Point prevalence and clinical course of proteinuria in dogs with idiopathic non-erosive immune-mediated polyarthritis

Objectives

To describe the point prevalence and clinical course of proteinuria in dogs diagnosed with idiopathic non‐erosive immune‐mediated polyarthritis.

Materials and Methods

Cases presenting to a single referral centre with a diagnosis of idiopathic non‐erosive immune‐mediated polyarthritis were retrospectively recruited from January 2009 to August 2018. Data including signalment, urinalysis, clinicopathological results, cytology from arthrocentesis, treatment and long‐term follow‐up were analysed. Dogs were defined as: non‐proteinuric (UPC <0.2), borderline proteinuric (UPC 0.2‐0.5) or overtly proteinuric (UPC >0.5).

Results

Fifty‐eight dogs met the inclusion criteria. Twenty‐two dogs were overtly proteinuric (38%), eight dogs were borderline proteinuric (14%) and 28 dogs were non‐proteinuric (48%). Repeated urinalysis was performed in nine of 12 dogs with UPC greater than 2.0. The UPC decreased in all nine dogs, with the UPC decreasing to less than 0.5 in 44% of dogs. A greater than 50% decrease in UPC was noted in 44% of dogs, despite seven of nine (77%) receiving prednisolone as either monotherapy or in conjunction with an adjunctive immunosuppressive medication.

Clinical Significance

Proteinuria was common in this cohort of dogs diagnosed with primary idiopathic non‐erosive immune‐mediated polyarthritis. The use of prednisolone does not appear to be contraindicated in proteinuric dogs with idiopathic non‐erosive immune‐mediated polyarthritis.

Serological markers of gluten sensitivity in Border terriers with gall bladder mucocoeles

OBJECTIVES

To evaluate serological markers of gluten sensitivity in conjunction with cholecystokinin measurement in Border terriers with gall bladder mucocoeles.

MATERIALS AND METHODS

Medical records from two referral hospitals were obtained between 2011 and 2019 to identify Border terriers with gall bladder mucocoeles, non-Border terriers with gall bladder mucocoeles and control Border terriers with non-biliary diseases. Enzyme-linked immunosorbent assays were performed on stored fasted serum samples for anti-gliadin IgG, anti-canine transglutaminase-2-IgA autoantibodies and cholecystokinin. Statistical analysis was performed using the Kruskall-Wallis test to identify differences between the groups.

RESULTS

Fifteen Border terriers with gall bladder mucocoeles, 17 non-Border terriers with gall bladder mucocoeles and 14 control Border terriers with non-biliary diseases were recruited. Median transglutaminase-2-IgA autoantibodies in Border terriers with gall bladder mucocoeles was 0.73 (range: 0.18 to 1.67), which was significantly greater than in control Border terriers at 0.41 (0.07 to 1.14). Median cholecystokinin concentration in Border terriers with gall bladder mucocoeles was 13 pg/mL (6 to 45 pg/mL), which was significantly lower than in control Border terriers at 103 pg/mL (9 to 397 pg/mL). There was no difference in the anti-gliadin IgG between these groups. There was no difference observed in the non-Border terriers with gall bladder mucocoeles with either of the other groups.

CLINICAL SIGNIFICANCE

Reduced cholecystokinin and increased transglutaminase-2-IgA autoantibodies was detected in Border terriers with gall bladder mucocoeles; which is in part homologous to gall bladder disease identified in human coeliac disease. The results suggest an immunological disease with impaired cholecystokinin release may be affecting gall bladder motility and possibly contributing to mucocoele formation in Border terriers.

Infiltrative laryngeal disease in dogs

OBJECTIVES

To describe the clinical features and outcome of neoplastic and inflammatory infiltrative laryngeal disease in dogs.

MATERIALS AND METHODS

Medical records at a single referral centre were retrospectively reviewed for dogs diagnosed with infiltrative laryngeal disease by CT or laryngoscopy.

