Liver transplantation for hepatitis B in the United States

AIM

To evaluate the impact of hepatitis B virus (HBV) on US health care system, we reviewed the Organ Procurement and Transplantation (OPTN, formerly UNOS) HBV database.

METHOD

We reviewed records of liver transplantations (LTx) performed in the United States listed for the diagnoses of HBV between 1993 and mid-October 2004. Both acute as well as chronic cases were included. Coinfection with hepatitis C virus was excluded from study. The specific states selected for review were chosen from those areas that are receiving large numbers of new immigrants from high HBV endemic areas (ie, Texas, Pennsylvania, California, New York, and Florida). One-, 3-, and 5-year patient survival rates for both cadaveric and living related donors were analyzed. Survival rates were obtained from OPTN database as Kaplan-Meyer survival test.

RESULTS

Between 1993 and mid-October 2004, 53,312 LTx had been performed nationwide. Of these, 2314 (4.34%) were performed for the diagnosis of HBV; 1816 cases (78%) were due to chronic HBV infection (45 of them were living donor LTx) and 498 cases (22%) were due to HBV-induced acute liver failure (seven of them were living donor LTx). Three- and 5-year survival rates of chronic HBV-related LTx patients were better than acute HBV-related and overall LTx patients.

CONCLUSION

HBV is generally considered to have a minor health significance by many community gastroenterologists. With growing immigration from overseas, it may eventually have a higher impact on LTx. Therefore, it is crucial to further educate gastroenterologists and primary care physicians caring for this specific group of patients.

A practical approach to the balance between acid production and renal acid excretion in humans

Precise measurements of net endogenous acid production (NEAP) to determine net acid balance require labor and laboratory intensive steady-state measurements of dietary nutrient intakes and urine and stool composition. In an effort to simplify the task, investigators have devised several alternative methodologies, especially computational predictive models based on diet composition. This paper describes the so-called gold standard, and the details of each alternative methodology, discussing their strengths and potential pitfalls. We also briefly discuss what we believe the optimal NEAP for adult humans, and how to achieve that through diet.

The impact of total plasma exchange on early allograft dysfunction

INTRODUCTION

Early allograft dysfunction (EAD) is a rare but serious complication encountered among patients undergoing liver transplant surgery. Total plasma exchange (TPE) in EAD has been suggested, but its role is still considered investigational. We retrospectively assessed the efficacy of TPE in EAD and its impact on other parameters of liver function.

MATERIALS AND METHODS

Between 1995 and 2001, 25 orthotopic liver transplant recipients developed EAD, which was defined as early postoperative prothrombin time (PT) >17 seconds, aspartate aminotransferase (AST) and/or alanine aminotransferase (ALT) >2500 IU/L, and/or the presence of hepatic encephalopathy, and development of renal failure. Daily TPE was performed using the Cobe Spectra TPE (Gambro) for 4 hours until an adequate clinical response, the patient underwent retransplantation, or the patient died. International normalizing ratio (INR), partial thromboplastin time (PTT), fibrinogen, ALT, AST, gamma-glutanyl transpeptidase (GGT), blood urea nitrogen (BUN), ammonia, and total bilirubin were analyzed before and after TPE. Student t and chi-square tests were used for statistical analysis.

RESULTS

Twenty-five patients with EAD included 13 females, 12 males of mean age 42.3 years (range, 1-63 years). Coagulopathy and hyperbilirubinemia significantly improved with TPE. Nineteen patients (76%) survived and 2 required retransplantation. Mean number of TPE sessions was 4.3.

CONCLUSION

TPE was effective to correct coagulopathy and improve liver function. These results suggest the benefit of potential temporary liver support until recovery or retransplantation, in the absence of sepsis or multi-system organ failure.

