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N Waterhouse

Publications and source records attributed to N Waterhouse.

At least 37 records · Page 2Linked to original sources
PubMed2000

A 5-year review of 71 consecutive anterior skull base tumours.

Techniques used in craniofacial surgery have found extensive application in the management of skull base tumours. The improved exposure gained via osteotomies for facial disassembly has facilitated the en-bloc resection of tumours with clear surgical margins, and the advent of vascularised seals has significantly reduced the risk of meningeal contamination. We present our experience with the extirpation and reconstruction of 71 benign and malignant tumours of the anterior skull base over a 5-year period. Survival and functional outcome data are presented, with an emphasis on the wide range of pathologies and primary treatment strategies seen at presentation. Criteria used in flap selection and the role of prosthetics are discussed. Observations are offered on salvage surgery, demonstrating that excellent palliation can be achieved, even in cases with massive recurrent disease.

Adolescent↗
PubMed1999

An investigation into the mechanism of orbital blowout fractures.

For over a century, since the first description of an orbital 'blowout' fracture, there has been debate and confusion regarding the mechanism of production of these fractures. An orbital blowout fracture throughout this paper refers to fractures exhibiting displacement of the orbital floor or walls without an associated fracture of the orbital rim. These are the so called 'pure' blowout fractures as described by Converse. Involvement of the orbit in a variety of facial fracture patterns is easily explained on anatomical grounds. The orbital blowout fracture and symptom complex are readily recognisable but explanation of the mechanisms involved is not easily apparent. Experimental and clinical studies have generally aimed to support one or other of two proposed mechanisms. The 'buckling' theory contends that the fracture is produced as a result of transmission of force to the orbital floor from a blow to the orbital rim (Fig. 1). The 'hydraulic' theory differs in suggesting the force is transmitted to the floor via a direct blow to the globe (Fig. 2). Review of the literature reveals that there are major flaws in the design and execution of previous experimental methods. Most studies have incorporated some or all of the following limitations: low numbers, unquantified forces, non human models, incomplete soft tissues, poor simulation of in vivo conditions and a failure to isolate the position of the striking force. No study has ever provided a direct comparison between the two mechanisms under identical conditions. We present the results of such a study undertaken on 47 fresh cadaver orbits using the same quantifiable force and under the same experimental conditions. The results demonstrate that the efforts to establish either mechanism as the primary aetiology have been misplaced. Both mechanisms produce orbital blowout fractures. The fractures produced, however, are fundamentally different in their size, position and likely clinical significance.

Aged↗
PubMed1998

Caspase-mediated cleavage of the ubiquitin-protein ligase Nedd4 during apoptosis.

The onset of apoptosis is coupled to the proteolytic activation of a family of cysteine proteases, termed caspases. These proteases cleave their target proteins after an aspartate residue. Following caspase activation during apoptosis, a number of specific proteins have been shown to be cleaved. Here we show that Nedd4, a ubiquitin-protein ligase containing multiple WW domains and a calcium/lipid-binding domain, is also cleaved during apoptosis induced by a variety of stimuli including Fas-ligation, gamma-radiation, tumor necrosis factor-alpha, C-8 ceramide, and etoposide treatment. Extracts from apoptotic cells also generated cleavage patterns similar to that seen in vivo, and this cleavage was inhibited by an inhibitor of caspase-3-like proteases. In vitro, Nedd4 was cleaved by a number of caspases, including caspase-1, -3, -6, and -7. By site-directed mutagenesis, one of the in vitro caspase cleavage sites in mouse Nedd4 was mapped to a DQPD237 downward arrow sequence, which is conserved between mouse, rat, and human proteins. This is the first report demonstrating that an enzyme of the ubiquitin pathway is cleaved by caspases during apoptosis.

Animals↗
PubMed1996

Heteronuclear ribonucleoproteins C1 and C2, components of the spliceosome, are specific targets of interleukin 1beta-converting enzyme-like proteases in apoptosis.

Apoptosis induced by a variety of agents results in the proteolytic cleavage of a number of cellular substrates by enzymes related to interleukin 1beta-converting enzyme (ICE). A small number of substrates for these enzymes have been identified to date, including enzymes involved in DNA repair processes: poly(ADP-ribose) polymerase and DNA-dependent protein kinase. We describe here for the first time the specific cleavage of the heteronuclear ribonucleoproteins (hnRNPs) C1 and C2 in apoptotic cells induced to undergo apoptosis by a variety of stimuli, including ionizing radiation, etoposide, and ceramide. No cleavage was observed in cells that are resistant to apoptosis induced by ionizing radiation. Protease inhibitor data implicate the involvement of an ICE-like protease in the cleavage of hnRNP C. Using recombinant ICE-like proteases and purified hnRNP C proteins in vitro, we show that the C proteins are cleaved by Mch3alpha and CPP32 and, to a lesser extent, by Mch2alpha, but not by ICE, Nedd2, Tx, or the cytotoxic T-cell protease granzyme B. The results described here demonstrate that the hnRNP C proteins, abundant nuclear proteins thought to be involved in RNA splicing, belong to a critical set of protein substrates that are cleaved by ICE-like proteases during apoptosis.

