Evolution in small populations: evidence from the literature and experimental results

The great taxonomic diversity of the Orchidaceae is often attributed to adaptive radiation for specific polli- nators driven by selection for outcrossing. However, when one looks beyond the product to the process, the evidence for selection is less than overwhelming. 

Invasive orchids: weeds we hate to love?

Rare species that show habitat specificity and an aversion to habitat disturbance may be common in the Orchidaceae (Tremblay et al. 1998; Bergman et al. 2006). Nonetheless, most orchids may not be in such a critical state and many are, quite frankly, weedy. We may learn much about rare species by asking what makes other orchids common and resilient or actually dependent on change. Most orchids do occur in ephemeral or frequently dis- turbed habitats (Ackerman 1983; Catling 1996) whether they are pastures, roadsides, citrus groves, coffee and tea farms, or simply as epiphytes whose substrates, by definition, are temporary and run the gamut from durable tree trunks to short-lived twigs (Johansson 1974). 

In-field gait retraining and mobile monitoring to address running biomechanics associated with tibial stress fracture

We sought to determine if an in-field gait retraining program can reduce excessive impact forces and peak hip adduction without adverse changes in knee joint work during running. Thirty healthy at-risk runners who exhibited high-impact forces were randomized to retraining [21.1 (± 1.9) years, 22.1 (± 10.8) km/week] or control groups [21.0 (± 1.3) years, 23.2 (± 8.7) km/week]. Retrainers were cued, via a wireless accelerometer, to increase preferred step rate by 7.5% during eight training sessions performed in-field. Adherence with the prescribed step rate was assessed via mobile monitoring. Three-dimensional gait analysis was performed at baseline, after retraining, and at 1-month post-retraining. Retrainers increased step rate by 8.6% (P < 0.0001), reducing instantaneous vertical load rate (-17.9%, P = 0.003), average vertical load rate (-18.9%, P < 0.0001), peak hip adduction (2.9° ± 4.2 reduction, P = 0.005), eccentric knee joint work per stance phase (-26.9%, P < 0.0001), and per kilometer of running (-21.1%, P < 0.0001). Alterations in gait were maintained at 30 days. In the absence of any feedback, controls maintained their baseline gait parameters. The majority of retrainers were adherent with the prescribed step rate during in-field runs. Thus, in-field gait retraining, cueing a modest increase in step rate, was effective at reducing impact forces, peak hip adduction and eccentric knee joint work.

The effect of an acute antioxidant supplementation compared with placebo on performance and hormonal response during a high volume resistance training session

Antioxidant supplementation is known to increase human endogenous antioxidant (AOX) capacity providing a means of blunting exercise induced reactive oxygen species (ROS). The purpose of this study was to compare the effects of a single acute dose of an AOX (vs blinded placebo) on muscle contractile performance and hormonal responses to a single bout of lower limb ‘hypertrophic’ resistance training (RT). Fifteen resistance trained subjects (age 23 ± 4 years: body mass 86 ± 6 kg) volunteered to participate in the study. Each subject attended the laboratory on three occasions, firstly to determine three repetition maximum (3-RM) isotonic strength in the back squat and perform a familiarisation of the experimental task. On the second/third visits subjects completed the hypertrophic training session (HTS) which consisted of six sets of 10 repetitions of 70% of a predicted 1 RM load (kg). Four hours prior to the HTS the subjects consumed 2 ml#x2219;kg⁻¹ total body mass of either the placebo mixture or AOX supplement in a randomised order. Work completed during the strength training session was completed with equipment that had an integrated linear force transducer (Gymaware system, Kinetic Performance Technology, Canberra, Australia). During the placebo trials concentric mean power significantly (p < 0.05) decreased from sets 1–6. Accumulated power output during the AOX HTS was 6746 ± 5.9 W which was significantly greater compared to the placebo HTS of 6493 ± 17.1 W (p < 0.05, ES’r = 0.99). Plasma growth hormone (GH) concentration was significantly less immediately following AOX supplementation (6.65 ± 1.84 vs 16.08 ± 2.78 ng#x2219;ml⁻¹; p < 0.05, ES’r = 0.89). This study demonstrates ingestion of an AOX cocktail prior to a single bout of resistance training improved muscle contractile performance and modulated the GH response following completion of the resistance exercise. Future studies should explore the mechanisms associated with the performance modification and specific muscle adaptations to AOX supplementation in conjunction with heavy RT.

