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Biomedical subjects

C Müller

Publications and source records attributed to C Müller.

At least 145 records · Page 8Linked to original sources

The effect of a green leaf volatile on host plant finding by larvae of a herbivorous insect.

The role of a general green leaf volatile (glv) in host finding by larvae of the oligophagous chrysomelid Cassida denticollis was investigated using a new bioassay which takes into account the need for neonate larvae of this species to climb fresh host plants from the ground. A "stem arena" was designed in which plant stems of the host, tansy (Tanacetum vulgare), and stem dummies (tooth picks), both wrapped in perforated filter paper, were offered to neonate larvae. The wrapping allowed olfactory responses to be tested by preventing access to contact stimuli of stems and dummies. Larvae significantly preferred to climb the wrapped tansy stems over dummies after a period of 15 min. The test glv, (Z)-3-hexen-1-ol, was not attractive when applied to dummies. However, when the glv was applied to the bottom of the arena, the ability of larvae to discriminate between host stems and untreated dummies was significantly enhanced. More larvae climbed wrapped host stems than dummies even within 5 min. While numerous other herbivorous insects are known to be directly attracted by glv, this study shows that a singly offered glv on its own is unattractive to an herbivore but enhances the herbivore's ability to differentiate between host and nonhost plants.

Animals↗

[The Neuro-Mental Index. An addition to the Barthel Index for detection of impairments in basic psychological-mental diemsnions in neurorehabilitation].

The Barthel Index (BI) is the most commonly used scale for assessing impairment of activities of daily living (ADL). For a global view of patients' abilities and the care needed in everyday neurorehabilitation practice, additional information about basic psychological and cognitive functions is essential. We therefore designed a new disability scale comprised of assessments of consciousness, approachability, orientation, memory, behaviour, emotions, communication, problem solving, perception, and behaviour at night. The scale shows exactly the same inner structure as the BI, with ten items and a score of up to 20 in steps from 0-100% (or 0-20 points). By a careful weighing of the items, the final score of the neuromental index (NMI) should create a clearer picture of both the disabilities and the needed resources. A second aim was to cover a broad range of patients including those in coma and coma remission states and those with only slight neuropsychological or behavioural symptoms. The NMI was examined with a group of 179 neurorehabilitation inpatients and proved to be highly valid, reliable, and practicable. It was designed to enable a global assessment of disability as well as the care resources needed, even in patients with different disability levels in ADL and psychological and cognitive functions.

Activities of Daily Living↗

Transplant activities in Germany in 1998--a survey facilitated by the National Registry for Hemopoietic Stem Cell Transplantation.

To improve the infrastructure of hemopoietic stem-cell transplantations in our country, the German Registry for Hemopoietic Stem-Cell Transplantations (DRST) was established in 1998. The present paper summarizes the current status of the DRST and gives a survey of transplant activities in Germany in 1998 in terms of transplant units, transplant types, transplant frequencies and underlying diseases.

Blood Cells↗

[Volume determination of pigment epithelium detachment in AMD by laser scanning tomography].

BACKGROUND: The possibility of using 3D mapping of AMD-related RPE detachments by means of laser scanning tomography was evaluated to correlate the fluorescein and tomographic findings. METHODS: Sixty eyes with AMD-related RPE detachments of 55 consecutive patients (19 men, 36 women) between 54 and 87 years of age (mean: 72.2 years) were examined using the Heidelberg Retina Tomograph (HRT). The parameters considered were area, volume, maximal height and 3D configuration of the RPE detachments. The tomographic data were analyzed and correlated with the fluorescein angiographic findings. Follow-up examinations were done at 3 and 6 months later. RESULTS: The mean +/- SD area of elevation was 10.59 +/- 5.51 mm2 (range, 0.93-19.73), which correlated well with the angiographic measurements. The mean maximal height was 0.42 +/- 0.19 mm (range, 0.11-0.83), mean volume was 2.55 +/- 1.9 mm3 (range, 0.073-6.63). We found a tendency to grow for untreated RPE detachments, depending on the volume at the first measurement. Three RPE detachments of high volume (mean 0.501 +/- 1.3 mm3) resulted in tearing of the RPE. The angiographic findings of localized neovascularizations in the RPE detachment area (39 of 60 eyes) showed a corresponding irregularity of the surface in most of the correlating 3D HRT figures. CONCLUSIONS: Confocal laser scanning tomography allows analysis of 3D configurations and a quantitative measurement of RPE detachments in AMD. Therefore, this diagnostic technique appears to be useful, especially for differentiated follow-up examinations (as in therapy-control studies). Furthermore, the analysis of 3D configurations seems to be useful to estimate the risk of tearing of the RPE and may help to indicate underlying neovascularizations.

