A novel plant-induced lysosomal storage disease was observed in goats from a village in Mozambique. Affected animals were ataxic, with head tremors and nystagmus. Because of a lack of suitable feed, the animals consumed an exotic hedge plant growing in the village that was identified as Ipomoea carnea (shrubby morning glory, Convolvulaceae). The toxicosis was reproduced by feeding I. carnea plant material to goats. In acute cases, histologic changes in the brain and spinal cord comprised widespread cytoplasmic vacuolation of neurons and glial cells in association with axonal spheroid formation. Ultrastructurally, cytoplasmic storage vacuoles in neurons were membrane bound and consistent with lysosomes. Cytoplasmic vacuolation was also found in neurons in the submucosal and mesenteric plexuses in the small intestine, in renal tubular epithelial cells, and in macrophage-phagocytic cells in the spleen and lymph nodes in acute cases. Residual alterations in the brain in chronic cases revealed predominantly cerebellar lesions characterized by loss of Purkinje neurons and gliosis of the Purkinje cell layer. Analysis of I. carnea plant material by gas chromatography—mass spectrometry established the presence of the mannosidase inhibitor swainsonine and 2 glycosidase inhibitors, calystegine B₂ and calystegine C₁, consistent with a plant-induced α-mannosidosis in the goats. The described storage disorder is analogous to the lysosomal storage diseases induced by ingestion of locoweeds (Astragalus and Oxytropis) and poison peas (Swainsona).

Human lysosomal acid lipase/cholesteryl ester hydrolase (hLAL) is essential for the intralysosomal metabolism of cholesteryl esters and triglycerides taken up by receptor-mediated endocytosis of lipoprotein particles. The key role of the enzyme in intracellular lipid homeostasis is illustrated by two lysosomal storage diseases inherited as autosomal recessive traits. Wolman disease, associated with deficient hLAL activity, leads to massive intracellular substrate accumulation and is always fatal in early infancy. Cholesteryl ester storage disease (CESD), in contrast, is characterized by very low levels of enzymic activity sufficient to allow survival of the affected patients into adulthood. In order to elucidate the underlying molecular defects in Wolman disease, we have characterized the hLAL gene in two female Wolman patients of German and Turkish origin by SSCP and DNA sequence analysis. Our results demonstrate that the German proband was compound heterozygous for an 8-bp deletion in exon 3 and a 2-bp deletion in exon 4 of the hLAL gene. These frameshift mutations lead to protein truncation at amino acid positions 24 and 116 and to complete loss of hydrolytic activity. The Turkish proband, in contrast, was homozygous for a G1064→T substitution in exon 10 of the hLAL gene which converts the completely conserved glycine (GGG) residue at position 321 of the mature enzyme to tryptophan (TGG). In vitro expression of the hLAL(Gly321→Trp) cDNA construct revealed that the amino acid replacement results in a more than 99% reduction of neutral lipid hydrolysis. The mutations provide new insights into the molecular basis of Wolman disease which is apparently more heterogeneous at the genetic level than cholesteryl ester storage disease.—Lohse, P., S. Maas, P. Lohse, A. C. Sewell, O. P. van Diggelen, and D. Seidel. Molecular defects underlying Wolman disease appear to be more heterogeneous than those resulting in cholesteryl ester storage disease. J. Lipid Res. 1999. 40: 221–228.

Potato, Solanum tuberosum, is the fourth-ranked food crop used to support a growing world population because of cultivar versatility and high complex carbohydrate content. Potatoes can be store for long periods for table and processing markets, but are plagued by storage disease problems. Diseases both in the field and during storage can be limiting factors in sustainable and profitable potato production wherever they are grown. In North America, many diseases caused by fungi are important and require a variety of management practices to reduce them to tolerable economic levels. Such diseases include late blight (Phytophthora infestans), silver scurf (Helminthosporium solani), pink rot (Phytophthora erythroseptica), dry rot (Fusarium sambucinum), verticillium wilt (Verticillium dahliae and Verticillium albo-atrum), black scurf (Rhizoctonia solani), and early blight (Alternaria solani). These diseases have both a field and storage component, and disease management inputs may be necessary throughout the season for disease control. A continuing combination of cultural practices, planting of resistant cultivars, clean seed, crop rotation, and fungicides (plant medicines) are necessary for disease control. This presentation highlights the basics of each disease and, based on disease epidemiology, the current strategies used for control, and strategies underway for future control, including the development of resistant cultivars.

