The high incidence of tuberculosis among renal transplant recipients in India

Tuberculosis is an important infection encountered after renal transplantation in third-world countries. Over an 8-year period, 36 cases of tuberculosis were encountered in 305 renal transplant recipients (11.8%) with grafts functioning for more than 3 months followed up at our center. The infection was limited to the thoracic cavity in 41.7% and a single extrapulmonary site in 11.1%, and it was disseminated in 27.8% cases. In 19.4% of cases, the disease appeared as pyrexia of unknown etiology and the diagnosis was confirmed by a good therapeutic response to antitubercular therapy. Tuberculosis was diagnosed within 1 year of transplantation in 58.3% of cases. There was no significant difference in the incidence of tuberculosis in patients on different immunosuppressive regimens. The Mantoux test was positive in 33.3% patients. A total of 23 patients were treated with isoniazid and rifampicin, with the addition of a third drug for the first 2 months. Treatment was continued for 9 months in 11 cases with isolated pleuropulmonary disease and for 12-15 months in the other 12 patients. The other 13 were on cyclosporine and were given isoniazid, pyrazinamide, and ethambutol for 18 months. Two patients died of fulminant disease and five more died from unrelated causes. No recurrence of disease has been noted in any of the patients after a mean follow-up of 14.6 months. We conclude that the incidence of tuberculosis in renal allograft recipients in third world countries is much higher than that seen in the western world. Most of the cases are encountered in the first posttransplant year. Tuberculosis must be considered seriously in all patients who have prolonged fever of undetermined etiology. Treatment with isoniazid and rifampicin for 9 months is adequate for patients with localized pleuropulmonary disease. In patients on cyclosporine to whom rifampicin cannot be given because of economic considerations, treatment with isoniazid, pyrazinamide, and ethambutol should be given for 18 months.

Evaluation of the efficacy of albendazole against the larvae of Taenia solium in experimentally infected pigs, and kinetics of the immune response

Cysticercosis, a disease of economic and public health importance, is caused by Cysticercus cellulosae, the metacestode stage of Taenia solium. Experimental induction of cysticercosis was achieved in young pigs by feeding an optimum dose of 20,000 T. solium (Indian strain) eggs after immunosuppression, to assess the effect of albendazole and development of the immune response to cysticercus antigens before and after treatment. Histopathological studies revealed the presence of cysticerei in liver, lungs and muscles. Treatment with albendazole at 15 mg kg-1 body weight daily for 30 days starting from day 0 or 15 days post-infection resulted in 100% cure rates. Increases in antibody titre to crude soluble extract and a Sephadek G-200 purified antigenic fraction of Cysticercus cellulosae were found on days 25, 40 and 55 post-infection in untreated pigs and those in which treatment started on day 15 post-infection, whereas no increase in antibody response was observed in pigs in which treatment started on day 0.

Effect of hematoporphyrin derivative and light on sulfhydryl groups in brain tumour cells

Effect of hematoporphyrin derivative (HpD) and light on sulfhydryl (SH) groups in brain tumor cells was studied. Sulfhydryl groups were measured by 5,5'-dithiobis-(2-nitrobenzoic acid) (DTNB) and a fluorescent probe 3,4-maleimidylphenyl-4-methyl-7-diethylaminocoumarin (CPM). Incubation of cells with HpD in dark resulted in the loss of DTNB as well as CPM reactive SH groups. After 2 hr of incubation DTNB reactive SH groups showed a negligible change while a continuous decrease was observed in CPM reactive SH groups. Cells treated with HpD showed a further degradation of SH groups upon light irradiation. A comparison of cytotoxicity and SH groups under identical conditions showed that blockage of SH groups by HpD binding is not leathal to the cells where as photoinduced cell death was observed on photodegradation of SH groups.

Structural alterations induced by photodynamic action of hematoporphyrin derivative (HpD) in plasma membrane of glioblastoma (U-87MG) cells: time dependent fluorescence spectroscopic study

