Albinism and agenesis of the corpus callosum with profound developmental delay: Vici syndrome, evidence for autosomal recessive inheritance

We report on two sibs and two other unrelated patients with agenesis of corpus callosum, oculocutaneous albinism, repeated infections, and cardiomyopathy. All manifested postnatal growth retardation, microcephaly, and profound developmental delay. Additional central nervous system anomalies present in at least one patient included hypoplasia of the cerebellar vermis, white matter neuronal heterotopia, or bilateral schizencephaly. Repeated viral, bacterial, and fungal infections were consistent with a primary immunodeficiency. However, immunological studies showed variable, nonspecific findings. Cardiomyopathy with progressive heart failure or infection led to death before age 2 years in three of the patients. This syndrome was first described by Vici et al. [1988: Am. J. Med. Genet. 29:1-8]. The four patients reported herein confirm this unique disorder. Affected sibs of both sexes born to unaffected parents provide evidence for autosomal recessive inheritance.

Initial results and long-term clinical and angiographic implications of coronary stenting in elderly patients

Results of 378 consecutive elderly patients (> or = 65 years) undergoing coronary stenting were compared with those of 601 younger patients. Although the restenosis rate was similar in the 2 groups, age > or = 65 years was an independent predictor of in-hospital mortality (relative risk 5.4, 95% confidence interval 1.2 to 20.1) and follow-up mortality (relative risk 2.8, 95% confidence interval 1.3 to 6.1).

Double stenting as a treatment for stent collapse in the left main coronary artery

We report on a case of double stent implantation in the left main coronary artery due to collapse of the first implanted stent. The case illustrates a complication of stenting presumably dictated by the specific characteristics of left main disease, and the feasibility and good long-term results of double stenting in this situation.

Long-term clinical and echocardiographic follow-up after percutaneous mitral valvuloplasty with the Inoue balloon

BACKGROUND

The objective of this study was to assess the long-term clinical outcome and valvular changes (area and regurgitation) after percutaneous mitral valvuloplasty (PMV).

METHODS AND RESULTS

After PMV, 561 patients were followed up for 39 (+/-23) months and clinical/echocardiographic data obtained yearly. Kaplan-Meier and Cox regression analyses were performed to estimate event-free survival, its predictors, and the relative risks of several patient subgroups. There were several nonexclusive events: 19 (3.3%) cardiac deaths, 55 (9.8%) mitral replacements, 6 (1%) repeated PMVs, 56 (10%) cases of restenosis, and 108 (19%) cases of clinical impairment. Survival free of major events (cardiac death, mitral surgery, repeat PMV, or functional impairment) was 69% at 7 years, ranging from 88% to 40% in different subgroups of patients. Wilkins score was the best preprocedural predictor of mitral opening, but the procedural result (mitral area and regurgitation) was the only independent predictor of major event-free survival. Mitral area loss, though mild [0.13 (+/-0.21)cm2], increased with time and was >/=0.3 cm2 in 12%, 22%, and 27% of patients at 3, 5, and 7 years, respectively. Regurgitation did not progress in 81% of patients, and when it occurred it was usually by 1 grade.

CONCLUSIONS

Seven years after PMV, more than two thirds of patients were in good clinical condition and free of any major event. The procedural result was the main determinant of long-term outcome, although a high score had also negative implications. Mitral area decreased progressively over time, whereas regurgitation did not tend to progress.

Quantitative and ultrastructural changes in glia and pericytes in the parietal cortex of the aging rat

