Ebstein's malformation of the tricuspid valve: genetic and environmental factors. The Baltimore-Washington Infant Study Group

Ebstein's anomaly is a specific structural deformity of the tricuspid valve, and its rarity has hampered etiologic evaluation. Cases of Ebstein's anomaly registered in the Baltimore Washington Infant Study (BWIS), a regional case-control study of cardiovascular malformations (CVM) in infancy, are reviewed. Between 1981 and 1989 a total of 4,390 CVM cases, including 47 Ebstein cases, and 3,572 controls were registered. The prevalence of Ebstein's anomaly was 5.2 per 100,000 livebirths. Additional cardiac anomalies were present in 38.3% of Ebstein cases. Non-cardiac malformations were present in 19.1% of Ebstein cases vs. 25.5% of other CVM, and 1.7% of controls. Case-fatality by 1 year of age was 23.4% in Ebstein vs. 18.1% in other CVM. Interviews of parents of Ebstein cases, other CVM, and controls (n = 44, 3,335, and 3,572, respectively) elicited information on family history of malformations, maternal illnesses, reproductive history, therapeutic drugs, parental lifestyle, and environmental exposures during the periconceptional period. Case-control analyses suggest genetic, reproductive, and environmental risk factors: twins [odds ratio (OR) 8.2, 95% confidence interval (CI) 2.6-25.3]; family history of CVM (OR 6.4, 95% CI 1.8-22.2); white race (OR 2.9 with non-whites as reference, 95% CI 1.2-7.0); previous miscarriages (OR 2.0, 95% CI 1.2-3.3); maternal exposure to benzodiazepines (OR 5.4, 95% CI 1.5-19.1); and varnishing (OR 3.4, 95% CI 1.3-9.1). Additional multicenter investigations are warranted to elucidate the role of genetic, reproductive, and environmental factors in the etiology of this anomaly.

Pursuit and practice of complementary therapies by cancer patients receiving conventional treatment

OBJECTIVES

To determine what proportion of oncology patients receiving conventional medical treatment also use complementary treatments; to assess which complementary treatments are the most popular and to assess patients' motivation for using them; to evaluate associated advantages and risks.

DESIGN

Postal screening questionnaire followed by semistructured interview.

SETTING

Two hospitals in inner London.

SUBJECTS

600 unselected oncology patients aged 18 or over who had known their diagnosis of cancer for at least three months.

MAIN OUTCOME MEASURES

Prevalence and demography of use of complementary therapies; patients' motivation and expectations of complementary therapies; areas of satisfaction and dissatisfaction associated with conventional and complementary therapies.

RESULTS

415 (69%) patients returned the questionnaire. 16% had used complementary therapies. The most popular were healing, relaxation, visualisation, diets, homoeopathy, vitamins, herbalism, and the Bristol approach. Patients using complementary therapies tended to be younger, of higher social class, and female. Three quarters used two or more therapies. Therapies were mostly used for anticipated antitumour effect. Ill effects of diets and herb treatments were described. Satisfaction with both conventional and complementary therapies was high, although diets often caused difficulties. Patients using complementary therapies were less satisfied with conventional treatments, largely because of side effects and lack of hope of cure. Benefits of complementary therapies were mainly psychological.

CONCLUSIONS

A sizeable percentage of patients receiving conventional treatments for cancer also use complementary therapies. Patient satisfaction with complementary therapies, other than dietary therapies, was high even without the hoped for anticancer effect. Patients reported psychological benefits such as hope and optimism.

Age and development-related changes in osteopontin and nitric oxide synthase mRNA levels in human kidney proximal tubule epithelial cells: contrasting responses to hypoxia and reoxygenation

