Brca1 deficiency results in early embryonic lethality characterized by neuroepithelial abnormalities.

The breast and ovarian cancer susceptibility gene, BRCA1, has been cloned and shown to encode a zinc-finger protein of unknown function. Mutations in BRCA1 account for at least 80% of families with both breast and ovarian cancer, as well as some non-familial sporadic ovarian cancers. The loss of wild-type BRCA1 in tumours of individuals carrying one nonfunctional BRCA1 allele suggests that BRCA1 encodes a tumour suppressor that may inhibit the proliferation of mammary epithelial cells. To examine the role of BRCA1 in normal tissue growth and differentiation, and to generate a potential model for the cancer susceptibility associated with loss of BRCA1 function, we have created a mouse line carrying a mutation in one Brca1 allele. Analysis of mice homozygous for the mutant allele indicate that Brca1 is critical for normal development, as these mice died in utero between 10 and 13 days of gestation (E10-E13). Abnormalities in Brca1-deficient embryos were most evident in the neural tube, with 40% of the embryos presenting with varying degrees of spina bifida and anencephaly. In addition, the neuroepithelium in Brca1-deficient embryos appeared disorganized, with signs of both rapid proliferation and excessive cell death.

Tetraploid wheats: seed protein electrophoretic patterns of the Emmer and Timopheevi groups.

Crude protein extracts were subjected to disk electrophoresis on polyacrylamide gel. The pattern obtained showed a fast and slow series of bands. In the fast series, the eight species of wheat of the Emmer group gave virtually identical eight-band patterns, and the four species of the Timopheevi group gave nearly identical six- or seven-band patterns. The groups consistently differed with respect to four bands. Two of these differences were attributable to the A genome.

Lactate dehydrogenase isozymes in human cardiac transplantation.

Lactate dehydrogenase (LDH) isozyme activities have been followed in 17 human cardiac allografts. A pattern of abnormality associated with cardiac rejection during the first month after operation has been determined: (i) LDH-1 activity is greater than LDH-2 activity; (ii) LDH-1 activity is greater than 35 percent of total LDH activity; and (iii) LDH-1 activity is greater than 100 international units. The LDH-1 abnormality helps to meet the need for an index of cardiac rejection during the early weeks after operation when the electro-cardiogram is least reliable.

Effects of organic matter on the distribution of uranium in soil and plant matrices.

This work studied interactions of uranium with pure organic compounds, such as glutathione, and more complex mixtures, such as humic acid and aqueous plant extracts. High performance liquid chromatography with UV absorption interfaced to inductively coupled plasma mass spectrometry sequential detection was used to detect organouranium complexes in a variety of soils and plant materials, indicating that nearly 100% of the uranium extracted from certain plant tissues was bound to organic ligands. In addition, soil sorption experiments indicated that humic acid generally decreased uranium sorption to soils and promoted subsequent desorption of uranium because of uranium partitioning to the organic phase. These experiments demonstrate that organic compounds influence the mobility and chemistry of uranium in the environment.

First Report of Sclerotinia sclerotiorum Infection on Cuphea.

