibers exhibit sprouting and loss of striations, as well as the occurrence of spontaneous Ca(2+) sparks. The average rate of occurrence of Ca(2+) sparks is >10-fold higher after 5-7 days in culture than in days 1-3. With the use of fibers cultured for 7 days, application of the Ca(2+) channel blockers Co(2+) or nifedipine almost completely suppressed the occurrence of Ca(2+) sparks, as previously shown in embryonic fibers, suggesting that Ca(2+) sparks may be generated by similar mechanisms in dedifferentiating cultured adult fibers and in embryonic fibers before final differentiation. The sarcomeric disruption observed under transmitted light microscopy in dedifferentiating fibers was accompanied by morphological changes in the transverse (T) tubular system, as observed by fluorescence confocal imaging of both an extracellular marker dye and membrane staining dyes. Changes in T tubule morphology coincided with the appearance of Ca(2+) sparks, suggesting that Ca(2+) sparks may either be a signal for, or the result of, disruption of DHPR-ryanodine receptor 1 coupling.

Delayed dedifferentiation and retention of properties in dissociated adult skeletal muscle fibers in vitro

Adult skeletal muscle fibers can be isolated and cultured but tend to dedifferentiate and sprout with time in culture. We examined isolated adult mouse flexor digitorum brevis muscle fibers under various culture conditions by monitoring maintenance of the same fibers at 2-d intervals using survival analysis. Fibers plated on laminin and cultured in serum-free media did not show sprouting and exhibited significantly (P < 0.0001) longer survival (median survival time, T(50) = 10.2 d) than fibers in serum-containing media (T(50) = 3.3 d). Cell proliferation was markedly suppressed in serum-free cultures. Multiple or delayed Ca(2+) transients in response to brief field stimulation were often observed in dedifferentiated fibers after several d in serum-containing media but were not observed in fibers in serum-free media. The addition of cytosine arabinoside to serum-containing cultures did not prolong fiber survival (P = 0.39) and did not eliminate sprouting but did greatly suppress proliferation of nonmuscle cells. Fibers cultured in agarose gel with serum exhibited small, bud-like extensions but no sprouts and did not survive as long (T(50) = 6.2 d) as fibers plated on laminin and cultured in serum-free media (T(50) = 10.2 d) did. These results demonstrate that both morphological and physiological properties of fibers become modified in serum-containing media but can be retained by culturing without serum.

Nonuniform distribution of myosin light chains within the thick filaments of lobster slow muscle: Immunocytochemical study

The in situ distribution of the alpha and beta myosin light chains was investigated at the subsarcomeric and subfilament levels in individual fibers of the superficial flexor muscle (SFM) of the lobster, Homarus americanus. Polyclonal antibodies were produced against the two classes of myosin light chains and used for subsequent immunolocalization on thin sections of sarcomeres and on isolated filaments from both the medial and lateral fiber bundles of the SFM. The beta myosin light chains were uniformly distributed within the crossbridge region of sarcomeres of both medial and lateral bundles. The alpha myosin light chains were uniformly distributed within the crossbridge region of sarcomeres from the medial bundle, but were nonuniformly distributed over the crossbridge region of lateral bundle sarcomeres. In the latter, the number of alpha myosin light chains was highest toward the center of the thick filaments, diminishing towards the ends. Similar distributions of alpha light chains were found in isolated myosin filaments. These data demonstrate that heterogeneity in protein composition extends to the level of the myosin filament and suggest that the myosin filament substructure in lobster may be different than that found in vertebrate skeletal muscle.

