Prevalence of Thiamine Deficiency in Pregnancy and its impact on fetal outcome in an area endemic for thiamine deficiency

BACKGROUND

Pregnancy is a metabolically challenging state with increased nutritional demand. Thiamine is an important cofactor in various metabolic pathways and thus its deficiency could have a serious impact on both maternal and fetal outcomes. Kashmir has thiamine deficiency in endemic proportions, with multiple reports of infantile beriberi, postpartum neuropathy, and gastric beriberi. This prompted us to assess the extent of the burden of thiamine deficiency during pregnancy.

METHODS

This cross-sectional study was conducted for a period of two years in pregnant women attending the antenatal clinic. A demographic, clinical, biochemical, and dietary assessment was done in all participants. The whole blood thiamine levels were assessed by high-performance liquid chromatography.

RESULTS

A total of 492 participants were included in the study with a mean age of 30.30±4.57 years and a mean BMI of 24.25±3.32 Kg/m2. The mean whole blood thiamine level of all participants was 133.29±14.32 nmol/L. Low thiamine status was present in 38.2% (n = 188) of participants. Participants with low thiamine had poor perinatal outcomes, with 3.1% (n = 6) reporting early infant death.

CONCLUSION

A high prevalence of thiamine deficiency occurs in pregnant women of Kashmir. Low thiamine is associated with poor nutritional status as well as poor perinatal outcomes.

TRIAL REGISTRATION

CTRI/2022/07/044217.

Androgen receptor signaling and pyrethroids: Potential male infertility consequences

Infertility is a global health concern inflicting a considerable burden on the global economy and a severe socio-psychological impact. Approximately 15% of couples suffer from infertility globally, with a male factor contribution of approximately 50%. However, male infertility remains largely unexplored, as the burden of infertility is mostly assigned to female people. Endocrine-disrupting chemicals (EDCs) have been proposed as one of the factors causing male infertility. Pyrethroids represent an important class of EDCs, and numerous studies have associated pyrethroid exposure with impaired male reproductive function and development. Therefore, the present study investigated the potentially toxic effects of two common pyrethroids, cypermethrin and deltamethrin, on androgen receptor (AR) signaling. The structural binding characterization of cypermethrin and deltamethrin against the AR ligand-binding pocket was performed using Schrodinger's induced fit docking (IFD) approach. Various parameters were estimated, such as binding interactions, binding energy, docking score, and IFD score. Furthermore, the AR native ligand, testosterone, was subjected to similar experiments against the AR ligand-binding pocket. The results revealed commonality in the amino acid-binding interactions and overlap in other structural parameters between the AR native ligand, testosterone, and the ligands, cypermethrin and deltamethrin. The estimated binding energy values of cypermethrin and deltamethrin were very high and close to those calculated for AR native ligand, testosterone. Taken together, the results of this study suggested potential disruption of AR signaling by cypermethrin and deltamethrin, which may result in androgen dysfunction and subsequent male infertility.

Structural binding perspectives of common plasticizers and a flame retardant, BDE-153, against thyroxine-binding globulin: potential for endocrine disruption

The human exposure to diverse endocrine-disrupting chemicals (EDCs) has increased dramatically over several decades with very adverse health effects. Plasticizers and flame retardants constitute important classes of EDCs interfering in endocrine physiology including the thyroid function. Thyroxine (T4) is an important hormone regulating metabolism and playing key roles in developmental processes. In this study, six phthalate and nonphthalate plasticizers and one flame retardant (BDE-153) were subjected to structural binding against thyroxine-binding globulin (TBG). The aim was to understand their potential role in thyroid dysfunction using structural binding approach. The structural study was performed using Schrodinger's induced fit docking, followed by binding energy estimations of ligands and the molecular interaction analysis between the ligands and the amino acid residues in the TBG ligand-binding pocket. The results indicated that all the compounds packed tightly into the TBG ligand-binding pocket with similar binding pattern to that of TBG native ligand, T4. A high majority of TBG interacting amino acid residues for ligands showed commonality with native ligand, T4. The estimated binding energy values were highest for BDE-153 followed by nonphthalate plasticizer, DINCH, with values comparable with native ligand, T4. The estimated binding energy values of other plasticizers DEHP, DEHT, DEHA, ATBC, and TOTM were less than DINCH. In conclusion, the tight docking conformations, amino acid interactions, and binding energy values of the most of the indicated ligands were comparable with TBG native ligand, T4, suggesting their potential for thyroid dysfunction. The results revealed highest potential thyroid disruptive action for BDE-153 and DINCH.

