Temporal Trends in the Initiation of Dialysis Among Patients With Heart Failure With or Without Diabetes: A Nationwide Study From 2002 to 2016

BACKGROUND

The incidence and distribution of acute and chronic dialysis among patients with heart failure (HF), stratified by diabetes, remain uncertain. We hypothesized that with improved survival and rising comorbidities, the demand for dialysis would increase over time.

METHODS AND RESULTS

Patients with incident HF, aged 18 to 100 years, between 2002 and 2016, were identified using Danish nationwide registers. Primary outcomes included acute and chronic dialysis initiation, HF-related hospitalization, and all-cause mortality. These outcomes were assessed in 2002 to 2006, 2007 to 2011, and 2012 to 2016, stratified by diabetes. We calculated incidence rates (IRs) per 1000 person-years and hazard ratios (HR) using multivariable Cox regression. Of 115 533 patients with HF, 2734 patients received acute dialysis and 1193 patients received chronic dialysis. The IR was 8.0 per 1000 and 3.5 per 1000 person-years for acute and chronic dialysis, respectively. Acute dialysis rates increased significantly among patients with diabetes over time, while no significant changes occurred in those without diabetes, chronic dialysis, HF-related hospitalization, or overall mortality. Diabetes was associated with significantly higher HRs of acute and chronic dialysis, respectively, compared with patients without diabetes (HR, 2.07 [95% CI, 1.80-2.39] and 2.93 [95% CI, 2.40-3.58] in 2002 to 2006; HR, 2.45 [95% CI, 2.14-2.80] and 2.86 [95% CI, 2.32-3.52] in 2007 to 2011; and 2.69 [95% CI, 2.33-3.10] and 3.30 [95% CI, 2.69-4.06] in 2012 to 2016).

CONCLUSIONS

The IR of acute and chronic dialysis remained low compared with HF-related hospitalizations and mortality. Acute dialysis rates increased significantly over time, contrasting no significant trends in other outcomes. Diabetes exhibited over 2-fold increased rates of the outcomes. These findings emphasize the importance of continued monitoring and renal care in patients with HF, especially with diabetes, to optimize outcomes and prevent adverse events.

Temporal trends in end-stage renal disease in patients with heart failure with or without diabetes: a nationwide study from 2002 to 2017

Background

Advances in treatment of heart failure (HF) have increased survival rates. However, whether the improved life expectancy for HF patients has resulted in an increased risk of a significant comorbidity like end-stage renal disease (ESRD) is less clear. Renal dysfunction is associated with increased morbidity and mortality in HF and constitutes an important prognostic factor for HF. Further, diabetes (DM) is closely related to both HF and ESRD, but it is unknown how DM affects the risk of ESRD in patients with HF.

Purpose

To investigate temporal trends in ESRD in patients with HF and the subsequent risk of mortality stratified by DM.

Methods

Using Danish nationwide registies, we identified patients, aged 18 to 100 years, with incident HF between 2002 and 2017. The outcomes were ESRD (defined as dialysis treatment), worsening of HF (wHF, defined as rehospitalization for HF) and all-cause mortality. Three study periods were investigated 2002–2006, 2007–2011 and 2012–2017. We estimated crude 5-year incidence rates (per 1000/person-years) of the outcomes stratified by DM. Multivariate Cox regression models were performed for all outcomes stratified by DM. Further, we computed the 1-year all-cause mortality risk after diagnosis with ESRD.

Results

Of 124,141 patients with HF, 50,690 (41%) were women and the median age was 74.5 years [95% confidence interval (CI) 64.5–82.8]. At baseline DM was present in 20% of the patients. These patients were older, more often men and more comorbid than HF patients without DM. Over time (2002–2006 to 2012–2017) the incidence rates of ESRD (9.0 to 7.9 and 2.1 to 1.9 per 1000/person-years for DM and no-DM, respectively) and wHF (124.0 to 124.8 and 84.3 to 81.9 per 1000/person-years for DM and no-DM) remained stable, while all-cause mortality rates decreased (217.0 to 170.3 and 172.9 to 127.8 per 1000/person-years for DM and no-DM). The incidence of ESRD was lower compared with the incidence of wHF and all-cause mortality [Figure 1]. HF patients with DM had significantly higher associated rates of all three outcomes (in 2012–2017 the rates for DM vs no-DM of ESRD: 3.99 [3.27–4.86], wHF: 1.42 [1.36–1.49], all-cause mortality: 1.36 [1.31–1.41]) compared with patients without DM. We found no significant interaction between time period and DM on the rates of outcomes (p>0.05 for all) [Figure 2]. One-year all-cause mortality risk after diagnosis with ESRD was high both for HF patients with and without DM through all time periods (identical risks and 95% CI in 2012–2017: 32% [0.25–0.39]).

Conclusions

We did not observe a change over time in the 5-year risk of ESRD for HF patients. The incidence of ESRD remained low compared to wHF and all-cause mortality. DM was associated with increased rates of all three events, not changed over time. Conversely, all-cause mortality after diagnosis with ESRD was markedly high, irrespectively of DM. Our analyses suggest that ESRD is a less common, but fatal event in HF patients.

Funding Acknowledgement

Type of funding sources: None.

Temporal trends in infection-related hospitalizations in patients with heart failure: a nationwide study from 1997 to 2017

Background

Over the last 20 years mortality has decreased for patients with heart failure (HF). However, re-hospitalization for HF is still a challenge. Further, whether the improved survival has resulted in increased rates of non HF hospitalization is unknown.

Purpose

This study examined the temporal trends in infection-related hospitalizations among new-onset HF patients and compared it to temporal trends in risk of worsening HF and death.

Methods

The study population included all Danish patients aged between 18 and 100 years old, with new-onset HF (defined according to the ICD10-code system) diagnosed between 1st January 1997 and 31st December 2017. Patients who were diagnosed with any type of cancer up to five years before their HF diagnosis were excluded to avoid cancer related infections.

