Does urban agriculture contribute to food security, and how might this be achieved?

OBJECTIVE

Food system challenges exacerbate inequalities in access to fresh healthy food and threaten food security. Lack of food security, referred to as food insecurity, is associated with poorer physical and mental health outcomes and has been identified as a key challenge to address by calls for food system transformation. Increasing food production through urban agriculture, the production of fruit and vegetables in urban areas, has been identified as a potentially effective contributor to food system transformation, but the effect of this on household or UK-level food security is unclear. This paper reviews international evidence of urban agriculture's impact on food security.

DESIGN

Narrative review.

SETTING

This paper reviews international evidence of urban agriculture's impact on food security.

PARTICIPANTS

Previously published international research.

RESULTS

Whilst findings are mixed, available evidence suggests that urban agriculture makes a modest, yet positive, contribution to food security by facilitating the availability of and access to fresh fruit and vegetables to food insecure households.

CONCLUSIONS

Capitalising on the potential for urban agriculture to benefit food security requires government investment and support at both the national and local levels; therefore, increasing access to land for food growing, reducing costs of related resources and collaboration with existing community groups to enhance sharing of skills and expertise are identified as avenues for exploration that may help to achieve this. This review also highlights opportunities for future research in this field that may strengthen the quality of the evidence supporting urban agriculture's impact on food security.

Zinc regulates reactive oxygen species generation in platelets

Vascular complications resulting from atherosclerosis development are a major cause of death. Reactive oxygen species (ROS) are produced by platelets during activation, and have been demonstrated to positively regulate platelet activatory responses. Zn2+ is also an important hemostatic cofactor in platelets, acting both as a platelet agonist and second messenger. Whilst the effect of Zn2+-dependent signaling mechanisms on ROS production in nucleated cells has been demonstrated, comparable roles in platelets have yet to be investigated. In this study we investigated the relationship between fluctuations in cytosolic Zn2 [Zn2+]i and platelet ROS production. Agonist-evoked ROS production, GSH levels and GPx activity are abrogated in platelets treated with the Zn2+-chelator, TPEN. Conversely, increasing platelet [Zn2+]i using Zn2+ ionophores potentiated ROS generation and decreased GSH levels and GPx activity. Zn2+-dependent ROS production was sensitive to pretreatment with DPI or mitoTEMPO, NADPH oxidase and mitochondria inhibitors respectively. Increasing [Zn2+]i resulted in increases of Erk1/2 and JNK phosphorylation. Our data are consistent with a functional association between [Zn2+]i and ROS production in platelets that could influence thrombus formation in a clinical context.

Improvements to the Rice Genome Annotation Through Large-Scale Analysis of RNA-Seq and Proteomics Data Sets

Rice (Oryza sativa) is one of the most important worldwide crops. The genome has been available for over 10 years and has undergone several rounds of annotation. We created a comprehensive database of transcripts from 29 public RNA sequencing data sets, officially predicted genes from Ensembl plants, and common contaminants in which to search for protein-level evidence. We re-analyzed nine publicly accessible rice proteomics data sets. In total, we identified 420K peptide spectrum matches from 47K peptides and 8,187 protein groups. 4168 peptides were initially classed as putative novel peptides (not matching official genes). Following a strict filtration scheme to rule out other possible explanations, we discovered 1,584 high confidence novel peptides. The novel peptides were clustered into 692 genomic loci where our results suggest annotation improvements. 80% of the novel peptides had an ortholog match in the curated protein sequence set from at least one other plant species. For the peptides clustering in intergenic regions (and thus potentially new genes), 101 loci were identified, for which 43 had a high-confidence hit for a protein domain. Our results can be displayed as tracks on the Ensembl genome or other browsers supporting Track Hubs, to support re-annotation of the rice genome.

Implementation of internet-delivered cognitive behavior therapy within community mental health clinics: a process evaluation using the consolidated framework for implementation research

BACKGROUND

Depression and anxiety are prevalent and under treated conditions that create enormous burden for the patient and the health system. Internet-delivered cognitive behavior therapy (ICBT) improves patient access to treatment by providing therapeutic information via the Internet, presented in sequential lessons, accompanied by brief weekly therapist support. While there is growing research supporting ICBT, use of ICBT within community mental health clinics is limited. In a recent trial, an external unit specializing in ICBT facilitated use of ICBT in community mental health clinics in one Canadian province (ISRCTN42729166; registered November 5, 2013). Patient outcomes were very promising and uptake was encouraging. This paper reports on a parallel process evaluation designed to understand facilitators and barriers impacting the uptake and implementation of ICBT.

