Increasing Black, Indigenous and People of Color participation in clinical trials through community engagement and recruitment goal establishment

Longstanding social and economic inequities elevate health risks and vulnerabilities for Black, Indigenous and People of Color (BIPOC) communities. Engagement of BIPOC communities in infectious disease research is a critical component in efforts to increase vaccine confidence, acceptability, and uptake of future approved products. Recent data highlight the relative absence of BIPOC communities in vaccine clinical trials. Intentional and effective community engagement methods are needed to improve BIPOC inclusion. We describe the methods utilized for the successful enrollment of BIPOC participants in the U.S. Government (USG)-funded COVID-19 Prevention Network (CoVPN)-sponsored vaccine efficacy trials and analyze the demographic and enrollment data across the efficacy trials to inform future efforts to ensure inclusive participation. Across the four USG-funded COVID-19 vaccine clinical trials for which data are available, 47% of participants enrolled at CoVPN sites in the US were BIPOC. White enrollment outpaced enrollment of BIPOC participants throughout the accrual period, requiring the implementation of strategies to increase diverse and inclusive enrollment. Trials opening later benefitted considerably from strengthened community engagement efforts, and greater and more diverse volunteer registry records. Despite robust fiscal resources and a longstanding collaborative and collective effort, enrollment of White persons outpaced that of BIPOC communities. With appropriate resources, commitment and community engagement expertise, the equitable enrollment of BIPOC individuals can be achieved. To ensure this goal, intentional efforts are needed, including an emphasis on diversity of enrollment in clinical trials, establishment of enrollment goals, ongoing robust community engagement, conducting population-specific trials, and research to inform best practices.

Epstein-Barr virus-associated gastric cancer reveals intratumoral heterogeneity of PIK3CA mutations

Background

Recent whole-genome sequencing identified four molecular subtypes of gastric cancer (GC), of which the subgroup of Epstein–Barr virus-associated GC (EBVaGC) showed a significant enrichment of PIK3CA mutations. We here aimed to validate independently the enrichment of PIK3CA mutations in EBVaGC of a Central European GC cohort, to correlate EBV status with clinico-pathological patient characteristics and to test for a major issue of GC, intratumoral heterogeneity.

Patients and methods

In a first step, 484 GCs were screened for EBV and PIK3CA hot spot mutations of exon 9/20 using EBER in situ hybridization and pyrosequencing, respectively. Secondly, an extended sequencing of PIK3CA also utilizing next generation sequencing was carried out in all EBVaGCs and 96 corresponding lymph node metastases.

Results

Twenty-two GCs were EBER-positive, all being of latency type I. Intratumoral heterogeneity of EBER-positivity was found in 18% of EBVaGCs. Twenty-three GCs held PIK3CA mutations in hot spot regions of exon 9 or 20, being significantly more common in EBVaGCs (P < 0.001). Subsequent extended sequencing of PIK3CA of EBVaGCs showed that 14% harvested three to five different PIK3CA genotypes (including wildtype) in the same primary tumor, albeit in histologically and spatially distinct tumor areas, and that intratumoral heterogeneity of PIK3CA was also present in the corresponding lymph node metastases.

Conclusions

Our findings unravel issues of tumor heterogeneity and illustrate that the assessment of the EBV status in tissue biopsies might carry the risk of sampling errors, which may significantly hamper adequate molecular tumor classification in a more clinical setting. Moreover, this is the first report of intratumoral heterogeneity of PIK3CA mutations in GC, and our findings lead to the conclusion that PIK3CA mutant and -wildtype tumor subclones are skilled to metastasize independently to different regional lymph nodes.

Demonstration of a beam loaded nanocoulomb-class laser wakefield accelerator

Laser-plasma wakefield accelerators have seen tremendous progress, now capable of producing quasi-monoenergetic electron beams in the GeV energy range with few-femtoseconds bunch duration. Scaling these accelerators to the nanocoulomb range would yield hundreds of kiloamperes peak current and stimulate the next generation of radiation sources covering high-field THz, high-brightness X-ray and γ-ray sources, compact free-electron lasers and laboratory-size beam-driven plasma accelerators. However, accelerators generating such currents operate in the beam loading regime where the accelerating field is strongly modified by the self-fields of the injected bunch, potentially deteriorating key beam parameters. Here we demonstrate that, if appropriately controlled, the beam loading effect can be employed to improve the accelerator's performance. Self-truncated ionization injection enables loading of unprecedented charges of ∼0.5 nC within a mono-energetic peak. As the energy balance is reached, we show that the accelerator operates at the theoretically predicted optimal loading condition and the final energy spread is minimized.Higher beam quality and stability are desired in laser-plasma accelerators for their applications in compact light sources. Here the authors demonstrate in laser plasma wakefield electron acceleration that the beam loading effect can be employed to improve beam quality by controlling the beam charge.