Apoptosis↗
PubMed1995

The transpelvic rectus abdominis flap: its use in the reconstruction of extensive perineal defects.

We present our experience of rectus abdominis flaps tunnelled transpelvically in 12 patients (mean age 48.4 years, range 19-72 years) with a diverse range of surgical pathologies, the largest reported series to date. Satisfactory obturation of the pelvic cavity and control of radionecrotic tissue sepsis was achieved. Average duration of hospital stay was 17.6 days with a mean follow-up of 18.7 months. The rectus abdominis flap provides a significant volume of well-vascularised tissue, ideally suited for reconstruction of extensive perineal defects after tumour ablative surgery. When tunnelled transpelvically, the flap is unique in its ability to obturate the pelvic inlet, eliminating the distressing complication of perineal bowel herniation and allowing for perineal radiotherapy.

Adult↗
PubMed1990

Vastus lateralis myocutaneous flap for reconstruction of defects around the groin and pelvis.

We present our experience using the vastus lateralis myocutaneous flap for the repair of defects around the groin and pelvis. It is a relatively new technique, with many advantages over other flaps used in this area, though it has limitations. The history, anatomy and surgical technique of raising the flap are described and clinical cases are discussed. The importance of patient selection is highlighted.

Adult↗
PubMed1990

The versatility of the lateral arm flap.

We present our experience of a personal series of 17 lateral arm flaps in a variety of forms and clinical situations. The anatomy of the flap is briefly reviewed in relation to the operative findings, and the advantages and disadvantages of the flap are discussed.

Adult↗
PubMed1988

The innervated trapezius flap in facial paralysis.

The use of an innervated lateral trapezius flap to allow movement of the paralysed face is described. Five cases are presented, all of whom achieved some facial movement postoperatively. The place of this technique in the armamentarium of procedures for facial reanimation is discussed.

Accessory Nerve↗
PubMed1988

The blood supply of the osteocutaneous free fibular graft.

The use of an osteocutaneous free fibular graft as a single-stage reconstructive procedure for composite tissue loss is increasingly common. Detailed anatomical study in cadavers of the blood supply to the graft demonstrates cutaneous arteries arising from the peroneal artery and then passing along the posterior surface of the lateral intermuscular septum. These vessels pierce the crural fascia and then ramify to supply the skin. Knowledge of the vascular anatomy of the skin overlying the fibula is essential to the success of the graft.

Aged↗
PubMed1987

The lateral arm flap: an anatomic study.

The anatomy of the lateral arm flap is further elucidated, and the surgical techniques involved in raising the flap are described in detail. The data are derived from studies in 25 cadavers and five clinical cases. The relative merits of this versatile free flap are discussed. Three clinical cases are cited for illustration.

Amputation, Traumatic↗
PubMed1987

Reconstruction of the pelvis using a composite island flap salvaged from the remaining leg.

The case of a patient who sustained horrific injuries resulting in the loss of his left leg and hemipelvis and damage to the right sacroiliac joint and leg is discussed. The remaining leg was paralyzed as a result of damage to the sacral plexus. As a salvage procedure, a right above-knee amputation was performed, preserving a large composite flap from the distal part of the limb. This flap, consisting of most of the skin and soft tissue of the lower leg, contained within it a 10 cm segment of tibia and fibula. By islanding the flap on a pedicle composed of the femoral vessels, saphenous, and sciatic nerves, it was possible to mobilize it sufficiently far proximally to reconstruct the bone and soft-tissue defect of the contralateral hemipelvis. Seven years after this appalling injury, the patient has achieved a remarkable psychological and functional rehabilitation. He is independent and is successfully pursuing a professional career. This case report is a dramatic illustration of what can be achieved in reconstruction following trauma using salvage techniques.

Adolescent↗
PubMed1987

Urinary retention after total hip replacement. A prospective study.

We report a prospective study of the factors associated with acute urinary retention after total hip replacement in 103 consecutive male patients. Eleven patients (10.7%) developed retention after operation. Of the factors investigated before operation three had predictive value: inability to pass urine into a bottle whilst lying in bed, urinary peak-flow rates indicative of obstruction, and a history of previous bladder outflow problems. This study suggests that patients showing one or more of these factors should be assessed and if necessary treated by a urologist before arthroplasty, so as to avoid the need for catheterisation, and the consequent risk of deep infection.

Adult↗