Search

We identified and characterized an HLA-A1 aberrant allele (A*0118N) resulting from a novel molecular mechanism; this allele was present in an unusually informative family with a near identical parental HLA haplotype (c d) differing only by one nucleotide substitution in one HLA-A allele, A*0118N, of the maternal HLA haplotype (c) and not of the paternal HLA haplotype (a). Although serologic HLA typing showed a “blank,” DNA molecular HLA typing detected a HLA-A*0118N allele. Sequence based typing identified the substitution of guanine by cytosine at the nucleotide position 215, which resulted in the replacement of arginine by proline at position 48 of the HLA-A1 H chain. The loss of surface protein expression was also found by FACS analysis. Isoelectric-focusing analysis detected a HLA-A H chain with a unique isoelectric-focusing pattern, which does not associate with the L chain (β2-microglobulin). These results suggest that the residue 48-containing interaction site on the α1 domain plays a critical role in the association between HLA class I H chain and β2-microglobulin. Functional studies showed that the T cells of the propositus (HLA haplotypes c d) carrying this null allele recognized its wild-type counterpart, HLA-A*010101, in her HLA-identical son that carries the HLA-A*0101 heterodimer. This is the first example of the generation of cytotoxic T cells in the absence of proliferation of CD4+ T cells (mixed lymphocyte culture) and the description of an aberrant allele, A*0118N, that may behave as a minor histocompatibility Ag, with implications in allorecognition by cytolytic T cells in solid organ and stem cell transplantation.

From an unusually informative family of 8 with near identical parental haplotypes (a and c), which differed by a single nucleotide substitution, we identified a new HLA-A1 null variant. While serologic antigen typing initially showed a “blank” allele in maternal haplotype “c” and 2 male offspring, more sophisticated DNA molecular HLA typing subsequently revealed the presence of a novel HLA-A0101 allele. Sequence-based typing showed a point mutation consisting of a nucleotide substitution of a cytosine for a guanine at nucleotide 215 yielding an amino acid change of arginine to proline at codon 48 in exon 2 (R48P). The impact on the HLA and immunogenetics laboratory is the need to not assume that all blanks are homozygous, as well as the need for the availability of high-resolution DNA molecular typing to clarify new alleles and to detect HLA-A null variants.

Technological changes in the clinical laboratory are usually driven by the goal of patient care optimization. The introduction of biosensor technology in the 1990s has set the trend for clinical laboratory decentralization. These miniaturized biosensors are easy to operate, require small specimen size, and provide reliable results with rapid turnaround time. Bedside testing using biosensor technology may allow earlier diagnosis, more frequent monitoring, and reduced hospital costs. This article assesses current biosensors and projects potential biosensors for the 21st century regarding their validity, economic justification, and clinical relevance.

Desktop computers have evolved to permit physicians in practice and/or training to access and manage information to enhance knowledge, understanding, and learning. There are compelling reasons why the personal computer is key to learning and important in medical education. Above all, the computer enhances and amplifies the learning process. Using the desktop computer effectively is relatively easy. We teach our students to research information in books and journals and hope that, as practicing physicians, they do it even more to be current and maintain their competency. Why not a desktop computer to access and manage information, analyze it, and present findings? Computer technology is available to do virtually all of these tasks. Some tools are critical for medical students. For some time, all medical students have needed a black bag and microscope. Now every medical student needs a computer. Ample courseware is available and expanding rapidly for basic sciences and clinical disciplines. The explosion in biomedical information will continue. Finding information is key to understanding and learning rather than depending solely on memory, recall, or library trips for information. The desktop computer will benefit students, faculty, and future physicians and other health professionals as life-long learners.

Febrile nonhemolytic transfusion reactions (FNHTRs) cause unwelcome interruptions during the course of blood product transfusions and necessitate measures to verify the nature of the reaction and to exclude certain dangerous reactions, such as hemolytic and septic phenomena.To examine transfusion medicine data to determine the clinical implications of the routine administration of antipyretic medication to adult patients before transfusion for the prevention of FNHTRs.A retrospective review was conducted of FNHTR data during 5 years (1998-2002), and a determination was made of the cost of a transfusion complicated by an FNHTR. In addition, a comparative cost analysis was performed using our data and published data on the incidence of FNHTRs. The clinical implications of medication with respect to possible drug-induced adverse effects were assessed, as well as the potential interference with diagnosing other forms of transfusion reactions and the mitigation of the clinical effect of an FNHTR.For nearly 120,000 U of transfused blood components, approximately 80% of which were preceded by antipyretic medication during the study period, the overall incidence of FNHTR was found to be 0.09%. Furthermore, there was no evidence of antipyretic-associated complications, nor any evidence that antipyretics prevented the recognition of other more dangerous complications of transfusions.Our findings indicate that this practice provides significant advantages to the recipient of a transfusion, but does not appear to yield significant cost benefits for the health care provider.

