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Bacteria are considered mini chemical factories that help us in providing a wide range of products for various purposes. These days, bacterial cellulose (BC) is getting attention by researchers due to its quality, eco‐friendly nature, and excellent physical‐mechanical qualities. It is being used in the fabrication of nanocomposites. Its nanocomposites can be used in various industries, including medicine, food, leather, textiles, environment, electronics, and cosmetics. This area of research is emerging and still in its infancy stage, as new applications are still coming up. Most of the work on BC has been done during the last two decades and serious inputs are required in this direction in order to make the production process commercially viable and ultimately the application part. Biowastes, such as fruits and vegetables wastes, can be used as a cost‐effective medium to minimize the cost for large‐scale production of BC‐based nanocomposites thus will valorize the biowaste material into a valuable product. Using biowaste as media will also aid in better waste management along with reduction in detrimental environmental effects. This review will help the readers to understand the potential applications of BC and its nanocomposites as well as their vital role in our daily lives. [ABSTRACT FROM AUTHOR]

Lead (Pb) is a ubiquitous toxic heavy metal that is known to induce damage to major macromolecules (lipids, proteins, and nucleic acids) by enhancing the level of reactive oxygen species (ROS). Naringenin, a predominant flavonoid primarily found in citrus fruits has attained increasing attention due to its various pharmacological properties. Thus, the present investigation aimed to explore the ameliorative role of naringenin against Pb‐induced toxicity in human peripheral blood lymphocytes (PBLs) under in vitro conditions. For this purpose, PBLs were exposed to Pb (350 µg/ml) alone as well in combination with naringenin (10 and 30 µg/ml). Sister chromatid exchange (SCE) and alkaline comet assay were used as genotoxic indices to evaluate the genotoxic and antigenotoxic activity of Pb and naringenin, respectively. Lipid peroxidation (LPO), glutathione peroxidase (GPx), catalase (CAT), superoxide dismutase (SOD), and reduced glutathione (GSH) assays were used as oxidative damage markers. The results revealed that Pb induced a significant (p < 0.05) increase in genetic and oxidative damage as compared with the untreated sample whereas the treatment of cells along with naringenin (10 and 30 µg/ml) and Pb (350 µg/ml) caused a significant reduction in genetic damage and elevation in SOD, GPx, and CAT activities and GSH level, accompanied by a significant reduction in LPO level as compared with Pb alone treated sample. So, the present investigation revealed that naringenin might be used as a protective agent against Pb‐induced toxicity due to its antigenotoxic and antioxidative properties. [ABSTRACT FROM AUTHOR]

Introduction: After traumatic nerve injury, neuromuscular junction remodeling plays a key role in determining functional outcomes. Immunohistochemical analyses of denervated muscle biopsies may provide valuable prognostic data regarding clinical outcomes to supplement electrodiagnostic studies.Methods: We performed biopsies on nonfunctioning deltoid muscles in two patients after gunshot wounds and visualized the neuromuscular junctions using two-photon microscopy with immunohistochemistry.Results: Although the nerves in both patients showed evidence of acute Wallerian degeneration, some of the motor endplates were intact but exhibited significantly decreased surface area and volume. Both patients exhibited substantial recovery of motor function over several weeks postinjury.Discussion: Two-photon microscopic assessment of neuromuscular junction integrity and motor endplate morphometry in muscle biopsies provided evidence of partial sparing of muscle innervation. This finding supported the clinical judgment that eventual recovery would occur. With further study, this technique may help to guide operative decisionmaking after traumatic nerve injuries. [ABSTRACT FROM AUTHOR]

