RESUMO
OBJECTIVES: Combination antiretroviral therapy has largely restored the lifespan of persons living with HIV. Data suggest early comorbidities of aging in this population. Past studies focused on men; limited data exist regarding the prevalence of dyslipidaemia in women living with HIV (WLWH). We investigated the prevalence of cardiometabolic abnormalities among WLWH and HIV-negative women in the Children and Women: Antiretrovirals and Markers of Aging (CARMA) cohort, and their relationships to cellular aging markers. METHODS: We conducted a cross-sectional analysis of nonpregnant female patients (156 WLWH and 133 HIV-negative controls, aged 12-69 years) enrolled in CARMA between 2013 and 2017. The Framingham risk score (FRS) and the prevalences of hypertension, diabetes, metabolic syndrome and dyslipideamia were determined using self-report, anthropometrics, chart review and laboratory data. Cellular aging was determined by assessing leukocyte telomere length and blood mitochondrial DNA content. Diagnoses were based on current Canadian guidelines and definitions. RESULTS: HIV-infected status was associated with dyslipidaemia [odds ratio (OR) 2.89; 95% confidence interval (CI) 1.69-5.01], but not diabetes, higher FRS, hypertension or metabolic syndrome. The median age was 43.5 [interquartile range (IQR) 36.8-50.9] years in WLWH and 46.2 (IQR 30.3-54.9) years in HIV-negative controls. WLWH were less likely to be menopausal or use alcohol, and more often had hepatitis C virus infection or a current or past smoking history. Lower mitochondrial DNA content was associated with metabolic syndrome; no other associations were noted between cardiometabolic abnormalities and markers of cellular aging. CONCLUSIONS: Despite their relatively young age, almost two-thirds of WLWH had dyslipidaemia, a significantly greater proportion than in controls. Strategies to address dyslipidaemia and decrease smoking rates may improve long-term outcomes among WLWH.
Assuntos
Antirretrovirais/uso terapêutico , Dislipidemias/epidemiologia , Infecções por HIV/tratamento farmacológico , Adolescente , Adulto , Idoso , Canadá/epidemiologia , Estudos de Casos e Controles , Estudos Transversais , Feminino , Humanos , Pessoa de Meia-Idade , Guias de Prática Clínica como Assunto , Prevalência , Fatores de Risco , Homeostase do Telômero , Adulto JovemRESUMO
We develop a simple model that can explain the current-voltage ( J- V) curves of excitonic photovoltaic solar cells, spanning polymer:polymer, polymer:fullerene, and polymer:nanocrystal devices. We show that by subtracting out the dark current, we can explain apparent intensity-dependent characteristics and thus identify geminate recombination as the dominant loss mechanism and establish its electric field dependence. We present an analytic fit to the J- V curves of all measured devices based on a single fitted parameter, the electric field required to split 50% of geminate charge pairs, which we term the critical field. Devices of different material combinations and morphologies can all be described by this method and yield critical fields varying between >1 x 10(8) V/m for blends of poly(9,9'-dioctylfluorene- co-bis- N, N'-(4-butylphenyl)-bis- N, N'-phenyl-1,4-phenylenediamine) (PFB) and poly(9,9'-dioctylfluorene- co-benzothiadiazole) (F8BT) and 8 x 10 (5) V/m for slow-grown blends of poly(3-hexylthiophene-2,5-diyl) (P3HT) and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM). A comparison with material properties reveals that the primary route to improved photovoltaic materials is enhanced charge delocalization.
