Sex and menstrual cycle differences in the subjective effects from smoked cocaine in humans

To investigate sex and menstrual cycle effects in response to cocaine administration, data from existing studies were analyzed. First, responses to a single delivery of 0.4 mg/kg smoked cocaine were investigated. Women reported lower ratings for measures of paranoid/suspicious and heart racing/pounding than did men. In addition, women in the luteal phase reported diminished ratings for a measure of feel high than did both women in the follicular phase of the menstrual cycle and men. Second, responses to up to 6 deliveries of 0.4 mg/kg smoked cocaine were investigated. Women, compared with men, had lower ratings on feel high, heart racing/pounding, and feel stimulated. Results suggest that there are significant sex and menstrual phase differences in the subjective effects of cocaine.

The wallstent I and II for malignant esophageal obstruction

The Wallstent I and II esophageal endoprostheses are effective in the palliation of malignant esophageal obstruction and the closure of digestive-respiratory fistulas. The author reviews the evolution of the Wallstent esophageal endoprosthesis and techniques for successful insertion, and summarizes the published literature with regard to clinical outcomes of the European and American Wallstent designs.

Exclusion criteria enhance the specificity and positive predictive value of NMP22 and BTA stat

PURPOSE

The limitation of current urinary tumor markers is the low specificity and positive predictive value, which clinically manifests as a high false-positive rate. We analyzed the false-positive data of 2 urinary tumor markers, NMP22 and the BTA stat tests. We examined the clinical categories of the false-positive results, established relative exclusion criteria, and recalculated the specificity and positive predictive value after using the exclusion criteria.

MATERIALS AND METHODS

A total of 278 symptomatic patients who presented to a urology clinic were asked to submit a single voided urine sample. Each sample was divided into 3 aliquots of which 1 was stabilized with the NMP22 test kit stabilizer and assayed for NMP22, 1 was tested for BTA stat and 1 was sent for cytological examination. All patients subsequently underwent office cystoscopy and bladder biopsy if indicated.

RESULTS

Of the 278 symptomatic patients 112 presented with microscopic hematuria, 77 gross hematuria and 89 chronic symptoms of urinary frequency or dysuria. Of 34 cases (12%) of histologically confirmed bladder cancer NMP22 detected 28 (82.4%), BTA stat 23 (67.7%) and cytology only 10 (29.4%). When atypical cytologies were considered positive, cytology then detected 19 cases (55.9%). Elevated NMP22 values were positive in 28 cases and false-positive in 44 for a specificity of 82% and a positive predictive value of 38.9%. Similarly, BTA stat test was positive in 23 cases and false-positive in 43 for a specificity of 82.4% and a positive predictive value of 34.9%. When atypical cytologies were considered positive, the specificity and positive predictive value were 93% and 55.9%. Greater than 80% of the false-positive results were clinically categorized as benign inflammatory or infectious conditions, renal or bladder calculi, recent history of a foreign body in the urinary tract, bowel interposition segment, another genitourinary cancer or an instrumented urinary sample. A category of "no known pathology" was included in analysis as a control. History of ureteral stents or any bowel interposition segment had a 100% false-positive rate. Exclusion of all 6 clinical categories improved the specificity and positive predictive value of NMP22 (95.6%, 87.5%) and BTA stat (91.5%, 69.7%), and was similar to urinary cytology.

CONCLUSIONS

Awareness and exclusion of the categories of false-positive results can increase the specificity and enhance the clinical usefulness of NMP22 and BTA stat tests. Similarly, treating an atypical cytology as positive can enhance the sensitivity and usefulness of urinary cytology.

Withdrawal and pre-menstrual symptomatology during the menstrual cycle in short-term smoking abstinence: effects of menstrual cycle on smoking abstinence

This study employs a rigorous inpatient laboratory setting to test the hypothesis that withdrawal symptomatology in short-term smoking cessation in women is increased in the late luteal phase when pre-menstrual symptomatology is the highest. Twenty-one female smokers with clinical, anatomical, and hormonal verification of their menstrual cycle phase were randomized to either a smoking abstinence group (n = 16) or a continued smoking group (n = 5). Participants were admitted to the General Clinical Research Center during alternate phases of their cycle for two 7-day admissions with a 1-month interim period when they resumed smoking. Dependent measures, i.e., Minnesota Nicotine Withdrawal Scale scores, Questionnaire on Smoking Urges scores and Pre-menstrual Assessment Form scores were collected during 2 days of baseline and 5 days of smoking deprivation. Smoking behavior was documented by self-report, breath CO levels and saliva cotinine measurements. Withdrawal symptomatology was not affected by menstrual cycle phase during short-term cessation in spite of increased pre-menstrual changes seen in the late luteal phase. In addition, no phase effect on smoking behavior was detected and cigarette consumption remained stable across the cycle in both groups. These results suggest that for some smoking cessation studies, complex strategies to control for menstrual cycle effects may not be necessary. However, Smoking Urges scores did suggest increased desire to smoke and desire to relieve negative affect in the late luteal phase when women have higher pre-menstrual symptomatology. This suggests women may have greater difficulty quitting smoking in late luteal phase, and it seems prudent to recommend that women quit during the follicular phase of their cycle.

"Lifepoint": a case study in using social science community identification data to guide the implementation of a needle exchange program

The public health benefits of needle exchange programs (NEPs) are well known. NEPs lower risk factors for HIV transmission by providing injection drug users (IDUs) with clean syringes and needles; harm reduction materials; and referrals to drug, sexually transmitted disease, mental health, and medical treatment facilities. While exchange programs continue to be implemented, there have been few reports illustrating how social science and community assessment research can be used to guide the development of NEPs. Using the Lifepoint needle exchange program in Milwaukee as a case study, this paper shows how social science methods can be used to understand IDU culture through the community identification process, link qualitative and observational findings to program decision making, and guide the implementation and operation of a needle exchange. The community identification process showed that there were different IDU subcultures in the city indicating that the NEP would need to be tailored to meet the distinctive needs of multiple drug use networks. Ethnographic field observations and key informant and systems representative interviews resulted in a two-stage NEP planning process that included a community task force on IDUs and of the development of methods to operationalize community assessment findings into the operating plan of the NEP. This process illustrates the importance of integrating a systematic community analysis in the planning of a NEP.

