WEBVTT 00:00:10.266 --> 00:00:14.799 [A woman walks up to a medical clinic.] 00:00:14.800 --> 00:00:19.200 [Narrator:] Today in the United States, one pregnancy in five fails to produce a living, 00:00:19.200 --> 00:00:25.900 healthy child; 126,000 mentally retarded children are born each year. 00:00:25.900 --> 00:00:33.600 Millions more suffer from various defects. 00:00:33.600 --> 00:00:42.566 Infections are among the preventable causes of abortions, stillbirths, and damaged infants. 00:00:42.566 --> 00:00:50.932 [A Research Approach: Infections and Birth Defects] 00:00:50.933 --> 00:00:56.833 [Narrator:] Research on the relationship between infections and birth defects is the major assignment of the section 00:00:56.833 --> 00:01:05.499 on infectious diseases, perinatal research branch, National Institute of Neurological Diseases and Blindness. 00:01:05.500 --> 00:01:11.566 The section works directly with other institutes, including Allergy and Infectious Diseases, 00:01:11.566 --> 00:01:22.132 and Child Health and Human Development, all within the federal government's Department of Health, Education, and Welfare. 00:01:22.133 --> 00:01:26.166 A number of infections can cause abnormal pregnancy outcomes. 00:01:26.166 --> 00:01:32.266 These include rubella, cytomegalic inclusion disease, rubeola, mumps, 00:01:32.266 --> 00:01:37.666 herpes simplex disease, western equine encephalitis, chicken pox, 00:01:37.666 --> 00:01:49.066 smallpox, gloxinia, polio, hepatitis, Coxsackie B virus, influenza, syphilis, tuberculosis, toxoplasmosis. 00:01:49.066 --> 00:01:54.799 The Perinatal Research Branch serves as research headquarters for 14 medical centers 00:01:54.800 --> 00:02:01.300 throughout the nation which participate with the Neurology Institute in the Collaborative Perinatal Research Project, 00:02:01.300 --> 00:02:06.500 a study of birth defect causes. 00:02:06.500 --> 00:02:14.066 This young woman, Mrs. Owens, represents one of 50,000 mothers who, with their infants, 00:02:14.066 --> 00:02:16.966 are taking part in this collaborative project. 00:02:16.966 --> 00:02:28.699 In addition to infections, genetic, obstetrical, and other perinatal factors will be considered in the study. 00:02:28.700 --> 00:02:34.933 Mrs. Owens will give blood at intervals to aid in the study of infections of pregnancy. 00:02:34.933 --> 00:02:41.399 Her child will contribute smaller amounts of sera at specified intervals. 00:02:41.400 --> 00:02:54.000 Each time Mrs. Owens' blood is taken, 40 ml is collected in two 20 ml vacutainer tubes. 00:02:54.000 --> 00:03:02.133 The specimens provided by Mrs. Owens are allowed to clot at room temperature. 00:03:02.133 --> 00:03:08.166 Then, placed in a refrigerator overnight to provide maximal retraction of the clot. 00:03:08.166 --> 00:03:13.466 This procedure allows the technicians to obtain a maximal yield of serum, 00:03:13.466 --> 00:03:22.666 that fraction of the blood containing the reactive particles to be studied. 00:03:22.666 --> 00:03:34.966 Tubes are ringed to loosen the clot prior to separating clot from serum in the centrifuge. 00:03:34.966 --> 00:03:49.866 Specimens are spun for 15 minutes at 2,000 revolutions per minute in a refrigerated centrifuge. 00:03:49.866 --> 00:04:04.032 [Samples are removed from the centrifuge.] 00:04:04.033 --> 00:04:21.599 Next, a technician employs a 20 or 25 ml pipette to pull the serum from the two tubes into a single container. 00:04:21.600 --> 00:04:55.733 [The technician examines the solution inside the long glass tube.] 00:04:55.733 --> 00:05:01.266 The serum is then transferred to four 1 gram vials. 00:05:01.266 --> 00:05:07.966 The contents of each vial can be used several times for different tests. 00:05:07.966 --> 00:05:12.699 The blue line indicates a critical 3 ml mark. 00:05:12.700 --> 00:05:26.033 If filled beyond this mark, the vial might break during freezing or thawing. 00:05:26.033 --> 00:05:40.599 Packets of sera are stored at minus 15 to minus 20 degrees centigrade. 00:05:40.600 --> 00:06:00.733 Cartons are filled with the packets. 00:06:00.733 --> 00:06:41.466 Fifty pounds of dry ice will keep the specimens frozen for four days, even at summer temperatures. 00:06:41.466 --> 00:06:59.866 Shipments are made to the Serum Center, Section on Infectious Disease, Bethesda, Maryland. 