Fulminant hepatic failure and the potential role of liver dialysis

Fulminant hepatic failure (FHF) carries a high mortality. We aimed to review the prognostic factors and explore the potential role of Liver Dialysis (LD). Fifty-two patients were reviewed. The etiologies were acetaminophen toxicity (33%), viral hepatitis (18%), autoimmune (10%), idiosyncratic drug reactions (8%), others (6%) and undetermined (25%). Patients with acetaminophen had a significantly higher survival compared to the non-acetaminophen group (p=0.04). Patients with grade 3 encephalopathy had a mortality of 68%, among 5 patients with grade IV encephalopathy, 2 survived and both had had treatment with LD. Chi-square with Fisher's exact test was used for statistical analysis. Our study confirmed that the diagnosis of non-acetaminophen induced FHF and reduced initial serum factor V level are associated with fatal outcome. Timely OLT significantly improved the survival. The role of LD in hepatic regeneration or as a bridge to OLT needs to be further studied with prospective control trials.

Characterization of the microbial community in indoor environments by chemical marker analysis: an update and critical evaluation

We published recently an integrated procedure for applying chemical marker analysis to characterize the microbiology of indoor environments comprising a scheme for extraction and analysis of markers of endotoxin, peptidoglycan/bacterial biomass, and fungal biomass. In the present paper, we report some significant improvements and also new possibilities of the described approach. We found that while 3-hydroxy fatty acids (3-OH FAs) of 10-14 carbon chain lengths are useful endotoxin markers, longer 3-OH FAs (i.e. with 16 carbon atoms and more) may rather serve as markers of Actinobacteria. We introduced 13C-labeled 3-hydroxytridecanoic acid, from labeled Pectinatus cerevisiiphilus, as an internal standard to improve quantification of the 3-OH FAs in the gas chromatography-mass spectrometry analysis. Finally, in experiments aiming to identify a suitable method for collection of house dust for chemical marker analysis, we found that the marker compositions of dusts sedimented on plexiglass plates that were spatially well-distributed in a studied room at different heights above floor level, were undistinguishable. This type of sampling thus appears to be well suited for use, e.g. in epidemiological studies. In summary, the presented work describes important new capabilities of chemical marker analysis in defining human exposure to microorganisms in indoor environments.

PRACTICAL IMPLICATIONS

We are developing an integrated methodology for characterizing the microbiology of indoor environments where specific microbial monomeric constituents in building materials and inhalable house dust particles are determined by using mass spectrometry-based methods. The methodology should represent a firm basis in research aiming to relate microbial exposure indoors to well-being and health.

Spontaneous rupture of liver in a non-pregnant patient: case report

Spontaneous rupture of the liver during pregnancy associated with preeclampsia is an uncommon and frequently fatal complication. A case of a 61-year-old non-pregnant female is described here who took estrogen replacement for 16 years and presented with spontaneous rupture of the right lobe of the liver with hemoperitoneum. The underlying cause of the rupture was not clear.

A liver transplant center experience with liver dialysis in the management of patients with fulminant hepatic failure: a preliminary report

Among extracorporeal liver support devices, liver dialysis is cleared by the U.S. Food and Drug Administration to be used for the management of fulminant hepatic failure (FHF). The outcomes of patients following liver dialysis need to be clearly evaluated. Among the 25 patients with FHF admitted to the Liver ICU between May 2000 and November 2002, 12 underwent liver dialysis, including 6 men and 6 women, of mean age 32 years. The causes of FHF were identified as acetaminophen (n = 10), herbal medications (n = 1) and autoimmune disease (n = 1). At presentation, the mean total bilirubin was 9.35 mg/dL (range, 0 to 1.3), mean ALT 3015 U/L (range, 0 to 48), mean AST 3457 (range, 0 to 42), mean ammonia 98 micromol/L (range, 10 to 60) and mean INR 1.88. A control group including 13 patients (2 men and 11 women), of mean age 27.8 years mean total bilirubin 5.66, mean ALT 3494, mean AST 3528, mean ammonia 113 and mean INR 3, were not treated with liver dialysis, due to the lack of machine availability or physician's choice. The causes of FHF were acute hepatitis B (n = 1), acetaminophen (n = 10) or unknown (n = 2). There was no statistically significant difference in the baseline characteristics of the two groups (P >.05). Among the liver dialysis group, 1 patient died, 2 underwent OLTx, and 9 were discharged home. Among the control group; 4 patients died, 2 underwent OLTx, and 7 were discharged home. Preliminary results seem to support survival benefit among patients who underwent liver dialysis compared to non-liver dialysis; however, further randomized control trials are warranted to verify this observation.

