[Trauma-induced arterial aneurysm in childhood. Report of a case and review of the literature]

We report a case of calloso-marginal artery aneurysm in a 3 year old child, revealed 3 weeks after a craniocerebral trauma with frontal embarrure, by a sudden subarachnoidal hemorrhage syndrome with loss of consciousness and coma. The CT scan confirmed the subarachnoid hemorrhage in all the basal cisterns, with an interhemispheric subdural hematoma. The carotid angiography showed a right calloso-marginal aneurysm. The child has been operated (coagulation of the artery and excision of the false aneurysm. We studied the mechanism of pediatric post-traumatic aneurysm, the histological and clinical presentation emphasizing the necessity of a complete neuroradiological exploration when new neurological symptoms develop after head trauma. Neurosurgical and/or endovascular neuroradiological treatment is mandatory.

Effects of interferon-gamma and tumor necrosis factor alpha on the expression of the genes encoding aggrecan, biglycan, and decorin core proteins in cultured human chondrocytes

OBJECTIVE

To determine the effects of interferon-gamma (IFN gamma) and tumor necrosis factor alpha (TNF alpha), alone or in combination, on the expression of aggrecan, biglycan, and decorin core protein genes in human chondrocytes.

METHODS

Isolated human chondrocytes were cultured on poly(2-hydroxyethyl methacrylate)-coated plastic dishes to prevent the loss of cartilage-specific phenotype, and the effects of IFN gamma and TNF alpha, alone or in combination, on aggrecan, biglycan, and decorin core protein gene transcription and steady-state messenger RNA (mRNA) levels were examined.

RESULTS

The addition of IFN gamma (1.5 pM) or TNF alpha (0.3 pM) caused a decrease in the steady-state level of aggrecan mRNA (-25% and -15%, respectively), and the combination of these low-concentration cytokines caused a potent inhibition (-66%). These effects were the result of a decrease (-50%) in the transcription rate of the corresponding gene. At the concentrations used, IFN gamma did not alter the levels of biglycan mRNA or the transcription rates of the biglycan core protein gene. In contrast, TNF alpha decreased biglycan steady-state mRNA levels (-62%) and the biglycan core protein gene transcription rate (-18%). The combination of IFN gamma and TNF alpha resulted in a potentiation of the inhibitory effects of TNF alpha on biglycan mRNA levels (-79%) and transcription rate of the biglycan core protein gene (-46%). IFN gamma produced a modest decrease in decorin mRNA levels (-23%) and decorin core protein gene transcription rate (-17%). In contrast, TNF alpha resulted in a marked increase in decorin mRNA levels (+260%) that was not the result of transcriptional regulation. Notably, the combination of IFN gamma and TNF alpha potentiated the inhibitory effects of IFN gamma on decorin mRNA (-80%) and on the transcription of the corresponding gene (-43%). Similar results were obtained in fetal and adult articular chondrocytes.

CONCLUSION

These data demonstrate that 1) the expression of the core protein genes encoding the cartilage proteoglycans aggrecan, biglycan, and decorin is differentially regulated by IFN gamma and TNF alpha; 2) these effects are mediated by transcriptional and posttranscriptional mechanisms; and 3) the combination of the 2 cytokines causes a potent inhibitory effect on the expression of the genes for the core proteins of these 3 proteoglycans, which occurs largely at the transcriptional level. The inhibition of aggrecan, decorin, and biglycan core protein gene expression by the combination of IFN gamma and TNF alpha may contribute to the cartilage destruction that is characteristic of inflammatory joint diseases.

A randomized, blinded, comparative trial of one pepsin-digested and two whole IgG antivenoms for Bothrops snake bites in Uraba, Colombia. The Regional Group on Antivenom Therapy Research (REGATHER)

The therapeutic efficacy and the incidence of early antivenom reactions (EARs) were compared in a clinical trial performed in 79 patients bitten by Bothrops sp. in Urabá, Colombia. Patients were randomized into three groups according to the antivenom administered: A (n = 30, Butantan polyspecific, pepsin-digested Bothrops antivenom); B (n = 27, Butantan polyspecific, whole IgG Bothrops antivenom); and C (n = 22, Colombian commercial, monovalent, whole IgG Bothrops antivenom). The groups were comparable in all clinical and epidemiologic aspects; 33 patients had mild, 22 moderate, and 24 severe envenoming. At the doses used (two, four, and six vials [10 ml/vial] for mild, moderate, and severe envenomings, respectively) there were no differences between the antivenoms in restoring normal hemostatic parameters within 24 hr. The evolution of local envenoming was comparable in the three groups. Serum venom/antivenom kinetics determined by ELISA showed a complete clearance of venom levels 1 hr after treatment in mild/moderate envenomings. In severe cases, venom levels remained detectable up to 24 hr and recurrence of antigenemia was observed in some cases. Antivenom concentrations remained at high levels up to 24 hr of treatment. The incidence of EARs was significantly different in the groups: A (36.7%), B (11.1.%), and C (81.8%). There were no life-threatening anaphylactic reactions. We conclude that the efficacy of the three antivenoms was similar in neutralizing human Bothrops envenomings and that the production of whole IgG antivenoms by caprylic acid fractionation is a good alternative for reducing the incidence of EARs.

Broad-spectrum, non-opioid analgesic activity by selective modulation of neuronal nicotinic acetylcholine receptors

Development of analgesic agents for the treatment of severe pain requires the identification of compounds that are devoid of opioid receptor liabilities. A potent (inhibition constant = 37 picomolar) neuronal nicotinic acetylcholine receptor (nAChR) ligand called ABT-594 was developed that has antinociceptive properties equal in efficacy to those of morphine across a series of diverse animal models of acute thermal, persistent chemical, and neuropathic pain states. These effects were blocked by the nAChR antagonist mecamylamine. In contrast to morphine, repeated treatment with ABT-594 did not appear to elicit opioid-like withdrawal or physical dependence. Thus, ABT-594 may be an analgesic that lacks the problems associated with opioid analgesia.

Multiple sclerosis in Gijon health district, Asturias, northern Spain

The objective of this study was to ascertain the prevalence and incidence of Multiple Sclerosis (MS) in a population of 33,775 in two primary health care centres in the sanitary district of Gijon, Asturias, northern Spain. Many information sources were used but the unique advantage of Gijon was that the city has a centralized computerized register of all diagnoses made for all consultations in the clinics and hospitals in the area. The HLA distribution in the population was already known and the Poser classification of MS was used. The crude MS prevalence was 65/100,000, a similar prevalence to that found in southern and eastern Spain, Sicily and Greek-speaking Cyprus. The mean incidence was 3.7/100,000 per year. The study demonstrated the advantage of a centralized and computerized medical recording system and demonstrates that northern Spain is a moderately high or medium MS risk zone.

