A comparison of the health status of Riverdale residents with residents of the rest of Toronto based on the Toronto Community Health Survey

OBJECTIVES

To compare the health status of Riverdale residents with residents of the rest of Toronto.

DESIGN

Cross-sectional telephone survey.

SETTING

Toronto. TIME FRAME: October 1988-June 1989.

PARTICIPANTS

Four hundred and fourteen residents of Riverdale, a residential-industrial area of Toronto, and 866 residents of the rest of Toronto, age 15 years and older in households with telephones.

MAIN RESULTS

Respondents in Riverdale compared to respondents in the rest of Toronto were more likely to speak languages other than English, have less formal education, and be of Oriental ethnic origin. Perceived health status varied between the two areas, but no significant difference existed in diagnosed morbidity. Riverdale respondents were much more aware of food and soil contamination than respondents from the rest of Toronto.

Glomerulocystic kidney disease--nosological considerations

Glomerulocystic kidneys can be categorized into three major groups: (1) glomerulocystic kidney disease, comprising nonsyndromal heritable and sporadic forms of severely cystic kidneys in children and adults, (2) glomerulocystic kidneys in heritable malformation syndromes, and (3) glomerular cysts in dysplastic kidneys. The first category includes diffusely glomerulocystic kidneys in newborns and young children, many of whom have family histories positive for classical polycystic kidney disease. No differences between familial and sporadic cases have been identified, apart from the family histories. The sporadic cases are conceivably new mutations of the same disease. The first category also includes sporadic and familial disease in older children and adults. The inheritance in adult familial disease, as in childhood familial disease, has been dominant. An apparently distinct entity is hypoplastic glomerulocystic kidney disease, a dominant reported in only a few families. These kidneys, apart from being glomerulocystic, are small, and imaging studies show abnormal pyelocaliceal anatomy. The second category includes glomerulocystic kidneys as major components of heritable syndromes such as tuberous sclerosis, orofaciodigital syndrome, brachymesomelia-renal syndrome, trisomy 13, and the short rib-polydactyly syndromes. The category also includes glomerular cysts in several syndromes, namely Jeune syndrome and familial juvenile nephronophthisis, better known for chronic progressive tubulointerstitial disease. Glomerular cysts occur as a minor component, i.e., scattered cortical cysts, in several other syndromes, among them Zellweger's, in which the cysts are typically present and are usually inconsequential, only occasionally serious enough to affect renal function. In all of these syndromes, the cysts are inconsistently expressed.(ABSTRACT TRUNCATED AT 250 WORDS)

Renal cystic disease in the tuberous sclerosis complex

Renal cysts are relatively common in tuberous sclerosis, occasionally causing severe cystic disease with renal failure. Although the imaging features and gross appearances resemble dominant polycystic kidney disease, the histopathological appearances are distinctive, perhaps unique, differing from appearances in other forms of renal cystic disease. The cysts are lined with hypertrophic and hyperplastic cells that probably cause the cysts by obstructing lumina. The renal abnormality may be inherent in tuberous sclerosis, although inconstantly expressed. Renal enlargement is sometimes the first recognized expression of tuberous sclerosis, and the occurrence of renal cysts in a child with seizures and developmental retardation leads to a strong suspicion of the diagnosis.

Hyperechoic kidneys in the newborn and young infant

Increased echogenicity of the kidney in the newborn has many causes, some of which reflect serious renal disease. The major abnormal imaging pattern is the large, diffusely hyperechoic kidney with abnormal architecture. Its differential diagnosis includes recessive and dominant polycystic kidney disease (PKD), glomerulocystic kidney disease, and diffuse cystic dysplasia. The family history and ultrasonic screening of the parents and siblings are essential in the evaluation. The identification of associated nonrenal abnormalities is important to the recognition of syndromal cystic disease. Glomerulocystic kidney disease, which comprises sporadic and syndromal forms, appears similar to dominant PKD. While renal biopsy almost always differentiates recessive from dominant PKD, renal biopsy cannot differentiate among the forms of glomerulocystic kidney disease, except in the case of tuberous sclerosis, which has unique histopathological characteristics. Other causes of the enlarged hyperechoic kidneys with abnormal architecture include renal vein thrombosis and congenital nephrotic syndrome. A second pattern is the hyperechoic small kidney with abnormal architecture. Many of these kidneys are dysplastic and associated with urinary tract obstruction. The combination of hyperechoic parenchyma and pyelocaliceal dilatation suggests obstructive cystic dysplasia. Cortical and medullary necrosis in the newborn also causes hyperechogenicity in small kidneys. A third pattern contains those kidneys with medullary hyperechogenicity, the most common cause of which in the newborn is nephrocalcinosis associated with furosemide therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Laparoscopy explosion hazards with nitrous oxide

BACKGROUND

During laparoscopic surgery utilizing carbon dioxide as the insufflating agent, nitrous oxide will diffuse into the peritoneal cavity if it is used as part of the anesthetic. Bowel perforation and the subsequent release of volatile bowel gas could create a explosion hazard.