The growth of certain bacterial and fungal contaminations on potatoes under laboratory conditions has been shown to result in the production of volatiles specific to these infections. The presence of specific volatiles could be used as an early warning sign of the presence of a specific disease in stored potatoes. This study was done to ascertain if volatiles could be sampled and detected under commercial potato storage conditions. A simple apparatus was developed to sample air in different storage compartments of a commercial potato storage facility. The apparatus and the procedure enable detection of volatiles under commercial storage conditions. Multiple point sampling and its application in sampling volatiles spatially are discussed.

Zill and Kent mangoes predisposed to anthracnose (Colletotrichum gloeosporioides) infection were exposed to various packline fungicidal treatments either incorporating benomyl or prochloraz. Following the treatment, the fruit were placed in cold-storage at 12.5 deg C for 28 days. After cold-storage, disease incidence and severity as well as various fruit quality attributes were assessed. All of the treatments incorporating prochloraz showed superior anthracnose control directly after cold-storage. On ripening, hot water dip at 50 deg C for 5 minutes, prochloraz added to the hot water bath (180 ml Omega/100 1 H2O), was the only treatment of those evaluated to result in a significant and marked reduction in disease in both cultivars. This treatment increased surface scald and internal reakdown in Zill but not in Kent. In Kent, it increased the ground skin colouration and total soluble solids content. Hot benomyl treatment (5 mins. at 50 deg C, 200 g Benlate/100 1 H2O) was as effective in controlling anthracnose as was hot water treatment alone (5 mins. at 50 deg C)

Silver scurf, caused by Helminthosporium solani, is an economically important postharvest disease of potato tubers. Organic and inorganic salts were evaluated for their ability to suppress silver scurf lesion development and sporulation of H. solani on potato tubers. Tubers were treated immediately after harvest with 0.2-M solutions of potassium sorbate, calcium propionate, sodium bicarbonate, sodium carbonate, ammonium bicarbonate, or water. Tween 20 was added as a surfactant to most treatments. Potassium sorbate (0.1 M), acidified potassium sorbate and calcium propionate treatments (0.2 M), and calcium chloride treatments (0.136 M) were included in additional experiments. Tubers were stored under commercial storage conditions for 4 to 6 months prior to disease evaluation. The extent of disease suppression varied among experiments; however, some treatments consistently reduced disease. Lesion formation on the tuber surface was reduced by 26 to 60% using potassium sorbate (in three of four experiments) compared to water-treated or untreated tubers. Sporulation was suppressed by 0.2 M potassium sorbate (78 to 99% reduction) in all four experiments. Sodium carbonate reduced lesion formation in two experiments and sporulation in three of four experiments. Other treatments inconsistently suppressed lesion formation or sporulation, or did not reduce disease. Addition of Tween or acidification of organic salt solutions did not improve silver scurf suppression in most cases. Potassium sorbate has very low mammalian toxicity and great potential as an innocuous and inexpensive postharvest fungicide for suppression of silver scurf during potato storage.

