Re-activation of HIF signalling pathway in the epicardium improves heart regeneration after myocardial infarction

Funding Acknowledgements

Type of funding sources: Foundation. Main funding source(s): British Heart Foundation

Background

In mouse, cardiac regenerative capacity is maintained for the first week after birth but lost thereafter. Reactivation of this process holds great therapeutic potential, however, the molecular pathways that might be targeted to extend neonatal regeneration remain elusive. Here, we explore a role for hypoxia inducible factor (HIF) family of transcription factors on the regulation of epicardial activity which is essential for cardiac response to injury.

Purpose

HIF signalling might be involved in the quiescence of the epicardium observed in the first week of life. Thus, HIF stabilisation may induce epicardial re-activation and extend the 7-day regenerative window in a neonate mouse model of myocardial infarction (MI).

Methods

We analysed epicardial expression of HIF signalling during embryonic development, and in a regenerative post-natal day 1 (P1) versus non-regenerative (P7) mouse model by single cell RNA-sequencing. Next, we established in vitro epicardial explants to confirm the role of HIF signalling in epicardial activation, and finally we induced MI by permanent ligation of the proximal left anterior descending (LAD) coronary artery in P7 mice to test weather HIF signalling re-activation improved heart regeneration in a non-regenerative model.

Results

Expression of both HIF-1α and HIF-2α is very pronounced at early stages of heart development and gradually decreases throughout gestation. The epicardium preferentially expresses HIF-1α by embryonic day (E) 16.5. Postnatally, GO term analysis showed an enrichment of hypoxia-related pathways in P1 compared to P7 hearts, largely in the epicardial cell population. Accordingly, expression of Phd2, encoding for the main suppressor of HIF signalling, was enriched in P7 derived epicardial cells. Notably, the increase in Phd2 levels coincided with a clear reduction in the expression of Wilms’ tumour 1 (Wt1) in P7 versus P1 hearts, a key player in the epicardial activation. In vitro studies on epicardial explants confirmed regulation of WT1 expression and migration capacity following genetical and pharmacological modulation of HIF signalling. Finally, in vivo targeting of PHD enzymes through pharmacological inhibition with clinically approved drugs in a neonatal mouse model of MI led to prolonged epicardial activation, increased vascularisation, augmented infarct resolution and preserved cardiac function up to 3 weeks after injury.

Conclusions

Together, these findings show that modulation of HIF signalling can regulate epicardial activity and improve heart regeneration capacity beyond the 7-day regenerative window and may represent a viable therapeutic strategy for treating ischaemic heart disease.

Co-incidence of RCC-susceptibility polymorphisms with HIF cis-acting sequences supports a pathway tuning model of cancer

Emerging evidence suggests that dysregulation of oncogenic pathways requires precise tuning in order for cancer to develop. To test this, we examined the overlap between cis-acting elements of the hypoxia-inducible factor (HIF) pathway and cancer-susceptibility polymorphisms as defined in genome-wide association studies (GWAS). In renal cancer, where HIF is constitutively and un-physiologically activated by mutation of the von Hippel-Lindau tumour suppressor, we observed marked excess overlap, which extended to potential susceptibility polymorphisms that are below the conventional threshold applied in GWAS. In contrast, in other cancers where HIF is upregulated by different mechanisms, including micro-environmental hypoxia, we observed no excess in overlap. Our findings support a 'pathway tuning' model of cancer, whereby precise modulation of multiple outputs of specific, activated pathways is important in oncogenesis. This implies that selective pressures to modulate such pathways operate during cancer development and should focus attempts to identify their nature and consequences.

Inherent DNA-binding specificities of the HIF-1α and HIF-2α transcription factors in chromatin

Hypoxia-inducible factor (HIF) is the major transcriptional regulator of cellular responses to hypoxia. The two principal HIF-α isoforms, HIF-1α and HIF-2α, are progressively stabilized in response to hypoxia and form heterodimers with HIF-1β to activate a broad range of transcriptional responses. Here, we report on the pan-genomic distribution of isoform-specific HIF binding in response to hypoxia of varying severity and duration, and in response to genetic ablation of each HIF-α isoform. Our findings reveal that, despite an identical consensus recognition sequence in DNA, each HIF heterodimer loads progressively at a distinct repertoire of cell-type-specific sites across the genome, with little evidence of redistribution under any of the conditions examined. Marked biases towards promoter-proximal binding of HIF-1 and promoter-distant binding of HIF-2 were observed under all conditions and were consistent in multiple cell type. The findings imply that each HIF isoform has an inherent property that determines its binding distribution across the genome, which might be exploited to therapeutically target the specific transcriptional output of each isoform independently.

