N Zafar

Publications (27)65.63 Total impact

• Source

  Available from: Michael Rost

  Article: Switchability of neoral and equoral according to Food and Drug Administration rules and regulations.

  M A Masri, M Haberal, A Rizvi, A Stephan, N Bilgin, A Naqvi, A Barbari, G Kamel, N Zafar, R Emiroğlu, T Colak, K Manzoor, V Matha, V Kamarad, M Rost, S Rizk, A Hazime, F Perlik
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  ABSTRACT: According to the US Food and Drug Administration (FDA), if a drug product contains a drug substance that is chemically identical and is delivered to the site of action at the same rate and extent as another drug product, then it is equivalent and can be substituted (switchable) for that drug product. Methods used to define bioequivalence as stated by the FDA rules (FDA 21 CFR 320, 24) are (1) pharmacokinetic (PK) studies in healthy volunteers, (2) comparative clinical trials, and (3) pharmacodynamic (PD) studies (bioactivity). We evaluated the switchability of Equoral (IVAX-USA) with Neoral (Novartis Switzerland using all FDA rules. In a single oral dose, we undertook a comparative bioavailability study of Equoral (IVAX, USA) Neoral (Novartis, USA), and Neoral (Novartis UK). The pharmacokinetics of Equoral and Neoral were determined with blood levels at 0, 0.25, 0.5, 0.75, 1, 1.25, 1.5, 1.75, 2, 2.5, 3, 3.5, 4, 5, 6, 8, 10, 12, 16, 24, 30, 36, 42, and 48 hours. The area under curve (AUC), AUC extrapolated to infinity (AUC0-inf), rate of absorption (Tmax), extent of absorption (Cmax), half time (t1/2) of Equoral and Neoral were all within the 90% confidence interval of 80% to 125% boundaries. A comparative multinational multicenter clinical trial in stable renal transplant patients included 70 patients (22 women and 48 men) of mean age of 33 years (range, 26 to 43) was performed in Turkey, Lebanon, and Pakistan. In this study the ratios of LSM and the 90% confidence intervals for the Nontransformed/Parameters (AUC0-t, AUCinf, Tmax, and Cmax) of Equoral and Neoral SGC were 98% and 95%, respectively, which are within the 80% to 125% FDA acceptance range. For immunosuppressive drugs, the site of action is the lymphocyte and the measurable response is the decrease in lymphocyte count caused by the relative concentration of the drug in the lymphocyte. In a controlled switch, fixed-dose study, both Equoral and Neoral achieved the same concentration in the lymphocytes and caused the same degree of lymphocyte count reduction. The results of the testing (bioavailability-bioequivalence, clinical studies, and pharmacodynamic-bioactivity) required by FDA for interchangeability ("switchability") of immunosuppressive agents suggests that Neoral and Equoral are switchable.
  Transplantation Proceedings 10/2005; 37(7):2988-93. · 1.00 Impact Factor
• Article: Palladium-related deep levels in silicon

  A A Gill, M Zafar Iqbal, N Zafar
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  ABSTRACT: The results of a study carried out on Pd-doped p+n Si junctions using deep-level transient spectroscopy (DLTS) are reported. Four deep levels associated with Pd at energy positions Ec-0.18 eV, Ec-0.22 eV, Ec -0.37 eV and Ec-0.59 eV are observed. These deep levels have been observed simultaneously in the same as-diffused Si:Pd samples for the first time, to the best of the authors knowledge. Detailed data on the emission rates, capture cross sections and their temperature dependence and deep-level distribution profiles of the palladium-related defects are presented. Isochronal annealing characteristics of these defects have also been studied up to 400 degrees C yielding some interesting new insights. The authors results cast doubts on some of the currently held models for the structure of some of these defects.
  Semiconductor Science and Technology 12/1998; 8(5):675. · 1.72 Impact Factor
• Article: Interaction of iron with transition metals and alpha radiation in thermally quenched p-silicon

