Brugia pahangi: infections and their effect on the lymphatic system of Mongolian jirds (Meriones unguiculatus)

Brugia pahangi has been found to be primarily a lymphatic-dwelling parasite in jirds when infections are induced by the subcutaneous injection of infective larvae or by allowing infected Aedes aegypti to feed.Migration to the regional lymphatics occurred as early as 1–4 days. Although some injected larvae remained in the skin for as long as 30 days and some became localized in the heart, lungs, pleural cavity, or peritoneal cavity, about three-fourths of the recovered filariae were found in the regional lymphatics. In contrast, when larvae were injected peritoneally they remained largely in the peritoneal cavity for at least 30 days.The relevant lymphatics and their drainage patterns in jirds have been described.The major pathological changes noted in jirds involved the regional lymphatic vessels and nodes, which were severely affected when they contained dead worms. Pulmonary granulomas due to dead microfilariae and occasionally to dead larvae or adult worms were noted.Observations are included on the susceptibility and course of B. pahangi infections in jirds.     

Brugia pahangi: Histopathological study of golden hamsters

Sixteen male hamsters were inoculated subcutaneously with 95 to 150 infective larvae of B. pahangi and were examined for histopathologic lesions at 39–109 days postinfection. The basic microscopic lesion observed was obstructive granulomatous lymphangitis. Analogous lymph node changes sometimes occurred along with lymphoreticular hyperplasia and increased numbers of eosinophils. Cellular infiltration of perivascular and perinodal tissues was common, with plasma cells and eosinophils predominating. Genital lesions included funiculitis, epididymitis, and mild orchitis. Live and dead worms were found in the testicular parenchyma. Pulmonary changes in hamsters infected more than 105 days included multiple small, granulomatous foci and periarteriolar, peribronchiolar, and subpleural cellular accumulations of plasma cells and eosinophils. Granulomatous obstruction of pulmonary arteries associated with dead worms was observed in two hamsters infected for 39–45 days and in one hamster infected for 109 days. Small liver granulomas were common. Disintegrating microfilariae occurred within giant cells in the lymph nodes, spleen, lungs, and testes.     

Anatomical variants of the lymphatic vessels connecting the inguinal lymph nodes]

The study of anatomical variants of lymphatic vessels connecting inguinal lymph nodes was carried out on 56 corpses of adult persons of both sex whose deaths were not connected with lesions in the lymphatic system of the pelvis and lower extremities. The inguinal lymph nodes and their afferent and efferent lymphatic vessels were detected by the method of intradermal injection and by the method of direct injection into the lymphatic vessels. It was stated that groups of the inguinal lymph nodes, as well as the nodes in every group determined, can serve as nodes of different stages for afferent lymphatic vessels running from different parts of the body and organs.     

Anatomy and topography of the common iliac lymph nodes in human beings in the 1st period of maturity

The investigation of common iliac lymph nodes has been performed in 20 corpses of the first mature age of both sex (5 male and 5 female corpses) of persons died from causes not connected with the lymphatic system diseases, the lower extremities and the pelvic organs. The common iliac lymph nodes with their afferent and efferent lymphatic vessels are revealed by means of interstitial injection into the lower extremities and the pelvic organs and with direct injection into the lymphatic vessels. The form, amount, size and topography of the common iliac lymphatic vessels have been studied. The lymphatic vessels, that go from certain body parts and organs to various subgroups of the common iliac lymph nodes, as well as the lymphatic vessels that connect the nodes both within the subgroup and also between the subgroups. The amount and size of the lymphatic nodes of the lateral subgroup predominate over the nodes of other subgroups of the common iliac lymph nodes; the amount of the common iliac lymph nodes predominates in men, and their size--in women. Amount of these nodes in the right and their size in the left predominate in both sex. Among the common iliac lymph nodes there are no teniform nodes, and efferent lymphatic vessels of the lateral and medial subgroup of the common iliac lymph nodes in 15% of cases run towards the lumbar nodes in the opposite side.     