The outcomes of interest were infections (defined according to the ICD10-code system) and worsening of heart failure (defined as a hospital admission with HF covering at least to dates).

The Aalen Johansen's estimator was used to estimate unadjusted 5-year absolute risk for all outcomes. Furthermore, a multivariate Cox analysis was made, and hazard ratios were estimated for the four time periods presented in a forest plot with the period 1997–2001 being the reference group. Adjustments for sex, age and history of comorbidities were conducted. Additionally, we stratified the infection outcome on different types of infections illustrated in 5-year cumulative incidence curves.

Results

The total population consisted of 147,737 patients. Over time there was a slight decrease in median age (1997–2001: 76.8 years, 2011–2017: 73.1 years) and the patients were more likely to be male (1997–2001: 53.5%, 2011–2017: 60%).

Figure 1 illustrates overall absolute risk of death decreased over time 1997–2001 (62.7% [95% CI 62.2–63.2]) vs. 2011–2017 (57.9% [95% CI 41.5–42.7]). Unadjusted curves for absolute risk showed that patients with HF had a higher risk of infection over time 1997–2001 (16.4% [95% CI 16.0–16.8] vs. 2011–2017 (24.5% [95% CI 24.0–24.9]). In contrast, they have a lower risk of worsening HF 1997–2011 (26.5% [95% CI 26.1–27.0] vs. 2011–2017 (23.2% [95% CI 22.8–23.7]). Adjusted analyses provided the same result for all outcomes illustrated in figure 2.

The risk of infection stratified by infection type, mark the risk of pneumonia infection as the most significant in all subintervals 1997–2001 (11.4% [95% CI 11.1–11.7]) vs. 2011–2017 (16.1% [95% CI 15.7–16.5]). The second most important was the risk of urogenital infection 1997–2001 (3.5% [95% CI 3.31–3.69]) vs. 2011–2017 (7.8% [95% CI 7.52–8.12]).

Conclusion

In this nationwide study, we observed that overall mortality risk and risk of hospitalization for worsening HF decreased from 1997 to 2017. In contrast, an increase in the risk of hospitalization for infection, especially pneumonia infections, increased during the same period. Future HF management programs should include strategies to prevent infections.

Funding Acknowledgement

Type of funding sources: None.

Comparison of the timing of development of immunity in Romney lambs from resistant and resilient selection lines

Variation in the timing of development of immunity to gastro-intestinal nematode parasites was assessed in resistant and resilient Romney selection lines exposed to mixed natural infection. From weaning, at mean 92 days-of-age, animals (n = 53) were sampled for faecal egg count (FEC) expressed as eggs per gram of faeces (epg), saliva for immunoglobulin (IgG and IgA) determination and fasted live weight (LW) every 10 days until 351 days-of-age. Overall, mean back-transformed FEC were consistently low for resistant animals (<200 epg) whereas resilient counterparts' FEC increased with time to reach a peak of 1400 epg at day 230 for females and 1800 epg for males at day 280 before declining to less than 500 epg by day 300, respectively (P < 0.001). Resistant lambs reached a threshold for Trichostrongylus colubriformis L3-specific IgG which was indicative of the presence of immunity earlier at 220.6 ± 8.8 days-of-age compared with resilient-line animals which reach this threshold 40 days later at 263.4 ± 6.9 days-of-age (P < 0.001). In addition, resistant females reached sexual maturity earlier compared with their resilient counterparts viz. 263.5 ± 3.7 c.f. 274.4 ± 3.4 days-of-age, respectively, (P = 0.048). Mean fasted live weight (LW) showed a selection line by time interaction (P < 0.001) which reflected greater LW in the early phase of the study in resilient males but increasing for all groups until day 280 before declining and being similar for all groups from day 330. In summary, differences appear to exist in the timing of immune development between these Romney lines, with resistant animals developing immunity earlier and these resistant-line animals also appear to be more physiologically mature at the same chronological age than resilient animals. These observations have implications on the timing of identification and selection of resistant animals.

Is there long-term value of pathology scoring in immunoglobulin A nephropathy? A validation study of the Oxford Classification for IgA Nephropathy (VALIGA) update

Background

It is unknown whether renal pathology lesions in immunoglobulin A nephropathy (IgAN) correlate with renal outcomes over decades of follow-up.

Methods

In 1130 patients of the original Validation Study of the Oxford Classification for IgA Nephropathy (VALIGA) cohort, we studied the relationship between the MEST score (mesangial hypercellularity, M; endocapillary hypercellularity, E; segmental glomerulosclerosis, S; tubular atrophy/interstitial fibrosis, T), crescents (C) and other histological lesions with both a combined renal endpoint [50% estimated glomerular filtration rate (eGFR) loss or kidney failure] and the rate of eGFR decline over a follow-up period extending to 35 years [median 7 years (interquartile range 4.1–10.8)].

Results

In this extended analysis, M1, S1 and T1–T2 lesions as well as the whole MEST score were independently related with the combined endpoint (P &lt; 0.01), and there was no effect modification by age for these associations, suggesting that they may be valid in children and in adults as well. Only T lesions were associated with the rate of eGFR loss in the whole cohort, whereas C showed this association only in patients not treated with immunosuppression. In separate prognostic analyses, the whole set of pathology lesions provided a gain in discrimination power over the clinical variables alone, which was similar at 5 years (+2.0%) and for the whole follow-up (+1.8%). A similar benefit was observed for risk reclassification analyses (+2.7% and +2.4%).

Conclusion

Long-term follow-up analyses of the VALIGA cohort showed that the independent relationship between kidney biopsy findings and the risk of progression towards kidney failure in IgAN remains unchanged across all age groups and decades after the renal biopsy.

Expression of iNOS mRNA associated with suppression of colonic contraction in rat colitis

AIM

Nitric oxide (NO) synthesis and inducible NO synthase (NOS) expression are increased in colon of patients with inflammatory bowel disease (IBD) and associated with decreased contractility. The aim was to investigate which subtype of NOS that is activated in experimental colitis.

