Mesenchymal stem cells: Cell therapy and regeneration potential

Rapid advances in the isolation of multipotent progenitor cells, routinely called mesenchymal stromal/stem cells (MSCs), from various human tissues and organs have provided impetus to the field of cell therapy and regenerative medicine. The most widely studied sources of MSCs include bone marrow, adipose, muscle, peripheral blood, umbilical cord, placenta, fetal tissue, and amniotic fluid. According to the standard definition of MSCs, these clonal cells adhere to plastic, express cluster of differentiation (CD) markers such as CD73, CD90, and CD105 markers, and can differentiate into adipogenic, chondrogenic, and osteogenic lineages in vitro. However, isolated MSCs have been reported to vary in their potency and self-renewal potential. As a result, the MSCs used for clinical applications often lead to variable or even conflicting results. The lack of uniform characterization methods both in vitro and in vivo also contributes to this confusion. Therefore, the name "MSCs" itself has been increasingly questioned lately. As the use of MSCs is expanding rapidly, there is an increasing need to understand the potential sources and specific potencies of MSCs. This review discusses and compares the characteristics of MSCs and suggests that the variations in their distinctive features are dependent on the source and method of isolation as well as epigenetic changes during maintenance and growth. We also discuss the potential opportunities and challenges of MSC research with the hope to stimulate their use for therapeutic and regenerative medicine.

Potential economic impacts from improving breastfeeding rates in the UK

RATIONALE

Studies suggest that increased breastfeeding rates can provide substantial financial savings, but the scale of such savings in the UK is not known.

OBJECTIVE

To calculate potential cost savings attributable to increases in breastfeeding rates from the National Health Service perspective.

DESIGN AND SETTINGS

Cost savings focussed on where evidence of health benefit is strongest: reductions in gastrointestinal and lower respiratory tract infections, acute otitis media in infants, necrotising enterocolitis in preterm babies and breast cancer (BC) in women. Savings were estimated using a seven-step framework in which an incidence-based disease model determined the number of cases that could have been avoided if breastfeeding rates were increased. Point estimates of cost savings were subject to a deterministic sensitivity analysis.

RESULTS

Treating the four acute diseases in children costs the UK at least £89 million annually. The 2009-2010 value of lifetime costs of treating maternal BC is estimated at £959 million. Supporting mothers who are exclusively breast feeding at 1 week to continue breast feeding until 4 months can be expected to reduce the incidence of three childhood infectious diseases and save at least £11 million annually. Doubling the proportion of mothers currently breast feeding for 7-18 months in their lifetime is likely to reduce the incidence of maternal BC and save at least £31 million at 2009-2010 value.

CONCLUSIONS

The economic impact of low breastfeeding rates is substantial. Investing in services that support women who want to breast feed for longer is potentially cost saving.

Birth weight and muscle strength: a systematic review and meta-analysis

OBJECTIVE

Lower muscle strength is associated with a range of adverse health outcomes in later life. The variation in muscle strength between individuals is only partly accounted for by factors in adult life such as body size and physical activity. The aim of this review was to assess the strength of the association between intrauterine development (indicated by birth weight) and subsequent muscle strength.

DESIGN

Systematic review and meta-analysis of studies that assessed the association between birth weight and subsequent muscle strength.

RESULTS

Nineteen studies met inclusion criteria with 17 studies showing that higher birth weight was associated with greater muscle strength. Grip strength was used as a single measure of muscle strength in 15 studies. Meta-analysis (13 studies, 20 481 participants, mean ages 9.3 to 67.5) showed a 0.86 kg (95% CI 0.58, 1.15) increase in muscle strength per additional kilogram of birth weight, after adjustment for age, gender and height at the time of strength measurement.

CONCLUSION

This review has found consistent evidence of a positive association between birth weight and muscle strength which is maintained across the lifecourse. Future work will be needed to elucidate the biological mechanisms underlying this association, but it suggests the potential benefit of an early intervention to help people maintain muscle strength in later life.

