Prevalence and Assessment of Factors Associated With Malnutrition in Children Residing in Slums of Mumbai: A Cross-Sectional Study.

Background Malnutrition in children continues to be a serious public health problem in India. Therefore, this study aims to evaluate the prevalence of malnutrition and assess factors contributing to it in children of the marginalized slum population of India, masked in the metropolitan cities.  Methods A retrospective data analysis with a cross-sectional model was conducted by medical volunteers affiliated with the Rotaract Club of Medicrew who had organized a free pediatric health check-up camp in the Dharavi village of Mumbai, India for children under five. Children under five years of age group of either sex residing in the slums of Dharavi and whose parents consented are included in the study. Neonates, children older than five years of age, and children whose parents did not consent for them to be included in the study were excluded. A pretested, pre-validated questionnaire was administered, and statistical analysis was done with p-values <0.05 considered to be statistically significant. Results  A total of 126 children were included. Out of these children, 109 of them (86.50%) had a mid-arm circumference of more than 12.5 cm (normal), 11 (8.73%) were between 11.5 cm and 12.5 cm (moderate acute malnutrition), and five (4.77%) were less than 11.5 cm (severe acute malnutrition). Among the 126 kids, 86 kids were above the age of two and their BMI was assessed, 36 (44.19%) were found to be underweight (<5th percentile) while 14 (16.3%) were obese (>95th percentile), and four (4.65%) were overweight (85th-95th percentile). For 106 (84.13%) of these children, the caregivers were mothers while others were fathers (n=4; 3.18%), grandmothers (n=5; 3.97%), sisters (n=5; 3.97%), and aunts (n=6; 4.76%). Out of those who had commenced receiving formal education, only 39 (55.71%) were in an appropriate grade for their age. The mean expenditure on food as a proportion of the total household income was 36.40% (standard deviation (SD) 15.0%). On the single-item sleep quality scale, the sleep of only 36 kids (28.58%) was reported by their caregivers as excellent. A high proportion of other medical problems were reported in the children. Conclusion Our study reports a substantial burden of malnutrition among children residing in the slums of Dharavi. Rigorous strengthening and conceptualization of on-ground nutritional programs targeted toward slum children should be done by Indian healthcare policymakers.

Perinatal Outcome in Overweight Women: An Audit.

BACKGROUND: Obesity in pregnancy is associated with a myriad of well-documented complications. However, the outcomes of pregnancy in overweight females, who are not classified as obese, have not been studied. The aim of the study was to assess foeto-maternal outcomes in primigravida who are overweight and compare them to normal-weight patients. MATERIAL AND METHODS: This was a prospective observational cohort study and included primigravida with full-term gestation (between 38 and 42 weeks), with a single live foetus in vertex presentation, who were admitted for labour induction. Based on pre-pregnancy weight, patients were divided into normal weight (body mass index, BMI<23kg/m2) and overweight (BMI≥23kg/m2 and<25kg/m2) categories labelled as groups A and B, respectively. Data was collected for gestational age, demographics (age, education, occupation), and obstetric and labour-related parameters per pre-designed proforma. Parameters included were the reason for induction, number of doses of prostaglandin E2 (PGE2) gel used, duration of labour, induction to delivery interval, and mode of birth- operative/ non-operative. Data was also collected for peri-partum maternal complications, neonatal Apgar score, and need for Neonatal Intensive Care Unit (NICU) admissions. RESULTS: One hundred and fifty patients were recruited in the study and divided based on weight into two groups- 115 in Group A (normal weight) and 35 in Group B (overweight). Compared to Group A, a higher proportion of patients in Group B needed a third dose of PGE2 gel (n=24, 20.8% vs n=18, 51.4%). Also, more patients in Group B had an induction to delivery time of longer than 30 hours (n=7, 20% vs n=5, 4.3%) and had a higher incidence of failed induction needing caesarean section (n=9, 25.7% vs n=13, 11.3%). Neonates born to overweight mothers had a poor Apgar score at 1 min. However, on reassessment, Apgar improved at 5 minutes, and no statistically significant difference was seen for admission to NICU- 5.7% (n=2) in Group B vs 1.7% (n=2) in Group A Conclusion: Pregnancy in overweight females is associated with prolonged labour, higher instances of failed induction, and poor neonatal outcomes at initial assessment. Thus, perinatal counselling and management should focus on weight control while also planning appropriate strategies for monitoring and treating pregnancy-related complications if weight control measures fail. Although obesity is the main focus of research, we suggest including overweight but non-obese females in such studies as they have similar adverse outcomes and complications.