Distinct inhibitory effects of spinal endomorphin-1 and endomorphin-2 on evoked dorsal horn neuronal responses in the rat

Intrathecal endomorphin-1 and endomorphin-2 (0.25-50 micrograms) dose-relatedly reduced all components of electrical evoked C-fibre responses of spinal neurones. These effects were partially reversed by naloxone. Endomorphin-1, but not endomorphin-2, dose-relatedly reduced the A beta-fibre evoked responses. Peak inhibitory effects of endomorphin-1 and -2 were at 15-20 min post-administration. Thus spinal endomorphin-2 had selective effects on noxious responses, whereas endomorphin-1 was non-selective.

BU-224 produces spinal antinociception as an agonist at imidazoline I2 receptors

In this electrophysiological study, the effect of BU-224 (2-(4,5-dihydroimidazol-2yl)-quinoline hydrochloride)), a novel high affinity imidazoline I2 receptor ligand, was tested on the responses of nociceptive neurones in the spinal dorsal horn. When applied spinally, akin to an intrathecal application (i.t.), BU-224 (5-250 microg) reduced the nociceptive responses of dorsal horn neurones, producing a dose-dependent inhibition of C-fibre evoked responses, postdischarge and wind-up of the cells. A complete block of the antinociceptive effects was produced when idazoxan (100 microg), with both alpha2-adrenoceptor and imidazoline I2 receptor antagonist actions, was administered i.t. 10 min prior to the maximal dose of BU-224 tested. The nonselective alpha2-adrenoceptor antagonist, yohimbine (150 microg) only partially attenuated the inhibitory effects of BU-224 when administered i.t. 10 min prior. The highly selective alpha2-adrenoceptor antagonist, atipamezole (100 microg) produced no greater reversal than yohimbine under the same conditions. Although BU-224 has been reported to possess high affinity for imidazoline I2 receptors, a minor action at spinal alpha2-adrenoceptor receptors cannot be discounted. These results demonstrate that BU-224 is an agonist and that imidazoline I2 receptors, present in the dorsal horn, might play a role in spinal nociception, although further studies are needed to fully elucidate their functional roles.

St. Thomas Immunization Initiative. A student-run community action project

The objectives of the St Thomas Immunization Initiative are to provide a clinical community medicine experience for first- and second-year medical students, expose students to a community immunization program, teach students the principles of a community immunization program, and demonstrate a working relationship between the residents of an underserved community and medical students. From 1993 to 1995, first- and second-year students at Tulane University Medical School participated in class projects known as Shots for Tots and the St Thomas Immunization Initiative. Students received instruction about immunizations and administered vaccinations to children and adults in low-income neighborhoods. A total of 754 immunizations were administered to 331 children from 1993 to 1995. Participating students were surveyed and 82% of those who responded to a questionnaire felt that the project benefited the community it served while 79% felt that they personally benefitted from participating in the project. Given their experience, 96% of the students would be more likely to participate in a community development project in the future.

On stage single cell identification of rat spermatogenic cells

The study of spermatogenic cell physiology has been hindered by the absence of unbiased methods of identification of cells upon which single cell techniques are being applied. In this work, we have used histochemical techniques, digital videoimaging, quantification of chromatin-bound DNA probes, and measurements of cell diameter to identify single spermatogenic cells at different periods of development. Our criteria of identification permit the definition of four developmental stages of spermatogenesis on which to perform single cell analyses: spermatogonia B/preleptotene spermatocytes, leptotene/zygotene spermatocytes, pachytene spermatocytes, and round spermatids. The use of voltage-sensitive dyes and Ca(2+)-sensitive dyes does not interfere with the estimations of DNA content. The estimations of DNA content of spermatogenic cells can be performed both with near-UV excited dyes (H33342) and long wavelength-excited dyes (ethidium bromide), allowing the use of a wide range of physiological and immunocytochemical fluorescent probes to study the spermatogenic process.

Interferon-gamma regulates collagen and fibronectin gene expression by transcriptional and post-transcriptional mechanisms

Interferon-gamma (IFN-gamma) regulates the expression of collagen and fibronectin genes by molecular mechanisms not completely understood. We investigated the effects of IFN-gamma on the expression of the genes encoding alpha 1 (I) procollagen (COL1A1), alpha 1 (III) procollagen (COL3A1), and fibronectin (FN) in cultured normal human lung fibroblasts. Labeled newly synthesized proteins were analysed by electrophoresis, mRNA levels and stability by Northern hybridizations, and transcription rates by in vitro assays. IFN-gamma caused a reduction in the production of alpha 1 (I) and alpha 1 (III) procollagens and of fibronectin. The reduction in the production of procollagen chains was shown to result from a combination of IFN-gamma-induced inhibition of the transcription rates of the COL1A1 and COL3A1 genes and destabilization of the corresponding transcripts. IFN-gamma increased the transcription rate of FN, but also decreased the stability of the corresponding transcripts. The net results indicate that the regulation of the expression of extracellular matrix genes by IFN-gamma is a complex process that involves changes in gene transcription rates, alterations in mRNAs stability, and possibly, modulation of the rates of translation.

Blockade of spinal N- and P-type, but not L-type, calcium channels inhibits the excitability of rat dorsal horn neurones produced by subcutaneous formalin inflammation

The effects of the intrathecal (i.t.) administration of different voltage-sensitive calcium channel (VSCC) blockers were studied in the formalin model of inflammation. The responses of convergent dorsal horn neurones after the subcutaneous injection of formalin (5% formaldehyde, 50 microliters volume) were recorded extracellularly in rats under halothane anaesthesia. Administration of the L-type calcium channel blocker verapamil, 5 and 50 micrograms, before formalin injection had no effect on either the first or second phase of the formalin response. Pre-treatment with the N-type calcium channel blocker omega-Conotoxin-GVIA, 0.1 and 0.4 microgram, reduced both phases of the formalin response. The low dose of omega-Conotoxin-GVIA significantly inhibited the first phase response whereas the high dose significantly reduced the second phase. Pre-treatment with the P-type calcium channel blocker omega-Agatoxin-IVA, 0.125 and 0.5 microgram, did not cause a significant inhibition of the first phase whereas a marked dose-related reduction in the second phase of formalin response was found with the high dose producing 95% inhibition. These results demonstrate that spinal N- and P-type, but not L-type, VSCCs are involved in the inflammation-evoked hyperexcitability of dorsal horn neurones after peripheral formalin injection. Since selective antagonists for each type of VSCC had differential effects on the formalin response, it is suggested that each type of VSCC could be preferentially regulating or coupled to the release of certain neurotransmitters in the enhanced nociceptive transmission at the spinal level following formalin inflammation.