Species of the genus Cuphea (family Lythraceae) are being developed as potential domestic sources of medium length fatty acids (lauric and capric) for use in industrial lubricants and detergents. During September 2004, patches of dead plants were observed in test plots of Cuphea sp. cv. PSR-23 (1) (Cuphea viscosissima Jacq. × C. lanceolata W.T. Aiton) near Morris, MN and Prosper, ND, approximately 200 km apart. Seed yield in the diseased Morris field was 78 kg/ha compared with 516 kg/ha in nearby, nonaffected fields of the same variety, for an 85% yield reduction. Stems were split open to reveal long, cylindrical sclerotia as much as 8 mm long. Isolations from diseased stem tissue and sclerotia were identified as Sclerotinia sclerotiorum (Lib.) de Bary and produced typical sized sclerotia (4 to 6 mm in diameter) after 7 days growth on potato dextrose agar (PDA). Cuphea PSR-23 plants were grown in the greenhouse in individual pots for 5 weeks and then inoculated. Three inoculation methods were used. For the first method, ascospores of a sunflower isolate of S. sclerotiorum were sprayed onto blooming flowers and foliage at a rate of 5,000 spores per ml. The inoculated plants were kept in a dark, 18°C mist chamber for 48 h and then returned to a greenhouse maintained at 24/20°C, day/night temperatures. All 20 inoculated plants were visibly colonized by Sclerotinia sp. after 3 days, and all plants were dead by 7 days. The second inoculation used the petiole inoculation technique employed by canola researchers (2). The blade from the third leaf was excised and a micropipette tip containing an agar disk of mycelia of the Cuphea isolate was placed over the cut end of the petiole. Five days after inoculation, all 30 inoculated plants were dead, while none of the 10 control plants (using sterile agar disks on the cut petiole) were affected. Isolations were made from diseased plants inoculated by all methods, and S. sclerotiorum colonies were observed on PDA medium with typical sclerotia from 4 to 6 mm in diameter. The third inoculation method tested root infection. S. sclerotiorum was grown on autoclaved proso millet (Panicum miliaceum L.) seed for 7 days, and 5 g of colonized millet seed was placed in a hole 6 cm from the base of a Cuphea plant, with one plant per 3.7 liter pot. Sunflower (Helianthus annuus L.; oilseed hybrid Cargill 270) plants served as inoculated controls. None of the 20 Cuphea plants were infected via soil inoculations compared with 70% of 30 sunflower plants that developed basal stalk rot and wilt within 2 weeks after inoculation. To our knowledge, this is the first report of S. sclerotiorum infection on Cuphea sp., and is believed to be the first report of infection on any genus within the Lythraceae (loosestrife family). With over 100 annual and perennial species in the genus Cuphea, the possibility of Sclerotinia spp. resistance needs to be investigated to further develop this potential oilseed crop. References: (1) S. J. Knapp and J. M. Crane. Crop Sci. 40:299, 2000. (2) J. Zhao et al. Plant Dis. 88:1033, 2004.

Design and selection of DMP 850 and DMP 851: the next generation of cyclic urea HIV protease inhibitors.

BACKGROUND: Recent clinical trials have demonstrated that HIV protease inhibitors are useful in the treatment of AIDS. It is necessary, however, to use HIV protease inhibitors in combination with other antiviral agents to inhibit the development of resistance. The daunting ability of the virus to rapidly generate resistant mutants suggests that there is an ongoing need for new HIV protease inhibitors with superior pharmacokinetic and efficacy profiles. In our attempts to design and select improved cyclic urea HIV protease inhibitors, we have simultaneously optimized potency, resistance profile, protein binding and oral bioavailability. RESULTS: We have discovered that nonsymmetrical cyclic ureas containing a 3-aminoindazole P2 group are potent inhibitors of HIV protease with excellent oral bioavailability. Furthermore, the 3-aminoindazole group forms four hydrogen bonds with the enzyme and imparts a good resistance profile. The nonsymmetrical 3-aminoindazoles DMP 850 and DMP 851 were selected as our next generation of cyclic urea HIV protease inhibitors because they achieve 8 h trough blood levels in dog, with a 10 mg/kg dose, at or above the protein-binding-adjusted IC90 value for the worst single mutant--that containing the Ile84-->Val mutation. CONCLUSIONS: In selecting our next generation of cyclic urea HIV protease inhibitors, we established a rigorous set of criteria designed to maximize chances for a sustained antiviral effect in HIV-infected individuals. As DMP 850 and DMP 851 provide plasma levels of free drug that are sufficient to inhibit wild-type HIV and several mutant forms of HIV, they could show improved ability to decrease viral load for clinically significant time periods. The ultimate success of DMP 850 and DMP 851 in clinical trials might depend on achieving or exceeding the oral bioavailability seen in dog.

First Report of White Mold Caused by Sclerotinia sclerotiorum on Echium (Echium vulgare).