Transcriptional activation of caspase-6 and -7 genes by cisplatin-induced p53 and its functional significance in cisplatin nephrotoxicity.

This study examined the role of cisplatin-induced p53 activation in regulation of caspases and cellular injury during cisplatin nephrotoxicity. The executioner caspase-6 and -7 but not caspase-3 were identified as transcriptional targets of p53 in cisplatin injury as revealed by chromatin immunoprecipitation, a reporter gene and electrophoretic mobility shift assays, and real-time PCR following overexpression and inhibition of p53. DNA binding by p53 involved the first introns of the human and mouse caspase-7 gene and the mouse caspase-6 gene. Studies in human kidney, breast, ovary, colon, and prostate tumor cell lines also validated these findings. Treatment of p53 (-/-) cells with cisplatin did not induce caspase-6 and -7 expression and subsequent activation. In caspase-3 (-/-) cells, inhibition of caspase-6 and -7 activations markedly prevented cisplatin-induced cell death. In an in vivo model of cisplatin nephrotoxicity inhibition of p53 activation by a p53 inhibitor suppressed transactivation of the caspase-6 and -7 genes and prevented renal failure. p53 (-/-) mice were resistant to cisplatin nephrotoxicity as assessed by renal function and histology. These studies provide first evidence for p53-dependent transcriptional control of the caspase-6 and -7 genes and its functional significance in cisplatin injury to renal cells and functional implication of cisplatin-induced p53 induction in vitro and in vivo in cisplatin nephrotoxicity.

An old enzyme with a new function: purification and characterization of a distinct matrix-degrading metalloproteinase in rat kidney cortex and its identification as meprin.

We have purified to homogeneity the enzyme in the kidney cortex which accounts for the vast majority of matrix-degrading activity at neutral pH. The purified enzyme has an apparent molecular mass of 350 kD by gel filtration and of 85 kD on SDS-PAGE under reducing conditions; and it degrades laminin, type IV collagen and fibronectin. The enzyme was inhibited by EDTA and 1,10-phenanthroline, but not by other proteinase inhibitors. The enzyme was not activated by organomercurials or by trypsin and was not inhibited by tissue inhibitors of metalloproteinases indicating that it is distinct from the other matrix-degrading metalloproteinases. Unexpectedly, the amino acid sequence of the NH2-terminal and two internal peptides of the enzyme showed complete homology to those alpha subunits of rat meprin, an enzyme previously shown to degrade azocasein and insulin B chain but not known to degrade extracellular matrix components. Immunoprecipitation studies, Western blot analyses and other biochemical properties of the purified enzyme confirm that the distinct matrix-degrading enzyme is indeed meprin. Our data also demonstrate that meprin is the major enzyme in the renal cortex capable of degrading components of the extracellular matrix. The demonstration of this hitherto unknown function of meprin suggests its potential role in renal pathophysiology.

Thalidomide protects endothelial cells from doxorubicin-induced apoptosis but alters cell morphology.

Antiangiogenesis agents are now being used in clinical trials to reduce the risk of recurrence of cancer. Several of these agents, however, are associated with thrombosis, especially when used in combination with chemotherapy. Antiangiogenesis and thrombosis are both endothelial-related activities, and we therefore evaluated one presumed antiangiogenesis agent (thalidomide) on intact cultured endothelial cells, and on cultured endothelial cells injured by preincubation with doxorubicin. We evaluated cell viability, caspase-3 activation, morphology of cells using light microscopy, and protease activated receptor-1 (PAR-l) expression. In our experiments, doxorubicin induced a dose- and incubation time-dependent and caspase-3-mediated apoptosis of endothelial cells. Thalidomide alone caused no changes in intact endothelial cells in terms of morphology, cell viability or activation of caspase-3. In contrast, when thalidomide was added to doxorubicin-injured endothelial cells, there was protection from cell death, increase in viability of endothelial cells, induction of differentiation and formation of neotubules. Doxorubicin reduced the expression of thrombin receptor, PAR-1, as evaluated by immunostaining and flow cytometry. Thalidomide did not alter PAR-1 expression in untreated cells but restored its expression reduced by doxorubicin. These findings suggest that thalidomide may be procoagulant, not by enhancing doxorubicin-mediated endothelial cell injury, but by altering the expression of PAR-1 on injured endothelium and resulting in endothelial dysfunction, which may explain hypercoagulability in patients treated with chemotherapy followed by thalidomide.

