Biomedical subjects
Publications and source records attributed to R M Austin.
Two examples of gas collections within the spinal canal, noted on computed tomography, are presented. A probable etiology is suggested and possible misinterpretations of such a finding are discussed.
Autologous baboon RBC stored at 4 C in acid-citrate-dextrose (ACD) or in citrate-phosphate-dextrose (CPD) for 3 weeks after collection had 24-hour 51Cr posttransfusion survival values of about 77%. When 20-day-old ACD and CPD baboon RBC were washed and then stored at 4 C for 24 hours before autotransfusion, the 24-hour 51Cr posttransfusion survival values were about 81%. These values were similar to those seen in studies of human RBC preserved in an identical manner. Our results indicated that the baboon can be used to evaluate RBC preservation techniques before human volunteers are studied.
Red blood cell volume was measured directly in baboons by infusion of 51Cr-labeled autologous RBC, and was indirectly estimated from the plasma volume measured with 125I-labeled albumin and the total body hematocrit. The total body hematocrit was calculated from the peripheral venous hematocrit multiplied by a correction factor; for nonanemic baboons the correction factor was 0.87, and for anemic baboons, 0.75. Within 2 weeks after the phlebotomy (150 ml of blood), the baboon's RBC volume was restored to normal. Posttransfusion survival of baboon RBC can be measured accurately in nonanemic baboons; the preserved RBC can be labeled with 51Cr and the RBC volume of the baboon can be measured indirectly from the plasma volume measured with 125I-labeled albumin and the total body hematocrit.
Infiltrating (intramuscular) lipomas and angiolipomas are benign mesenchymal tumors that usually appear as a deep, nontender mass within soft tissue, particularly in the extremities. The average tumor size in six cases studied was 11.2 cm (range, 2.0 to 22.0 cm). On gross examination, these tumors are circumscribed but unencapsulated, with infiltration of adjacent skeletal muscle. The correct preoperative diagnosis is seldom made, and the characteristic infiltrating pattern seen microscopically can lead to a mistaken diagnosis of sarcoma. Soft-tissue roentgenograms can be helpful in diagnosis and localization. The recommended mode of therapy is complete local excision with tumor-free soft-tissue margins. None of the six patients described here have experienced recurrence of tumor an average of two years after surgical resection. Prolonged follow-up is recommended, however, since inadequate resection can result in late tumor recurrence.
Because of atypical clinical presentations, two children with intussusception had intravenous urography as their initial examination of following plan films. In both patients the intussusception was outlined by an opaque rim due to the total body opacification effect on the bowel wall. One patient had a target-like blush on following films which strongly suggested the correct diagnosis. The authors do not advocate intravenous urography to diagnosis intussusception, but if this study is performed because of atypical clinical findings, the radiographic sign should be recognized and lead to a barium enema.
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The adherence of staphylococcal protein A-containing Cowan I bacteria to influenza-infected cells was enhanced up to 5 times following incubation of the monolayers with antiinfluenzal serum, but not following treatment with nomimmune serum. Significantly increased binding of Cowan I bacteria was detected at antiinfluenzal serum dilutions as high as 1:40,960. None of the several antibody concentrations tested enhanced the binding of staphylococcal protein A-negative staphylococci. In addition, extracellular staphylococcal protein A was found to inhibit complement-mediated cytolysis of antibody-coated, virus-infected cells. The possible significance of staphylococcal protein A in the synergistic interaction between staphylococcal and influenza virus infections is discussed.
Incubation of herpes simplex virus-infected human fibroblasts with the serum from a patient with herpes labialis rendered the cells susceptible to immune lysis by human mononuclear leukocytes (MNL) as well as complement. If, before the addition of MNL, the antibody-treated, infected monolayers were incubated with either IgM rheumatoid factor (RF), staphylococcal protein A (SPA), or anti-Fc gamma serum, antibody-dependent cell-mediated cytolysis (ADCC) was markedly depressed. SPA and anti-Fc caused maximal inhibition (greater than 90%), whereas RF resulted in a 72% depression. The inhibition of ADCC was dependent on both the concentration of the Fc-reacting materials incubated with the antibody-coated target cells and the concentration of antiviral antibody incubated with the virus-infected fibroblasts. Experiments indicated that the Fc-reacting materials depressed ADCC at the target cell level by covering or altering Fc sites on cell-bound antiviral antibody.
Interaction of staphylococcal protein A (SPA) with human serum depressed the ability of such serum to neutralize herpes simpled virus (HSV)-antibody labialis. SPA-induced depression of serum-dependent virus neutralization appeared to be due to consumption of complement by SPA. In addition, SPA attached to antibody-treated, HSV-infected cells and inhibited complement mediated immune cytolysis. The amount of inhibition obtained depended upon the with the infected cells. The possible significance of SPA in the pathogenesis of viral disease complicated by secondary staphylococcal infection is discussed.
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Three patients were scanned in whom the sonographic diagnoses of perisplenic fluid collections were made. Computed tomography scanning demonstrated that the appearances were not caused by perisplenic pathology but by lateral extent of normal left lobe of the liver. Methods to avoid this potential sonographic pitfall are suggested.