Darwin's orchids: their variation, plasticity, and natural selection

Las consecuencias de los patrones de variación en el éxito de una planta son críticas para revelar la selección natural. Uno de los grupos más variados de plantas son las orquídeas que llevan a cabo polinización por engaño las mismas engañan a los polinizadores los cuales buscan una recompensa alimentaria en ellas. La selección negativa dependiente de frecuencia y la selección disruptiva han sido sugeridas para explicar el mantenimiento de altos niveles de variación. En la mayoría de los casos estas selecciones no han sido detectadas, provocando otras explicaciones alternas como la deriva genética. ¿Podrá la selección natural ser nublada por la plasticidad fenotípica? Usando poblaciones de Tolumnia variegata como sistema modelo, nosotros realizamos un experimento de trasplante recíproco para determinar los efectos de la luz en las características de la parte vegetativa, inflorescencia y flores, a través de diferentes épocas del año. Los resultados fueron complejos, la mayoría de los rasgos medidos presentaron respuestas significativas a la luz, pero la mayoría de estos cambios fueron obscurecidos por respuestas variadas a través de los años, probablemente por una diferencia dramática en la precipitación. La producción de frutos fue similar entre sitios de sombra y sol, pero las trayectorias de selección de las características entre los dos lugares fueron en su mayoría incongruentes. Nuestros datos indican que la selección en un ambiente heterogéneo puede ser disfrazada por la plasticidad fenotípica, pero no todas las características responden de la misma manera. 

Phosphorus removal from anaerobically digested swine wastewater through struvite precipitation

Phosphorus removal from agricultural wastewater streams is an important aspect of managing surface water quality, due to the contribution of phosphorus to eutrophication. Removal of phosphorus through struvite precipitation allows for its recovery as a potential fertilizer, and by determining the best conditions for struvite precipitation the removal process can be optimized. The effects of pH, Mg:P ratio, and time on struvite precipitation from anaerobically digested swine manure effluent were investigated. Effluent with Mg:P ratios from 1.0:1 to 1.6:1 were adjusted to pH values between 7.5 and 9.5 and left to equilibrate for 24 h. Results indicate that phosphorus removal increased with increasing pH and Mg:P ratio; the maximum phosphorus removal achieved was 80% at pH 9.0 and a Mg:P ratio of 1.6:1. The purest struvite precipitate was found at pH 7.5, with calcium carbonate and struvite precipitating at higher pH values. A continuously stirred batch of centrate was adjusted to pH 8.4 to determine the struvite formation rate constant. The rate constant was found to be 1.55 h(-1), with 17% phosphorus removal during the first 20 min. The results indicate that struvite precipitation could be a viable method of phosphorus removal from anaerobically digested swine manure.

Phase II study of the efficacy and safety of intravenous (IV) AVE0005 (VEGF Trap) given every 2 weeks in patients (Pts) with platinum- and erlotinib- resistant adenocarcinoma of the lung (NSCLA)