Emergency department mortality: Fair and square

OBJECTIVE

This study explored the therapeutic approaches used for end-of-life (EOL) patients admitted to the emergency department (ED) and examined whether the decision to perform life-extending treatment (LET) or to allow natural death (AND) depends on patient characteristics, medical staff variables, and ED setting.

METHODS

A retrospective archive study was conducted from January 2015 to December 2017 in the ED of a tertiary hospital. The study sample were 674 EOL patients who had died in the ED. For each patient, data were collected and measured for dying process (LET vs. AND), patient characteristics, ED-setting variables, and medical-staff characteristics.

RESULTS

The proportion of EOL patients undergoing LET increased from 18.1% in 2015 to 25.9% in 2016 and to 30.3% in 2017 (p = .010), and a quarter of them were treated by emergency medical services. Males tended to receive LET more than females (p < .001). An association was found between Jewish physicians and nurses and AND (p = .001). Heavier workload in the ED and greater severity of the triage classification predicted more LET (OR-1.67, CI = 1.05-1.76, p = .003 and OR = 1.42, CI-0.60-0.81, p < .001, respectively). Receiver operating characteristic analysis showed that patient characteristics contributed most crucially to the therapeutic approaches (C statistic 0.624-0.675, CI-0.62-0.71).

CONCLUSIONS

The therapeutic approach used for EOL patients in the ED depends on variables in all three treatment layers: patient, medical staff, and ED setting. Applicable national programs should be developed to ensure that no external factors influence the dying-process decision.

Multiple renal cancer susceptibility polymorphisms modulate the HIF pathway

Un-physiological activation of hypoxia inducible factor (HIF) is an early event in most renal cell cancers (RCC) following inactivation of the von Hippel-Lindau tumor suppressor. Despite intense study, how this impinges on cancer development is incompletely understood. To test for the impact of genetic signals on this pathway, we aligned human RCC-susceptibility polymorphisms with genome-wide assays of HIF-binding and observed highly significant overlap. Allele-specific assays of HIF binding, chromatin conformation and gene expression together with eQTL analyses in human tumors were applied to mechanistic analysis of one such overlapping site at chromosome 12p12.1. This defined a novel stage-specific mechanism in which the risk polymorphism, rs12814794, directly creates a new HIF-binding site that mediates HIF-1α isoform specific upregulation of its target BHLHE41. The alignment of multiple sites in the HIF cis-acting apparatus with RCC-susceptibility polymorphisms strongly supports a causal model in which minor variation in this pathway exerts significant effects on RCC development.

Genetic variation at the 8q24.21 renal cancer susceptibility locus affects HIF binding to a MYC enhancer

Clear cell renal cell carcinoma (ccRCC) is characterized by loss of function of the von Hippel-Lindau tumour suppressor (VHL) and unrestrained activation of hypoxia-inducible transcription factors (HIFs). Genetic and epigenetic determinants have an impact on HIF pathways. A recent genome-wide association study on renal cancer susceptibility identified single-nucleotide polymorphisms (SNPs) in an intergenic region located between the oncogenes MYC and PVT1. Here using assays of chromatin conformation, allele-specific chromatin immunoprecipitation and genome editing, we show that HIF binding to this regulatory element is necessary to trans-activate MYC and PVT1 expression specifically in cells of renal tubular origins. Moreover, we demonstrate that the risk-associated polymorphisms increase chromatin accessibility and activity as well as HIF binding to the enhancer. These findings provide further evidence that genetic variation at HIF-binding sites modulates the oncogenic transcriptional output of the VHL-HIF axis and provide a functional explanation for the disease-associated effects of SNPs in ccRCC.

