Safety and Efficacy of Oxaliplatin Pressurized Intraperitoneal Aerosolized Chemotherapy (PIPAC) in Colorectal and Appendiceal Cancer with Peritoneal Metastases: Results of a Multicenter Phase I Trial in the USA

BACKGROUND

Pressurized intraperitoneal aerosolized chemotherapy (PIPAC) is a laparoscopic locoregional treatment for peritoneal metastases (PM) from colorectal cancer (CRC) or appendiceal cancer (AC) in patients who cannot undergo cytoreductive surgery (CRS). While PIPAC has been studied in Europe and Asia, it has not been investigated in the USA.

PATIENTS AND METHODS

We evaluated PIPAC with 90 mg/m2 oxaliplatin alone (cycle 1) and preceded by systemic chemotherapy with fluorouracil (5-FU) and leucovorin (LV) (cycle 2-3) as a multicenter prospective phase I clinical trial (NCT04329494). The primary endpoint was treatment-related adverse events (AEs). Secondary endpoints included survival and laparoscopic, histologic, and radiographic response.

RESULTS

12 patients were included: 8 with CRC and 4 with AC. Median prior chemotherapy cycles was 2 (interquartile range (IQR) 2-3). All patients were refractory to systemic oxaliplatin-based chemotherapy. Median peritoneal carcinomatosis index (PCI) was 28 (IQR 19-32). Six (50%) of twelve patients completed three PIPAC cycles. No surgical complications or dose-limiting toxicities were observed. Two patients developed grade 3 treatment-related toxicities (one abdominal pain and one anemia). Median overall survival (OS) was 12.0 months, and median progression-free survival (PFS) was 2.9 months. OS was correlated with stable disease by Response Evaluation Criteria in Solid Tumors (RECIST) criteria but not with laparoscopic response by PCI or histologic response by peritoneal regression grading system (PRGS).

CONCLUSIONS

This phase I trial in the USA demonstrated safety, feasibility, and early efficacy signal of PIPAC with oxaliplatin and chemotherapy in patients with PM from AC or CRC who are refractory to standard lines of systemic chemotherapy.

Cumulative menstrual months and breast cancer risk by hormone receptor status and ethnicity: The Breast Cancer Etiology in Minorities Study

Reproductive and hormonal factors may influence breast cancer risk via endogenous estrogen exposure. Cumulative menstrual months (CMM) can be used as a surrogate measure of this exposure. Using harmonized data from four population-based breast cancer studies (7284 cases and 7242 controls), we examined ethnicity-specific associations between CMM and breast cancer risk using logistic regression, adjusting for menopausal status and other risk factors. Higher CMM was associated with increased breast cancer risk in non-Hispanic Whites, Hispanics and Asian Americans regardless of menopausal status (all FDR adjusted P trends = .0004), but not in African Americans. In premenopausal African Americans, there was a suggestive trend of lower risk with higher CMM. Stratification by body mass index (BMI) among premenopausal African American women showed a nonsignificant positive association with CMM in nonobese (BMI <30 kg/m² ) women and a significant inverse association in obese women (OR per 50 CMM = 0.56, 95% CI 0.37-0.87, P_trend  = .03). Risk patterns were similar for hormone receptor positive (HR+; ER+ or PR+) breast cancer; a positive association was found in all premenopausal and postmenopausal ethnic groups except in African Americans. HR- (ER- and PR-) breast cancer was not associated with CMM in all groups combined, except for a suggestive positive association among premenopausal Asian Americans (OR per 50 CMM = 1.33, P = .07). In summary, these results add to the accumulating evidence that established reproductive and hormonal factors impact breast cancer risk differently in African American women compared to other ethnic groups, and also differently for HR- breast cancer than HR+ breast cancer.

A convergence of rRNA and mRNA quality control pathways revealed by mechanistic analysis of nonfunctional rRNA decay

Eukaryotes possess numerous quality control systems that monitor both the synthesis of RNA and the integrity of the finished products. We previously demonstrated that Saccharomyces cerevisiae possesses a quality control mechanism, nonfunctional rRNA decay (NRD), capable of detecting and eliminating translationally defective rRNAs. Here we show that NRD can be divided into two mechanistically distinct pathways: one that eliminates rRNAs with deleterious mutations in the decoding site (18S NRD) and one that eliminates rRNAs containing deleterious mutations in the peptidyl transferase center (25S NRD). 18S NRD is dependent on translation elongation and utilizes the same proteins as those participating in no-go mRNA decay (NGD). In cells that accumulate 18S NRD and NGD decay intermediates, both RNA types can be seen in P-bodies. We propose that 18S NRD and NGD are different observable outcomes of the same initiating event: a ribosome stalled inappropriately at a sense codon during translation elongation.

A late-acting quality control process for mature eukaryotic rRNAs

Ribosome biogenesis is a multifaceted process involving a host of trans-acting factors mediating numerous chemical reactions, RNA conformational changes, and RNA-protein associations. Given this high degree of complexity, tight quality control is likely crucial to ensure structural and functional integrity of the end products. We demonstrate that ribosomal RNAs (rRNAs) containing individual point mutations, in either the 25S peptidyl transferase center or 18S decoding site, that adversely affect ribosome function are strongly downregulated in Saccharomyces cerevisiae. This downregulation occurs via decreased stability of the mature rRNA contained in fully assembled ribosomes and ribosomal subunits. Thus, eukaryotes possess a quality-control mechanism, nonfunctional rRNA decay (NRD), capable of detecting and eliminating the rRNA component of mature ribosomes.

