Providing free pregnancy test kits to community health workers increases distribution of contraceptives: results from an impact evaluation in Madagascar.

OBJECTIVES: To improve access to contraceptives in remote and rural areas, sub-Saharan African countries are allowing community health workers (CHWs) to distribute hormonal contraceptives. Before offering hormonal contraceptives, CHWs must determine pregnancy status but often lack a reliable way to do so. No studies have evaluated the impact of providing CHWs with urine pregnancy test kits. We assessed the impact of giving CHWs free pregnancy test kits on the number of new clients purchasing hormonal contraceptives from CHWs. STUDY DESIGN: We implemented a randomized experiment in Eastern Madagascar among CHWs who sell injectable and oral hormonal contraceptives. A total of 622 CHWs were stratified by region and randomly assigned at the individual level. Treatment-group CHWs were given free pregnancy tests to distribute (n analyzed=272) and control-group CHWs did not receive the tests (n analyzed=263). We estimated an ordinary least-squares regression model, with the monthly number of new hormonal contraceptive clients per CHW as our primary outcome. RESULTS: We find that providing CHWs with free pregnancy test kits increases the number of new hormonal contraceptive clients. Treatment-group CHWs provide hormonal contraceptives to 3.1 new clients per month, compared to 2.5 in the control group. This difference of 0.7 clients per month (95% confidence interval 0.13-1.18; p=.014) represents a 26% increase. CONCLUSIONS: Giving CHWs free pregnancy tests is an effective way to increase distribution of hormonal contraceptives. As pregnancy tests become increasingly affordable for health-care systems in developing countries, community-based distribution programs should consider including the tests as a low-cost addition to CHWs' services. IMPLICATIONS: No study has evaluated the impact of giving CHWs free urine pregnancy test kits for distribution to improve provision of hormonal contraceptives. Giving CHWs free pregnancy test kits significantly increases the number of clients to whom they sell hormonal contraceptives. Community-based distribution programs should consider including these tests among CHWs' services.

Application of fiberoptic sensors for the study of hepatic dysoxia in swine hemorrhagic shock.

OBJECTIVES: To determine whether the simultaneous measurement of tissue pH, Pco2, and Po2 with a multiple-parameter fiberoptic sensor can be used to indicate the onset of hepatic dysoxia, to determine critical values, and to assess their use in predicting negative outcomes. DESIGN: Prospective animal study. SETTING: University research laboratory. SUBJECTS: Fourteen Yorkshire swine. INTERVENTIONS: Hemorrhagic shock (n = 11) was induced over 15 mins to lower systolic blood pressure to 40 mm Hg and was maintained for 30, 60, or 90 mins. Resuscitation was achieved with shed blood and warm saline to maintain mean pressure >60 mm Hg for 120 mins. Sham animals (n = 3) were subjected to 90 mins of sham shock, followed by a 120-min recovery period. MEASUREMENTS AND MAIN RESULTS: The multiple-parameter sensor continuously measured tissue pH, Pco2, and Po2. pH and Pco2, indicators of anaerobic metabolism, were plotted against tissue Po2. All shocked animals, but no sham animals, showed a biphasic relationship between Po2 and both pH and Pco2. Curves were fit to both an exponential and a dual-line linear function to determine critical values for Po2, pH, and Pco2. The length of time the animal was dysoxic was evaluated as a predictor of negative outcome. Critical values determined from the exponential models were more sensitive indicators of negative outcome than values determined from the linear model and more sensitive than arterial lactate and tonometric intramucosal pH and Pco2. CONCLUSIONS: The multiple-parameter sensor offers the unique opportunity to study solid as well as hollow organ dysoxia through the simultaneous measurement of interstitial pH, Pco2, and Po2 in a small tissue region. The gradual transition from sufficient oxygen availability to dysoxia as a result of hemorrhage was better described by an exponential equation. The length of time that pH was below or Pco2 was above the critical value determined from the exponential model was predictive of a negative outcome.