Abstract: Aim: Henoch‐Schönlein purpura (HSP), a primary vasculitis, characterized by purpura, abdominal pain, arthritis and renal involvement, is predominantly a disease of childhood. However, rarely it can occur in adults in whom it is believed to be a more severe form with poor renal outcomes. We aimed to answer if the age of onset affected the clinical spectrum and renal outcomes of the disease in a north Indian population. Hence, we studied the differences in clinical spectrum and renal outcomes between adult‐onset HSP and childhood‐onset HSP. Methods: Case records of all adult patients diagnosed with HSP (onset ≥ 18 years) over the last 25 years in our department (1992–2017) were retrieved. Data on clinical features, lab abnormalities and outcomes were extracted and compared with that in pediatric HSP patients (onset < 18 years) seen during the same period. Results: A total of 87 patients, including 30 adults and 57 children, were seen during this period. Compared to children, most of the adults had purpura as the first clinical manifestation (86.7% vs. 56.1%, P < 0.01) whereas abdominal pain was only rarely the initial symptom in adults (10.0% vs. 36.8%, P < 0.02). During the disease course, adults had a higher frequency of joint involvement as compared to children (90.0% vs. 43.9%, P < 0.001). There was no significant difference in the frequency of renal involvement (60.0% vs. 50.9%, P = NS) and gastrointestinal involvement (66.7% vs. 84.2%, P = NS) between adults and children. Outcomes were good in both groups and most adults and children achieved complete recovery (83.3% and 86.0%, respectively). There was no difference in the frequency of immunosuppressive treatment required by the two groups. None of the patients developed renal insufficiency on follow‐up. Conclusion: Compared to children, adults with HSP seldom have abdominal pain as the first clinical manifestation while joint involvement is seen more commonly in them during the disease course. [ABSTRACT FROM AUTHOR]

This study investigated genetic damage in paint workers mainly exposed to toluene as it is a major solvent used in paint thinners. Sister chromatid exchange (SCE) assay was used as biomarker of genotoxicity. Blood samples were collected from 30 paint workers and 30 control subjects matched with respect to age and other confounding factors except for exposure to toluene. SCE frequency was found to be significantly higher in paint workers (4.81±0.92) as compared to control individuals (1.73±0.54) (p<0.05). We also investigated influence of polymorphisms of CYP2E1 and CYP1A1m2 genes on SCE frequency. Our results showed that there was significant increase in frequencies of SCE among the mutant genotypes of CYP2E1 and CYP1A1m2 as compared to wild genotypes. Our study indicated that long term exposure of toluene can increase genotoxic risk in paint workers. [ABSTRACT FROM AUTHOR]

Lupus nephritis (LN) has significant impact on the outcome of patients with systemic lupus erythematosus (SLE). In the absence of any new breakthrough for management of LN over the last few years, using existing treatment modalities in a more effective manner is the mainstay of improving outcomes. For effectively using the drugs, disease activity needs to be assessed accurately and more objectively, which is not possible with present clinical assessment tools. Biomarkers help in accurate assessment of disease activity and enable the physician to individualize the therapy. Conventional disease activity markers have limitations which need to be addressed and research in the area of biomarker discovery in LN has immensely expanded over the last two decades as evident by the literature. Moreover, biomarkers for LN should be different from the markers of overall disease activity as LN requires significant immunosuppression, unlike other non-renal manifestations of SLE. Newly discovered biomarkers exhibit qualities pertaining to different aspects of disease activity and damage. In this review, we discuss the established as well as new biomarkers of SLE in the light of their role in LN diagnosis, follow- up, prediction of renal flare and correlation with renal histology findings. [ABSTRACT FROM AUTHOR]

In recent years, the use of organophosphorus pesticides has been extensively increased and these compounds signify a major class of agricultural pesticides today. We studied antigenotoxic potential of curcumin and carvacrol against the parathion induced DNA damage in cultured peripheral blood lymphocytes using sister chromatid exchanges as a biomarker of genotoxicity. Heparinised fresh blood fromhealthy individuals was treated with 2.5 µg/mL concentration of parathion in presence of curcumin and carvacrol in order to observe the antigenotoxic potential of both curcumin and carvacrol. Significant reduction (P < 0.05) was observed in the frequencies of SCEs in presence of 10 µg/mL and 15 µg/mL concentrations of curcumin as compared to parathion exposed sample. Similarly carvacrol had significant (P < 0.05) antigenotoxic effect at the concentrations of 2.5 µg/mL and 5.0 µg/mL against the parathion. We also studied the effect of GSTT1 and GSTM1 on genotoxicity of parathion and antigenotoxic potential of curcumin and carvacrol. We did not observe any significant effect (P > 0.05) of GSTT1 and GSTM1 polymorphism on genotoxicity of parathion and antigenotoxic potential of curcumin and carvacrol. [ABSTRACT FROM AUTHOR]

