The utility of brain natriuretic peptide as a prognosticating marker in critical care patients

Background

Brain natriuretic peptide (BNP) is an established biomarker of morbidity and mortality in cardiac failure. Data also suggest potential prognostic utility in non-heart failure cohorts. The utility of BNP in predicting intensive care unit (ICU) outcomes has not been well evaluated in a mixed critical care population in the South African (SA) context.

Objectives

To evaluate the ability of BNP to predict ICU mortality in a heterogeneous critical care population in SA.

Methods

This was a retrospective observational study of 100 patients admitted to a multidisciplinary, closed, intensivist-run ICU in a tertiary academic hospital serving KwaZulu-Natal Province (1 January 2020 - 31 July 2022). Initial BNP was evaluated as a predictor of ICU mortality using univariate and multivariable analyses.

Results

There was a statistically significant difference in BNP between survivors and non-survivors in the cohort of patients without heart failure. The median initial BNP in the non-heart failure cohort was 411 (interquartile range (IQR) 116 - 848) ng/L in non-survivors, and 150 (44 - 356) ng/L in survivors (p=0.028). The optimal cut-off for BNP was determined as 366 ng/L. A BNP ≥366 ng/L was an independent predictor of ICU outcome.

Conclusion

This study highlights the potential utility of BNP as a predictor of ICU mortality in a heterogeneous ICU population, with the greatest utility in patients without heart failure. Further studies are required to confirm this finding.

Contribution of the study

The study is a retrospective, observational study conducted in multidisciplinary, closed, intensivist-run ICU at a tertiary academic hospital. It showed an elevated BNP is associated with increased ICU mortality, particularly in those without a baseline diagnosis of heart failure. This identifies the need for further prospective studies evaluating BNP as a prognostic marker in non-cardiac critically ill patients, and its utility as an addition in pre-existing ICU outcome prediction scores.

Clinical impact of plasma concentrations of first-line antituberculosis drugs

BACKGROUND

The clinical significance of low antituberculosis (anti-TB) drug concentrations has not been fully elucidated.

OBJECTIVES

To investigate the clinical consequences of first-line drug concentrations in adult patients with drug-susceptible pulmonary TBin South Africa (SA).

METHOD

We conducted a pharmacokinetic study nested within the control arm of the Improving Treatment Success (IMPRESS) trial(NCT02114684) in Durban, SA. During the first 2 months of treatment, participants received weight-based dosing of first-line anti-TBdrugs (rifampicin, isoniazid, pyrazinamide and ethambutol), and had plasma drug concentrations measured at 2 and 6 hours after drugadministration during the 8th week of treatment. Intermediate (8 weeks), end-of-treatment (6 months) and follow-up TB outcomes wereassessed using World Health Organization criteria.

RESULTS

We measured plasma drug concentrations on available samples in 43 participants. Peak drug concentrations were below thetherapeutic range in 39/43 (90.7%) for rifampicin, 32/43 (74.4%) for isoniazid, 27/42 (64.3%) for pyrazinamide and 5/41 (12.2%) forethambutol. At the end of the intensive phase of treatment (week 8), 20.9% (n=9/43) of participants remained culture positive. We did notfind a relationship between the concentrations of first-line drugs and treatment outcomes at week 8. All participants were cured at the endof treatment, and there were no relapses during the 12-month follow-up period.

CONCLUSION

Treatment outcomes were favourable despite low drug concentrations as defined by current reference thresholds.

Altered drug exposures of first-line TB drugs in a moxifloxacin-containing treatment regimen

BACKGROUND: Pharmacokinetic variability arising from drug-drug interactions and pharmacogenetics may influence the effectiveness of treatment regimens for TB. The Improving Treatment Success Trial compared the WHO-recommended standard treatment in TB patients with an experimental regimen substituting ethambutol with moxifloxacin (MFX) in Durban, South Africa.METHODS: Non-linear mixed-effects modelling was used to investigate the population pharmacokinetics of rifampicin (RIF), isoniazid (INH) and pyrazinamide (PZA). A total of 25 single-nucleotide polymorphisms, including pregnane-X-receptor, were selected for analysis.RESULTS: TB drug concentrations were available in a subset of 101 patients: 58 in the MFX arm and 43 in the control arm. Baseline characteristics were well-balanced between study arms: median age and weight were respectively 36 years and 57.7 kg; 75.2% of the patients were living with HIV. Although weight-based drug dosing was the same in the two arms, we found that RIF exposure was increased by 19.3%, INH decreased by 19% and PZA decreased by 19.2% when administered as part of the MFX-containing regimen. Genetic variation in pregnane-X-receptor (rs2472677) was associated with a 25.3% reduction in RIF exposure.CONCLUSION: Optimised weight-based TB treatment dosing is essential when RIF, INH and PZA are co-administered with fluoroquinolones. The reduction in RIF exposure associated with pharmacogenetic variation is worrying.

