Lead-Time Corrected Effect on Breast Cancer Survival in Germany by Mode of Detection

(1) Background: Screen-detected breast cancer patients tend to have better survival than patients diagnosed with symptomatic cancer. The main driver of improved survival in screen-detected cancer is detection at earlier stage. An important bias is introduced by lead time, i.e., the time span by which the diagnosis has been advanced by screening. We examine whether there is a remaining survival difference that could be attributable to mode of detection, for example, because of higher quality of care. (2) Methods: Women with a breast cancer (BC) diagnosis in 2000-2022 were included from a population-based cancer registry from Schleswig-Holstein, Germany, which also registers the mode of cancer detection. Mammography screening was available from 2005 onwards. We compared the survival for BC detected by screening with symptomatic BC detection using Kaplan-Meier, unadjusted Cox regressions, and Cox regressions adjusted for age, grading, and UICC stage. Correction for lead time bias was carried out by assuming an exponential distribution of the period during which the tumor is asymptomatic but screen-detectable (sojourn time). We used a common estimate and two recently published estimates of sojourn times. (3) Results: The analysis included 32,169 women. Survival for symptomatic BC was lower than for screen-detected BC (hazard ratio (HR): 0.23, 95% confidence interval (CI): 0.21-0.25). Adjustment for prognostic factors and lead time bias with the commonly used sojourn time resulted in an HR of 0.84 (CI: 0.75-0.94). Using different sojourn times resulted in an HR of 0.73 to 0.90. (4) Conclusions: Survival for symptomatic BC was only one quarter of screen-detected tumors, which is obviously biased. After adjustment for lead-time bias and prognostic variables, including UICC stage, survival was 27% to 10% better for screen-detected BC, which might be attributed to BC screening. Although this result fits quite well with published results for other countries with BC screening, further sources for residual confounding (e.g., self-selection) cannot be ruled out.

Longer Survival From Melanoma in Germany

BACKGROUND

New treatment options for cutaneous melanomas with a poor prognosis have been available since 2011, including immune therapies and targeted drugs. Randomized controlled trials have demonstrated that these treatments improve survival, but no population- level studies have been available to date.

METHODS

All patients in the database of the Center for Cancer Registry Data (Zentrum für Krebsregisterdaten) who had a diagnosis of melanoma (ICD10: C43) in the years 2000 to 2019 were included in the study. The relative five-year survival (5YRS) was calculated for four 5-year periods (2000-04, 2005-09, 2010-14, 2015-19). The data were standardized/stratified according to sex, age group, and UICC stage to correct for differences between regions and over time. Regression models were used to detect statistically significant secular trends.

RESULTS

301 486 individuals were included in the study. The overall 5YRS rose from 93% (2000-04) to 95% (2015-19). The 5YRS in 2015-19 was similar to or greater than that in 2000-04 for all subgroups. The largest rises in 5YRS were between 2010-14 and 2015-19, and specifically in advanced stages: for UICC stage IV tumors, the 5YRS rose from 31% to 36%. There was a significant rising trend across the four time periods (p < 0.001).

CONCLUSION

The survival of melanoma patients has improved over the past 20 years. From 2010-14 to the most recent period, the largest changes were seen in advanced tumor stages. This favorable development coincided with the introduction of new therapies.

Evaluation der Hautkrebsfrüherkennung in Deutschland mit Krebsregisterdaten - Herausforderungen, Lösungen und aktuelle Trends

Hintergrund und Ziele

Die Evidenz für einen Nutzen des 2008 in Deutschland eingeführten Hautkrebsscreenings ist schwach. Wir untersuchen, inwieweit Daten der deutschen epidemiologischen Krebsregister geeignet sind zur Evaluation des Hautkrebsscreenings beizutragen, und berichten diese Evaluationsergebnisse.

Material und Methodik

Die Hautkrebsdaten der Krebsregister aus den Jahren 1999–2019 wurden hinsichtlich Vollzähligkeit und Vollständigkeit beschrieben. Regionale Datenpools unterschiedlicher Validität wurden definiert, fehlende Daten sofern sinnvoll mehrfach imputiert und zeitliche Trends analysiert. Ergänzend wurden Daten der Todesursachenstatistik herangezogen.