Wild-type but not interferon-gamma-deficient T cells induce graft arterial disease in the absence of B cells

OBJECTIVE

Interferon-gamma (IFN-gamma), a cytokine produced primarily by T cells and by activated macrophages, plays a central role in the pathogenesis of graft arterial disease (GAD). This study investigated whether T cells can induce GAD in the absence of humoral alloresponses and whether activated macrophages or other host cell types can substitute as sources of IFN-gamma in GAD.

METHODS

Wild-type (WT), IFN-gamma-/-, or recombination-activating-gene-1-/- (RAG-1-/-; lacking mature T and B cells) mice received MHC II-disparate hearts. The grafts were harvested 8 weeks post-transplant and histological and immunohistochemical analyses, RNase protection assay (RPA), and flow cytometry were used to evaluate GAD lesions, infiltrating cell populations, and IFN-gamma expression by infiltrating cells.

RESULTS

Moderate-to-severe GAD developed in WT recipient allografts, associated with abundant IFN-gamma expression by both infiltrating T cells and macrophages. No GAD developed in IFN-gamma-/- or in RAG-1-/- hosts, nor was any IFN-gamma expression evident. RAG-1-/- hosts receiving naïve WT or IFN-gamma-/- T cells (10(7)) after heart transplantation demonstrated no mature B cells but showed persistence of transferred T cells up to 8 weeks post-transplant. In the complete absence of B cells and alloantibody, transfer of WT T cells into RAG-1-/- recipients yielded GAD, with associated IFN-gamma expression by the transferred T cells and the host macrophages. Transfer of IFN-gamma-/- T cells induced neither GAD nor host macrophage IFN-gamma expression.

CONCLUSIONS

T cells, even in the absence of B cells, suffice to induce GAD, and T cell-derived IFN-gamma plays a critical role in GAD pathogenesis.

Detection of multiple macrolide- and lincosamide-resistant strains of Streptococcus pyogenes from patients in the Boston area

Macrolide (including erythromycin and azithromycin) and lincosamide (including clindamycin) antibiotics are recommended for treatment of penicillin-allergic patients with Streptococcus pyogenes pharyngitis. Resistance to erythromycin in S. pyogenes can be as high as 48% in specific populations in the United States. Macrolide and lincosamide resistance in S. pyogenes is mediated by several different genes. Expression of the erm(A) or erm(B) genes causes resistance to erythromycin and inducible or constitutive resistance to clindamycin, respectively, whereas expression of the mef(A) gene leads to resistance to erythromycin but not clindamycin. We studied the resistance of S. pyogenes to erythromycin and clindamycin at an urban tertiary-care hospital. Of 196 sequential isolates from throat cultures, 15 (7.7%) were resistant to erythromycin. Three of these were also constitutively resistant to clindamycin and had the erm(B) gene. Five of the erythromycin-resistant isolates were resistant to clindamycin upon induction with erythromycin and had the erm(A) gene. The remaining seven erythromycin-resistant isolates were susceptible to clindamycin even upon induction with erythromycin and had the mef(A) gene. Pulsed-field gel electrophoresis analysis and emm typing demonstrated that the erythromycin-resistant S. pyogenes comprised multiple strains. These results demonstrate that multiple mechanisms of resistance to macrolide and lincosamide antibiotics are present in S. pyogenes strains in the United States.

Human metapneumovirus in children tested at a tertiary-care hospital

BACKGROUND

Respiratory infections are the leading cause of outpatient visits in the United States, but the etiology of many of these infections is unknown. Human metapneumovirus (hMPV) is a recently discovered virus that causes respiratory infections.

METHODS

Respiratory specimens obtained from patients <or=18 years old, between 1 October 2000 and 31 August 2002, were tested for hMPV. The results of testing for other viruses and epidemiological information were obtained from the hospital databases. A logistic regression model, including sex and age of the patient and year and season in which the specimen was obtained, was used to determine the factors associated with hMPV infection.

RESULTS

hMPV was detected in 6.2% of patients tested and was significantly more common among children 3-24 months old than in older or younger children. The seasonal occurrence of hMPV was similar to that of respiratory syncytial virus and influenza virus, with most cases occurring in the winter and spring. In this tertiary care-center population, patients with hMPV infection often had underlying chronic conditions.

CONCLUSIONS

hMPV is common among young children with apparent respiratory infections, suggesting that it is a significant cause of symptomatic respiratory infections.

Almonds vs complex carbohydrates in a weight reduction program

OBJECTIVE

To evaluate the effect of an almond-enriched (high monounsaturated fat, MUFA) or complex carbohydrate-enriched (high carbohydrate) formula-based low-calorie diet (LCD) on anthropometric, body composition and metabolic parameters in a weight reduction program.

DESIGN

A randomized, prospective 24-week trial in a free-living population evaluating two distinct macronutrient interventions on obesity and metabolic syndrome-related parameters during weight reduction.

SUBJECTS

In total, 65 overweight and obese adults (age: 27-79 y, body mass index (BMI): 27-55 kg/m(2)).

INTERVENTION

A formula-based LCD enriched with 84 g/day of almonds (almond-LCD; 39% total fat, 25% MUFA and 32% carbohydrate as percent of dietary energy) or self-selected complex carbohydrates (CHO-LCD; 18% total fat, 5% MUFA and 53% carbohydrate as percent of dietary energy) featuring equivalent calories and protein.

MAIN OUTCOME MEASUREMENTS

Various anthropometric, body composition and metabolic parameters at baseline, during and after 24 weeks of dietary intervention.