METHODS

Two related studies were undertaken. The first quantified the transfer of nitrous oxide, over time, in 19 female patients undergoing laparoscopy. The second established the lower limits of flammability of a range of concentrations of methane and hydrogen diluted with nitrogen (simulated bowel gas) in a range of concentrations of nitrous oxide diluted with carbon dioxide (simulated peritoneal gas).

RESULTS

The mean concentrations of N2O at 10, 20, and 30 min from the time of insufflation were 19.9 +/- 4.8%, 30.3 +/- 6.8%, and 36.1 +/- 6.9%, respectively. The maximum reported concentrations of methane and hydrogen in bowel gas are 56% and 69%, respectively. The concentration of nitrous oxide necessary to support combustion of 56% methane is approximately 47%. By contrast, the concentration of nitrous oxide needed to support combustion of 69% hydrogen is approximately 29%.

CONCLUSIONS

The authors have shown that it is possible for nitrous oxide to reach concentrations in the peritoneal cavity that can support combustion of bowel gas.

Phenylketonuria: variable phenotypic outcomes of the R261Q mutation and maternal PKU in the offspring of a healthy homozygote

Phenylketonuria (PKU) and benign hyperphenylalaninaemia (HPA) result from a variety of mutations in the gene for the hepatic enzyme phenylalanine hydroxylase. PKU has been found in the Israeli population in two variants, classical and atypical. The two are clinically indistinguishable and require treatment with low phenylalanine diet to prevent mental retardation, but show differences in serum phenylalanine levels and in tolerance to this amino acid. Maternal PKU is a syndrome of congenital anomalies and mental retardation that appears in offspring of PKU mothers as a result of fetal exposure to the high phenylalanine level in the maternal blood. We studied a family in which two children with severe, classical PKU and their unaffected brother showed mild signs of maternal PKU. Their mother had no clinical signs of PKU, but the phenylalanine concentration in her serum reached a level that usually characterises PKU patients. This woman represents a rare phenotype, benign atypical PKU. Such 'hidden' PKU in women may lead to maternal PKU in the offspring, similar to overt PKU. Special attention should therefore be paid to women having children with any of the clinical hallmarks of maternal PKU, and to children born to women known to have benign HPA. The mother was also found to be homozygous for a missense mutation at the phenylalanine hydroxylase locus, R261Q, which does not abolish enzymatic activity completely. In two other families, homozygosity for this mutation resulted in atypical PKU in four children. This observation suggests that mutations that do not completely destroy phenylalanine hydroxylase activity may exhibit variable phenotypic expression which is unpredictable. Compound heterozygosity for R261Q and other mutations led in other patients either to classical PKU or to mild benign HPA.

Age-period-cohort modelling of large-bowel-cancer incidence by anatomic sub-site and sex in Connecticut

In order to investigate etiologic distinctions among the anatomic sub-sites of the large bowel by sex, the relationship between large-bowel-cancer incidence and age at diagnosis, time period at diagnosis, and birth cohort was analyzed by anatomic sub-site and by sex, using data from the Connecticut Tumor Registry. Included in the study were all incident large-bowel-cancer cases occurring between 1950 and 1984 among Connecticut residents aged 40 to 79. Cancers of the large bowel were classified into 5 anatomic sub-sites: ascending colon (including cecum), transverse colon (including flexures), descending colon, sigmoid colon, and rectum (including rectosigmoid junction, anal canal, and anus). The data were fitted to log-linear age-period-cohort models. For each of the sub-sites, the age-period-cohort patterns for males and females differed. Within each sex, sub-site groupings with common patterns were indicated. Among males, the age-period-cohort patterns for the colon sub-sites were fairly similar; but the pattern for the rectum differed markedly from that for the colon sub-sites. There were secondary differences among the colon sub-sites that pointed to a secondary distinction between the right and the left colons. Among females, the age-period-cohort patterns for the left colon sub-sites and the rectum were fairly similar. The pattern for the transverse colon differed moderately from that of the left colon, and differed substantially from that of the rectum and the ascending colon. The ascending colon differed markedly from each of the other sub-sites. It is possible that these differences in age-period-cohort patterns reflect etiologic distinctions among sub-site groupings and between the sexes.