Staying Positive: Women's illness narratives and the stigmatized vernacular

This article uses the stigmatized vernacular (Goldstein & Shuman, 2012) as a conceptual framework for examining the public construction and reception of women’s illness narratives. I begin by making the case that personal illness narratives – a genre that works to translate the subjective illness experience to a public audience – are rich sites for exploring how discourses of veneration and repudiation can become inextricably intertwined.  Discussing illustrative examples of the construction and reception of women’s illness narratives shared in contexts of breast cancer and fibromyalgia, I show how popular understandings of emotions, particularly positive emotions like happiness, play a major role in the regimes of value shaping how women’s illness experiences become tellable or untellable, and thereby valued or devalued.  Integrating scholarship on illness narratives, stigma, and happiness, I aim to contribute to a richer and more multifaceted view of the illness narrative genre and the discursive contagion of stigma.

First experiences with pudendal nerve stimulation in fecal incontinence: a technical report

Sacral nerve stimulation (SNS) is an established treatment for refractory lower urinary tract and bowel dysfunction. In some urological patients, SNS does not have satisfactory results. Pudendal nerve stimulation (PNS) has recently been proposed for these patients and successfully tested. Given the sometimes unsatisfactory results after SNS in fecal incontinence (FI), we tested PNS on patients suffering from FI. We used the device and implantation technique described by Spinelli et al. By making a slight change in the device, we developed a quick and easy-to-use method for successful PNS implantation, based on electrophysiological response. We present the results of a feasibility study, in which we tested the effectiveness of PNS with our modified implantation technique on 2 patients, with very satisfactory early results in a 4-month follow-up.

[Group B streptococcus screening: a retrospective study in 1,674 pregnancies]

OBJECTIVE

To evaluate our clinical practice for Group B streptococcus (GBS) screening during pregnancy and antibiotic therapy during delivery.

MATERIAL AND METHODS

We performed a retrospective evaluation of our SBS screening protocol, by vaginal swab, for a period of two years, including 1,674 asymptotic patients. Intra partum antibiotic prophylaxis was administrated for GBS-positive women.

RESULTS

The rate of GBS carriage was 6.9%. Antibiotics were administrated for 79.3% patients with GBS-positive culture. Of these women only 39% had an interval greater than four hours between antibiotic injection and delivery. In the group of patients with positive GBS culture, no newborn was infected and only 5% were colonised. In the GBS-negative group with 1.3% of the newborns were GBS positive.

CONCLUSION

We were surprised by our low rate of GBS carriage and the non optimal application of antibiotics during labor. We reviewed our results with all our team and a prospective evaluation has been initiated.

Periarterial application of papaverine during laparoscopic donor nephrectomy improves early graft function after kidney transplantation in pigs

BACKGROUND

Laparoscopic donor nephrectomy (LDN) increases incentives to donation by subjects who might refuse an open operation. However, the incidence of delayed graft function is higher after LDN than after open operation. This may be caused by the reduction of renal perfusion as a result of the raised intraabdominal pressure and mechanically induced renal angiospasm during the operation. We conducted experiments to find out whether the application of papaverine around the renal artery during LDN could improve early graft function after transplantation.

METHODS

Renal function was studied in 10 male pigs (weight approximately 25 kg). The left kidney was harvested laparoscopically (intraabdominal pressure 8 mmHg). Five animals were randomly selected to have perivascular application of 50 mg papaverine (treatment group) before preparation of the vessels. In controls no papaverine was used. After LDN and open right nephrectomy the left kidney was autotransplanted. The main outcome measures were volume of urine produced and creatinine clearance during the first 20 h after the transplant.

RESULTS

The groups were comparable in respect of body weight, hemodynamic values, amount of infusions, warm and cold ischemia time, and duration of anastomosis. Urine output and creatinine clearance were significantly higher in pigs treated with papaverine than in controls.

CONCLUSIONS

Papaverine substantially improved early graft function in pigs when applied around the renal artery during LDN. Whether this is applicable to procurement of human kidneys remains to be evaluated.

Analysis of nerve fibers and their distribution in histologic sections of the human brain

The field of quantitative analysis and subsequent mapping of the cerebral cortex has developed rapidly. New powerful tools have been applied to investigate large regions of complex folded gyrencephalic cortices in order to detect structural transition regions that might partition different cortical fields of disjunct neuronal functions. We have developed a new mapping approach based on axoarchitectonics, a method of cortical visualization that previously has been used only indirectly with regard to myeloarchitectonics. Myeloarchitectonic visualization has the disadvantage of producing strong agglomerative effects of closely neighbored nerve fibers. Therefore, single and neurofunctional-relevant parameters such as axonal branchings, axon areas, and axon numbers have not been determinable with satisfying precision. As a result, different staining techniques had to be explored in order to achieve a suitable histologic staining for axon visualization. The best results were obtained after modifying the Naoumenko-Feigin staining for axons. From these contrast-rich stained histologic sections, videomicroscopic digital image tiles were generated and analyzed using a new fiber analysis framework. Finally, the analysis of histologic images provided topologic ordered parameters of axons that were transferred into parameter maps. The axon parameter maps were analyzed further via a recently developed traverse generating algorithm that calculated test lines oriented perpendicular to the cortical surface and white matter border. The gray value coded parameters of the parameter maps were then transferred into profile arrays. These profile arrays were statistically analyzed by a reliable excess mass approach we recently developed. We found that specific axonal parameters are preferentially distributed throughout granular and agranular types of cortex. Furthermore, our new procedure detected transition regions originally defined by changes of cytoarchitectonic layering. Statistically significant inhomogeneities of the distribution of certain axon quantities were shown to indicate a subparcellation of areas 4 and 6. The quantification techniques established here for the analysis of spatial axon distributions within larger regions of the cerebral cortex are suitable to detect inhomogeneities of laminar axon patterns. Hence, these techniques can be recommended for systematic and observer-supported cortical area mapping and parcellation studies.