Prospective comparison of open vs. laparoscopic colon surgery for carcinoma. Five-year results

Laparoscopy for colonic diseases began in 1990 and has established a role in benign disease. Early observations and experiences demonstrated feasibility of laparoscopic surgery for a variety of colonic disease processes, but the applicability to colonic carcinoma was unclear.

METHODS

In 1990, we began a comparative study of open (OCR) vs. laparoscopic (LCR) approach to colon cancer. The study progressed 65 months, with 224 patients in OCR group and 191 patients in LCR group. Parameters studied are stage, location, length of specimen, number of lymph nodes resected, margins, postoperative course, wound complications, recurrence rates, and immediate and long-term survival. OCR were standardized by one group, and LCR were standardized by a second group. All patients undergoing LCR were given freedom to choose either OCR or LCR, and informed consent was obtained.

RESULTS

Equal or greater lymph node retrieval, resections, and distal margins were evident with LCR. Benefits with LCR were shown with shorter hospitalization (5.7 vs. 9.7 days), less blood loss, less wound problems (1 vs. 14), and quicker return of bowel function. Survival, recurrence, and death rates were essentially the same. There were no trocar implants in the LCR group.

CONCLUSION

After five years, this study shows that laparoscopy does no harm to the patient, offers comparable oncologic resections, and seems to be patient-friendly, with less pain, quicker return of bowel functions, shortened hospitalization, and quicker return to full activity.

Autoradiographic evidence of mu-opioid receptors down-regulation after prenatal stress in offspring rat brain

In order to visualize neuroanatomical alterations in specific brain regions, light microscopy autoradiography was carried out on offspring (postnatal day 10) from female rats stressed in different periods of gestation and controls. Group 1 was subjected to restraint stress from day 2 to 6; group 2, from day 7 to 11; group 3, from day 12 to 16; group 4, from day 2 to 16. Group 2 showed pronounce decreases in mu-opioid receptor density in different brain regions. The decrease in mu-opioid receptor density was less marked in the group 1, 3 and 4. Present data suggest that the prenatal stress induce down-regulation of mu-receptors in different brain regions.

Measurement of general health status in obstructive sleep apnea hypopnea patients

Sleep apnea hypopnea syndrome (SAHS) is an entity that occurs frequently in the population and produces an elevated morbidity and mortality, especially at an apnea index greater than 20 events per hour. To our knowledge there are only a few studies available addressing the general health status of sleep apnea hypopnea patients. Such information may be useful for both clinical management and better understanding of the physiopathological mechanisms of the disease, particularly with the consideration that not infrequently the physiological disturbances found in such patients do not always agree with their own health perception. Therefore, the aim of the present study was to assess the general health status and the degree of daytime somnolence, as a major symptom in SAHS patients, and relate them to the number of respiratory events per hour. Measurements of general health status and the degree of daytime somnolence were assessed in 103 consecutive patients 50.4 +/- 12 years old [mean +/- standard deviation (SD)] with an apnea/hypopnea index (AHI) of 38 +/- 27 events per hour. Forty nonsnoring healthy subjects were used as the control group. During the afternoon preceding the full polysomnography, a medical history was taken; basic anthropometric data and the presence of other diseases were recorded. The Nottingham Health Profile (NHP) questionnaire and a questionnaire assessing the degree of daytime somnolence were administered to the patients. No significant differences were found in the general health status and the degree of daytime hypersomnolence when patients were divided into three groups according to the severity of the respiratory events during the night, but there were significant differences between SAHS patients and control subjects. It was concluded that in spite of the fact that SAHS patients showed a deterioration of general health status parameters in comparison with healthy subjects, these parameters do not correlate with the physiological disturbances of SAHS, expressed as the number of respiratory events per hour.

[Hip screening in children. Comparison of various ultrasonographic methods]

750 Hips of 375 babies under 5 months were sonographically examined. We used the procedures following Graf and Suzuki and compared the methods and the results. The authors suggest that the ultrasound study following Graf provides more advantages and today is the best procedure in the screening of hip dislocation.

Mu-opioid receptor regulation during opioid tolerance and supersensitivity in rat central nervous system

We have analyzed by radiometric procedures in rat central nervous system the changes in the properties of mu-opioid receptors associated with tolerance and supersensitivity to the opioid agonist sufentanil. This study has used [3H]-[D-Ala2,MePhe4,Gly- (ol)5(2)]-enkephalin, a highly selective ligand, to label mu-opioid receptors in both membranes and tissue sections. The induction of opioid tolerance by chronic infusion for 7 days of high doses of sufentanil, a high efficacy agonist, produced mu-opioid receptor down-regulation, with a significant decrease in their density in both cortical (-67%) and spinal cord membranes (-55%) and no changes in the affinity constant. Autoradiographic studies showed an overall decrease of[3H]-Ala2,MePhe4,Gly-(ol)5(2)]-enkephalin binding in the somatosensory cortex (around -30%). When the dihydropyridine-Ca++ channel antagonist nimodipine was administered alone for 7 days, no significant changes in the density or affinity constant of mu-opioid receptors were observed. However, the chronic and simultaneous administration of nimodipine and sufentanil (7 days), induced a pronounced modification on the density of mu-opioid receptors of the rat central nervous system and blocked the down-regulation observed in sufentanil-treated (tolerant) rats. These neurochemical findings may account for the functional interaction we have observed previously in the analgesic studies between nimodipine and sufentanil. Our data strongly suggest a functional role of L-type Ca++ channels in the mediation of opioid tolerance and super-sensitivity.