Apoptotic mechanisms in acute renal failure.

It has been generally accepted that a catastrophic breakdown of regulated cellular homeostasis, known as necrosis, is the mode of cellular injury in various forms of acute renal failure. One of the major advances in our understanding of cell death has been the recognition that the pathways traditionally associated with apoptosis as described in the landmark study by Kerr, Wyllie, and Currie in 1972 maybe very critical in the form of cell injury associated with necrosis. The pathway that is followed by the cell varies with both nature and severity of insults and may evolve from an apoptotic to a necrotic form of cell death. It is also likely that there are some common pathways that are shared and regulated in the two modes of cell death. In this review, we first describe evidence for the role of apoptotic pathways in ischemic acute renal failure, and then consider the potential mechanisms that may participate in this model of acute renal tubular injury. We then summarize the current information of apoptotic pathways related to other common causes of acute renal failure including endotoxin-induced, toxic acute renal failure and transplant rejection. A better understanding of the mechanisms of apoptosis could lead to safer and more specific therapeutic interventions for acute renal failure.

The JNK, ERK and p53 pathways play distinct roles in apoptosis mediated by the antitumor agents vinblastine, doxorubicin, and etoposide.

Assessment of specific apoptosis and survival pathways implicated in anticancer drug action is important for understanding drug mechanisms and modes of resistance in order to improve the benefits of chemotherapy. In order to better examine the role of mitogen-activated protein kinases, including JNK and ERK, as well as the tumor suppressor p53, in the response of tumor cells to chemotherapy, we compared the effects on these pathways of three structurally and functionally distinct antitumor agents. Drug concentrations equal to 50 times the concentration required to reduce cell proliferation by 50% were used. Vinblastine, doxorubicin, or etoposide (VP-16) induced apoptotic cell death in KB-3 carcinoma cells, with similar kinetic profiles of PARP cleavage, caspase 3 activation, and mitochondrial cytochrome c release. All three drugs strongly activated JNK, but only vinblastine induced c-Jun phosphorylation and AP-1 activation. Inhibition of JNK by SP600125 protected cells from drug-induced cytotoxicity. Vinblastine caused inactivation of ERK whereas ERK was unaffected in cells exposed to doxorubicin or VP-16. Inhibition of ERK signaling by the MEK inhibitor, U0126, potentiated the cytotoxic effects of vinblastine and doxorubicin, but not that of VP-16. Vinblastine induced p53 downregulation, and chemical inhibition of p53 potentiated vinblastine-induced cell death, suggesting a protective effect of p53. In contrast, doxorubicin and VP-16 induced p53, and inhibition of p53 decreased drug-induced cell death, suggesting a pro-apoptotic role for p53. These results highlight the differential roles played by several key signal transduction pathways in the mechanisms of action of key antitumor agents, and suggest ways to specifically potentiate their effects in a context-dependent manner. In addition, the novel finding that JNK activation can occur without c-Jun phosphorylation or AP-1 activation has important implications for our understanding of JNK function.

Differential toxicity of anthracyclines on cultured endothelial cells.

Anthracyclines are known for their endothelial toxicity. Newer derivatives may have fewer toxic effects on endothelium. The authors therefore evaluated the effects of doxorubicin, doxorubicin analogs (daunorubicin, idarubicin), and pegylated liposomal doxorubicin (doxil) in human coronary artery endothelial cells (HCAECs). Endothelial viability did not change significantly with doxil, but was decreased with doxorubicin, daunorubicin, or idamycin. Similarly caspase-3 activity was significantly elevated in HCAECs treated with doxorubicin, daunorubicin, and idamycin. In contrast, doxil did not cause significant increase in caspase activity. The authors also characterized the levels of antiapoptotic and prosurvival proteins using Western blot analysis. There was no significant difference in the expression levels of Bcl-2, Bax, and phospho-Akt in endothelial cells treated with anthracycline derivatives. However, the expression levels of Mcl-l protein were unaltered in endothelial cells treated with doxil but were significantly decreased when treated with other anthracycline analogs. Doxil minimally affected the expression levels of p53, whereas other anthracyclines induced p53 protein levels to a significant level, resulting in endothelial cell apoptosis. The authors conclude that the liposomal anthracycline protects endothelial cells from injury by preventing caspase-3 activation and maintaining the expression of antiapoptotic molecule Mcl-1.

Antibody response to crude cell lysate of propionibacterium acnes and induction of pro-inflammatory cytokines in patients with acne and normal healthy subjects.

