Improving access to child abuse evaluations through innovation & telemedicine

Many children and families do not have access to specialized pediatric health care, including child abuse pediatricians. Medical evaluations in cases of suspected child maltreatment including physical abuse, sexual abuse, and neglect are a critical component of the multidisciplinary team response to these concerns. We review the role of child abuse pediatricians in cases of suspected child maltreatment. We discuss the advantages and disadvantages of current models of care including co-location of child abuse specialists within children's advocacy centers, hospital-based medical evaluation programs and community-based clinics. We review barriers to universal and equitable access to specialized care. We then highlight the significance of telemedicine as an important tool for improving access to care for children who would not otherwise have access.

Ingestion of Illicit Substances by Young Children Before and During the COVID-19 Pandemic

Importance

Information about the trend in illicit substance ingestions among young children during the pandemic is limited.

Objectives

To assess immediate and sustained changes in overall illicit substance ingestion rates among children younger than 6 years before and during the COVID-19 pandemic and to examine changes by substance type (amphetamines, benzodiazepines, cannabis, cocaine, ethanol, and opioids) while controlling for differing statewide medicinal and recreational cannabis legalization policies.

Design, Setting, and Participants

Retrospective cross-sectional study using an interrupted time series at 46 tertiary care children's hospitals within the Pediatric Health Information System (PHIS). Participants were children younger than 6 years who presented to a PHIS hospital for an illicit substance(s) ingestion between January 1, 2017, and December 31, 2021. Data were analyzed in February 2023.

Exposure

Absence or presence of the COVID-19 pandemic.

Main Outcome(s) and Measure(s)

The primary outcome was the monthly rate of encounters for illicit substance ingestions among children younger than 6 years defined by International Statistical Classification of Diseases, Tenth Revision, Clinical Modification diagnosis code(s) for poisoning by amphetamines, benzodiazepines, cannabis, cocaine, ethanol, and opioids. The secondary outcomes were the monthly rate of encounters for individual substances.

Results

Among 7659 children presenting with ingestions, the mean (SD) age was 2.2 (1.3) years and 5825 (76.0%) were Medicaid insured/self-pay. There was a 25.6% (95% CI, 13.2%-39.4%) immediate increase in overall ingestions at the onset of the pandemic compared with the prepandemic period, which was attributed to cannabis, opioid, and ethanol ingestions. There was a 1.8% (95% CI, 1.1%-2.4%) sustained monthly relative increase compared with prepandemic trends in overall ingestions which was due to opioids. There was no association between medicinal or recreational cannabis legalization and the rate of cannabis ingestion encounters.

Conclusions and Relevance

In this study of illicit substance ingestions in young children before and during the COVID-19 pandemic, there was an immediate and sustained increase in illicit substance ingestions during the pandemic. Additional studies are needed to contextualize these findings in the setting of pandemic-related stress and to identify interventions to prevent ingestions in face of such stress, such as improved parental mental health and substance treatment services, accessible childcare, and increased substance storage education.

How Should Clinicians and Students Cope With Secondary Trauma When Caring for Children Traumatized by Abuse or Neglect?

When health care professionals encounter child abuse and neglect, they can experience a range of emotions, such as anger, sadness, and frustration. Such feelings can cloud judgment, compromise care, or even undermine one's capacity to complete evaluation of a child. This article discusses key ethical values of honesty, objectivity, compassion, professionalism, respect for persons, and justice, which can be used to guide one's approaches to navigating secondary trauma during and after clinical interactions with children who have suffered abuse or neglect. Strategies for coping with intense feelings, especially during interactions with abused and neglected children's families, are also offered herein.

Recent Trends in Marijuana-Related Hospital Encounters in Young Children

OBJECTIVE

Multiple states have passed legislation permitting marijuana use. The impact of legalization on trends in hospital encounters for marijuana exposures in young children across states remains unknown. We aimed to describe trends in marijuana-related hospital encounters over time in children <6 years and assess the association of state-level marijuana legislation with the rate of marijuana-related hospitalizations.

METHODS

We identified inpatient, emergency department and observation encounters for children <6 years with marijuana exposures (defined by International Classification of Diseases diagnosis codes) unique on the patient-year level at 52 children's hospitals in the Pediatric Health Information System database from 01/01/2004 to 12/31/2018. Trends in encounters across the study period were evaluated using negative binomial regression with outcome of marijuana-related hospital encounters and year as the predictor variable accounting for clustering by hospital. We then estimated a negative binomial regression difference-in-difference model to examine the association between the main outcome and state recreational and medical marijuana legalization.

RESULTS

Of the 1296 included unique patient-year encounters, 50% were female with mean age 2.1 years (standard deviation = 1.4). Fifty percent were inpatient (n = 645) and 15% required intensive care with 4% requiring mechanical ventilation. There was a 13.3-fold increase in exposures in 2018 compared to 2004 (P< .001). We did not find an effect of state legalization status for recreational (P = .24) or medical (P = .30) marijuana.

CONCLUSIONS

The observed dramatic increase in marijuana-related hospital encounters highlights the need for prevention strategies aimed at reducing unintentional marijuana exposures in young children, even in states without legislation permitting marijuana use.

