Simulating development and survival of Aedes vexans (Diptera: Culicidae) preimaginal stages under field conditions

Ecology and population dynamics of Aedes vexans (Meigen), were studied for 3 yr in southern Switzerland. Demographic data were compiled into single and multicohort stage-frequency lifetables that indicated variability in individual developmental times and losses caused by mortality. The structure of life table matrices suggested an analysis using a timevarying distributed delay model with attrition. Field data then were used to construct and validate a simulation model that input the number of 1st instars and output the number of emerging adults. The delay was the time required to complete development and attrition corresponded to mortality. Under optimal food supply, temperature was the most important driving variable. The model was parameterized with data obtained from laboratory experiments and evaluated with field data. Development and survival of preimaginal Ae. vexans were simulated reasonably well under 2 different pool habitats. Addition of a hydrology component to the model would enhance control operations by predicting hatch rates in the field.

[Thrombosis of the ascending aorta--a rare cause for recurrent arterial embolism]

A 41-year-old man suffered 3 episodes of transitory left leg ischemia before he was admitted with right brachial artery embolism. The diagnostic evaluation (i/v DSA, CT Scan) revealed a mass in the ascending aorta which was removed under hypothermic cardiocirculatory arrest. Histologically the mass was shown to be a thrombus adjacent to a arteriosclerotic plaque.

Progressive multifocal leukoencephalopathy in persons infected with human immunodeficiency virus, San Francisco, 1981-1989

Progressive multifocal leukoencephalopathy (PML), a rare neurological disease, has been sporadically reported in persons infected with human immunodeficiency virus (HIV), the causative agent of acquired immune deficiency syndrome (AIDS). From January 1981 through February 1989, in San Francisco, we identified 94 HIV-infected persons with PML, of whom 48 (51%) were pathologically confirmed (as required for AIDS case reporting). These 48 patients were significantly older when diagnosed with AIDS (20% older than 50 years) than patients with AIDS without PML. The remaining 46 (49%) patients, diagnosed clinically and by neuroimaging, did not differ significantly from definitive patients in demographic or survival characteristics after PML diagnosis. We detected antibodies to JC virus, the causative agent of PML, in 9 of 14 (64%) AIDS-related patients with PML, and in 9 of 14 (64%) matched control subjects, suggesting that determination of JC virus antibody status before AIDS diagnosis does not reliably indicate which patients will contract PML. Our study shows that the proportion of patients with AIDS who contracted PML remained stable between 1981 and 1988, but increased in the first 2 months of 1989. Our findings further indicate that PML in HIV-infected patients may be underestimated by as much as 50%.

Use of immunoglobulins in prevention and treatment of infection in critically ill patients: review and critique

The study of the use of standard intravenous immunoglobulin (IVIG) preparations as adjunctive therapy for seriously ill patients is motivated by the need to restore immunoglobulin G depleted because of trauma or surgery and/or by the need to provide patients with specific antibodies to various microorganisms. Whereas no clinical studies have shown that standard IVIG has therapeutic efficacy, some data suggest that its prophylactic use is beneficial. Antisera or IVIG prepared from individuals who are hyperimmunized with the biologically active, highly conserved core portion of the endotoxin of gram-negative bacteria confer variable degrees of protection in animal models and clinical trials. Two clinical trials with use of monoclonal antibodies to core lipopolysaccharide have been completed. Only subsets of patients with gram-negative sepsis were protected by the monoclonal antibodies, but the results of the studies were discrepant in regard to the specific characteristics of patients who benefited from the administration of these antibodies. Further studies will be necessary to establish whether this therapy can be recommended for critically ill patients.

Evidence for molecular subtypes of HIV-associated lymphoma: division into peripheral monoclonal, polyclonal and central nervous system lymphoma

The pathogenesis of the HIV-associated lymphomas is not well understood. In order to begin characterizing this class of lymphoma, we initiated a molecular genetic study of DNA extracted from 31 diagnostic biopsy specimens from patients diagnosed with AIDS-associated non-Hodgkin's lymphoma. Analysis of 25 peripheral lymphomas showed that 14 were monoclonal B-cell processes, while 11 appeared to be of polyclonal origin. Five of the 14 monoclonal lymphomas were found to have rearrangements of the c-myc gene. Epstein-Barr virus (EBV) genomes were found in seven out of 14 monoclonal samples, but only two out of nine polyclonal samples. The six primary central nervous system (CNS) lymphoma samples were more homogeneous than the peripheral samples and all were monoclonal, positive for EBV and lacked detectable c-myc gene rearrangements. This study allows us to subdivide the HIV-associated lymphomas into three major molecular subtypes: (1) monoclonal B-cell process frequently associated with c-myc rearrangement or detectable EBV genomes, (2) polyclonal B-cell process typically without evidence of EBV, and (3) monoclonal primary CNS process associated with EBV genomes and lacking detectable c-myc rearrangement.

Estimation of the quality of irradiated spermatozoa from cockerels using the classical method and zona-free hamster ova

1. The quality of gamma irradiated spermatozoa from cockerels was investigated by measuring motility, oxygen consumption and ability to penetrate zona-free hamster ova. 2. Doses of 750 Gy slightly reduced motility and oxygen consumption; however, irradiated spermatozoa penetrated on average 56% (minimum 33%) of hamster ova. 3. The zona-free hamster ova test may be useful for estimating avian sperm quality.