Aged↗

[Ophthalmodynamometry. A reliable procedure for noninvasive determination of intracranial pressure].

BACKGROUND: Central vein pressure depends on intracranial pressure (ICP). Baurmann in 1925 therefore recommended measuring central vein pressure to determine ICP, but the accuracy of this method has not yet been verified. To test the method we measured venous outflow pressure (VOP) by noninvasive ophthalmodynamometry (ODM). METHODS AND MATERIALS: We studied 31 patients with suspected increased ICP. ICP was recorded continuously for a minimum of 24 h by intraventricular catheters, and ODM was performed during ICP measurement. The findings were compared with the results of conventional invasive ICP measurement. RESULTS: Pressure in the central retinal vein was highly correlated with ICP. CONCLUSION: Measuring VOP by ODM seems to be a reliable method for noninvasive recording of ICP. It is a useful screening test in all cases of presumed ICP elevation.

Adolescent↗

[C-reactive protein as an independent marker of prognosis in acute coronary syndrome: comparison with troponin T].

BACKGROUND: It has been suggested that inflammatory processes play a role in the pathogenesis of acute coronary syndromes (ACS). C-reactive protein (CRP) is a classic acute phase protein. It is yet unclear whether, in addition to established markers as troponin T (TnT), determination of CRP in patients admitted for ACS contributes significantly to the diagnosis and prognosis of ACS. PATIENTS AND METHODS: We investigated 50 patients with ACS (59.4 SD 13.9 years) in the first hour after admission and 4-24 h later with respect to TnT (Elecsys, Roche Diagnostics) and CRP (biokit, modified Quantex CRP plus, analytical sensitivity 0.02 mg/dL). Fifty percent of the patients were classified as having unstable angina retrospectively. All patients were followed in the 6 weeks post discharge regarding death and recurrent ACS. RESULTS: The cumulative event rate at 6 weeks after discharge was 62.5% for patients being CRP and TnT positive compared to 35.3% in TnT positive and CRP negative patients. In TnT negative patients a positive CRP test predicted 33.3% of events and 28.8% of patients negative for CRP and TnT had events at 42 days post discharge. Logistic regression analysis regarding the primary endpoint including TnT and CRP (4-24 h values), age, gender and diagnosis resulted in independent prediction of ACS or death by TnT (cutoff 0.1 microgram/L, p = 0.048, odds ratio = 7.5) and CRP (cutoff 0.862 mg/dL, p = 0.026, odds ratio = 5.3). Sensitivity/specificity for AMI diagnosis were 69.6%/75% for TnT and 12%/72% for CRP in the first hour and 91.3%/68.2% for TnT and 68%/72% for CRP 4-24 h later. CONCLUSIONS: Besides TnT, high sensitivity CRP determination has no additional value for early AMI diagnosis. The prognosis of these patients during the first 24 hours is significantly and independently predicted by CRP measurements in addition to troponin T.

Acute Disease↗

The role of carcinoembryonic antigen for the detection of recurrent disease following curative resection of large-bowel cancer.