Experimental use of an illuminated and magnetic tip, flow-directed pulmonary artery catheter for lung resection.

The authors performed a study to design and evaluate a device giving the surgeon added protection against pulmonary artery injury in a closed thoracic compartment. Eleven swine were used for a total of 12 lobectomies. A light-bearing, magnetic-tipped, modified Swan-Ganz catheter was passed through the jugular vein into the left pulmonary artery. By using magnetic guidance through a port site and balloon inflation, cessation of flow in the pulmonary artery was documented by Doppler. Twelve video-assisted lobectomies were performed. Nine of 12 (75%) lobectomies were completed successfully by using the magnetic-tipped, illuminated balloon catheter. In 4 cases, the catheter displaced because of the short left main pulmonary artery in swine. In one case, the balloon was recovered, and successful lobectomy was performed. The use of a magnetic-tipped, flow-directed device may provide an effective means of endovascular control during thoracoscopic pulmonary arterial dissection.

Simultaneous measurement of hepatic tissue pH, venous oxygen saturation and hemoglobin by near infrared spectroscopy.

The purpose of this study was to investigate the feasibility of using near infrared (NIR) spectroscopy of the liver to simultaneously assess oxygen content in combination with tissue pH, an indicator of anaerobic metabolism. Six anesthetized swine were subjected to 45 min of hemorrhagic shock followed by resuscitation with blood and crystalloid. Calibration models between NIR spectra and reference measurements of tissue pH, hepatic venous oxygen saturation (S(V)O2), and blood hemoglobin concentration (Hb) were developed using partial least-squares regression. Model accuracy was assessed using cross validation. The average correlation (R2) between NIR and reference measurements was 0.87, 0.68, and 0.93, respectively for pH, Hb, and S(V)O2. Estimated accuracy, the root mean squared deviation between spectral, and reference measurements was 0.03 pH units, 0.3 g/dL, and 6%. NIR determination of hepatic oxygen content and tissue pH during shock and resuscitation demonstrated that there can be a variance between hepatic venous oxygenation and regional tissue acidosis. NIR spectroscopy provides a technique to explore the implications of post-shock depression of tissue pH and evaluate new methods of resuscitation.

Chronic pulmonary artery balloon counterpulsation in sheep via percutaneous route.

BACKGROUND: In clinical practice pulmonary artery balloon counterpulsation (PABC) has been utilized only in the operative setting with the balloon housed in a graft attached to the pulmonary artery. Clearly, percutaneous insertion of a dedicated pulmonary artery balloon is a desirable goal for patients requiring temporary assist for right ventricular failure. METHODS: To address the question of right sided cardiopulmonary tolerance for a chronic indwelling pulmonary artery balloon, six adult ewes underwent percutaneous placement of an 11 ml pulmonary artery balloon, via the femoral vein. Effective pumping and timing were monitored for 48 hours at which time the animals were sacrificed. At autopsy gross and microscopic study of all right heart structures, the pulmonary arteries and the lungs were studied for adverse effects. RESULTS: There were inconsequential minor abrasions to right heart structures in most animals. The pulmonary artery in five of six animals revealed ecchymoses and some transmural hemorrhage, but no necrosis or perforation. There was no pulmonary injury that could not be ascribed to postoperative atelectasis. CONCLUSIONS: This study demonstrates that chronic pulmonary artery balloon counterpulsation can be carried out for a period of 48 hours without significant injury to right heart and pulmonary structures in the ovine model

Thoracoscopic lobectomy with endoarterial vascular control: an experimental study in swine.