METHODS

Experimental colitis was induced in Sprague-Dawley rats by Escherichia coli endotoxin. Expression of different subtypes of NOS was compared in normal and inflamed colon using reverse transcriptase-polymerase chain reaction. In organ baths, isometric contractile responses to acetylcholine (ACh) were studied in the colon, before and after incubation with the NOS inhibitor; N(omega)-nitro-L-arginine methyl ester (L-NAME) and NO donor glyceryl trinitrate.

RESULTS

Inflammation decreased colonic contraction to ACh from a pD(2) value of 7.09 +/- 0.16 to 5.30 +/- 0.17 (P < 0.001), and reduced maximal response to ACh. Pre-treatment with L-NAME reversed contractility and shifted the pD(2) for ACh from 5.30 +/- 0.17 to 6.60 +/- 0.19 (P < 0.001) along with a normalized contraction efficacy. RT-PCR product of iNOS was obtained only in rats treated with endotoxin.

CONCLUSION

Expression of iNOS is increased in inflamed colonic tissue. The induced overproduction of NO is likely to be responsible for the decreased motility in colitis where NO is suggested to exert a suppressive tone on colonic contractility, which is reversed by blockade of the enzyme.

Three-month neoadjuvant hormonal therapy before radical prostatectomy: a 7-year follow-up of a randomized controlled trial

OBJECTIVE

To describe the outcome, assessed as the level of prostate specific antigen (PSA), of a mature (more than half the events recorded) prospective randomized study with a median follow-up of 82 months of neoadjuvant hormonal therapy before radical prostatectomy, as this has been suggested to decrease the rate of positive surgical margins (i.e. provide greater potential to completely excise the tumour).

PATIENTS AND METHODS

From December 1991 to March 1994, 126 patients with clinically localized prostate cancer were randomized between direct radical prostatectomy or a 3-month course of a gonadotrophin-releasing hormone analogue before surgery. The patients were followed by PSA determinations and a value of > 0.5 ng/mL used to define progression.

RESULTS

The incidence of positive surgical margins decreased from 45.5% to 23.6% (P = 0.016) with hormone treatment. Despite this there was no difference in PSA progression-free survival at the last follow-up; it was 51.5% for those undergoing radical prostatectomy only and 49.8% for those who received hormonal pretreatment (P = 0.588).

CONCLUSIONS

Three months of neoadjuvant hormonal therapy before radical prostatectomy offers no benefit to the patient and cannot be recommended for routine clinical use.

MRI in rolandic epilepsy

Hippocampal and/or white matter abnormalities have been found on the MRIs in 10/18 children with typical rolandic epilepsy. The etiology of the first-mentioned is not evident, whereas the latter may be a result of a maturational delay involving a defective myelination. Both abnormalities may cause cognitive dysfunction. In order to get a better understanding of rolandic epilepsy both MRI and neuropsychological studies are wanted in groups of children with typical rolandic seizures with and without rolandic sharp waves, as well as in groups of children with typical rolandic sharp waves and atypical seizures.

Neuroendocrine differentiation is not prognostic of failure after radical prostatectomy but correlates with tumor volume

OBJECTIVES

To study neuroendocrine (NE) tumor cell differentiation in prostate cancer in relation to failure after radical prostatectomy.

METHODS

Radical prostatectomy specimens from 103 of 111 patients randomized to 3-month neoadjuvant luteinizing hormone-releasing hormone-analogue treatment (neoadjuvant group) or to surgery alone (control group) were available for analysis. Immunohistochemistry using antibodies to chromogranin A (CGA) enabled detection of tumor cells with NE differentiation. NE differentiation was scored as NE-negative (0 to 1+) or NE-positive (2 to 3+). The number of CGA-positive cells/cm(2) tumor area on the slides was assessed in a separate analysis. The patients were followed up for 39 months after surgery, and a prostate-specific antigen value of 0.5 ng/mL or greater in two consecutive blood samples was considered biochemical failure.

RESULTS

Kaplan-Meier analysis stratified for neoadjuvant hormonal treatment showed the failure rate to be significantly greater among those with NE-positive tumors than among those with NE-negative tumors. However, the number of CGA-positive cells/cm(2) was not a variable of prognostic significance. Instead, both NE differentiation and the CGA-positive cell count correlated with the tumor area on the slides (P = 0.0001). Multivariate analysis revealed the tumor area on the slide (P <0.0001) and positive surgical margins (P = 0.03) to be the only significant predictors of biochemical failure.

CONCLUSIONS

The extension of NE differentiation in prostate cancer correlates with tumor volume and is not an independent prognostic factor of failure after radical prostatectomy.

Regressive changes and neuroendocrine differentiation in prostate cancer after neoadjuvant hormonal treatment

BACKGROUND

We studied the extent of neuroendocrine (NE) tumor cell differentiation and its relation to regressive changes in prostate cancer after 3-month hormonal treatment.

METHODS

Radical prostatectomy specimens from 103 patients, randomized to 3-month neoadjuvant LH-RH-analogue treatment (neoadjuvant group) or to surgery alone (control group), were available for analysis. The effects of hormonal treatment in terms of positive surgical margins, the degree of histopathological changes, and tumor cell proliferation were evaluated in relation to NE-differentiation assessed with antibodies against chromogranin A (CGA).

RESULTS

Both the number of CGA-positive cells/cm(2) (P < 0.003) and the proportion of NE-positive tumors (P = 0.07) were greater in the neoadjuvant group than in the control group. No correlation existed between NE-differentiation and the effects of the neoadjuvant hormonal treatment; nor did NE-differentiation correlate to the decrease in serum PSA.

CONCLUSIONS

Neuroendocrine differentiation in prostate cancer increases after 3 months of neoadjuvant hormonal treatment but does not correlate to the effects of hormonal treatment.