Immunologic consequences of multiple, high-dose administration of allogeneic mesenchymal stem cells to baboons

Mesenchymal stem cells (MSCs) express low immunogenicity and demonstrate immunomodulatory properties in vitro that may safely allow their transplantation into unrelated immunocompetent recipients without the use of pharmacologic immunosuppression. To test this hypothesis, three groups of baboons (three animals per group) were injected as follows: group 1 animals were injected with vehicle; group 2 animals were injected IV with DiI-labeled MSCs (5 x 106 MSCs/kg body weight) followed 6 weeks later by IM injections of DiO-labeled MSCs (5 x 10(6) MSCs/kg) from the same donor; and group 3 animals were treated similarly as group 2 except that MSCs were derived from two different donors. Muscle biopsies, performed 4 weeks after the second injection of MSCs, showed persistence of DiO-labeled MSCs in 50% of the recipients. Blood was drawn at intervals for evaluation of basic immune parameters (Con A mitogen responsiveness, PBMC phenotyping, immunoglobulin levels), and to determine T-cell and alloantibody responses to donor alloantigens. Host T-cell responses to donor alloantigens were decreased in the majority of recipients without suppressing the overall T-cell response to Con A, or affecting basic parameters of the immune system. All recipient baboons produced alloantibodies that reacted with donor PBMCs. Two of six animals produced alloantibodies that reacted with MSCs. We conclude that multiple administrations of high doses of allogeneic MSCs affected alloreactive immune responses without compromising the overall immune system of recipient baboons. The induction of host T-cell hyporesponsiveness to donor alloantigens may facilitate MSC survival.

A selective androgen receptor modulator that reduces prostate tumor size and prevents orchidectomy-induced bone loss in rats

The pharmacological activity of JNJ-26146900 is described. JNJ-26146900 is a nonsteroidal androgen receptor (AR) ligand with tissue-selective activity in rats. The compound was evaluated in in vitro and in vivo models of AR activity. It binds to the rat AR with a K(i) of 400nM and acts as a pure androgen antagonist in an in vitro cell-based assay. Its in vitro profile is similar to the androgen antagonist bicalutamide (Casodex). In intact rats, JNJ-26146900 reduces ventral prostate weight with an oral potency (ED(50)) of 20-30mg/kg, again comparable to that of bicalutamide. JNJ-26146900 prevented prostate tumor growth in the Dunning rat model, maximally inhibiting growth at a dose of 10mg/kg. It slowed tumor growth significantly in a CWR22-LD1 mouse xenograft model of human prostate cancer. It was tested in aged male rats for its ability to prevent bone loss and loss of lean body mass following orchidectomy. After 6 weeks of dosing, bone volume decreased by 33% in orchidectomized versus intact vehicle-treated rats with a probability (P) of less than 0.05, as measured by micro-computerized tomography analysis. At a dose of 30mg/kg, JNJ-26146900 significantly reduced castration-induced tibial bone loss as indicated by the following parameters: bone volume, trabecular connectivity, trabecular number and spacing between trabeculae. Bone mineral density decreased from 229+/-34mg/cm(3) of hydroxyapatite to 166+/-26mg/cm(3) following orchidectomy, and was maintained at 194+/-20mg/cm(3) with JNJ-26146900 treatment (P<0.05 relative to orchidectomy alone). Using magnetic resonance imaging, the compound was found to partially prevent orchidectomy-induced loss of lean body mass. Our data show that selective androgen receptor modulators (SARMs) have the potential for anabolic effects on bone and muscle while maintaining therapeutic efficacy in prostate cancer.

Potential involvement of BMP receptor type IB activation in a synergistic effect of chondrogenic promotion between rhTGFbeta3 and rhGDF5 or rhBMP7 in human mesenchymal stem cells

Chondrogenic promotion by rhGDF5 with or without rhTGFbeta3 was studied in pellet culture of human mesenchymal stem cells (HMSCs). A synergy between rhGDF5 and rhTGFbeta3 was observed in promoting chondrogenesis. rhBMP2, rhBMP6, rhBMP7 and rhTGFbeta1 were further tested and showed the same effect. To explore the mechanism, the expression of TGFbetatype I and II receptors, ALK5, ALK2, ALK3, ALK6, TGFbetaRII, BMPRII, ActRII was studied. ALK6 showed increase by the rhTGFbeta1 or rhTGFbeta3 treatment. ALK6 protein expression also showed increase by rhTGFbeta3. rhTGFbeta1/rhTGFbeta3 induced ALK6 up-regulation was inhibited by SD-208, a TGFbeta type I receptor inhibitor. Chondrogenesis by rhTGFbetal/rhTGFbeta3 or the combination between rhTGFbetal/rhTGFbeta3 and rhGDF5 also was diminished by SD-208. SMAD1/5/8 phosphorylation in nascent human mesenchymal stem cells (HMSCs) was stimulated weakly by rhGDF5 but strongly by rhBMP7. The rhGDF5 stimulated SMAD1/5/8 phosphorylation was enhanced by rhTGFbetal/rhTGFbeta3 but inhibited by SD-208. The rhBMP7 stimulated SMAD1/5/8 phosphorylation did not show influence by rhTGFbeta3 and SD-208. Our results indicated the potential involvement of ALK6 activation by rhTGFbetas in the synergy between rhTGFbetas and rhBMPs.

