Biomedical subjects

C W Ollayos

Publications and source records attributed to C W Ollayos.

8 recordsLinked to original sources

PubMed1999

The false-negative fraction: a statistical method to measure the efficacy of cervical smear screening laboratories.

The false-negative fraction (FNF) is emerging as a statistical parameter that may be used to evaluate the efficacy of Papanicolaou smear screening laboratories. Our objectives for this paper are to acquaint non-laboratorians with this important measurement and to measure the FNF of the Air Force Cyto-center (AFCC) at the Armed Forces Institute of Pathology in Washington, DC. The FNF is defined as estimated false negatives divided by (true positives plus estimated false negatives). Most often, the number generated is multiplied by 100 and expressed as a percent. We have determined the FNF of the AFCC to be 3.7%. This value compares favorably with most others reported in the medical literature.

Aerospace Medicine↗

PubMed1998

PAPNET-assisted rescreening of cervical smears: cost and accuracy compared with a 100% manual rescreening strategy.

CONTEXT: The Food and Drug Administration has recently approved several devices that use computerized image analysis to rescreen Papanicolaou (Pap) smears that have already been examined by cytotechnologists. Physicians and laboratories must decide whether the utility of these devices justifies the cost. OBJECTIVE: To determine the effectiveness and cost of PAPNET-assisted rescreening in identifying cervical abnormalities not identified by manual rescreening. DESIGN: PAPNET-assisted rescreening of 5478 Pap smears obtained in 1994 and 1995 previously identified as "within normal limits" or "benign changes" on both initial and random screening. PATIENTS: Female service members and dependents aged 12 to 88 years. SETTING: Air Force clinics in the United States and Japan. INTERVENTION: Rescreening of Pap smears by PAPNET, followed by reevaluation of abnormal smears by the consensus panel, consisting of 3 cytotechnologists and 3 pathologists. MAIN OUTCOME MEASURES: Proportion of Pap smears initially screened as normal identified as abnormal by both PAPNET and consensus panel; costs of rescreening. RESULTS: PAPNET screening identified 1614 (29%) slides requiring additional microscopic review. On further review, 448 (8% of total) had possibly abnormal cells. Ultimately, 11 of these cases were reviewed by the consensus panel for potentially atypical cells. Of these 11 cases, 5 were reclassified as atypical squamous cells of undetermined significance (ASCUS) and 1 as atypical glandular cells of undetermined significance (AGUS). No additional squamous intraepithelial neoplasia (SIL) was identified in these smears; the patient with a diagnosis of AGUS on rescreening was diagnosed as having a low-grade SIL (LSIL) on follow-up. Costs were $5825 to $33781 for each additional ASCUS or AGUS diagnosis. A cost of $17475 to $101343 is expected for each case of LSIL identified by PAPNET-assisted rescreening and not by traditional manual rescreening. CONCLUSIONS: PAPNET-assisted rescreening identified a few more cases of ASCUS than did manual rescreening, but at a relatively high cost. The costs of rescreening should be carefully compared with the expected efficacy in reducing cervical cancer mortality.

Adolescent↗

PubMed1997

Update on the Papanicolaou smear: new issues for the 1990s.

The Papanicolaou (Pap) smear is a complex examination that has undergone refinement in recent years. It is now widely accepted that a false-negative rate of perhaps 10 to 20% is inevitable for a variety of reasons. The diagnosis of "atypical cells of undetermined significance" is not a benign diagnosis and is often followed by a more severe lesion on follow-up. The Pap smear appears to be an inefficient method for detecting glandular neoplasms, and clinical features remain the most important diagnostic clue. A Pap smear and cervical biopsy should correlate in 75% or more of cases. In cases of noncorrelation, a positive Pap smear diagnosis is supported in the vast majority of cases.

Biopsy↗

PubMed1996

Papillary squamous cell carcinoma of the uterine cervix: report of a case with HPV 16 DNA and brief review.