RESULTS

Fifteen dogs were included, with a median age of 6 years (range 1-14 years). Thirteen dogs were diagnosed with inflammatory disease including granulation tissue (n = 4) and neutrophilic (n = 2), septic neutrophilic (n = 2), eosinophilic (n = 1) lymphocytic/plasmacytic (n = 1) and mixed/unclassified (n = 3) inflammation. One dog was diagnosed with large cell lymphoma and one dog was diagnosed with mast cell tumour. Twelve dogs survived to discharge. Follow-up was available for 10 dogs diagnosed with inflammatory disease. Four had fully recovered (7, 10, 23 and 32 months) and one dog developed acute leukaemia and was euthanased at 2 months. Five dogs had recurrence of clinical signs at 1, 1, 5, 17 and 26 months. The dog with lymphoma was euthanased at 8 months and the dog with mast cell tumour died at 5 months.

CLINICAL SIGNIFICANCE

In this cohort, infiltrative inflammatory lesions of the larynx were more common than neoplastic infiltration. For dogs that survived to discharge, outcome was fair although relapse was common.

Gall bladder mucoceles in Border terriers

Background

Gall bladder mucoceles (GBM) are a leading cause of biliary disease in dogs with several breeds, including the Shetland Sheepdog, American Cocker Spaniel, Chihuahua, Pomeranian, and Miniature Schnauzer apparently predisposed.

Objective

To determine risk factors, clinical features, and response to treatment of GBM in Border terriers (BT).

Animals

Medical records of 99 dogs (including 51 BT) with an ultrasonographic (±histopathologic) diagnosis of GBM from three referral centers in the United Kingdom were collected. A control group of 87 similar‐aged BT with no ultrasonographic evidence of gall bladder disease was selected for comparison.

Method

Retrospective case‐control study. Odds ratios were calculated to establish breed predisposition. Signalment, presence of endocrine disease, clinicopathologic results, and outcome were compared between the BT, other breeds, and control BTs.

Results

The odds of identifying a GBM in a BT in this hospital population was 85 times that of all other breeds (95% confidence interval 56.9‐126.8). BT had similar clinical signs and clinicopathologic changes to other breeds with GBM. There was no evidence that endocrinopathies were associated with GBM in BT.

Clinical Significance

A robust breed predisposition to GBM is established for the BT.

Southern African guidelines on the safe use of pre-exposure prophylaxis in persons at risk of acquiring HIV-1 infection

The Southern African HIV Clinicians Society published its first set of oral pre-exposure prophylaxis (PrEP) guidelines in June 2012 for men who have sex with men (MSM) who are at risk of HIV infection. With the flurry of data that has been generated in PrEP clinical research since the first guideline, it became evident that there was a need to revise and expand the PrEP guidelines with new evidence of safety and efficacy of PrEP in several populations, including MSM, transgender persons, heterosexual men and women, HIV-serodiscordant couples and people who inject drugs. This need is particularly relevant following the World Health Organization (WHO) Consolidated Treatment Guidelines released in September 2015. These guidelines advise that PrEP is a highly effective, safe, biomedical option for HIV prevention that can be incorporated with other combination prevention strategies in Southern Africa, given the high prevalence of HIV in the region. PrEP should be tailored to populations at highest risk of HIV acquisition, whilst further data from studies in the region accrue to guide optimal deployment to realise the greatest impact regionally. PrEP may be used intermittently during periods of perceived HIV acquisition risk, rather than continually and lifelong, as is the case with antiretroviral treatment. Recognition and accurate measurement of potential risk in individuals and populations also warrants discussion, but are not extensively covered in these guidelines.

HIV testing in the critical care setting: views of patients, family members and health providers from urban South Africa

As antiretroviral treatment has led to decreased morbidity, HIV testing policy has increasingly shifted towards routine, provider-initiated approaches. Yet, few studies have examined the acceptability of provider-initiated HIV testing in the intensive, or critical care setting, where knowledge of HIV status is likely to impact on clinical management but explicit consent for testing is difficult to obtain. We conducted qualitative research in an urban hospital and clinic in Johannesburg. In-depth interviews were conducted among HIV testing clients (n = 20), recently discharged critical care patients (n = 13) and family members of critical care patients (n = 14). One focus group discussion was held with health care providers (n = 10). HIV testing in critical care was viewed as acceptable but challenging to implement. An overarching theme of ambivalence emerged from patients and families, who saw HIV testing as a pre-requisite to appropriate clinical care, but were concerned about the quality of its delivery. While providers were aware of the current "no testing without consent" policy, they expressed frustration in cases when testing was in the patient's best interest but consent could not be obtained. Furthermore, providers found it stressful to weigh up patient confidentiality against medical necessity when assessing patients' "best interests". Without specific guidelines, they often developed pragmatic, ad hoc ways to resolve dilemmas around testing in critical care. Our findings suggest that HIV testing guidelines specific to the critical care setting may help providers do their jobs more ethically and transparently. Provider-initiated approaches are likely to be acceptable to patients and may improve clinical outcomes, but training and support in policy implementation and ethical decision-making are essential.