METHODS

Therapists (n = 22) and managers (n = 11) from seven community mental health clinics dispersed across one Canadian province who were involved in implementing ICBT over ~2 years completed an online survey (including open and closed-ended questions) about ICBT experiences. The questions were based on the Consolidated Framework for Implementation Research (CFIR), which outlines diverse constructs that have the potential to impact program implementation.

RESULTS

Analyses suggested ICBT implementation was perceived to be most prominently facilitated by intervention characteristics (namely the relative advantages of ICBT compared to face-to-face therapy, the quality of the ICBT program that was delivered, and evidence supporting ICBT) and implementation processes (namely the use of an external facilitation unit that aided with engaging patients, therapists, and managers and ICBT implementation). The inner setting was identified as the most significant barrier to implementation as a result of limited resources for ICBT combined with greater priority given to face-to-face care.

CONCLUSIONS

The results contribute to understanding facilitators and barriers to using ICBT within community mental health clinics and serve to identify recommendations for improving uptake and implementation of ICBT in clinic settings.

The contribution of zinc to platelet behaviour during haemostasis and thrombosis

Platelets are the primary cellular determinants of haemostasis and pathological thrombus formation leading to myocardial infarction and stroke. Following vascular injury or atherosclerotic plaque rupture, platelets are recruited to sites of damage and undergo activation induced by a variety of soluble and/or insoluble agonists. Platelet activation is a multi-step process culminating in the formation of thrombi, which contribute to the haemostatic process. Zinc (Zn(2+)) is acknowledged as an important signalling molecule in a diverse range of cellular systems, however there is limited understanding of the influence of Zn(2+) on platelet behaviour during thrombus formation. This review evaluates the contributions of exogenous and intracellular Zn(2+) to platelet function and assesses the potential pathophysiological implications of Zn(2+) signalling. We also provide a speculative assessment of the mechanisms by which platelets could respond to changes in extracellular and intracellular Zn(2+) concentration.

Modified platelet deposition on matrix metalloproteinase 13 digested collagen I

BACKGROUND

Atherothrombosis underlies acute coronary syndromes, including unstable angina and acute myocardial infarction. Within the unstable plaque, monocytes express collagenolytic matrix metalloproteinases (MMPs), including MMP-13, which degrades fibrous collagen. Following rupture, vessel wall components including degraded collagen are exposed to circulating platelets. Platelet receptors then mediate the recruitment and activation of platelets to form a thrombus, blocking blood flow and resulting in myocardial infarction and sudden death.

OBJECTIVES

Here we aim to provide information on the effects of collagen degradation on platelet adhesion and thrombus formation.

METHODS

Using increasing concentrations of MMP-13, we induced progressive degradation of fibrous and monomeric collagen I, visualized by electrophoresis, and then investigated the capacity of the resulting fragments to support static platelet adhesion and thrombus formation in whole flowing blood.

RESULTS

Both integrin and glycoprotein VI-dependent interactions with fibrous collagen underpin high levels of platelet adhesion under both conditions, with little obvious effect of MMP-13 treatment. Static platelet adhesion to monomeric collagen was strongly α2β1-dependent regardless of degradation status. Under flow conditions, partially degraded monomeric collagen supported increased thrombus deposition at 10 μg mL(-1) MMP-13, falling close to background when collagen degradation was complete (100 μg mL(-1) MMP-13).

CONCLUSIONS

New binding activities come into play after partial digestion of collagen monomers, and net platelet-reactivity through all axes is abolished as degradation becomes more complete.

A role for adhesion and degranulation-promoting adapter protein in collagen-induced platelet activation mediated via integrin α(2) β(1)

BACKGROUND

Collagen-induced platelet activation is a key step in the development of arterial thrombosis via its interaction with the receptors glycoprotein (GP)VI and integrin α(2) β(1) . Adhesion and degranulation-promoting adapter protein (ADAP) regulates α(IIb) β(3) in platelets and α(L) β(2) in T cells, and is phosphorylated in GPVI-deficient platelets activated by collagen.

OBJECTIVES

To determine whether ADAP plays a role in collagen-induced platelet activation and in the regulation and function of α(2) β(1).

METHODS

Using ADAP(-/-) mice and synthetic collagen peptides, we investigated the role of ADAP in platelet aggregation, adhesion, spreading, thromboxane synthesis, and tyrosine phosphorylation.

