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V J Patel

Publications and source records attributed to V J Patel.

At least 19 recordsLinked to original sources
PubMed2000

A stable archaeal pyruvate carboxylase from the hyperthermophile Methanococcus jannaschii.

The pyruvate carboxylase (PYC) of the hyperthermophilic, strictly hydrogenotrophic, autotrophic and marine methanarchaeon Methanococcus jannaschii was purified to homogeneity. Optimal activity was at pH 8.5, > or = 80 degrees C, and a KCl concentration of 0.175 M. This enzyme is the most thermophilic PYC so far studied. Unlike the Methanobacterium thermoautotrophicum enzyme, Mc. jannaschii PYC was expressed in cells grown without an external source of biotin and in the purified form was stable during storage at 4, -20 and -80 degrees C. However, it was rapidly inactivated at 80 degrees C. The enzyme was insensitive to aspartate and glutamate, mildly inhibited by alpha-ketoglutarate, and was strongly inhibited by ATP and ADP (apparent Km, for ATP, 0.374 +/- 0.039 mM; apparent Ki for ATP, 5.34 +/- 2.14 mM; Ki for ADP, 0.89 +/- 0.18 mM). It was also strongly inhibited when the Mg2+ concentration in the assay exceeded that of ATP. Thus, this stable PYC could serve as a model for mechanistic studies on archaeal PYCs. It was apparently an alpha4beta4-type PYC composed of a non-biotinylated 55.5-kDa subunit (PYCA) and a 64.2-kDa biotinylated subunit (PYCB). The determined NH2-terminal sequences for these subunits provided additional support for our earlier proposal to rename the ORFs MJ1229 and MJ1231 in the NCBI Mc. jannaschii genome sequence database as PYCA and PYCB, respectively; even very recently, these have been misidentified as a subunit of acetyl-CoA carbxoylase (AccC) and the alpha-subunit of ion-pumping oxaloacetate decarboxylase (OADalpha), respectively.

Adenosine Diphosphate↗
PubMed2000

Schedule-dependent activity of temozolomide plus CPT-11 against a human central nervous system tumor-derived xenograft.

Temozolomide, an imidazole tetrazinone, and CPT-11, a camptothecin derivative, have previously been shown to have anti-central nervous system tumor activity in laboratory and clinical studies. The current experiments were designed to evaluate the activity of temozolomide plus CPT-11 against a malignant glioma-derived xenograft, D-54 MG, growing s.c. in athymic nude mice. The initial schedule of i.p. drug administration was temozolomide at 0.1 LD10 on day 1 and CPT-11 at 0.1 LD10 on days 1-5 and 8-14. The combination of these two agents produced greater than additive activity against D-54 MG. This enhanced activity was maintained when the initial administration of CPT-11 was delayed to day 3 or day 5. However, when CPT-11 was administered first on day 1 using 0.5 LD10 (for the single dose schedule) followed by temozolomide (0.1 LD10) 5 h, 3 days, or 5 days later, the enhancement of activity was substantially reduced. These results demonstrate that the combination of temozolomide plus CPT-11 displays a schedule-dependent enhancement of antitumor activity, suggest a mechanistic explanation for the enhanced activity, and provide the rationale for a Phase I trial of this regimen.

Animals↗
PubMed1988

Retrograde transvenous perfusion cooling of the kidney, a valuable adjunct to in situ partial nephrectomy in complex renal cell carcinoma. First clinical results.

We report two cases of complex renal carcinoma in which retrograde transvenous perfusion cooling (RTPC) of the kidney was used as adjunct to in situ partial nephrectomy. Definite advantages seem to favour this technique of regional renal hypothermia. We are hopeful that RTPC of the kidney will in future allow to reduce the frequency of potentially harmful extracorporeal bench surgery with autotransplantation in the conservative management of renal carcinoma. Renal RTPC is applicable whenever the kidney is approached transperitoneally with preliminary exposure of the renal vascular pedicle. Tumour cell spill has to be discussed as possible complication of this method. Both patients are alive 25 and 19 months, respectively, after surgery without evidence of haematogenous, peritoneal or retroperitoneal tumour disease.

Carcinoma, Renal Cell↗
PubMed1982

Isolated perianal verrucoid familial benign chronic pemphigus.

A case is described in which verrucous perianal lesions of familial benign chronic pemphigus (Hailey-Hailey disease) were initially mistaken for condylomata acuminata. The verrucoid, atypical form of the disease has only relatively recently been recognized and perianal lesions may easily be mistaken as manifestations of other conditions.

Adult↗
PubMed1978

[Myotropic spasmolysis in the treatment of ureteric colics (author's transl)].

The effectiveness of parasympathicolytic drugs in the treatment of ureteric colics is doubtful. Bencyclane is a new myotropic substance. Its spasmolytic effect on smooth muscle is five times stronger than that of papaverine. The results of the clinical use of Bencyclane in cases of ureteric colic are described and discussed.

Bencyclane↗
PubMed1978

[Tantalum in diagnosing tumors of the ureter and renal pelvis. A preliminary report (author's transl)].

Differential diagnosis of small tumors of the ureter and renal pelvis is often difficult. Retrograde pyelogramm and tri-iodied contrast material is not effective in diagnosing small tumors and their surface condition. A retrograde pyelogram with a tantalum powder solution offers the following advantages: 1. Clearer representation of the tumor surface. 2. X-ray films show sharper contrast. 3. Small tumors could be seen that are not visible with routine contrast material. Preparation of tantalum solution and the technique of retrograde pyelogram are described.

Aged↗
PubMed1978

[Early catheter removal in water-tight bladder closure following transversical prostatic adenometomy].

It is reported on 124 patients in whom after a transvesical adenomectomy an early removal of the catheter was aspired to. A watertight closure of the urinary bladder is one of the most important prerequisites. The 5th day after operation seems to be best suited for the removal of the catheter. A temporary fistulisation lasting 2 days occurred only in one case. Secondary infection of the wound as well as epididymitis could not be observed. 96% of the patients could be discharged with sterile urine. Advantages of the early removal of the catheter: 1. Shortened hospitalisation and shortened convalesence. 2. Reduced danger of a secondary infection of the urinary tract 3. Early symptom-free subjective condition of the patient.

Humans↗
PubMed1975

A rapid assay technique for RNA ribose methylases.

A rapid technique for quantitative separation of ribose-methylated nucleosides from base-methylated and non-methylated nucleosides by chromatography on DEAE-cellulose paper in the presence of borate is described. The method has been used as an assay for tRNA ribose methylases from yeast, using under methylated Escherichia coli tRNA as substrate. The main product formed with a partly purified yeast enzyme was characterized as 2'-O-methylcytidine.

Albumins↗