Ergebnisse

Belastbare Vollzähligkeitsschätzungen liegen nur für das maligne Melanom (ICD‐10: C43) vor. Auf Basis eines regionalen Datenpools, der circa 21% der deutschen Bevölkerung abdeckt, kann das melanombezogene Krankheitsgeschehen seit 2005 valide beschrieben werden. Für T‐Stadium und Lokalisation liegen ausreichend Informationen für eine multiple Imputation vor. Die Trendanalysen zeigen im zeitlichen Zusammenhang mit der Einführung der Früherkennung kurzfristig erwartbare Inzidenzänderungen, die in eine langanhaltende hohe Inzidenz übergehen. Die Rate fortgeschrittener Stadien geht nicht wesentlich zurück. Ab 2014 sinkt die bis dahin steigende Melanommortalität.

Schlussfolgerungen

Adäquat ausgewählte und aufbereitete Krebsregisterdaten eignen sich zur bevölkerungsbezogenen Bewertung des Hautkrebsscreenings. Eine Erklärung des anhaltend hohen Inzidenzniveaus gelingt auf Basis der Krebsregisterdaten nicht. In Betracht kommen insbesondere Überdiagnosen oder ein Anstieg der Hintergrundinzidenz. Der Nutzen des Hautkrebsscreenings bleibt offen.

Zusammenhang zwischen der Inzidenz früher Stadien und der Mortalität beim malignen Melanom - eine bevölkerungsbasierte ökologische Studie

Hintergrund

In Deutschland wurde 2008 ein flächendeckendes Hautkrebsscreening eingeführt, um die Hautkrebsmortalität und ‐morbidität zu senken. Noch unklar ist jedoch die Wirksamkeit des Programms. Wir untersuchen den Zusammenhang zwischen der Inzidenz von Melanom‐Frühstadien und Melanom‐Mortalität in den Folgejahren, wobei die Inzidenz von Melanom‐Frühstadien als Surrogatparameter für Screening‐Teilnahme und Früherkennung verwendet wird.

Methodik

Für 244 deutsche Landkreise wurden Daten zur Melanom‐Inzidenz von 2005–2016 und zur Melanom‐Mortalität von 2005–2018 erhoben. Die Zusammenhänge zwischen verschiedenen Maßen der Inzidenz und Mortalität wurden mit Korrelationsanalysen und linearen Regressionen untersucht.

Ergebnisse

Die Melanom‐Inzidenz früher Stadien (in situ und T1) stieg nach Einführung des Screenings (2005–2007 vs. 2008–2010) um 69%. Im Gegensatz dazu gab es bei der Mortalität keinen zeitlichen Trend. Die Korrelationen zwischen Inzidenz‐ und Mortalitätsvariablen lagen zwischen –0,14 und 0,10 (nicht signifikant). Die linearen Regressionsanalysen ergaben, dass die Mortalität sechs Jahre nach Einführung des Screenings mit zunehmendem Anstieg der Inzidenz früher Stadien abnimmt (b  =  –0,0029, 95%‐Konfidenzintervall [–0,0066; 0,0007]).

Schlussfolgerungen

Die geschätzten bevölkerungsbezogenen Auswirkungen des Hautkrebsscreenings auf die Melanom‐Mortalität waren minimal und nicht signifikant. Eine mögliche Wirksamkeit kann daher nicht nachgewiesen werden.

Evaluation of early skin cancer detection in Germany with cancer registry data - challenges, solutions and current trends

BACKGROUND AND AIMS

The evidence for the benefit of the skin cancer screening introduced in Germany in 2008 is weak. We investigate to what extent data from the German epidemiological cancer registries are suitable to contribute to the evaluation of skin cancer screening and report these evaluation results.

MATERIAL AND METHODS

Skin cancer-related cancer registry data from 1999-2019 were described in terms of completeness and comprehensiveness. Regional pools with data of different validity were defined, missing data were multiply imputed where appropriate, and temporal trends were analyzed. In addition, data from the cause of death statistics were used.