Propionibacterium acnes (P. acnes) plays an important role in the disease pathogenesis of acne vulgaris, a disorder of pilosebaceous follicles, seen primarily in the adolescent age group. In the present study, the presence of antibodies against P. acnes (MTCC1951) were detected in acne patient (n=50) and disease free controls (n=25) using dot-ELISA and Western blot assay. The ability of P. acnes to induce pro-inflammatory cytokines by human peripheral blood mononuclear cells (PBMCs), obtained from acne patients and healthy subjects, were also analysed. The patients (n=26) who were culture positive for skin swab culture, were found to have a more advanced disease and higher antibody titres (1:4000 to > 1:16000) compared to the P. acnes negative patients (n=24) and normal controls (n=25). An analysis of patients' sera by western blot assay recognized a number of antigenic components of P. acnes, ranging from 29 to 205 kDa. The major reactive component was an approximately 96 kDa polypeptide, which was recognised in 92% (24 of 26) of the patients sera. Further, the P. acnes culture supernatant, crude cell lysate and heat killed P. acnes whole cells, obtained from 72-h incubation culture, were observed to be able to induce significant amounts of IL-8 and tumor necrosis factor alpha (TNF-alpha) by the PBMCs in both the healthy subjects and patients, as analysed by cytokine-ELISA. The levels of cytokines were significantly higher in the patients than the healthy subjects. A major 96 kDa polypeptide reactant was eluted from the gel and was found to cause dose dependent stimulation of the productions of IL-8 and TNF-alpha. Thus, the above results suggest that both humoral and pro-inflammatory responses play major roles in the pathogenesis of acne.

Response of Mycobacterium habana vaccine in patients with lepromatous leprosy and their household contacts. A pilot clinical study.

Single dose vaccination was carried out with Mycobacterium habana vaccine, 31 lepromatous leprosy cases receiving 1.5 mg (1.5 mg = 6.27 x 10(8) bacilli) and 36 household contacts randomly receiving 1.5, 2.0, 2.5 mg vaccine intradermally. Duration of study was 18 weeks. Vaccination induced lepromin conversion in 100% of lepromatous leprosy cases and lepromin negative household contacts and augmentation of lepromin reactivity in 100% of lepromin positive household contacts, which was stable for the 15 weeks duration of follow-up. The maximum augmentation in lepromin reactivity was obtained with 1.5 mg of vaccine, which is probably the supramaximal dose. Overall, post-vaccination, those without prior BCG vaccination scars showed higher mean values of lepromin augmentation. Local vaccination site changes included induration, ulceration, itching, pain and uncomplicated regional lymphadenopathy, all of which remitted spontaneously by 15 weeks. Systemic side-effects noted were pyrexia, ENL and jaundice, and were seen with no greater frequency than that reported in other vaccine trials. Overall, systemic side-effects were easily controlled and were not accompanied by clinically detectable nerve or ocular damage. The safety profile investigations revealed an increase in the mean values of Hb%, RBC count and PCV in household contacts and of PCV in lepromatous patients, post-vaccination. Alterations in the liver function tests were also observed in patients of lepromatous leprosy. Thus, M. habana vaccine appears to be useful in stimulating specific CMI against M. leprae as evidenced by increased lepromin reactivity.

Anti-inflammatory effects of erythromycin and tetracycline on Propionibacterium acnes induced production of chemotactic factors and reactive oxygen species by human neutrophils.

Propionibacterium acnes (P. acnes), an anaerobic pathogen, plays an important role in the pathogenesis of acne and seems to initiate the inflammatory process by producing neutrophil chemotactic factors (NCF). Once neutrophils attracted by bacterial chemoattractants reach the inflamed site, they release inflammatory mediators such as lysosomal enzymes and reactive oxygen species (ROS). Previously, it has been shown that antibiotics may affect acne by means other than their anti-bacterial effects. Thus, we investigated the effect of subminimal inhibitory concentration (sub-MIC) of tetracycline and erythromycin on production of NCF and ROS. NCF was tested in vivo in a mouse model and ROS was estimated on human PMNL in vitro, by nitroblue tetrazolium dye reduction test (NBT) and cytochrome-C reduction test. Tetracycline (CS-T) and Erythromycin (CS-E) treated cultures showed a significant reduction of 35.8% and 58.3% in NCF production respectively, as compared to P. acnes stimulated cultures. Tetracycline and erythromycin at their sub-MIC also significantly inhibited release of ROS from human PMNL. Thus, tetracycline and erythromycin, besides having antibacterial activity, also have an anti-inflammatory action. These antibiotics reduce the capacity of P. acnes to produce NCF, as well decrease its ability to induce ROS from PMNL.

