Clinical Outcomes of Patients With Nontyphoidal Salmonella Infections by Isolate Resistance-Foodborne Diseases Active Surveillance Network, 10 US Sites, 2004-2018

BACKGROUND

Nontyphoidal Salmonella causes an estimated 1.35 million US infections annually. Antimicrobial-resistant strains are a serious public health threat. We examined the association between resistance and the clinical outcomes of hospitalization, length-of-stay ≥3 days, and death.

METHODS

We linked epidemiologic data from the Foodborne Diseases Active Surveillance Network with antimicrobial resistance data from the National Antimicrobial Resistance Monitoring System (NARMS) for nontyphoidal Salmonella infections from 2004 to 2018. We defined any resistance as resistance to ≥1 antimicrobial and clinical resistance as resistance to ampicillin, azithromycin, ceftriaxone, ciprofloxacin, or trimethoprim-sulfamethoxazole (for the subset of isolates tested for all 5 agents). We compared outcomes before and after adjusting for age, state, race/ethnicity, international travel, outbreak association, and isolate serotype and source.

RESULTS

Twenty percent of isolates (1105/5549) had any resistance, and 16% (469/2969) had clinical resistance. Persons whose isolates had any resistance were more likely to be hospitalized (31% vs 28%, P = .01) or have length-of-stay ≥3 days (20% vs 16%, P = .01). Deaths were rare but more common among those with any than no resistance (1.0% vs 0.4%, P = .01). Outcomes for patients whose isolates had clinical resistance did not differ significantly from those with no resistance. After adjustment, any resistance (adjusted odds ratio 1.23, 95% confidence interval 1.04-1.46) remained significantly associated with hospitalization.

CONCLUSIONS

We observed a significant association between nontyphoidal Salmonella infections caused by resistant pathogens and likelihood of hospitalization. Clinical resistance was not associated with poorer outcomes, suggesting that factors other than treatment failure (eg, strain virulence, strain source, host factors) may be important.

Health assets in transgender adolescents: The role of socio-political engagement and competence

Background

Research has shown lower mental health in transgender youth compared to cisgender peers. However, little is known about assets in their development. Self-determination theory posits that certain behaviours increase wellbeing, such as engaging in activities that meet the psychological need for competence and relatedness. This study analyses the mediator roles of political interest, sense of unity, and social self-efficacy in the association between gender identity and health.

Methods

Two samples of Spanish adolescents (15-18 years-old) were analysed. The first sample included 170 transgender and 575 cisgender (selected through a matching process) students who participated in the 2018 Health Behaviour in School-Aged Children study. The second sample included 67 transgender and 2,100 cisgender participants who collaborated in the UNICEF OPINA Barometer. Political interest, social self-efficacy, and sense of unity scales were used to measure community engagement and were considered as sources of resilience. Health-related quality of life (HRQL) was measured using the Kidscreen-10 scale. Data analysis was conducted using linear regressions and parallel mediation effects.

Results

Gender identity predicted well-being, showing lower HRQL in transgender adolescents than cisgender peers. Furthermore, sense of unity and social self-efficacy - but not political interest - significantly predicted wellbeing (higher levels have a positive impact on HRQL) in both groups, and indirectly mediated between gender identity and HRQL.

Conclusions

Sense of unity and social self-efficacy act as sources of resilience, increasing adolescent wellbeing. Thus, social inclusion and active citizenship can help adolescents to better cope with pressure and promote health. Moreover, the positive contributions of sense of unity and social self-efficacy was similar for cisgender and gender minority adolescents, suggesting similar underlying mechanisms.

Antlers - Evolution, development, structure, composition, and biomechanics of an outstanding type of bone

Antlers are bony appendages of deer that undergo periodic regeneration from the top of permanent outgrowths (the pedicles) of the frontal bones. Of the "less familiar" bone types whose study was advocated by John Currey to gain a better understanding of structure-function relationships of mineralized tissues and organs, antlers were of special interest to him. The present review summarizes our current knowledge about the evolution, development, structure, mineralization, and biomechanics of antlers and how their formation is affected by environmental factors like nutrition. Furthermore, the potential role of antlers as a model in bone biology and several fields of biomedicine as well as their use as a monitoring tool in environmental studies are discussed.

