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Biomedical subjects

J Linder

Publications and source records attributed to J Linder.

At least 163 records · Page 9Linked to original sources
PubMed1982

Amyloidosis complicating hairy cell leukemia.

A patient development renal failure following a ten-year affliction with hairy cell leukemia. Renal biopsy showed amyloidosis, characterized by the presence of potassium permagnate-sensitive congophilia in deposits within glomeruli and renal blood vessels. Electron microscopy demonstrated amyloid fibrils. Immunohistochemical technics showed the deposits were composed of AA Protein. These Congo red staining properties, and the presence of AA Protein are characteristic of deposits in secondary amyloidosis. Secondary amyloidosis is a known complication of many chronic illnesses. This report shows it may concur with hairy cell leukemia, and that amyloidosis should be considered in the differential diagnosis of renal failure in patients with hairy cell leukemia.

Amyloid↗
PubMed1982

Effects of cervical sympathetic stimulation on cerebral and ocular blood flows during hemorrhagic hypotension and moderate hypoxia.

The effect of cervical sympathetic stimulation upon regional blood flows was investigated in albino rabbits during graded hemorrhagic hypotension and mild to moderate hypoxic hypoxia. Regional blood flows were determined using labelled microspheres. Cerebral blood flow (CBF) decreased in response to progressive hypotension and increased considerably during hypoxia (100-200%). Unilateral sympathetic stimulation did not change the ipsilateral cerebral flow responses under either condition. There was a greater tendency to autoregulate down to lower blood pressures in deep than in superficial cerebral structures. During hypoxia cortical gray matter blood flow increased relatively more than did white matter blood flow. Blood flow in different parts of the eye decreased during hypotension and tended to increase during hypoxia. Unilateral sympathetic stimulation reduced flow rates on the stimulated side (10-50% of control side) under both conditions. The vasoconstrictory effect upon retinal blood flow tended, however, to be less during hypoxia. Dural blood flow showed a poor autoregulation and also no consistent vasodilatory response upon hypoxia. Sympathetic stimulation had a very marked effect. The results suggest that the cervical sympathetic nerves do not have any appreciable effect upon cerebral circulation during profound hypotensive and moderate hypoxic states. Dural and most ocular blood flows seem, however, to be clearly affected by sympathetic stimulation even under these extreme conditions.

Animals↗
PubMed1981

Effects of facial nerve section and stimulation on cerebral and ocular blood flow in hemorrhagic hypotension.

Albino rabbits were anesthetized and artificially ventilated. In two groups of animals the facial nerve on one side was sectioned and/or electrically stimulated at the internal acoustic pore. Hemorrhagic hypotension was induced to reveal a possible parasympathetic vasodilator mechanism, normally masked. The labelled microsphere method was used for flow determination. Section of the facial nerve did not produce any difference between sectioned and intact side, concerning cerebral, ocular and mandibular gland blood flows at normal or low blood pressures. Stimulation of the facial nerve at arterial hypotension produced significant ipsilateral increases in the choroidal and the mandibular gland blood flows. Regional and total cerebral blood flow remained unaffected. The results indicate no or only minimal contribution of the facial nerve to the cerebral vascular tone under conditions of general anesthesia. Further evidence is given in this study for a vasodilator pathway to the eye via the facial nerve, but the resting vasodilator tone under general anesthesia seems to be very low at normotensive as well as hypotensive states.

Animals↗
PubMed1981

Cerebral and ocular blood flow during alpha 2-blockade: evidence for a modulated sympathetic response.

The effect upon regional blood flows of alpha 2-blockade by yohimbine was investigated in albino rabbits before and during unilateral cervical sympathetic stimulation. The combined effects of i.v. angiotensin, alpha 2-blockade and sympathetic stimulation were also investigated. Regional blood flows were determined using the labelled microsphere method. Yohimbine produced high flow rates in the eyes, the dura, the choroid plexus and in the peripheral organs. Sympathetic stimulation during alpha 2-blockade caused significant blood flow reductions in the brain, the eye and in all other tissues investigated. In the brain the flow reduction was 20-25% in several structures. Angiotensin caused marked reductions in blood flow in the dura and in most peripheral tissues. The effects of sympathetic stimulation were not appreciably changed. The results suggest that vascular alpha 2-receptors affect the vascular tone in some organs and that presynaptic alpha 2-receptors modulate the response to sympathetic stimulation in the brain, the optic nerve and in the choroid plexus.

