Advancing early relational health: a collaborative exploration of a research agenda

Here, we introduce the Early Relational Health (ERH) Learning Community's bold, large-scale, collaborative, data-driven and practice-informed research agenda focused on furthering our mechanistic understanding of ERH and identifying feasible and effective practices for making ERH promotion a routine and integrated component of pediatric primary care. The ERH Learning Community, formed by a team of parent/caregiver leaders, pediatric care clinicians, researchers, and early childhood development specialists, is a workgroup of Nurture Connection-a hub geared toward promoting ERH, i.e., the positive and nurturing relationship between young children and their parent(s)/caregiver(s), in families and communities nationwide. In response to the current child mental health crisis and the American Academy of Pediatrics (AAP) policy statement promoting ERH, the ERH Learning Community held an in-person meeting at the AAP national headquarters in December 2022 where members collaboratively designed an integrated research agenda to advance ERH. This agenda weaves together community partners, clinicians, and academics, melding the principles of participatory engagement and human-centered design, such as early engagement, co-design, iterative feedback, and cultural humility. Here, we present gaps in the ERH literature that prompted this initiative and the co-design activity that led to this novel and iterative community-focused research agenda, with parents/caregivers at the core, and in close collaboration with pediatric clinicians for real-world promotion of ERH in the pediatric primary care setting.

Randomized pilot trial of the "Mom Power" trauma- and attachment-informed multi-family group intervention in treating and preventing postpartum symptoms of depression among a health disparity sample

Introduction

Perinatal depression, a common complication related to childbearing, impacts mothers, children, and families. Efficacious interventions reduce perinatal depression symptoms; effort is needed to prevent the onset of perinatal depression. To determine feasibility and preliminary efficacy in reducing perinatal depression, we conducted a community-based, randomized parallel open pilot trial of Mom Power, a group-based intervention to improve mental health and parenting in mothers with young children.

Methods

Mom Power consists of 10 group sessions, focused on parenting, child development and self-care and three individual sessions, to build rapport and provide personalized referrals. Control group participants received psychoeducational mailings. Computer-based urn randomization assigned mothers with experiences of interpersonal violence, depression, or other traumatic experiences to Mom Power (68) or control (54).

Results

At 3-months post-treatment, the 31 retained women assigned to Mom Power were half as likely to meet criteria for probable depression (26%) as the 22 women retained in the control group (55%), with treatment predicting lower incidence of probable depression (OR = 0.13, p = 0.015). Moreover, among the 23 women who did not meet criteria for depression diagnosis at baseline, no women in the treatment group developed depression (n = 0, 0%) compared to control group women (n = 3, 30%). Logistic regression controlling for selective attrition confirmed the treatment effect on preventing new onset of depression (OR = 0.029, p = 0.012).

Conclusion

These findings support the use of Mom Power for both treatment and prevention of perinatal depression.

Clinical trial registration

https://classic.clinicaltrials.gov/ct2/show/NCT01554215, NCT01554215.

Profiles of Early Childhood Adversity in an Urban Pediatric Clinic: Implications for Pediatric Primary Care

Pediatricians are well-positioned to screen for early childhood adversities, but effective responses to positive screens require an understanding of which adversities typically co-occur, and to what extent they are associated with other risk or protective factors. Among children seen at an urban academic pediatric practice, this study aimed to (1) examine the prevalence of different types of early adversity and protective experiences reported by primary caregivers, and (2) define latent classes of co-occurring adversities. Of 1434 children whose parents completed the Safe Environment for Every Kid (SEEK) at well-child visits during November 2019-January 2021, three classes of adverse experiences emerged, including those reporting low adversity (L; 73%), caregiver stress (CS; 17%), and both caregiver stress and depression (CSD; 10%). Among those who also completed the Adverse Childhood Experiences Questionnaire (ACE-Q, n = 1373) and the Protective and Compensatory Experiences Scale (PACES, n = 1377), belonging to the L class was associated with lower ACE-Q and higher PACES scores. For parent-respondents only, ACE-Q scores were significantly greater for the CSD class compared to the CS and L classes. Pediatricians should attend to the needs of caregivers reporting both stress and depression, as these families may face especially high levels of adversity and low levels of protective factors.

