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Biomedical subjects

K Hewan-Lowe

Publications and source records attributed to K Hewan-Lowe.

At least 19 recordsLinked to original sources
PubMed2002

Epithelioid sarcoma: clinical, MR imaging and pathologic findings.

OBJECTIVE: To report and describe the MR imaging features of eight new cases of this rare soft tissue sarcoma and correlate them with the clinical and histologic findings. DESIGN AND PATIENTS. Retrospective analysis was carried out for the MR imaging characteristics and histologic findings of eight patients with pathologically proven epithelioid sarcoma and the literature was reviewed. Findings were correlated in each case with the patient's clinical presentation and eventual outcome. RESULTS: The patients, whose primary tumors ranged from 2.5 cm to 19 cm in maximum dimension, were 1 to 90 years of age. Tumors involved the extremities ( n=5), the scalp ( n=2) and the paraspinal muscles ( n=1). Five tumors presented as well-defined, frequently painful, deeply situated masses and three as subcutaneous nodules or cutaneous ulcers with no palpable mass. Four patients had associated regional lymphadenopathy and one had distant metastases at diagnosis. MR imaging showed tumor infiltration of adjacent tissues in seven patients. Signal characteristics reflected varying degrees of cellularity, and the presence of necrosis, hemorrhage, fibrosis, hyalinization and inflammation. Bone marrow involvement was demonstrated in one patient. Clinical outcomes were generally poor. CONCLUSIONS: Epithelioid sarcoma is an aggressive soft tissue sarcoma with a varied clinical presentation, growth pattern, MR signal characteristics and histologic picture. The tumor favors the distal extremities and is commonly infiltrative and accompanied by enlarged regional lymph nodes. This neoplasm may present as an intramuscular mass but should also be suspected in patients with ulcerating cutaneous nodules with or without regional lymphadenopathy.

Adult↗
PubMed2000

Cocaine and the kidney: a synthesis of pathophysiologic and clinical perspectives.

Cocaine abuse has reached epidemic proportions in the United States, and several forms of renal disease have been associated with this widespread use. The hemodynamic actions of cocaine, as well as its effects on matrix synthesis, glomerular inflammation, and glomerulosclerosis, may contribute to renal injury. Cocaine abuse has been associated with various forms of acute renal failure and acid-base and/or electrolyte disorders and may also have a role in the progression of chronic renal failure to end-stage renal disease. In utero exposure to cocaine has been associated with urogenital tract anomalies. Medical management of a hypertensive emergency caused by acute cocaine toxicity requires a multisystem approach, with close monitoring of cardiac, neurological, and renal functions.

Abnormalities, Drug-Induced↗
PubMed2000

Prevalence of non-diabetic renal disease among African-American patients with type II diabetes mellitus.

OBJECTIVE: This study aimed to characterize the prevalence of non-diabetic renal disease among African-Americans (AA) with type II diabetes mellitus based on a biopsy series. No previous study has investigated the nature of renal lesions in AA with type II DM. MATERIAL AND METHODS: Thirty AA patients with type II DM who were being managed at an inner-city hospital had kidney biopsies to evaluate suspected non-diabetic renal disease (NDRD) between 1994 and 1998. The demographic, clinical and histopathological data on these patients were analysed retrospectively. Kidney biopsies were reviewed by light microscopy, immunofluorescence and electron microscopy. RESULTS AND CONCLUSIONS: Three patterns of glomerular disease were observed. Diabetic nephropathy alone was seen in 13 patients (41.9%), diabetic nephropathy coexisted with glomerulonephritis in 12 patients (38.7%), while NDRD was seen in six patients (19.4%).

Adult↗
PubMed2000

Genitourinary tuberculosis in patients with HIV infection: clinical features in an inner-city hospital population.

BACKGROUND: There has been a resurgence of tuberculosis (TB) in the United States, largely because of the HIV epidemic. The impact of this epidemic on the incidence and clinical presentation of genitourinary TB is largely unknown. We describe the clinical findings and outcomes of genitourinary TB in patients infected with HIV and compare them with those in patients not infected with HIV. METHODS: We retrospectively studied the case records of 16 patients infected with HIV and genitourinary TB and compared them with those of 8 patients without HIV infection diagnosed with genitourinary TB between January 1, 1991, and December 31, 1997, at a large, urban, inner-city, tertiary hospital. Data abstracted from records include demographics, symptoms, signs, laboratory and radiologic findings, and in-hospital mortality. RESULTS: Of 1282 patients with tuberculosis, 24 patients had positive urine cultures for Mycobacterium tuberculosis. HIV infection was present in 16 patients (75%). Patients infected with HIV were younger (mean age, 39.1 +/- 6.2 versus 53.9 +/- 17.2, P = 0.047) but did not differ significantly in clinical presentation from patients who did not have HIV infection. The combined mortality rate was 16.7%. Advanced age was the strongest predictor of poor outcome (P = 0.03). CONCLUSIONS: HIV infection was present in 66.7% of patients with genitourinary TB seen an inner-city hospital. Increasing age was associated with poor survival. No significant differences in clinical presentation nor in-hospital mortality were observed between those with HIV infection and those without HIV infection.