From an unusually informative family of 8 with near identical parental haplotypes (a and c), which differed by a single nucleotide substitution, we identified a new HLA-A1 null variant. While serologic antigen typing initially showed a "blank" allele in maternal haplotype "c" and 2 male offspring, more sophisticated DNA molecular HLA typing subsequently revealed the presence of a novel HLA-A0101 allele. Sequence-based typing showed a point mutation consisting of a nucleotide substitution of a cytosine for a guanine at nucleotide 215 yielding an amino acid change of arginine to proline at codon 48 in exon 2 (R48P). The impact on the HLA and immunogenetics laboratory is the need to not assume that all blanks are homozygous, as well as the need for the availability of high-resolution DNA molecular typing to clarify new alleles and to detect HLA-A null variants.

and Introduction Abstract In this age of ever-increasing demands for and uses of patient data, technologic advancements in the form of electronic patient records permit improved data access and prompt retrieval of higher quality patient care data, with more versatility in display, facilitating the integration of information concerning patients over time and between settings of care, which is in turn more accessible for use by practitioners and provides more efficient and effective decision support in areas of patient care. The graphic display of laboratory data is central to the evolving computerized patient record and needs to be taken into careful consideration along with clinician perception and ease of data interpretation in redesigning the graphic reporting of numeric clinical pathology laboratory data. An ideal system should generate user-friendly, graphic-based comprehensive reports highlighting abnormalities with trends for diagnosis, clinical management, and risk-factor detection.

Current protocols utilize systolic blood pressure (SBP) of less than 80 mmHg as objective evidence of hypotension during hemapheresis. However, tissue hypoperfusion is the pathophysiologic endpoint of low blood pressure, and mean arterial pressure (MAP), rather than SBP, is the physiologic driving force behind blood flow to organs and tissues. It is thus hypothesized that MAP is more appropriate than SBP in the assessment of hypotension and that a threshold MAP can be utilized as a sensitive indicator of hypotension during hemapheresis. Thirty-one patients who experienced hypotension during hemapheresis over a 4.5 year period reflecting forty-four hypotensive episodes were selected. The initial phase of each hemapheresis procedure provided baseline MAP and blood pressure (BP) measurements as control values. BP and MAP were then determined at the onset of subjective hypotension and compared to one another by using regression and sensitivity analyses. Correlation coefficients between SBP and MAP were found to be 0.8097 in baseline normotensive patients and 0.7725 in hypotensive patients. Sensitivity in the detection of hypotension was 0.09% for SBP equal to 80 mmHg and 56.81% for MAP equal to 70 mmHg. An SBP of 80 mmHg or less was therefore concluded to be a less sensitive and physiologically less appropriate measurement of hypotension than MAP. As a single value less than 70 mmHg or a series of successive measurements trending downward toward 70 mmHg, MAP provides an objective assessment of hypotension that may precede hemodynamic decompensation.

The collection of peripheral blood progenitor cells (PBPC) requires the combined efforts of the Transfusion Medicine/Hemapheresis and Hematology/Oncology services and HLA/Progenitor Cell and Immunology laboratories. Coordination and communication among these different services and laboratories are key to attaining an optimal collection in a timely manner for the patient undergoing PBPC collection. In an effort to improve patient care by same-day decision to cease or continue collections avoiding unnecessary collections, needless patient trips to the hospital and ultimately increasing patient satisfaction, a flow chart was used to capture the sequence of events. The flow chart served as a powerful tracking tool that defined system process and steps to attain enumeration of CD34+ cells the same day of collection. It provided documentation of work flow from each of the independent operations involved in progenitor cell collection and enumeration turn-around-time including attending and staff time involvement. By using the flow chart, potential and actual problem areas were demonstrated and this allowed for creative thinking and problem solving by individual sections rather than recriminations. Finally, it focused all the staff involved in the common goal of a shorter turn-around-time for CD34+ cell enumeration the same day of collection. This allowed a prompt decision for subsequent leukapheresis as improved service to oncology patients and their physicians. J. Clin. Apheresis 14:35–41, 1999. © 1999 Wiley-Liss, Inc.