Anatomy and topography of external iliac lymph nodes in adults]

The investigation of the external iliac lymph nodes has been performed in 152 preparations of corpses of mature persons of both sex, who died from causes not connected with any disease of the lymphatic system, lower extremities and pelvic organs. The external iliac lymph nodes and their afferent and efferent lymphatic vessels have been revealed by means of interstitial injection of the lower extremities and pelvic organs, as well as by means of direct injection of Gerota mass into the lymphatic vessels. Form, amount, dimensions and topography of common iliac lymph nodes have been studied. Lymphatic vessels, running from certain parts and organs of the body to various subgroups of the external iliac lymph nodes have been described, as well as efferent lymph vessels of these nodes. The external iliac lymph nodes are constant formations; the largest of them--lymph nodes of the lacuna--are nodes of the I step for the lower extremity lymph vessels. In 54% of cases in persons of both sex positive (right-sided) asymmetry has been revealed. Total amount of the iliac lymph nodes prevails in men, while their size is greater in women. The size of these nodes in persons of both sex is greater to the left than to the right. There are connections (in 3% of cases) between the external iliac lymph nodes and aortal and lumbar nodes of the opposite side.     

Brugia pahangi: comparative susceptibility of the Mongolian jird, Meriones unguiculatus, and the PD4 inbred hamster, Mesocricetus auratus

The susceptibility of Mongolian jirds, Meriones unguiculatus, and PD4 hamsters, Mesocricetus auratus, to Brugia pahangi was compared based on the percentage adult worm recoveries, mean microfilaremia levels, and adult worm lengths. Fourteen male jirds and seventeen male PD4 hamsters were each inoculated subcutaneously in the left inguinal region with 90-100 L3 of B. pahangi and necropsied 130-150 days after inoculation. There were no significant differences between jirds and hamsters in mean adult worm recoveries (24.7 vs 25.4%) and prepatent periods (69.9 vs 77 days after inoculation). In hamsters, 85% of recovered worms were found in the heart and lungs and 15% were found in genital lymphatic vessels. In jirds, distribution of recovered worms was 66% in genital lymphatics, 23% in the heart and lungs, 8% in the peritoneal cavity, and 3% in lymphatic vessels in other sites. The mean microfilaremia level in jirds (16.5/20 microliter) was significantly higher than in hamsters (8.7/20 microliter. Female worms in the genital lymphatics of jirds were significantly longer than female worms in the genital lymphatics of PD4 hamsters (33.5 vs 27.3 mm). Lengths of worms in other locations were similar between the two species.     

Anatomy and topography of the lymphatic vessels and regional lymph nodes of the rectum in newborn infants and children to 3 years of age

In 30 corpses of newborns and children up to 3 years of age, by means of the intratissue and direct injection of the modified Gerota's mass, certain increase in number and size of the superficial inguinal lymph vessels belonging to the superior-medial group, as well as the pararectal and superior rectal lymph nodes has been noted. The diameter of both afferent and efferent lymphatic vessels in the nodes mentioned in children of 1-3 years of age is greater than in the newborns. The number of the afferent vessels running towards these nodes in most cases, regardless the age, prevail over the efferent ones, and the diameter of the latter is greater than in the afferent vessels. The pararectal lymph nodes in 80% of cases are the nodes of the first step for the lymph flowing from the rectum, in 15% - the nodes of the first and second steps, simultaneously, and in 5% - of the third and fourth steps. The superior pararectal lymph nodes in 80% of cases are the nodes of the third and fourth steps, and in 20% of cases - those of the first and second steps for the lymph flowing from the rectum.     

Isolation and purification of afferent lymph dendritic cells that drain the skin of cattle

Dendritic cells (DCs) are central to the induction of immune responses and are a pivotal control point that determines the outcome of infectious challenge. Cannulation of afferent lymphatic vessels allows the isolation of large numbers of lymph DCs. First, lymph nodes that are draining the skin are surgically removed (takes approximately 1 h). Over a period of 6-8 weeks, afferent lymphatic vessels re-anastomose with the efferent duct, forming larger 'pseudoafferent' lymphatic vessels that can be surgically cannulated. Surgical cannulation takes 2 h to perform; daily maintenance of the catheter requires 30 min. Isolation of lymph cells requires 1 h and an additional 60-180 min to enrich or purify the DCs. The lymph can be harvested for up to 1 month, with relatively constant cell numbers and subset distribution throughout this period. This technique, although technically demanding, facilitates studies of DCs and other cells that traffic in the lymph in both the steady state and following antigenic exposure.     