Prostate-specific antigen levels among cirrhotic patients

PURPOSE

The aim of this study was to determine serum prostate-specific antigen (PSA) levels in patients with liver cirrhosis.

PATIENTS AND METHODS

Between January 1995 and August 2001, 216 men with cirrhosis were evaluated. The extent of their liver disease was classified according to the Child-Pugh classification. Serum PSA levels were measured with the Hybritech Tandem-R RIA method and matched with age-related reference PSA levels. Digital rectal examination (DRE) was performed in all patients. Patients with elevated PSA levels and/or abnormal DRE were recommended to undergo further assessment including transrectal ultrasonography (TRUS) and biopsy performed by an urologist.

RESULTS

Two hundred and sixteen men (mean age 54.09 +/- 9.09 years, range 25-76) with cirrhosis were examined. Their mean PSA value was 0.57 +/- 0.84 ng/mL and tended to be lower than in the normal population. The degree of PSA decrease was found to parallel the severity of the liver disease (p=0.002). The mean serum PSA level increased with each age decade in a statistically significant manner (p<0.001). Four patients (three with elevated PSA values) underwent prostate biopsy. Three biopsies were positive for prostate cancer, the other showed evidence of benign prostatic hyperplasia (BPH).

CONCLUSION

Serum PSA is influenced by the severity of liver disease and its levels tend to be lower in cirrhotic patients than in the normal population. However, serum PSA can still be considered a reliable marker in the clinical management of prostatic disease in patients with cirrhosis.

Diet, evolution and aging--the pathophysiologic effects of the post-agricultural inversion of the potassium-to-sodium and base-to-chloride ratios in the human diet

Theoretically, we humans should be better adapted physiologically to the diet our ancestors were exposed to during millions of years of hominid evolution than to the diet we have been eating since the agricultural revolution a mere 10,000 years ago, and since industrialization only 200 years ago. Among the many health problems resulting from this mismatch between our genetically determined nutritional requirements and our current diet, some might be a consequence in part of the deficiency of potassium alkali salts (K-base), which are amply present in the plant foods that our ancestors ate in abundance, and the exchange of those salts for sodium chloride (NaCl), which has been incorporated copiously into the contemporary diet, which at the same time is meager in K-base-rich plant foods. Deficiency of K-base in the diet increases the net systemic acid load imposed by the diet. We know that clinically-recognized chronic metabolic acidosis has deleterious effects on the body, including growth retardation in children, decreased muscle and bone mass in adults, and kidney stone formation, and that correction of acidosis can ameliorate those conditions. Is it possible that a lifetime of eating diets that deliver evolutionarily superphysiologic loads of acid to the body contribute to the decrease in bone and muscle mass, and growth hormone secretion, which occur normally with age? That is, are contemporary humans suffering from the consequences of chronic, diet-induced low-grade systemic metabolic acidosis? Our group has shown that contemporary net acid-producing diets do indeed characteristically produce a low-grade systemic metabolic acidosis in otherwise healthy adult subjects, and that the degree of acidosis increases with age, in relation to the normally occurring age-related decline in renal functional capacity. We also found that neutralization of the diet net acid load with dietary supplements of potassium bicarbonate (KHCO3) improved calcium and phosphorus balances, reduced bone resorption rates, improved nitrogen balance, and mitigated the normally occurring age-related decline in growth hormone secretion--all without restricting dietary NaCl. Moreover, we found that co-administration of an alkalinizing salt of potassium (potassium citrate) with NaCl prevented NaCl from increasing urinary calcium excretion and bone resorption, as occurred with NaCl administration alone. Earlier studies estimated dietary acid load from the amount of animal protein in the diet, inasmuch as protein metabolism yields sulfuric acid as an end-product. In cross-cultural epidemiologic studies, Abelow found that hip fracture incidence in older women correlated with animal protein intake, and they suggested a causal relation to the acid load from protein. Those studies did not consider the effect of potential sources of base in the diet. We considered that estimating the net acid load of the diet (i. e., acid minus base) would require considering also the intake of plant foods, many of which are rich sources of K-base, or more precisely base precursors, substances like organic anions that the body metabolizes to bicarbonate. In following up the findings of Abelow et al., we found that plant food intake tended to be protective against hip fracture, and that hip fracture incidence among countries correlated inversely with the ratio of plant-to-animal food intake. These findings were confirmed in a more homogeneous population of white elderly women residents of the U.S. These findings support affirmative answers to the questions we asked above. Can we provide dietary guidelines for controlling dietary net acid loads to minimize or eliminate diet-induced and age-amplified chronic low-grade metabolic acidosis and its pathophysiological sequelae. We discuss the use of algorithms to predict the diet net acid and provide nutritionists and clinicians with relatively simple and reliable methods for determining and controlling the net acid load of the diet. A more difficult question is what level of acidosis is acceptable. We argue that any level of acidosis may be unacceptable from an evolutionarily perspective, and indeed, that a low-grade metabolic alkalosis may be the optimal acid-base state for humans.