[Vascular complications in surgery of the hip joint]

The mechanisms of severe vascular injury during surgery of the hip joint are depicted with reference to the authors' own patient series and a review of the literature. Massive arterial hemorrhage is most commonly caused by the tip of a Hohmann retractor. Special care must be given to placement of the proximal retractor directly against the pelvis behind the anterior lip of the acetabulum, and this must be checked with the finger tip. Other mechanisms of injury are: massive venous bleeding can result if a coil of pelvic vein is rolled up with a Kirschner wire; arterial thrombosis can be caused by the polymerization heat of bone cement; or intimal dissection can be caused by pressure of a retractor or loosening of an intimal plaque, resulting in ischemia of the corresponding limb; arterio-arterial embolism can originate from appositional thrombus formation on a chronically weakened arterial wall; false aneurysms may be due to instrumental arterial injury; and arteriovenous fistulae can be caused by a piercing instrument. Laceration of the external iliac or common femoral artery is best treated by interposition of a saphenous vein graft. Angiological examination before and immediately after hip surgery is advocated.

DNA content of spermatozoa in different genetic lines of turkeys

The variability of DNA content in turkey spermatozoa of four different lines and its correlation with body weight and sperm concentration were studied. In lines selected for lower body weight the DNA content was 2.034 and 2.036 pg per spermatozoon. In lines selected for higher body weight the DNA content was 2.267 and 2.370 pg per spermatozoon. Sperm concentration in 1 mm3 of semen, however, was higher in lines with a lower body weight (6.08-6.21 million) in comparison with lines selected for higher body weight (5.46-5.67 million). The correlations between the DNA content and sperm concentration were negative (r ranged from -.457 to -.860).

An attempt at genetic transformation in chickens through cock sperm irradiation

Two experiments were conducted to verify the real possibility for use of the "genetic transformation technique" as described by Pandey and Patchel in chickens in commercial poultry breeding. Multiple recessive and multiple dominant marker stocks were employed, as well as a tester and a donor line. Recipient tester females were first inseminated with dominant donor semen which was irradiated with doses of (60)Co gamma irradiation ranging from 100 to 800 Gy (control group) and 24 h later were reinseminated with unirradiated, normal semen of the recipient strain (experimental group). One "genetic transformed" chicken was found in the first experiment; no genetic transformed event occurred in the second experiment but one embryo was present in the 600 Gy irradiated group with parthenogenetic development capable of giving a live chick. One hundred Gy was observed not to be enough to destroy completely sperm fertilizing ability. An increased frequency of parthenogenetic development was found in all groups after insemination with irradiated semen. There were 11 individuals with developmental abnormalities from the total of 1264 analysed embryos which died after the 18th day of incubation. We concluded that egg transformation is a rare event in domestic fowl and further research for use of this technique in commercial poultry breeding is needed.

The effect of total body gamma-irradiation on mortality, egg production and egg weight of Japanese quails

Male and female Japanese quail 21 weeks old, that were given total body doses of 60Co gamma-rays ranging from 0 to 30 Gy, showed a peak in mortality at 6-8 days post-irradiation. The LD 50/30 was 22.5 Gy, and the LD 90/30 was 26.7 Gy. No differences were evident in mortality between males and females. The reduction in egg production by 30 days post-irradiation was related linearly to the dose, for doses above 6 Gy. The reduction in egg weight (30 days post-irradiation laying period) was also related linearly to the dose.

Methylation of plasmacytoma c-myc genes

The chromosomal translocation associated with many tumors of immunoglobulin-producing cells frequently results in the joining of the immunoglobulin heavy-chain locus and the c-myc oncogene. This translocation of c-myc has profound structural and functional consequences for the oncogene, including loss of the 5' end of the gene and transcriptional deregulation. We report in this communication that translocation results in a new methylation pattern of c-myc. In normal kidney and liver tissue, the c-myc gene is methylated at its 3' end. The translocated gene in plasmacytoma DNA is extensively demethylated. On the other hand, the nonrearranged c-myc gene in plasmacytoma DNA (which is transcriptionally silent) is extensively methylated. In addition, we confirm the nucleotide sequence (with 19 discrepancies out of 1400 bp) 5' to the murine c-myc gene, as reported by Corcoran et al. [Cell 40 (1985) 71-79].

Number of response alternatives and spatial arrangement on a visual discrimination task

Normal children, 30 each from ages 5 and 7 yr., were administered a visual discrimination test through a programmed learning machine. Visual discrimination was defined as a match-to-sample task in which subjects pointed to the geometric form, number, or printed letter of the alphabet that matched the stimulus form. Procedures were designed to eliminate learning variables. Although both age groups performed well, there was a statistically significant difference in the total performance at the two ages. A 3-way analysis of variance showed age, number of response alternatives, and type of stimulus form were significant variables; all interactions were significant. It appeared that the significant variable for the 5-yr.-olds was the type of geometric configuration, while the variable most important for the 7-yr.-olds was the number of response alternatives. Patterns of errors on the most difficult item showed the 5-yr.-olds made errors involving a reversal or rotation of the stimulus figure, while the 7-yr.-olds made errors involving some detail of the stimulus figure.

[HLA-B27 antigen and alkaptonuria]

Study of urinary homogentisic acid and a determinantion of group HLA were carried out for 36 members of a family spread over three generations with three cases of ochronotic rheumatism in the second generation. Alkaptonuria was discovered in seven other subjects, six of them members of the third generation: urinary elimination was poor, less than 0.60 g/24 hours. There is a certain degree of consanguinity in the family studied here and these findings do not therefore rule out a recessive autosomal transmission of the alkaptonuria. They do however lead to the consideration that alkaptonuria may sometimes be found in heterozygotic subjects. A genetic relationship between HLA complex and alkaptonuria can only be claimed with difficulty from this familial study, but the high frequency of B 27 antigen (29 out of 36 members carring it) leaves room for the hypothesis that the B 27 gene, or more precisely a gene associated with the B 27 gene, plays a part in the development of ochronotic rheumatism.