Interventions in a heart transplant recipient with a histrionic personality disorder

Organ transplantation is a psychosocially demanding process. Patients must undergo a comprehensive evaluation to await a donor organ that may never become available. After transplantation, recipients must deal with the acceptance of a new organ and comply with a medical regimen that includes numerous medications, follow-up exams, and procedures. Emotional well-being is monitored throughout the transplant process. However, despite the best of efforts and thorough pretransplant bio-psycho-social evaluations, it is possible for patients to have significant psychopathology that remains undetected. Following the stress of transplantation, such patients may present with exacerbation of symptomatology, which has the potential to negatively affect compliance and long-term outcome.

Patient characteristics associated with vasectomy reversal

PURPOSE

More than 30 million couples throughout the world are using vasectomy as a method of birth control. It is estimated that up to 6% of men who undergo voluntary sterilization will eventually request reversal, despite the high cost and relatively low success rate of the procedure. We identified characteristics that predict which vasectomy patients may request reversal. We also examined the cost and effectiveness of pre-vasectomy sperm cryopreservation followed by intrauterine insemination as an alternative method of achieving pregnancy.

MATERIALS AND METHODS

We reviewed medical charts of 365 patients who underwent vasectomy and 290 who underwent vasectomy reversal between 1990 and 1997. Data were collected on patient age at the time of vasectomy, religion, occupation, wife employment status, number of marriages, number of children, reason for reversal, and number of years between vasectomy and reversal. Based on previously reported values, pregnancy rates and cost per successful pregnancy were estimated for vasectomy reversal surgery, and compared with a calculated cost per pregnancy for sperm cryopreservation and intrauterine insemination.

RESULTS

Patient factors significantly associated with increased vasectomy reversal included younger age at time of vasectomy (p < 0.001) and a wife who worked outside the home (p < 0.001). Vasectomy reversal occurred 12.5 times more often (95% confidence interval [CI] 7.6 to 20.7) in men who underwent vasectomy in their 20s than in men who were older. Men whose wives were not employed requested reversal 0.48 times as often (95% CI 0.33 to 0.71) as those whose wives worked. Men who were younger at vasectomy tended to wait longer before reversal (median 10 years) than other patients (p < 0.001). At 10 years our calculated pregnancy rates and cost per pregnancy were 44% and $12,727 for vasectomy reversal, and 41% and $9,512 for intrauterine insemination with banked sperm (3 attempts).

CONCLUSIONS

Patients who requested vasectomy reversal most often chose voluntary sterilization at a younger age. We believe that younger men should be given better pre-vasectomy counseling. However, the success rate and cost-effectiveness of sperm cryopreservation before vasectomy, with subsequent intrauterine insemination, may make this nonsurgical alternative desirable for younger couples who choose vasectomy even when properly informed about reversal rates.

Development of a consumer survey for behavioral health services

A consumer survey was designed to assess the quality of mental health and substance abuse services and evaluate insurance plans that provide such services. This paper describes the development of the Consumer Assessment of Behavioral Health Services instrument, which began with a review of existing consumer satisfaction surveys and input from several groups working toward development of nationally standardized satisfaction instruments. Consumer focus groups were used to ensure that all the important domains of quality were included, and group members were interviewed to ensure that all items on the instrument were understandable. Results of a pilot test conducted with 160 consumers, 82 enrolled in Medicaid plans and 78 in commercial plans, suggested that the survey was able to distinguish between the two groups in terms of evaluations of their care and insurance plans. Future efforts will focus on further testing of larger, more diverse samples and on developing scoring and reporting formats for the survey that will be useful to consumers and purchasers in choosing behavioral health services and plans.

Reduced mRNA for G3BP in fragile X cells: evidence of FMR1 gene regulation

Although fragile X syndrome is caused by the absence of fragile X gene expression, little is known about the pathogenic processes underlying the mental retardation. Recent findings that the fragile X protein, FMRP, contains RNA binding motifs and nuclear transport signals and associates with ribosomes suggest that FMRP may be involved in either mRNA processing, transport, or translation. To test the hypothesis that absence of FMRP may affect the processing of specific transcripts, we have used an RNA differential display assay (RDDA) to identify differentially expressed transcripts in lymphoblast lines derived from fragile X syndrome patients. A 0.9-kb cDNA fragment that showed reduced expression in a fragile X lymphoblast cell line was found to be identical to G3BP (Ras-GTPase-Activating protein SH3-domain-binding protein). Quantitative reverse transcriptase-polymerase chain reaction showed that the expressed levels of G3BP mRNA in fragile X lymphoblast cell lines were significantly less than controls. Our results indicate that G3BP mRNA may be regulated by FMRP and supports the hypothesis that FMRP may modulate the transcription of specific transcripts.

Tumor antigens are constitutively presented in the draining lymph nodes

Tumor growth is rarely associated with a strong specific CTL response, suggesting that the immune system is ignorant of the presence of tumor because the Ags are not readily available to or are sequestered from potential effector cells. We studied the in vivo activation of naive TCR transgenic hemagglutinin (HA)-specific CD8+ T cells adoptively transferred into mice bearing HA-expressing tumor using 5,6-carboxy-succinimidyl-fluorescein-ester labeling, which allows the identification of proliferating HA-specific T cells. We demonstrate that tumor Ags are constitutively presented in the lymph nodes draining tumors and are powerfully mitogenic for responding T cells despite the absence of anti-tumor CTL responses. Importantly, this proliferative signal occurs throughout tumor growth and is still detectable 6 mo after tumor inoculation when tumor is not palpable. These results provide the first evidence that there is constitutive presentation of tumor Ags in draining lymph nodes.

Distress and growth outcomes in mothers of medically fragile infants

BACKGROUND

With recent advances in medical and nursing care, many high-risk infants are surviving the neonatal period with severe, life-threatening chronic illnesses, resulting in extended hospitalizations and/or frequent rehospitalizations and long periods of dependence on technology for survival.

OBJECTIVE

To describe the factors predicting maternal adjustment in mothers caring for medically fragile infants.