Acute tacrolimus overdose and treatment with phenytoin in liver transplant recipients

As a potent immunosuppressive agent, Tacrolimus is widely used in organ transplantation. Although complications due to chronic Tacrolimus use are rather well recognized, little is known about acute overdose and its treatment. Phenytoin, an anti-convulsant agent, can induce the Cytochrome P450 enzyme in the liver, which metabolizes Tacrolimus. Therefore, it can be considered as a potential treatment option for acute Tacrolimus toxicity. We hereby report two cases of acute Tacrolimus overdose after Orthotopic Liver Transplantation and the treatment with Phenytoin. Probable mechanisms of metabolism and interactions of these two drugs are discussed and the literature is reviewed.

High incidence of noninfectious esophagitis in orthotopic liver transplant (OLT) recipients

Incidence of esophagitis among cirrhotics is similar to the general population; post-OLT course of this entity is not well known. The aim of this study was to assess the incidence of non-infectious esophagitis among OLT recipients. Patients with chronic liver disease who have been considered for transplantation have undergone esophagogastroduodenoscopy (EGD) for examination of the upper gastrointestinal tract. Following transplantation, some of these patients have required EGD for various reasons. EGD findings following transplantation were compared to that individual's pre-transplant findings. There were 173 patients and the median age was 49. The incidence of pre-transplant esophagitis was 7.5%, which increased to 22% after OLT (p > 0.0001). None had specific etiology. Etiology of this increase needs to be further investigated and the effects of immunosuppressive drugs on lower esophageal sprinter and gastric motility should be clarified. Use of acid suppressing drugs during the early post-transplant period should be considered.

A high ratio of dietary animal to vegetable protein increases the rate of bone loss and the risk of fracture in postmenopausal women. Study of Osteoporotic Fractures Research Group

BACKGROUND

Different sources of dietary protein may have different effects on bone metabolism. Animal foods provide predominantly acid precursors, whereas protein in vegetable foods is accompanied by base precursors not found in animal foods. Imbalance between dietary acid and base precursors leads to a chronic net dietary acid load that may have adverse consequences on bone.

OBJECTIVE

We wanted to test the hypothesis that a high dietary ratio of animal to vegetable foods, quantified by protein content, increases bone loss and the risk of fracture.

