Control of orthodontic pain.

Orthodontics is an elective dental procedure generally believed to involve pain. In certain individuals, the pain caused by orthodontic tooth movement can be a major negative component of the entire therapy. Clinicians who are aware of this fact can attempt to prevent pain rather than ameliorate it once it is present and help make the experience a more positive one for the patient. Orthodontic forces should be kept at suitable levels and care taken to prevent trauma due to hyperocclusion. In procedures suspected to cause significant painful stimuli (such as forcing bands on unseparated teeth, removal of fixed expanders, initial placement of archwires, or lingual arches), or in particularly sensitive patients, the use of analgesics may be indicated. These agents should be taken prior to the procedure and for a minimum of 24 hours following the procedure. Acetaminophen is recommended in young children, while nonsteroidal anti-inflammatory agents are indicated in older patients.


Signs and symptoms of temporomandibular joint dysfunction in a Saudi Arabian population.

The signs and symptoms of temporomandibular joint dysfunction present in 219 Saudi Arabians attending a dental clinic for routine dental treatment are described. Joint sounds (36%) and muscle tenderness to palpation (34%) were common findings. Of the subjects examined, 31% reported suffering from frequent headaches. The study demonstrated a high incidence of signs and symptoms of temporomandibular joint dysfunction. Findings were similar to those of a previous study of an investigation in a bedouin community in Western Egypt (Abdel-Hakim, 1983).


Analysis of a central maxillary incisor by using a three-dimensional finite element method.

An attempt is made for determining the stress distribution in a maxillary central incisor by using a three-dimensional finite element model. The tooth is assumed isotropic, homogeneous, elastic and unsymmetrical. A load of 450N, 26 degrees to the longitudinal axis is applied on the incisal margin of the tooth. The distribution of compressive, tensile and shear stresses were plotted for the whole tooth structure. It is found that cracks or fractures occur under the given load.


Effect of metal strengthener's surface roughness on fracture resistance of acrylic denture base material.

The aim of this study was to clarify the effect of the surface roughness of various metal wires on the fracture resistance of the acrylic test specimens. The number of test groups compared were 16, and there were 30 test specimens in each group. The investigation showed that the surface roughening of the metal wires used to reinforce acrylic resin denture base material increased the fracture resistance of the test specimens. The best results were achieved by sandblasting. The differences in resistance were also statistically significant.


The masticatory pattern as an adjunct for diagnosis and treatment.

The sagitally-viewed masticatory pattern was investigated in 125 dentate patients. In 25 patients, the phenomenon of an incisal guided phase during mastication was observed. Clinical examination of these cases revealed slight to severe incisal attrition or various degrees of flaring. The hypothesis that the incisal guided phase contributes to this phenomenon and should therefore be taken into consideration during treatment is put forward.


Methodological observations on positive and negative work (teeth grinding) by human jaw muscles.

Through electrognathography and surface electromyography of the right and left masseter muscle (MM), this methodologic study examined the excentric (lengthening) and concentric (shortening) contractions of brief (2000 ms) voluntary teeth grinding performed through canine as well as group function of the opposing teeth. We inferred that the most anterior and superior portions of the right and left MM were lengthened and shortened by at least 4.23 mm (right MM) and 4.82 mm (left MM). For the negative work efforts (excentric contractions) of canine function, the tensions of the ipsilateral MM ranged from 10 to 20% MVC and those of the contralateral MM from 4 to 14% MVC. For the positive work efforts (concentric contractions) of canine function, the tensions of the ipsilateral MM ranged from 11 to 44% MVC and those of the contralateral MM from 20 to 41% MVC. A comparison between canine and group function showed that the negative as well as positive work efforts of group function exceeded those of canine function.


A comparative study of two methods for the orientation of the occlusal plane and the determination of the vertical dimension of occlusion in edentulous patients.

The aim of this study was to compare two methods used to orientate the occlusal plane (OP) and to determine the vertical dimension of occlusion (VDO). In method A the VDO was established by means of the rest position, the minimal speaking distance, and the patient's profile. Method B used a newly developed registration pin assembly. The VDO was registered using a silicone occlusion rim and the swallowing technique. The results were compared to the values of the new dentures. Three standardized lateral radiographs were taken at the VDO obtained with methods A, B, and at that of the final dentures. On each radiograph the orientation of the OP to the Camper plane and the VDO were measured by two investigators independently. The results indicated no statistically significant differences between the mean VDO with method A and B compared with the new dentures (P greater than 0.05). With both methods it was not possible to orientate the OP parallel to the Camper plane. None of the occlusal planes of the new dentures were parallel either. Their OP diverged on average by 7 degrees dorso-caudally. The time spent with method B to orient the OP and to determine the VDO was significantly lower than with method A (17-50 min).


Frequency analysis of electromyographic signals in mandibular elevators at maximum clench level.

Power spectral analysis of electromyogram (ENG) was used to investigate the relationship between mean power frequency (MPF) and sustained contraction time. Surface EMG activity was recorded from masseter and anterior temporal muscles on both sides for seven healthy subjects while clenching at intercuspal position in maximum potential level of these muscles. A visual sense feedback of EMG potential was used to control clenching level. According to linear regression analysis, there was a negative correlation between MPF of EMG and sustained contraction time. The results indicate that the slope of MPF versus contraction time may be used for detecting muscular fatigue in the stomatognathic system.


Chemically humanized murine monoclonal antibody against a cell nuclear antigen: usefulness in autoimmune diagnostics.

The cellular nuclear antigen SS-B/La is known to be a major antigenic target to an autoantibody in patients with Sjogren's syndrome and systemic lupus erythematosus. It is useful to detect an anti-SS-B/La antibody from patients' sera in a clinical point of view. We purified SS-B/La from rabbit thymus acetone powder by affinity chromatography with a murine anti-SS-B/La monoclonal antibody (1C3-H7). An enzyme-linked immunosorbent assay method, in which SS-B/La was used to coat a plate, was also successfully established. It is difficult to obtain a large volume of patient's serum with high antibody titer and high specificity as a positive control. We investigated whether or not a positive control from human could be replaced by a murine monoclonal antibody to SS-B/La. The 1C3-H7 was conjugated with a human IgG Fc' fragment using N-gamma-maleimidobutyryloxysuccinimide as a cross-linker. The chemically humanized murine monoclonal antibody (1C3-Fc') was recognized by antiserum specific for human IgG Fc fragment. 1C3-Fc' reacted to SS-B/La but not to other antigens. Furthermore, the titration curve of this conjugate ran parallel with those of patients' sera specific for SS-B/La. It is concluded that a chemically humanized murine monoclonal antibody is useful as a positive control in place of a human patient's serum.


Simultaneous expression of type I procollagen mRNA and albumin in cirrhotic human liver.

The gene expression of human type I procollagen was investigated in cirrhotic human liver by using in situ hybridization with nonradioactive DNA probes. Using in situ hybridization can provide direct evidence for the cell type capable for type I collagen synthesis in tissues. T-T dimerized DNA probes were used and DNAs hybridized in situ were detected immunohistochemically using specific antibodies against T-T dimer. The data demonstrated that type I collagen is synthesized in hepatocytes and stellate cells in pseudolobules and in fibroblasts in Glissons capsules in cirrhotic human livers. We indicated hepatocytes morphologically and functionally by using immunohistochemical localization of albumin, which was used as a marker of hepatocyte, since albumin is synthesized exclusively by hepatocytes.


Comparison of various methods for the enumeration of blood cells in urine.

This study compared the use of conventional urine microscopy, the KOVA system, Neubauer hemacytometry, and the Yellow IRIS for the determination of white blood cell (WBC) and red blood cell (RBC) counts in urine samples. Both KOVA WBC and RBC counts correlated better with the IRIS counts than with conventional microscopy. KOVA WBC counts correlated with Neubauer hemacytometry to the same degree as they did with IRIS WBC counts. The RBC count correlation was fairly similar between KOVA, hemacytometry, and the conventional method. It was concluded that the KOVA system is a suitable replacement for conventional urine microscopy.


Influence of biological variations and sample handling on measured microalbuminuria in diabetic patients.

Five immunochemical assays for determining low concentrations of albumin were investigated. These were a radioimmunoassay (RIA); turbidimetric immunoassays (TIA) both according to end-point measuring principle on a Cobas Fara and Hitachi 717 analysers, and according to kinetic measuring principle on a Turbitimer instrument; and a nephelometric immunoassay (NIA). All achieved the analytical goal necessary for optimal patient care. The correlations between the albumin concentrations measured with the different techniques were very good. In vitro glycation of albumin did not influence albumin concentrations measured by the five assays. Urine albumin excretion measured over 3 consecutive days showed considerable day-to-day variation. This was highest for spot-urine specimens and significantly lower for 24 h and timed-overnight samples. Variation of storage temperature (room temperature, 4 degrees C, -20 degrees C), time (up till 3 months), and pH (within the range pH 5-8) of the urine samples did not change significantly the measured albumin concentrations. Different sample preparations (vortex-mixing, centrifugation, and thawing) had no influence on the measured albumin concentration. In conclusion, a maximum standardization of the collection of timed-overnight urine samples for screening and 24 h urine samples for confirmation of microalbuminuria during 3 consecutive days is more crucial than the choice of the immunological technique.


A homogeneous assay system of aspartate aminotransferase iso-enzymes using proteases and application for clinical evaluation of myocardial infarction.

We designed a rapid, homogeneous assay for human aspartate aminotransferase (AST) isoenzymes, by a selective proteolysis of soluble AST (s-AST), using chymotrypsin and protease 401. The linearity of mitochondrial (m-AST) was elongated up to 4000 U/l. m-AST values from the human liver, and determined by a homogeneous assay using protease 401 or chymotrypsin, were relative to those obtained using an immunoprecipitation method. In perioperative patients or those with an acute myocardial infarction, the peaks of s-AST and m-AST values were noted 13 h and at 57 h after ictus, respectively, whereas the peak of ratio between was seen 6 h after ictus. In the case of Budd-Chiari syndrome, the maximum levels of the two AST activities were evident 14 days after hospitalization and the peak of ratio between them was seen after 7 days. We propose that this homogeneous assay can serve as a diagnostic tool for early phase detection of myocardial infarction and of Budd-Chiari syndrome.


Enzyme immunoassay for specific analysis of pancreatic stone proteins in human pancreatic juice.