METHOD

Subjects were mothers (n = 67) whose infants had a serious life-threatening illness requiring hospitalization and technology for survival. Data for this longitudinal study were collected at enrollment and hospital discharge, and at 6, 12, and 16 months after birth. Distress was measured as depressive symptoms using the Center for Epidemiologic Studies Depression Scale, and growth was assessed using a personal developmental impact rating scale. Data about personal characteristics, parental role attainment, infant-illness characteristics, and maternal illness distress were collected.

RESULTS

Mothers of medically fragile infants experience distress and growth as a result of their child's illness. Mean scores on the depression scale at both time points were moderately high and a high percentage of mothers scored at risk for depressive symptoms. Maternal developmental impact ratings at 6 months were neutral to slightly negative and at 16 months were between neutral and positive. While the mean depressive symptom scores and maternal developmental ratings were lower at the later time points, these differences were not significant. Maternal depressive symptoms and developmental impact ratings were moderately but negatively correlated at 6 and 16 months, indicating that higher depressive symptoms were related to more negative developmental impact ratings. Distress was influenced by maternal characteristics, hospital environmental stress, and worry about the child's health. Growth was influenced by characteristics of the child's illness, hospital environmental stress, concern about the child's health, and level of maternal role attainment.

CONCLUSIONS

Nurses should consider personal characteristics and level of parental role attainment as well as characteristics of the child and illness-related distress in their approaches to intervention with mothers of critically ill infants.

Purification and characterization of a novel cysteine proteinase (periodontain) from Porphyromonas gingivalis. Evidence for a role in the inactivation of human alpha1-proteinase inhibitor

Periodontal disease is characterized by inflammation of the periodontium manifested by recruitment of neutrophils, which can degranulate, releasing powerful proteinases responsible for destruction of connective tissues, and eventual loss of tooth attachment. Although the presence of host proteinase inhibitors (serpins) should minimize tissue damage by endogenous proteinases, this is not seen clinically, and it has been speculated that proteolytic inactivation of serpins may contribute to progression of the disease. A major pathogen associated with periodontal disease is the Gram-negative anaerobe Porphyromonas gingivalis, and in this report, we describe a novel proteinase that has been isolated from culture supernatants of this organism that is capable of inactivating the human serpin, alpha1-proteinase inhibitor, the primary endogenous regulator of human neutrophil elastase. This new enzyme, referred to as periodontain, belongs to the cysteine proteinase family based on inhibition studies and exists as a 75-kDa heterodimer. Furthermore, periodontain shares significant homology to streptopain, a proteinase from Streptococcus pyogenes, and prtT, a putative proteinase from P. gingivalis. Clearly, the presence of this enzyme, which rapidly inactivates alpha1-proteinase inhibitor, could result in elevated levels of human neutrophil elastase clinically detected in periodontal disease and should be considered as a potential virulence factor for P. gingivalis.

Prolyl tripeptidyl peptidase from Porphyromonas gingivalis. A novel enzyme with possible pathological implications for the development of periodontitis

Porphyromonas gingivalis possesses a complex proteolytic system, which is essential for both its growth and evasion of host defense mechanisms. In this report we characterized, both at a protein and genomic level, a novel peptidase of this system with prolyl tripeptidyl peptidase activity. The enzyme was purified to homogeneity, and its enzymatic activity and biochemical properties were investigated. The amino acid sequence at the amino terminus and of internal peptide fragments enabled identification of the gene encoding this enzyme, which we refer to as PtpA for prolyl tripeptidyl peptidase A. The gene encodes an 82-kDa protein, which contains a GWSYGG motif, characteristic for members of the S9 prolyl oligopeptidase family of serine proteases. However, it does not share any structural similarity to other tripeptidyl peptidases, which belong to the subtilisin family. The production of prolyl tripeptidyl peptidase may contribute to the pathogenesis of periodontal tissue destruction through the mutual interaction of this enzyme, host and bacterial collagenases, and dipeptidyl peptidases in the degradation of collagen during the course of infection.

Identification of an integration center for cross-talk between protein kinase C and G protein modulation of N-type calcium channels

The modulation of presynaptic calcium channel activity by second messengers provides a fine tuning mechanism for neurotransmitter release. In neurons, the activation of certain G protein-coupled receptors reduces N-type channel activity by approximately 60%. In contrast, activation of protein kinase C (PKC) results in an approximately 50% increase in N-type channel activity, and subsequent G protein inhibition is antagonized. Here, we describe the molecular determinants that control the dual effects of PKC-dependent phosphorylation. The double substitution of two adjacent PKC consensus sites in the calcium channel domain I-II linker (Thr422, Ser425) to alanines abolished both PKC-dependent up-regulation and the PKC-G protein cross-talk. The single substitution of Ser425 to glutamic acid abolished PKC up-regulation but had no effect on G protein modulation. Replacement of Thr422 with glutamic acid eliminated PKC-dependent up-regulation and mimicked the effects of PKC phosphorylation on G protein inhibition. Our data suggest that Thr422 mediates the antagonistic effect of PKC on G protein modulation, while phosphorylation of either Thr422 or Ser425 are sufficient to increase N-type channel activity. Thus, Thr422 serves as a molecular switch by which PKC is able to simultaneously trigger the up-regulation of channel activity and antagonize G protein inhibition.

Localization and characterization of antithrombin in human kidneys

Antithrombin is a serine protease inhibitor that is critical in maintaining a thromboresistant vasculature. The association between low serum antithrombin concentration and renal disease suggests that the kidney plays a role in the conservation of plasma antithrombin. We used immunohistochemical techniques to determine the spatial distribution, heparin binding characteristics, and intracellular and intercellular localization of antithrombin in biopsy specimens (n = 53) of human donor kidneys obtained at the time of transplantation. In the renal cortex, double antibody techniques demonstrated the presence of intracellular antithrombin in proximal tubule epithelial cells. The reactivity was granular and was co-localized with vesicle-like structures. Distal and collecting tubules did not demonstrate intraepithelial antithrombin reactivity. No tubule structures in the medullary region demonstrated intracellular antithrombin, but all these structures showed intense basement membrane antithrombin reactivity. Double antibody techniques also demonstrated that the heparin binding domain of intraepithelial antithrombin was occupied. Semiquantitative scores for intraepithelial antithrombin were significantly decreased in renal biopsy specimens obtained 30 min after anastomosis compared with biopsies from the same organ obtained before anastomosis. These findings suggest that antithrombin, probably in association with heparin or heparan sulfate, is internalized by renal proximal epithelial cells. Although the ultimate fate of intraepithelial antithrombin is not known, this may represent a mechanism by which the kidney helps to maintain plasma antithrombin concentrations.