A Pilot Study on the Impact of Accelerometer Data Reduction Algorithm Selection and the Potential Implications on Behavior Change Recommendations (OR08-03-19)

Objectives

Physical activity (PA) estimates obtained from recent accelerometer data reduction algorithms have not been compared in women of reproductive-age, a population more likely to engage in unstructured and intermittent PA (such as household cleaning, walking) than men. We investigated whether the accelerometer data from the Crouter, Sasaki and Santos-Lozano algorithms: 1) reported significantly different PA estimates; 2) interacted with weight and age to modify PA estimates; and 3) provided different prevalence of adults meeting PA guidelines.

Methods

At least four days of accelerometer data were collected from 29 women, ages 18 to 38 years, and processed through three algorithms using an Excel model that automatically removed non-wear data and simultaneously calculated PA estimates [i.e., wear minutes, metabolic equivalent minutes (MET-min)]. A combination of mixed-effects linear regression models and bivariate correlation analyses were used to examine associations between accelerometer data with weight, age, and clinical markers of metabolic status across algorithms.

Results

The Crouter algorithm estimated significantly more wear minutes in Moderate intensity compared to the Sasaki and Santos-Lozano algorithms [+384 (SE 33) and+356 (SE 33) minutes, respectively]. There were significant interactions between Crouter estimates of Sedentary/Light and Moderate wear minutes with weight and age (all Pinteraction ≤ 0.001, Santos-Lozano algorithm as the reference). Algorithm selection also provided inconsistent findings in the prevalence of adults meeting PA guidelines.

Conclusions

Recently proposed data reduction algorithms varied in their PA estimates in women of reproductive age. Algorithm selection interacted with weight and age to influence PA estimates and provided inconsistent classification of those who met PA guidelines. Thus, depending on the algorithm selected, behavior change recommendations might differ for each individual due to varying PA estimations. Larger sample sizes are needed to confirm these findings.

Funding Sources

This research is partially supported by the Cornell University Human Ecology Alumni Association. The first author is currently being supported by the National Institutes of Health.

678. Outbreak of Shiga Toxin-Producing Escherichia coli Infections at Marine Corps Recruit Depot (MCRD), San Diego and Camp Pendleton, California: October–November, 2017

Background

Shiga toxin-producing Escherichia coli (STEC) infections are a major cause of foodborne illness and the principal cause of hemolytic-uremic syndrome (HUS). In November 2017, CDC and the US Navy responded to an outbreak of STEC illnesses in military recruits at the Marine Corps Recruit Depot in San Diego (MCRD). We investigated to determine the source of this outbreak and identify prevention and mitigation measures.

Methods

In October 2017, medical staff identified a high number of gastrointestinal (GI) illnesses at MCRD. Recruits with diarrhea submitted stool specimens for culture and/or culture-independent diagnostic testing (CIDT) for GI pathogens. We performed pulsed-field gel electrophoresis (PFGE) on culture isolates. Case-patients were defined as confirmed (PFGE-confirmed STEC infection matching outbreak strains), probable (diagnosis of HUS and/or CIDT evidence of STEC), or suspected (bloody diarrhea). We conducted environmental evaluations of dining facilities, training areas, and barracks. A case–control study was performed using PFGE-confirmed case-patients and platoon-matched controls. We performed product traceback for foods identified as exposure risks by interview or case–control study.

Results

We identified 64 confirmed, 105 probable, and 91 suspected case-patients. Thirty case-patients required hospitalization and 15 had HUS. Ages ranged from 17 to 28 years (median: 18 years). Poor hygiene practices among recruits and inconsistent cooking temperatures within dining facilities were noted. Forty-three case-patients and 135 controls were interviewed about food, hygiene, and environmental exposures. Consumption of undercooked beef was significantly associated with illness (mOR 2.40, CI 1.04–5.72, P = 0.04). We identified a single ground beef supplier for MCRD, but dining facility records did not document the dates on which specific lots of ground beef were used.

Conclusion

Case–control analysis and environmental observations suggested undercooked ground beef as a potential source for this outbreak. We recommended the Navy and Marine Corps retain lot information, address food handling concerns, and improve hygiene among recruits.

Disclosures

All authors: No reported disclosures.