A recently available portable clinical analyzer (PCA), which examines sodium, potassium, chloride, glucose, urea nitrogen, and hematocrit levels on 60 microL of blood and calculates hemoglobin and osmolality levels within 2 minutes, was evaluated. Blood from 574 patients was drawn by emergency department staff, who immediately tested the samples with the PCA and transported them for plasma analysis on a reference analyzer in the clinical laboratory. Correlations between the PCA and the reference analyzer were as follows: R2 = 0.987 for urea nitrogen; R2 = 0.97, glucose; R2 = 0.937, K;R2 = 0.79, hematocrit; R2 = 0.751, sodium; and R2 = 0.689 for chloride. With its rapid turnaround, small sample requirement, and ease of operation, the PCA is most useful in an emergency department setting, where immediate access to clinically relevant laboratory testing is required in support of urgent clinical decision-making.

The subtitle of this text, How to Reach Any Audience Through Focused Preparation, Inspired Delivery, and Smart Use of Technology , sums up the two authors’ experience from years of teaching and giving workshops on presentations and provides a systematic approach for preparation of a presentation that should be read by anyone who teaches or has to make a presentation. Once the reader picks up this book, he or she will be hard-pressed to put it down. In preparation for a presentation, it will be invaluable because it clearly is a roadmap in itself and …

By means of a set of questionnaires, the Joint ASCP/CAP Task Force on Manpower survey of fact and opinion regarding manpower problems and needs of pathology in the United States was completed. The response from pathologists approached 75%. From this survey, there appears to emerge an accurate picture of the number of pathologists in solo or group practice in the United States in terms of board certification and age group; so that over a five-year period, there will be a net addition of approximately 1,800 pathologists from 500–700 residents completing their training annually. This survey showed a demand of 22% of pathology practices seeking to fill funded positions with a projected need within the next five years of approximately 2,700 to meet primarily expanded patient loads. The number of pathologists in the graduate medical education “pipeline” revealed 2,153 residents with about 76% of the residency positions filled. A match of approximately 2,153 residents entering pathology practice against 2,160 vacancies anticipated in the next four years was identified. However, it is likely that there will continue to be a modest deficit of pathologists five years from now in view of the possibility that not all will enter practice. In conclusion, the demand for pathologists and supply from residency programs seem to match well in numbers so that supply and demand for pathology manpower are in approximate balance.

For the year 1975, we examined 12,848 blood specimens using the type and screen as well as the crossmatch and detected 283 antibodies in 247 patients. Our screening reagent red blood cells were able to detect 96.11 per cent of these antibodies. If the antigen frequencies corresponding to those antibodies not detectable by our screening reagent red blood cells are taken into consideration. i.e., the incompatibility frequencies, the type and screen can be shown to be 99.99 per cent effective in preventing the transfusion of incompatible blood. Therefore, we believe that the type and screen may be safey substituted for the routine two-unit crossmatch in those operative procedures usually not requiring transfusions. Adoption of this approach would reduce patient charges, provide for more efficient distribution of our limited blood supplies, and allow for more effective utilization of blood-bank technologist time.

Effective utilization of clinical laboratories requires that underutilization, overutilization, and malutilization be appreciated and eliminated or reduced. Optimal patient care service, although subjective to a major extent, is reflected in terms of outcome and cost. Increased per diem charges, reduced hospital stay, and increased laboratory workload over the past decade all require each laboratory to examine its internal operations to achieve economy and efficiency as well as maximal effectiveness. Increased research and development, an active managerial role on the part of pathologists, internal self-assessment, and an aggressive response to sophisticated scientific and clinical laboratory data base requirements are not only desirable but essential. The importance of undergraduate and graduate medical education in laboratory medicine to insure understanding as well as effective utilization is stressed. The costs and limitations as well as the accuracy, precision, sensitivity, specificity, and pitfalls of measurements and examinations must also be fully appreciated. Medical malpractice and defensive medicine and the use of critical values, emergency and routine services, and an active clinical role by the pathologist are of the utmost value in assuring effective utilization of the laboratory. A model for the optimal use of the laboratory including economy and efficiency has been achieved in the blood bank in regard to optimal hemotherapy for elective surgery, assuring superior patient care in a cost effective and safe manner.

Summary. HLA-A and -B antigens were determined for 94 children with acute lymphocytic leukaemia (ALL) and for 376 normal controls. Sixty-four of these 94 patients were typed for lymphocyte surface markers and 59 were defined as ‘null cell’ ALL. There was no difference in the distribution of the HLA-A or -B locus antigens between the control group and the entire group of patients with ALL or the ‘null cell’ subgroup. Patients with HLA-A9 determinants had a significant increase in early, first remission duration compared to patients without HLA-A9. This was particularly evident in the ‘null cell’ ALL subgroup. In addition, HLA-A9 appeared to be an independent factor affecting the length of first remission since there was no correlation between known prognostic factors such as patient age, sex or WBC and the presence or absence of the HLA-A9 antigen. Survival for the first 12–18 months was also greater in the HLA-A9 group than in the non-HLA-A9 population. Thus, the presence of HLA-A9 appears to be associated with some protective effect among patients with ALL.