RESULTS AND CONCLUSIONS

Platelet aggregation and phosphorylation of phospholipase Cγ2 induced by collagen were attenuated in ADAP(-/-) platelets. However, aggregation and signaling induced by collagen-related peptide (CRP), a GPVI-selective agonist, were largely unaffected. Platelet adhesion to CRP was also unaffected by ADAP deficiency. Adhesion to the α(2) β(1) -selective ligand GFOGER and to a peptide (III-04), which supports adhesion that is dependent on both GPVI and α(2) β(1), was reduced in ADAP(-/-) platelets. An impedance-based label-free detection technique, which measures adhesion and spreading of platelets, indicated that, in the absence of ADAP, spreading on GFOGER was also reduced. This was confirmed with non-fluorescent differential-interference contrast microscopy, which revealed reduced filpodia formation in ADAP(-/-) platelets adherent to GFOGER. This indicates that ADAP plays a role in mediating platelet activation via the collagen-binding integrin α(2) β(1). In addition, we found that ADAP(-/-) mice, which are mildly thrombocytopenic, have enlarged spleens as compared with wild-type animals. This may reflect increased removal of platelets from the circulation.

Monitoring the intracellular store Ca2+ concentration in agonist-stimulated, intact human platelets by using Fluo-5N

BACKGROUND

Most Ca(2+) signaling research in platelets has relied solely on monitoring the cytosolic Ca(2+) concentration ([Ca(2+)](cyt)). Changes in [Ca(2+)](cyt) constitute the net effect of Ca(2+) fluxes into the cytosol across the plasma membrane (PM) and from intracellular stores, and Ca(2+) sequestration into the stores and Ca(2+) removal across the PM. This makes interpretation of the effects of pharmacologic or genetic interventions on Ca(2+) signaling difficult and subject to error.

OBJECTIVES

To validate the use of the low-affinity Ca(2+) indicator Fluo-5N to monitor the concentration of Ca(2+) in the intracellular stores ([Ca(2+)](st)) of human platelets as a first step in developing assays for a systems-level analysis of platelet Ca(2+) signaling.

METHODS

Fluo-5N-loaded and Fura-2-loaded human platelets were used to observe the effects of agonist stimulation and other manipulations on [Ca(2+)](cyt) and [Ca(2+)](st).

RESULTS

Fluo-5N fluorescence changed appropriately in response to compounds that induce passive depletion of intracellular Ca(2+) stores and to physiologic agonists. Ca(2+) reuptake inhibitors and blockers of Ca(2+) release channels had the expected effects on Fura-2 and Fluo-5N fluorescence. Agonist-evoked Ca(2+) release was reversed by Ca(2+) addition to the medium, and required intact Ca(2+) reuptake mechanisms. Store refilling was observed in the presence of sarcoplasmic/endoplasmic reticulum Ca(2+) -ATPase (SERCA) inhibitors and ionomycin, suggesting the presence of a non-SERCA Ca(2+) reuptake mechanism. Evidence for a role for Ca(2+) -induced Ca(2+) release in agonist-evoked responses was obtained.

CONCLUSIONS

Our data provide a validation of the use of Fluo-5N as a method for monitoring changes in [Ca(2+)](st) in human platelets.

Lubrication regime of the contact between fat and bone in bovine tissue

Fat pads are masses of encapsulated adipose tissue located throughout the human body. Whilst a number of studies describe these soft tissues anatomically little is known about their biomechanics, and surgeons may excise them arthroscopically if they hinder visual inspection of the joint or bursa. By measuring the coefficient of friction between, and performing Sommerfeld analysis of, the surfaces approximating the in vivo conjuncture, this contact has been shown to have a coefficient of friction of the order of 0.01. The system appears to be lubricated hydrodynamically, thus possibly promoting low levels of wear. It is suggested that one of the functions of fat pads associated with subtendinous bursae and synovial joints is to generate a hydrodynamic lubricating layer between the opposing surfaces.

The functional anatomy of Kager's fat pad in relation to retrocalcaneal problems and other hindfoot disorders

Kager's fat pad is a mass of adipose tissue occupying Kager's triangle. By means of a combined magnetic resonance imaging, ultrasound, gross anatomical and histological study, we show that it has three regions that are closely related to the sides of the triangle. Thus, it has parts related to the Achilles and flexor hallucis longus (FHL) tendons and a wedge of fat adjacent to the calcaneus. The calcaneal wedge moves into the bursa during plantarflexion, as a consequence of both an upward displacement of the calcaneus relative to the wedge and a downward displacement of the wedge relative to the calcaneus. During dorsiflexion, the bursal wedge is retracted. The movements are promoted by the tapering shape of the bursal wedge and by its deep synovial infolds. Fibrous connections linking the fat to the Achilles tendon anchor and stabilize it proximally and thus contribute to the motility of its tip. We conclude that the three regions of Kager's fat pad have specialized functions: an FHL part which contributes to moving the bursal wedge during plantarflexion, an Achilles part which protects blood vessels entering this tendon, and a bursal wedge which we suggest minimizes pressure changes in the bursa. All three regions contribute to reducing the risk of tendon kinking and each may be implicated in heel pain syndromes.