BACKGROUND AND AIMS: During recent years, a discussion about cost-effectiveness and importance of follow-up evaluation after curative resection of large-bowel cancer has developed. It is not known whether the determination of carcino-embryonic antigen (CEA) plays a crucial role in the early detection of recurrent disease. PATIENTS/METHODS: We conducted an analysis of the prospective follow-up database of 1321 patients after curative resection of colorectal cancer in our institution between 1990 and 1998 to evaluate the role of CEA in the early detection of recurrent disease. RESULTS: Of the 1321 patients included in our study, 306 developed recurrent disease following curative resection (23.2%). These patients with recurrent disease were divided into: Group I. No pre-operative CEA determination/insufficient follow-up (n=47; 15.4%). Group II. No elevation of CEA with primary cancer (n=156; 51.0%): (IIa) elevation with recurrent disease (n=62); (IIb) no elevation at any time point (n=53); and (IIc) role of CEA not completely elucidated (n=41). Thirteen patients of group II underwent curative relapse surgery (8.3%). Group III. Elevated CEA with primary cancer (n=103; 33.7%): (IlIa) no increase with recurrent disease (n=21); (IIIb) increase with other symptoms of recurrent disease (n=45); and (IIIc) increased values as an early symptom of recurrent disease (n=37). Sixteen patients of group III underwent curative relapse surgery (15.5%). In patients after relapse surgery, recurrent disease developed again after a median time of 12 months (mean 17.9+/-3.8 months). CONCLUSIONS: Our findings indicate that 2.8% of all patients (12.1% of patients with recurrent disease) who underwent curative resection of colorectal cancer profit from follow-up CEA determinations. With careful observation of CEA kinetics, 6.2% (n=82) of all patients or 26.8% of patients with recurrent disease could profit from routine follow-up CEA determinations. In 9.5% of patients with recurrent disease, curative resection of relapse was achieved and these patients remained disease free for a median time of 12 months. Regular CEA measurements remain an important part of routine patient care after curative resection of colorectal cancer.

Adult↗

Endosonographic examination of gastrointestinal anastomoses with suspected locoregional tumor recurrence.

BACKGROUND: Endoscopic ultrasound is considered one of the best tools for the preoperative staging of esophageal, gastric, and rectal carcinoma. Depending on the individual investigator, the sensitivity of preoperative tumor staging by endosonography of the upper gastrointestinal tract (GEUS) is 80-92% for gastric carcinoma and 86-95% for esophageal carcinoma. However, the sensitivity and specificity of endosonography for the staging of lymph node metastases is less accurate. The accuracy of rectal endosonography (REUS) is approximately 90% for tumor assessment and approximately 80% for the detection of lymph node metastases. In this study, we address the question of whether endosonography enables the surgeon to distinguish scar tissue, which is rather homogeneous and echo-rich, from changes such as an anastomositis or a locoregional tumor recurrence, which are typically non-inhomogeneous and echo-poor. METHODS: During a 24-months period, we studied patients enrolled in a special tumor follow-up care program by either upper gastrointestinal (GEUS, n = 37 patients) or rectal endosonography (REUS, n = 49 patients) for exclusion of a locoregional tumor recurrence. In each patient, local tumor recurrence was suspected because of either medical history, clinical examination, or other diagnostic procedures. RESULTS: As in previous studies, our retrospective analysis revealed that endosonography has a high sensitivity in the detection of local tumor recurrences (>90%) for both GEUS and REUS. CONCLUSION: Endosonography is a highly accurate means of detecting local tumor recurrence.

Aged↗

Long-term results after video-assisted thoracoscopic surgery for first-time and recurrent spontaneous pneumothorax.

BACKGROUND: Few investigators have reported on results after video-assisted thoracoscopic surgery (VATS) for spontaneous pneumothorax (SP) with follow-up periods longer than 24 months. The aim of this study was to evaluate VATS for first-time and recurrent SP and to follow patients long-term. METHODS: One hundred nine patients were followed long-term after treatment of SP by VATS. Ninety-five patients had primary SP and 14 had secondary SP. Sixty-two patients had a first episode and 47 had a recurrence. In 72 patients leaks or ruptured blebs were identified and excised without subsequent pleurodesis. In 37 patients showing no ruptured bullae or leaks only pleurodesis was applied. RESULTS: Median follow-up was 53.2 months. Postoperative complications were rare. Three patients (2.7%) had a prolonged air leak. The long-term recurrence rate was 4.6%. Only those patients who had not received pleurodesis at the time of first treatment by VATS experienced recurrence. CONCLUSIONS: Immediate postoperative results show VATS to be a safe and reliable method in first-time and recurrent SP to obtain quick reexpansion of the lung. Long-term recurrence rates are acceptable and compare with results after open thoracotomy. Pleurodesis should be included in each procedure for adequate recurrence prevention.

Adult↗

The acute coronary syndrome diagnosis and prognostic evaluation by troponin I is influenced by the test system affinity to different troponin complexes.

