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Biomedical subjects

J K Smith

Publications and source records attributed to J K Smith.

At least 19 recordsLinked to original sources
PubMed1997

A new flap for nasal tip reconstruction.

Aesthetic reconstruction of tumor defects of the nasal tip and supratip areas remains a challenge. Because of our dissatisfaction with the current reconstructive options, we have developed a modification of the nasalis flap based on the angular artery for the management of nasal tip defects. This is an axial flap-pattern that rotates toward the midline and nasal tip, leaving donor scars in the nasojugal and alar creases. A second rotation flap from the alar groove fills the donor defect in the nasojugal region to minimize scarring. We have utilized this flap 19 times in 18 consecutive patients with nasal tip and supratip tumor defects with follow-up ranging from 10 to 72 months. Donor scars are well concealed and nasal contour is minimally altered. Color and texture matches are excellent, and the pincushion deformity has been eliminated. On the basis of these results, we believe the modified nasalis flap is ideally suited for nasal tip reconstruction.

Aged↗
PubMed1996

Persistent urticarial eruption in an asthmatic patient.

This case demonstrates the importance of recognizing urticarial vasculitis in patients with chronic urticarial eruptions. The salient points in history that point towards the diagnosis of urticarial vasculitis include the presence of painful urticarial lesions that last longer than 24 hours and that heal leaving residual pigmentation. In some cases the urticaria may evolve into palpable purpura. An associated systemic illness that may resemble systemic lupus erythematosus should also suggest the diagnosis, which is established by skin biopsy. Histopathology reveals a leukocytoclastic vasculitis involving postcapillary venules. When associated with systemic vasculitis, the urticaria is likely to be of the hypocomplementemic variety, with immunoglobulin and complement deposition on biopsies, and with serum complement studies demonstrating classical pathway activation, low C1q levels, and anti-C1q precipitins. A variety of agents have been used in the management of urticarial vasculitis, including aspirin, nonsteroidal anti-inflammatory agents, corticosteroids, colchicine, dapsone, hydroxychloroquine, and cytotoxic agents such as cyclophosphamide and azathioprine.

Adult↗
PubMed1996

Lymphoblastoid interferon-alpha inhibits T cell proliferation and expression of eosinophil-activating cytokines.

T cell-derived cytokines, such as interleukin-5 (IL-5) and granulocyte-macrophage colony-stimulating factor (GM-CSF) activate eosinophils, whereas other cytokines, such as tumor necrosis factor (TNF)-alpha and IL-13, determine eosinophil recruitment. Interferon-alpha (IFN-alpha), a leukocyte-derived cytokine, has been shown to have beneficial effects in eosinophil-mediated disorders, such as the hypereosinophilic syndrome and a murine model of allergic asthma, where it inhibited eosinophil recruitment. We tested the hypothesis that IFN-alpha acted in eosinophil-mediated disorders by modulating T cell cytokine expression. Peripheral blood mononuclear cells (PBMC) or human ragweed-specific TH1 (2B8) and TH2 (2D2) T cell clones were cultured in the presence of 5 micrograms/ml of phytohemagglutinin (PHA) or 25 micrograms/ml of antigen Amb a 1 (short ragweed allergen), respectively, and lymphoblastoid IFN-alpha (varying from 0 to 10,000 U/ml). We assessed T cell proliferation by [3H]thymidine incorporation and production of IL-5 and GM-CSF by ELISA. Expression of cytokine transcripts was analyzed by the reverse transcription-polymerase chain reaction technique (RT-PCR). IFN-alpha induced a dose-dependent suppression of T cell proliferation of both PBMC (p < 0.001) and the T cell clones (p < 0.001). IFN-alpha inhibited gene expression of IL-5, GM-CSF, TNF-alpha, and IL-13 in PBMC. Furthermore, IFN-alpha significantly inhibited mitogen-induced and antigen-induced production of IL-5 and GM-CSF. IFN-alpha may benefit eosinophil-mediated disorders by inhibiting T cell function and production of cytokines active on human eosinophils.

Adult↗
PubMed1996

Postmortem MR imaging of lobar cerebral infarction with pathologic and in vivo correlation.

Postmortem magnetic resonance (MR) imaging features of different types of lobar cerebral infarction are correlated with the findings in gross and histologic specimens. The postmortem findings are also correlated with in vivo findings in similar cases selected from teaching files. In acute infarction, white matter vasogenic edema leads to high signal intensity on T2-weighted images and blurring of the gray-white matter junction. Petechial hemorrhage in the cortex results in inhomogeneous signal intensity on T2-weighted images. In laminar necrosis, the hyperintense cortex on T1-weighted images is due not to hemorrhage but possibly to necrosis and the presence of lipid-laden macrophages. In subacute infarction, cortical edema and necrosis may cause the gyral pattern of enhancement. Meningeal inflammation and early fibrosis are probably responsible for meningeal enhancement. In chronic infarction, gliosis and cystic malacia are responsible for the increased signal intensity of white matter on T2-weighted images. Knowledge of the pathologic features of cerebral infarction helps in understanding the MR imaging findings.