The frequency of astrocytes, microglia plus oligodendrocytes, and pericytes displaying nuclei was analyzed and quantified in 160-microm-wide strips of the parietal cortex (Par1 region) from young and aged Wistar rats. The study was performed on two groups of rats aged 3-4 and 32-36 months. Quantifications of the glial cell types and pericytes were made in 1-microm-thick sections stained with toluidine blue. Ultrathin sections were also made to analyze the ultrastructural features of these cells during aging. Astrocytes and pericytes increased in number by about 20% and 22%, respectively, with age. These increases were most significant in layers II-IV and V for both cellular types. Clusters of astrocytes were common in these layers of aging rats. The ultrastructural analysis also indicated changes in all cell types that stored inclusions and vacuoles with age, which were particularly abundant in microglial cells. End-feet astrocytes and pericytes surrounding the vascular wall also contained vacuoles and inclusions, and consequently the vascular wall increased in thickness. In conclusion, the aging process increased astrocyte and pericyte populations, but not microglia plus oligodendrocyte populations, in the rat parietal cortex. Although no significant change in nuclear size could be observed in any cell type, all glial cells as well as pericytes underwent morphological ultrastructural changes. These modifications may result from the need to correct possible homeostatic imbalances during aging.

Comparison of genomic DNA in various strains of Boophilus microplus (Acari: Ixodidae)

The conventional method of identifying acaricide resistance in a suspect tick population by the United Nations Food and Agriculture Organization packet assay is a laborious and time-consuming process. DNA probes have been demonstrated as rapid and accurate tools for detecting pesticide resistance in insect species. Random-amplified polymorphic DNA (RAPD) has been used by other groups to differentiate species of mosquitoes and populations within a mosquito species. By using different arbitrary oligonucleotides as primers with RAPD, we have demonstrated that various strains of Boophilus microplus (Canestrini) show different patterns of DNA fragments on agarose gel electrophoresis. The unique DNA fragments may be useful for developing probes that can detect acaricide resistance in field pest populations.

Chemotherapy as a part of each treatment fraction in a twice-a-day hyperfractionated schedule: a new chemoradiotherapy approach for advanced head and neck cancer

BACKGROUND

Using chemotherapy as a part of each treatment fraction remains unexplored. This study integrates the concomitant administration of carboplatin with hyperfractionated irradiation by optimizing chemopotentiation through carboplatin administration with each irradiation fraction.

METHODS

From February 1993 to August 1996, 52 patients with advanced head and neck cancer were treated on a twice-a-day chemoradiotherapy schedule. Each fraction consisted of 115 cGy preceded by 5 mg/m2 of carboplatin. Treatment was given 5 days a week up to total doses of 350 mg/m2 of carboplatin + 8050 cGy in 7 weeks.

RESULTS

All (100%) of patients tolerated the treatment (83% as scheduled). Acute and late toxicities were moderate. Rates of 96% complete response (CR) and 4% partial response (PR) were achieved. At 52 months, local control and cause-specific survival rates are 72% and 59%, respectively. Nodal control rate is 95%.

CONCLUSION

These results show potential for improvement upon hyperfractionated radiotherapy alone and compare favorably with those of most reported trials.

Differences in cytotoxicity of native and engineered RIPs can be used to assess their ability to reach the cytoplasm

Ricin is a heterodimeric cytotoxin composed of RTB, a galactose binding lectin, and RTA, an enzymatic N-glycosidase. The toxin is endocytosed, and after intracellular routing, RTA is translocated to the cytoplasm where it inactivates ribosomes resulting in a loss of host cell protein synthesis and cell death. We show for the first time that the cytotoxicity against cultured T cells by several RTA mutants is directly proportional to the enzyme activity of RTA, suggesting this is a reliable system to measure translocation effects. Large discrepancies between cytotoxicity and enzyme action for a given pair of toxins are therefore attributable to differences in cell binding, uptake, or membrane translocation. Fluid phase uptake and cytotoxicity of isolated RTA are essentially identical to that of the single chain toxin PAP. This important finding suggests that RTA, and the A chain of class 2 RIPs in general, has not evolved special translocation signals to complement the increased target cell binding facilitated by RTB. Experiments with the lectin RCA and with ebulin suggest those toxins have diminished cytotoxicity probably mediated by comparative deficiencies in B chain binding. Addition of a KDEL sequence to RTA increases fluid phase uptake, consistent with the notion that transport to the ER is important for cytotoxicity. Fusion of MBP or GST to the amino terminus of RTA has little effect on enzyme action or cytotoxicity. This result is not altered by protease inhibitors, suggesting the fusion proteins are probably not cleaved prior to translocation of the toxic A chain and implying that the toxins can carry large passenger proteins into the cytoplasm, an observation with interesting potential for analytical and therapeutic chemistry.