In order to study the concentration of pancreatic stone protein (PSP) in human pancreatic juice, we investigated the influence of the insoluble form of PSP-S1 converted from PSP-S2-5 on PSP determination and the assay method for PSP-S1 precipitate after solubilizing PSP-S1. When bovine trypsin was added to pancreatic juice, PSP-S1 was converted from PSP-S2-5 and precipitated about 45-85% after 1 h. The precipitated PSP-S1 was dissolved in 0.1 M sodium acetate buffer, pH 4.0, and the concentration was measured by the enzyme immunoassay, with similar reactivity to PSP-S1 and PSP-S2-5. The proposed method can offer accurate and specific analysis of the PSP level in pancreatic juice. The results of the fractionation of pancreatic juice and duodenal juice on Mono S cation-exchange chromatography suggested that the major component of PSP was PSP-S2-5 in pancreatic juice and PSP-S1 in duodenal juice.


Automated microparticle enzyme immunoassay for neural thread protein in cerebrospinal fluid from Alzheimer's disease patients.

An automated microparticle enzyme immunoassay (MEIA) with the IMx analyzer for the detection of neural thread protein (NTP) in cerebrospinal fluid (CSF) from Alzheimer's disease (AD) patients was developed. This assay uses monoclonal antibodies produced against the purified pancreatic form of the protein. The assay employs one monoclonal antibody covalently coupled to the microparticle to capture immunoreactive material in CSF or brain tissue. The second monoclonal antibody was conjugated to alkaline phosphatase and serves as detection antibody. The assay provides results in approximately 45 minutes with a sensitivity of 60 pg/ml (3 fmoles/ml). The titration curve of both normal and AD CSF resulted in a linear relationship with respect to the volume of CSF used. A similar relationship was observed when normal and AD brain tissue extracts were serially diluted. The molecular weight of NTP in CSF was approximately 20 kD as determined by gel filtration method under non-denaturing conditions. The recovery for pancreatic thread protein (PTP) spiked in either normal or AD CSF was 104% and 108%, respectively. Intra-, inter-, and total assay CVs (coefficient of variation) for controls were less than 2.9%, 3.3% and 3.0%, respectively. This assay will provide a useful tool in the study of the Alzheimer's disease and may help research in diagnosis and prognosis of Alzheimer's disease and related disorders.


A flexible, efficient, checkerboard immunoblot system for the detection and semiquantitation of specific antinuclear antibodies.

In this paper an uncomplicated method for the simultaneous detection and semiquantitation of 11 of the 12 commonly studied antinuclear antibodies (ANA) in a single run is described. This new application of checkerboard immunoblotting (CBIB) is based upon available technology and employs purified antigens which can be either purchased or produced in-house. CBIB requires no electronic instrument, can be formatted to meet the needs of the user, is rapidly performed, and has acceptable labor and materials costs. Data on the use of the method to examine available reference antisera is presented. CBIB has also proven practical for the clinical study of 18 sera, at two dilutions per membrane, for each set of specific antinuclear antibodies, also at two or more dilutions.


Comparison of two automated nephelometers.

The intercalibration precision and linearity were determined for two representative analytes, apolipoprotein A1 (apo A1) and immunoglobulin G (IgG), on the Beckman Array and the Behring Nephelometer 100 (BN-100). For two of nine samples analyzed, poor precision was observed for IgG with the Array. The poor precision for these two samples is attributed to large systematic shifts. A statistical non-linearity was observed for apo A1 with the BN-100, but this non-linearity does not exclude use of this assay for clinical diagnosis. Method comparisons were done for 12 analytes: apo A1, apo B, IgG, IgA, IgM, IgE, C3, C4, albumin, C-reactive protein, alpha-1-antitrypsin, and ceruloplasmin. These comparisons showed proportional biases of > 10% for seven of 12 analytes. Furthermore, correlation coefficients were < 0.96 for seven of 12 analytes. We conclude that comparing results obtained from the two different nephelometers is of only limited value for the individual patient.


Streptomyces: a superior source for cholesterol oxidase used in serum cholesterol assay.

The present study compared three cholesterol oxidase sources (Nocardia, Streptomyces, and Pseudomonas sps.) for serum cholesterol assay. We found cholesterol oxidase isolated from Streptomyces was superior than those isolated from Nocardia and Pseudomonas sps. Performances of the reagent contained Streptomyces cholesterol oxidase was excellent and comparable to the performances obtained from reagent contained Nocardia cholesterol oxidase. Moreover, the reagent containing Streptomyces cholesterol oxidase had the lowest cost and had the longest shelf-life ($U.S. 0.17/mL, 10 weeks) compared to the reagent contained Nocardia ($U.S. 0.50/mL, 8 weeks) or Pseudomonas ($U.S. 0.20/mL, 6 weeks) cholesterol oxidase.


Immunoelectron microscopic localization of antigens which react with islet cell cytoplasmic antibodies within human pancreatic beta cells.

The presence of circulating autoantibody to islet cell cytoplasm is considered to be an important marker of Type 1 (insulin-dependent) diabetes mellitus. In the present study using islet cell cytoplasmic antibody positive patient sera as the first antibody, we studied the intracellular distribution of its antigen at the electron microscopic level using the pre-embedding immunoperoxidase method. Specific immunoreactivity was found in the membranes of beta cell-secretory granules and cytoplasmic membranes. This result is compatible with the interpretation that the antigen(s) on the membranes of beta cell secretory granules is (are) the target of islet cell cytoplasmic antibody.


Single point quantification of antibody by ELISA without need of a reference curve.

A new method for the quantification of antibodies in the enzyme-linked immunosorbent assay is described. This procedure replaces titer determinations based on end-point dilution of the antibody under investigation. Here, the sample is tested in a single dilution and the optical density (OD) obtained is used in the equation log10 titer = alpha.OD beta. The titer can then be calculated by inserting into the formula the values for the constants alpha and beta, which are specified by the manufacturer for each separate batch of kit reagents. This so-called alpha-method saves time and reagents while providing results which are equal to the titration method in accuracy and superior in precision. The alpha-method is also a simpler and reliable alternative to the use of standard or reference curves for the quantification of the antibodies in I.U./ml.


Quality of life across age and family stage.

It is clear that the quality of life of the individual is intertwined with that of his or her family. Therefore, health care professionals and other professionals who work with families facing terminal illness must (1) identify those factors that put the patient and the family at risk of suffering further disruption of psychosocial quality of life and (2) seek out whatever resources are necessary to help the patient and the family improve their quality of life. Families with young children are more dependent on external resources than are other families, and they place more strains on the spouse caregiver. If these resources are not available, parents are less able to handle crucial developmental family matters. Clinicians who are aware of this deficit are better able to recognize role performance problems and help families obtain the external resources. Secondly, families who have relied on ascribed roles before the parent fell ill are at greater risk of psychosocial dysfunction: they lack appropriate ways to deal with role reallocation in order to make the best use of their talents. Professionals who are sensitive to this can help families adapt to role changes. A third area that places families at risk is poor spousal communication. Good communication patterns appear to facilitate adjustment to both terminal illness and bereavement (4,6). Professionals trained in family and social therapy are equipped to help family members develop effective communication, which can in turn help them prioritize tasks, seek outside resources when needed, and negotiate role assignments.


Quality of life: the family and Alzheimer's disease.

AD possesses unique features that make caregiving particularly burdensome. The quality of life of the caregiver is inevitably affected, but there are many intervening variables such as the strength of the existing relationship and the presence of a social support system that can mediate the outcome. Health professionals can play a vital role by providing a continuous source of advice, support, and help to assist the caregiver in the difficult task of tending a loved one during this long and stressful illness.


Photoinduced cutaneous inflammatory response by psoralens.

Our studies describe the inflammatory response in rabbit skin induced by topical application of 8-methoxypsoralen (8-MOP) and UVA-visible irradiation (320-700 nm). Increase in vascular permeability (iVP) and accumulation of polymorphonuclear leucocytes (aPMN) at the test sites were quantitated using 125I-albumin and 51Cr-labelled PMNs respectively. Erythema was graded visually. 8-MOP cream was applied topically and irradiated. The erythemal response, aPMN and iVP at the test sites were quantitated at 6, 24, 48 and 72 h post-irradiation. The iVP and aPMN were maximal at 24 h; the erythemal response was the same at 24-48 h. The responses were dependent on 8-MOP concentration and irradiation dose. Topical application of 200 micrograms 8-MOP cream followed by irradiation for 2 h (9.4 J cm-2) produced 3-7 times iVP, 2-4 times aPMN and intense erythema at the test sites after 24 h. Neither aPMN nor iVP was detected before 6 h and erythemal response was not observable up to 16 h after irradiation. The aPMN and iVP gradually subsided in 72 h, although the erythemal response was still present. The repeated exposure of 8-MOP-treated sites for three consecutive days 24 h apart did not produce appreciable iVP or aPMN at 72 h or 24 h after the last exposure; however, erythema persisted. The 8-MOP-treated sites previously exposed for three consecutive days on reapplication of 8-MOP cream plus irradiation showed significantly less response compared with non-pretreated sites. Our results suggest that the erythemal response is not directly related to either iVP or aPMN.


Synthesis of psoralens and analogues.

This review presents briefly the various classical syntheses of psoralens and angelicins which generally start from preformed suitably substituted coumarin or benzofuran derivatives. However, the discovery of the photocyclo-C-4 addition of psoralens to pyrimidine bases prompted new developments in this area. In particular, improved synthesis of psoralens and substituted angelicins, and synthesis of new analogues such as furochromenes, pyridopsoralens, pyrano benzopyrandiones, dioxinocoumarins and aza-psoralens were described recently. This review focuses on the chemical syntheses of these various compounds.


The evolution of photochemotherapy with psoralens and UVA (PUVA): 2000 BC to 1992 AD.

