COVID-19 and Pregnancy: Risk, Symptoms, Diagnosis, and Treatment

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is a novel virus responsible for causing an infection known as COVID-19. Several pulmonary and systemic manifestations of the illness have been described since the discovery of this virus. However, there have been higher-risk populations in which this infection has not been well studied nor documented. One of these populations includes the pregnant cohort. The purpose of this article is to describe the clinical manifestations of COVID-19 infection in the pregnant population and review the implications and sequelae of the infection throughout pregnancy and outcomes of live births. Also, we summarize the understanding and safety of current treatments and vaccination in pregnancy. This comprehensive review article comprises several case reports, case series, cohort studies, retrospective studies, and randomized clinical trials. Findings regarding maternal morbidity included an increased risk of acquiring severe COVID-19 infection requiring a higher level of inpatient hospital care along with an increased risk of preterm labor and cesarean delivery. Neonatal COVID-19 vertical transmission was shown to have conflicting data as there was a presence of transmission in certain retrospective studies and absence in others. There was also no evidence of teratogenicity from maternal COVID-19 infection. In conclusion, in part due to the unique physiologic state of pregnancy and part due to unknown factors, pregnant patients are at increased risk for negative outcomes of COVID-19 infection and must be classified as a high-risk population.

Hypoglycemic Confidence in the Partners of Adults with Type 1 Diabetes

Background: Hypoglycemic confidence (HC) represents the degree to which an individual feels secure regarding his or her ability to stay safe from hypoglycemia-related problems. Self-report scales assessing HC in adults with type 1 diabetes (T1D) have found that greater HC is associated with better glycemic control and that HC rises significantly after real-time continuous glucose monitoring is introduced. To determine whether HC might be similarly meaningful in the partners of T1D adults, we developed the Hypoglycemic Confidence Scale for Partners (Partner-HCS). This article describes the construction and validation of the Partner-HCS and examines how HC in T1D partners is related to hypoglycemia-related experience and key psychosocial constructs. Methods: Items were developed from interviews with seven T1D partners, resulting in 12 self-report items. Exploratory factor analysis (EFA) was then conducted on data collected from T1D partners (n = 218). Variables to establish construct validity for the Partner-HCS included partner-reported diabetes distress, hypoglycemic fear, generalized anxiety, and confidence regarding glucagon use, as well as frequency of recent severe hypoglycemia in the T1D adult. Hierarchical regression analyses examined the unique contribution of Partner-HCS scores, independent of hypoglycemic fear, to key psychosocial constructs and hypoglycemia-related factors. Results: EFA of the 12 items yielded a single-factor solution, accounting for 51.2% of the variance. Construct validity was demonstrated by significant univariate associations with key psychosocial constructs. Importantly, Partner-HCS total score was, independent of hypoglycemic fear, significantly associated with diabetes distress (P < 0.05), overall relationship satisfaction (P = 0.004), number of severe hypoglycemic episodes in the last 6 months (P < 0.05), and confidence using glucagon (P = 0.007). In total, 38.5% of T1D partners indicated relatively low HC. Conclusions: HC is an important facet of the experiences of T1D partners. It is related to, yet distinct from, hypoglycemic fear. The Partner-HCS is a reliable, valid method for assessing HC in partners of T1D adults.

The phenylephrine concentration-response relationship for blood pressure after nasal delivery in children

BACKGROUND

Intranasal phenylephrine is commonly used to vasoconstrict the nasal mucosa, reducing bleeding associated with nasotracheal intubation or endoscopic sinus surgery. There are few data quantifying either absorption pharmacokinetics or phenylephrine concentration effect on blood pressure in children.

METHODS

Published observations of plasma concentration and blood pressure changes after phenylephrine nasal administration (0.1 mL kg^-1 , 0.25% or 0.5%) in children (n = 52, 2-12 years, 10-40 kg) were pooled with those in adults (23-81 years) given phenylephrine 2.5% (n = 10) and 10% (n = 10) eyedrops. Further pharmacokinetic (PK) data were available from healthy volunteers given oral phenylephrine 10 mg alone, with blood for concentration assay taken at 5, 15, 30, 45 minutes and 1, 2, 3, 6 hours (n = 28). Intravenous time-concentration data were available from four healthy volunteers given phenylephrine 1 mg and who had blood taken for assay on 17 occasions over the subsequent 4 hours. Data were analyzed using an integrated pharmacokinetic-pharmacodynamic (PK-PD) model using nonlinear mixed-effects models. Allometry, scaled to a 70-kg person, was used for PK size standardization. Effect was described using an E_MAX model.

RESULTS

A two-compartment model was used to fit PK data while an additional compartment, linked by an equilibration half-time (T_1/2 keo), was used to describe effect. PK parameter estimates for the nasal formulation were clearance (CL) 160 L h^-1 , central volume of distribution (V1) 13.3 L, intercompartment clearance (Q) 25.3 L h^-1 , peripheral volume of distribution (V2) 225 L, absorption half-time (Tabs) 6.2 minutes, absorption lag time (Tlag) 1.5 minutes, and bioavailability (F) 0.183. Bioavailability and absorption of the ophthalmic solution were concentration dependent (F 0.13, Tabs 5.5 minutes for 2.5% solution; F 0.15, Tabs 9.6 minutes for 10% solution). Absorption of the oral formulation was slow (Tabs 48 minutes) with poor bioavailability (F 0.0128). The pediatric PD interrogation revealed a baseline mean arterial pressure of 60 mm Hg, a maximum effect (E_MAX ) of 25 mm Hg, and an EC₅₀ of 10.3 μg L^-1 . The effect on vasculature was immediate and T_1/2 keo was not estimable.

CONCLUSION

Absorption of phenylephrine through the nasal mucosa was rapid and similar to the ophthalmic formulation. Bioavailability was also similar to the ophthalmic formulation. The maximum effect (E_MAX ) in children was half that in adults (E_MAX 50 mm Hg).

Hemodynamic responses and plasma phenylephrine concentrations associated with intranasal phenylephrine in children

INTRODUCTION

Intranasal phenylephrine, an alpha-1 adrenergic agonist, causes vasoconstriction of the nasal mucosa and is used to reduce bleeding associated with nasotracheal intubation or endoscopic sinus surgery. The purpose of this study was to describe the hemodynamic effects associated with plasma phenylephrine concentrations following topical intranasal administration of 0.25% and 0.5% phenylephrine in children.