Bacterial artificial chromosome (BAC) library as a tool for physical mapping of the archaeon Methanosarcina thermophila TM-1

We have used a variety of methods to characterize the genome of the archaeon Methanosarcina thermophila TM-1. Pulsed-field gel analysis indicates a genome size of 2.8 Mb. We have constructed a bacterial artificial chromosome (BAC) library of M. thermophila and have used it to generate physical maps for this organism. The library is made up of 384 clones with an average insert size of 58 kb representing 8.0 genome equivalents. The utility of the library for low-resolution physical mapping was shown by identifying NotI linking clones and using these to order the NotI macrorestriction fragments of M. thermophila into a 2.8 Mb map. Hybridization of nine single copy genes and a 16S rRNA sequence to these macrorestriction fragments forms the basis for the first genetic map in this organism. High-resolution physical maps, consisting of overlapping clones, have been created using HindIII fingerprints of BAC clones. In this way, we identified a minimal path of five clones that span a 270 kb NotI fragment. The ease of manipulating BAC clones makes the BAC system an excellent choice for the construction of low-resolution and high-resolution physical and genetic maps of archaeal genomes. It also provides a substrate for future genome-sequencing efforts.

Actions implemented to improve hypertension control in Spain

Hypertension prevalence is estimated at approximately 30% of the adult population in Spain, using the 140/90 mm Hg cutoff. This represents a heavy public health burden when compared with other European countries, although the direct cost per person is one of the lowest in Europe. The programs implemented regionally since 1985 are presented here. As a result of them, a decade later the number of hypertensives with controlled blood pressure has increased from 10% in 1986 to 13% in 1995, and cerebrovascular mortality has steadily decreased.

Biological characterization and genetic diversity of Mexican isolates of Trypanosoma cruzi

The present work reports the in vitro biological characterization of 17 Trypanosoma cruzi isolates from southern and central México, and compares these results to those of four South American strains and one clone from Brazil. The parameters evaluated were growth rates, percentage of parasites undergoing transformation from epimastigotes to trypomastigotes, infectivity to, and in vitro killing of cultured Vero and P388 cells. Isoenzyme patterns of 11 enzymatic systems and 16 loci were also determined for the Mexican isolates. The parasites showed differences in growth, depending if they were cultured in LIT with hemin or in Grace's media. Transformation was obtained only in Grace's medium and differences were observed between the stocks. Stocks Z10 and Z21 showed the highest percentage of transformation within the Mexican isolates (39 and 41%, respectively). A second group showed percentages of transformation between 15 and 28%. In contrast, the South American strains showed higher rates of transformation (36-65%). Infection of cultured cells by isolates Z10 and H5 was evaluated in both Vero and P388 cells. Differences were observed both in the percentage of infected cells as well as in the number of amastigotes per cell. Differences in the ability to cause in vitro killing of P388 cells were also observed among the isolates. Isoenzyme analysis revealed genetic variation between the isolates, each of them with an unique zymodeme. This genetic analysis revealed, in general, a clustering based on the geographical origin of the isolates. Finally, correlation with clinical symptoms is discussed.

The role of ultrasonography in the diagnosis of pyloric stenosis: a decision analysis

BACKGROUND/PURPOSE

The appropriate role for ultrasonography (US) as a replacement for the upper gastrointestinal series (UGI) in vomiting infants remains undefined. The authors have used decision analysis techniques to determine whether the use of ultrasonography as an initial screen in vomiting infants is cost effective when compared with the UGI as the only study.

METHODS

Two diagnostic strategies were compared: 1) UGI alone and 2) ultrasonography followed by an UGI series in 50% of cases when ultrasonography scan was negative for pyloric stenosis. The test sensitivity (US, 0.9; UGI, 1.0) and test specificity (US, 1.0; UGI, 1.0) and the incidence of pyloric stenosis among vomiting infants presenting to the community pediatrician (0.30) or after a negative examination by an experienced examiner (0.02 to 0.18) were obtained from a review of the literature. The relative charges for ultrasonography and UGI were obtained from a national survey from which the cost ratio of US to UGI was estimated to range from 0.67 to 1.81 with a median of 1.06.

