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Biomedical subjects

D H Connor

Publications and source records attributed to D H Connor.

At least 55 records · Page 3Linked to original sources
PubMed1984

Lymphadenitis caused by Loa loa.

The World Health Organization's Collaborating Centre for the Histopathology of Filarial Diseases of Man contains specimens of lymph node from 13 patients infected by the filarial nematode Loa loa. Ten of these nodes have distinctive microscopic features characterized by distended sinuses that contain histiocytes and eosinophils and by atrophy of lymphoid follicles. Less striking features include fibrosis of capsule and trabeculae, dilated lymphatic vessels of capsule and medulla, and inflammatory cell infiltrates. We believe that these changes, although in themselves nonspecific, are characteristic of lymphadenitis caused by Loa loa. These 10 lymph nodes were removed from the inguinal region--one from each of 10 native Zairians . At the time of herniorrhaphy the nodes in eight patients were found to be enlarged and were removed for diagnosis. Seven of the 10 patients were infected with Dipetalonema perstans as well as Loa loa, and one of these seven had three filarial infections--L. loa, D. perstans and D. streptocerca . Lymph nodes from other patients infected by other filariae that were available for study at the AFIP did not have these histopathologic features.

Adult↗
PubMed1984

Mycobacterium ulcerans in Liberia: a clinicopathologic study of 6 patients with Buruli ulcer.

Two patients with Buruli ulcer (infection by Mycobacterium ulcerans) in the Foya region of Liberia have recently been reported. We describe three more patients which together with the two original patients establish the Mayor River basin as an endemic area of Buruli ulcer. We also describe a patient from the St. Paul River basin. This disease, unrecognized in Liberia before 1978, now seems to be widespread in Liberia and has been reported in neighboring Sierra Leone and observed in Ivory Coast as well. The possibility of Buruli ulcer appearing in other regions of West Africa should be anticipated. Diagnosis involves finding acid-fast bacilli in smears of the exudate from typical lesions or by finding in biopsy specimens the characteristic zone of coagulation necrosis containing acid-fast bacilli. The bacillus, Mycobacterium ulcerans, stains readily with the Ziehl-Neelsen (ZN) and Fite-Faraco (FF) procedures. Treatment is excision when the lesion is small and by debridement and grafting, combined with heat and chemotherapeutic agents when the lesion is large.

Adult↗
PubMed1984

Pathology of experimental infection with Brugia malayi in ferrets: comparison with occult filariasis in man.

Ferrets experimentally infected with Brugia malayi (subperiodic strain) developed eosinophilia at patency and usually became amicrofilaremic. Ferrets necropsied within 3 months after becoming amicrofilaremic had granulomas and focal reactions to degenerating microfilariae in their livers, lungs and lymph nodes essentially identical to those of tropical eosinophilia. Four of 7 ferrets that received multiple inoculations of larvae, developed edema of the inoculated paw and leg after becoming amicrofilaremic and 6 of these 7 ferrets had granulomatous lymphangitis and lymphadenitis of inoculated limbs but not the lesions of lung and liver characteristic of occult infection.

Animals↗
PubMed1984

Deposition of eosinophil granule major basic protein onto microfilariae of Onchocerca volvulus in the skin of patients treated with diethylcarbamazine.

We investigated the association between eosinophil degranulation, as evidenced by the deposition of granule major basic protein (MBP), and the killing of microfilariae of Onchocerca volvulus in vivo following treatment with diethylcarbamazine (DEC). Utilizing an immunofluorescence procedure for the cellular and extracellular localization of eosinophil MBP in formalin-fixed, paraffin-embedded tissues, we studied skin biopsies from onchocerciasis patients before and during treatment with topically or orally administered DEC. Before DEC, there was little or no inflammatory response in either dermis or epidermis and microfilariae were essentially intact. Immunofluorescent staining for MBP revealed some filamentous fluorescence associated with dermal collagen fibers, very few eosinophils, and no fluorescence in association with intact microfilariae. In contrast, during treatment with DEC, immunofluorescent staining for MBP revealed extensive eosinophil infiltrates in both dermis and epidermis with numerous intraepidermal eosinophil abscesses containing degenerating microfilariae. An intense extracellular immunofluorescence for MBP surrounded degenerating microfilariae in the dermis and epidermis in both the presence and absence of eosinophil infiltrates as early as 4.5 hours after starting therapy. Many intact nondegenerating microfilariae were also present, but they did not show immunofluorescent staining for MBP nor a surrounding inflammatory infiltrate. The results show that immediately following administration of DEC, eosinophils localize and degranulate around microfilariae in the skin and release granule MBP onto or in close proximity to the parasite's surface. Because of the striking association between eosinophil localization, degranulation, and deposition of MBP onto microfilarial surfaces, and the degeneration of microfilariae in the skin, these observations support the hypothesis that the eosinophil, through helminthotoxic granule proteins such as MBP, damages the microfilariae of O. volvulus.