Adult↗
PubMed1999

A transitional variant of Castleman's disease presenting as a chylous pleural effusion.

Castleman's disease is an uncommon clinicopathologic entity that results in unregulated growth of lymphoid tissue. It may present as benign involvement of one lymph node group or as multicentric disease with serious systemic symptoms. Pleural effusions are an uncommon manifestation of Castleman's disease. We present a patient with Castleman's disease who initially presented with a chylous pleural effusion.

Adult↗
PubMed1998

Acute renal failure in pregnancy: a review of clinical outcomes at an inner-city hospital from 1986-1996.

Acute renal failure is a serious complication of pregnancy. Over the past few decades, the overall incidence of acute renal failure in pregnancy has decreased in Western societies. In less developed countries, the incidence of acute renal failure in pregnancy has remained high. This retrospective study examined the incidence, morbidity, fetomaternal mortality, and renal prognosis among pregnant inner-city patients. Serum creatinine levels of all pregnant patients seen at an inner-city hospital from January 1986 to December 1996 were reviewed. Twenty-one consecutive cases of acute renal failure were identified for an incidence of 2 in 10,000 pregnancies. Maternal mortality was high (15.7%) as was morbidity, with a tendency toward a high rate of intrauterine fetal growth retardation. These results suggest that the outlook for acute renal failure in inner-city patients is dismal in sharp contrast to the prognosis for other patient groups with acute renal failure in pregnancy in Western societies. Preventive strategies should be aimed at this subpopulation with a view to improving early prenatal care as well as enhancing overall access to the health-care system.

Acute Kidney Injury↗
PubMed1998

Rapid progression to end-stage renal disease in young hypertensive African Americans with proteinuria.

Hypertensive nephrosclerosis (HN) remains the most common cause of end-stage renal disease (ESRD) in blacks. This study examined whether renal histology corresponds with clinical hypertension in proteinuric blacks. Nondiabetic hypertensive blacks who satisfied inclusion criteria were enrolled in this study. Four male patients, each with a family history of hypertension and mean age 41 years, consented to kidney biopsy. Their mean arterial pressure was 116.5 mm Hg, mean urine protein excretion was 7.7 +/- 3.5 g/day. All patients progressed to ESRD within a mean duration of 14 months; the mean rate of decline in glomerular filtration rate was 53 mL/min/y, with an ESRD incidence of 80%/y. The histologic findings were consistent with previously described features of HN. Prominent glomerulosclerosis involved 30% to 75% of the glomeruli and extensive arteriolosclerosis/arteriosclerosis, tubular atrophy, and interstitial fibrosis. There was no evidence of immune complex disease by either immunofluorescence, electron microscopy, or serologic studies. The mean arterial pressure showed a strong but nonsignificant correlation with progression to ESRD (r = 0.8) and arteriosclerosis/arteriolosclerosis (r = 0.8). Glomerular sclerosis correlated with the reciprocal of serum creatinine (r = 0.6), interstitial fibrosis (r = 0.8), and arteriosclerosis/arteriolosclerosis (r = 0.3). Urine protein excretion correlated weakly with progression to ESRD (r = 0.4). These results indicate a poor correlation between clinical findings and histologic features on renal biopsy in young hypertensive African Americans. Hypertension remains a major cause of ESRD among African Americans, and progression to ESRD may be rapid in patients with marked proteinuria. Early and aggressive intervention is warranted.

Adult↗
PubMed1997

Granulomatous interstitial nephritis and uveitis presenting as salt-losing nephropathy.

Salt-wasting nephropathy is a rare syndrome in which renal insufficiency is associated with extracellular volume depletion from marked natriuresis in the absence of adrenal insufficiency or diuretics. We report the clinical course of a 23-year-old woman with renal insufficiency, in association with orthostatic hypotension and salt wasting. A combination of daily infusion of saline, a high-salt diet and oral fludrocortisone did not compensate for her salt loses. Renal biopsy showed noncaseating granulomas and marked interstitial inflammation. Renal function and salt loss improved with prednisone therapy and 6 months after withdrawal of steroids, her renal function remains stable.