Adrenergic alpha-Antagonists↗
PubMed1976

Sympathetic control of cerebral blood flow in acute arterial hypertension.

The cervical sympathetic chain on one side was stimulated electrically at 10-20 Hz and an acute rise in arterial blood pressure was produced by: intravenous injection of angiotensin, ligation of the thoracic aorta, or ligation of the aorta combined with injection of metaraminol. The blood flow through the cerebrum and the cerebellum was determined by using labelled microspheres. At high blood pressures there was multifocal breakdown of the blood-brain barrier in the cerebrum as indicated by leakage of Evans blue. The breakdown was restricted to the control side or much more marked on that side than on the stimulated side. Sympathetic stimulation prevented also breakdown of the blood-aqueous barrier. The blood flow through the cerebrum on the control side was higher than that on the stimulated side in all experiments. Regions with breakdown of the blood-brain barrier had flow rates which were about 10 times normal values. Cerebellar blood flow was less affected by the hypertension and did not react significantly to sympathetic stimulation. The results indicate that stimulation of the sympathetic nerves to the brain tends to prevent forced dilatation of the arterioles with a resulting regional overperfusion with blood and breakdown of the blood-brain barrier. It is concluded that one role of the sympathetic nerves supplying the brain is to extend the pressure region with autoregulation in its upper part under conditions of a general increase in sympathetic vasomotor activity.

Acute Disease↗
PubMedDate not supplied

Ancient neurilemmoma of the infratemporal fossa: a case report.

Ancient neurilemmoma (schwannoma) is a rare variant of the neurilemmoma. It is a slow-growing, benign neoplasm with a favorable clinical course. Histologically, it can be confused with a sarcoma. A case of an ancient neurilemmoma of the infratemporal fossa is reported. The clinical, histologic, radiologic, and surgical aspects of this tumor are discussed with an emphasis on diagnosis and treatment.

Adult↗
PubMedDate not supplied

Peripheral T-cell lymphoma: a clinicopathologic study of 42 cases.

We analysed the clinical and pathologic features of 42 patients with immunologically confirmed peripheral T-cell lymphoma. The median age was 60 years and the male to female ratio was 1:1. A prior lymphoproliferative or autoimmune disorder was present in 14 per cent of the patients. Signs of advanced disease were usually present from the onset, such as B symptoms (55 per cent), generalized lymphadenopathy (57 per cent), stage III/IV disease (62 per cent), and elevated levels of serum lactate dehydrogenase (68 per cent). Primary extranodal disease (14 per cent), hepatomegaly (12 per cent), splenomegaly (12 per cent), lung/pleural involvement (12 per cent), skin involvement (21 per cent), and bone marrow involvement (28 per cent) were uncommon. Lymphocytopenia was present in 64 per cent of the patients, and none of nine patients tested were serologically positive for human T-cell leukemia/lymphoma virus (HTLV-I) infection. Among 38 patients receiving combination chemotherapy, 20 (53 per cent) achieved a complete remission. The actuarial median survival of all patients was 17 months. Age greater than 60 years and stage III/IV disease predicted a poor clinical outcome, whereas the large cell histological subtype predicted a favourable outcome. Prospective clinical studies using uniform treatments and a uniform histologic classification scheme are needed to confirm these findings.

Adult↗
PubMedDate not supplied

Evaluation in an inpatient setting of DTREE, a computer-assisted diagnostic assessment procedure.