Child Abuse Imaging and Findings in the Time of COVID-19

OBJECTIVE

To assess the impact of the COVID-19 pandemic on physical abuse in young children, we compared the following before and during the pandemic: (1) skeletal survey volume, (2) percent of skeletal surveys revealing clinically unsuspected (occult) fractures, and (3) clinical severity of presentation. We hypothesized that during the pandemic, children with minor abusive injuries would be less likely to present for care, but severely injured children would present at a comparable rate to prepandemic times. We expected that during the pandemic, the volume of skeletal surveys would decrease but the percentage revealing occult fractures would increase and that injury severity would increase.

METHODS

We conducted a retrospective study of children younger than 2 years undergoing skeletal surveys because of concern for physical abuse at a tertiary children's hospital. Subjects were identified by querying a radiology database during the March 15, 2019-October 15, 2019 (pre-COVID-19) period and the March 15, 2020-October 15, 2020 (COVID-19) period, followed by chart review to refine our population and abstract clinical and imaging data.

RESULTS

Pre-COVID-19, 160 skeletal surveys were performed meeting the inclusion criteria, compared with 125 during COVID-19, representing a 22% decrease. No change was observed in identification of occult fractures (6.9% pre-COVID vs 6.4% COVID, P = 0.87). Clinical severity of presentation did not change, and child protective services involvement/referral decreased during COVID.

CONCLUSIONS

Despite a >20% decrease in skeletal survey performance early in the pandemic, the percent of skeletal surveys revealing occult fractures did not increase. Our results suggest that decreases in medical evaluations for abuse did not stem from decreased presentation of less severely injured children.

Evaluation of the abdomen in the setting of suspected child abuse

Abusive intra-abdominal injuries are less common than other types of injuries, such as fractures and bruises, identified in victims of child physical abuse, but they can be deadly. No single abdominal injury is pathognomonic for abuse, but some types and constellations of intra-abdominal injuries are seen more frequently in abused children. Identification of intra-abdominal injuries can be important clinically or forensically. Injuries that do not significantly change clinical management can still elevate a clinician's level of concern for abuse and thereby influence subsequent decisions affecting child protection efforts. Abusive intra-abdominal injuries can be clinically occult, necessitating screening laboratory evaluations to inform decisions regarding imaging. Once detected, consideration of developmental abilities of the child, type and constellation of injuries, and the forces involved in any provided mechanism of trauma are necessary to inform assessments of plausibility of injury mechanisms and level of concern for abuse. Here we describe the clinical, laboratory and imaging evaluation of the abdomen in the setting of suspected child abuse.

Clinical evaluation and management of children with suspected physical abuse

Evaluating and managing children with suspected physical abuse is challenging. Few single injuries are pathognomonic for abuse and, as a result, child abuse is easily missed. As such, a healthy bit of skepticism is needed to recognize and protect abused children. The medical history and clinical presentation should guide evaluation. Medical providers must consider the differential diagnosis, epidemiology of injuries, and child development to inform the assessment. In this review, we address evidence-based recommendations to inform child physical abuse evaluations. We also discuss the role of medical providers in communicating with families, mandated reporting and interpreting medical information for investigative agencies and other non-medical colleagues entrusted with protecting children.

The Impact of Child Sexual Abuse Discovery on Caregivers and Families: A Qualitative Study

In this qualitative study with nonoffending caregivers of suspected child sexual abuse victims, we aimed to explore the perceived impact of sexual abuse discovery on caregivers and their families, and caregivers' attitudes about mental health services for themselves. We conducted semistructured, in-person interviews with 22 nonoffending caregivers of suspected sexual abuse victims <13 years old seen at a child advocacy center in Philadelphia. Interviews were audio-recorded, transcribed, coded, and analyzed using modified grounded theory. Recruitment continued until thematic saturation was reached. We found that caregivers experienced significant emotional and psychological distress, characterized by anger, depressed mood, and guilt, after learning that their child may have been sexually abused. We identified four specific sources of caregiver distress: concerns about their child, negative beliefs about their parenting abilities, family members' actions and behaviors, and memories of their own past maltreatment experiences. Some caregivers described worsening family relationships after discovery of their child's sexual abuse, while others reported increased family cohesion. Finally, we found that most caregivers in this study believed that mental health services for themselves were necessary or beneficial to help them cope with the impact of their child's sexual abuse. These results highlight the need for professionals working with families affected by sexual abuse to assess the emotional and psychological needs of nonoffending caregivers and offer mental health services. Helping caregivers link to mental health services, tailored to their unique needs after sexual abuse discovery, may be an acceptable strategy to improve caregiver and child outcomes after sexual abuse.

Health Care Utilization for Children in Foster Care

OBJECTIVE

To utilize hospital EMR data for children placed in foster care (FC) and a matched control group to compare: 1) health care utilization rates for primary care, subspecialty care, emergency department (ED) visits, and hospitalizations; 2) overall charges per patient-year; and 3) prevalence of complex chronic conditions (CCC) and their effect on utilization.

METHODS

Children ≤18 years old with a designation of FC placement and controls matched on age, race/ethnicity, gender, and zip code who had an encounter at an urban pediatric health system between 7/1/11 and 6/30/12 were identified in the EMR. Data on outpatient, ED, and inpatient encounters and charges for 7/1/12 to 6/30/13 were obtained. A general linear mixed-effects model was applied to estimate means and rates for each group. Analyses were repeated among the subpopulations of children with and without CCCs.