Adult↗
PubMed1984

Trapping, care, and laboratory management of the silvered leaf monkey (Presbytis cristatus).

The silvered leaf monkey (Presbytis cristatus) from South Kalimantan ( Borneo ), Indonesia is a natural host for a variety of filarial nematodes including Brugia malayi and Wuchereria kalimantani . Experimental studies show that it is host for W. bancrofti, a filarial nematode causing elephantiasis in man. Presbytis cristatus is a gregarious primate of primary and secondary forests, roaming in troops of 20-30 members. Primarily a fruit and leaf eater under natural conditions, this monkey can adapt to a laboratory diet of commercial monkey chow supplemented with fruits and vegetables. Troops, led by an alpha male, immediately respond to protect their young during stressful or dangerous situations. Infants are born singly and are bright orange. Transition to the adult grey and black coloration begins three to five months after birth. Silvered leaf monkeys can be readily trapped. Initially they are aggressive and will attack but become tractable several days after capture. Reaching upward is an important feeding behavior of the silvered leaf monkey and they will not feed from the floor of the cage. In the laboratory they are nonaggressive and lend themselves to various procedures such as blood drawing and examination. Silvered leaf monkeys travel well in commercial animal transport cages. In the United Stages they are not an endangered species and can be readily imported. In Indonesia they are not protected by law and can be exported.

Animal Husbandry↗
PubMed1983

Sowda--onchocerciasis in north Yemen: a clinicopathologic study of 18 patients.

Sowda is an unusual form of onchocerciasis in Yemenites that differs from African onchocerciasis. Clinical and pathological studies were performed on 18 patients in Yemen Arab Republic (North Yemen). Biopsies of skin and lymph nodes were taken, and then processed at the Armed Forces Institute of Pathology, Washington, D.C. The most striking clinical features were swollen, darkened, pruritic, papular skin changes that were usually limited to one leg, more rarely to one arm, and large soft regional lymph nodes. Dermal changes were deeper and more diffuse than in African onchocerciasis, with many large fibroblasts and plasma cells. Microfilariae of Onchocerca volvulus were much rarer in skin from Yemenites with sowda. When patients were treated with diethylcarbamazine, the dermatitis became suddenly worse as the microfilariae degenerated and provoked acute inflammation. The dermatitis decreased after several days of treatment. Enlarged lymph nodes from sowda have shown follicular hyperplasia, in contrast to follicular atrophy and perivascular fibrosis that are characteristic of lymph nodes from cases of African onchocerciasis. Cell-mediated and humoral immunity may be more active in sowda than in African onchocerciasis.

Adolescent↗
PubMed1983

Sowda-type onchocerciasis in Guatemala.

The usual pattern of onchocercal dermatitis in Africans and Guatemalans is a generalized and symmetrical dermatitis located on legs, arms and trunk. These patients appear to be anergic, with depressed immune responses and numerous microfilariae in the skin. In contrast, "sowda" is an unusual type of onchocercal dermatitis found in Yemenites and in a minority of African patients. Here the dermatitis is localized and asymmetrical - typically confined to one limb or one region of the body. Patients with sowda appear to be hypergic, with active humoral and cellular immune responses; microfilariae are rare or absent. This study describes two Guatemalan patients with sowda-type dermatitis. The diagnosis in these two patients is based on the asymmetrical papular pruritic dermatitis, rare or absent microfilariae, a positive Mazzotti reaction, and histopathologic changes characteristic of the sowda-type onchocercal dermatitis.

Adult↗
PubMed1983

Proliferating larval cestodiasis: report of a case.

A 72-year-old Filipino man who had emigrated to Canada had an abdominal infection with a proliferating acephalic larval cestode. Small, irregularly shaped parasites were within the substance of a lymph node, where they provoked a fibrogranulomatous and eosinophilic reaction. The parasite is described and is identified as an undifferentiated sparganum or tetrahyridium based upon comparison with two similar parasites from patients in Taiwan and Paraguay.

Aged↗
PubMed1982

Cardiac mucormycosis. A report of five patients and review of 14 previously reported cases.

