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R Rajah

Publications and source records attributed to R Rajah.

31 records · Page 2Linked to original sources

Protein distribution and gene expression of collagen type IV in the neonatal rat ovary during follicle formation.

Protein distribution and mRNA expression of basement membrane collagen (type IV) during follicle formation were studied using serial sections from 24, 48 and 72 hrs. old rat ovaries. Collagen type IV, a protein found only in the basal lamina of the basement membrane, was localized under light microscope using a polyclonal antibody. During the first 24 hrs. postpartum, immunostaining was found as thin septa separating the clusters from the stroma. By 72 hrs. postpartum, immunostaining was found around each newly formed primordial follicle. The cell types involved in collagen type IV synthesis were determined by in situ hybridization using a biotinylated riboprobe. Before the follicles had been formed, the stromal cells showed intense staining while the epithelial presumptive granulosa cells showed a pale staining. However, after a follicle had been formed, some of the granulosa cells enclosed within the follicular basement membrane showed strong staining for the message. The presumptive granulosa cells are presumed to be the progenitors of granulosa cells. If so, these observations suggest that the expression of the message coding for collagen type IV by the granulosa cells may be a marker for commitment of the undifferentiated cell to the granulosa cell lineage.

Animals↗

Pathologic changes in the small bowel in nine patients with diarrhea associated with a coccidia-like body.

OBJECTIVE: To confirm a suspected small-bowel injury in patients with a syndrome of protracted diarrhea associated with a coccidia-like body (CLB). DESIGN: Investigation of an epidemic including a case-control study. SETTING: Outpatient clinic in Kathmandu serving primarily the tourist and expatriate community in Nepal. PATIENTS: Nine patients with diarrhea with at least one stool specimen that was positive for the presence of a CLB and seven noninfected volunteer controls. MEASUREMENTS: Clinical data, microscopic examination of stool, bacteriologic and viral studies on submitted stool specimens, upper gastrointestinal endoscopy including duodenal aspiration and microscopy, small-bowel biopsy with subsequent light and electron microscopy. RESULTS: Endoscopic evidence of inflammation of the distal duodenum was present in five of nine patients with CLB and in none of the seven controls. All nine patients with CLB were noted to have histologic evidence of small-bowel injury, which included acute and chronic inflammation, surface epithelial disarray, and varying degrees of villous atrophy and crypt hyperplasia. One of the seven controls had similar pathologic findings and developed CLB-related diarrhea 5 days later. The other controls had normal distal duodenal histologic results. The organism was found in two of nine duodenal aspirates but was not present in the preserved biopsy specimens as determined by light or electron microscopy. CONCLUSIONS: The pathologic basis of CLB-associated diarrhea appears to be small-bowel injury whose cause remains to be elucidated.

Adult↗

Epidemiology of diarrhoeal illness associated with coccidian-like organism among travellers and foreign residents in Nepal.

A newly described organism called CLB (coccidian-like or cyanobacterium-like body) has been identified in cases of prolonged diarrhoea. To confirm an association of CLB with disease and identify risk factors for transmission, we conducted a case-control study of travellers and foreign residents at two outpatient clinics in Kathmandu, Nepal. Patients without diarrhoea were matched to CLB cases by clinic and date of visit. For comparison, patients with other causes of diarrhoea were also studied. Stools were examined for enteric pathogens with standard microbiological and molecular genetic techniques. CLB was identified in 108 (11%) of 964 individuals with gastrointestinal symptoms compared with only 1 (1%) of 96 symptom-free controls (p = 0.003). 7% of residents in the US Embassy community acquired the infection. The diarrhoeal illness associated with CLB lasted a median of 7 weeks (interquartile range 4-9) compared with 9 days (4-19) for individuals with other causes of diarrhoea (p < 0.0001). The prevalence of other enteric pathogens was no higher among CLB cases than among symptom-free controls. Patients with CLB infection were more likely than controls to report consumption of untreated water (odds ratio 3.98; 95% CI 1.29-13.14); organisms of the same appearance were identified in an epidemiologically implicated water sample. The significant association of CLB with prolonged diarrhoea, and the low rate of other enteropathogens in CLB cases, strongly supports the hypothesis that CLB is a new pathogen. Epidemiological and environmental data suggest that the organism is waterborne.

Adolescent↗

Fatigue fracture of the sacrum in a child.

Fatigue fractures involving the sacrum are extremely rare, and to our knowledge no occurrence of such a fracture in a child has been reported in the English-language literature. These fractures may mimic primary bone tumours or infection, and it is important to make an accurate diagnosis so that unnecessary biopsy can be avoided. We report a fatigue fracture of the sacrum in an 11-year-old child following prolonged aerobic exercise.

Child↗

The changing architecture of the neonatal rat ovary during histogenesis.