The influence of periarterial papaverine application on intraoperative renal function and blood flow during laparoscopic donor nephrectomy in a pig model

BACKGROUND

The transplantation of live donor kidneys harvested laparoscopically is associated with a higher incidence of delayed graft function than the transplantation of grafts harvested via the open technique. The delay is believed to be due to a decrease in renal blood flow during laparoscopic donor nephrectomy (LDN). The aim of this study was to evaluate whether renal function and blood perfusion can be enhanced by the periarterial application of papaverine during LDN.

METHODS

Renal function and blood flow were studied in a porcine model that included a total of 24 pigs (20-30 kg). In 12 of the pigs, urine output and creatinine clearance were determined as measures of renal function. In the other 12 pigs, renal blood flow was determined using fluorescent-labeled microspheres. In each group, the pigs were randomized into two subgroups, one with and one without a perivascular injection of 50 mg papaverine.

RESULTS

As compared to the controls, the animals receiving papaverine had a significantly higher urine output (3.1 +/- 1.6 vs 0.9 +/- 0.45 ml/h/kg; p = 0.02), superior creatinine clearance (2.22 +/- 0.5 vs 0.95 +/- 0.1 ml/min/kg; p = 0.038), and enhanced renal blood flow (4.9 +/- 2.2 vs 2.1 +/- 0.8 ml/min/g; p = 0.008).

CONCLUSIONS

When applied to the tissue surrounding the renal artery, papaverine substantially improves renal function and blood flow during laparoscopic live kidney donation. Whether graft optimization during kidney procurement also translates into improved posttransplantation function remains to be established.

[Acute carbon monoxide poisoning during pregnancy: 2 cases with different neonatal outcome]

We report two cases of moderate maternal poisoning during the third trimester. They underwent hyperbaric oxygen therapy at 2.5 atmospheres for 90 minutes and were delivered at term. In one case the newborn presented an antenatal ischemic cerebral lesion probably due to monoxide poisoning. Pathophysiology and treatment of such accidents are discussed.

HIV incidence among repeat HIV testers at a county hospital, San Francisco, California, USA

OBJECTIVES

To estimate HIV incidence, characterize correlates of HIV seroconversion, and monitor temporal trends in HIV transmission among patients repeatedly tested for HIV by a county hospital in San Francisco.

DESIGN

Retrospective longitudinal study.

METHODS

HIV incidence was retrospectively calculated among persons voluntarily tested for HIV antibody more than once at San Francisco's county hospital or one of its affiliated satellite community clinics between 1993 and 1999. Linkage of HIV test results in computerized databases identified "seroconverters" as individuals who had a negative antibody test followed by a positive test. The interval between tests was used as the person-time at risk. Cox proportional hazards analysis identified correlates of HIV seroconversion.

RESULTS

A total of 84 HIV seroconversions were identified among 2893 eligible patients repeatedly tested for HIV antibody over a cumulative 5860 person-years (PYs) (incidence of 1.4 per 100 PYs, 95% confidence interval [CI]: 1.2-1.7). The majority of seroconversions (71 [84.5%]) were among injection drug users (IDUs) (incidence of 2.0 per 100 PYs, CI: 1.6-2.4). HIV incidence was highest among men who have sex with men (MSM) who were also IDUs (incidence of 3.8 per 100 PYs, CI: 2.7-5.1) and lowest among non-IDUs, heterosexual men, and non-IDU women (incidence of 0.3 per 100 PYs, CI: 0.1-0.6). In multivariate analysis, correlates of HIV seroconversion were age 25 to 29 years (hazard ratio [HR] = 3.9, CI: 2.4-6.3), MSM (HR = 2.9, CI: 1.9-4.4), and IDU (HR = 3.2, CI: 1.8-5.8). Overall, no temporal trend in annual HIV incidence was noted during the study period; however, HIV incidence among MSM IDUs increased from 2.9 per 100 PYs in 1996 to 4.7 per 100 PYs in 1998.

CONCLUSIONS

The rate of seroconversion in this hospital and affiliated clinic population is unexpectedly high. Moreover, HIV transmission among IDU patients has not decreased over the last several years. The San Francisco county hospital provides a high-risk sentinel population to monitor emerging trends in HIV transmission, especially among IDUs, and presents multiple opportunities for prevention interventions, because these patients are being seen repeatedly by clinicians.