This study examined the procedural validity of DTREE, a microcomputer-based expert system that guides the user through the diagnostic logic of DSM-III-R. A DTREE-guided DSM-III-R diagnosis of 20 inpatients (made by the treating clinician) was compared with a "standard" diagnosis made simultaneously during a weekly 2-hour case conference consisting of a presentation by the treating clinician and other staff, a chart summary, and the administration of the Structured Clinical Interview for DSM-III-R (SCID), and culminating in a group consensus diagnosis. The kappa agreements were .80 for schizophrenia (N = 10), .83 for major depression (N = 3), and -.08 to 1.00 for other disorders. These results suggest that DTREE can produce valid assessments, at least in an acute setting of primarily patients with schizophrenia.

Adolescent↗
PubMedDate not supplied

Cell preparation methods and criteria for sample adequacy. International Academy of Cytology Task Force summary. Diagnostic Cytology Towards the 21st Century: An International Expert Conference and Tutorial.

ISSUES: Cell Preparation Methods Standardized fixation and optimal staining Sampling of cervix, sampling error, homogenization of sample, subsampling Assessment of liquid-based preparations: efficacy and economic impact Training and transitional procedures before full implementation of new technologies Criteria for Sample Adequacy Clinician responsibility for collecting and providing representative sample to laboratory Collection instruments, number of slides Cellular content of samples: evidence of transformation zone (TZ) sampling, number of squamous cells present, obscuring factors Screening issues CONSENSUS POSITION The conventional cervical smear remains the standard method of cervical cancer screening but has limitations in individual test sensitivity and specificity. Sample takers should: (1) receive appropriate training in sample collection, (2) be held responsible for providing the laboratory with appropriate samples, and (3) have their performance monitored. The instruments used for sampling should collect cells from both the ectocervix and endocervix; optimally, TZ sampling, represented by the presence of endocervical or squamous metaplastic cells, should be identifiable in samples other than atrophic specimens. The adequacy of a specimen (as judged microscopically) does not guarantee that it is representative of the cervix. Each cytology report should include a comment on cellular content/adequacy of the specimen. Liquid-based preparations may overcome many of the inherent problems with the conventional cervical smear. ONGOING ISSUES: We need further data on the cost-effectiveness of making two slides from cervical specimens and/or using two samplers rather than a single one. Do we have enough information to make recommendations as to the appropriate type of sampler to be used in particular situations, such as routine screening? What is the best method of screening for/detecting endocervical glandular neoplasia? How are such terms as unsatisfactory and inadequate defined in cervical cytology classifications other than the Bethesda System? What number and types of epithelial cells should be present (visualized) in a cervical smear or liquid-based preparation for it to be considered adequate? Do we need to have evidence of TZ sampling in specimens taken during the follow-up period after treatment of squamous intraepithelial lesion or after detection of endocervical glandular neoplasia? What criteria for obscuring factors, such as blood and inflammation, should be used in assessing adequacy? Cost-benefit analyses of utilizing liquid-based preparations are needed. Should we inform women about the technical details of the test methods available or chosen by the laboratory? Are women in a position to decide which method is the most appropriate to assess their cervical scrape sample? We need to obtain more information about the properties of proprietary liquid fixative/transport media with respect to inactivation of viral pathogens, tuberculosis and other bacterial pathogens and suitability for immunobiologic and molecular tests, etc. We need to obtain more information on the use of stoichiometric stains and the limitations of Papanicolaou stain for image analysis systems. The use of liquid-based preparations for nongynecologic cytopathology and ancillary tests must be considered, including criteria for adequacy. We need to obtain more information on the time required for and best methods of training experienced cytotechnologists to become competent at assessing liquid-based cervical preparations.

Cell Biology↗
PubMedDate not supplied

The ThinPrep Pap test. A review of clinical studies.