Gastrointestinal calcium absorption and dietary calcium load: relationships with bone remodelling in vertebral osteoporosis

Patients with vertebral osteoporosis have a wide range of bone loss rates, bone remodelling rates and capacities for gastrointestinal (GI) calcium absorption. To test the hypothesis that variations in GI absorptive capacity determine rates of bone loss or remodelling, we have sought relationships between calcium absorption or vitamin D metabolite levels on the one hand and rates of cancellous and cortical bone loss (measured by serial quantitative computed tomography in the radius; n = 25) or indices of bone remodelling in tetracycline-prelabelled transiliac biopsies (n = 41) on the other, in a sequential untreated group. Calcium absorption (net and true) was measured in 18-day balances and by a two-isotope deconvolution method (fractional absorption and maximum absorption rate, MAR). There was no significant seasonal effect on any of these four measures of calcium absorption (variance ratio, F = 0.52-1.61, p > 0.1) or on 1,25-dihydroxyvitamin D levels (F = 0.13, p > 0.1; range 11-69 pg/ml), notwithstanding the expected seasonal effect on 25-hydroxyvitamin D levels (mean 18.7 ng/ml, zenith mid July, semi-amplitude 7.5 ng/ml; F = 6.82, p < 0.01). Neither this metabolite nor 1,25-dihydroxyvitamin D correlated with any index of calcium absorption (p > 0.1). No measure of calcium absorption (or intake) had a significant relationship with radial cortical or cancellous bone loss (p all > 0.1) but cancellous bone loss was associated with the rate of endogenous calcium excretion (r = 0.50, p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Growth effects of tamoxifen and estradiol on laryngeal carcinoma cell lines

OBJECTIVES

We tested the in vitro and in vivo growth effects of estradiol and tamoxifen citrate to determine whether patients with laryngeal carcinoma could benefit from antiestrogen therapy as demonstrated for cancers of other estrogen-responsive organs.

DESIGN

A comparison of growth effects of the hormones relative to controls by using a tetrazolium dye reduction assay and nude mice.

MATERIALS

Two estrogen-positive laryngeal carcinoma cell lines (UMSCC5 and UMSCC11B) and athymic mice were used.

RESULTS

There were marked growth inhibitory effects of tamoxifen alone in concentrations of 3 to 8 mumol/L on both cell lines. There were no in vitro growth effects of estradiol-17 beta alone in concentrations of 0.1 to 9.6 mumol/L, but there was antagonism of the estradiol to the growth inhibitory effects of tamoxifen. In athymic mice, estradiol markedly stimulated the growth of UMSCC5, whereas tamoxifen inhibited growth.

CONCLUSIONS

These results support the concept of chemotherapeutic growth inhibition of estrogen receptor-positive laryngeal cancer with antiestrogens.

Production and partial characterization of an endopolygalacturonase from Saccharomyces cerevisiae

Saccharomyces cerevisiae CECT1389 secreted an extracellular endopolygalacturonase (EC 3.2.1.15) when grown in shake flasks in medium containing galactose alone, or either galactose and polygalacturonic acid or galactose and galacturonic acid as the carbon sources. The synthesis of the enzyme was repressed by glucose and by high oxygen tensions. The enzyme was partially purified by gel exclusion chromatography over Sephacryl S-200, where it showed an apparent molecular mass of 39 kDa; the value determined by high-performance liquid chromatography (HPLC) was 65 kDa. The optimal temperature and pH for enzyme activity were 45 degrees C and 5.5, respectively. The Km and Vmax values for polygalacturonic acid were 4.7 mg.mL-1 and 6.4 nmol.mL-1.min-1. The Ki for HgCl2 was 6.8 x 10(-5) M. The enzyme exhibited an endo-splitting mechanism as deduced from viscosimetry experiments as well as from an HPLC study of the end products.

Indications for and the significance of seminal vesicle irradiation during 3D conformal radiotherapy for localized prostate cancer

PURPOSE

To evaluate the use of pretreatment prostate specific antigen, Gleason score, and clinical stage as predictors of the risk of seminal vesicle involvement in patients with clinically localized prostatic cancer, and to determine the impact of excluding the seminal vesicles on the dose received by surrounding normal tissues.

METHODS AND MATERIALS

An empirically derived equation combining the preoperative prostate specific antigen and Gleason score was applied to 188 patients treated with radical prostatectomy, for whom pathologic evaluation of the seminal vesicles was available. High and low risk groups for seminal vesicle involvement were defined using this equation. The observed risks of seminal vesicle involvement was compared to the predicted risk using the preoperative prostate specific antigen, Gleason score or clinical stage alone or using the empirical equation. Dose-volume histograms for five patients treated using six-field conformal radiotherapy were compared including and excluding the seminal vesicles.

RESULTS

Using the empirically derived equation, a low risk group of 109 patients was identified with a calculated risk of seminal vesicle involvement of < or = 13% and an observed incidence of 7.3%. Among the high risk group of 79 patients, which included all patients with a calculated risk > 13%, 37% had seminal vesicle involvement (p < 0.001 low vs. high risk). Twenty percent of the rectal volume received on average above 86% of the total dose for the five plans which included the seminal vesicles compared to 68% for the five plans excluding the seminal vesicles. The doses to 40% of the rectal volume were 64% and 37% if the seminal vesicles were included and excluded, respectively. The dose to the bladder and femoral heads was also decreased but to a lesser extent.

CONCLUSION

The empirical formula predicts risk of seminal vesicle involvement with a higher degree of significance for a larger number of patients than either Gleason score, clinical stage, or prostate specific antigen alone. Based on an analysis of our first 100 patients treated with definitive conformal therapy alone, approximately 47% of those patients could have been treated excluding the seminal vesicles. Excluding the seminal vesicles may allow us to go to a higher total dose with less rectal toxicity.

Epidermal growth factor coordinately regulates the expression of prostaglandin G/H synthase and cytosolic phospholipase A2 genes in embryonic mouse cells

Confluent, primary cultures of mouse embryo palate mesenchyme (MEPM) cells are refractory to activation of phospholipase A2 (PLA2) by the calcium ionophore A23187. However, treatment of these cultures with epidermal growth factor (EGF) permits the cells to activate PLA2 in response to A23187. We have developed this finding by exploring molecular mechanisms by which growth factors modulate mobilization and metabolism of arachidonic acid. We found chronic treatment (> 6 h) of confluent MEPM cells with EGF (a) increases their ability to metabolize exogenous arachidonic acid to prostaglandin E2 (PGE2) and (b) stimulated constitutive expression of activities of PLA2 and cyclooxygenase (CyOx). Immunoprecipitation of [35S]proteins and Western blot analysis revealed EGF treatment stimulated synthesis and accumulation of PLA2c, CyOx-1, and CyOx-2. Northern hybridization analysis revealed EGF increased the steady-state levels of a transcript for the high molecular weight, cytosolic PLA2 (PLA2c), and both the 2.8- and 4.2-kb transcripts for CyOx-1 and CyOx-2, respectively. In vitro nuclear transcription assays showed a parallel increase in the transcription rate of the genes corresponding to CyOx-1 and PLA2c, but not CyOx-2, in response to EGF. Treatment with EGF had no effect on either synthesis of the low molecular weight, group II PLA2, accumulation of its transcript, or the transcription rate of its gene. Coordinate regulation of activities of PLA2 and CyOx in response to EGF did not parallel the mitogenic effects of EGF on confluent MEPM cells.