Reduced skilfulness of arm motor behaviour among motor stroke patients with good clinical recovery: does it indicate reduced automaticity? Can it be improved by unilateral or bilateral training? A kinematic motion analysis study

Functional cortical reorganisation had been demonstrated to accompany recovery from motor stroke. In agreement with a previous study, quantitative kinematic analysis of aimed movements in 14 almost completely recovered hemiparetic stroke patients and 14 healthy control subjects indicated a reduced skilfulness of both the more ballistic initial movement phase and the more feedback-guided late homing-in phase of aimed movements. By means of two dual motor tasks it was further investigated whether the reduced skilfulness of patients was due to an increased attentional demand and thus a reduced automaticity of motor control. Interference effects by dual tasks, however, were similar for patients and control subjects. Thus, the notion of reduced automaticity could not be supported empirically, and reduced skilfulness seemed rather related to residual pyramidal motor deficits. By means of a repetitive daily training for 1 week based on the Arm Ability Training approach, patients were able to reduce their performance deficits in both movement phases significantly. Whether patients practised with the affected arm or simultaneously with both the affected and non-affected arm only marginally modified outcome, unilateral training being slightly more efficacious. These findings demonstrate that even clinically minor residual motor deficits can be improved by a structured training for the affected arm.

Effect of a specific cysteinyl leukotriene-receptor 1-antagonist (montelukast) on the transmigration of eosinophils across human umbilical vein endothelial cells

BACKGROUND

Leukotrienes have been implicated in the selective infiltration of eosinophils into the bronchial mucosa in asthma.

OBJECTIVE

We studied whether eosinophil transmigration through cultured human umbilical vein endothelial cells (HUVECs) can be blocked by a specific cysteinyl LT1-receptor-antagonist.

METHODS

Unstimulated and stimulated eosinophils from patients with asthma and normal controls were subjected to confluent human umbilical vein endothelial cell (HUVEC) monolayers separating the upper and lower chamber of Transwell culture plates. Unstimulated eosinophils or cells pre-incubated in the presence of the eosinophil activating cytokines GM-CSF or IL-13 were placed in the upper chambers while PAF, a potent chemoattractant factor for eosinophils, was added to the lower chamber. Migration of eosinophils was quantified by a beta-glucuronidase assay.

RESULTS

The assumption that eosinophils express CysLT1 (cysteinyl-leukotriene 1)-receptors was based on our demonstration of mRNA-expression for the CysLT-1-receptor by polymerase chain reaction on purified eosinophils. The chemotactic response to PAF was significantly reduced when eosinophils were pre-incubated with montelukast for 15 min. When eosinophils were pre-incubated with GM-CSF and/or IL-13, the migratory response to PAF was also significantly reduced by montelukast.

CONCLUSION

From these data we conclude that the specific cysteinyl LT1-receptor antagonist montelukast can inhibit PAF-induced eosinophil transmigration through cultured HUVEC monolayers.

Detailed heat/mass transfer distributions in a rotating two pass coolant channel with engine-near cross section and smooth walls

This paper shows results obtained by experimental and numerical investigations concerning flow structure and heat/mass transfer in a rotating two-pass coolant channel with engine-near geometry. The smooth two passes are connected by a 180 degrees U-bend in which a 90 degrees turning vane is mounted. The influence of rotation number, Reynolds number and geometry is investigated. The results show a detailed picture of the flow field and distributions of Sherwood number ratios determined experimentally by the use of the naphthalene sublimation technique as well as Nusselt number ratios obtained from the numerical work. Especially the heat/mass transfer distributions in the bend and in the region after the bend show strong gradients, where several separation zones exist and the flow is forced to follow the turbine airfoil shape. Comparisons of numerical and experimental results show only partly good agreement.

[Amniotic fluid leakage and premature rupture of membranes after amniocentesis. A review of the literature]

BACKGROUND

Amniotic fluid leakage and premature rupture of membranes following amniocentesis is uncommon.

MATERIAL AND METHODS

We reviewed the literature. Thirteen recent studies including 17 186 amniocenteses and 280 cases of amniotic fluid leakage were analyzed.

RESULTS AND DISCUSSION

Risk increases when early amniocentesis is performed prior to 15 weeks gestation and when the needle is inserted far from the placenta. Significant loss of amniotic fluid compromises pregnancy. Conservative management with bed rest seems to give good results. When amniotic leakage persists for more than two weeks, there is little spontaneous resolution. The risk of pursuing the pregnancy should be discussed with the couple in this case. Risks include respiratory disorders, skeletal malformations and premature birth.

CONCLUSION

New techniques such as 'amniopatch' may play an important role in the near future.

Testing a motor performance series and a kinematic motion analysis as measures of performance in high-functioning stroke patients: reliability, validity, and responsiveness to therapeutic intervention

OBJECTIVE

To assess measurement properties of motor performance tests when used with high-functioning stroke patients.

DESIGN

Test-retest reliability study with an interval of 2 days; responsiveness study with assessment before and after training; validity study assessing the tests' ability to discriminate between the high-functioning stroke patients and healthy subjects.

SETTING

Referral center for neurorehabilitation.

PARTICIPANTS

Twenty-nine high motor-functioning stroke patients and 20 healthy control subjects.

INTERVENTION

Two special training sessions per day on 5 consecutive days, plus regular therapy.

OUTCOME MEASURES

Scores on the motor performance series, a two-dimensional tracking test, and a kinematic task analysis.