RESULTS

Reliable estimates of completeness are only available for malignant melanoma (ICD-10: C43). Based on a regional data pool covering approximately 21% of the German population, melanoma-related incidence can be validly described since 2005. Sufficient information for multiple imputation is available for T-stage and localization. The trend analyses show incidence changes that can be expected in the short term in the temporal context of the introduction of early detection, which changes into a long-lasting high incidence. The rate of advanced stages does not decrease significantly. From 2014 onwards, the melanoma mortality rate, which had been rising until then, decreases.

CONCLUSIONS

Adequately selected and processed cancer registry data are suitable for population-based evaluation of skin cancer screening. An explanation of the persistently high incidence level is not possible based on the cancer registry data. Overdiagnosis or an increase in the background incidence can be considered. The benefit of skin cancer screening remains open.

Association of early-stage incidence and mortality in malignant melanoma - a population-based ecological study

BACKGROUND

Germany-wide skin cancer screening was introduced in 2008 to reduce skin cancer mortality and morbidity. However, the effectiveness of the program is still unclear. We explore the relationship between early-stage melanoma incidence and melanoma mortality in subsequent years, using early-stage melanoma incidence as surrogate for screening participation and early detection.

PATIENTS AND METHODS

Data on melanoma incidence for 2005-2016 and melanoma mortality for 2005-2018 were obtained for 244 German counties. We investigated the correlation between several measures of incidence and mortality with correlation analyses and linear regressions.

RESULTS

Melanoma incidence of early stages (in situ and T1) rose by 69% between pre-screening (2005-2007) and screening period (2008-2010). In contrast, there was no temporal trend in mortality over time. Correlation coefficients between incidence and mortality variables ranged between -0.14 and 0.10 (not significant). Linear regression indicated that mortality 6 years after screening introduction decreases with increasing change in early-stage incidence (b = -0.0029, 95% confidence interval [-0.0066, 0.0007]).

CONCLUSIONS

The estimated population-based effects of skin cancer screening on melanoma mortality were minimal and not significant. A potential effectiveness cannot be demonstrated.

The role of human papillomavirus in screening for cervical cancer

PURPOSE

To review the options for effectively screening for cervical cancer, including human papilloma virus (HPV) identification, cytologic screening, colposcopy, or a combination approach. Current pathophysiology, diagnostic criteria, treatment approaches, and patient preparation and education related to cervical cancer screening and prevention are also included.

DATA SOURCES

Comprehensive review of current literature, including research and review articles.

CONCLUSION

Because the Papanicolau (Pap) smear is a screening tool, not a diagnostic tool, further studies must be done to identify the actual nature of discovered abnormalities. Of particular concern is the classification of atypical squamous cells of undetermined significance (ASCUS), which may simply indicate inflammation, or may be the first indicator of serious pathology. Following ASCUS Pap smears with HPV screening will allow for a clarification of the best approach to treatment. A screening algorithm supported by a review of the literature is proposed.

IMPLICATIONS FOR PRACTICE

Cervical cancer is a preventable disease caused by certain forms of HPV. Current screening protocols are based on the use of the Pap smear; and in areas where this test is routine and available, morbidity and mortality rates have dropped dramatically. Many women throughout the world and in underserved regions of the U. S. do not have adequate access to routine screening with Pap smear technology. As long as women continue to die needlessly of cervical cancer, more comprehensive and accessible screening methods must be explored. (Cutting the unnecessary worldwide and in the U. S.).

Dysmenorrhea

Dysmenorrhea is a common complaint that causes considerable disruption in a woman's life. Accurate diagnosis of primary and secondary causes with appropriate therapeutic intervention leads to significant improvements in quality of life.

Diagnostic evaluation for hypertension

Evaluation and management of hypertension requires careful monitoring by the practitioner. A positive patient-provider relationship and an individualized approach to treatment are essential for a positive therapeutic outcome.

Congestive heart failure

The differentiation between systolic and diastolic CHF is clinically important because it allows one to formulate an appropriate therapeutic regimen. As a rule, ACE inhibitors have become a major component in the treatment of systolic heart failure; diuretics, digoxin, and other vasodilators are used in conjunction with them. Optimal therapy for diastolic heart failure remains to be defined. Further research is required for this subset of patients. Numerous other support measures, such as counseling, activity, diet, patient knowledge of medications, and compliance, all affect the patient's outcome.