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Background: AVE0005 (VEGF Trap) is a recombinant fusion molecule of the human VEGF receptor extracellular domains and the Fc portion of human IgG1. Methods: This is an open-label, single arm, multi-center trial employing a Simon 2-stage design. A total of 94 pts are planned. Three responses in the first 37 evaluable pts are required to progress to the second stage. IV AVE0005 (VEGF Trap) 4.0 mg/kg is given every 2 weeks to pts with platinum- and erlotinib-resistant, locally advanced or metastatic NSCLA. Other eligibility requirements include prior treatment with at least two cancer drug regimens in the advanced disease treatment setting, measurable disease, and ECOG performance status (PS) =2. Exclusions include squamous-cell lung cancer, prior treatment with a VEGF or VEGF receptor inhibitor with the exception of bevacizumab, history of brain metastasis, significant bleeding diathesis. End points are objective response rate, safety profile, duration of response, progression-free survival, overall survival and quality of life. Results: The study is ongoing and response and safety data are available for 33 pts (median age=60; males/females=14/19; ECOG PS 0/1/2=6/26/1 pts). A total of 132 cycles have been administered (median=4). Most common reason for withdrawal was progressive disease. Grade 3–4 treatment emergent adverse events (TEAEs) included (pts/percent) dyspnea (5/15%), hypertension and non-cardiac chest pain (3 pts each/9 %) fatigue (2/6 %), and anxiety, epistaxis, nausea, bone pain, proteinuria, febrile neutropenia, pneumonia, pulmonary embolism, and renal pain (1 each/3%). No grade 3 or greater hemoptysis has occurred. Two partial responses (PRs) have been reported to date. Conclusions: AVE0005 (VEGF Trap) 4 mg/kg IV has shown to be generally well tolerated; no significant hemoptysis has been seen to date. Single agent activity has been observed in this heavily treated population; interim futility analysis is awaited. The safety and preliminary activity profile supports further investigation with other targeted agents and cytotoxic chemotherapy.

[Table: see text]

Maize fine streak virus, a New Leafhopper-Transmitted Rhabdovirus

ABSTRACT A previously uncharacterized virus was isolated from fall-planted sweet corn (Zea mays L., Syngenta GSS 0966) leaves showing fine chlorotic streaks. Symptomatic plants were negative in enzyme-linked immunosorbent assay against many maize viruses, but reacted weakly with antisera to Sorghum stunt mosaic virus suggesting a distant relationship between the viruses. The virus was readily transmitted by vascular puncture inoculation (VPI), but not by leaf-rub inoculation. Symptoms on maize included dwarfing and fine chlorotic streaks along intermediate and small veins that developed 12 to 17 days post-VPI. The isolated virus was bacilliform (231 +/- 5 nm long and 71 +/- 2 nm wide), with a knobby surface, and obvious helical structure typical of rhabdovirus morphology. Nucleorhabdovirus virions were observed by transmission electron microscopy of infected maize leaf tissue sections. Proteins unique to infected plants were observed in extracts of infected leaves, and the isolated virion contained three proteins with molecular masses 82 +/- 2, 50 +/- 3, and 32 +/- 2 kDa. Preliminary sequence analysis indicated the virus had similarity to members of the family Rhabdoviridae. The virus was transmitted by Graminella nigrifrons under persistent conditions. The data indicate the virus, provisionally designated Maize fine streak virus, is a new species in the genus Nucleorhabdovirus.

The weak interdomain coupling observed in the 70 kDa subunit of human replication protein A is unaffected by ssDNA binding