Functional analysis of human alpha 1(I) procollagen gene promoter. Differential activity in collagen-producing and -nonproducing cells and response to transforming growth factor beta 1

To gain a further understanding of the regulation of human type I collagen gene expression under physiologic and pathologic conditions, we characterized 5.3 kilobase pairs (kb) of the human alpha 1(I) procollagen gene promoter. A series of deletion constructs containing portions of the alpha 1(I) procollagen 5'-flanking region (with end points from -5.3 kb to -84 base pairs (bp)) ligated to the chloramphenicol acetyltransferase (CAT) reporter gene were transiently transfected into NIH/3T3 cells. Maximal CAT activity was observed with constructs having 5' end points from -804 to -174 bp. A further 5' deletion to -84 bp caused a marked reduction in CAT activity. Cells transfected with plasmids containing longer 5'-flanking fragments of the alpha 1(I) procollagen gene (-2.3 or -5.3 kb) showed reduced CAT activity compared with the -804 bp construct. The activity of the alpha 1(I) procollagen promoter was much lower in cells that do not normally express type I collagen (HeLa cells) compared with collagen-producing NIH/3T3 cells. The CAT activity of deletion constructs containing longer 5' regions than -84 bp was increased by approximately 2-fold in NIH/3T3 cells treated with transforming growth factor beta 1 (TGF beta 1). Electrophoretic mobility shift assays indicated that protein-DNA complex formation with a probe corresponding to the -170 to -80 bp fragment of the alpha 1(I) procollagen promoter was markedly enhanced in nuclear extracts prepared from TGF beta 1-treated fibroblasts as compared with untreated fibroblasts. The DNA binding activity stimulated by TGF beta 1 was specific for an Sp1-like sequence at positions -164 to -142 bp in the promoter. These results demonstrate that 1) there are both positive and negative cis-acting regulatory elements in the human alpha 1(I) procollagen promoter, 2) these regulatory regions function differently in collagen-producing and -nonproducing cells, 3) the alpha 1(I) procollagen promoter contains TGF beta 1-responsive sequences located between -174 and -84 bp from the transcription start site, and 4) TGF beta 1 caused marked stimulation of the DNA binding activity of a nuclear factor interacting with an Sp1-like binding site located within a region encompassing -164 to -142 bp of the alpha 1(I) procollagen promoter.

Glucocorticoid-mediated inhibition of interleukin-2 receptor alpha and -beta subunit expression by human T cells

To determine the mechanism of glucocorticoid (GC)-mediated inhibition of T cell functions, the effect of dexamethasone (DM) on T cell proliferation and interleukin-2 receptor (IL-2R) generation were studied. Dexamethasone inhibited IL-2-induced T cell proliferation by 30%-88%, relative to its concentration within the cultures. The effect of DM on expression of IL-2R alpha (Tac, p55, CD25) and beta (p75) genes in activated T cells was examined next. In T cells stimulated with purified phytohemagglutinin (PHA-p) and 4 beta-phorbol 12-myristate 13-acetate (PMA) addition of DM to the cultures resulted in a 60% reduction in IL-2R alpha and a 30% reduction in IL-2R beta membrane expression compared to T cells cultured in the absence of DM (p < 0.01). Inhibition of membrane IL-2R alpha and IL-2R beta expression by 10(-6) M DM was partially reversible by recombinant human IL-2 (rhIL-2). By Northern blot analysis, DM caused a comparable decrease in IL-2R alpha and in IL-2R beta mRNA levels to membrane receptor expression in mitogen-stimulated T cells. By in vitro transcription assays, DM regulated IL-2R alpha gene expression at a transcriptional level while transcription of IL-2R beta gene was unaffected by DM. The mechanism of action of DM on IL-2R alpha transcription was examined by determining the mRNA levels of the p50 subunit of nuclear factor kappa B (NF-kappa B), a transcription factor that stimulates IL-2R alpha gene expression. The data indicate that 10(-6) M DM increased T cell p50 NF-kappa B mRNA levels by four-fold compared to the levels obtained in the absence of DM. Further, the level of nuclear proteins capable of binding to the NF-kappa B sites in activated T cells increased in response to DM. In sum, DM regulates T cell membrane expression of IL-2R by more than one molecular mechanism.

Human immunodeficiency virus seropositivity in adolescents with syphilis

OBJECTIVE

The purpose of this study was to assess the relationship between syphilis and human immunodeficiency virus (HIV) infection among inner-city, minority group adolescents.

METHODS

From August 1989 through June 1990, serum from all positive serologic tests for syphilis, obtained from patients attending a comprehensive adolescent health center in an acquired immunodeficiency syndrome epicenter and its two school-based clinics, were frozen without patient identifiers and were subsequently screened for HIV by enzyme-linked immunosorbent assay with confirmatory Western blot for positives. In addition, a retrospective chart review was performed for all patients with a positive serologic test for syphilis during the study period.

RESULTS

Of the 59 specimens with a positive syphilis serologic test, 9 (15.3%) were HIV seropositive. Of the patients with syphilis, 57.4% were black and 42.6% were Hispanic; 16.4% were male (mean age 18.1) and 83.6% were female (mean age 17.8). Only 1 subject (female) was an injection drug user; 4 of the male subjects self-identified as having had sex with other males. Of the subjects, 27.8% had primary, 19.7% had secondary, and 52.5% had latent syphilis at the time of diagnosis. A prior or concurrent sexually transmitted disease was present in 90% of the males and 80% of the females; gonorrhea was the most prevalent sexually transmitted disease in the males (89%) and chlamydia was most prevalent in the females (35%). A history of chancroid and/or herpes was present in 16.4% of the subjects.