Acute Disease↗
PubMed1996

Resolution of the neutropenia of Felty's syndrome by longterm administration of recombinant granulocyte colony stimulating factor.

Felty's syndrome is characterized by neutropenia, splenomegaly, and recurrent infection in patients with rheumatoid arthritis. We used recombinant granulocyte colony stimulating factor (rGCSF) in a patient with Felty's syndrome and recurrent sepsis. rGCSF induced a statistically significant increase in the patient's absolute neutrophil and total white blood cell counts. During 14 months of followup taking rGCSF, disseminated varicella zoster was the only infectious complication. Except mild thrombocytopenia and a transient flare of arthritis, no serious adverse effects occurred. rGCSF may be a safe and effective therapy for Felty's syndrome in selected patients.

Aged↗
PubMed1996

Effect of interferon alpha on HLA-DR expression by human buccal epithelial cells.

/We have studied the effect of interferon alpha (IFN-alpha) on MHC class II expression by human buccal epithelial cells (BEC), and mRNA expression by BEC and mucosal-associated mononuclear cells (MAMC). In 6 experiments, freshly collected BEC were suspended at a concentration of 1.0 x 10(5)/ml in RPMI 1640 and incubated in the presence of 0-10,000 IU/ml of human lymphoblastoid IFN-alpha (HuIFN-alpha). Zero and six hour samples were analyzed by single color flow cytometry using FITC-labeled murine IgG1 monoclonal antibody to HLA-DR. Preparations were also analyzed for expression of cytokine transcripts (IL-2, IL-4, IL-5, IL-6, IL-8, IFN-gamma, GM-CSF) by reverse transcriptase polymerase chain reaction (RT-PCR). Increasing concentrations of IFN-alpha resulted in proportionate increases in the percentage of HLA-DR + BEC (r = 0.7897, p = 0.0627) and in the percentage of HLA-DR+ staining at higher intensities (10(1) to 10(2) log fluorescence intensity) (LFI) (r = 0.4010, p = 0.0424). The percentage of HLA-DR + BEC rose from a mean of 1.5% with no IFN-alpha to 7% with 10,000 IU/ml IFN-alpha (p < 0.05). The percentage of HLA-DR + BEC staining at 10(1) to 10(2) LFI rose from a mean of 8.3% with no added IFN-alpha to 19.2% with 10,000 IU/ml IFN-alpha (p < 0.05). Unstimulated BEC constitutively expressed IL-8 and GM-CSF. IFN-alpha stimulated preparations also expressed IFN-gamma, possibly due to the presence of MAMC, which comprised 2-9% of the total cell population. These data indicated that HuIFN-alpha upregulates MHC class II expression by human BEC, possibly by enhancing IFN-gamma production by MAMC present in the culture preparations.

Cells, Cultured↗
PubMed1995

The Mercedes incision in hair restoration.

Standard technique for hair transplantation includes plug composite grafts placed in circular recipient defects of smaller diameter. The plugs can also be placed in slit incisions that are temporarily dilated to accommodate grafts. Two drawbacks of these techniques are the appearance of row cropping resulting from the regular pattern and compression of individual grafts caused by scar contracture. These drawbacks result in tufting and a "doll's head" appearance. The expansile Mercedes incision as described here camouflages these failings. Donor minigrafts are taken with a biopsy punch knife or as strips in a standard fashion. A Mercedes logo-shaped defect is then made at the recipient site using a no. 11 scalpel to create a three-armed stellate incision. The incisions are rapidly made with the axis oriented parallel to the direction of the native hair shafts. The graft is then pushed in flush with the skin. The triangulation eliminates compression of grafts because they are spread in three directions rather than squeezing in a tight circular or slit configuration. The use of the stellate incision along with altering its rotational orientation in a haphazard pattern also prevents row cropping. Thus, the Mercedes incision is quicker and yields an overall improved result.

Alopecia↗
PubMed1995

MR appearance of cerebral cortex in children with and without a history of perinatal anoxia: preliminary observations.

OBJECTIVES: The purpose of this study was to characterize the MR signal intensity of the cerebral cortex in children and to determine if the cortex is abnormal on MR images of patients with anoxia at birth (defined as persistent O2 saturation of less than 80% and requiring intubation or assisted ventilation for more than 24 hr). SUBJECTS AND METHODS: MR imaging was done in 10 patients with no history of anoxia and in nine patients with a history of anoxia. The T2 and T1 signals from the central gyri, the pre- and postcentral gyri, and the calcarine and insular regions of the gray matter were visually graded according to their intensity and to the degree that the low and high signal intensity each involved the entire length of that region. RESULTS: Low T2-signal intensity from the central gyri, the pre- and postcentral gyri, and the calcarine and insular regions of the gray matter was present on MR images made in patients without a history of anoxia and was absent in patients with a history of anoxia. High T1-signal intensity was seen in the central gyri in patients without a history of anoxia. Patients aged 1 year or older with a history of anoxia had no MR signal differences in any gray-matter region on either T1- or T2-weighted images. CONCLUSION: Low T2-signal intensity was seen in the central gyri, the pre- and postcentral gyri, and the calcarine and insular regions of the gray matter on MR images of patients with no history of anoxia but was not seen in those with a history of anoxia. Loss of the normal cortical T2 hypointensity may aid in establishing the diagnosis of anoxic brain injury.