Infant Mental Health Home Visiting Mitigates Impact of Maternal Adverse Childhood Experiences on Toddler Language Competence: A Randomized Controlled Trial

OBJECTIVE

The goal of this study was to test the impact of maternal adverse childhood experiences (ACEs) on subsequent child language competence; higher parental ACEs were expected to predict risk of toddler language delay. Participation in Infant Mental Health Home Visiting (IMH-HV) treatment, which aims to enhance responsive caregiving and improve child social-emotional development, was expected to mitigate this association.

METHODS

A randomized controlled trial (RCT) design was used. ACEs data were collected at baseline. Child language screening (using the Preschool Language Scales Screening Test) was conducted 12 months later by masters-level evaluators who were blind to treatment condition. Visits occurred in participants' homes. Participants were community-recruited and were randomized to treatment (psychotherapeutic IMH-HV) or control (treatment as usual). Data come from 62 families who participated in all waves of an RCT testing the efficacy of IMH-HV; mothers were eligible based on child age (<24 mo at enrollment) and endorsement of ≥2 sociodemographic eligibility criteria (economic disadvantage, depression, perceived parenting challenges, and/or high ACEs).

RESULTS

The age of mothers enrolled in this ranged from 19 to 44 years (M = 31.91; SD = 5.68); child age at baseline ranged from prenatal to 26 months (M = 12.06; SD = 6.62). The maternal ACE score predicted child language competence (t (5,55) = -3.27, p = 0.002). This effect was moderated by treatment (t (6,54) = 1.73, p = 0.04), indicating no association between maternal ACEs and child language for those randomized to IMH-HV.

CONCLUSION

The results highlight that the effects of parent ACEs on early childhood outcomes may be buffered by participation in psychotherapeutic home visiting (trial registration: NCT03175796).

Parenting Mediates Associations Between Intimate Partner Violence at Different Life Stages and Toddler Social-Emotional Problems

BACKGROUND

Researchers have linked parent experiences of intimate partner violence (IPV) to engagement in more negative and less positive parenting behaviors with their own children. This parenting behavior is associated with more negative child social-emotional outcomes. There is little research examining the impact of exposure to IPV during childhood on subsequent parenting and child outcomes in the next generation. This study aimed to better understand the complex relationship between IPV, parenting, and child social-emotional development among mothers of toddler-aged children, using both mothers' self-reported and observed parenting.

METHOD

This study utilized longitudinal data from an economically disadvantaged, racially diverse sample of 120 women who participated in data collection across the perinatal period, until children were 2 years of age. Measures included self-reported and observed parenting, mother-reported IPV history, and mother-report of toddler social-emotional difficulties.

RESULTS

Childhood exposure to IPV predicted observed parenting problems, which in turn predicted greater toddler social-emotional problems. Conversely, adult experiences of IPV predicted self-reported parenting difficulties, which predicted greater toddler social-emotional problems.

SUMMARY

Findings suggest that exposure to IPV at different time points may influence parenting in different ways, representing unique pathways between maternal IPV experiences and child social-emotional difficulties.

Nonspecific Binding of Complement by Digestion Fragments from Antiviral Gamma Globulin

The nonspecificity of rabbit gamma-globulin (antibody) to western equine encephalitis virus and the non-specificity of normal rabbit gamma-globulin in complement-fixation tests with anti-gens prepared from chick-embryo cells infected with this virus and normal chick-embryo cells resided primarily in Porter's fragment III. Addition of complement to fragment III from the anti-body globulin, followed by inactivation of the added complement, abolished the complement-fixing ability of fragment III with both specific and nonspecific antigens. Similar treatment of the undigested antibody abolished its complement-fixing ability with nonspecific antigen only.

Inhibition of human immunodeficiency virus by N-methylisatin-beta 4':4'-diethylthiosemicarbazone and N-allylisatin-beta-4':4'-diallythiosemicarbazone

N-methylisatin-beta 4':4'-diethylthiosemicarbazone(M-IBDET) and N-allylisatin-beta-4':4'-diallylthiosemicarbazone(A-IBDAT ) inhibit the production of Human Immunodeficiency virus (HIV). Virus inhibition was related to the thiosemicarbazone derivative (TSCD) concentrations and time of treatment. Inhibition of HIV production was confirmed by various parameters of virus assay employing reverse transcriptase activity, plaque forming units (PFU) and levels of viral structural proteins. Effective antiviral TSCD concentrations ranged from 0.17 microM to 2.04 microM for M-IBDET, and from 1.45 microM to 17.4 microM for A-IBDAT. Treatment of the chronic HIV-infected cells for 48 h with 0.34 microM M-IBDET or 2.9 microM A-IBDAT caused about 50% inhibition in as virus yield ED50 as assayed by the PFU method. Almost 2 logs of virus infectivity (PFU) was suppressed after 48 h of treatment with 17.4 microM A-IBDAT. Therapeutic index values of 20 and 30 were found for M-IBDET and A-IBDAT, respectively. A significant selective inhibition of HIV structural protein synthesis was shown by both M-IBDET and A-IBDAT.