Echium, also known as common viper's bugloss, is a member of the botanical family Boraginaceae. Echium is being evaluated for its potential use as an oilseed crop in North Dakota. In 2003, 40% of echium plants in a field in Cass County were observed showing classical symptoms of infection by Sclerotinia sclerotiorum. Plants in advanced stages of infection were dead. Stems of dead plants peeled off easily when touched and numerous cylindrical, black sclerotia that were 2 to 3 mm in diameter and 4 to 7 mm long were found in the pith. Younger stem lesions were watery soft, many of them with a white cottony growth on them. Sclerotia and infected stem tissues collected from the field were surface disinfested in a 0.5% NaOCl solution for 30 s, rinsed with sterile distilled water, and air dried before plating on potato dextrose agar (PDA). Samples were incubated at room temperature for 1 week. White mycelium and black sclerotia, characteristic of S. sclerotiorum (Lib.) de Bary, were produced in all dishes. Koch's postulates were fulfilled using the petiole inoculation technique (2). Briefly, 4-mm agar plugs containing hyphal tips of a 2-day-old S. sclerotiorum colony growing on PDA were excised and loaded in the wide opening of 100-µl pipette tips. The second true leaf of 15 3-week-old echium seedlings, growing in plastic pots containing Ready-Mix soil, was cut off with a razor blade leaving an approximately 25-mm long petiole attached to the stem. The leafless petioles of 10 seedlings were capped with a loaded pipette, agar plug first, until the petiole tip broke the inner surface of the plug and the petiole came in contact with the mycelium. The other five seedlings were inoculated with agar plugs without mycelium and used as control plants. Three days after inoculation, all seedlings inoculated with S. sclerotiorum wilted and expressed symptoms similar to those observed in the field. None of the control plants showed symptoms of infection. Black sclerotia were retrieved from infected stems 2 weeks after inoculation, and the pathogen was successfully reisolated onto PDA. Several important North Dakota crops are susceptible to S. sclerotiorum. The identification of echium as a new host for S. sclerotiorum should be considered in the event that this crop is promoted as an alternative for North Dakota agriculture. To our knowledge, this is the first report on the susceptibility of echium to S. sclerotiorum. Other members of the Boraginaceae have been identified as hosts for this pathogen (1). References: (1) G. J. Boland and R. Hall. Can. J. Plant Pathol. 16:93, 1994. (2) L. E. del Río et al. (Abstr.) Phytopathology 91 (suppl.):S176, 2001.

First Report of Soft Rot Caused by Sclerotinia sclerotiorum on Borage in North Dakota.

Borage (Borago officinalis) is an oilseed crop that is being evaluated as an alternative crop in North Dakota. During September 2004, borage plants in a field in Cass County, North Dakota were dying from a watery soft rot. The main stems and lateral branches were affected, and affected plants were usually completely lodged and prostrate. Dead plants had bleached and shredded stems with black sclerotia (9.1 ± 3.0 × 2.6 ± 0.5 mm) inside the pith and on the epidermis. At the time of observation, borage plants were flowering and forming pods and seed. Approximately 60% of the plants were visually affected by the watery soft rot. Sclerotia were collected from diseased plants, soaked in a 0.5% NaOCL solution for 30 s, air dried, and placed in petri dishes containing potato dextrose agar (PDA). A fungus grew from the plated sclerotia that subsequently produced white mycelium and black sclerotia (4.8 ± 1.2 × 2.5 ± 1.0 mm), which is characteristic of Sclerotinia sclerotiorum (Lib.) de Bary (3). To confirm pathogenicity, borage plants were inoculated in the greenhouse with a S. sclerotiorum isolate from field-infected borage. Thirteen borage plants were grown from seed in the greenhouse under natural sunlight at a temperature range of 24 ± 3°C. When plants were at the four-leaf stage (approximately 16 cm high), the second leaf was excised from each plant with the petiole remaining on the plant. The leafless petioles were inoculated using a method previously described (2). Petioles of 10 plants were inoculated with PDA containing mycelium of the S. sclerotiorum borage isolate, while petioles of five plants were inoculated with PDA to serve as a control. Three days after inoculation, plants inoculated with the S. sclerotiorum borage isolate were beginning to wilt and 5 days after inoculation, these plants were completely wilted and prostrate, similar to observations made on field-infected plants. Sclerotia collected from the diseased, inoculated plants were placed on PDA, and S. sclerotiorum was successfully recovered. Control plants inoculated with PDA did not show any disease symptoms. Other plant genera in the Boraginaceae are known hosts of S. sclerotiorum (1); however, to our knowledge, this is the first report of borage as a host. References: (1) G. J. Boland and R. Hall, Can. J. Plant Pathol. 16:93, 1994. (2) L. E. del Río et al. (Abstr.) Phytopathology 90(suppl.):S176, 2000. (3) D. L. Tourneau, Phytopathology 69:887, 1979.

Identification of a human RAD52 pseudogene located on chromosome 2.

A human testis cDNA library was screened with a hybridization probe encoding the mouse RAD52 gene. Two classes of clones were identified, one derived from the human RAD52 homolog (hRAD52), the other derived from a pseudogene. In addition to many point mutations, several of which encode stop codons, the pseudogene contains a number of frame shifts and a 103-bp deletion. We further determined that the pseudogene is processed and is located on human chromosome 2, in contrast to hRAD52 which is found on chromosome 12. Reverse transcription-PCR analysis of cultured human diploid fibroblasts, as well as fibrosarcoma cells, revealed that while hRAD52 is expressed at low, but detectable levels in these cells, the pseudogene is not.