A-band architecture in vertebrate skeletal muscle: polarity of the myosin head array

Despite extensive knowledge of many muscle A-band proteins (myosin molecules, titin, C-protein (MyBP-C)), details of the organization of these molecules to form myosin filaments remain unclear. Recently the myosin head (crossbridge) configuration in a relaxed vertebrate muscle was determined from low-angle X-ray diffraction (Hudson et al. (1997), J Mol Biol 273: 440-455). This showed that, even without C-protein, the myosin head array displays a characteristic polar pattern with every third 143 A-spaced crossbridge level particularly prominent. However, X-ray diffraction cannot determine the polarity of the crossbridge array relative to the neighbouring actin filaments; information crucial to a proper understanding of the contractile event. Here, electron micrographs of negatively-stained goldfish A-segments and of fast-frozen, freeze-fractured plaice A-bands have been used to determine the resting myosin head polarity relative to the M-band. In agreement with the X-ray data, the prominent 429 A-spaced striations are seen outside the C-zone, where no non-myosin proteins apart from titin are thought to be located. The head orientation is with the concave side of the curved myosin heads (containing the entrance to the ATP-binding site) facing towards the M-band and the convex surface (containing the actin-binding region at one end) facing away from the M-band.

Window shopping: state health reform politics in the 1990s

Throughout the 1990s states sought politically acceptable policies to reduce the ranks of the uninsured. Visions of comprehensive health reform and universal coverage yielded by mid-decade to more modest measures to repair private health insurance markets, and to these enactments were added several new public programs (state and federal) to expand coverage for lower-income children and, in some cases, adults. Because governments remain ill equipped to counter the power of business, insurers, and providers in conflicts fought on private turf, reform agendas have been more readily set, moved, and cleared in public-sector arenas. Although the number of uninsured rose steadily until 1999, "catalytic federalism"--the accelerating interplay between state and federal reform forces and funds--may be putting the programmatic foundations for broader coverage incrementally into place.

An evaluation of the impact of training Honduran health care providers in interpersonal communication

OBJECTIVE

To evaluate the impact of interpersonal communication (IPC) training on practice and patient satisfaction and to determine the acceptability of this training to providers in a developing country.

DESIGN

The study used a pre-post design with treatment and control groups. Data collection methods included interaction analysis of audio-taped clinical encounters, patient exit interviews, and a self-administered questionnaire for health providers.

STUDY PARTICIPANTS

Interaction analysis was based on an experimental group of 24 doctors and a control group of eight with multiple observations for each provider). Exit interviews were carried out with 220 pre-test patients and 218 post-test patients. All 87 health providers who received training responded to the self-administered questionnaire.

INTERVENTION

A brief in-service training programme on interpersonal communications was presented in three half-day sessions; these focused on overall socio-emotional communication, problem solving skills and counselling.

MAIN OUTCOME MEASURES AND RESULTS

The IPC intervention was associated with more communication by trained providers (mean scores of 136.6 versus 94.4; P = 0.001), more positive talk (15.93 versus 7.99; P = 0.001), less negative talk (0.11 versus 0.59; P = 0.018), more emotional talk (15.7 versus 5.5; P = 0.021), and more medical counselling (17.3 versus 11.3; P = 0.026). Patients responded by communicating more (mean scores of 113.8 versus 79.6; P = 0.011) and disclosing more medical information (54.7 versus 41.7; P = 0.002). Patient satisfaction ratings were higher for providers who had received the training and providers reported training to be relevant and useful.

CONCLUSIONS

Further validation of IPC skills and simplification of assessment methods are needed if IPC is to be an area for routine monitoring and quality improvement.

Uneasy alliances: managed care plans formed by safety-net providers

Health care providers that have traditionally served the poor are forming their own managed care plans, often in alliance with local safety-net peers. These alliances make it easier to raise needed capital, increase the pool of likely enrollees, and enable plans to benefit from efficiencies of scale. At the same time, however, the alliances often are undermined by conflicts of interest among the different sponsors and between the sponsors and the plan. This paper suggests that these plans are most likely to do well when the state makes special efforts to help and when plans have the leadership and financial reserves to take advantage of their supportive state policies.

Implementing Medicaid managed care: the New York City story

Across the nation, public officials are encouraging or requiring Medicaid beneficiaries to enroll in managed care. In this article, we report on a study of the implementation of Medicaid managed care in New York City. Several findings are clear. First, government officials need to treat health plans as partners rather than adversaries; in New York, the relationship between the state and the plans is far too adversarial. Second, effective managed care requires good management information systems; New York officials are collecting an enormous amount of data but not much useful information. Third, effective implementation of Medicaid managed care is slow going; New York's effort to dramatically accelerate the enrollment process did not work.