The purpose of this study was to describe the changing histological organization of the rat ovary during postpartum days one through three (p1-p3). A PC-based image-combining microscope system was used to reconstruct the ovary in three dimensions. On p1, cyclindrical pocket-like structures radiated from the core of the ovary that were open toward the surface epithelium. The walls of the pockets contained connective tissue cells and capillaries (stroma). By p2, these pockets had completely closed; each pocket enclosed a small nest of oocytes and a few presumptive granulosa cells. By p3, the pocket-like organization had disappeared. On p1, only one or two primordial follicle-like structures were observed in the core and toward the periphery of the ovary; most oocytes were not enclosed in follicles. By p3, very few naked oocytes remained; primordial follicles predominated in all the regions of the ovary and some of the follicles had multiple layers of granulosa cells. There were changes in location, area, and volume of the rete tubules during these postnatal days. The extraovarian rete was visible on all 3 days but changed its orientation relative to the ovary. The connecting rete was found beneath the epithelial layer of the ovary on all 3 days and showed dramatic increase in area on p2. The wide lumen of the intraovarian rete was in direct contact with some of the oocytes near by on all 3 days, but these "communication points" were most abundant on p2. Based on our observations of different cell-cell associations during this time period, we hypothesize (1) that the mesenchymal-presumptive granulosa cell association is essential for the completion of folliculogenesis, and (2) the rete ovarii may have an inductive role in follicle assembly. These observations suggest that the first 3 days postpartum are critically important for studying the heterogeneous cell interactions that lead to the assembly of primordial follicles. The regional differences in tissue organization during this formative period may have significant implications on later aspects of follicular development.

Animals↗

The role of hysterosalpingography in modern gynaecological practice.

A retrospective review of hysterosalpingography (HSG) in a major gynaecological centre was carried out. 324 patients attended (95%) for HSG out of 341 patients referred for this investigation. 189 examinations (58.3%) were abnormal. The requests and radiological findings were reviewed and the results compared with laparoscopy. HSG remains an integral part of gynaecological investigation and its value has not diminished in modern practice.

Adult↗

An alga-like organism associated with an outbreak of prolonged diarrhea among foreigners in Nepal.

An unidentified organism was found in the stools of 55 immunocompetent patients who presented to the CIWEC Clinic in Kathmandu, Nepal between June and November 1989. The microscopic features of the organism share characteristics of both coccidia and cyanobacteria species. From June 26, 1989 to November 17, 1989, 55 persons were identified as having the organism in at least one stool sample. The illness was characterized by prolonged watery diarrhea, anorexia, fatigue, and weight loss. The mean +/- SD duration of illness was 43 +/- 24 days (range 4-107). Thirty-four patients received a total of 78 courses of antimicrobial treatment (2.3 courses/patient). The mean +/- SD duration of illness in 34 treated patients was 46 +/- 24 days. In 14 untreated patients, the mean +/- SD duration of illness was 35 +/- 23 days. The organism is 8.0-9.0 microns in diameter, floats in Sheather's solution, and stains red with the modified acid-fast stain. Since the agent was closely associated with a prolonged, self-limited diarrheal illness, it could easily have been misdiagnosed as Cryptosporidium. The organism should be looked for in the stools of patients with persistent diarrhea and a history of foreign travel.

Adolescent↗

Bone mineralization and mineral homeostasis in very low-birth-weight infants fed either human milk or fortified human milk.

Abnormalities in bone mineral metabolism are frequently found in very low-birth-weight infants, especially if fed breast milk. To assess the efficacy of a breast-milk fortifier in the feeding of these very small infants, very low-birth-weight babies (between 1,000 g-1,500 g at birth) were randomly assigned to one of two groups on day 4 of life. The fortified group received the fortifier mixed in equal proportions with their own mother's milk, while the breast-milk group received only their own mother's milk. All infants received an oral vitamin D supplement of 750 IU/day. The study was continued until the infants weighed 1,800 g, at which stage breast feeding was encouraged. Thirty infants in the breast-milk group and 29 in the fortified group completed the study. Infants in the fortified group had significantly lower alkaline phosphatase values, a greater bone mineral content (BMC) and BMC/bone width ratio, and lower urinary calcium excretion than the breast-milk group at a weight of 1,800 g. At follow-up study 3 months after delivery, when most of the infants in both groups had been breast fed for at least 6 weeks, the breast-milk group's biochemical and BMC abnormalities were almost totally corrected and were now similar to those of the fortified group. Thus, the addition of the fortifier to breast milk during the first 4-6 weeks of life decreased the biochemical evidence of abnormal bone mineral homeostasis and increased BMC in very low-birth-weight infants. By 3 months of age, however, the breast-milk group had almost totally corrected its abnormalities.

Body Weight↗

The effect of feeding four different formulae on stool weights in prolonged dehydrating infantile gastroenteritis.

Prolonged diarrhea following an acute episode of dehydrating gastroenteritis in infants is often treated by the empirical removal of both cow's milk protein and lactose from the feed, as they both have been implicated in the prolongation of diarrhea. In order to assess the efficacy of this policy and to determine whether there are any advantages in using a lactose-free semi-elemental feed in this situation, infants with prolonged dehydrating gastroenteritis from a developing community in South Africa were studied. Male black children between the ages of 6 weeks and 2 years with prolonged dehydrating gastroenteritis (requiring intravenous fluids for longer than 72 h to maintain hydration) were randomly assigned to receive one of four feeds if the stool weight was greater than 30 g/kg body weight/24 h on the fourth day of admission. The four formula feeds were a partially modified cow's milk formula; a lactose-free, casein-containing formula; a lactose-free, soy-protein-containing formula; and a lactose-free, whey-hydrolysate-containing formula. Stool weights were measured for the following 3 days. Seventy-two children were enrolled into the study. Stool weights were similar in the four groups at the start of the trial, and fell significantly over the trial period in those groups receiving the lactose-free feeds. Mean stool weight in the cow's milk formula group did not change. Thus, it appears that the continued feeding of a cow's milk-based lactose-containing formulae to infants with prolonged dehydrating gastroenteritis adversely affects their recovery.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