Review of the vascularisation of the human Achilles tendon

A region of avascularity mid-way along the length of the Achilles tendon has long been associated with rupture. Whilst it is agreed that this region is the location most common to rupture, the exact vascular distribution appears unclear. Regions of avascularity identified within the tendon have included the origin and insertion, as well as the midsection. This review aims to analyse critically and summarise all previous studies of the vascularisation of the healthy human Achilles tendon, in order to determine the most likely region of avascularity and, thereby establish whether a relationship exists between vascularisation and rupture. Whilst no definitive conclusion was reached, it was concluded that the vascularisation does affect the tensile strength and so rupture vulnerability of the healthy Achilles tendon, although it is unlikely to be either the sole, or most significant, contributor. Other factors, such as thinning and twisting of the tendon at the midsection are mechanical influences that will increase the incidence of rupture by increasing the concentration of stress.

Isolation of three high molecular weight polysaccharide preparations with potent immunostimulatory activity from Spirulina platensis, aphanizomenon flos-aquae and Chlorella pyrenoidosa

This research describes the identification of three new high molecular weight polysaccharide preparations isolated from food-grade microalgae that are potent activators of human monocytes/macrophages: "Immulina" from Spirulina platensis, "Immunon" from Aphanizomenon flos-aquae, and "Immurella" from Chlorella pyrenoidosa. These polysaccharides are structurally complex and have estimated molecular weights above ten million daltons. All three polysaccharides are highly water soluble and comprise between 0.5 % and 2.0 % of microalgal dry weight. Immunostimulatory activity was measured using a transcription factor-based bioassay for nuclear factor kappa B (NF-kappa B) activation in THP-1 human monocytes/macrophages. Using this system the EC(50) values for these microalgal polysaccharides are between 20 and 110 ng/ml (about 10pM). THP-1 activation was confirmed by measuring immune cytokine mRNA induction using reverse transcriptase-polymerase chain reaction (RT-PCR). Each polysaccharide substantially increased mRNA levels of interleukin-1beta (IL-1beta) and tumor necrosis factor-alpha (TNF-alpha). These polysaccharides are between one hundred and one thousand times more active for in vitro monocyte activation than polysaccharide preparations that are currently used clinically for cancer immunotherapy.

Characterization of human monocyte activation by a water soluble preparation of Aphanizomenon flos-aquae

Aphanizomenon flos-aquae (AFA) is a fresh-water microalgae that is consumed as a nutrient-dense food source and for its health-enhancing properties. The current research characterizes the effect of a water soluble preparation from AFA on human monocyte/macrophage function and compares the effect of AFA with responses from known agents that modulate the immune system. At 0.5 pg/ml the AFA extract robustly activated nuclear factor kappa B (NF-kappa B) directed luciferase expression in THP-1 human monocytic cells to levels at 50% of those achieved by maximal concentrations (10 microg/ml) of bacterial lipopolysaccharide (LPS). In addition, the AFA extract substantially increased mRNA levels of interleukin-1beta (IL-1beta) and tumor necrosis factor-alpha (TNF-alpha), and enhanced the DNA binding activity of NF-kappa B. The effects of AFA water soluble preparation were similar to the responses displayed by LPS, but clearly different from responses exhibited by tetradecanoyl phorbol acetate (TPA) and interferon-gamma (INF-gamma). Pretreatment of THP-1 monocytes with factors known to induce hyporesponsiveness suppressed both AFA-dependent and LPS-dependent activation. These results suggest that the macrophage-activating properties of the AFA water soluble preparation are mediated through pathways that are similar to LPS-dependent activation.

Quantification of power Doppler energy and its future potential

OBJECTIVE

To test a new software package (Color Quantifier, Kinetic Imaging, Liverpool, United Kingdom) that quantifies power Doppler energy and to determine its reproducibility.

DESIGN

Intraobserver and interobserver reproducibility study.

SETTING

University tertiary referral center.

PATIENT(S)

Transvaginal power Doppler ultrasound images were recorded from women taking part in a study evaluating the physiological vascular changes in the uterus and ovaries during the normal menstrual cycle.

INTERVENTION(S)

Nineteen consecutive frames of regions of interest in the uterus, ovary, and follicle, respectively, were analyzed by each of four observers on 10 occasions.

MAIN OUTCOME MEASURE(S)

Analysis of variance to determine the image and observer effect as well as the intraobserver and interobserver coefficients of variation.

RESULT(S)

Significant image and observer effects were found. However, the image effect was by far the largest component of the total variation. The large image-to-image variability was expected because the cardiac cycle was included within the 19 frames (images) analyzed. The combined intraobserver and interobserver variation, expressed as the coefficients of variation, was found to be small for the above indices (as low as 1.9%), particularly for total ovary and endometrium.