Capture-C reveals preformed chromatin interactions between HIF-binding sites and distant promoters

Hypoxia-inducible factor (HIF) directs an extensive transcriptional cascade that transduces numerous adaptive responses to hypoxia. Pan-genomic analyses, using chromatin immunoprecipitation and transcript profiling, have revealed large numbers of HIF-binding sites that are generally associated with hypoxia-inducible transcripts, even over long chromosomal distances. However, these studies do not define the specific targets of HIF-binding sites and do not reveal how induction of HIF affects chromatin conformation over distantly connected functional elements. To address these questions, we deployed a recently developed chromosome conformation assay that enables simultaneous high-resolution analyses from multiple viewpoints. These assays defined specific long-range interactions between intergenic HIF-binding regions and one or more promoters of hypoxia-inducible genes, revealing the existence of multiple enhancer-promoter, promoter-enhancer, and enhancer-enhancer interactions. However, neither short-term activation of HIF by hypoxia, nor long-term stabilization of HIF in von Hippel-Lindau (VHL)-defective cells greatly alters these interactions, indicating that at least under these conditions, HIF can operate on preexisting patterns of chromatin-chromatin interactions that define potential transcriptional targets and permit rapid gene activation by hypoxic stress.

NOTCH1 mediates a switch between two distinct secretomes during senescence

Senescence, a persistent form of cell-cycle arrest, is often associated with a diverse secretome, which provides complex functionality for senescent cells within the tissue microenvironment. We show that oncogene-induced senescence is accompanied by a dynamic fluctuation of NOTCH1 activity, which drives a TGF-β-rich secretome, while suppressing the senescence-associated pro-inflammatory secretome through inhibition of C/EBPβ. NOTCH1 and NOTCH1-driven TGF-β contribute to 'lateral induction of senescence' through a juxtacrine NOTCH-JAG1 pathway. In addition, NOTCH1 inhibition during senescence facilitates upregulation of pro-inflammatory cytokines, promoting lymphocyte recruitment and senescence surveillance in vivo. As enforced activation of NOTCH1 signalling confers a near mutually exclusive secretory profile compared with typical senescence, our data collectively indicate that the dynamic alteration of NOTCH1 activity during senescence dictates a functional balance between these two distinct secretomes: one representing TGF-β and the other pro-inflammatory cytokines, highlighting that NOTCH1 is a temporospatial controller of secretome composition.

Heterogeneous Effects of Direct Hypoxia Pathway Activation in Kidney Cancer

General activation of hypoxia-inducible factor (HIF) pathways is classically associated with adverse prognosis in cancer and has been proposed to contribute to oncogenic drive. In clear cell renal carcinoma (CCRC) HIF pathways are upregulated by inactivation of the von-Hippel-Lindau tumor suppressor. However HIF-1α and HIF-2α have contrasting effects on experimental tumor progression. To better understand this paradox we examined pan-genomic patterns of HIF DNA binding and associated gene expression in response to manipulation of HIF-1α and HIF-2α and related the findings to CCRC prognosis. Our findings reveal distinct pan-genomic organization of canonical and non-canonical HIF isoform-specific DNA binding at thousands of sites. Overall associations were observed between HIF-1α-specific binding, and genes associated with favorable prognosis and between HIF-2α-specific binding and adverse prognosis. However within each isoform-specific set, individual gene associations were heterogeneous in sign and magnitude, suggesting that activation of each HIF-α isoform contributes a highly complex mix of pro- and anti-tumorigenic effects.

Impact of artifact removal on ChIP quality metrics in ChIP-seq and ChIP-exo data

With the advent of ChIP-seq multiplexing technologies and the subsequent increase in ChIP-seq throughput, the development of working standards for the quality assessment of ChIP-seq studies has received significant attention. The ENCODE consortium's large scale analysis of transcription factor binding and epigenetic marks as well as concordant work on ChIP-seq by other laboratories has established a new generation of ChIP-seq quality control measures. The use of these metrics alongside common processing steps has however not been evaluated. In this study, we investigate the effects of blacklisting and removal of duplicated reads on established metrics of ChIP-seq quality and show that the interpretation of these metrics is highly dependent on the ChIP-seq preprocessing steps applied. Further to this we perform the first investigation of the use of these metrics for ChIP-exo data and make recommendations for the adaptation of the NSC statistic to allow for the assessment of ChIP-exo efficiency.