Assuntos
Fontes de Energia Elétrica , Eletroquímica/instrumentação , Fulerenos/química , Modelos Teóricos , Fotoquímica/instrumentação , Simulação por Computador , Condutividade Elétrica , Eletroquímica/métodos , Desenho de Equipamento , Análise de Falha de Equipamento , Fulerenos/efeitos da radiação , Luz , Fotoquímica/métodos , Polímeros/química , Polímeros/efeitos da radiação , Doses de RadiaçãoRESUMO
CASE REPORT: A patient with extensive burns was intubated with an 8.0 mm internal diameter endotracheal tube (ETT) equipped with a subglottic suction port (Mallinckrodt HiLo Evac). The ETT was secured to a left upper molar with wire sutures throughout the hospitalization course to ensure airway stability. On the 40th day of intubation, the patient exsanguinated and died from a tracheo-innominate artery fistula. Postmortem examination revealed a 1 cm lesion of the left anterior tracheal wall at the position of the ETT tip. The prolonged stationary position of the ETT was considered the primary factor responsible for the fistula. Yet tracheo-innominate artery fistula normally is associated with high cuff pressures rather than with the tube tip. The special ETT construction required for the subglottic suction feature was suspected to have increased tube rigidity and may have played a contributory role. METHODS: The rigidity of the Mallinckrodt HiLo Evac was measured with a mechanical model and compared to 5 other commercially-available ETTs. Rigidity was expressed as the force generated by the ETT tip when the tube curvature was altered by 5 cm and 10 cm of flexion from its resting position. RESULTS: The mean force exerted by the Mallinckrodt HiLo Evac was 10.1 +/- 2.8 g at 5 cm of flexion and 17.7 +/- 5.1 g at 10 cm of flexion. This was significantly greater than all other ETT brands tested (by one-way analysis of variance and Student-Newman-Kuels test, p < 0.05). CONCLUSION: This case of fatal tracheo-innominate artery fistula formation associated with an ETT tip was unusual because of the extended duration of endotracheal intubation and the complexity of the patient's airway management problems. Our data suggest that the higher rigidity of the HiLo Evac ETT may have contributed to fistula development at the tube tip. However, we do not believe that the higher rigidity of the HiLo Evac ETT necessarily poses any greater risk than other ETTs under normal circumstances, in which the tube tip is not fixed in a stationary position for an extended period.
Assuntos
Tronco Braquiocefálico/lesões , Fístula/etiologia , Intubação Intratraqueal/efeitos adversos , Traqueia/lesões , Adulto , Queimaduras/terapia , Evolução Fatal , Humanos , MasculinoRESUMO
BACKGROUND: Patient work of breathing (WOB) during assisted ventilation is reduced when inspiratory flow (V(I)) from the ventilator exceeds patient flow demand. Patients in acute respiratory failure often have unstable breathing patterns and their requirements for V(I) may change from breath to breath. Volume control ventilation (VCV) traditionally incorporates a pre-set ventilator V(I) that remains constant even under conditions of changing patient flow demand. In contrast, pressure control ventilation (PCV) incorporates a variable decelerating flow wave form with a high ventilator V(I) as inspiration commences. We compared the effects of flow patterns on assisted WOB during VCV and PCV. METHODS: WOB was measured with a BICORE CP-100 monitor (incorporating a Campbell Diagram) in a prospective, randomized cross-over study of 18 mechanically ventilated adult patients with acute lung injury (ALI) or acute respiratory distress syndrome (ARDS). Tidal volume, inspiratory time, and mean ventilator V(I) were constant in each mode. RESULTS: At comparable levels of respiratory drive and minute ventilation, patient WOB was significantly lower with PCV than with VCV (0.59 +/- 0.42 J/L vs 0.70 +/- 0.58 J/L, respectively, p < 0.05). Ventilator peak V(I) was significantly higher with PCV than with VCV (103.2 +/- 22.8 L/min vs 43.8 L/min, respectively, p < 0.01). CONCLUSIONS: In the setting of ALI and ARDS, PCV significantly reduced patient WOB relative to VCV. The decrease in patient WOB was attributed to the higher ventilator peak V(I) of PCV.
Assuntos
Respiração Artificial/métodos , Síndrome do Desconforto Respiratório/fisiopatologia , Síndrome do Desconforto Respiratório/terapia , Trabalho Respiratório , Adulto , Idoso , Estudos Cross-Over , Esôfago/fisiopatologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Ensaios Clínicos Controlados Aleatórios como Assunto , Síndrome do Desconforto Respiratório/etiologiaRESUMO
OBJECTIVES: First, to determine whether the severity of shock, as measured by systemic hypotension and metabolic acidosis, is significantly associated with a higher risk of acute lung injury in patients with severe trauma. Second, to determine whether the volumes of blood and crystalloid solutions administered in the early posttrauma period are independent risk factors for acute lung injury in severely traumatized patients. DESIGN: Prospective observational study. SETTING: Level I urban trauma center in a university hospital. PATIENTS: A total of 102 severely injured, mechanically ventilated trauma patients with an Injury Severity Score > or =16 and aged between 18 and 75 yrs. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Initial clinical and laboratory data were collected in the emergency department, and on a daily basis thereafter during the patient's intensive care unit stay. Of the 102 severely injured patients enrolled, 42 developed acute lung injury (41%) and 60 did not (59%). A total of 93% of the trauma patients who developed acute lung injury during the 17-month study period were included in the study. Initial base deficit was significantly lower in patients who developed acute lung injury than in those who did not (-8.8+/-4.5 vs. -5.6+/-5.1, p<.01). The difference in systolic blood pressure between the two groups was not significant. CONCLUSIONS: In this group of severely injured trauma patients, the degree of metabolic acidosis at the time of admission identified those patients with the highest probability of developing acute lung injury. In addition, the volume of crystalloid solution administered during the first 24 hrs was significantly greater in patients who later developed acute lung injury. Finally, there was a significantly higher morbidity in patients who developed acute lung injury, whereas mortality did not differ between the two groups.