The therapeutic uses of naturally occurring psoralens in modern-day medicine (8-methoxypsoralen (8-MOP), 5-methoxypsoralen (5-MOP), 4,5',8-trimethylpsoralen, and a few other synthetic psoralens) have evolved through five stages of development. (1) In the historical period (2000 BC to 1930 AD), the pigment-stimulating properties of naturally occurring plants containing psoralens were described anecdotally. (2) The second period (1930-1960) dealing with the chemistry of psoralens involved extraction, identification of their structure, synthesis, and the relationship between chemical structure and their photoreactivity and pigment-stimulating properties. The treatment of vitiligo with oral and topical 8-MOP became popular. (3) In the third period (1960-1974), we witnessed a new beginning and the growth of basic science studies and clinical investigations into various biological properties of psoralens including action spectrum studies, mutagenesis and carcinogenesis studies, in vitro and in vivo photoreactivity studies of various psoralens with DNA, RNA, proteins, and pharmacological and toxicological studies in vitiligo patients undergoing long-term therapy for repigmentation. (4) The fourth period (1974-1988) is recognized as the period of photochemotherapy and the development of the science of photomedicine which established the therapeutic effectiveness of psoralens in combination with newly developed UV irradiation systems that emitted high-intensity UVA radiation in the treatment of severe psoriasis, mycosis fungoides, and over 16 other skin diseases. The effectiveness of PUVA (psoralen + UVA) was confirmed by well controlled clinical trials in thousands of patients, both in the USA and in European countries. Combination therapy with oral retinoids and PUVA contributed to greater effectiveness and long-term safety of psoralen photochemotherapy. (5) In the fifth period (1989 and beyond), psoralens are now emerging as photochemoprotective agents against non-melanoma skin cancers and as immunologic modifiers in the management of certain patients with disorders of circulating T-cells using new techniques of photopheresis. In the final analysis, perhaps the application of pharmacological and therapeutic concepts and principles of using psoralens in combination with UVA has contributed to the development of a new science of photomedicine in which the interaction between basic scientists, photobiologists, and physicians has produced both basic and new clinical knowledge for the care and control of human suffering.


New aspects of the repair and genotoxicity of psoralen photoinduced lesions in DNA.

Several approaches are described aiming at a better understanding of the genotoxicity of psoralen photoinduced lesions in DNA. Psoralens can photoinduce different types of photolesions including 3,4- and 4',5'-monoadducts and interstrand cross-links, oxidative damage (in the case of 3-carbethoxypsoralen (3-CPs)) and even pyrimidine dimers (in the case of 7-methylpyrido(3,4-c)psoralen (MePyPs)). The characterization and detection of different types of lesions has been essential for the analysis of their possible contributions to genotoxicity. For example, oxidative damage photoinduced by 3-CPs can be detected by the formamidopyrimidine glycosylase (FPG) protein. Furthermore, it is shown how the presence of MePyPs induced monoadducts may interfere with the photoreactivation of concomitantly induced pyrimidine dimers, how the ratio of monoadducts and interstrand cross-links (CL) affects the occurrence of double-strand breaks during the repair of photolesions and genotoxicity. In vitro treatment of yeast plasmids, followed by transformation, also indicates that the repair of photoadducts on exogenous DNA differs for 8-methoxy-psoralen (8-MOP) induced mono- and diadducts and for monoadducts alone. The recombinational rad52 dependent pathway is not needed for the repair of 8-MOP induced monoadducts. The results obtained suggest that the genotoxic effects of psoralens are conditioned by the nature, number, ratio and sequence distribution of the photolesions induced in DNA.


Recent advances in the synthesis and structure determination of site specifically psoralen-modified DNA oligonucleotides.

We have developed novel methods for the preparation of multimicromole quantities of extremely pure, uniquely photoadducted psoralen-DNA cross-links, furan-side monoadducted DNA and pyrone-side monoadducts. Psoralen cross-linked and furan-side monoadducted DNA were produced by employing high intensity argon ion and krypton ion lasers as light sources. Pyrone-side monoadducts were prepared by base-catalyzed photoreversal of psoralen cross-links. The various psoralen-adducted DNA oligomers were efficiently purified by high performance liquid chromatography. These methods have permitted us to synthesize 4 mumol each of a self-complementary 8-mer d(GCGTACGC) 4'-(hydroxymethyl)-4,5',8-trimethylpsoralen (HMT) furan-side monoadduct and HMT cross-link. Preliminary nuclear magnetic resonance (NMR) data on the HMT cross-linked 8-mer d(GCGTACGC) have been obtained which confirmed the presence of the diadducted psoralen at the unique 5'TpA3' site. NMR data obtained from the 8-mer furan-side monoadduct revealed that the psoralen molecule is intercalated into the DNA double helix. Preliminary crystals of 8-mer cross-linked DNA molecule have been grown. Conditions for the growth of X-ray diffraction-quality crystals and the further analysis of these crystals are now in progress.


Benzoangelicins: new monofunctional DNA photobinding agents.

4,6-Dimethylbenzoangelicin, obtained by fusing a benzene ring at the furan side of 4,6-dimethylangelicin, was studied in terms of crystal structure and interactions with DNA in both ground and excited states. 4,6-Dimethylbenzoangelicin has a planar structure and forms a molecular complex with DNA, undergoing intercalation inside the double helix. Under UVA irradiation, it photoconjugates covalently with the macromolecule, showing a DNA photobinding rate slightly lower than that of 8-methoxypsoralen, involving however only its 3,4 double bond, i.e. behaving as a pure monofunctional agent. The parameters of dark binding and photobinding were determined, and two C4 cycloadducts with thymine were isolated and characterized.


Synthesis and photobiological activity of new methylpsoralen derivatives.

The synthesis and the photobiological activity of two new derivatives of psoralen (3,4'-dimethylpsoralen and 3,4',8-trimethylpsoralen) has been described. They are congeners of the monofunctional linear furocoumarin 3,4'-dimethyl-8-methoxypsoralen. Both compounds bind very efficiently to DNA, the extent of this process being modulated by the nature of substituents at position 8. The number of photolesions is linearly related to adenine-thymine content of the nucleic acid which indicates lack of specificity for particular sequences of the nucleic acid. The structural arrangement of DNA (single stranded, double stranded, nucleosomes and chromatin) plays an additional role in affecting the photobinding process. Unlike their 8-methoxy congener the new derivatives cross-link DNA to a substantial extent. Their photobiological properties, including erythema formation, reflect very closely those of 8-methoxypsoralen (8-MOP). The conclusion can be drawn that 3,4'-dimethyl-8-MOP represents a unique derivative in its family.


Current perspectives of singlet oxygen detection in biological environments.

There is widespread acceptance that singlet oxygen is a key intermediate on one of the pathways leading to the phenomenon of photodynamic action. However, the identification of this moiety within a particular biological system and the determination of a direct link between its presence and a particular photodynamic effect is a goal which photobiologists have hitherto failed to achieve. The aim of this review is to assess the problems associated with such a goal and methods whereby they might be overcome. Initially the general photochemical and environmental factors which govern the ability of a photosensitizer to promote photodynamic action via the intermediacy of singlet oxygen are introduced and the fundamental parameters defining the formation, decay and reactivity of this species summarized. The experimental requirements for relating a particular photodynamic effect to singlet oxygen intermediacy are then analysed and the intrinsic properties of singlet oxygen which will influence this goal are discussed. Having concluded that the singlet oxygen detection method of choice for this purpose is that in which the IR emission at 1269 nm of this molecule is monitored, the advantages and disadvantages of pulsed and continuous wave photoexcitation of cellular systems are analysed. It becomes evident that, no matter what the future improvements in instrumentation are likely to be, the inherent natures of singlet oxygen and the biological system lead to a kinetic situation which will preclude a successful time-resolved solution to this problem. In contrast, experimentation with continuous wave systems holds out significant hope for the future. In particular, the use of phase modulation techniques to overcome background emission problems, the enhancement of photosensitizer optical densities as a consequence of higher extinction coefficients and/or improved photosensitizer delivery systems and the use of high power lasers and/or improved light delivery systems can, at least in principle, lead to the solution of the problem addressed herein.


Photobleaching of 1,3-diphenylisobenzofuran by novel phthalocyanine dye derivatives.

As part of a wider programme to identify novel photosensitizers for photodynamic therapy, the ability of a number of phthalocyanine dyes, including some novel copper phthalocyanine derivatives with a range of water solubilities, to produce potentially cytotoxic species in solution was examined. The experiments were performed in dimethylformamide using 1,3-diphenylisobenzofuran (DPIBF) as the scavenger. The study revealed that all the dyes tested produced DPIBF photobleaching on illumination in vitro, but with widely different (greater than 12x) rates. The possible correlation of DPIBF photobleaching rates with a number of the dyes' properties is discussed.


Photodynamic properties of naphthosulfobenzoporphyrazines, novel asymmetric, amphiphilic phthalocyanine derivatives.

Metallo naphthosulfobenzoporphyrazines sulfonated to different degrees (M-NSBP) were prepared, and their potential as photosensitizers for the photodynamic therapy (PDT) of cancer was evaluated. M-NSBP can be viewed as hybrid molecules between sulfophthalocyanines and naphthalocyanines resulting in distinct differences in the absorption spectra between the mono-through tetrasulfonated derivatives. This feature greatly facilited their purification. Using V-79 Chinese hamster cells in vitro, the disulfonated derivatives were found slightly more photoactive than the hydrophilic trisulfonated derivatives while the monosulfonated derivative was inactive, in spite of a sixfold higher cell uptake. In the case of the di- and trisulfonated derivatives, differences in phototoxicity correlated well with their relative cell uptake. Substitution of Al for Zn had little effect on the extent of phototoxicity of the M-NSBP. In vitro PDT of the EMT-6 cells after in vivo dye administration, revealed a similar potency for direct cell killing between the di- and trisulfonated AlOH-NSBP, while the monosulfonated analog was inactive. PDT with the amphiphilic disulfonated AlOH-NSBP on the EMT-6 mammary tumor in BALB/c mice induced a significant tumor response, while the monosulfonated derivative was much less active.


Light-induced fluorescence spectroscopy of adenomas, adenocarcinomas and non-neoplastic mucosa in human colon. I. In vitro measurements.

In an attempt to evaluate whether induced fluorescence could be exploited to discriminate neoplastic from non-neoplastic tissue, fluorescence spectroscopy was performed at 450-800 nm on 83 biopsy specimens of colonic mucosa. Measurements showed that fluorescence spectra of adenoma, adenocarcinoma and non-neoplastic mucosa manifest dissimilar patterns. Nine variables, whose photophysical and/or biological bases need further investigation, were derived from the spectra. Discriminant functions between the groups of lesions were determined by using a stepwise discriminant analysis. The diagnostic test had a sensitivity of 80.6% and 88.2%, and a specificity of 90.5% and 95.2% in discriminating neoplastic from non-neoplastic mucosa and adenoma from non-neoplastic mucosa respectively. These results suggest that fluorescence spectroscopy has the potential to improve endoscopic diagnosis of premalignant and malignant lesions of colonic mucosa.


Inactivation and mutation induction in Saccharomyces cerevisiae exposed to simulated sunlight: evaluation of action spectra.