A systematic review and meta-analysis of first-line tuberculosis drug concentrations and treatment outcomes

Low serum concentrations of first-line tuberculosis (TB) drugs have been widely reported. However, the impact of low serum concentrations on treatment outcome is less well studied. A systematic search of MEDLINE/Pubmed and the Cochrane Central Register of Controlled Trials up to 31 March 2018 was conducted for articles describing drug concentrations of first-line TB drugs and treatment outcome in adult patients with drug-susceptible TB. The search identified 3073 unique publication abstracts, which were reviewed for suitability: 21 articles were acceptable for inclusion in the qualitative analysis comprising 13 prospective observational cohorts, 4 retrospective observational cohorts, 1 case-control study and 3 randomised controlled trials. Data for meta-analysis were available for 15 studies, 13 studies of rifampicin (RMP), 10 of isoniazid (INH), 8 of pyrazinamide (PZA) and 4 of ethambutol (EMB). This meta-analysis revealed that low PZA concentration appears to increase the risk of poor outcomes (8 studies, n = 2727; RR 1.73, 95%CI 1.10-2.72), low RMP concentrations may slightly increase the risk of poor outcomes (13 studies, n = 2753; RR 1.40, 95%CI 0.91-2.16), whereas low concentrations of INH (10 studies, n = 2640; RR 1.32, 95%CI 0.66-2.63) and EMB (4 studies, n = 551; RR 1.12, 95%CI 0.41-3.05) appear to make no difference to treatment outcome. There was no significant publication bias or between-study heterogeneity in any of the analyses. The potential clinical impact of low concentrations of PZA and RMP warrants further evaluation. Also, comprehensive assessments of the complex pharmacokinetic-pharmacodynamic relationships in the treatment of TB are urgently needed.

Use of Biologics in Pityriasis Rubra Pilaris Refractory to First-Line Systemic Therapy: A Systematic Review [Formula: see text]

Pityriasis rubra pilaris (PRP) is an uncommon, inflammatory, papulosquamous skin disease. Treatment of PRP is challenging as the disease is often refractory to conventional therapies, such as retinoids and methotrexate. There has been an increasing number of studies reporting the successful use of biologic therapy in patients with PRP; however, the data on the efficacy and safety are limited. Our objective was to evaluate the existing evidence for utilizing biologics, whether alone or in combination with established systemic therapies, in patients with treatment-resistant PRP. We systematically reviewed evidence within Medline and Pubmed databases between January 1, 2000, to March 31, 2019. Articles consisted of patients diagnosed with PRP who have failed to respond sufficiently to first-line systemic therapies, or who had comorbidities that precluded their use. In total, 363 unique articles were identified, 56 of which were considered relevant to the clinical question. Of the 56 articles highlighted, 35 met the inclusion criteria and were limited to case series and case studies. Therapy with biologics was found to be successful for both monotherapy (81.1% [27/33]) and when used in combination with existing systemic therapies (87.5% [14/16]). The existing evidence suggests that biologics may be regarded as a tool for PRP treatment alone or in combination therapy with existing treatments, although large-scale randomized clinical trials are necessary to better assess their efficacy and safety.

"A tale of two cities." A snapshot survey of neurosurgical procedures performed in public and private sectors in eThekwini

Access to neurosurgical care in South Africa is influenced by prevailing inequities in healthcare. It is generally perceived that the public sector performs mainly emergencies relating to trauma, and the private sector performs mainly elective spinal surgery. In March 2015, emergencies constituted 51% of cases in the public sector compared to 8% in the private sector. Trauma, paediatric hydrocephalus and intracranial sepsis constituted nearly 75% of the operative workload in the public sector. Cranial surgery accounted for the majority (95%) of operations in the public sector, whereas the majority in the private sector was spinal (75%). There is considerable disparity in the type of neurosurgery being performed in the public and private sectors in KwaZulu-Natal and with the current financial constraints, there is a potential unmet need for elective spinal surgery in the public sector.

