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Biomedical subjects

M Lichtenstein

Publications and source records attributed to M Lichtenstein.

At least 55 records · Page 3Linked to original sources
PubMed1990

Conversion of an old gamma camera to a bone mineral densitometer.

A 1974-vintage 25 cm field of view gamma camera was converted to a bone mineral densitometer using a purpose-built converging collimator with attached C-arm holding a 250 mCi gadolinium (Gd) 153 source. After addition of a second pulse-height analyser, increasing the high voltage gain and connecting to a digital computer, spinal and hip bone mineral density measurements were made. Accuracy of 2% and long-term reproducibility of 2.7% were obtained using an anthropomorphic bone phantom. For lumbar spine measurements in normal volunteers, long-term reproducibility was 3.2% and for osteoporotic (spinal fracture) patients (mean density 831 mg cm-2) reproducibility was 3.7%.

Absorptiometry, Photon↗
PubMed1990

Early detection of left ventricular mural thrombi after acute Q wave myocardial infarction using 111In oxine-labelled autologous platelets.

Autologous 111In oxine-labelled platelet scintigraphy was used to detect left ventricular thrombi in 20 patients with anterior and 18 patients with inferior Q wave myocardial infarction within 48-72 h. Left ventricular thrombi were found in 8/20 patients with anterior myocardial infarction and in 1/18 patients with inferior myocardial infarction, giving a total incidence of 24%. Patients with left ventricular thrombi were older (64.3 versus 58.2 years), had higher peak creatinine kinase (CK) levels (4523 versus 2749 IU 1-1), lower ejection fraction (19.5 versus 37.8%, P less than 0.005) and were more likely to have an enlarged left ventricle than those without left ventricular thrombi (87.5 versus 54.5%, P less than 0.001). Left ventricular thrombi were found overlying sites of myocardial infarction in 8 out of 9 patients. Apical left ventricular thrombi were 1.7 times more common than septal left ventricular thrombi. All patients received minidose heparin for prevention of deep venous thrombosis. This technique is complementary to echocardiography and may provide additional information in the difficult cases where the decision about full-dose anticoagulation is in doubt.

Adult↗
PubMed1990

A serial study of gastric emptying in anorexia nervosa and bulimia.

To determine the natural history of delayed gastric emptying of solid foods in anorexia nervosa (AN), gastric emptying was assessed by scintigraphy in 20 consecutive inpatients; eight had restrictive AN, ten had both AN and bulimia nervosa (BN), and two BN alone. Initial gastric half-emptying time (HET) exceeded 110 min (the upper limit of normal for the laboratory) in 16; their body mass index ranged from 11.7 to 18.1. HET showed a significant negative correlation with body mass (r = 0.71; p less than 0.001) but not age, duration of illness or use of psychotropic medication. Fourteen patients with prolonged emptying were retested; HET improved in nine of 12 retested at one month (p = 0.0005) but none showed a change in the lag phase of emptying. All four patients retested a further one to two months later achieved a HET less than 110 min. Fourteen patients reached a body mass index of 16.3 during treatment and HET improved to better than 110 min in all but one of these. However, normalisation occurred while body mass was still subnormal (less than 20.3) and with amenorrhea still present. This study shows that delayed gastric emptying in AN improves quite rapidly as feeding recommences; thus the motility disturbance is secondary to restriction in food intake and is not fundamental to the disorder.

Adult↗
PubMed1990

A single-photon emission computed tomography study of hypoperfusion after subarachnoid hemorrhage.

We used single-photon emission computed tomography with technetium-99m hexamethylpropylene amine oxime in 18 studies on 13 patients with subarachnoid hemorrhage to determine whether any changes in cerebral blood flow could be correlated with clinical or computed tomographic evidence of delayed ischemia. Among the seven patients without focal neurologic deficits, regional cerebral hypoperfusion was demonstrated in only one who died. Among the 10 patients with aneurysmal subarachnoid hemorrhage, one died before surgery, and six developed postoperative delayed ischemic deficits, of whom two died. Among the patients with angiographically documented aneurysms, regional hypoperfusion correlated with the presence and severity of delayed neurologic deficits, whereas correlative computed tomographic scans showed either early infarction or no relevant abnormality. This technique facilitates early diagnosis of cerebral tissue hypoperfusion due to vasospasm after subarachnoid hemorrhage.