Phenotypic characterisation of canine epileptoid cramping syndrome in the Border terrier

OBJECTIVES

To characterise the phenotype of Border terriers suspected to be affected by canine epileptoid cramping syndrome and to identify possible contributing factors.

METHODS

Owners of Border terriers with suspected canine epileptoid cramping syndrome were invited to complete an online questionnaire. The results of these responses were collated and analysed.

RESULTS

Twenty-nine Border terriers were included. Most affected dogs had their first episode before 3 years of age (range: 0·2 to 7·0 years). The majority of episodes lasted between 2 and 30 minutes (range: 0·5 to 150 minutes). The most frequent observations during the episodes were difficulty in walking (27 of 29), mild tremor (21 of 29) and dystonia (22 of 29). Episodes most frequently affected all four limbs (25 of 29) and the head and neck (21 of 29). Borborygmi were reported during episodes in 11 of 29 dogs. Episodes of vomiting and diarrhoea occurred in 14 of 29, with 50% of these being immediately before or after episodes of canine epileptoid cramping syndrome (7 of 14). Most owners (26 of 29) had changed their dog's diet, with approximately 50% (14 of 26) reporting a subsequent reduction in the frequency of episodes.

CLINICAL SIGNIFICANCE

This study demonstrates similarities in the phenotype of canine epileptoid cramping syndrome to paroxysmal dystonic choreoathetosis, a paroxysmal dyskinesia reported in humans. This disorder appears to be associated with gastrointestinal signs in some dogs and appears at least partially responsive to dietary adjustments.

Is Option B+ the best choice?

This article is reprinted from The Lancet, with permission from Elsevier: Coutsodis A, Goga A, Desmond C, Barron P, Black V, Coovadia H. Is Option B+ the best choice? Lancet 2013;381(9863):269-271. [http://dx/doi.org/10.1016/S0140-6736(12)61807-8] The success of prevention of mother-to-child transmission (PMTCT) programmes (Options A and B) in middle-income countries, together with clinical trial data on antiretroviral (ARV) treatment as prophylaxis, has emboldened UN agencies to aggressively promote lifelong ARVs for PMTCT (Option B+). Unsubstantiated claims submit that Option B+ is cost-effective at population-level, will protect HIV-negative male partners, improve maternal and infant health, and increase ARV coverage. We provide counterfactual arguments about the ethics, medical safety, programme feasibility and economic benefits of Option B+. Option B+ offers no advantage to PMTCT and there are social hazards associated with privileging pregnant woman for treatment over men and non-pregnant women, especially with the absence of data to suggest that discordant relationships are more frequent among pregnant women or that they contribute disproportionately to the horizontal HIV transmission. The benefits and safety of long-term ARVs – including adherence and resistance – in mothers who do not need treatment for their own health, need to be considered, as well as, crucially, health service costs. The assumption that a decrease in efficiency caused by inappropriate targeting is compensated for by lower recruitment costs, is untested. Lives could be saved instead with appropriately targeted interventions. Countries should make individual decisions based on their HIV epidemiology, resources, priorities and local evidence. S Afr J HIV Med 2013;14(1):8-10. DOI:10.7196/SAJHIVMED.898

Tuberculosis prevention in HIV-infected pregnant women in South Africa

The high burden of HIV and tuberculosis (TB) among pregnant women in South Africa contributes to a high maternal mortality rate. Isoniazid preventive therapy (IPT) is recommended for the prevention of active TB in HIV-infected individuals, including pregnant women. However, there are few data regarding IPT use in the latter, with concern regarding the concurrent use of IPT with nevirapine in pregnancy, as both treatments are hepatotoxic. The benefit and safety of IPT in HIV-infected pregnant women has not been established. We recommend a simplification of HIV and TB interventions by providing triple antiretroviral therapy to all HIV-infected pregnant women.