Photodynamic action of hematoporphyrin derivative (HpD) on the plasma membrane of human glioblastoma U-87MG cells was investigated using lipid and protein specific fluorescent probes trimethylammonium-1,6-diphenyl 1,3,5-hexatriene (TMA-DPH) and N-(1-pyrene)-maleimide (PM) respectively. Steady state anisotropy, decay time and time dependent anisotropy of these probes in U-87MG cells were measured. Light irradiation caused an increase in the steady state anisotropy of TMA-DPH in cells treated with HpD; however, no change in decay time was observed. Time dependent anisotropy measurements were performed and the data were analyzed using wobbling in cone model. A decrease in the rotational relaxation time (phi) as well as the cone angle (theta(c)) and an increase in the order parameter (S) of TMA-DPH were observed on photosensitization of cells. A decrease in the order parameter (S) of TMA-DPH were observed on photosensitization of cells. A decrease in the steady rate anisotropy and the rotational relaxation time (phi) of PM and enhancement in the lipid peroxidation were also observed. Our results show that the photodynamic action of HpD increases the order in the lipid bilayer and the mobility of the proteins in the plasma membrane of cells.

An ascending non-obstructive model for chronic pyelonephritis in BALB/c mice

Chronic pyelonephritis was successfully produced in female BALB/c mice with Escherichia coli after introduction of the bacterial inoculum by the ascending route. E. coli strain 31-B, a nalidixic acid-resistant derivative of strain TN675 expressing type-1 pili, and E. coli strain BH-5, a mutant of 31-B, not expressing type-1 pili, were used in the model. Both the strains were able to induce chronic renal inflammation in the experimental animals. Whereas the initial colonisation was greater with strain 31-B, its non-pilate mutant BH-5 caused a significantly greater inflammatory response and also caused renal scarring observable 5 months after the infection.

Gastrointestinal complications after renal transplantation. 10 Year data from a North Indian Transplant Center

Gastrointestinal complications are responsible for substantial morbidity and mortality among renal allograft recipients in developing countries. During a 10 year period, 166 (62.6%) of 265 allograft recipients developed gastrointestinal complications. This figure reflects the high incidence of infectious complications, especially acute diarrheas. Also notable was the incidence of esophageal candidiasis (7.2%), ischemic colitis (2.6%), and gastrointestinal and peritoneal tuberculosis (3.0%). Almost one quarter of the complications developed in the first 6 months after transplantation. Mortality was the highest with acute ischemic colitis (100%), pancreatitis (60%), and upper gastrointestinal hemorrhage (40%). Improvements in standards of living and sanitary conditions, pre transplant evaluation and assessment of risk factors, prophylaxis with anti ulcer drugs, early diagnosis, and appropriate treatment are needed to decrease the frequency and severity of gastrointestinal complications in renal allograft recipients.

A case of non-Hodgkin's lymphoma presenting with polyuria and acute renal insufficiency

A case of non-Hodgkin's lymphoma presenting with polyuria, enlarged kidneys, and renal insufficiency is reported. The diagnosis was made by percutaneous needle biopsy of the kidney. Renal failure reversed and the kidneys regressed in size on exhibition of the first cycle of chemotherapy. The rarity of polyuria at presentation, the role of renal biopsy in the diagnosis, and the response of renal failure to specific chemotherapy are discussed.

Ca2+ influx induced by photodynamic action in human cerebral glioma (U-87 MG) cells: possible involvement of a calcium channel

The plasma membrane has been implicated as a critical target of photodynamic action on cells. We have observed that the photosensitization of human cerebral glioma (U-87 MG) cells by hematoporphyrin derivative (HpD) causes a large increase in intracellular calcium [Ca2+]i. This increase in [Ca2+]i was solely due to the influx of extracellular Ca2+ through the plasma membrane and showed a dependence on HpD concentration, light dose and concentration of calcium in the extracellular medium. The magnitude of the Ca2+ influx decreased with increasing postirradiation time, which suggests that the cell membrane partially recovers from the photodynamic injury. The photoinduced Ca2+ influx was inhibited by the Ca2+ channel blocker diltiazem and the reducing agent dithioerythritol. These findings are discussed in terms of possible activation of a Ca2+ channel as a result of photosensitization.

De novo diabetic glomerulosclerosis in a renal allograft recipient

Posttransplant diabetes mellitus is a well-recognized complication of renal transplantation. Although such patients are at risk for the development of de novo diabetic glomerulosclerosis with increasing graft survival, this has rarely been reported. We describe a patient with posttransplant diabetes mellitus who developed end-stage renal failure due to diabetic glomerulosclerosis 12 years after renal transplantation.