Hippocampal asymmetries and white matter abnormalities on MRI in benign childhood epilepsy with centrotemporal spikes

PURPOSE

To look for brain abnormalities by using magnetic resonance imaging (MRI) in patients with benign childhood epilepsy with centrotemporal spikes (BCECTS), which is the most common epilepsy syndrome in children.

METHODS

Eighteen children, aged 6-12 years, with typical BCECTS were examined with MRI, six of them twice.

RESULTS

Some hippocampal abnormality was found in six (33%) of the children, all with the syndrome's typical electroencephalogram (EEG) pattern ipsilaterally. Hippocampal size asymmetry was found in five (28%) children (right side < left in two and left < right in three), and high signal intensities on T2-weighted images were found in three (17%). Two children also had other abnormalities; one had a heterotopic nodule near the contralateral frontal horn, and one had an Arnold-Chiari malformation. The hippocampal asymmetry remained unchanged in three of the children who were reexamined after 2 years. High signal intensities on T2-weighted images were seen beneath the cortex-white matter junction in the frontal and temporal lobes of five (28%) children, one of whom also had a hippocampal asymmetry. MRIs were normal in eight (44%) children.

CONCLUSION

For the first time, hippocampal asymmetries and white-matter abnormalities have been detectable on the MRIs of children with typical BCECTS. The etiology of the former is unclear, whereas the latter may be a result of a maturational delay involving a defective myelination. Long-term follow-up studies are needed to evaluate the relation between these findings and the clinical course of BCECTS.

Neuropsychological findings in children with benign childhood epilepsy with centrotemporal spikes

Benign childhood epilepsy with centrotemporal spikes (BCECTS) is a well-known idiopathic age- and localization-related epileptic syndrome with characteristic clinical and EEG manifestations. Due to the reported benign evolution of this epilepsy syndrome, neuropsychological assessment has been considered unnecessary. However, the benign nature of BCECTS has recently been challenged: verbal dysfunction as well as impaired visuomotor coordination, specific learning disabilities, and attention deficit have been noticed. These findings prompted this research study in which all children with BCECTS attending our epilepsy clinic underwent neuropsychological assessment. Seventeen children (10 boys and seven girls) aged 7 to 14 years were investigated with a neuropsychological test battery focusing on immediate and delayed recall of auditory-verbal and visual material, verbal fluency, problem-solving ability, and visuospatial constructional ability. Raven's coloured matrices and questionnaires regarding school functioning and behaviour were also administered. The children were matched with control subjects for age, sex, and school. Children with BCECTS had significantly lower scores than their control subject partners on the neuropsychological items. Intellectual abilities did not differ and neither did school functioning or behaviour according to teachers. Parents, however, recognized greater difficulties with concentration, temperament, and impulsiveness in children with BCECTS.

Tumor cell proliferation in prostate cancer after 3 months of neoadjuvant LHRH analogue treatment is a prognostic marker of recurrence after radical prostatectomy

OBJECTIVES

To evaluate tumor cell proliferation in relation to histopathologic regressive changes and failure after radical prostatectomy after a 3-month course of neoadjuvant luteinizing hormone-releasing hormone (LHRH) analogue treatment.

METHODS

We evaluated slides from 103 radical prostatectomy specimens of the 111 patients participating in a randomized trial of a 3-month course of neoadjuvant LHRH analogue treatment before radical retropubic prostatectomy (n = 50) versus surgery alone (n = 53). The histopathologic regressive changes in the specimens were scored by two pathologists. Sections were stained with the anti-Ki-67 monoclonal antibody MIB-1. The proliferation index (PI) was defined as the proportion of Ki-67-positive cells in a random cell count. The patients were followed up until treatment failure or for a mean of 39 months among those without failure.

RESULTS

In the neoadjuvant group, increasing histopathologic regressive changes correlated with a decrease in capsular penetration, positive surgical margins, and tumor cell proliferation but did not correlate with Gleason score in biopsies. Treatment failure was not related to the histopathologic regressive changes. In the neoadjuvant treatment group, progression-free survival was longer in the subgroup of patients with tumors with a PI less than 1.2% compared with those with tumors with a PI greater than 1.2% (P = 0.02). Multivariate analysis of PI and histopathologic and clinical features showed the PI (P = 0.002) and the pretreatment serum prostate-specific antigen level (P = 0.003) to be significant prognostic markers of failure in the neoadjuvant group.

CONCLUSIONS

Tumor cell proliferation after 3 months of neoadjuvant hormonal treatment is a prognostic marker of failure after radical prostatectomy without correlation to Gleason score or the histopathologic regressive changes resulting from hormonal treatment.

The chemotactic response of Vibrio anguillarum to fish intestinal mucus is mediated by a combination of multiple mucus components

Chemotactic motility has previously been shown to be essential for the virulence of Vibrio anguillarum in waterborne infections of fish. To investigate the mechanisms by which chemotaxis may function during infection, mucus was isolated from the intestinal and skin epithelial surfaces of rainbow trout. Chemotaxis assays revealed that V. anguillarum swims towards both types of mucus, with a higher chemotactic response being observed for intestinal mucus. Work was performed to examine the basis, in terms of mucus composition, of this chemotactic response. Intestinal mucus was analyzed by using chromatographic and mass spectrometric techniques, and the compounds identified were tested in a chemotaxis assay to determine the attractants present. A number of mucus-associated components, in particular, amino acids and carbohydrates, acted as chemoattractants for V. anguillarum. Importantly, only upon combination of these attractants into a single mixture were levels of chemotactic activity similar to those of intestinal mucus generated. A comparative analysis of skin mucus revealed its free amino acid and carbohydrate content to be considerably lower than that of the more chemotactically active intestinal mucus. To study whether host specificity exists in relation to vibrio chemotaxis towards mucus, comparisons with a human Vibrio pathogen were made. A cheR mutant of a Vibrio cholerae El Tor strain was constructed, and it was found that V. cholerae and V. anguillarum exhibit a chemotactic response to mucus from several animal sources in addition to that from the human jejunum and fish epithelium, respectively.