The literature is reviewed regarding estimation of the postmortem interval (PMI) by chemical analysis of cadaver fluids. The most useful measurements on blood and CSF are amino nitrogen, nonprotein nitrogen, ammonia, creatine, and inorganic phosphate; these have some value in the early PMI. Probably the single most accurate determination is the potassium content of the vitreous humor, which shows a linear rise with time in the interval 12-100 hours postmortem. The rate of vitreous potassium rise is fairly independent of environmental influence. Other determinations that may prove valuable include the potassium content of the aqueous humor and the ammonia and magnesium content of the vitreous. Although no single measurement gives a completely reliable estimate of the PMI, combinations of chemical determinations can be useful adjuncts in cases of unwitnessed death.

Guidelines for preoperative crossmatch schedules based on patterns of blood usage in an individual institution and the benefits of the type and screen are explored. The safety of the type and screen as a pretransfusion evaluation is critiqued in light of the increasing frequency of providing uncrossmatched or partially crossmatched blood.

Several laboratory methods are currently available for the detection of barbiturates, but few are suitable for emergency use, The authors evaluated use of an ultraviolet spectrophotometric method as a screening procedure and compared the results with results obtained by other barbiturate methods (colorimetric, gas-liquid chromatographic, and immunochemical), Procedure time was approximately 40 minutes, sensitivity 0.2 mg/dl, precision (coefficient of variation) 5.4%, recovery 97.8% for phenobarbital, and there was good correlation with results obtained by gas-liquid chromatography and the EMIT system for phenobarbital. The authors recommend ultraviolet spectrophotometry as an excellent screening procedure for assessing the severity of barbiturate intoxication.

During a 20- month evaluation period from July 1977 through February 1979, blood specimens from 6,656 patients were given a type and screen. One hundred and fifty-four (2.3%) of these patients required blood transfusions, and so type and screen requests were converted to crossmatch. Although irregular antibodies were detected on type and screen for five of the 154 patients, all blood transfusion outcomes were uneventful. In previous reports, a procedure to develop guidelines for ordering blood,and the efficacy and safety of the type and screen were described. For five years at the State University of New York, the type and screen has been successfully and safely used for elective-surgery patients who are unlikely to require transfusions, but for whom blood should be available on demand if needed for an unexpected hemorrhage. The type and screen is a safe, resource-conserving, practical alternative to the more expensive traditional two-unit crossmatch for surgical procedures usually not requiring a blood transfusion.

Schumann, G. Berry, Burleson, Richard L., Henry, John Bernard, and Jones, David B.: Urinary cytodiagnosis of acute renal allograft rejection using the cytocentrifuge. Am. J Clin Pathol 67: 134–140, 1977. The clinical diagnosis of acute renal allograft rejection in immunosuppressed recipients can often be predicted or confirmed on the basis of characteristic urinary cytologic findings. Use of cytocentrifiigation permits a simple, rapid, reproducible and semiquantitative means of preparing cytologic urinary specimens of diagnostic quality from small quantities of urine. The cytodiagnosis of acute renal rejection was established before or on the same day a clinical diagnosis of rejection was made in the majority of renal transplant cases studied over a 12-month period. Renal tubular cells were found to be the exfoliated cells of greatest value in predicting an acute rejection episode, and their persistence has prognostic importance.

Five lactate dehydrogenase isoenzymes are normally observed in human serum: H4 (LDH1), H3M (LDH2), H2M2 (LDH3), HM3 (LDH4), and M4 (LDH5). This study presents evidence that these isoenzymes vary in the ratio of LDH activity (pyruvate → lactate) to LDH activity (lactate → pyruvate).

An Automatic Clinical Analyzer (DuPont ACA Prototype IV) was field evaluated. It is a discrete-sample, random-access analyzer which incorporates a new and unique method of performing chemical analyses. The analytical system is based on an expendable, clear plastic pack which serves as a reaction chamber and test cuvette. Serum specimens are introduced in plastic cups followed by plastic packs which are specific for each measurement. A report slip is generated which contains positive patient identification together with a list of measurements and results. Instrument performance was critically analyzed. Downtime was carefully noted. Erroneous results were detected by replicate analyses and comparisons with other methods. Acceptability by laboratory personnel was determined. The precision and accuracy of each method was analyzed, and normal ranges for young adults were determined. The Automatic Clinical Analyzer was found to be a reliable laboratory instrument with considerable potential for large and small volume workloads.