Outbreak of Salmonella Chailey Infections Linked To Precut Coconut Pieces - United States and Canada, 2017

Foodborne salmonellosis causes an estimated 1 million illnesses and 400 deaths annually in the United States (1). In recent years, salmonellosis outbreaks have been caused by foods not typically associated with Salmonella. On May 2, 2017, PulseNet, CDC's national molecular subtyping network for foodborne disease surveillance, identified a cluster of 14 Salmonella Chailey isolates with a rare pulsed-field gel electrophoresis (PFGE) pattern. On May 29, Canadian health officials informed CDC that they were also investigating a cluster of five Salmonella Chailey infections in British Columbia with the same PFGE pattern. Nineteen cases were identified and investigated by CDC, U.S. state health departments, the Public Health Agency of Canada, and the British Columbia Centre for Disease Control. Isolates from all cases were highly related by whole genome sequencing (WGS). Illness onset dates ranged from March 10 to May 7, 2017. Initial interviews revealed that infected persons consumed various fresh foods and shopped at grocery chain A; focused questionnaires identified precut coconut pieces from grocery chain A as a common vehicle. The Canadian Food Inspection Agency (CFIA) and the U.S. Food and Drug Administration (FDA) conducted a traceback investigation that implicated a single lot of frozen, precut coconut as the outbreak source. Grocery chain A voluntarily removed precut coconut pieces from their stores. This action likely limited the size and scope of this outbreak.

Affective Atmospheres of Terror on the Mexico–U.S. Border: Rumors of Violence in Reynosa’s Prostitution Zone

This article examines the effects of rumors within the Mexican and U.S. governments’ militarized war on drugs. Focusing on a period during which Mexican drug organizations were strengthened and violence increased, the article follows the lives of Mexican sex workers and their clients, as well as American missionaries living in a prostitution zone in Reynosa, Tamaulipas. Borders between narco-controlled and state-controlled territory were shifted in and through the bodies of Reynosa’s residents as a contagion of performative rumors came to occupy la zona. As residents told or listened to stories about torture and murder at the hands of narcos, their perceived vulnerability increased and fear came to predominate. In this article I theorize how rumors of violence shaped affective atmospheres of terror and altered spatial practices in a drug-war zone. Feelings of bodily risk first affected vulnerable populations and later spread to people who had previously felt secure in border zones. These narco-stories not only circulated terror but also allowed people to achieve intimacy and maintain social bonds through the shared experience of terror.

The association between sleep quality, low back pain and disability: A prospective study in routine practice

BACKGROUND

The objective of this study was to estimate the association between sleep quality (SQ) and improvements in low back pain (LBP) and disability, among patients treated for LBP in routine practice.

METHODS

This prospective cohort study included 461 subacute and chronic LBP patients treated in 11 specialized centres, 14 primary care centres and eight physical therapy practices across 12 Spanish regions. LBP, leg pain, disability, catastrophizing, depression and SQ were assessed through validated questionnaires upon recruitment and 3 months later. Logistic regression models were developed to assess: (1) the association between the baseline score for SQ and improvements in LBP and disability at 3 months, and (2) the association between improvement in SQ and improvements in LBP and disability during the follow-up period.

RESULTS

Seventy-three per cent of patients were subacute. Median scores at baseline were four points for both pain and disability, as assessed with a visual analog scale and the Roland-Morris Questionnaire, respectively. Regression models showed (OR [95% CI]) that baseline SQ was not associated with improvements in LBP (0.99 [0.94; 1.06]) or in disability (0.99 [0.93; 1.05]), although associations existed between 'improvement in SQ' and 'improvement in LBP' (4.34 [2.21; 8.51]), and 'improvement in SQ' and 'improvement in disability' (4.60 [2.29; 9.27]).

CONCLUSIONS

Improvement in SQ is associated with improvements in LBP and in disability at 3-month follow-up, suggesting that they may reflect or be influenced by common factors. However, baseline SQ does not predict improvements in pain or disability.

SIGNIFICANCE

In clinical practice, sleep quality, low back pain and disability are associated. However, sleep quality at baseline does not predict improvement in pain and disability.