Incidence of trampoline related pediatric fractures in a large district general hospital in the United Kingdom: lessons to be learnt

AIM

To test the observation that the incidence of trampoline related pediatric fractures is increasing-both nationally and in a large district general hospital.

METHOD

A retrospective analysis was undertaken of patient records establishing mechanism of injury of pediatric fractures over three consecutive summers from 2000-03. Theatre records of fractures treated operatively were used as the initial data source.

RESULTS

A statistically significant increase in trampoline related injuries was discovered. This reflects the rising incidence of injuries from national data and furthermore corresponds to the growing popularity of domestic use trampolines in the UK.

CONCLUSION

The incidence of injuries is increasing. There are lessons to be learnt from existing work from countries where trampoline prevalence has been greater for longer. The authors recommend various safety measures that may reduce children's injuries.

Proteolytic Excision of a Repressive Loop Domain in Tartrate-resistant Acid Phosphatase by Cathepsin K in Osteoclasts

Tartrate-resistant acid phosphatase (TRAP) is a metallophosphoesterase participating in osteoclast-mediated bone turnover. Activation of TRAP is associated with the redox state of the di-iron metal center as well as with limited proteolytic cleavage in an exposed loop domain. The cysteine proteinases cathepsin B, L, K, and S as well as the matrix metalloproteinase-2, -9, -13, and -14 are expressed by osteoclasts and/or other bone cells and have been implicated in the turnover of bone and cartilage. To identify proteases that could act as activators of TRAP in bone, we report here that cathepsins K and L, in contrast to the matrix metalloproteinases, efficiently cleaved and activated recombinant TRAP in vitro. Activation of TRAP by cathepsin K/L was because of increases in catalytic activity, substrate affinity, and sensitivity to reductants. Processing by cathepsin K occurred sequentially by an initial excision of the loop peptide Gly(143)-Gly(160) followed by the removal of a Val(161)-Ala(162) dipeptide at the N terminus of the C-terminal 16-kDa TRAP subunit. Cathepsin L initially released a shorter Gln(151)-Gly(160) peptide and completed processing at Ser(145) or Gly(143) at the C terminus of the N-terminal 23-kDa TRAP subunit and at Arg(163) at the N terminus of the C-terminal 16-kDa TRAP subunit. Mutation of Ser(145) to Ala partly mimicked the effect of proteolysis on catalytic activity, identifying Ser(145) as well as Asp(146) (Funhoff, E. G., Ljusberg, J., Wang, Y., Andersson, G., and Averill, B. A. (2001) Biochemistry 40, 11614-11622) as repressive amino acids of the loop region to maintain the TRAP enzyme in a catalytically latent state. The C-terminal sequence of TRAP isolated from rat bone was consistent with cathepsin K-mediated processing in vivo. Moreover, cathepsin K, but not cathepsin L, co-localized with TRAP in osteoclast-resorptive compartments, supporting a role for cathepsin K in the extracellular processing of monomeric TRAP in the resorption lacuna.

Studies of the route of administration and role of conditioning with radiation on unrelated allogeneic mismatched mesenchymal stem cell engraftment in a nonhuman primate model

OBJECTIVE

The aim of this study was to examine the effects of the route of administration [intrabone marrow (IBM) vs intravenous (IV)] and the role of conditioning with irradiation in optimizing mesenchymal stem cell (MSC) transplantation.

MATERIALS AND METHODS

To determine if irradiation resulted in depletion of colony-forming unit fibroblasts (CFU-F), which might favor the engraftment of donor MSC, the number of CFU-Fs was assayed from animals receiving either hemibody irradiation (HBI) or total body irradiation (TBI).