How can we reduce the risk of mother-to-child transmission of HIV during invasive obstetric procedures?

Antenatal invasive obstetric procedures may be diagnostic or therapeutic, and are performed at different stages of pregnancy for various indications. The commonest indication for an invasive procedure during pregnancy is for fetal karyotyping when a chromosomal abnormality or a genetic defect is suspected, either from the couple’s history or from ultrasound assessment of the fetus. Other less common but equally important indications may be diagnostic (fetoscopy, fetal tissue sampling, estimation of fetal haemoglobin) or therapeutic (aspiration of various fetal cavities, fetal blood transfusion and embryo reductions). In a high HIV prevalence setting like South Africa, a significant proportion of pregnant women in need of invasive procedures will be HIV-infected.

Guideline on safer conception in fertile HIV-infected individuals and couples

Ninety years ago the isolation of insulin transformed the lives of people with type 1 diabetes. Now, models based on empirical data estimate that a 25-year-old person with HIV, when appropriately treated with antiretroviral therapy, can expect to enjoy a median survival of 35 years, remarkably similar to that for someone of the same age with type 1 diabetes. It is high time we normalised the lives of people living positively with HIV. This includes the basic human right to conceive and raise children. HIV-positive individuals may be in serodiscordant relationships or in seroconcordant relationships. As health care providers, it is our responsibility to ensure we understand the opportunities and risks of natural conception in these scenarios, so that we can help our patients to make informed decisions about their own lives. Most of all, it is our duty to make family planning in the setting of positive prevention as safe as we can. This includes informed decisions on contraception, adoption, fostering, conception and prevention of mother-to-child transmission. Some months ago a dedicated group of individuals, invited and sponsored by the Southern African HIV Clinicians Society, came together in Cape Town to devise guidance in this area, recognising that there are ideal strategies that may be outside the realm of the resource constraints of the public sector or health programmes in southern Africa. This guideline therefore attempts to provide a range of strategies for various resource settings. It is up to us, the providers, to familiarise ourselves with the merits/benefits and risks of each, and to then engage patients in meaningful discussions. All the above, however, is based on the premise and prerequisite that the subject of family planning is actively raised and frequently discussed in our patient encounters.Please find a link to the update of this guideline: http://sajhivmed.org.za/index.php/hivmed/article/view/399

Incidence of nevirapine-associated hepatitis in an antenatal clinic

OBJECTIVE

To describe the incidence, clinical presentation and management of nevirapine-associated hepatitis among antiretroviral-naïve pregnant women treated with nevirapine-based antiretroviral therapy at a dedicated antenatal antiretroviral clinic.

METHODS

Retrospective analysis of pregnant women initiated on nevirapine-based highly active antiretroviral therapy at a dedicated antenatal antiretroviral clinic between July 2004 and December 2006.

RESULTS

Three hundred and ninety women were included in the analysis. Median age was 29 (interquartile range (IQR) 26-32) years and median pre-treatment CD4 cell counts was 157 (IQR 104-193) cells/microl. Baseline alanine transaminase (ALT) was elevated in 2.8% of women (11/390). After initiation of nevirapine-based ART 8% (31/390) experienced an ALT elevation. Three of these patients developed clinical hepatitis with jaundice (0.8%, 3/390). The mean and median time to clinical presentation was 5 weeks. Hepatitis resolved following discontinuation of ART. Non-nevirapine regimens were initiated following biochemical and symptomatic improvement; symptoms did not recur.

CONCLUSIONS

Among pregnant women, nevirapine-containing ART has a favourable safety profile, with a low incidence of serious hepatic events.

The detection of urethritis pathogens among patients with the male urethritis syndrome, genital ulcer syndrome and HIV voluntary counselling and testing clients: should South Africa's syndromic management approach be revised?

OBJECTIVES

To determine the prevalence of urethritis pathogens amongst male symptomatic urethritis (MUS) patients, genital ulcer (GUS) patients without urethritis symptoms and men requesting HIV testing at a voluntary counselling and testing (VCT) clinic.