Naringenin prevents doxorubicin-induced toxicity in kidney tissues by regulating the oxidative and inflammatory insult in Wistar rats

This study is undertaken to investigate the effects of naringenin on doxorubicin- (Dox) induced nephrotoxicity in Wistar rats. Dox 10 mg/kg body weight was administered intraperitoneally once and naringenin 50 and 100 mg/kg body weight was administered orally daily for 21 d. Dox-induced oxidative stress lead to steep elevation in blood urea nitrogen (BUN), creatinine, lactate dehydrogenase (LDH), and kidney injury molecule-1 (KIM-1), compared to control, treatment with naringenin preserved kidney functions. With Dox treatment significant decrease in antioxidant enzymes with increase in malondialdehyde (MDA) compared to control was observed. Naringenin treatment reversed these values compared to Dox in kidney tissue. Dox treatment showed increased tissue nitric oxide levels naringenin treatment decreased nitric oxide (NO) in kidney tissue. Furthermore, Dox-induced inflammatory burst as indicated by up-regulation of nuclear factor-κB (NF-κB), tumour necrosis factor-α (TNF-α) tissue levels and prostaglandin-E2 (PGE-2). All such events were normalised back to normal by naringenin treatment.

Structural studies on the endocrine-disrupting role of polybrominated diphenyl ethers (PBDEs) in thyroid diseases

Polybrominated diphenyl ethers (PBDEs) are synthetic brominated flame retardants with extensive applications in daily-life consumer products. However, PBDEs have become ubiquitous environmental contaminants due to their leach-out capability. The hazardous human health effects and endocrine-disrupting activity of PBDEs have led many governmental organizations to impose ban on their manufacture, causing their gradual phase out from commercial products. However, PBDEs and their metabolites are still being detected from biological and environmental samples owing to their persistence and bioaccumulation. The PDBE metabolites in these samples are present in concentrations often higher and even with higher toxic potential than parent PBDEs. The two commonly detected environmental PBDE congeners, 2,2',4,4'-tetra-bromodiphenyl ether (BDE-47) and 2,2',4,4',5-penta-bromodiphenyl ether (BDE-99), and their HO- and MeO- metabolites were considered in this study for their potential disrupting activity on thyroid hormone transport. Specifically, the study involved structural binding characterization of BDE-47 and BDE-99 including their two HO- and two MeO- metabolites with thyroxine-binding globulin (TBG), which is the main thyroid hormone transport protein in blood. The results showed that the binding pattern and molecular interactions of above two PBDEs and their metabolites exhibited overall similarity to native ligand, thyroxine in dock score, binding energy, and amino acid interactions with TBG. The BDE-99 and its metabolites were predicted to have stronger binding to TBG than BDE-47 with the metabolite 5-MeO-BDE-99 showing equal binding affinity to that of thyroxine. It is concluded that BDE-47 and BDE-99 and their metabolites have the potential to disrupt thyroid hormone transport and interfere in thyroid function.

Chemopreventive efficacy zingerone (4-[4-hydroxy-3-methylphenyl] butan-2-one) in experimental colon carcinogenesis in Wistar rats

Colorectal cancer is one of the most common cancers worldwide. Development of naturally occurring inexpensive and safe alternatives can be effective in suppressing colon related proliferations. Zingerone (4-[4-hydroxy-3-methylphenyl] butan-2-one), a polyphenolic alkanone of ginger, has massive pharmacological properties and thus can be used as promising candidate against various ailments. In the current study, we aimed at demonstrating the protective effect of zingerone against experimental colon carcinogenesis and elucidating its possible mechanism by studying inflammatory and Nrf-2 signaling cascade. Four groups of animals (I-IV) were made with six animals each. Group I (control) was given normal saline orally. Group II was given 1,2-dimethylhydrazine (DMH) at the dose rate of 20 mg/kg body weight. Group III and IV were treated with DMH at the dose rate of 20 mg/kg body weight and also received oral treatment of zingerone at a dose rate of 50 and 100 mg/kg body weight, respectively, for first 5 weeks and animals were euthanized after 16 weeks. Our results reveal that DMH treated rats exhibited elevated ROS and MDA levels, increased activity of cytochrome P450 2E1 and serum marker enzyme carcinoembreyonic antigen (CEA), increased no of aberrant crypts of foci (ACF), and elevated expression of inflammatory and proliferative proteins. Nrf-2 was downregulated by DMH treatment. Treatment with zingerone to DMH treated rats, resulted in alterations in the activity of the cytochrome P450 2E1 and CEA. In addition, immunostaining of NF-kB-p65, COX-2, iNOS, and PCNA, Ki-67 was suppressed by zingerone. Furthermore, zingerone administration also attenuated the level of IL-6 and TNF-α and it also helps in preserving mucous layer. Thus, zingerone could be considered as a good chemopreventive agent in experimental model of colon carcinogenesis. Further studies are required to study other pathways involved in colon carcinogenesis and their modulation buy zingerone.