OBJECTIVE: To review the literature describing the use of the ThinPrep system in gynecologic cytology. STUDY DESIGN: Clinical trials of the ThinPrep Beta and the ThinPrep 2000 performed in the United States were reviewed. In each a single sample was used to first prepare a conventional slide and the remainder to perform a ThinPrep cervical cytologic test. Slides were examined in a blind fashion by cytotechnologists and classified according to Bethesda System terminology. RESULTS: The ThinPrep test provided significantly more effective detection of low grade intraepithelial neoplasia or more severe diagnoses without loss of diagnostic specificity. The ability of the ThinPrep system to detect infection and reactive cellular changes was equivalent to or better than that of the conventional cytologic smear. Specimen adequacy was significantly enhanced with the ThinPrep test by reducing the number of cases classified as "Satisfactory but limited by...". CONCLUSION: The ThinPrep test offers increased detection of cervical disease and a clear improvement in specimen adequacy. In addition to potentially lowering the false negative rate of cervical smears, collection of cells in liquid medium allows additional testing, such as human papillomavirus typing and computer imaging, to provide a more comprehensive diagnosis than that obtainable with the cervical cytologic test.

Automation↗
PubMedDate not supplied

Sage advice. Experienced physician executives share the secrets of their success. Interview by David O. Weber.

Seven successful physician executives, now retired from distinguished careers, look back over their experiences and offer advice for those who follow. Be a good doctor first, and never let business interests undermine the ethics of the health care profession. Prepare for management responsibilities with business training. Seek out mentors and develop a network of knowledgeable colleagues and advisors. Exert leadership rather than authority. Expect disappointments and arm yourself for them.

Commerce↗
PubMedDate not supplied

Bronchoalveolar lavage in liver transplant patients.

Because immunosuppression is required to control rejection, liver allograft recipients are susceptible to a variety of opportunistic pathogens. A total of 191 bronchoalveolar lavage (BAL) specimens from 89 patients (53 adults and 36 children) who underwent orthotopic liver transplantation was reviewed. One case each of cytomegalovirus (CMV), staphylococcal and Enterobacter pneumonia was diagnosed with the aid of pretransplant BAL. The pretransplant BAL in 62 patients showed rare yeasts in 24.2%; these probably represent oropharyngeal contaminants since the patients involved had no symptoms of Candida pneumonia. Among 54 patients who developed respiratory symptoms and underwent posttransplant BAL, 23 (42.6%) were infected with opportunistic pathogens, including Pneumocystis carinii (22.2%), CMV (22.2%) and herpes simplex virus (HSV) (7.4%). Frequently, infection with multiple organisms was present. Adults constituted 100% of the HSV-infected group, 69.2% of the CMV-infected group and 16.6% of the group infected with P carinii. The diagnosis of these infections was aided by a combination of cytology, microbial culture and in situ hybridization techniques. Although BAL permitted the diagnosis and treatment of opportunistic infections, high mortality (62.5%) occurred with CMV and HSV pneumonia. Further studies into methods that permit earlier diagnoses of these infections are necessary.

Adult↗
PubMedDate not supplied

Bronchoalveolar lavage in the assessment of pulmonary Hodgkin's disease.

Abnormal chest radiographs in patients with Hodgkin's disease are occasionally due to pulmonary Hodgkin's disease. The fluids recovered from bronchoalveolar lavages (BALs) from 50 patients prior to autologous bone marrow transplantation for advanced Hodgkin's disease were examined. Abnormal chest roentgenograms were present in 24 patients (48%); 4 (17%) of these had Reed-Sternberg cells or their mononucleated variants in the lavage fluid and an alveolar lymphocytosis averaging 31.4% (normal: 11.5%). The lymphocytes were small and monotonous. Of the 20 patients with abnormal chest roentgenograms but no Reed-Sternberg cells in the lavage fluid, the lymphocyte count was 10.88%, with only 3 patients exceeding 17%. Two patients with normal chest roentgenograms had Reed-Sternberg-like cells in their lavage fluids and averaged 23% lymphocytes in their lavage differential count. Eosinophils averaged 1% or less of the lavage differential and were not predictive of pulmonary Hodgkin's disease. This experience suggests that pulmonary Hodgkin's disease can be diagnosed by BAL. Reed-Sternberg cells and their mononucleated variants can be recognized by their characteristic cytomorphologic features, although care must be taken not to misinterpret reactive binucleated macrophages as neoplastic cells. In patients with Hodgkin's disease, Reed-Sternberg cells should be sought when an alveolar lymphocytosis is present.

Bone Marrow Transplantation↗