Comparison of detection of antibody to the acquired immune deficiency syndrome virus by enzyme immunoassay, immunofluorescence, and Western blot methods

There was 100% agreement between enzyme immunoassay (EIA) (Abbott Laboratories), Western blot, and indirect immunofluorescence (IF) when these three methods were used to measure antibody to the acquired immune deficiency syndrome (AIDS) virus in sera from 142 high-risk individuals, indicating that IF was a sensitive alternative method for detecting antibody to this agent. Thirty-two (64%) of 50 EIA-positive plasma specimens from a blood bank and 6 (21%) of 28 EIA-positive sera from alternative testing sites were negative by IF. In addition, two EIA-negative sera from the latter group were positive by IF. Western blotting agreed with IF on those 40 specimens which gave discrepant results by EIA and IF. The IF method was determined to be equal to Western blotting in sensitivity and specificity for detection of AIDS antibody, and it was found to be useful for confirming positive EIA results, especially in specimens from individuals in low-risk groups.

Diagnosis and prognosis of manganese deficiency in Lupinus angustifolius L

Relationships diagnostic of manganese (Mn) deficiency in Lupinus angustifolius were examined in growth chamber experiments by studying the effects of Mn supply on plant growth and on photosynthesis and Mn concentrations in young leaves and whole shoots. A critical Mn concentration in youngest fully expanded leaves (YFEL) of 30 8g/g dry matter was found to be diagnostic of reduced dry matter production. A similar critical concentration was found for whole shoots, and the criteria were consistent over a wide range of ontogeny until at least early flowering. A less sensitive criterion of Mn deficiency was that for chlorophyll 'a' fluorescence characteristics of YFEL's (17 8g/g in YFEL), which estimates photosynthetic dysfunction in relation to Mn supply. The distal segments of lupin leaves best reflected changes in fluorescence in relation to their Mn status. The prognosis of impending Mn deficiency in maturing lupin plants was also examined in field and growth chamber experiments by studying the effects of Mn supply on the relationships between the concentrations of Mn in plant components at anthesis, and the subsequent appearance of Mn deficient ('split') seed on maturing plants. The absence of Mn deficient seed in main axis and first-order lateral inflorescences of maturing lupins could be predicted by Mn concentrations in stems at anthesis of >20 8g/g. Manganese concentrations of buds, leaves and tissues containing a high proportion of leaf, were found to be poor predictors of subsequent Mn deficiency in maturing lupins.

Anomalous antibody responses in viral infection: specific stimulation or polyclonal activation?

Eighteen paired serum samples submitted for serodiagnosis of current infection showed anomalous antibody results by complement fixation test when tested with a battery of agents (viruses, Mycoplasma pneumoniae, and chlamydia) selected for testing on the basis of the symptoms of the patient. Seventeen serum pairs showed a fourfold or greater rise in titer of antibody to two agents in the battery, and one showed only a twofold rise in titer of antibody to the identified causative agent but an eightfold rise in titer of antibody to a heterologous agent. The 18 serum pairs were tested for IgM antibody to the two involved agents to determine whether IgM antibody tests would better distinguish the probable cause of the current infection. The serum pairs were separated into three groups based on their IgM responses. Group I consisted of six serum pairs with IgM antibody to both agents, four pairs of which showed a fourfold or greater rise in titer of IgM antibody to both agents, and two of which showed a rise in titer of IgM antibody to only one of the two agents. Group II consisted of 10 serum pairs with IgM antibody to one of the two agents, 7 pairs of which showed a fourfold or greater rise in titer of IgM antibody to the agent. Group III consisted of two serum pairs with no IgM antibody to either agent. Results show that determination of presence or absence of IgM antibody per se or demonstration of a fourfold or greater rise in specific IgM antibody titer does not always help in distinguishing the causative agent in current infections.