Clinical health problem: failure to thrive

Families in which NOFTT is present need interventions that target behaviors and identify stressors that contribute to decreased caloric intake. A holistic approach to the situation is required, to deal with considering the problem which may stem from multiple sources. Maternal perceptions of health and diet can be influenced by the practitioner in a sensitive manner, encouraging balance. Infant feeding difficulties can be identified by the practitioner and appropriate referrals can be made to FTT clinics that are experienced in working with these infants and their caregivers. Public health nurses can be utilized to further assess families, follow up on health teaching, and provide referrals to community resources to alleviate stressors. Management of NOFTT by a practitioner in the primary care setting is feasible and cost-effective.

[Relationship between respiratory reserve in the flow-volume curve and the expected ergometric capacity]

To evaluate the physical work capacity in patients with chronic obstructive lung disease (COLD) it was checked, if determination of breathing reserve can replace the exercise test with blood gas analysis. In 28 patients with lung disease and 7 healthy subjects the flow-volume-curve under resting conditions and during the forced breathing maneuver to measure the breathing reserve and the exercise test with blood gas analysis were examined. A correlation was found between both. Therefore, in patients with COLD the determination of breathing reserve is a practicable method for estimating the physical work capacity, especially in cases with absent breathing reserve. Nevertheless, for medical opinion exercise testing is necessary.

Microcirculation of the fingernail fold in CAPD patients: preliminary observations

OBJECTIVE

To study changes in the peritoneal microcirculation during continuous ambulatory peritoneal dialysis (CAPD) by studying change in the microcirculation of the fingernails of CAPD patients.

SETTING

A university department.

DESIGN

A cross-sectional study of 10 nondiabetic patients on CAPD.

INTERVENTION

Hemorrheological tests of fingernail microcirculation using equipment built at our university.

MAIN OUTCOME MEASURES

Microcirculation was characterized by estimation of capillary density, red blood cell (RBC) column diameter, torque index, and RBC flow velocity semiquantitatively using videocapillaroscopy at the fingernail fold and plasma viscosimetry. Findings were correlated with treatment duration, peritoneal clearance, state of capillary morphology and hemodynamics, and lipid and fibrinogen levels.

RESULTS

Treatment duration was significantly correlated (p < or = 0.05) with low-density lipoprotein (LDL) (r = 0.776) and clearances of urea (r = -0.583), uric acid (r = -0.666), and potassium (r = -0.764). Changes in capillary morphology were correlated to clearances of urea (r = 0.643) and uric acid (r = 0.701). The fibrinogen concentration increases plasma viscosity (r = 0.799) and deteriorates the capillary state (r = -0.706). In addition, plasma viscosity correlates to cholesterol (r = 0.620, NS) and LDL (r = 0.781), but not to high-density lipoprotein and triglycerides.

CONCLUSION

CAPD treatment results in lipid abnormalities and high fibrinogen levels that may cause microvascular damage and poor perfusion. These interactions may explain the deterioration of peritoneal transport in some CAPD patients.

Comparison of three methods of measurement of pulmonary artery catheter readings in critically ill patients

BACKGROUND

Pulmonary artery catheter readings are critical for clinical decision making and therapeutic intervention in critically ill patients. Research data of digital display versus graphic strip chart recording of hemodynamic pressures during spontaneous breathing and mechanical ventilation are inconclusive.

OBJECTIVES

To compare three methods of measurement of hemodynamic pressure readings from the pulmonary artery catheter in critically ill patients during mechanical ventilation and spontaneous breathing.

METHODS

A nonrandomized, repeated-measures design was used to compare hemodynamic pressures (right atrial, systolic, diastolic, and wedge pressures) from the pulmonary artery catheter in cardiovascular patients during mechanical ventilation (n = 25) and again during spontaneous breathing (n = 19).

RESULTS

Using repeated measures analysis of variance, statistically significant differences were noted in the pulmonary artery diastolic, wedge, and right atrial pressure during mechanical ventilation. During spontaneous breathing, significant differences occurred in pulmonary artery systolic and wedge pressures only. No statistically significant difference occurred in the systolic pressure during mechanical ventilation, or the pulmonary artery diastolic and right atrial pressures during spontaneous breathing.