Prognostic factors for advanced diffuse histiocytic lymphoma following treatment with combination chemotherapy.

Combination chemotherapy can dramatically improve the survival of those patients with advanced diffuse histiocytic lymphoma who enter complete remission. The age, sex, stage, constitutional symptoms, sites of disease and tumor mass of 56 consecutive patients with advanced diffuse histiocytic lymphoma were analyzed as prognostic factors. Twenty-four patients received cytoxan, vincristine, procarbazine and prednisone (C-MOPP) and 32 patients received bleomycin, adriamycin, cytoxan, vincristine and prednisone (BACOP). In 26 of 56 (46 per cent) a complete remission was achieved, in 21 of 56 (38 per cent) a partial remission and in nine of 56 (16 per cent) no response. Median survival with a complete remission was not reached at three years with 82 per cent still alive, but was significantly greater than with a partial remission (7.6 months median) or no response (3.2 months median). Survival of those with a partial remission and no response did not differ statistically. Stage IV disease, bone marrow involvement, gastrointestinal involvement and a tumor mass greater than 10 cm in diameter in a single location were all poor prognostic factors. No other analyzed factor significantly affected survival in this study. Complete response rates and survival curves for patients treated with C-MOPP were similar to those treated with BACOP.

Treatment of cutaneous granulocytic sarcoma in a patient with myelodysplasia.

In this report, we have presented our experience with a patient with a rare cutaneous granulocytic sarcoma. In addition to hematoxylin and eosin, myeloperoxidase stain and specific stains for lysozyme and esterase were helpful in confirming the histologic diagnosis of granulocytic sarcoma. Despite multiple attempts to control this patient's tumor by conservative surgery, radiation therapy, and chemotherapy, we eventually had to resort to limb amputation. This procedure restored a meaningful quality of life to this patient for one and a half years prior to the development of acute leukemia. Treatment with corticosteroids at the time of surgery may have prevented a local recurrence of granulocytic sarcoma despite positive tissue margins. Our experience underscores the importance of directing treatment toward the granulocytic sarcoma whereas the myelodysplasia concurrently present may not require therapy for several years.

Non-Hodgkin's lymphomas in leukemic phase: clinicopathologic correlations.

A leukemic phase occurred in 30 (14 percent) of 214 patients with non-Hodgkin's lymphoma. To determine the significance of peripheral blood involvement in each type of NHL, patients were subdivided according to a modified Rappaport classification. Each histologic subtype presented a homogeneous clinical picture which differed from that seen in other histologic subtypes. Of particular note was the recognition of two distinctive cytologic and clinical subtypes within the category of nodular lymphoma, poorly differentiated lymphocytic lymphoma (NPDL). In one subtype, the predominant cells had cytologic features akin to those of lymphoblasts. In these cases, although the interval to peripheral blood involvement was variable, the median leukemic survival was only two months. In contrast in conventional NPDL the median leukemic survival was 43+ months, and peripheral blood involvement did not appear to exert an independent effect on prognosis. In diffuse large cell lymphomas the median leukemic survival was 0.5 months, with peripheral blood involvement appearing as a terminal event associated with unresponsive disease in multiple sites. The recognition of adult lymphoblastic lymphoma as a clinicopathologic entity with a high risk of leukemic conversion, 100 percent in this study, is also confirmed.

A model of wound healing in chronically radiation-damaged rat skin.

The aim of this investigation was to develop a model for studying the chronic effects of radiation on wound healing in the rat. Six months after rats received a single radiation exposure of 20 Gy, a random-pattern dorsal skin flap was elevated. Two weeks after the flap was elevated, irradiated animals showed diminished scar formation and wound breaking strength, as compared with controls (P < 0.05). The effect of hyperbaric oxygen treatment was investigated in some rats who received 20 sessions at 2.4 atmospheres absolute for 90 min daily, 5 days per week, prior to flap elevation and 10 sessions after creation of the flap. Treated animals showed a trend toward improvements in wound breaking strength and scar formation (P = 0.06). A reproducible model of chronic radiation damage in the rat was established. Further studies involving investigations at times more that 2 weeks post-wounding are needed.

Environmental epidemiologic issues and minority health.

