Faculty Bibliography

An analysis of a blood sample preserved since 1959 from the oldest documented case of infection with the AIDS virus called H.I.V.-1 shows that the first such infections probably occurred in people in the late 1940's or early 1950's, about a decade earlier than many estimates, scientists said today. The researchers compared that sample with others to build a family tree to trace changes in the fast-mutating AIDS virus. The family tree, or phylogenetic analysis, is in the shape of a starburst, with branches radiating from the center, and the 1959 virus is close to the center. The scientists used calculations to estimate the date when the virus first developed. The 1959 sample came from a Bantu man who lived in Leopoldville, Belgian Congo (now Kinshasa in the Democratic Republic of Congo). In 1986, scientists used what were then the latest laboratory techniques to show that he had been infected by H.I.V.-1. But only now could scientists, using the latest powerful tools of molecular biology, identify key fragments of the virus in the last few drops of the blood sample in a quest for the origins of the AIDS virus

AIDS deaths in New York City plummeted by 48 percent last year, accelerating earlier gains attributed to improved drug therapies, health officials said at a scientific meeting here today. They said the declines crossed sex and racial lines, suggesting that the new therapies were reaching all segments of the AIDS population. Theoretically, the decline in AIDS deaths could have resulted from prevention efforts or some unknown factor, the health experts meeting here said. But the likeliest explanation is expanded use of combinations of newer and older drugs that began to be introduced in recent years, New York City and Federal health officials said. ''This is a new era'' in AIDS, Dr. Kevin DeCock, an AIDS official from the Centers for Disease Control and Prevention in Atlanta, said at a news conference. ''We can't think that the end of the epidemic is in sight, but it certainly is the beginning of a new period.'' Dr. DeCock heads the unit at the centers that monitors AIDS cases in this country. ''The challenge now is to improve prevention,'' he told the 3,400 participants in the meeting here

A 'bird flu' strain of influenza virus has caused only 20 confirmed or suspected cases of human illness in Hong Kong, all since May, and has not been found elsewhere. Yet Hong Kong health officials are so worried about the virus that last Monday they began slaughtering all 1.2 million chickens in the territory. And virologists around the world have been burning the midnight oil for several weeks, studying the strain and attempting to make a vaccine for it

A 'bird flu' strain has caused only 20 confirmed or suspected cases of human illness in Hong Kong, all since May, and has not been found elsewhere. Yet Hong Kong health officials are so worried about the virus that they have slaughtered 1.3 million chickens in the territory. And virologists around the world have been burning the midnight oil for several weeks, studying the strain and attempting to make a vaccine for it. The main reason is the strain's novelty for humans. It has been seen only in poultry before, and the strain infecting humans is the same one that has killed thousands of chickens in Hong Kong. Scientists believe that the virus is transmitted when someone touches an infected person, not through the air - the usual way influenza spreads. But scientists are puzzled about exactly how the virus is transmitted. Whether the destruction of Hong Kong chickens will stop the transmission of the virus is an unanswered question. But as long as A(H5N1) infections continue to occur, no one can know where the Hong Kong outbreak will lead. For now, [Keiji Fukuda] said, 'there is clearly a great deal of concern that this virus could take hold and lead to a pandemic.'

OBJECTIVES: To update the WHO global and regional estimates of the prevalence and incidence of syphilis, gonorrhoea, chlamydia, and trichomoniasis. METHODS: Prevalence estimates for syphilis, gonorrhoea, chlamydia, and trichomoniasis were generated for each of the nine UN regions for males and females between the ages of 15 and 49 in 1995 based on an extensive review of the published and unpublished medical literature since 1985. Incidence estimates were based on the prevalence figures and adjusted to take into account the estimated average duration of infection for each disease in a particular region. The latter was assumed to depend upon a number of factors including the duration of infection in the absence of treatment, the proportion of individuals who develop symptoms, the proportion of individuals treated, and the appropriateness of treatment. RESULTS: In 1995 there were over 333 million cases of the four major curable STDs in adults between the ages of 15 and 49--12 million cases of syphilis, 62 million cases of gonorrhoea, 89 million cases of chlamydia, and 170 million cases of trichomoniasis. Geographically, the vast majority of these cases were in the developing world reflecting the global population distribution. CONCLUSIONS: STDs are among the most common causes of illness in the world. Estimates of the global prevalence and incidence of these infections are limited by quantity and quality of data available from the different regions of the world. Improving global STD estimates will require more well designed epidemiological studies on the prevalence and duration of infection.

SETTING: Five IS6110 chromosomal insertion sites were characterized in the multidrug resistant Mycobacterium tuberculosis 'W' strain. OBJECTIVE: To use insertion site probes to study the phylogenetic distribution of IS6110 in the M. tuberculosis genome. DESIGN: A total of 722 M. tuberculosis isolates, previously genotyped using the standard IS6110 Southern blot hybridization methodology, were re-hybridized with the Region A insertion site probe and representative strains were further hybridized with the Region B and C probes. Strains were grouped on the basis of having IS6110 insertions in these different regions and their relatedness was further compared by sequencing the IS6110 insertion sites. RESULTS: The insertion site probes revealed that the collection of Chinese isolates previously grouped as the Beijing strain family shared IS6110 insertions in common with the W and other genotypic group 1 strains. Unexpectedly, we found that IS6110 integrated at least 10 independent times between the dnaA and dnaN genes encoding deoxyribonucleic acid replication proteins. CONCLUSIONS: IS6110 insertion site mapping is able to identify genetic relatedness among a collection of M. tuberculosis clinical strains representing the breadth of species diversity. The mapping data indicate that IS6110 insertion sites are not always random

OBJECTIVES: We investigated the role of three-dimensional echocardiography in assessing mitral valve anatomy in greater detail in patients immediately before and after balloon mitral valvuloplasty (BMV). BACKGROUND: Three-dimensional echocardiography is a recently developed, evolving imaging technique that allows visualization of intracardiac structures from any perspective. METHODS: We studied 19 patients undergoing BMV using transesophageal echocardiography (TEE) (Chicago, Illinois) to image the mitral valve. The TEE was interfaced to a TomTec three-dimensional workstation that allows electrocardiographic and respiratory cycle gated image acquisition. The acquired images are digitized, and after postprocessing a three-dimensional image is reconstructed. The mitral valve was viewed 'en-face' as if looking up from the left ventricle. RESULTS: The mean mitral valve area (by pressure half-time from the Doppler of the two-dimensional echocardiogram) increased after BMV from 0.86+/-0.06 cm2 to 2.07+/-0.10 cm2, p < 0.0001. This was similar to the mitral valve areas obtained by planimetry from the three-dimensional images. The three-dimensional reconstructions showed a complete commissural split in 10 patients and partial splitting in 9 patients. In three of the eight patients who had an increase in the amount of mitral regurgitation secondary to BMV, the three-dimensional reconstructions were able to detect tears within the valve leaflet. One leaflet tear actually extended up to the mitral valve annulus and was associated with the only case of severe mitral regurgitation. CONCLUSIONS: The three-dimensional echocardiographic reconstruction enabled visualization of the mitral valve so that commissural splitting and leaflet tears not seen on the two-dimensional echocardiogram became visible