RESULTS

A total of 1156 FC cases were matched to 4062 controls (mean = 3.5 controls/case). FC cases had significantly higher rates (per 100 patient-years) of hospitalizations (18.5 vs 12.7, P = .005), and subspecialty visits (173.3 vs 113.6; P < .001) but not ED (50.4 vs 45.2, P = .056) or primary care visits (154.6 vs 149.8; P = .50). FC cases had higher charges ($14,372 vs $7082; P < .001). Among children with CCCs, health care utilization rates and charges were higher among FC cases (all P < .001). Among children without CCC, rates and charges were similar for FC cases and controls (all P > .20).

CONCLUSIONS

FC children utilized more hospitalizations and subspecialty office visits. The increased utilization rates and charges among children in FC were driven by the subset of children with CCCs.

Moisture, anisotropy, stress state, and strain rate effects on bighorn sheep horn keratin mechanical properties

This paper investigates the effects of moisture, anisotropy, stress state, and strain rate on the mechanical properties of the bighorn sheep (Ovis Canadensis) horn keratin. The horns consist of fibrous keratin tubules extending along the length of the horn and are contained within an amorphous keratin matrix. Samples were tested in the rehydrated (35wt% water) and ambient dry (10wt% water) conditions along the longitudinal and radial directions under tension and compression. Increased moisture content was found to increase ductility and decrease strength, as well as alter the stress state dependent nature of the material. The horn keratin demonstrates a significant strain rate dependence in both tension and compression, and also showed increased energy absorption in the hydrated condition at high strain rates when compared to quasi-static data, with increases of 114% in tension and 192% in compression. Compressive failure occurred by lamellar buckling in the longitudinal orientation followed by shear delamination. Tensile failure in the longitudinal orientation occurred by lamellar delamination combined with tubule pullout and fracture. The structure-property relationships quantified here for bighorn sheep horn keratin can be used to help validate finite element simulations of ram's impacting each other as well as being useful for other analysis regarding horn keratin on other animals.

STATEMENT OF SIGNIFICANCE

The horn of the bighorn sheep is an anisotropic composite composed of keratin that is highly sensitive to moisture content. Keratin is also found in many other animals in the form of hooves, claws, beaks, and feathers. Only one previous study contains high rate experimental data, which was performed in the dry condition and only in compression. Considering the bighorn sheep horns' protective role in high speed impacts along with the moisture and strain rate sensitivity, more high strain rate data is needed to fully characterize and model the material. This study provides high strain rate results demonstrating the effects of moisture, anisotropy, and stress state. As a result, the comprehensive data allows modeling efforts to be greatly improved.

Caregiver perceptions about mental health services after child sexual abuse

The objective of this study was to describe caregiver perceptions about mental health services (MHS) after child sexual abuse (CSA) and to explore factors that affected whether their children linked to services. We conducted semi-structured, in-person interviews with 22 non-offending caregivers of suspected CSA victims<13 years old seen at a child advocacy center in Philadelphia. Purposive sampling was used to recruit caregivers who had (n=12) and had not (n=10) linked their children to MHS. Guided by the Health Belief Model framework, interviews assessed perceptions about: CSA severity, the child's susceptibility for adverse outcomes, the benefits of MHS, and the facilitators and barriers to MHS. Interviews were audio-recorded, transcribed, coded, and analyzed using modified grounded theory. Recruitment ended when thematic saturation was reached. Caregivers expressed strong reactions to CSA and multiple concerns about adverse child outcomes. Most caregivers reported that MHS were generally necessary for children after CSA. Caregivers who had not linked to MHS, however, believed MHS were not necessary for their children, most commonly because they were not exhibiting behavioral symptoms. Caregivers described multiple access barriers to MHS, but caregivers who had not linked reported that they could have overcome these barriers if they believed MHS were necessary for their children. Caregivers who had not linked to services also expressed concerns about MHS being re-traumatizing and stigmatizing. Interventions to increase MHS linkage should focus on improving communication with caregivers about the specific benefits of MHS for their children and proactively addressing caregiver concerns about MHS.

Epidemiology of scabies prevalence in the U.K. from general practice records

BACKGROUND

Scabies is a contagious parasitic infestation which causes an allergic reaction to just a few mites.

OBJECTIVES

To examine the epidemiology of scabies consultations in the U.K. by age, sex, region of the country and time.

METHODS

Data were obtained from the THIN (The Health Information Network) database provided by EPIC U.K. in which each consultation episode is coded according to a 'READ' code. Data were available for 1997-2005 inclusive (9 years) for approximately 8·5% of the U.K. population from 12 regions of the U.K. We used harmonic analysis to model the data over time and derived cycle amplitudes and phases for each region in the U.K.

RESULTS

There was a significantly greater infestation rate among females with a relative risk of 1·24 (P < 0·001) relative to males. The age group 10-19 years had the highest infestation rates (with rates of 4·55 per 1000 and 5·92 per 1000 for males and females, respectively). The middle age groups had the smallest infestation rates. A cycle with length of between 15 and 17 years was derived, and the phase times of the cycles for each region suggested a progression of the disease originating from the North East, spreading to Northern parts of the U.K. and then to the Midlands and the South.

CONCLUSIONS

The study confirms earlier studies with regard to the age/sex distribution of scabies. We suggest a contagious pattern of spread of scabies infestation in the U.K. with an epidemic cycle length of 15-17 years.

Metformin reduces C-reactive protein but not complement factor C3 in overweight patients with Type 2 diabetes mellitus

AIMS

To determine the influence of metformin treatment on plasma C-reactive protein (CRP) and complement factor C3.