Booster vaccination with recombinant hepatitis B vaccine four years after priming with one single dose

We here studied the antibody response to a booster dose four years after the administration of one single dose of recombinant HB vaccine. Before receiving the booster dose, levels of protective antibodies (anti-HBs) were generally low and 24/41 (59%) individuals lacked detectable antibodies (< 1 IU/L). Within 14 d of booster vaccination, 36/38 (95%) vaccinees showed levels of antibodies > 100 IU/L. Notably, these levels were at least as high as those of a reference group 12 months after initiation of vaccination according to the standard three-dose vaccination at intervals of 0, 1 and 6 months. In conclusion, one single dose of HB vaccine seemed to confer on young healthy individuals a well preserved B cell memory, disclosed as a rapid and strong antibody response to a second dose four years later.

Population dynamics of resource limited plants and their pollinators

In this paper we build upon and generalize an earlier model of the interactions between a plant and its pollinator (Ingvarsson and Lundberg, 1995). In this model we assume that the performance of the pollinator population is directly linked to the size of the plant population. To avoid the problem of both populations growing exponentially we have, without loss of generality, assumed the plant population to be resource limited. Analysis of the system shows that there exists either two or no internal equilibrium points. The case with no equilibrium points corresponds to the trivial case where the system cannot persist, resulting in the extinction of both the plant and pollinator population. When the two internal equilibrium points do exist, one of them will always be unstable. This unstable equilibrium can be viewed as an equivalent of the threshold criteria derived in Ingvarsson and Lundberg (1995) in the sense that whenever the system is initiated above the unstable equilibrium point, persistence of the system is assured, while both species will go extinct whenever the system is initiated below the unstable equilibrium point. The analytical results were verified by numerical simulations of the system. We conclude that the existence of a threshold criteria, below which the system cannot persist is a general feature of plant-pollinator systems. We discuss how the existence of the threshold criteria will affect the persistence of plant-pollinator systems in light of, for instance, habitat fragmentation or stochastic reductions in the densities of either the plant or pollinator population. We further highlight some recent empirical studies that indicate the existence of a threshold in natural populations below which extinction is inevitable.

Hormonal treatment before radical prostatectomy: a 3-year followup

PURPOSE

Hormonal treatment administered before radical prostatectomy has been shown to decrease the rate of positive surgical margins. We determine whether preoperative hormonal treatment has any impact on the subsequent failure rate.

MATERIALS AND METHODS

We prospectively evaluated 122 patients with stages T1bNxM0 to T3aNxM0, grades 1 to 3 prostate cancer, including 64 randomly assigned to immediate radical retropubic prostatectomy and 58 randomly assigned to radical retropubic prostatectomy preceded by 3 months of pretreatment with a gonadotropin-releasing hormone agonist. We performed intention to treat analysis on the data with failure defined as lymph node involvement, serum prostate specific antigen greater than 0.5 ng./ml., or the need for postoperative hormonal or radiation adjuvant treatment.

RESULTS

The positive margin rate was 23.6 versus 45.5% in the pretreatment plus prostatectomy versus prostatectomy only groups (p = 0.016). There were 20 failures (34.5%) in the pretreatment plus prostatectomy subgroup and 26 (40.6%) in the prostatectomy only group (p = 0.48). A negative surgical margin was associated with a significantly lower risk of progression than a positive surgical margin (20.8 versus 50.0%, p = 0.0016), and progression was delayed by approximately 1 year after hormonal pretreatment. However, at a median followup of 38 months there was no difference in progression-free survival (p = 0.57).

CONCLUSIONS

Although hormonal pretreatment significantly decreased the positive margin rate, it did not result in any difference in progression-free survival when followup exceeded 3 years. Thus, our current results do not support the routine administration of hormonal treatment before radical prostatectomy.

Hormonal treatment before radical prostatectomy: a 3-year followup

PURPOSE

Hormonal treatment administered before radical prostatectomy has been shown to decrease the rate of positive surgical margins. We determine whether preoperative hormonal treatment has any impact on the subsequent failure rate.

MATERIALS AND METHODS

We prospectively evaluated 122 patients with stages T1bNxM0 to T3aNxM0, grades 1 to 3 prostate cancer, including 64 randomly assigned to immediate radical retropubic prostatectomy and 58 randomly assigned to radical retropubic prostatectomy preceded by 3 months of pretreatment with a gonadotropin-releasing hormone agonist. We performed intention to treat analysis on the data with failure defined as lymph node involvement, serum prostate specific antigen greater than 0.5 ng./ml., or the need for postoperative hormonal or radiation adjuvant treatment.

RESULTS

The positive margin rate was 23.6 versus 45.5% in the pretreatment plus prostatectomy versus prostatectomy only groups (p = 0.016). There were 20 failures (34.5%) in the pretreatment plus prostatectomy subgroup and 26 (40.6%) in the prostatectomy only group (p = 0.48). A negative surgical margin was associated with a significantly lower risk of progression than a positive surgical margin (20.8 versus 50.0%, p = 0.0016), and progression was delayed by approximately 1 year after hormonal pretreatment. However, at a median followup of 38 months there was no difference in progression-free survival (p = 0.57).

CONCLUSIONS

Although hormonal pretreatment significantly decreased the positive margin rate, it did not result in any difference in progression-free survival when followup exceeded 3 years. Thus, our current results do not support the routine administration of hormonal treatment before radical prostatectomy.