Irreproducibility of the activity and chronicity indices limits their utility in the management of lupus nephritis. Lupus Nephritis Collaborative Study Group

Histological indices of renal pathology in lupus nephritis have been proposed as prognostic signs and as a method to quantitate therapeutic response. We tested the reproducibility of the activity (AI) and chronicity indices (CI) in the renal biopsies from 83 patients with lupus nephritis, enrolled in a controlled therapeutic trial. The AI/CI were calculated separately by four renal pathologists using published criteria. Pair-wise Spearman's rank correlation coefficient was used to examine the relationship among the scores of the four raters, and their degree of reproducibility was evaluated using the coefficient of reliability. The mean CI scores ranged from 2.84 to 4.61, and the mean AI ranged from 9.64 to 12.89. The correlation among the different pathologist's scores ranged from 0.44 to 0.63 for the AI and 0.60 to 0.76 for the CI. One pathologist (M.M.S.) rated the biopsies twice, and the correlation between the two ratings was 0.58 for the AI and 0.74 for the CI. Thus, the AI and CI calculated by different pathologists and the temporally separate observations of a single observer were only moderately correlated. The reproducibility of a single rating was low, showing a reliability coefficient of 0.48 for the AI and 0.57 for the CI. The low reliability coefficient suggests that the variability among pathologists was the result of interpretative differences. We conclude that the AI/CI are too subjective to be used as therapeutic guides or as prognosticators.

Antibodies against a 30 kilodalton cochlear protein and type II and IX collagens in the serum of patients with inner ear diseases

Collagen molecules are major extracellular matrix proteins involved in the development and support of delicate auditory sensory organs. Type II collagen is widely distributed within inner ear tissues, while type IX is found only within the labyrinthine membrane and dense fibers of the tectorial membrane. Antibody specific for type II collagen has been shown to be elevated in some patients with hearing loss due to several presumably autoimmune illnesses (including Meniere's disease, otosclerosis, chronic progressive sensorineural hearing loss, and relapsing polychondritis). Purified human type II and IX collagens and an extract of human cochlear tissue were subjected to isolation by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and transferred to nitrocellulose. The sera of 21 patients with inner ear disease were examined for the presence of anticollagen and anticochlear antibodies; the sera were used to probe Western blots of purified human collagens II, IX, and XI, and cochlear protein extract with peroxidase-conjugated goat anti human polyvalent immunoglobulin as the second antibody. Anti-type II collagen antibodies were seen in 12 of 21 (57%) patients, while 13 of 21 (62%) had anti-type IX antibodies detectable by Western blot. A previously unreported 30 kd (probably noncollagen) protein was 21 (62%) had anti-type IX antibodies detectable by Western blot. A previously unreported 30 kd (probably noncollagen) protein was found by SDS-PAGE of human cochlear tissue extracts, with 3 patients, all with Meniere's disease, having antibody activity to this protein detected by Western blot.(ABSTRACT TRUNCATED AT 250 WORDS)

Renal cortical and renal medullary necrosis in the first 3 months of life

Renal cortical necrosis, renal medullary necrosis, and combined renal cortical-medullary necrosis result from renal ischemia without vascular occlusion. Renal hypoperfusion and ischemic injury in infants have been ascribed to massive blood loss, hemolytic disease, septicemia, and severe hypoxemia. In a postmortem study we identified 82 cases among 1,638 autopsies during the 20 years between 1970 and 1989 in infants 3 months old or less at the time of death. The frequency of renal necrosis in autopsy cases increased significantly during the last 6 years of the study. The distribution of the renal lesion was cortical in 28, medullary in 23, and combined in 31. Forty infants carried diagnoses of congenital heart disease, 17 of asphyxial shock, 9 of sepsis, 3 of infectious myocarditis, 9 of major malformations, 4 of anemic shock, 1 of vascular malformation, and 1 of gastroenteritis and dehydration. A significantly higher proportion of babies with congenital heart disease had cortical involvement. Comparison of clinical characteristics revealed a significantly higher frequency of prematurity, respiratory distress syndrome, bleeding diathesis, and possibly sepsis in the children with congenital heart disease, suggesting that these factors are important in the pathogenesis of the renal lesion. Fourteen infants underwent cardiac catheterization; there was no demonstrable association between the renal lesions and the use of radiographic contrast medium. We conclude that severe congenital heart disease itself is a risk factor for life-threatening renal cortical and medullary necrosis.