Osteopontin (OPN) encodes a secreted glycosylated phosphoprotein containing a GRGDS motif that can mediate cell attachment through the alpha v beta 3 integrin, and has recently been shown to down-regulate nitric oxide synthase (NOS) expression. We report here that primary cultures of renal proximal tubule epithelial (PTE) cells prepared from human kidneys of different developmental stages and ages show a positive correlation between developmental age and the expression, at the mRNA level, of both OPN and constitutive NOS. However, OPN and NOS responded in different manners, as assessed by mRNA measurements, to hypoxia-reoxygenation injury. The OPN mRNA level, assessed by Northern blotting, increased slightly during 60 min of hypoxia and more substantially during subsequent reoxygenation of primary PTE cells derived from the kidneys of young but not of aged donors. The abundance of NOS mRNA, measured using a cDNA probe to the constitutive form of the enzyme, was enhanced during hypoxia in kidneys derived from humans of all ages, and then decreased during reoxygenation--possibly as the result of increased OPN expression. PTE cells from aged kidneys are more susceptible to cell death under hypoxic conditions that PTE cells from young kidneys. An investigation of the effect of an oxidant on OPN and NOS mRNA levels revealed that within 30 min of exposure to H2O2, NOS mRNA levels decreased simultaneously with an increase in OPN mRNA levels. Nitric oxide (NO), the product of NOS, is at low levels an important signal transduction molecule participating in the regulation of vascular tone and renal reabsorption; at high levels it is cytotoxic. We suggest that the diminished ability of cells from old kidneys to down-regulate NO production and to increase OPN expression after hypoxia-reoxygenation may contribute to their increased susceptibility to oxidant injury.

Diarrheal morbidity during the first 2 years of life among HIV-infected infants

OBJECTIVE

To determine the incidence, cause, and patterns of diarrhea during the first 2 years of life among infants infected perinatally with the human immunodeficiency virus (HIV).

DESIGN

A cohort study in which infants were enrolled shortly after birth and followed up longitudinally using biweekly surveillance for the occurrence of diarrhea. Stool specimens collected at the onset of diarrhea were evaluated for enteropathogens. Infants who were infected with HIV were compared with uninfected infants.

SUBJECTS

Infants born to HIV-infected women at the University of Maryland Hospital, Baltimore, were recruited at 0 to 3 months of age. This analysis included 58 infants enrolled in the cohort and followed up at least 15 months (unless death intervened) whose HIV status was established (18 HIV-infected infants and 40 HIV-uninfected infants).

MEASUREMENTS AND RESULTS

The overall incidence of diarrhea in HIV-infected infants was 3.2 episodes per 12 child-months compared with 1.5 episodes per 12 child-months among HIV-uninfected infants (incidence density ratio, 2.2; P < .05). An enteropathogen was identified in stool specimens collected during 20% of diarrheal episodes occurring in HIV-infected infants and during 25% of diarrheal episodes occurring in HIV-uninfected infants. Episodes that persisted for 14 days or longer were significantly more common among HIV-infected infants. The peak incidence of diarrhea occurred at 0 to 5 months of age for HIV-infected infants compared with 6 to 11 months for HIV-uninfected infants. Early onset of diarrhea (< 6 months old) in HIV-infected infants was associated with the later development of persistent episodes of diarrhea, and those with persistent episodes had more severe HIV infection, characterized by a significantly higher frequency of opportunistic infections and lower CD4+ T-lymphocyte counts by 1 year of age.

CONCLUSION

Both acute and persistent episodes of diarrhea are major sources of morbidity in HIV-infected infants. Moreover, persistent diarrhea is a marker for rapid progression of HIV disease.

The organic surface of 5145 Pholus: constraints set by scattering theory

No known body in the Solar System has a spectrum redder than that of object 5145 Pholus. We use Hapke scattering theory and optical constants measured in this laboratory to examine the ability of mixtures of a number of organic solids and ices to reproduce the observed spectrum and phase variation. The primary materials considered are poly-HCN, kerogen, Murchison organic extract, Titan tholin, ice tholin, and water ice. In a computer grid search of over 10 million models, we find an intraparticle mixture of 15% Titan tholin, 10% poly-HCN, and 75% water ice with 10-micrometers particles to provide an excellent fit. Replacing water ice with ammonia ice improves the fits significantly while using a pure hydrocarbon tholin, Tholin alpha, instead of Titan tholin makes only modest improvements. All acceptable fits require Titan tholin or some comparable material to provide the steep slope in the visible, and poly-HCN or some comparable material to provide strong absorption in the near-infrared. A pure Titan tholin surface with 16-micrometers particles, as well as all acceptable Pholus models, fit the present spectrophotometric data for the transplutonian object 1992 QB1. The feasibility of gas-phase chemistry to generate material like Titan tholin on such small objects is examined. An irradiated transient atmosphere arising from sublimating ices may generate at most a few centimeters of tholin over the lifetime of the Solar System, but this is insignificant compared to the expected lag deposit of primordial contaminants left behind by the sublimating ice. Irradiation of subsurface N2/CH4 or NH3/CH4 ice by cosmic rays may generate approximately 20 cm of tholin in the upper 10 m of regolith in the same time scale but the identity of this tholin to its gas-phase equivalent has not been demonstrated.

