Biomedical subjects

S A Land

Publications and source records attributed to S A Land.

8 recordsLinked to original sources

PubMed2000

Percent free prostate specific antigen and cancer detection in black and white men with total prostate specific antigen 2.5 to 9.9 ng./ml.

PURPOSE: The ratio of free-to-total prostate specific antigen (PSA), or percent free PSA, is a useful adjunct to total PSA for estimating the risk of prostate cancer when total PSA is 2.5 to 9.9 ng./ml. Relationships between cancer detection and total PSA are influenced by race but to our knowledge relationships between cancer detection and percent free PSA have not been studied. MATERIALS AND METHODS: A total of 222 black and 298 white consecutive and evaluable men with total PSA 2.5 to 9.9 ng./ml. underwent prostate biopsy for suspected cancer at a Veterans Affairs Medical Center. Clinical measurements included digital rectal examination, total and free serum PSA, prostate volume, PSA density and Gleason score of malignant biopsy specimens. RESULTS: Median percent free PSA was 14.1 (range 3.6 to 49.2) in 201 men with prostate cancer and 21.9 (range 5.7 to 83.3) in 319 without detectable cancer (p <0.0001). Significant racial differences in demographic characteristics and clinical measurements were limited to total PSA, which was higher in black men (p = 0.03). Cancer was detected in 156 black (47%) and 206 white (33%) men (p = 0.001). Areas under receiver operating characteristics curves for percent free PSA and total PSA were 0.66 and 0.58, respectively, for black men (p = 0.15), and 0.76 and 0.58, respectively, for white men (p <0.00001). Percent free PSA was 35.2 in black men and 29.2 in white men, and specificity was 9.1% and 28.7%, respectively, when sensitivity for percent free PSA was set at 95%. Of 156 black and 206 white men with percent free PSA less than 25, 83 (53%) and 85 (41%), respectively, had detectable cancer (p = 0.03). Of 66 black and 92 white men with percent free PSA 25 or greater 21 (32%) and 12 (13%), respectively, had detectable cancer (p = 0.005). CONCLUSIONS: Our study demonstrates racial differences in relationships between percent free PSA and cancer detection in men with suspected prostatic carcinoma and total PSA 2.5 to 9.9 ng./ml. Clinical application of the commonly used percent free PSA cutoff of less than 25 to determine the advisability of prostate biopsy may lead to under diagnosis of early stage prostate cancer in black men, who are at greater risk of morbidity and mortality from disease than white men.

Aged↗

PubMed1999

Results of transition zone biopsy in black and white men with suspected prostate cancer.

OBJECTIVES: To determine whether biopsy-detectable transition zone tumors are more common in black than in white men with suspected Stage T1c and T2 prostate cancer. METHODS: We performed a prospective study of transition zone prostate biopsy (TZ biopsy) in 1 78 black and 261 white men who had not undergone previous prostate biopsy and in 61 black and 65 white men who had undergone one benign sextant peripheral zone prostate biopsy (PZ biopsy). RESULTS: The mean age of the 239 black and 326 white study patients was 68.6+/-7.4 and 67.2+/-7.2 years, respectively (P = 0.02), the mean prostate-specific antigen (PSA) was 8.4+/-7.4 and 6.4+/-5.4 ng/mL, respectively (P = 0.003), and the mean PSA density was 0.20+/-0.23 and 0.16+/-0.16 ng/mL/mL, respectively (P = 0.006). Overall, cancer was diagnosed by TZ biopsy only in 7 black men (3%) and in no white men (0%) (P = 0.003). However, cancer detection with a TZ biopsy only was not significantly different in the black and white men when controlled for age, PSA, or PSA density (P>0.90). A TZ biopsy only detected cancer in 1% of patients who had not undergone prior PZ biopsy and in 2% of patients who had undergone prior PZ biopsy. Of the seven cancers detected with TZ biopsy, six (86%) had a Gleason score of 2 to 6. CONCLUSIONS: Prostate cancer detection with a TZ biopsy only is not common and when controlled for confounding variables is the same in black and white men. The preferential use of TZ biopsies in black men is not warranted, and the low diagnostic yield argues against routine use of the biopsy technique in men of either race.

Aged↗

PubMed1999

Relationships between prostate-specific antigen and prostate volume in black and white men with benign prostate biopsies.

OBJECTIVES: To determine whether the higher age-adjusted serum prostate-specific antigen (PSA) levels in black compared with white men with no clinical evidence of prostate cancer reflect racial differences in relationships between PSA and prostate volume. METHODS: The age, PSA, findings on digital rectal examination (DRE), prostate volume, and PSA density were assessed prospectively in 810 consecutive, evaluable men who underwent prostate biopsy for suspected cancer but who had benign histologic findings. RESULTS: Among the black and white patients, there were significant differences in age (mean 67.2 +/- 8.1 and 65.9 +/- 7.7 years, respectively, P = 0.02), PSA (median 4.7 and 3.9 ng/mL, respectively, P <0.0001), prostate volume (median 41 and 36 mL, respectively, P = 0.004), and PSA density (median 0.11 and 0.08 ng/mL/mL, respectively, P = 0.005). Multiple linear regression analyses showed that black race was significantly associated with increased prostate volume when controlled for age (P = 0.02), with increased PSA when controlled for prostate volume and age (P = 0.002), and with increased PSA density when controlled for age (P = 0.007). When controlled for prostate volume, PSA was not significantly different in black and white men 50 to 59 years old but was significantly greater in black men 60 to 69 and 70 to 79 years old (P = 0.02 and 0.002, respectively). CONCLUSIONS: On a volume/volume basis, the benign prostatic tissue of black men appears to contribute more PSA to the circulating blood than does the benign prostatic tissue of white men, and the difference increases with advancing age. These phenomena provide a reasonable explanation for the age-adjusted racial differences in the PSA of men with no clinical evidence of cancer.