The effectiveness of polychromatic light irradiation was investigated for haploid yeast cells. Inactivation and mutation induction were measured in both a RAD-wildtype strain and an excision-repair defective strain. The behaviour of vegetative "wet" cells was compared to that of dehydrated cells. The aim of the study was to assess the interaction of UVC with other wavelengths in cells of different states of humidity. The irradiation procedure was therefore carried out using a solar simulator either with full spectrum or with a UVC-blocking filter (modified sunlight) added. The results were analysed on the basis of separately determined action spectra. The summation of the efficiency of individual wavelengths was compared to the values obtained from polychromatic irradiation. It is shown that the effects caused by the whole-spectrum irradiation in wet cells can be predicted sufficiently from the calculation, while dried wildtype cells exhibit higher mutation rates. Thus it can be assumed that drying-specific damage leads to lethal and mutagenic lesions which are processed in different ways, causing a synergistic behaviour in mutation induction. Irradiation of vegetative cells with modified sunlight (UVC-) results in less inactivation and lower mutation rates than were calculated. From these results it can be concluded that this antagonistic behaviour is caused by the interaction of near-UV photoproducts.


UVA- and UVB-induced changes in collagen and fibronectin biosynthesis in the skin of hairless mice.

The modifications induced in hairless mouse skin by chronic UV irradiation were investigated. Skin explant cultures were used to study UVA- and UVB-induced changes occurring in interstitial collagen (type I and type III) and fibronectin biosynthesis. To study the long-term effects, albino hairless mice were irradiated with UVA radiation alone from two sources with different spectral qualities or with UVB. UVA and UVB radiation produced a significant increase in the ratio of type III to type I collagen (more than 100% for UVA-irradiated skin and about 60% for UVB-irradiated skin) accompanied by a significantly increased fibronectin biosynthesis (50% or more in all irradiated groups). Irradiation with either UVA or UVB alone had no significant effect on the total collagen synthesis and resulted in only a slight decrease in the total collagen content of the skin determined as hydroxyproline. This decrease was significant only in the case of the group irradiated with UVA (xenon) (decrease of 25%, expressed as micrograms of hydroxyproline per milligram wet weight). A significant decrease in collagen hydroxylation (expressed as radioactive hydroxyproline/radioactive hydroxyproline plus proline in neosynthesized collagen) was observed of about 50% in skin irradiated with UVA (xenon) but not in UVB-treated skin. Several of the above modifications (increased fibronectin biosynthesis, increased collagen type III to type I ratio) correspond to the modifications observed during the aging of non-irradiated hairless mice. Therefore it appears that UV irradiation accelerates the modifications of extracellular matrix biosynthesis observed during aging.


Photochemistry of nucleic acids in cells.

A survey of the recent aspects of the main photoreactions induced by far-UV radiation in cellular DNA is reported. This mostly includes the formation of cyclobutadipyrimidines, pyrimidine(6-4)pyrimidone photoadducts and related Dewar valence isomers in various eukaryotic and prokaryotic cells, as monitored by using either specific or more general assays. Information is also provided on mechanistic aspects regarding the formation of 5,6-dihydro-5-(alpha-thyminyl) thymine, the so-called "spore photoproduct" within far-UV-irradiated bacterial spores. The second major topic of the review deals with the effects of near-UV radiation and visible light on cellular DNA which are mostly mediated by photosensitizers. The main photoreactions of furocoumarins with DNA, one major class of photosensitizers used in the phototherapy of skin diseases, involve a [2 + 2] cycloaddition to the thymine bases according to an oxygen-independent mechanism. In contrast a second type of photosensitized reaction which appears to play a major role in the genotoxic effects of both near-UV and visible light requires the presence of oxygen. The photodynamic effects which are mediated by either still unidentified endogenous photosensitizers or defined exogenous photosensitizers lead to the formation of a wide spectrum of DNA modifications including base damage, oligonucleotide strand breaks and DNA-protein cross-links.


Effect of light on calcium transport in bull sperm cells.

The effect of light on calcium transport was studied. Bull sperm cells were irradiated with an He-Ne (630 mm) laser and a 780 nm diode laser at various energy doses, and 45Ca2+ uptake was measured by the filtration technique. It was found that there is an accelerated Ca2+ transport in the irradiated cells, which means that laser light can stimulate Ca2+ exchange through the cell membrane. This may cause transient changes in the cytoplasmic Ca2+ concentration which, in spermatozoa, has a regulatory role in control of motility and acrosome reaction, and in other cells can trigger mitosis.


An animal model for extracorporeal photochemotherapy based on contact hypersensitivity.

Recently, photopheresis was introduced as a specific immune suppressor in several T cell mediated disorders. In order to study photopheresis, animal models are indispensable. This report describes an easy to handle model for this purpose. It concerns the Wistar-derived rat with contact hypersensitivity (CHS), also a T cell mediated disorder that has already been studied extensively in several other fields of research. After subsequent exposure to 8-methoxypsoralen (8-MOP) and ultraviolet A radiation (UVA), white blood cells from CHS rats were intravenously injected into other syngeneic rats suffering from the same disorder. This treatment appears to be very efficacious in suppressing the immunological response against the applied contact allergen, 2,4-dinitrofluorobenzene (DNFB). Cells subsequently exposed to UVA and 8-MOP did not have any effect.


Substance abuse and B-cluster disorders. I: Understanding the dual diagnosis patient.

The patient population that presents with both a B-cluster personality disorder and substance abuse is a challenge to professionals in both the mental health and substance abuse treatment fields. The coexistence of both disorders is not uncommon and is frequently encountered in substance abuse treatment, social welfare, and mental health settings. The complexity of the clinical picture for these patients and their greater resistance to treatment severely taxes the practitioner's skills. Even without a clear understanding of the primary causative pathology, effective treatment modes based on a recognition of the interactive and interdependent nature of the two disorders can be developed. Part I of this two-part article presents the characteristics and clinical features of the population as well as a model for understanding some of the motivating principles behind the patient's conduct, feelings, thoughts. This is followed by guidelines for the clinician's attitude, desired characteristics, and role in dealing with this population. Part II presents guidelines for the treatment of this patient population.


Risk and reciprocity: HIV and the injection drug user.

Injecting practices of illicit drug users in San Antonio, Texas, were studied by means of informal field interviews and participant observation. The methods injection drug users (IDUs) employed to obtain drugs seemed to affect their HIV risk behaviors. Many of the methods involve reciprocal exchanges between a person who has drugs and a person who wants drugs. The exchanges frequently occur in the context of asymmetrical social interactions. The person with the drugs usually occupies the dominant role in the interaction and determines the needle hygiene for both parties. Analysis of the decision-making process of IDUs indicates that the party in the dominant role may choose not to disinfect a syringe for a variety of reasons. An understanding of the subcultural rules that govern these interactions may provide valuable clues to researchers or educators who are designing interventions aimed at reducing HIV risk behaviors among IDUs. This research suggests that for IDUs in subordinate roles, education alone may be insufficient to produce behavior changes necessary to eliminate risk of HIV infection.


The disease controversy and psychotherapy with alcoholics.

This article discusses conducting psychotherapy with alcoholics in light of the controversy about whether alcoholism is a disease. The belief that alcoholism is a disease forces many clinicians to offer abstinence from alcohol as the only option for alcoholics who seek treatment. From this perspective, the alcoholic must be helped to accept the idea that he or she has a disease and that to recover from this problem, drinking must stop. Others maintain that alcoholism may not be a disease and view alcoholic drinking as maladaptive behavior. From this vantage point, helping the patient to control or to moderate drinking might be considered. These two distinct paradigms lead to divergent treatment goals, which leaves the clinician in a quandary about how best to treat an individual who experiences a drinking problem. To resolve this dilemma, it is suggested that the clinician who works with alcoholics entertain a multiplicity of perspectives and should not be blinded by any one paradigm. While control of alcohol intake must take place if such patients are to improve their functioning, the author argues that recovery can occur either by abstinence or through moderating drinking.


Substance abuse and B-cluster disorders. II: Treatment recommendations.

Part I of this two-part article described the characteristics and clinical features of the patient population that presents with both a B-cluster personality disorder and substance abuse. It also included guidelines for the clinician. Part II presents further recommendations for the treatment of this population, taking into account how the combination of these disorders manifests itself. The treatment approach should be kept simple and easy for patients to understand and should promote their ability to think rationally about the effect of their emotions on their behavior and its outcomes. A firm structure is critical to compensate for the lack of internal control of these patients and to prevent the manipulation that results from their view of the instrumentality of others. Denial, resistance, countertransference, and relapse to addictive behaviors are all potential barriers that are often encountered when attempting to treat this population. Group therapy with this population presents unique challenges to the clinician. As with individual therapy, a firm structure is imperative, with the clinician in charge of process and content.


Smoked cocaine: patterns of use and pulmonary consequences.

This article offers a perspective on the use of volatilized alkaloidal cocaine in its freebase and crack forms and on the pulmonary consequences of such use. The inhalational route of administration of freebase and crack cocaine exposes the lung to their combustion products, raising concern about possible adverse pulmonary effects. A brief historical review of cocaine and its methods of use precedes the presentation of data concerning current modes and patterns of use and some pulmonary complications of crack and freebase use. Results from a systematic study of a large sample of cocaine users document a high frequency of occurrence of acute respiratory symptoms in temporal association with cocaine smoking. No relationship was detected between the prevalence of acute pulmonary symptoms and identifiable aspects of techniques of cocaine administration. These results suggest that the respiratory consequences of alkaloidal cocaine are most likely attributable to the inhaled cocaine itself, rather than to variable characteristics of usage.


An overview of cocaethylene, an alcohol-derived, psychoactive, cocaine metabolite.

Cocaethylene is a psychoactive ethyl homologue of cocaine, and is formed exclusively during the coadministration of cocaine and alcohol. Not a natural alkaloid of the coca leaf, cocaethylene can be identified in the urine, blood, hair, and neurological and liver tissue samples of individuals who have consumed both cocaine and alcohol. With a pharmacologic profile similar to cocaine, it can block the dopamine transporter on dopaminergic presynaptic nerve terminals in the brain. It increases dopamine synaptic content, provoking enhanced postsynaptic receptor stimulation, resulting in euphoria, reinforcement, and self-administration. Equipotent to cocaine with regard to dopamine transporter affinity, cocaethylene appears to be far less potent than cocaine with regard to serotonin transporter binding. Lacking the serotonergic-related inhibitory mechanism, cocaethylene appears to be more euphorigenic and rewarding than cocaine. Synthesized and administered cocaethylene has a behavioral stimulation profile similar to cocaine. Cocaethylene has been shown to be less potent and equipotent to cocaine, and alcohol plus cocaine produces more stimulatory locomotor behavior in mice than either drug alone. Equipotent to cocaine with regard to primate reinforcement and self-administration, cocaethylene can substitute for cocaine in drug discrimination studies, and can produce stimulation of operant conditioning in rats. With regard to lethality, cocaethylene has been shown to be more potent than cocaine in mice and rats. The combination of cocaine and alcohol appears to exert more cardiovascular toxicity than either drug alone in humans. Alcohol appears to potentiate cocaine hepatotoxicity in both humans and mice.