TNF, but not hyperinsulinemia or hyperglycemia, is a key driver of obesity-induced monocytosis revealing that inflammatory monocytes correlate with insulin in obese male mice

Inflammation contributes to obesity-related hyperinsulinemia and insulin resistance, which often precede type 2 diabetes. Inflammation is one way that obesity can promote insulin resistance. It is not clear if the extent of obesity, hyperinsulinemia, or hyperglycemia, underpins changes in cellular immunity during diet-induced obesity. In particular, the requirement for obesity or directionality in the relationship between insulin resistance and monocyte characteristics is poorly defined. Inflammatory cytokines such as tumor necrosis factor (TNF) can contribute to insulin resistance. It is unclear if TNF alters monocytosis or specific markers of cellular immunity in the context of obesity. We measured bone marrow and blood monocyte characteristics in WT and TNF-/- mice that were fed obesogenic, high fat (HF) diets. We also used hyperglycemic Akita mice and mice implanted with insulin pellets in order to determine if glucose or insulin were sufficient to alter monocyte characteristics. We found that diet-induced obesity in male mice increased the total number of monocytes in blood, but not in bone marrow. Immature, inflammatory (Ly6Chigh ) monocytes decreased within the bone marrow and increased within peripheral blood of HF-fed mice. We found that neither hyperinsulinemia nor hyperglycemia was sufficient to induce the observed changes in circulating monocytes in the absence of diet-induced obesity. In obese HF-fed mice, antibiotic treatment lowered insulin and insulin resistance, but did not alter circulating monocyte characteristics. Fewer Ly6Chigh monocytes were present within the blood of HF-fed TNF-/- mice in comparison to HF-fed wild-type (WT) mice. The prevalence of immature Ly6Chigh monocytes in the blood correlated with serum insulin and insulin resistance irrespective of the magnitude of adipocyte or adipose tissue hypertrophy in obese mice. These data suggest that diet-induced obesity instigates a TNF-dependent increase in circulating inflammatory monocytes, which predicts increased blood insulin and insulin resistance independently from markers of adiposity or adipose tissue expansion.

Implementing isoniazid preventive therapy in a tuberculosis treatment-experienced cohort on ART

SETTING

Urban clinical research site in Durban, South Africa.

OBJECTIVE

To describe outcomes associated with the implementation of isoniazid preventive therapy (IPT) in a cohort of tuberculosis (TB) treatment-experienced human immunodeficiency virus (HIV) infected patients on antiretroviral therapy (ART).

DESIGN

We conducted a secondary analysis of data collected between October 2009 and October 2013 from patients enrolled in a prospective cohort study conducted in Durban, South Africa.

RESULTS

Of the 402 patients enrolled in the parent study, 344 (85.6%) were eligible for IPT, 212 of whom (61.6%) initiated IPT. Of those who initiated IPT, 184 (86.8%) completed the 6-month course, while 24 (11.3%) permanently discontinued IPT, 3.8% of whom due to side effects. More women than men initiated IPT (n = 130, 61.3% vs. n = 82, 38.7%, P = 0.001). Overall median adherence to IPT was 97.6% (interquartile range 94.2-99.4). There were 22 cases of incident TB in this cohort: 13 occurred before IPT and 9 after (incidence rate ratio 0.67, 95%CI 0.29-1.58, P = 0.362).

CONCLUSIONS

IPT implementation among ART and TB treatment-experienced patients was well tolerated, with good completion rates and fewer TB cases diagnosed after IPT.

TNF Drives Monocyte Dysfunction with Age and Results in Impaired Anti-pneumococcal Immunity

Monocyte phenotype and output changes with age, but why this occurs and how it impacts anti-bacterial immunity are not clear. We found that, in both humans and mice, circulating monocyte phenotype and function was altered with age due to increasing levels of TNF in the circulation that occur as part of the aging process. Ly6C⁺ monocytes from old (18–22 mo) mice and CD14⁺CD16⁺ intermediate/inflammatory monocytes from older adults also contributed to this “age-associated inflammation” as they produced more of the inflammatory cytokines IL6 and TNF in the steady state and when stimulated with bacterial products. Using an aged mouse model of pneumococcal colonization we found that chronic exposure to TNF with age altered the maturity of circulating monocytes, as measured by F4/80 expression, and this decrease in monocyte maturation was directly linked to susceptibility to infection. Ly6C⁺ monocytes from old mice had higher levels of CCR2 expression, which promoted premature egress from the bone marrow when challenged with Streptococcus pneumoniae. Although Ly6C⁺ monocyte recruitment and TNF levels in the blood and nasopharnyx were higher in old mice during S. pneumoniae colonization, bacterial clearance was impaired. Counterintuitively, elevated TNF and excessive monocyte recruitment in old mice contributed to impaired anti-pneumococcal immunity since bacterial clearance was improved upon pharmacological reduction of TNF or Ly6C⁺ monocytes, which were the major producers of TNF. Thus, with age TNF impairs inflammatory monocyte development, function and promotes premature egress, which contribute to systemic inflammation and is ultimately detrimental to anti-pneumococcal immunity.