BACKGROUND: Video-assisted lobectomy lacks vascular control and presents the potential for serious hemorrhage in a closed cavity. The use of a lighted, flow-directed balloon catheter in the pulmonary artery as an endovascular control device was evaluated. METHODS: A modified light-bearing Swan-Ganz catheter was placed in the left or right pulmonary artery using fluoroscopy. The lit catheter was identified easily through the arterial wall at thoracoscopy. Its inflation allowed the control of proximal blood flow as required. Fully thoracoscopic lobectomy was carried out by isolating and dividing the lobar branches of the pulmonary artery, the pulmonary vein, and the bronchus in anesthetized swine. RESULTS: Forty-two video-assisted anatomic lobectomies were completed in 30 pigs with balloon catheter control of the pulmonary artery. The balloon effectively controlled experimental hemorrhage caused by puncturing arterial branches (n = 4). It allowed the transection of unlooped lobar arteries (n = 42) and the main interlobar pulmonary artery (n = 3). Catheter displacement back to the heart occurred in 5 animals and balloon catheter technical failures occurred in 3. CONCLUSIONS: The lighted, flow-directed balloon catheter was an effective means of avoiding acute hemorrhage and achieving vascular control in a swine lobectomy model.

Hypothermic cardioplegic arrest is associated with increased myocardial adenosine.

The current study examined the effects of temperature on myocardial pH, contractile function and adenosine triphosphate metabolism, particularly the production of adenosine. We matched intermittent delivery of blood cardioplegia in two groups (hypothermia 15 degrees C; normothermia 37 degrees C), for 2 h of cardioplegic arrest. Hypothermic perfusion resulted in a markedly alkalotic pH, and nearly a threefold increase in adenosine and adenosine monophosphate levels compared to normothermic hearts. Tissue levels of adenosine triphosphate were preserved to the same extent in each group, despite the increased energy requirements of normothermia. Myocardial contractile function was not statistically different between the two groups at 30 min and 2 h after the cross clamp was removed. These data suggest that both methods, hypothermia via its reduced energy demands, and normothermia through continued glycolytic metabolic activity, allow the myocardium to maintain energy stores and resume adequate function. However, hypothermic perfusion results in an accumulation of adenosine, demonstrating that temperature should be considered when attempting to manipulate the generation and accumulation of the compound.

Feasibility of non-invasive measurement of tissue pH using near-infrared reflectance spectroscopy.

OBJECTIVE: Tissue pH measurement has a number of clinical applications, including the monitoring of both muscle pH and organ pH as an indicator of compromised blood flow and anaerobic metabolism. The objective of this work was to demonstrate the feasibility of a noninvasive measurement of deep tissue pH using near-infrared reflectance spectroscopy and multivariate calibration techniques. METHODS: Six studies were done on five New Zealand white rabbits. Two pH electrodes were implanted in the teres major muscle and a vascular clamp placed across the single artery feeding the muscle. Reflected light was collected through the skin from a site between the two electrodes as the pH was lowered by closing the clamp and raised by opening the clamp. Partial least squares analysis with cross-validation techniques was used to relate pH to light absorption at 201 evenly spaced wavelengths between 700 and 1100 nm. RESULTS: On average, the tissue pH started at 7.13 +/- 0.09 and decreased to 6.74 +/- 0.09, returning to 7.13 +/- 0.09 after reperfusion. Calibration models fit for each rabbit had an average of nine factors with an R2 of 0.98 and a prediction error of 0.016 +/- 0.002 pH units. CONCLUSIONS: We believe this to be the first in vivo demonstration of a non-invasive method for measuring tissue pH in skin-covered muscle using near-infrared reflectance spectroscopy and multivariate calibration techniques.

Retrograde abdominal visceral perfusion: is it beneficial?

BACKGROUND: It is proposed that retrograde abdominal perfusion be used in combination with retrograde cerebral perfusion to provide total body visceral protection during aortic reconstruction; however, its physiologic effects remain unknown. METHODS: We compared the effect of superior vena caval perfusion alone with that of combined superior and inferior vena caval perfusion on the liver and kidney in 6 mongrel dogs. Organ blood flow was measured using ultrasonic flow probes on the hepatic artery, the portal vein, and the renal artery. Regional tissue blood flow to the liver and the kidney was assessed using colored microspheres and pH probes. Anesthetized dogs were placed on total cardiopulmonary bypass. After cooling to 20 degrees C, retrograde perfusion was begun with 30 minutes of superior vena caval perfusion followed by another 30 minutes of bicaval perfusion, or vice versa. RESULTS: Very little renal blood flow was measured with either method of retrograde perfusion. Although the liver received more blood flow in comparison to the kidney, there was no significant difference between superior vena caval perfusion alone and bicaval perfusion. The addition of inferior vena caval perfusion results in portal hypertension, hepatic congestion, ascites, and bowel edema. CONCLUSIONS: In the canine model, bicaval perfusion does not provide superior protection to the liver and kidneys when compared with superior vena caval perfusion alone.