RESULTS

LCD supplementation with almonds, in contrast to complex carbohydrates, was associated with greater reductions in weight/BMI (-18 vs -11%), waist circumference (WC) (-14 vs -9%), fat mass (FM) (-30 vs -20%), total body water (-8 vs -1%) and systolic blood pressure (-11 vs 0%), P=0.0001-0.05. A 62% greater reduction in weight/BMI, 50% greater reduction in WC and 56% greater reduction in FM were observed in the almond-LCD as compared to the CHO-LCD intervention. Ketone levels increased only in the almond-LCD group (+260 vs 0%, P<0.02). High-density lipoprotein cholesterol (HDL-C) increased in the CHO-LCD group and decreased in the almond-LCD group (+15 vs -6%, P=0.05). Glucose, insulin, diastolic blood pressure, total cholesterol, triglycerides, low-density lipoprotein cholesterol (LDL-C) and LDL-C to HDL-C ratio decreased significantly to a similar extent in both dietary interventions. Homeostasis model analysis of insulin resistance (HOMA-IR) decreased in both study groups over time (almond-LCD: -66% and CHO-LCD: -35%, P<0.0001). Among subjects with type 2 diabetes, diabetes medication reductions were sustained or further reduced in a greater proportion of almond-LCD as compared to CHO-LCD subjects (96 vs 50%, respectively) [correction].

CONCLUSION

Our findings suggest that an almond-enriched LCD improves a preponderance of the abnormalities associated with the metabolic syndrome. Both dietary interventions were effective in decreasing body weight beyond the weight loss observed during long-term pharmacological interventions; however, the almond-LCD group experienced a sustained and greater weight reduction for the duration of the 24-week intervention. Almond supplementation of a formula-based LCD is a novel alternative to self-selected complex carbohydrates and has a potential role in reducing the public health implications of obesity.

Tumor necrosis factor receptor -1 and -2 double deficiency reduces graft arterial disease in murine cardiac allografts

Graft arterial disease (GAD) remains the leading cause of long-term solid organ allograft failure. Tumor necrosis factor (TNF) promotes multiple aspects of allograft rejection via binding to type 1 (p55) and type 2 (p75) receptors. We used TNF type 1 receptor deficient (TNFR1KO), type 2 receptor deficient (TNFR2KO) and receptor double-deficient (TNFRDKO) mice to assess the relative roles of TNFR in acute rejection and GAD. Heterotopic cardiac transplantation was performed between C57BL/6 (B/6) and Balb/c (B/c) mice (total allomismatches) to assess the effects on graft survival; B/6 and Bm12 mice (class II mismatches) were used to assess the effects on GAD 8 weeks after transplantation. We found that graft survival in the total allomismatch combinations was the same regardless of TNFR status. In class II mismatches, wild-type (WT) combinations showed severe GAD, and GAD was not diminished when WT hearts were transplanted into TNFRDKO hosts. TNFR1KO donors or TNFR2KO donors had GAD comparable to WT donors, however, GAD was significantly diminished in B/6 TNFRDKO donor hearts. We conclude that both p55 and p75 signals on donor vascular wall cells are involved in the development of GAD, and either TNFR is capable of mediating a response that will culminate in GAD.

Overexpression of S100beta in transgenic mice does not protect from serotonergic denervation induced by 5,7-dihydroxytryptamine

Transgenic mice overexpressing S100beta were used to examine whether the chronic elevation of this protein alters the response to selective partial serotonergic lesions produced by bilateral intracerebroventricular injections of 5,7-dihydroxytryptamine (5,7-DHT). Basal levels of S100beta mRNA examined by in situ hybridization were two- to threefold higher throughout the brain in transgenic than in control mice, whereas 5-HT levels in forebrain were similar in both. After the 5,7-DHT-induced lesions, no differences were found in the S100beta mRNA levels in either normal or transgenic mice. At 5 and 60 days after the lesion, forebrain 5-HT levels were reduced by 56% and 35%, respectively, in control mice and by 51% and 35%, respectively, in the transgenic mice. Analysis of the 5-HT immunostaining showed a marked decrease of the immunoreactivity in various brain regions, which was comparable at the two intervals postlesion. One exception was the medial hypothalamus, where an almost complete disappearance of 5-HT immunoreactivity was observed in the medial region at 5 days after lesion, followed by a marked reinnervation 60 days later. These hypothalamic changes were seen in both controls and S100beta-overexpressing transgenic mice. Quantitative analysis of the density of 5-HT transporter sites using [(3)H]citalopram binding, a marker of serotonergic terminals, showed a marked decrease in different brain regions at both 5 and 60 days after 5,7-DHT injections. No difference in basal and postlesion levels of [(3)H]citalopram binding was seen between transgenic and control mice. In conclusion, this study demonstrates that constitutive overexpression of S100beta in transgenic mice does not modify serotonin levels during development, nor does it protect the serotonergic neurons from selective neurotoxicity or modify the serotonergic sprouting induced by partial lesion.

Perfect conserved linkage across the entire mouse chromosome 10 region homologous to human chromosome 21

The distal end of human Chromosome (HSA) 21 from PDXK to the telomere shows perfect conserved linkage with mouse Chromosome (MMU) 10. This region is bounded on the proximal side by a segment of homology to HSA22q11.2, and on the distal side by a region of homology with HSA19p13.1. A high-resolution PAC-based physical map is described that spans 2.8 Mb, including the entire 2.1 Mb from Pdxk to Prmt2 corresponding to HSA21. Thirty-four expressed sequences are mapped, three of which were not mapped previously in any species and nine more that are mapped in mouse for the first time. These genes confirm and extend the conserved linkage between MMU10 and HSA21. The ordered PACs and dense STS map provide a clone resource for biological experiments, for rapid and accurate mapping, and for genomic sequencing. The new genes identified here may be involved in Down syndrome (DS) or in several genetic diseases that map to this conserved region of HSA21.

