Biomedical subjects
Publications and source records attributed to R Chin.
Bronchopulmonary Kaposi's sarcoma (KS) occurs in 20 percent of AIDS patients with cutaneous involvement; however, complete endobronchial occlusion is uncommon. Moreover, bronchopulmonary KS is infrequent in the absence of cutaneous manifestations. We report a case of documented complete endobronchial obstruction by KS without cutaneous involvement.
OBJECTIVE: The association of human immunodeficiency virus with a clinical picture of motor neuron disease is uncommon, with three cases reported to date. This case represents an additional case of a human immunodeficiency virus-infected patient with apparent motor neuron disease. DESIGN: Single patient case report. SETTING: Large urban public hospital. PATIENT: A 45-year-old human immunodeficiency virus-positive Hispanic man who presented with muscle wasting, fasciculations, areflexia, cranial nerve deficits, and weakness progressing to a complete quadriplegia. RESULTS: Electrophysiologic data showed evidence of diffuse denervation with normal sensory and motor nerve conductions and no evidence of demyelination. Electromyography showed diffuse sharp waves and fibrillation. CONCLUSIONS: This case demonstrates a progressive motor neuron dysfunction in a patient positive for the human immunodeficiency virus and provides additional evidence that infection with the human immunodeficiency virus should be considered in the differential diagnosis of apparent motor neuron disease.
Consensus primers specific for the L1 and E1 regions were used to amplify HPV DNA fragments. These fragments were then directly sequenced using the consensus primers as the sequencing primers. The linking of PCR amplification, direct sequencing, and computer data bank analysis provides a new approach in the detection of different HPVs and has several advantages over existing methodology. These advantages include increased precision in the rapid characterization of known HPVs, detection of mutations, and identification of new HPV types.
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In the case study presented in this article, the patient had many of the historical risk factors for bilateral adrenal hemorrhage that Rao outlined. He had recently undergone surgery and was receiving heparin for anticoagulation for a thromboembolic event. Further clues included his fever, hypotension refractory to pressors, and abdominal discomfort. In addition, he had received a blood transfusion in the early 1980s, putting him at risk for the development of human immunodeficiency virus infection. His low baseline cortisol level and the lack of ACTH stimulation confirmed the diagnosis of adrenal insufficiency, probably on the basis of bilateral adrenal hemorrhage given his presentation. Although true adrenal insufficiency is an uncommon event in the intensive care unit, the question of its presence is often considered. In addition, the use of exogenous glucocorticoids is so widespread that the possibility of secondary adrenal insufficiency is a frequent concern. Careful history taking and physical examination complemented by review of the laboratory data and the awareness of certain risk factors should help identify most cases. However, the presentation is often not classical and empiric therapy may be required while awaiting results of diagnostic testing.
Mytilus edulis has been the subject of recent studies to determine whether the relationship between the immune and neuroendocrine systems seen in vertebrates also exists in invertebrates. The effects of mammalian monokines were studied in Mytilus immunocytes previously shown to produce and react to opioid peptides. These invertebrate cells respond to interleukin 1 (IL-1) and tumor necrosis factor (TNF), both in vitro and in vivo, in a manner similar to that of human granulocytes. As in the mammalian monokine network, the effect of IL-1 on the immunocytes is brought about, at least in part, by its stimulatory effect on the formation of TNF. In addition, the presence of immunoreactive IL-1 and TNF in Mytilus hemolymph was demonstrated.
Clinicians who were interested and considerably experienced in assessing patients with hemoptysis were surveyed during a computer-assisted interactive presentation at the 1988 ACCP Annual Scientific Assembly. The approach to ambulatory patients with minor bleeding was consistent with recently published guidelines: fiberoptic bronchoscopy has a central role, with a less apparent impact of other new technologies. Although specific diagnostic results were significantly more useful (p less than 0.01), even nonspecific bronchoscopy findings were though to have clinical value. External factors such as medicolegal concerns and obligations to provide service were acknowledged to influence selection of patients for bronchoscopy, and community-based clinicians cited such effects more often than academicians (p less than 0.02). Approaches to patients with massive hemoptysis reflected caution essential to acute management. Bronchoscopy was performed earlier (p less than 0.01) than in patients with minor bleeding, but opinions differed regarding instrument selection, the best method of airway support, and the roles of interventional angiography. This survey suggests that real-world settings are addressed incompletely by published experiences accumulated in tertiary centers. Clarification of optimum approaches to patients with hemoptysis requires further input from practicing clinicians.