METHODS

After Institutional Review Board and parental approval, 77 children between the ages of 2 and 12 years were studied in a prospective, double-blind manner and randomized into three groups. Group 1 received intranasal saline, while groups 2 and 3 received 0.1 mL/kg of 0.25% or 0.5% phenylephrine, respectively. All received the same anesthetic of halothane, N₂ O, O₂ , and vecuronium. After inhalation induction, endtidal halothane and PaCO₂ were maintained at 1.5% and 35 mm Hg, respectively. Heart rate and rhythm, systolic, diastolic, and mean, noninvasive arterial blood pressures were recorded and venous blood was obtained for measurement of plasma phenylephrine concentration by high-performance liquid chromatography at baseline and at 2, 5, 10, and 20 minutes following intranasal spray application of the study drug. Nasotracheal intubation was performed immediately following the 5-minute measurements, and the presence of bleeding was assessed. Hemodynamic data were compared by analysis of variance for repeated measures. Bleeding and arrhythmia incidence among groups were analyzed using chi-squared tests. Phenylephrine levels were correlated with hemodynamic values via regression analysis.

RESULTS

Fifty-two patients received intranasal phenylephrine. Increases in blood pressure correlated with increasing plasma phenylephrine concentration. Systolic blood pressure increased 8%, and mean blood pressure increased 14%, which were statistically significant but clinically insignificant. Heart rate did not change, and the incidence of arrhythmia was low and similar among groups. Bleeding following nasotracheal intubation was less frequent in Group 3 (11/27 subjects) than in Group 1 (17/25). Peak plasma phenylephrine concentrations were observed by 14±7 minutes following intranasal administration, and were highly variable among individuals (37.8±39.7 and 49.6±93.9 ng/mL [mean±SD] in Groups 2 and 3).

DISCUSSION

Administration of intranasal phenylephrine, 0.25% and 0.50%, results in rapid but highly variable systemic absorption that is associated with mild increases of blood pressure that are clinically insignificant. Bleeding associated with nasotracheal intubation was less following administration of 0.5% intranasal phenylephrine than following intranasal saline.

What big size you have! Using effect sizes to determine the impact of public health nursing interventions

BACKGROUND

The Omaha System is a standardized interface terminology that is used extensively by public health nurses in community settings to document interventions and client outcomes. Researchers using Omaha System data to analyze the effectiveness of interventions have typically calculated p-values to determine whether significant client changes occurred between admission and discharge. However, p-values are highly dependent on sample size, making it difficult to distinguish statistically significant changes from clinically meaningful changes. Effect sizes can help identify practical differences but have not yet been applied to Omaha System data.

METHODS

We compared p-values and effect sizes (Cohen's d) for mean differences between admission and discharge for 13 client problems documented in the electronic health records of 1,016 young low-income parents. Client problems were documented anywhere from 6 (Health Care Supervision) to 906 (Caretaking/parenting) times.

RESULTS

On a scale from 1 to 5, the mean change needed to yield a large effect size (Cohen's d ≥ 0.80) was approximately 0.60 (range = 0.50 - 1.03) regardless of p-value or sample size (i.e., the number of times a client problem was documented in the electronic health record).

CONCLUSIONS

Researchers using the Omaha System should report effect sizes to help readers determine which differences are practical and meaningful. Such disclosures will allow for increased recognition of effective interventions.

PCR offers no advantage over culture for microbiologic diagnosis in cellulitis

PURPOSE

Most cases of cellulitis are traditionally attributed to β-hemolytic Streptococcus and Staphylococcus species, although in most cases, no organism is identified. Development of PCR using the conserved bacterial 16 S rRNA DNA permits identification of bacteria independent of conventional culture approaches and prior use of antibiotics.

METHODS

We used PCR-based techniques to identify cellulitis etiology using aspirate samples from affected skin. Saline was infiltrated and aspirated at the site of greatest erythema or at the cellulitic border. Samples were tested for 16 S rRNA DNA, and organism-specific probes used to identify bacteria commonly seen in skin infections.

RESULTS

Aspirates from 32 patients were studied, and 16 S rRNA DNA was detected in nine of these patient samples (28.1%). Bacterial species were identified by PCR methods in six of these nine samples (66.6%), with S. aureus and methicillin-resistant S. aureus (MRSA) identified in four and two, respectively, of these samples. Of the patients with positive aspirate bacterial cultures (3/9, 33.3%), S. aureus and coagulase-negative Staphylococcus (CoNS) were present on cultures of two of the three (both 66.6%) positive samples. Only in one of the three positive bacterial cultures did the PCR method detect the same organism as was detected by culture. Among patients with positive provider-collected clinical cultures, MRSA was the predominant organism (11/18, 61.1%) and when present, it was found as the sole organism. Where S. aureus or Streptococcus species were detected by molecular methods, clinical cultures yielded a positive result as well.

CONCLUSIONS

PCR-based techniques do not appear to be more sensitive than aspirate cultures for the detection of pathogens in cellulitis.

Mantle oxidation state and its relationship to tectonic environment and fluid speciation

The earth's mantle is degassed along mid-ocean ridges, while rehydration and possibly recarbonaton occurs at subduction zones. These processes and the speciation of C-H-O fluids in the mantle are related to the oxidation state of mantle peridotite. Peridotite xenoliths from continental localities exhibit an oxygen fugacity (fo(2)) range from -1.5 to +1.5 log units relative to the FMQ (fayalite-magnetite-quartz) buffer. The lowest values are from zones of continental extension. Highly oxidized xenoliths (fo(2) greater than FMQ) come from regions of recent or acive subduction (for example, Ichinomegata, Japan), are commonly amphibole-bearing, and show trace element and isotopic evidence of fluid-rock interaction. Peridotites from ocean ridges are reduced and have an averae fo(2) of about -0.9 log units relative to FMQ, virtually coincident with values obtained from mid-ocean ridge basalt (MORB) glasses. These data are further evidence of the genetic link between MORB liquids and residual peridotite and indicate that the asthenosphere, although reducing, has CO(2) and H(2)O as its major fluid species. Incorporation of oxidized material from subduction zones into the continental lithosphere produces xenoliths that have both asthenospheric and subduction signatures. Fluids in the lithosphere are also dominated by CO(2) and H(2)O, and native C is generally unstable. Although the occurrence of native C (diamond) in deep-seated garnetiferous xenoliths and kimberlites does not require reducing conditions, calculations indicate that high Fe(3+) contents are stabilized in the garnet structure and that fo(2) deareases with increasing depth.

Using one question to identify women at risk for an alcohol-exposed pregnancy

CONTEXT

Consumption of 8 alcoholic drinks per week or 5 alcoholic drinks on one occasion by a pregnant woman can affect the developing fetus. However, it can be difficult to determine which patients are at risk.