Treatment of acute, adverse psychedelic reactions: "I've tripped and I can't get down".

The resurgence of the use of LSD by a young, inexperienced population increases the likelihood of the occurrence of adverse psychedelic reactions. While the treatment of choice remains supportive, nonjudgmental talkdown, intramuscular lorazepam and haloperidol offer invaluable and specific adjuncts to care.


Selecting diagnostic tests to identify febrile infants less than 3 months of age as being at low risk for serious bacterial infection: a scientific overview.

To select diagnostic tests that confidently identify febrile infants less than 3 months of age seen at an outpatient facility as being at low risk for serious bacterial infection (SBI). An English-language literature search employing MEDLINE (1966 to 1991), Science Citation Index (1977 to 1991) using key citations, bibliographic reviews of primary research and review articles, and correspondence with authors of recent articles. After independent review by two observers, 10 of 333 originally identified titles were selected on the basis of prespecified selection criteria. Two observers independently assessed studies by using explicit methodologic criteria for evaluating the quality of studies dealing with diagnostic tests. One reviewer extracted all the data from the articles; the second reviewer checked these data for accuracy. On the basis of prespecified criteria, results were pooled from two studies that used the Rochester criteria, had high methodologic validity, and did not have significant heterogeneity (p = 0.32, Breslow-Day test), to give an estimate of the best negative likelihood ratio (95% confidence interval) for SBI = 0.03; 0 to 0.23). The negative likelihood ratio of 0.03 allowed us to conclude that after the Rochester criteria for low risk of SBI have been satisfied, the probability of SBI in a febrile infant less than 3 months of age drops from a baseline rate of 7% (or 1 in 14 infants) to 0.2% (or 1 in 500). An expectant approach in these low-risk infants is therefore a reasonable choice.


"Living with the dirty secret": problems of disclosure for methadone maintenance clients.

This article focuses on the management of stigma by methadone maintenance patients. It explores (1) the consequences of this persistent stigma, which necessitates the need for secrecy, (2) the adaptations made in order to successfully "pass as normal," and (3) the contexts in which methadone-maintained individuals decide to disclose their stigmatized status. The data reported and analyzed were gathered between 1980 and 1989 during a series of studies funded by the National Institute on Drug Abuse. The three studies--"Women on Methadone," "Getting Off Methadone," and "Alameda County Methadone Study"--utilized qualitative, in-depth interviews and ethnographic sampling techniques, primarily chain referral sampling. After ten years of interviewing women and men in various stages of their methadone maintenance careers, recurring themes emerged, one of which was that being a methadone patient is a marginal identity; not quite junkie, not quite conventional. Clients' efforts to manage this stigmatized identity were often shrouded in anguish and secrecy. Methadone patients were in a kind of identity limbo; a holding pattern between two extremely different social worlds. They were trying to effect an identity transformation; however, in many circumstances they were still associated with and defined by their "dirty secret."


Defining the population of human immunodeficiency virus-infected children at risk for Mycobacterium avium-intracellulare infection.

We reviewed the 22 cases of Mycobacterium avium-intracellulare (MAI) infection that occurred among 196 human immunodeficiency virus-infected children seen at the National Cancer Institute Pediatric Branch from December 1986 through April 1991, and an additional 65 charts from children with cultures negative for MAI. All patients with proven MAI were receiving antiretroviral therapy with zidovudine, dideoxyinosine, or a combination of zidovudine and dideoxycytidine. All patients had disseminated MAI infection, except one adolescent who had only evidence of localized lymphadenitis. All cases of MAI but one were diagnosed before death. The overall incidence of MAI was 11% in our patients but increased to 24% in patients whose absolute CD4 cell counts were < 100 cells/mm3. Symptoms most commonly associated with MAI infection included recurrent fever (86% of patients), weight loss or failure to thrive (64%), neutropenia (55%), night sweats (32%), and abdominal pain (27%). Children infected with MAI had a mean CD4 percentage of 2% (range, 0% to 7%) and a mean absolute CD4 count of 12 cells/mm3 (range, 0 to 48 cells/mm3), significantly lower than in the remainder of the clinic population or the group of children with cultures negative for MAI. Of 20 patients with MAI infection who were tested, 10 had measurable p24 antigen with a mean value 939 pg/ml (range, 77 to 3270 pg/ml) compared with 19 of 59 patients without MAI infection in whom the mean positive value was 413 pg/ml. There was no difference in survival time between those children with documented MAI infection (median survival time, 45.5 weeks) and those with similarly low CD4 counts and cultures negative for MAI (median survival time, 50.4 weeks). Future improvements in therapeutic options may make screening of pediatric human immunodeficiency virus-infected patients with low CD4 counts a reasonable plan.


Vasodilatory response of the coronary arteries after Kawasaki disease: evaluation by intracoronary injection of isosorbide dinitrate.

To determine coronary artery diameter change before and after an intracoronary infusion of isosorbide dinitrate in patients who have had Kawasaki disease, we performed coronary angiography in 188 such patients. Four patient groups were studied. Groups 1 to 3 consisted of patients with Kawasaki disease: group 1 (the "normal" group; n = 65) had no coronary artery lesions; patients in group 2 had regression to normal of a coronary artery aneurysm after Kawasaki disease and were divided, according to the time since onset, into two subgroups, group 2-a (n = 20) being at an early stage after regression to normal (followed for 1.7 +/- 0.7 years) and group 2-b (n = 34) being at a later stage after regression (followed for 8.7 +/- 2.9 years); and group 3 (the "abnormal" group; n = 25) had persistent coronary artery aneurysm or stenosis or both. Group 4, the control group (n = 44), consisted of patients without Kawasaki disease who had congenital heart disease with normal coronary arteries. The coronary artery diameter change was calculated by the following formula: Percentage of change = (Diameter after infusion - Diameter before infusion)/Diameter before infusion x 100. The percentages of change in the coronary artery diameter after isosorbide dinitrate infusion were 16.2% +/- 13.4% (normal group), 11.3% +/- 7.2% (early-regression group), 7.8% +/- 8.3% (late-regression group), 6.8% +/- 7.8% (abnormal group), and 15.2% +/- 11.8% (control group). In the abnormal group, there was significantly poorer dilation than in the control and normal groups. The late-regression group also had significantly less change in diameter than did the control and normal groups (p < 0.05). These data suggest (1) that the coronary artery after Kawasaki disease becomes stiff not only in patients with persistent abnormal lesions but also in those with regressed aneurysms and (2) that stiffness of the coronary artery may be a risk factor for atherosclerosis.


Outcome of coronary artery aneurysms after Kawasaki disease.

From 1974 through 1991, a total of 583 children with Kawasaki disease were seen at the Hospital for Sick Children, in Toronto, of whom 80 (13.7%) had coronary artery involvement. There were 55 boys and 25 girls, whose mean age at onset was 2.9 +/- 2.5 years, followed for a mean period of 4.0 +/- 3.6 years. Giant aneurysms (maximum diameter > or = 8 mm) were found in 22 children, moderate-sized aneurysms (> or = 4 to < 8 mm) in 44, and dilation lesions (< 4 mm) in 14. Myocardial infarction occurred in 9 (1.5%), all of whom had giant aneurysms. The persistence rate for aneurysms was 72% at 1 year and 41% at 5 years of follow-up. In multivariate analysis, the regression of an aneurysm was significantly related to the severity of coronary artery lesions, initial treatment, and gender. Although > 80% of small or moderate-sized aneurysms regressed within 5 years, giant aneurysms did not regress during the follow-up period. In patients who received immune globulin therapy, coronary lesions tended to resolve more rapidly than in those treated with salicylate therapy alone, because 91% of the lesions in the former were small or moderate. These findings suggest that the severity of coronary artery involvement during the initial stages of Kawasaki disease influences the regression of these lesions, and that immune globulin treatment may improve outcome by reducing the incidence of severe lesions.


Independent effects of lead exposure and iron deficiency anemia on developmental outcome at age 2 years.

For a prospective study of lead exposure, iron status, and infant development, we recruited infants living in a smelter town and a non-lead-exposed town in Kosovo, Yugoslavia. Among 392 infants assessed at age 2 years, the mean Mental Development Index (MDI), Bayley Scales of Infant Development, was 105.2. At age 2 years, geometric mean blood lead concentrations were 35.5 and 8.4 micrograms/dl, respectively, among infants from the exposed and nonexposed towns. After controlling for variables associated with MDI, we found significant independent associations for both blood lead and hemoglobin concentrations. For example, a rise in blood lead concentration at age 2 years from 10 to 30 micrograms/dl was associated with an estimated 2.5 point decrement in MDI (p = 0.03); statistically nonsignificant decrements were associated with blood lead levels measured at birth and at 6, 12, and 18 months of age. A decrease in hemoglobin concentration at 18 months of age from 12 to 10 gm/dl was associated with an estimated 3.4 point decrement in MDI (p = 0.02); the latter association was present in both towns, suggesting that it was due to iron deficiency anemia independent of lead exposure. The findings suggest that the brain is vulnerable to the effects of both lead exposure and anemia before 2 years of age. On a global basis, the developmental consequences of anemia may exceed those of lead exposure.


Responses to hypoxia and hypercapnia in infants of substance-abusing mothers.