Cerebral Angiography↗
PubMed1990

[Studies on the allergenic potential of palladium alloys].

Epicutaneous tests with test solutions of the European standard series and palladium chloride (1%) were performed in 486 patients of the University Hospital for Dermatology in Aachen. 17.9% of the patients exhibited Ni, 8.6% Co, 7.4% Pd and 4.1% Cr allergy. In 18 of 36 patients with a positive patch test reaction a further epicutaneous and epimucosal testing with metallic plates of pure palladium and a palladium alloy was performed. In 34 cases a positive skin reaction to palladium chloride was combined with a positive skin reaction to nickel sulphate. Only in one case was it possible to demonstrate an allergic reaction to a palladium metallic plate, which was tested additionally in artificial saliva. The results show that a dental alloy envisaged for use should be tested in an epicutaneous test, if the patient shows a positive reaction to the metallic salt solution. In case of positive patch tests to nickel sulphate, dental palladium alloys should not be used as an alternative unless sensitivity to palladium has been tested.

Dental Alloys↗
PubMed1989

Immunolymphoscintigraphy for the detection of lymph node metastases from breast cancer.

The presence of metastases in the regional lymph nodes is the major prognostic factor in breast cancer in the absence of overt distant metastases and is also an important indicator of the need for adjuvant therapy in "early" breast cancer. Currently, the accurate assessment of axillary lymph node status requires axillary dissection which has an associated morbidity. An alternative method of identifying patients who are "node positive" has been developed by means of immunolymphoscintigraphy with s.c. administered radioiodinated monoclonal antibody. The 131I-labeled anti-breast cancer antibody (RCC-1; 400 micrograms) and cold iodine-labeled "blocking" antibody (Ly-2.1; 2 mg which is nonreactive with breast cancer) were injected s.c. into both arms and scintigraphy images were obtained 16-18 h after the injection, using the axilla contralateral to the side of the breast cancer as the control. Studies were reported as positive (and therefore indicative of lymph node metastases) if the amount of background-subtracted radioactive count in the axilla of interest exceeded the normal side by a radio equal to or greater than 1.5:1.0 as assessed by computer analysis. In 38 of 40 patients the findings on scintigraphy were correlated with operative and histopathological findings on the axillary dissection specimen or cytological findings of fine needle aspiration of axillary lymph nodes. In a prospective study of 26 patients, the method is more sensitive (86%) and specific (92%) than preoperative clinical assessment (57% sensitivity, 58% specificity) in the detection of axillary lymph node metastases; and by combining both modalities of assessment, there was an improvement in the sensitivity (100%) but a deterioration in the specificity (50%). There was no significant complication from this essentially outpatient procedure and only 1 of 40 patients developed a human anti-mouse antibody response. This novel and safe method of imaging may become a most useful adjunct in the surgical management of breast cancer.

Animals↗
PubMed1989

The detection of axillary lymph node metastases from breast cancer by radiolabelled monoclonal antibodies: a prospective study.

In a prospective study to assess the accuracy of monoclonal immunoscintigraphy for the detection of axillary lymph node metastases in breast cancer, two murine monoclonal antibodies that react with human breast cancer (3E1.2 and RCC-1) were labelled with 131iodine, and the radiolabelled antibody was injected subcutaneously into the interdigital spaces of both hands of 40 patients, 36 of whom had breast cancer and the remaining four of whom had fibroadenoma (the normal, contralateral axilla was used as a control). Of the patients with breast cancer, the findings from the scintigraphy images were correlated with histopathology or cytology of the axillary lymph nodes; images were regarded as positive and hence indicative of lymph node metastases if the amount of background-subtracted radioactive count in axilla on the side of breast cancer exceeded the contralateral normal side by a ratio greater than or equal to 1.5:1.0 as assessed by computer analysis. Using this method, immunoscintigraphy had an overall sensitivity of 33% (23% with 131I-3E1.2 and 50% with 131I-RCC-1) for the detection of lymph node metastases and a specificity of 63% (67% with 131I-3E1.2 and 60% with 131I-RCC-1) with problems of non-specific uptake by presumably normal lymph nodes. The results of immunoscintigraphy obtained with 131I-RCC-1 (IgG) were superior to 131I-3E1.2 (IgM) although the accuracy of immunoscintigraphy using 131I-RCC-1 (56%) was not much better than preoperative clinical assessment (50%). However, there were cases when immunoscintigraphy using radiolabelled antibody (IgM or IgG) detected axillary lymph node metastases not suspected by clinical examination. Thus it appears that while immunoscintigraphy may be a useful adjunct to preoperative clinical assessment and is simple and safe, a major improvement in its accuracy is needed before it can replace axillary dissection and histological examination in the accurate staging of axilla in breast cancer.