OBJECTIVE

To evaluate how well the answer to a single question about binge drinking could help identify women at risk of an alcohol-exposed pregnancy (AEP).

METHODS

Using data from a study of methods to prevent AEPs, the authors compared the efficacy of self-reported answers to a screening question about binge drinking (5 or more standard drinks on one occasion) within the past 90 days with answers to a question about drinking quantity (weekly consumption of 8 or more standard drinks) within the past 90 days.

RESULTS

The participants were 354 women of childbearing age who met screening criteria for being at risk of an AEP. The binge question was answered positively by 346 women (97.7%) at risk, while only 209 women (59.0%) reported that they drank 8 or more drinks in a week.

CONCLUSION

A single question about binge drinking can effectively and quickly identify the majority of women at risk of an AEP.

Endurance and strength training outcomes on cognitively impaired and cognitively intact older adults: a meta-analysis

BACKGROUND

Dementia is a common syndrome in the geriatric population. Subsequent impairment of cognitive functioning impacts the patient's mobility, ADLs, and IADLs. It is suggested that older persons with lower levels of cognition are less likely to achieve independence in ADLs and ambulation (1-2). Frequently, nursing home residents are viewed as too frail or cognitively impaired to benefit from exercise rehabilitation. Often, persons with Mini Mental State Score (MMSE) score below 25 are excluded from physical rehabilitation programs. However, Diamond (3) and Goldstein (4) concluded that geriatric patients with mild to moderate cognitive impairment were just as likely as cognitively intact patients to improve in functional abilities as a result of participation in exercise rehabilitation programs.

PURPOSE

The objective of this study is to compare, through a meta-analysis endurance and strength outcomes of Cognitively Impaired (MMSE < 23) and Cognitively Intact (MMSE superior 24) older adults who participate in similar exercise programs.

METHODS

Published articles were identified by using electronic and manual searches. Key search words included exercise, training, strength, endurance, rehabilitation, cognitive impairment, cognition, MMSE, older adult, aged, and geriatrics. Articles were included if the were from RCTs or well-designed control studies.

RESULTS

A total of 41 manuscripts met the inclusion criteria. We examined 21 exercise trials with cognitively impaired individuals (CI=1411) and 20 exercise trials with cognitively intact individuals (IN=1510). Degree of cognitive impairment is based on the reported MMSE score. Moderate to large effect sizes (ES = dwi, Hedges gi) were found for strength and endurance outcomes for the CI groups (dwi = .51, 95% CI= .42- .60), and for the IN groups (dwi = .49, 95% CI= .40- .58). No statistically significant difference in ES was found between the CI and IN studies on strength (t=1.675, DF= 8, P= .132), endurance (t=1.904, DF= 14, P=.078), and combined strength and endurance effects (t=1.434, DF= 56, P= .263).

CONCLUSIONS

These results suggest that cognitively impaired older adults who participate in exercise rehabilitation programs have similar strength and endurance training outcomes as age and gender matched cognitively intact older participants and therefore impaired individuals should not be excluded from exercise rehabilitation programs.

Agreement Between Insurance Claim and Self-Reported Hospital and Emergency Room Utilization Data Among Persons with Diabetes

As part of a retrospective evaluation of a diabetes management program, the agreement between self-reported and insurance claim data on hospitalization and emergency room utilization was examined. Data agreement on hospitalization or emergency room visits between the two collection modes was evaluated through the use of simple agreement proportions and the kappa agreement statistic. A total of 1,230 participant responses were studied. The proportions of patients with hospitalization or emergency room visits were indistinguishable between the self-reported and medical claims data, and kappa statistics also indicated good-to-excellent agreement between data sets. The percentages of participants whose self-reported hospitalization and emergency room utilization exactly matched data derived from insurance claims were high (89.1% and 87.2%, respectively). Furthermore, the kappa statistics of agreement for the number of hospitalizations (0.6366) and emergency room visits (0.5390) indicate good agreement between self-reported and insurance claim data. The results of this study suggest either self-reported or insurance claims data can be used to evaluate the impact of health care interventions on hospital or emergency room utilization.

The North-West Diabetes Foot Care Study: incidence of, and risk factors for, new diabetic foot ulceration in a community-based patient cohort

AIMS

To determine the incidence of, and clinically relevant risk factors for, new foot ulceration in a large cohort of diabetic patients in the community healthcare setting.

METHODS

Diabetic patients (n = 9710) underwent foot screening in six districts of North-west England in various healthcare settings. All were assessed at baseline for demographic information, medical and social history, neuropathy symptom score, neuropathy disability score, cutaneous pressure perception (insensitivity to the 10 g monofilament), foot deformities, and peripheral pulses. Two years later, patients were followed up via postal questionnaire to determine the incidence of new foot ulcers. Cox's proportional hazards regression analysis was used to determine the independent, relative risk of baseline variables for new foot ulceration.

RESULTS

New foot ulcers occurred in 291/6613 patients who completed and returned their 2-year follow-up questionnaire (2.2% average annual incidence). The following factors were independently related to new foot ulcer risk: ulcer present at baseline (relative risk (95% confidence interval)) 5.32 (3.71-7.64), past history of ulcer 3.05 (2.16-4.31), abnormal neuropathy disability score (> or = 6/10) 2.32 (1.61-3.35), any previous podiatry attendance 2.19 (1.50-3.20), insensitivity to the 10 g monofilament 1.80 (1.36-2.39), reduced pulses 1.80 (1.40-2.32), foot deformities 1.57 (1.22-2.02), abnormal ankle reflexes 1.55 (1.01-2.36) and age 0.99 (0.98-1.00).

CONCLUSIONS

More than 2% of community-based diabetic patients develop new foot ulcers each year. The neuropathy disability score, 10 g monofilament and palpation of foot pulses are recommended as screening tools in general practice.