RESULTS

TBI resulted in a marked reduction of CFU-F numbers that spontaneously resolved, whereas animals receiving HBI did not experience depletion of CFU-F. Animals receiving MSC grafts by the IV route had higher numbers of marrow CFU-F. MSC were transduced using retroviral vectors encoding the neomycin resistance gene (Neo(R)) and a second gene encoding either the human soluble tumor necrosis factor receptor (hsTNFRII) or beta-galactosidase (beta-Gal). MSCs were administered by either the IV or IBM route to animals receiving HBI. The Neo(R) transgene was detectable in hematopoietic tissues of all animals and nonhematopoietic tissues in a single animal. Evidence of transgene expression was documented by detection of beta-Gal(+) cells in BM smears and transiently elevated serum levels of hsTNFRII.

CONCLUSION

These studies indicate that 1) MSC possess the ability to engraft and persist in an unrelated mismatched allogeneic hosts; 2) 250-cGy HBI did not favor engraftment of MSC; 3) the IBM route was not more effective than the IV route in delivering MSC grafts; and 4) transplanted MSC preferentially localized to the marrow rather than nonhematopoietic tissues.

Antiretroviral therapy in HIV infection: are we using resources appropriately and cost effectively?

The provision of antiretroviral therapy to HIV-positive patients attending the Department of Genitourinary Medicine at the Royal Infirmary of Edinburgh was assessed, to examine whether clinicians were offering treatment in line with the departmental protocol. A total of 195 patients attended in 1998, of whom 169 fulfilled the protocol criteria for treatment. Although only 115 of these were on therapy, no patient who fulfilled treatment criteria and wished to be treated was denied treatment. Of the 26 patients not fulfilling any treatment criteria, 9 had transferred in from another unit already on treatment. The remaining 17 were not on treatment.

Cathepsin K knockout mice develop osteopetrosis due to a deficit in matrix degradation but not demineralization

Cathepsin K is a cysteine protease expressed predominantly in osteoclasts. Activated cathepsin K cleaves key bone matrix proteins and is believed to play an important role in degrading the organic phase of bone during bone resorption. Mutations in the human cathepsin K gene have been demonstrated to be associated with a rare skeletal dysplasia, pycnodysostosis. The degree of functional activity of the mutated forms of cathepsin K in these individuals has not been elucidated, but is predicted to be low or absent. To study the role of cathepsin K in bone resorption, we have generated mice deficient in the cathepsin K gene. Histologic and radiographic analysis of the mice revealed osteopetrosis of the long bones and vertebrae, and abnormal joint morphology. X-ray microcomputerized tomography images allowed quantitation of the increase in bone volume, trabecular thickness, and trabecular number in both the primary spongiosa and the metaphysis of the proximal tibiae. Not all bones were similarly affected. Chondrocyte differentiation was normal. The mice also had abnormalities in hematopoietic compartments, particularly decreased bone marrow cellularity and splenomegaly. The heterozygous animals appeared normal. Close histologic examination of bone histology revealed fully differentiated osteoclasts apposed to small regions of demineralized bone. This strongly suggests that cathepsin K-deficient osteoclasts are capable of demineralizing the extracellular matrix but are unable to adequately remove the demineralized bone. This is entirely consistent with the proposed function of cathepsin K as a matrix-degrading proteinase in bone resorption.

The three-in-one proximal and distal soft tissue patellar realignment procedure. Results, and its place in the management of patellofemoral instability

The three-in-one procedure for extensor mechanism realignment of the knee combines lateral release, vastus medialis obliquus muscle advancement, and transfer of the medial one-third of the patellar tendon to the tibial collateral ligament. We observed 37 patients (42 knees) receiving this treatment at a minimum 25-month follow-up (range, 25 to 85 months; mean, 44). Thirty-two of 42 knees (76%) with recurrent patellar dislocation had good or excellent results after surgery. Redislocation occurred in four knees (9.5%). Skeletal immaturity, chondral damage, and generalized ligament laxity did not seem to affect outcome. Thirty patients (37 knees) were studied 2 years earlier as well (mean follow-up, 29 months). When comparing the results 2 years later, there was a significant deterioration in outcome over time. These results are comparable with the published results for other techniques of patellar stabilization. We describe the place of the three-in-one operation in our surgical protocol for patellofemoral instability, which is based on the principle that a procedure should be selected to address the underlying pathologic features in an individual case rather than always using one operation for all cases.

