The antimicrobial activity and biocompatibility of a controlled gentamicin-releasing single-layer sol-gel coating on hydroxyapatite-coated titanium

Aims

The aim of this study was to develop a single-layer hybrid organic-inorganic sol-gel coating that is capable of a controlled antibiotic release for cementless hydroxyapatite (HA)-coated titanium orthopaedic prostheses.

Methods

Coatings containing gentamicin at a concentration of 1.25% weight/volume (wt/vol), similar to that found in commercially available antibiotic-loaded bone cement, were prepared and tested in the laboratory for: kinetics of antibiotic release; activity against planktonic and biofilm bacterial cultures; biocompatibility with cultured mammalian cells; and physical bonding to the material (n = 3 in all tests). The sol-gel coatings and controls were then tested in vivo in a small animal healing model (four materials tested; n = 6 per material), and applied to the surface of commercially pure HA-coated titanium rods.

Results

The coating released gentamicin at > 10 × minimum inhibitory concentration (MIC) for sensitive staphylococcal strains within one hour thereby potentially giving effective prophylaxis for arthroplasty surgery, and showed > 99% elution of the antibiotic within the coating after 48 hours. There was total eradication of both planktonic bacteria and established bacterial biofilms of a panel of clinically relevant staphylococci. Mesenchymal stem cells adhered to the coated surfaces and differentiated towards osteoblasts, depositing calcium and expressing the bone marker protein, osteopontin. In the in vivo small animal bone healing model, the antibiotic sol-gel coated titanium (Ti)/HA rod led to osseointegration equivalent to that of the conventional HA-coated surface.

Conclusion

In this study we report a new sol-gel technology that can release gentamicin from a bioceramic-coated cementless arthroplasty material. In vitro, local gentamicin levels are in excess of what can be achieved by antibiotic-loaded bone cement. In vivo, bone healing in an animal model is not impaired. This, thus, represents a biomaterial modification that may have the potential to protect at-risk patients from implant-related deep infection.

Cite this article: Bone Joint J 2021;103-B(3):522–529.

In vivo safety and efficacy testing of a thermally triggered injectable hydrogel scaffold for bone regeneration and augmentation in a rat model

Bone loss resulting from degenerative diseases and trauma is a significant clinical burden which is likely to grow exponentially with the aging population. In a number of conditions where pre-formed materials are clinically inappropriate an injectable bone forming hydrogel could be beneficial. The development of an injectable hydrogel to stimulate bone repair and regeneration would have broad clinical impact and economic benefit in a variety of orthopedic clinical applications.

We have previously reported the development of a Laponite^® crosslinked pNIPAM-co-DMAc (L-pNIPAM-co-DMAc) hydrogel delivery system, loaded with hydroxyapatite nanoparticles (HAPna), which was capable of inducing osteogenic differentiation of mesenchymal stem cells (MSCs) without the need for additional growth factors in vitro. However to enable progression towards clinical acceptability, biocompatibility and efficacy of the L-pNIPAM-co-DMAc hydrogel to induce bone repair in vivo must be determined.

Biocompatibility was evaluated by subcutaneous implantation for 6 weeks in rats, and efficacy to augment bone repair was evaluated within a rat femur defect model for 4 weeks. No inflammatory reactions, organ toxicity or systemic toxicity were observed. In young male rats where hydrogel was injected, defect healing was less effective than sham operated controls when rat MSCs were incorporated. Enhanced bone healing was observed however, in aged exbreeder female rats where acellular hydrogel was injected, with increased deposition of collagen type I and Runx2. Integration of the hydrogel with surrounding bone was observed without the need for delivered MSCs; native cell infiltration was also seen and bone formation was observed within all hydrogel systems investigated.

This hydrogel can be delivered directly into the target site, is biocompatible, promotes increased bone formation and facilitates migration of cells to promote integration with surrounding bone, for safe and efficacious bone repair.