RESULTS

Under these baseline assumptions, UGI only was the preferred strategy. The results of the decision analysis were sensitive to, or dependent on, assumptions made regarding the incidence of pyloric stenosis, the US to UGI cost ratio, the sensitivity of the US, and the proportion of patients that proceed to UGI when the US scan was negative for pyloric stenosis. When at least 50% of patients whose US scan was negative for pyloric stenosis proceeded to a UGI, UGI remained the preferred strategy for all cost ratios examined (0.6 to 1.7). Even when no patients proceeded to UGI, the cost ratio of US to UGI had to be less than 0.7 under the typical incidence (0.30) of pyloric stenosis among vomiting infants presenting to the community pediatrician for US to be cost effective. Finally, only UGI was indicated when an olive was not appreciated by an experienced examiner.

CONCLUSION

Under assumptions that fit most clinically relevant circumstances, the UGI as the initial study is the most cost-effective radiological diagnostic test in the evaluation of the vomiting infant.

Advantage of stents in the most proximal left anterior descending coronary artery

OBJECTIVES

Balloon angioplasty of the proximal left anterior descending artery is associated with a high rate of restenosis. We hypothesized that the significant reduction in restenosis rates demonstrated by stent implantation in the coronary arteries in general would be especially prominent in the most proximal left anterior descending coronary artery.

METHODS

We reviewed 65 consecutive patients in whom stents were placed in the most proximal left anterior descending artery between March 1990 and July 1995 and compared them with 56 consecutive patients with angioplasty. Minimum luminal diameter was measured angiographically before, after, and 6 months after the intervention. We compared the change in minimum luminal diameter and restenosis rate between the patients with stents and the patients with angioplasty to clarify the response of this important artery to these different procedures.

RESULTS

There was 6-month angiographic follow-up of the treated lesion in 99% of the patients. The postprocedure minimum luminal diameter, acute gain, and minimum luminal diameter at follow-up were greater in arteries treated with stents than in those treated with balloons. Of importance, late loss was not significantly different between the two groups after treatment at this site. Thus the restenosis rate after angioplasty was 52% compared with 20% after stent implantation (p < 0.001).

CONCLUSIONS

Stent implantation in the most proximal left anterior descending artery is associated with an even greater reduction in restenosis rate than implantations elsewhere in the coronary arteries. This enhanced reduction in restenosis appears to be due to an unusually large amount of late loss after angioplasty at this site.

Combined trabeculectomy and phacoemulsification: a one-site vs a two-site approach

PURPOSE

To compare the results of combined trabeculectomy and phacoemulsification surgery with intraocular lens implant by means of a one-site vs a two-site approach.

METHODS

Glaucomatous patients with a coexisting cataract were randomly assigned to undergo either a one-site or two-site combined procedure. One-site surgery was performed with a limbus-based conjunctival flap and scleral tunnel at the 12-o'clock position. Two-site surgery was performed with a limbus-based conjunctival flap for the trabeculectomy in the superior nasal quadrant and a temporal clear cornea incision for phacoemulsification. Mitomycin C (0.4 mg/ml for 2 minutes) was applied to the scleral surface at the trabeculectomy site for both approaches. All patients received intraocular lens implants at the time of combined surgery.

RESULTS

Thirty-three eyes of 33 patients were included in this study. Preoperative intraocular pressure and number of glaucoma medications were similar in the two groups. Corrected visual acuity improved similarly in both groups. Intraocular pressure decreased in both groups at last follow-up but was not significantly different (P = .129) between the one-site and two-site groups. At last follow-up, the one-site group required significantly more (P = .030) medications than did the two-site group.

CONCLUSIONS

Combined trabeculectomy and phacoemulsification surgery in which one-site and two-site techniques were used yielded similar improvements in corrected visual acuity and intraocular pressure reduction. However, the one-site group required more medication to maintain intraocular pressure control than did the two-site group.