β-Sitosterol derived compound from onion husks non-polar fraction reduces quorum sensing controlled virulence and biofilm production

Quorum sensing is an important regulatory factor of P. aeruginosa virulence induction such as BF, motility, formations of proteases, pyocyanin, and some toxins. The aim of the current study is to detect the effect of the pet.ether extract from onion husk and compound drive from it on quorum sensing and virulence formations of P. aeruginosa. Quorum sensing inhibiting effect of the pet.ether extract of onion husk and a compound drive from it, was evaluated by C. violaceum reporter using dilution method as well as an antioxidant by using DPPH. The efficacious of: Quorum sensing inhibiting on pet.ether fraction and compound derived from it, were investigated for their activities toward biofilm and pyocyanin synthesis as well as motility from P. aeruginosa. The pet.ether fraction and compound derived from it of onion husk exhibited potent antimicrobial, antioxidant and Quorum sensing inhibiting effects. The pet.ether fraction and compound derived from it possesses significant reduction on pyocyanin and biofilm induction of P. aeruginosa. Moreover, they significantly inhibited swimming motilities of P. aeruginosa. For the first time, our study showed the medical importance of Allium cepa L. as antimicrobial, antioxidant as well as Quorum sensing inhibiting and virulence suppressors of P. aeruginosa. Thus, these might emphasized on Allium cepa L as a natural source for attenuating toxins of the Pseudomonas.

Lactoperoxidase, an Antimicrobial Milk Protein, as a Potential Activator of Carcinogenic Heterocyclic Amines in Breast Cancer

BACKGROUND

Lactoperoxidase (LPO) is an antimicrobial protein secreted from mammary, salivary and other mucosal glands. It is an important member of heme peroxidase enzymes and the primary peroxidase enzyme present in breast tissues. In addition to the antimicrobial properties, LPO has been shown to be associated with breast cancer etiology. Heterocyclic amines, an important class of environmental and dietary carcinogens, have been increasingly associated with breast cancer etiology. Heterocyclic amines undergo activation in breast tissue as a result of oxidation by LPO. The current study includes three important heterocyclic amines, 2-amino-3-methylimidazo[4,5-f]quinoline (IQ), 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) and 2-amino-1-methy-6-phenylimidazo[4,5-b]-pyridine (PhIP), that have carcinogenic activity.

MATERIALS AND METHODS

The structural binding characterization of IQ, MeIQx and PhIP with LPO was done using in silico approaches. Their binding pattern and interactions with LPO amino acid residues were analyzed.

RESULTS

The three compounds bound in the distal heme cavity of LPO without replacing the important water molecule required for oxidation of substrate compounds. PhIP displayed lesser binding affinity for LPO in comparison to IQ and MeIQx. The binding mode of heterocyclic amines in distal heme cavity of LPO resembled to that of substrate binding pattern.

CONCLUSION

The three heterocyclic amines are suggested to act as LPO substrate. The undisturbed water molecule present in distal heme cavity of the LPO is expected to facilitate the oxidation and activation of the three heterocyclic amines. These activated compounds may potentially bind with DNA in breast tissues forming DNA adducts and may subsequently lead to breast cancer initiation.

Molecular Interactions of Carcinogenic Aromatic Amines, 4-Aminobiphenyl and 4,4'-Diaminobiphenyl, with Lactoperoxidase - Insight to Breast Cancer

BACKGROUND/AIM

Lactoperoxidase (LPO) is an antimicrobial protein present in milk, saliva, gastric secretions, tears and upper respiratory tract secretions. LPO constitutes an important enzyme of the human immune defense system. However, LPO has also been suggested to be involved in breast cancer etiology through production of reactive free radicals and activation of carcinogenic aromatic compounds. Aromatic compounds are generally highly lipophilic and thus accumulate in highly fatty breast tissues. The aromatic compounds 4-aminobiphenyl (ABP) and 4,4'-diaminobiphenyl (BZ) are known to have carcinogenic properties. LPO catalyzes their oxidation and converts them into reactive products which bind to DNA and form adducts. These DNA adducts subsequently lead to breast cancer.

MATERIALS AND METHODS

The crystal structure of LPO was obtained from Protein Data Bank. Structures of ABP and BZ were retrieved from PubChem database. Induced Fit Docking was performed using glide module from Schrodinger.

RESULTS

The present study reports the structural binding of ABP and BZ with LPO using in silico approaches. The amino acid residues of LPO involved in the binding with the two aromatic ligands were characterized and binding energy values were calculated.

CONCLUSION

Both ABP and BZ were placed in the substrate binding site present in the distal heme cavity of LPO with good affinity. The binding mode mimicked that of the natural substrate since these compounds did not disturb the water molecule that plays an important role in the oxidation reaction. Thus, the water molecule is potentially available for facilitating the subsequent activation of the aromatic amines to reactive species which may form DNA adducts leading to breast cancer.