Ambulatory oxygen improves the effectiveness of pulmonary rehabilitation in selected patients with chronic obstructive pulmonary disease

The effect of ambulatory oxygen use during pulmonary rehabilitation (PR) has not yet been clearly established, but many studies have shown benefit from oxygen acutely. Two small studies to date demonstrated no clear benefit when oxygen was used in patients who desaturated on exertion during a PR programme. One study showed the benefit of using oxygen during PR in patients who were normoxic at rest and desaturated to a minimum of 88% on exertion. We conducted a single-blind, randomised controlled trial comparing PR undertaken either with or without ambulatory oxygen, in those with demonstrable benefit from oxygen at baseline. Subjects from three PR services were recruited who, during baseline assessment, desaturated by more than 4% and to less than 90% on exertion, and walked 10% or more further with ambulatory oxygen on endurance shuttle walk test. Patients were randomised to either room air or oxygen via portable cylinder, titrated to optimise pulse oxygen saturation but up to a maximum flow rate of 6 L/min. All patients then completed a twice weekly, 6- to 7-week PR programme. Data were analysed as per protocol. Totally 51 patients completed the study. At the end of PR, both groups improved with PR, with patients in the oxygen group demonstrating a highly statistically significantly greater mean improvement in endurance walking distance than the controls, 490 m (95% confidence interval 228–750; p ≤ 0.001), as well as clinically, although not statistically, significant changes in quality of life. The use of ambulatory oxygen during a 6- to 7-week PR programme greatly improved endurance walking distance in patients who desaturated on exertion with a positive acute response to ambulatory oxygen at baseline.

Atopy, autonomic function and beta-adrenergic receptor autoantibodies

Atopic individuals (with asthma, allergic rhinitis or atopic eczema) have impaired sensitivity to beta-adrenergic agents. After the finding of antibodies to the beta-adrenergic receptor in the serum of a subject with allergic rhinitis, coded sera from atopic and control subjects were assayed for immunoglobulins that inhibited the specific binding of 125I-labelled hydroxybenzylpindolol to beta-receptors in mammalian lung membranes. Antibodies were present in nine of 60 subjects: 3/19 normal control subjects, 1/9 pre-allergic, 4/17 asthma, 0/8 allergic rhinitis, and 1/7 cystic fibrosis patients. Antibodies of the IgG class in these sera were also demonstrated by indirect precipitation of solubilized lung beta-receptors. The autonomic sensitivity of the nine antibody-positive subjects (Ab+) was compared with that of antibody-negative subjects (Ab-). The Ab+ subjects required 15.0 +/- 1.9 ng isoprenaline (isoproterenol) kg-1 min-1 i.v. to increase pulse pressure by at least 22 mmHg (Ab-, 7.7 +/- 0.4; n = 20; P less than 0.001), and 12.4 +/- 1.8 ng isoprenaline kg-1 min-1 i.v. to increase plasma cyclic AMP concentrations by 50% (Ab-, 8.08 +/- 0.62; n = 13; P less than 0.02). Ab+ subjects required 2.06 +/- 0.3% phenylephrine to dilate their pupils (Ab-, 2.55 +/- 0.08; n = 57; P less than 0.05) and 0.61 +/- 0.08% carbachol to constrict their pupils (Ab-, 0.78 +/- 0.03%; n = 57; P less than 0.05). A role for autoantibodies as beta-receptor antagonists was further supported by showing that human lung cells (VA-13 line) cultured in the presence of globulins from Ab+ subjects had a markedly impaired cyclic AMP response to isoprenaline. These results suggest that autoantibodies to beta-receptors play a pathogenetic role in asthma and related disorders. They have important implications for the concept of autoimmunity.