After storage in the liquid state at 4 C for up to three weeks, washing with sodium chloride solutions, and storage in a sodium chloride-glucose-phosphate solution for 24 hours at 4 C, dog red blood cells had excellent post-transfusion survival. After freeze-preservation with 40% W/V glycerol at -80 C or with 20% W/V glycerol at -150 C, thawing, washing with sodium chloride solutions, and storage in a sodium chloride-glucose-phosphate solution for 24 hours at 4 C, dog red blood cells had satisfactory recovery values in vitro, acceptable 24-hour post-transfusion survival and long-term survival values, and normal oxygen transport function. Controlled addition and removal of the cryoprotectant, glycerol, helped reduce the amount of osmotic damage to the red blood cells and enhanced freeze-preservation. Osmotic damage can also be prevented by warming the dog blood to a temperature of 22 +/- 2 C prior to centrifugation to concentrate the red blood cells and remove the plasma. This step enhances removal of the cold agglutinins. Another processing step used by the authors was to add a sodium chloride solution to the dog red blood cells before adding the glycerol solution in order to eliminate rouleaux formation.
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ISSUES: Increasing litigation over alleged false negative cervical cytologic (CC) smears threatens the viability of this test for cervical cancer detection. The problem appears to be largely American but is beginning to appear in some other countries. In the vast majority of cases there is either a settlement or jury verdict for the plaintiff based largely on the testimony of expert witnesses. Cases are judged on an individual basis without significant consideration of the general performance of the CC smear in laboratories operating in compliance with a wide array of laboratory regulations and with documented and comprehensive quality control practices in place. It is acknowledged that there are problem laboratories and cytology practitioners. There is an emerging issue of automated preparation and screening devices and issues of informed patient consent. CONSENSUS POSITION: Cytology professionals have done an extraordinary and commendable job of educating the public about the benefits of the CC smear. We have been less successful and conscientious about explaining and defining the limitations of the CC test. There is a need for public and professional education as to the benefits and limitations of the CC smear for cervical cancer detection. The process suggested is to work with women's groups, public health agencies, government agencies, and state and national legislatures and to coordinate professional committees working on liability issues. Contextual information could be included with the CC smear report to indicate that a negative report confers a low probability of developing cervical cancer. It is suggested that appropriate language and a menu of statements be developed. Increased efforts should be directed to physician education with respect to informed consent concerning the benefits and limitations of CC smear testing and the application of new technology to improve smear accuracy. The process should include development of appropriate statements on the use of alternative technology. The profession should develop "process guidelines" for review of CC smears in the context of possible litigation, including standardized methods for blind slide review of smears that reduce or eliminate context and outcome bias. It is suggested that review panels be anonymous, that the process be standardized and that there be limitations on liability for participating organizations. Professional cytopathology and pathology societies should formulate acceptable guidelines for expert witnesses. The standards should be applicable to both defendant and plaintiff experts. All materials to the extent practical, including consultant opinions, should be available for peer review. Professional cytopathology and pathology societies should monitor expert testimony for objectivity and scientific accuracy. ONGOING ISSUES: For the near future, litigation will continue to focus on false negative CC smears on a case-by-case basis. Laboratories and individuals can reduce the risk of malpractice liability by directing their attention to proactive quality control and quality assurance methods. In the final analysis, consumer education about the benefits and limitations of the test is key to limiting malpractice claims. To stem the tide of continued medicolegal challenges to the integrity of cytology practice, the cytology community has now focused its efforts on developing and utilizing standards that convey to patients, attorneys and cytologists the contemporary status of and reasonable expectations for the practice of cytology. Guidelines such as those for uniform reporting terminology and clinical management of cervical abnormalities form the basis of cytology practice standards on which legal standards of practice can be based. Consensus conference reports, clinical management trials and scientifically valid studies of false negative rates that analyze the type, frequency and cause of missed cases represent sounder methods of establishing defensible
OBJECTIVE: To review published and other available data comparing the effectiveness of liquid-based cytology preparations in detecting epithelial cell abnormalities in cervicovaginal (gynecologic) cytology as compared to the conventional Papanicolaou test. STUDY DESIGN: Available split-sample data comparing liquid-based gynecologic cytology preparations with the conventional cervical cytologic test were collated from published studies, unpublished studies reported on at professional meetings or in the press, and from Food and Drug Administration Premarket Clinical Trials on ThinPrep and AutoCyte PREP. Data were stratified with regard to use of newer preparatory instrument models, use of varying collection devices and different split-sample protocols. RESULTS: Available data from split-sample studies of liquid-based methods showed overall increased detection of epithelial cell abnormalities. Results have varied considerably from study to study and appear to be influenced by collection protocol methods and probably by collection devices' different delivery of cellular material in split-sample studies, first to the conventional smear and second to the liquid-based medium. Newer preparatory instrument models may also enhance detection. CONCLUSION: Liquid-based gynecologic cytology preparations increase detection of epithelial cell abnormalities, as compared to the conventional, single-slide cervical cytologic smear, based on available data from split-sample studies. The true potential impact of these methods in enhancing detection of epithelial cell abnormalities awaits accumulation of data from direct-to-vial studies, especially data on detection of biopsy-confirmed high grade squamous intraepithelial lesions from a wide variety-of clinical practice settings.