The effect of soil- and foliar-applied manganese in preventing the onset of manganese deficiency in Lupinus angustifolius

The efficacy of the application of manganese, either applied to soil or as foliar sprays at three stages of flower development, in preventing the expression of manganese deficiency (ruptured seed coats ('split seed'); delayed maturity ('regreening'); and poor grain yield) in two cultivars of Lupinus angustifolius (cvv. Marri and Illyarrie) was assessed on sandy soils of the upper South East and Eyre Peninsula regions of South Australia. Six experiments were conducted during 1979 and 1980. A single foliar application of manganese (1.7 kg Mn/ha, in 200 litre water) when the upper-lateral shoots were in mid-flower, prevented the onset of the disorder. Applications of manganese to the soil at sowing at rates of up to 11.1 kg Mn/ha were usually less effective. The appearance of 'split-seed' symptoms in mature grain was a more sensitive indicator of manganese deficiency than was grain yield response to manganese fertilization. The degree to which these symptoms appeared increased markedly when the manganese concentration in intact seed became less than 8-10 �g/g dry seed, an observation which is consistent with other studies.

Detection of Giardia lamblia by immunofluorescence

High-titer immune sera to cysts of Giardia lamblia, produced in guinea pigs, were labeled with fluorescein isothiocyanate. The resulting conjugates were used to detect G. lamblia in stool specimens by fluorescence microscopy. The sera also reacted with cysts of Chilomastix mesnili, but the two organisms could be differentiated by their size.

Improved immunofluorescence antigens for detection of immunoglobulin M antibodies to Epstein-Barr viral capsid antigen and antibodies to Epstein-Barr virus nuclear antigen

Epstein-Barr viral capsid antigen and nuclear antigen produced by modified procedures were evaluated for use in measuring viral capsid antigen immunoglobulin M and Epstein-Barr virus nuclear antigen antibody responses in sera from patients with suspected Epstein-Barr virus infections. Viral capsid antigen production was stimulated with a phorbol ester, and the Epstein-Barr virus nuclear antigen cells were fixed in suspension to eliminate loss of antigen during the drying process. Both preparations proved to be sensitive and reliable.

A 27-nm virus isolated during an outbreak of acute infectious nonbacterial gastroenteritis in a convalescent hospital: a possible new serotype

An outbreak of acute infectious nonbacterial gastroenteritis began among elderly patients in a convalescent hospital in Marin County in northern California in March 1978 and persisted through May 1978. The overall clinical attack rate was 51% of 187 residents and 12% of 180 employees. A 27-nm viruslike particle was observed by immune electron microscopy in stools obtained at or near the onset of illness from four of 32 patients. Seroresponses to the 27-nm particles were found by immune electron microscopy in 16 of 18 patients. In addition, serologic evidence of infection with this or a related agent was demonstrated in persons who developed illness in another large outbreak of acute infectious nonbacterial gastroenteritis which occurred in a nearby county. This agent is morphologically similar to but serologically unrelated to the Norwalk and Hawaii gastroenteritis agents and has been designated the Marin agent pending further classification.

Multiple-antigen slide test for detection of immunoglobulin M antibodies in newborn and infant sera by immunofluorescence

A microimmunofluorescence test was evaluated for use in measuring immunoglobulin M (IgM) antibodies in infant sera to five of the agents implicated in congenital and neonatal disease. Pen point dots of Toxoplasma gondii, cytomegalovirus, rubella virus, herpes simplex virus, and chlamydial cell culture antigens were applied to each circle of eight-circle printed slides. These multiple-antigen slides greatly facilitated the screening of 607 sera from infants and 117 sera from mothers for the presence of IgM antibody to these agents. Forty sera could be examined microscopically in approximately 30 min. All sera reacting with one or more antigens were tested for rheumatoid factor by the latex method, absorbed with glutaraldehyde-cross-linked human IgG, and retested for the presence of IgM antibody. IgM antibody to cytomegalovirus was demonstrated in sera from four newborns, but IgM antibody to rubella virus could not be detected until 21 days after birth, although rubella virus was isolated from sera from five younger infants. This may indicate that rubella IgM levels in many congenitally infected newborns are too low to be measured by the immunofluorescence method. Five percent of the sera from infants in this study possessed demonstrable IgM antibody to one of the antigens.