The transosseous-equivalent (TOE) rotator cuff repair technique increases failure loads and contact pressure and area between tendon and bone compared to single-row (SR) and double-row (DR) repairs, but no study has investigated if this translates into improved healing in vivo. We hypothesized that a TOE repair in a rabbit chronic rotator cuff tear model would demonstrate a better biomechanical profile than SR and DR repairs after 12 weeks of healing. A two-stage surgical procedure was performed on 21 New Zealand White Rabbits. The right subscapularis tendon was transected and allowed to retract for 6 weeks to simulate a chronic tear. Repair was done with the SR, DR, or TOE technique and allowed to heal for 12 weeks. Cyclic loading and load to failure biomechanical testing was then performed. The TOE repair showed greater biomechanical characteristics than DR, which in turn were greater than SR. These included yield load ( p < 0.05), energy absorbed to yield ( p < 0.05), and ultimate load ( p < 0.05). For repair of a chronic, retracted rotator cuff tear, the TOE technique was the strongest biomechanical construct after healing followed by DR with SR being the weakest. © 2013 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 31:1254-1260, 2013 [ABSTRACT FROM AUTHOR]

Objective Traumatic peripheral nerve injuries often produce permanent functional deficits despite optimal surgical and medical management. One reason for the impaired target organ reinnervation is degradation of motor endplates during prolonged denervation. Here we investigate the effect of preserving agrin on the stability of denervated endplates. Because matrix metalloproteinase 3 (MMP3) is known to degrade agrin, we examined the changes in endplate structure following traumatic nerve injury in MMP3 knockout mice. Methods After creation of a critical size nerve defect to preclude reinnervation, we characterized receptor area, receptor density, and endplate morphology in denervated plantaris muscles in wild-type and MMP3 null mice. The level of agrin and muscle-specific kinase (MuSK) was assessed at denervated endplates. In addition, denervated muscles were subjected to ex vivo stimulation with acetylcholine. Finally, reinnervation potential was compared after long-term denervation. Results In wild-type mice, the endplates demonstrated time-dependent decreases in area and receptor density and conversion to an immature receptor phenotype. In striking contrast, all denervation-induced changes were attenuated in MMP3 null mice, with endplates retaining their differentiated form. Agrin and MuSK were preserved in endplates from denervated MMP3 null animals. Furthermore, denervated muscles from MMP3 null mice demonstrated greater endplate efficacy and reinnervation. Interpretation These results demonstrate a critical role for MMP3 in motor endplate remodeling, and reveal a potential target for therapeutic intervention to prevent motor endplate degradation following nerve injury. ANN NEUROL 2013;73:210-223 [ABSTRACT FROM AUTHOR]

Spondyloepiphyseal dysplasia (SED) is a descriptive term used for group of inherited disorders of bone growth resulting in short stature, skeletal abnormalities, and problems with hearing and vision. SED have three major forms, SED congenital, pseudoachondroplastic SED, and SED tarda. SED tarda is milder than SED congenita. True generalized microdontia is a rare condition in which all the teeth are abnormally small. This is a report of a rare case having SED with generalized microdontia in a 26-year-old patient. [ABSTRACT FROM AUTHOR]

Objective: Chronic nerve compression (CNC) injuries occur when peripheral nerves are subjected to sustained mechanical forces, with increasing evidence implicating Schwann cells as key mediators. Integrins, a family of transmembrane adhesion molecules that are capable of intracellular signaling, have been implicated in a variety of biological processes such as myelination and nerve regeneration. In this study, we seek to define the physical stimuli mediating demyelination and to determine whether integrin plays a role in the demyelinating response. Methods: We used a previously described in vitro model of CNC injury where myelinating neuron-Schwann cell cocultures were subjected to independent manipulations of hydrostatic pressure, hypoxia, and glucose deprivation in a custom bioreactor. We assessed whether demyelination increased in response to applied manipulation and determined whether integrin-associated signaling cascades are upregulated. Results: Biophysical stimulation of neural tissue induced demyelination and Schwann cell proliferation without neuronal or glial cytotoxicity or apoptosis. Although glucose deprivation and hypoxia independently had minor effects on myelin stability, together they potentiated the demyelinating effects of hydrostatic compression, and in combination, significantly destabilized myelin. Biophysical stimuli transiently increased phosphorylation of the integrin-associated tyrosine kinase Src within Schwann cells. Silencing this integrin signaling cascade blocked Src activation and prevented pressure-induced demyelination. Colocalization analysis indicated that Src is localized within Schwann cells. Interpretation: These results indicate that myelin is sensitive to CNC injury and support the novel concept that myelinating cocultures respond directly to mechanical loading via activating an integrin signaling cascade. ANN NEUROL 2012;72:112-123 [ABSTRACT FROM AUTHOR]