00:06:59.866 --> 00:07:16.166 The specimens are logged in by coding clerks at the Serum Center. 00:07:16.166 --> 00:07:21.732 Each specimen is checked for quantity and quality. 00:07:21.733 --> 00:07:36.933 Good quality frozen serum is straw-colored. 00:07:36.933 --> 00:07:47.266 Records are prepared. 00:07:47.266 --> 00:07:53.899 The packets are placed in aluminum trays, then they are stored at minus 20 degrees Centigrade 00:07:53.900 --> 00:07:56.966 in one of the four Serum Center freezers. 00:07:56.966 --> 00:08:07.499 More than one million specimens are available for testing. 00:08:07.500 --> 00:08:13.700 Priorities for study are determined at staff conferences. 00:08:13.700 --> 00:08:24.066 For example, during the German measles epidemics, rubella virus was investigated extensively. 00:08:24.066 --> 00:08:34.732 As a result of the staff conference, statistical personnel using the records in the Serum Center, select the sera of patients to be tested. 00:08:34.733 --> 00:08:50.833 A tally sheet prepared after the selection enabled personnel to locate the sera. 00:08:50.833 --> 00:08:58.666 The vials to be tested are taken from their trays, placed in polystyrene blocks and transported to the laboratory. 00:08:58.666 --> 00:09:04.832 These lightweight polystyrene blocks, tailored to the needs of the section, 00:09:04.833 --> 00:09:12.399 each hold up to 200 vials. 00:09:12.400 --> 00:09:17.400 A micro-technique has been perfected to simplify, extend, 00:09:17.400 --> 00:09:25.133 and speed up the testing. It employs smaller tools, smaller test amounts, yet gives reliable results. 00:09:25.133 --> 00:09:31.266 With countless blood tests to perform, ordinary procedures would not be feasible. 00:09:31.266 --> 00:09:39.866 When the vials of sera have thawed, an automatic diluting machine mixes one part of thawed serum with three parts of saline. 00:09:39.866 --> 00:09:53.132 The dropper takes up the serum, then flushes it out with the saline. 00:09:53.133 --> 00:10:19.233 In preparation for the test, each cup in this disposable plastic plate receives a drop of saline solution. 00:10:19.233 --> 00:10:30.566 Long-handled loops calibrated to pick up .025 ml of solution are dipped into the various sera specimens. 00:10:30.566 --> 00:10:35.266 Several loops can be handled simultaneously. 00:10:35.266 --> 00:10:38.199 Each contains a different specimen. 00:10:38.200 --> 00:10:53.366 One of the loops holds the solution made from the sera contributed by Mrs. Owens. 00:10:53.366 --> 00:10:59.766 The stylus of each loop is rotated in the fingertips to ensure good mixing. 00:10:59.766 --> 00:11:12.632 The loops carry solution from one row to another for serial dilutions. 00:11:12.633 --> 00:11:17.799 Specific antigen is added by pipette. 00:11:17.800 --> 00:11:21.900 A drop measures .025 ml. 00:11:21.900 --> 00:11:24.600 Mumps antigen, for example, is added. 00:11:24.600 --> 00:11:29.300 By using different antigens derived from various microorganisms, 00:11:29.300 --> 00:11:32.866 the section is testing for more than 100 infections, 00:11:32.866 --> 00:11:42.466 which are of importance to man, to determine to what extent they may contribute to birth defects. 00:11:42.466 --> 00:11:47.566 The red line marks a serum control which receives no antigen. 00:11:47.566 --> 00:11:51.132 This will pick up false positive reactions. 00:11:51.133 --> 00:11:54.033 Few false-positive reactions occur. 00:11:54.033 --> 00:11:57.966 Next, complement is added to the antibody/antigen mixture. 00:11:57.966 --> 00:12:03.432 Complement is a substance that takes part in the reaction of antibody with antigen 00:12:03.433 --> 00:12:08.999 and provides an indirect measurement of the reaction. 00:12:09.000 --> 00:12:15.000 The plates are refrigerated at 4 degrees Centigrade for 16 to 18 hours. 00:12:15.000 --> 00:12:20.100 This gives time for the fixation of complement, if any, to take place. 00:12:20.100 --> 00:12:26.000 If Mrs. Owens' sera has mumps antibodies, evidence that she has been exposed to this virus, 00:12:26.000 --> 00:12:29.500 the antibodies would react with the antigen. 00:12:29.500 --> 00:12:41.833 At the same time, complement is being fixed, or used up as part of the reaction. 