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Biomedical subjects

J W Patterson

Publications and source records attributed to J W Patterson.

At least 73 records · Page 4Linked to original sources
PubMed1989

Effects of Ca++ depletion on lens equatorial currents in frog lenses.

The combination of the vibrating probe measuring the outward equatorial current (J) with microelectrodes measuring PD and the response to injected current provides one of the best means of relating macro findings of lens currents to the micro data that have been reported using the patch clamp technique. In standard frog Ringers solution the equatorial current appears to be a relatively pure K+ current with a reversal potential of -95 mV. This agrees with the reversal potential of the 45 pS K+ channel. When Ca++ is removed from the medium bathing the lens the input resistance (R) decreases, the PD becomes less negative and the current J increases. This process can be reversed by adding Ca++ or Mn++ to the Ca++ deficient medium. When all Ca++ is removed from the medium by adding EGTA in the absence of Ca++, the increase in J is less than expected. However, if Na+ is replaced by TMA in the Ca++ depleted EGTA medium the current is seven times as great. These changes are consistent with those found in non-selective cation channels in the absence of Ca++.

Animals↗
PubMed1989

Cranial fasciitis.

We present the clinical, roentgenographic, light-microscopic, immunohistochemical, and ultrastructural findings in two children with cranial fasciitis. A 7-year-old boy and a 3-year-old girl presented with rapidly expanding masses on the scalp. Roentgenographic studies showed erosion of the underlying cranium in one case. Both lesions showed proliferations of elongated spindle cells in a focally myxoid matrix, together with areas of hemorrhage, vascular proliferation, and chronic inflammation. Occasional cells with atypical nuclei were observed, but mitotic figures were uncommon. Immunoperoxidase studies showed negative or equivocal staining for desmin, factor VIII-associated antigen, S100 protein, and macrophage antigen. In one lesion there was focal positivity for alpha 1-antichymotrypsin, and in another lesion, some cells stained positively for smooth-muscle actin. Electron microscopy showed cells with dilated endoplasmic reticulum, bundles of microfilaments, pinocytotic vesicles, and focal external membrane material, features of myofibroblasts. Both lesions were excised and there has been no recurrence in 7 years in one case and 1 year in the other case. Cranial fasciitis is closely related to nodular fasciitis, but it has a predilection for the scalp of children. Despite its rapid growth, it has a benign clinical course and is cured by excision with or without curettage of the underlying bone. Our immunohistochemical and ultrastructural observations indicate that, like nodular fasciitis, cranial fasciitis represents a proliferation of fibroblasts and myofibroblasts.

Age Factors↗
PubMed1989

Eosinophils in skin lesions of erythema multiforme.

To investigate the controversy regarding the presence of eosinophils in skin lesions of erythema multiforme, we undertook a retrospective clinicopathologic study of 19 recent cases that fulfilled clinical and histopathologic criteria for the disease. At least a few eosinophils were observed in 13 of 19 cases, and in four cases there were more than three per high-power field, qualifying as "tissue eosinophilia." Immunofluorescence studies in three cases with eosinophils failed to show the linear basement membrane zone fluorescence characteristic of bullous pemphigoid. Giemsa stains revealed that mast cells were present in lesions both with and without eosinophils. The only clinical features that distinguished patients with tissue eosinophilia from those without were an older age of incidence and a longer duration of disease prior to biopsy. Drugs were implicated as a causative factor in some patients both with and without eosinophils, but all four patients with tissue eosinophilia were believed to have drug-induced disease. We conclude that eosinophils do occur in skin lesions of erythema multiforme and are occasionally numerous.

Adult↗
PubMed1988

Equatorial potassium currents in lenses.

Earlier work with the vibrating probe demonstrated the existence of outward potassium currents at the equator and inward sodium currents at the optical poles of the lens. By adding microelectrodes to the system, it is possible to relate steady currents (J) to the potential difference (PD) measured with a microelectrode. By injecting an outward current (I), it is possible to determine resistances and also the PD at which the steady outward potassium current becomes zero (PDJ = 0). At this PD the concentration gradient for potassium efflux and the electrical gradient for potassium influx are balanced so that there is no net flow of potassium across the membranes associated with the production of J. The PDJ = 0 for 18 rat lenses was 86 mV and that for 12 frogs lenses was -95 mV. This agrees with the potassium equilibrium potential and provides strong evidence to support the view that the outward equatorial current, J, is a potassium current. With the injection of outward current, I, the PD becomes more negative, the outward equatorial current, J, decreases, and the inward current at the optical poles increases. This suggests that there are separate electrical loops for K+ and Na+ that are partially linked by the Na, K-pump. Using Ohm's law, it is possible to calculate the input resistance (R = delta PD/I), the resistance related to the production of J (RJ = delta PD/delta J), and the effect of the combined resistances (delta J/I). The driving force for J can be estimated (PDJ = 0-PD). The relationships among currents, voltages and resistance can be used to determine the characteristics of the membranes that are associated with the outward potassium current observed at the equator. The effects of graded deformation of the lens were determined. The effects were reversible. The sites of inward and outward currents were not altered. Following deformation, the equatorial current, J, increased, and the PD became less negative. The PDJ = 0 remains the same so the ratio of K+ concentrations across the membrane responsible for J is unchanged. Therefore, the decrease in PD is ascribed to an increase in Na+ permeance with a resultant increase in driving force accounting for the increase in J.