Brevican and phosphacan expression and localization following transient middle cerebral artery occlusion in the rat

The ECM (extracellular matrix) is a complex molecular framework that provides physical support to cells and tissues, while also providing signals for cell growth, migration, differentiation and survival. The ECM of the CNS (central nervous system) is unusual in that it is rich in CSPGs (chondroitin sulfate proteoglycans), hyaluronan and tenascins. The CSPGs are widely expressed throughout the developing and adult CNS and have a role in guiding or limiting neurite outgrowth and cell migration. Alterations in the synthesis or breakdown of the ECM may contribute to disease processes. Here, we examine changes in the brain-specific CSPGs, brevican and phosphacan, following transient middle cerebral artery occlusion, a model of stroke in the rat. We have investigated their expression at various time points as well as their spatial relationship with ADAMTS-4 (adisintegrin and metalloprotease with thrombospondin motifs 4). The co-localization of ADAMTS or its activity may indicate a functional role for this matrix–protease pair in degeneration/regeneration processes that occur in stroke.

Carcinosarcoma of the penis

BACKGROUND

Carcinosarcoma of the penis is extremely rare and little is known about its biological behaviour.

AIMS

We report the second such case and discuss its histological categorisation and biological behaviour.

METHODS

A total penectomy with perineal urethrostomy was performed without lymphadenectomy in an 83-year old presenting with a fungating penile mass.

RESULTS

Microscopy of the gross specimen showed a biphasic tumour with both squamous and spindle cell elements. Immunohistochemical staining for epithelial markers showed positivity in the squamous cell elements but was uniformly negative in the spindle component. Immunohistochemistry of the spindle cell element demonstrated mesenchymal markers. The patient refused further treatment and follow up but presented at 26 months with inguinal lymphadenopathy. Biopsy confirmed squamous cell carcinoma metastasis consistent with penile origin. The patient refused further surgery and received pelvic irradiation. He died 6 months later.

CONCLUSIONS

This case illustrates the biological behaviour of this rare tumour.

Ischemic Steal Syndrome: A Case Series and Review of Current Management

BACKGROUND

Currently over 5000 patients are receiving hemodialysis in Australia, which is an increase by approximately 7% each year. Distal ischemia secondary to the steal syndrome (ISS) is an uncommon but recognized complication. Several methods are now available to manage this problem including ligation, banding, and distal revascularization with interval ligation (DRIL). The aim of this report is to review the experience of the authors on this complication and its management at Royal Perth Hospital.

METHODS

The Vascular Physiology Laboratory Database was used to identify those patients referred for investigation of ISS. Data were collected retrospectively from these patients' files concerning their demographics, graft particulars, and type of interventional procedure. Patients were then recalled to assess long-term patency and current venous access and for postoperative vascular studies.

RESULTS

Eighteen people were identified with ischemic symptoms. The mean age was 66 (range, 44 to 82). Fourteen (77.8%) were men, and 15 (83.3%) were diabetic. Renal failure was secondary to diabetes in 8 patients, hypertension in 3, and a combination of both in 7 patients. Intervention was via the DRIL procedure in 12, ligation in 5, and banding in 1. One patient underwent angioplasty of the ulnar artery before DRIL. At follow-up (between 1 and 12 months), all DRIL bypass were patents. The 5 ligated patients all improved, and the patient who underwent banding thrombosed their graft.

CONCLUSION

The DRIL procedure should be considered the standard operation to manage ISS in that it manages the ischemia while maintaining the functional fistula. It is, however, still necessary to ligate some fistulae and seek alternative access. There are still no preoperative indicators as to who will suffer ISS.