It was suggested recently that cardiac troponins are released as T-I-C complexes and then further degraded to T and I-C. It is not known whether the various affinity to the T-I-C and I-C complex of different troponin I test systems influence the diagnostic and prognostic value of the test results in clinical practice. We studied 162 patients (61.3 S.D. 11.1 years) with suspected acute myocardial infarction (AMI) in a single center study. AMI was confirmed in 109 patients. Blood samples were taken at admission, after 1, 2, 4, 8, 12 and 24 h. Troponin I (TnI) was measured using the OPUS plus (TnI-O, cut-off 1.6 microg/l) and the Stratus II (TnI-S, cut-off 1.5 microg/l) analyzers. TnI-O has high affinity to the binary (I-C) and TnI-S to the ternary (T-I-C) troponin complex. A 6-month follow-up with respect to death and recurrent AMI was performed. The sensitivity (SE) and specificity (SP) for AMI diagnosis were 82.6 and 86.8% for TnI-S; 75.2 and 92.5% for TnI-O 0-2 h after admission. The ROC analysis showed a slightly better curve for TnI-S at 4 h (P<0.05). Logistic regression analysis shows prediction of 6 months outcome by 0-24 h serial TnI-S measurements (odds ratio 5.21, P=0.0356), and serial TnI-O measurements (odds ratio 4.92, P=0.0186). High affinity to the ternary troponin complex enhances the diagnostic but not the prognostic value of a test system. Indeed, the resulting differences are small but underline the need for standardization of biochemical markers.

Acute Disease↗

Neuronal-glial interactions and behaviour.

Both neurons and glia interact dynamically to enable information processing and behaviour. They have had increasingly intimate, numerous and differentiated associations during brain evolution. Radial glia form a scaffold for neuronal developmental migration and astrocytes enable later synapse elimination. Functionally syncytial glial cells are depolarised by elevated potassium to generate slow potential shifts that are quantitatively related to arousal, levels of motivation and accompany learning. Potassium stimulates astrocytic glycogenolysis and neuronal oxidative metabolism, the former of which is necessary for passive avoidance learning in chicks. Neurons oxidatively metabolise lactate/pyruvate derived from astrocytic glycolysis as their major energy source, stimulated by elevated glutamate. In astrocytes, noradrenaline activates both glycogenolysis and oxidative metabolism. Neuronal glutamate depends crucially on the supply of astrocytically derived glutamine. Released glutamate depolarises astrocytes and their handling of potassium and induces waves of elevated intracellular calcium. Serotonin causes astrocytic hyperpolarisation. Astrocytes alter their physical relationships with neurons to regulate neuronal communication in the hypothalamus during lactation, parturition and dehydration and in response to steroid hormones. There is also structural plasticity of astrocytes during learning in cortex and cerebellum.

Animals↗

Comparison between a nucleic acid sequence-based amplification and branched DNA test for quantifying HIV RNA load in blood plasma.

HIV RNA was quantified in blood plasma from 209 patients and in control specimen comparing the NucliSens HIV-1 QT test (Organon Teknika), which is based on the nucleic acid sequence amplification procedure, and the Quantiplex 3.0 test (Bayer), which uses hybridization signal enhancement by branched DNA (bDNA) probes. A highly significant correlation (P=0.01) was found between the two methods with 88% of the samples showing similar results. In cases of discrepant findings, higher virus load was observed with either test (14xNASBA>bDNA; 12xbNDA>NASBA). Differences could neither be related to clinical features nor to divergent virus subtypes. Standard preparations containing 35000 and 222000 copies were quantified with intra-assay coefficients of variation of <20% using both methods. A preparation of 192 copies was measured with lower precision by both tests, yet was detected more reliably by the bDNA method.

Blotting, Western↗

Hepatitis B virus DNA in sera and liver tissue of HBsAg negative patients with chronic hepatitis C.