Introduction: Myelinating Schwann cells compartmentalize their outermost layer to form actin-rich channels known as Cajal bands. Herein we investigate changes in Schwann cell architecture and cytoplasmic morphology in a novel mouse model of carpal tunnel syndrome. Methods: Chronic nerve compression (CNC) injury was created in wild-type and slow-Wallerian degeneration ( Wld S) mice. Over 12 weeks, nerves were electrodiagnostically assessed, and Schwann cell morphology was thoroughly evaluated. Results: A decline in nerve conduction velocity and increase in g-ratio is observed without early axonal damage. Schwann cells display shortened internodal lengths and severely disrupted Cajal bands. Quite surprisingly, the latter is reconstituted without improvements to nerve conduction velocity. Conclusions: Chronic entrapment injuries like carpal tunnel syndrome are primarily mediated by the Schwann cell response, where decreases in internodal length and myelin thickness disrupt the efficiency of impulse propagation. Restitution of Cajal bands is not sufficient for remyelination after CNC injury. Muscle Nerve, 2012 [ABSTRACT FROM AUTHOR]

Chronic nerve compression (CNC) injuries, such as carpal tunnel syndrome, are common musculoskeletal conditions that affect patients with debilitating loss of sensory function and pain. Although early detection and treatment are important, our understanding of pain-related molecular mechanisms remains largely unclear. Here we investigate these mechanisms using an animal model for CNC injury. To confirm that CNC injury induces pain, we assessed expression of c-fos, a gene that is rapidly expressed in spinal sensory afferents in response to painful peripheral stimuli, and TNF-α and IL-6, two proinflammatory cytokines that are crucial to development of inflammatory-mediated pain. Results show c-fos upregulation 1-2 weeks postinjury in the absence of TNF-α or IL-6 expression, indicating increased neural sensitivity without an inflammatory response. This is consistent with previous studies that showed no morphologic evidence of inflammation in the CNC model. Surprisingly, we also found de novo expression of NaV1.8, a sodium channel linked to the development of neuropathic pain, in endoneurial Schwann cells following injury. Until now, NaV1.8 expression was thought to be restricted to sensory neurons. CNC injury appears to be a unique model of noninflammatory neuropathic pain. Further investigation of the underlying molecular basis could yield promising targets for early diagnosis and treatment. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:753-761, 2010 [ABSTRACT FROM AUTHOR]

An introduction is presented in which the editor discusses various reports within the issue on topics including seronegative spondyloarthropathies (SSA) link with infection, serum procalcitonin (PCT) levels in ankylosing spondylitis (AS) patients, and relationship of microbes and arthritis.

While many studies have focused on modulating the immune response and enhancing axonal regeneration after spinal cord injury (SCI), there is limited work being performed on evaluating the role of glial scar in SCI. We sought to evaluate the effects of glial scar resection in contusion models and dorsal hemisection models of SCI. At 1-week postinjury, 2 mm of glial scar was excised from specimens in one of the two groups from each injury model. Functional outcome was measured weekly using the Basso, Beattie, Bresnahan (BBB) Locomotor Rating Scale along with histologic evaluation of spinal cord tracts to determine axonal regeneration. Within the dorsal hemisection model, there was no significant difference in recovery for animals that underwent glial scar excision versus animals that did not have scar excision ( p = 0.61). Animals subjected to the contusion model, however, demonstrated lower BBB scores in the glial resection group during the earlier postoperative periods (<4 weeks; p < 0.05). Histological analysis revealed no axons within the glial resection contusion model, and moderate axonal growth within the nonresection contusion group and both hemisection groups ( p > 0.05 for differences among the three groups). While glial scar may serve to stabilize the preserved axonal tracts and thereby permit modest recovery in a contusion model of SCI, it may be of less importance with a dorsal hemisection model. These experiments highlight that basic biologic processes following SCI may vary tremendously based on the injury mechanism and that the role of glial scar in spinal cord regeneration must be elucidated. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27: 931-936, 2009 [ABSTRACT FROM AUTHOR]

