Chemistry: molecular biology and microbiology – Measuring or testing process involving enzymes or... – Involving antigen-antibody binding – specific binding protein...
Reexamination Certificate
2001-03-15
2003-07-22
Nguyen, Bao-Thuy L. (Department: 1641)
Chemistry: molecular biology and microbiology
Measuring or testing process involving enzymes or...
Involving antigen-antibody binding, specific binding protein...
C435S007100, C435S007940, C435S288100, C435S962000, C435S970000, C435S975000, C436S514000, C436S518000, C436S528000, C436S808000, C436S810000, C436S825000, C422S051000, C422S051000, C422S067000, C422S105000
Reexamination Certificate
active
06596502
ABSTRACT:
FIELD OF THE INVENTION
The present invention is generally in the field of kits, and more specifically concerns kits for domestic use for the self-detection of various physiological conditions.
BACKGROUND OF THE INVENTION
Parasitology is one of the very few remaining tests in clinical medicine which relies on the visual recognition skills of a trained technologist. It involves, in fact, two visual recognition skills. One is the identification of particular morphological features characterizing an organism as belonging to a certain species, and being able to recognize it by name. The other, and much more difficult skill is the ability to recognize old, young, damaged, deformed, or even partially degraded organisms—perhaps occurring only at the edge of a microscopic field—and know that it is a particular parasite. Such being the case, a negative result for a parasitology test only indicates that no parasite was found, and can not be conclusive that a patient is negative for parasites.
The problem of parasite identification for the laboratory is additionally difficult due to the fact that parasite frequency can vary widely, and may not have any relation to severity of disease. Parasite reports are typically graded from rare to many. It is possible, in fact for a person to have a serious parsitological infestation, but to have only infrequent, periodic, or occasional shedding of parasitic organisms. In the case of low frequency of occurrence in the stool, organisms may or may not be present in the particular specimens being examined under the microscope.
The problem of parasite identification for the laboratory is additionally complicated due to the fact that transportation of specimens from the patient to the clinical laboratory is usually delayed and during this delay the parasites may die or be degraded, thus decreasing even further the chances of identification.
Thus, the situation exists where many clinical laboratories fail to detect parasites which, in fact, are present in patient specimens. Clinical laboratory surveys in the United States frequently report a positive prevalence of parasites of 1-3%, and rarely over 5%. Yet various published studies by specialty, or university based laboratories, show that the true positive rate can be as much as 4- or 5-fold higher than
In response to this situation, parasitologists have developed methods of concentrating parasites and staining them with contrasting colors so as to improve recognition ability. Thus, a concentration procedure followed by a trichrome staining procedure has been developed as the standard method of properly performed parasitology analysis. This method, however, is laborious and time consuming. It is, therefore, not done by all labs all the time, in spite of recommendations to that effect. Even when performed, it does not address or solve all the problems mentioned above.
In recognition of this situation diagnostic device companies have developed tests for particular parasites. Notably tests for
giardia lamblia, entamoeba histolytica,
and cryptosporidium sp. are commercially available. These take two forms, either being an ELISA test (i.e.: Alexon-Trend, Inc), or fluorescent tagging of the organisms followed by direct microscopic examination (ie:Meridian Diagnostics, Inc). The problem with these tests, however, is that they attempt to identify a particular organism, and not all organisms or the overall presence of parasites. Furthermore these tests require laboratory procedures and the intervention of skilled technicians.
The nature of parasite examination, and prevalence in the world, divides the parasites into two large groups: protozoans, and worms and eggs. Protozoans are single celled organisms, and are the most common parasites found in developed countries of the world. They are, also, as a rule, smaller than worms and eggs, and are examined on high power (40×) of the microscope. Worms and eggs on the other hand are multi-cellular organisms, and are very common in underdeveloped countries of the world. They are, as a rule, larger than protozoans and are examined at low power (10×) of the microscope.
What is needed by medical science and the market, therefore, are two tests—one for protozoans, and one for worms and eggs. It would be sufficient to identify those specimens which are positive and differentiate them from those that are negative. It would be even more advantageous, however, to identify specifically those particular parasites which are present in each specimen.
SUMMARY OF THE INVENTION
The present invention is based on the realization that there is a need for a non-invasive, fast, accurate, and user friendly method for diagnosing the presence of parasites, both protozoan and non-protozoan, in stool. The need is especially evident in view of the high false negative diagnosis of many standard laboratory tests and the high level of skill required to identify, under a microscope the instance and type of the parasite. The present invention is further based on the realization that detection of the presence of parasites in stool is of the type of detections which may be carried out at home, or at a doctor's clinic, without involving an analyzing laboratory, since the patient (or doctor) can easily understand a positive result of such a test, and proceeds to treat the parasite, with consultation with a doctor by the administration of anti-parasitic compounds. Furthermore, there is a great advantage of detecting parasites in fresh stool instead of waiting until the parasite reaches the laboratory resulting many times in non-viable or degraded parasites.
The present invention is further based on the realization that it is possible to develop a kit for such a non-invasive, reliable and home (and practitioner's office) testing.
Thus the present invention by its first aspect concerns a home kit for detection of the presence of a parasite in a stool sample, the kit comprising:
(a) a vessel for mixing a stool specimen with a diluting liquid to produce a diluted stool specimen;
(b) a housing holding within a substrate, the substrate comprising at least one zone containing at least one anti-parasitic antibody, the housing further comprising reagents for producing a visually detected reaction when an antibody-parasite antigen complex is formed, the housing further comprising at least one conveying means for receiving diluted stool specimen and transferring it to the anti-parasitic antibody containing zone of the substrate;
(c) the housing further comprises an indicator for showing the presence of the visually detected reaction.
Preferably the anti-parasitic antibodies are polyclonal, in order to ensure that they interact effectively with all varieties of a specific specie of parasites. The antibodies may be prepared by any method known in the art, for example, by immunizing an animal with a suitable parasite or an immunogenic portion thereof, and then collecting the antibodies produced. Where the antibody is monoclonal, it should be against a conserved epitope of the specific parasite spears which is common to any many varieties of the parasite species as possible.
The antibodies may be against an immunogenic epitope present on the external surface of the protozoa or non-protozoa parasite, or against an immunogenic epitope of a compound shed of secreted from the parasites, such as parasite eggs.
The term “home kit” in the context of the present invention refers to the fact that the kit of the invention, and the detection reaction produced therein, does not necessitate any complicated machinery for collecting the specimen and preparing it, for positioning the specimen in the kit, and for reading and interpreting the results—and typically, the results can be viewed by the naked eye, or by simple optical reactor. The term does not necessarily mean that the kit is only operable at home, since due to its non-invasiveness and it is easy, user friendly manner of operation, it can be also used in a practitioner's office or even in hospitals without involving an analytical laboratory.
The kit
Browdy and Neimark , P.L.L.C.
Lee Research Laboratory, Inc.
Nguyen Bao-Thuy L.
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