Adult↗

PubMed1996

Syncytium-inducing phenotype and zidovudine susceptibility of HIV-1 isolated from post-mortem tissue.

OBJECTIVE: To establish the syncytium-inducing (SI) phenotype and zidovudine (ZDV) susceptibility of HIV-1 isolates obtained from autopsy specimens. METHODS: Isolation of HIV was attempted from autopsy specimens obtained from 76 AIDS patients. Specimens of lymph node, spleen, spinal cord, brain and cerebrospinal fluid (CSF) were processed and cultured with peripheral blood mononuclear cells (PBMC) from seronegative donors. Biological phenotype was determined in a T-lymphocyte line (MT-2). ZDV susceptibility was evaluated in a PBMC-based assay. Sequencing of amino-acid codons in the reverse transcriptase gene previously shown to be associated with ZDV resistance was carried out on a subgroup of isolates. RESULTS: HIV was recovered from tissue specimens and CSF up to 5 days post-mortem, but recovery rate of infectious virus decreased as the time between autopsy and specimen processing increased. There was a lack of concordance between PBMC isolates and isolates from different tissue sites with respect to SI phenotype. ZDV-resistant virus was isolated from post-mortem specimens of patients who had received long-term ZDV therapy up until or shortly before their death. ZDV-sensitive virus re-emerged in the lymph node of patients who ceased treatment several months prior to death. Phenotypically sensitive virus obtained from lymph node tissue of three patients after a relatively short time off ZDV (4-6 months) retained some of the amino-acid substitutions known to be associated with resistance. CONCLUSION: The data suggests that ZDV resistance and re-emergence of sensitive virus does not originate in peripheral cells, and that these cells and tissues are seeded with virus present elsewhere, possibly in the germinal centres of the lymph node.

Acquired Immunodeficiency Syndrome↗

PubMed1995

Reverse transcriptase mutations in sequential HIV-1 isolates in a patient with AIDS.

Sequential human immunodeficiency virus type 1 (HIV-1) isolates were obtained over a 29-month period from a person before, during, and after AZT therapy. DNA sequence analysis of polymerase chain-amplified reverse-transcriptase gene showed a gradual accumulation of mutations to peak resistance (IC50 2.13 microM AZT) in association with mutations at codons 44, 210, and 369, as well as at 41, 67, 70, and 215. Eight months after cessation of AZT therapy, when an HIV-1 isolate from the patient was again sensitive to AZT, these mutations had all returned to the pretherapy sequence.

Acquired Immunodeficiency Syndrome↗

PubMed1988

Outbreak of enterovirus 71 infection in Victoria, Australia, with a high incidence of neurologic involvement.

An outbreak of infections caused by enterovirus 71 occurred in southeastern Australia during the winter of 1986. Infection was confirmed by virus isolation or serology in 114 patients, 65 of whom were admitted to hospital. Fifty-one percent of inpatients were infants younger than 12 months old and 85% were younger than 5 years old. Many cases of hand, foot and mouth disease occurred in the community during the epidemic, but 51% (33 of 65) of patients admitted to hospital had central nervous system involvement, often associated with severe symptoms. Six patients had encephalitis and one had a poliomyelitis-like paralytic illness. Various skin manifestations other than hand, foot and mouth disease occurred, especially in young children, and 25 patients had significant respiratory disease including at least 7 with pneumonia. Enterovirus 71 is one of very few viruses that cause hand, foot and mouth disease as well as a variety of other clinical manifestations. The most important of these is meningoencephalitis, which causes significant morbidity, especially in infants and young children.

Child↗

PubMed1984

Rapid diagnosis of herpes simplex virus infections by enzyme-linked immunosorbent assay.

A total of 457 clinical specimens were tested for the presence of herpes simplex virus (HSV) by isolation in cell culture and by enzyme-linked immunosorbent assay. HSV antigen was detected by enzyme-linked immunosorbent assay in 94% of the clinical specimens from which the virus was isolated. The detection rate was improved to 100% when specimens were either assayed within 24 h or stored frozen at a constant temperature (-20 degrees C) for up to 14 days. Type-specific HSV antigen was also detected in 6% of culture-negative specimens. The assay can be completed in 5 h or less, and commercially available immunoglobulins are used. Enzyme-linked immunosorbent assay is a rapid and sensitive method for the diagnosis of HSV infection and can be used to improve the management of pregnant women with a history of genital herpes and of neonates and others with serious HSV infection which may require specific antiviral therapy. It also offers an alternative to cell culture for routine diagnosis of HSV infections.

Antigens, Viral↗

PubMedDate not supplied

Significance of semen cultures for men with questionable semen quality.

Semen cultures often yield inconclusive results probably due to bacterial contaminants. We were able to isolate enteric pathogens with greater specificity by comparing two cultures from the same individual: one obtained from the midstream urine and the other from ejaculate obtained following midstream urine collection and eliminating the bacteria present in the midstream urine. Bacterial growth was found in semen cultures from 102 (79%) of the 129 men with questionable semen quality; 31 (30%) had aerobic bacteria, 28 (27%) had anaerobic bacteria, and 43 (42%) had both. A high incidence of positive cultures in our study was probably due to stringent patient selection and our comparative culturing procedure. The presence of pathogens may indicate the need for treatment especially prior to IVF and IUI.

Bacteria↗