Total hip arthroplasty in cerebral palsy. Long-term follow-up results

Patients with cerebral palsy frequently develop coxarthrosis after acquired hip dislocation or dysplasia. Nineteen total hip arthroplasties (THA) were performed in 18 patients with cerebral palsy and end-stage hip degeneration. The average age at arthroplasty was 30 years (range, 16-52 years). All components were cemented, and four hips required bone graft augmentation of the deficient acetabulum. Spica casts were used in 16 of 18 patients to minimize the incidence of dislocation and trochanteric nonunion. The average follow-up time was ten years (range, three to 17 years). Seventeen of 18 patients (94%) had pain relief and improved function after arthroplasty. One stem loosened at three years, and one acetabular component loosened at 15 years. One stem and one acetabular component were revised for malposition. Survivorship analysis was 95% at ten years for loosening and 86% with removal for any reason. Total hip arthroplasty can provide long-term relief and improved function in cerebral palsy patients with severe coxarthrosis.

Custom-designed femoral prostheses in total hip arthroplasty done with cement for severe dysplasia of the hip

A custom-designed femoral prosthesis was implanted with cement and a standard acetabular component was used to treat nineteen severely dysplastic hips in fourteen consecutively managed patients. Components that had been custom-designed with the use of plain radiography were used because the anatomical reconstructive goals could not be achieved with commercially available implants. These goals were to match the offset of the femoral head and the length of the lower limb with those on the normal side for patients who had unilateral involvement and to provide an average (thirty to forty-millimeter) offset with equal limb lengths for patients who had bilateral involvement. A retrospective clinical and radiographic analysis was performed. The diagnoses included coxa vara (one hip), congenital dislocation (twelve hips), achondroplasia (three hips), and spondyloepiphyseal dysplasia (three hips). The mean age at the time of the reconstruction was forty-nine years (range, twenty-two to seventy-three years), and the mean duration of follow-up was fifty-seven months (range, twenty-seven to 108 months). In five hips, bone-grafting of the acetabulum was needed to obtain superolateral coverage. The clinical result was excellent in eighteen hips and good in one. No revisions have been performed to date. Two femoral components were possibly loose radiographically. One was associated with a definite loosening of the acetabular cup. In addition, one other cup was possibly loose. There was a 100 per cent rate of survival if only a revision procedure was considered as a failure.(ABSTRACT TRUNCATED AT 250 WORDS)

Heterogeneity of osteopontin expression among nephrons in mouse kidneys and enhanced expression in sclerotic glomeruli

BACKGROUND

Osteopontin (OPN) is a secreted Ca(2+)-binding phosphoprotein able to mediate cell attachment to bone via an RGD sequence and the alpha v beta 3 integrin. OPN mRNA is found at high levels in the kidney, and the protein is found in the urine. Because published reports of where the protein is produced conflict, we undertook a comprehensive study to localize OPN expression.

EXPERIMENTAL DESIGN

In situ hybridization with a mouse cDNA probe and immunohistochemical staining with three different antisera to mouse OPN were used to identify those cells that contained significant levels of mRNA and protein, respectively.