Clinical application of a new disposable lithotripter: a prospective multicenter study

BACKGROUND

Mechanical lithotripsy has become a well-accepted method of bile duct stone fragmentation and removal. The Olympus lithotripter (Olympus American, Melville, NY) is the standard reusable lithotripter at the institutions that participated in this study. A disposable device with a preassembled pistol grip may perform equally well and facilitate operation.

METHODS

Twenty patients with bile duct stones were evaluated as part of a multicenter prospective study. Data were obtained regarding stone size and number, bile duct diameter, and configuration, ease of cannulation, basket function, stone capture and crushing success, and complications.

RESULTS

The maximum stone size averaged 16.5 +/- 1.2 mm (range 10 to 30 mm). Sixteen patients had multiple stones (median 5, range 2 to 12). The mean bile duct diameter was 20.5 +/- 1.5 mm (range 12 to 38 mm). Cannulation was successful in all within 5 attempts. Basket deployment failed in 1 patient because of stone size and the basket was misshapen in 14. Bile duct clearance was complete in 16 subjects (80%), incomplete in 2 patients, and failed in 2 patients. Abnormal duct configuration (sigmoid, stricture) was noted in 2 of 4 patients with failed capture and 7 of 16 patients with successful clearance. No statistically significant difference was observed between the bile duct diameter, maximum stone size, number of stones, and successful clearance.

CONCLUSION

The disposable lithotripter is easy to use and, compared with the published results for the reusable lithotripter, performs almost as well.

Effect of seminal oxidative stress on fertility after vasectomy reversal

OBJECTIVE

To evaluate seminal oxidative stress in men after vasectomy reversal and to determine whether seminal oxidative stress could predict fertility after vasectomy reversal.

DESIGN

Measurement of seminal reactive oxygen species (ROS) and total antioxidant capacity (TAC) in normal donors, men who were fertile after vasectomy reversal, and men who were infertile after vasectomy reversal.

SETTING

A male infertility clinic of a tertiary care center.

PATIENT(S)

Thirty men who underwent vasectomy reversal and 17 normal donors.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Semen characteristics, seminal ROS, and TAC were measured with chemiluminescence assays in samples from donors and reversal patients.

RESULT(S)

Mean adjusted seminal ROS (log [ROS+1]) was higher in infertile reversal patients (2.38+/-0.25) than in normal donors (1.30+/-0.14). Seminal ROS was also higher in all (fertile and infertile reversal combined) reversal patients than in donors. Total antioxidant capacity did not differ between groups. The ROS-TAC score, a composite index of seminal oxidative stress, was a significant predictor of fertility. A ROS-TAC score of 45 or greater had a positive predictive value of 73% in predicting fertility.

CONCLUSION(S)

Seminal oxidative stress is associated with vasectomy reversal. The ROS-TAC score is a possible predictor of infertility after vasectomy reversal.

Adaptation to hypoxia alters energy metabolism in rat heart

The present study characterized metabolic changes in the heart associated with long-term exposure to hypoxia, a potent stimulus for pulmonary hypertension and right ventricular hypertrophy. When anesthetized rats adapted to chronic hypoxia spontaneously respired room air, their mean right intraventricular peak systolic pressure (RVSP) was twice that in normal control animals with the same arterial PO2. RVSP was linearly related to right ventricular mass (r = 0.78). Oxidative capacity (O2 consumption) of homogenates of right and left ventricles from both groups of rats was measured with one of the following substrates: pyruvate, glutamate, acetate, and palmitoyl-L-carnitine. Oxidation of all substrates was significantly greater in the left than in the right ventricle in normal rats but not in hypoxia-adapted animals, where it was the same, within the experimental error. O2 consumption by the left ventricle was greater in control than in experimental rats, but right ventricular O2 consumption was similar in the two groups. Maximal reaction velocity of cytochrome-c oxidase was about the same in the two ventricles, and there were no significant differences between control and hypoxia-adapted animals. HPLC analyses showed significantly higher aspartate levels and aspartate-to glutamate concentration ratios in both ventricles of hypoxic rats than in corresponding tissues from controls, indicative of a decreased flux through the malate-aspartate shuttle under conditions of O2 limitation. Myocardial glutamine levels were lower in hypoxic rats, and glutamine-to-glutamate concentration ratios decreased, although primarily in the pressure-overloaded right ventricle. These findings indicate that normal energy metabolism in the left ventricle differs from that in the right and that the differences, particularly those of amino acid metabolism, are markedly influenced by chronic exposure to hypoxia.

Comparing i.v. and non-i.v. cocaine users. Characteristics of a sample of cocaine users seeking to participate in research

The authors examined differences between current intravenous (i.v.), past i.v., and no i.v. cocaine use among a sample of cocaine users on measures of drug use, medical history, psychiatric history, and criminal history. Past i.v. cocaine users were older than non-i.v. cocaine users. The current i.v. cocaine-using group included more white participants, and the non-i.v. group included more African Americans. Those with past or current i.v. use had more extensive drug use histories than non-i.v. users. Also, more current and past i.v. cocaine-using groups reported having been tested for HIV and reported testing positive for hepatitis. Former i.v. cocaine users reported more emergency room visits for complications stemming from cocaine use. They also reported more treatment for substance abuse and were convicted of more crimes. These results suggest that the route of administration is important in studying the characteristics of drug users.

Decentralizing unit coordinator services

Restructuring unit coordinator/unit clerk services by decentralizing this staff and having them report directly to nurse managers can totally integrate them into the functions and activities of a patient-centered team. This article describes how nurse managers can evaluate the feasibility of decentralizing unit coordinators in their own institutions.

Newer antidepressants. Beyond selective serotonin reuptake inhibitor antidepressants

This article outlines the use of alternative agents to TCAs and SSRIs. Features of the more commonly used alternative antidepressant agents are outlined. In addition, antidepressant agents that are currently either under development or used in other countries are indicated for completeness because it seems likely that many of these will be introduced in the United States within the next few years. Many of these agents will be used by pediatricians and child psychiatrists for treatment of depression in children, and although much further research is needed, the future for alternative antidepressants and augmenting strategies is extremely promising.