  Akbar Ali, U S Qurashi, M Zafar Iqbal, N Zafar
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  ABSTRACT: Iron-induced deep levels have been studied in p-type silicon quenched from high temperatures, using deep-level transient spectroscopy. The interstitial iron donor and the iron - boron pair defect are observed and identified by a number of their characteristics including their mutual transformation. Our recent work revealed an interesting new property of the interstitial iron donor defect, namely its complete bleaching by the transition metals Ag, Au, Pt and Pd in samples which have received thermal treatment identical to the undoped samples. The study reported here was intended to investigate the relationship of this effect to the well known iron - boron complex defect known to act as a source of the interstitial iron defect by injection-induced dissociation in boron doped p-silicon. Our results show that both the iron - boron complex and the isolated interstitial iron defects disappear concurrently in our transition-metal-doped samples. Thus the bleaching of the iron interstitial in the presence of the transition metals used is found to be associated with the bleaching of this source rather than due to some unknown complex mechanism inhibiting the dissociation of these pairs in the presence of the transition metals. In addition, the response of the iron interstitial defect to irradiation with alpha-particles and its thermal annealing behaviour have been studied. Alpha-irradiation is seen to lead to a significant suppression of the iron interstitial defect, in agreement with the hitherto reported results of electron irradiation, without causing any significant change in its thermal annealing characteristics.
  Semiconductor Science and Technology 12/1998; 12(9):1100. · 1.72 Impact Factor
• Article: Pharmacokinetics of cyclosporine microemulsion in Pakistani renal allograft recipients: correlation of trough peak levels with 7-point and 3-point AUC.

  M Hussain, N Zafar, A Bux, S Sultan, A Hashmi, Z Hussain, S Hafiz, A Naqvi, A Rizvi
  Transplantation Proceedings 12/1998; 30(7):3555. · 1.00 Impact Factor
• Article: Correlation between biopsies and noninvasive assessment of acute graft dysfunction.

  F Akhtar, T A Rana, J Kazi, N Zafar, A Hashmi, S Bhatti, R Naqvi, R Mohsin, A Naqvi, A Rizvi
  Transplantation Proceedings 12/1998; 30(7):3069. · 1.00 Impact Factor
• Article: Factors influencing renal transplantation in a developing country.

  S A Rizvi, S A Naqvi, Z Hussain, S Hafiz, F Akhtar, N Zafar, H Altaf, E Ahmed, M Hussain
  Transplantation Proceedings 09/1998; 30(5):1810-1. · 1.00 Impact Factor
• Article: Conversion of patients to cyclosporine E microemulsion.

  N Zafar, M Lal, B Muzzamil, S Khalil, Z Hussain, A Naqvi, A Rizvi
  Transplantation Proceedings 06/1998; 30(3):830. · 1.00 Impact Factor
• Article: Factors influencing graft survival in living-related donor kidney transplantation at a single center.

  A Rizvi, A Naqvi, Z Hussain, S Hafiz, A Hashmi, N Zafar, F Akhtar, E Ahmed, M Hussain, A Askari
  Transplantation Proceedings 06/1998; 30(3):712-6. · 1.00 Impact Factor
• Article: Outcome of living-related donor renal allografts in hepatitis C antibody-positive recipients.

  A Naqvi, T Aziz, M Hussain, N Zafar, R Muzaffar, J Kazi, F Akhtar, E Ahmad, A Hashmi, Z Hussain, A Rizvi
  Transplantation Proceedings 06/1998; 30(3):793. · 1.00 Impact Factor
• Article: Histocompatibility in live related donor renal transplantation.

  N Zafar, S Hafiz, S Khan, K Abbas, S Ahmed, M Khalique, T Aziz, R Shaikh, S Abidi, A Yawar, N Ahmed, A Naqvi, A Rizvi
  Transplantation Proceedings 12/1997; 29(7):2973-4. · 1.00 Impact Factor
• Article: Prediction of renal function recovery in obstructive renal failure due to stones.