Differentiation of cytomegalovirus antigens by their reactivity with various classes of human antibodies in the indirect fluorescent antibody test

Human sera containing immunoglobulin G (IgG), IgA, and IgM antibodies were tested by immunofluorescence for reactivity with cytomegalovirus-infected cell cultures and with early antigens of cytomegalovirus produced by treating the infected cultures with either bromodeoxyuridine or cytosine arabinoside. IgG antibody but not IgM antibody reacted with early antigens produced in bromodeoxyuridine-treated infected cultures. This observation on a small sample of sera suggested that a positive IgM reaction with an infected, nontreated culture and a negative reaction with a bromodeoxyuridine-treated infected culture may indicate a positive specific IgM reaction for cytomegalovirus, even in the presence of IgM rhematoid factor. The hyothesis requires further testing. The different classes of antibody did not all react or did not react to the same extent with early antigens produced in infected cells blocked with cytosine arabinoside or bromodeoxyuridine. This observation indicates that different antigens were being produced as a result of the two treatments.

Production of fibronectin by human epithelial cells in culture

Human epithelial cell lines derived from both carcinomatous and nomalignant tissues were characterized with respect to the presence and distribution of fibronectin by immunofluorescence microscopy. In cell lines derived from nonmalignant tissues or from primary carcinomas, fibronectin was found predominantly in an extracellular matrix. In contrast, cell lines derived from metastatic carcinomas displayed very little or no fibronectin. Metabolic labeling studies indicated that a positive line synthesized fibronectin de novo rather than absorbing the protein from the media. Negative lines neither synthesized fibronectin nor secreted it into the culture fluid, suggesting that they were not producing fibronectin. Evidence is presented that cells in culture change their properties after extensive subculture since a small amount of fibronectin in an extracellular matrix was observed after extensive subculture of two metastatic lines that were originally negative.

Properties of epithelial cells cultured from human carcinomas and nonmalignant tissues

Human epithelial cell cultures were examined for expression of plasminogen activator and fibronectin matrix. All of the cells examined showed ultrastructural evidence suggesting their epithelial origin, including microvilli and specialized junctions. The nonmalignant cells were also negative for endothelial cell markers (ie. they lacked factor VIII antigen, a nonthrombogenic surface and Weibel-Palade bodies). The nonmalignant lines all produced large amounts of plasminogen activator, whereas the tumor-derived lines showed a gradation of activities, ranging from lines having as much activity as the nonmalignant lines to lines having little or no activity above background. For both normal and malignant cells, addition of dexamethesone only slightly decreased the levels of plasminogen activator. By immunofluorescence microscopy, normal bladder and fetal intestine epithelial cells showed fibronectin in a globular and fibrillar matrix. In contrast, normal mammary epithelial cells had a much diminished amount of fibronectin with a punctate distribution.

Comparative sensitivity of various cell culture systems for isolation of viruses from wastewater and fecal samples

In efforts to define the most sensitive cell culture systems for recovery of viruses from wastewaters, 181 samples were inoculated in parallel into tube cultures of various cell types and were plaqued in bottle and petri dish cultures of three types of monkey kidney cells. Polioviruses were recovered most frequently in the RD line of human rhabdomyosarcoma cells, group A coxsackieviruses in RD and human fetal diploid kidney (HFDK) cells, group B coxsackieviruses in the BGM line of African green monkey kidney cells, echoviruses in RD and primary rhesus monkey kidney (RhMK) cells, and reoviruses in RhMK cells. BGM cells were unsatisfactory for recovery of viruses other than polioviruses and group B coxsackieviruses, and a line of fetal rhesus monkey kidney (MFK) was not a satisfactory substitute for primary RhMK. With RhMK cells, comparable numbers of virus isolations were made in tube cultures and in plaque assays conducted in bottle cultures, but with BGM and MFK cells, fewer isolations were made by plaquing than by inoculation of tube cultures. In comparative plaque assays on fecal samples under three different overlays in bottle and plate cultures of RhMK, BGM, and MFK cells, it was found that plaquing in the most sensitive system, RhMK, was less efficient for virus recovery than was inoculation of tube cultures of RhMK or HFDK cells. Overall, plaque assays performed in petri dishes in a CO(2) incubator yielded fewer virus isolates than did parallel plaque assays performed in closed bottle cultures. Other limitations of plaque assays for recovery of human enteric viruses are discussed.