Enhanced Heavy Metal Tolerance in Two Strains of Photosynthetic Euglena gracilis by Preexposure to Mercury or Cadmium

The effects of different concentrations of Hg, Cd, and Pb on cell growth, oxygen consumption, and production and contents of chlorophyll a and b of Z and B strains of Euglena gracilis was studied. Cell uptake of Cd and Pb was also determined. A greater cell density reached in the presence of Cd2+ correlated with a lower metal uptake capacity in B-strain cells. Cells of Z strain, preexposed to low concentrations of either Hg2+ (1.5 μM) or Cd2+ (50 μM) for several generations showed improved heavy metal tolerance (greater cell density and viability) together with similar metal uptake capacity. Because Cd2+ preadaptation but not Hg2+ pretreatment induced a significant increase in the content of acid-soluble thiols, the data suggest the existence of different mechanisms of heavy metal detoxification in Euglena. The fact that Z-strain cells showed a greater Cd2+ uptake under all the conditions assayed suggests that Z strain would be more suitable for bioremediation of polluted waters.

Heritable genetic alterations in a xeroderma pigmentosum group G/Cockayne syndrome pedigree

A search for genetic alterations within the XPG gene has been conducted on skin and blood cells cultured from a newly characterized xeroderma pigmentosum (XP) patient (XP20BE). This patient is the ninth known case that falls into the extremely rare XP complementation group G. Four genetic markers within the XPG gene (including two polymorphisms) demonstrated the Mendelian distribution of this gene from the parents to the patient and to an unaffected sibling. The patient (XP20BE) inherited a G to T transversion from his father in exon 1 of the XPG gene that resulted in the conversion of a glutamic acid at codon 11 to a termination codon. The patient also inherited an XP-G allele from his mother that produces an unstable or poorly expressed message. The cause of the latter defect is still uncertain. In addition to these alterations, XP20BE cDNA contained an mRNA species with a large splicing defect that encompassed a deletion from exon 1 to exon 14. This splicing defect, however, appears to be a naturally occurring low-frequency event that results from abnormal splicing that occurs between certain conserved non-consensus splicing signals within the human XPG gene.

Angioscopic evaluation of angiographically complex coronary lesions

Coronary angioscopy (CA) provides direct visualization of the endoluminal surface of coronary vessels. The usefulness of CA during coronary angioplasty of angiographically complex lesions remains to be established. This study was designed to determine the value of CA to elucidate the underlying substrate of angiographically complex lesions. Forty-seven consecutive patients with angiographically complex lesions were studied with CA before coronary intervention. Mean age of the group was 59 +/- 9 years; six patients were women. Forty (85%) patients had unstable angina. Complex angiographic lesions included coronary occlusions (n = 23) (14 with Thrombolysis in Myocardial Infarction coronary flow grade 0 and nine with flow grade 1), lesions with intraluminal filling defects suggestive of thrombus or ulceration (n = 8), and lesions that were highly eccentric (n = 16). Items analyzed with CA included red thrombus (lining or protruding) and plaque color (yellow, white, or mixed). In all patients, CA visualized the protruding material causing the angiographic appearance. At this site CA detected red thrombus in 34 (72%) patients (14 protruding, 20 lining) and atherosclerotic plaque in 45 (96%) patients. At the site of the angiographically complex lesion, plaque was classified as predominantly yellow in 24 patients, mixed in 12, and white in nine. The incidence of thrombus on CA was higher for occluded vessels (91%) or lesions with intraluminal filling defects or ulceration (87%) than in eccentric lesions (37%) (p < 0.05). However, plaque coloration was not significantly different among these three angiographic subgroups. Initial procedural success (without stent requirement) was lower in lesions showing protruding thrombus on CA (64% vs 91 %, p < 0.05). Thus most angiographically complex lesions contain thrombus. On CA red thrombus was more frequently identified on occluded vessels and lesions with filling defects or ulceration than in eccentric lesions. Yellow or mixed plaques are common in these patients, suggesting lipid-laden plaques as the underlying pathologic substrate of angiographically complex lesions.