As we age, levels of inflammatory cytokines in the blood and tissues increase. Although this appears to be an inevitable part of aging, it ultimately contributes to declining health. Epidemiological studies indicate that older adults with higher than age-average levels of inflammatory cytokines are at increased risk of acquiring, becoming hospitalized with and dying of Streptococcus pneumoniae pneumonia but how age-associated inflammation increased susceptibility to was not entirely clear. We demonstrate that the increase in the inflammatory cytokine TNF that occurs with age cause monocytes to leave the bone marrow prematurely and these immature monocytes produce more inflammatory cytokines when stimulated with bacterial products, thus further increasing levels of inflammatory cytokines in the blood. Furthermore, although old mice have higher levels of these inflammatory monocytes arriving at the site of S. pneumoniae, they are not able to clear the bacteria. By pharmacologically or genetically removing the inflammatory cytokine TNF or reducing the number of inflammatory monocytes we were able to restore antibacterial immunity in aged mice. Thus we demonstrate that monocytes are both influenced by and contributors to age-associated inflammation and that chronic exposure to age-associated inflammation increases susceptibility to S. pneumoniae due to altering monocyte maturity and function.

Circulating TNF and mitochondrial DNA are major determinants of neutrophil phenotype in the advanced-age, frail elderly

Tumor necrosis factor (TNF), a potent inflammatory cytokine, and mitochondrial DNA (mtDNA), a product of inflammation-induced tissue damage, increase with age ("inflammaging") and many chronic diseases. Peripheral blood neutrophils, a critical component of innate immunity, have also been shown to be altered with age, and are exceptionally sensitive to external stimuli. Herein, we describe that the phenotype of neutrophils from the advanced-age, frail elderly (ELD) is determined by levels of circulating TNF and mtDNA. Neutrophils from ELD donors are morphologically immature, and have higher levels of intracellular reactive oxygen species (ROS) and expression of the activation markers CD11b and HLA-DR. The frequency of CD11b(++) neutrophils correlated with plasma TNF, and recombinant TNF elevated neutrophil CD11b ex vivo and in vivo. Furthermore, neutrophils from aged TNF-deficient mice expressed CD11b similar to young counterparts. The frequency of HLA-DR(+) neutrophils, on the other hand, positively correlated with circulating mtDNA, which increased neutrophil HLA-DR expression in a dose-dependent manner ex vivo. Cell-surface TLR-9 expression, however, was unaltered on neutrophils from ELD donors. In summary, we provide novel evidence that products of age-related inflammation modulate neutrophil phenotype in vivo. Given this, anti-inflammatory therapies may prove beneficial in improving neutrophil functionality in the elderly.

Resistance to antiretroviral drugs in newly diagnosed, young treatment-naïve HIV-positive pregnant women in the province of KwaZulu-Natal, South Africa

In 2004, KwaZulu-Natal initiated one of the world's largest HIV/AIDS treatment programs. Studies in South Africa have shown that patients on antiretroviral therapy (ART) develop rapidly and transmit drug resistant mutations. Since resistance testing is not widely available in Kwazulu-Natal, the Department of Health conducted the first HIV drug resistance (HIVDR) threshold survey in 2005, which did not identify any mutations associated with HIVDR. The objective of this study was to conduct a follow-up threshold survey to update the information on HIVDR. This study was conducted in 2009 in five antenatal care sites in Kwazulu-Natal using the HIVDR threshold survey method developed by WHO. Two hundred and thirteen newly-diagnosed HIV positive, drug-naïve primigravidae, less than 22 years of age were included in the survey. Of the 82 HIV positive specimens, 17 had insufficient volume for genotyping and, of the remaining 65, 47 were genotyped sequentially. Drug resistance was identified by sequencing the HIV-1 pol gene, using the ViroSeq® HIV-1 genotyping system v2.0. Of the 47 samples that were genotyped, only one presented with a K103N mutation, which equates to a prevalence of transmitted HIVDR of <5%. The low prevalence of transmitted HIVDR is in keeping with statistical models of the early stages of ART rollout. As ART coverage is increasing continuously, there is a need to ensure that vigilance of HIVDR continues so that the emergence and spread of HIVDR is minimized.