Spontaneous coronary artery dissection in a healthy postmenopausal woman

Spontaneous coronary artery dissection (SCAD) is rare and when it occurs is most commonly seen in young females following childbirth. We report a case of a 55-year-old female who was found dead at her home. She had no history of cardiovascular disease. She smoked approximately 10 cigarettes per day. She complained of mild chest discomfort the night before her death, lasting for 10 minutes, for which no medical attention was sought. She had been seen and appeared well 15 minutes before death. At autopsy, the only abnormality was in the left anterior descending coronary artery, which showed a two cm segment with periluminal blood in the wall of the vessel compressing the lumen. Histologically, a dissection was seen between the media and the external elastic lamina of the affected artery. There was a mixed inflammatory infiltrate including eosinophils and very occasional giant cells. Alcian blue staining was negative. The appearances were those of a localised dissection. The remaining coronary arteries were free of atheroma. SCAD should be suspected in young females in their postpartum period presenting with chest pain since emergency treatment can greatly increase survival.

Soft tissue infection with Absidia corymbifera in a patient with idiopathic aplastic anemia

We describe a case of primary cutaneous mucormycosis (zygomycosis) in a patient with idiopathic aplastic anemia which responded to surgical debridement and therapy with liposomal amphotericin B. The tissue removed at surgery showed dense infiltration with fungal hyphae on histopathological examination. Primary cultures of tissue on solid media were negative, but Absidia corymbifera was isolated from unprocessed tissue placed in brain heart infusion broth.

Hybrid capture as a means of detecting human papillomavirus DNA from liquid-based cytology specimens: a preliminary evaluation

The connection between human papillomavirus (HPV) and cervical cancer is well documented, as is the benefit of an adjunctive, standardised objective test to complement cervical screening. Here, 197 liquid-based cytology (LBC) specimens previously processed for cytological examination (75 negative, 108 borderline/mild dyskaryosis, and 14 moderate/severe dyskaryosis) are examined for the presence of HPV using a hybrid capture assay. Of the 197 specimens tested for HPV DNA, 97 (49.2%) were positive using the combined high/low-risk probe, and 59 (29.9%) were negative cytologically and with the hybrid capture HPV test; however, 16/175 (21.3%) specimens classified as negative cytologically with LBC proved positive for HPV by hybrid capture. Of the 122 samples that showed abnormal cytology, 81 (66.4%) were positive for HPV. Although the number of samples tested is small, the results show that the use of LBC technology for both cervical cytological screening and the hybrid capture test has the potential to reduce both false-negative and -positive rates associated with cytological screening alone.

Fibrous histiocytoma of tendon sheath of the hand

The hand is not uncommonly afflicted by Fibrous histiocytoma/Giant Cell tumour of tendon sheath, an enigmatic and loosely-defined clinical entity only occasionally entering into the literature. The 26 cases in this clinico-pathologic review were obtained by a computerised search of histological files at the Dept. of Pathology, UCHG. Twice as many of these were female, more often in their fourth decade of life. The condition has a propensity for the long digits, more often the volar aspect and roughly evenly distibuted over each of the joints. Resection of these neoplasia is tedious due to it's propensity to grow between local anatomical structures contributing to a high recurrence rate. Interestingly it rarely figures in guesses at pre-operative diagnosis although the second commonest cause of a benign superficial hand mass after ganglion. We suggest that if this condition is suspected, referral to a specialist hand surgeon in the first instance is wise.

hMLH1 and hMSH2 expression correlates with allelic imbalance on chromosome 3p in non-small cell lung carcinomas