Because infants of substance-abusing mothers (ISAM) have an increased risk of sudden infant death syndrome and have abnormal sleeping ventilatory patterns, we studied the effects of mild hypoxia during quiet sleep on ventilatory pattern, heart rate, and arousal in 23 healthy ISAM (mean +/- SEM: 9.0 +/- 0.49 weeks of age) and 15 healthy, similarly aged, control infants. Hypercapnic challenges were performed in six ISAM and eight control subjects. Hypoxic arousal responses were elicited by rapidly decreasing inspired oxygen tension to 80 mm Hg for 3 minutes or until arousal occurred. Failure to arouse to hypoxia occurred in the majority of infants in both groups. All infants had a fall in end-tidal carbon dioxide tension during hypoxia, suggesting that each had a hypoxic ventilatory response. However, the fall in end-tidal carbon dioxide tension was significantly less in the ISAM (mean +/- SEM: -4.0 +/- 0.3 vs -8.0 +/- 1.0 mm Hg), suggesting blunted ventilatory responses to hypoxia. Periodic breathing occurred during 9.5% of hypoxic challenges in control infants compared with 37% in ISAM (p = 0.056). Heart rates were significantly higher in the ISAM before, during, and after hypoxic challenges. Hypercapnic challenges (inspired carbon dioxide tension of 60 mm Hg for a maximum of 3 minutes) resulted in arousal in all infants; however, ISAM required a significantly longer exposure to hypercapnia before arousal (mean +/- SEM; 116 +/- 7.8 vs 79 +/- 13.9 seconds; p < 0.02). We conclude that ISAM have an impaired repertoire of protective responses to hypoxia and hypercapnia during sleep, and that this may play a role in their increased risk for sudden infant death syndrome.


Long-term neurologic consequences of nutritional vitamin B12 deficiency in infants.

A review of the clinical findings in six infants with nutritional vitamin B12 deficiency seen during the last 10 years was undertaken and an attempt made to obtain long-term neurologic follow-up. There was a consistent clinical pattern in vitamin B12-deficient infants; irritability, anorexia, and failure to thrive were associated with marked developmental regression and poor brain growth. Two of the four patients who qualified for long-term review had a poor intellectual outcome. Although early response to treatment is satisfying, the long-term consequences of nutritional vitamin B12 deficiency in infants emphasize the need for prevention or early recognition of this syndrome.


Hypercalciuria in children with renal glycosuria: evidence of dual renal tubular reabsorptive defects.

During the past 5 years, we have identified idiopathic hypercalciuria in five of seven patients referred for evaluation of renal glycosuria between 1985 and 1991. The children, all boys, ranged in age from 6 to 12 years. Endocrine function was normal, and none of the patients had hyperparathyroidism, hypercalcemia, renal tubular acidosis, or other secondary causes of hypercalciuria. The calcium/creatinine ratio in a fasting urine specimen was elevated in all five children who had hypercalciuria, with a mean value (+/- SD) of 0.34 +/- 0.06 (normal, < 0.2). In one child who had renal colic with spontaneous passage of gravel-like material, the idiopathic hypercalciuria persisted after 1 week on a diet containing 2000 mg of sodium and 300 mg of calcium. On the basis of studies that examined the site along the nephron responsible for hypercalciuria in rats with streptozocin-induced diabetes, we speculate that in children with renal glycosuria, there is defective reabsorption of glucose and calcium in the straight portion of the proximal tubule or in the collecting duct. It is likely that a similar mechanism accounts for the idiopathic hypercalciuria in children with diabetes mellitus.


Upper gastrointestinal tract motility in children with progressive muscular dystrophy.

Gastric emptying was evaluated in 15 children (mean age, 8.0 years) with progressive muscular dystrophy to detect early gastrointestinal smooth muscle involvement; 10 of the children also underwent esophageal manometry. Clinical evidence of skeletal muscle dysfunction was minimal in 14 of the 15 patients; 10 of them had no gastrointestinal symptoms. Gastric emptying studies were performed by using 500 muCi of technetium 99m-sulfur colloid bound to a scrambled egg, and scintigraphic measurements were made continuously for 60 to 90 minutes. Gastric emptying studies and manometric tracings were compared with those from 11 children (mean age, 8.4 years) without gastrointestinal or muscular disorders. Mean (+/- SD) percentage retention of gastric isotope was significantly greater in patients with muscular dystrophy than in control subjects. No differences were found between the two groups in distal esophageal motility or in upper and lower esophageal sphincter pressures or relaxation. Contraction amplitudes in the upper portion of the esophagus, however, were significantly lower in patients with myopathy than in control subjects. These data suggest that dysfunction of smooth muscle of the upper gastrointestinal tract is detectable in children with muscular dystrophy early in the course of the disease, even when gastrointestinal symptoms are absent and skeletal muscle symptoms are minimal.


Hyperammonemia-hyperornithinemia-homocitrullinuria syndrome: neurologic, ophthalmologic, and neuropsychologic examination of six patients.

We report the clinical, electrophysiologic, ophthalmologic, and neuropsychologic features of six patients with hyperammonemia-hyperornithinemia-homocitrullinuria syndrome, an inborn error of ornithine metabolism. Pyramidal signs, decreased vibration sense, bucco-facio-lingual dyspraxia, and learning difficulties or subnormal intelligence were found in the majority. Anomalies of peripheral nerve conduction velocity and of evoked potentials were common, and one patient had markedly abnormal white matter images on cranial magnetic resonance imaging. One patient had retinal depigmentation and chorioretinal thinning. The clinical severity varied greatly among patients; in general, the three younger patients had less neurologic and intellectual impairment than did the three older patients. Only two of our patients have had episodes of symptomatic hyperammonemia. We conclude that hyperammonemia-hyperornithinemia-homocitrullinuria syndrome can be associated with widespread manifestations in the central and peripheral nervous systems. Although the control of hyperammonemia is an essential element in the treatment of these patients, the relationship of hyperammonemia to the chronic neuropsychologic problems of these patients is unclear.


Arcanobacterium haemolyticum in children with presumed streptococcal pharyngotonsillitis or scarlet fever.

Arcanobacterium haemolyticum was cultured from pharyngeal specimens obtained from 12 of 129 children with pharyngotonsillitis, some of whom had a scarlatiniform rash. This organism should be considered to be a cause of infections that are clinically similar to those caused by beta-hemolytic streptococci.


Soft tissue swelling and acute skull fractures.

To determine whether soft tissue swelling, as identified by computed tomography, invariably accompanies acute calvarial fracture, the computed tomography scans of 35 children aged 3 months to 8 years with acute skull fractures were evaluated. Bone window settings revealed at least 4 mm of soft tissue swelling in all instances. We conclude that a skull fracture without overlying soft tissue swelling demonstrable by computed tomography is probably inconsistent with an acute injury.


Pancreatitis heralding Kawasaki disease.

A 5 1/2 year-old boy was hospitalized with clinical and laboratory evidence of pancreatitis. Four days later the classic signs and symptoms of Kawasaki disease developed. This case suggests that Kawasaki disease should be included in the differential diagnosis of acute pancreatitis in children.


Autoantibody production after cardiopulmonary bypass with special reference to postpericardiotomy syndrome.

A prospective study of children undergoing open heart surgery with cardiopulmonary bypass showed that many of them produced autoantibodies. No association was found between these antibodies, including anticardiolipin antibodies, and the occurrence of postpericardiotomy syndrome.


Benign acute myositis associated with rotavirus gastroenteritis.

Acute myositis developed concomitantly with gastroenteritis in a 2-year-old girl. She had temporary pain and swelling of the calf muscles and transient marked elevation of serum creatine kinase values. Rotavirus antigen was detected in stool by latex agglutination, and there was seroconversion of complement-fixation antibody to rotavirus.


Variability of clinical presentation in fumarate hydratase deficiency.

A 5-year-old girl with a previous diagnosis of cerebral palsy, nonprogressive psychomotor retardation, and hypotonia was found to excrete excessive fumaric acid in urine. Fumarate hydratase activity in skin fibroblasts was 10% of the control value. This case underscores the clinical heterogeneity of neurometabolic disorders and the importance of organic acid analysis in the diagnosis of static encephalopathy.


Charting infant distress: an aid to defining colic.

The value of a 24-hour distress diary, previously validated against a voice-activated audiotape record, was investigated in 30 infants with colic and 30 control infants. The infants with colic had significantly more distress behavior (300.0 minutes vs 102.5 minutes; p < 0.001), although overlap of duration of distress was noted. On the basis of a clinical definition of colic--total distress lasting 180 minutes in a 24-hour period--the diary had a sensitivity of 77% and a specificity of 87%. The sensitivity of the chart was confirmed in a separate study of another 90 infants with colic.


Effect of liposomal content of lipid emulsions on plasma lipid concentrations in low birth weight infants receiving parenteral nutrition.

We studied the effects of phospholipid liposomes present in intravenously administered lipid emulsions on plasma lipid levels in preterm infants given 10% and 20% lipid emulsions. Twenty premature infants (birth weight 1454 +/- 54 gm) on a parenteral nutrition regimen received up to 4 gm triglycerides per kilogram per day in a 20% lipid emulsion for 2 weeks, and then received the 10% emulsion at 2 gm triglycerides per kilogram per day, which delivered the same total phospholipid load but twice the amount of liposomes. Triglyceride, total cholesterol, and phospholipid concentrations increased significantly when the infants were given 2 gm triglycerides per kilogram per day in the 10% emulsion rather than 4 gm/kg per day in the 20% emulsion (44 +/- 4 to 57 +/- 5 mg/dl, 134 +/- 6 to 162 +/- 9 mg/dl, and 204 +/- 8 to 251 +/- 10 mg/dl, respectively). Lipoprotein analysis indicated the presence of lipoprotein X-like particles in the low-density lipoprotein fraction and an increase of the intermediate-density lipoprotein fraction in infants who received the 10% emulsion. The presence of excess phospholipids in the 10% emulsion was associated with greater plasma lipid alterations. Therefore the use of 20% rather than 10% emulsion allows for more efficient triglyceride clearance, even at a higher triglyceride intake. Administration of emulsions that are relatively poor in phospholipid liposomes may allow delivery of > 2 gm triglycerides per kilogram per day to low birth weight infants.


Role of delayed feeding and of feeding increments in necrotizing enterocolitis.

In spite of a number of studies on necrotizing enterocolitis, there remains controversy concerning prevention regimens, especially with regard to enteral alimentation. This report is of a matched case-control study of the relationship of necrotizing enterocolitis to timing of first feeding, size of feeding volumes and increments, and a risk factor index in 59 case patients with necrotizing enterocolitis and 59 matched control patients. Comparison with control patients showed that case patients were fed earlier, received full-strength formula sooner, and received larger feeding volumes and increments. More highly stressed infants, as measured by the risk index, were more vulnerable to larger feeding increments. Among case patients there was significant correlation of age at first feeding and age at diagnosis (p < 0.0001) even after control for birth weight and risk index score, indicating that delayed feeding was related to delayed onset of disease. These analyses support the theory that earlier, more rapid feeding places stressed infants at greater risk for the development of necrotizing enterocolitis, and that infants with more severe respiratory problems are more vulnerable to such feeding practices.