Role of meprin A in renal tubular epithelial cell injury.

Meprins are zinc-dependent metalloproteinases that are highly expressed in the brush-border membranes of both the kidney and the intestines. Meprins are capable of proteolytically degrading extracellular matrix proteins, proteolytically processing bioactive proteins, and play a role in inflammatory processes. In this study, the function of meprin A in the acute kidney injury (AKI) model of cisplatin nephrotoxicity was examined. Normal linear localization of meprin A in the brush border membranes of proximal tubules was altered in AKI. The meprin A alpha-subunit was detected in the urine of both control and cisplatin-treated mice. A cleaved product of the meprin A beta-subunit, undetected in the urine of control mice, was found to be significantly increased in the urine during the progression of cisplatin nephrotoxicity. The excretion of this beta-fragment was found to be before the rise in serum creatinine and blood urea nitrogen (BUN) suggesting usefulness as a biomarker for AKI. Pretreatment of mice with a meprin A inhibitor afforded protection from cisplatin nephrotoxicity as reflected by significant decreases in serum creatinine, BUN, and the excretion of kidney injury molecule-1. These decreases in serum and urine biomarkers were accompanied by significant decreases in histologic markers such as leukocyte infiltration and apoptosis. Meprin A appears to be an important therapeutic target and urinary excretion appears to be a potential biomarker of AKI.

Partial purification and characterization of beta-mannosyltransferase from suspension-cultured soybean cells.

The beta-mannosyltransferase that catalyzes the synthesis of Man-beta-GlcNAc-GlcNAc-PP-dolichol from GDP-mannose and dolichyl-PP-GlcNAc-GlcNAc was solubilized from microsomes of suspension-cultured soybean cells by treatment with 1.5% Triton X-100 and was purified about 700-fold by chromatography on DEAE-cellulose, hydroxylapatite, and a GDP affinity column. The purified enzyme was reasonably stable in the presence of 20% glycerol and 0.5 mM dithiothreitol. The enzyme required either detergent (Triton X-100 or NP-40) or phospholipid for maximum activity, but the effects of these two were not additive. Thus, either phosphatidylcholine or Triton X-100 could give maximum stimulation. In terms of phospholipid stimulation, both the head group and the acyl chain appeared to be important since phosphatidylcholines with 18-carbon unsaturated fatty acids were most effective. The purified enzyme had a sharp pH optimum of 6.9-7.0 and required a divalent cation. Mg2+ was the best metal ion with optimum activity occurring at 6 mM, but Mn2+ was reasonably effective while Ca2+ was slightly stimulatory. The Km for GDP-mannose was calculated to be 1.7 X 10(-6) M and that for dolichyl-PP-GlcNAc-GlcNAc about 9 X 10(-6) M. The enzyme was inhibited by a number of guanosine nucleotides such as GDP-glucose, GDP, GMP, and GTP, but various uridine and adenosine nucleotides were without effect. The purified enzyme was apparently free of alpha-1,3-mannosyltransferase (and perhaps other mannosyltransferases) and dolichyl-P-mannose synthase since the only product seen from dolichyl-PP-GlcNAc-GlcNAc and GDP-mannose was Man-beta-GlcNAc-GlcNAc-PP-dolichol.(ABSTRACT TRUNCATED AT 250 WORDS)

Purification and Properties of UDP-GlcNAc:Dolichyl-Pyrophosphoryl-GlcNAc GlcNAc Transferase from Mung Bean Seedling.

The N-acetylglucosamine (GlcNAc) transferase that catalyzes the formation of dolichyl-pyrophosphoryl-GlcNAc-GlcNAc from UDP-GlcNAc and dolichyl-pyrophosphoryl-GlcNAc was solubilized from the microsomal enzyme fraction of mung beans with 1.5% Triton X-100, and was purified 140-fold on columns of DE-52 and hydroxylapatite. The partially purified enzyme preparation was quite stable when stored in 20% glycerol and 0.5 millimolar dithiothreitol, and was free of GlcNAc-1-P transferase and mannosyl transferases. The GlcNAc transferase had a sharp pH optimum of 7.4 to 7.6 and the K(m) for dolichyl-pyrophosphoryl-GlcNAc was 2.2 micromolar and that for UDP-GlcNAc, 0.25 micromolar. The enzyme showed a strong requirement for the detergent Triton X-100 and was stimulated somewhat by the divalent cation Mg(2+). Uridine nucleotides, especially UDP and UDP-glucose inhibited the enzyme as did the antibiotic, diumycin. However, a variety of other antibiotics including tunicamycin were without effect. The product of the reaction was characterized as dolichyl-pyrophosphoryl-GlcNAc-GlcNAc.