DNA mismatch repair genes have been implicated in the pathogenesis and predisposition of certain malignancies through a mutator phenotype. In this study, we investigated, in 150 non-small cell lung carcinomas, the expression levels of hMLH1 and hMSH2 proteins in relation to loss of heterozygosity on chromosomes 3p and 2p, the mutational status of these genes' promoters and the hot spot exons. We have demonstrated that 88 of 150 (58.6%) tumor specimens had reduced expression levels of the hMLH1 protein, whereas 85 of 147 (57.8%) specimens had reduced expression levels of the hMSH2 protein. Reduced expression levels of both proteins were observed in 51 of 150 (34%) specimens. In adenocarcinomas, the reduction of hMSH2 expression was more frequently observed than that of hMLH1 (P<0.003), whereas in squamous cell carcinoma of the lung hMLH1 expression was more frequently reduced than hMSH2 (P<0.006). Reduced expression of hMLH1correlated with allelic imbalance on loci D3S1289 (P<0.0002) and D2S391 (P<0.05). It is of note that an inverse correlation was found between hMSH2 reduced expression and loss of heterozygosity at locus D3S1300 (P = 0.016). In addition, hMLH1 reduced expression was more frequently associated with heavy smokers, assessed by daily tobacco uptake (P = 0.018) and total smoking exposure (pack-years; P<0.05). In addition, a correlation between hMLH1 reduced expression and nodal metastasis in squamous cell carcinoma of the lung was observed (P = 0.015). No mutations were identified in the promoters or exons examined in these two genes. These findings indicate that hMLH1 and hMSH2 gene inactivation is a common event in the development of non-small cell lung carcinoma and allelic loss seems to be a major genetic event involved in hMLH1 silencing. In addition, we propose that a putative negative regulator of hMSH2 gene may be located at the locus 3p14.

Telomerase activity in non-small cell lung carcinomas correlates with smoking status

Human telomerase is a ribonucleoprotein DNA polymerase which maintains the telomeric region of human chromosomes and has been detected in all types of human cancer tested. We used the telomeric repeat amplification protocol (TRAP) assay to examine 71 non-small cell lung carcinomas (NSCLC) and their adjacent normal tissue. Telomerase activity was detected in 61 (86%) of the 71 NSCLC examined but not in any of the matched normal lung tissues. A significant correlation was found between the presence of telomerase activity and current smoking status at the time of diagnosis (p=0. 0076). In addition, a trend was found between telomerase activity and smoking exposure (p=0.06). Our findings demonstrate that telomerase activity is a common phenomenon in NSCLC cases but not in the normal lung. However, certain cases in former smokers may follow a telomerase independent pathway.

Direct interaction of EEA1 with Rab5b

The early endosomal autoantigen EEA1 is essential for early endosomal membrane fusion. It binds to endosomes via a C-terminal domain (EEA1-CT). To identify proteins interacting with EEA1-CT, we screened a human brain library in the yeast two-hybrid system. Fourteen clones reacted strongly with EEA1-CT. Sequencing of these clones revealed that they all contained the ORF of the small GTPase, Rab5b. Further two-hybrid analysis suggested that Rab5b also interacts with the N-terminus of EEA1 (EEA1-NT). The interaction of both EEA1-CT and EEA1-NT with Rab5b was confirmed biochemically, and was found to be GTP dependent. Confocal immunofluorescence microscopy indicated that EEA1 colocalizes with Rab5b on early endosomes. Although EEA1-CT and EEA1-NT interacted strongly with wild-type Rab5b in the two-hybrid system, we detected no interaction with wild-type Rab5a, even though GTPase-deficient mutants of both Rab5a and Rab5b interacted equally well with EEA1. This difference could not be explained by differences in intrinsic GTPase activities, as these were found to be very similar. Instead, we speculate that yeast may contain a GTPase-activating protein (GAP) activity that stimulates Rab5a but not Rab5b. In contrast, pig brain cytosol was found to contain a GAP activity that stimulates the GTPase activity of Rab5b in preference to that of Rab5a. These data provide evidence that EEA1 interacts with both Rab5a and Rab5b, and that the GTPase activities of the two proteins are differentially regulated in vivo.