High-resolution comparative physical mapping of mouse chromosome 10 in the region of homology with human chromosome 21

Comparative mapping of human and mouse chromosomes can be used to predict locations of homologous loci between the species, provides the substrate to examine the process of chromosomal evolution, and facilitates the continuing development of mouse genetic models for human disorders. A YAC contig of the region of mouse Chromosome (Chr) 10 (MMU10) that demonstrates conserved linkage with the distal portion of human Chr 21 (HSA21) has been constructed. The contig contains all known genes mapped in both species, defines the proximal region of homology between MMU10 and HSA22, and contains the evolutionary junction between HSA21 and HSA22 on MMU10. It consists of 23 YACs and 2 PACs, and covers 3.2 Mb of MMU10. The average marker density for this region is 1 marker/69 kb. Nine of 22 expressed sequences are mapped here for the first time in mouse, and two are newly characterized expressed sequences. The contig also contains 12 simple sequence repeats (SSRs) and 16 YAC and PAC endclone markers. YAC fragmentation analysis was used to create a physical map for the proximal 2.2 Mb of the contig. Cloning of the corresponding region of HSA21 has proven difficult, and the mouse contig includes segments absent from previously described sequence ready maps of HSA21.

A cluster of keratin-associated proteins on mouse chromosome 10 in the region of conserved linkage with human chromosome 21

A gene cluster of three to five high-cysteine keratin-associated proteins (KAPs) has been identified on mouse Chromosome 10 (MMU10) in the region of conserved linkage with human chromosome 21 (HSA21). One of these genes, Krtap12-1, has been sequenced in its entirety and shown to be an intronless gene encoding a predicted 130-amino-acid protein. Krtap12-1 is most closely related to two previously identified KAP4 genes, but variation in sequence and cysteine content suggests that it represents a new KAP family. Krtap12-1 is expressed in the skin of a 3-day-old mouse. The corresponding region of HSA21, between ITGB2 (integrin beta2) and PFKL (the liver isoform of phosphofructokinase), has proven refractory to cloning, and thus mapping of this region at high resolution has been problematic. Based on the KAP gene cluster position in mouse, evidence has been found for an orthologous human KAP cluster on HSA21q22.3, reinforcing the observation that comparative genomics can play an essential and practical role in determining mammalian genome organization.

Unilateral asymptomatic carotid disease does not require surgery

BACKGROUND AND PURPOSE

The efficacy of carotid endarterectomy (CEA) in symptomatic patients with > 70% stenosis is accepted. The stroke risk of asymptomatic patients may not justify surgical intervention. The aim of this study is to use natural history data from a single unit to identify asymptomatic patients who would benefit from CEA.

METHODS

Five hundred and sixty-four patients attending for duplex ultrasound assessment of the internal carotid artery between 1986 and 1993 were retrospectively identified as focally asymptomatic with > 40% ipsilateral stenosis. Patients were traced using hospital records, family practitioner databases and the Office of Population of Census and Surveys. The number of strokes, transient ischaemic attacks and cause of death were determined. Exclusions were 15 (2.7%) asymptomatic occlusions and 49 patients (8.7%) who underwent surgery for asymptomatic disease.

RESULTS

Thirteen patients (2.6%) were not traced, leaving 487 study patients. The average follow-up was 41 months (range, 1-120 months). Mean presentation age was 69 years (S.D. 8.9), and the male to female ratio was 3:2. One hundred and fifty-six (32%) patients died. Forty-three patients suffered strokes, of whom two had bilateral strokes. In total there were 16 (i/p) strokes, 25 (c/l) strokes and four strokes undetermined. The average yearly stroke rate was 2.74 per 100 person years and the (i/p) rate 1.02 per hundred person years. There was no effect of age, sex or degree of stenosis on stroke. The presence of bilateral disease did increase the risk of stroke (rel risk 2.35, p = 0.029) but not ipsilateral stroke (rel risk 1.6, p = 0.39). Patients with unilateral asymptomatic carotid disease had an all stroke rate of less than 5% in the first year after presentation and this was unaffected by degree of stenosis. In patients with bilateral disease the stroke rate in the first year after presentation increased with degree of stenosis to a stroke rate of 9.6 per 100 person years in patients with > 90% contralateral stenosis.

CONCLUSIONS

This data suggests that CEA will not benefit patients with unilateral asymptomatic disease. Patients with bilateral disease warrant inclusion in clinical trials.

Physical mapping of the evolutionary boundary between human chromosomes 21 and 22 on mouse chromosome 10

Adjacent regions of mouse Chromosome 10 (MMU10) show conserved synteny with human chromosome 22 (HSA22) and the telomeric region of HSA21. Physical mapping on MMU10 using YAC fragmentation and PAC contig analyses demonstrates that Prmt2 has a position consistent with its human homolog, HRMT1L1, being telomeric to S100B on HSA21. This result establishes Prmt2 as the new proximal boundary of the region of conserved synteny between MMU10 and HSA21 and predicts that it is the most telomeric gene known on HSA21. Physical mapping refines the positions and order of HSA22 homologs Mmp11, Mif, and Ddt, demonstrates the orientation of S100b on the mouse chromosome, and localizes the junction of conserved synteny between HSA21 and HSA22 on MMU10. Comparative mapping in this region is important for defining gene structure and dosage imbalance in Down syndrome (DS), for developing animal models of DS, and for understanding processes of chromosome evolution.

Computerised audit of carotid endarterectomy: audit loopholes closed?