Replication protein A (RPA) is a heterotrimeric, multi-functional protein that binds single-stranded DNA (ssDNA) and is essential for eukaryotic DNA metabolism. Using heteronuclear NMR methods we have investigated the domain interactions and ssDNA binding of a fragment from the 70 kDa subunit of human RPA (hRPA70). This fragment contains an N-terminal domain (NTD), which is important for hRPA70-protein interactions, connected to a ssDNA-binding domain (SSB1) by a flexible linker (hRPA70(1-326)). Correlation analysis of the amide (1)H and (15)N chemical shifts was used to compare the structure of the NTD and SSB1 in hRPA70(1-326) with two smaller fragments that corresponded to the individual domains. High correlation coefficients verified that the NTD and SSB1 maintained their structures in hRPA70(1-326), indicating weak interdomain coupling. Weak interdomain coupling was also suggested by a comparison of the transverse relaxation rates for hRPA70(1-326) and one of the smaller hRPA70 fragments containing the NTD and the flexible linker (hRPA70(1-168)). We also examined the structure of hRPA70(1-326) after addition of three different ssDNA substrates. Each of these substrates induced specific amide (1)H and/or (15)N chemical shift changes in both the NTD and SSB1. The NTD and SSB1 have similar topologies, leading to the possibility that ssDNA binding induced the chemical shift changes observed for the NTD. To test this hypothesis we monitored the amide (1)H and (15)N chemical shift changes of hRPA70(1-168) after addition of ssDNA. The same amide (1)H and (15)N chemical shift changes were observed for the NTD in hRPA70(1-168) and hRPA70(1-326). The NTD residues with the largest amide (1)H and/or (15)N chemical shift changes were localized to a basic cleft that is important for hRPA70-protein interactions. Based on this relationship, and other available data, we propose a model where binding between the NTD and ssDNA interferes with hRPA70-protein interactions.

Reflections on validity and epistemology in a study of working relations between deaf and hearing professionals

In this article, a research study that examined the working relationships between Deaf and hearing professionals in health and educational services in the United Kingdom is addressed. These service providers worked in bilingual organizations where both British Sign Language and English were used and in which Deaf people's identity as a cultural-linguistic minority was accepted. The focus of this article is on issues of validity and epistemology that arose for the Deaf and hearing research team in the course of this study. In particular, it examines the influence of identity attributions on the research process for researchers operating within a context of historical oppression, minority language use and legitimization of research knowledge, and challenges to the interpretative analysis used in the study that arose from the dynamics of majority-minority power relations in the wider social world.

Abnormal umbilical cord coiling is associated with adverse perinatal outcomes

The normal umbilical cord coil index is one coil/5 cm, i.e., 0.2 +/- 0.1 coils completed per cm. We report the frequency and clinical correlations of abnormally coiled cords among 1329 cases referred to our placental pathology services. Twenty-one percent of cords were overcoiled and 13% were undercoiled. Abnormal cord coiling was seen at all gestational ages. Principal clinical correlations found in overcoiled cords were fetal demise (37%), fetal intolerance to labor (14%), intrauterine growth retardation (10%), and chorioamnionitis (10%). For undercoiled cords, the frequencies of these adverse outcomes were 29%, 21%, 15%, and 29%, respectively. Abnormal cord coiling was associated with thrombosis of chorionic plate vessels, umbilical venous thrombosis, and cord stenosis. Thus, abnormal cord coiling is a chronic state, established in early gestation, that may have chronic (growth retardation) and acute (fetal intolerance to labor and fetal demise) effects on fetal well-being. The cause of abnormal cord coiling is not known. Its effects on neurological status of survivors are also unknown. Antenatal detection of abnormal cord coil index by ultrasound could lead to elective delivery of fetuses at risk, thereby reducing the fetal death rate by about one-half. We recommend that the cord coil index become part of the routine placental pathology examination.

In utero diagnosis of trichothiodystrophy by endoscopically-guided fetal eyebrow biopsy

OBJECTIVE

To describe the prenatal diagnosis of trichothiodystrophy (TTD) through endoscopically-guided fetal eyebrow biopsy.

MATERIALS AND METHODS

A 32-year-old patient, gravida 4, para 3, with a history of 2 previous infants affected with TTD was referred at 17(5)/(7) weeks for fetal hair biopsy. DNA repair studies had been normal in the previous children. Four 1-mm biopsies were obtained from the external aspect of the fetal eyebrows under direct endoscopic guidance. Fetal hair samples were assessed with polarized microscopy, electron microscopy, hematoxylin and eosin staining, and were also sent for analysis of sulfur content (cystine levels).

RESULTS

The fetal eyebrows were the only adequate source of hair in the early second trimester. The biopsy samples yielded adequate material for all tests. Polarized microscopy showed characteristic banding patterns, but trichoschisis was not apparent. Cystine levels (19 micromol/l) in the biopsy sample were significantly lower than an age-matched (fresh spontaneous abortion) control (368 micromol/l).