Intraglomerular pressure and mesangial stretching stimulate extracellular matrix formation in the rat

To define the interplay of glomerular hypertension and hypertrophy with mesangial extracellular matrix (ECM) deposition, we examined the effects of glomerular capillary distention and mesangial cell stretching on ECM synthesis. The volume of microdissected rat glomeruli (Vg), perfused ex vivo at increasing flows, was quantified and related to the proximal intraglomerular pressure (PIP). Glomerular compliance, expressed as the slope of the positive linear relationship between PIP and Vg was 7.68 x 10(3) microns 3/mmHg. Total Vg increment (PIP 0-150 mmHg) was 1.162 x 10(6) microns 3 or 61% (n = 13). A 16% increase in Vg was obtained over the PIP range equivalent to the pathophysiological limits of mean transcapillary pressure difference. A similar effect of renal perfusion on Vg was also noted histologically in tissue from kidneys perfused/fixed in vivo. Cultured mesangial cells undergoing cyclic stretching increased their synthesis of protein, total collagen, and key components of ECM (collagen IV, collagen I, laminin, fibronectin). Synthetic rates were stimulated by cell growth and the degree of stretching. These results suggest that capillary expansion and stretching of mesangial cells by glomerular hypertension provokes increased ECM production which is accentuated by cell growth and glomerular hypertrophy. Mesangial expansion and glomerulosclerosis might result from this interplay of mechanical and metabolic forces.

Morphological characteristics of segmental renal scarring in vesicoureteral reflux

We examined 25 complete and partial nephrectomy specimens from 21 patients with advanced reflux nephropathy, all of which showed severe renal atrophy and loss of parenchyma. All specimens that included nonatrophic or partially atrophic renal tissue contained small medullary scars that involved only portions of the medullary pyramids. These sublobar medullary scars, which appeared linear and were typically discrete, extended from the inner medulla to the cortex. They obliterated collecting ducts, vasa recta and recurrent loops. The cortical portions of the scars contained remnants of nephrons and variable infiltrates of chronic inflammatory cells with lymphoid follicles. Seven of the specimens also contained acute disruptive ductal lesions with histopathological features characteristic of intrarenal reflux. We believe that the linear scars are the result of single duct medullary disruptions, mediated perhaps through obstruction of the several thousand nephrons subtended by each papillary duct and perhaps through localized disruption of the renal microvasculature. These sublobar scars accumulate as scarring progresses to end stage renal atrophy.

Role of pathology indices in the management of severe lupus glomerulonephritis. Lupus Nephritis Collaborative Study Group

The principal value of the renal biopsy in patients with SLE is as a therapeutic guide. Although semiquantitative indices of nephron loss (chronicity = CI) and acute potentially reversible inflammation (activity = AI) are reported by some to have separate values from traditional classifications of glomerular pathology as predictors of outcome and therapeutic guides, this point remains controversial. We have tested the predictive value of the AI and CI in a large group of patients with severe lupus glomerulonephritis (SLE GN) and a mean follow-up of 281 weeks +/- 116 (mean +/- SD). A total of 86 patients entered into the study of plasmapheresis in severe SLE GN by the Lupus Nephritis Collaborative Study Group, and long-term follow-up was available in 83. The predictive value of the AI and the CI was described over the entire range of cut-off points by the method of receiver operator characteristics (ROC). ROC analysis demonstrated that there was no level of either AI or CI that predicted the outcome of death or renal failure with sufficient sensitivity and specificity to be useful in the individual patient. The CI signifies renal damage and nephron loss, whereas the AI describes potentially reversible pathology. Neither the CI nor the AI taken by itself predicts individual outcomes of renal failure or death in patients with aggressively treated SLE GN. Since the indices fail to identify the patient whose disease will progress to renal failure, they are both insufficient as therapeutic guides and add little to the management of the patient with severe SLE GN.