The endosome fusion regulator early-endosomal autoantigen 1 (EEA1) is a dimer

EEA1, an early-endosomal protein originally identified as an autoantigen, is essential for endocytic membrane fusion. It interacts with early endosomes via binding to the membrane lipid phosphatidylinositol 3-phosphate (PtdIns3P) and the active form of the small GTPase Rab5. Most of the EEA1 sequence contains heptad repeats characteristic of proteins involved in coiled-coil protein-protein interactions. Here we have investigated the ability of EEA1 to self-interact. Crosslinking of cytosolic and recombinant EEA1 resulted in the disappearance of the 180-kDa monomer in SDS/PAGE and the strong appearance of a approximately 350-kDa crosslinked product. Glycerol gradient centrifugation experiments indicated that native EEA1 had the same hydrodynamic properties as the approximately 350-kDa crosslinked complex. Two-hybrid analysis indicated that N- and C-terminal fragments of EEA1 can interact with themselves, but not with each other, suggesting that EEA1 forms parallel coiled-coil dimers. The ability of the C-terminus of EEA1 to dimerize correlates with its ability to bind to Rab5 and early endosomes, whereas its binding to PtdIns3P is independent of dimerization. These data enable us to propose a model for the quaternary structure of EEA1.

EEA1 links PI(3)K function to Rab5 regulation of endosome fusion

GTPases and lipid kinases regulate membrane traffic along the endocytic pathway by mechanisms that are not completely understood. Fusion between early endosomes requires phosphatidylinositol-3-OH kinase (PI(3)K) activity as well as the small GTPase Rab5. Excess Rab5-GTP complex restores endosome fusion when PI(3)K is inhibited. Here we identify the early-endosomal autoantigen EEA1 which binds the PI(3)K product phosphatidylinositol-3-phosphate, as a new Rab5 effector that is required for endosome fusion. The association of EEA1 with the endosomal membrane requires Rab5-GTP and PI(3)K activity, and excess Rab5-GTP stabilizes the membrane association of EEA1 even when PI(3)K is inhibited. The identification of EEA1 as a direct Rab5 effector provides a molecular link between PI(3)K and Rab5, and its restricted distribution to early endosomes indicates that EEA1 may confer directionality to Rab5-dependent endocytic transport.

Elder abuse and one community's response

Elder abuse has come to be recognized as any act of both commission or omission that causes harm or loss to elderly people. This can include active or passive neglect, violence, sexual or emotional abuse, various kinds of theft, and deprivation of the person's human rights. Elder abuse has many causes. The Hastings and Prince Edward Council on Aging developed an Elder Abuse Community Response Protocol to help address this problem.

Inhibition of dihydropyrimidine dehydrogenase by 5-propynyluracil, a metabolite of the anti-varicella zoster virus agent netivudine

OBJECTIVE

To study the effects of the anti-herpetic drug netivudine on dihydropyrimidine dehydrogenase activity in elderly volunteers and to relate them to concentrations of netivudine and its metabolite 5-propynyluracil.

METHODS

Three groups of eight elderly volunteers received 400 or 800 mg netivudine or placebo once daily for 8 days. Plasma netivudine, 5-propynyluracil, and uracil, an indirect measure of dihydropyrimidine dehydrogenase activity, were assayed before the first dose and on days 2, 3, 5, 7 and 8. Full plasma profiles of netivudine and 5-propynyluracil were determined after the last dose.

RESULTS

Plasma uracil was unquantifiable in all subjects before the first dose and at all time points in the placebo group. In recipients of netivudine it reached a plateau between days 3 and 5, with mean values of 23.2 and 23.5 mumol/L on day 8 in the subjects who received 400 and 800 mg. Plasma netivudine concentrations were approximately dose proportional, but 5-propynyluracil concentrations were similar in both groups. The half-maximal rise in plasma uracil occurred after a cumulative 5-propynyluracil exposure of 120 mumol/L.hr; such exposures will be achieved even after doses as low as 50 to 100 mg daily.

CONCLUSIONS

Netivudine dosing produces complete inhibition of plasma dihydropyrimidine dehydrogenase. Coadministration with the antimetabolite 5-fluorouracil will require a substantial reduction in 5-fluorouracil dose to avoid toxicity but may also improve the therapeutic index of 5-fluorouracil.