Cellular senescence and its effector programs

Cellular senescence is a stress response that accompanies stable exit from the cell cycle. Classically, senescence, particularly in human cells, involves the p53 and p16/Rb pathways, and often both of these tumor suppressor pathways need to be abrogated to bypass senescence. In parallel, a number of effector mechanisms of senescence have been identified and characterized. These studies suggest that senescence is a collective phenotype of these multiple effectors, and their intensity and combination can be different depending on triggers and cell types, conferring a complex and diverse nature to senescence. Series of studies on senescence-associated secretory phenotype (SASP) in particular have revealed various layers of functionality of senescent cells in vivo. Here we discuss some key features of senescence effectors and attempt to functionally link them when it is possible.

Redistribution of the Lamin B1 genomic binding profile affects rearrangement of heterochromatic domains and SAHF formation during senescence

Senescence is a stress-responsive form of stable cell cycle exit. Senescent cells have a distinct gene expression profile, which is often accompanied by the spatial redistribution of heterochromatin into senescence-associated heterochromatic foci (SAHFs). Studying a key component of the nuclear lamina lamin B1 (LMNB1), we report dynamic alterations in its genomic profile and their implications for SAHF formation and gene regulation during senescence. Genome-wide mapping reveals that LMNB1 is depleted during senescence, preferentially from the central regions of lamina-associated domains (LADs), which are enriched for Lys9 trimethylation on histone H3 (H3K9me3). LMNB1 knockdown facilitates the spatial relocalization of perinuclear H3K9me3-positive heterochromatin, thus promoting SAHF formation, which could be inhibited by ectopic LMNB1 expression. Furthermore, despite the global reduction in LMNB1 protein levels, LMNB1 binding increases during senescence in a small subset of gene-rich regions where H3K27me3 also increases and gene expression becomes repressed. These results suggest that LMNB1 may contribute to senescence in at least two ways due to its uneven genome-wide redistribution: first, through the spatial reorganization of chromatin and, second, through gene repression.

Towards the bioequivalence of pressurised metered dose inhalers 2. Aerodynamically equivalent particles (with and without glycerol) exhibit different biopharmaceutical profiles in vitro

Two solution-based pressurised metered dose inhaler (pMDI) formulations were prepared such that they delivered aerosols with identical mass median aerodynamic diameters, but contained either beclomethasone dipropionate (BDP) alone (glycerol-free formulation) or BDP and glycerol in a 1:1 mass ratio (glycerol-containing formulation). The two formulations were deposited onto Calu-3 respiratory epithelial cell layers cultured at an air interface. Equivalent drug mass (∼1000ng or ∼2000ng of the formulation) or equivalent particle number (1000ng of BDP in the glycerol-containing versus 2000ng of BDP in the glycerol-free formulation) were deposited as aerosolised particles on the air interfaced surface of the cell layers. The transfer rate of BDP across the cell layer after deposition of the glycerol-free particles was proportional to the mass deposited. In comparison, the transfer of BDP from the glycerol-containing formulation was independent of the mass deposited, suggesting that the release of BDP is modified in the presence of glycerol. The rate of BDP transfer (and the extent of metabolism) over 2h was faster when delivered in glycerol-free particles, 465.01ng±95.12ng of the total drug (20.99±4.29%; BDP plus active metabolite) transported across the cell layer, compared to 116.17ng±3.07ng (6.07±0.16%) when the equivalent mass of BDP was deposited in glycerol-containing particles. These observations suggest that the presence of glycerol in the maturated aerosol particles may influence the disposition of BDP in the lungs.

Independence of repressive histone marks and chromatin compaction during senescent heterochromatic layer formation

The expansion of repressive epigenetic marks has been implicated in heterochromatin formation during embryonic development, but the general applicability of this mechanism is unclear. Here we show that nuclear rearrangement of repressive histone marks H3K9me3 and H3K27me3 into nonoverlapping structural layers characterizes senescence-associated heterochromatic foci (SAHF) formation in human fibroblasts. However, the global landscape of these repressive marks remains unchanged upon SAHF formation, suggesting that in somatic cells, heterochromatin can be formed through the spatial repositioning of pre-existing repressively marked histones. This model is reinforced by the correlation of presenescent replication timing with both the subsequent layered structure of SAHFs and the global landscape of the repressive marks, allowing us to integrate microscopic and genomic information. Furthermore, modulation of SAHF structure does not affect the occupancy of these repressive marks, nor vice versa. These experiments reveal that high-order heterochromatin formation and epigenetic remodeling of the genome can be discrete events.