The consequences of treatment and disease in patients with primary CNS non-Hodgkin's lymphoma: cognitive function and performance status. North Central Cancer Treatment Group

Per protocol, patients with primary CNS non-Hodgkin's lymphoma in an intergroup phase II trial conducted by the North Central Cancer Treatment Group and the Eastern Cooperative Oncology Group had their cognitive functions measured using the Folstein and Folstein Mini-Mental Status Examination (MMSE) and their physical functions measured using the Eastern Cooperative Oncology Group Performance Score (PS) at study entry, at each treatment evaluation, and at quarterly intervals thereafter until disease progression or death. Of the 53 eligible participants who began therapy, 46 (87%) had baseline MMSE scores recorded, 36 (68%) had at least one follow-up MMSE, and 32 (60%) had both, while 52 (98%) had baseline PS, 49 (92%) had at least one follow-up PS, and 48 (91%) had both. Patterns of MMSE and PS values over time were studied in each individual, in the group as a whole, in the 20 patients who completed the study regimen, in the 23 who survived more than a year, and in patients who were classified as nonprogressors at each key evaluation. For each patient, all recorded values were plotted versus time, with dates of disease progression and death included, to look for signs of decline in cognitive or physical function preceding adverse events. Long-term declines in scores of both cognitive and physical function were observed in many treated patients with primary CNS non-Hodgkin's lymphoma. Nearly all patients who were alive more than 52 weeks after study entry had a demonstrable decline in cognitive and physical functionality. Such declines may occur before disease progression is documented; they may also occur in some patients who have long-term follow-up without evidence of disease progression. Declining MMSE and PS was a poor predictor of disease progression. There was no association of PS and toxicity. The data from this study demonstrated the considerable difficulties we encountered conducting an ancillary study such as this within a multicenter clinical trial. Firstly, the test instruments written into the protocol were unable to tell if the declines seen were due to disease, treatment, co-morbidity, or other factors. Secondly, the missing data created difficulties in interpreting outcome.

Management by objection? Public policies to protect choice in health plans

Consumer choice is a watchword of the market reforms now sweeping the U.S. health care system. Policy makers, however, must grapple with an important ambiguity; is the objective to expand choice or protect choosers, and what should be done if the two goals conflict? Concerns about health care market malfunctions trigger a politics of consumer protection that may emphasize regulatory standards over market flexibility. To complicate matters further, hopes that deluging consumers with information can ensure that choices are at once ample and prudent are likely to be disappointed.

Nothing exceeds like success: managed care comes to Medicaid in New York City

Nearly every state is encouraging or requiring Medicaid beneficiaries to enroll in managed care delivery systems. In New York City, Medicaid officials began with an incremental, but not insignificant, managed care initiative. Buoyed by its success, New York policy makers tried, and failed, to accelerate the transition to managed care. The legacy of that failure still plagues them. A comparison of such initiatives in other states indicates that most state officials have remembered what New York's leaders temporarily forgot, namely, that Medicaid managed care is a complex exercise that demands consultation and consensus building.

'Manacled competition': market reforms in German health care

In 1993 Germany joined the small but swelling ranks of societies determined to explore managed competition as a means of slowing the growth of health spending by giving stakeholders new incentives for efficiency. Realizing the benefits of competition, however, demands changes in institutional norms and regulatory practices that now largely handcuff those who would follow competitive logic into "managed care." In time Germany's system of "manacled competition" may evolve into a happy higher synthesis of managed care and managed competition. Or policymakers may conclude that the political price of installing workable market forces in health care is too high and reconcile themselves to more traditional applications of political pressure.

Primary central nervous system non-Hodgkin's lymphoma (PCNSL): survival advantages with combined initial therapy? A final report of the North Central Cancer Treatment Group (NCCTG) Study 86-72-52

PURPOSE

We herein report updated survival and toxicity data on the entire cohort of 53 eligible patients treated on North Central Cancer Treatment Group (NCCTG) protocol 86-72-52, which is now closed.

METHODS AND MATERIALS

An initial report was published in this journal in 1995. No substantive changes in the conclusions of that report were identified in this analysis. Median survival was 9.6 months for the entire cohort; median survival for the 20 patients who completed the prescribed protocol treatment was 20.7 months. The hematologic and non-hematologic toxicity distributions are virtually the same as those reported in the original paper.