Comparison of pregnancy outcome in mares among methods used to evaluate and select spermatozoa for insemination

An artificial insemination dose for mares consisting of 500 million progressively motile spermatozoa is considered "standard" by most clinicians. However, little information is available directly comparing pregnancy outcome among methods of evaluating and selecting spermatozoa for insemination. The objective of this study was to determine if the method of spermatozoal evaluation and selection influences fertility as measured by pregnancy outcome. Mares were inseminated with 100 or 500 million spermatozoa that were selected for progressive motility, normal morphology, hypoosmotic swelling or absolute number regardless for evaluation method or quality. Thirty-two breeding cycles were tested for each treatment group and at each spermatozoal dose. Pregnancy outcomes were 44 and 41%, 55 and 41%, 39 and 31%, and 45 and 41%, for the 100 and 500 million progressively motile, morphologically normal, hypoosmotic swelling positive and absolute number treatment groups, respectively. Pregnancy outcome did not differ among methods of spermatozoal evaluation and selection for artificial insemination in the 100 (P=0.52) or 500 (P=0.78) million spermatozoa groups. Also the total number of spermatozoa and the absolute number of progressively motile, morphologically normal or hypoosmotic swelling positive spermatozoa inseminated, were not closely associated with pregnancy outcome in the 100 (P=0.24, 0.29, 0.33 and 0.38, respectively) or 500 (P=0.20, 0.84, 0.50 and 0.74, respectively) million spermatozoa groups. In this study, we found that the method of spermatozoal evaluation did not offer an advantage for pregnancy when used to select spermatozoa for insemination at the doses tested. These results were surprising, as we expected there would be differences among the evaluation methods. Instead, we found that evaluating spermatozoa offered no advantage for pregnancy over simply inseminating with a specified number of spermatozoa not selected for any particular characteristic under the conditions of our experiment.

Impact of varying levels of expertise on decisions of category typicality

Experts on domains of basic level object categories possess extensive knowledge of features used to both individuate and categorize groups of similar members. Two studies were conducted to determine the impact of high knowledge on intermediate and advanced experts' typicality decisions for basic and subordinate level category exemplars, and to investigate whether the pattern of influence of factors (in particular, central tendency and subjective familiarity) remained fixed throughout the continuum of expertise. Example goodness increased as a function of the level of specificity of the category for which typicality was rated. Subjective familiarity was the principal determinant of typicality for individuals with high knowledge, whereas central tendency was related to typicality when knowledge was not particularly high. Advanced and intermediate experts produced similar ratings of typicality, indicating that individuals' decisions of typicality do not change markedly once intermediate levels of competency have been attained. The incorporation of knowledge effects into models of semantic memory, as well as interactions among knowledge, psychological factors, and environmental factors in determining typicality, are discussed.

An active site tyrosine influences the ability of the dimethyl sulfoxide reductase family of molybdopterin enzymes to reduce S-oxides

Dimethyl sulfoxide reductase (DMSOR), trimethylamine-N-oxide reductase (TMAOR), and biotin sulfoxide reductase (BSOR) are members of a class of bacterial oxotransferases that contain the bis(molybdopterin guanine dinucleotide)molybdenum cofactor. The presence of a Tyr residue in the active site of DMSOR and BSOR that is missing in TMAOR has been implicated in the inability of TMAOR, unlike DMSOR and BSOR, to utilize S-oxides. To test this hypothesis, Escherichia coli TMAOR was cloned and expressed at high levels, and site-directed mutagenesis was utilized to generate the Tyr-114 --> Ala and Phe variants of Rhodobacter sphaeroides DMSOR and insert a Tyr residue into the equivalent position in TMAOR. Although all of the mutants turn over in a manner similar to their respective wild-type enzymes, mutation of Tyr-114 in DMSOR results in a decreased specificity for S-oxides and an increased specificity for trimethylamine-N-oxide (Me(3)NO), with a greater change observed for DMSOR-Y114A. Insertion of a Tyr into TMAOR results in a decreased preference for Me(3)NO relative to dimethyl sulfoxide. Kinetic analysis and UV-visible absorption spectra indicate that the ability of DMSOR to be reduced by dimethyl sulfide is lost upon mutation of Tyr-114 and that TMAOR does not exhibit this activity even in the Tyr insertion mutant.

Using immunohistochemistry to study plant metabolism: the examples of its use in the localization of amino acids in plant tissues, and of phosphoenolpyruvate carboxykinase and its possible role in pH regulation

To understand many aspects of the metabolism of complex plant structures such as leaves, fruit and roots it is important to understand how metabolic processes are compartmentalized between tissues. The aim of this article is to show how immunohistochemistry, in conjunction with biochemical and physiological studies, is useful in understanding both the function of an enzyme in a tissue and metabolic processes occurring in plant tissues. This is illustrated by two examples. Firstly, the use of immunohistochemisty in the localization of amino acids in plant tissues is described. Secondly, the use of immunohistochemistry in understanding the function of an enzyme in a tissue and the metabolic processes occurring within the tissue is described. To illustrate this the example of phosophoenolpyruvate carboxykinase (PEPCK), an enzyme which is present in many plant tissues in which its function is unknown, is used. Evidence is provided that PEPCK may play a role in pH regulation in tissues active in the metabolism of nitrogen.

The effect of an interactive experience on music majors' perceptions of music for deaf students

The purpose of this study was to examine the effect of an interactive experience on music majors' perceptions of music experiences for deaf students. Twenty-three members of a pre-existing college brass ensemble served as subjects, and a 1-hour interactive concert/presentation for 10 deaf elementary children served as the independent variable. The interactive experience was designed to provide social, musical, and educational interactions between the college musicians and the deaf children. A pretest-posttest design was utilized, and the dependent variable was a questionnaire designed to examine the subjects' perceptions regarding music for deaf students, including how prepared, comfortable, and willing they felt to provide music experiences for deaf students. Results reveal that this single interactive experience had a significant effect on the subjects' perceptions of the value of music in the education of deaf children (p <.05). Although the pretest and posttest scores indicate that the subjects felt apprehensive about their preparedness to work with deaf students, the subjects felt significantly more positive about their preparedness following the interaction (p <.001). An analysis of open comments indicates that the subjects perceived the experience as (a) very positive, (b) increasing their knowledge and perception of music for deaf students, (c) helping them better relate to the deaf population, (d) promoting interest in similar experiences and in gaining more information, and (e) eliciting a feeling that future teachers should have similar experiences. Quotes from the subjects are given, and implications for teacher training/music therapy programs are discussed.

