Epilenticular intraocular lens implantation in traumatic cataract with a ruptured posterior capsule

PURPOSE: To present a case of rapidly progressing traumatic cataract caused by posterior capsule rupture after nonpenetrating ocular injury, as well as a surgical procedure to safely implant the intraocular lens in such a traumatized eye. METHODS: In a 23-year-old man with traumatic cataract and posterior lens capsule rupture, a one-piece polymethylmethacrylate IOL was implanted before cataract extraction into the ciliary sulcus in front of the cataractous lens. Subsequently, the cataract was removed by pars plana lensectomy. RESULTS: The surgery and postoperative course were uneventful. Postoperative visual acuity was 20/20. CONCLUSION: We present a method of intraocular lens implantation in cases of rapidly progressing traumatic cataract caused by posterior capsule rupture after a blunt ocular trauma.     

Myotonic dystrophy and cardiac disorders

Myotonic dystrophy (MD) is a multisystem disease affecting numerous organs and systems. Cardiac involvement is frequent. Sudden death, due to fatal cardiac rhythm and conduction disturbances occurs in 30% of patients with MD. The aim of this study was to assess the possibilities and methods of early detection of myocardial and conduction system disturbances. ECG, 24-hr Holter monitoring, echocardiography and electrophysiologic studies of the conduction system (electrophysiologic study) were carried out in 45 patients. Analysis of late ventricular potentials was done in 36 patients. Genetic studies revealed multiplication of CTG triplets in all patients. Cardiological abnormalities were detected in 89% of our patients. Disturbances of intraventricular conduction with prolongation of HV interval were most frequent (72%). Electrophysiologic study was the most sensitive method for detecting heart involvement in MD (positive findings in 87% patients). Abnormal findings were also discovered by Holter monitoring (64%), ECG (58%), analysis of late ventricular potentials (55%) and by echocardiography in 46% patients. The results of this study indicate a high rate of cardiac involvement in MD.     

Retroviral gene transfer of dominant negative raf-1 mutants suppresses ha-ras-induced transformation and delays tumor formation

Activating mutants of ras are among the most frequently found genetic alterations in human cancers. Therefore, Ras appears to be an attractive target for therapeutic intervention using gene transfer. The protein kinase Raf-1 acts as a direct downstream effector of Ras and is involved in Ras-induced cellular transformation. Using the NIH3T3 fibroblast-derived tumor cell line PEJ, which expresses oncogenic Ha-rasG12V, we analyzed whether dominant negative mutants of Raf-1 can inhibit Ras-mediated transformation. Retroviral gene transfer was used to stably transduce PEJ cells with three different dominant negative mutants of Raf-1. This resulted in reversion of the transformed phenotype in vitro as evidenced by an increase in contact inhibition and reduced anchorage-independent growth. However, tumor formation in nude mice was significantly delayed only by one of these mutants. Therefore, dominant negative mutants of the oncoprotein Myc, which is known to synergize with Raf-1 in tumor formation, were transduced into PEJ cells expressing a dominant negative Raf mutant. This leads to killing of the cells. These results indicate that although interference with Ras-induced transformation using dominant negative mutants of Raf is feasible and effective in vitro using retroviral vectors, an additional block (e.g., that of Myc) is necessary to kill PEJ cells. These results also indicate that interference with Ras-dependent signaling is not sufficient for inhibition of tumor formation of PEJ cells in vivo.     

Induction of long-lasting cytokine effect by injection of IL-12 encoding plasmid DNA

We have recently demonstrated that DNA coding for both subunits of the murine IL-12 heterodimer exhibits a strong antimetastatic effect against B16-melanoma in C57BL/6 mice and after intratumoral injection tumor regression. Here we show that the antimetastatic effect can be detected when the DNA is injected intramuscularly 30 days before tumor cell challenge. A long-term IL-12 expression was measured for up to 50 days in the serum with a peak at day 20 amounting to about 10 ng/mL in C57BL/6 mice. CpG oligodeoxynucleotides also induce IL-12 expression, however, only for a few hours. IL-12 DNA administration induces long-lasting systemic IFN -gamma production, whereas IL-4 and TNF-alpha levels remained undetectable. NK cell-depleted mice showed a strong but reduced expression of murine IL-12. Expression of DNA encoding human instead of murine IL-12 resulted in a significantly lower and transient expression, indicating that not plasmid-derived IL-12 production alone but the immune system of the host contributes to the long- lasting antimetastatic effect. It may be attributable to an autocrine feedback mechanism maintaining murine IL- 12 expression, whereby several cell populations including NK cells are involved.     