Chronic nerve compression injuries (CNC) are progressive demyelinating disorders characterized by a gradual decline of the nerve conduction velocity (NCV) in the affected nerve region. CNC injury induces a robust Schwann cell response with axonal sprouting, but without morphologic evidence of axonal injury. We hypothesize that early CNC injury occurs without damage to neuromuscular junction of motor axons. A well-established animal model was used to assess for damage to motor axons. As sprouting is considered a hallmark of regeneration during and after axonal degeneration and sprouting was confirmed visually at 2 weeks in CNC animals, we assessed for axonal degeneration in motor nerves after CNC by evaluating the integrity of the neuromuscular junction. NCV exhibited a gradual progressive decline consistent with the human condition. Compound motor action potential amplitudes decreased slightly immediately and plateaued, indicating that there was not sustained and increasing axonal loss. Sprouting was confirmed using immunofluorescence and by an increase in number of unmyelinated axons and Remak bundles. Blind analysis of the neuromuscular junction showed no difference between control and CNC images, indicating that there was no evidence for end-unit axonal loss in the soleus muscle. Because the progressive decline in NCV was not paired with a similar progressive decline in amplitude, it is likely that axonal loss is not responsible for slowing of action potentials. Blind analysis of the neuromuscular junction provides further evidence that the axonal sprouting seen early after CNC injury is not a consequence of axonal degeneration in the motor nerves. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27:114-119, 2009 [ABSTRACT FROM AUTHOR]

The role of Schmidt–Lanterman incisures (SLIs) within the myelin sheath remains the subject of much debate. Previous studies have shown a positive correlation between the number of SLIs per internode and internodal width for both normal and pathological myelin internodes. As chronic nerve compression (CNC) injury induces demyelination, we sought to evaluate if CNC injury altered the occurrence of SLIs using nerve-teasing techniques and light microscopy. Rigorous examination of the teased axons from nerves subjected to CNC injury for 1 month, 2 months or 8 months revealed that there is indeed a positive correlation between the number of SLIs per internode and the internodal width. However, unlike previous studies, the degree of positive correlation between these two parameters was greater in the internodes that had undergone remyelination in response to CNC injury as compared with the internodes from control nerves. These findings support the theory that SLIs are likely to assist in the metabolic processes of the myelin sheath, including growth and maintenance of the myelin sheath. [ABSTRACT FROM AUTHOR]

Abstract: Schwann cells within a peripheral nerve respond robustly after an axonal injury. Recent results have revealed that Schwann cells undergo concurrent proliferation and apoptosis after a chronic nerve injury that is independent of axonal pathology. Although the exact nature of the stimulus that produces this Schwann cell response remains unknown, we postulated that this response may be triggered directly by mechanical stimuli. Thus, we sought to determine how pure Schwann cells responded to a sustained shear stress in the form of laminar fluid flow by evaluating for proliferation, expression of S-100, myelin-associated glycoprotein (MAG), and myelin basic protein (MBP). Immunohistochemistry demonstrated that the Schwann cells were positive for S-100, MAG, and MBP in greater than 99% of the experimental cells. Stimulated cells also revealed an increased rate of proliferation by as much as 100% (p &#60;.001). The mRNA expression of MAG and MBP was down-regulated by 21% (p &#60;.035) and 18% (p &#60;.015), respectively, in experimental cells from RT-PCR assays. Furthermore, Western blot showed a down-regulation in MAG and MBP protein expression by 29% (p &#60;.035) and 35% (p &#60;.02), respectively. This study provides novel information regarding Schwann cell direct response to this physical stimulus that is not secondary to an axonal injury. [Copyright &y& Elsevier]