CONCLUSION

Prenatal diagnosis of TTD is possible in the second trimester through endoscopically-guided eyebrow biopsy. An adequate amount of hair is present in the eyebrows by then, and the disease is already manifest. Analysis of sulfur content of the hair samples is preferred over polarized or electron microscopy, as many classic microscopic findings of TTD may not be present in the early second trimester.

On creating a workable signing environment: deaf and hearing perspectives

This article studies teams of service providers in education and psychiatric services, in which a substantial number of both deaf and hearing people work together as colleagues. It focuses specifically on the challenges involved in cooperatively creating a signing work environment. Using a methodology that draws on the principles of ethnography, it identifies and explores the meaning constructions associated with signing at work, from deaf and hearing perspectives. Data were collected through interviews in three organizations all in the United Kingdom: two specialist psychiatric units for deaf adults and a school for deaf children. Forty-one informants participated (20 deaf, 21 hearing). Results show that from a deaf perspective, hearing people's use of sign language in their presence at work is closely associated with demonstrating personal respect, value, and confidence, and hearing colleagues' willingness to sign is more significant than their fluency. From a hearing perspective, results demonstrate that sign language use at work is closely associated with change, pressure, and the questioning of professional competence. The challenges involved in improving deaf/hearing relations are perceived from a deaf perspective as largely person-centered, and from a hearing perspective as primarily language-centered. The significance of organizational factors such as imbalances in power and status between deaf and hearing colleagues is explored in relation to the findings.

Reconstruction of the severely atrophic maxilla in a young adult with periodontosis

Reconstruction of the atrophic maxilla in a young adult presents unique challenges. This article describes reconstruction in a 30-year-old patient using a two-stage procedure. Bilateral maxillary sinus augmentations with simultaneous corticocancellous grafting to the anterior maxilla and alveolar ridge were performed. Eight endosseous implant fixtures were subsequently placed into the maxilla after a five-month healing phase. Six months later the implants were uncovered, healing abutments placed and a maxillary vestibuloplasty performed. The rationale behind this treatment and a review of the literature are discussed.

Immunological studies of the placenta in maternal connective tissue disease

Maternal connective tissue disease is an important cause of second-trimester fetal loss. In order to assess the pathological changes in the placenta in maternal connective tissue disease, we reviewed the clinical histories and performed histologic and immunofluorescence studies on nine placentas: five from mothers with systemic lupus erythematosus (SLE), two from mothers with mixed connective tissue disease (MCTD), one from a mother with rheumatoid arthritis (RA), and one from a mother without prior known connective tissue disease. Excessive intervillous fibrin deposition and infarction were noted in all cases. Immunofluorescent and immunoperoxidase studies showed deposits of fibrinogen, IgG, IgM, IgA, and complement 3 (C3) localized to the trophoblast basement membrane (TBM). Electron microscopy documented thickening of the trophoblast basal lamina in three SLE placentas examined. The use of immunofluorescence may be enhanced further if antitrophoblast antibodies can be linked to placental compromise.

Histological and ultrastructural features of atherosclerosis in progeria

This histological and ultrastructural study of a limited amount of vascular tissue from a progeric woman of 20 years who died of traumatic subdural hemorrhage supports the belief that the vascular changes are atherosclerotic. The unusual features observed were collagen fibrils with a relatively small diameter in the atherosclerotic intima and media, extensive loss of mural smooth muscle cells particularly in the aorta, and widespread contraction bands in smooth muscle cells in vascular and nonvascular tissues. Smooth muscle cells appear to be unusually susceptible to hemodynamic and ischemic stress. Further autopsy studies are required to elucidate the etiology and pathogenesis of this unique disease.