RESULTS

All tests (except the bimanual test) were able to document performance deficits with these patients and showed a moderately high to high test-retest reliability without systematic trend from test to retest (intraclass correlation coefficients for main variables, .61 to .89). The kinematic task especially demonstrated changes after training (standardized response means for timing variables, .53 to .66). A subset of variables indicated a modifying effect of limb side, age, and gender.

CONCLUSION

All tests (except the bimanual test) can be used for both cross-sectional and follow-up group studies with high-functioning stroke patients. Measurement properties and the lack of comprehensive normative data limit their use with individual patients.

Oesophageal motility patterns and arterial blood pressure in patients with chest pain and normal coronary angiogram

BACKGROUND AND OBJECTIVES

In previous manometric investigations, we observed that patients with chest pain and arterial hypertension frequently tend to display oesophageal motility abnormalities. Therefore, we set out to study this systematically.

METHODS

Patients with chest pain and normal coronary angiogram (n=40) and healthy controls (n=20) were studied prospectively in a standardized fashion using a portable oesophageal manometry and blood pressure registration system over 24 hours.

RESULTS

Twenty patients exhibited increased arterial blood pressure (24 h median > 135/85 mmHg), while in the other 20 patients and all controls the 24 h blood pressure patterns were normal. Median pressure amplitudes in the distal oesophagus were 46.5, 33 and 27 mmHg in patients with or without arterial hypertension and controls, respectively, and 30, 27 and 27 mmHg in the proximal oesophagus, respectively. The durations of distal contractions were 3.9, 3.4 and 3.4 s, respectively, and those of proximal contractions were 3.2, 3.0 and 3.2 s, respectively. Percentages of propulsive contractions were 53%, 44% and 59%, respectively, and those of simultaneous contractions were 23%, 25% and 10%, respectively.

CONCLUSIONS

Patients and controls differ significantly regarding their oesophageal motility patterns. Patients without arterial hypertension exhibit impaired propulsion of oesophageal contractions, whereas patients with arterial hypertension tend to produce oesophageal hypermotility. This suggests that, depending on the presence or absence of arterial hypertension, different pathomechanisms of oesophageal motility disturbances come into play.

[Increased occurrence of esophageal hypermotility disorders in patients with arterial hypertension]

BACKGROUND AND OBJECTIVE

It has been noted in previous manometric examinations of the oesophagus in patients with chest pain that abnormal motility was often associated with arterial hypertension. A systematic study of this relationship was therefore undertaken.

PATIENTS AND METHODS

In 40 patients with chest pain (18 women and 22 men, mean age 54.7 [24-70] years) and in 20 healthy volunteers (12 men, 8 women, mean age 50.8 [22-63] years) standardized oesophageal manometry and arterial blood pressure monitoring were performed over 24 hours. Coronary heart disease and gastrointestinal lesions had been excluded by angiography and endoscopy, respectively.

RESULTS

20 patients (group H) had hypertension (median 24-hour blood pressure > 135/85 mmHg), while 20 patients (group N) and the normal controls (group K) were normotensive. Oesophageal manometry data differed significantly between the three groups regarding distal pressure amplitude (in hPa [hectopascals]; group H: 62 hPa*,**, group N 44 hPa* and group K 36 hPa**; [*P < 0.0005]) and the proportion of simultaneous contractions (group H 23%, group N 22%**, group K 10%***; ***P < 0.001). The hypertensive patients had significantly more frequent motility abnormalities than normal controls (13/20 vs 4/20, P < 0.001); while normotensive patients had more frequent episodes of abnormal propulsion in the oesophagus (proportion of propulsive contractions in group H: 53%, in N: 44%, in K: 59%; P < 0.01).

CONCLUSION

Oesophageal motility differed significantly in patients with chest pain from that in healthy controls. Patients with chest pain and hypertension more frequently had oesophageal hypermotility. This suggests a generalized abnormality of smooth muscle.

Pattern of inheritance in hereditary myeloperoxidase deficiency associated with the R569W missense mutation

Myeloperoxidase (MPO) is an essential component of the oxygen-dependent microbicidal system of neutrophils and monocytes. Hereditary deficiency of MPO occurs in 1 in 2,000 to 4,000 individuals in the general population and has been generally considered an autosomal recessive trait. Previous studies have used the peroxidase activity of blood leukocytes to assess the phenotype of affected family members. Eosinophil peroxidase (EPO) also contributes to the peroxidase activity of blood leukocytes. Because EPO expression is normal in MPO-deficient subjects, eosinophil contamination can significantly contribute to peroxidase activity in leukocytes from family members of an MPO-deficient subject and thereby undermine correct interpretation of the inheritance pattern. To avoid this potential problem, we used cytochemical, immunochemical, and genetic techniques to assess the inheritance pattern of MPO deficiency in sixteen individuals from five unrelated kindreds. Each kindred had an index case with MPO deficiency and the R569W missense mutation, a genotype that causes MPO deficiency. Our analysis demonstrated that MPO deficiency was not inherited as a simple autosomal recessive trait. Most subjects were compound heterozygotes with respect to the R569W mutation and demonstrated a spectrum of phenotypes. Our data demonstrate the broad phenotypic impact of compound heterozygosity on the expression and function of a multimeric protein such as MPO.