CONCLUSION(S)

The indices obtained with this color quantification software are reproducible in an in vitro setting using prerecorded images. Its applicability as a useful assay in the clinical setting requires further evaluation.

Podophyllotoxin lignans enhance IL-1beta but suppress TNF-alpha mRNA expression in LPS-treated monocytes

There exists a growing body of research which indicates that antimitotics such as taxol and colchicine influence cytokine gene expression. In the present study we examined the effect of podophyllotoxin and six analogs on nuclear factor kappa B (NF-kappa B) activation, and on interleukin-1 beta (IL-1beta) and tumor necrosis factor alpha (TNF-alpha) mRNA expression in human THP-1 monocytes. All compounds were inactive between 0.001microM and 10microM when tested alone. However, podophyllotoxin (0.1 microM) enhanced LPS-induced NF-kappa B activation and IL-1beta mRNA expression between 2 and 3-fold. In contrast, LPS-induced TNF-alpha mRNA expression was decreased between 3 and 6-fold. Comparable results were also observed with the three analogs acetylpodophyllotoxin, 4'-demethylpodophyllotoxin and alpha-peltatin. The remaining three analogs (podophyllotoxin-4-O-glucoside, beta-peltatin-beta-D-glucopyransoide and 1,2,3,4-dehydrodesoxypodophyllotoxin) were inactive. Clearly certain structural features such as the presence of a glycosidic group or ring aromatization results in loss of biological activity. Interestingly, the analogs that were inactive in our assays have also been previously shown to lack affinity for tubulin binding. These results suggest that during the initial hours of exposure to podophyllotoxin or specific analogs these compounds do not act as independent stimulants of human monocyte activation, but can selectively enhance or suppress LPS-induced cytokine gene expression.

Characterization of Aloeride, a new high-molecular-weight polysaccharide from Aloe vera with potent immunostimulatory activity

We have characterized a new immunostimulatory polysaccharide called Aloeride from commercial aloe vera (Aloe barbadensis) juice. Aloeride is between 4 and 7 million Da, and its glycosyl components include glucose (37.2%), galactose (23.9%), mannose (19.5%), and arabinose (10.3%). At 0.5 microg/mL Aloeride increased NF-kappa B directed luciferase expression in THP-1 human monocytic cells to levels 50% of those achieved by maximal concentrations (10 microg/mL) of LPS. Aloeride induced the expression of the mRNAs encoding IL-1beta and TNF-alpha to levels equal to those observed in cells maximally activated by LPS. Acemannan, the major carbohydrate component from aloe, used at 200 microg/mL in the macrophage assay resulted in negligible NF-kappa B activation. Analysis of acemannan and Aloeride using size-exclusion chromatography suggests that the low activity of acemannan is due to trace amounts of Aloeride. Although Aloeride comprises only 0.015% of the aloe juice dry weight, its potency for macrophage activation accounts fully for the activity of the crude juice.

Immunostimulatory effects of cycloartane-type triterpene glycosides from astragalus species

In the course of our research on the oligoglycosidic constituents of Turkish Astragalus species, we have isolated a number of cycloartane-type triterpene glycosides. The current study examines the immunostimulatory effects of nineteen of these cycloartane-type compounds using a transcription-based bioassay for Nuclear Factor kappa B (NF-kappaB) activation in a human macrophage/monocyte cell line, THP-1. All compounds were inactive at 100 microg/ml except astragaloside I which increased NF-kappaB directed luciferase expression to levels about 65% as compared with maximal stimulation by E. coli lipopolysaccharide (LPS) at 10 microg/ml. None of the compounds were active at low dosage levels (0.1 microg/ml) in combination with 50 ng/ml LPS. Astragaloside I also increased mRNA expression of the inflammatory cytokines interleukin-1beta (IL-1beta) and tumor necrosis factor-alpha (TNF-alpha) as measured using reverse transcriptase-polymerase chain reaction (RT)-PCR. Based on these results it is clear that certain structural features are required for immunostimulation of cycloartane-type triterpene glycosides.

Is there carotid artery aneurysm formation following saphenous vein patch endarterectomy?