Supporting breastfeeding of babies in neonatal units

Breastmilk is invaluable for premature and sick babies. Recognition of the unique qualities of breastmilk has led to increasing encouragement to women to express breastmilk for their babies, if they are unable to feed directly from the breast. The National Childbirth Trust (NCT) had become increasingly concerned about the shortcomings in some areas in the practical and professional support available to women wanting to breastfeed when their babies are in neonatal units. The NCT therefore funded an investigation of the provision of facilities to express breastmilk in hospitals, including the availability of electric breast pumps for loan to mothers at home. We found that facilities for mothers in hospital were patchy, with only a third of neonatal units providing a separate room where mothers could express breastmilk or breastfeed in private. More than half the units on which we collected information had no specialist breastfeeding professional available. A quarter of units loaned out free electric breast pumps and a further 28% were able to provide some free breast pumps. 24% of hospitals did not provide any pumps to mothers who needed to express breastmilk at home while their babies were in hospital.

Induction and expression of human cartilage glycoprotein 39 in rheumatoid inflammatory and peripheral blood monocyte-derived macrophages

Human cartilage glycoprotein 39 (HC gp-39) has been described as a major secreted product of cultured articular chondrocytes, synovial fibroblasts, and the osteosarcoma line MG63. However, its expression in these cells types has not been directly linked to corresponding cell types in vivo. In this report, expression of HC gp-39 is demonstrated from peripheral blood-derived macrophages in association with their differentiation from monocytes to macrophages. Consistent with macrophage specificity, HC gp-39 expression is also induced upon selective stimulation of the pluripotent promyelocytic leukemia cell line HL-60 toward the monocyte/macrophage lineage with vitamin D3 or phorbol 12-myristate 13-acetate (PMA), while treatments stimulating granulocyte and eosinophilic pathways do not induce expression. Furthermore, HC gp-39 expression levels correlate with the degree of morphological differentiation induced by PMA and vitamin D3 treatments. PMA-induced mRNA expression occurs by 36 h and is a secondary transcriptional response since its synthesis is inhibited by cycloheximide. Apparently, HC gp-39 expression is tied to later events in the differentiation of monocytes into macrophages. The in vivo significance of these results is validated by the in situ detection of HC gp-39 mRNA in inflammatory macrophages associated with rheumatoid synovium. Thus, macrophages appear to be an important source of HC gp-39, which has been shown to be present at elevated levels in the blood and synovium of rheumatoid arthritis patients. The implications of this extend well beyond the previously restricted observations in cell types associated with the joint and suggest a potential involvement of macrophage-derived HC gp-39 in other aspects of inflammation, tissue remodeling, and host defense.

Low blood glucose--an NCT investigation

Babies are being tested for hypoglycaemia and treated unnecessarily. Inaccurate blood glucose testing strips are still being used. In many units research evidence is not being followed. Differences in care between hospitals means that some babies are not receiving the most appropriate care. Mothers receive conflicting advice. Some health professionals do not have confidence in breast feeding. Formula milk is being given to breast fed babies, interfering with the establishment of lactation.

Management of lung cancer in South East Scotland

BACKGROUND

There are few reports which describe the management of unselected groups of patients with lung cancer. This study was undertaken to audit prospectively the presentation, diagnosis, management, and outcome of patients presenting with lung cancer in South East Scotland.

METHODS

Data were recorded on all patients with newly diagnosed lung cancer who presented to a multidisciplinary group of clinicians over a 12 month period. Subsequent follow up data on treatment and survival were collected.

RESULTS

Six hundred and twenty two patients were registered, 80% of whom were referred from primary care. There was a considerable variation in the length of history, but the diagnosis was rapidly made after referral (87% within two weeks). In 82% of patients the pathological examination was positive; 70% were treated with palliative intent. Only 36% of patients who underwent surgery had computed tomographic scanning and 55% had sampling of mediastinal nodes. A wide variety of regimens was used for treatment with radiotherapy and chemotherapy, and follow up data were difficult to obtain in these patients. Survival was poor in all patients treated with palliative intent.

CONCLUSIONS

This audit confirms the importance of previously noted prognostic factors. Significant variation in referral practice, diagnostic and management evaluation has been shown. The data serve as a useful background for the formation of local management guidelines.

Should there be a trial of home versus hospital delivery in the United Kingdom?