METHODS

A prospective study was conducted in Johannesburg, South Africa. Men from the three groups were screened for urethritis pathogens using molecular tests. Culture for Neisseria gonorrhoeae and, initially, trichomoniasis was performed. Antimicrobial susceptibility testing was undertaken for ciprofloxacin on all gonococcal isolates; ciprofloxacin resistant isolates were screened for ceftriaxone resistance.

RESULTS

664 participants were recruited (438 MUS, 76 GUS and 158 VCT) over 2 years. Gonorrhoea was detected in 62.3% MUS, 15.8% GUS and 3.2% VCT participants. Chlamydial infection was detected in 19.3% MUS, 13.2% GUS and 8.2% VCT participants. Trichomoniasis was detected in 4.9% MUS, 19.7% GUS and 3.8% VCT participants. Mycoplasma genitalium infection was detected in 14.4% MUS, 13.2% GUS and 7.0% VCT participants. Ciprofloxacin resistance increased from 13.0% in the first year to 26.3% in the second year; all resistant isolates were susceptible to ceftriaxone.

CONCLUSIONS

Urethritis pathogens, including Trichomonas vaginalis, should be covered in syndromic management treatment of genital ulcers in the absence of clinical urethritis. Consideration should be given to adding metronidazole to existing MUS treatment. Ciprofloxacin can no longer be relied upon to treat presumptive gonococcal infections in South Africa.

Adrenal androgen excess in the polycystic ovary syndrome: sensitivity and responsivity of the hypothalamic-pituitary-adrenal axis

Over 50% of patients with the polycystic ovary syndrome (PCOS) demonstrate excess levels of adrenal androgens (AAs), particularly dehydroepiandrosterone sulfate (DHS). Nonetheless, the mechanism for the AA excess remains unclear. It has been noted that in PCOS the pituitary and ovarian responses to their respective trophic factors (i.e. GnRH and LH, respectively) are exaggerated. Similarly, we have postulated that excess AAs in PCOS arises from dysfunction of the hypothalamic-pituitary-adrenal axis, due to 1) exaggerated pituitary secretion of ACTH in response to hypothalamic CRH, 2) excess sensitivity/responsivity of AAs to ACTH stimulation, or 3) both. To test this hypothesis we studied 12 PCOS patients with AA excess (HI-DHS; DHS, > 8.1 mumol/L or 3000 ng/mL), 12 PCOS patients without AA excess (LO-DHS; DHS, < 7.5 mumol/L or 2750 ng/mL), and 11 controls (normal subjects). Each subject underwent an acute 90-min ovine CRH stimulation test (1 microgram/kg) and an 8-h incremental i.v. stimulation with ACTH-(1-24) at doses ranging from 20-2880 ng/1.5 m2.h) with a final bolus of 0.25 mg. All patient groups had similar mean body mass indexes and ages, and both tests were performed in the morning during the follicular phase (days 3-10) of the same menstrual cycle, separated by 48-96 h. During the acute ovine CRH stimulation test, no significant differences in the net maximal response (i.e. change from baseline to peak level) for ACTH, dehydroepiandrosterone (DHA), androstenedione (A4), or cortisol (F) or for the DHA/ACTH, A4/ACTH, or F/ACTH ratios was observed. Nonetheless, the net response of DHA/F and the areas under the curve (AUCs) for DHA and DHA/F indicated a greater response for HI-DHS vs. LO-DHS or normal subjects. The AUC for A4 and A4/F and the delta A4/delta F ratio (delta = net maximum change) indicated that HI-DHS and LO-DHS had similar responses, which were greater than that of the normal subjects, although the difference between LO-DHS patients and normal subjects reached significance only for the AUC of the A4 response. No difference in the sensitivity (i.e. threshold or minimal stimulatory dose) to ACTH was noted between the groups for any of the steroids measured. Nonetheless, the average dose of ACTH-(1-24) required for a threshold response was higher for DHA than for F and A4 in all groups. No difference in mean responsivity (slope of response to incremental ACTH stimulation) was observed for DHA and F between study groups, whereas the responsivity of A4 was higher in HI-DHS patients than in normal or LO-DHS women. The net maximal and the overall (i.e. AUC) responses of DHA were greater for HI-DHS than for normal or LO-DHS women. The response of A4 and the delta A4/delta F ratio were greater for HI-DHS patients than for LO-DHS patients or normal subjects. Alternatively, HI-DHS and LO-DHS patients had similar overall responses (i.e. AUC) for A4 or A4/F, although both were greater than those of normal subjects. The relative differences in response to incremental ACTH stimulation between steroids was consistent for all subject groups studied, i.e. A4 > F or DHA. In conclusion, our data suggest that AA excess in PCOS patients is related to an exaggerated secretory response of the adrenal cortex for DHA and A4, but not to an altered pituitary responsivity to CRH or to increased sensitivity of these AAs to ACTH stimulation. Whether the increased responsivity to ACTH for these steroids is secondary to increased zonae reticularis mass or to differences in P450c17 alpha activity, particularly of the delta 4 pathway, remains to be determined.