Effect of dopamine on failure of indomethacin to close the patent ductus arteriosus.

To test the hypotheses that administering dopamine before and concurrently with indomethacin therapy would (1) increase successful ductal closure rate, (2) act by maintaining a diuresis, and (3) prevent oliguria or high serum creatinine concentrations, we conducted a randomized, controlled trial in infants whose gestational age was <36 weeks and who had hemodynamically significant ductus arteriosus. Thirty-six infants were selected to receive a continuous infusion of either placebo or dopamine at either a low dosage of 2 micrograms/kg per minute or a higher dosage of 5 micrograms/kg per minute, beginning 6 hours before the use of indomethacin and continuing until 12 hours after the third dose of indomethacin. A total of 12 patients were selected to receive placebo, 14 were selected to receive "low dopamine," and 10 were selected to receive "high dopamine." The three groups were similar in their initial characteristics. Serum creatinine concentrations, urine output, and fractional excretion of sodium were not different in the three groups after indomethacin treatment. Two patients receiving placebo required a second course of indomethacin compared with four patients in the low-dopamine group and one in the high-dopamine group. The proportion of failures of medical treatment was not statistically different among the three groups. We conclude that concomitant dopamine therapy neither decreases the failure rate in indomethacin-treated infants nor reduces the magnitude of the indomethacin-induced oliguria.


Risk factors for early intraventricular hemorrhage in low birth weight infants.

Because earlier studies suggested that preterm infants with germinal matrix hemorrhage or intraventricular hemorrhage or both (GMH/IVH) present within the first 12 postnatal hours are at greatest risk for the development of high-grade hemorrhage and neurodevelopmental disability, we examined the risk factors for this insult among 229 neonates of 600 to 1250 gm birth weight in a multicenter study. All had echoencephalography (ECHO) within the first 11 hours and serially for the next 20 days; risk factor data were collected prospectively. Forty-three infants had GMH/IVH within the first 5 to 11 hours (mean age at ECHO 7.7 hours): 18 GMH and 21 grade II, 1 grade III, and 3 grade IV IVH. One hundred eighty-six infants did not have GMH/IVH at a mean age of 7.9 hours. Both groups of infants were similar in birth weight, gestational age, maternal risk factors, cord pH values, and surfactant therapy before ECHO. The group with early IVH had more vertex presentations than the group without early IVH (79% vs 55%, p = 0.043), less maternal tocolytic use (42% vs 60%, p = 0.029), and more vaginal deliveries (67% vs 44%, p = 0.005). In the first 21 days, severe IVH developed in 12 infants with early IVH and in 6 infants without early IVH (p < 0.001). There were more neonatal deaths (16% vs 6%, p = 0.035) and more deaths at any time during the primary hospitalization (23% vs 9%, p = 0.010) among the early IVH group than among the group without early IVH. Multivariate analysis indicated that the mode of delivery, fetal presentation, and birth weight were important and independent prognostic indicators of IVH.


Renal function in very low birth weight infants: normal maturity reached during early childhood.

Development of glomerular and tubular renal function is delayed in preterm infants. To study the pattern of maturation during infancy and childhood, we re-evaluated renal function in 22 very low birth weight infants--in 14 of the infants at 18 months postconceptional age (9 months corrected age) and in the remaining 8 infants at 8 years of age. The glomerular filtration rate remained lower at 9 months corrected age than in term infants of the same postconceptional age: 82 +/- 23 versus 125 +/- 18 ml/min per 1.73 m2 (p < 0.001). At 8 years of age the glomerular filtration rate did not differ from that of healthy control subjects. Effective renal plasma flow, filtration fraction, albumin excretion, maximal concentrating ability, and kidney size determined by ultrasonography were all normal at 8 years of age. We conclude that renal function, which is markedly reduced during the neonatal period in very low birth weight infants, reaches normal maturity by 8 years of age but not by 9 months corrected age.


Cognitive and behavioral deficits in nonhuman primates associated with very early embryonic binge exposures to ethanol.

This study was undertaken to evaluate teratogenesis associated with early weekly ethanol exposure followed by later gestational abstinence. Ethanol, 1.8 gm/kg, was orally administered weekly to gravid nonhuman primates (Macaca nemestrina) for the first 3, 6, or the entire 24 weeks of pregnancy. Control animals received weekly sucrose solution as did the 3- and 6-week cohort animals in subsequent weeks. Thirty-five viable infants were assessed for growth, malformations, and behavioral and cognitive dysfunction. Animals in the 6-week and 24-week cohorts were uniformly abnormal in behavior and inconsistently abnormal in physical development relative to the control animals. Animals in the 3-week cohort were equivocally normal. These results demonstrate ethanol's capacity to produce behavioral teratogenesis (brain dysfunction) in isolation from physical anomalies in the rest of the body. The results strongly suggest that binge drinking in the first 6 to 8 weeks of pregnancy (a period when women may not know that they are pregnant), followed by later gestational abstinence, is as dangerous to the fetus as exposure throughout gestation.


Effect of therapy with a new glucocorticoid, deflazacort, on linear growth and growth hormone secretion after renal transplantation.

Deflazacort is an oxazoline compound derived from prednisolone with similar antiinflammatory effects but fewer side effects. We studied changes in kidney function, growth velocity, weight/height ratio, and growth hormone secretion before and a year after substitution of deflazacort for methylprednisone in nine patients aged 9 to 15 years, 4 years after renal transplantation; all were in Tanner pubertal stage 1. Methylprednisone (mean +/- SEM: 0.2 +/- 0.02 mg/kg per day) was replaced by deflazacort (0.3 +/- 0.03 mg/kg per day) for a mean period of 15 months. Serum creatinine and calculated creatinine clearance did not change significantly during deflazacort treatment. Growth velocity increased from 1.5 +/- 0.3 to 3.2 +/- 0.5 cm/yr (p < 0.005) in the nine patients. Weight/height ratio decreased from 28.4% +/- 8.5% to 16% +/- 6.7% (p < 0.005). Cushingoid appearance decreased in all patients. Mean spontaneous growth hormone secretion increased from 2.5 +/- 0.4 to 4.4 +/- 1.2 ng/ml (p < 0.05). Our findings indicate that immunosuppressive treatment with deflazacort is as effective as methylprednisone and is associated with fewer side effects.


Low recovery in vivo of highly purified factor VIII in patients with hemophilia.

To assess whether the response and recovery of highly purified factor VIII products approach the levels predicted by use of manufacturers' suggestions, we studied response in vivo and percentage of recovery in boys and men with hemophilia after infusion of 50 IU of an immunoaffinity-purified factor VIII preparation (Hemofil M) per kilogram of body weight. We also studied dose response and percentage of recovery in the same boys after infusion of a factor VII concentrate prepared by solvent detergent treatment and gel filtration (Koate-HP). For boys the difference between mean peak factor VIII response with Hemofil M (1.02% +/- 0.07%) and the response with Koate-HP (1.21% +/- 0.10%) was not significant (p = 0.10), but the response of both products was considerably less than the predicted response of 2.0%. The response to Hemofil M in men (1.38% +/- 0.12%) was significantly better than the response in boys (p = 0.004) but, again, fell short of the anticipated response of 2.0%. In boys the percentage of recovery of Hemofil M was 38.4% +/- 2.1%, compared with Koate-HP recovery, which was 47.0% +/- 3.6% (p = 0.034). The percentage of recovery in men was 47.5% +/- 2.8%. The better response observed in men appears to be, in part, a function of larger body size. We conclude that peak factor VIII response and recovery in boys and men who receive highly purified factor VIII concentrates are lower than those predicted by use of current prescribing recommendations.


Effect of add-on amantadine therapy for refractory absence epilepsy.

Amantadine hydrochloride was administered as an add-on drug to four children with refractory absence epilepsy, resulting in complete resolution of absence episodes within 1 week. All patients remained free of symptoms for 27 to 36 months without adverse effects related to this drug. An attempt to discontinue the use of this medication in three children resulted in a prompt relapse. The suggestion that amantadine may be an effective drug in the treatment of refractory absence epilepsy, should be tested in a double-blind, controlled study.


Pharmacokinetics and pharmacodynamics of erythropoietin during therapy in an infant with renal failure.

We treated an infant with anemia and chronic renal failure with recombinant human erythropoietin (300 to 750 U/kg subcutaneously per week) and iron (6 mg/kg enterally) from 1 to 4 months of age. A suboptimal pharmacodynamic response was seen at the lower dose. This may have been due to developmental erythropoietin pharmacokinetic differences, that is, relatively greater neonatal plasma clearance and steady-state volume of distribution compared with those in adults.


Improved direct epifluorescent filter technique for rapid bioburden control in intravenous solutions.

Epifluorescence microscopy of the microcolonies obtained after filtration of a deliberately contaminated intravenous solution, was used for the rapid detection and enumeration of the bacteria. The technique is adequate for the test of low volume solution (with low contamination). Also it allows one to detect a single colony forming unit (c.f.u.)/mL, with great correlation between fluorescence counts and pour plate colony counts; the morphology of microcolonies is typical for most of the microorganisms and it allows a primoidentification (for a trained analyst).


Industrial perspective on validation of tangential flow filtration in biopharmaceutical applications. Technical Report No. 15. Parenteral Drug Association. Biotechnology Task Force on Purification and Scale-up.

Validation of tangential flow filtration is required to ensure the process delivers a product of consistent quality, safety, and efficacy. A thorough and sound validation program not only satisfies regulatory requirements, but also provides a valuable source of information which facilitates development of future processes, training of production personnel, and trouble shooting for the validated process. Validation of TFF shares many common elements with validation of other traditional operations and equipment. Existing personnel and procedures should be readily adapted to execute the TFF validation protocols. IQ's and OQ's will most likely follow familiar formats. In performance qualification, key areas needing attention include: assessment of compatibles, testing of parameters affecting membrane retention and selectivity, cleaning, sanitization, and membrane lifetime. Finally, the hallmark of a sound validation program is the quality of its scientific approach and its congruence with the definition of validation contained in the 1987 guidelines (6).


A novel method of determination of protein stability.