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Expression of osteopontin mRNA by osteoclasts and osteoblasts in modelling adult human bone

Over recent years several non-collagenous matrix proteins of bone have been isolated and characterized. One of these proteins, osteopontin, has been shown to be synthesized by osteoblasts and deposited in the bone matrix where it is thought to bind to hydroxyapatite. However much of the functional evidence is circumstantial, and the precise function of osteopontin has not been fully elucidated. We have used in situ hybridization techniques to investigate the expression of osteopontin mRNA in a variety of human bone tissues. Cryostat sections of human osteophyte and osteoclastoma tissue were hybridized with an antisense RNA probe for osteopontin. Sense transcripts were used as a negative control to assess non-specific binding. There was a very distinct pattern of osteopontin mRNA expression in these tissues. Plump osteoblasts adjacent to the osteoid matrix expressed high levels of osteopontin mRNA, whilst flattened osteoblasts demonstrated weaker expression. The most striking feature of osteopontin mRNA expression was the high levels detected in osteoclasts. Osteoclasts in resorption lacunae and those distant from resorption sites both expressed osteopontin mRNA, suggesting that attachment was not a prerequisite for osteopontin expression. A population of mononuclear cells in resorption lacunae was also observed to express high levels of osteopontin mRNA. The whole population of osteoclasts in the osteoclastoma tissue expressed high levels of osteopontin mRNA, indicating that expression is not restricted to osteoclasts involved in bone resorption. This study confirms that human osteoblasts are capable of synthesizing osteopontin.(ABSTRACT TRUNCATED AT 250 WORDS)

Protein intake and blood glucose as modulators of GFR in hyperfiltering diabetic patients

Glomerular hyperfiltration has been claimed to be a risk factor for the development of diabetic nephropathy. Protein intake and hyperglycemia can both increase GFR in diabetic and normal subjects. Our study was designed to explore the relative importance of short-term changes in protein intake and glycemia on the modulation of renal hemodynamics in insulin-dependent diabetic (IDDM) patients with and without glomerular hyperfiltration. The renal hemodynamic response to a protein challenge was studied in eight hyperfiltering (HF) and eight normofiltering (NF) patients after a three week period of low or normal protein diet (LPD, NPD), each study being conducted twice, in random order, under conditions of prevailing hyperglycemia (H) and euglycemia (E). In HF patients GFR failed to increase significantly in response to protein challenge during NPD under conditions of either H or E (Baseline vs. 2 hr H: 151 +/- 4 vs. 155 +/- 6, NS; E 147 +/- 4 vs. 157 +/- 7 ml/min/1.73 m2, NS). A more normal response was restored following LPD with GFR increasing in all but one patient after challenge during H and in all patients during E (Baseline vs. 2 hr H: 130 +/- 7 vs. 145 +/- 8, P less than 0.07; E: 127 +/- 7 vs. 143 +/- 7 ml/min/1.73 m2, P less than 0.01). Changes in RPF paralleled the changes in GFR and filtration fraction remained stable under all study conditions.(ABSTRACT TRUNCATED AT 250 WORDS)

Renal, metabolic and hormonal responses to ingestion of animal and vegetable proteins

Renal and hormonal responses were studied in a group of healthy individuals fed, in random order, for three weeks, a vegetable protein diet (N = 10), an animal protein diet (N = 10), or an animal protein diet supplemented with fiber (N = 7), all containing the same amount of total protein (chronic study). In seven additional subjects the acute renal, metabolic and hormonal response to ingestion of a meat or soya load of equivalent total protein content was investigated (acute study). In the chronic study GRF, RPF and fractional clearance of albumin and IgG were significantly higher on the animal than the vegetable protein diets (GFR: 121 +/- 4 vs. 111 +/- 4 ml/min/1.73 m2, P less than 0.001; RPF: 634 +/- 29 vs. 559 +/- 26 ml/min/1.73 m2, P less than 0.001; theta alb: 19.5 +/- 3.1 vs. 10.2 +/- 1.6 x 10(-7), P less than 0.01; theta IgG: 11.6 +/- 3.1 vs. 7.5 +/- 1.7 x 10(-7), P less than 0.05). Renal vascular resistance was lower on the animal than vegetable protein diet (82 +/- 5 vs. 97 +/- 5 mmHg/min/liter; P less than 0.001). Fiber supplementation to APD did not have any effect on the renal variables measured which were indistinguishable from APD. In the acute study, GFR and RPF both rose significantly by approximately 16% (P less than 0.005) and approximately 14% (P less than 0.05), respectively, after the meat load, while RVR fell by approximately 12% (P less than 0.05). There were no significant changes in these parameters following the soya load.(ABSTRACT TRUNCATED AT 250 WORDS)