Maternal nursing behaviour and the delivery of milk to the neonatal spontaneously hypertensive rat

Fostering spontaneously hypertensive rat (SHR) pups to Wistar-Kyoto (WKY) dams permanently lowers their adult blood pressure. SHR dams show increased nursing behaviour and the SHR pup displays an exaggerated pressor response to milk ingestion. We have therefore measured pup feeding rates and dam milk secretion rates in SHR and WKY dams nursing natural and foster litters. Maternal behaviour displayed by SHR and WKY dams nursing natural or foster litters and the milk delivery rate to non-fasted pups were measured over postnatal days 1-21. Total milk yield by SHR and WKY dams at postnatal day 6 was measured by comparing the relative weights of milk filled and empty mammary tissue. Fostering SHR pups to WKY dams significantly lowered their mean arterial blood pressure compared with naturally reared SHR pups. SHR dams nursing their natural litters spent more time nursing and less time away from their litters than WKY dams. This difference in behaviour was reduced when dams nursed pups of the opposite strain. SHR dams delivered less milk compared with WKY dams, regardless of pup strain. Total milk yield by SHR dams was significantly lower than that of WKY dams at postnatal day 6, despite comparable mammary tissue mass, suggesting that milk intake by the SHR pup is limited by milk availability, rather than an attenuated maternal response to pup suckling stimuli. The antihypertensive effect of fostering SHR pups to WKY dams may therefore reflect an increase in milk intake during a critical period of growth and development.

Modelling acidification at Beacon Hill-a low rainfall, high pollutant deposition site in Central England

The model MAGIC (Model of Acidification of Groundwater In Catchments) has been applied to the Beacon Hill site, near Loughborough in Central England. This site is heavily impacted by wet and dry deposition of oxides of sulphur and nitrogen. The high acid inputs have caused soil acidification and acid stream waters. Long term simulations suggest that there has been a major decline in alkalinity and pH over the past 50 years. Despite recent reductions in deposition levels, soils and streams are predicted to continue to acidify in the future. For this heavily impacted site, deposition must be reduced by 80-90% to reverse the acidification trend and allow recovery of soil and stream waters.

Mechanism of the antiproteinuric effect of indomethacin in nephrotic humans

To elucidate the mechanisms by which indomethacin lowers proteinuria, we studied 20 patients with the nephrotic syndrome. We performed differential macromolecule clearances before and after 3 days of therapy (150 mg/24 h). The fractional clearances of albumin and immunoglobulin G (IgG) decreased by 42 +/- 7 and 44 +/- 10%, respectively (P less than 0.05). Separation of IgG into fractions by preparative electrofocusing in eight selected individuals revealed a proportionate reduction of fractional clearances among anionic (pI = 5.0), neutral (pI = 7.5), and cationic species (pI = 8.5) of IgG. Indomethacin elevated the fractional clearance of uncharged dextrans of radius 28-44 A, while depressing those of dextrans of radius 50-60 A. A heteroporous model that depicts the major portion of the glomerular capillary wall as an isoporous membrane (pore radius = 56 A) and the minor portion as a nondiscriminatory shunt, revealed the former to be unchanged and the latter to be less prominent following indomethacin. A lower fraction of total filtrate volume permeating the shunt, together with a concomitant lowering of overall glomerular filtration rate by 24%, reduced the absolute rate of flux of macromolecule-rich fluid through the shunt pathway from 0.40 to 0.25 ml.min-1.73(-2) (P less than 0.01). We conclude that indomethacin lowered the filtered protein load by restoring barrier size-selectivity while reducing the rate of glomerular ultrafiltration.