Acute renal cortical necrosis--a study of 113 patients

Over a 28-year period, 113 out of 2986 (3.8%) patients dialysed for acute renal failure at a referral center in North India were diagnosed to have acute renal cortical necrosis (ACN). Obstetric causes were responsible for ACN in 56.6% patients and nonobstetric causes in 43.4%. Within the obstetric group, ACN developed in association with complications of late pregnancy in 37.1% and following septic abortion in 19.5%. The various nonobstetric causes included viperine snake bite in 14.2%, hemolytic uremic syndrome in 11.5%, renal allograft rejection in 5.3%, acute gastroenteritis in 4.4%, acute pancreatitis in 3.5%, septicemia in 2.7%, and trauma and drug-induced IV hemolysis in 0.9% patients. Total anuria was the commonest presenting feature and was noted in 78.8% of patients. Renal histology showed diffuse cortical necrosis in 62.8% and patchy lesions in 37.2% patients. Computerized tomography (CT scan) of the kidneys revealed characteristic diagnostic findings in all the 5 patients in whom it was done. Dialytic support could be withdrawn as a result of improvement in renal function in 19 patients with patchy cortical necrosis. Dialysis-free survival of as long as 12 years has been recorded. The present study shows that, in contrast to the Western world, ACN continues to be a common cause of acute renal failure in developing countries. CT scan of the kidneys is helpful in establishing an early diagnosis.

Acute renal failure in a case of fatal chromic acid poisoning

Despite its frequent use in industry, acute poisoning by chromic acid has very rarely been reported. We report a patient who developed massive gastrointestinal hemorrhage, acute renal failure, and hepatic injury following chromic acid ingestion, and subsequently died. Postmortem liver and kidney biopsies revealed centrilobular necrosis and severe acute tubular necrosis, respectively.

Choroid plexus tumours--an immunohistochemical analysis with review of literature

Immunohistochemical analysis of 9 choroid plexus papillomas (CPPs) and 3 choroid plexus carcinomas (CPCs) using a panel of antibodies against glial fibrillary acidic protein (GFAP), cytokeratin (CK), epithelial membrane antigen (EMA), S-100 protein, vimentin (vim), and neuron specific enolase (NSE) is presented. Focal positivity was observed for GFAP in 11, vimentin in 7, cytokeratin in 2 and EMA in 3 cases. Diffuse and intense immunoreactivity for S-100 protein was seen in all papillomas, however, unreactive areas were noted in carcinomas. All cases exhibited focal to diffuse NSE positivity. Location and type of the tumour and age of the patient did not influence the staining pattern except for predominant S-100 positivity in papillomas. The significance of these findings is discussed in relation to the differential diagnosis or immunoreactivity patterns of these tumours.

Carcinosarcoma of parotid gland having osteosarcoma as sarcomatous component: a case report

We report a rare case of carcinosarcoma of parotid gland in a pleomorphic adenoma. The tumor showed two distinct heterologous components, a ductal carcinoma and an osteosarcoma. The latter has not been described so far in such tumors arising in pleomorphic adenoma of parotid gland.

Renal amyloidosis in juvenile rheumatoid arthritis

We report a child who developed juvenile rheumatoid arthritis at the age of 7 years and nephrotic syndrome due to renal amyloidosis within 2 years of the onset of arthropathy. Literature on the management and prognosis has also been reviewed.

Autopsy findings and clinical diagnoses: a review of 1,000 cases

The protocols of 1,000 consecutive adult patients autopsied during the period June 1983 to December 1988 were retrospectively analyzed and the findings were compared with clinical diagnoses. The autopsy rates during this period ranged between 23% and 27% of hospital deaths. Eighty-seven percent of the autopsied patients were between 15 and 59 years of age. Major discrepancies between the autopsy reports and the clinical diagnoses were present in 31.7% of all autopsy reports reviewed. Infectious diseases were the most common cause of death (46.8%), followed by cardiovascular diseases (17.1%) and neoplastic diseases (14.3%). Infections were clinically recognized in 66.7% of cases and were missed or found to be incorrect in 33.3% of cases. Tuberculosis comprised 33.8% of the major bacterial infections and was clinically diagnosed in 82% of cases. Eighty-nine percent of the major fungal infections were not suspected clinically. Rheumatic heart disease (43.8%) was the most common cardiovascular disorder and was clinically diagnosed in 93.3% of cases. Pulmonary vascular episodes were the least common cause of death and were not suspected clinically in 62.9% of cases. Malignancies were incorrectly diagnosed in 25.8% of cases. We conclude from this study that routine autopsies revealed major unexpected findings that are of clinical importance, and that a continued emphasis on autopsy evaluation is necessary for the improvement of the quality of patient care.