Falloposcopy in conjunction with laparoscopy: possibilities and limitations

Falloposcopy is a transvaginal microendoscopic technique to explore the human Fallopian tube from the uterotubal ostium to the fimbrial end. Falloposcopy provides a unique possibility to visualize endotubal disease and may be used therapeutically for removal of debris and for cutting down filmy intraluminal adhesions. To assess the clinical performance of falloposcopy as part of an infertility investigation, a total of 43 women scheduled for laparoscopy as part of an investigation of infertility had a falloposcopy performed in conjunction with the laparoscopy. All women were investigated at Danderyd Hospital, Stockholm and Akademiska Hospital, Uppsala, during 1995 and 1996. Images from the endosalpinx were obtained in 26 of 43 women (60.5%). In 10 women (23.3%), it was possible to obtain images from both tubes. No images were of sufficient quality to describe the entire tubal mucosa in detail. Falloposcopy represents a unique tool for visualization of endotubal disease and may provide a valuable instrument for in-vivo exploration of tubal physiology. However, certain technical problems limit the usefulness of this method in routine clinical practice. These technical problems have to be solved before falloposcopy can achieve a central position in investigation and treatment of tubal disease.

Radionuclide hysterosalpingography is not predictive in the diagnosis of infertility

OBJECTIVE

To investigate whether radionuclide hysterosalpingography (radionuclide HSG), which has been suggested as a more functional approach to the diagnosis of tubal infertility than conventional patency tests, is predictive in the diagnosis of infertility.

DESIGN

A retrospective analysis of data from an inquiry form containing questions about pregnancy outcome after radionuclide HSG.

SETTING

University hospital-based, tertiary care infertility clinic.

PATIENT(S)

Two hundred sixteen women had an infertility work-up including radionuclide HSG performed between April 1986 and April 1993. Forty-one (18.9%) women were excluded from the study; 9 had moved to unknown addresses, 16 did not answer the inquiry, and 16 gave answers that were not interpretable. There were 175 (81.1%) women in the final study group.

INTERVENTION(S)

An inquiry form containing questions regarding pregnancy was sent to 207 women who undergone radionuclide HSG as a routine procedure in their infertility workup.

MAIN OUTCOME MEASURE(S)

Occurrence of pregnancy related to outcome of radionuclide HSG and its test properties calculated.

RESULT(S)

Bilateral or unilateral tubal transport was demonstrated by radionuclide HSG in 129 women, of whom 66 (51%) later became pregnant. Of the pregnant women, 36 (55%) had successful infertility treatment, whereas 30 (45%) reported spontaneous pregnancy. Forty-six women showed no transport at radionuclide HSG. Twenty-five (54%) of these women became pregnant, 14 (56%) with infertility treatment and 11 (44%) without infertility treatment. The predictive values of transport and no transport radionuclide HSG were 0.51 and 0.46, respectively. The sensitivity of radionuclide HSG was 0.25, and the sensitivity was 0.73. Likelihood ratios for pregnancy when radionuclide HSG showed transport and no transport were 1.03 and 0.93, respectively.

CONCLUSION(S)

Our data strongly indicate that a single radionuclide HSG investigation is not able to predict fertility potential.

Calcium-binding mechanism of human nonerythroid alpha-spectrin EF-structures

We have used circular dichroism and 1H- and 15N-NMR spectroscopy to investigate calcium binding to the two EF-hands of human nonerythroid or alphaII-spectrin. Comparison of the 1H-NMR spectra from the peptide containing both EF-hands to the peptides containing the single EF-I and EF-II structures showed that both the structural and calcium-binding properties are significantly different. Further studies of the 121 amino acid peptide containing both EF-hands using circular dichroism and NMR showed that the binding of calcium ions induces conformational changes. To investigate the calcium-binding mechanism, the chemical shifts changes were recorded using multidimensional NMR spectroscopy during calcium titration. A total of 25 titration curves were obtained, each corresponding to the chemical shift changes of individual amino acid residues. The shapes of these titration curves were either hyperbolic or sigmoidal. Using factor analysis, two functions were extracted, one hyperbolic and one sigmoidal, which accounted for nearly all information present in the titration curves. By fitting the two functions to binding curves based on different binding models, we found that the binding mechanism is best described as sequential. Since the sigmoidal type was more pronounced in the titration curves corresponding to residues from the first EF-hand, we suggest that calcium binding to the first EF-hand is described by the sigmoidal function, and that the hyperbolic function describes calcium binding to the second EF-hand. Therefore, is seems likely that the second EF-hand must contain bound calcium before the first EF-hand can bind.

Radionuclide hysterosalpingography does not distinguish between fertile women, before tubal sterilization, and infertile women

The female genital tract is capable of active transport that can be demonstrated by serial scintigraphic imaging over time (radionuclide hysterosalpingography; RN-HSG). RN-HSG has been suggested to offer a more functional approach to tubal infertility diagnosis than conventional patency tests. However, before RN-HSG can be recommended as a routine method, its reliability in showing active transport in fertile women must be demonstrated. Therefore we compared RN-HSG in two groups: 38 fertile women before tubal sterilization and 38 women undergoing infertility work-up. Tubal transport demonstrated by RN-HSG was comparably distributed in both groups and classified as bilateral (17 versus 19), unilateral (12 versus 7) or no transport (6 versus 9). In each group three RN-HSG images were not interpretable. There was no association between patency test results and RN-HSG in the two groups. Our data suggest that RN-HSG in its present form does not seem to be a reliable method for infertility work-up. Because RN-HSG and patency tests most probably measure different properties of the genital tract, the phenomenon of active particle transportation should be studied further to enable the development of a reliable tool for the investigation of tubal function.

The risk of malignancy in the surgical margin at radical prostatectomy reduced almost three-fold in patients given neo-adjuvant hormone treatment

OBJECTIVES

To investigate the outcome of neo-adjuvant hormone treatment before radical prostatectomy regarding local tumour extension, peri-operative blood loss and operation time.

PATIENTS

Of 111 surgically treated patients with prostate cancer (T1b-T3a, N0, M0, G1-3), 55 were randomised to immediate radical prostatectomy and 56 to 3 months of neo-adjuvant treatment with triptorelin (3.75 mg i.m. every 28 days) and cyproterone acetate (50 mg b.i.d. for 3 weeks to prevent flare).

RESULTS

No differences were found in blood loss or operation time but patients who had neo-adjuvant treatment had a significantly lower frequency of positive margins (41 vs. 23%, p = 0.013).