Zellweger syndrome amniocytes: morphological appearance and a simple sedimentation method for prenatal diagnosis

Zellweger syndrome is the prototype of a growing group of genetic diseases caused by an absence or deficiency of peroxisomes. The defect causes the enzyme catalase to remain in the cytosol instead of being packaged into peroxisomes. This mislocalization can be easily detected by sedimentation analysis. Amniocytes were homogenized and then centrifuged to pellet organelles. Catalase was found to sediment with the peroxisomes in the homogenates of normal cells, but to remain in the supernatant with Zellweger syndrome amniocyte homogenates. This striking difference is unambiguous and reproducible, and provides a simple method for prenatal diagnosis. Moreover, it allows one to differentiate diseases in which peroxisomes are deficient from other peroxisomal diseases in which the organelle is intact, but one enzyme is defective. Electron microscopic observations support the biochemical determinations. Normal amniocytes contain small peroxisomes in which a weak cytochemical reaction for catalase may be demonstrated. Zellweger amniocytes appear to lack these organelles, although some cells have rare structures that might be residual or abnormal peroxisomes.

Development of stereological analysis software for the calculation of volume, number and surface density

COSAS, an acronym for COmputerized Stereological Analysis System, is software designed to facilitate the process of quantitative morphological analysis. It is a flexible, reliable, and easy to use software system which provides the biologist with a simple means for performing stereological analysis. It provides for estimation of volume and surface density and allows for direct calculation of diameter information from planimetric data. The latter capability is unique to COSAS and provides the ability to calculate longest and shortest diameters for convex profiles, enabling calculation of number density. Access to all intermediate calculations is possible, so the process of transformation of raw data into the stereological descriptors can be completely exposed. This serves two purposes: (1) it provides a means for tracing results; (2) the intermediate values can be utilized independently. This system was used to analyze peroxisomes in tissues from patients with Zellweger's disease and neonatal-onset adrenoleukodystrophy. The system was also used to facilitate an immunocytochemical analysis of cytochrome P450 topology in the endoplasmic reticulum membrane.

Nonimmune hydrops fetalis in Noonan's syndrome

Nonimmune hydrops fetalis has been reported to be associated with congenital malformations. We describe two newborns with Noonan's syndrome who presented with nonimmune hydrops fetalis that was most likely secondary to a generalized lymphatic vessel dysplasia. Other manifestations of lymphatic abnormalities in Noonan's syndrome, such as pedal edema and pulmonary and intestinal lymphangiectasis, have been observed in children. Nonimmune hydrops represents one end of the spectrum of abnormalities seen in this syndrome.

Zellweger syndrome: biochemical and morphological studies on two patients treated with clofibrate

Two infants with Zellweger syndrome (cerebro-hepato-renal syndrome) have been studied biochemically and morphologically. Peroxisomal enzymes involved in respiration, fatty acid beta-oxidation, and plasmalogen biosynthesis were assessed. In liver, catalase was present in normal amounts but was located in the cell cytosol. Dihydroxyacetone phosphate acyltransferase activity was less than one-tenth of normal. The amount of the bifunctional protein catalyzing two beta-oxidation reactions was found by immunoblotting to be greatly reduced. Catalase activity was normal in intestine. D-Amino acid oxidase was subnormal in kidney. The observed enzyme deficiencies may plausibly explain many of the metabolite imbalances observed clinically. Morphologically, peroxisomes were absent from liver. In intestine, normal peroxisomes were also missing, but some rare, smaller (0.04-0.13 micrometer) bodies were seen with a slight positive cytochemical reaction for catalase. These results, together with current concepts of peroxisome biogenesis, suggest but do not prove, that the primary defect in Zellweger syndrome may be in peroxisome assembly. The infants were treated with clofibrate, but it was ineffectual as assessed biochemically, morphologically, and clinically.