Possible impact of plasma RNase activity on immune dysfunction in juvenile diabetes mellitus

AIM: The ribonuclease (RNase) family represents important enzymes used widely in biomedical and biotechnological applications, as well as for diagnostic and therapeutic purposes. This study was undertaken to test the possibility that plasma alkaline RNase (free or inhibitory bound) determination may be useful in studying the dysregulation of nucleic acid and oligonucleotide metabolism as a possible pathogenetic mechanism in development of immune dysfunction in juvenile diabetes mellitus. PATIENTS AND METHODS: Children with type 1 diabetes (n=32, age group of 5--14 yr), together with age-matched control subjects (n=35), were enrolled in the study. None had microvascular complications. According to the metabolic regulation of the disease and the hemoglobin A1c (HbA1c) level, all patients were divided into two groups (HbA1c<7.5% and HbA1c>7.5%). According to the duration of diabetes, diabetic children were divided into two groups: duration of diabetes less than 1 yr and duration of diabetes greater than 1 yr. The control group consisted of age-matched subjects (n=35; 15 girls and 20 boys) who were clinically healthy. The activity of free and inhibitory-bound RNase and the level of acid soluble nucleotides were measured in heparinized plasma. RESULTS: The inhibitory-bound enzyme activity was higher in diabetic children, followed by sharply decreased free enzyme, especially in the group with the level of HbA1c above 7.5%. Recent-onset diabetic patients had lower free RNase activity compared with those with longer duration of the disease. The amount of pre-existing acid-soluble oligonucleotides was significantly increased in diabetic children, especially in those with poor metabolic control. CONCLUSION: Our observed preliminary results may suggest a hypothesis that a persistent increase of oligonucleotide fragments, most probably due to insufficient RNase activity, may lead to T-cell hyperactivity in type 1 diabetes through the activation of toll-like receptors (TLRs). The measurement of RNase(s) activity (free, inhibitory-bound, or specific toward different substrates), together with the well-known immunobiochemical parameters of diabetes, may help further efforts in identifying a disease-specific early biological marker of immunity dysfunction in juvenile diabetes.     

Heterotopic pregnancy: successful management with aspiration of cornual/interstitial gestational sac and instillation of small dose of methotrexate

OBJECTIVES: Terminating a corneal pregnancy without jeopardizing a coexistent intrauterine pregnancy. METHODS: A 29-year-old woman with a 4-year history of primary infertility became pregnant after in-vitro fertilization and embryo transfer. A heterotopic pregnancy with a left cornual and intrauterine sacs was confirmed by early transvaginal scan examinations. The ectopic sac was aspirated under ultrasound guidance followed by local injection of 12.5 mg methotrexate. This was followed by serial ultrasound scans and serum betahCG assays. RESULTS: The fetal pole in the ectopic pregnancy disappeared following the procedure. She had no significant vaginal bleeding or any other unusual symptoms. The intrauterine pregnancy progressed satisfactorily until spontaneous onset of labour and vacuum extraction delivery at 39 weeks. The baby weighed 2.9 kg. CONCLUSIONS: Local injection of low-dose methotrexate following aspiration of a cornual pregnancy proved effective in halting the ectopic trophoblasts' growth without adversely affecting a coexistent intrauterine pregnancy. The injected ectopic trophoblasts resolved quickly despite the small dose of methotrexate used. This technique avoided a more costly surgical treatment with its associated risks in subsequent pregnancies.     

Rates of nucleotide substitution,mutation at a locus,and the "beanbag" gene number in man

We estimated the number of different human genes by relating the patterns of spontaneous mutation at the population and individual level. A geometric distribution model of mutation was used in which the average rates of nucleotide replacement (P) and mutation at a locus (p), obtained by experiment, were used to determine the estimate of the physical size of the coding genome (n) in man. The probabilistic relation used, P = (1 −p) ⁿ⁻¹ p, integrates two different referential time scales of mutation, that of a nucleotide and year and that of a coding gene and generation. The estimates of n, for different values of P and p, are compatible with the experimentally determined genome sizes. The size of the coding portion of the genome appears to be evolutionarily constrained by an interplay between the rate of nucleotide replacement and the pattern of mutation at the level of the individual locus. The evolution of the size of the coding genome may be more dependent on the number of generations than on time. Received: October 26, 2001 / Accepted: January 16, 2002     

Electronic Estimations of Renal Function Are Inaccurate in Solid-Organ Transplant Recipients and Can Result in Significant Underdosing of Prophylactic Valganciclovir

In a prospective study of solid-organ transplant recipients (n = 22; 15 hepatic and 7 renal) receiving valganciclovir for cytomegalovirus (CMV) prophylaxis, electronic estimation of glomerular filtration rate (eGFR) underestimated the true GFR (24-h urine creatinine clearance) by >20% in 14/22 (63.6%). Its use was associated with inappropriate underdosing of valganciclovir, while the Cockroft-Gault equation was accurate in 21/22 patients (95.4%). Subtherapeutic ganciclovir levels (≤0.6 mg/liter) were common, occurring in 10/22 patients (45.4%); 7 had severely deficient levels (<0.3 mg/liter).