The number of carotid endarterectomies being performed in the UK is increasing. The role of carotid endarterectomy (CEA) in the prevention of stroke depends on the procedure being associated with as few operative strokes as possible. Good clinical practice, with minimum morbidity, depends upon the integration of recent advances. Continuing audit has been used to examine changes in surgical practice and in case mix. There was a combined death and permanent stroke rate of 3.6% after 333 CEAs in a 6-year period (1990-1995) compared with 4.4% in 203 CEAs in an earlier 5-year audit period (1985-1989). The impact of an increase in the number of operations performed after recovered strokes, those performed by trainees and the use of prosthetic patches on the results of CEA has been assessed. Specific areas to be targeted in future audits are identified.

Risk prediction of outcome following carotid endarterectomy

The quoted combined mortality and morbidity following carotid endarterectomy is about 5-7%. In an attempt to identify a subgroup of high risk patients, a review has been undertaken of 404 carotid endarterectomies performed between January 1985 and March 1994. The perioperative mortality rate was 2%, with 3.4% of patients experiencing transient neurological deficits and 4% permanent strokes. Multiple logistic regression analysis was used to estimate the influence on outcome of age, gender, indication for surgery, bilateral internal carotid artery disease, hypertension and smoking. No significant explanators were identified.

Assessment of a mutation in the H5 domain of Girk2 as a candidate for the weaver mutation

A mutation in the GIRK2 inwardly rectifying K+ channel was mapped recently to the region of mouse chromosome 16 containing the wv gene and shown to occur in mutant but not in wild-type mice. We demonstrate tight linkage of the Girk2 mutation to the wv phenotype and refine the localization of the weaver (wv) gene on recombinational and physical maps. This linkage between Girk2 and wv has existed since at least 1988 in descendants of the original mutation maintained in C57BL/6 animals. Girk2 is shown to be transcribed in brain before the first recognized manifestation of the wv phenotype and in cultures of granule cells (GCs) isolated from cerebellum at postnatal day 8. Wild-type GCs grown in this culture system display an important developmental property--the ability to extend neurites. However, no inwardly rectifying K+ current is detected in GCs cultured from either wv/wv or +/+ cerebellum under a variety of conditions that activate related channels in other tissues. This suggests that if the Girk2 mutation is responsible for the wv phenotype, it does not act by altering these electrical properties of developing GCs.

Colour duplex in assessing the infrainguinal arteries in patients with claudication

Non-invasive assessment of the lower-limb vasculature may avoid unnecessary arteriography. Colour duplex scanning of the femoral and popliteal arteries was performed in claudicants who were potential candidates for endoluminal therapy. This was compared with the findings of biplanar conventional arteriography and intra-arterial digital subtraction angiography. In 112 lower limbs duplex gave the following results compared with angiography: the sensitivity, specificity, positive predictive value, negative predictive value and accuracy for occlusions (n = 48), stenoses (n = 31), atheromatous vessel (n = 21) and disease-free (n = 12) were all greater or equal to 94%. The lengths of the occlusions were accurately identified by duplex. Clinical examination and spectral analysis at the common femoral artery failed to identify two patients who had an iliac lesion. Colour duplex examination is the investigation of choice in assessing the major infrainguinal arteries in patients with claudication.

Magnetic resonance angiography or IADSA for diagnosis of carotid pseudo occlusion?

Accurate diagnosis of internal carotid artery (ICA) occlusion is essential in the investigation of carotid disease yet may be difficult using Duplex. Traditionally contrast arteriography has been used to confirm the diagnosis despite its cost and potential dangers. Twenty-one patients with 23 ICA occlusions were evaluated by a 3-dimensional time of flight magnetic resonance angiography (MRA) technique. The cervical carotids and circle of Willis were imaged during the MRA examination which lasted 30 minutes. Confirmatory conventional angiography was performed in all patients. Using angiography as the gold standard, all occlusions were correctly diagnosed by MRA and 22 of 23 occlusions correctly diagnosed by Duplex. There was good agreement between MRA and angiography for all 42 ICAs imaged (Kappa statistic 0.83). Diagnosis of internal carotid artery occlusion is critical as it determines the need for operation. In this situation MRA provides a useful non-invasive complement to Duplex. A combination of non-invasive studies may enable arteriography to be rejected with greater confidence in this high risk group.

Angioplasty gives good results in critical lower limb ischaemia. A 5-year follow-up in patients with known ankle pressure and diabetic status having femoropopliteal dilations

137 consecutive patients with known ankle pressures and diabetic status had attempted femoro-popliteal dilatation for lower limb ischaemia in an English provincial teaching hospital. All except one were followed until failure or death to assess survival and amputation rates. Non-diabetic patients with critical limb ischaemia had a 5 year survival rate of 62.2% (SE 17.1) compared to 50.5% (SE 7.0) for claudicants, with no significant difference on logrank testing. Diabetics had a relative risk of amputation of 11.2 compared to nondiabetics. Patients with pre-treatment ankle pressures of 50 mm or less had a relative risk of amputation of 2.6 compared to those with higher resting pressures. It is concluded that angioplasty should be the treatment of first choice in critical lower limb ischaemia whenever it is technically possible. Including patients with rest pain in the critical ischaemia group does not significantly affect cumulative patency rates.