CONCLUSIONS

It is concluded that the diagnosis of syphilis in an adolescent is a risk factor for HIV infection. All sexually active adolescents should be routinely screened for syphilis, regardless of sexual practices. Those with syphilis should be specifically counseled about their increased risk for HIV infection and the importance of consistent condom use, and they should be referred for formal HIV pretest counseling.

Transcriptional modulation of cartilage-specific collagen gene expression by interferon gamma and tumour necrosis factor alpha in cultured human chondrocytes

To examine the possibility that cytokines produced in inflamed joint tissues may contribute to the loss of articular cartilage by causing inhibition of synthesis of cartilage-specific matrix macromolecules, we studied the effects of interferon gamma (IFN gamma) and tumour necrosis factor alpha (TNF alpha), alone and in combination, on the expression of the genes for types-II, -IX and -XI collagens in cultured human chondrocytes. Chondrocytes isolated from human fetal epiphyseal cartilage by sequential enzymic digestions were cultured in the presence of IFN gamma (30 pM), TNF alpha (15 pM) or a combination of suboptimal concentrations of both cytokines (1.5 pM IFN gamma plus 0.3 pM TNF alpha). IFN gamma caused a maximal decrease of 23.3-32.6% in the biosynthesis of collagen by chondrocytes. TNF alpha was a more potent inhibitor causing a 42.8-45.3% decrease at one-half the concentration of IFN gamma. A synergistic inhibitory effect of 58.2% was observed with the combination of 1.5 pM IFN gamma plus 0.3 pM TNF alpha. Electrophoretic analysis of the biosynthesized proteins showed a co-ordinate decrease in the production of the three cartilage-specific collagen types II, IX and XI. These effects were accompanied by parallel changes in the steady-state levels of their corresponding mRNAs. In vitro transcription assays showed that the collagen inhibitory effects of the cytokines occurred largely at the transcriptional level. Similar effects of the cytokines were observed on biosynthesis of types-II, -IX and -XI collagens and steady-state mRNA levels for type-II collagen by chondrocytes obtained from adult articular cartilage. These observations indicate that IFN gamma and TNF alpha can induce a synergistic inhibition of the synthesis of cartilage-specific collagens by fetal and adult human chondrocytes and suggest that these effects may contribute to the articular cartilage loss that occurs in inflammatory joint diseases.

Regulation of human lung fibroblast alpha 1(I) procollagen gene expression by tumor necrosis factor alpha, interleukin-1 beta, and prostaglandin E2

We investigated the participation of prostaglandin (PG) E2 in the regulation of the alpha 1(I) procollagen gene expression by tumor necrosis factor alpha (TNF alpha), and interleukin-1 beta (IL-1 beta) in normal adult human lung fibroblasts. TNF alpha (100 units/ml) and IL-1 beta (100 units/ml) stimulated the production of PGE2 and caused a dose-dependent inhibition of up to 54 and 66%, respectively, of the production of type I procollagen. Preincubation of cultures with indomethacin partially reversed the inhibition of procollagen production induced by the cytokines. Cytokine-stimulated endogenous fibroblast PG accounted for 35 and 68% of the inhibition induced by TNF alpha and IL-1 beta, respectively. Steady-state mRNA levels for alpha 1(I) procollagen paralleled the changes in collagen production. The transcription rate of the alpha 1(I) procollagen gene was reduced by 58% by TNF alpha and by 43% by IL-1 beta. Cytokine-stimulated endogenous PG production accounted for half of these effects. These results indicate that TNF alpha and IL-1 beta inhibit the expression of the alpha 1(I) procollagen gene in human lung fibroblasts at the transcriptional level by a PGE2-independent effect as well as through the effect of endogenous fibroblast PGE2 released under the stimulus of the cytokines.

Effect of anti-gamma-interferon and anti-interleukin-4 administration on the resistance of mice against infection with reticulotropic and myotropic strains of Trypanosoma cruzi

We studied the effect of in vivo administration of anti-gamma-IFN and anti-IL-4 monoclonal antibodies on the resistance of mice against myotropic and reticulotropic strains of Trypanosoma cruzi. Anti-gamma-IFN treatment augmented the susceptibility of mice when infected with the reticulotropic RA and Tulahuén strains of T. cruzi but did not alter the course of infection with the myotropic CA-I strain of the parasite. In vivo administration of anti-IL-4 enhanced the resistance of mice when infected with either Tulahuén or RA strains but did not affect the course of parasitemia when infected with CA-I. The possible biological relevance of these observations is discussed.

Pigmented paravenous retinochoroidal atrophy

Pigmented paravenous retinochoroidal atrophy is a rare disorder that is not well understood or classified. We examined a patient who had chorioretinal atrophy with pigment clusters located in the paravenous areas without macular involvement. Other conditions which may also present retinochoroidal atrophy and/or pigmentary degeneration are discussed. The electroretinography results were subnormal but the evoked potentials were not totally extinguished. Fluorescein angiography and retinography confirmed the relative and absolute scotomas corresponding to the atrophic paravenous areas.

Time-resolved fluorescence study of human recombinant interferon alpha 2. Association state of the protein, spatial proximity of the two tryptophan residues

Human recombinant interferon alpha 2 belongs a to family of proteins active against a wide range of viruses. It contains two tryptophan residues located at positions 77 and 141 in the peptide sequence. The fluorescence emission spectrum of these tryptophan residues displays a maximum at 335 nm. The fluorescence intensity decay is described by one broad excited-state-lifetime population centered around a value of 1.7 ns (full width at half maximum, 1.5 ns). These observations suggest that in the native protein, both tryptophan residues emit from similar environments, not directly exposed to the surrounding solvent. The anisotropy decay is essentially biexponential. The correlation-time value characterizing the Brownian rotation of the protein varies linearly with the viscosity/temperature ratio. The calculated hydrodynamic volumes are compatible with the existence of a dimer and a tetramer, at pH 5.5 and 9.4, respectively. Addition of urea at pH 5.5 disrupts the dimer and modifies to some extent the excited-state-lifetime distribution which becomes more heterogeneous. Disulfide-bond reduction also dissociates the dimer and leads to a highly heterogeneous fluorescence-intensity decay with four excited-state-lifetime populations. An opening of the local structure in the Trp region of the protein is likely to occur in these conditions. The fast-anisotropy-decay components can be due to either fast rotation or energy transfer between the indoles. Close proximity of the two Trp residues (less than 1 nm) is suggested from steady-state and time-resolved fluorescence-anisotropy measurements in vitrified medium [95% (by mass) glycerol at -38 degrees C]. This suggestion is in agreement with the recently published three-dimensional structure of the homologous protein murine interferon beta [Senda, T., Shimazu, T., Matsuda, S. Kawano, G., Shimizu, H., Nakamura, K. T. & Mitsui, Y. (1992) EMBO J. 11, 3193-3201].