Studies with Brugia pahangi. I. Parasitological observations on primary infections of cats (Felis catus)

The large majority of cats given a single inoculation of third stage larvae of Brugia pahangi became microfilaraemic. Some cats had microfilariae in their blood 53 or 54 days after infection and most had become positive before 72 days after infection. In the majority of cats microfilarial counts remained very steady between 2 and 10 microfilariae per mm³ for long periods. At autopsy 10·7% of the infective larvae injected were recovered as adult worms. The recovery of adult worms was directly related to the number of larvae injected. The microfilarial level did not increase significantly with an increase in the number of adult worms.     

Oral transmission of Brugia pahangi and Dipetalonema viteae to adult and neonatal jirds

Sullivan J. J. and Chernin E. 1976. Oral transmission of Brugia pahangi and Dipetalonema viteae to adult and neonatal jirds. International Journal for Parasitology6: 75–78. Confirming previous studies, anaesthetized adult jirds became infected after oral doses of 100 infective larvae of B. pahangi; 4 of 5 jirds became microfilaria-positive and all 5 harbored adult worms. Among 7 unanaesthetized adult jirds similarly exposed, none developed microfilaraemia although 5 each harbored a few adult worms. In these unanaesthetized jirds, presumably, rapid passage of the inoculum through the mouth permitted fewer larvae to penetrate the mucosa, and the rest were probably killed in the stomach. Unanaesthetized 4-day old jirds proved highly and equally susceptible to oral or subcutaneous infection with B. pahangi as indicated by microfilaraemias and large worm-burdens. Direct and indirect evidence suggest that the baby's stomach and small intestine are not inimical to swallowed larvae, thus accounting for the relatively numerous mature worms in the peritoneal cavity. Third-stage larvae of D. viteae, readily infective subcutaneously, succeeded relatively infrequently in maturing when given orally to anaesthetized adult or to unanaesthetized baby jirds. Consistent oral infectivity may thus be a feature of filariae more closely related to B. pahangi.     

Infectivity, growth, development and pathology of Echinostoma caproni (Trematoda) in the golden hamster

Laboratory hamsters (Mesocricetus auratus) were experimentally infected with 75 ± 15 metacercarial cysts of Echinostoma caproni. Worms were recovered from days 7 to 89 post-infection with eight to 90 (average 37) parasites in the small intestine. Worm wet weights averaged 0.85 mg at 10 days, 1.8 mg at 17 days, 3.4 mg at 45 days, and 7.7 mg at 89 days; average dry weights for the identical days were, 0.15, 0.30, 0.70 and 2.2 mg, respectively. The average body area of worms fixed in hot (80°C) alcohol-formalin-acetic acid was 0.21 mm² on day 3, 4.9 mm² on day 10, and 17.7 mm² on day 42. Clinical signs in some hamsters included progressive unthriftiness and watery diarrhea. Gross examination revealed enlarged lymphatic nodules along the length of the small intestine. The histopathological responses of hamsters to the parasite showed erosion of the intestinal villi with lymphocytic infiltration being the primary response; hemorrhagic areas were also observed in the villi.     

Age and variability in the inguinal lymph nodes of adult humans]

Lymphatic nodes on the anterior surface of the femur, in the region of the femoral triangle were studied in 56 corpses of humans of either sex from 31 to 82 years of age, dead of accidental causes or of diseases not related to lymphatic nodes. The investigation was carried on by the method of interstitial and direct injection of the Gerota's mass to some regions of foot skin, external genitalia and the skin of the anterior wall of the abdomen. It has been established that the size of inguinal lymphatic nodes (both superficial and profound) in humans of either sex, are in direct dependence on the age of the person. The amount of inguinal lymphatic nodes in young people prevails over that in old people. The external diameter of the afferent and efferent vessels in elderly humans is greater than in young ones. The amount of afferent lymphatic vessels to inguinal lymphatic nodes in most cases prevails over the amount of efferent ones, independent of age and sex. The external diameter of the former is greater than that of the latter.     