RESULTS

Both methods of analysis revealed that OPN expression in the normal mouse kidney was primarily restricted to the thick ascending limbs of the loop of Henle and to the distal convoluted tubules. Protein was detected predominantly at the apical surface of cells lining the lumen of a subset of tubules. The alpha v beta 3 integrin, which is a receptor for vitronectin and osteopontin, was uniformly localized by immunostaining not on the apical surface but rather to the baso-lateral surface of cells in the distal part of the tubule. OPN expression was not detected in healthy glomeruli, proximal tubules, thin limbs of the loop of Henle, collecting ducts, or interstitial fibroblasts. In contrast to the localization of Tamm-Horsfall protein expression, in all distal nephrons, expression of OPN was detected by both methods of analysis in only some nephrons. OPN expression (relative to male mice) was somewhat increased in female, pregnant and lactating mice and markedly increased in the parietal epithelium of glomeruli undergoing sclerosis in aging mice. OPN was also detected in the macula densa.

CONCLUSIONS

OPN is synthesized and secreted into the tubule fluid by the luminal epithelia of the distal portions of a subset of kidney nephrons. As animals age expression is found in more proximal portions of the tubule. OPN may contribute to, or be a consequence of, glomerular sclerosis, and may be an indicator of subclinical injury or infection.

Nutrient intake of Dunedin women during pregnancy

AIM

To assess the adequacy of dietary intake of women during the three trimesters of pregnancy.

METHOD

Dietary intakes of 63 primiparous and 32 multiparous healthy pregnant Dunedin women were obtained by 3 day weighed records at about 12 weeks, 24 weeks, and 36 weeks of gestation. Energy and nutrient intakes were derived using the University of Otago food composition database.

RESULTS

Mean energy and nutrient intakes differed remarkably little between primiparous and multiparous women; data were combined for analysis. Energy intakes at first and second trimesters were similar to that for non pregnant women in the National Heart Foundation 1977 survey but greater than in the LINZ 1989 survey. Energy and carbohydrate intakes had increased at third trimester; across the trimesters carbohydrate accounted for 44-46% energy intake, fat for 39% and protein for 15%. Protein intakes at the 10th centile were almost the same as the recommended low risk intake of 51 g/d set by WHO/FAO: No vitamin or mineral showed a trend in intake through the trimesters. Vitamin and mineral intakes were in general greater for the pregnant women than for nonpregnant women in both 1977 and 1989 studies. By comparison with recommended intakes for NZ, Australia, USA and UK, intakes for folate, vitamin B-6, iron and possibly zinc and thiamin were potentially inadequate. Over 10% were heavy smokers and 20% were light smokers; nutrient intakes were less for the smokers than for the nonsmokers, as were birth weights; energy intakes for smokers had not increased at the third trimester.

CONCLUSION

An improvement in quality of diet is needed during pregnancy and in prenatal period; smoking should continue to be strongly discouraged.

Bicycle safety programs: targeting injury prevention through education

Children especially are prone to bicycle injuries, many of which are preventable. Data from an assessment of pediatric bicycle-related injuries at a major Southeastern Tennessee trauma center were used to support the need for a public awareness program about children's bicycle safety. Results of the assessment are reviewed and program planning, implementation, and evaluation are described.

A putative Wilms tumor-secreted growth factor activity required for primary culture of human nephroblasts

Establishment of cell culture systems for the study of organogenesis during human embryonic development could provide the basis for the study of molecular mechanisms that regulate cellular proliferation and organ morphogenesis. We have developed a cell culture system for undifferentiated mesenchymal cells isolated from the human fetal kidney, which retain the potential for conversion to differentiated epithelia in vitro. Microdissected marginal zone nephroblasts were treated with trypsin and plated on gelatin prior to unlimited serial passage in suspension. An absolute requirement for the indefinite proliferation of these undifferentiated progenitors was nephroblast growth factor (NB-GF), a growth factor activity secreted by a Wilms tumor cell line. The mitogenic effects of NB-GF were not reproduced by previously described growth factors known to be mitogenic for renal cells or by leukemia inhibitory factor. In addition, cultured nephroblasts were shown to retain their ability to differentiate into epithelia when exposed to 10% serum-containing medium in the absence of NB-GF. Immunocytochemical cytoskeletal protein marker analysis showed mutually exclusive staining of vimentin in nephroblasts and cytokeratin in epithelia. These findings suggest that NB-GF may play an important role in the regulation of nephroblast proliferation during renal development and in Wilms tumor biology.

