BBI

"Ever since Charnley designed the first total hip replacements in the 1960s, there has been a succession of new materials and material surfaces introduced into clinical practice attempting to produce better performance. Attempts to improve performance with the introduction of composite materials, hard coatings and bioactive coatings have not really improved performance and, indeed, have often resulted in inferior performance." This somewhat pessimistic overview by professor David Williams of the department of clinical engineering at the University of Liverpool (Liverpool, UK) encapsulates the situation today.

There are more than 100 different hip implant systems on the market today, all of which have been rigorously tested before being used on patients. Although technology and materials used in prostheses have changed over the years, many implants still last only 10 to 15 years, with loosening of the implant the main cause of failure. The major cause is believed to be debris arising from implant wear (metal and polythene) and osteolysis or bone degradation. Investigations of wear debris are usually restricted to examination of tissue removed from the joint cavity at the time of revision arthroplasty.

Hitachi High-Technologies (Toyko) has developed a technique using scanning transmission electron microscopy (STEM) and quantitative energy dispersive X-ray (EDX) methods to detect and identify metallic particles from the patient's artificial joint in the patient's skin. In its UK trials, Hitachi used a PC-controlled H7500 thermionic TEM with a scanning attachment and an EDX analysis system. X-ray analysis showed a close relationship between the chemical composition of the stainless steel used in the prosthesis and of the particles present in the patient's skin, indicating that remedial surgery would be needed. STEM would appear to provide good imaging capabilities for this application and to provide independent confirmation of clinical investigations.

Roche moves ahead on multiple fronts

Roche (Basel, Switzerland) has signed a collaborative agreement with Stressgen (Victoria, British Columbia) for the development and subsequent marketing of the Canadian company's HspE7 drug for human papillomavirus (HPV) treatment. Roche has made a $5 million investment in Stressgen and may pay up to $200 million more for exclusive worldwide marketing rights for the product, which is in Phase II trials in the U.S.

Separately Roche reported that the European Medicines Evaluation Agency (EMEA; London) has approved its Pegasys and Tamiflu drugs. Pegasys (PEG-interferon Alpha-2a) is cleared for treatment of chronic hepatitis C either singly or in combination with synergistic ribavirin. Tamiflu oral flu treatment has been approved for juveniles and adults, but not yet for small children.

In Mannheim, Germany, Roche Diagnostics is to install new logistics software systems from Swisslog (Buchs, Switzerland) at a price of $10 million to $15 million. By 2005, Swisslog will have completed installation of an updated storage/distribution system for diagnostic products at the Mannheim logistics center.

Marijuana for MS and cancer pain

Marijuana-based drugs are expected to be legalized in Britain within the next two years for the management of multiple sclerosis (MS) and cancer pain. The UK government already has asked the National Institute of Clinical Excellence to assess whether cannabinoids should be available for prescription on the National Health Service to treat MS patients. A decision will depend on the findings of Phase III clinical trials being carried out by G W Pharmaceuticals (Salisbury, UK) and due for completion by the end of this year. The cannabinoids used in the trials are developed for use in sublingual and inhaler presentations, and the company said that Phase II trials have shown that patients can benefit from these medications.

The first Phase III clinical trial uses a sublingual spray and is a self-administered study with the patient controlling the amount used up to a maximum dose of 120 mg per 24 hours. Cancer pain is the second target area and a double-blind, placebo-controlled study is under way at more than 20 UK centers with more than 100 terminal cancer patients who are not responding to current therapy.

G W Pharmaceuticals also has started a Canadian Phase II trial of its sublingual spray for relieving the symptoms of MS, spinal cord injury and other forms of chronic pain. Last July, Canada became the first country to legalize marijuana for medicinal use. The company projects the first prescription medicines will be launched in early 2004 in Canada and Europe, with a U.S. launch targeted for 2006.

X-ray scattering in breast cancer screening

A two-year interval breast cancer screening for women aged 50 and over will reduce the risk of mortality from breast cancer by 35%, according to a recent report by the International Agency for Research on Cancer (IARC; Lyon, France). Although highly effective, X-ray mammography can only highlight abnormalities non-specifically, so that a further percutaneous or surgical breast biopsy is then needed. Furthermore, statistics show that less than 20% of the 5% to 10% of women recalled following the initial screening have cancer.

Histological and cytological examination of the core biopsy specimen is lengthy and expensive. The Central Laboratory for Research on Cancer (CLRC; Warrington, UK) has developed the use of small-angle X-ray scattering (SAXS) to detect the changes in collagen scaffold structure in biopsies that follow from invasive tumor expansion in breast carcinomas.

Dr. A.G. Buckley and his team at CLRC have discovered that interpretable diffraction data can differentiate between normal, benign and malignant breast tissue. Current pathology techniques take at least 24 hours for results to be processed. The use of scattered X-rays beamed at tissues and automated procedures could, in principle, provide immediate results, he said.

The long-term aim of the SAXS research is to create a diagnostic technique for breast cancer which reduces the need for biopsies. "In the short term, it is likely that the SAXS method should be carried out in parallel with normal pathological diagnosis, to build up the sample numbers and fully test the validity of the technique," Buckley said. "There is also scope for in vivo applications, which would both eliminate the need for breast tissue removal and greatly reduce the analysis time compared to that of current methods."