Papillary squamous cell carcinoma (PSCC) of the uterine cervix is a rare variant of squamous cell carcinoma (SCC). It is characterized by a papillary architecture and markedly atypical epithelium. Invasion and metastasis have been reported. We report a case of PSCC in a 72-year-old woman who subsequently tested positive for HPV 16. To our knowledge, this is the first report of HPV typing in a case of PSCC. Our finding of a high-risk HPV type in PSCC may help explain why PSCC has been reported to have a clinical course similar to that of nonpapillary SCC.

Aged↗

PubMed1995

Abnormal cervical smears in the military recruit population.

Human papillomavirus is a common genital tract infection believed to be a causative agent of uterine cervical dysplasia. In a minority of cases, dysplasia progresses to squamous cell carcinoma. We reviewed the cervical smear reports for all female recruits who reported for training at Navy Recruit Training Center, Orlando, in calendar year 1993. During this period, 8,029 female recruits reported for training. We found that 24 recruits (0.30%) had a finding of high-grade squamous intra-epithelial lesion (HSIL); 203 (2.5%) had a finding of low-grade squamous intraepithelial lesion (LSIL); 377 (4.7%) had abnormalities other than HSIL or LSIL; and 7,425 (92%) had no abnormalities. These prevalence rates are lower than those reported for other populations.

Adult↗

PubMed1994

Tolerance of the bladder to intraoperative radiation in a canine model: a five-year follow-up.

PURPOSE: Late effects of intraoperative radiation therapy (IORT) on bladder were investigated in a canine model. METHODS AND MATERIALS: After laporatomy and cystotomy in adult female foxhounds weighing 25-35 kg, 12 MeV electrons were delivered intraoperatively to a 5 cm circular bladder field which included the trigone and both uretero-vesicle junctions. Each animal received doses of 0, 20, 25, 30, 35, or 40 Gy. All the dogs were followed 5 years postoperatively. An unoperated dog receiving no surgery or radiation treatment was followed as a control. Close clinical monitoring was performed with regular cystometrics and intravenous pyelography. Animals were killed as scheduled with complete necropsies, including histopathology, with special attention to genitourinary structures. RESULTS: There were no acute or late bladder complications detected clinically in any animal. The dog receiving 30 Gy IORT developed rhabdomyosarcoma in the treatment field at 58 months. On follow-up testing over 5 years, there was no loss of bladder contractility on cystometry, and mild changes in the ureters on intravenous pyleography when animals receiving IORT were compared with baseline pretreatment values or with control animals. Histologically, a difference was evident between irradiated and unirradiated animals, but the changes were not clearly dose-related. CONCLUSION: Intraoperative radiation therapy may by safely delivered to the canine bladder with few acute or chronic complications. It is an approach which has potential for clinical use and should continue to be explored in human clinical trials.

Animals↗

PubMed1994

Estrogen receptor detection in paraffin sections of adenocarcinoma of the colon, pancreas, and lung.

We performed a retrospective analysis for the presence of estrogen receptors (ERs) in known cases of adenocarcinoma of the colon, pancreas, and lung. Estrogen receptor status was determined by immunohistochemical methods using the ER-ICA (Abbott Laboratories, North Chicago, Ill) antibody on paraffin sections. None of 43 colon and 18 pancreatic adenocarcinomas demonstrated ERs by this method. Three of 42 lung adenocarcinomas exhibited some degree of nuclear staining for ERs. When evaluating an adenocarcinoma of unknown primary site, the ER-ICA antibody can be useful when included in a panel of antibodies. Positive results tend to exclude colonic or pancreatic, but not pulmonary, primary sites.

Adenocarcinoma↗

PubMed1984

Personal computer based programs for the handicapped.

This is an experience report concerning the utilization of personal (micro) computers for in and outpatients of The Burke Rehabilitation Center. Three Apple II Plus desk computers and peripherals are in use with the following objectives:-- To provide access via a variety of interface switches. To motivate and train child and juvenile amputees undergoing upper limb amputation rehabilitation. To provide a different approach to neuropsychological testing and behavioural assessment. To provide cognitive rehabilitation programs for patients with head trauma and stroke. To add another option for pre-vocational evaluation. The report discusses computer access technology along with a description of program applications. Conclusions based on the preliminary results of observing 101 patients are given.

Computers↗