DESIGN

This was a prospective cohort study with a mean (+/-SD) of 7.0+/-1.5 y of follow-up of 1035 community-dwelling white women aged >65 y. Protein intake was measured by using a food-frequency questionnaire and bone mineral density was measured by dual-energy X-ray absorptiometry.

RESULTS

Bone mineral density was not significantly associated with the ratio of animal to vegetable protein intake. Women with a high ratio had a higher rate of bone loss at the femoral neck than did those with a low ratio (P = 0.02) and a greater risk of hip fracture (relative risk = 3.7, P = 0.04). These associations were unaffected by adjustment for age, weight, estrogen use, tobacco use, exercise, total calcium intake, and total protein intake.

CONCLUSIONS

Elderly women with a high dietary ratio of animal to vegetable protein intake have more rapid femoral neck bone loss and a greater risk of hip fracture than do those with a low ratio. This suggests that an increase in vegetable protein intake and a decrease in animal protein intake may decrease bone loss and the risk of hip fracture. This possibility should be confirmed in other prospective studies and tested in a randomized trial.

Liver transplantation in a patient at psychosocial risk

Psychosocial assessment of transplant candidates is a challenging task. Securing adequate information is made more difficult when patients present with fulminant hepatic failure. When the patient cannot be interviewed and the family is reluctant to provide vital information, a comprehensive pretransplant psychosocial evaluation is virtually impossible. However, even the most difficult cases have the potential for a positive result when a good psychosocial profile of the patient is obtained after transplantation, a team treatment plan is developed and carried out which addresses current and anticipated problems, and the patient obtains mental health treatment.

Effect of transjugular intrahepatic portosystemic shunt on thrombocytopenia associated with cirrhosis

Thrombocytopenia is a frequent complication of cirrhosis. Its pathogenesis is not well known, but it has been suggested that splenic congestion induced by portal hypertension may be a major contributory factor. However, the available data regarding the effect of portal decompression either by surgical shunts or transjugular intrahepatic portosystemic shunt (TIPS) on peripheral platelet count in cirrhotics is conflicting. We studied the effects of TIPS on platelet count and mean platelet volume, following a successful TIPS placement. The platelet count had a tendency to decrease but was not statistically significant (120,100 +/- 72,100/mm3 before TIPS vs 99,800 +/- 51,400/mm3 after TIPS). The mean platelet volume remained essentially unchanged (9.8 +/- 1.5 fL before TIPS and 9.9 +/- 1.5 fL after TIPS). These results confirm that TIPS has an unpredictable effect on platelet count in cirrhotic patients with thrombocytopenia. The lack of a consistent increase in the peripheral mean platelet volume following TIPS placement suggests that TIPS is unable to significantly enhance the release of platelets sequestered in the splenic compartment in portal hypertension.

Worldwide incidence of hip fracture in elderly women: relation to consumption of animal and vegetable foods

BACKGROUND

Hip fracture, a major health problem in elderly persons, varies in incidence among the populations of different countries and is directly related to animal protein intake, a finding that suggests that bone integrity is compromised by endogenous acid production consequent to the metabolism of animal proteins. If that is so, vegetable foods might provide a countervailing effect, because they are a rich source of base (bicarbonate) in the form of metabolizable organic anions, which can neutralize protein-derived acid and supply substrate (carbonate) for bone formation.

METHODS

We analyzed reported hip fracture incidence (HFI) data among countries (N = 33) in women aged 50 years and older, in relation to corresponding country-specific data on per capita consumption of vegetable and animal foods as reported by the United Nations Food and Agriculture Organization.