Identification and evaluation of agents isolated from traditionally used herbs against Ophiophagus hannah venom

The aim of this study was firstly to identify active molecules in herbs, that are traditionally used for the treatment of snake bite, such as Curcuma antinaia, Curcuma contravenenum, Andrographis paniculata, and Tanacetum parthenium; secondly to test similar structurally related molecules and finally to prepare and evaluate an efficient formulation against Ophiophagus hannah venom intoxification. Three labdane based compounds, including labdane dialdehyde, labdane lactone, and labdane trialdehyde and two lactones including 14-deoxy-11,12-didehydroandrographolide and parthenolide were isolated by column chromatography and characterised. Using the isolated rat phrenic nerve-hemidiaphragm preparation, the antagonistic effect of crude extracts, isolated compounds and prepared formulations were measured in vitro on the inhibition of the neuromuscular transmission. Inhibition on muscle contraction, produced by the 5 μg/mL venom, was reversed by test agents in organ bath preparations. A labdane trialdehyde, isolated from C. contravenenum, was identified as the best antagonising agent in the low micromolar range. Tests on formulations of the most potent C. contravenenum extract showed, that the suppository with witepsol H15 was an effective medicine against O. hannah venom. This study elucidated the active compounds, accounting for the antivenin activity of traditionally used herbs and suggested the most suitable formulation, which may help to develop potent medicines for the treatment of snake bite in the future.

The metabolism of vitamin D3 in response to testosterone

Sex steroids were suggested as regulators of vitamin D metabolism. While considerable data is available regarding interaction between estradiol and vitamin D, very little is known about interactions between testosterone and vitamin D. A similar gap exists with regard to the involvement of the vitamin D endocrine system in the pathogenesis of the female versus the male osteoporosis syndrome. In the present study we studied the effect of long-term treatment with testosterone on the metabolism of vitamin D in vitamin D3 replete sexually immature male chicks. We were able to show under this treatment, circulating levels of 1,25-dihydroxy vitamin D3 (1,25(OH)2D3) are significantly reduced, but intestine and bone concentrations are significantly increased. The increased concentration of 1,25(OH)2D3 in bone was accompanied by an increase in the ash content of this tissue. The reduction in serum 1,25(OH)2D3 was not dependent on reduced activity of the renal 25-hydroxy vitamin D3 - alpha - hydroxylase. Based on these findings it is proposed that testosterone is involved in the stimulation of the biological response to vitamin D in the classical target-organs, such as intestine and bone, and this observation may provide partial explanation to the pathogenesis of osteoporosis in hypogonadal men.

Natural history of impacted subcapital femoral fractures and its relevance to treatment options

A study of 123 patients with impacted, subcapital femoral fractures was undertaken to determine the natural history of this injury. It was found that the angle of the fracture, the degree of valgus and the degree of retroversion were without significant effect on the incidence of subsequent disimpaction. Age was important, with a 20 per cent incidence of disimpaction in patients over the age of 68 years. In patients younger than this the incidence was only 2 per cent. These results indicate that conservative treatment may be appropriate for some younger patients, but the advantages of this approach must be compared with the medical, social and economic benefits of early mobilization that the relatively simple operative procedure permits.

The clinical use of autologous marrow to improve osteogenic potential of bone grafts in pediatric orthopedics

The high osteogenic potential of living autologous marrow cells can be combined with foreign bone to enhance new bone formation. Xenogeneic bone was combined with autologous red marrow and used in 23 patients aged 5-17 years. Kiel bone was impregnated with marrow aspirated from the iliac crest and, apart from one case of lesion recurrence, gave excellent results in all patients under conditions covering a wide range of indications for bone grafting. Unlimited supplies of xenograft bone and other bone substitutes can be rendered osteogenic by a simple procedure. Combining fresh autologous red marrow with other types of bank bone allograft or xenograft, or even with biological or synthetic biocompatible material that favors the induction of new bone, may provide even better results.