CONCLUSIONS

The results of this study indicate that graphic recording is the most reliable means of measuring hemodynamic pressure at end-expiration. Further research is needed to validate these findings with other models of monitoring equipment and other patient populations.

Comparison of three methods of measurement of pulmonary artery catheter readings in critically ill patients

BACKGROUND: Pulmonary artery catheter readings are critical for clinical decision making and therapeutic intervention in critically ill patients. Research data of digital display versus graphic strip chart recording of hemodynamic pressures during spontaneous breathing and mechanical ventilation are inconclusive. OBJECTIVES: To compare three methods of measurement of hemodynamic pressure readings from the pulmonary artery catheter in critically ill patients during mechanical ventilation and spontaneous breathing. METHODS: A nonrandomized, repeated-measures design was used to compare hemodynamic pressures (right atrial, systolic, diastolic, and wedge pressures) from the pulmonary artery catheter in cardiovascular patients during mechanical ventilation (n = 25) and again during spontaneous breathing (n = 19). RESULTS: Using repeated measures analysis of variance, statistically significant differences were noted in the pulmonary artery diastolic, wedge, and right atrial pressure during mechanical ventilation. During spontaneous breathing, significant differences occurred in pulmonary artery systolic and wedge pressures only. No statistically significant difference occurred in the systolic pressure during mechanical ventilation, or the pulmonary artery diastolic and right atrial pressures during spontaneous breathing. CONCLUSIONS: The results of this study indicate that graphic recording is the most reliable means of measuring hemodynamic pressure at end-expiration. Further research is needed to validate these findings with other models of monitoring equipment and other patient populations.

Determination of glomerular filtration rate (GFR) on two consecutive days using inulin in a single-sample plasma clearance method

Reliable estimation of the GFR is essential in nephrological practice for the early recognition and follow-up of latent or residual renal disturbance. The GFR of ten healthy volunteers on two consecutive days and of 40 patients with different renal diseases were investigated by means of a plasma slope clearance technique. After injection of 5 g/50 ml inulin solution, eight plasma samples were taken at 10, 20, 30, 40, 120, 180, 240, 300 min p.i. and analyzed with the aid of a fully enzymatic method. The results were correlated on the basis of 1- and 2-compartment models (1 CM, 2 CM) and the one-sample method (1 S), using only the plasma inulin concentration of the 240 min p.i. sample. The accuracy of the GFR data of volunteers estimated in these models was checked by comparison with the standardized agewise normal values, while for the patient group we found in terms of equations of correlation: 1. GFR (2 CM) = 4.46 + 0.763*GFR (1 S), n = 31, r = 0.985 2. GFR (2 CM) = 1.27*GFR (1 CM)0.9, n = 40, r = 0.996 3. GFR (1 CM) = 0.568*(GFR[1 S] + 5.85)1.11, derived The single-sample method using inulin is closely correlated to multi-sample methods but much more suitable for patients and staff. Therefore, it is recommended for clinical use.

The competitive effects of horizontal mergers in the hospital industry: a closer look

Woolley (1989) attempted to analyze the competitive impact of horizontal hospital mergers using the 'event study' method. Woolley characterized his results as consistent with traditional 'oligopoly' theories of market behavior. We scrutinize in detail a large number of his events, however, and find that most either generated concentration increases too small to plausibly produce market power, or could not have conferred monopoly returns on firms improperly characterized as rivals. Accordingly, any observed abnormal returns are likely attributable to some other cause; we suggest some alternative interpretations of his results. Our paper highlights the need for care in the selection of events and the identification of rivals when applying the event study method to the analysis of mergers.

[Simultaneous determination of the GRF and the ERPF (effective renal plasma flow) using a single blood sample in the slope clearance with 99mTc-DTPA and I 131-hippurate]

In patients with various indications to renal split function diagnostics the plasma slope clearance of the Tc99m-DTPA and J131-Hippurate to the estimation of GFR and ERPF were performed with two or three blood samples in the monocompartment model (1 KM). In comparison these functional parameters were calculated on the basis of the only least blood sample (single-point procedure--EPV). The results of linear regression GFR (1 KM) = 12.7 + 0.978 * GFR (EPV), r = 0.986, N = 102 or ERPF (1 KM) = 22 + 1.13 * ERPF (EPV), r = 0.889, N = 68 may recommend the use as patient-safe procedure especially in poor venous access. Two short BASIC programs for estimation of GFR and ERPF are presented and the error ranges discussed.