00:12:41.833 --> 00:12:48.566 Next day, sensitized sheep red blood cells are added with a .05 ml dropper. 00:12:48.566 --> 00:13:13.199 They will provide a way to detect whether complement remains in the test solution or has been fixed. 00:13:13.200 --> 00:13:26.933 The plates are sealed with a press, 00:13:26.933 --> 00:13:45.999 taken to a 37 degrees centigrade walk-in incubator, and placed in the shaking machine for 15 minutes. 00:13:46.000 --> 00:13:55.333 After shaking, the plates remain in the incubator for an additional 30 minutes. 00:13:55.333 --> 00:14:02.366 A sedimentation period of four hours at room temperature is routine to allow any red cells that were not broken up, 00:14:02.366 --> 00:14:15.132 or lysed, by unfixed complement to settle. 00:14:15.133 --> 00:14:48.933 A centrifuge speeds up the process of concentrating intact cells. 00:14:48.933 --> 00:15:13.833 The test plates are ready to read. 00:15:13.833 --> 00:15:19.833 Infection is evident when the reaction between antibody and antigen fixes complement, 00:15:19.833 --> 00:15:24.466 then complement is not free to lyse the red cells. 00:15:24.466 --> 00:15:30.699 As a result, the positive test appears as a button of red cells. 00:15:30.700 --> 00:15:35.766 In a negative test, there is no such accumulation of intact red cells. 00:15:35.766 --> 00:15:39.599 They are broken up, and the liquid appears pink. 00:15:39.600 --> 00:15:46.366 The more diluted samples had less antibody and a less-apparent button of red cells. 00:15:46.366 --> 00:15:56.466 In a positive test, the button is decidedly visible. 00:15:56.466 --> 00:16:01.332 The data on infections is a vital part of the mother's history. 00:16:01.333 --> 00:16:16.766 Other variables, such as age, number of previous pregnancies, manner of delivery, also are recorded. 00:16:16.766 --> 00:16:23.166 The IBM cards become masses of information to be fed into modern electronic computers. 00:16:23.166 --> 00:16:35.099 These can give answers in days that formerly would have taken months to acquire. 00:16:35.100 --> 00:16:44.300 The computers enable scientists to correlate millions of bits of information...to view related events from new perspectives. 00:16:44.300 --> 00:16:59.700 However, the judgment of highly trained investigators is essential in analyzing this data on birth abnormalities correctly. 00:16:59.700 --> 00:17:07.166 The section of infectious diseases conducts a number of related studies employing a variety of test methods. 00:17:07.166 --> 00:17:17.432 For example, the fluorescent antibody technique permits the viewer to see fluorescent-labeled antibody attached to specific antigen. 00:17:17.433 --> 00:17:20.866 Ultraviolet light excites the fluorescence. 00:17:20.866 --> 00:17:33.832 Literally, spotlighting the reaction. 00:17:33.833 --> 00:17:42.099 Tissue cultures of placenta and cord are studied to detect pathogenic effects of viruses. 00:17:42.100 --> 00:17:51.966 A characteristic pattern of cell destruction identifies certain viruses. 00:17:51.966 --> 00:17:58.199 Animals are studied, including ferrets, and monkeys. 00:17:58.200 --> 00:18:03.500 Pregnant Rhesus monkeys are injected with rubella virus or other agents 00:18:03.500 --> 00:18:10.333 to determine at what stage in development of the fetus effects might be observed. 00:18:10.333 --> 00:18:20.633 An infant monkey is delivered by caesarean to see whether virus can be recovered from organs or if defects are occurring. 00:18:20.633 --> 00:18:28.799 Mrs. Owens and other mothers participating in the study, the laboratory workers, 00:18:28.800 --> 00:18:36.500 hospital and clerical personnel, special testing procedures, 00:18:36.500 --> 00:18:51.633 are all a part of the research story on infections and birth defects. 00:18:51.633 --> 00:18:56.166 The accomplishments of this research and of the overall perinatal studies 00:18:56.166 --> 00:19:01.566 will become part of medical communications useful to family doctors, 00:19:01.566 --> 00:19:12.366 obstetricians, pediatricians, and other specialists throughout the world. 00:19:12.366 --> 00:19:17.799 [Produced by: Information Office, National Institute of Neurological Diseases and Blindness, 00:19:17.800 --> 00:19:25.900 Medical Arts and Photography Branch, National Institutes of Health]