Infectivity, growth, development and pathology of Echinostoma caproni (Trematoda) in the golden hamster

Laboratory hamsters (Mesocricetus auratus) were experimentally infected with 75 ± 15 metacercarial cysts of Echinostoma caproni. Worms were recovered from days 7 to 89 post-infection with eight to 90 (average 37) parasites in the small intestine. Worm wet weights averaged 0.85 mg at 10 days, 1.8 mg at 17 days, 3.4 mg at 45 days, and 7.7 mg at 89 days; average dry weights for the identical days were, 0.15, 0.30, 0.70 and 2.2 mg, respectively. The average body area of worms fixed in hot (80°C) alcohol-formalin-acetic acid was 0.21 mm² on day 3, 4.9 mm² on day 10, and 17.7 mm² on day 42. Clinical signs in some hamsters included progressive unthriftiness and watery diarrhea. Gross examination revealed enlarged lymphatic nodules along the length of the small intestine. The histopathological responses of hamsters to the parasite showed erosion of the intestinal villi with lymphocytic infiltration being the primary response; hemorrhagic areas were also observed in the villi.     

Individual and sexual characteristics of the common iliac lymph nodes in elderly persons

The common iliac lymph nodes (CILN) have been investigated on 24 preparations from corpses of elderly persons (5 male and 7 female corpses), died from the causes not connected with the lymphatic system diseases, lower extremities and pelvic organs. The CILN with their afferent and deferent lymphatic vessels are revealed by means of interstitial injection into the lower extremities and pelvic organs, as well as by means of direct injection into lymphatic vessels. The form, amount, size and topography of CILN are studied. Lymphatic vessels, running from certain parts of the body and organs to various subgroups of CILN are described, as well as lymphatic vessels, connecting the nodes both within each subgroup and between the subgroups. There is a tendency in prevalence of amount and size of the lateral subgroup of the lymph nodes over the nodes of other subgroups of CILN; tendency in prevalence of amount of the lymph nodes in men, and their size--in women; prevalence of amount of right CILN and their size in the left--in persons of both sex; in 70% of the cases the amount of afferent lymphatic vessels to CILN prevails over that of the deferent lymph nodes.     

Anatomy of the lymph vessels and nodes of the head and neck in green marmosets]

In 50 mature green monkeys, the lymphatic system of the skin on the hairy part of the skull (occipital, parietal, frontal) and on the face was studied. The lymphatic vessels of cranial and cervical organs flow into submental, submandibular (anterior, medial, posterior) lymph nodes and into profound cervical (cranial, medial, caudal) lymph nodes. Lymph nodes together with efferent lymphatic vessels form lymph collectors of the neck which follow the blood vessels branching: superficial jugular, profound jugular and paratracheal network.     

The effects of crowding on adults of Echinostoma caproni in experimentally infected golden hamsters.

Fifty-nine of 60 (98%), 6-month-old male golden hamsters, Mesocricetus auratus, fed 15 (group A), 50 (group B), or 200 (group C) metacercarial cysts of Echinostoma caproni (Digenea: Echinostomatidae) were infected 7-34 days postexposure. The mean number of worms recovered in groups A, B and C were 9, 10, and 50, respectively. The percentage recovery was significantly different between group A (63%) and groups B (21%) and C (23%). The intestine was divided into three equal regions (I, II, III). Worms from group A were located in segments II and III of the small intestine whereas worms from groups B and C were distributed in all three segments. The body area, ovarian and testicular areas of worms from group A were greatest, followed in decreasing order by body and gonadal areas of worms from groups B and C. Echinostoma caproni eggs were found in the faeces of all the hamsters examined from groups A, B and C by days 9, 10 and 11, respectively. Physical damage occurred at the site of attachment of the echinostome. Pathological observations indicated the presence of enlarged lymphatic nodules with lymphocytes being the primary cellular infiltrate at the site of parasite attachment.     

