Laboratory diagnosis of immune inner ear disease

Inherited antithrombin deficiency is associated with an increased risk of thrombosis, primarily venous rather than arterial. Most affected individuals have inherited only a single copy of an abnormal antithrombin (AT) gene. Homozygously affected individuals, although rare, have a severe thrombotic history of early onset and often affecting the arteries. We report two new cases of type II HBS (heparin binding site) deficiency in which the propositi are homozygous for the previously reported mutation 99 Leu to Phe, and who have a severe thrombotic history. These cases are considered alongside existing homozygote and compound heterozygote cases.     

Laboratory evaluation in the diagnosis of Lyme disease

PURPOSE: To provide a qualitative evaluation of the predictive value of the laboratory diagnosis of Lyme disease and to use the resultant data to formulate guidelines for clinical diagnosis. DATA SOURCES: A MEDLINE search of English-language articles or articles with English-language abstracts published from 1982 to 1996. DATA EXTRACTION: Sensitivity, specificity, and likelihood ratios were calculated, and a random-effects model was used to combine the proportions from the eligible studies. Prespecified criteria were used to determine which studies were eligible for analysis. DATA SYNTHESIS: Laboratory testing in general is not clinically useful if the pretest probability of Lyme disease is less than 0.20 or greater than 0.80. When the pretest probability is 0.20 to 0.80, sequential testing with enzyme-linked immunosorbent assay and Western blot is the most accurate method for ruling in or ruling out the possibility of Lyme disease. CONCLUSIONS: Laboratory testing is recommended only in patients whose pretest probability of Lyme disease is 0.20 to 0.80. If the pretest probability is less than 0.20, testing will result in more false-positive results than true-positive results; a negative test result in this situation effectively rules out the disease.     

Laboratory diagnosis before onset and prediction of Graves'' disease

BACKGROUND: The Canadian Coronary Atherectomy Trial (CCAT) assessed, in a randomized comparison, the clinical and angiographic outcomes following atherectomy with those following balloon angioplasty for the treatment of de novo lesions in the proximal one-third of the left anterior descending artery (LAD). Although the procedural success rate was somewhat higher and the postprocedure lumen larger in patients treated with atherectomy, lumen dimensions, restenosis rates and clinical outcomes were similar in the two groups at six months. To determine whether late differences emerged between the groups, clinical follow-up was obtained at a median of 18 (range 10 to 31) months after randomization. METHODS AND RESULTS: Patients were contacted monthly by telephone for the first six months. Subsequent follow-up information was obtained in 272 (99%) of the 274 randomized patients via a clinic visit or telephone interview with the patient and/or a relative. Additional information was obtained from the referring physician as required. There were no differences in adverse events between the two groups during follow-up. In patients randomized to atherectomy compared with balloon angioplasty, death occurred in 1.5% versus 2.2% (cardiac death 0.7% versus 0.7%); myocardial infarction in 5.1% versus 5.9% (Q wave 1.5% versus 1.5%); coronary bypass surgery in 13.1% versus 12.6%; and repeat target lesion intervention in 22.6% versus 21.5%. Persistent or recurrent Canadian Cardiovascular Society class III/IV angina not treated by a further intervention was present in 1.5% versus 2.2%. The combined end-point of death or nonfatal myocardial infarction occurred in nine (6.6%) versus 11 (8.1%) patients and any adverse cardiac event in 50 (36.5%) versus 53 (39.3%). Multivariate logistic regression indicated that unstable angina, reference vessel size and preprocedure minimum lumen diameter were the only variables independently associated with adverse events. CONCLUSIONS: The initial choice of directional atherectomy or balloon angioplasty had no impact on clinical outcome over a period of 18 months in this patient population. With either technique, just over 60% of patients with proximal LAD disease experienced sustained symptomatic improvement without an adverse event following a single procedure, and 80% achieved this status following a repeat percutaneous intervention.     

Laboratory diagnosis of plague

Recently, progress of studies and technique developments on human and mammalian fertilization and early embryonic development in vitro are markedly. At the present time, however, some problems are remaining. In mammalian embryo culture, the major obstacles to progress in analysing epigenic regulation of development in other than the mouse and rabbit are the infamous blocks to development in vitro. At the present time, further studies are needed to dissolve the precise mechanism of these blocks. Factors which affect on embryo development are a great number and analysis of them is considered to be important for clinical application of the embryo culture system. Intracytoplasmic sperm injection(ICSI), at the present time, is employed widely for basic research and the treatment of male infertility. Using ICSI, recent studies are showing that mouse round spermatids can fertilize mature oocyte and the fertilized oocytes(embryos) develop into normal offspring after embryo transfer to foster mothers. Also, a recent report indicates development of normal mice from oocytes injected with secondary spermacyte nuclei. However, since some unsolved problems on spermatogenic cells such as round spermatids and secondary spermacytes remain, further studies are needed.     