Peroxisome Proliferator-activated Receptors as Potential Targets for Carcinogenic Activity of Polychlorinated Biphenyls: A Computational Perspective

BACKGROUND

Polychlorinated biphenyls (PCBs) are ubiquitous environment-contaminating synthetic chemicals that have been associated with increased risk of hepatic cancer, melanoma, non-Hodgkin lymphoma and cancer of many other body organs. Structural binding analyses of PCB 77 and PCB 118 with peroxisome proliferator-activated receptors (PPARα, PPARβ/δ and PPARγ) was performed to predict the association of PCBs with potential disruption of PPAR signaling pathways.

MATERIALS AND METHODS

The crystal structures of human PPARα, PPARβ/δ and PPARγ were obtained from the Protein Data Bank. Structures of PCB 77 and PCB 118 were obtained from PubChem database. Docking was performed using glide (Schrodinger) induced fit docking (IFD) module.

RESULTS

The PCB 77 and PCB 118 interacted with PPARα, PPARβ/δ and PPARγ showing an overlapping of 40-58% interacting amino acid residues with synthetic co-complex agonists of the three PPARs. The binding affinity was higher for PCB 118 than for PCB 77 during docking interactions with each of the three PPARs.

CONCLUSION

The consistent commonality of interacting residues for PCB 77 and PCB 118 with co-complex synthetic agonists of the PPARs together with good binding affinity suggested that the PPAR signaling pathway is a potential target for toxicologic activity of PCBs.

Stereoselectivity and the potential endocrine disrupting activity of di-(2-ethylhexyl)phthalate (DEHP) against human progesterone receptor: a computational perspective

Di-(2-ethylhexyl)phthalate (DEHP) is a phthalate plasticizer and is one of the very common endocrine-disrupting chemicals (EDCs) contaminating our ecosystem. It is used for imparting flexibility to plastics and frequently used in personal and industrial products. Clinical and experimental studies have indicated that exposure to DEHP is associated with developmental abnormalities of the reproductive system particularly of male neonates, endometriosis and miscarriage in women, low sperm counts and lower sperm motility and DNA integrity in men, and placental problems with higher rates of low birth weight, premature birth, and fetal loss in laboratory animals. Binding of DEHP to progesterone receptor (PR) represents a potential mechanism of interference in the reproductive functions. DEHP is a chiralmolecule and is available commercially as a racemic mixture of RR, SS and RS stereoisomers. The ability of individual stereoisomers of DEHP to interfere with the reproductive functions of humans and animals is not known and molecular interactions of DEHP stereoisomers with PR are not available. In the present study, in silico approaches were adopted for molecular simulation studies of the three stereoisomers of DEHP with PR. The study suggested that all three stereoisomers of DEHP have the potential to compete with the normal substrate binding of PR. However, the binding of DEHP to PR was stereoselective with RR stereoisomer of DEHP having the best binding characteristics compared with SS, and RS stereoisomers. It has been suggested that stereoselectivity may be employed for improving the safety of the commercial compounds using pure stereoisomers instead of racemic mixtures.

Hypertension in renal transplantation: saudi arabian experience

To evaluate the prevalence, etiologic factors and therapy of hypertension in actively followed up transplant population in Saudi Arabia; we retrospectively reviewed the records of the active renal transplant patients at two large transplant centers in Riyadh and Jeddah in Saudi Arabia. These subjects were transplanted between January 1979 and November 1998. The patients were grouped according to the measurement of blood pressure; group 1 (considered normo-tensive): blood pressure below 140/90 mmHg, group2: blood pressure between 140-159/90-99, group 3: blood pressure 160-179/100-109 group 4: equal to or above 180/110. There were 1115 patients' records included in the study. The mean duration of transplantation was 66.9 +/- 50.1 months. According to the level of measured blood pressure, there were 641 (57.5%) patients in the normotensive group (group 1), 404 (36.3%) patients in the mildly hypertensive group (group 2) 64 (5.7%) patients in the moderately severe hypertension group (group 3) and only six (0.5%) patients in the severe hypertension group (group 4). The estimated prevalence of hypertension in this study was almost 85%. We found no significant difference in the prevalence of hypertension in terms of gender, year of transplantation, duration of transplantation, type of donor, number of previous transplants, diagnosis of renal artery stenosis, etiology of kidney disease, diagnosis of diabetes after transplantation, diagnosis of cerebrovascular accidents, or mean dose of prednisolone and cyclosporine. There was a statistically significant association between increased level of blood pressure and old age (above 50 years), original disease associated with hypertension, history of hypertension on dialysis, acute rejection (once or more), presence of protienuria (more than 0.3 mg/day), abnormality of ECG, or serum creatinine above 300 micromol/L. We conclude that hypertension is highly prevalent in the renal transplant population in Saudi Arabia. Risk factors for the development of hypertension or its complication should be more aggressively approached in order to protect the patients and their grafts alike.