Measurement of hepatic Ra UDP-glucose in vivo in rats: relation to glycogen deposition and labeling patterns

We previously described an isotopic method for quantifying the rate of appearance of hepatic UDP-glucose (Ra UDP-Glc) and the direct entry of glucose into hepatic UDP-Glc in humans. Here, the method is tested in depth in rats. The basic principles are that dilution of labeled galactose in hepatic UDP-Glc, sampled noninvasively by the xenobiotic glucuronate (GlcUA) method, reveals Ra UDP-Glc. First, labeling patterns in secreted acetaminophen-GlcUA were compared with hepatic glycogen and plasma glucose by use of mass isotopomer distribution analysis from [2-(13)C]glycerol. Labeling was consistent with common precursor pools of glucose 6-phosphate and triose-phosphate for all end products studied in fasted and in intravenous glucose- and fructose-infused states. Next, [1-(3)H]galactose was administered. After a 24-h fast, Ra UDP-Glc was 25.0 +/- 1.7 mumol.kg body wt-1.min-1 and rose to 57.7 and 72.7 mumol.kg-1.min-1 at intravenous glucose infusion rates of 111 and 167-194 mumol.kg-1.min-1, respectively. Liver glycogen deposition correlated closely with Ra UDP-Glc (R2 = 0.76), although the turnover value was approximately 50% higher than the net deposition rate. In conclusion, the turnover of an intrahepatic metabolite, UDP-Glc, can be measured noninvasively, and Ra UDP-Glc correlates with liver glycogen deposition in rats.

Insulin- and insulin-like growth-factor-I receptor tyrosine-kinase activities in human renal carcinoma

We studied expression and functional characteristics of the insulin- and insulin-like-growth-factor-I (IGF-I) receptors in human renal carcinoma. Ligand-binding properties and tyrosine-kinase activity of both receptors, as well as the expression of the 2 isoforms of the human insulin receptor (HIR-A and -B) were analyzed in renal carcinoma and normal adjacent kidney tissue of 8 adult patients. Partially purified insulin- and IGF-I receptors from normal and renal cell carcinoma tissue possessed identical affinities for their ligands. Renal cell carcinoma, however, contained 3- to 4-fold more specific insulin-binding sites and 2-fold more IGF-I binding sites than adjacent normal kidney tissue. In addition, we determined the relative content of insulin/IGF-I receptor hybrids in both tissues. Renal cell carcinoma and adjacent normal tissue revealed similar amounts of insulin/IGF-I receptor hybrids, i.e., 44 +/- 8.2% of tracer IGF-I binding in normal tissue and 46 +/- 12.0% in renal cell carcinoma. When equal amounts of insulin- and IGF-I receptor protein were studied, we found significantly increased receptor autophosphorylation and elevated substrate phosphorylation in carcinoma tissue. To assess whether the differences in insulin-receptor tyrosine-kinase activity were caused by an altered pattern of insulin receptor isoform expression, we determined mRNA levels for HIR-A and -B. The 2 insulin receptor isoforms were, however, expressed in highly variable ratios in both normal and tumor tissue. Our experiments show that renal carcinoma expresses an elevated amount of insulin- and IGF-I receptor protein with increased specific autophosphorylation and tyrosine-kinase activity each. The increase of insulin-receptor tyrosine-kinase activity in renal carcinoma cannot be explained by an altered expression pattern of insulin receptor isoforms.

Cytogenetic and growth factor gene analysis of a renal carcinoma cell line

Although there are many studies analyzing cytogenetic or molecular alterations of human renal primary tumors, there have only been a few reports addressing both questions on renal cell carcinoma (RCC) cell lines. We have therefore investigated an RCC cell line, namely KTCTL-26A, by banding techniques and simultaneous growth factor gene expression analysis. KTCTL-26A represents a well-defined stemline and sidelines in the near-diploid range with clonal aberrations involving chromosomes 2, 3, 5, 7, 9, 13, 16, 21, 22, and Y in structure and/or number. The predominant karyotypic changes were a partial loss of chromosome 3p (ie, 3p14) and a gain of copies of chromosome 7 (trisomy or partial tetrasomy). By Northern analysis, in KTCTL-26A we found underexpression of the proEGF-gene (located on chromosome 4) and overexpression of the genes for proTGF-alpha and the EGF-receptor, which are located on chromosomes 2 and 7, respectively. By Southern blot analyses there was no evidence for an amplification in the case of the EGF-R and proTGF-alpha genes. Because these changes of gene expression were observed in both the cell line and in primary kidney tumor samples, they seem to be of constitutive (and not adaptive) nature. Hence, KTCTL-26A can serve as a model for the study of the origin of these molecular alterations and as a preclinical model for their genetic manipulation (e.g., by using antisense-oligonucleotides) for therapeutic purposes.