The influence of inhibitory afferents on the development of postsynaptic dendritic arbors

The growth and maintenance of dendritic form is dependent on normally functioning excitatory afferents. We have now examined the development of dendritic arbors in the gerbil lateral superior olive (LSO), following contralateral cochlear removal at postnatal day 7, a manipulation that substantially eliminates driven inhibitory transmission. Previous studies have demonstrated that the morphology of LSO dendritic arbors varies with tonotopic position and becomes more restricted with age. The presumed decrease of inhibitory transmission in the contralateral LSO resulted in a hypertrophic response. Quantification of Golgi-impregnated neurons revealed that dendrites had a significantly greater number of branch points, and their arbors were more spread out along the frequency axis compared to normal. This was especially apparent in the high frequency projection region where the glycine receptor density is known to be 4-fold higher than in the low frequency projection region. A measure of LSO nucleus size, cross-sectional area, was identical to control values, indicating no overt signs of degenerative phenomena. Cochlear ablation resulted in a significant atrophy of the ipsilateral LSO, with significant effects on dendritic structure. We conclude that decreased inhibitory transmission during development does not lead to a net degenerative response. Rather, the postsynaptic neurons exhibit a hypertrophic phenotype that may be due to the persistence of an immature state. These results indicate that activity-dependent morphogenetic events are a consequence of both excitatory and inhibitory synaptic transmission.

Heat-resistant variants of the Chinese hamster ovary cell: alteration of cellular structure and expression of vimentin

Three heat-resistant mutant cell lines (78-1, 78-2, 78-3) were previously selected from Chinese hamster ovary cells. In this study, we investigated whether the differences in intrinsic thermal sensitivity result from alteration of stress protein levels or cellular structural changes. Although there was no significant difference in the levels of stress proteins, i.e., constitutive HSP70 in wild type and three heat-resistant mutant strains, there were marked differences in the amounts of vimentin among the cell lines. Two-dimensional gel electrophoresis and Western blot showed a 2.3-2.9-fold increase in the level of vimentin in the mutant cells under normal growth conditions. Northern blot also revealed higher amounts of vimentin mRNA in the mutant cells. Electron microscopy and immunofluorescence suggest that increased amounts of the vimentin-containing intermediate filaments are correlated with the heat-resistant phenotypes.

Treatment of mesangiocapillary glomerulonephritis with alternate-day prednisone--a report of the International Study of Kidney Disease in Children

It has been claimed that long-term prednisone treatment ameliorates the course of children with mesangiocapillary glomerulonephritis (MCGN). The International Study of Kidney Disease in Children conducted a randomized, double-blinded, placebo-controlled clinical trial in 80 children with idiopathic MCGN, including 42 patients with type I disease, 14 with type II disease, 17 with type III disease, and 7 with nontypable disease. Criteria for admission included heavy proteinuria and a glomerular filtration rate of greater than or equal to 70 ml/min per 1.73 m2. Prednisone or lactose, 40 mg/m2, was given every other day as a single morning dose. The mean duration of treatment was 41 months, renal failure being the most common reason for termination of therapy. Treatment failure was defined as an increase from baseline of 30% or more in serum creatinine, or more than 35 mumol/l. Overall, treatment failure occurred in 55% of patients treated with lactose, compared with 40% in the prednisone group. Life-table analysis showed a renal survival rate (i.e., stable renal function) at 130 months of 61% among patients receiving prednisone and 12% among patients receiving lactose (P = 0.07). Of patients with type I or III MCGN, 33% treated with prednisone were treatment failures, compared with 58% in the lactose group. Long-term treatment with prednisone appears to improve the outcome of children with MCGN.

A defective splice site at the phenylalanine hydroxylase gene in phenylketonuria and benign hyperphenylalaninemia among Palestinian Arabs

Phenylketonuria (PKU) and benign hyperphenylalaninemia (HPA) result from different combinations of mutations at the locus for phenylalanine hydroxylase (PAH). While some of these mutations show widespread ethnic distribution, others are unique to specific communities. We report here the first point mutation common among Palestinian Arabs. The mutation (IVS2nt1) involves a dinucleotide substitution (Gg-->Aa) at the donor splice site of intron 2 of the PAH gene and abolishes a recognition site of the restriction enzyme MnlI. IVS2nt1 is associated with two PAH polymorphic haplotypes, 7 and 42. Homozygotes for this mutation are affected with severe, classical PKU. Compound heterozygotes carrying the IVS2nt1 allele and one of several other yet unknown mutations show different degrees of benign HPA.