Assuntos
Acidose/complicações , Escala de Gravidade do Ferimento , Traumatismo Múltiplo/complicações , Síndrome do Desconforto Respiratório/etiologia , Choque Traumático/complicações , APACHE , Adolescente , Adulto , Idoso , Feminino , Humanos , Hipotensão/complicações , Unidades de Terapia Intensiva , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Substitutos do Plasma/efeitos adversos , Valor Preditivo dos Testes , Estudos Prospectivos , Fatores de Risco , Choque Traumático/patologia , Reação TransfusionalRESUMO
The victim-blaming tendency toward people with AIDS was examined in relation to gender, fraternity-sorority affiliation, classification (freshmen vs. others), religion (Catholic vs. others), and academic major (business college vs. others) in a survey of 818 students at a midwestern state university in the United States. Desired social distance from gay men and lesbians, the intervening variable in these relations, significantly mediated the indirect effect of fraternity-sorority affiliation, classification, and gender on the victim-blaming tendency. Gender and desired social distance were found to be significant direct determinants of the victim-blaming tendency toward people with AIDS. The study suggests that attitudes toward gay men and lesbians must change if attitudes toward people with AIDS are to change.
Assuntos
Síndrome da Imunodeficiência Adquirida , Vítimas de Crime , Estudantes/psicologia , Adulto , Feminino , Humanos , Masculino , UniversidadesRESUMO
The effect of moderate left atrial (LA) hypertension on alveolar liquid clearance (ALC) was investigated in anesthetized, ventilated sheep, surgically prepared to measure lung lymph flow as well as hemodynamics. To simulate alveolar edema, 3-4 ml/kg of isosmolar 5% albumin in Ringer lactate were instilled into each lower lobe, and ALC was measured. After 4 h of LA hypertension (24 cmH2O), ALC was similar to that in control sheep (31 +/- 3% with LA hypertension vs. 34 +/- 10% with normal LA pressure). Because plasma epinephrine levels were moderately elevated in the presence of LA hypertension, ALC was then studied in the presence of LA hypertension following bilateral adrenalectomy. Without endogenous release of epinephrine, ALC was significantly reduced compared with normal LA pressure (20 +/- 7% compared with 34 +/- 10%, P < 0.05). Thus endogenous catecholamines caused a submaximal stimulation of ALC in the presence of LA hypertension. Exogenous administration of aerosolized beta2-agonist therapy with salmeterol increased ALC in the presence of normal LA pressure but had no stimulatory effect in the presence of moderate LA hypertension. Therefore, we tested the hypothesis that endogenous release of atrial natriuretic factor (ANF) may downregulate alveolar epithelial Na+ and fluid transport in the presence of LA hypertension. There was a modest twofold increase in plasma ANF levels after LA hypertension. Additional in vitro studies demonstrated that, in the presence of beta2-agonist stimulation, ANF decreased Na+ pump activity (Na+-K+-ATPase) in isolated rat alveolar epithelial type II cells. ANF may downregulate vectorial Na+ and fluid transport stimulated by endogenous or exogenous beta-adrenergic agonist stimulation in the presence of LA hypertension. In summary, ALC continues even in the presence of moderate LA hypertension. Aerosolized beta2-adrenergic agonist therapy significantly increased ALC, but only when LA pressure was normal.