Femoropopliteal angioplasty for severe limb ischaemia

Fifty patients undergoing 51 percutaneous transluminal angioplasties of the femoropopliteal segment for severe limb ischaemia were reviewed regularly. They comprised 30 men and 20 women of median age 70 (range 56-85) years. There were two deaths within 30 days. At 2 years the cumulative patient survival rate was 60 per cent. Eleven angioplasties were technical failures, 25 failed in the first 6 months and 14 were successful at 6 months' follow-up; in addition one patient died from myocardial infarction within 30 days of technically successful angioplasty. Subsequent vascular procedures were successful in 11 limbs following failed angioplasty. The primary limb survival rate was 42 per cent at 2 years. There were eight major complications after angioplasty, requiring amputation in five instances. Of the 23 long occlusions (greater than 5 cm) that were recanalized and dilated, 22 procedures failed within 6 months. The run-off score and diabetic status did not predict outcome. In this group of patients angioplasty had a low durability. Dilatation of long occlusions is associated with high rates of reocclusion and, on the basis of these results, should not be performed.

A 5-year review of carotid endarterectomy in a vascular unit using a computerised audit system

BIPAS, a computerised vascular audit has been used to analyse the results of 203 carotid endarterectomies performed over a 5-year period in a vascular unit. In addition, all but two patients have been followed up with regular duplex scans. The indications and surgical techniques have remained similar over the study period though preoperative carotid arteriography is no longer considered essential and intraoperative monitoring with transcranial Doppler insonation is becoming routine. There were six perioperative deaths and 20 postoperative neurological defects. However, only three survivors had any long-term disability. It was not possible to identify any particular patients at high risk of perioperative stroke, although simultaneous major surgery and significant bilateral carotid endarterectomy seemed to be more hazardous. Routine follow-up using duplex scanning identified patients with late occlusion (5%) and restenosis (8%), but only three patients (1.5%) suffered a late stroke. Once the perioperative hazards of death and permanent stroke (4.4% in this series) have been overcome, carotid endarterectomy provides good protection against subsequent stroke.

Duplex ultrasonography and pulse-generated run-off in selecting claudicants for femoropopliteal angioplasty

Non-invasive assessment of lower limb vasculature may avoid unnecessary angiography in claudicants. Colour duplex ultrasonography of the femoral and popliteal arteries was performed to assess patency and the presence of any stenoses, and pulse-generated run-off (PGR) was used to assess the distal vasculature. In 65 legs colour duplex scanning was successful, compared with angiography, in identifying the site and type of disease in the femoropopliteal segment and 23 lesions were correctly identified as suitable for angioplasty. More patent distal vessels were demonstrated by PGR than by angiography; no vessels patent on angiography were missed by PGR. The estimated cost of diagnostic angiography was 330 pounds per test compared with 52 pounds for non-invasive assessment. By using duplex examination as a screening test, a potential saving of 8062 pounds could have been made in this series. Duplex ultrasonography offers a non-invasive and cost-effective alternative to diagnostic angiography for clinically suspected infrainguinal arterial disease presenting as claudication. PGR was not of clinical value in assessing suitability for angioplasty.

The effect of diabetes mellitus on the outcome of angioplasty for lower limb ischaemia

Angioplasty is an important tool in the armamentarium of the clinician dealing with atherosclerotic disease. Diabetic patients with occlusive disease pose special problems. Four hundred and twenty-five lesions were dilated in 370 patients. No difference in site was found when comparing the diabetic and non-diabetic groups (p less than 0.001), but a significant difference in indication for treatment was observed. Cumulative patency at 5 years for iliac lesions in non-diabetic patients was 61.2% and in diabetic patients was 35.6% (p less than 0.05), for superficial femoral and popliteal artery lesions in non-diabetic patients it was 49.7% and in diabetic patients it was 38.8% (NS). The need for subsequent surgical intervention (p less than 0.01) and risk of death (p less than 0.001) are both significantly greater in the diabetic group. This study shows that angioplasty is a technique that can be used with success in diabetic patients and if the indications for interventions are compared, diabetic patients do not worse.

Complications in percutaneous transluminal angioplasty: relationships with patient age

Five hundred consecutive attempted lower limb angioplasties for ischaemic disease (370 patients, mean age 65.6 years, range 33-91 years) were reviewed. Significant complications occurred in 44 cases (8.8%). Nine patients (1.8%) underwent emergency surgery related to a complication. A further 12 patients (2.4%) underwent elective surgery related to a complication. In addition, four patients died within 30 days of the procedure; one following surgery performed because of a complication of angioplasty, one following a myocardial infarction, one following severe bleeding associated with subsequent thrombolytic therapy and one during emergency surgery related to a complication of angioplasty. A correlation was found between complication rate and age. This relationship was independent of the approach to, the position of, and the severity of the treated lesion. Elderly patients are at increased risk of complication in lower limb angioplasty.

Fate of patients undergoing transluminal angioplasty for lower-limb ischemia

A prospective study of 370 patients who underwent 500 percutaneous transluminal angioplasties (PTAs) for lower-limb ischemia over a 7-year period was performed. A 97% follow-up rate was achieved. The first PTA was successful in 188 patients (51%). Of the failures, 31% were failed attempts at dilation and 73% occurred within 1 month of intervention. Of the patients with failed PTA, 39% underwent bypass surgery and 24% underwent amputation. The 30-day mortality rate was 3%, with 1% of the deaths attributed to PTA. The survival rate at 5 years for the successes was double that for the failures (P less than .0005). The best results were in femoropopliteal stenoses with two or three patent calf vessels (cumulative patency rate, 78% at 3 years) and the worst in femoropopliteal occlusions with one or no patent calf vessels (cumulative patency rate, 25% at 3 years). Log rank tests on the life-table data were used to show factors favoring a good outcome. It is concluded that PTA is the treatment of first choice in suitable patients and, although the failure of intervention in critical ischemia has a significant risk, it is a valuable addition to the therapeutic options in patients with little chance of surgical treatment.