Cerebral Cortex↗
PubMed1995

Nasopharyngeal nonossifying variant of ossifying fibromyxoid tumor: CT and MR findings.

The CT and MR findings of a nasopharyngeal nonossifying variant of an ossifying fibromyxoid tumor are presented. The findings are radiographically indistinguishable from more common malignant neoplasms encountered in this region. The tumor was isointense with muscle on T1-weighted images. On proton density- and T2-weighted images, the mass was mostly isointense with gray matter but contained some areas of lower intensity that might reflect the fibrous tissue component. The tumor eroded through the floor of the middle cranial fossa.

Adult↗
PubMed1995

Imaging of nasopharyngeal atresia.

CT and MR revealed a case of nasopharyngeal atresia, a malformation in which the soft palate is not formed, and the hard palate extends posteriorly to fuse with the anterior surface of the clivus, resulting in complete isolation of the nasal and oral cavities and the absence of a nasopharynx. We believe this rare anomaly results from abnormal persistence of the embryologic bucconasal plate and/or anomalous migration of the nasoseptal elements.

Abnormalities, Multiple↗
PubMed1993

Verapamil intoxication: a literature review of overdoses and discussion of therapeutic options.

Calcium channel antagonists can be quite toxic. In the management of poisoning, early recognition is critical. Calcium channel antagonists are frequently prescribed, and the potential for serious morbidity and mortality with overdosage is significant. Ingestion of these agents should be suspected in any patient who presents in an overdose situation with unexplained hypotension and conduction abnormalities. The potential for toxicity should be noted in patients with underlying hepatic or renal dysfunction who are receiving therapeutic doses. Because there is no specific antidote, decontamination of the gastrointestinal tract is crucial. Intravenous calcium should be administered to symptomatic patients because it is relatively innocuous and may be beneficial. Volume expansion should be the initial approach to hypotension unrelated to bradycardia. Patients who have had a verapamil overdose should be observed in intensive care units where Swan-Ganz catheterization and ventricular pacing are routinely available. The choice of sympathomimetic agents for treatment remains controversial. According to the published literature, isoproterenol, epinephrine, and norepinephrine may be more effective in improving bradycardia and the resultant hypotension than dopamine. However, none of these agents is universally effective. A more logical approach may be to improve cardiac output with agents like amrinone. Bay K 8644 and 4-aminopyridine show promise as potential antidotes but at present are still experimental.

Adult↗
PubMed1993

Mediastinal mass with right pleural effusion.

We have described the case of a 65-year-old man who had a right hemothorax from rupture of an aneurysm of the ascending thoracic aorta and survived. This type of subacute presentation with survival of the patient has not been documented previously in contemporary medical literature.

Aged↗
PubMed1993

Multiple Beau's lines in a patient with fever of unknown origin.

We describe a case of fever of unknown origin (FUO) of 9 months' duration in which the finding of regularly spaced multiple Beau's lines (the "ladder nail" sign) pointed to the possibility of a relapsing fever of the Pel-Ebstein variety and an underlying lymphoma. Subsequent investigation confirmed the association of the Beau's lines and fever, as well as the diagnosis of Hodgkin's disease as the cause of the FUO. In this setting, Beau's lines may provide an important diagnostic clue and should be carefully looked for on physical examination.

Fever of Unknown Origin↗
PubMed1993

Regulation of tobacco acetolactate synthase gene expression.

Acetolactate synthase (ALS) catalyzes the first common step in the biosynthesis of isoleucine, leucine, and valine. The previous cloning of two tobacco (Nicotiana tabacum) ALS genes (SurA and SurB) has allowed transcript accumulation from these genes to be monitored. mRNA blot analysis of ALS transcripts showed a message size of 2.2 kb. Quantitation of the levels of ALS messages in tobacco organs indicated that there was 3- to 4-fold variation in the levels of expression of the ALS genes in different organs. This variability correlated with the developmental stage of the samples, with the highest levels of expression found in developing organs. In situ hybridizations of anti-mRNA probes to plant sections established that ALS messages are most prevalent in metabolically active and dividing cells of roots, stems, and floral tissue. Using RNase protection assays, the transcriptional start sites of the ALS genes were determined, and the expression levels of the two tobacco ALS genes were then followed separately. Both tobacco ALS genes are expressed in a coordinated manner in all tobacco organs examined, with the SurB gene being consistently expressed at higher levels than the SurA gene.

Acetolactate Synthase↗
PubMed1993

Sonography of the scrotum after orchiectomy: normal and abnormal findings.

Sonography is the primary imaging technique for evaluating the scrotal contents. In this pictorial essay, we illustrate a range of normal and abnormal sonographic findings in patients after orchiectomy, including the appearances of the normal postorchiectomy space, acute and subacute hematomas, recurrent neoplasm, second primary tumor in the remaining testis, and testicular prostheses.

Adult↗