[Ergometric results of r-erythropoietin treatment of hemodialysis patients]

To investigate the effect of partial correction of anemia in patients maintained by chronic intermittent hemodialysis on exercise capacity, patients underwent a bicycle acido-ergometry before and after treatment with recombinant human erythropoietin. The results demonstrate a (subjective) improvement of exercise capacity without any evidence for that in the pH values.

An improved method to determine renal function using inulin and p-aminohippurate (PAH) steady-state kinetic modeling

Steady-state clearances using inulin and PAH are the most reliable reference procedures if new test substances or techniques are developed to estimate the GFR or the of these methods we developed an open monocompartment model with an expanding distribution volume of the substance of interest. In this model we derived prescriptions for the concentration of inulin and PAH in the infusion procedure. The resulting improvement was verified by the F-test on the variance of plasma concentration in a 3-hour examination of 15 patients. The final results are of direct benefit to the patient because the number of blood samples required for the control of the steady-state plasma level can be reduced. Furthermore, we derived an individual correction of the so-called input steady-state clearance (without urine collection) which relates better to the usual output clearance of inulin or PAH. A PC-BASIC program is available that calculates the proper concentrations for the infusion and executes the complete analysis (GFR, ERPF, filtrate fraction [FF], maximal tubular transport of PAH [TmPAH] and the renal vascular resistance [RVR], each of which is related to the BSA and the age of the patient).

[Pathophysiologic-nephrologic hypothesis of the protective function of an endogenous natriuretic and digoxin-like substance (endoxin) for residual nephrons]

A dualistic function for the natriuretic ATP.inhibiting factor is formulated on the basis of a phenomenon like compensatory renal adaption of residual nephrons: 1. Support of the tubular sodium excretion to the maintenance of homoeostasis of the organism. 2. Inhibition of the forced up vasodilation of the afferent glomerular vessel. It should suggested that the renal vasoconstrictive effect is a part of a protective system for residual nephrons against the pathogenic hyperfiltration and hyperperfusion.

[Steps for solutions and hindrances in progress in relation to an implantable bio-artificial hemofilter-intestine-hybrid kidney]

On the view of 1989 older and modern developments to a bioartificial implantable hybrid kidney are presented. To the realization proof of the implantable hemofilter-intestine-hybrid kidney the routes were described in an experimental rat model to the plasmakinetic simulation of the urea and sodium level as a marker of the hybrid kidney functions. The results of the bioartificial hemofilter-intestine-hybrid kidney development are presented, but significant detail problems must be solved, especially the hemofilter biocompatibility problem.

[Contribution of animal experiments in the problem of a long-term indomethacin therapy in advanced nephron loss]

Residual nephrons are subject to compensatory adaptation at which the glomerular hyperfiltration and convection of macromolecules (proteins) are of pathogenic character in the progression of nephropathy. The influence of indomethacin at dosages of 2 or 3 mg/kg body weight/day was investigated in long-term feeding trials (8 months) on inbred female Wistar rats after unilateral nephrectomy and additional resection of both kidney poles. The results show a significant deterioration of vital prognosis under indomethacin medication independently of the dosage.

[Standardization of methods and assessment of conventional and radionuclide clearance investigations: recommendations of the Renal Diagnostics Study Group of the Society of Nephrology, GDR]

Recommendations of the Study Group "Renal Function Diagnostics" of the Society of Nephrology to the performance of the steady state clearance using inulin or PAH and the slope clearance with radionuclides for estimation of effective renal plasma flow are presented. These investigations are indicated in the early recognition and follow-up of latent or residual disturbance of the renal function in the creatinine-blind area. Recommendations have been done on selection and dosage of test substances, timing of examination and evaluation of results.

[Development of a model as a pathophysiologic study method in clinical and experimental nephrology]

After explanations concerning principal qualities of the models follow examples from nephrology about theoretical and concrete modelling. Consequences for the renal functional, performance and reagibility diagnostics are discussed. The ability of mathematical modellings for statements is shown at the instance of the ureal plasma kinetics in apparative peritoneal detoxication methods and in connection with investigations about the implantable kidney as well as supplemented by explanations concerning the dynamic compartment modelling of the potassium balance.