METHODS

A double-blind, placebo-controlled trial of metformin in patients with poorly controlled Type 2 diabetes mellitus and body mass index > 25 kg/m2. CRP and C3 were analysed in stored plasma samples by in-house ELISAs. Patients attended two baseline visits before randomization and subsequently attended at 3, 6, 12 and 24 weeks post randomization. All patients gave informed consent according to a protocol approved by the Leeds Teaching Hospitals Research Ethics Committee.

RESULTS

Baseline CRP in the patients randomized to placebo [1.33 (0.79, 2.25) mg/l] and metformin [1.24 (0.89, 1.71) mg/l] were similar (P = 0.8). Baseline CRP correlated with baseline C3 (r = 0.366) and HbA1c (r = 0.327). The difference in ratios of CRP levels at each visit to baseline between placebo- (n = 16) and metformin-treated (n = 26) subjects was significantly different at the 12-week (P = 0.002) and 24-week (P = 0.03) visits. The difference in CRP ratios between the two treatment groups remained significant after accounting for glycaemic control at both visits (P = 0.001 and P = 0.003, respectively). Baseline C3 was correlated with CRP. Baseline C3 was lower in the placebo-treated group [0.97 (0.88, 1.05) mg/ml] compared with the metformin-treated group [1.09 (1.02, 1.17) mg/ml, P = 0.03]. There was no difference in the mean change in C3 at any visit from baseline between placebo- and metformin-treated groups.

CONCLUSION

Metformin may have a specific interaction with mechanisms involved in CRP synthesis or secretion, not directly related to improved insulin sensitivity and dampening of chronic inflammation.

Studies on the synthesis of landomycin A: synthesis and glycosidation reactions of L-rhodinosyl acetate derivatives

An efficient, eight-step synthesis of L-rhodinosyl acetate derivative 3 is described. The synthesis originates from methyl (S)-lactate and involves a highly stereoselective, chelate-controlled addition of allyltributylstannane to the lactaldehyde derivative 7. The beta-anomeric configuration of 3 was established with high selectivity by acetylation of the pyranose precursor with Ac(2)O and Et(3)N in CH(2)Cl(2). Preliminary studies of glycosidation reactions of 3 and L-rhodinosyl acetate 10 containing a 3-O-TES ether revealed that these compounds are highly reactive glycosidating agents and that trialkylsilyl triflates are effective glycosylation promoters. The best conditions for reactions with 15 as the acceptor involved use of diethyl ether as the reaction solvent and 0.2 equiv of TES-OTf at -78 degrees C. However, the TES ether protecting group of 10 proved to be too labile under these reaction conditions, and mixtures of 16a, 17, and 18a are obtained in reactions of 10 and 15. Disaccharide 17 arises via in situ cleavage of the TES ether of disaccharide 16a, while trisaccharide 18a results from a glycosidation of in situ generated 17 (or of 16a itself) with a second equivalent of 10. These problems were largely suppressed by using 3 with a 3-O-TBS ether protecting group as the glycosyl donor and 0.2 equiv of TES-OTf as the reaction promoter. Attempts to selectively glycosylate the C(3)-OH of diol acceptors 20 or 28 gave a 70:30 mixture of 21 and 22 in the reaction of 20 and a 43:27:30 mixture of regioisomeric trisaccharides 29 and 30 and tetrasaccharide 31 from the glycosidation reaction of 28. However, excellent results were obtained in the glycosidation of differentially protected disaccharide 34 using 1.5 equiv of 3 and 0.05 equiv of TBS-OTf in CH(2)Cl(2) at -78 degrees C. The latter step is an important transformation in the recently reported synthesis of the landomycin A hexasaccharide unit.

Fasciola hepatica: surfaces involved in movement of miracidia and cercariae

Rapid freezing and substitution with fixative prior to scanning electron microscopy was used to demonstrate the pattern of beat and recovery of the cilia of free swimming miracidia of Fasciola hepatica. There were stages of dexioplectic metachronal co-ordination and the power stroke was approximately 15 degrees anticlockwise from the anterior-posterior axis. Around the circumference of the body of the miracidia there were approximately 12 metachronal waves of power and recovery. Free-swimming cercariae were recorded by time-lapse photography and, after conventional fixation, by scanning electron microscopy. Cercarial tail-beats were to the posterior of the body in the lateral plane at a rate of 8 Hz. The tail has paired lateral ridges positioned to act as leading edges. There is an array of 32 sensory papillae on the mid-ventral surface of the tail. The tegument of the most distal part of the tail is described: it is free of sensory endings and the surface shows a spiral pattern.

2-Deoxy-2-iodo- and 2-deoxy-2-bromo-alpha-glucopyranosyl trichloroacetimidates: highly reactive and stereoselective donors for the synthesis of 2-deoxy-beta-glycosides

[formula: see text] 2-Deoxy-2-iodo- and 2-deoxy-2-bromoglucopyranosyl trichloroacetimidates 8-10 and 22 are extremely useful precursors of 2-deoxy-beta-glycosides. These reactive glycosyl donors undergo highly stereoselective glycosidation reactions at -78 degrees C with a range of glycosyl acceptors using TBS-OTf as the activating agent. beta-Glycosides are obtained with > or = 19:1 selectivity in six of the seven examples reported herein.