Assuntos
Hipertensão/fisiopatologia , Alvéolos Pulmonares/fisiologia , Adrenalectomia , Agonistas alfa-Adrenérgicos/farmacologia , Anestesia , Animais , Fator Natriurético Atrial/sangue , Proteínas Sanguíneas/metabolismo , Permeabilidade Capilar/fisiologia , Epinefrina/sangue , Hemodinâmica/efeitos dos fármacos , Hemodinâmica/fisiologia , Técnicas In Vitro , Linfa/efeitos dos fármacos , Linfa/fisiologia , Masculino , Alvéolos Pulmonares/citologia , Alvéolos Pulmonares/enzimologia , Edema Pulmonar/fisiopatologia , Ratos , Ratos Sprague-Dawley , Respiração Artificial , Ovinos , ATPase Trocadora de Sódio-Potássio/metabolismoRESUMO
With the rapid aging of end-stage renal disease patients have come increasing burdens on families to provide care and support. This article focuses on the role changes, strains, and burdens for family caregivers, particularly spouses. Analysis is on the process of dramatic role changes and losses that occur within families and the resulting risks to dialysis patients and caregivers. Importance of constant assessment of caregivers by renal professionals is emphasized. Suggestions for families and professionals coping with role change and care burdens are offered. Concern is raised about American society shifting more care burdens onto families at a time of cultural change and stress on families, without enough societal support and programs to assist families adequately with care burdens of aging members.
Assuntos
Envelhecimento/fisiologia , Cuidadores , Falência Renal Crônica , Cuidadores/psicologia , Humanos , Relações Interpessoais , Apoio SocialRESUMO
Minority students are at risk in majority institutions. Students face personal, academic, and institutional barriers to their success. Low retention and graduation rates at majority institutions, and particularly in nursing programs, are cause for alarm and compel nursing faculty to take action in order to reverse the trend of under-representation of minorities in the ranks of the profession. Based on the literature and personal experiences, the authors maintain that commitment of both minority and majority faculty is the primary factor in promoting minority student success. Such commitment can lead to increased involvement of faculty in the success of minority students and to the establishment of organized programs and services that facilitate minority student success. Case illustrations are included.
Assuntos
Atitude , Docentes de Enfermagem , Grupos Minoritários , Apoio Social , Estudantes de Enfermagem , Humanos , Descrição de Cargo , Evasão EscolarRESUMO
This article describes research funded by a Dean's New Investigator Award conducted to describe and evaluate nursing education research on predictors of retention, graduation, and National Council Licensure Examination success of baccalaureate-degree nursing students through an integrative review and meta-analysis of nursing research. The sample (n = 47) for the integrative review included all nursing research conducted within the years 1981 to 1990 related to predicting student success that had at least one nurse author and was published in US nursing journals or dissertations from a US university. Four studies from the corpus were appropriate to be treated meta-analytically. Ninety-four per cent of the studies were descriptive, used convenience samples, and most often identified quantitative measures, including American College Test, Scholastic Aptitude Test, and grade point average as predictor variables. Findings of the integrative review showed grade point averages in nursing and science courses as the greatest cognitive predictors of student success and parental education and age as the greatest demographic predictors. The meta-analysis portion of the study showed significant effectiveness of interventions used in the experimental studies. The Fail-Safe N (NFS) was used to assess the comprehensiveness and exhaustiveness of the literature searches. The NFS = 162 studies indicated that it would require 162 studies to overturn the conclusions.
Assuntos
Logro , Bacharelado em Enfermagem , Pesquisa em Educação em Enfermagem , Psicometria/métodos , Humanos , Valor Preditivo dos TestesRESUMO
Health care reform will affect the relationship of trauma centers to health maintenance organizations and other managed care plans. We studied Kaiser Permanente Medical Center (Kaiser) members admitted to the Trauma Center at San Francisco General Hospital (SFGH) to determine: (1) variables predicting transfer from SFGH to a Kaiser Hospital (repatriation), (2) the length of hospital stay (LOS), and (3) the cost of their care. The SFGH trauma registry provided data on 7,794 patients admitted before 1994. To investigate LOS, 89 Kaiser patients over 1 year were matched with non-Kaiser patients on age, maximum Abbreviated Injury Scale score (MAIS) by body region, Injury Severity Score (ISS), head injury severity, and blunt or penetrating injury and disposition. Kaiser patients were significantly younger, more likely to have blunt injury, and had a lower death rate. Significant predictors of repatriation were an MAIS score > or = 3, abdominal or extremity injury, and an ISS score of 26 to 40. The mean LOS for all Kaiser patients was 7.6 days, compared with 4.8 for controls (p = 0.20). However, mean LOS was significantly longer in repatriated Kaiser patients compared with controls (16 vs. 7.8 days, p < 0.0005). Kaiser reimbursement rates were comparable with commercial payors, but higher than others. A relatively small number of severely injured patients account for a large percentage of costly trauma care. Analyses of patient subsets are necessary for trauma centers to negotiate suitable relationships with managed care plans. A prospective study is needed to examine the cost efficiency of early transfer of managed care patients.