Role of duplex scanning in the selection of patients for carotid endarterectomy

A retrospective review of 63 patients undergoing duplex scanning and angiography for suspected carotid artery disease was performed to evaluate the need for routine angiography before carotid endarterectomy. A consultant surgeon (M.H.) made a simulated management decision on the basis of a clinical summary and a duplex scan report. Twenty-four patients were selected for surgery without angiography; duplex scanning had a sensitivity of 100 per cent and a specificity of 90 per cent in the detection of internal carotid artery stenosis. In two cases duplex scanning misdiagnosed a total occlusion as a critical stenosis. Eighteen patients failed to meet the criteria for surgery and were referred for angiography. Twenty-one patients were selected for conservative treatment on the basis of the duplex scan report. Combining the surgical and conservative groups (45 patients), duplex scanning had a sensitivity of 96 per cent and specificity of 95 per cent for the detection of stenosis greater than 50 per cent. In the identification of a total occlusion, duplex scanning had a poor sensitivity of 50 per cent. These results suggest that routine angiography before carotid endarterectomy is unnecessary in selected patients but that a suspected occlusion should be confirmed by angiography.

Uptake kinetics of monoclonal antibodies by human malignant melanoma multicell spheroids

Detailed uptake kinetics by multicell spheroids of three tumor associated monoclonal antibodies was investigated. The spheroids were established from a human melanoma cell line and the human colon adenocarcinoma cell line HT29 as in vitro models of poorly vascularized micrometastases in vivo. The selected antibodies 96.5, 140.240, and OST15 showed a wide range of reactivity against the melanoma cell but they all had negligible binding with the colon cancer cell. Uptake of the antibodies by small spheroids (about 300 micron diameter) was generally sigmoidal in shape with respect to incubation time, and amount of uptake followed the same trend of immunoreactivity of the antibodies with single cells. The correlation was weaker for spheroids with diameter greater than 500 micron presumably due to the increasing size of the necrotic core. By varying the concentration of the antibodies in the incubation medium from tracer dose (0.2 microgram/ml) to a higher dose (3 micrograms/ml), negligible changes in the amount of antibodies bound with their target spheroids were observed. Nonspecific binding between antibodies and spheroids, however, resulted in proportional increase in uptake.

Duplex scanning and plaque histology in cerebral ischaemia

Twenty-seven patients undergoing carotid endarterectomy (21 M, 6 F), with a mean age of 62 years, were studied by carotid ultrasound imaging, angiography, and histological examination of endarterectomy specimens, including Perl's stain to detect haemorrhage more than a week old. Haemorrhage into a plaque was seen histologically in 21 patients (78%), compared with 19 (70%) diagnosed preoperatively as echolucent heterogeneous plaques on ultrasound imaging. The remainder were echogenic homogeneous, fibrous plaques. In only one case was the nature of the plaque diagnosed by contrast arteriography. Excised endarterectomy specimens were inspected independently of the ultrasound assessment to determine whether the site of haemorrhage communicated with the base of an atherosclerotic ulcer. Communicating haemorrhages were present in 9 of 11 with episodic symptoms and non-communicating haemorrhages in 7 of 10 patients with a single cerebrovascular event. Perl's stain showed recent haemorrhage in 7 of 11 patients with multiple symptoms, and old haemorrhage in 9 of 10 patients with a single event. These findings suggest that ultrasonically heterogeneous communicating carotid plaques are symptomatically more active than homogeneous non-communicating plaques.

The role of balloon angioplasty in the management of lower limb ischaemia

Three hundred and twenty-three angioplasties (159 iliac; 164 femoro-popliteal) were performed for lower limb ischaemia on 253 consecutive patients from 1980-86. The mean resting ankle/brachial pressure index (ABPI) was increased at one month in open angioplasties as follows: Femoro-popliteal 0.56-0.82; iliac with open superficial femoral artery (SFA) 0.7-0.95; iliac with occluded SFA 0.52-0.63. Successful angioplasty virtually abolished the post-exercise fall in ABPI except for patients having iliac dilations when multisegment disease was present. At 5 years, cumulative patency was 72% for iliac angioplasty and 53% for femoro-popliteal angioplasty. The results of angioplasty were compared with operative arterial reconstructions during 1985. Eighty-eight (91%) of 96 surgical bypasses were alive and patent at hospital discharge and 44 (71%) of 62 angioplasties were patent at 1 month. There were many fewer complications with angioplasty which involved a much shorter hospital stay (2 days vs 16 days).

Detection of arterial stenosis: increased accuracy using biplanar angiography and Doppler signal analysis

Femoral artery Doppler signals were analysed from 68 patients with lower limb ischaemia undergoing biplanar angiography. These studies (pulsatility index, P.I. and LaPlace transform damping, LTD) were compared with clinical examination using this biplanar angiographic standard. Accuracy of femoral pulse palpation in predicting upstream stenosis was 67%. Biplanar angiography unmasked single plane stenosis underestimates in 21% of patients. In a subgroup of 39 lower limbs with aorto-iliac stenoses between 26 and 85% femoral LTD was the best predictor, being 84% accurate: whereas PI did not improve upon clinical examination. The need for biplanar angiography is underlined and the place of Doppler signal analysis in the assessment of arterial stenosis is confirmed.

The efficacy of graduated compression stockings in the prevention of deep vein thrombosis after major gynaecological surgery

The efficacy of graduated compression stockings in the prevention of deep vein thrombosis (DVT) after major gynaecological surgery was investigated in a controlled randomized prospective trial in 196 patients who were greater than 35 years of age. The stockings were worn by 104 of the 196 patients throughout their stay in hospital, the other 92 patients did not wear the stockings (control group). All the patients were scanned for DVT postoperatively with the 125I-labelled fibrinogen test. None of the 104 patients who wore the stockings developed a thromboembolism, but four of the 92 control patients who did not wear the stockings had DVT. This difference between the two groups was statistically significant.