Properties of Solubilized UDP-GlcNAc: Dolichyl Phosphate-GlcNAc-1-P-Transferase from Soybean Cultured Cells.

The GlcNAc-1-P-transferase was solubilized from microsomal preparations of soybean cultured cells by treatment with 1% Triton X-100. The solubilized enzyme catalyzed the formation of dolichyl pyrophosphoryl-GlcNAc when incubated with UDP-GlcNAc and dolichyl phosphate. The GlcNAc-1-P-transferase activity was stimulated by the addition of phosphatidylglycerol and phosphatidylinositol, but was inhibited by phosphatidylcholine, phosphatidylethanolamine, and phosphatidylserine. The K(m) value for dolichyl-phosphate was 6.2 micromolar and that determined for UDP-GlcNAc was 0.42 micromolar. The pH optimum for the GlcNAc-1-P reaction was between 7.2 and 7.6; maximum activity occurred at about 10 millimolar Mg(2+). The addition of unlabeled GDP-mannose or UDP-glucose considerably inhibited enzyme activity which could be restored to nearly the original value by addition of more dolichyl phosphate to the incubation mixture. On the other hand, the addition of unlabeled ADP-glucose and GDP-glucose enhanced the enzyme activity. This stimulation by these sugar nucleotides was found to be due to the protection of the substrate UDP-[(3)H]-GlcNAc from pyrophosphatase degradation. The GlcNAc-1-P-transferase reaction was very sensitive to tunicamycin and 50% inhibition required less than 1 microgram of antibiotic per milliliter. Amphomycin, showdomycin, and diumycin also inhibited this reaction but at higher concentrations.

Purification and properties of UDP-GlcNAc:dolichyl-phosphate GlcNAc-1-phosphate transferase. Activation and inhibition of the enzyme.

The GlcNAc-1-P transferase was solubilized from pig aorta microsomal fractions using 0.5% Nonidet P-40. The activity of the solubilized enzyme was stimulated by exogeneously added phospholipids in the order phosphatidylglycerol greater than phosphatidylinositol greater than phosphatidylserine. When the enzyme was stored in 20% glycerol containing 20 micrograms of phosphatidylglycerol/mg of protein, more than 80% of the activity remained after storage for 6 days at 0-4 degrees C. On the other hand, in the absence of the stabilizers, the enzyme lost most of its activity within 24 h. The transferase was purified about 68-fold using ammonium sulfate and DEAE-cellulose fractionation. The DEAE-cellulose chromatography separated a heat-stable factor from the enzyme, which when added back to the partially purified enzyme stimulated about 5-fold. With this partially purified enzyme, the Km for UDP-GlcNAc was found to be 1 X 10(-7) M, and that for dolichyl-P about 1 X 10(-6) M. The stimulatory factor increased the Vmax for both UDP-GlcNAc and dolichyl-P 5-10-fold, but the Km values remained the same. The pH optimum for the enzyme was between 7.4 and 7.6, and either Mn2+ (1 mM) or Mg2+ (10 mM) was required for optimum activity. The GlcNAc-1-P transferase was also stimulated by the addition of GDP-mannose (or other purine sugar nucleotides) or dolichyl-phosphoryl-mannose to the incubation mixtures. These two compounds acted in different ways on the enzyme since their stimulatory effects were additive. The effect of GDP-mannose was found to be due to protection of the substrate, UDP-GlcNAc, from degradation, but the effect of dolichyl-P-mannose remains to be established. In addition, the stimulations shown by phosphatidylglycerol, GDP-mannose, and factor, or phosphatidylglycerol, dolichyl-P-mannose, and factor, were all additive, indicating that they were acting at different sites on the enzyme. The transferase was quite sensitive to the action of sulfhydryl reagents such as N-ethylmaleimide or p-chloromercuribenzene sulfonate, and was rapidly inactivated in their presence. The enzyme could be protected to the extent of about 50% when all of the substrates (UDP-GlcNAc, dolichyl-P, Mn2+) were added before the addition of the sulfhydryl reagents.