AccidentalMycobacterium bovisinfection in a veterinarian

CASE

A veterinarian developed tenosynovitis and secondary carpal tunnel syndrome following accidental inoculation of Mycobacterium bovis during the necropsy of a tuberculous possum from Westland, New Zealand.

CLINICAL RELEVANCE

M. bovis infection is a zoonotic disease, and occupational exposure to tuberculous animals places people at risk of contracting the disease.

CONCLUSIONS

Adhering to safe work practices reviewed in this article is important to minimise the risk of infection to people handling tuberculous animals.

Vasectomy under local anaesthesia performed free of charge as a family planning service: complications and results

OBJECTIVE

To evaluate the safety and efficacy of vasectomy performed under local anaesthesia by junior doctors at a secondary level hospital as part of a free family planning service.

METHOD

Men requesting vasectomy were counselled and given written instructions to use alternative contraception until two semen analyses 3 and 4 months after vasectomy had confirmed azoospermia. Bilateral vasectomy was performed as an outpatient procedure under local anaesthesia by junior urology registrars. Statistical analysis was performed using the Mann-Whitney, Kruskal-Wallis, Fisher's exact or Spearman's rank correlation tests as appropriate.

RESULTS

Between January 2004 and December 2005, 479 men underwent vasectomy at Karl Bremer Hospital, Western Cape, South Africa; their average age was 36.1 (range 21 - 66) years, they had a median of 2 (range 0 - 10) children, and only 19% had 4 or more children. The average operation time was 15.5 (range 5 - 53) minutes. Complications occurred in 12.9%; these were pain (7.3%), swelling (5.4%), haematoma (1.3%), sepsis (1%), difficulty locating the vas (1%), vasovagal episode (0.6%), bleeding (0.6%), wound rupture (0.4%) and dysuria (0.2%) (some men had more than one complication). Of the men 63.3% returned for one semen analysis and 17.5% for a second. The vasectomy failure rate ranged from 0.4% (sperm persisting > 365 days after vasectomy) to 2.3% (sperm seen > 180 days after vasectomy and/or in the second semen specimen). No pregnancies were reported. The complication (5.6%) and failure rates (0%) were lowest for the registrar who had performed the smallest number of vasectomies and whose average operation time was longest. Comparing the first one-third of procedures performed by each of the doctors with the last one-third, there was a significant decrease in average operating times but not in complication rates.

CONCLUSIONS

Vasectomy can be performed safely and effectively by junior doctors as an outpatient procedure under local anaesthesia, and should be actively promoted in South Africa as a safe and effective form of male contraception.

Renal vein thrombosis in transitional cell carcinoma

A rare case of renal transitional cell carcinoma (TCC) associated with bland thrombus of the renal vein extending into the inferior vena cava is described. Tumour thrombus in renal cell carcinoma is frequently encountered, but only very rarely occurs with TCC. Bland renal vein thrombosis occurring with renal TCC has not been described before. Contrast enhanced computed tomography assisted in distinguishing between bland and tumour thrombosis and aided in surgical management.

Cholera: a continuous epidemic in Africa

Cholera continues to plague many parts of the world, but has largely been concentrated in Africa, which contributes more than 80% of the total cases worldwide. Natural disasters, like the 2000 floods in Mozambique and the volcanic eruption in the Democratic Republic of the Congo in 2002, generally lead to new outbreaks of the disease. The refugee problem in many countries throughout the world also causes potential threats for disease outbreaks. Case fatality rates are high, and we are not anywhere near curbing new cholera epidemics, especially in Africa. It is thus imperative to renew discussions about the nature of this deadly disease, its treatment, measures for prevention and control, modes of transmission, its physical, social and economic impact, and potential solutions.