Decreasing myocardial pH reflects ischemia during continuous warm retrograde cardioplegic arrest.

Warm continuous retrograde cardioplegia is thought to prevent myocardial ischemia. We tested this hypothesis by subjecting canine hearts to 2 hours of either antegrade or retrograde perfusion with normothermic blood cardioplegia. Ischemic alterations were evaluated through the measurement of myocardial pH, tissue levels of adenosine triphosphate and lactate, and the preservation of left ventricular contractility. Antegrade perfusion resulted in uniformly positive changes in the myocardial pH in both ventricles, preserved levels of adenosine triphosphate, and small increases in the myocardial lactate levels. In contrast, retrograde perfusion caused the myocardial pH to decrease, especially in the right ventricle. Tissue lactate levels rose to a significantly greater extent during retrograde perfusion and adenosine triphosphate levels declined, although not to a statistically significant degree. Finally, myocardial function, as assessed by the preload recruitable work area, was preserved (103% +/- 20% of baseline) in the antegrade group but was markedly diminished (33% +/- 6%) in retrogradely perfused left ventricles 35 minutes after the aortic cross-clamp was removed. These data suggest that ischemic metabolism and the subsequent alteration of myocardial function take place despite continuous retrograde perfusion with normothermic blood cardioplegia.

Correction of intramyocardial hypercarbic acidosis with sodium bicarbonate.

Although it has been hypothesized that exogenously administered bicarbonate can exacerbate intramyocardial acidosis and compromise contractile function, this phenomenon has not been demonstrated in an intact model in which intramyocardial pH (pH(int)), regional venous pCO2, and regional contractile function have been simultaneously monitored. In 20 anesthetized dogs, we studied the effects of intracoronary infusions of sodium bicarbonate NaHCO3 30 mEg over 15 min, on regional pH(int), (glass electrode) and regional stroke work (SW, sonomicrometry) before and after creating systemic hypercarbic acidosis by hypoventilation. During NaHCO3 administration, regional coronary venous pCO2 increased rapidly during the first minute (eucapnea; 34 +/- 7 to 55 +/- 18 mm Hg; hypercapnea: 70 +/- 15 to 98 +/- 23 mm Hg, P < 0.05 for both increases). Regional venous pH rose from 7.36 +/- .04 to 7.55 +/- .06 (P < 0.05) after the first minute of NaHCO3 infusion during eucapnea and from 7.09 +/- .09 to 7.22 +/- .09 (P < 0.05) during hypercapnea. During the first minute of NaHCO3 infusion, pH(int) declined minimally. However, during the remaining 14 min of each infusion, pH(int) increased significantly (eucapnea: 7.19 +/- 0.10 to 7.43 +/- 0.12; hypercapnea: 6.86 +/- 0.14 to 7.02 +/- 0.15, P < 0.05 for both changes). Regional SW decreased significantly during the first minute of infusion, both during eucapnea (23,400 +/- 7,400 to 18,000 +/- 6,300 ergs/cm2, P < 0.05) and hypercapnea (27,000 +/- 9,100 to 25,000 +/- 10,000 ergs/cm2, P < 0.05). The first minute of contractile dysfunction was followed by recovery and ultimately supranormal contractile function during the remainder of each bicarbonate infusion. To test the hypothesis that transient intracellular acidosis during bicarbonate infusions was underestimated by measurements of pH(int), measurements of intracellular pH using the pH-sensitive dye, BCECF, were performed in isolated guinea pig papillary muscles incubated in vitro. These measurements confirmed the presence of transient intracellular acidosis during bicarbonate infusion. In conclusion, (1) the intracoronary administration of sodium bicarbonate causes a transient depression in myocardial contractile function that is related to transient intracellular acidosis; and (2) despite exacerbating hypercarbia, sodium bicarbonate ultimately neutralizes intracellular acid and augments myocardial contractile function.