Iodoacetoxylation of glycals using cerium(IV) ammonium nitrate, sodium iodide, and acetic acid: stereoselective synthesis of 2-deoxy-2-iodo-alpha-mannopyranosyl acetates

[formula: see text] The reactions of glycals with ceric(IV) ammonium nitrate and sodium iodide in the presence of acetic acid provides 2-deoxy-2-iodo-alpha-mannopyranosyl acetates with good stereoselectivity. In the majority of the cases examined, the selectivity was considerably better than that from reactions using N-iodosuccinimide and HOAc.

Issues regarding data on race and ethnicity: the Census Bureau experience

In this paper, the authors describe some of the complexities of collecting and presenting data on race and ethnicity based on the experiences of the Bureau of the Census. Different methods of data collection, different content and format of questions, and different definitions make it difficult to collect consistent race and ethnic data across data systems. The Bureau of the Census experiences have shown that changing ethnic self-identity and concepts, intent of the question, consistency of reporting, and the classification of persons of mixed racial parentage affect the quality of the data. These are some of the issues that must be addressed as statistical agencies and researchers seek to provide comparable race and ethnic data.

Retrograde femoral angioplasty: a new technique

Percutaneous transluminal angioplasty cannot be used for lesions of the superficial femoral artery when the origin of the vessel is occluded. A new technique, retrograde femoral angioplasty, is described in which angioplasty is performed from below via the exposed popliteal artery. In four out of six patients retrograde femoral angioplasty was successfully completed, and three of the four vessels remain patent up to 1 year later. The method provides an alternative to the femoropopliteal bypass graft in some patients.

Small bowel function after aortic surgery

One cause of post-operative morbidity in the elective repair of abdominal aortic aneurysms is the development of a paralytic or 'adynamic' ileus. In a series of 20 consecutive patients undergoing such a procedure, the maintenance of small bowel motility and absorptive capacity in the immediate post-operative period was assessed using barium sulphate and xylose passed down a naso-duodenal tube sited at the time of surgery. This simple study demonstrated that small bowel function was preserved in all cases, and hence that patients could be fed enterally via naso-duodenal tube (in particular using very low residue formulae) rather than using costly parenteral regimens, should an ileus persist.

Light reflection rheography: an effective non-invasive technique for screening patients with suspected deep venous thrombosis

Light reflection rheography is a simple non-invasive technique for assessing venous function in the leg. One hundred and twenty-four patients referred for venography with a clinically suspected deep venous thrombosis were investigated by light reflection rheography to determine the accuracy of the technique in diagnosing acute thrombosis. In half of the patients venography confirmed a deep venous thrombosis. Light reflection rheography had a sensitivity of 92 per cent and a specificity of 84 per cent in detecting acute thrombosis. The technique had a negative predictive value of 92 per cent in selecting those patients with no thrombosis. Light reflection rheography can be performed at the bedside or in the radiography department which makes it a suitable technique for screening patients with suspected deep venous thrombosis.

Bile leaks after simple cholecystectomy

Drains after cholecystectomy are used commonly to avoid biliary leaks and subsequent peritonitis. Thirty-five patients who had had cholecystectomy without drainage underwent 99mTc-labelled dimethylphenylcarbamoylmethyliminodiacetic acid (HIDA) and ultrasound scans the morning after surgery. Biliary leaks detected by positive HIDA scans occurred in 11 patients. Subhepatic fluid collections were seen on 20 ultrasound scans. There was no relation between biliary leaks and subhepatic collections. Many of the collections were not seen on the HIDA scan, suggesting that they contained blood and not bile. Many of the patients with bile leaks showed no fluid collection. Clinical complications were few and evenly distributed between those with positive and negative scans. We conclude that bile leaks are not an occasional event but occur after 31 per cent of undrained cholecystectomies and that these bile leaks remain clinically unimportant.

Immunity during pregnancy: lymphocyte subpopulations and mitogen responsiveness

Many hypotheses have been proposed to explain the alteration of maternal immune status that allows the fetus to escape rejection. Published data using monoclonal antibodies have stated that there are small variable reductions in circulating T-lymphocytes and little or no change in helper-to-suppressor ratios. Specific decreased levels of helper T-cells have been claimed by other workers. Our laboratory has previously reported alterations in tritiated thymidine uptake (3H-TdR) and HLA antibodies during pregnancy. The present study evaluates total T-cells, lymphocyte T-cell subsets, helper-to-suppressor ratios of T-cells, B-cells, and lymphocyte blast transformation (LBT) throughout pregnancy. These lymphocyte measurements were compared to hormonal changes occurring during pregnancy to determine whether or not hormonal levels have a significant correlation on the maternal immune response during gestation. Data from 100 women revealed no significant alteration of total T-cells or T-cell subsets during pregnancy or after parturition, as measured by monoclonal antibodies. Helper-to-suppressor ratios were within normal limits. B-cells showed a significant decrease (P less than 0.001) during the postpartum period. There was decreased lymphocyte responsiveness to mitogenic stimulation by phytohemagglutinin-P (PHA-P), concanavalin-A (CON-A), and pokeweed mitogen (PWM) in the first, second and third trimesters (P less than 0.01). The mechanisms of fetal protection from maternal immune recognition remain obscure.