Intravenous methylmethacrylate following cemented total hip arthroplasty

Both cemented and noncemented techniques have been used for total hip arthroplasty (THA). Each technique has advantages and disadvantages. Among the disadvantages of cemented THA are several perioperative complications, such as intraoperative cardiac or respiratory failure and hypotension, called "cement implantation syndrome," and extrusion of cement beyond the confines of the medullary canal. Cement extrusion can be the result of overreaming of the femoral canal and cortical perforation. This is a worrisome finding, as the risk of subsequent femoral fracture at the site of perforation is increased. Extruded cement, however, does not always indicate a problem. Extruded cement located within the femoral venous system, intravenous methylmethacrylate, for example, is not associated with long-term complications. While uncommon, it is important to differentiate this finding from the more serious cortical perforation. We report four examples of intravenous methylmethacrylate following THA and describe the imaging features that allow differentiation of this entity from the more significant finding of cortical perforation.

Twenty-five years of gallbladder surgery in a small rural hospital

BACKGROUND

During a 25-year period from 1967 to 1991, 1,058 gallbladder operations were done by one surgeon in solo practice in a rural 50-bed hospital.

METHODS

Open cholecystectomy was performed on all but 6 patients who had cholecystostomy. Operative cholangiography was liberally used, and 19% of all patients required common duct exploration. The majority of the patients were older than 65 years of age and 19% were older than 75 years of age.

RESULTS

The overall mortality was 0.7%. There were no deaths following cholecystectomy for chronic or acute nongangrenous cholecystitis, and all deaths occurred in patients older than 77 years of age. Most of the deaths occurred prior to 1978 and the last death was recorded in 1984.

CONCLUSIONS

Rural America has a comparatively large proportion of the elderly population of our nation. Most of these patients prefer to have their surgery performed locally, provided the results are comparable with those of large neighboring medical centers. The results from this current series from a small rural hospital compare favorably with the published results from large medical and academic centers.

A twenty-five year survey of a solo practice in rural surgical care

A large proportion (55 million) of our population lives in rural America, but there is a paucity of published material regarding the surgical care of this large group. This report is based on 13,793 patients treated in a 50-bed rural hospital by one surgeon during a period of 25 years from 1967 to 1991. Gynecologic, obstetric, orthopedic and urologic surgical treatment accounted for 41 percent of extensive operations, but endoscopic procedures have been increasing in recent years. Good surgical results can be obtained in the smaller rural hospital, but more emphasis on broader training for the would-be rural surgeon is necessary for this to continue.

Surgery for Crohn's disease

In the last 12 years, 72 operations have been performed on 41 patients for Crohn's disease in this hospital. The patients were predominantly young (mean age 32 yrs) and there were more females than males. 28 had ileocolic disease, three small intestinal, two pan-enteric and eight colonic. Pain (in 76%), diarrhoea (56%) and weight loss (66%) were the main presenting symptoms. Diarrhoea occurred in all those with colonic disease, but in only 43% of those with ileocolic disease. A right hemicolectomy (28 patients), colonic resection (12) and small intestinal resection (9) were the commonest operations. There were no deaths. 22 patients had a total of 26 complications after surgery, eight necessitating further surgery. The mean post-operative stay was 15 days, being lowest in those with ileocolic disease. 19 patients have required only one operation, with a mean follow-up of 5.3 years. These patients also had significantly less complications (p < 0.05). Half of the patients requiring surgery for Crohn's disease have done very well. The other half require many operations and have a substantial morbidity.

Chondro-osteodystrophy (Morquio Brailsford disease, mucopolysaccharidosis type IV A)

We report three cases of Morquio Brailsford Disease (Mucopolysaccharidosis Type IV A) in an Irish family. We are unaware of any previous similar report from this Country.