The CXCR4 agonist ligand stromal derived factor-1 maintains high affinity for receptors in both Galpha(i)-coupled and uncoupled states

The alpha chemokine receptor CXCR4 and its only characterized chemokine ligand, stromal cell-derived factor-1 (SDF-1), are postulated to be important in the development of the B-cell arm of the immune system. In addition, CXCR4 is a critical coreceptor in support of viral entry by T-cell line tropic strains (X4) of the Human Immunodeficiency Virus Type 1 (HIV-1), viral variants which predominate in some infected individuals in end stage disease. SDF-1 can block X4-tropic HIV-1 infection of CD4+ target cells in vitro, and allelic variants of the human gene encoding SDF-1 in vivo correlate with delayed disease progression. Therefore, CXCR4 may be an appropriate target for therapeutic intervention in acquired immunodeficiency syndrome (AIDS), and knowledge of the pharmacology of SDF-1 binding to its cognate receptor will be important in the interpretation of these experiments. We report here a Kd derived using a competition binding assay of 4.5 nM for CXCR4 endogenously expressed on peripheral blood monocytes and T-cells. This affinity is similar to that which SDF-1 exhibits when binding to endogenous CXCR4 on an established immortal Jurkat T-cell line as well as recombinant CXCR4 transfected into Chinese Hamster Ovary (CHO) cells. We also demonstrate that the determined affinity of SDF-1 for CXCR4 is reflective of its ability to induce a CXCR4-mediated signal transduction in these different cell types. Furthermore, using Bordetella pertussis toxin, we observe that high affinity binding of SDF-1 to CXCR4 is independent of the G-protein coupled state of the receptor, as uncoupling of G-protein did not lead to the appearance of measurable low affinity SDF-1 binding sites. Moreover, binding affinity and receptor number were unaffected by uncoupling for both recombinant and endogenously expressed CXCR4. Thus, SDF-1 is novel among agonist ligands of G protein-coupled receptors in that it appears to have equal affinity for both the G protein-coupled and uncoupled states of CXCR4.

Quantitative determination of a chemically modified hammerhead ribozyme in blood plasma using 96-well solid-phase extraction coupled with high-performance liquid chromatography or capillary gel electrophoresis

Versatile bioanalytical assays to detect chemically stabilized hammerhead ribozyme and putative ribozyme metabolites from plasma are described. The extraction protocols presented are based on serial solid-phase extractions performed on a 96-well plate format and are compatible with either IEX-HPLC or CGE back-end analysis. A validation of both assays confirmed that both the HPLC and the CGE methods possess the required linearity, accuracy, and precision to accurately measure concentrations of hammerhead ribozyme extracted from plasma. These methods should be of general use to detect and quantitate ribozymes from other biological fluids such as serum and urine.

An analysis of trends, perceptions, and use patterns of electronic medical records among US family practice residency programs

BACKGROUND AND OBJECTIVES

This study intended to quantify electronic medical record (EMR) use in family practice residencies, associate program characteristics with EMR use, and identify perceptions and issues about the use of EMRs.

METHODS

A survey was mailed to all 454 US family practice residency programs, with a 72% response rate. The survey, which was pretested and revised, was designed to identify benefits, problems, perceptions, and trends regarding the use of EMRs.

RESULTS

Fifty-five of 329 programs (17%) were using an EMR, while 10 (3%) had used an EMR but discontinued. Programs in the South reported the highest EMR use (21%, 21/99), and those in the North Central region reported the lowest use (11%, 11/102). EMR use was highest in university settings (19%, 15/81), programs offering fellowships (26%, 24/92), new programs (36%, 18/48), and programs that require research (22%, 20/91). Of the 329 programs that responded, 43% (143 programs) reported having information systems (IS) committees. Of the 55 programs currently using EMRs, 78% had at least one full-time equivalent IS technician. Of programs that discontinued use, software inadequacy was the most frequently cited reason (40%, 4/10). Programs that had never used EMR systems (n = 264) were more likely than those that had used EMRs (n = 65) to favorably perceive EMRs with respect to 1) meeting program requirements (44% versus 34%), 2) documenting improved patient care (65% versus 43%), 3) providing a reliable research database (94% versus 55%), and 4) documenting resident experience (92% versus 53%). Of the 264 (80%) programs that had never used an EMR, 172 (65%) plan to implement one.

CONCLUSIONS

EMR use is low among US family practice residency programs, but some success in implementation of EMRs has been achieved. Based on the responses to this survey, use will likely increase from 55 of 329 programs (17%) to 153 of 329 (47%) by 2000.

Computed tomography of necrotizing meningoencephalitis in 3 Yorkshire Terriers

A necrotizing meningoencephalitis of Yorkshire terriers has recently been reported in 6 dogs in Switzerland, 1 dog in Japan and 1 dog in the United States. The purpose of this report is to describe the computed tomographic (CT) findings in 3 dogs with this disease, and to correlate the CT abnormalities with the clinical and pathologic findings in each case. Three Yorkshire Terriers between 2 and 10 years old were evaluated. Physical and neurologic examinations, complete blood count (CBC), serum biochemistry profile, cerebrospinal fluid analysis, and CT scan were performed on all 3 dogs. Brainstem auditory evoked responses (BAER) were evaluated for 2 dogs. Two dogs were euthanized at the owners' request and necropsies were performed. Neurologic examination findings were consistent with a multifocal/diffuse encephalitis involving the cerebrum and brainstem in all 3 dogs. Complete blood count and biochemistry profiles were normal. Elevated protein concentration and a mononuclear pleocytosis were demonstrated in 2 of 3 dogs on cerebrospinal fluid evaluation. Multifocal, extensive areas of decreased opacity throughout the cerebral hemispheres, asymmetric ventriculomegaly, and lack of contrast enhancement were appreciated on CT images of all three dogs. No mass effect was seen. These findings correlated well with pathologic findings at necropsy, which included multiple malacic cavitations within the brain, representing areas of locally extensive necrosis. CT abnormalities in combination with signalment, clinical findings and cerebrospinal fluid analysis should facilitate a presumptive diagnosis of Yorkshire Terrier necrotizing meningoencephalitis.

Economic and gastrointestinal safety comparisons of etodolac, nabumetone, and oxaprozin from insurance claims data from patients with arthritis

This study was conducted to compare the effect of etodolac, nabumetone, and oxaprozin use on gastrointestinal (GI) safety and associated costs based on insurance claims information from practice settings. Data were obtained from a national claims database (MarketScan) for the years 1992 to 1994. The claims data of interest were for patients with arthritis who had used etodolac, nabumetone, or oxaprozin exclusively during a 9-month follow-up period (ONLY groups), or these drugs plus (PLUS groups) the other nonsteroidal anti-inflammatory drugs (NSAIDs) ibuprofen, naproxen, diclofenac, sulindac, piroxicam, ketoprofen, or indomethacin. For each group, we obtained information on the use of inpatient and outpatient services for GI-related events and the associated costs. All GI admissions were classified as NSAID-induced or possibly NSAID-induced events based on International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9 CM) codes. All outpatient upper GI ulcers or bleeding episodes were also identified by specific ICD-9 CM code. There were no significant between-group demographic differences. The proportions of patients with NSAID-induced and possibly NSAID-induced GI admissions were 0.1% and 0.4% for the etodolac-ONLY, 0.3% and 1.0% for the nabumetone-ONLY, and 0.1% and 0.5% for the oxaprozin-ONLY groups, respectively (P > 0.05), and a similar pattern was observed among the PLUS groups. In outpatient settings, 3.9%, 4.2%, and 4.9% of the etodolac-, nabumetone-, and oxaprozin-ONLY patients, respectively (P > 0.05), and 6.0%, 5.3%, and 4.7% of the etodolac-, nabumetone-, and oxaprozin-PLUS patients, respectively, had at least one upper GI ulcer/bleeding claim (P > 0.05). The total health care costs for 9 months were approximately $3000 each for the etodolac-, nabumetone-, and oxaprozin-ONLY groups. Oxaprozin, nabumetone, and etodolac had similar GI-safety and associated-costs profiles based on information from practice settings. Also, in patients who used multiple NSAIDs, the groups did not differ in their GI-safety and cost profiles.