RESULTS

Results are given for the entire group and for subsets defined by age < or = 60 versus > 60 years, and < 70 versus > or = 70 years of age.

CONCLUSIONS

No significant differences were observed in any of the outcome variables by age group. There was, however, a nonsignificant suggestion of poorer outcome in those who were > 60 years of age.

Health reform in America: the mystery of the missing moral momentum

Examining health policy and its recent reform misadventures in the United States from a moral viewpoint is painful. That the nation devotes 14% of its Gross Domestic Product to health services—sometimes of doubtful clinical efficacy and value for money—and yet lets more than 40 million citizens go without health coverage strikes critics, both foreign and domestic, as a disgrace explicable only by ethical deficiencies distinctive to the American value system. There is certainly merit in this critique, which understandably incites fire and brimstone about the urgent moral imperative of getting the nation on the path of righteousness at last.

Exceptionalism as the rule? U.S. health policy innovation and cross-national learning

American health care reformers, who often look to other nations for models of desirable health systems, are often surprised nowadays by cross-national infatuation with health policy innovations minted in the United States. American innovations appeal to policy makers abroad as they struggle with cost pressures, distinguish knowledge about how health systems work, and deal with changing images of what constitutes good public policy. These strategems are adapted, not adopted; however, the premises and practices with which other nations follow American directions differ deeply from those in the United States. Ironically, even cross-national experiments may end up offering instructive policy "rules" to the exceptionalist United States.

The effect of developmental care on preterm infant outcome

Using a retrospective comparative design, the investigators evaluated the effects of training 10% of a nursing staff in the Neonatal Individualized Developmental Care and Assessment Program (NIDCAP) on preterm infant outcomes. A convenience sample of 25 preterm infants (< 1500 grams) cared for during the NIDCAP implementation and training period were matched by birth weight and gestational age to infants born before NIDCAP implementation. Outcome measures collected through chart review showed NIDCAP infants had significantly fewer and less severe intraventricular hemorrhages, fewer days of ventilatory support, shorter hospitalizations, and greater rate of weight gain. Findings suggest that benefits of developmental care are achievable with only a portion of the staff being NIDCAP trained.

Pharmacokinetics and kinetic-dynamic modelling of aminophenones as methaemoglobin formers

Methaemoglobin, the oxidized form of haemoglobin, can be formed by a variety of agents, most of which act to oxidize haemoglobin directly or indirectly. Cyanide has a higher affinity for methaemoglobin than for mitochondrial cytochromes, making methaemoglobin formation a basis for the treatment of cyanide poisoning. We used the beagle dog model to investigate the relationship between drug concentration and methaemoglobin levels for two candidate anti-cyanide compounds. The compounds studied were the aminophenones p-aminopropiophenone (PAPP) and p-aminoheptylphenone (PAHP). Both PAPP and PAHP were given as intravenous boluses and as two different oral formulations. The kinetics of both compounds appeared to follow a three-compartment open model for intravenous bolus administration and a two-compartment open model for oral administration. The first distribution phase seen with the intravenous administration was obscured by the absorption phase during oral administration. Bioavailability for all formulations varied between 20 and 47%. For both compounds there was a delay between the appearance of drug in the plasma and the appearance of methaemoglobin (counter-clockwise hysteresis) which is suggestive of an active metabolite causing methaemoglobin formation. The pharmacodynamics were fit with an effect-compartment kinetic-dynamic model linked to a sigmoid Emax pharmacodynamic model. Maximum amounts of methaemoglobin occurred between 2 and 4 h for PAHP and between 1 and 3 h for PAPP. When administered intravenously estimates of EC50 were lower than the estimates of EC50 from oral administration for both compounds. This might be because of oral first-pass inactivation or a 'first-pass' activation through the lungs contributing to the formation of an active metabolite. The phenones as a class appear to have the drug cleared and methaemoglobin return to near baseline within 12 h. Both compounds seem to produce sufficient methaemoglobin to treat acute cyanide poisoning and to serve as prophylactic agents against acute cyanide poisoning in a military setting.