The use of saphenous vein patching following carotid endarterectomy is reported to produce aneurysmal dilatation with the risk of thrombosis and possible rupture. The authors have studied patients who have had saphenous vein patch angioplasty following carotid endarterectomy to assess whether there is any progressive arterial dilatation. Thirty-five patients who had undergone saphenous vein patch carotid endarterectomy were age- and sex-matched with 31 subjects that had direct closure endarterectomy. All participants underwent carotid duplex scanning. The external diameters of the mid common carotid artery, the bulb and the proximal internal carotid artery were measured bilaterally. The diameters of the endarterectomized carotid were compared with the contralateral side using a paired t-test. Using an unpaired t-test, the saphenous vein angioplasty group was compared with the directly closed group. A graph was plotted of the ratio of internal carotid artery diameter of the saphenous vein angioplasty group (endarterectomized artery to the contralateral artery) against the length of follow-up, and the Pearson correlation coefficient was calculated. When the saphenous vein angioplasty group was compared with the directly closed group there was a significant difference between the carotid bulb (11.6 versus 9.7mm, P < 0.001) and internal carotid artery diameters (9.0 versus 7.0mm, P < 0.001). Longitudinal analysis of the saphenous vein angioplasty group showed that the increased diameter of the endarterectomized internal carotid artery progressed with time after surgery (r = 0.51, P < 0.005, and r = 0.56, P < 0.001). Vein patching increases the diameter of the internal carotid artery, and this may further increase with time possibly predisposing to aneurysm formation. Further longitudinal studies of paired data are required.

A vascular basis for repetitive strain injury

OBJECTIVE

The blanket term 'repetitive strain injury' (RSI) covers a wide variety of work-related clinical syndromes, most of which are localized lesions. However, some patients complain of diffuse forearm pain, a clinically distinct form of RSI, the aetiology of which is unknown.

METHODS

Using Doppler ultrasound, we measured the vascular responses to muscular work in the radial artery in 13 patients with bilateral diffuse forearm pain, seven with unilateral diffuse pain and 19 controls with localized arm pain.

RESULTS

We found that in diffuse forearm pain the radial artery is relatively constricted compared to the controls and fails to vasodilate with exercise, which suggests that diffuse forearm pain may be due to physiological claudication of the working forearm muscle.

CONCLUSION

A possible explanation is inhibition of local endothelial nitric oxide function, and this may be an unusual secondary, but self-perpetuating, pain condition which can follow other more specific, but chronic, arm pain syndromes in susceptible individuals.

The influence of total knee arthroplasty on lower limb blood flow

Ischaemic complications of total knee arthroplasty (TKA) are unusual and tend to occur in patients with peripheral vascular disease (PVD). A prospective study was undertaken to investigate the effect of TKA on blood flow in patients without clinical evidence of PVD. Ankle brachial index (ABI) did not alter post-operatively and no changes in arterial waveforms were found. Unless there is clinical evidence of PVD, TKA under tourniquet control is therefore very unlikely to cause ischaemic complications.

Colour-coded duplex assessment alone before carotid endarterectomy

This study assessed whether carotid colour-coded duplex imaging can provide sufficient information to investigate patients before carotid endarterectomy. One hundred patients with symptomatic carotid artery disease (amaurosis fugax 24, transient ischaemic attack 38 and established stroke 38) were assessed by both colour-coded duplex imaging and arch angiography. Stenoses were graded at angiography using the linear method from the European Carotid Surgery Trial and on duplex using peak systolic velocity criteria. Angiograms were also analysed for any arch or intracerebral pathology which would alter surgical management. In defining 70-99 per cent stenoses, duplex had a sensitivity of 98 per cent, specificity 96 per cent, positive predictive value of 96 per cent, negative predictive value 98 per cent and accuracy 97 per cent compared with angiography for both symptomatic and asymptomatic carotids (chi 2 = 1.22, 1 d.f., P = 0.25). With respect to the symptomatic carotid arteries angiography gave different information from duplex in six patients (6 per cent): definition of 70-99 per cent carotid stenosis was different (four), visualization was poor on duplex (one) and an intracerebral aneurysm was identified by angiography. One patient died following arch angiography as a result of mesenteric thrombosis. Carotid duplex imaging alone would appear to be sufficient to assess most patients before carotid endarterectomy as an accurate, safe and relatively cheap investigation compared with angiography. In cases where duplex assessment does not allow full visualization of the carotid bifurcation angiography is required.

Flush saphenofemoral ligation and multiple stab phlebectomy preserve a useful greater saphenous vein four years after surgery

PURPOSE

Flush saphenofemoral ligation, with multiple cosmetic stab phlebectomy, successfully treats saphenofemoral reflux and superficial varicosities. The long-term effect on the residual greater saphenous vein (GSV) requires evaluation.

METHODS

Noninvasive triplex ultrasound assessment of the residual GSV for potential use as a vein graft was used. We evaluated the independent objective and subjective cosmetic outcomes. We also used analysis to determine the correlation between GSV reflux, symptoms, and cosmetic outcome.