Animals↗
PubMed1988

Cutaneous involvement of multiple myeloma and extramedullary plasmacytoma.

We recently performed a retrospective clinicopathologic study of five patients with cutaneous involvement of multiple myeloma or extramedullary plasmacytoma. Cutaneous nodules without extension from an underlying bony focus of disease developed in each case. In two cases skin lesions occurred in the more common setting of advanced disease, but in two others skin lesions provided early clues to the diagnosis. In three patients the appearance of skin lesions heralded a rapidly deteriorating clinical course, but two other patients had reasonably long survivals despite cutaneous disease (6 and 3 years, respectively). Two histopathologic configurations were identified in cutaneous lesions: nodular and infiltrative. Both patients with the latter form had multiple myeloma. In all cases tumor cells were pyroninophilic. Immunoperoxidase studies on fixed, paraffin-embedded tissues confirmed the electrophoretic findings in two cases, but findings were equivocal in three others. In one case, cells were positive for epithelial membrane antigen, and in another, alpha 1-antichymotrypsin-positive cells were observed in the centers of tumor islands. Cutaneous involvement with plasma cell neoplasms is recognized infrequently. Immunohistochemical techniques may prove to be valuable in evaluating these cases, but they are not without technical and interpretative difficulties.

Aged↗
PubMed1988

Rheumatoid nodule and subcutaneous granuloma annulare. A comparative histologic study.

We performed histologic and selected histochemical and immunohistochemical studies on rheumatoid nodules (RN) from 12 patients and lesions of subcutaneous granuloma annulare (SGA) from nine patients. The mean age for patients with RN was 56 years, while that for SGA patients was 19 years. In contrast to those with RN, none of the patients with SGA had arthritis. RN tended to show homogeneous, eosinophilic necrobiosis, giant cells within palisaded foci, and significant stromal fibrosis; while lesions of SGA showed pale, edematous necrobiosis, an absence of giant cells, and lesser degrees of fibrosis. The single most helpful histochemical method was alcian blue, which stained necrobiotic foci in all cases of SGA but in only one case of RN. Epithelioid cells in both disorders stained positively for muramidase. IgM was found in vessel walls in two cases of RN. While the mechanisms of these disorders are not entirely clear, it appears that RN can usually be reliably distinguished from SGA on histologic grounds alone.

Adult↗
PubMed1988

Cutaneous cytomegalovirus infection in a liver transplant patient. Diagnosis by in situ DNA hybridization.

A 39-year-old woman who had cryptogenic cirrhosis and who had received two liver transplants developed necrotic skin lesions over the chest, upper arms, and thighs. Biopsy showed enlarged endothelial cells with intranuclear and intracytoplasmic inclusions characteristic of cytomegalovirus (CMV) infection. However, a few multinucleated gaint cells were observed beneath a necrotic epidermis. This, combined with the clinical presentation, suggested to infectious disease consultants an infection with herpes simplex virus. Using the immunoperoxidase technique, inclusions stained positively with antibody to CMV and showed a negative reaction for herpes simplex antigen. In situ hybridization using biotinylated DNA probes on formalin-fixed, paraffin-embedded tissue sections confirmed the diagnosis of CMV infection and failed to substantiate infection with herpes simplex virus. Subsequently, blood cultures became positive for CMV. The early recognition of CMV infection in the skin permitted institution of antiviral therapy with gancyclovir. Specific skin lesions of CMV infection are likely to be encountered with increasing frequency among immunosuppressed patients. Lesions may be vesicular, and epidermal multinucleated giant cells can occasionally be identified. In situ hybridization is a technique that is readily adaptable to surgical pathology laboratories and permits both a rapid, specific diagnosis and the early institution of appropriate therapy.