Hereditary nephritis (Alport's syndrome)--clinical profile and inheritance in 28 kindreds

Sixty-three patients, (52 males and 11 females) from 28 kindreds of hereditary nephritis (Alport's syndrome) were identified over a 14-year period from 1977 to 1991. Group I included 51 patients with (a) positive family history of haematuria with or without chronic renal failure, (b) characteristic GBM changes on electron-microscopy, (c) characteristic ocular signs, and (d) high-frequency sensorineural deafness. Group II included 12 patients with a negative family history. All of them had evidence of renal disease with characteristic ocular signs and deafness and four had characteristic GBM changes on electron-microscopy. The main clinical features were haematuria in 96.8%, deafness in 82.5%, and diminished visual acuity in 66.7% of affected subjects. Hypertension was present in 71.4% patients. Pure tone audiometry revealed high-frequency sensorineural deafness in 96.8%. Ocular examination showed bilateral anterior lenticonus in 37.8%, retinal flecks in 22.2%, cataract in 20%, and keratoconus in 6.7% patients. Proteinuria (> 2.0 g/24 h) was detected in 31.8%. Sixteen (57.1%) of the 28 index patients (all males) were diagnosed for the first time when they presented with end-stage renal disease. Serum creatinine in the overall group ranged from 0.9 to 18.7 mg/dl(7.81 +/- 5.37 mg/dl). Adequate renal tissue was obtained by biopsy in 14 patients. Light-microscopy revealed focal segmental glomerulosclerosis in five, mesangial proliferation in four, chronic interstitial nephritis in three, and mesangiocapillary and crescentic glomerulonephritis in one each. Electron-microscopy showed characteristic changes in the GBM in seven specimens.(ABSTRACT TRUNCATED AT 250 WORDS)

Myxoid variant of primary cutaneous malignant melanoma

We report a rare case of primary cutaneous myxoid melanoma. Histologically, the tumour was composed of spindle and stellate-shaped cells, embedded in a myxoid stroma. Positivity for S-100 protein and the presence of melanosomes were demonstrated in the tumour. Primary cutaneous myxoid melanoma is rare. This is the second report of such a case.

The diagnostic value of CT scan in acute renal cortical necrosis

We report the characteristic CT scan findings of renal cortical necrosis in a patient of acute renal failure, which was confirmed on renal biopsy. CT scan is a useful, noninvasive investigative modality for an early diagnosis of renal cortical necrosis.

Binding of hematoporphyrin derivative to brain tumor cells--a fluorescence spectroscopic study

The binding of hematoporphyrin derivative (HpD) to brain tumor cells and their photosensitivity was studied as a function of HpD concentration, time of incubation and growth phase of cells. Upon binding to cells, HpD showed three fluorescence bands at 616, 636 and 678 nm. In plateau phase cells a fluorescence band at 636 nm was predominant, which was further enhanced by increasing HpD concentration and/or increasing incubation time. In exponential phase cells the maximum fluorescence was exhibited at 616 nm. After 1 h incubation of exponential phase cells with increasing HpD concentration an overall intensity enhancement occurred with no change in the distribution of bands, whereas longer incubation time caused an increase in relative intensity of the 636 nm band similar to that observed in plateau phase cells. After 1 h incubation with HpD plateau phase cells were more photosensitive than exponential phase cells, although cell bound HpD was much less in the former case. Incubation of cells for 24 h drastically enhanced the photosensitivity irrespective of the growth phase. Our results suggest a relationship between the fluorescence emission band of HpD at 636 nm and photosensitivity of cells.

Crescentic glomerulonephritis associated with puerperal sepsis

Acute renal failure developed in a young female having puerperal sepsis due to beta-haemolytic streptococci. The patient succumbed to her illness and an autopsy revealed extensive crescentic glomerulonephritis. The association between chronic visceral sepsis and glomerulonephritis is discussed.

Retinitis following disseminated cryptococcosis in a renal allograft recipient. Efficacy of oral fluconazole

A case of retinitis following disseminated cryptococcus neoformans infection in a renal allograft recipient is reported. Therapy with oral fluconazole showed a remarkable improvement at the end of 8 weeks. This is the first report of the use of fluconazole in the treatment of cryptococcal retinitis.