Photochemical inactivation of DNA and RNA viruses by psoralen derivatives

Western equine encephalitis virus, and RNA virus, and herpes simplex virus type I, a DNA virus, were efficiently inactivated in less than I min by exposure to long-wave ultraviolet light (320 to 380 nm) in the presence of several psoralen derivatives. The psoralen photochemical reaction was chosen for study due to its known specificity for nucleic acids. Neither the light nor any of the drugs alone caused appreciable inactivation. The inactivation kinetics and dependence on light intensity and on different derivatives of psoralen were studied. The high solubility of a new aminomethyl psoralen derivative was found to be advantageous in the photochemical inactivation of the RNA virus, but was not in the case of the more easily inactivated DNA virus. Within its limited solubility range trimethylpsoralen was superior to its aminomethyl derivative on a molar basis for the inactivation of both types of viruses under most of the conditions studied.

Two syngeneic cell lines from human breast tissue: the aneuploid mammary epithelial (Hs578T) and the diploid myoepithelial (Hs578Bst) cell lines

We characterized two human cell lines (Hs578T and Hs578Bst), which provide several unique features that should be useful in the study of breast disease. Hs578T, derived from a carcinosarcoma, is epithelial in origin. Hs578Bst, established from normal tissue peripheral to the tumor, is myoepithelial in origin. This is the first report of companion cell lines, one malignant and one normal, established from the same organ.

Distinction between envelope antigens of murine xenotropic and ecotropic type C viruses by immunoelectron microscopy

The indirect ferritin-labelled antibody technique was used to determine the reactivity of an antiserum prepared against the NZB xenotropic virus with three murine xenotropic viruses, a feline xenotropic virus and a murine ecotropic virus. The envelope antigens of the xenotropic type C viruses isolated from the NZB, NIH Swiss and C57L mice were tagged with ferritin. The feline RD114 virus was not. Gross murine leukaemia virus was tagged, but only at high serum concentrations. The cross-reactivity titre of Gross virus to anti-NZB serum was removed by a serum dilution which was still reactive to xenotropic viruses. This difference in reactivity titres between a xenotropic and an ecotropic virus was sufficient to distinguish one from the other in doubly infected cultures. Specific tagging of membrances of cells infected by xenotropic virus was also observed.

Expression of antigenic crossreactivity to RD114 p 30 protein in a human fibrosarcoma cell line

An antigen crossreacting with the 30,000-molecular-weight protein (p30) of the feline endogenous oncornavirus (RD114) was detected in a well-characterized human fibrosarcoma cell line, HT1080, by indirect immunofluorescence. Three antisera against RD114 p30 gave similar positive results, while two antisera prepared against simian sarcoma virus p30, one antiserum prepared against murine leukemia virus p30, and one antiserum prepared against feline leukemia virus p30 gave no immunofluorescence. The reactivity observed with the antiserum against RD114 p30 was detected in 10-40% of the cells at early passages and was no longer expressed by the forty-first subculture. The reactivity could be removed by adsorption of the antiserum with RD114-infected dog or human cells, but not by uninfected cells or by cells infected with an antigenically unrelated oncornavirus, feline leukemia virus. Neither complete virus particles nor reverse transcriptase (RNA-dependent DNA nucleotidyltransferase) activity was detected in the culture. These experiments suggest that the fibrosarcoma cell line is expressing an antigen related to the p30 protein of RD114 baboon endogenous virus group of oncornaviruses without producing complete virions.

Induction of lymphoma and associated xenotropic type C virus in C57L mice by whole-body irradiation

Adult C57L mice received sublethal whole-body X-irradiation. Between 3 and 11 months later, 5 of the 7 exposed mice developed histopathologically confirmed malignant lymphomas (lymphocytic type) that primarily involved the thymus. The lymphomas were readily transplantable to other C57L mice of any age, which developed fetal lymphomatous involvement; the tumor cells could also be propagated in tissue culture. A xenotropic murine type C virus (MuX) was isolated from the cultured lymphoma cells after cocultivation with a permissive dog line. MuX activity was demonstrated by electron microscopy, complement fixation, indirect fluorescent antibody, infectivity, and genome rescue.

Continuing search for the etiology of cat scratch disease

Fifty cat scratch disease patients were tested for antibodies against candidate etiological agents, with inconclusive results. Future research should emphasize new viral isolation methods to discover the elusive agent.

Viral identification by scanning electron microscopy of preparations stained with fluorescein-labeled antibody

A new technique combines the specificity of fluorescent-antibody labeling and the resolution of the scanning electron microscope to identify and distinguish between viruses. Hemagglutination of chicken erythrocytes by influenza virus was used as a model system to demonstrate the technique.