INDEPTH Wide-Angle Reflection Observation of P-Wave-to-S-Wave Conversion from Crustal Bright Spots in Tibet

Three-component wide-angle seismic data acquired in southern Tibet during Project INDEPTH show strong P-to-S converted reflections from reflectors that are aligned at a depth of approximately 15 kilometers beneath the northern Yadong-Gulu rift. These converted reflections are locally higher in amplitude than the corresponding P-wave reflections. Modeling of reflection mode conversion as a function of incidence angle indicates that this condition obtains for a reflector that is a solid over fluid interface; it is not typical of a solid-solid interface. The likely candidates for a fluid trapped within the crystalline crust of southern Tibet are granitic magma and water (brine).

Bright Spots, Structure, and Magmatism in Southern Tibet from INDEPTH Seismic Reflection Profiling

INDEPTH seismic reflection profiling shows that the decollement beneath which Indian lithosphere underthrusts the Himalaya extends at least 225 kilometers north of the Himalayan deformation front to a depth of approximately 50 kilometers. Prominent reflections appear at depths of 15 to 18 kilometers near where the decollement reflector apparently terminates. These reflections extend north of the Zangbo suture to the Damxung graben of the Tibet Plateau. Some of these reflections have locally anomalous amplitudes (bright spots) and coincident negative polarities implying that they are produced by fluids in the crust. The presence of geothermal activity and high heat flow in the regions of these reflections and the tectonic setting suggest that the bright spots mark granitic magmas derived by partial melting of the tectonically thickened crust.

Partially Molten Middle Crust Beneath Southern Tibet: Synthesis of Project INDEPTH Results

INDEPTH geophysical and geological observations imply that a partially molten midcrustal layer exists beneath southern Tibet. This partially molten layer has been produced by crustal thickening and behaves as a fluid on the time scale of Himalayan deformation. It is confined on the south by the structurally imbricated Indian crust underlying the Tethyan and High Himalaya and is underlain, apparently, by a stiff Indian mantle lid. The results suggest that during Neogene time the underthrusting Indian crust has acted as a plunger, displacing the molten middle crust to the north while at the same time contributing to this layer by melting and ductile flow. Viewed broadly, the Neogene evolution of the Himalaya is essentially a record of the southward extrusion of the partially molten middle crust underlying southern Tibet.

Using lot quality assurance sampling to assess measurements for growth monitoring in a developing country's primary health care system

BACKGROUND

Local supervisors used lot quality assurance sampling (LQAS) during routine household visits to assess the technical quality of Costa Rican community-based health workers (CHW): measuring and recording weights of children, interpreting their growth trend and providing nutrition education to mothers.

METHOD

Supervisors sampled 10 households in each of 12 Health Areas (4-8 hours per area). No more than two performance errors were allowed for each CHW. This LQAS decision rule resulted in judgments with a sensitivity and specificity of about 95 percent.

RESULTS

Three categories of results are reported: (1) CHW adequately weighed children, calculated ages, identified children requiring nutritional services, and used the growth chart. (2) They needed to improve referral, education, and documentation skills. (3) The lack of system support to regularly provide growth cards, supplementary feeding to identified malnourished children, and other essential materials may have discouraged some CHW resulting in them not applying their skills.

CONCLUSIONS

Supervisors regularly using LQAS should, by the sixth round of supervision, identify at least 90 percent of inadequately performing CHW. This paper demonstrates the strength of LQAS, namely, to be used easily by low level local health workers to identify poorly functioning components of growth monitoring and promotion.

Lessons learned in institutionalization of quality assurance programs: an international perspective

A sustainable quality assurance (QA) program depends on development of a QA structure, ongoing standard setting, routine monitoring, quality improvement activities and the development of a culture of quality. A review of QA implementation in five countries identifies some practical guidelines for successful institutionalization of QA. These experiences underscore the importance of organizational assessment and provide insight about the advantages and disadvantages of an initial QA assessment. Developing a methodology that is both standardized and flexible is stressed, as well as a training strategy that integrates classroom learning, coaching and application. Gradual development of QA structure, based closely on existing systems, is recommended. Issues relating to gaining and sustaining political support, dealing with personnel changes, using appropriate incentives and dissemination are also discussed. Finally, the definition and dimensions of quality are put forth as the foundation for a culture of quality, which develops as individuals and groups commit themselves to their quality ideal.