Unilamellar vesicles composed of phosphatidylcholine (PC) and either phosphatidic acid (PA) or phosphatidylglycerol (PG) partition to the upper poly(ethylene glycol) (PEG)-rich phase of a charge-sensitive 5%:5% (w/w) PEG 8000/Dextran T-500 phase system containing 10 mM sodium phosphate at pH 7, consistent with the vesicles bearing a net negative charge. When prepared in the presence of a pH gradient (interior acidic), PC/PA vesicles exhibit an increased partition to the top PEG-rich phase, consistent with a redistribution of the PA from the inner to the outer monolayer of the vesicle bilayer. Conversely, when prepared in the presence of a pH gradient (interior basic), PC/PG vesicles exhibit a decreased top-phase partition, consistent with a redistribution of the PG from the outer to the inner monolayer of the vesicle bilayer. Unilamellar vesicles composed of PC and stearylamine partition to the lower dextran-rich phase of a 5%:5% (w/w) PEG 8000/Dextran T-500 phase system containing 10 mM sodium phosphate at pH 8.5, consistent with the vesicles bearing a net positive charge. When prepared in the presence of a pH gradient (interior acidic), conditions under which the stearylamine is trapped on the inner monolayer of the bilayer, the vesicles now partition predominantly to the interface in a manner similar to vesicles composed of PC alone. These results demonstrate that partitioning in aqueous two-phase polymer systems is a sensitive method for monitoring the asymmetry of charged lipids in model membrane systems and also suggests that partitioning in charge-sensitive systems depends only on the physical nature of the exterior surface of the membrane.
An enteric syndrome of turkey poults, characterized by enteritis, crop mycosis, intestinal changes (pale, thin-walled ballooning with watery contents), and rickets, occurred during 1988 in 74 turkey flocks from different farms belonging to 9 California turkey growers. The flocks ranged in size from 9,000 to 120,000 birds. Pools of intestine sections from 618 birds, representing 78 field cases, were examined. Histopathological examination of the intestines showed a mild to severe atrophy with a reduced depth of crypts, which was more prominent in the distal part of the small intestine. Viral isolation attempts with primary cell cultures of chicken embryo kidney cells were negative. Examination by electron microscopy of negatively stained intestinal specimens revealed the presence of Reoviridae particles of 58.8 to 80 nm in diameter. Enzyme-linked immunosorbent assay results on the intestinal pools for mammalian and group A avian rotaviruses were negative. A statistically significant relationship was found for the presence of Reoviridae particles in the intestines of 10-21-day-old birds. Of the 7 most common pathological conditions analyzed, 2, rickets and intestinal changes (thin-walled ballooning intestine with watery contents), showed a statistically significant association with the presence of Reoviridae particles.
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Peripheral blood mononuclear lymphocytes (PBL) from thermal injury patients were examined for their ability to mediate natural killer (NK) cell activity against K562 tumour cells and against herpes simplex virus type 1 (HSV-1) infected Raji tumour cells. Using fluorescein isothiocyanate-conjugated monoclonal antibodies, the number of T3, T4, T8, Leu11, and Leu7 positive cells in PBL obtained from patients and normal controls was determined. Thermal injury patients had decreased levels of T3+ cells and a T4:T8 ratio which was significantly lower than that found in normal control individuals. Although patients had normal percentages of Leu7+ and Leu11+ cells, they had depressed NK cell activity against both K562 tumour cells and HSV-1 infected Raji cells. NK cell activity against K562 tumour cells was severely depressed during the first 20 days after injury. This defective NK cell activity did not appear to be due to a defect in PBL binding to the K562 tumour cells. In patients, the level of NK cell activity against HSV-1 infected cells did not correlate with the level of NK cell activity against K562 tumour cells. This finding further supports previous reports showing that NK cells which kill K562 tumour cells are different from the NK cell population which kills HSV-1 infected cells. Pretreatment of PBL obtained from patients with IL-2 or IFN-alpha, in some cases greatly enhanced NK cell killing of K562 tumour cells. However, IL-2 or IFN-alpha did not enhance NK cell activity in patients who had severely depressed levels of NK cell activity. Interestingly, in some patients, differential responsiveness to IL-2 and IFN-alpha was observed. In some patients, NK cell activity was enhanced by IL-2 but not by IFN-alpha. These results, while only suggestive, may indicate that different populations of NK cells respond preferentially to IL-2 and that IFN-alpha and/or IL-2 enhance NK cell activity in PBL obtained from some, but not all, thermal injury patients. Finally, this study clearly shows that thermal injury patients have defective NK cell activity not only against K562 tumour cells but also against virus-infected cells.