The cost of inpatient endometriosis treatment: an analysis based on the Healthcare Cost and Utilization Project Nationwide Inpatient Sample

OBJECTIVE

To determine the prevalence and cost of endometriosis-related hospitalizations based on the Nationwide Inpatient Sample (NIS) from the Healthcare Cost and Utilization Project (HCUP-3).

STUDY DESIGN

Retrospective analysis based on nationwide clinical practice data.

PATIENTS AND METHODS

Data were obtained for 1991 and 1992 from the HCUP-NIS database, which was a 20% sample of all US hospital discharges. ICD-9 codes (236.0, 617.0 to 617.9) were used to identify females, aged 15 to 54, with endometriosis as a diagnosis. The distribution of endometriosis admissions by admission type, length of stay (LOS), mean total charge, specific types of endometriosis, principal procedures, and other diagnosed diseases was described.

RESULTS

In 1991 and 1992, 37,273 (22.6/1000) and 38,834 (23.7/1000) hospital admissions, respectively, were for endometriosis (as any diagnosis). The average LOS and total hospital charges for endometriosis as the primary diagnosis were 3.8 days and $6,597 for 1991, and 3.5 days and $7,450 for 1992. Most endometriosis admissions occurred in females aged 35 to 49. About 87% of the endometriosis hospitalizations were routine admissions. The most common diagnosis was endometriosis of the uterus (51%); the most common procedure was a total abdominal hysterectomy (55%-60%). Older and African-American patients had the longest LOS and the highest total charges. The estimated total hospitalization costs, as represented by hospital charges, for women with endometriosis as the primary diagnosis in the United States were $504 million for 1991 and $579 million for 1992.

CONCLUSION

Endometriosis-related hospitalization is a major burden on healthcare systems.

The effectiveness of a magnetized water oral irrigator (Hydro Floss) on plaque, calculus and gingival health

The purpose of this study was to evaluate the effects of a magnetized water oral irrigator on plaque, calculus and gingival health. 29 patients completed this double-blind crossover study. Each patient was brought to baseline via an oral prophylaxis with a plaque index < or = 1 and a gingival index < or = 1. Subjects used the irrigator for a period of 3 months with the magnet and 3 months without the magnet. After each 3 month interval, data were collected using the plaque index, gingival index, and accretions index. The repeated measures analysis on plaque, gingival and calculus indices yielded a statistically-significant period effect for PlI (p=0.0343), GI (p=0.0091), and approached significance for calculus (p=0.0593). This meant that the effect of irrigation resulted in a decrease of all indices over time. Therefore, the treatment effect on each index was evaluated using only the measurements obtained at the end of the first period (i.e., assuming a parallel design). Irrigation with magnetized water resulted in 64% less calculus compared to the control group. The reduction was statistically significant (p< or =0.02). The reduction by 27% in gingival index was not statistically significant. The reduction in plaque was minimal (2.2%). A strong positive correlation between the plaque index and the Watt accretion index was observed. The magnetized water oral irrigator could be a useful adjunct in the prevention of calculus accumulation in periodontal patients, but appears to have minimal effect on plaque reduction. The results indicated a clinical improvement in the gingival index, but this was not a statistically significant finding.

Blastomeres show differential fate changes in 8-cell Xenopus laevis embryos that are rotated 90 degrees before first cleavage

To study the mechanisms of dorsal axis specification, the alteration in dorsal cell fate of cleavage stage blastomeres in axis-respecified Xenopus laevis embryos was investigated. Fertilized eggs were rotated 90 degrees with the sperm entry point up or down with respect to the gravitational field. At the 8-cell stage, blastomeres were injected with the lineage tracers, Texas Red- or FITC-Dextran Amines. The distribution of the labeled progeny was mapped at the tail-bud stages (stages 35-38) and compared with the fate map of an 8-cell embryo raised in a normal orientation. As in the normal embryos, each blastomere in the rotated embryos has a characteristic and predictable cell fate. After 90 degrees rotation the blastomeres in the 8-cell stage embryo roughly switched their position by 90 degrees, but the fate of the blastomeres did not simply show a 90 degrees switch appropriate for their new location. Four types of fate change were observed: (i) the normal fate of the blastomere is conserved with little change; (ii) the normal fate is completely changed and a new fate is adopted according to the blastomere's new position: (iii) the normal fate is completely changed, but the new fate is not appropriate for its new position; and (4) the blastomere partially changed its fate and the new fate is a combination of its original fate and a fate appropriate to its new location. According to the changed fates, the blastomeres that adopt dorsal fates were identified in rotated embryos. This identification of dorsal blastomeres provides basic important information for further study of dorsal signaling in Xenopus embryos.

Impact of intuitive theories on feature recruitment throughout the continuum of expertise

Expertise in object domains involves both the perceptual learning of the differentiating and higher order features that are indicative of concepts and the elaboration of intuitive theories. Triad-similarity judgments, feature-salience ratings, and verbal protocols were used to investigate the effects of theories on the recruitment of features across different categorization contexts, as well as the degree to which expert categorization skills transferred to less familiar domains. Whereas novices considered features that indicated overall similarity to be more perceptually salient than were modified parts that indicated taxonomic relations, experts found them equally salient. Experts' theories were instrumental in directing feature recruitment in contexts involving identification, image generation, and similarity decisions. Experts' theories also supported the transfer of categorization skills to related, less familiar domains. The relation of mutual dependence between perceptual learning and theory development throughout the continuum of expertise is considered.