RESULTS

HFI varied directly with total (r = +.67, p < .001) and animal (r = +.82, p < .001) protein intake and inversely with vegetable protein intake (r = .37, p < .04). The countries in the lowest tertile of HFI (n = 11) had the lowest animal protein consumption, and invariably, vegetable protein (VP) consumption exceeded the country's corresponding intake of animal protein (AP): VP/AP > 1.0. By contrast, among the countries in the highest tertile of HFI, animal protein intake exceeded vegetable protein intake in nearly every case (10 of 11 countries). Among all countries, HFI correlated inversely and exponentially with the ratio of vegetable/animal protein intake (r = -.84, p < .001) and accounted for 70% of the total variation in HFI. Adjusted for total protein intake, vegetable food consumption was an independent negative predictor of HFI. All findings were similar for the subset of 23 countries whose populations are predominantly Caucasian.

CONCLUSION

The findings suggest that the critical determinant of hip fracture risk in relation to the acid-base effects of diet is the net load of acid in the diet, when the intake of both acid and base precursors is considered. Moderation of animal food consumption and an increased ratio of vegetable/animal food consumption may confer a protective effect.

Comparative effects of potassium chloride and bicarbonate on thiazide-induced reduction in urinary calcium excretion

BACKGROUND

The chronic low-grade metabolic acidosis that occurs in various renal disorders and in normal people, and that is related both to dietary net acid load and age-related renal functional decline, may contribute to osteoporosis by increasing urine calcium excretion. Administration of potassium (K) alkali salts neutralizes acid and lowers urine calcium excretion. Urine calcium excretion also can be reduced by the administration of thiazide diuretics, which are often given with supplemental K to avoid hypokalemia. We determined whether the K alkali salt potassium bicarbonate (KHCO3) and the thiazide diuretic hydrochlorothiazide (HCTZ) combined is more effective in reducing urinary calcium than KHCO3 alone or HCTZ combined with the conventionally coadministered nonalkalinizing K salt potassium chloride (KCl).

METHODS

Thirty-one healthy men and women aged 50 or greater were recruited for a four-week, double-blind, randomized study. After a baseline period of 10 days with three 24-hour urine and arterialized blood collections, subjects were randomized to receive either HCTZ (50 mg) plus potassium (60 mmol daily) as either the chloride or bicarbonate salt. Another 19 women received potassium bicarbonate (60 mmol) alone. After two weeks, triplicate collections of 24-hour urines and arterialized bloods were repeated.

RESULTS

Urinary calcium excretion decreased significantly in all groups. KHCO3 alone and HCTZ + KCl induced similar decreases (-0.70 +/- 0.60 vs. -0.80 +/- 1. 0 mmol/day, respectively). Compared with those treatments, the combination of HCTZ + KHCO3 induced more than a twofold greater decrease in urinary calcium excretion (-1.8 +/- 1.2 mmol/day, P < 0. 05). Both HCTZ + KHCO3 and KHCO3 alone reduced net acid excretion significantly (P < 0.05) to values of less than zero.

CONCLUSIONS

KHCO3 was superior to KCl as an adjunct to HCTZ, inducing a twofold greater reduction in urine calcium excretion, and completely neutralizing endogenous acid production so as to correct the pre-existing mild metabolic acidosis that an acid-producing diet usually induces in older people. Accordingly, for reducing urine calcium excretion in stone disease and osteoporosis, the combination of HCTZ + KHCO3 may be preferable to that of HCTZ + KCl.

Selective decontamination of the digestive tract helps prevent bacterial infections in the early postoperative period after liver transplant