The reticulocyte count is a useful tool for evaluating anemia. However, its value depends on proper interpretation of the counting method used, taking into account any inherent error.

There is evidence that Q10 in the lactate to pyruvate spectrophotometric LDH assay may differ for heart and liver homogenates. The optimal lactate concentration for heart homogenate may increase from 0.4 to 0.6 M with change in temperature from 25° to 37°. Optimal lactate concentration for liver homogenate was 0.8 M at 25° and 0.6 M at 37°. These shifts in lactate optima with temperature are similar to those found by Vesell3. Differences in Q10 between LDH isoenzymes may make it difficult to compare LDH assays run at different temperatures on sera with different isoenzyme patterns. “Heart type” LDH would seem preferable for interlaboratory comparisons, since it conforms to the accepted Q10.

The method described is based on Dubowski’s o-toluidine procedure for the determination of glucose in plasma, serum, or cerebrospinal fluid. It utilizes the rapidity, precision, and closed system of continuous flow analysis of an unmodified AutoAnalyzer to substantially increase sensitivity and accuracy in the low range. The method is more specific than the ferricyanide reduction method. Protein precipitation or dialysis are unnecessary except for hemolyzed specimens and only 0.042 ml of sample are required. The method is inexpensive, easily performed, and compares favorably on a practical basis with enzymatic, reducing, and other aniline dye methods.

We evaluated a revised serum calcium method (o-cresolphthalein complexone) used with the Du Pont aca. Our results correlated well with those obtained by atomic absorption spectrometry. Within-run and day-to-day coefficients of variation were 0.5 and 1.5%, respectively. Color produced and calcium concentration are linearly related and the relation is not affected by hemolysis, lipemia, or icterus.

Quantitation of isoenzymes of lactate dehydrogenase by electrophoresis aids in diagnosis of diseases such as hepatitis and myocardial infarction. For accurate results, knowledge of isoenzyme distribution in various tissues and the half-life of each isoenzyme is important.

Free or unbound thyroxine (FT4) in serum comprises less than .1% of total circulating thyroxine. This small fraction is thought to be responsible for the physiologic action of thyroxine. Protein-bound iodine (PBI) butanol-extractable iodine (BE1) T4 by column and T4 by competitive protein binding are all measurements of total T4 in serum. They usually reflect thyroid status. However during pregnancy and with estrogen therapy total T4 is elevated and is not an accurate measure of thyroid disease as FT4 levels remain normal. This report describes a simplified rapid reproducible procedure for determining FT4 in serum. A 3.5-hour dialysis technic in which serum was diluted and labeled with T4-125 iodine was used. Subsequent purification of the dialysate was done with protein-coated charcoal. The shortened dialysis period eliminated the effects of bacterial contamination noted by longer methods. The protein-coated charcoal purification of the dialysate is less complicated than those previously described. Results compared favorably. Details of preparation of reagents and technics employed are given. Blood specimens were obtained from hyperthyroid and hypothyroid patients pregnant women women using oral contraceptives and euthyroid women sick with diseases not known to affect thryoid function. Diluted radioactive serum was prepared for each patient. Repeated freezing and thawing of serum samples with repetition of tests had no significant effect on results. Values between the various groups of patients agree with those found by other workers. Thyroid function in pregnant women and in women using oral contraceptives is shown by FT4 not total T4. The method described is suitable for routine use in clinical laboratories.

The use of microplate methods in extended erythrocyte typing of persons referred for paternity testing is described. Not only are the results as reliable as those of conventional tube methods, but a significant cost reduction and considerable savings in reagents and examination time are realized.

The Coleman 91 nephelometer provides rapid, simple amylase and lipase assays, which are particularly suited to emergency requests. Linearity of amylase compares favorably with that of the Phadebas assay, and comparable precision was obtainable with serum and urine. Normal ranges for serum amylase are slightly higher than those based on the amyloclastic end-point assay. The serum lipase assay shows improved linearity over titrimetric procedures, although kinetics remain variably non-linear. Occasional sera show discordantly elevated nephelometric lipase and normal titrimetric lipase. Precision of the nephelometric lipase assay is somewhat lower than that of amylase; normal ranges are considerably higher than those based on titrimetry. Extremely lactescent sera may yield falsely low nephelometric amylase and lipase activities: these sera must be serially diluted to achieve actual values.