Activation of expression of genes coding for extracellular matrix proteins in Tat-producing glioblastoma cells

The Tat protein of human immunodeficiency virus type 1 has been increasingly implicated in directly contributing to the disease AIDS by altering the expression of strategic cellular genes. In this study we demonstrate that the presence of the human immunodeficiency virus type 1 regulatory protein Tat is associated with a significant induction in the expression of certain protein components of the extracellular matrix in glial-derived cells. Northern blot analysis reveals that in cells expressing Tat there is a marked elevation in the steady-state RNA levels for fibronectin and types I and III collagen. Metabolic labeling of the Tat-producing cells demonstrates that this induction is also reflected at the level of protein synthesis. Transient transfection experiments indicate that the presence of Tat results in increased transcription of fibronectin and alpha I type I collagen promoters. Possible mechanisms for this phenomenon and their significance with regard to AIDS are discussed.

Alternative splicing of human prostaglandin G/H synthase mRNA and evidence of differential regulation of the resulting transcripts by transforming growth factor beta 1, interleukin 1 beta, and tumor necrosis factor alpha

Prostaglandin G/H synthase (PGG/HS) is the rate-limiting enzyme in the conversion of arachidonic acid to prostaglandins and thromboxanes. We screened a human lung fibroblast cDNA library with an ovine PGG/HS cDNA and isolated a 2.3-kilobase clone (HCO-T9). Sequence analysis of this clone showed that (a) it contained the entire translated region of PGG/HS and (b) it displayed an in-frame splicing of the last 111 base pairs encoded by exon 9, which resulted in the elimination of the N-glycosylation site at residue 409. Polymerase chain reaction amplification with specific oligonucleotides of reverse-transcribed mRNA from diverse human tissues and cultured cells yielded 400- and 300-base pair fragments that corresponded, respectively, to the intact and spliced transcripts. The expression of these two transcripts in cultured human lung fibroblasts was differentially regulated by serum, transforming growth factor beta 1, interleukin 1 beta, tumor necrosis factor alpha, and phorbol 12-myristate 13-acetate, as each of these conditions stimulated preferentially the expression of the unspliced transcripts. The elimination of one of the four N-glycosylation sites by the alternative splicing of exon 9 and the differential regulation of this process by relevant cytokines and growth factors may represent a mechanism for the regulation of PGG/HS enzymatic activity under physiological or pathological conditions.

Predictors of repeat pregnancy outcome among black and Puerto Rican adolescent mothers

This prospective study investigated predictors of repeat pregnancies by 12 months after the delivery of a first child and their outcomes in inner-city adolescent mothers. The sample included four groups: those who had therapeutic abortions, miscarriages, full-term deliveries, and no repeat pregnancy. The therapeutic abortion group had more pregnancies before their first delivery (41%) than did full term (20%) and no repeat (15%), p less than .01. More delayed grade placement was found in therapeutic abortion -1.6 years (1.3) and full term -1.8 years (.9) than in no repeat pregnancy -.6 years (1.1), p less .001. Reading achievement scores were higher in no repeat 86.3 (17.1) than in full term 75.0 (16.5), p less than .05. School attendance was higher in no repeat (65%) than in therapeutic abortion (35%) and full-term (24%) p less than .01 groups. Depressive symptoms at baseline were higher among therapeutic aborters 18.9 (9.9) than among full term 10.2 (8.2) and no repeat pregnancy groups 12.2 (6.2). Logistic regression analyses identified delayed grade placement as the most important predictor of pregnancy outcome.

Streptococcus pneumoniae DNA polymerase I lacks 3'-to-5' exonuclease activity: localization of the 5'-to-3' exonucleolytic domain

The Streptococcus pneumoniae polA gene was altered at various positions by deletions and insertions. The polypeptides encoded by these mutant polA genes were identified in S. pneumoniae. Three of them were enzymatically active. One was a fused protein containing the first 11 amino acid residues of gene 10 from coliphage T7 and the carboxyl-terminal two-thirds of pneumococcal DNA polymerase I; it possessed only polymerase activity. The other two enzymatically active proteins, which contained 620 and 351 amino acid residues from the amino terminus, respectively, lacked polymerase activity and showed only exonuclease activity. These two polymerase-deficient proteins and the wild-type protein were hyperproduced in Escherichia coli and purified. In contrast to the DNA polymerase I of Escherichia coli but similar to the corresponding enzyme of Thermus aquaticus, the pneumococcal enzyme appeared to lack 3'-to-5' exonuclease activity. The 5'-to-3' exonuclease domain was located in the amino-terminal region of the wild-type pneumococcal protein. This exonuclease activity excised deoxyribonucleoside 5'-monophosphate from both double- and single-stranded DNAs. It degraded oligonucleotide substrates to a decameric final product.

Regulation of transforming growth factor-beta 1 gene expression by glucocorticoids in normal human T lymphocytes

Glucocorticoids (GC) modulate immune function in a number of ways, including suppression of T cell proliferation and other IL-2-mediated T cell functions. These inhibitory effects are similar to those induced by transforming growth factor-beta 1 (TGF-beta 1), a cytokine with potent T cell inhibiting activities. We examined the hypothesis that GC effects may be at least partially achieved through modulation of the expression of the TGF-beta 1 gene in activated T cells. Normal T cells were cultured with or without purified phytohemagglutinin (PHA-p) and 4 beta-phorbol 12-myristate 13-acetate (PMA) in the presence or absence of the synthetic GC, dexamethasone (100-200 micrograms/ml). The production of latent and active forms of TGF beta by these cells were analyzed by immunoblotting and bioassays. The steady-state levels of TGF-beta 1 mRNA were analyzed in total RNA from these cells by Northern hybridizations using a human TGF-beta 1 cDNA. The results showed that dexamethasone caused an increase in TGF beta production and a dose-dependent two to fourfold increase in TGF-beta 1 mRNA in activated as well as in unstimulated T cells, 1 h after exposure of the cultures to the steroid. The increase in TGF-beta 1 mRNA levels by dexamethasone was further potentiated two to threefold by cycloheximide, suggesting that the steroid effect may be due to inhibition of the synthesis of proteins that decrease TGF-beta 1 gene transcription or the stability of its transcripts. Finally, in vitro nuclear transcription studies indicated the dexamethasone effects on TGF-beta 1 gene expression to be largely transcriptional.