Laboratory diagnosis of allergic inflammation

Monitoring of allergic inflammation includes direct examination of biopsy specimens from mucosa and epithelium, and indirect study by sputum, bronchoalveolar and nasal lavage fluid and peripheral blood. Although, some of these detection assays are not applicable to clinical use, it is now possible to measure a number of inflammatory mediators released from cells participating in allergic disease. The release of performed histamine from peripheral blood basophils challenged with specific antigen remains a valuable in vitro correlate of immediate hypersensitivity reactions. However, other mediators such as LTC4 and IL-4 are also generated by basophils upon IgE dependent activation. Tryptase and PGD2 are released from mast cells upon activation. Eosinophils contain in their granules proteins that cause damage to the bronchial epithelium: MBP and ECP. It is possible to measure soluble markers from other cells (T cells, macrophages, platelets, endothelial cells) involved in allergic inflammation. Detection of mediators have produced data that have significantly added to our understanding of the mechanisms and allowed better pharmacological control of allergic inflammation.     

Laboratory diagnosis of Lyme borreliosis

Three stages can be observed in Lyme borreliosis: the acute stage (with dermal and systemic disease), an intermediate stage (with neurological and cardiovascular complaints and myositis), and a chronic stage (with arthritis, low back pain, dermatological and neurological complaints). If no acute stage with erythema chronicum migrans is seen, laboratory tests must provide the diagnosis. In the so-called two-test protocol at least two different tests must be positive for a definite diagnosis. Because culture is difficult, serology (demonstration of specific IgM and IgG antibodies against spirochaetal antigens) is the preferred technique. Cross reactions, antigenic variations and differences in antigenic expression in American and European strains may cause false-negative and false-positive results with the current tests. Moreover, previous use of antibiotics can interfere with the production of specific antibodies, and the effect of therapy is not correlated with height and behaviour of antibody titres. Additional investigation with immunoblot techniques, demonstrating specific antibody patterns may be valuable. An interesting alternative, not yet fully developed, is detection of specific antigens in tissues.     

Laboratory diagnosis of bacterial vaginosis

Microbiological analysis of discharge from the genitals in passenger car conductors (5787 women and 1496 men aged 20 to 40) showed Gardnerella vaginalis to be the most frequent agent of urogenital infection. It was isolated in 26% cases, whereas Trichomonas were isolated in 2.5%, fungi in 1.5%, and gonococci in 0.27% cases. The diagnosis of gardnerellosis is reliable if the key cells are found. Monoinfection with G. vaginalis was diagnosed in 80% patients, the overwhelming majority (74%) of carriers of this bacterium had no inflammatory symptoms, and in only 26% the carrier state was associated with the presence of leukocytes and histiocytes, more often in the cervix. In men the carrier state was detected in 0.4% cases. The clinical picture of Gardnerella infection is similar to that of infection with Mobiluncus, which is little known. This infection occurred 10 times less frequently (2.5%) than gardnerellosis, but in 92% cases it was a component of mixed infection, most frequently in association with G. vaginalis. A little known fungus Leptothrix was found in the genital discharge of 4% examinees, mostly women, but sometimes in men as well; it is represented by 3 types of ramifying threads. The practitioners are to know these infections causing specific diseases, such as bacterial vaginosis, which are often responsible for serious complications in gynecology and obstetrics.     

Laboratory diagnosis of perinatal infections

The application of new technology to the diagnosis of infectious disease in neonates has markedly increased the potential for early clinical intervention. Although far from perfect, the new tests have increased knowledge of the nature of these diseases and give physicians the opportunity to apply current treatments more effectively as well as to develop new modes of therapy for this important class of diseases.     

Laboratory medicine in ulcer disease

The role of laboratory medicine in ulcer disease is poorly defined. However there is increasing evidence of the clinical usefulness of some laboratory tests that investigate secretory functions and defensive properties of the stomach, gastrointestinal hormones and Helicobacter pylori infection. These tests may modify the clinical management of patients with peptic ulcer by identifying H. pylori positive subjects, patients with high acid output, patients who do not respond to antisecretory therapy, and patients with high gastrin levels in whom Zollinger-Ellison syndrome may be suspected. Here we review the clinical value of laboratory tests in ulcer disease, particularly as concerns the cost/benefit ratio. The relative merits of these tests are described giving an indication of their possible role in the diagnostic algorithm.     

Laboratory confirmation of the diagnosis of cystic fibrosis

The recent commercial introduction of a method for detecting albumin in meconium makes screening for cystic fibrosis feasible for many hospitals. If the tests is adopted, confirmatory tests should be available. Quantitative analyses of sweat for sodium by flame photometry and for chloride by silver titration and ion-sleective electrodes are now used as confirmatory tests. We compare results of these confirmatory methods applied to presons with cystic fibrosis, respiratory disorders, or digestive disorders, and to control subjects.     