Acute Renal Failure and HELLP Syndrome: A Single Center's Experience

A total of 52 patients were referred to our center from gynecology and obstetric units in our area with acute renal failure during the last two years. Seven patients were found to have so called syndrome of hemolysis (H), elevated liver enzymes (EL) and low platelets (LP) associated with acute renal failure. The syndrome can easily be confused with other diagnoses like hemolytic uremic syndrome, idiopathic thrombotic thrombocytopenic purpura and disseminated intravascular hemolysis. Six patients had renal biopsies to confirm the diagnosis, while one did not consent for biopsy. Four patients were found to have acute tubular necrosis, one had acute cortical necrosis and one was not enough for interpretation. We conclude that the patients can easily be misdiagnosed if we are not familiar with the diagnosis and that the overall prognosis is good if the patient survives the acute stage.

Reversible uremic deafness: is it correlated with the degree of anemia?

Hearing loss is a common finding in patients with end-stage renal failure. Uremic toxins, ototoxins, and axonal uremic neuropathy appear to be likely pathogenic factors. We analyzed whether an improvement in hearing capacity can be achieved with an improvement of anemia by erythropoietin (EPO) administration. Fifty patients on long-term hemodialysis in a single center were examined audiologically by otoscopy, tympanometry, pure tone audiometry, and the short increment sensitivity index. Twenty-five patients were treated with EPO in a dose of 120 U/kg per week over a period of 5 to 8 months, and the remaining 25 patients were not treated with EPO (controls). Both groups were reexamined audiologically after the study period, and the results were compared. In the group treated with EPO, the hemoglobin level increased from 7 +/- 0.9 to 11 +/- 0.8 g/dL, as against the control group, whose hemoglobin increased from 7.1 +/- 0.9 to 8 +/- g/dL. The audiologic tests were repeated at the end of the study period, and a significant improvement of hearing was found in the patients treated with EPO as compared with the control group (p < .001). Our study suggests that improvement of anemia in patients on long-term hemodialysis by administration of EPO is associated with an improvement in hearing capacity in a significant number of patients. Thus, anemia seems to be an important factor responsible for hearing disorders in patients with end-stage renal failure. Studies with larger numbers of patients are required to confirm this observation.

Possible interaction between cyclosporine and glibenclamide in posttransplant diabetic patients

The possible occurrence of a kinetic interaction between cyclosporine A and glibenclamide was assessed by reviewing data of six posttransplant diabetic patients who received the two drugs concurrently. Coadministration of the two drugs resulted in a 57% increase in the steady-state plasma cyclosporine levels despite normal hepatic and renal functions in the patients. This elevation in cyclosporine level is possibly due to an interaction between the two drugs resulting from an inhibition of CYP3A4-mediated metabolism of cyclosporine by glibenclamide. This observation calls for a closer monitoring of cyclosporine plasma levels during concomitant administration of these two drugs in this group of patients.

Renal transplantation at the jeddah kidney center

Renal transplantation is the optimal treatment for patients with end-stage renal failure. During the period 1991 to 1995, a total of 279 renal transplantations were performed at the Jeddah Kidney Center. They included 115 kidneys from cadaveric donors and 164 living related donor transplants. There were 160 males and 119 females; age of the patients ranged between 4 and 45 years. During the follow-up period, 32 grafts were lost and 26 patients died. The overall 5-year graft and patient survival rates were 79.2% and 90.7% respectively. Sepsis and pulmonary embolism constituted the common causes of death.

The impact of long-term cyclosporin-A therapy on hematological and biochemical profile in renal transplant patients

With over a decade of extensive clinical use of cyclosporin A (CsA), assessment of its long-term safety implications is due. In this study the impact of long-term continuous use of CsA on a number of hematological and biochemical parameters in renal transplant patients was evaluated. Two groups of 13 patients each, one on conventional therapy (azathioprine + prednisolone) and the other on triple therapy (azathioprine + prednisolone + CsA) for 4 to 15 years post-transplantation were compared with respect to their current and overall laboratory values and clinical outcome. Laboratory values were also compared with those of 23 matched healthy subjects. No significant difference in the clinical outcome was found between conventional and triple therapy groups, however, the triple therapy group had significantly less favorable mean values compared to the conventional therapy group with respect to hemoglobin (12.1 +/- 2.2 vs 13.3 +/- 2.1 g/dl, p < 0.02), hematocrit (0.36 +/- 0.06 vs 0.42 +/- 0.03 l/l, p < 0.05), urea (13.0 +/- 3.7 vs 6.7 +/- 4.3 mmol/l, p < 0.01) and uric acid (460.0 +/- 112 vs 330 +/- 88 mumol/l, p < 0.05). The increase in serum uric acid levels in the triple therapy group was progressive throughout the post-transplant period. For the 19 other parameters measured corresponding mean values in the 2 groups were comparable. Mean laboratory values for many parameters in both groups, however, still differed from those in the control group. These results showed that kidney transplant patients on long-term triple therapy have more hematological and biochemical abnormalities and no better clinical outcome than those on conventional therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