A novel method of determination of protein stability is described, which involves interfacial shear rheology of adsorbed protein layers. This technique provides information on the structural-mechanical properties of the adsorbed protein layers which can be related to: the rate of interfacial adsorption, interfacial interactions, and conformational changes in the adsorbed layers. The interfacial shear rheology of the blood proteins, bovine serum albumin and human immunoglobulin G was investigated. The air/aqueous and oil/aqueous interfaces were studied and the interfacial rheological activity of BSA was shown to be similar at three hydrophobic interfaces: air, squalene and mineral oil. The kinetics of interfacial film formation was shown to be time dependent, and aging effects were detected in both interfacial and bulk molecules. The absolute interfacial elasticity values decreased as the temperature increased. The protein solutions exhibited no interfacial rheological activity in the presence of the small surfactant molecules, Tween 80 and lecithin, under the conditions studied.


Validation of automated systems--system definition.

A Parenteral Drug Association (PDA) Committee on Software Validation was formed about three years ago to address some of the issues associated with validating automated systems, particularly where all, or part, of the automated system is supplied by outside vendors. A Technical Report that describes a process which emphasizes system definition, a comprehensive system specification, system qualification and ongoing evaluation will issue later this year. The concepts described in this document will be consistent with the PMA's System Development Life Cycle approach which is commonly used for computer system validation. The following article has been developed from the System Definition section of this PDA Technical Report.


"Points to consider" in the validation of equipment cleaning procedures.

Cleaning validation has received increasing attention by the FDA in recent inspections, yet very little has been published regarding practices within the pharmaceutical industry. This presentation will review several of aspects of the validation of equipment cleaning procedures. A significant portion of the presentation is derived from round table discussions the author has led over the last several years on this subject. Specific areas to be defined include: sampling methods, analytical methods, physical parameters, and of greatest interest, the selection of acceptance criteria. The presentation also includes some additional perspectives on the subject of cleaning validation developed by the author which may prove useful to the practitioner.


The role of the effective concentration in interpreting hemolysis data.

Problems inherent in traditional methods of determining the hemolytic activity of parenteral compounds are discussed. Data taken from a study which closely models the conditions present for an intravenous injection are re-examined. An equation is given which combines several variables into a single parameter, the effective concentration. A strong relationship is found between the effective concentration of the compound of interest and the hemolysis produced.


Reduction of bioavailability of aluminium in neonatal parenteral nutrition solutions by prior complexation in the dosage form.

Aluminium (Al ) is abundant in our environment and is a contaminant of electrolyte solutions used in the manufacture of Total Parenteral Nutrition (TPN) solutions administered to neonates, who are unable to tolerate oral feeding. Previous studies by McHalsky et al. (1) have shown concern over the levels of aluminium in parenteral products, and there are special considerations needed with regard to neonatal TPN solutions, (2). It is felt that neurotoxicology and abnormalities of bone histology may be seen with aluminium deposition in the tissues. In the present study it was shown that the average aluminium contamination in TPN solutions was in the order of 205 micrograms/L. It is well documented that aluminium is chelated successfully in dialysis solutions by desferrioxamine (DFO), Allain et al. (3). Using an AA spectrophotometer equipped with a graphite furnace, the average amount of aluminium in compounded neonatal TPN solutions was determined. Equimolar amounts of DFO to aluminium were added to various neonatal TPN formulations, and the physical stability of each solution was determined using microscopic and electronic particle counting analysis. This study suggests that aluminium can be irreversibly chelated with DFO and stable TPN solutions can be prepared.


Volatile fatty acids, lactic acid, and pH in the stools of breast-fed and bottle-fed infants.

We measured fecal pH, volatile fatty acids (VFA), and lactic acid concentrations in 67 healthy infants ranging in age from 1 to 5 months. The babies were divided into five groups according to their diet: group 1: human milk, with subgroups of 1 month of age (n = 8), and 2-5 months (n = 12); group 2: formula milk, with subgroups of 1 month of age (n = 9) and 2-5 months (n = 10); group 3: cow's milk, one group of 2-5 months of age (n = 12); group 4: human milk supplemented with formula milk, 2-5 months of age (n = 8); and group 5: human milk supplemented with cow's milk, 2-5 months of age (n = 8). Fecal VFA concentration and pH of bottle-fed infants (groups 2 and 3) were significantly higher and lactic acid concentrations significantly lower than those of the breast-fed group. Groups 4 and 5 showed significantly higher pH and propionic acid concentration, and lower lactic acid concentration than Group 1 did. There were no significant differences in the data on pH, VFA, and lactic acid concentrations between the feces of formula and cow's milk groups. On the other hand, the addition of formula or cow's milk to the human milk was sufficient to alter the profile of VFA, the pH, and the lactic acid concentration of breast-fed infants stools. Low pH, low VFA, and high lactic acid concentrations make the colonic content of breast-fed babies an environment favorable for Bifidobacteria growth, and this is probably the main protective factor against gastrointestinal infections.


Efficient assimilation of lactose carbon in premature infants.

Previous studies have shown that there is minimal fecal excretion of carbohydrate energy in premature infants with high breath H2 concentrations, implying that the colon plays an important role in salvaging lactose energy. The present study extends this work by using a stable isotope method for serial assessment of lactose carbon excretion. Thus, in nine premature infants (30-32 weeks of gestation and 11-36 days of age), we conducted 23 longitudinal studies of breath hydrogen concentration and the cumulative fecal excretion of 13C derived from a single dose of [D-1-13C]lactose. The ranges of values (mean +/- SD) for breath hydrogen concentration and lactose absorption were respectively 4-440 ppm/5% CO2 (92 +/- 100) and 82-100% tracer dose (98.4 +/- 3.9). In 21 studies, lactose carbon excretion was less than 2% of the dose. There was a significant correlation between postnatal age and breath hydrogen concentration (R = 0.48; p = 0.02). These studies suggest that colonic fermentation activity is adequate for efficient colonic salvage of lactose even during the second week of life.


Developmental changes in lactase-phlorizin hydrolase precursor isoforms in the rat.

The purpose of this study was to determine whether the developmental decline in lactase specific activity (mumol/min/g protein) in the rat was associated with (a) changes in the relative quantities of immunoisolated precursor and mature forms of the enzyme purified by SDS-PAGE and/or (b) immunohistologic changes in the jejunal mucosa. We studied 10- and 16-day-old suckling rat pups, 22-day-old weaned rat pups, and adult female rats (nongravid, pregnant, and lactating). Lactase activity was three- to fourfold higher in 10-day-old pups than in adult rats. Lactase activity was 27% greater in lactating compared with nongravid or pregnant rats. Three molecular forms of the enzyme that migrated identically in all animals were observed on SDS-polyacrylamide gels stained with Coomassie blue: 140-kDa (mature brush border form), 200-kDa, and 220-kDa (apparent precursor forms). There was a striking difference in the proportions of the three polypeptides at different ages that was unrelated to animal status, i.e., pregnant or lactating. As the animals aged, the relative amount of the 140-kDa band declined from 86 +/- 1.1% of the total immunoprecipitated lactase in 10-day old suckling pups to 68 +/- 0.7% in adults. Simultaneously, the relative concentration of the 200-kDa band rose from 1.7 +/- 0.4% in the 10-day-old to 19 +/- 0.6% in adults. The relative concentration of the 220-kDa polypeptide did not change as a function of age.(ABSTRACT TRUNCATED AT 250 WORDS)


Iron absorption and incorporation into red blood cells by very low birth weight infants: studies with the stable isotope 58Fe.

Measurements of iron absorption and incorporation into RBCs were obtained with the stable isotope 58Fe, administered as a reference dose, in 11 premature infants with birth weights between 780 and 1,520 g and gestational ages between 24 and 33 weeks. Each study included a timed stool and urine collection, nasogastric tube administration of a single dose of about 228 micrograms of 58Fe/kg of body weight (as FeSO4, with 10 mg/kg of vitamin C) between feedings, and blood samples before 58Fe (day 1) and then 2 weeks (day 15) later. Gastrointestinal absorption of the 58Fe dose as measured by fecal isotope balance was 41.6 +/- 17.6% (mean +/- SD). However, only 12.0 +/- 9.6% of the 58Fe dose (28.7 +/- 22.3% of the absorbed 58Fe dose) was incorporated into RBCs on day 15. 58Fe absorption and 58Fe incorporation into RBCs on day 15 were significantly correlated with the hemoglobin concentration and reticulocyte count on day 1. Transfusion history did not affect 58Fe absorption or 58Fe incorporation into RBCs. We conclude that concurrent measurement of 58Fe absorption with fecal monitoring and of 58Fe incorporation into RBCs permits a better understanding of the fate of iron ingested by premature infants than either measurement alone.


Surfactant-like material in the antral gastric mucosa of children.

It has been proposed that the hydrophobicity of the gastric mucosa is due to surfactant-like material (SLM), mainly composed of phospholipid, adsorbed to the mucosal surface. Biochemical and physiological studies have been performed in different mammals but morphological data on children are lacking. In the present work, the presence of SLM on the antral gastric mucosa of children has been studied by electron microscopy. The results demonstrate that SLM is present and shows two different forms, lamellar bodies and lamellar layers. In the mucosae without endoscopic, histologic, and ultrastructural alterations we have found SLM when the tannic acid method has been used but not when the tissue has been fixed only in glutaraldehyde. Our results suggest that in children with ultrastructural alterations of the epithelium, the amount of gastric SLM is increased in respect to children with a normal mucosa and that the amount of SLM on the surface of the gastric antral mucosa is modified in pathologic conditions.


Low bone mineral content in summer-born compared with winter-born infants.

Possible seasonal differences in newborn bone mineral content (BMC) have not been studied. Adult studies show seasonal variations with lower BMC in winter versus summer. Assuming that BMC variations may relate in part to vitamin D status, we hypothesized that newborn BMC would be lower in winter than summer. BMC of one third distal radius was measured in 55 healthy term newborns using a single beam photon absorptiometer [coefficient of variation (CV) for phantom standard 2.1%]. Infants were enrolled during summer (July-September, 1988) and winter (January-March, 1989) for a longitudinal nutrition study. Contrary to our hypothesis, there was a 12% lower BMC in summer versus winter (mean +/- SD 75.94 +/- 17.42 vs. 86.55 +/- 17.54 mg/cm, respectively; p = 0.035). The difference remained significant after controlling for possible race and gender effects (p = 0.02). We conclude that BMC is lower in summer- compared with winter-born infants. Since any seasonal effects on fetal bone are presumably related to effects through the mother, we speculate that if maternal vitamin D status influences fetal bone mineralization, the effect (possible sunshine deprivation in winter) may operate especially in early pregnancy, thus resulting in lower BMC, evident at birth in summer.