Effect of normal ageing on the sites of aortic bifurcation and inferior vena cava confluence: a CT study

The object of this retrospective study was to determine the sites of abdominal aortic bifurcation and inferior vena cava confluence in relation to age and sex. The study group comprised 180 subjects (90 males and 90 females) divided into 9 groups by age (in decades). The positions of the aortic bifurcation and the inferior vena cava confluence were evaluated by CT, and linear regression models were fitted to the data. The positions of the aortic bifurcation and venous confluence showed a highly significant downward shift with increasing age (p = 0.0001). The shift was more pronounced in women. The mean site of the aortic bifurcation for the whole group was at lower L4 (range, upper L3 to upper S1); in males, it was at upper L4 (range, upper L3 to upper L5), and in females at lower L4 (range, upper L3 to upper S1). The mean site of the venous confluence for the whole group was at disc L4-L5 (range, lower L3 to upper S1); in males, it was at disc L4-L5 (range, upper L4 to disc L5-S1), and in females at disc L4-L5 (range, lower L3 to upper S1). Thus, the aorta and the inferior vena cava can extend as low as the level of S1. These data are of relevance in laparoscopic procedures, especially in laparoscopic lumbar discectomy.

Variation in pollinator abundance and selection on fragrance phenotypes in an epiphytic orchid

Extraordinary floral variation is common among some orchids that employ deception to attract pollinators. This variation may be maintained by frequency-dependent selection where rare phenotypes are preferred. Over a 2-yr period, 1993-1994, we monitored the reproductive success of Tolumnia variegata, an obligately outcrossing epiphytic orchid, at three localities in Puerto Rico that differed in pollinator service. Plants varied in floral morphology and fragrance characteristics. Artificial arrays of varying frequencies of scentless and fragrant phenotypes were established to test for frequency-dependent selection. Where pollinators were rare (Cambalache, range of census average = 0-0.2 bees/h), 0.9-1.2% of the flowers were effectively visited (pollinarium removals and pollinations). At Tortuguero where 0.4-1.1 bees/h were observed, 4-9.2% of the flowers were visited. At Pi;atnones where bees were the most abundant (1.4-5.2 bees/h), 20.9-25.0% of the flowers were visited. A significant portion of the variance in all measures of reproductive success (male, female, and combined) was explained by differences among populations, which we attribute mostly to variation in pollinator abundance. Neither the fragrance phenotype nor its frequency had a significant effect on success as revealed by a split-plot ANOVA. There was a significant interaction between population and phenotypic frequencies in all our measures of reproductive success, but only for the 1994 flowering season. Thus, variation in floral fragrance phenotypes is not likely maintained by frequency-dependent selection. High levels of variation remain unexplained.

Submarine pollination in the marine angiosperm Zostera marina (Zosteraceae). II. Pollen transport in flow fields and capture by stigmas

Flow chamber observations of the filamentous pollen of Zostera marina L. (Potamogetonales) revealed that pollen rotated and moved toward inflorescences where they were captured by stigmas. The mechanics of this abiotic pollination process were examined and found to be related to the flow environment around emergent flowers. The translational movement of pollen was imparted by the advection of the fluid (e.g., pollen kinetic energy, K, ranged from 0.8 x 10-14 to 2.4 x 10-14 J, and the average K of the fluid was _ 0.7 x 10-14 J), while the rotational motion was imparted by the fluid shear stress (tau) within the velocity gradient (e.g., pollen shear stress, sigmat = omegamu where omega is the rotational velocity and mu is the dynamic viscosity, ranged from 3.4 x 10-4 to 26 x 10-4 Pa, and the average fluid shear stress was tau _ 10 x 10-4 Pa; Ackerman, 1997, American Journal of Botany 84: 1099-1109). These results indicate that there is a greater potential for pollination by filamentous pollen relative to spherical pollen. Functionally, while spherical pollen needs to be directly upstream from stigmas to be captured, filamentous pollen need only be in the vicinity of inflorescences and flowers to be captured by stigmas. Thus, in addition to direct interception on stigmas, filamentous pollen can be captured while they rotate past flowers or when they are redirected through the velocity gradient towards flowers. Filamentous pollen is an adaptation to submarine pollination in seagrasses.