Tubular antithrombin at transplantation determines subsequent renal allograft function

BACKGROUND

Antithrombin is found in the microvasculature and tubules of normal and transplanted human kidneys. Although depletion of vascular antithrombin is associated with renal allograft dysfunction, neither the distribution nor clinical significance of tubular antithrombin is known.

METHODS

Changes in tubular antithrombin in biopsy specimens (n=41) obtained from donor kidneys at transplantation were studied immunohistochemically. The relationship between these changes and subsequent graft function was analyzed.

RESULTS

Granular intracellular antithrombin was found only within the proximal tubular epithelium. Allografts with depleted tubular antithrombin at transplantation (n=20) had significantly greater plasma creatinine concentrations at posttransplant days 3 (P < 0.001) and 5 (P < 0.03) than allografts with normal tubular antithrombin (n=21). Indeed, depletion of tubular antithrombin at transplantation correlated with the degree of graft dysfunction at 3 days after transplantation.

CONCLUSIONS

Depleted tubular antithrombin at transplantation is associated with reduced early graft function, and this may identify patients at risk of a complicated follow-up.

Methylmalonate toxicity in primary neuronal cultures

Several inhibitors of mitochondrial complex II cause neuronal death in vivo and in vitro. The goal of the present work was to characterize in vitro the effects of malonate (a competitive blocker of the complex) which induces neuronal death in a pattern similar to that seen in striatum in Huntington's disease. Exposure of striatal and cortical cultures from embryonic rat brain for 24 h to methylmalonate, a compound which produces malonate intracellularly, led to a dose-dependent cell death. Methylmalonate (10 mM) caused >90% mortality of neurons although cortical cells were unexpectedly more vulnerable. Cell death was attenuated in a medium containing antioxidants. Further characterization revealed that DNA laddering could be detected after 3 h of treatment. Morphological observations (videomicroscopy and Hoechst staining) showed that both necrotic and apoptotic cell death occurred in parallel; apoptosis was more prevalent. A decrease in the ATP/ADP ratio was observed after 3 h of treatment with 10 mM methylmalonate. In striatal cultures it occurred concomitantly with a decline in GABA and a rise in aspartate content and the aspartate/glutamate ratio. Changes in ion concentrations were measured in similar cortical cultures from mouse brain. Neuronal [Na+]i increased while [K+]i and membrane potential decreased after 20 min of continuous incubation in 10 mM methylmalonate. These changes progressed with time, and a rise in [Ca2+]i was also observed after 1 h. The results demonstrate that malonate collapses cellular ion gradients, restoration of which imposes an additional load on the already compromised ATP-generation machinery. An early elevation in [Ca2+]i may trigger an increase in activity of proteases, lipases and endonucleases and production of free radicals and DNA damage which, ultimately, leads to cells death. The data also suggest that maturational and/or extrinsic factors are likely to be critical for the increased vulnerability of striatal neurons to mitochondrial inhibition in vivo.

Comparative properties of two cysteine proteinases (gingipains R), the products of two related but individual genes of Porphyromonas gingivalis

Proteolytic enzymes produced by Porphyromonas gingivalis are important virulence factors of this periodontopathogen. Two of these enzymes, referred to as arginine-specific cysteine proteinases (gingipains R), are the product of two related genes. Here, we describe the purification of an enzyme translated from the rgpB/rgp-2 gene (gingipain R2, RGP-2) and secreted as a single chain protein of 422 residues. The enzyme occurs in several isoforms differing in pI, molecular mass, mobility in gelatin zymography gels, and affinity to arginine-Sepharose. In comparison to the 95-kDa gingipain R1, a complex of catalytic and hemagglutinin/adhesin domains, RGP-2 showed five times lower proteolytic activity, although its activity on various P1-arginine p-nitroanilide substrates was generally higher. Gingipains R amidolytic activity, but not general proteolytic activity, was stimulated by glycyl-glycine. However, in cases of limited proteolysis, such as the inactivation of alpha-1-antichymotrypsin, glycyl-glycine potentiated inhibitor cleavage. In contrast, alpha-1-proteinase inhibitor was not inactivated by gingipains R and only underwent proteolytic degradation during boiling in reducing SDS-polyacrylamide gel electrophoresis treatment buffer. Similarly, native type I collagen was completely resistant to cleavage by gingipains but readily degraded after denaturation. Together, these data explain much of the controversy regarding gingipains structure and substrate specificity and indicate that these enzymes function as P. gingivalis virulence factors by proteolysis of selected target proteins rather than random degradation of host connective tissue components.

The timing of skin acidification in very low birth weight infants

OBJECTIVE

The purpose of this study was to examine the development of the pH mantle of the skin in very low birth weight (VLBW) infants.

STUDY DESIGN

Forty VLBW infants underwent repeated measurements of skin pH over the first month of life using a glass flat-surface pH electrode. Six skin sites were measured, daily for the first week of life and then twice weekly for the next 3 weeks.

RESULTS

The only factor that affected the initial skin pH was sex, with males having a significantly higher pH at birth. Over time, birth weight, skin area, and postnatal age had significant effects on skin pH. The pattern of postnatal change in skin pH was similar to that described in term infants, a rapid decrease in pH over the first week followed by a more gradual decrease over the next 3 weeks.

CONCLUSION

The development of the skin's acid mantle in VLBW infants occurs rapidly during postnatal life and closely mimics the pattern seen at term.

Inactivation of alpha1-proteinase inhibitor as a broad screen for detecting proteolytic activities in unknown samples

The need for a quick, simple screening method for the detection of general proteolytic activity prompted us to determine whether cleavage within the reactive site loop region (RSL) of alpha1-proteinase inhibitor (alpha1-PI), a well-characterized member of the serpin family known to be susceptible to proteolytic inactivation, can be utilized for this purpose. Inactivation of alpha1-PI in the RSL region can be measured by loss of residual inhibitory capacity of alpha1-PI against its target proteinase. While we originally utilized this assay to detect a new proteinase from culture supernatants of Porphyromonas gingivalis, the feasibility of extending this assay to scan for proteolytic activity from other systems was also assessed. As an example, we found that the serine proteinase from Staphylococcus aureus (SSP) had virtually the same catalytic efficiency in inactivating alpha1-PI in our assay as it did in the hydrolysis of the synthetic substrate Z-Phe-Leu-Glu-pNA (kcat/Km value of 2 x 10(4) M-1 s-1 vs 2.6 x 10(4) M-1 s-1, respectively). Additionally, in both assays activity could be readily detected in less than a 1 h incubation at SSP concentrations in the picomolar range. This assay is unique in that proteinases which hydrolyze peptide bonds within the RSL of alpha1-PI can readily be detected as measured by loss of alpha1-PI inhibitory activity.

