posted 12-25-2005 08:26 PM            

This is sort of off our topic, but interesting. Should we write requesting that they put a clear maker's mark on the catheter?

quote:

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Old medical cure, silver, is new tool to fight infection

By Barnaby Feder
The New York Times
Silver, one of humankind's first weapons against bacteria, is receiving new respect for its antiseptic powers, thanks to the growing ability of researchers to tinker with its molecular structure.

Doctors used silver to fight infections at least as far back as the days of ancient Greece and Egypt. Their knowledge was absorbed by Rome, where historians such as Pliny the Elder reported that silver plasters caused wounds to close rapidly.

In 1884, a German doctor named C.S.F. Crede demonstrated that a few drops of silver nitrate into the eyes of babies born to women with venereal disease virtually eliminated the risk of blindness among such infants.

But silver's time-tested if poorly understood versatility as a disinfectant was overshadowed in the latter half of the 20th century by the rise of antibiotics.

Now, with more and more bacteria developing resistance to antibiotic drugs, some researchers and health-care entrepreneurs have returned to silver for another look. This time around, they are armed with nanotechnology, a fast-developing collection of products and skills that help researchers deploy silver compounds in ways that maximize the availability of silver ions -- the element's most potent form. Scientists also now have a better understanding of the weaknesses of their microbial adversaries.

One of the urgent goals is to prevent bacterial infections that each year strike 2 million hospital patients and kill 90,000, according to the Centers for Disease Control and Prevention. Such infections usually are treated with large doses of antibiotics and sometimes with repeat surgeries. They cost the health-care system roughly $4.5 billion annually, and the challenge is growing with the spread of drug-resistant microbes.

The latest advance for silver therapy comes from AcryMed, a company in Portland, Ore., that has invented a process to deposit silver particles averaging about 10 nanometers -- less than a thousandth the diameter of a human hair -- on medical devices. AcryMed's first customer, I-Flow, makes a silver-coated catheter that pumps painkillers into wounds from surgery.

I-Flow got federal regulatory clearance on Dec. 2 to sell the devices and has begun shipping them to customers. The nanoscale particles have so much surface area to react with the microbes, in relation to their volume, that small concentrations are effective antiseptics.

"The equivalent of a teaspoon of silver in a seven-lane Olympic-size swimming pool is enough to do the job," said Bruce Gibbons, the microbiologist who is AcryMed's founder and chief executive.

AcryMed hopes to reach agreements with catheter companies larger than I-Flow, including the makers of urinary catheters, the most common breeding ground for hospital infections. Eventually, nanoscale silver also could make its way onto permanently implanted devices such as silicone breast implants, artificial hips and knees, and pacemakers.

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posted 12-26-2005 04:55 PM            

I have had a boxed set of 4 graduated silver urethral catheters (j shape 9" long) from late 19th c. Germany. They had the manufacturers marks, and tested 80% silver. They also tarnished.

Really neat looking and probably silver for just that reason... Antiseptic.

Naturally, one shudders at the thought of
having any of them used on ones self. Yikes!

So silver was considered a "clean" metal at least that far back.

And the Germans were leaders in Chemistry at that time. I would think that they were also progressive in the medical field.

posted 05-25-2006 11:06 PM            

The oligodynamic effect (greek oligos = few, dynamis = force ) was discovered in 1893 by the Swiss KW Nägeli as a toxic effect of metal-ions on living cells, algae, moulds, spores, fungi, virus, prokaryotic and eukaryotic microorganisms, even in relatively low concentrations. This antimicrobial effect is shown by ions of: mercury, silver, copper, iron, lead, zinc, bismuth, gold, aluminium and other metals.

Especially heavy metals show this effect. The exact mechanism of action is still unknown. Data from silver suggest that these ions denature proteins (enzymes) of the target cell or organism by binding to reactive groups resulting in their precipitation and inactivation. Silver inactivates enzymes by reacting with the sulfhydryl groups to form silver sulfides. Silver also reacts with the amino-, carboxyl-, phosphate-, and imidazole-groups and diminish the activities of lactate dehydrogenase and glutathione peroxidase. Bacteria (gram+ and gram-) are in general affected by the oligodynamic effect, but they can develop a heavy-metal resistance, or in the case of silver a silver-resistance. Virus in general are not very sensitive. The toxic effect is fully developed often only after a long time (many hours).

Applications of the oligodynamic effect: Silver is capable of rendering stored drinking water potable for a long period of time (several months). Water tanks on ships and airplanes are often "silvered". Silver or silver compounds are used externally in wound and burns treatment.

posted 05-25-2006 11:11 PM            

Extremely small amounts of silver have significant effects on bacteria, a phenomenon referred to as oligodynamic activity. Silver has the most powerful oligodynamic activity of the metals, followed closely by copper.5 These differential oligodynamic effects are shown in the figure. The oligodynamic activity of metals provides a valuable alternative to the use of systemic antibiotics and/or disinfectants in certain situations.6

The most convincing application of the oligodynamic activity of silver is the routine use of indwelling Foley catheters coated with a silver alloy hydrogel. This silver alloy leaches silver ions into the immediate environment of the catheter, thereby reducing bacterial colonization, preventing biofilm formation, and ultimately reducing rates of urinary tract infection.7 This reduction resulted in a significant cost saving over the range of cost estimates modeled.7 In response to the clinical and financial success of silver-coated Foley catheters, investigators have explored other silver-coated devices, including central venous catheters, endotracheal tubes, bandages, sutures, and tubing.

posted 05-26-2006 01:41 PM            

With the advent of antibiotics, physicians have forgotten about the old remedies. Argyrol nosedrops were widely used for nasal and sinus infectrions when I was young - a few years ago I found it still available in a drug store. An EMT friend of mine kept his infection-prone comatose father-in-law alive and free of antibiotic-resistant infections for several years with adnministrations of a home prepared colloidal silver solution, to the consternation of his physicians, who had never heard of the treatment.

This is the one of the best arguments that the latter day Soviet PC Lamarckian disciple, Lysenko, was wrong that acquired characteristics could be inherited - if we retained a racial memory, each generation would not have to learn everything over again, and nothing would be forgotten!