BACKGROUND/AIMS: Hepatitis B virus (HBV) DNA has been detected in HBsAg-negative patients with hepatitis C. We determined the rate and explored the clinical significance of HBsAg negative HBV coinfections in Austrian patients with chronic hepatitis C. METHODS: Sera (n=82, group I) or liver tissue (n=16, group II) from 98 HBsAg negative Austrian patients with chronic hepatitis C were examined for HBV DNA by nested polymerase chain reaction (PCR). For control purposes, sera from 15 patients with chronic HBV infection (8 HBsAg positive, 7 HBsAg negative, all HBV PCR positive) were examined. RESULTS: HBV DNA was detected in 22% of sera and 19% of liver tissue specimens of patients with chronic hepatitis C. No significant difference in mean aminotransferase values, markers of HBV infection, inflammatory disease activity, or degree of hepatic fibrosis was observed in patients with or without HBV DNA. Anti-HBc alone as a marker of past HBV infection was more frequent in chronic hepatitis C patients compared to control individuals. Negative HCV PCR was more common (p=0.009) among patients with positive HBV PCR in serum. When examining repeat sera for HBV DNA, positive results were obtained in previously negative, but also negative results in previously positive patients. CONCLUSIONS: Coinfection with HBV can be demonstrated by PCR in a considerable number of HBsAg negative Austrian patients with chronic hepatitis C. HBV infection seems to suppress HCV replication even in HBsAg negative patients with dual infection. HBV coinfection in HCV infected patients cannot be excluded by negative HBsAg status alone. Repeat PCR examinations are needed to exclude dual infections.

Adult↗

Multiple sclerosis associated amino acids of polymorphic regions relevant for the HLA antigen binding are confined to HLA-DR2.

Among the candidate genes for multiple sclerosis (MS), the strongest influence is conferred by human leucocyte antigen (HLA) class II genes, in particular the DR2, DQ6, Dw2 haplotype (DRB1*1501, DQA1*0102, DQB1*0602). Similar to other autoimmune diseases, it is not clear yet how the presence of a specific HLA-DR or -DQ molecule translates into an increased disease susceptibility. Previous observations by us and others imply a HLA-DR2 dependent propensity of antigen-specific T-cell lines to produce increased amounts of TNF-alpha/beta as one mechanism how DR2 could contribute to susceptibility. In this article, we investigated the distribution of polymorphic stretches of the DRB1, DQA1, and DQB1 chains known to be relevant for antigen binding, in 66 unrelated patients with relapsing remitting MS and 210 unrelated controls. We found a significant association with disease for the appearance of proline at position 11, arginine at position 13, and alanine at position 71 of HLA-DRbeta1. Surprisingly, we identified only residues preferentially expressed in the MS group that were related to HLA-DR2. Thus, the contribution of HLA class II to the pathogenesis of MS is not mediated by allele-overlapping antigen binding sites, but is confined to the disease associated HLA allele.

Alleles↗

Cyanotic nephropathy and use of non-ionic contrast agents during cardiac catherization in patients with cyanotic congenital heart disease.

BACKGROUND: Chronic cyanosis with its associated rheologic changes is a known risk factor for glomerular nephropathy. Therefore, contrast-induced nephrotoxicity should be an important consideration for angiographers comparable to diabetics. On the other hand, progressions in diagnostic and interventional techniques have led to expanded indications and a more widespread use of x-ray contrast agents. The aim of this study was to investigate the risk of contrast-induced nephropathy in the small group of patients with cyanotic heart disease prior to surgical repair. METHODS: We investigated 23 cyanotic patients with an oxygen saturation of 82 (50-92)%, age 25 (5-63) years, and 13 control subjects with atrial septal defect, age 37 (20-66) years. Blood viscosity was measured before and after cardiac catherization. Renal damage was evaluated by selective analysis of urinary proteins and enzymes. RESULTS: Before cardiac catheterization, 48% of the cyanotic patients had a moderate glomerulopathy. Cardiac catherization was performed with 3.0 (1.2-6.8) mls/kg non ionic contrast medium. Only one of the 23 patients (4.3%) with normal urinary analysis before cardiac catheterization showed renal damage, which involved tubular and glomerular function. Elevated blood viscosity in cyanotic patients was slightly reduced by the contrast. None of the acyanotic controls had contrast-induced nephropathy. CONCLUSIONS: The use of non-ionic contrast medium does not worsen cyanotic glomerulopathy. This finding may be due to the reduction of blood viscosity by the application of the contrast medium. The finding of contrast-induced nephropathy in one patient underlines the importance of monitoring renal function after cardiac catheterization.

Adolescent↗

[Acute pancreatitis--clinical and technical laboratory diagnostic and prognostic assessment].