Sensation and Tommy Atkins mangoes were placed in cool-storage at 12.5 deg C for 28 days 12, 36, 60 or 84 hours after harvest. The fruits were held at 20 deg C prior to and after cool-storage. On fruit ripening after cool-storage, shelf-life and various fruit quality attributes were assessed. In Sensation, pulp penetration pressure, pulp colouration, and total soluble solids content were assessed on fruit placement in cool-storage and one week after the commencement of cool-storage. Shelf-life decreased markedly with the delay in time of fruit placement in cool-storage. In Sensation, ripening rate during the initial period of cool-storage increased with the delay prior to cool-storage. On fruit ripening, the incidence of lenticel damage in Tommy Atkins and Sensation generally increased with the delay prior to cool-storage. The trend was non-significant in Sensation. In this cultivar, taste appeal tended to decrease slightly with the delay prior to cool-stroage. A similar trend was not apparent in Tommy Atkins. In Sensation and Tommy Atkins, differences in ground skin colouration, total soluble solids content, pH, pulp colouration and physiological disorder severity relating to treatment were not apparent. In Sensation, differences relating to treatment in disease, blotch and surface scald were not evident. These disorders did not occur in Tommy Atkins. The present study shows that unduly time delays in placing fruits in cool-storage after harvest can result in fruits in cool-storage after harvest can result in fruit being soft on arrival at ports and distributors overseas.

The aetiology of the disease was refered. The main ochratoxin-producing fungi and the necessary condition for ochratoxinogenesis were also refered. The review was made in order to clarify the most commonly encountered nephrotoxic contaminants in various feeds and foods of animal origin, their contamination levels and their importance in development of mycotoxic nephropathy. The reference was made concerning the chemical structure and physicochemical properties of various ochratoxin-metabolites as well their stability in the storage conditions. The feeds and foods optimized growing of ochratoxinogenic fungi as well most suitable storage conditions were also refered.

Numerous apple varieties have been tested parallel with traditional Jonathan varieties during four years, 1990-1994 on three different geographical areas of Hungary. The picking time took place at three different times in a year: ten days before the probably optimal picking time, at close-to-optimal picking time, and ten days after the optimal picking time. The effect of storage on quality of fruits have been tested in February, March, and April under circumstances of a semi-industrial storage experiment. The results of experience can contribute to answer numerous current, from point of view of practice important topics: • The stochastic relations between various fruit quality parameters at different varieties • The change of fruit — quality during storage • The effect of different picking date on storage losses • The possibilities of storage — loss predicting by the utilization of multiple regression analysis. The most important results of experiences are as follows : • The starch — degradation test and Streiff — index are well applicable for practical purposes to determine the optimal harvest-date. • On base of analysis of various losses and physiological diseases the high importance of mass loss is obvious. In the variety Jonnee the earlier picking date considerably increased the mass loss. The effect of variety on mass loss is rather limited. In the Jonathan varieties the Jonathan spot was a rather important physiological disease. The late picking time increased the frequency of Jonathan - spot. At optimal date of harvest at Jonnee the frequency of Jonathan -spot was lower, than at Jonathan M 41. In the Jonathan M41 and Jonnee the importance of scald was rather limited, but in the Wellspur Delicious and Smoothee this disease occurred relatively frequently. In the Smoothee the earlier picking time considerably increased the probability of scald. • The multiple regression analysis yielded reliable results, fit for prediction of storage losses and diseases on the base of chemical and physical properties, determined at the time of picking.

It is proposed that an important function of leptin is to confine the storage of triglycerides (TG) to the adipocytes, while limiting TG storage in nonadipocytes, thus protecting them from lipotoxicity. The fact that TG content in nonadipocytes normally remains within a narrow range, while that of adipocytes varies enormously with food intake, is consistent with a system of TG homeostasis in normal nonadipocytes. The facts that when leptin receptors are dysfunctional, TG content in nonadipocytes such as islets can increase 100-fold, and that constitutively expressed ectopic hyperleptinemia depletes TG, suggest that leptin controls the homeostatic system for intracellular TG. The fact that the function and viability of nonadipocytes is compromised when their TG content rises above or falls below the normal range suggests that normal homeostasis of their intracellular TG is critical for optimal function and to prevent lipoapoptosis. Thus far, lipotoxic diabetes of fa/fa Zucker diabetic fatty rats is the only proven lipodegenerative disease, but the possibility of lipotoxic disease of skeletal and/or cardiac muscle may require Investigation, as does the possible influence of the intracellular TG content on autoimmune and neoplastic processes.