Adult↗
PubMed1997

Coinfection with Giardia lamblia and Enterocytozoon bieneusi in a patient with acquired immunodeficiency syndrome and chronic diarrhea.

Diarrhea is an important clinical problem in immunosuppressed patients with acquired immunodeficiency syndrome (AIDS). There are numerous classical as well as emerging enteric pathogens that can produce diarrhea; however, these agents can be missed when only one method, such as microbiological examination of stool, is used for diagnosis. The endoscopic biopsy is a sensitive method for diagnosis of many viral, fungal, and parasitic infections of the gastrointestinal tract. Although only one agent is often identified in mucosal biopsies from these immunosuppressed patients, coinfection with multiple microbial agents is being increasingly recognized. Giardia infection is not as prevalent as other pathogens in patients with AIDS, but it remains an important diarrheal agent that is potentially curable. However, there have been only rare reports of coinfections with giardiasis and other infectious agents. This report describes a patient with AIDS and chronic diarrhea who had repeated negative stool examinations for ova and parasites. Light and electron microscopic examination of subsequent endoscopically obtained small intestinal biopsies revealed coinfection with two parasites, Enterocytozoon bieneusi and Giardia lamblia. Following treatment with metronidazole for giardiasis, the diarrhea persisted, but was less severe. This report also describes the diagnostic features of Giardia and Enterocytozoon infections in biopsy tissues and emphasizes the importance of identifying enteric coinfections in patients with AIDS to ensure timely and specific modes of therapy.

AIDS-Related Opportunistic Infections↗
PubMed1995

The flexor digitorum longus: an anatomic and microscopic study for use as a tendon graft.

Recent experimental studies have shown that intrasynovial donor tendons have the capacity to heal with minimal alteration in the gliding surface when grafted to an intrasynovial location. In order to evaluate the flexor digitorum longus of the foot as a potential matched donor tendon for use in flexor tendon grafting, we dissected 15 feet (75 toes) and 10 hands (50 fingers) to determine the intrasynovial lengths of the flexor digitorum longus and flexor digitorum profundus and to determine a method of tendon graft harvest. Specimens were taken from the intrasynovial portion of each tendon for evaluation by light and electron microscopy. The intrasynovial tendons of the hand and foot were similar in vascularity, cellularity, gliding surface, and ultrastructure. The flexor digitorum longus tendon of the foot was a mean length of 12 cm to the area of tendon confluence in the midfoot, which will usually provide enough tendon length for grafting from the distal phalanx to the palm of the hand. Because of the difference in length of the synovial sheaths of the fingers and toes, some extrasynovial tendon will be transferred to the synovial space when a flexor digitorum longus tendon is used.

Cadaver↗
PubMed1994

Determination of the compartment pressure threshold of muscle ischemia in a canine model.

A canine model was used to test the hypothesis that critical intracompartmental pressure leading to ischemic muscle necrosis is linked to diastolic blood pressure. Twenty adult dogs were subjected to an infusion of autologous plasma into the anterolateral muscle compartment of the left hindlimb to create an elevation in compartment pressure. There were four experimental groups of five dogs each. In group I, the compartment pressure (CP) was maintained at the animals' diastolic blood pressure (DBP); in group II, at 10 mm Hg less than the DBP; in group III, at 20 mm Hg less than the DBP; and in group IV, at 30 mm Hg. The pressure was measured continuously in the proximal, central, and distal segments of the compartment during an 8-hour period. Immediately postoperatively, and, on the first, fourth, seventh, and fourteenth days one animal from each group was killed. The tibialis cranialis muscle was then removed and analyzed using light and electron microscopy. The critical pressure threshold for ischemic muscle necrosis was found to be 20 mm Hg less than the diastolic blood pressure.

Analysis of Variance↗
PubMed1994

Splenic infection simulating lymphoma: an unusual presentation of disseminated Pneumocystis carinii infection.

This report of disseminated pneumocystosis in an HIV-infected patient describes an unusual presentation consisting of splenic disease mimicking lymphoma, absence of typical roentgenographic signs of pulmonary or disseminated pneumocystis, and absence of use of aerosolized pentamidine. Because of these factors, a diagnosis of disseminated pneumocystosis was not considered. Our case in combination with other recent reports emphasizes the need to consider disseminated pneumocystosis in HIV-infected patients, even if they have no obvious pulmonary disease and have not received aerosolized pentamidine therapy. Timely recognition of this lethal infection is important for initiation of potentially curative therapy.