  M Hussain, B Ali, S Ahmed, N Zafar, S A Naqvi, S A Rizvi
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  ABSTRACT: Two hundred and thirty-nine patients with renal and ureteric calculi associated with renal failure were evaluated for recovery potential before definitive surgery. Ultrasonography was carried out pre-operatively in all, followed by percutaneous nephrostomy (PCN) as an initial management before definitive surgery. Diethylene triamine penta acetic acid (DTPA) scan was done in 125 patients after percutaneous nephrostomy, findings of pre- operative DTPA scan were correlated with post-operative drop in serum creatinine. Urine pH, urine Na+, initial diuresis, creatinine clearance and serum creatinine were measured serially after 24 hours and then every week for 6 weeks. Patients were re-evaluated with serum creatinine after 3 months of surgery. Ultrasonography was found to be reliable in predicting future recovery of renal functions in 76.5% cases and true obstruction of shorter duration (F4-group) on DTPA scan in 81.9% cases. Urine pH of 6 or less, post-PCN diuresis and natriuresis were good prognostic indicators. PCN was found to be most reliable method of predicting future recovery of renal function after relief of obstruction with 97.8% accuracy.
  Journal of the Pakistan Medical Association 07/1997; 47(6):159-61.
• Article: Evaluation of ureteropelvic junction obstruction (UPJO) by diuretic renography.

  S Sultan, M Zaman, S Kamal, N Zafar, A Naqvi, A Rizvi
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  ABSTRACT: Of 52 cases with 56 affected renal units having symptoms and signs suggestive of Ureteropelvic Junction Obstruction (UPJO) evaluated by conventional (F + 15) diuretic renography where frusemide is given 15 minutes post-injection of radiopharmaceutical m99TC.DTPA.F + 15, twelve (21%) showed a good clearance (group A), 16 (28%) showed partial (group B) and 28 (50%) a poor clearance pattern (group C) indicating a definite obstruction. A high flow (F-15) diuretic renography where frusemide is given 15 minutes prior to the radiopharmaceutical m99TC.DTPA, was done in 23 cases with 27 affected renal units. Eleven renal units showed a good clearance (group A). Of these, 7 (64%) showed a persistent good clearance, 3 (27%) converted to poor clearance and 1 (9%) to partial clearance pattern. Of 8 renal units in group B, 5 (63%) converted to poor clearance and two (25%) to good clearance on F-15 and one remained unchanged. All renal units which presented as poor clearance (group C) on conventional (F + 15) diuretic renography remained unchanged on high flow (F-15) diuretic renography. In majority of cases conventional (F + 15) renography gave a reliable assessment of the upper tract drainage, however, since equivocal group was resolved by the F-15 and the intermittent obstruction group was definitely diagnosed, high flow (F-15) diuretic renography was more conclusive in assessment as compared to F + 15.
  Journal of the Pakistan Medical Association 08/1996; 46(7):143-7.
• Article: Serology versus polymerase chain reaction-sequence-specific primers in typing for HLA-DR in Pakistani populations.

  N Zafar, N Ahmed, K Saeedullah, A Naqvi, A Rizvi
  Transplantation Proceedings 07/1996; 28(3):1270-1. · 1.00 Impact Factor
• Article: Factors influencing patient and graft survival in living related renal transplantation at a single centre.

  A Naqvi, K Abbas, N Zafar, R Naqvi, H Askari, E Ahmed, A Hashmi, F Akhtar, A Rizvi
  Transplantation Proceedings 07/1996; 28(3):1574-5. · 1.00 Impact Factor
• Article: Two cadaveric renal transplants in Pakistan from non-heart-beating donors from Maastricht.

  A Naqvi, N Zafar, A Hashmi, F Akhtar, Z Hussain, A Rizvi
  The Lancet 03/1996; 347(8999):477-8. · 38.28 Impact Factor
• Article: HLA frequencies in Pakistani population groups.