Sodium bicarbonate versus Carbicarb in canine myocardial hypercarbic acidosis.

The objective of this study was to compare the in vivo effects of sodium bicarbonate (NaHCO3) and Carbicarb infusion on regional contractile performance and acid-base status in the setting of hypercarbic acidosis. Animals (N = 9) were anesthetized and paralyzed using sodium pentothal, halothane, and pancuronium bromide, and mechanically ventilated with an air-O2 mixture so that arterial PO2 was > or = 300 mm Hg. Following beta-adrenergic blockade, alveolar ventilation was gradually reduced over a 50-minute period to increase arterial PCO2 to 60 to 80 mm Hg. Each of the following solutions was then infused in consecutive order directly into the left anterior descending artery coronary artery for 15 minutes: (1) 8.4% NaHCO3 at 2 mL/min; (2) 5% sodium chloride at 2 mL/min, equivalent to NaHCO3 in osmolality; (3) 6.3% Carbicarb at 0.5 mL/min, equivalent to NaHCO3 in buffer capacity; and (4) 6.3% Carbicarb at 2 mL/min, equivalent to NaHCO3 in volume. Regional stroke work analog (ultrasonic dimension transducers), interstitial myocardial pH (Khuri electrode), coronary blood flow (doppler flow probe), and hemodynamic/metabolic variables (heart rate, blood pressure, arterial and coronary venous blood gases) were measured at 1, 5, 10, and 15 minutes during each infusion and 10 minutes after the infusion was discontinued, ie, at 25 minutes. Animals were allowed to recover for 45 minutes between interventions. Values at each time point were compared with baseline for statistical significance. Small reductions in interstitial myocardial pH (P < .05) and stroke work (P > .05) were observed within 1 minute of NaHCO3 administration. Both parameters increased significantly from baseline levels thereafter, ie, interstitial myocardial pH at 5 minutes and stroke work at 15 minutes. Infusion of Carbicarb invariably was associated with an increase (P < .05) in interstitial myocardial pH. Stroke work increased (P < .05) during low-dose Carbicarb administration, but infusion of the higher dose was accompanied by a biphasic response, ie, an increase (P < .05) from 0 to 5 minutes, followed by a gradual decrease that achieved statistical significance 10 minutes after termination of the infusion. End-diastolic length was inversely proportional to changes in stroke work, and coronary blood flow varied directly with changes in coronary venous Pco2. Myocardial O2 consumption decreased (P < .05) during Carbicarb infusion, but changes during NaHCO3 did not reach statistical significance. Our findings lend support to the hypothesis that intramyocardial pH determines myocardial function independent of CO2 production by buffer therapy.(ABSTRACT TRUNCATED AT 400 WORDS)

Retrograde coronary sinus perfusion provides non-homogeneous myocardial blood flow.

The ability of retrograde cardioplegia to protect the right ventricle has been questioned. Canine myocardial circulation was assessed by infusing colored microspheres through the coronary sinus. The relative flow index (RFI), a normalized measure of tissue blood flow, was determined for 76 sections of myocardium. Three distinct flow regions were evident from these measurements. A paucity of blood flow through some basal sections of the right ventricle (RFI = 0.23 +/- 0.19) was found to be significantly different (p < 0.005) from regions of the heart with normal flow (RFI = 1.12 +/- 0.06). Sections from the right ventricular apex demonstrated augmented flow (RFI = 3.72 +/- 1.18). These data indicate that retrograde coronary perfusion provides nonuniform flow and under some conditions may provide inadequate perfusion to portions of the right ventricle.