Submarine pollination in the marine angiosperm Zostera marina (Zosteraceae). I. The influence of floral morphology on fluid flow

An understanding of the process of submarine pollination should provide insight into the evolutionary and reproductive ecology of the marine angiosperms (seagrasses). The flow around the reproductive organs of the seagrass Zostera marina L. (Potamogetonales) was, therefore, examined in a flow chamber. The phenological emergence of flowers during (1) pollen capture and (2) pollen release, and by fruit during (3) seed release, led to a reduction in flow rate toward the inflorescence. This change in flow due to floral emergence was associated with a 50% increase in the fluid shear stress [tau = (2.2 _ 0.3) x 10-3 Pa for an immature flower vs. tau = (3.1 _ 0.5) x 10-3 Pa for a receptive flower]. The Reynolds number (Re) and fluid shear stress around inflorescences and infructescences were comparable, indicating a dynamic similarity in the processes of pollen capture and fruit dehiscence [Re = 47 _ 5, tau = (1.6 _ 0.3) x 10-3 Pa for inflorescences; Re = 38 _ 5, tau = (1.3 _ 0.1) x 10-3 Pa for infructescences]. These results indicate that the emergence of reproductive organs leads to changes in fluid shear stress, which will affect the release, transport, and capture of particles including pollen. Theoretical considerations of these observations using aerosol-filtration theory suggest that pollen capture in Z. marina occurs through direct interception of pollen by stigmas.

Malignancy metastatic to the products of conception: a case report with literature review

Breast cancer is rare in adolescent females. Breast cancer metastatic to the products of conception is equally uncommon. We describe a 15-year-old girl who at 30 weeks of gestation was diagnosed with metastatic adenocarcinoma of probable breast origin. The placenta showed extensive intervillous disease. Metastatic disease within the intervillous space indicates hematogenous dissemination of cancer and a poor prognosis for the mother. The infant is almost always free of maternal disease unless there is villous invasion. Hormonal changes or immunotolerance by the mother may be involved in the pathogenesis. All placentas in which maternal malignancy is known or suspected should be examined grossly and microscopically.

Suspended rocking cradles, positional asphyxia, and sudden infant death

OBJECTIVE

To describe the risk of unexpected death in infants who are placed in suspended rocking cardles.

MAIN OUTCOME MEASURES

Ten cases of sudden infant death and 5 cases of infant asphyxia with successful resuscitation reported to the Consumer Product Safety Commission were analyzed. The death scene investigation reports and autopsy material were made available for evaluation. All 15 cases implicated a suspended head-to-toe rocking cradle.

RESULTS

Infants were aged 3 months or younger and were found in the facedown prone position when discovered. The cradle was tilted at greater than 5 degrees, and the head was wedged at one end of the cradle. A locking pin was not used in 14 cases. Ten of the 15 infants died. The autopsy reports listed sudden infant death syndrome as the cause of death.

CONCLUSIONS

Suspended rocking cradles represent a potentially lethal sleeping environment and should not be used without a locking pin in place. Infants should be placed in the supine position for sleep.

IS outlook '96: predictions & predilections. Roundtable discussion

Musings from some of the leading national and international HIT organizations make it clear that the need for a computer-based patient record is approaching the critical point. Half of our respondents identified the CPR as the single most important technology in 1996. One of our participants goes so far as to say that the era prior to the electronic medical record will one day be remembered as the "paper age." Progress in the development of standards--crucial to the CPR--could be dramatic this year, say experts from two of the major standards organizations. For a look at these issues and others, including key government policies to watch this year, read on.