CONCLUSION

Neo-adjuvant treatment does not facilitate radical prostatectomy but may improve the chance of local cure. This must, however, be documented with long-term follow-up in randomised patients.

Cloning, expression and characterization of two putative calcium-binding sites in human non-erythroid alpha-spectrin

The C-terminus of alpha-spectrins contains two putative calcium-binding sites or EF-hands. To characterize the binding, we have isolated clones from a human fetal liver cDNA library and expressed several fragments comprising either one or both of these sites. When the isolated clones were sequenced, we found that three consecutive nucleotides differed compared to the published sequence. The discrepancy affected two codons in the first of the two putative calcium sites. These codons translated into glutamate and phenylalanine, which are identical to the residues present at the same position in other alpha-spectrins. In the presence of magnesium, only recombinant peptides comprising the second putative site bound calcium as determined by a calcium overlay assay. Although the first putative EF-hand appeared to bind some calcium in the absence of magnesium, no binding could be detected under stringent conditions. Therefore, it is likely that the second EF-hand constitutes the only functional calcium-binding site in the C-terminus of human non-erythroid alpha-spectrin. Since peptides comprising the second EF-hand bound calcium nearly as well as intact spectrin, it is also apparent that the second EF-hand constitutes the major binding site for calcium in spectrin. The relative change in negative ellipticity, induced by the binding of calcium, indicates a dissociation constant of approximately 120 microM.

Characterization of the binding of calmodulin to non-erythroid spectrin

Both brain and erythrocyte spectrin bound calmodulin in a calcium-dependent manner when immobilized on a polyvinylidene difluoride (PVDF) membrane, though the affinity of the non-erythroid spectrin was much greater than that of the erythroid isoform. The interaction was characterized further using equilibrium partition. In the presence of calcium, the partition behavior of calmodulin was affected by both spectrins, though brain spectrin caused a much larger change in partition. However, in both cases it was evident that the observed partition behavior of calmodulin was due to complex formation with spectrin. Analysis of the equilibrium partition data indicated the presence of a high-affinity site characterized by a dissociation constant of about 0.3 microM and probably one or more much weaker sites (> 0.3 mM). The presence of at least two distinct binding sites was substantiated by the observation that truncated recombinant spectrin fusion proteins comprising either the middle part or the C-terminal of non-erythroid alpha-spectrin bound calmodulin.

Adolescent fertility and the educational attainment of young women

Analyses based on a sample of 2,795 women interviewed annually from 1979 through 1991 in the National Longitudinal Survey of Youth show that early childbearing lowers the educational attainment of young women. After controls for an extensive set of personal and community characteristics are taken into account, having a child before age 20 significantly reduces schooling attained by almost three years among whites, blacks and Hispanics. Having a child before age 18 has a significant effect only among blacks, reducing years of schooling by 1.2 years.

Parent-offspring conflicts over reproductive efforts: variations upon a theme by Charnov

A novel formulation of the theory of parent-offspring conflict is proposed. The basis of this formulation is an application of traditional life-history theory in combination with simple genetic arguments. The advantage with this approach is conceptual, and the formulation is not in variance with earlier studies in the area. Parent-offspring conflict is, in our formulation, not seen as a conflict between individuals, but as a tradeoff--an age-specific selection pressure acting on a trait, which is favourable when an individual is offspring and disadvantageous when it becomes parent. Using an ESS approach we investigate a simple offspring-wins problem: we find that a gene causing assertiveness of offspring will increase when rare, because the advantage thus gained by an assertive individual when young exceeds the cost incurred as adult by that half of its own offspring which belongs to the same assertive genotype.

Health problems and self-medication among Swedish travellers

500 consecutive travellers seeking pre-travel health advice were issued a questionnaire before leaving Sweden to continuously record health problems and use of medication during travel. Of 442 subjects who turned in assessable questionnaires (232 male and 210 female, mean age 37 years), 81% travelled to areas at high risk for the acquisition of diarrhea. The mean duration of travel was 4 weeks. During travel 218 (49% at 95% CI 44.3 to 53.7%) of the travellers experienced some illness and 61 (14%) had symptoms of more than one illness. The mean duration of illness was 4.5 days, and 65 subjects (30% of ill travellers) were confined to bed for a mean duration of 2 days. The incidence of illness was significantly (p < 0.01) higher among travellers to high risk than to low risk areas (55% vs 26%), among young travellers than among elderly (65% vs 33%), and among those going on adventure tours compared with recreational tourists (74% vs 41%). Diarrhea was reported by 36% (95% CI 31.6 to 40.5%), and respiratory tract infection by 21% (95% CI 17.2 to 24.8%). Self-medication with one or several drugs was initiated by 163 (75%) travellers experiencing illness during travel. Thus, every second Swedish traveller to tropical and subtropical areas experienced some kind of travel-related, often incapacitating, health problem.

Modeling and simulating the evolution of resistance against antibiotics

An epidemiological model is proposed for the spread of resistance against antibiotics in populations of bacterial pathogens. The host population, which is assumed to be constant, is divided into three compartments, viz. susceptible, hosts infected by an antibiotic-sensitive strain and hosts infected by a resistant strain. It is further assumed that susceptibles can be infected by either strain and that there is a possibility for cross-infection between hosts infected by the two strains. The rate of cross-infection can be enhanced by mutations or the transfer of plasmids conferring resistance. Equilibrium analysis was performed in order to determine which of the strain 'wins' the competition by the host. It is assumed that the eventual shift in the competition between the two strains is due to treatment by antibiotic (selective pressure).

Developmental steps for radionuclide hysterosalpingography

The active oviductal transportation capacity was studied in 73 infertile women by the use of a new deposition technique of radioactive particles into the internal cervical os. The main reason for this study was that a previous observation had shown that such a transportation capacity was lacking in 41% of the infertile patients with a normal hysterosalpingogram. The examination was performed in the immediate preovulatory phase, i.e. on days -3 to 0 before the ovulation, as measured by the basal body temperature during two preceding cycles. The deposition of 99mTc-labelled albumin particles of 0.2-1.0 micron at the internal cervical os and the interpretation of the radionuclide images are described in detail. The results show that the bilateral active tubal transportation capacity was present in 42 patients. An impaired transportation capacity was diagnosed in 22 patients. In 9 patients, the particles never reached the uterine cavity, or all activity leaked back to the vagina.