The spatial distribution of human immunoglobulin genes within the nucleus: evidence for gene topography independent of cell type and transcriptional activity

The three-dimensional positioning of immunoglobulin (Ig) genes within the nucleus of human cells was investigated using in situ hybridization and confocal microscopy. The visualization of heavy and light chain genes in B-lymphoid cells showed that the three Ig genes are differentially and nonrandomly distributed in different nuclear subvolumes: the kappa genes were found to be preferentially confined to an outer nuclear volume, whereas the gamma and lambda genes consistently occupied more central positions within the nucleus, the lambda genes being more interior when compared with the gamma genes. The data further show that these overall topographical distributions are independent of gene transcriptional activity and are conserved in different cell types. Although subtle gene movements within those defined topographical regions cannot be excluded by this study, the results indicate that tissue specificity of gene expression is not accompanied by drastic changes in gene nuclear topography, rather suggesting that gene organization within the nucleus may be primarily dependent on structural constraints imposed on the respective chromosomes.

DNA demethylation and pericentromeric rearrangements of chromosome 1

Rearrangements in the vicinity of the centromere of chromosome 1 are over-represented in many types of human cancer and are a characteristic feature of a rare genetic disease called ICF (immunodeficiency, centromeric heterochromatin instability, and facial anomalies). Evidence is presented that implicates DNA hypomethylation in the formation of these pericentromeric chromosomal anomalies. The DNA methylation inhibitors 5-azadeoxycytidine and 5-azacytidine, but not other tested genotoxins, induced the preferential formation of pericentromeric rearrangements of chromosome 1 at a very high frequency in a pro-B-cell line (FLEB14) and at a lower frequency in a mature B-cell line (AHH-1). These abnormal chromosomes appear identical to the diagnostic chromosomal aberrations in the ICF syndrome. A major component of the pericentromeric DNA in chromosome 1, satellite 2, was shown to be hypomethylated in an ICF B-cell line, although DNA from this cell line did not display detectable overall hypomethylation. It is hypothesized that demethylation in certain DNA regions, including in pericentromeric satellite DNA, helps lead to pericentromeric chromosomal rearrangements in lymphocytes from ICF patients and in normal lymphoblastoid cells incubated in vitro with DNA demethylating agents.

Angioscopic characteristics of coronary narrowing in patients with recurrent myocardial ischemia after myocardial infarction

Coronary angioscopy was used to elucidate the underlying substrate of the culprit lesion in 20 patients with postinfarction ischemia and in 19 patients with other types of unstable angina. Plaque characteristics were similar in both groups, but red thrombi and occlusive thrombi were more frequently seen in patients with postinfarction ischemia.

Low intensity physical training in older subjects

BACKGROUND

This study was designed to evaluate the effects of a low intensity general training program (< 50% of heart rate reserve) on physical fitness of healthy older subjects, by comparing maximal and submaximal indices of training response.

METHODS

Twenty-two volunteers over 60 years of age participated in the present study. The sample was randomly divided in an experimental group of 13 older subjects (3 men and 10 women, mean age 63.5 +/- 3 years) while the remaining 9 subjects (3 men and 6 women, mean age 64.2 +/- 4 years) served as inactive control group. After medical screening all participants were evaluated before and after 12 weeks in which the experimental subjects underwent a low intensity training. Each subjects-either inactive or active-performed two treadmill tests at two-days interval, to measure maximal and submaximal responses to exercise, respectively. Heart rate (HR), oxygen uptake (VO2) and pulmonary ventilation (VE) were measured using a telemetric apparatus.

RESULTS

The major finding of the study was the significant improvement in submaximal response to exercise of experimental subjects, expressed by the reduction in HR, VO2 VE while VO2 max did not change.

CONCLUSIONS

Thus, it appears that a low intensity general training similar to that followed in the present study may represent a good means to improve physical fitness in healthy elderly people. Similarly, this study supports the effectiveness of evaluation tests based on submaximal responses to exercise in this population.