Radial head and neck fractures in children

This report is a review of long-term results of 42 consecutive fractures of the neck of the radius in children. More than half the patients were followed for greater than 4 years. The results were assessed clinically and radiologically at 6 months and at review. Twenty-seven children (64%) had a good result, 2 (5%) had a fair result, and 13 (31%) had a poor result. Primary angulation was the most important factor affecting the results. Periarticular ossification, avascular necrosis, enlargement of the radial head and of the proximal end of the radius were the most important causes of poor results. Unlike other fractures with unpredictable results, more accurate reduction is mandatory to improve the final outcome.

Residual adduction of the forefoot. A review of the Turco procedure for congenital club foot

Forty-four feet in 28 children previously treated by a one-stage posteromedial release operation (the Turco procedure) were reviewed clinically and radiologically to determine the cause of residual adduction of the forefoot. In 21 clinically adducted feet (48%) the main cause of residual deformity was metatarsus varus alone or metatarsus varus in spite of talonavicular overcorrection; in five feet the cause was talonavicular subluxation. There was no residual adduction in 23 feet (52%) but only 12 had normal radiographic measurements. In the remaining feet, various forms of spurious correction of metatarsus varus and talonavicular subluxation or both were seen, resulting in normal-looking feet. Recession of the origin of abductor hallucis and release of the short plantar muscles and fascia at the time of posteromedial release is recommended. The forefoot adduction was satisfactorily corrected in 91% of the feet subsequently operated on using this modified procedure.

An analysis of the results of a modified one-stage posteromedial release (Turco operation) for the treatment of clubfoot

Between 1971 and 1977, posteromedial release was performed on 47 feet of 30 children 9 months to 4 years of age. At review, full correction of equinus was achieved in 98%, heel varus in 91%, and cavus in 85%, but in only 50% of feet with forefoot adduction. Between 1978 and 1982, surgery was performed on 22 feet of 18 children 3-10 months of age. Recessions of the abductor hallucis and short plantar muscles and fascia were also performed at operation. Correction of equinus, heel varus, and cavus demonstrated results similar to those of the earlier group, but forefoot adduction was also satisfactorily corrected in 91% of feet.

The effect of vitamin D and its metabolites on fracture repair in chicks

One-day-old chicks were depleted of vitamin D. At 3 weeks their right tibiae, and those of a control group given vitamin D3, were fractured and pinned. After fracture the controls were kept on vitamin D3. Another group was left vitamin D-deficient. The remaining depleted chicks, divided into four groups, were given vitamin D3, 24,25-dihydroxyvitamin D3 [24,25(OH)2D3], 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] or a combination of 24,25(OH)2D3 and 1,25(OH)2D3. The callus obtained after 9 and 14 days was subjected to torsional stress. The callus of chicks given vitamin D continuously showed the greatest resistance, whereas that of vitamin D-deficient chicks showed the smallest resistance. Repletion with either vitamin D3 or its metabolites increased the strength of the callus. Repletion with the combination of 24,25(OH)2D3 and 1,25(OH)2D3 produced the most marked results, in that the callus was even stronger than that of chicks replete with vitamin D3. It is concluded that 24,25(OH)2D3 is essential for bone formation in addition to the known active vitamin D metabolite 1,25(OH)2D3, and the possible clinical implications of these findings are discussed.

Xenogeneic bone grafting in humans

The beneficial effect of a composite autologous red bone marrow and bone graft is well documented in experimental animals. In an attempt to improve the osteogenic potential of xenogeneic bone for clinical use, xenogeneic bone was combined with autologous red marrow and used in 110 bone grafting operations in 98 patients. Hydrogen peroxide-macerated (Kiel) bone was immersed in autologous red marrow obtained by iliac crest punctures. The results were excellent in conditions covering a wide range of indications for bone grafting. The results of treatment of pseudarthroses were most satisfactory. Deproteinized xenogeneic bone serves as a bank bone implant when impregnated with living autologous marrow or placed in a bed of bleeding cancellous bone.

Hip fractures in patients with Parkinson's syndrome

Hip fractures in patients with Parkinson's syndrome present a continuing challenge to orthopaedic surgeons. Sixty-two consecutive such patients have been reviewed. With or without operation, there was very high rate of mortality (31%) and complications. However, the functional results, the ability to walk, progression of the disability, and the quality of life were significantly better after operation. The results suggest that operation is the preferable solution for these patients. They require, however, much more particular care than other patients with hip fractures. This includes adequate adjusted antiparkinson medication, appropriate anesthesia with special attention to adequate ventilation and postoperative analgesia, more intensive respiratory and functional physiotherapy, very meticulous nursing care, and a relatively extended period of preventive antibiotics.