Aluminum compounds are used as adjuvants in certain types of vaccines, toxoids and allergenic extracts for human use. The most common Al compounds used in biological products to enhance the immune response are aluminum potassium sulphate (alum), aluminum hydroxide and aluminum phosphate. This study describes an atomic absorption spectrometric method for the determination of the Al content of Al adsorbed toxoid preparations and allergenic extracts at levels of less than 0.85 mg of Al per half millilitre human dose. Aliquots of the samples which contained Al suspensions were acid digested with nitric and sulphuric acid and analysed in the nitrous oxide-acetylene flame of an atomic absorption spectrometer. The 396.2 nm Al line was used for analysis. The Al content of the National Bureau of Standards (NBS) Standard Reference Material No. 1075a aluminum 2- ethylhexanoate was determined to within 1% of the NBS certificate value by this method. Atomic absorption results for the Al content of tetanus toxoids containing aluminum potassium sulphate and aluminum phosphate were compared with polarographic and inductively coupled argon plasma (ICP) emission spectrometry results. Reproducibility and recovery data for Al are tabulated for a variety of biological products containing aluminum phosphate, aluminum potassium sulphate and aluminum hydroxide adjuvants. In addition, ICP has been used to characterize the Al and P compositions of the precipitates and supernatant solutions which resulted from centrifuging toxoid suspensions that contained the three different Al adjuvants.
While performing thyroid function tests, we noticed that protirelin (TRH) raised BP, and, therefore, we investigated the effect of diagnostic dosages of protirelin (500 micrograms) on plasma catecholamine levels and cardiovascular function in eight patients one day before, one day after, and four weeks following heart surgery. Mean arterial pressure (MAP), heart rate (HR), plasma norepinephrine (NE), epinephrine (EPI), dopamine (DA), thyroid hormone (triiodothyronine [T3], thyroxine), and thyrotropin (TSH) levels were measured before and after the intravenous injection of protirelin. Protirelin increased MAP transiently from 88 +/- 2 to 103 +/- 3 mm Hg (before surgery), 86 +/- 4 to 102 +/- 4 mm Hg (one day after surgery), and 86 +/- 4 to 104 +/- 5 mm Hg (four weeks after surgery). There were no notable changes in HR or plasma NE, EPI, or DA levels. The T3 and TSH response to protirelin was normal on all three study days. Protirelin raised MAP by an effect on systemic vascular resistance (SVR) rather than an increase in cardiac output. We conclude the following: (1) diagnostic dosages of protirelin transiently elevate MAP and SVR by a noncatecholamine mechanism, (2) clinicians who perform protirelin tests should be aware of protirelin's transient pressor effects.
Gastroesophageal (GE) reflux has been etiologically linked to a number of pulmonary diseases. Subclinical pulmonary aspiration from nocturnal GE reflux has been proposed as a cause of asthma. A patient with severe asthma, refractory to conventional medical therapy, is presented. The asthma was presumed to be secondary to gastroesophageal reflux and indeed the patient became asymptomatic following a Nissen fundoplication procedure. This case report documents that surgical correction of GE reflux may be an appropriate therapeutic maneuver in asthmatics who subclinically aspirate as a consequence of GE reflux.
Ultra-large-scale integrated devices have been investigated by a reflection mode scanning near-field optical microscope designed for semiconductor analyses. Although it could be found that imaging the reflectivity of metal structures buried underneath thin, optically transparent passivation layers is practicable, shading of the reflected light by the SNOM probe complicated the interpretability of the achieved results. This issue has been overcome by using the SNOM probe as both illumination source and detector, simultaneously. The application of focused ion beam milling to the probes has allowed the increase of the transmittivity of the probes to such an extent that coated fibres could be utilized and the interpretability of the results could be enhanced. Furthermore, the investigated structures are of great interest for an investigation of z-motion artefacts, as the presence of the polished passivation layers allows topographical influences to be distinguished from pure optical contrast.
Thermal dosimetry studies of the Helios ultrasound system were performed in a tissue-equivalent phantom and in porcine tissues in vivo. SAR distributions in the phantom demonstrate the adjustability of the power deposition pattern from the 50 cm diameter annular array of 30 transducers. Examples are given of well-localized SAR patterns (< 3 cm diameter) in the phantom, and of peripherally enhanced (doughnut-shaped) SAR patterns up to 10 cm in diameter at the focal plane. In vivo trials in porcine thigh muscle demonstrate the ability of the Helios system to produce regions of therapeutic heating (42-45 degrees C) as small as 20 cm3 and as large as 200 cm3 at depths of greater than 10 cm at a frequency of 0.5 MHz.