Spiral computer tomography in diagnosis of hepatic diseases]

Spiral computer tomography (SCT) is a new method of computer tomography by which, in contrast to conventional CT, the information about absorptional capacity of tissues is obtained without omission of images which makes it possible to build MPR and 3D of a very high quality. 205 patients with diseases of hepatopancreatoduodenal area were examined, in 189 patients the diagnosis being verified. Optimal technique of intravenous bolus contrasting in SCT was developed. Using various time interval between the start of the scanning and the beginning of infusion of contrast media, it is possible to obtain primary image of the arteries (arterial phase of contrasting, time of delay 18-25 sec.), the picture of veins and the image of saturation of hepatic parenchyma--(venous return phase, time of delay 60-80 sec.), to reveal characteristics of contrasting of the liver masses during delay (8-15 min) phase. The largest quantity of masses are revealed in arterial phase of contrasting. Specific features of contrasting in hemangiomas and malignant tumors of the liver has been revealed. Hemangiomas absorb contrast medium already at the early phase as hypercontrasted lacunas in an outlying areas, at a late phase they are hyperdenced in relation to hepatic parenchyma. Primary and metastatic tumors of the liver accumulate contrast medium in an early phase along the whole area and quickly lose contrast medium during parenchymal phase. The method of contrast intensification enables evaluation of interrelation between tumor and vessels, to determine passage of hepatic arteries and branches of portal and hepatic veins, to visualise choledochal duct, to determine the distance between hepatic and tumor surface, and to produce these data as a view of multiplanar and three-dimensional image (reconstruction). The effectiveness of obtained reconstructions in planning of the extent of surgical intervention is demonstrated.     

SPECT diagnosis of Creutzfeld-Jacob disease

SPECT with 99mTc-HMPAO was performed on a 65-yr-old patient with Creutzfeld-Jacob disease. Cerebral blood flow was heterogeneously decreased throughout the brain, differing from the pattern observed in other common types of dementia. These results suggest that HMPAO-SPECT may provide useful information in the differential diagnosis of dementia, specifically when Creutzfeld-Jacob disease is suspected.     

Early diagnosis of Alzheimer's disease

The diagnosis of dementia of Alzheimer type (DTA) in the early stage of the disease may be possible with the development of specialized memory consultations. After this diagnosis, we can inform family and even the patient in some cases, monitor the progression of disease, give or not treatment, and help family for daily life management (money, car driving, administration papers, etc.). The first step is to analyse the memory complaints of the patient and if possible of his family. The difficulties in everyday life are more informative than an anxious complaint of memory and some IADL deficiency appear early: difficulty to use phone, drugs, transports or checks. The patient examination by a practitioner or a neurologist has to be complete, even if normal in most of the cases. The practitioner has to explore without specific material, the main cognitive domain: the "5 words test" illustrates a useful memory tool, analysing two types of recall. We also must observe writing, digit span, naming and verbal fluency. The examination by a psychologist using standardized batteries of tests must always be driven by this clinical exploration using common scales like MMS or ADAS. In very early DTA, we may observe a cognitive decline limited to some aspects of memory (free long term recall, cued recall, working memory...) with a decline of the most controlled attentional tasks. An isolated memory disorder has to be identified either as onset of DTA or as an aging related cognitive decline (ARCD): the difference is qualitative and may appear only on repeated exams by experimented psychologist.     

Differential diagnosis of Alzheimer's disease

The differential diagnosis of Alzheimer's disease has dramatically changed since the evolution of the diagnostic strategies (with definition of neuropsychological, behavioural, and imaging patterns) and disposal of cholinergic drugs indicated in Alzheimer's disease. The question is no more centred on exclusion of the traditional reversible dementias or depression. It is centred on the distinction between Alzheimer's disease and other degenerative diseases still often misdiagnosed with Alzheimer's disease such as frontotemporal dementias, dementia with Lewy bodies, and some focal atrophies that do not have the same physiopathology and should not be treated with anticholinesterase drugs. Besides, better knowledge on the links between cerebrovascular pathology and Alzheimer's disease, remind us that both pathologies may coexist and should be taken into account.     

Difficult diagnosis of Crohn's disease

It is often difficult to diagnose Crohn's disease because of the numerous clinical symptoms. In a retrospective study from 1963-1975 the initial diagnosis was examined in 101 patients with Crohn's disease. In 22% of the patients the initial diagnosis was correct, in 78% one or more wrong diagnoses were made. The most regular wrong diagnosis was colitis ulcerosa (30%). 41 patients were unnecessarily treated surgically before the correct diagnosis was established. The mean time from the on-set of the symptoms until the correct diagnosis was 3.6 years, the mean time from the first wrong diagnosis to the correct diagnosis, 2.9 years. In the later few years a decrease in wrong diagnoses, an increase in initially correct diagnoses and a shortening of the interval between beginning of symptoms until final diagnosis are recognizable. The possible reasons are discussed.