A clinical trial of a slow-release formulation of acetylsalicylic acid in patients at risk for preeclampsia

The formation of thromboxane A2 (TXA2) in maternal and foetal cord serum was measured at birth in eight control patients and in 13 patients taking 100 mg of a slow-release formulation of acetylsalicylic acid. The serum concentrations of TXB2 (a stable end product of TXA2 hydrolysis) in both maternal and cord serum from patients who ingested the acetylsalicylic acid formulation were significantly lower (P < 0.01) than those in control subjects. Acetylsalicylic acid was not detected (< 30 ng ml-1) in maternal plasma from six mothers and in cord plasma from seven foetuses in the acetylsalicylic acid-treated group. The mean cord to maternal plasma concentration ratios for detectable acetylsalicylic acid and salicylate were 0.62 +/- 0.19 (s.d.) (n = 6) and 0.84 +/- 0.16 (n = 13), respectively. We conclude that low doses of acetylsalicylic acid given in a slow-release form to mothers during pregnancy cause depression of TXA2 formation in the foetal blood.

Autocrine, endocrine and paracrine regulation of growth abnormalities in autosomal dominant polycystic kidney disease

Genetic polycystic kidney disease (ADPKD) is an autosomal dominant trait in man, the phenotypic expression of which is characterized by enormous cystic enlargement of renal tubules. Since this is, in part, a result of aberrant epithelial cell proliferation, the nature of this defect has been characterized by comparison of growth factor action on defined epithelial primary monolayer cultures derived from individually microdissected normal human renal proximal and distal tubules and ADPKD cyst-lining epithelia. Mitogenic assays showed an increased sensitivity of ADPKD epithelia to stimulation by the combination of the endocrine factors hydrocortisone (dexamethasone) and insulin, and Northern analysis suggested increased levels of insulin receptor steady state mRNA. The most potent, single mitogen was epidermal growth factor (EGF), and hypersensitivity to EGF in ADPKD epithelia was correlated with increased mRNA levels for EGF receptor in ADPKD kidneys. The localization in vivo of EGF immunoreactivity in ADPKD cyst-lining epithelia and in (apical) cyst fluids and the demonstration of EGF-receptor immunostaining and specific [125I]EGF binding to apical cell surfaces suggested an autocrine mechanism of growth stimulation by EGF in ADPKD epithelia. Transforming growth factor beta was an inhibitor of normal renal tubule proliferation but was unable to completely inhibit EGF stimulation in ADPKD cultures. Platelet-derived growth factor (PDGF) immunoreactivity which was also seen in ADPKD cyst epithelia, was not mitogenic to ADPKD epithelia but did stimulate division in ADPKD fibroblasts in vitro. This suggested a paracrine regulation of the observed fibrosis in ADPKD.

Temporal trends in prevalence of cardiovascular malformations in Maryland and the District of Columbia, 1981-1988. The Baltimore-Washington Infant Study Group

We studied the yearly occurrence of isolated cardiovascular malformations in liveborns for the period 1981-1988 in Maryland and the District of Columbia. We used Poisson regression to fit yearly prevalence at birth as a function of time for all cardiovascular malformation case types combined and for three diagnostic subgroups. We give results separately by diagnostic method and race (white/nonwhite), with categories combined when appropriate. Time trends were similar for both races except in pulmonic stenosis diagnosed by echocardiography. The yearly prevalence for all case types, all races, and all diagnostic methods combined increased from 28 to 43 per 10,000 livebirths over the 8 years, due to an increase in the rate among infants diagnosed by echocardiography. For every diagnostic-type-by-race group studied, there were increases in the prevalence for those diagnosed by echocardiography and decreases (or no change in one group) for those diagnosed by cardiac catheterization and/or surgery. Although there may have been an increase in actual occurrence of cardiovascular malformation over our study period, it is also possible that wider use of a new echocardiography technology resulted in increased detection.