Assuntos
Custos de Cuidados de Saúde , Programas de Assistência Gerenciada/organização & administração , Centros de Traumatologia/organização & administração , Ferimentos e Lesões/mortalidade , Adulto , Feminino , Humanos , Escala de Gravidade do Ferimento , Reembolso de Seguro de Saúde , Tempo de Internação/estatística & dados numéricos , Masculino , Programas de Assistência Gerenciada/economia , Mortalidade , Transferência de Pacientes/economia , Sistema de Registros , São Francisco , Fatores Sexuais , Centros de Traumatologia/economia , Ferimentos e Lesões/economiaRESUMO
Many functions of polymorphonuclear leukocytes (PMNs) appear to alter and be affected by changes in the intracellular and/or extracellular acid-base milieu, suggesting that carbonic anhydrase (CA) may be important. Although small amounts of CA activity in PMNs have been reported, it has not been characterized fully. We therefore studied isolated mature circulating human PMNs and cultured HL-60 cells, an undifferentiated myelopoietic cell line, and compared these to human red cells (RBCs) for CA activity. Activity and sulfonamide inhibition were measured by a modified micromethod assay. Isoenzyme and total CA concentrations were determined by radioimmunoassay for human isozyme CA I, differential inhibition by MK-927, inhibition by 0.2% sodium dodecyl sulfate (SDS), and quantitative sulfonamide binding. Total CA activity (units/10(6) cells) was 0.04 in PMNs, 0.06 in HL-60 cells, and 0.62 in RBCs. Human PMNs have a total CA concentration of 1.3 microM, of which 0.9 microM is CA I and the remainder is CA II. Total loss of CA activity with 100 microM ethoxzolamide and 0.2% SDS ruled out significant CA III or CA IV activity. Subcellular fractionation of PMNs revealed that all CA activity was cytosolic. The absence of CA activity in mitochondrial and microsomal membrane fractions argues against any mitochondrial CA V or membrane-bound CA IV contribution to total CA activity. Neutrophils contain both CA I and II isozymes in roughly the same proportion as RBCs but at much lower concentrations, suggesting that in the course of maturation the CA content of neutrophils is regulated differently from that in erythrocytes.
Assuntos
Anidrases Carbônicas/análise , Anidrases Carbônicas/química , Neutrófilos/enzimologia , Inibidores da Anidrase Carbônica/farmacologia , Anidrases Carbônicas/metabolismo , Cromatografia Líquida de Alta Pressão , Eletroforese em Gel de Poliacrilamida , Eritrócitos/citologia , Eritrócitos/enzimologia , Etoxzolamida/farmacologia , Humanos , Immunoblotting , Isoenzimas , Leucemia Mieloide/patologia , Neutrófilos/citologia , Radioimunoensaio , Dodecilsulfato de Sódio/farmacologia , Sulfonamidas/farmacologia , Tiofenos/farmacologia , Células Tumorais CultivadasRESUMO
A total of 31 cervical biopsy specimens were taken from 29 women attending a genitourinary medicine clinic, nine women (11 biopsy specimens) were known to have Chlamydia trachomatis cervicitis and 20 women were known to be free of chlamydial infection. The specimens were routinely processed to paraffin wax and stained by an anti-Chlamydia immunoperoxidase technique to localise the organisms. Of the 11 positive biopsy specimens three showed positive staining of elementary/reticulate bodies. In one case the surface endocervical cells showed large inclusions which were packed with chlamydial bodies. The diagnosis of chlamydial infection is difficult to make clinically and in routine cytological and histological specimens but immunoperoxidase staining can clearly identify C trachomatis inclusions in cervical biopsy specimens provided infection is severe.