RESULTS

Seventy-two limbs were assessed at a median follow-up of 4 years (interquartile range 3 to 5 years). Fifty-nine limbs had patent GSVs above and below the knee. The mean length patent was 51 cm, and the mean internal diameters above and below the knee were 3.6 and 2.8 mm, respectively. In 65% of cases the vein had suitable ultrasonic characteristics, suggesting that it would be suitable for use as a conduit for a vascular bypass graft. Sixty-two limbs were considered a symptomatic success and 61 an objective cosmetic success. There was no correlation between the symptomatic and cosmetic outcome and the presence of superficial GSV reflux (linear regression analysis).

CONCLUSIONS

These findings support the effectiveness of the procedure of flush saphenofemoral ligation and multiple stab phlebectomy with regard to cosmetic and symptomatic outcome and may preserve the GSV for use as an autologous bypass graft.

Management of advanced cervical metastasis using intraoperative radiotherapy

Seventy-five patients who had advanced cervical metastasis with possible invasion of the deep muscles or carotid artery were approached with aggressive resection and intraoperative radiotherapy (IORT). All metastatic nodes were greater than 3 cm, 65% were fixed on clinical examination, and 35% involved the carotid artery. Forty-six (61%) of the patients had previously received irradiation. Fifteen of the patients required extended neck dissections with carotid resections and grafting. After the resection an average single dose of 2000 cGy of electron beam IORT was delivered. At 2 years, the local control rate within the IORT port was 68% and the absolute survival rate was 45%. Local control rates for close and microscopic margins (76% and 73%, respectively) were significantly better than the control rate for gross residual disease (25%, P < .05). The combination of extended neck dissection, including carotid artery resection if necessary, and IORT appears to offer improved control.

Blood flow in breast cancer and fibroadenoma estimated by colour Doppler ultrasonography

Blood flow was measured by colour Doppler ultrasonography in 33 fibroadenomas of size 5-31 mm and 28 malignant breast masses of 8-37 mm visible on ultrasonography. There was detectable blood flow in 11 fibroadenomas and 21 cancers (P < 0.01). The median peak systolic frequency was 1.0 (range 0.25-2.0) kHz in malignant tumours and 0.5 (range 0.2-1.25) kHz in fibroadenomas. Blood flow was not detected in the eight fibroadenomas of less than 13 mm but was present in five of seven cancers smaller than this. Five of six carcinomas with three or more detectable vessels were classified as grade III on histological examination, compared with two of 11 carcinomas with one or two vessels. Similarly, five of seven cancers with three or more detectable vessels had axillary lymph node metastases compared with two of 13 with only one or two vessels. Detectable blood flow in breast masses is more common in cancer than in fibroadenoma and is highly suggestive of malignancy if the mass is less than 13 mm in size. Malignant tumours with a larger number of vessels are more likely to be of high grade and to have associated axillary node metastases.

An assessment of the long saphenous vein for potential use as a vascular conduit after varicose vein surgery

PURPOSE

There is controversy in the surgical management of varicose veins between stripping of the long saphenous vein (LSV) and high ligation. Moreover, preservation of the LSV is desirable for future coronary or peripheral artery bypass. We have studied 75 limbs in 44 patients after high saphenous ligation with multiple stab phlebectomy.

METHODS

Subjective assessment of the outcome of surgery was made with a linear analog scale, and objective cosmetic outcome was assessed by an independent observer (LF) who had not been involved in the surgical treatment of these patients with our modification from the criteria first described by Jakobsen. Patency, length, and diameter of the LSV was measured 6 to 14 months (mean 12 months) after operation with a duplex scanner and a color-flow scanner. Valvular incompetence in the LSV and perforators was also assessed.

RESULTS

Results show a good subjective and objective outcome in 95% and 97% of limbs, respectively. The LSVs were patent from ankle to groin in 68% and from ankle to knee in 82%, with a mean diameter of 4.0 +/- 0.1 mm (mean +/- SEM). There was no statistically significant difference in symptomatic outcome and presence of reflux in the LSV (X2 = 0.465; p = 0.4954; NS) or objective cosmetic outcome and the presence of reflux in the LSV (chi 2 = 2.916; p = 0.0877; NS).

CONCLUSIONS

It is concluded that high saphenofemoral ligation combined with multiple "stab avulsions" preserves an LSV with characteristics suggesting suitability for future use as a vascular prosthesis with good early symptomatic and cosmetic results.