Clinical importance of P-glycoprotein-related resistance in leukemia and myelodysplastic syndromes--first experience with their reversal

P-glycoprotein (P-gp) expression in mononuclear bone marrow cells was analyzed in 119 patients, including 60 with chronic myelogenous leukemia (CML), 48 with myelodysplastic syndromes (MDS), and 11 with acute myelogenous leukemia (AML). For P-gp measurement an immunocytological method using monoclonal antibodies C219, 4E3, and MRK 16 and the reverse transcription-polymerase chain reaction technique were applied. According to our results obtained in healthy volunteers using the immunocytological method, the limit for P-gp overexpression was set at > or = 10% P-gp-positive mononuclear bone marrow cells and at > or = 30% P-gp-positive mononuclear peripheral blood cells. All 42 CML patients in chronic phase had normal P-gp expression. P-gp overexpression was demonstrated in four of six patients in accelerated myelogenous blast cell phase and in four of 12 CML-BC patients. Of eight CML patients in blast crisis (BC) with normal P-gp expression, partial remission was achieved in three and minor response in five after prednisone/vindesine therapy. All four of the 12 CML-BC patients with P-gp overexpression did not respond to this therapy. Normal P-gp expression was seen in 41 (85.4%) of 48 untreated MDS patients. While P-gp overexpression did not develop during therapy in any of the myelodysplastic syndrome patients treated with low-dose ara-C alone, four of eight treated with low-dose ara-C plus GM-CSF and four of 11 treated with low-dose ara-C and IL-3 developed P-gp overexpression after therapy. Furthermore, 11 AML patients at primary diagnosis, including five AML patients with P-gp overexpression, who were treated with idarubicin, vepesid, and cytarabine V (ara-C) showed a complete remission. Additionally, one daunorubicin-cytarabine-pretreated refractory AML patient was treated with the oral form of the P-gp modulator drug dexniguldipine and achieved complete remission for a duration of 7 months. Our results suggest that in CML patients in BC, P-gp expression influences outcome after therapy. Further more, studies in a larger series of patients are necessary to prove the efficacy and toxicity of idarubicin/vepesid and cytardbine--or dexniguldipine-containing--therapy in relation to P-gp expression of AML patients.

The problem of fuzzy cause-specific death rates in mortality context analysis: the case of Panama City

In studies of mortality, small and fluctuating numbers of deaths are problems which are caused by infrequent reporting and small spatial unit reporting. To use Panama City as an example, the paper will introduce a Monte Carlo simulation which allows for the analysis of mortality even with small absolute numbers. In addition, Panama City will be used as an example where good medical care is available in every city district, so that social class differences between the districts have a negligible effect on most cause-specific death rates and infant mortality.

Deficient interferon-alpha response of newborns in comparison to adults

Human peripheral blood mononuclear cells (PBMC) respond efficiently to viral infections with interferon (IFN)-alpha production. Using Newcastle disease virus (NDV) and Sendai virus as inducers, our experiments with purified mononuclear cell populations of healthy adult volunteers showed that monocytes were the main IFN-alpha producers in these systems. Using an ELISA, which specifically recognized IFN-alpha 2, and a bioassay, in which all subtypes were detected, IFN-alpha 2 was a major subtype expressed. Furthermore, IFN-alpha release was higher after induction with NDV than after stimulation with Sendai virus. To compare the IFN-alpha response of adult PBMC to human cord blood mononuclear cells the cells were stimulated with NDV or Sendai virus. The IFN-alpha response of cord blood mononuclear cells to Sendai virus was slightly reduced compared to that of adult cells. However, IFN-alpha 2 was a major subtype produced. In contrast, when cord blood mononuclear cells were stimulated with NDV the IFN-alpha release was strongly diminished. Furthermore, IFN-alpha 2 was not the major subtype expressed. By in situ hybridization the number of IFN-alpha-producing cells was quantified. We found that 1% of adult PBMC and newborn leukocytes showed detectable IFN-alpha mRNA after stimulation with either Sendai virus or NDV. In conclusion, these data suggest that the ability of cord blood mononuclear cells to produce IFN-alpha is diminished compared to adult PBMC. This impaired IFN-alpha response is not based on a reduced number of IFN-alpha-producing cells, but rather due to underlying control mechanisms of the newborns that are different from the regulation of adult PBMC.

Detection of somatic changes in human renal cell carcinomas with oligonucleotide probes specific for simple repeat motifs

The purpose of our study was to detect somatic changes in renal cell carcinoma by multilocus fingerprinting. DNA fingerprints were generated from the DNA of normal and malignant renal tissue samples of 29 patients with nonhereditary kidney carcinoma by using oligonucleotide probes specific for simple repeat motifs such as (GTG)5, (CA)8, (GACA)4, or (TTAGGG)3. Each probe rendered a typical fingerprint pattern, because it is specific with respect to the target regions recognized in the genome. The restriction enzymes used were HinfI and HaeIII. Changed banding patterns were detected by using (GTG)5 in 20% of the tumors, in 20% for (CA)8 after HinfI digestion, and in 10% after HaeIII digestion. Even more informative probes were (GACA)4, showing 70% changes after HaeIII digestion, and (TTAGGG)3, with 80% changes after digestion with either enzyme. Since the simple repeat motifs recognized by (GACA)4 are localized on the short arms of the acrocentric chromosomes (13, 14, 15, 21, and 22), it is possible that sequences important for renal carcinogenesis are present in these regions. The observation of changes in regions to which (TTAGGG)3 hybridizes points to an involvement of DNA elements in telomeric sequence related regions in human kidney tumor formation.