Use of the electrosurgical unit in a carbon dioxide atmosphere

The electrosurgical unit (ESU) utilizes an electrical discharge to cut and coagulate tissue and is often held above the surgical site, causing a spark to form. The voltage at which the spark is created, termed the breakdown voltage, is governed by the surrounding gaseous environment. Surgeons are now utilizing the ESU laparoscopically with carbon dioxide insufflation, potentially altering ESU operating characteristics. This study examines the clinical implications of altering gas composition by measuring the spark gap distance as a marker of breakdown voltage and use of the ESU on a biologic model, both in room air and carbon dioxide. Paschen's Law predicted a 35% decrease in gap distance in carbon dioxide, while testing revealed an average drop of 37-47% as compared to air. However, surgical model testing revealed no perceivable clinical difference. Electrosurgery can be performed in carbon dioxide environments, although surgeons should be aware of potentially altered ESU performance.

Isolated sulfite oxidase deficiency

BACKGROUND

Sulfite oxidase deficiency is an uncommon metabolic disease. Only few cases of its isolated form have been reported in the literature.

CASE PRESENTATION

We report a case of severe neonatal onset. A newborn baby of 41 weeks gestational age, weighted at birth of 3240 grams and had an Apgar score of 6-10-10. Fifty-three hours after being born, the baby started with seizures that were refractory to antiepileptic treatment. Brain function was monitored using a-EEG. Laboratory and imaging tests were performed. All of them were consistent with sulfite oxidase deficiency. The diagnosis was confirmed by genetic testing.

CONCLUSIONS

We highlight the importance of this disease as part of the differential diagnosis of seizures during the neonatal period, as well as the importance of the therapeutic support based on dietary restrictions. It's also remarkable the possibility of prenatal diagnosis by quantifying enzyme activity and it's also possible carrying out DNA mutational analysis.

Accuracy of noninvasive estimated continuous cardiac output (esCCO) compared to thermodilution cardiac output: a pilot study in cardiac patients

OBJECTIVE

To compare the noninvasive estimated continuous cardiac output (esCCO), device-derived cardiac output (CO) to simultaneous pulmonary artery catheter (PAC) thermodilution (TD) CO.

DESIGN

A prospective study comparing pulse wave transit time (estimated continuous cardiac output, esCCO; Nihon Kohden, Tokyo, Japan) to intermittent TD CO.

SETTING

One academic hospital.

PARTICIPANTS

Patients presenting for cardiac surgery.

INTERVENTIONS

Intraoperative CO measurements at 4 distinct time points (after induction, after sternotomy, after cardiopulmonary bypass, and after chest closure).

MEASUREMENTS AND MAIN RESULTS

The study population consisted of American Society of Anesthesiologists (ASA) IV subjects, 27 (77%) males and 8 (23%) females, with a mean age of 64.6 ± 12.2 years. Data points from esCCO and TD were collected simultaneously and means per time point compared using Bland-Altman, Pearson R coefficient, and percent error. Mean TD CO for the study was 5.4 L/min. The Pearson R coefficient, percent error, and bias in L/min were: 0.57, 44%, 0.66 (after induction); 0.54, 51%, 0.88 (after sternotomy); 0.60, 60%, 0.95 (after cardiopulmonary bypass); and 0.57, 60%, 0.75 (after chest closure) respectively.

CONCLUSIONS

esCCO is easy to use and provides continuous CO measurements, but has wide limits of agreement and large percentage errors with a consistently positive bias in comparison to TD.

Labeling studies on cortical bone formation in the antlers of red deer (Cervus elaphus)

The formation and mineralization process of antlers, which constitute the fastest growing bones in vertebrates, is still not fully understood. We used oxytetracycline injections to label different stages of bone formation in antlers of 14 red deer between days 28 and 156 of antler growth. Results show that initially a trabecular scaffold of woven bone is formed which largely replaces a pre-existing scaffold of mineralized cartilage. Lamellar bone is then deposited and from about day 70 onwards, primary osteons fill in the longitudinal tubes lined by the scaffold in a proximal to distal sequence. Mineral apposition rate (MAR) in early stages of primary osteon formation is very high (average 2.15 μm/d). Lower MARs were recorded for later stages of primary osteon formation (1.56 μm/d) and for the smaller secondary osteons (0.89 μm/d). Results suggest a peak in mineral demand around day 100 when the extent of mineralizing surfaces is maximal. A few secondary osteons were formed in a process of antler modeling rather than remodeling, as it occurred simultaneously with formation of primary osteons. The degree of cortical porosity reflects a reduction in MAR during later stages of osteonal growth, whereas cortical thickness is determined earlier. Injections given when the antlers were largely or completely clean from velvet produced no labels in antler bone, strongly suggesting that antlers are dead after velvet shedding. The rapidity of antler mineralization and the short lifespan of antlers make them an extraordinary model to assess the effects of chemicals impairing or promoting bone mineralization.