The Diagnosis of Acute Renal Allograft Rejection Using T-lymphocyte Subsets in the Peripheral Blood: A Better Test Now?

Measuring the T-lymphocyte subsets CD4/CD8 ratio is known to be useful in the early diagnosis of acute rejection. A ratio of 1.3 or more is said to indicate the presence of acute rejection, but the sensitivity and specificity rates of the test are too low to render it of diagnostic value. We revisited this test on twenty-three renal allograft recipients who developed graft dysfunction within the first three months following transplantation. All cases were investigated thoroughly to identify the cause of graft dysfunction. Two groups of patients were identified. Group 1: patients confirmed to have acute rejection as the cause of graft dysfunction (13 patients); and group 2: patients found to have other causes of graft dysfunction (10 patients). Results of subsets with cluster of differentiation ratio CD4/CD8 were correlated with incidence of acute rejection. Of the 13 patients with acute rejection 10 revealed a CD4/CD8 ratio more than 1.7, while in the other three CD4/CD8 ratio was less than 1.7. In the second group of 10 patients in whom the cause of graft dysfunction was not acute rejection, the CD4/CD8 ratio was less than 1.7 in all cases. Our study indicates that T-lymphocyte subset ratio is useful in diagnosing acute rejection with a sensitivity and specificity of 81% and 100% respectively when the cutoff point is taken as 1.7. Studies with larger series of patients are needed to confirm this observation.

Early changes in volume and function of the remaining kidney after unilateral donor nephrectomy

The early changes that occur in the volume and function of the remaining kidney, after uni-nephrectomy for organ donation, were studied in 25 living donors. Serum creatinine (S Cr), creatinine clearance (Cr Cl), renographic clearance tests for total and split renal functions as well as renal volume using ultrasound were determined before and three months after donation. In 76% of the donors, Se Cr showed an increase after kidney donation, but all values were within normal range. The total kidney function in terms of Cr Cl, showed a drop of 36% from the pre-donation value. After three months post donation, the clearance of the remaining kidney increased by 5% to 64% (mean 34%) of the pre-donation values, measured by Tc 99m DTPA renography. Compensatory hypertrophy of the remaining kidney also occurred as evidenced by the ultrasound evaluation which showed an increase in the renal volume by 15%. Our study shows that compensatory changes occur early i.e., within the first three months after uni-nephrectomy. However, prolonged follow-up of these donors is necessary to assess the long-term structural and functional changes in the remaining kidney.

Impact of donor source on short-term outcome of renal transplantation in children

Renal transplantation is the ideal renal replacement therapy for children with endstage renal disease (ESRD). Follow-up of pediatric transplant recipients is tedious because of special problems like non-compliance to treatment and a very active immunological status. Twenty-five pediatric patients with ESRD who received kidney transplants in four different centers were followed up at the Jeddah Kidney Center, Saudi Arabia for a mean period of 22 months. The donor source for transplantation was as follows: living related (LR) in seven, cadaveric (CAD) and living unrelated (LUR) in nine patients each. The overall graft survival was 88% and patient survival 100% at the end of the follow-up period. Living related kidney recipients exhibited 100% graft survival at 22 months and also had the best kidney function. All the graft losses were due to irreversible rejection episodes. Medical complications were common and comprised of hypertension (82%), infection (52%) and rejection (44%). Recipients of LR donor kidneys had the lowest incidence of these complications. Surgical problems encountered were few and minor and needed only conservative management. In our experience, children having renal transplantation have an excellent outcome at short-term particularly with LR donors.