Synthesis and transport of GAP-43 in entorhinal cortex neurons and perforant pathway during lesion-induced sprouting and reactive synaptogenesis

Metabolic labeling and quantitative 2D gel autoradiography were used to assess changes in the synthesis and transport of GAP-43 in entorhinal cortex (EC) neurons and perforant pathway during lesion-induced sprouting and reactive synaptogenesis. In normal adult rats, there is a high constitutive level of GAP-43 synthesis and transport in EC neurons projecting to the hippocampus. Following unilateral EC lesions, there is a 2-fold (100%) increase in the transport of newly synthesized GAP-43 to the contralateral or 'sprouting' hippocampus. The timing of this upregulation (between 6 and 15 days) suggests that changes in GAP-43 expression occur in response to the growth of presynaptic terminals during sprouting.

Immunoreactive low-molecular-weight epidermal growth factor in urine of patients with renal cell carcinoma

A specific heterogeneous enzyme-linked immunosorbent assay (ELISA) has been established in order to determine levels of low-molecular-weight epidermal growth factor (EGF) in the urine of patients with renal cell carcinoma who had undergone unilateral radical nephrectomy. Urine specimens, i.e., 20 pre- and postsurgical specimens from a group of patients and 22 from a control group, were assayed after the urine had been freed from high-molecular-weight proteins (greater than 30 kDa) and salts. EGF levels were expressed as urinary EGF/creatinine ratios, and a highly significant decrease (alpha = 0.0005 by Student's t-test) of urinary EGF was found in the patient group prior to surgery. The cancer patients also showed an additional loss of urinary EGF after unilateral nephrectomy (alpha = 0.0005 by Student's t-test). These data correlate with our previous findings that pro-EGF gene expression is decreased in human renal carcinoma and support the concept that low-molecular-weight urinary EGF is derived from high-molecular-weight kidney pro-EGF.

Expression of the insulin like growth factor-binding protein 3 (IGFBP-3) gene is increased in human renal carcinomas

After we had established that the IGFBP-3 gene is expressed in normal human kidney we examined renal adenocarcinoma tissue for alterations of the expression of this gene. For this purpose we prepared poly(A)+ RNA from normal kidney tissue and adjacent renal adenocarcinoma of 18 adult patients and compared the levels of IGFBP-3 mRNA by Northern analysis in both samples. The mean content by densitometry was markedly increased in the carcinoma tissues; in 17 of 18 patients the carcinoma contained significantly more IGFBP-3 mRNA than the normal kidney sample. The highest mRNA levels were found in patients with N2 and N3 lymph node extensions. Comparative Southern analysis of paired samples of four of these patients did not reveal amplification of the gene as the cause of these increased mRNA levels. In one patient, however, we identified a restriction fragment length polymorphism (RFLP) present in normal and malignant cellular DNA. This suggests a participation of the IGFBP-3 gene in the development of human renal cell cancer.

Modulation of pro-epidermal growth factor, pro-transforming growth factor alpha and epidermal growth factor receptor gene expression in human renal carcinomas

We have analyzed the expression of the genes for the precursors of epidermal growth factor (pro-EGF) and transforming growth factor alpha (proTGF-alpha) as well as for the EGF receptor in tissue specimens of a large number of adult patients with renal cell carcinoma. Since normal kidney tissue was available from the same patients we could directly compare the expression of these genes in tumors with that in adjacent normal renal tissue. Our experiments reveal underexpression of the proEGF gene in all tumors analyzed (21 of 21) and overexpression of the genes for proTGF-alpha (33 of 33 analyzed) and EGF receptor (22 of 23 analyzed) in tumor samples, when compared with normal kidney tissue. The expression of the proTGF-alpha gene appeared to depend on grade and differentiation of the tumor, since well differentiated tumors (grade 1) expressed more proTGF-alpha mRNA than the adjacent normal tissue but significantly less than poorly differentiated tumors (grade 2 or 3), which are the most aggressive ones. In none of these tissue specimens did we find, by Southern analysis, amplification of the proTGF-alpha or EGF receptor gene. Therefore, overexpression of these genes must be due to another effect, perhaps an alteration of their mRNA turnover. Although the EGF receptor gene (c-erbB1) is overexpressed in nearly all carcinomas analyzed, there was no linear coexpression with the proTGF-alpha gene. In contrast, transcription of the proEGF gene was completely turned off in tumor tissue. Although we have found by restriction fragment length polymorphism analysis, in one of three tumor samples, evidence for a somatic mutation within the proEGF gene, we do not know yet, due to the limited number of Southern analyses, whether this somatic mutation is causally involved in the decrease of proEGF mRNA expression and, hence, is representative of renal cell carcinoma. To our knowledge, this is the first observation on primary tumor tissue in humans that upon malignant transformation the gene for a polypeptide growth factor gene is underexpressed.