Effects of cotinine on cigarette self-administration

Previous studies have shown that cotinine, a metabolite of nicotine, antagonizes some of the effects of nicotine. One study showed that cotinine eliminates the beneficial effects of the nicotine patch in reducing cigarette withdrawal symptoms. The purpose of this study was to examine the effects of various doses of cotinine on cigarette self-administration. Subjects were randomly assigned to one of three doses of cotinine fumarate (40, 80 and 160 mg) and placebo, each for a period of 10 days, in a randomized order. Outcome variables included measures of nicotine intake and subjective responses to smoked cigarettes. Results showed no differences in the number of cigarettes smoked, carbon monoxide levels, and weights of cigarette butts across the various doses of cotinine and placebo. However, higher nicotine serum levels were observed in the 160 mg cotinine fumarate condition compared to placebo and to 40 mg cotinine fumarate. No systematic effects of cotinine on subjective responses to cigarettes were observed. Cotinine appears potentially to have a selective modulatory effect on nicotine withdrawal symptoms but not on cigarette smoking.

Toxicity of dopamine to striatal neurons in vitro and potentiation of cell death by a mitochondrial inhibitor

Intrastriatal injections of the mitochondrial toxins malonate and 3-nitropropionic acid produce selective cell death similar to that seen in transient ischemia and Huntington's disease. The extent of cell death can be attenuated by pharmacological or surgical blockade of cortical glutamatergic input. It is not known, however, if dopamine contributes to toxicity caused by inhibition of mitochondrial function. Exposure of primary striatal cultures to dopamine resulted in dose-dependent death of neurons. Addition of medium supplement containing free radical scavengers and antioxidants decreased neuronal loss. At high concentrations of the amine, cell death was predominantly apoptotic. Methyl malonate was used to inhibit activity of the mitochondrial respiratory chain. Neither methyl malonate (50 microM) nor dopamine (2.5 microM) caused significant toxicity when added individually to cultures, whereas simultaneous addition of both compounds killed 60% of neurons. Addition of antioxidants and free radical scavengers to the incubation medium prevented this cell death. Dopamine (up to 250 microM) did not alter the ATP/ADP ratio after a 6-h incubation. Methyl malonate, at 500 microM, reduced the ATP/ADP ratio by approximately 30% after 6 h; this decrease was not augmented by coincubation with 25 microM dopamine. Our results suggest that dopamine causes primarily apoptotic death of striatal neurons in culture without damaging cells by an early adverse action on oxidative phosphorylation. However, when combined with minimal inhibition of mitochondrial function, dopamine neurotoxicity is markedly enhanced.

Increased platelet microvesicle formation is associated with mortality in a porcine model of endotoxemia

BACKGROUND

Gram-negative sepsis in humans and endotoxemia in pigs induce the formation of platelet microvesicles. These microvesicles are active in homeostasis and may thus contribute to the outcome in patients with activated coagulation and fibrinolysis. We decided to prospectively evaluate the effects of endotoxemia on microvesicle formation and some common physiologic variables against survival in a porcine model.

METHODS

Nineteen included pigs were anesthetized, monitored and subjected to an infusion of E. coli endotoxin. Microvesicle formation was determined by flow cytometry.

RESULTS

The formation of microvesicles was significantly increased in the 6 pigs that died during endotoxin exposure. This increased formation became significant from the 3rd hour of endotoxemia. Microvesicle formation did not increase in surviving endotoxemic pigs. Cardiac index, mean arterial blood pressure, base excess and systemic vascular resistance index were distinctly reduced in the animals that died as compared to those surviving the endotoxemic period.

CONCLUSION

The increased formation of platelet microvesicles seems to be associated with poor prognosis in porcine endotoxemia. Since microvesicles are active in coagulation, they may contribute to the derangement of the coagulation system caused by endotoxemia. Different degrees of microvesicle formation may reflect inter-individual responses to a given challenge.

The B-subunit of cholera toxin induces immunoregulatory cells and prevents diabetes in the NOD mouse

The B-subunit of the cholera toxin molecule (CT-B) has T-cell immunomodulatory properties. Because the pathogenesis of diabetes in the nonobese diabetic (NOD) mouse model of IDDM is thought to be a T-cell-mediated process due to an imbalance of immunoregulatory and anti-islet effector cells, we examined the effect of CT-B administration on the development of diabetes in the NOD mouse and assessed whether this potential diabetes-sparing effect of CT-B is mediated by changes in immunoregulatory and/or anti-islet cytotoxic effector cell activity. The administration of either intravenous or intraperitoneal CT-B decreased the development of diabetes with no apparent drug toxicity. At 6 months of age, only 18% of CT-B vs. 75% of saline-treated animals had diabetes. Histopathological examination revealed less islet atrophy in CT-B-treated animals. The in vitro proliferative responses of mononuclear splenocytes and thymocytes to concanavalin A and lipolysaccharide and the proportion of B-cells and T-cell subsets were not altered by CT-B treatment. CT-B administration did not inhibit the primary immunization of mice to tetanus toxoid. The development of diabetes in irradiated NOD mice was slower in the animals injected with spleen cells (SC) from CT-B-treated than from saline-treated NOD mice, suggesting that CT-B decreases anti-islet effector cell activity. The injection of SC from CT-B-treated mice inhibited the adoptive transfer of diabetes by SC from diabetic mice into irradiated NOD mice, documenting that CT-B administration induces regulatory cell activity. In conclusion, CT-B administration prevents the development of diabetes in NOD mice by inhibiting the immune destruction of islets. This islet-sparing activity appears mediated, at least in part, by the induction of regulatory cells and, in turn, suppression of anti-islet effector cells, which is not associated with generalized immunosuppression or T- or B-cell depletion.