Can Uremia and Hemodialysis Affect Plasma Levels of Circulating TNF-alpha

It is well known that uremia is associated with increased susceptibility to infection. In addition, patients on haemodialysis (HD) experience a variety of dialysis associated complications, both acute and chronic, many of them having features similar to acute phase response. Immunoregulatory cytokines such as tumor necrosis factor-a (TNF-a) have been implicated in the pathogenesis of immunological as well as inflammatory diseases. Thus, TNF-a levels could be expected to be high in uremic patients as well as in HD patients. We investigated the plasma levels of TNF-a in 17 patients with renal failure, seven patients with chronic renal failure (CRF) before commencement of HD and 10 patients maintained on regular HD. Eight age matched healthy subjects were studied as normal control. All CRF patients, who were not yet on dialysis, had high plasma levels of TNF-a (mean + SD 71.33 + 33.25 pg/ml). Out of the HD group, TNF-a plasma levels were not detectable in five patients and in the remaining five, TNF-a plasma level (mean + SD 21.06 + 7.72) were comparable to the normal controls (mean + SD 21 + 7.87). Our findings suggest that factors related to uremia, but not to HD, are responsible for high TNF-a plasma levels in these patients and that, HD probably has a beneficial effect by removal and/or neutralising of uremic toxins.

Residual renal function after living related kidney donation. Is it enough? An early report

The utilization of living's kidneys as renal replacement for Chronic Renal Failure (CRF) patients was debated for long time. However, the lack of renal pool in one hand and the proper employment of modern investigatory armamentarium in another hand could justify such donation. Living related donors (LRD) are subjected to extensive non invasive investigations to assess their general fitness for donation and split renal function. The impact of uni-nephrectomy on the renal function was studied in 25 LRD. Serum Creatinine (S. Cr.) Creatinine Clearance (Cr. Cl.) and renographic clearance tests for total and split renal function and renal volume using ultrasound were determined before and 3 months after donation. An initial increase in s.cr was seen in 76% of donors, but all levels are within normal range. Total kidney function by cr.cl showed significant drop by 36% of the pre donated value. Remaining kidney clearance increased by 5% to 64% with an average of 34% of the pre donated level as measured by Tc 99m DTPA renography. Following nephrectomy, compensatory hypertrophy of the remaining kidney attributed to an increase in the renal volume of 15%. In conclusion, kidney donation from living's is safe. Cr. clearance using the chemical method is a good screening test for potential LRD and for monitoring the renal function after donation. Renographic clearance using Tc 99m DTPA is as excellent useful test for split renal function in LRD work up. Long-term follow up might be needed.

Acute Renal Failure due to Rhabdomyolysis Following Human Stampede

Acute renal failure (ARF) following rhabdomyolysis is a well known entity. In this paper, we present an unusual cause for trauma that resulted in rhabdomyolysis associated with renal failure. Rhabdomyolysis resulted from human stampede that occurred in a mountain tunnel on the occasion of The Pilgrimage to Makkah in 1990. To the best of our knowledge, human stampede as a cause of rhabdomyolysis has not been reported in the literature. A total of eight patients were referred to our center. Laboratory investigations revealed rhabdomyolysis as well as evidence of moderate to severe renal impairment in all patients. They were treated with forced alkaline diuresis, but three required hemodialysis. All patients recovered. Treatment with forced alkaline diuresis was found to be useful in the treatment of these patients and instituting such treatment is worthwhile even in those cases where renal failure is established.

Mechanism of digestion of bradykinin and lysylbradykinin (kallidin) in human serum. Role of carboxypeptidase, angiotensin-converting enzyme and determination of final degradation products

Degradation of bradykinin and lysylbradykinin was studied in plasma and serum, and the results were compared to those seen with mixtures of carboxypeptidase N and angiotensin-converting enzyme (ACE), the two recognized kininases in blood. Angiotensin-converting enzyme was an effective kininase in mixtures with carboxypeptidase N at physiologic concentration and digested bradykinin to the dipeptides Phe- Arg and Ser-Pro plus the pentapeptide Arg-Pro-Pro-Gly-Phe. Carboxypeptidase N slowly removed the C-terminal Arg from bradykinin to yield des-Arg9-bradykinin (DBK); the latter was digested by ACE to yield the aforementioned pentapeptide and the tripeptide Ser-Pro-Phe. In serum, however, the C-terminal Arg was removed from bradykinin about five times faster than was accounted for by the activity of carboxypeptidase N. The primary substrate of ACE in serum, therefore, was des-Arg9-bradykinin and not bradykinin. The products of this reaction, pentapeptide and tripeptide, were unstable in serum and were cleaved by enzymes that have not yet been characterized. One product, free phenylalanine, was used to monitor these reactions by HPLC. Our studies indicate that the final products of bradykinin degradation were the tripeptide Arg-Pro-Pro, one mole each of Ser, Pro, Gly, and Arg, and two moles of phenylalanine. Since the serum level of carboxypeptidase N did not account for the rapid kinin degradation seen, other carboxypeptidases may have been operative, perhaps released as a result of blood clotting, or a serum cofactor may augment carboxypeptidase N activity.