Effects of ethyl alcohol on human peripheral lymphocytes

Chronic alcoholics are more susceptible to infection and have increased incidences of certain types of carcinomas. One explanation for this may be suppressed immune responses secondary to ethyl alcohol consumption. This project was initiated to study the effect of ethyl alcohol on lymphocyte responses in vitro by monitoring tritiated thymidine uptake. Lymphocytes were incubated in the presence of phytohemagglutinin-P, concanavalin A, and pokeweed mitogen. The response of normal lymphocytes was noted after mitogen stimulation in the presence of ethyl alcohol in graded doses. Ethyl alcohol levels greater than or equal to 50 mg/dL suppressed tritiated thymidine uptake of normal lymphocytes for phytohemagglutinin-P and concanavalin A. Since ethyl alcohol exposure in concentrations consistent with blood levels that may be attained during routine ingestion significantly decreased lymphocyte blastogenesis, it is speculated that chronic ethyl alcohol ingestion may alter immune surveillance sufficiently to be responsible in part for the increased incidence of infection and/or neoplasms seen in alcoholic subjects.

Antitumor effects of abrin and ricin used singly and in combination with cisplatin

Abrin, ricin, and cisplatin produced significant increases in survival times of mice inoculated with 10(6) Ehrlich ascites carcinoma or L1210 leukemia cells 24 hours prior to treatment. Combinations of abrin or ricin with cisplatin produced markedly synergistic action in prolonging survival times of mice bearing cell line A of L1210 leukemia. For example, a dosage of 1.33 micrograms per kg abrin produced a 40 percent increased length of survival (ILS) and 2.5 mg per kg of cisplatin produced a 45 percent ILS while a combination of the two agents resulted in a 229 percent ILS and produced 60-day survivors or "cures" in 20 percent of the mice treated. Similar combinations of abrin or ricin with cisplatin also produced significant additive or synergistic increases in survival times of mice bearing cell line B of L1210 leukemia or Ehrlich ascites carcinoma. Aged solutions of abrin and ricin appeared to be less toxic, but have similar antitumor effect alone or in combination with cisplatin, than freshly prepared solutions.

Alterations of lymphocyte responsiveness in Guillain-Barré syndrome. Effects of plasma exchange

Various antibodies and immune complexes have been demonstrated in patients with Guillain-Barré syndrome (GBS). These factors may be part of the pathogenesis of the disease process through immune complex deposition and/or suppression of the immune system. Four patients with typical GBS were treated by plasma exchange. Aliquots from the first 100 ml of plasma removed from each patient were incubated with cultures of normal human peripheral lymphocytes that subsequently were exposed to mitogens, followed by incubation with tritiated thymidine. A decrease (p less than 0.001) in response to each of the mitogens was noted after incubation with patient plasma. Peripheral lymphocytes were taken from the patients before and after plasma exchange. An increase (p less than 0.01) in DNA synthesis following mitogen exposure was observed after plasma exchange in each patient. All patients exhibited subjective and objective clinical improvement. Plasma exchange for GBS appeared to remove a lymphocyte suppressor factor, which was characterized by column fractionation. The suppressor factor was determined to be a substance of approximately 10,000 to 12,000 daltons that reproducibly decreased the responsiveness of normal lymphocytes to mitogens.

Demonstration of juvenile-specific antigens of Fasciola hepatica

A hyperimmune serum was raised in rabbits against soluble antigens of Fasciola hepatica metacercariae. This was subsequently absorbed with antigens from adult flukes and examined by immunoelectrophoresis (IEP) and by an indirect fluorescent antibody test (IFAT). When the absorbed antiserum was tested with F. hepatica metacercarial homogenate and adult homogenates by IEP, three distinct arcs appeared against the metacercarial homogenate and none against the adult homogenate. When tested by IFAT against a developmental series of flukes obtained from mice, the absorbed antiserum was positive on surfaces of whole flukes up to 4 days postinfection (PI) and on the tegument of sectioned flukes up to 7 days PI. Thus juvenile-specific antigens were demonstrated in the tegument of young (up to 7 days in mice) F. hepatica.

Studies on the toxicity and binding kinetics of abrin in normal and Epstein-Barr virus-transformed lymphocyte culture-I. Experimental results - 4

The effects of treatment with varying doses of abrin, a D-galactose binding lectin, on DNA and protein synthesis of normal and Epstein-Barr virus (EBV)-transformed lymphocytes have been previously investigated. Using data on EBV-transformed lymphocyte cell density as a function of both time and dose of abrin, the authors introduced the concept of self- and cross-coupling metabolic variables as a means of understanding how abrin affected DNA and protein uptake. In this paper, the self-coupling constant is studied in more detail and the relationship between DNA and protein synthesis is further expanded. We find that there is a significant linear relationship between DNA and protein synthesis in normal lymphocyte culture as measured by abrin interaction in the culture. We further find that there is a much stronger relationship between these variables in EBV-transformed lymphocyte culture. This relationship is further examined, and possible analytic equations are expressed.

DNA and protein synthesis in normal and transformed lymphocytes exposed to abrin

The dose dependent effects of abrin, a toxic D-galactose binding plant lectin, on 3H-TdR and 14C-leucine uptake are studied in normal and Epstein Barr Virus (EBV) transformed lymphocyte cultures. Results show that while abrin is highly toxic to both the DNA and protein synthesis in EBV lymphocytes, some toxicity to the normal cells is also seen. It is postulated that lymphocyte DNA synthesis is affected by ribosomal shutdown induced by the abrin.