Myopic and nonmyopic aphakic retinal detachment: time interval and location of breaks

Of 471 retinal detachments occurring in aphakic patients after undergoing intracapsular cataract extraction, we reviewed 318 eyes with uncomplicated aphakia (no vitreous loss). Myopic eyes had equatorial breaks 38% of the time versus 19% for nonmyopic eyes. The time interval between aphakia and detachment was shorter for myopic than for nonmyopic eyes. Our results showed a significant incidence of: (1) equatorial breaks in myopic eyes versus nonmyopic eyes (P less than 0.005), and (2) earlier detachments for myopic eyes versus nonmyopic eyes (P less than 0.005). The presence of equatorial breaks seemed to be associated with earlier retinal detachments.

Protein restriction, blood pressure and the progression of diabetic nephropathy

Diabetic nephropathy is the long-term complication of diabetes responsible for the greatest increased mortality. Clinical nephropathy is characterised by a triad consisting of persistent proteinuria (total urinary protein greater than 0.5 g/24 h), rising arterial pressure and declining renal function. The role of treatment of raised blood pressure and the influence of dietary protein restriction on the established progressive phase of the disease are discussed. Subclinical elevations of urinary albumin excretion rates (greater than 30 micrograms/min; microalbuminuria), glomerular hyperfiltration and marginal elevations of arterial pressure are early markers of later clinical nephropathy which appear to respond to strict blood glucose control, blood pressure treatment and lowered dietary protein intake. Recent evidence to suggest that an inherited predisposition to raised arterial pressure may confer the susceptibility to diabetic nephropathy is presented.

Effect of protein-restricted diet on renal response to a meat meal in humans

To study the influence of preceding dietary protein intake on the renal response to a protein meal we examined renal hemodynamic and excretory responses to a meat meal in six normal human subjects either taking their normal-protein diet (NPD, 75 +/- 5 g/day) or after 3 wk of a low-protein diet (LPD, 43 +/- 3 g/day; P less than 0.005). Glomerular filtration rate (GFR) was lower on LPD than on NPD (107 +/- 7 vs. 124 +/- 5 ml X min-1 X 1.73 M-2, respectively; P less than 0.01), as was renal plasma flow (RPF) (NPD, 666 +/- 44; LPD, 605 +/- 43 ml X min-1 X 1.73 M-2; P less than 0.05). Filtration fraction (FF) was not different (NPD, 0.19 +/- 0.01; LPD, 0.18 +/- 0.01). Urinary excretion of albumin was also lower after LPD than NPD (2.1 +/- 0.5 vs. 4.2 +/- 0.8 micrograms/min; P less than 0.05). After an 80-g protein meat meal, GFR rose to a ceiling significantly higher on NPD than on LPD (132 +/- 4.8 vs. 120 +/- 5.2 ml X min-1 X 1.73 M-2; P less than 0.02), even though the percent changes were greater on LPD than on NPD (12.7 +/- 3.3 vs. 6.6 +/- 1.5%, respectively; P less than 0.05). There was a rise in RPF that was entirely attributable to a fall in renal vascular resistance, and FF did not change. On both diets, oral protein loading produced a 200-300% increase in the urinary excretion and fractional clearance of albumin and IgG, but failed to alter that of beta 2-microglobulin.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of protein restriction in insulin dependent diabetics at risk of nephropathy

Persistent proteinuria is strongly associated with increased mortality in insulin dependent diabetes, and risk of this condition can be predicted many years in advance by subclinical increases in albumin excretion rate (microalbuminuria). Eight normotensive insulin dependent diabetics with microalbuminuria who had overnight albumin excretion rates of between 15 and 200 micrograms/min underwent a three week randomised crossover study of their normal protein diet (median 92 (range 55-117) g/day) and a low protein diet (47 (38-57) g/day). Both diets were isoenergetic, and the low protein diet was supplemented with calcium and phosphate. Median overnight albumin excretion rate fell from 23.0 (15.0-170.1) micrograms/min during the normal diet to 15.4 (4.1-97.8) micrograms/min during the low protein diet. No consistent change was found in urinary excretion of beta 2 microglobulin during the two diets. The reduction in albumin excretion rate was accompanied by a significant fall in median glomerular filtration rate and fractional renal clearance of albumin. Kidney volume remained unchanged. There were no significant changes in glycaemic control or arterial blood pressure. In these few patients restriction of dietary protein had a beneficial effect on microalbuminuria, independent of changes in glucose concentrations and arterial blood pressure.