Assessment of kininases in rheumatic diseases and the effect of therapeutic agents

Bradykinin is degraded in human plasma by a carboxypeptidase to yield desArg9-bradykinin (DBK) which is then digested by angiotensin-converting enzyme (ACE) to the pentapeptide Arg-Pro-Pro-Gly-Phe and the tripeptide Ser-Pro-Phe. We have studied the rate of kinin degradation by each of these enzymes in patients with rheumatoid arthritis (RA) and with systemic lupus erythematosus (SLE), compared with the degradation rate in degenerative joint disease and normal subjects. Carboxypeptidase activity was the same in all individuals, but ACE activity was increased in the RA and SLE patients. We examined the effects of aspirin, sodium salicylate, auranofin, penicillamine, and corticosteroids on kinin metabolism, and all of these were marked inhibitors of ACE; however, only penicillamine had any demonstrable inhibition of carboxypeptidase. These observations suggest rapid degradation of DBK in patients with untreated RA and SLE, whereas drugs utilized in therapy have the opposite effects. Studies to examine the role of DBK in disease manifestations are in progress.

Studies of the digestion of bradykinin, Lys-bradykinin, and des-Arg9-bradykinin by angiotensin converting enzyme

We have studied the degradation of bradykinin, lysyl bradykinin and des-Arg9-bradykinin by the angiotensin converting enzyme. Bradykinin was cleaved at two sites to produce the pentapeptide Arg-Pro-Pro-Gly-Phe plus dipeptides Ser-Pro and Phe-Arg. Lysyl bradykinin was cleaved similarly to release the same dipeptides plus the hexapeptide Lys-Arg-Pro-Pro-Gly-Phe. The tripeptidase activity of ACE was observed when des-Arg9-bradykinin was digested. A single cleavage yielded the above pentapeptide plus Ser-Pro-Phe. Although des-Arg9-bradykinin was the most rapidly digested, when mixtures of des-Arg9-bradykinin and bradykinin or lysyl bradykinin were tested, virtually all of the bradykinin and most of the lysyl bradykinin was digested prior to the onset of digestion of des-Arg9-bradykinin. This was shown to be due to inhibition of des-Arg9-bradykinin cleavage by kinins and kinin-degradation products. The order in terms of potency was bradykinin greater than lysyl bradykinin greater than Ser-Pro much greater than Phe-Arg greater than Arg-Pro-Pro-Gly-Phe. The concentration of chloride ion was an important parameter which affected the rate of digestion of each substrate examined. des-Arg9-bradykinin was not digested by ACE in the absence of sodium chloride and the rate of digestion increased as the chloride concentration was increased to 100-150 mM. On the other hand, increasing NaCl concentration was inhibitory for bradykinin digestion. The rate of Lys-bradykinin digestion was increased from 0 to 1 mM NaCl and decreased thereafter up to physiologic concentration. A half-maximal rate was seen at 100-150 mM NaCl compared to no salt. Of the divalent cations examined, cupric ion inhibited further digestion of des-Arg9-bradykinin at physiologic concentrations. Our data indicate that the rate of degradation of kinins and the nature of the stable final cleavage products in plasma or serum (studied in vitro) are dependent upon the effects of chloride ion, metal ions, and the kinetic effects of multiple metabolites produced by at least two kininases.

Studies of the digestion of bradykinin, lysyl bradykinin, and kinin-degradation products by carboxypeptidases A, B, and N

We have compared the digestion of bradykinin, lysyl bradykinin, and kinin degradation products by carboxypeptidases N, B and A (CPN, CPB and CPA). Carboxypeptidase N removed the C-terminal arginine from bradykinin or lysyl bradykinin to leave the des-Arg derivative of each, and no further degradation occurred regardless of enzyme concentration or time of incubation. However, both CPB and CPA degraded the des-Arg derivatives to remove the C-terminal phenylalanine. The inhibitory effect of phosphate ions upon this activity of CPB (but not CPA) suggests that CPA may be responsible for the formation of free phenylalanine seen upon degradation of kinins in plasma or serum. However, angiotensin converting enzyme degraded des-Arg9-bradykinin in plasma or serum prior to such Phe removal to yield the pentapeptide Arg-Pro-Pro-Gly-Phe and the tripeptide Ser-Pro-Phe. We demonstrated that CPB degraded Arg-Pro-Pro-Gly-Phe but not Ser-Pro-Phe; this reaction was also inhibited by phosphate ions. Carboxypeptidase A, on the other hand, liberated Phe from both peptides in phosphate-buffered saline and accounted, at least in part, for the free phenylalanine detected. Carboxypeptidase N did not digest the aforementioned pentapeptide or tripeptide. It is clear that carboxypeptidase B and carboxypeptidase A had overlapping activities, depending upon the substrate tested, and were distinguished by the effects of different ionic environments. We further suggest a role for carboxypeptidases other than CPN in the degradation of kinins in human plasma or serum.