There exist great differences in morbidity and mortality across racial, cultural, and socioeconomic groups. Certain factors, like limited access to health care, are known to contribute to these differences. The contribution of other factors, like disparities in exposure to environmental hazards, is largely unknown as to the effect on minority groups' morbidity and mortality. This article describes select environmental hazards faced by minorities, such as lead toxicity in children, proximity to hazardous waste sites, and consumption of food contaminated with toxic substances, as well as the role of epidemiologists in documenting adverse health effects and participation in interventions to prevent them.

Kenny-Caffey syndrome and microorchidism.

We report on two adolescent boys with Kenny-Caffey syndrome and microorchidism. The first patient had elevated levels of serum follicle-stimulating hormone, but normal levels of luteinizing hormone and testosterone. There was no evidence of a microdeletion of the Y chromosome. The second patient had Leydig cell hyperplasia with normal seminiferous tubules and spermatogenesis, and normal pituitary histologic findings at autopsy. The presence of microorchidism in these patients confirms the previous observations and suggests subfertility, but does not fully clarify the pathogenesis.

Spindle cell lipoma of the orbit.

A 42-year-old woman had an orbital mass lesion removed surgically that proved histologically to be a spindle cell lipoma. To our knowledge, this is the first reported case of a spindle cell lipoma arising in the orbit. This specific type of lipoma occurs chiefly in male patients and is believed to affect the shoulder and posterior neck regions almost exclusively. Spindle cell lipomas, while having unusual features histologically, are benign and should not be mistaken for liposarcomas or other spindle cell soft-tissue tumors.

Fine-needle aspiration biopsy. Its use in orbital tumors.

Fifteen orbital tumors have been evaluated with the fine-needle aspiration biopsy (FNAB) technique. The best indication for FNAB is supposed malignant orbital disease. The technique has not been helpful in tumors or inflammatory disease with a high fibrous content. Lesions that are suspected of being pseudotumors are not recommended for FNAB since, even in histologic sections, they are notoriously difficult to distinguish from well-differentiated lymphocytic malignant lymphoma. Benign encapsulated tumors should not be subjected to FNAB.

Fuchs' adenoma affecting the peripheral iris.

An elevated, pigmented lesion of the peripheral iris developed in a 73-year-old woman. The lesion was believed to be a malignant melanoma and was excised at the time of routine cataract extraction. Pathologic examination disclosed a Fuchs' adenoma. These lesions are common in the elderly and are almost invariably clinically silent. This case, however, demonstrates that under rare circumstances a Fuchs' adenoma may induce cataractous changes or produce clinical findings that can mimic an iris melanoma.

Ocular findings in Kenny's syndrome.

In 1966, Kenny described two patients with an unusual congenital syndrome including dwarfism, thickened long bone cortex, transient hypocalcemia, and normal intelligence. These and other patients previously were incorrectly described as "myopic". Ocular findings in four subjects ranged from uncomplicated nanophthalmos with hyperopia to extreme pseudopapilledema, vascular tortuosity, and mucular crowding. Postmortem findings from one patient showed calcium deposits demonstrable only by special histochemical stains that were distributed uniquely in the cornea. This distribution differed greatly from the pattern seen in band keratopathy. Retinal calcification was also an unusual feature. Because one patient exhibited a pseudodoubling of the optic papilla, the literature was reviewed. We conclude that no convincing case of true doubling of the optic nerve has been described. Ophthalmologists should be alert for undiagnosed electrolyte abnormalities, especially hypocalcemia, in patients with Kenney's syndrome.

Mycobacterium avium: a pathogen of patients with acquired immunodeficiency syndrome.

Mycobacterium avium complex has been isolated with increasing frequency from humans during the last few decades. Thirteen patients admitted to the UCLA Medical Center with the diagnosis of acquired immunodeficiency syndrome (AIDS), in addition to having Kaposi's sarcoma, Pneumocystis pneumonia, and other opportunistic infections, also had M. avium complex isolated from a variety of tissues and fluids submitted for culture. Of these patients, 10 had histologic and bacteriologic evidence of disseminated mycobacterial infection, and M. avium complex was isolated from the blood of 5. The organisms were isolated from routine bacteriologic and diphasic fungal blood culture bottles. Periodic cultures of sputum, urine, and other body fluids and tissues should be performed for mycobacterial infections in all such patients. Routine blood cultures should be kept for at least 8 weeks to check for the presence of acid-fast bacteria in general and for M. avium complex in particular from all patients with immune deficiencies.