The clinician and the vascular laboratory in the diagnosis of aortoiliac stenosis

Two hundred and twenty-one lower limbs in 116 arteriopaths were examined for evidence of aortoiliac stenosis, by analyses of common femoral artery Doppler waveforms for pulsatility index (PI) Laplace delta, and principal components, pulse volume recordings (PVR) and thigh pressure measurements. Clinical assessment of the aortoiliac segment was also recorded in 124 limbs. The accuracy of prediction of aortoiliac stenosis, measured on biprojectional arteriograms, was calculated for the different methods, using multiple regression analysis. Considering all grades of stenosis together, clinical judgement was the best predictor of severity (R2 - the correlation coefficient squared = 0.66): addition of non-invasive tests increased the accuracy of prediction to R2 = 0.70. For stenoses greater than 50 per cent PVR amplitude was the best non-invasive test (R2 = 0.39), but was no better than clinical assessment (R2 = 0.40). However, for stenoses less than 50 per cent clinical judgement was poor (R2 = 0.13), and derived most benefit from addition of Laplace delta (R2 = 0.20) or PVR upstroke time (R2 = 0.26). In addition, common femoral PI and Laplace delta were compared in the arteriopaths, and in 146 limbs of normal control subjects, by calculation of sensitivity and specificity. PI was superior to Laplace delta for detecting severe stenoses and occlusions, but Laplace delta was more accurate in the detection of lesser degrees of disease. These results suggest that conventional clinical assessment is the best method for detecting aortoiliac stenoses greater than 50 per cent, but for less severe disease addition of vascular laboratory tests is helpful - especially PVR and Laplace waveform analysis.

Percutaneous transluminal angioplasty for lower limb ischaemia

Forty successful percutaneous transluminal angioplasties (PTA) were performed in the iliac and femoropopliteal segments of 33 patients with lower limb ischaemia. There was immediate symptomatic relief in 37 limbs (92 per cent) although 7 relapsed and 5 patients required reconstructive arterial surgery within a month of PTA. Objective testing showed that the longer term relapse rate (median follow-up 12 months) was low (10 per cent). Despite a significant incidence of early complications and relapse, PTA provided a good long term result in the majority of patients treated.

Physiological interpretation of Doppler shift waveforms: the femorodistal segment in combined disease

A new method is presented for assessing the femorodistal segment in multisegmental arterial disease, using the Laplace transform technique of Doppler waveform analysis. Blood velocity/time waveforms were obtained at femoral and ankle levels in three groups of limbs--50 without arterial disease, 12 with isolated aortoiliac stenoses, and 32 with femoropopliteal occlusions, with and without proximal disease. The waveforms were analysed for Laplace transform and pulsatility index values. The omega 0 coefficients of the Laplace transform analysis at femoral and ankle levels were compared in each subject, as the omega 0 gradient (femoral/ankle omega 0): and pulsatility index damping factor (femoral/ankle P1) was also calculated. The omega 0 gradient was shown to detect femoropopliteal occlusion in the presence of multisegmental arterial disease and to give some indication of its haemodynamic significance. The diagnostic accuracy of the omega 0 gradient was superior to that of pulsatility index damping factor. When combined with its existing ability to detect aortoiliac stenosis, this new application of the Laplace transform method offers the possibility both of a system for complete localisation of significant arterial lesions, and potential for follow-up of vascular surgical procedures in the lower limb, from two simple Doppler recordings.

Differential diagnosis of arterial disease of the lower limb using Doppler ultrasound

Doppler arterial waveforms from the femoral and ankle arteries of 55 normal control subjects and 76 arteriopaths were analysed for Laplace transform coefficients, delta and omega omicron, and pulsatility index (PI). At the femoral artery delta was superior to PI in accurately detecting mild and moderate aortoiliac stenosis, as assessed from arteriograms. In the femoropopliteal segment, the ratio of omega omicron from femoral to ankle level compared favourably with PI damping factor in the detection of occlusive disease. The Laplace transform system provides a helpful diagnostic method in lower limb arterial disease.

Serological comparisons between strains of Agrobacterium tumefaciens

Agrobacterium tumefaciens B6and Agrobacterium tumefaciens B6TP were compared serologically. Antigen–antibody precipitations produced by the use of the agar double-diffusion technique show cross reactions indicating similarity in addition to a line of precipitation specific for the virulent strain, Agrobacterium tumefaciens B6.

Production of gibberellin-like substances by bacteria and actinomycetes

The production of gibberellin-like substances by bacteria and actinomycetes was investigated. Most of the bacterial cultures tested produced a gibberellic acid-like substance (A3) in amounts varying from 1 to 14 μg/liter. The production of a gibberellin-A9-like compound was much more limited, 6 out of 15 cultures yielding small amounts. Six out of 11 actinomycetes showed evidence of A3 synthesis; two produced A9. Antigibberellin substances co-chromatographing with A3 were detected in culture filtrates of Bacillus polymyxa and two actionmycetes. Cultural conditions and concentration of the ingredients of the medium influenced gibberellin synthesis by Agrobacterium radiobacter. Production of these substances was not growth linked and none was detected in stationary cultures. Microbial synthesis of the gibberellins was demonstrated also by means of assays with the dwarf maize mutants d1, d2, and d5.As added to soil was rapidly inactivated and it was postulated that the plant could derive maximum benefit from microbial synthesis of gibberellins and related substances only at the root surface—the rhizoplane.