An evaluation of the usefulness of primary tumour expression of MCA and CA15-3 as prognostic indicators in breast carcinoma

CA15-3 antigen and mucin-like carcinoma associated antigen (MCA) show potential as clinically useful serum markers of breast carcinoma. Recently, immunohistochemical versions of these monoclonal antibodies have become available but few data are available as to their clinical usefulness. The aims of this study were (i) to assess CA15-3 and MCA expression by primary breast tumours and to correlate tumour immunoreactivity with tumour behaviour, and (ii) to investigate the relationship between immunohistological staining and oestrogen receptor (ER) status. Pathological material from 39 stage 1 (node free) breast carcinoma patients was assessed. The mean age was 51.3 (range 34-70) years, 19 were premenopausal and the mean duration of follow-up was 3.6 years (range 0.8-14 years). In each case two further sections were stained with antisera to the CA15-3 and MCA antigens. Staining of primary tumour was achieved in 38 cases. Low (less than 30% tumour cell staining) and intermediate (30-60% of cells staining) grade immunoreactivity with both monoclonals correlated with significantly shorter disease free intervals (P less than 0.05). Neither monoclonal can predict ER status. We conclude that the use of monoclonal antibodies to CA15-3 and MCA in staining primary breast carcinoma tumours and their axillary nodes may be a significant (P less than 0.05) prognostic indicator of future tumour behaviour and that this requires further evaluation.

A preliminary report on the usefulness of monoclonal antibodies to CA 15-3 and MCA in the detection of micrometastases in axillary lymph nodes draining primary breast carcinoma

The most critical factor affecting survival in patients with breast carcinoma is axillary nodal involvement. Monoclonal antibodies raised against specific human mammary tumour associated antigens may increase detection of micrometastases. This preliminary report examines two of these antigens; CA15-3 antigen and mucin-like carcinoma associated antigen (MCA) in the detection of such deposits. Specimens from 39 stage 1 (node negative) breast carcinoma patients were assessed. Two further 'negative' sections were stained with antisera to CA15-3 and MCA antigens. Micrometastases were detected in 5 patients and in each, MCA and CA15-3 identified the same micrometastases. 3 of these patients had disease progression compared with 3/34 of the remaining patients. The use of monoclonal antibodies to CA15-3 and MCA significantly (P less than 0.05) increases detection rates of micrometastases and this is associated with significantly worse disease-free survival rates (P less than 0.001).

Purification and partial amino acid sequence of human aconitase

Aconitase has been purified from membranes prepared from both the human gastric carcinoma cell line Okajima and from porcine gastric mucosa by chromatography on concanavalin A-Sepharose and carboxymethyl-Sepharose, and preparative polyacrylamide gel electrophoresis. Automated Edman degradation of the intact proteins yielded no N-terminal amino acid sequence due, presumably, to N-terminal blockage. Sequence analysis of tryptic peptides derived from S-carboxymethyl porcine and human aconitases established the positions of 95 and 64 amino acid residues, respectively. The amino acid sequence data for porcine aconitase was in perfect agreement with the previously reported cDNA-deduced amino acid sequence [Zheng et al. (1990) J Biol Chem 265:2814-2821]. Comparison of the human amino acid sequence data with the cDNA-deduced amino acid sequence of porcine aconitase indicated that these two proteins have 95% amino acid sequence identity within the sequenced region.

Colorectal cancer in a small rural hospital

Over a 20-year period, 168 cases of colorectal cancer were treated in a 50-bed rural hospital by 1 surgeon. The majority of the patients were older than 70 years of age. The stage of disease was comparatively advanced, with 71% of the patients having nodal or distant metastases, 19% with bowel obstruction, and 8% with perforation. The operability and resectability rates were 100% and 96%, respectively. The crude 5-year survival was 50% for the entire series. The 5-year survival after curative operations in which there was no gross residual tumor at the end of the operation was 63%, and the 5-year survival for resection of localized node-negative disease was 81%. The wound infection rate was 2%, and the operative mortality rate was 1% for combined elective and emergency operations. The results of treatment of colorectal cancer in small rural hospitals are infrequently reported, and this series may be compared with the published results from large teaching institutions.