Studies on the toxicity and binding kinetics of abrin in normal and Epstein Barr virus-transformed lymphocyte culture-I: experimental results - 3

The effects of treatment with varying doses of abrin, a D-galactose binding lectin, on DNA and protein synthesis of normal and Epstein Barr virus-transformed lymphocytes have been investigated. Using data on EBV-transformed lymphocyte cell density as a function of time and dose of abrin, one can demonstrate that the mean number of sites bound/EBV-lymphocyte needed to exert a biological influence upon the cell DNA synthesis lies between 59,264 and 370,000 sites/cell. Using a simple packing model, one can demonstrate that a theoretical estimate places the number of binding sites between 57,600 and 360,000 sites/cells.

Effects of insulin on phytohemagglutinin-P, concanavalin-A, and pokeweed mitogen in diabetic and nondiabetic lymphocytes

Blast transformation of lymphocytes from diabetics and nondiabetics was evaluated after adding insulin at various concentrations. Responses to phytohemagglutinin-P (PHA-P), concanavalin-A (CON-A) and pokeweed mitogen (PWM) were measured in the presence of exogenous insulin added in physiologic increments of 0, 10, 20, 30, and 40 microunits of activity per ml of culture medium. A modified method utilizing heparinized whole blood was used. After a four day incubation period, 3H-TdR uptake was evaluated and used as the index of stimulation. A standard pooled z test for comparison of 3H-TdR uptake showed a decrease in blast transformation of diabetic lymphocytes compared to nondiabetic lymphocytes to the mitogens PHA-P (p less than 0.01), CON-A (p less than 0.01), and PWM (p less than 0.01). Added insulin increased the diabetic lymphocyte blast transformation response to each of the mitogens. Blast transformation in diabetics never reached the leve of blast transformation in nondiabetics. It is hypothesized that there is a cellular defect in either membrane receptors or intracellular metabolic pathways which accounts for the decrease in diabetic lymphocyte blast transformation.

On the dynamics of abrin binding to receptor sites in normal and Epstein Barr Virus transformed lymphocyte cell cultures

The effects of treatment with varying doses of abrin, a D-galactose binding lectin, on DNA an protein synthesis of normal and Epstein Barr Virus transformed lymphocytes has been investigated. Activation, stimulation, and relative toxicity factor indices are studied, as well as possible relationships between DNA and protein synthesis rates, as measured by simultaneous tritiated thymidine (3H-TdR) and 14C-leucine uptake. Studies of the two new indices, the metabolic self and cross coupling indices lead to the prediction that there are three morphologically distinct subpopulations of EBV-transformed lymphocytes with different abrin receptor site concentrations. This prediction is supported by SEM morphological differences. Using data on EBV-transformed lymphocyte cell density as a function of time and dose of abrin, one can demonstrate that the mean number of receptors bound-EBV-lymphocyte needed to exert a biological influence lies in the interval 59,264 receptors/cell to 370.040 receptors/cell. Using a simple packing model, one can demonstrate that a theoretical estimate places the number of binding sites between 57,600 receptors/cell and 360,000 receptors/cell.

Studies on toxicity and binding kinetics of abrin in normal and Epstein Barr virus-transformed lymphocyte culture-I: experimental results - 2

The effects of treatment with varying doses of abrin, a D-galactose binding lectin, on DNA and protein synthesis of normal and Epstein Barr virus-transformed lymphocytes have been investigated. Studies of activation and stimulation indices, as well as two new indices; the metabolic self and cross-coupling indices, lead to the prediction that there are three morphologically distinct subpopulations of EBV-transformed lymphocytes with different abrin binding site numbers. This conclusion is supported by SEM morphological differences.

Studies on the toxicity and binding kinetics of abrin in normal and Epstein Barr virus-transformed lymphocyte culture-I: experimental results - 1

The effects of treatment with varying doses of abrin, a D-galactose binding lectin, on DNA and protein synthesis of normal and Epstein Barr virus-transformed lymphocytes have been investigated. Activation, stimulation and relative toxicity factor indices are studied as well as possible relationships between the DNA and protein synthesis rates, as measured by simultaneous 3H-TdR and 14C-leucine uptake.

B and T lymphocytes: quantitation, function, and clinical applicability

Methodologies for T and B lymphocyte quantitation, lymphocyte blast transformation (LBT) and carbohydrate (CHO) metabolism are important for assessing host lymphocyte response in the clinical laboratory. Modifications of methods for each of these techniques are presented. Results from studies of normal ambulatory adults, patients with diabetes mellitus, sickle cell disease and hyperlipidemia are reported. LBT of normal lymphocytes before and after ethanol exposure are examined. LBT during pregnancy is evaluated. T cell populations are abnormally high in black diabetics and decreased in patients with sickle cell anemia. B cell subpopulations are increased in patients with sickle cell anemia. LBT responses are decreased in maturity onset diabetes, during pregnancy and in patients with sickle cell disease. Ethanol in amounts attainable during human consumption results in significantly decreased LBT response. CHO metabolism (especially hexose monophosphate shunt [HMPS] and HMPS by pentose sugar recycling) is abnormal in diabetic lymphocytes. The low HMPS activity is partially reversible by treatment with prostaglandin synthetase inhibitors. Information related to lymphocytes in normal states remains to be collected by further clinical application of these techniques of quantitation and in vitro function.

Biofeedback-regulated asymmetries in facial skin temperature

Although 5 of 7 subjects regulated asymmetries in skin temperature, differences between right and left temperatures were small. No relationship between hemisphere-specialized cognitions and asymmetries in facial skin temperature was demonstrated.