Cotinine: effects with and without nicotine

The purpose of this study was to examine the effects of the metabolite of nicotine, cotinine, in comparison to the effects of the nicotine patch, and a combination thereof during cigarette abstinence. More specifically, this study examined the effects of cotinine on physiological measures, subjective measures assessing craving, withdrawal symptoms and mood, and performance measures. A between-subject, 2 x 2 factorial design was used, with the daily administration of a 15-mg nicotine patch (Nicotrol) versus placebo patch as one factor and 80 mg of oral cotinine fumarate versus placebo drug as the other factor. Baseline measures were obtained while the subjects smoked cigarettes on an ad lib basis for 1 week. Subjects (n = 106) were then randomly assigned to one of four treatment conditions and for the next 14 days were required to be abstinent from cigarettes and take the study drugs. Cotinine administration, with or without nicotine patch, produced serum cotinine concentrations 3 4 times higher than during ad lib smoking. Results showed a reduction of self-reported tobacco withdrawal symptoms using the nicotine patch alone. Cotinine alone had no effect on withdrawal symptoms. However, when nicotine patch was combined with cotinine, the beneficial effect of the nicotine patch on withdrawal symptoms was absent. Therefore, cotinine appears to antagonize the effects of nicotine in the alleviation of withdrawal symptoms at concentrations higher than that attained from normal smoking. This effect does not appear to be mediated by changes in nicotine disposition.

Effects of ethnicity and age or menopause on osteoblast function, bone mineralization, and osteoid accumulation in iliac bone

We measured histologic indices of osteoblast function, bone mineralization, and osteoid accumulation separately on the cancellous, endocortical, and intracortical subdivisions of the endosteal envelope and on the combined total surface in transiliac biopsies obtained after double tetracycline labeling in 142 healthy women, aged 20-74 years, 34 who were black (19 pre- and 15 postmenopausal) and 108 white (42 pre- and 66 postmenopausal). The data were subjected to two-way analysis of variance of the four groups defined by age/menopause and ethnicity. Also, linear regressions of selected variables on age and between functionally related but independently measured variables were examined. None of the interaction terms was significant, and none of the regression slopes on age differed between blacks and whites, indicating that, as for the previously reported structural and remodeling indices, the effects of ethnicity and of age/menopause are independent. Accordingly, the data were analyzed separately for the effects of ethnicity (pre- and postmenopausal combined) and age/menopause (blacks and whites combined). The analyses led to the following conclusions (1) Osteoid surface and volume were higher and adjusted apposition rate and osteoid mineralization rate lower in postmenopausal than in premenopausal subjects, but none of the indices of osteoid accumulation differed between blacks and whites. (2) Each index of osteoid accumulation was significantly correlated with its primary independently measured kinetic determinant (osteoid thickness with adjusted apposition rate, osteoid surface/bone surface with activation frequency, and osteoid volume/bone volume with bone formation rate/bone volume). None of the regression parameters differed significantly between blacks and whites. (3) The ratio of mineralizing surface to osteoid surface (MS/OS) was substantially lower in all demographic groups than could be accounted for by the later onset of mineralization than of matrix apposition at individual bone forming sites. (4) The low values for MS/OS can be explained by terminal mineralization being too slow to trap enough tetracycline molecules to produce detectable fluorescence, and do not require that mineralization be interrupted. (5) MS/OS was about 25% lower in blacks than in whites on all surfaces with corresponding differences in derived indices based on MS/OS, including adjusted apposition rate, mineralization lag time, and formation period. (6) The lower values for MS/OS in blacks are most likely due to slower terminal mineralization. This could not be accounted for by a lower serum level of calcidiol, but is consistent with the reported effect of reduced bone blood flow. (7) All differences in bone cell function between blacks and whites that we have observed could be the result of the ethnic, and presumably genetic, difference in bone accumulation during growth. Higher bone mass would result in less fatigue microdamage, less need for repair by directed bone remodeling, lower bone turnover, lower bone blood flow, and slower terminal mineralization. (8) If this explanation is correct, there are no fundamental differences in the biology of bone remodeling between ethnic groups.

Surveying managed care members on chronic disease

We compare prevalence estimates of self-perceived health status and chronic disease risk factors from a managed care member survey with estimates from the Behavioral Risk Factor Surveillance System (BRFSS) survey. Unadjusted prevalence estimates for diabetes, high blood pressure, and current smoking status were similar in the two surveys. In contrast, 5.1 percent of respondents to the managed care member survey reported fair-to-poor health status, compared with 12.4 percent of respondents to the BRFSS survey. Standardization of demographic characteristics reduced the prevalence of reported fair-to-poor health status among BRFSS respondents to 9 percent. We conclude that standardized survey questions added to annual member surveys in managed care organizations are a feasible and potentially useful method of chronic disease surveillance.

Immune suppression by lysosomotropic amines and cyclosporine on T-cell responses to minor and major histocompatibility antigens: does synergy exist?

BACKGROUND

Using murine models, we have shown that the lysosomotropic amine, chloroquine, is effective in the prevention of graft-versus-host disease (GVHD) mediated by donor T cells reactive with recipient minor histocompatibility antigens (MiHCs). Because lysosomotropic amines can suppress major histocompatibility complex (MHC) class II antigen presentation, their mechanism of action is potentially different from current immune suppressant drugs used to control GVHD such as cyclosporine.

METHODS

We investigated the use of cyclosporine and the lysosomotropic amines chloroquine and hydroxychloroquine in combination for additive or synergistic immunosuppression on T-cell responses in vitro to MiHC and MHC in mice.

RESULTS

We found that similar concentrations of chloroquine and hydroxychloroquine suppress the T-cell response to MiHC in mice (C57BL/6 anti-BALB.B) and that lysosomotropic amines in combination with cyclosporine result in synergistic suppression of a proliferative response to MiHC. Similar suppression and synergy appear to be present in an alloreactive response (C57BL/6 anti-BALB/c). Direct inhibition by chloroquine of T-cell proliferative responses induced by anti-CD3epsilon in the absence of antigen-presenting cells is present at higher concentrations than that required to suppress responses to MiHC or MHC. Chloroquine appears to induce decreased T-cell viability at high concentrations. This effect does not appear to be due to decreased T-cell production of interleukin-2 or interferon-gamma. At lower concentrations (<25 microg/ml), chloroquine can also decrease the ability of antigen-presenting cells to stimulate an a C57BL/6 anti-BALB/c T-cell response and can inhibit MHC class II expression after activation with lipopolysaccharide.