Relationship between locomotor forces, hoof position and joint motion during the support phase of the stride of galloping horses

Three methods were used simultaneously to determine the relationships between the vertical forces exerted on the hooves and the positions of the limbs and hooves at the times of peak vertical forces from 2 horses galloping on a track straightaway. Vertical forces were recorded from an instrumented shoe, fetlock joint motion was measured with an electrogoniometer and the angles of the carpus, fetlock and hoof were determined from slow-motion films. At hoof contact, the mean angles of the carpus and fetlock were 181-182 degrees and 199-206 degrees, respectively. Peak vertical forces on the heel occurred at or near maximum extension of the carpal and fetlock joints. Peak forces on the toe occurred during flexion of the fetlock joint and at mean hoof angles of 28-31 degrees from the horizontal. The mean angles of the hoof from the horizontal at the time of heel contact were 6-7 degrees. Hoof lift occurred at mean carpal angles of 173-174 degrees and mean fetlock angles of 199-200 degrees.

Abnormal extracellular matrix and excessive growth of human adult polycystic kidney disease epithelia

Human autosomal dominant polycystic kidney disease (ADPKD) epithelia were grown in primary monolayer cultures and their properties compared with intact kidney epithelial cultures derived from individually microdissected normal human kidney proximal convoluted tubules (PCT), proximal straight tubules (PST), and cortical collecting tubules (CCT). In vivo, ADPKD cyst epithelia exhibited a thickened basement membrane, and immunofluorescence demonstrated the presence of laminin, fibronectin, type IV collagen, and heparan sulfate proteoglycan in basement membranes and type I collagen in the interstitium. ADPKD epithelia grown in culture synthesized and secreted basally a unique, extracellular matrix that took the form of proteinaceous spheroids when the cells were grown on dried, type I collagen. Incorporation of H2[S35O4] into basement membrane extracts was increased more than ten-fold in ADPKD epithelia by comparison to normal PST and CCT. In addition to incorporation into the normal tubular basement membrane 220 kD band, radioactivity was also seen at 175 kD and 150 kD in ADPKD extracts. Growth in culture of cyst-lining ADPKD epithelia was more rapid than normal tubules, and was abnormal since there was no absolute requirement for added extracellular matrix. However, when ADPKD epithelia were grown on different, exogenous matrix protein components, a profound influence on both structure and epithelial cell proliferation was seen. Growth on a complete basement membrane three-dimensional gel derived from the Engelbreth-Holm-Swarm (EHS) sarcoma led to a reduction in the numbers of spheroids and increase in amorphous filaments. Incorporation of [3H]-thymidine into ADPKD epithelia was greater than into normal PCT, PST, and CCT and was also greatly modified by the type of extracellular matrix components provided. In studies using single matrix components, the strongest proliferative response was seen when ADPKD epithelia were plated on type I collagen greater than type IV collagen greater than fibronectin greater than laminin. These findings suggest that the excessive growth of cyst-lining epithelia may be, at least in part, a result of abnormal basement membrane and extracellular matrix production by ADPKD cells.

Age-associated decrease in vasopressin-induced renal water transport: a role for adenylate cyclase and G protein malfunction

Aging is associated with a decline in renal concentrating ability in response to dehydration-induced arginine vasopressin (AVP) release. To examine target tissue sensitivity, cortical collecting tubules (CCT) were individually microdissected from young (3 months), middle-aged (2-3 years) and old (4-5.5 years) rabbits and subjected to in vitro perfusion analysis and tissue culture of defined epithelial monolayers. Osmotic fluid transport was compared with adenylate cyclase activity and an age-associated decline in both parameters detected in response to increasing doses of AVP. [3H]-AVP binding was unchanged in CCT epithelia of different ages, excluding receptor alterations as the underlying mechanism. Also, hydraulic conductivity measurements of isolated young and old CCT were not significantly different, excluding post-cAMP events as a major mechanism of reduced sensitivity. Effects of cholera toxin and forskolin on hydraulic conductivity and adenylate cyclase activity showed a dramatic decrease in the ability of these compounds to elicit a response in CCT epithelia from old rabbits. It was concluded that alterations in Gs proteins and the catalytic unit of adenylate cyclase-were responsible for the age-associated decline in CCT response to AVP.

