Partial nephrectomy in cystic partially differentiated nephroblastoma

Cystic partially differentiated nephroblastoma (CPDN) is an uncommon renal neoplasm in children. It is now recognized as a tumor with low but definite malignant potential. The authors report a patient that was treated with partial nephrectomy and chemotherapy with successful outcome. The literature on CPDN is briefly discussed.

Long term survival in a young girl with renal cell carcinoma

A young girl with an uncommon renal tumour is the subject of this communication. A diagnosis of renal cell carcinoma was established post-operatively. Combined modality treatment including chemotherapy and radiotherapy has helped achieve a disease free survival of nearly 5 years.

Retro-peritoneal cystic lymphangioma in association with fetal hydantoin syndrome

Antiepileptic drugs are known to be teratogenic. Use of phenytoin during pregnancy can cause various congenital malformations leading to 'fetal hydantoin syndrome'. One such case reported is unique in the sense that it occurred with retroperitoneal cystic lymphangioma, itself a rare condition. Such an association is not described elsewhere.

Facial nerve palsy in an infant with hemophilia A

A 5-month-old infant with hitherto undiagnosed hemophilia A, who developed a unilateral lower motor neurone type of facial palsy, is described. A high-resolution CT scan confirmed the nerve palsy to be a consequence of a hemotympanum. The patient recovered completely in 7-10 days after therapy with factor VIII concentrate.

Urinoma--an unusual complication following kidney biopsy

Development of urinoma is an unusual complication following kidney biopsy. We describe one such case who was managed successfully by ultrasound guided percutaneous catheter drainage.

Recent approaches in insulin delivery

Insulin remains indispensable in the management of diabetes mellitus since its discovery in 1921. The foreignness of early available porcine and bovine insulin led to the development of human insulin by transpeptidation and biosynthesis in microorganisms. Needle phobia and stress of multiple daily injections led to the investigation and exploitation of all promising routes, ranging from nasal to rectal, by a wide variety of devices and delivery systems. This article describes the development of human insulin, various routes for delivery of insulin (including oral, nasal, buccal, rectal, and pulmonary), and various devices for regulated, safe, and convenient insulin delivery. The article reviews some recent advances in insulin delivery such as the bioresponsive and self-regulated insulin delivery system.

Blue rubber bleb nevus syndrome: a cause for recurrent episodic severe anemia

A 7-year-old boy had several episodes of severe anemia, requiring hospitalizations and blood transfusions. Skin hemangiomas characteristic of blue rubber bleb nevus syndrome were present since infancy, but were not recognized as being indicative of simultaneous existence of bowel hemangiomas, resulting in a delay of several years before an accurate diagnosis could be made.

Human immunodeficiency virus infection transmitted through breast milk

Perinatal acquisition of human immunodeficiency virus is responsible for most cases of pediatric AIDS. Breast feeding has been found to carry a higher risk of transmission of HIV and is not recommended to HIV infected mothers in the western world. In our country we have to be aware of the increasing incidence of pediatric AIDS and the varied constellation of symptoms it can present with. Also, we have to ensure that safe blood is available to avoid transfusion acquired diseases.

Active site-directed thrombin inhibitors--II. Studies related to arginine/guanidine bioisosteres

A series of N-arylsulfonylarginine amides was synthesized wherein the guanidine or arginine moiety was isosterically replaced by a number of heterocyclic functionalities. These compounds were evaluated as potential active-site inhibitors of thrombin. Bisamidines 11a-n showed a similar SAR to that of simple arginine compounds. The ex vivo clotting time measurement of 11d after ip dosing showed prolongation of clotting time in rats.

Comparative study on the chromophore binding sites of rod and red-sensitive cone visual pigments by use of synthetic retinal isomers and analogues

A comparative study on the chromophore (retinal) binding sites of the opsin (R-photopsin) from chicken red-sensitive cone visual pigment (iodopsin) and that scotopsin) from bovine rod pigment (rhodopsin) was made by the aid of geometric isomers of retinal (all-trans, 13-cis, 11-cis, 9-cis, and 7-cis) and retinal analogues including fluorinated (14-F, 12-F, 10-F, and 8-F) and methylated (12-methyl) 11-cis-retinals. The stereoselectivity of R-photopsin for the retinal isomers and analogues was almost identical with that of scotopsin, indicating that the shapes of the chromophore binding sites of both opsins are similar, although the former appears to be somewhat more restricted than the latter. The rates of pigment formation from R-photopsin were considerably greater than those from scotopsin. In addition, all the iodopsin isomers and analogues were more susceptible to hydroxylamine than were the rhodopsin ones. These observations suggest that the retinal binding site of iodopsin is located near the protein surface. On the basis of the spectral properties of fluorinated analogues, a polar group in the chromophore binding site of iodopsin as well as rhodopsin was estimated to be located near the hydrogen atom at the C10 position of the retinylidene chromophore. A large difference in wavelength between the absorption maxima of iodopsin and rhodopsin was significantly reduced in the 9-cis and 7-cis pigments. On the assumption that the retinylidene chromophore is anchored rigidly at the alpha-carbon of the lysine residue and loosely at the cyclohexenyl ring, each of the two isomers would have the Schiff-base nitrogen at a position altered from that of the 11-cis pigments.(ABSTRACT TRUNCATED AT 250 WORDS)

Inhibitors of retinyl ester formation also prevent the biosynthesis of 11-cis-retinol

Lecithin retinol acyl transferase (LRAT) from the retinyl pigment epithelium is potently inhibited by all-trans-retinyl alpha-bromoacetate in the micromolar range. The inhibition is competitive and reversible. The retinyl pigment epithelium also contains an enzymatic activity capable of converting added all-trans-retinol into 11-cis-retinol. This isomerization is likely to require the intermediate formation of all-trans-retinyl esters, which are themselves produced by LRAT action. Here this possibility is directly tested by studying the effect of all-trans-retinyl alpha-bromoacetate on the isomerization reaction. When pigment epithelium membranes are preincubated with all-trans-retinyl alpha-bromoacetate, they form neither retinyl esters nor 11-cis-retinol from added all-trans-retinol. However, if the pigment epithelium membranes are first allowed to form all-trans-retinyl esters from all-trans-retinol before the addition of all-trans-retinyl alpha-bromoacetate, then 11-cis-retinol formation proceeds at close to the rate found in the absence of inhibitor. In addition, 11-cis-retinyl esters are not formed under these conditions, eliminating the possibility of a direct ester-ester isomerization route. Therefore, all-trans-retinyl esters are obligate intermediates in the biosynthesis of 11-cis-retinol.

9,13-dicis-rhodopsin and its one-photon-one-double-bond isomerization

Incubation of purified 9,13-dicis-retinal with cattle opsin in 2% digitonin at 20 degrees C produced two pigments, one unstable (lambda max 478 nm) and the other stable (lambda max 485 nm) in hydroxylamine. The two pigments exhibited different characteristics. HPLC analysis revealed that the chromophores of these pigments have respectively 9,13-dicis and 9-cis geometries. Under various conditions the amount of 9,13-dicis-rhodopsin formed never exceeded 30% of the total pigments. The addition of 9,13-dicis-retinal to the ROS suspension containing opsin produced 9-cis-rhodopsin in 97% yield. Irradiation of the 9,13-dicis-rhodopsin mainly produced 13-cis-retinal, while 9-cis-rhodopsin produced the all-trans isomer. These results demonstrated that the one-photon-one-double-bond isomerization process took place in 9,13-dicis-rhodopsin.