The effectiveness of intermittent rat parathyroid hormone (1-34) treatment on low bone mass due to oestrogen or androgen depletion in skeletally mature rats

Rat parathyroid hormone (PTH) 1-34 (4 microg/kg/day) was applied for 2.5 months to 9 month-old rats immediately after ovariectomy or orchidectomy or to 15 month-old rats with low bone mass which had been castrated 6 months before in order to know the effects on serum biochemistry parameters, lumbar and femoral bone mineral density, histology, cancellous and cortical bone histomorphometry, mineralisation content profile in cortical bone by backscattered-electron microscopy, and femoral torsion biomechanical testing. In ovariectomised rats, preventive PTH treatment avoided cancellous bone loss in tibial metaphysis and partially in lumbar vertebra, while in cortical bone, PTH increased endosteal resorption and periosteal formation. In intervention study, PTH did not restore cancellous bone but a strong endosteal and periosteal new bone formation was detected. In orchidectomised rats, PTH, in preventive study, avoided cancellous bone loss in metaphysis and lumbar vertebra, and a mild new bone formation in cortical bone was found. In intervention study, PTH maintained baseline cancellous bone mass, but in cortical bone a strong endosteal and periosteal new bone formation was detected. The PTH-induced new bone formation was confirmed by histology and by mineral content profiles. After castration, biomechanical properties were affected in females but not in male rats and PTH reverted this effect.

HER2/neu overexpression/amplification in advanced gastric cancer (AGC) patients (pts): Correlation with clinicopathological parameters

15046

Background: HER2/neu protein is overexpressed in several types of human cancers. Its amplification is associated with poor prognosis and constitutes a predictive factor of response to therapy. In this phase II study, we investigate the correlation between the HER2/neu overexpression/amplification and clinicopathological characteristics of AGC pts. Objective: To prospectively determine the frequency of HER2/neu expression and to evaluate the relationship with clinicopathological characteristics in AGC pts. Methods: HER2/neu expression/amplification has been examined by immunohistochemistry (IHC) and/or fluorescence in situ hybridization (FISH). HER2/neu has been considered overexpressed if: IHC=3; IHC=2 and FISH+ or FISH+. Clinical stage, prior therapies, tumor localization and histological characteristics have been also recorded. Results: Between Feb/2004 and Dec/2006, 181 pts have been tested for HER2/neu status. 132 (73%) males, median age 66 yrs (r-29–83). 24 (13.5%) pts were HER2/neu +. At screening, metastatic disease was the most frequent clinical stage (163, 91.1% vs 16, 8.9% locoregional advanced), being mainly localized in liver (45.3%), lymph nodes (41.4%), peritoneum (28.2%). 88 pts underwent prior surgery, 19 pts received adjuvant irradiation and 24 prior chemotherapy (21 pts adjuvant, 4 neoadjuvant). Primary tumor localization was 140 (79.5%) gastric and 33 (18.8%) gastroesophageal junction (GEJ). HER2/neu overexpression was found in 10.9% of tumors with gastric localization and in 24.2% of GEJ tumors (p=0.084). Adenocarcinoma was the histological type in 98% cases (34.9% diffuse, 43.2% intestinal, 0.6% mucoid, 21.3% unknown subtype). No statistically significant relationship was found between HER2/neu expression and histological subtype (7% type diffuse, 18.1% type intestinal, 13.9% unknown; p=0.186). Conclusions: HER2/neu overexpression/amplification was found in 13.5%. There were no significant correlation of HER2/neu overexpression/amplification with both tumor localization and histological subtype. The study is ongoing.

No significant financial relationships to disclose.