Changes in renal function in response to protein restricted diet in type 1 (insulin-dependent) diabetic patients

Glomerular filtration rate, renal plasma flow and urinary albumin excretion rate were measured during insulin-induced euglycaemia in 12 male Type 1 (insulin-dependent) diabetic patients after a 3-week period of low protein diet (45 g/day) or a similar period on unchanged conventional diet (103 g/day). No changes in glycaemic control, indicated by home blood glucose profiles and serum fructosamine concentration, or in arterial pressure, were noted on either diet. On low protein diet, glomerular filtration rate was lower (p less than 0.001) in all patients, but there was no difference in renal plasma flow between low protein diet and normal protein diet; filtration fraction fell significantly on low protein diet (p less than 0.001). Fractional clearance of albumin was also lower (p less than 0.05) on low protein diet. This study suggests that reduction of dietary protein induces, independently of changes in plasma glucose and arterial pressure, modifications in glomerular filtration rate, filtration fraction and fractional clearance of albumin, which may be associated with a beneficial effect on the evolution of diabetic renal disease.

Hypertriglyceridemia and lipid inclusions in a case of Philadelphia chromosome-positive, acute nonlymphocytic leukemia

We report a case of a 71-year-old female patient with an unusual morphological variant of Philadelphia chromosome-positive, acute nonlymphocytic leukemia. The myeloblasts exhibited an extreme degree of lipid vacuolization and the serum exhibited hyperlipidemia. The initial serum triglyceride level was 756 mg/dL. There were 26,000 white blood cells per cubic millimeter with 19% myeloblasts. The bone marrow contained greater than 80% myeloblasts that were myeloperoxidase- and chloracetate esterase-positive and typed positive for OKM1 and Leu 1 myeloid cellular markers. At remission, the lipid inclusions disappeared and the serum triglyceride levels returned to normal. Both abnormalities recurred at relapse. The cause of the hyperlipidemia and lipid inclusions was most likely an acquired hyperlipoproteinemia and secondary absorption of lipids into the malignant cells.

Bilateral and massive lipoidal infiltration of the cornea (secondary lipoidal degeneration)

A 41-year-old white man presented with bilateral white infiltration of the cornea from limbus to limbus. Extensive examination revealed no manifestations of disorders of lipid metabolism and the patient gave no history of previous ocular disease. VDRL and other serological tests were negative. The corneal button removed by penetrating keratoplasty from the right eye was studied by light microscopy, histochemistry and electron microscopy. The light microscopic appearance was consistent with lipoidal degeneration of the cornea associated with stromal vascularization and chronic keratitis, more likely a secondary lipoidal degeneration. Cholesterol clefts were seen in all levels of the stroma focally surrounded by a foreign body giant cell reaction. Lipid vacuoles were observed in extracellular and intracellular locations within histiocytes and fibroblasts in vascularized and inflammed areas. Lipid stains disclosed cholesterol crystals, neutral fats, and phospholipids.

Heparin and dihydroergotamine prophylaxis against thrombo-embolism after hip arthroplasty

A prospective study involving 500 consecutive patients undergoing hip replacement was performed to find out whether a combination of heparin and dihydroergotamine was effective in preventing postoperative fatal and non-fatal emboli. Deep-vein thrombosis was demonstrated in 131 cases (26.2%), in 99 of whom thrombi were confined to the ipsilateral (operated) limb and in 13 to the contralateral limb; 19 patients developed bilateral thrombi. Nine patients (1.8%) died during the first four weeks after operation, before they were discharged from hospital; in one, major emboli were demonstrated in the right pulmonary artery. Three of the 500 patients developed non-fatal pulmonary emboli. Excessive bleeding occurred in 21 (4.2%) and in 19 of these prophylaxis was discontinued. Wound haematomas developed in 25 patients (5.0%); only six required evacuation but in none of these six did deep infection occur while in hospital; in three patients, however, the wound haematoma prolonged the stay in hospital. Thus the combination of heparin and dihydroergotamine proved an effective prophylaxis against pulmonary embolism in patients undergoing total hip replacement. The risk of bleeding complications is wholly acceptable when balanced against the advantages of the therapy.