Recurrent focal segmental glomerulosclerosis after renal transplantation

In a young adult male with chronic renal failure from focal segmental glomerulosclerosis, massive proteinuria appeared within two weeks after transplantation. Although allograft biopsy at eight weeks was normal, a second biopsy eight months after transplant showed focal segmental glomerulosclerosis again. Sixteen months after transplantation maintenance hemodialysis had to be restarted.

Hemangioma of the temporalis muscle

A rare case of an intramuscular hemangioma of the temporalis muscle is reported. The clinical examination, carotid arteriogram, computed tomographic scan, and aspiration cytology suggested the vascular nature of the tumor, but an exact diagnosis could only be made after histopathologic examination. Temporary occlusion of the ipsilateral external carotid artery and subperiosteal dissection permitted complete, wide excision without much bleeding.

An ultrastructural analysis of changes in surface architecture of intestinal mucosa following Giardia lamblia infection in mice

The oral inoculation of Giardia lamblia trophozoites (Portland 1 strain) resulted in the establishment of infection by day 3-5 in NMRI mice. By 9-11 days postinfection, the trophozoites load reached maximum (acute phase) and later declined by day 17-21. The tissue sections from infected animals during the establishment phase of infection indicated limited changes in surface epithelium with normal villous length. Although trophozoites of G. lamblia were seen in all sections lying free in the lumen as discrete parasite, the active invasion by the parasite could not be demonstrated. During the acute phase of infection, fuzzy appearance of brush border, marked reduction in villous height and infiltration of intraepithelial lymphocytes were commonly seen in all tissues. Electron microscopic observation demonstrated large numbers of trophozoites of G. lamblia preferentially aggregated at the base of the villi. At some sites, adhesive marks indicating attachment of Giardia trophozoites were also seen by scanning electron microscopy. In addition, severe flattening and blunting of microvilli and occasional loss of basic morphology of intracellular organelles of columnar cells were noticed at the site of parasite colonization under electron microscopy. The brush border microvilli were noted to be damaged in areas where parasites were attached to surface epithelium with the help of suction discs. The morphological changes associated with Giardia infection tended to reverse as the parasite load declined by day 17-21. Thus we feel that malabsorption in giardiasis with total or varying degrees of morphological alterations of surface mucosa can be explained on the basis of reduced absorptive surface area.

Histomorphological criteria for prognosis in breast cancer

One hundred cases of carcinoma breast were analysed with regard to histological features and clinical follow-up. Bad prognostic factors included tumour size larger than 5cms; absent or minimal intraduct component in the tumour and absent or minimal periductal elastosis. Conversely significant intraduct component in the tumour and periductal elastosis were associated with better survival. Degree of lymph nodal involvement did not influence the outcome. One reason for this unexpected finding could be that patients with more than 3 lymph node involvement were given additional chemotherapy.

Retinoblastoma metastatic to the contralateral orbit

In a 9-month-old girl a subperiosteal metastasis of the maxillary bone developed in the contralateral orbit about one year after enucleation of a poorly differentiated retinoblastoma.

Interactions of macrophages from in vivo stimulated guineapigs & the trophozoites of Entamoeba histolytica

The interactions between peritoneal macrophages obtained from guineapigs immunized with a Sephadex chromatographed fraction (FI) of crude amoebic extract proteins and trophozoites of axenic E. histolytica (NIH:200) were studied in vitro in the presence or absence of anti FI antiamoebic antibodies. Unstimulated macrophages killed trophozoites to some extent. Incorporation of anti FI antiamoebic antibodies or IgG of FI antibodies in the amoebae macrophages mixture significantly enhanced the cytotoxic potentials of both unstimulated and in vivo stimulated peritoneal macrophages. Transmission electron microscopy revealed a close contact between macrophages and E. histolytica trophozoites. A large number of lysosomal vacuoles were seen accumulating near the contact areas. The contact between peritoneal macrophages and amoebic trophozoites in the presence of anti FI antibodies led to extensive degeneration of amoebic trophozoites. The antiamoebic antibodies induced cytotoxicity by macrophages in an opsonic manner. The data suggest that antiamoebic IgG binding to the trophozoites by its Fab portion and to the macrophages by its Fc portion initiated the cytotoxic mechanism(s) of macrophages.