Characterization of calcium binding to spectrins

Calcium binding to brain and erythrocyte spectrins was studied at physiological ionic strength by a calcium overlay assay and aqueous two-phase partitioning. When the spectrins were immobilized on nylon membranes by slot blotting, the overlay assay showed that even though both spectrins bound 45Ca2+, the brain protein displayed much greater affinity for calcium ions than erythrocyte spectrin did. Since the observed binding was weaker than that displayed by calmodulin under similar conditions, the overlay assay results indicated that the binding must be weaker than 1 microM. The phase partition experiments showed that there are at least two sites for calcium on brain spectrin and that calcium binding to one of these sites is reduced significantly by magnesium ions. From the partition isotherm, the dissociation constants were estimated as 50 microM for the Mg(2+)-independent site and 150 microM for the Mg(2+)-dependent site. The phase partition results also showed that erythrocyte spectrin bound calcium ions at least 1 order of magnitude weaker. By examining calcium binding to slot-blotted synthetic peptides, we identified two binding sites in brain spectrin. One mapped to the second putative calcium binding site (EF-hand) in alpha-spectrin and the other to the 36 amino acid residue long insert in domain 11. In addition, a tryptic fragment derived from the C-terminal of erythrocyte alpha-spectrin, which contained the two postulated EF-hands, also bound calcium. These findings suggest that the calcium signal system may also involve direct binding of calcium to spectrin beside known calcium modulators such as calmodulin and calpain.(ABSTRACT TRUNCATED AT 250 WORDS)

Evolution of increased susceptibility to infectious diseases in age structured populations

Current theory on the epidemiology of infectious diseases in genetically heterogeneous host populations ignores age structure. Thus, the possibility that microparasites might have negative effects on fitness in different ways during different phases of the lives of their hosts is not accounted for. For example, infections causing mortality and morbidity among juveniles might also have an impairing effect on reproduction among adults, as is the case in many so called childhood diseases. I demonstrate that when this is the case there may be a selective pressure for the host to evolve a higher level of susceptibility to an infection, provided it has the following properties: it should (i) provide life-long immunity, (ii) have a negative effect on reproduction and (iii) not cause too many mortalities.

Measurement of human cervical compliance

A critical evaluation of the various methods for the measurement of the compliance of the human cervix uteri was made. The resistance of this tissue to a dilating force was measured by a previously constructed strain gauge instrument equipped with exchangeable Pratt cervical dilators. The dilating resistance offered by the cervical canal was recorded on a polygraph at a constant paper speed. Control experiments in which the dilating instrument was allowed to meet artificial cellulose tissue showed that the peak value recorded was of importance for estimating cellulose tissue resistance. Measurements of the area under the curve were shown to be of minor importance in this system. Using this technique in clinical applications, it was also shown that peak resistance provides the most accurate measurement of human cervical resistance.

Gangrenous dermatitis caused by Corynebacterium ulcerans in Richardson ground squirrels

Gangrenous dermatitis caused by Corynebacterium ulcerans developed in 63 of 350 wild Richardson ground squirrels (Spermophilus richardsonii). Six squirrels died of toxemia and/or septicemia, but 57 responded to topical and parenteral administration of antibiotics. The epizo-otic was believed to be associated with fighting; infected and carrier ground squirrels most likely transmitted the C ulcerans through bite wounds. Individuals handling ground squirrels should be cautioned that C ulcerans may produce a diphtheria-like disease in human beings.

DNA flow cytometry and histopathological grading of paraffin-embedded prostate biopsy specimens in a survival study

Methods to disintegrate old paraffin-embedded tissue blocks for the application of DNA flow cytometry open up new possibilities for retrospective studies on the correlation between tumor cell nuclear DNA pattern and prognosis of the neoplastic disease. In the present work we used such a method to study the relationship between DNA ploidy, histopathological grade, and survival for 50 patients with prostate carcinomas diagnosed 1958-1974. Plugs of histologically identified tissue from benign and tumor areas were sampled from paraffin blocks of prostate biopsy specimens by using a 4-mm skin biopsy punch. Thirty-micron sections were cut from each plug for dewaxing and disintegration. The cell suspensions obtained were stained with 4',6-diamidino-2-phenylindole dihydrochloride and analyzed by flow cytometry. In about one-half of the cases where two or more plugs were analyzed we found a heterogeneous tumor cell nuclear DNA pattern. No apparent correlation was found between the histopathological grade and the DNA ploidy. Using Cox's multiple regression analysis, we found a significant correlation between DNA ploidy and survival of these patients (P = 0.043) when we controlled for histopathological grade (Dhom grade), acid phosphatase level, occurrence of metastases, age, year of diagnosis, and type of biopsy. The correlation between DNA ploidy and survival was just above the level of significance (P = 0.059) when Gleason grade was substituted for Dhom grade in the regression model.

Isolation and nephrotoxic studies of orellanine from the mushroom Cortinarius speciosissimus

A nephrotoxic substance has been isolated from Cortinarius speciosissimus. The 1H-NMR and 13C-NMR mass spectra indicated the chemical structure to be 3,3',4,4'-tetrahydroxy-2,2'-bipyridine-N-N'-dioxide. The toxin was quantitated using reversed phase high performance liquid chromatography (HPLC) with electrochemical detection. The detection limit of this method was 500 pg, corresponding to a signal-to-noise ratio of 2.5. The toxin had an LD50 in mice of approximately 20 mg/kg i.p. Light microscopic examination of the kidneys of mice surviving treatment with the toxin showed interstitial nephritis and tubular necrosis.