The role of p53 mutations in bilateral breast carcinoma

Mutations of the tumor suppressor gene p53 have been implicated in certain familial cases of breast cancer. We examined a series of 38 cases of nonfamilial bilateral breast cancer using antibodies CM1 and DO7 to p53 wild-type and mutant protein (Novocastra Laboratories) by the avidin-biotin-peroxidase complex method. The two antibodies reacted similarly. Mutant p53 protein was detected in 17 of 76 (22%) tumors but in only 3 of 38 (8%) paired tumors. There were no significant differences in p53 expression between synchronous (< 12 mos) and metachronous tumors (29% vs 17%, P = 0.09) or between first and second tumors (14% vs 26%, P = 0.29). Mutant p53 was detected bilaterally in one metachronous and two synchronous cases, which were amplified and sequenced and two synchronous cases, which were amplified and sequenced by polymerase chain reaction and single strand confirmation polymorphism. One synchronous case showed a bilateral mutation in exon 2-3; the other had a bilateral mutation in exon 8-9. In the metachronous case, a mutation could be demonstrated in only one breast. Analysis of all tumors demonstrated that when p53 protein is overexpressed in the first tumor, there is a 60% probability of overexpression in the second, whereas if absent from the first, it is unlikely to be present in the second. These data suggest that p53 mutations do not play a major role in the pathogenesis of bilateral disease in most women.

Competition turns to United Healthcare for technology edge. Interview by Carolyn Dunbar and Michael L. Laughlin

Joel Ackerman serves as director of advanced technologies for Minneapolis-based ProviderLink, an electronic claims software subsidiary of United Healthcare Corporation. United Healthcare is a managed-care company that owns and operates 19 fee-for-service and capitated health maintenance organizations in 15 states serving almost two million members. In addition, United Healthcare has subsidiary operations selling services to more than 80 other Blue Cross Blue Shield plans and indemnity and HMOs--including its competitors. These services include managing departments such as pharmacy, providing specialized contract clinics like mental health or chemical dependency, performing utilization-review services, and providing computer outsourcing such as enrollment and electronic claims processing. Ackerman has been involved in both American National Standards Institute (ANSI) efforts and the Health and Human Service's Workgroup on Electronic Data Interchange (WEDI).

Anti-CD4 mediates clonal anergy during transplantation tolerance induction

Depletion of CD4+ cells using anti-CD4 monoclonal antibodies leads to allograft tolerance. Here we show that anti-CD4-mediated tolerance to pancreatic islets of Langerhans transplanted from an A/J (IEk) donor to a diabetic C57B1/6 (B6) (IE-) recipient occurs in the absence of clonal deletion of the potentially IE-reactive V beta 11+ T cells. Instead, a state of clonal anergy is induced in both the CD4+V beta 11+ and CD8+V beta 11+ T cell subsets. This clonal anergy can be partially overcome in vitro by the addition of recombinant interleukin 2.

Effect of maternal administration of thyrotropin-releasing hormone or DN1417 on functional and morphologic fetal rabbit lung maturation and duration of survival after premature delivery

Though maternal treatment with thyrotropin-releasing hormone (TRH) for prevention of hyaline membrane disease has been utilized, precise mechanisms of TRH in accelerating fetal lung maturation remain unclear. We studied the effect of maternally administered TRH or DN1417 (an analog of TRH) on functional and morphologic fetal rabbit lung maturation and the duration of survival after premature delivery. Because DN1417 retains the neurotransmitter but not the neuroendocrine effects of TRH, this study enables us to determine which of these effects was responsible for enhancement of lung maturation. TRH or DN1417 (0.2 mg/kg/dose) or saline was injected intravenously into New Zealand White rabbit does 48, 36, 24, 12 and 2 h prior to sacrifice on day 27 of gestation. Functional pulmonary maturity was assessed by pressure-volume hysteresis, and morphologic maturity was assessed by histologic technique. Maternal administration of TRH or DN1417 enhanced both functional and morphologic fetal lung maturation as well as the duration of neonatal survival after premature delivery. We propose that the effect of TRH in fetal lung maturation is due to neurotransmitter rather than neuroendocrine effects.