Synovial sarcoma of the finger

Synovial sarcoma is a rare tumour in the hand. We report an unusual case of such a tumour that was located in the distal phalanx of a finger of an elderly woman. A synovial tumour in this location and at such an age seems to be unique.

Osteoarthritis of the hip and fracture of the proximal end of the femur

The purpose of this investigation was to verify a long-standing clinical observation that patients with fracture of the proximal end of the femur have less evidence of osteoarthritic changes in their hip joints than would have been expected in patients of similar age groups. The radiographs of 342 patients with fractures and those of 157 controls were examined. The statistical results gave uncontroversial evidence that the incidence of osteoarthritic joints was lower in the fracture group. The difference was even greater with severe osteoarthritic changes. This suggests that patients with osteoarthritis have a "better quality" of bone. They are less likely to be suffering from osteoporosis and less liable to fractures of the proximal end of the femur.

The development of the normal infantile hip as expressed by radiological measurements

Acetabular and centre edge angles were measured on normal radiographs of 164 children (328 hips) aged from three months to five years. Using regression and correlation analysis, mathematical formulae were derived which allow the calculation of the normal acetabular and centre edge angles for a given age. The relationship between age, acetabular angle and centre edge angle was studied.

Skeletal findings in human neutrolethyrism. Is there a human osteolathyrism?

In a review of the roentgenological files of 22 patients suffering from spastic paraplegia due to neurolathyrism, 3 patients were found to present abnormal skeletal findings. 2 patients showed absence of union of the secondary ossification centres of the iliac crests, the ischial tuberosities and the vertebral bodies. Their age at the time of ingestion of poisonous Lathyrus sativus plants was 19 and 20 years. The 3rd patient had bowing and thickening of his right femoral shaft. He was 22 years old at the time of poisoning. These findings which are similar to those found in experimental osteolathyrism have never been described in clinical neurolathyrism. They are of a nature to throw some doubt on the correctness of the currently prevailing concept of sharp distinction between these two pathological entities.

[Treatment of fractures of the femoral neck by primary femoral prosthesis (author's transl)]

The authors have reviewed 230 case of fractures of the femoral neck treated by primary femoral prosthesis. The mortality was 12,6 p. 100 during the first three post operative months, and 16,5 p. 100 after three additional months. The infection rate was 13,9 p. 100, 4,7 p. 100 of the cases being severely infected. The postero lateral approach was more favourable than the antero-lateral approach. Late results were studied on 142 cases. The average follow-up was 4 years. The clinical results were closely dependent on the radiological appearance. When the prosthesis progressively penetrated into the femoral medullary canal incapacitating pain was always present. It is concluded that the use of cement may improve the results in a number of cases.

An evaluation of surgical and conservative treatment of fractures of the ankle in 200 patients

The longterm results of surgical and conservative treatment in two almost identical groups of patients with fractures of the ankle have been analyzed. The results were better after conservative treatment; delayed operation and repeated manipulations were found to be the main reason for the poorer postoperative results, especially in elderly osteoporotic patients. The damage consequent to repeated manipulations, the difficulties resulting from delaying operation, and the advantages of early open reduction are discussed. It may be that under certain conditions of unavoidable delay, a mild residual displacement should be accepted rather than repeated manipulation and delayed open reduction. It is concluded that, when indicated, operations should be performed as early as possible after injury, probably giving the best end results as evidenced by the preliminary findings of a prospective study currently under way.

The clinical use of combined xenografts of bone and autologous red marrow. A preliminary report

The beneficial effect upon osteogenesis of imprenating bone grafts with autologous red marrow is well documented. The experimental findings reported in a previous paper suggested that prepared xenograft bone might provide a good medium for osteogenesis by marrow cells. This paper is a preliminary report of the first clinical attempt to use xenografts of bone combined with autologous red marrow. Kiel bone, which was found the most suitable, was impregnated with marrow aspirated from the iliac crest and, apart from one case of infection, gave excellent results in twenty-eight patients under conditions covering a wide range of indications for bone grafting. Further trials should allow a more valid assessment.