Intraoperative radiation therapy for recurrent head and neck cancer

Forty-seven patients with recurrent head and neck cancer in a previously irradiated field were treated with surgical resection and intraoperative radiation therapy (IORT). Recurrent disease occurred at a median of 18 months from primary treatment, and was at the primary tumor site in 31 and metastatic to regional lymph nodes in 16. Recurrences were squamous cell carcinomas in 42 and adenoid cystic in five. Surgical resection left microscopic residual disease in 41 and gross residual in six. All patients received IORT with a median of 20 Gy. Two-year actuarial survival is 54.9%, and 15 patients are alive and disease free with a median survival of 29 months. Two-year actuarial local control is 61.5%. A trend toward increased survival (P less than 0.09) and local recurrence control (P = 0.05) was noticed when treating microscopic residual disease as opposed to gross residual disease. Perioperative mortality was seen in 8.5% and there was no increase in morbidity secondary to IORT. The authors believe that surgical resection and IORT is an effective treatment modality for head and neck cancers recurrent in previously irradiated fields and is adaptable to tertiary care hospitals.

Intraoperative radiotherapy of skull base cancer

As the head and neck surgeon expands the boundaries of resectability into the skull base, the margin of tumor clearance diminishes. Intraoperative radiotherapy (IORT) can be used as an adjunct to skull base surgery and external beam radiation to enhance local control in areas with close margins or remaining microscopic disease. During the period from May 1982 to May 1988, 25 patients underwent IORT of the skull base following resection and prior to closure to treat microscopic disease in 9 patients, sterilize close margins in 14 patients, and attempt to eliminate remaining gross disease in 2 patients. The types of tumors treated were 13 squamous cell carcinomas, 4 adenoid cystic carcinomas, 3 high-grade mucoepidermoid carcinomas, 3 sarcomas, 1 malignant mixed tumor, and an oncocytic adenocarcinoma. The majority of the tumors either originated in the sinuses or were skull base extensions of oral cavity or oropharyngeal cancers. In 22 patients with 1-year follow-up, IORT prevented local recurrence in 14 (64%) patients. This may represent improved control of local disease in patients who historically have a very dismal prognosis. The indications, techniques, and complications of this exciting therapeutic modality are also reviewed.

Adjuvant radiation therapy in endometrial carcinoma

Between 1983 and 1987, 79 patients received radiation therapy in combination with surgery for cancer of the endometrium. The pathology in all cases was adenocarcinoma. Most cases had deep myometrial penetration with moderate or poor differentiation. More than two-thirds of the patients had stage I disease. Twenty-two patients received preoperative radiation, and 57 patients received radiation following surgery. There were 10 recurrences in the 79 patients treated. Most recurrences were from distant disease, and there was only one case of an isolated pelvic recurrence. Adjuvant radiation is well-tolerated, and the failure rate in the pelvis is low, even with aggressive lesions.

Intraoperative radiotherapy of head and neck cancer

Intraoperative radiotherapy (IORT) was developed as an adjuvant to surgery and external beam radiation for aggressive, extensive, or recurrent cancers of the head and neck. This report reviews the indications, technique, response, and complications of IORT. From May 1982 to May 1988, 104 patients received 15 to 20 Gy of radiation delivered through a Lucite cone to areas of high risk of recurrence following resection and prior to closure. The indications for treatment were (1) aggressive primary or recurrent cancer; (2) disease fixed to deep muscle, carotid, or bone; or (3) close margins in an effort to preserve vital structures or function. The IORT was effective in preventing local recurrence in 14 (40%) of 35 patients with 2-year follow-up of squamous cell carcinoma. The complication rate was acceptable. Intraoperative radiotherapy appears to be a safe and beneficial adjunctive therapy for cancers that historically have extremely dismal prognoses.

Intraoperative radiation therapy for advanced or recurrent head and neck cancer

Between 1982 and 1984, we treated 28 patients with advanced head and neck cancer with surgery, combined with intraoperative radiation. All patients had squamous cell carcinoma. One patient had two separate sites treated and a second patient was treated on two occasions, allowing 30 sites for analysis. The overall survival for all patients treated was 67% at 1 year. Local failure occurred in 13% of those with close surgical margins and 25% of those with microscopic residual disease. With gross residual disease 100% had local failure. Patients with gross residual disease had significantly higher local failure than microscopic residual disease (p less than 0.02) or close surgical margins (p less than 0.01). Carotid blowout was the major treatment complication. We believe intraoperative radiation is an effective treatment for advanced or recurrent head and neck cancer when all gross disease has been resected.

Irradiated mandibular autografts

The cosmetic and functional disability associated with mandibular resection has been a major problem to the patient with direct invasion of the mandible by oral cancer. Marginal resections with combined postoperative radiation therapy have frequently been substituted for the more preferred segmental resections and resultant deformities. Presented are 15 cases of oral cavity cancer involving resection of the mandible, immediate radiation to 10,000 rad, and primary reconstruction as irradiated mandibular autografts. The longest following is 4 years and 3 months, with a success rate of 66%. Morbidity is minimal as compared to autogenous bone grafting. Tumor size, previous radiation, or use of regional flaps have not been a factor in the success of this method in reconstruction of the mandible primarily.