Adult↗
PubMed1992

Merkel cell carcinoma of the labial mucosa. An immunohistochemical and ultrastructural study with a review of the literature on oral Merkel cell carcinomas.

Merkel cell carcinoma is a rare cutaneous neuroendocrine tumor that occurs predominantly in the head and neck region of older patients. An 88-year-old white man had an erythematous, umbilicated tumor on his lower lip, which on histopathologic examination showed solid sheets of infiltrating basaloid round cells with a high mitotic index. Globular, paranuclear immunostaining for low-molecular-weight cytokeratins (Nos. 8, 18, and 19) and neurofilament was observed. On ultrastructural examination, the tumor cells demonstrated paranuclear whorls of intermediate filament aggregates and occasional electron-dense granules. This unique cytokeratin- and neurofilament-staining pattern with coexpression enabled the Merkel cell carcinoma to be differentiated from other small cell malignant tumors that included metastatic neuroendocrine carcinomas from other regions. The follow-up 1 year after surgery and radiation showed that the patient remained disease free. Review of the literature revealed 11 cases of oral Merkel cell carcinomas with a predilection for the labial mucosa of older men. The mode of treatment and the clinical course of these cases are also presented, with an update on therapeutic management of Merkel cell carcinomas.

Aged↗
PubMed1991

Association of human papillomavirus with penile carcinoma: a study using polymerase chain reaction and in situ hybridization.

Although carcinoma of the uterine cervix has been shown to be strongly associated with human papillomavirus (HPV) infection, a sexually transmitted disease, similar detailed data are lacking in penile carcinoma. To determine the association of HPV with penile carcinoma, we examined 30 specimens of penile carcinoma from 23 patients by the highly sensitive polymerase chain reaction (PCR) and in situ hybridization assays. We also examined nonneoplastic penile foreskins from 20 adults using the polymerase chain reaction assay. Human papillomavirus type 16 genome was found in 15 patients (65%), HPV type 30 was found in three (13%), and HPV type 6/11 was found in two (9%). These HPV types were not detected in any of the nonneoplastic foreskins. As in cervical carcinoma, HPV, particularly type 16, is strongly associated with penile carcinoma and may play an etiologic role in the development of this neoplasm.

Base Sequence↗
PubMed1991

Glassy cell features in adenosquamous carcinoma of the uterine cervix. Histologic, ultrastructural, immunohistochemical, and clinical findings.

Glassy cell features (GCF) were identified as composing a predominant pattern (more than 85% of histology) in six cases and a focal pattern (33-85% of histology) in 10 cases of a series of 53 adenocarcinomas (AC) and adenosquamous carcinomas (ADSQ) of the uterine cervix. In three cases examined ultrastructurally, GCFs correlated with many cytoplasmic polyribosomes and abundant rough endoplasmic reticulum, but Golgi complexes and tonofilaments were scant and intracytoplasmic lumina were absent. Intracellular mucin was present in the areas showing GCFs of four ADSQs with predominant GCFs and six ADSQs with focal GCFs. Two of three cases examined ultrastructurally showed intracellular electron-dense material that corresponded to mucin secretory material. Immunohistochemical studies of the six ADSQs with predominant GCF cases showed the following pattern of reactivity: monoclonal carcinoembryonic antigen (CEA), 2 of 6 cases; polyclonal CEA, 3 of 6; CA 125, 0 of 6; CA 19-9, 0 of 6; placental alkaline phosphatase, 0 of 6; and vimentin, 1 of 6. Focal GCF areas showed monoclonal CEA, 4 of 9 cases; polyclonal CEA, 3 of 9; vimentin, 4 of 9; while CA 125, CA 19-9, and placental alkaline phosphatase were negative in areas of GCFs. One of three patients with ADSQ with predominant GCFs and five of nine patients with ADSQ with focal GCFs with at least 1 year of follow-up were disease free. No association between GCFs (combined focal and predominant) and recurrent disease was present when compared to the other 29 AC and ADSQ patients with follow-up. Recurrent disease in our series of AC and ADSQ was only associated with stage III or IV disease at presentation (P less than 0.001). There was no association with adenosquamous histology, histologic grade, lymphatic invasion, or age. There were insufficient cases of ADSQ with predominant GCFs with follow-up to evaluate fully prognostic significance of this subgroup. Our study suggests that GCFs are part of the spectrum of differentiation in ADSQ of the cervix rather than a distinct histologic type of carcinoma with unique clinical significance.

Adenocarcinoma↗