In liver transplant (LTx) recipients, gut-associated bacterial and fungal organisms produce significant postoperative morbidity and mortality. We sought to assess the role of selective digestive decontamination (SDD) in preventing postoperative infections in a large single-center cohort of liver recipients transplanted under two non-simultaneous protocols. In 212 consecutive patients transplanted between 1/1/91 and 7/31/92, SDD (gentamicin 80 mg, polymyxin B 100 mg, nystatin suspension 10 mL) was employed, starting after induction of anesthesia and continued until POD 21 (SDD Group). In 157 consecutive patients transplanted between 1/1/93 and 12/31/93, SDD was not used (non-SDD Group). Both groups received IV vancomycin and cefotaxime prophylaxis. All culture-positive infections within the first 30 days post-LTx were recorded and classified as bacterial or fungal. Infection-related mortality (patients who died of infectious complications without any technical complication) was recorded. Groups did not differ in patient demographics, United Network for Organ Sharing (UNOS) status, use of veno-venous bypass, total/warm ischemia, or length of ICU stay. Infections developed in fewer SDD patients (56/212; 26%) than non-SDD patients (69/157; 44%) (p<0.001). The incidence of gram-negative infection was less in the SDD group (11% vs. 26%, p<0. 001) as was gram-positive infection (16% vs. 26%, p<0.001). Among patients who developed infection, there was no difference between groups in infections per patient. Primary graft non-function (PNF) developed in 20 SDD patients (7/20 had infections) and 8 non-SDD patients (6/8 had infections) (p=0.06). There were no differences in incidence of fungal infections or of infection-related mortality between groups. In the SDD group, there were fewer abdominal (p<0. 001), lung (p<0.001), wound (p<0.01), and urinary tract infections (p<0.05).

CONCLUSION

Use of SDD in liver recipients early after transplant was associated with significantly fewer infections in the early postoperative period.

Differing effects of supplemental KCl and KHCO3: pathophysiological and clinical implications

Compared to the prehistoric diet, the modern human diet contains not only excessive NaCl and deficient K+, but also deficient precursors of HCO3- and sometimes excessive precursors of nonvolatile acid. The mismatch between the modern diet and the still ancient biological machinery of humans subtly but chronically disorders their internal milieu, giving rise to a prolonged state of low-grade potassium deficiency and low-grade metabolic acidosis whose severity increases with age. Supplemental KCI cannot redress this mismatch and correct this state. However, the mismatch is redressed and the state corrected by restoring intakes of K+ and HCO3- to levels approaching those in the diet of our prehistoric forebearers, with either fruits and vegetables or with supplemental KHCO3. So restored, KHCO3 can: 1) attenuate hypertension and possibly prevent its occurrence by suppressing the phenomenon of normotensive NaCl-sensitivity, in part by its natriuretic effect; (2) prevent kidney stones by reducing urinary excretion of calcium and increasing urinary excretion of citrate; (3) ameliorate and protect against the occurrence of osteoporosis by increasing the renal retention of calcium and phosphorus, and by suppressing bone resorption and enhancing bone formation; and (4) likely prevent stroke.

Medication nonadherence and its relation to financial restriction

The question of patient nonadherence has always been an important factor in determining candidate suitability for organ transplantation. Data that explore the association of financial problems and posttransplant medication nonadherence are limited. Findings suggest that medication nonadherence was more likely to occur when recipients did not have insurance coverage and had to rely on Medicaid or indigent drug programs. Our center developed a formalized program within the outpatient pharmacy, including a full-time medication counselor who helped recipients secure resources to pay for pre- and posttransplant medications. To determine whether the availability of posttransplant medications could reduce medication nonadherence, we conducted a survey with 50 consecutive liver transplant recipients in the outpatient clinic. Nonadherence rates were significantly reduced from 25% to 10% (P < .01) compared with recipients who had been transplanted before the development of our drug program. These results suggest that optimum medication adherence can be obtained when recipients are provided guidance in securing their necessary medications without financial restriction.

Nitrocinnamoyl and chlorocinnamoyl derivatives of dihydrocodeinone: in vivo and in vitro characterization of mu-selective agonist and antagonist activity