Lymphocyte blast transformation and peripheral lymphocyte percentages in patients with sickle cell disease

Twenty patients with sickle cell disease (14 black females and 6 black males, mean age 31.5 +/- 9.3) were studied by quantitating peripheral T and B lymphocyte percentages and measuring lymphocyte blast transformation (LBT) in response to phytohemagglutinin-P, concanavalin-A and pokeweed mitogen. Compared to normal black controls (19 black females and 1 black male, mean age 32.0 +/- 9.2 years) sickle cell patients had decreased T lymphocytes (50.2 percent +/- 6.2 compare; to 66.2 percent +/- 1.7) and increased B lymphocytes (17.0 percent +/- 3.4 compared to 7.7 percent +/- 1.1). Sickle patients exhibited decreased LBT to all three mitogens.

Trace metal levels in commercially prepared tissue culture media

Four trace elements, lead, copper, tin and zinc, in addition to certain electrolytes, were measured in 11 commercially prepared tissue culture media. Glass media bottles and plastic tissue culture dishes and flasks were treated with a HCl acid solution to determine the amounts of trace metals leached from their surfaces. Zinc, lead and copper were detected in all media. Tin was detected only in RPMI Medium 1640, fetal bovine serum, minimum essential medium and penicillin-streptomycin. It is possible that a major cause of variability in tissue culture experimental results may be due to effects on growth caused by fluctuation in trace element contamination from batch to batch. Variability in establishing primary cultures of corneal endothelial cells was traced to high lead levels in commercially prepared tissue culture media. A strong case is made for continued diligent efforts to expand analytical horizons and our definition of substances in culture media.

Corneal endothelium: a modified method for cultivation

A modified method for establishing cultures of rabbit corneal cells is described. The new technique utilized a Lucite disc in combination with a Tygon ring for growth of pure cell cultures and was compared with an explant method for growing cells. Each method provided adequate cell cultures for biochemical or ultrastructure studies of rabbit corneal cells, but the ring and disc method described here allowed the isolation of specific cell types without the interference of stromal cell contamination.

Redundant nutritive tubes in insect ovarioles: the fate of an extensive microtubule transport system

The developing oocytes in the ovarioles of hemipteran insects receive materials from nutritive cells by way of channels known as nutritive tubes. The tubes contain an extensive system of microtubules which are thought to be involved in the transport between the two cell types. At the onset of vitellogenesis the connection is discontinued. Redundant nutritive tubes have been identified, compared with functional tubes, and their fate discussed.

Relationship between virus neutralization and serum protection bioassays for IgG and IgM antibodies to foot-and-mouth disease virus

The time interval between administering the serum and the virus was found to influence the results of the in vivo mouse protection test for foot-and-mouth disease antibodies. In particular, for both IgG and IgM antibodies to strain A12 virus, the mouse protection index increased from zero to a maximum at about 6 h and remained high for at least five days. Variations in the antiserum concentration, on a log scale, had a proportional effect on the mouse protection index, if between 1 and 3. The constant of proportionality was unity for IgM and 2 for IgG antibody. Comparison with in vitro neutralization tests revealed essentially parallel neutralization curves. The lower serum titre in the protection test, if computed for less than 10(3) LD50/dose, was accounted for by the simple dilution of the inoculated serum into the volume of the mouse. Consequently, in the low titre range, the same virus-antibody reaction and its effect are operable in each of the two tests. Analysis of literature data in which both the in vivo protection test and the in vitro neutralization test results were available on the same sera showed consistency with the above conclusions for both cattle and swine sera. The protection test had a highly atypical survival pattern occurring at antibody concentrations expected to neutralize more than 10(3) LD50/dose. The resulting in vivo dampening effect on virus titre is postulated to be caused by the excess antibody of the passive immunity test interfering with the spread of infection. The effect is analogous to an anomaly caused by not removing the inoculum in quantal tissue culture assays and it prevents quantification of antibody levels in strong sera.

Cryopreservation of human lymphocytes: a brief review and evaluation of an automated liquid nitrogen freezer

Successful cryopreservation of human lymphocytes has been previously described. Cryopreserved lymphocytes are useful for a variety of in vitro immunologic studies. This study was performed to determine the applicability and/or advantages of using a programmable freezing system, and compares glycerol versus dimethyl sulfoxide (DMSO) at varying concentrations on post-thaw viability, E-rosetting and immunoglobulin fluorescence. Prefreeze T and B lymphocyte percentages were determined. Cells were then frozen in varying concentrations of glycerol and DMSO. Optimum cryoprotectant type and concentration was determined. Lymphocytes from seven individuals were frozen by the batch method in a mechanical freezer and with the automated liquid nitrogen injection system. Data on post-thaw T and B percentages and viability revealed 10% DMSO and liquid nitrogen control freezing method at 1 C/minute as the best conditions for lymphocyte preservation as reflected by post-thaw in vitro testing.

The identification of soluble adult antigen on the tegumental surface of juvenile Fasciola hepatica

An antiserum was raised in rabbits against a soluble extract of fresh homogenized adult Fasciola hepatica of rat origin and was then absorbed with rat and mouse tissue antigens. This antiserum reacted specifically with the surface coat of adult flukes, of both rat and mouse origin, by indirect immunofluorescence to show the detail of surface spines. When tested against juvenile stages recovered from mice the reaction was positive with all but the earliest hepatic parenchyma stages. No reaction was present on the tegumental surface of newly excysted juveniles or stages 1 or 2 days post-infection (p.i.) whether recovered from the peritoneal cavity or the hepatic parenchyma.