Responses of serum androgen and insulin resistance to metformin and pioglitazone in obese, insulin-resistant women with polycystic ovary syndrome

Severe insulin resistance is a key abnormality in obese women with polycystic ovary syndrome (PCOS). The purpose of this study was to evaluate whether pioglitazone decreases insulin resistance (IR) and hyperandrogenism to the same extent as metformin in obese women with PCOS who have not received any previous treatment. Fifty-two women with PCOS were randomly allocated to receive either pioglitazone (30 mg/d, n = 25) or metformin (850 mg three times daily, n = 27) and were assessed before and after 6 months. Body weight, body mass index, and waist to hip ratio increased significantly (P </= 0.05) after pioglitazone treatment but not after metformin treatment. Fasting serum insulin concentration (P < 0.001 for both drugs) and the area under the insulin curve during a 2-h oral glucose tolerance test decreased after pioglitazone (P < 0.002) or metformin (P < 0.05) treatment. IR (homeostasis model of assessment-IR index) decreased and insulin sensitivity (elevation of the quantitative insulin sensitivity check index and the fasting glucose to insulin ratio) increased (P </= 0.008) after treatment with either drug. Hirsutism (P < 0.05) and serum concentrations of free testosterone (P < 0.02) and androstenedione (P < 0.01) declined to a similar extent after treatment with the drugs. Treatment with pioglitazone or metformin was associated with the occurrence of pregnancy (n = 5 and n = 3, respectively). These results suggest that pioglitazone is as effective as metformin in improving insulin sensitivity and hyperandrogenism, despite an increase in body weight, body mass index, and the waist to hip ratio associated with pioglitazone.

Risk factors in miscarriage: a review

Miscarriage is one of the most frequent problems in human pregnancy. The most widely accepted definition is that proposed by the World Health Organization (WHO) in 1977. The incidence among clinical pregnancies is about 12-15% but including early pregnancy losses it is 17-22%. The only two etiologic factors recognized by all authors are uterine malformations and parental balanced chromosomal rearrangements. There have been many other suggested risk factors. In this revision we discuss these.

Vaccination against Taenia solium cysticercosis in underfed rustic pigs of México: roles of age, genetic background and antibody response

Vaccination of pigs of mixed genetic make-up, raised as rustically as done in rural Mexico, resulted in effective protection to experimental challenge against Taenia solium cysticercosis. Maximum protection was achieved if pigs were immunized at 70 days of age. There was large variation of viable parasite load within vaccinated pigs and controls, which is suggestive of significant genetic factors influencing susceptibility, besides immunization. Our results strengthen the advisability of pig vaccination for control of T. solium cysticercosis, since it lowers the number of viable cysticerci capable of transforming into tapeworms.

[Systematic study of gastrectomy specimens for cancer, in search of synchronous carcinomas]

Multiple carcinomas were searched in 50 successive gastrectomies, 17 females (34%) 33 males (66%) from 40 to 83 years old. Macroscopic handling of the specimens included pinning on a board, fresh, half-fixed and completely fixed examination, not only by naked eye but also through a magnifying glass. The stomach were totally studied, according to Japanese method. A satisfactory slide was obtained from each block, stained with H.E. and examined by each of the authors. Synchronous tumors were found in 4 cases (8%), 3 males and one female. Compared to the main lesion, two cases showed a proximal tumor, one case showed a distal tumor, and the last one showed two tumors, one of them proximal and the other distal. Three tumors were macroscopically and two were microscopically detected. Two of them coexisted with advanced carcinoma and three with early carcinoma. Four of them were located in mucosa with intestinal metaplasia. Histologically, four cases belong to the same type of the original tumor, and one of them did not coincide. We conclude that stomachs resected for cancer must be thoroughly and methodically studied before and after fixation. We suggest that resection must include the whole mucosa with intestinal metaplasia, in order to avoid leaving a synchronous tumor in the gastric stump.

Biologic Relevance of Elevated Red Cell Adenosine Deaminase Activity in Myelodysplastic Syndromes and Paroxysmal Nocturnal Hemoglobinuria

Red cell adenosine deaminase (ADA-RBC) activity in patients with myelodysplastic syndromes and paroxysmal nocturnal hemoglobinuria is significantly increased compared to that observed in normal controls. ADA-RBC activity is not related to fetal hemoglobin concentration, but it is significantly correlated with hemoglobin concentration at diagnosis and with the degree of morphologic dysplasia in the erythroid lineage. The results of our study suggest that the observed enzymatic abnormality may constitute a non-specific manifestation of the stem cell alteration that determines these disorders.