Antibodies, Monoclonal↗
PubMed1987

Social stereotypes and information-processing strategies: the impact of task complexity.

Subjects read information about a defendant in a criminal trial with initial instructions to judge either his guilt (guilt judgment objective) or his aggressiveness (trait judgment objective). The defendant was either Hispanic or ethnically nondescript. After considering the evidence, subjects made both guilt and aggressiveness judgments (regardless of which type of judgment they were instructed to make at the time they read the information) and then recalled as much of the information they read as they could. Results favored the hypothesis that when subjects face a complex judgmental situation, they use stereotypes (when available and relevant) as a way of simplifying the judgment. Specifically, they use the stereotype as a central theme around which they organize presented evidence that is consistent with it, and they neglect inconsistent information. Subjects with a (complex) guilt judgment objective judged the defendant to be relatively more guilty and aggressive and recalled more negative information about him if he was Hispanic than if he was ethnically nondescript. In contrast, subjects with a (simple) trait judgment objective did not perceive either the guilt or aggressiveness of the two defendants to be appreciably different, and did not display any significant bias in their recall of the evidence. These and other results are discussed in terms of the information-processing strategies subjects are likely to use when they expect to make different types of judgments.

Aggression↗
PubMed1987

Heterogeneity of the human transferrin receptor and use of anti-transferrin receptor antibodies to detect tumours in vivo.

The human transferrin receptor (TFR) which is present on dividing cells, many tumours and erythroid precursors is readily identified using specific monoclonal antibodies. A new anti-human TFR monoclonal antibody, HuLy-m9, is described and its distribution on cell lines, normal and tumour tissue was examined and compared with two other anti-TFR monoclonal antibodies, namely, OKT9 and 5E9. The three antibodies were shown to recognise different epitopes on the surface of the TFR and have different reactivities with in vitro cell lines. Peptide map analyses of the TFR recognised by each monoclonal antibody from the same cell line were identical; however, differences were observed between cell lines. 131I-radiolabelled HuLy-m9 was used to successfully localise a nasopharyngeal carcinoma in vivo.

Antibodies, Monoclonal↗
PubMed1987

Uptake of 99mTc pertechnetate in a partial volvulus of the proximal jejunal loop.

High uptake of Technetium-99m Pertechnetate (99mTcO4) in situations unrelated to the presence of acid-secreting gastric cells has attracted recent attention. A 10 year old white girl, investigated for the possible presence of a Meckel's diverticulum, was found to have a partial volvulus of the proximal jejunal loop that exhibited intense localization of Technetium-99m Pertechnetate.

Child↗
PubMed1987

Technetium-99m radiopharmaceutical preparation by surface adsorbed stannous ions.

A method of producing technetium-99m (99mTc) radiopharmaceuticals is described, where reduction of pertechnetate occurs through stannous ions adsorbed on the surface of an infusion catheter. This leads to radiopharmaceuticals containing microgram quantities of stannous ions and that, therefore, results in minimal blood-pool labeling and essentially the elimination of tin colloids. Other advantages of the method include a reduction in quantities of ligand required and the possibility to mass produce the "tinned" catheters as technetium "reduction" kits. A wide variety of 99mTc radiopharmaceuticals have been prepared in high yield. Excellent biodistribution in several of these is demonstrated.

Adsorption↗
PubMed1986

Visualization of metastases from colon carcinoma using an iodine 131-radiolabeled monoclonal antibody.