Primary central nervous system non-Hodgkin's lymphoma: survival advantages with combined initial therapy?

PURPOSE

Results of multiple radiation, chemotherapy, and combined treatment trials have shown that the fate of primary central nervous system lymphoma (PCNSL) patients is very different from that of patients with similarly treated systemic IE non-Hodgkin's lymphoma. This study was designed to improve the survival of PCNSL patients by the use of combined initial therapy.

METHODS AND MATERIALS

Forty-six eligible primary PCNSL patients were treated with whole brain irradiation and adjuvant chemotherapy consisting of preirradiation cyclophosphamide-adriamycin-vincristine-prednisone (CHOP) and postirradiation high-dose cytosine arabinoside (HDAC) as part of an ongoing Phase II Mayo/North Central Cancer Treatment Group/Eastern Cooperative Oncology Group (M/NCCTG/ECOG) intergroup effort, which opened in April 1986.

RESULTS

This cohort consisted of 23 men and 23 women with median age 63.5 years (range 24 to 75 years). Only 5% were under age 40; 36% were age 40 to 59, 37% were age 60 to 69, and 22% were age 70 and over. Forty-six percent had good performance scores of ECOG 0-1 at time of study entry. Forty-six patients were evaluable for treatment outcome as of October 6, 1993. Of these, 10 were still alive. Estimated median survival and 21-month survival were 45.3 weeks and 29%, respectively. There were four early deaths ranging from Day 9 to Day 15 (three drug-related, one from other complications), and two CHOP responders died at 32 and 35 days, soon after Cycle 2 of CHOP (one probably drug-related, one from other complications). There was no significant difference in survival according to baseline performance status. However, survival was consistently worse for patients > 60 years old than for the younger patients (< or = 60 years). With deaths recorded for 21 of 21 older patients, but only 9 of the 14 younger patients, 21-month survival for older vs. younger was 14 vs. 50% based on the 35 patients who entered the study at least 21 months ago (p = 0.0365). Of the 46 patients evaluable for response, 63% had objective remissions on CHOP and another 20% remained stable.

CONCLUSION

Combined modality therapy in this study did not produce an overall survival advantage in treating PCNSL. The 50% 21-month survival of younger patients may be a reflection of age only.

Phase II evaluation of recombinant interferon alpha and BCNU in recurrent glioma

The goal of this study was to determine the antitumor activity and toxicity of 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) plus recombinant interferon-alpha (IFN-alpha) in patients with recurrent glioma. As single agents, both BCNU and IFN-alpha can cause tumor regression in patients with recurrent glioma. In vitro studies suggest synergy between the two agents. Thirty-five patients in whom computerized tomography (CT) or magnetic resonance (MR) evidence was obtained of progressive astrocytoma, oligoastrocytoma, or oligodendroglioma received recombinant IFN-alpha 2a (12 x 10(6) U/m2 intramuscularly) on Days 1 through 3 and BCNU (150 mg/m2 intravenously) on Day 3 of each 6-week cycle. All patients had tumor progression despite radiation therapy and had received no prior chemotherapy. Response was assessed by CT or MR evidence and by neurological examination while the patients were on a regimen of stable or decreasing doses of corticosteroids. All patients could be evaluated for response and toxicity. Twenty-nine percent of the patients demonstrated objective tumor regression; 37% remained stable for more than 6 months and 25% were stable for less than 6 months. The median duration of response to IFN-alpha and BCNU was 9.9 months and the median survival for all patients was 13.3 months. Toxicity consisted primarily of moderate myelosuppression, venous irritation, vomiting, flulike symptoms, and transient reversible exacerbation of underlying neurological symptoms. The use of BCNU plus IFN-alpha is a safe, active regimen in the treatment of patients with recurrent glioma who have failed to respond to prior radiation therapy. The contribution of IFN to the antitumor activity observed in this study compared with that previously described with BCNU alone cannot be assessed from this trial.