Pitfall in the diagnosis of nuchal cystic hygroma

We present a case of spontaneous resolution of a nuchal cystic hygroma in a fetus with a normal karyotype. This unusual case is important in the counseling of patients with affected fetuses, since the transitory nature of the disease is not well known.

Acquisition of estradiol-mediated regulatory mechanism of steroidogenesis in cultured fetal rat Leydig cells

The inability of the fetal and immature Leydig cell to be desensitized by gonadotropin treatment, a characteristic of the adult cell, is attributed to the absence of an estrogen-mediated regulation of the androgen pathway. Cultures of fetal rat Leydig cells were employed to analyze this differential response. The fetal rat Leydig cells revealed low aromatization capacity, undetectable estradiol production, a low level of estrogen receptors, and a minimally detectable level of an estradiol-regulated protein. However, exogenous estradiol caused up-regulation of its own receptor, increase of an estradiol-regulated protein, and induction of a steroidogenic lesion at the microsomal level, resulting in decreased androgen production. This estrogen-mediated enzymatic inhibition resembles that observed in gonadotropin-desensitized adult Leydig cells. The absence of this regulation in fetal life is likely due to insufficient aromatase activity, with lack of consequent receptor-mediated estrogen action. The cultured fetal Leydig cell provides a useful model to elucidate the molecular mechanism involved in the development of estradiol-mediated desensitization.

Opiate receptors are present in the rat testis. Identification and localization in Sertoli cells

We have characterized opioid binding sites in the Sertoli cells of adult and 18-day-old rat testes. Maximal specific etorphine binding was attained after 30 min at 4 C. The binding was reversible, with association and dissociation rate constants of 0.98 X 10(5) M-1 min-1 and 0.33 min-1, respectively. Scatchard analyses and saturation curves revealed a single class of high-affinity, low-capacity binding sites. No opioid binding was observed in Leydig cell cultures. Exposure to opioids for 3 days caused a significant increase in [3H]etorphine specifically bound to the Sertoli cells that was completely prevented by naloxone, demonstrating opioid up-regulation of its own receptor. Chronic opioid treatment of the cultures significantly inhibited androgen-binding protein production, and this effect was prevented by naloxone. Since the circulating concentrations of endorphins (10(-12) M) are lower than the Kd of testis opiate receptors, it is conceivable that opioids of Leydig cell origin act on the specific high-affinity receptors of the Sertoli cells, and may play a role in modulating their function.

Receptors and inhibitory actions of gonadotropin-releasing hormone in the fetal Leydig cell

The receptors and actions of gonadotropin-releasing hormone (GnRH) were analyzed in cultured testicular cells from 20.5-day fetal rats, in which treatment with luteinizing hormone (LH) maintained Leydig cell steroidogenesis and gonadotropic responses for up to 2 weeks. Testicular GnRH receptors were present on the 5th postnatal day, but were not demonstrable in fetal testes or 2-day cultures thereof. However, GnRH receptors were readily detectable in 4-day cultured fetal testes and were increased by exposure to GnRH agonists. In LH-treated cultures, GnRH sites were reduced by about 50% and did not increase during incubation with GnRH agonists. In such cultures, GnRH agonists inhibited LH-dependent steroid production and abolished the acute testosterone response to human chorionic gonadotropin. The half-maximal inhibitory concentration of [D-Ala6]des-Gly10-GnRH-N-ethylamide (3 X 10(-10)M) was commensurate with its binding affinity for testis receptors (Kd = 1.4 X 10(-10)M). In contrast, GnRH agonists had no inhibitory effects in 2-day cultures prior to the detection of GnRH receptors. The expression of functional GnRH receptors during culture in the absence of gonadotropin and their suppression in LH-treated cultures suggest that pituitary gonadotropins exert a tonic inhibitory effect upon testicular GnRH receptors. The demonstrated inhibitory actions of GnRH on steroidogenesis, with the expression of GnRH receptors in cultured fetal testes and 5-day postnatal testes, indicate that GnRH agonists could influence the actions of gonadotropins upon Leydig cell function in the neonatal testis.

Nail-patella syndrome

Images