Fates of the blastomeres of the 32-cell stage Pleurodeles waltl embryo

Cell fate of the blastomeres at the 32-cell stage in the Pleurodeles waltl embryo was analyzed by injection of rhodamine or fluorescein lysinated-dextran (RLDx or FLDx). At the tailbud stage, the progeny of each blastomere contributed to more than one germ layer with unequal distribution along the anteroposterior and dorsoventral axis. Such a regionalized positioning of the descendants of the 32-cell blastomeres was found in the neuroectoderm, the epidermis, the notochord, the somites, the lateral plate, and the endoderm, but not in the head mesenchyme, the pronephros, or the blood islands. Results of double labeling of juxtaposed blastomeres showed that cell mixing and rearrangement take place during organ formation. Results are compared with those of the 32-cell stage fate map in Xenopus and Rana and reveal the more restricted fate of 32-cell stage blastomeres in Pleurodeles germ layers.

Development of children's understanding of basic-subordinate inclusion relations

Four studies focused on developmental differences in the representation of basic-subordinate inclusion relations. Tests of comprehension and production of category names, induction, and responses to direct questions pertaining to inclusion revealed a marked developmental gap between the production of subordinate category names and complete understanding of basic-subordinate inclusion relations. However, even 3-year-olds showed rudimentary knowledge of the asymmetry of inclusion. Discrepancies between children's performance on categorization tasks involving familiar and unfamiliar subordinate categories suggest that understanding of the logical nature of inclusion relations is constructed through the integration of categorical knowledge from familiar domains. Interactions among the knowledge base, pragmatic sensitivity, and information processing efficiency in the development of inclusion are discussed.

Effects of varying levels of expertise on the basic level of categorization

Six experiments were conducted on the effects of expertise on basic-level categorization. Individuals with varying levels of knowledge about songbirds generated lists of attributes, named objects, identified and discriminated among object silhouettes, verified category membership at 4 hierarchical levels, and visually identified songbirds primed either by species-specific, related, or unrelated birdsong. Results indicated that the original basic level never lost its privileged status. Expertise increased access to categorical information at the subordinate level for intermediate exports and at both the subordinate and sub-subordinate levels for advanced experts, causing these sublevels to function as basic. Throughout the continuum of expertise, conceptual knowledge interacted with perception. Accordingly, experts attended to different and more subtle perceptual features than novices.

Development of children's understanding of basic-subordinate inclusion relations

Four studies focused on developmental differences in the representation of basic-subordinate inclusion relations. Tests of comprehension and production of category names, induction, and responses to direct questions pertaining to inclusion revealed a marked developmental gap between the production of subordinate category names and complete understanding of basic-subordinate inclusion relations. However, even 3-year-olds showed rudimentary knowledge of the asymmetry of inclusion. Discrepancies between children's performance on categorization tasks involving familiar and unfamiliar subordinate categories suggest that understanding of the logical nature of inclusion relations is constructed through the integration of categorical knowledge from familiar domains. Interactions among the knowledge base, pragmatic sensitivity, and information processing efficiency in the development of inclusion are discussed.

Effects of varying levels of expertise on the basic level of categorization

Six experiments were conducted on the effects of expertise on basic-level categorization. Individuals with varying levels of knowledge about songbirds generated lists of attributes, named objects, identified and discriminated among object silhouettes, verified category membership at 4 hierarchical levels, and visually identified songbirds primed either by species-specific, related, or unrelated birdsong. Results indicated that the original basic level never lost its privileged status. Expertise increased access to categorical information at the subordinate level for intermediate exports and at both the subordinate and sub-subordinate levels for advanced experts, causing these sublevels to function as basic. Throughout the continuum of expertise, conceptual knowledge interacted with perception. Accordingly, experts attended to different and more subtle perceptual features than novices.

Immunocytochemical localization of growth factors and their receptors in human pre-embryos and Fallopian tubes

We utilized indirect immunocytochemistry to demonstrate the presence of growth factors and their receptors in human pre-embryos and Fallopian tubes. In pre-embryos, only transforming growth factor-alpha (TGF-alpha) and the intracellular domain of epidermal growth factor receptor (EGFR) were found at the 4-cell stage. In 8- to 14-cell pre-embryos, TGF-alpha, the intracellular and extracellular domains of EGFR, and insulin-like growth factor-I and its receptor were found. Antibodies against TGF-alpha stained all Fallopian tube specimens, while the extracellular domains of EGFR was only found in specimens from patients with either blood type A or AB. These results suggest a cross-reactivity between the extracellular domain of the EGFR and blood group antigens. Our novel demonstration of growth factor receptor staining in human pre-embryos shows that growth factor receptor localization is dependent on the developmental stage of human pre-embryos. We have also established a potentially important link between the Fallopian tube which secretes growth factors and the localization of growth factor receptors in pre-embryos. These findings are compatible with the hypothesis that tubal secretions are embryotrophic for the early development of the pre-embryo.

Gender differences in injuries among rural youth

GOAL

This paper presents injury data from the first year of a three year longitudinal study of risk taking behaviors among adolescents.

SAMPLE

Study subjects were a cohort of 758 rural students from Maryland's Eastern Shore who were in the eighth grade in 1987.

METHODS

Students completed a 45 minute, self administered survey in which they reported numbers of injuries experienced in the past year, risk taking behaviors, anger expression, delinquency, alcohol and drug use, physical exercise, work experience, and level of parental supervision. In addition, students had their height and weight measurements taken by trained research staff and completed a self rating of pubertal development using Tanner drawings.

RESULTS

Slightly more than half (53.2%) of the boys and over one third (37.7%) of the girls reported experiencing one or more medically attended injuries during the last year. Poisson regression analyses were conducted to estimate the extent to which gender differences in injuries could be accounted for by adolescent behaviors. Gender effects became non-significant when adjustments were made for risk taking, school discipline problems, and exercise frequency. Gender differences in injuries were reduced but remained significant when substance use, employment, and anger were controlled. Poisson regression analyses were conducted separately for males and females to assess whether factors associated with injuries were similar across genders. For boys, risk taking, anger, and school discipline problems were significantly related to number of injuries. Boys with a low body mass index and late pubertal development (mean ratio 3.09), as well as those with high body mass index and early pubertal development (mean ratio 2.16), reported greater numbers of injuries than average boys. For girls, substance use, cruising, risk taking, anger, and exercise frequency were significantly associated with injuries. Girls with an early onset of menses reported, on average, twice the number of injuries than those who were on time. Girls with high body mass index who were late in their pubertal development reported, on average, five times more injuries than other girls.

CONCLUSIONS

Although gender is a significant risk factor for injuries, certain behaviors like risk taking, school related delinquency, and physical exercise partially explain the higher number of injuries among adolescent males in this study. For both males and females, indicators of pubertal and physical development are important factors to consider in studies of injuries during early adolescence.