Five patients with mucormycosis of the heart are described. Two had leukemia,, one had multiple myeloma, one sideroblastic anemia, and one had been wounded when a body trap exploded. None had diabetes. In addition to heart involvement, each had mucormycosis of the lungs. Kidney was infected in two patients and gastrointestinal tract, spleen, liver, adrenal, brain, and skin were each involved in one patient. Three patients had cardiac symptoms. The findings in ten previously reported patients with de novo cardiac mucormycosis and in four patients with mucormycosis occurring in association with cardiovascular surgery are summarized.

Adult↗
PubMed1982

An onchocercal nodule appearing during diethylcarbamazine therapy.

We describe the appearance of an onchocercal nodule in a patient during treatment with diethylcarbamazine (DEC). This is a unique occurrence. DEC has been employed in the treatment of onchocerciasis for many years, but there have been no reports of any effects of DEC on nodules. Histopathological studies in which nodules have been examined before and after treatment of patients with DEC have not revealed any changes induced by such treatment. The histological appearance of this nodule is described, and the probable mechanism of its enlargement is discussed.

Adult↗
PubMed1982

The ferret (Mustela putorius furo) as an experimental host for Brugia malayi and Brugia pahangi.

Ferrets inoculated subcutaneously with 150--200 infective larvae of Brugia malayi (subperiodic strain) usually developed patent infection during the 3rd month post inoculation. Microfilaremia was transient, and most animals became amicrofilaremic after the 6th month of infection. Ferrets developed a persistent eosinophilia at the time of patency. At necropsy, 5--8 months post infection, adult worms were recovered principally from lymphatic vessels and recovery ranged from 0.5--13% of the inoculated larvae. The inflammatory response of ferrets to microfilariae was characterized by nodules 1--5 mm in diameter in the liver, lungs, spleen, and submucosa of the gastrointestinal tract. The center of these lesions contained a degenerated microfilaria or the cast of a microfilaria embedded in Splendore-Hoeppli substance. The Splendore-Hoeppli substance was surrounded by eosinophils and/or foreign body giant cells. Identical lesions were observed in ferrets experimentally infected with Brugia pahangi. Sera from ferrets infected with B. malayi demonstrated a 3- to 5-fold increase in IgG by the 4th month of infection and these sera produced 2--3 precipitin bands in double gel diffusion assays with an extract of B. malayi microfilarial antigen. Skin tests with B. malayi microfilarial antigen showed that the majority of the infected ferrets had immediate hypersensitivity responses, but none had Arthus or delayed hypersensitivity responses.

Animals↗
PubMed1980

Phaeomycotic cyst. A clinicopathologic study of twenty-five patients.

The clinical and pathologic features of 25 cases of phaeomycotic cyst, collected at the Armed Forces Institute of Pathology between 1959 and 1978, are described. Phaeomycotic cyst is infection of the deep dermis and subcutaneous tissue by dematiaceous (brown) fungi. Species of Phialophora were most frequently isolated from these lesions. Synonyms for phaeomycotic cyst are--among others--phaeomycosis and phaeosporotrichosis. Phaeohyphomycosis includes phaeomycotic cyst and some other mycoses. The term "phaeo" is derived from the Greek phi alpha iota omicron sigma, meaning grey or black, and refers to the brown color in vivo and in vitro of these fungi. Phialophora species are world-wide saprophytes, common in soil, decaying wood, and vegetation. They have low virulence and low pathogenicity, and are inoculated along with slivers whose retention is probably an important causal factor in establishing infection. Proliferation of the fungi provokes a mixed suppurative and granulomatous reaction which remains localized. Early the characteristic histopathologic picture is one of multiple stellate abscesses. These progress to a single circumscribed lesion with a central cavity filled with pus and surrounded by a fibrous wall. There are no systemic signs or symptoms, regional lymph nodes are not involved, nor has any patient had systemic spread. The infection is rare but tends to be more common in warm climates. No race, sex, or age group is predisposed, but patients with immune deficiency or debilitating disease are at increased risk. In older publications phaeomycotic cysts have been described as variants of chromomycosis, sporotrichosis, and mycetoma. Phaeomycotic cysts, however, do not provoke hyperplasia of the epidermis or ulceration--characteristic features of both chromomycosis and sporotrichosis, nor do phaeomycotic cysts form sinus tracts or contain grains--both typical features of mycetoma. The strictly localized abscess or "cyst" is the characteristic feature of phaeomycotic cysts.

Abscess↗
PubMed1978

Onchocerciasis.

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Anthelmintics↗