CONCLUSIONS

Lysosomotropic amines in combination with cyclosporine appear to be synergistic in the suppression of T-cell proliferation to MiHC and MHC. Use of chloroquine in combination with cyclosporine may result in improved control of GVHD.

Energetic dysfunction in quinolinic acid-lesioned rat striatum

Impairment of mitochondrial energy metabolism may contribute to the selective neuronal degeneration observed in Huntington's disease and other neurodegenerative disorders. Intrastriatal injection of the excitotoxin, quinolinic acid, produces a pattern of neuronal death similar to that seen in Huntington's disease. However, little is known about the effects of quinolinic acid on striatal energetics. In the present work, time-dependent changes in energy metabolism caused by injection of quinolinic acid into rat striatum were examined. Oxygen consumption by free and synaptic mitochondria was quantified and correlated with the concentrations of nucleotides and amino acids at different times after injection. Compared with saline-treated controls, a decrease in ADP-stimulated (state 3) to basal (state 4) oxygen consumption (respiratory control ratio) by free mitochondria was apparent in quinolinic acid-injected striata as early as 6 h after treatment. No significant changes were seen in nucleotide concentrations at this time. By 12 h after injection, the decline in the respiratory control ratio was more pronounced (45%), and reductions in ATP, NAD, aspartate, and glutamate (30-60%) were also observed. These results show that injection of quinolinic acid in vivo produces progressive mitochondrial dysfunction, which may be a common and critical event in the cell death cascade initiated in Huntington's disease and in animal models of this neurodegenerative disorder. The indicators of mitochondrial function examined in this study, therefore, may be useful in evaluating the efficacy of neuroprotective agents.

The test-retest reliability of an inclined squat strength test protocol

Functional testing of the lower extremity is supported as a good predictor for successful return to premorbid activity. However, current reliable functional tests may be too strenuous for a patient in the acute stage of recovery. A functional testing protocol utilizing an inclined sliding board apparatus was evaluated for test-retest reliability. Thirty-five subjects (ages = 18-25, mean = 20.49 +/- 1.71) with no known knee pathologies were tested. Subjects performed a 20-second test for squat repetitions and a 50-squat repetition test for time, executing a single leg squat in an inclined position on the sliding board apparatus. The test was repeated 1 week later. The intraclass correlation coefficient equaled 0.80 for the 50-repetition timed test and 0.89 for the 20-second repetition test. The results indicate an acceptable test-retest reliability for the inclined sliding board apparatus protocol. We advocate the use of this testing protocol for the purpose of evaluating functional ability during the early stages of rehabilitation of lower extremity conditions.

Collegial support and barriers to behavioral programs for severe mental illness

Previous investigations have identified staff beliefs about barriers to implementing behavioral interventions in programs for persons with severe mental illness. One of these barriers, institutional constraints, was found to be associated with collegial support; i.e., staff who report more collegial support were less likely to endorse institutional constraints. The purpose of this study was to determine how the components of collegial support were associated with beliefs about institutional constraints. Fifty-six staff members completed measures of staff opinions about barriers to implementing behavior therapy, satisfaction with collegial support, source of support, and functions of support. Results suggested that collegial support is significantly associated with co-worker and supervisor support, but not the support of family and friends. Endorsing institutional constraints was inversely associated with the support of co-workers and supervisors; institutional constraints were positively associated with the support of family and friends. Endorsing institutional constraints was also inversely associated with the sense that others rely upon the individual for their well-being. Implications of these findings for diminishing barriers to behavioral interventions are discussed.

Vitamin A exerts potential therapeutic effects in the endotoxaemic pig

BACKGROUND

Pretreatment with an injection of vitamin A has beneficial effects on cardiac and pulmonary functions in normally bred endotoxaemic pigs. The present study was performed in order to elucidate whether the response of an ongoing infusion of E. coli can be modulated by a single injection of vitamin A.

METHODS

Sixteen healthy (not vitamin A-depleted) pigs were anaesthetized, monitored, mechanically ventilated and subjected to an infusion of E. coli endotoxin (10 micrograms.kg-1.h-1). This infusion resulted within 30 min in a progressive haemodynamic derangement. When the mean pressure in the pulmonary artery was twice the baseline value, vitamin A (460 IU.kg-1) or a corresponding volume of vehicle was injected intravenously. After sacrificing the animals, the right lung was excised and weighed, and biopsy specimens were taken from the left lung for microscopical examination.

RESULTS

Mean arterial blood pressure was significantly less affected (P < 0.01) between the 1st and 6th hour in endotoxaemic pigs treated with vitamin A than in those given vehicle. The mean lung weight in the vitamin A-treated pigs was significantly lower than that in the vehicle group (164 +/- 5.3 vs 199 +/- 19.8 g; P < 0.01). Microscopical examination showed significantly less oedema (0.93 +/- 0.17 vs 2.00 +/- 0.26; P < 0.01) and microatelectasis (0.56 +/- 0.17 vs 1.75 +/- 0.31; P < 0.01) in the vitamin A group. Endotoxaemia was also accompanied by an initial, steep decline in neutrophil counts in all animals; this decrease was significantly less pronounced (P < 0.05) in vitamin A-injected pigs than in the vehicle-injected group. The major difference was a more rapid restitution in the vitamin A group.

CONCLUSION

Several manifestations of endotoxaemia were expressed less in the vitamin A group. Thus, vitamin A may turn out to be a tool in the management of endotoxaemia.

Recombinant interferon alpha-2b in the management of malignant pleural effusions

Twenty-one patients with malignant pleural effusion (MPE) were prospectively entered into a nonrandomized, single-armed study to evaluate the efficacy and safety of recombinant interferon (IFN) alpha-2b (INTRON A; Schering-Plough; Kenilworth, NJ) as an intrapleural palliative agent. From March 1989 through February 1993 (48 months), 21 patients were entered into the study. No symptomatic effusion recurred and no substantial side effects were associated with treatment. This suggests recombinant IFN alpha-2b represents a safe and effective intrapleural agent for the palliation of MPE.