  N Zafar, S Khan, A Qadir, Y Raza, A Naqvi, A Rizvi
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  ABSTRACT: HLA Antigen A, B and DR frequencies were determined in 912 subjects who were prospective donors and recipients for renal transplantation. Of the 912, 305 were Sindhi, 248 Punjabi, 315 Urdu and 44 Pushto speaking. HLA A1, A2, A11 and A19 were common in all these groups. A3 was more frequent in Pushto, A9 (24) in Punjabi, A10 (26) in Sindhi and A28 in Urdu-speaking group. HLA B5 (51) and B40 (60) were common in all, while B8 in Sindhi and Punjabi, B35 in Sindhi, Urdu and Pushto and B27 in Punjabi and Urdu speaking individuals. HLA-DR3 and DR2 (15) were common in all groups. DR6 (13) in Sindhi, Urdu and Pushto and DR6 (14) in Punjabi, DR5 (11) in Urdu, Punjabi and Pushto speaking subjects. Overall, Pakistani frequencies showed linkage to Caucasians and Orientals. This paper describes differences in frequencies in various population groups within Pakistan which may have relevance in factors where HLA system plays a crucial role.
  Journal of the Pakistan Medical Association 02/1996; 46(1):12-3.
• Article: Early experience of renal transplantation in hepatitis C patients.

  H Askari, S Abidi, K Abbas, S Sultan, F Akhtar, N Zafar, S Hafiz, A Naqvi, A Rizvi
  Transplantation Proceedings 11/1995; 27(5):2600-1. · 1.00 Impact Factor
• Article: Management of urinary calculi associated with renal failure.

  M Hussain, M Lal, B Ali, S Ahmed, N Zafar, S A Naqvi, S Adib-ul-Hassan Rizvi
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  ABSTRACT: Three hundred and sixty patients of urinary calculi associated with renal failure were included in this prospective study. The male to female ratio was 4.1:1 while adult to paediatric ratio was 6.5:1. One hundred and eighteen (32.8%) patients presented with calculus anuria while 242 (67.2%) were admitted with symptoms of chronic renal failure. Serum creatinine at the time of first admission ranged from 3-35 mg/100 ml. In the initial management, percutaneous needle nephrostomy was done in 217 cases, dialysis in 106, dialysis and PCN in 22 and retrograde catheterisation followed by JJ stent in 15. Definitive surgical procedures were undertaken in 277 cases; 29 passed stones spontaneously after PCN. At two year follow-up 72% patients of calculus anuria and 49.5% of calculus renal failure improved their renal function and remained with serum creatinine below 2 mg/100 ml. There was 13.6% mortality in calculus anuria group and 17.4% in calculus renal failure. Overall loss to follow-up was 7.6% and 12% in the two groups respectively.
  Journal of the Pakistan Medical Association 09/1995; 45(8):205-8.
• Article: Acute renal failure due to traumatic rhabdomyolysis.

  R Naqvi, F Akhtar, I Yazdani, S Hafiz, N Zafar, A Naqvi, A Rizvi
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  ABSTRACT: Trauma and non-traumatic insults can cause muscle damage to such an extent that serious sequelae to other organs may result. Myoglobinuria and subsequent acute renal failure (ARF) is a well known and widely studied fact of such sequelae. Twelve cases of ARF (between 1990-1993) who have developed renal dysfunction after prolonged muscular exercise e.g., squat jumping, sit-ups and blunt trauma from sticks or leather belts mainly given by law enforcing personnel for certain issues were studied. None of them had previous history of myopathy, neuropathy or renal disease. All were critically ill on presentation and required renal support in the form of dialysis. Although morbidity was high in all, eleven of them recovered and one expired due to sepsis.
  Journal of the Pakistan Medical Association 04/1995; 45(3):59-61.
• Article: HLA frequencies in the Pakistani population.

  N Zafar, H Askari, A Naqvi, S Hafiz, A Rizvi
  Transplantation Proceedings 09/1994; 26(4):1883. · 1.00 Impact Factor