The incidence of acute pancreatitis within 100,000 inhabitants a year differs between 5 (Bristol) and 80 (USA). Even though the diagnosis of pancreatitis has become easier by the measurement of specific pancreatic enzymes there are still 30-40% of the fatal cases which are first diagnosed at autopsy. It is of utmost importance to assess the diagnosis and the severity of acute pancreatitis in the beginning to identify those patients with severe or necrotising disease who benefit from an early initiated intensive care therapy. Additionally, in view of new therapeutical concepts (e.g. antibiotic therapy in severe forms) and for the evaluation of new drugs, patients should be staged into mild and severe disease as early as possible. In most cases it is not possible to assess the severity clinically on hospital admission. Up to now the "gold standard" are imaging procedures (contrast-enhanced CT and MRI) which should be reserved for the severe cases to estimate the extent of pancreatic necrosis. The ideal predictor in blood or in urine should be objective, reliable, inexpensive, easy to measure, widely available, sensitive and specific. There are a variety of mediators of the "systemic inflammatory response syndrome" which are elevated in this disease (C-reactive protein, antiproteases, enzyme activation peptides like trypsinogen activation peptide (TAP) and carboxypeptidase B activation peptide (CAPAP), PMN-elastase, complement factors, chemokines and interleukins and others). Among all these mediators, C-reactive protein is the parameter best analysed. It has to be taken into account that it is not specific for AP and it's highest efficacy is reached after > 48 hours after the onset of disease. However, because usually a certain time elapses (approximately 24-48 hours) until patients are hospitalised the time delay seems not to a major disadvantage.

Acute Disease↗

Going back to the roots: effective utilisation of HLA typing information for bone marrow registries requires full knowledge of the DNA sequences of the oligonucleotide reagents used in the testing.

Information obtained by DNA-based HLA typing assays is more detailed and of higher quality than that obtained by conventional serological techniques. Nevertheless, it is common for data acquired in this way to be presented in the more familiar serological format. In many cases this representation can lead to significant loss of information, which may only become apparent at a later time, with the discovery of novel allele sequences. DNA-based typing methods, such as sequence-specific oligonucleotide probing (SSOP) or sequence-specific priming (SSP) generate fragmentary sequence data which is information rich. An alternative to assigning allele names to these fragments is to simply store the sequence data itself without interpretation. Bone marrow donor repositories can then be searched directly with sequence information, which though complex is more complete, rather than searching by derivative allele names.

Base Sequence↗

18F-fluorodeoxyglucose (FDG)-PET features of focal nodular hyperplasia (FNH) of the liver.

AIM: The aim of this paper is to describe the imaging pattern of focal nodular hyperplasia (FNH) by l8F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET). METHODS: Eight consecutive asymptomatic patients with histologic proof of FNH underwent 18F-FDG PET imaging. The lesions were found incidentally. The 18F-FDG PET imaging was performed with a dedicated PET tomograph after intravenous injection of 300-370 MBq 18F-FDG. The 18F-FDG accumulation in the lesions was (semi)quantified by calculating the standardized uptake value (SUV) and SUV has been corrected for the lean body mass (LBM). Eight patients with liver metastases spread from melanoma (n=2) and colorectal carcinoma (n=6) served as controls. The size of the FNH lesions and of the control group ranged from 2.0 to 8.5 cm (mean 4.83 cm +/- 2.37) and from 1.5 to 6 cm (mean 3.28 +/- 1.52), respectively. RESULTS: While in malignant liver lesions the accumulation of 18F-FDG was significantly increased, all FNH lesions showed normal or even decreased accumulation of 18F-FDG. In FNH lesions, SUV ranged between 1.5 and 2.6 (mean 2.12 +/- 0.38), whereas all liver metastases showed an increased SUV ranging between 6.20 and 16.00 (mean 10.07 +/- 3.79). The SUV corrected for LMB (SUVLBM) was similar to the SUV and ranged between 0.9 and 2.2 (mean 1.81 +/- 0.41) for FNH and between 5.9 and 16.3 (mean 9.15 +/- 4.03), respectively. CONCLUSION: In contrast to liver metastases, there is no increased glucose metabolism in FNH in vivo. The imaging feature of FNH by 18F-FDG-PET imaging is not specific for FNH; however, it may be helpful to differentiate FNH from liver metastases in cancer patients if radiological methods are not diagnostic.

Adult↗