Two 14beta-p-nitrocinnamoyl derivatives of dihydrocodeinone, 14beta-(p-nitrocinnamoylamino)-7,8-dihydrocodeinone (CACO) and N-cyclopropylmethylnor-14beta-(p-nitrocinnamoylamino)- 7, 8-dihydrocodeinone (N-CPM-CACO), and the corresponding chlorocinnamoylamino analogs, 14beta-(p-chlorocinnamoylamino)-7, 8-dihydrocodeinone (CAM) and N-cyclopropylmethylnor-14beta-(p-chlorocinnamoylamino) -7, 8-dihydrocodeinone (MC-CAM), were tested in opioid receptor binding assays and the mouse tail-flick test to characterize the opioid affinity, selectivity, and antinociceptive properties of these compounds. In competition binding assays, all four compounds bound to the mu opioid receptor with high affinity. When bovine striatal membranes were incubated with any of the four dihydrocodeinones, binding to the mu receptor was inhibited in a concentration-dependent, wash-resistant manner. Saturation binding experiments demonstrated that the wash-resistant inhibition of mu binding was due to a decrease in the Bmax value for the binding of the mu-selective peptide [3H][D-Ala2, MePhe4,Gly(ol)5] enkephalin and not a change in the Kd value, suggesting an irreversible interaction of the compounds with the mu receptor. In the mouse 55 degrees C warm water tail-flick test, both CACO and N-CPM-CACO acted as short-term mu-selective agonists when administered by i. c.v. injection, whereas CAM and MC-CAM produced no measurable antinociception at doses up to 30 nmol. Pretreatment of mice for 24 h with any of the four dihydrocodeinone derivatives produced a dose-dependent antagonism of antinociception mediated by the mu but not the delta or kappa receptors. Long-term antagonism of morphine-induced antinociception lasted for at least 48 h after i.c. v. administration. Finally, shifts in the morphine dose-response lines after 24-h pretreatment with the four dihydrocodeinone compounds suggest that the nitrocinnamoylamino derivatives may produce a greater magnitude long-term antagonism of morphine-induced antinociception than the chlorocinnamoylamino analogs.

NaCl-induced renal vasoconstriction in salt-sensitive African Americans: antipressor and hemodynamic effects of potassium bicarbonate

In 16 African Americans (blacks, 14 men, 2 women) with average admission mean arterial pressure (MAP, mm Hg) 99.9+/-3.5 (mean+/-SEM), we investigated whether NaCl-induced renal vasoconstriction attends salt sensitivity and, if so, whether supplemental KHCO3 ameliorates both conditions. Throughout a 3-week period under controlled metabolic conditions, all subjects ate diets containing 15 mmol NaCl and 30 mmol potassium (K+) (per 70 kg body wt [BW] per day). Throughout weeks 2 and 3, NaCl was loaded to 250 mmol/d; throughout week 3, dietary K+ was supplemented to 170 mmol/d (KHCO3). On the last day of each study week, we measured renal blood flow (RBF) and glomerular filtration rate (GFR) using renal clearances of PAH and inulin. Ten subjects were salt sensitive (SS) (DeltaMAP >+5%) and 6 salt resistant (SR). In NaCl-loaded SS but not SR subjects, RBF (mL/min/1.73 m2) decreased from 920+/-75 to 828+/-46 (P<0.05); filtration fraction (FF, %) increased from 19. 4+/- to 21.4 (P<0.001); and renal vascular resistance (RVR) (10(3)xmm Hg/[mL/min]) increased from 101+/-8 to 131+/-10 (P<0.001). In all subjects combined, DeltaMAP varied inversely with DeltaRBF (r =-0.57, P=0.02) and directly with DeltaRVR (r = 0.65, P=0.006) and DeltaFF (r = 0.59, P=0.03), but not with MAP before NaCl loading. When supplemental KHCO3 abolished the pressor effect of NaCl in SS subjects, RBF was unaffected but GFR and FF decreased. The results show that in marginally K+-deficient blacks (1) NaCl-induced renal vasoconstrictive dysfunction attends salt sensitivity; (2) the dysfunction varies in extent directly with the NaCl-induced increase in blood pressure (BP); and (3) is complexly affected by supplemented KHCO3, GFR and FF decreasing but RBF not changing. In blacks, NaCl-induced renal vasoconstriction may be a pathogenetic event in salt sensitivity.