Adult↗
PubMed1988

Characterization of the equatorial current of the lens.

The vibrating probe detects and measures currents around cells and organs. With its use, it is possible to demonstrate strong outward potassium currents at the equator of the lens and strong inward sodium currents at the optical poles. The addition of microelectrodes to the system permits one to define the nature of these currents and to determine how they are modified by various perturbing influences.

Animals↗
PubMed1988

Effect of ouabain on lens equatorial currents.

The equatorial potassium current measured with the vibrating probe is a segment of the potassium electrical loop. The equatorial current, J, was measured simultaneously with the PD and with the response to an injected current, I. The injection of sufficient inward current, I, made the PD more negative and increased the electrical gradient so that the current J became zero. The PD at which this occurs (PDJ-0) is the reversal potential. Following treatment with ouabain, the PD and PDJ-0 both become less negative. Since the driving force for the current, J, is equal to the difference between PD and PDJ-0, J may increase, stay the same or decrease depending on the relative changes in PD and PDJ-0. In the presence of ouabain, the PDJ-0 changes in parallel with or more rapidly than the PD.

Animals↗
PubMed1988

Lichen planus of the vulva.

Lichen planus is an uncommon cutaneous disease that can affect the vulva. Vulvar pruritus and pain are common symptoms in patients with genital involvement. Examination reveals an erythematous, friable vestibule with adherent exudate. Marked resorption of the labia minor and atrophy may occur in time. Diagnosis is based on associated clinical findings involving the oral mucosa and/or the skin and on vulvar biopsy.

Atrophy↗
PubMed1987

Cutaneous botryomycosis in a patient with acquired immunodeficiency syndrome.

A patient with acquired immunodeficiency syndrome presented with multiple pruritic papules and nodules over the trunk and extremities. Biopsy specimens from two of these lesions contained granules within abscesses of the papillary dermis. There were numerous gram-positive cocci within the granules. Culture of one lesion failed to produce growth. A mouse inoculated with tissue from a lesion revealed no evidence of sepsis or organ involvement. The skin lesions showed no obvious response to systemic antimicrobial therapy but gradually resolved after treatment had been discontinued. Such lesions should be clinically distinguished from other cutaneous manifestations of acquired immunodeficiency syndrome, such as Kaposi's sarcoma.

Acquired Immunodeficiency Syndrome↗
PubMed1987

"Clear cell" atypical fibroxanthoma.

An 87-year-old man with extensive solar damage presented with a 2-month history of a dome-shaped, crusted lesion on the dorsum of the left hand. Microscopically, the tumor consisted of fascicles of spindle cells with bizarre nuclei and clear, vacuolated cytoplasm. Histochemical, immunohistochemical, and ultrastructural features supported the diagnosis of atypical fibroxanthoma. There was no evidence of metastatic disease. The lesion was completely excised, and there has been no recurrence in 3 months of observation. This unusual "clear cell" variant of atypical fibroxanthoma must be distinguished from other clear cell tumors, such as metastatic renal cell carcinoma, clear cell eccrine carcinoma, and clear cell sarcoma (malignant melanoma) of soft parts. Although atypical fibroxanthoma is usually cured by complete surgical excision, metastases have been reported.

Aged↗
PubMed1987

Predicting length of hospital stay in a pediatric ward.

The purpose of this study was to develop a statistical model for predicting hospital length of stay for pediatric patients. A sample of n = 589 patient records, representing a two year time period, was selected from a large, acute care hospital. The variables identified as possible determinants of length of stay and investigated for their effect were: age, sex, financial class, isolation status, number of operative procedures, presence of nosocomial infections, number of complications, resulting death and a classification variable identifying the final diagnosis as one of 24 mutually exclusive major diagnostic categories. An eight variable model was derived (p less than .0001) with a coefficient of multiple determination of 0.1612.

Diagnosis-Related Groups↗
PubMed1987

Atypical fibroxanthoma in a patient with xeroderma pigmentosum.

A 3-year-old boy with xeroderma pigmentosum developed a papule on the right ala nasi that had the light-microscopic, immunohistochemical, and ultrastructural features of atypical fibroxanthoma. This lesion most commonly arises on the sun-exposed skin of older adults. The occurrence of an atypical fibroxanthoma in such a patient adds weight to the concept that this tumor of "fibrohistiocytic" origin is induced by ultraviolet exposure. Mechanisms of tumor formation in a patient with xeroderma pigmentosum may be similar to those occurring in the more typical situation in adults.

Biopsy↗