Carboxylesterases, a key factor in evaluating potential genotoxicity of Trinem antibiotics

Sanfetrinem cilexetil, a hexetil ester of a Trinem antibiotic, does not induce micronuclei in rat bone marrow cells or induce DNA repair synthesis in rat hepatocytes following oral dosing. However, in vitro chromosome damage and mutations are induced in mammalian cells lacking carboxylesterase activity (human lymphocytes and mouse lymphoma L5178Y cells). In cells possessing carboxylesterase activity (CHL cells), chromosome damage induced by Sanfetrinem cilexetil is not observed. Similarly, if induced rat liver preparations or non-induced preparations from rat or human intestinal cells are present during exposure, genotoxic activity is lost, even in those cells lacking carboxylesterase enzymes. Thus the lack of demonstrable genotoxicity in vivo, in the assays used, is likely to be due to hydrolysis of the parent molecule by non-specific carboxylesterases present within the intestinal epithelium. In turn this data indicates that a genotoxic hazard to humans under therapeutic conditions is unlikely.

Sex education sources and attitudes about premarital sex of Seventh Day Adventist youth

37 Seventh Day Adventist youth were surveyed about their sex education and attitudes towards premarital sex. Analysis indicated differences between their attitudes and actual sexual behaviour. While 70% endorsed the church's prohibition on premarital sex, 54% had engaged in premarital sex.

Black South African students' use of counseling service

This paper reports the demographic and summative annual data for presenting concerns of students seeking counseling at a Black South African university. Rankings of the major presenting concerns identified by the clients are presented.

Comparison of Salmonella typhimurium TA102 with Escherichia coli WP2 tester strains

In 1982, Levin et al. published a paper describing a new Salmonella typhimurium strain, TA102, for detecting mutagenic agents that react preferentially with AT base pairs. This strain has an AT base pair at the critical mutation site within the hisG gene, which is located on a multicopy plasmid, pAQ1; the chromosomal copy of the hisG gene has been deleted. It also has an intact excision repair system, thus facilitating the detection of cross-linking agents, and carries the mutator plasmid, pKM101. Although TA102 has been shown to be reverted by certain mutagenic agents that are not detected in the usual battery of strains (TA1535, TA1537, TA1538, TA98 and TA100), there has been a general reluctance within the field to include TA102 as one of the standard screening strains. This may in part result from the difficulties which have been experienced in many laboratories in maintaining the strain, and in obtaining reproducible spontaneous and induced revertant counts. At Glaxo we routinely include certain Escherichia coli strains in our microbial test battery, and were aware that some of the genetic features offered by TA102 were already being covered by these strains. For example, E.coli WP2 (pKM101) has an AT base pair at the critical mutation site within the trpE gene, is excision proficient (and thus will detect cross-linking agents) and carries the pKM101 plasmid to enhance error-prone repair. From the published literature it was apparent that a number of the 'TA102 specific' mutagens could be detected in E.coli e.g. neocarzinostatin, UV and 8-MOP plus UV.(ABSTRACT TRUNCATED AT 250 WORDS)

Pericapillary fibrin in the ulcer-bearing skin of the leg: the cause of lipodermatosclerosis and venous ulceration

Forty-one biopsy specimens, taken from the ulcer-bearing skin of 41 legs of 21 patients attending the varicose vein clinic, were selectively stained for fibrin with phosphotungstic acid haemotoxylin before being blindly assessed,. Layers of fibrin were found surrounding the dermal capillaries in all 26 legs with lipodermatosclerosis. None of the specimens from the 15 legs with clinically normal skin contained fibrin. There was also an increased number of dermal capillaries cut in cross section per high powered field in 24 of the 26 legs with lipodermatosclerosis compared with two of the 15 legs with normal skin (p less than 0.001). The mean reduction in foot vein pressure during exercise was significantly less in the 26 limbs with pericapillary fibrin than in the other 15 limbs (p less than 10(-6). Lipodermatosclerosis is synonymous with pericapillary fibrin deposition and is associated with, and probably secondary to, both a persistently raised venous pressure and an increase in the size of the dermal capillary bed. This extravascular deposition of fibrin probably stimulates tissue fibrosis and blocks the diffusion of oxygen to the overlying epidermis, producing cellular death and venous ulceration.

Acute leukemia in children: experience in Saskatchewan in 1966-72

In 1966-72 in Saskatchewan there was a significant improvement in survival of patients up to 16 years old with acute leukemia treated intensively. The rate of complications was low. Attention to the emotional needs of the patients and parents and formation of parent mutual-support groups improved the acceptibility of intensive therapy.