Left ventricular systolic and diastolic dysfunction after infusion of tumor necrosis factor-alpha in conscious dogs.

We used a load-insensitive index of systolic left ventricular (LV) function and an analysis of diastolic pressure-dimension relationships to test the hypothesis that recombinant human (rh) tumor necrosis factor-alpha (TNF alpha) impairs LV function in dogs. Animals were studied 7-10 d after aseptic implantation of instrumentation to monitor cardiac output, external anterior-posterior LV diameter, and LV and pleural pressures. Data were analyzed from seven dogs that received active rhTNF alpha (100 micrograms/kg over 60 min) and from five dogs that received heat-inactivated rhTNF alpha. At 24 h after infusion of active rhTNF alpha, the slope of the LV end-diastolic dimension-stroke work relationship decreased significantly, indicating a decrement in LV systolic contractility. Simultaneously, LV unstressed dimension increased significantly, suggesting diastolic myocardial creep. The end-diastolic relationship between LV transmural pressure and normalized LV dimension (strain) was markedly displaced to the left, suggesting increased diastolic elastic stiffness. Despite these changes in LV performance, cardiac index was maintained by tachycardia. The abnormalities in LV function were resolved by 72 h. We conclude that rhTNF alpha reversibly impairs LV systolic and diastolic function in unanesthetized dogs. Because dysfunction occurs greater than 6 h after the infusion of rhTNF alpha and persists for 24-48 h, the mechanism underlying this phenomenon may involve secondary mediators or a change in myocardial gene expression.

Dystrophin immunostaining in muscles from patients with different types of muscular dystrophy: a Brazilian study.

The localization of the protein dystrophin was studied using the immunofluorescence method, in muscle biopsies from 74 patients affected by different types of muscular dystrophy and 4 normal controls. In 15 patients with limb-girdle muscular dystrophy (LGMD) the pattern was indistinguishable from normal. Among 42 Duchenne patients (DMD), 3 were totally negative and 39 showed a variable proportion (4-30%) of partially labelled fibers. With one exception 17 Becker dystrophy patients (BMD), showed a positive sarcolemmal reaction. A diffuse reaction inside the fibers, which was not observed in normal controls, was seen in the majority of DMD and also in some of the BMD patients. Based on these observations it is suggested that in DMD, a small quantity of protein is still present or there is a cross-reaction with other proteins which share some homology with dystrophin. The present results suggest that it is possible to make a differential diagnosis between DMD and BMD through dystrophin immunohistochemistry. However, to distinguish between patients with BMD and LGMD phenotypes, or DMD and outliers, complementary immunoblot studies and quantitative determination of dystrophin are necessary.

Studies on a new pathogenic lung fluke--Paragonimus hueit' ungensis sp. nov.

This paper records the discovery of a new pathogenic lung fluke Paragonimus hueit'ungensis sp. nov. in Hueit'ung County of Hunan Province. The salient features of the adults of this lung fluke, its first and second intermediate hosts, rediae, cercariae, metacercariae and the results of feeding experiments on laboratory animals (albino rats, cats, and dogs) are described and compared with the relevant species of lung flukes already known. Biopsies of the migratory subcutaneous nodules done in 2 pediatric cases seen in the endemic area of Hueit'ung County have both shown the presence of immature adolescent lung flukes, whose morphological features agree in general with those obtained through feeding experiments in laboratory animals. But the reproductive organs of these biopsied adolescent flukes are poorly developed; and they do not produce eggs in the human body where they appear to migrate blindly from one place to another, indicating that man is not a suitable final host for this parasite, in spite of its pathogenic implications. Hence one has to be careful not to confuse clinical cases of this new form of paragonimiasis with those due to paragonimiasis szech'uanensis. Studies on the different aspects of this new lung fluke are obviously of practical importance in the early diagnosis, treatment, and prevention of the disease in the localities concerned.