Role of culture for mycobacteria in fine-needle aspiration diagnosis of tuberculous lymphadenitis

A total of 390 cases of tuberculous lymphadenitis was subjected to fine-needle aspiration cytology; 100 of the aspirates were subjected to culture for mycobacteria. The overall acid-fast bacilli (AFB) positivity in smears was 23.58%, with a maximum positivity of 32.94% in smears with both necrosis and granuloma. The overall rate of isolation of mycobacteria on culture was 35%. Mycobacteria were more frequently isolated from caseating lesions (40%) than noncaseating lesions (9%). Caseating lesions with granuloma had the highest AFB (smear and/or culture) positivity at 52%. Mycobacterium avium infection was diagnosed by culture in one case.

Nuclear morphometric analysis of non-Hodgkin's lymphoma

Nuclear morphometric data on resin-embedded sections have been utilized to classify 50 cases of non Hodgkin's lymphoma (NHL) and to compare with morphological classification. Nuclear morphometric parameters studied were maximum diameter (Dmax), area, perimeter, form factor (FF) and nuclear contour index (NCI). The first three are determinants of the size, and the latter two indicate the shape of nuclei. Based on Dmax, small (4.5-5.5 microns), intermediate (5.5-7.0 microns) and large (7.0-12.0 microns) cell lymphomas were identified, which correlate with the low, intermediate and high grade lymphomas respectively of the Working Formulation. Determination of form factor further helped to subclassify these cases into lymphomas of B cell other than of follicular centre cell origin (FF = 0.7-1.0), follicular centre cell lymphomas (FF = 0.55-0.75) and T-cell lymphomas (FF less than 0.55). Pleomorphism factor is an objective assessment of the degree of morphological pleomorphism and is generally proportional to the grade of malignancy.

Congenital cyst of Krause's gland

Cysts of Krause's glands usually occur as retention cysts in cicatricial conditions of the conjunctiva. We report a rare case of congenital cyst of Krause's gland in a 2-year-old boy.

Disseminated mucormycosis presenting with acute renal failure

An unusual presentation of disseminated mucormycosis as acute renal failure in a patient without any predisposing condition, is reported. The diagnosis was established at autopsy.

Cell proliferation in the human mammary epithelium. Differential contribution by epithelial and myoepithelial cells

The ductal system of the human breast consists of epithelial, myoepithelial, and basal clear cells. By labeling ducts and alveoli dissected from reduction mammoplasty specimens with 3H-thymidine in vitro and labeling human breast organoids xenografted in nude mice in vivo, it was found that cellular proliferation in the human breast is virtually confined to epithelial and basal clear cells. A pulse label of 3H-thymidine in organ culture explants was followed over a period of time, and it was found that myoepithelial cells originate from a precursor cell population within the mammary epithelium after a number of cell divisions. Myoepithelial cells were not seen to divide when fully mature.

Cellular proliferation in the rat mammary gland during pregnancy and lactation

Cellular proliferation during different stages of pregnancy and lactation in the rat mammary gland was studied by use of autoradiography at the ultrastructural level or in combination with immunocytochemistry. The study consisted of two groups of animals, young 45-day-old rats undergoing their first pregnancy and old multiparous rats undergoing their third pregnancy. Both groups of animals were injected with [3H]thymidine, 2 hours before sacrifice. The timing of proliferative activity through pregnancy and lactation was similar in the two groups. A peak level of proliferation was observed on the 5th day of gestation and the rate of proliferation was at its lowest at the end of gestation. A second small peak was observed on the 3rd day of lactation. In virgin animals, both epithelial and myoepithelial cells showed a high level of proliferative activity. The epithelial cells continued to divide during all stages of their differentiation, throughout pregnancy and lactation. Myoepithelial cells showed active division in early pregnancy but their rate of proliferation declined as the cells acquired abundant cytoplasmic filaments for their contractile function. Intra-alveolar dendritic cells, which have been recently identified in the lactating rat breast, showed a high proliferative rate at the end of gestation.

Ultrastructural identification of Ia positive dendritic cells in the lactating rat mammary gland

Dendritic cells which express Ia antigen have been demonstrated for the first time in the lactating rat mammary gland. Ultrastructurally, the dendritic cells appear as electron-lucent pale cells interspersed among the epithelial cells of the alveoli, forming a cell population distinct from classical macrophages. They show morphological resemblance to the dendritic cells of lymphoid organs as well as the Langerhans cells of skin. The Ia antigen has been localised by electron microscopic immunocytochemistry on the cell membrane and endocytotic vesicles and tubules. Ia positive cells are also seen in the stroma of the mammary gland. It is proposed that the dendritic cells of the mammary gland belong to the lineage of epidermal Langerhans cells and lymphoid dendritic cells, subserving an immunological role in the lactating breast.