A murine monoclonal antibody that reacts with human colonic cancer (250-30.6) was labeled with radioactive iodine (131I) and the antibody was injected intravenously into 15 patients with known metastases originating from carcinoma of the colon (10 cases), malignant melanoma (1), breast (1), pancreas (1), hepatocellular carcinoma (1), and adenocarcinoma of unknown origin (1). Of the patients with metastatic colon carcinoma, there were 19 known deposits as judged by the techniques of clinical examination, x-rays, and scans obtained using sulpha-colloid. Of these 19 deposits, 17 (90%) were found using the 131I-labeled monoclonal antibody. In one case, the primary tumor, previously undiagnosed, was found. In only 1 of the 10 patients was tumor not found and this was due to the subsequent finding that the undifferentiated tumor did not react with antibody. Of the five patients who did not have carcinoma of the colon, three had negative scans, but two were positive. Thus, the technique of immunoscintography can readily detect both primary and metastatic tumors.

Adenocarcinoma↗
PubMed1986

Assessment of bile flow by radioscintigraphy in patients with biliary-type pain after cholecystectomy.

Scintigraphy of the biliary system using 99mTc di-isopropyl iminodiacetic acid (DIDA) was performed in 65 subjects who had previously undergone cholecystectomy. Of the 65 subjects, 20 were free of pain and 45 had biliary-type pain both with (group I) and without (group II) features of sphincter of Oddi dysfunction. This dysfunction comprised dilatation of the bile duct, a transient rise in serum levels of liver enzymes after episodes of pain, or both abnormalities. After computer acquisition of images at intervals of 60 seconds for at least 90 minutes, time/activity curves were generated for five regions of interest: liver, common hepatic duct, common bile duct, duodenum, and background. The time at which counts in the common bile duct reached 50% of maximum (CBD T50) and the time of first entry of isotope into the duodenum (TD) were used to compare asymptomatic subjects with those with biliary-type pain. Patients in group I, but not those in group II, showed significant prolongation of CBD T50 (p less than 0.002) and TD (p less than 0.02) when compared to values in asymptomatic subjects. Six patients had a second scan at six to 12 months after endoscopic sphincterotomy and all showed a reduction in values for CBD T50 and TD. In patients with pain, a significant correlation was shown between bile duct diameter and CBD T50 (p less than 0.01) and between bile duct diameter and TD (p less than 0.02) but results from scintigraphy were independent of responses to morphine-neostigmine and motility in the sphincter of Oddi as assessed by endoscopic manometry.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1985

Associative storage and retrieval processes in person memory.

In this article, a general associative storage and retrieval theory of person memory is proposed, and seven experiments that test various aspects of the theory are reported. Experiment 1 investigated memory for behavioral information that is congruent with, incongruent with, or irrelevant to a prior impression. The results indicated that incongruent events are best recalled and irrelevant events are most poorly recalled. Experiment 2 replicated this effect and demonstrated that there are systematic individual differences that are consistent with the general nomothetic model proposed. The results of Experiment 3 indicated that, relative to a baseline condition, adding incongruent items to the list increases the probability of recalling congruent items but has no effect on the recall of irrelevant items. Both effects are predicted by the model. Experiment 4 provided support for the retrieval assumptions of the theory by demonstrating that there is a systematic order in which various types of items are recalled, as well as consistent differences in interresponse times. Experiments 5 and 6 demonstrated that the model is relevant to situations in which data driven, as well as conceptually driven, processes are involved. Finally, Experiment 7 examined a special case in which the theory predicts greater recall of congruent than incongruent behavioral events. The results of all seven experiments provide converging evidence for a general theory of person memory, and they have implications for a number of issues related to the study of person memory and social judgment.

Association↗
PubMed1984

Immunoscintigraphy for detection of lymph node metastases from breast cancer.

A radiolabelled monoclonal antibody that reacts with human breast cancer was injected into the web space of each hand in eight women with breast cancer, and the axillae were scanned 16-24 h later. Scans were positive in seven axillae with palpable lymph nodes and in two axillae with impalpable lymph nodes (metastases later confirmed by needle aspiration). The scan was negative in one axilla with a palpable mass, and here no tumour cells were obtained on needle aspiration. In a man with axillary lymphoma, no specific binding of antibody was observed. This technique could lead to earlier and more precise diagnosis of lymph node metastasis in patients with breast cancer.

Adult↗