Ultrasound in breast cancer screening

B-K Medical (Copenhagen, Denmark) has developed the Type 8811 transducer with multiple scanning frequencies of up to 12MHz specially for breast scanning and for the scanning of superficial muscular and skeletal structures. This new transducer is said to have a wide image field, high resolution and good penetration for imaging of soft tissues.

Professor Pierre Kerbrat of the medical oncology clinic at the Centre Eug ne Marquis (Rennes, France), reviewing recently at the annual congress of the French Society of Senology and Mammary Pathology breast cancer of women over 70, said that echography should be used whenever diagnosis by mammography is unclear, and that with suspect opacities a high-frequency probe should be used. At the same meeting, Dr. Marc Espie of the Hopital St. Louis (Paris) said that since the average age for the appearance of breast cancer is around 60 and since at that time the average life expectancy is now around 25 years, an increased attention to older women and cancer screening is becoming of greater importance.

The Kretz Ultrasound (Zipf, Austria) division of GE Medical Systems (Waukesha, Wisconsin) has added to its 4-D ultrasound scanner, the Voluson 730, two additional imaging functionalities, Volume Contrast Imaging (VCI) and Compound Resolution Imaging (CRI). In particular, the VCI function uses 4-D transducers to automatically scan multiple adjacent slices with improved contrast resolution to facilitate the diagnosis of smaller lesions difficult to differentiate from normal tissue.

Targeted drug delivery via red blood cells

A new system of controlled drug delivery using red blood cells has been developed by Gendel (Coleraine, Northern Ireland). The cells are "loaded" with drugs that can be released as required at specific sites in the human body using focussed ultrasound. This technique may have a wide range of applications, particularly in administrating powerful toxic drugs like those used in chemotherapy, where a precisely targeted effect could be much more effective. Conventional drug delivery often introduces the product to the entire blood circulatory system, increasing risks of side effects.

This new system enables the clinician to control the site where the drug will be released in the patient's body, and has successfully completed animal trials. The next stage will be to start clinical trials on humans. "What it is really exciting is that our system also can be used to deliver novel gene-based drugs that are known to be effective in treating certain diseases but which cannot be used routinely because of the severe side effects they cause when administered conventionally," said Dr. Les Russell, CEO at Gendel.

Lightweight U/S scanners for emergency use

Metrax (Rottweil, Germany) is launching its Primedic HandyScan emergency scanner weighing less than 2 kilos in Europe this month. The company says that its high-resolution, five-inch TFT display ensures good readability. A rechargeable Primedic AkuPak provides up to three hours of operation from each charge.

Even lighter at 800 grams is the 50S Tringa from Pie Medical (Maastricht, the Netherlands) for use with 3.5/5.0 or 5.0/7.5 MHz dual frequency mechanical probes. The image quality, battery operation and small size make it particularly suitable for diagnosing abdominal trauma in the emergency room, ambulance or accident site. The rechargeable battery provides up to four hours of use. For added convenience, the Tringa scanner can be mounted on a special arm-mounting glove on the forearm.

Liver cirrhosis not always irreversible

Physicians have long believed that cirrhosis of the liver leads to the inexorable destruction of liver cells and eventual death from hepatic insufficiency, hemorrhage or liver cancer. An international team led by Professor Thierry Poynard at the Hopital Pite -Salpetri re (Paris) has treated more than 3,000 cirrhotic patients infected with hepatitis C and treated either with ribavirin, pegylated interferon (Pegasys) from Roche (Basel, Switzerland) or a mixture of the two molecules. Results have shown that fibrous growths and liver lesions, which appear at the stage preceding cirrhosis, have regressed and that the best results (73% of positive results) have been produced with a mixture of ribavirin and Roche's Pegasys. These results will encourage the 150,000 to 200,000 hepatitis C-positive patients in France to maintain their therapy regimes that often are abandoned because of unpleasant side effects.

These improvements also have to be verified in cases of cirrhosis due to hepatitis B or of autoimmune origin, but for liver cirrhosis of alcoholic origin, the most common in France, the improvements observed seem to be remarkable.

Telemedicine service uses GPS

The telemedicine management system from Vitaphone (Mannheim, Germany) is much more than a regular GSM mobile telephone. The Herz Handy is a technologically advanced telemedical instrument which can also record, store and transmit an ECG for immediate analysis. Measurement data of blood pressure and blood glucose levels also can be transmitted for monitoring and diagnostic purposes.

In an emergency situation, expert medical advice and support can be obtained via a single push button, and the patient can be located to within 15 meters by GPS (global positioning satellite). The two-way communication between healthcare professional and patient can be made as with any regular mobile phone. The back of the phone is equipped with four electrodes. When required, the patient places the back of the phone against his chest and presses a button. Up to three episodes of 40 seconds worth of ECG can be recorded and transmitted.

In Germany, the GPS positioning system is linked to a map of the country. At the diagnostic center, the support team has a visual image of the street map and a zoom function helps to locate the patient. A GIS (geographic information system) with maps of other European countries is currently being developed.

Amersham grows diagnostic imaging unit

Amersham Health, the diagnostic imaging business of Amersham plc (London), said its secondary production facility in Cork, Ireland, received FDA approval for manufacturing and packaging its Omnipaque, Omniscan and Visipaque diagnostic products. The approval allows Amersham Health to ship the products to the U.S. market.

Amersham recently made a substantial investment to expand Amersham Health's bulk chemical production site in Lindesnes, Norway, nine months after its opening.

No Comments