Mechanisms of cyclosporine A toxicity in defined cultures of renal tubule epithelia: a role for cysteine proteases

The mechanisms of toxicity of cyclosporine A (CsA) were studied in primary cultures of individually microdissected rabbit and human renal tubules of proximal and distal regions of the nephron. A direct toxic effect of CsA on renal tubule epithelia was demonstrated using nigrosine uptake and LDH release as indicators of cell death. Proximal convoluted tubules (PCT) and proximal straight tubules (PST) were shown to be highly sensitive, while thick ascending limbs of Henle (TAL) were much less sensitive and cortical collecting tubules (CCT) relatively resistant. The effects of CsA were time and dose dependent over the range 50 ng/ml to 100 micrograms/ml. Protection against CsA-induced PST cell death was afforded by reduction in extracellular calcium levels in the media or addition of the calcium entry antagonists: verapamil, nifedipine or diltiazem. In addition, treatment with the cysteine protease inhibitor, E64, attenuated CsA-induced cell damage. A role for the lysosomal cysteine proteases (cathepsins), however, was ruled out on the basis of identical activity levels in all cell types; no beneficial effects of lysosomal enzyme depletion and no evidence of lysosomal rupture prior to death. By contrast, a role for the cytoplasmic, calcium-dependent cysteine protease calpain was suggested since activity levels were significantly higher in PST than CCT cultures and were inducible by CsA.

Albumin escape from microvessels in kidney, heart and skeletal muscle in experimental diabetes mellitus in the anaesthetized rat

Diabetes was induced with streptozotocin in rats weighing about 160 g. These were maintained with age-matched controls for up to 14 months, blood glucose being periodically monitored. Half the diabetic and control rats received the aldose reductase inhibitor, Ponalrestat, in their diet. Distribution of volumes of 131I-albumin (5 min) and 125I-albumin (100 min) were estimated in various tissues at 3 weeks, 6-7 months and 13-14 months of diabetes. The former space was assumed to represent the intravascular plasma space, while the latter was taken to include both the extravascular and intravascular albumin volumes in the kidney. In heart and skeletal muscle, equilibration between the specific activities of extravascular albumin and of plasma albumin was not assumed to be complete at 100 min. In the cortex and medulla of kidney, the extravascular albumin pool increased significantly at 13-14 months of diabetes (for both, P less than 0.01). Significantly increased entry of albumin into the interstitium occurred at 6 months (P less than 0.05) and at 13-14 months (P less than 0.01) in skeletal muscle, and at 13-14 months (P less than 0.05) in heart. The intravascular plasma volumes were not influenced by diabetes and the aldose reductase inhibitor had no effect at any time in either diabetic or control rats. These findings indicate increased movement of plasma albumin into the interstitium in the late phase of diabetes in the heart, skeletal muscle and in the kidney. Enlargement of the interstitial albumin pool is likely to affect the fluid balance between capillary and interstitium and may contribute to the effect of diabetes on the function of these organs.

Varus rotational femoral osteotomies in adults with hip dysplasia

Fifty-six hips in 48 consecutive patients operated on for congenital dysplasia of the hip during the years 1971 through 1986 were evaluated for an average follow-up period of nine years (range, two-21 years). Twenty-three percent of the patients were treated with revision to total hip arthroplasty by the time of follow-up examination. The average time before revision was 8.6 years. All but three of the remaining hips were rated good or excellent (72%). These patients tended to have minimal or no preoperative degenerative joint disease. Complications included one subtrochanteric fracture, two cases of loss of fixation, and one superficial wound infection. The authors conclude that the operation provides predictable, high-quality results in those patients with minimal or no degenerative changes preoperatively. In those patients with mild or moderate degenerative changes, it may forestall the onset of severe symptoms by several years.

The biologic effects of implant materials

The interaction between implant materials and the surrounding biological environment continues to be an area of intense research and clinical interest. This article presents the information presented in a symposium, held during the 36th Annual Meeting of the Orthopaedic Research Society, in which several important issues concerning the biologic effects of implant materials were discussed. These issues included the mechanisms by which implant materials are released to the surrounding tissues and the ways in which these tissues respond to implant materials. The problem of bone loss around cementless implants was discussed as a specific example of a biologic effect resulting in both bone remodelling and endosteal erosion.