[Secondary penetration of a ventriculo-peritoneal shunt into the intestines. Possible cause of a recurring sepsis?]

We present a 28-year-old-patient with a severe head injury: skull fractures, epidural hematoma, subarachnoid hemorrhage, Glasgow coma score 7, and aspiration following a motorbike accident. A systemic infection with symptoms of shock and Staphylococcus aureus in blood culture specimens developed a few days after admission (later Staphylococcus epidermidis was also cultured). A posttraumatic hydrocephalus was treated by a ventriculo-peritoneal shunt inserted at mini-laparotomy. In multiple microbiological and cytological tests the cerebrospinal fluid (CSF) was always sterile. Enterocolitis occurred with Clostridium difficile and Staphylococcus aureus in stool cultures. After 6 months' intractable sepsis the patient died with multiple-system failure. Autopsy revealed secondary displacement of the shunt catheter into the intestinal lumen. A possible ascending infection was found in the form of a cerebral ventricular empyema. However, prior to death there was no specific clinical sign of peritonitis or encephalitis or a positive microbiological or cytological CSF findings. Despite insertion of a ventriculo-peritoneal shunt under visual control, this case shows that secondary displacement of the peritoneal extremity into the bowel can occur, which may cause a cerebral and eventually a systemic infection. CSF examinations may fail to show contamination; specific clinical signs may be absent or, with multiple-system failure, misleading. An autopsy is generally to be recommended as it contributes to a better understanding of the clinical problems in most cases.

Ultrasonic forms of posterior staphyloma

The most frequent deformations of the globe encountered in pediatric ophthalmology are staphylomas and colobomas. In this paper we reviewed 16 ultrasonographically diagnosed staphylomas and classified the ultrasonographic patterns produced by staphyloma cases into four types: (1) staphylomas involving the posterior pole but not the optic nerve head, (2) staphylomas involving the posterior pole and the optic nerve head, (3) peripapillary staphylomas, and (4) giant peripapillary staphylomas. Morphologic and ultrasonographic characteristics are described.

Frequency of use, knowledge, and attitudes toward the contraceptive sponge among inner-city black and Hispanic adolescent females

This study assessed the frequency of use, knowledge, and attitudes toward the contraceptive sponge in sexually active, inner-city, black and Hispanic adolescent females. A 54-item, self-administered questionnaire was completed by 208 adolescents (mean age 17.9 years) attending a gynecology/family planning clinic within a comprehensive adolescent health center. Twenty-nine (13.9%) had never used any birth control, and 49 (23.6%) had not used any form of birth control in the 3 months prior to the study. Fifty-three (25.5%) of the adolescents had used a less reliable method such as rhythm and/or withdrawal. The birth control method used least was the sponge. Only four (1.9%) of the adolescents had used the sponge in the 3 months prior to the study, and only ten (4.8%) had ever used it. Knowledge of the correct use of the sponge was poor. However, 69 (44.8%) of the 156 girls who knew about the sponge had a positive attitude toward it, and only 19% said they did not like it. The contraceptive sponge may be a viable option for adolescents, particularly those who are not using birth control or who are using a less reliable method.

The staphylococcal toxic shock syndrome toxin 1 triggers B cell proliferation and differentiation via major histocompatibility complex-unrestricted cognate T/B cell interaction

The Staphylococcus aureus exotoxin toxic shock syndrome toxin 1 (TSST-1) is a potent activator of T cells and monocytes. We have recently demonstrated that TSST-1 is a superantigen that binds monomorphic determinants on MHC class II molecules. In the present study, we have examined the effect of TSST-1 on the activation and differentiation of high density human tonsillar B cells. TSST-1 bound to tonsilar B cells with high affinity and saturation kinetics. This binding was effectively inhibited by a combination of anti-HLA-DR and anti-HLA-DQ mAbs. Treatment of purified B cells with TSST-1 failed to induce B cell proliferation or Ig production. However, in the presence of irradiated T cells, TSST-1 induced resting B cells to proliferate and differentiate into Ig secretory cells. TSST-1 mimicked nominal antigen in that its induction of B cell responses was strictly dependent on physical contact between T and B cells, and was profoundly inhibited by anti-MHC class II mAbs, anti-CD3 mAbs, and, to a lesser extent, by anti-CD18 mAbs. However, unlike nominal antigen, TSST-1-mediated T/B cell interactions were MHC unrestricted. These results suggest that TSST-1 induces T cell-dependent B cell proliferation and differentiation by virtue of its ability to mediate MHC-unrestricted cognate T/B cell interaction via the TCR/CD3 complex and MHC class II antigens.

Transforming growth factor-beta stimulation of lung fibroblast prostaglandin E2 production

Transforming growth factor-beta (TGF beta) stimulated the production of total protein, collagen, and fibronectin by normal human lung fibroblasts. The stimulatory response was maximal at 100 pM TGF beta and reversed toward control at higher concentrations. Inhibition of fibroblast prostaglandin (PG) synthesis enhanced TGF beta-induced stimulation of total protein, collagen, and fibronectin production and reversed the negative slope of the dose-response curve at high concentrations of TGF beta. Determination of the steady-state levels of Types I and III procollagens and fibronectin mRNAs employing specific cDNA probes demonstrated that inhibition of fibroblast PG production increased the stimulatory effect of TGF beta on the levels of these transcripts. Exogenous PGE2 abrogated the stimulatory effects of TGF beta. These findings suggest that fibroblast stimulation by TGF beta may be down-regulated by endogenous PG synthesized in response to TGF beta. This notion was supported by the demonstration that TGF beta markedly stimulated fibroblast PGE2 production. These results indicate that TGF beta-induced stimulation of fibroblast PGE2 production may be an autoregulatory control mechanism to limit the effects of TGF beta on connective tissue protein synthesis.

Arbitrarily high focal depth with a quasioptimum real and positive transmittance apodizer

Focal depth is assessed by the average value of the square modulus of the slope associated with the complex amplitude along the optical axis. Then, the calculus of variations is used for identifying the optimum apodizer, characterized by a Strehl ratio vs defocus with high focal depth, for a specified light throughput. We show that a certain Lorentzian profile is a quasioptimum solution for the above requirements. This apodizer has real and positive transmittance, and it can be modified to achieve arbitrarily high focal depth. A closed formula relates focal depth to light throughput.