Assuntos
Infecções por Chlamydia/diagnóstico , Chlamydia trachomatis/isolamento & purificação , Colo do Útero/microbiologia , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Técnicas Imunoenzimáticas , Cervicite Uterina/microbiologiaAssuntos
Herpes Genital/complicações , Linfonodos/patologia , Doenças Linfáticas/etiologia , Linfoma/diagnóstico , Adulto , Diagnóstico Diferencial , Feminino , Herpes Genital/diagnóstico , Herpes Genital/patologia , Humanos , Doenças Linfáticas/diagnóstico , Doenças Linfáticas/patologia , Microscopia Eletrônica , NecroseRESUMO
As CAPD passes its 13 year mark as an ESRD therapy, a current controversy centers on whether it is the ideal treatment choice for almost all dialysis patients. Peritoneal dialysis has changed greatly since the late 1970s and now offers safer, more effective and varied types of treatment choices for patients. Concurrently, the patient population has changed and now includes older and more multiproblem patients than in the past. While some professionals may view CAPD as the best or even the only choice for most patients, it is important to realize that CAPD may not always be the best choice for either patients or staff. This paper looks at the controversy from the standpoint of both patient and PD staff. The question is raised as to "should we" rather than "can we" manage almost anyone on CAPD?
Assuntos
Falência Renal Crônica/terapia , Diálise Peritoneal Ambulatorial Contínua , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Cooperação do Paciente , Educação de Pacientes como Assunto , Pacientes/psicologia , Apoio SocialRESUMO
Successful retention of at-risk nursing students is best accomplished through an organized system that addresses their individual needs in the areas of academic, cognitive, and self-enhancement skills. The cooperative endeavors of students, faculty, and administrators in the development of one such system, Enrichment for Academic Success, has resulted in a 95% retention rate among participants. The authors describe the incentive, development, implementation, and value of the system which can be adapted to any setting with adequate human and material resources.
Assuntos
Bacharelado em Enfermagem , Critérios de Admissão Escolar , Evasão Escolar , Ensino/métodos , HumanosRESUMO
Concentration of any substance in the air of a room is determined by the ratio between the rates of its production and removal. Thus, high concentrations can result from high production, low removal, or a combination of the two. Air filtration can supplement ventilation in removing allergens from the air. Control of aeroallergen exposure at any particular location would be more rational and effective if the contribution of production, ventilation, and filtration were known. Using immunochemical assays for rat urinary protein allergen, we measured the rate of production by individual rats and the concentration of allergens in the air of rat animal quarters where the ventilation rate was about 15 changes per hour. We introduced two different high-efficiency filtration systems that provided additional clean air changes up to a maximum of 127 changes per hour. Male rats shed about 20 ng/min of allergen. Because of this high rate of production, substantial reduction in rooms that housed large numbers of animals required the very high air-exchange rates that were achieved with laminar flow small animal isolator racks. Measured concentrations agreed well with concentrations calculated from a mass balance equation whose terms included numbers of animals in the room, production rate by individual animals, and rates of ventilation and filtration. We suggest that this principle of considering both production and removal rates applies not only to devising means of reducing levels of rat allergens in rat rooms, but generally to other indoor allergens as well.
Assuntos
Poluentes Ocupacionais do Ar/análise , Alérgenos/análise , Abrigo para Animais , Ratos/urina , Ventilação , Animais , Feminino , Filtração , Humanos , Masculino , Doenças Profissionais/prevenção & controleRESUMO
1. Some of the actions of pertussis toxin on the rabbit luteal adenylyl cyclase system were analyzed. 2. Incubation of luteal membranes with pertussis toxin and [32P]NAD resulted in the [32P]ADP-ribosylation of a 40,000 Da protein that is distinct from the proteins ADP-ribosylated by cholera toxin. 3. Pertussis toxin specific [32P]ADP-ribosylation was time-dependent and dependent upon the concentration of pertussis toxin present during the incubation. 4. Pertussis toxin mediated [32P]ADP-ribosylation was enhanced by ATP, ADP, adenylyl imidodiphosphate, GTP, guanosine-5'-O-(2-thiodiphosphate), guanosine-5'-O-(3-thiotriphosphate), and NaF but not AMP or guanylyl imidodiphosphate [GMP-P(NH)P]. 5. Treatment of luteal membranes with NAD and pertussis toxin prevents GTP and enkephalin but not GMP-P(NH)P mediated inhibition of forskolin stimulated adenylyl cyclase, demonstrating the existence of a functional Gi in the rabbit corpus luteum.