Nanocellulose is the renewable biopolymer produced in nature by different bacteria. The widespread use of nanocellulose in industrial processes increases the demand for this valuable biomaterial. To overcome the high cost of producing nanocellulose using the Hestrin–Schramm medium, alternative agricultural waste has been studied as a potential low‐cost supply. This study investigated the optimization and physicochemical characterization of cellulose membrane obtained, utilizing a low‐cost substrate—‐papaya peel‐based medium, with Novacetimonas hansenii BMK‐3.The maximum yield of nanocellulose was found at an inoculum age 24 h, inoculum size 10% (v/v), incubation time 15 days, pH 3.5, media:flask volume ratio 1:2.5, and temperature 30°C. Cellulose yield produced using the papaya peel‐based medium was nearly four times more than using the Hestrin–Schramm medium. The structural and physical properties of cellulose were characterized using field emission scanning electron microscopy, Fourier‐transform infrared spectroscopy, X‐ray diffraction, thermogravimetric analysis, and derivative of thermogravimetric analysis. Cellulose produced using papaya peel‐based medium had similar properties to cellulose produced in the Hestrin–Schramm medium. The results suggested papaya peels as a cost‐effective substrate for cellulose production with enhanced yield. This study reports an eco‐friendly approach for the management of papaya peels waste disposal and production of value‐added product. This is the first report mentioning the valorization of papaya fruit peel waste for the production of cellulose. [ABSTRACT FROM AUTHOR]

Lead (Pb) is a well‐known carcinogenic heavy metal. Exposure to Pb induces DNA damage by enhancing the generation of reactive oxygen species (ROS). One of the possible ways to shield DNA from this damage is to supply antioxidants that can remove free radicals generated by genotoxicants. Hence, the current study was designed to evaluate the antigenotoxic potential of a flavonoid compound; morin against Pb‐induced genomic damage on cultured human peripheral blood lymphocytes (PBL). The effect of Pb or morin or their combination was evaluated on the DNA damage using comet and sister chromatid exchange (SCE) assays. The results indicated a significant (p < 0.05) increase in the SCE frequency and various comet parameters in a dose‐dependent manner upon treatment with lead as compared to control in cultured PBL. Supplementation of morin along with Pb effectively negated DNA damage as measured by SCE frequency and comet parameters. Practical applications: Results of our current study suggest that the DNA damage induced by genotoxicants can be overcome by co‐treatment with natural antioxidants, found in dietary supplements such as vegetables and fruits. [ABSTRACT FROM AUTHOR]

Arsenic exposure is one of the major health problem worldwide. It is related with various cancers and numerous other pathological effects. The present work was aimed to study the ameliorative effects of eugenol against arsenic mediated oxidative DNA damage using Sister chromatid exchanges (SCE), comet, and lipid peroxidation assays as biomarkers. For the genotyping of GSTO2, PCR RFLP method was used. The treatment with sodium arsenite showed dose dependent increase in frequency of SCE, comet tail moment (Tm), and lipid peroxidation (TBARS levels). On administration of eugenol (10 and 20 µM) significant dose dependent decrease in the number of SCE, Tm value, and TBARS levels observed in arsenic treated cultured peripheral blood lymphocytes. Nonsignificant effects of GSTO2 polymorphism perceived on arsenic genotoxicity and eugenol antigenotoxicity. The results of the present work suggest a protective role of eugenol against arsenic induced genotoxic and oxidative damage in cultured human peripheral blood lymphocytes. Practical application: Arsenic contamination of groundwater is one of the leading environmental issues worldwide. Chronic exposure of arsenic cause several health problems including tumor manifestation. The results of the present study suggest the use of indigenous dietary elements, herbs, shrubs as a safer and effective preventative medicine against heavy metal induced genotoxicity and oxidative stress. [ABSTRACT FROM AUTHOR]

We report the variation in birth weight among the Tibetans at different altitudes in India to test the hypothesis of greater protection from intrauterine growth retardation (IUGR) among Tibetan compared with other high-altitude native populations. We found that the birth weight of Tibetans at Leh (3521 m, high altitude) is quite similar to what has been reported previously for Tibetans at similar altitudes and is significantly higher than the low-altitude native populations living at similar altitudes. Tibetan birth weights are greater than those of other ethnic groups, both at high and low altitudes. Compared with Tibetans at high altitude (Leh, India; 3521 m), Tibetans at low altitudes (Bylakuppe, India; 800 m and Chandragiri, India; 970 m) have heavier birth weights. This finding is similar to what has been observed previously for other high-altitude native populations. Greater protection from IUGR is not observed for Tibetans compared with other high-altitude native populations as was reported previously. Genetic potential for birth weight is seemingly manifested only at low altitude.