Lineage tracing demonstrates that blastomeres of early cleavage-stage human pre-embryos contribute to both trophectoderm and inner cell mass

We injected a fluorescent lineage tracer (Texas Red-lysine-dextran) into individual blastomeres of donated human diploid 2- to 8-cell pre-embryos and cultured them to blastocysts. Once pre-embryos reached the expanded blastocyst stage, they were fixed and examined in a scanning confocal microscope to identify the location of fluorescent tracer. In successfully injected pre-embryos that developed to expanded blastocysts, we found that randomly injected blastomeres formed both trophectoderm (TE) and inner cell mass (ICM). More labelled progeny were found in TE than in ICM. Our results show that individual early blastomeres are not yet committed to form either TE or ICM but instead can form both rudiments.

Superficial cells in the early gastrula of Rana pipiens contribute to mesodermal derivatives

We have studied the fate of presumptive mesodermal cells in the early Rana pipiens gastrula. We labeled superficial cells of the early gastrula with 125I. We also labeled all cells in a gastrula with rhodamine-lysine-dextran cell lineage tracer and superficial cells with 125I and then grafted small pieces of the marginal zone orthotopically into unlabeled host embryos. Labeled progeny were identified in sectioned embryos at the tail bud stage. The use of double-labeled grafts allowed us to study the relative contributions by superficial and deep cells to different derivatives. We found that the notochord and somite regions are both derived from the superficial and deep portions of circumblastoporal regions. In contrast, pronephros, lateral plate, cardiac anlagen, and blood cells only arise from deep cells in circumblastoporal regions. Such observations indicate that the fate map for R. pipiens is different from that of Xenopus laevis, where mesodermal derivatives appear to be restricted to the deep layers, and from that of Pleurodeles waltl, where all mesodermal derivatives are formed both from superficial and deep layers. We also have shown that from the neurula stage there is substantial mixing between cells due to the ingression of cells in the dorsal region so that superficial labeled cells, initially located in the roof of the archenteron, contribute to ventral regions of both the somites and notochord.

When cultural practices are health risks: the dilemma of female circumcision

The circumcision of young women and girls is widespread in African countries as well as in other parts of the world and clearly places them at risk for serious health consequences. Plans to eradicate the practice must recognize the cultural underpinnings that have maintained it. This article discusses the types of female circumcision and the concomitant short- and long-term health risks. The cultural aspects and origins of the procedure are described and a simple model of risk-taking based on control, information, and time is used to explain the complexity of issues that may be involved in the decision of women to consent to the procedure.

Degradation of Degradable Starch-Polyethylene Plastics in a Compost Environment

The degradation performance of 11 types of commercially produced degradable starch-polyethylene plastic compost bags was evaluated in municipal yard waste compost sites at Iowa State University (Ames) and in Carroll, Dubuque, and Grinnell, Iowa. Masterbatches for plastic production were provided by Archer Daniels Midland Co. (Decatur, Ill.), St. Lawrence Starch Co. Ltd. (Mississauga, Ontario, Canada), and Fully Compounded Plastics (Decatur, Ill.). Bags differed in starch content (5 to 9%) and prooxidant additives (transition metals and a type of unsaturated vegetable oil). Chemical and photodegradation properties of each material were evaluated. Materials from St. Lawrence Starch Co. Ltd. and Fully Compounded Plastics photodegraded faster than did materials from Archer Daniels Midland Co., whereas all materials containing transition metals demonstrated rapid thermal oxidative degradation in 70°C-oven (dry) and high-temperature, high-humidity (steam chamber) treatments. Each compost site was seeded with test strips (200 to 800 of each type) taped together, which were recovered periodically over an 8- to 12-month period. At each sampling date, the compost row temperature was measured (65 to 95°C), the location of the recovered test strip was recorded (interior or exterior), and at least four strips were recovered for evaluation. Degradation was followed by measuring the change in polyethylene molecular weight distribution via high-temperature gel permeation chromatography. Our initial 8-month study indicated that materials recovered from the interior of the compost row demonstrated very little degradation, whereas materials recovered from the exterior degraded well. In the second-year study, however, degradation was observed in several plastic materials recovered from the interior of the compost row by month 5 at the Carroll site and almost every material by month 12 at the Grinnell site. The plastic bags collected from each community followed a similar degradation pattern. To our knowledge, this is the first scientific study demonstrating significant polyethylene degradation by these materials in a compost environment.

Mesodermal cell adhesion to fibronectin-rich fibrillar extracellular matrix is required for normal Rana pipiens gastrulation

New observations on thin strips of cells from the leading edge of the involuting presumptive mesoderm explanted onto FN-coated substrate show a striking preferential cellular emigration from the leading edge of explants. Microinjected probes (Fab' anti-FN, Fab' anti-integrin and RGD-peptides) that disrupt cell adhesion to the FN-matrix on basal surface of the blastocoel roof also disrupt normal anuran gastrulation, producing blocked embryos with no adhesion of leading edge mesodermal cells to the blastocoel roof, abnormal epiboly, and defects of mesodermal cell spreading across the basal surface of the blastocoel roof toward the animal pole. These results show that the FN-rich fibrillar extracellular matrix on the basal surface of the blastocoel roof is required for normal gastrulation in Rana pipiens embryos.

Lactic Acid Production in a Mixed-Culture Biofilm Reactor

Novel solid supports, consisting of polypropylene blended with various agricultural materials (pp composite), were evaluated as supports for pure- and mixed-culture continuous lactic acid fermentations in biofilm reactors. Streptomyces viridosporus T7A (ATCC 39115) was used to form a biofilm, and Lactobacillus casei subsp. rhamnosus (ATCC 11443) was used for lactic acid production. For mixed-culture fermentations, a 15-day continuous fermentation of S. viridosporus was performed initially to establish the biofilm. The culture medium was then inoculated with L. casei subsp. rhamnosus. For pure-culture fermentation, L. casei subsp. rhamnosus was inoculated directly into the reactors containing sterile pp composite chips. The biofilm reactors containing various pp composite chips were compared with a biofilm reactor containing pure polypropylene chips and with a reactor containing a suspension culture. Continuous fermentation was started, and each flow rate (0.06 to 1.92 ml/min) was held constant for 24 h; steady state was achieved after 10 h. Lactic acid production was determined throughout the 24-h period by high-performance liquid chromatography. Production rates that were two to five times faster than those of the suspension culture (control) were observed for the pure- and mixed-culture bioreactors. Both lactic acid production rates and lactic acid concentrations in the culture medium were consistently higher in mixed-culture than in pure-culture fermentations. Biofilm formation on the chips was detected at harvest by chip clumping and Gram staining.