Suppression of parasitemia in rodent filariasis (Litomosoides carinii) by immunization with BCG and microfilaria. I. Intracutaneous inoculation of BCG

After intracutaneous inoculation of BCG and challenge by subcutaneous injection of infective larvae of Litomosoides carinii, the parasitaemia of the filarial infection in cotton rats remains significantly lower when BCG and larvae are applied in the region of the same popliteal and ileal lymph nodes. However, when the infective larvae are directed to other regional lymph nodes (Ln cubitales and axillares), the depression of microfilaraemia is missed. The worm load (recovery rate) and the expulsion of microfilariae by the adult worms are not influenced by the BCG inoculation. Obviously BCG stimulates the lymphatic tissue unspecifically, and the infective larvae produce the first antigen contact, which is boostered by the microfilariae at the onset of patency. When the intracutaneous BCG inoculation is combined with specific antigen stimulation by simultaneous injection of blood microfilariae in the region of the same lymph nodes, the microfilaraemia of the challenge infection disappears completely or remains extremely low.     

Transdiaphragmatic lymphatic transport of intraperitoneally administered marker in hamsters.

OBJECTIVE: To determine whether transdiaphragmatic transport in hamsters is similar to that described in other animals by examining transport of an intraperitoneally administered marker. METHODS: Monastral blue B suspension was administered intraperitoneally to 28 male Syrian hamsters (Mesocricetus auratus). Four hamsters each were euthanized 7, 15, and 30 min, and 1, 2, 3, and 24 h later. Specimens were examined microscopically for presence of marker. RESULTS: Marker was present in intrathoracic lymphatic vessels and cranial and caudal mediastinal lymph nodes by 7 min after its administration. The amount of marker in lymph nodes increased with time. The subcapsular distribution of marker was consistent with lymphatic transport. By 1 h after its administration, marker was present in the liver, spleen, bone marrow, and mesenteric and mandibular lymph nodes. Patterns of marker distribution in these tissues were consistent with hematogenous transport, but the amount of marker was considerably less than that in the intrathoracic lymph nodes at corresponding times. CONCLUSIONS: Particulates were most likely translocated from the hamster peritoneal cavity to intrathoracic lymph nodes via transdiaphragmatic lymphatic vessels. A portion of the translocated particulates entered the blood, where they were distributed to a variety of tissues within a short time.     

Brugia pahangi and Dirofilaria immitis: experimental infections in the ferret, Mustela putorius furo.

Ferrets were inoculated with 160 third-stage larvae of the filarial nematode Brugia pahangi, followed 23 days later by 15 larvae of another filarial nematode, Dirofilaria immitis. Other ferrets received only one of these species. Microfilaremia developed in some ferrets with single infections of each species and in some ferrets with dual infections. The nature of the experiment did not permit a thorough study of microfilaremia, but B. pahangi microfilariae were found in numbers as high as 15,650/ml. At necropsy, approximately 8 months after inoculation, adult B. pahangi were recovered from the lymphatic vessels of all 8 ferrets inoculated only with that species, the recovery rate (based on 6 animals only) varying from 2 to 50% of the inoculum (mean 25%). Adult D. immitis were recovered from the heart of all three ferrets inoculated only with that species, the recovery rate being 7, 47, and 60% (mean 38%) of the inoculum. All 5 ferrets inoculated with both species yielded both adult B. pahangi (6 to 23%, mean 16% of inoculum) and adult D. immitis (13 to 67%, mean 37% of inoculum). It is concluded that the ferret is highly susceptible to both species and that concurrent infections with both species may readily be established.     

Lymphatic vessels in the capsule of the lymph node

By means of the injection method the lymphatic vessels, running to the lymph nodes of various localization, have been studied. Their architectonics in the lymph node capsule is revealed. In the capsule the afferent vessels make peculiar broom-like formations. They are named terminal arborizations of afferent lymphatic vessels (TAALV). Two types of such arborizations are described: palm-like, peculiar for the somatic type of the lymph nodes, and tree-like, specific for visceral nodes. The TAALV diameter is 15-20 mcm. They come across the nodal capsule, penetrating it obliquely with numerous holes. In the TAALV wall myocytes are revealed. Together with the capsule muscular elements they might play a role of the most important factors in the mechanism of lymph circulation.