Bacterial and fungal growth after freezing or refrigerating parenteral nutrient solutions

Parenteral nutrient (PN) solutions were evaluated for growth of pathogenic organisms after refrigeration or freezing and then thawing. Sixteen bags of hypertonic dextrose and amino acid solutions were divided into two series (refrigerated and frozen), inoculated with Escherichia coli. Candida albicans, Staphylococcus aureus, or Streptococcus faecalis, and exposed to freezing or refrigeration. The inoculum concentration was greater than would likely occur with patient contamination of the solution. Microbial growth in the solutions was determined after warming to room temperature and at 17 or 18 hours after reaching room temperature. There was no increased growth of C. albicans in PN solutions that were frozen versus the refrigerated samples. Counts for all of the organisms in the frozen series, immediately after freezing and then thawing, decreased or stayed the same compared with baseline counts. Growth of E. coli, Staph. aureus, and Strep. faecalis increased in the frozen samples compared with the refrigerated samples after room-temperature storage, suggesting a possible increased risk of infectious complications if contaminated solutions are left at room temperature for extended periods. Since no increased risk of microbial growth is likely in frozen versus refrigerated PN solutions that are thawed and promptly infused, batch freezing may be an effective and convenient means of preparing PN solutions for home patients.

[Mediator concepts and modulation of renal compensatory adaptation]

In the renal compensatory adaptation after the definition and the description of the fundamental phenomena of the functional compensation as well as of the structural adaptation is reported on mediator concepts and on modulations of the renal adaptation processes. Issuing from the central position of the sodium balance a mediator concept on natriuretic hormones (Auriculin and Endoxin) is developed which is supplemented by the renotropin mediator concept. The authors deal with the modulation of the renal compensatory adaptation (e.g. influences of age diet and so on). The pharmacotherapeutic modulation of the renal compensatory adaptation is discussed with regard to the stimulation of the tubulosecretory transport of foreign substances with para-amino hippuric acid as principal substance (including own investigations with cyclopenthiazide [Benesal].

[Experimental animal studies of compensatory renal adaptation of residual nephrons in physical stress caused by daily swim training]

The influence of a regular physical training after unilateral nephrectomy carried out on the experimental animal rat on the function of the residual kidney was investigated. A significant decrease of the glomerular filtration rate by 22% and an increase of TmPAH by 36% in the loaded animals could be proved 12 weeks after unilateral nephrectomy and two-month load by swimming training. These findings allow the interpretation that physical conditioning for adapting nephrons may be regarded as progression as well as protection factor. Additional long-term investigations are necessary to clarify this problem and finally to prove present therapeutic recommendations for the physical conditioning with regard to prove protective reactions to the renal compensatory adaptation of the residual nephrons without any doubt.

Prediction of whole blood selenium levels in patients on long-term parenteral nutrition

In an attempt to define clinical variables which might predict the whole blood selenium level prior to supplementation, whole blood selenium levels were determined in 21 home parenteral nutrition patients who were not receiving selenium supplementation. These levels were examined for possible correlations by single and multivariant analysis with the following clinical parameters: age at initiation of home parenteral nutrition, months of home parenteral nutrition received, hematocrit, albumin, estimated length of remaining small bowel, kilocalories per kilogram actual body weight infused per day, grams protein per kilogram actual body weight infused per day, and multiple of ideal body weight. Of all the combinations of variables examined, the best correlation obtained was between whole blood selenium levels and the total kilocalories per kilogram body weight per day delivered intravenously (r = -0.89, p less than 0.001). A statistically significant correlation (r = -0.67, p less than 0.01) was also observed between selenium levels and the grams protein per kilogram actual body weight infused per day. However, inclusion of this or additional variables did not increase the predictive value of the equation describing whole blood selenium levels as a function of the calories delivered. The implication of this study is that patients requiring more intensive nutritional support develop lower selenium levels during the course of treatment. Despite these correlations, no single clinical parameter or combination of parameters, however, was of sufficient predictive value to preclude laboratory determination of whole blood selenium values in deciding which patients might benefit from selenium supplementation.