Rewinding Extinction in the Northern White Rhinoceros: Genetically Diverse Induced Pluripotent Stem Cell Bank for Genetic Rescue

Extinction rates are rising, and current conservation technologies may not be adequate for reducing species losses. Future conservation efforts may be aided by the generation of induced pluripotent stem cells (iPSCs) from highly endangered species. Generation of a set of iPSCs from multiple members of a species can capture some of the dwindling genetic diversity of a disappearing species. We generated iPSCs from fibroblasts cryopreserved in the Frozen Zoo^®: nine genetically diverse individuals of the functionally extinct northern white rhinoceros (Ceratotherium simum cottoni) and two from the closely related southern white rhinoceros (Ceratotherium simum simum). We used a nonintegrating Sendai virus reprogramming method and developed analyses to confirm the cells' pluripotency and differentiation potential. This work is the first step of a long-term interdisciplinary plan to apply assisted reproduction techniques to the conservation of this highly endangered species. Advances in iPSC differentiation may enable generation of gametes in vitro from deceased and nonreproductive individuals that could be used to repopulate the species.

A review of optical pacing with infrared light

Optical pacing (OP) uses pulsed infrared light to initiate heartbeats in electrically excitable cardiac tissues without employing exogenous agents. OP is an alternative approach to electrical pacing that may overcome some its disadvantages for some applications. In this review, we discuss the initial demonstrations, mechanisms, safety, advantages and applications of OP.

Decreased myoblast differentiation in chronic binge alcohol-administered simian immunodeficiency virus-infected male macaques: role of decreased miR-206

Skeletal muscle stem cells play a critical role in regeneration of myofibers. We previously demonstrated that chronic binge alcohol (CBA) markedly attenuates myoblast differentiation potential and myogenic gene expression. Muscle-specific microRNAs (miRs) are implicated in regulation of myogenic genes. The aim of this study was to determine whether myoblasts isolated from asymptomatic CBA-administered simian immunodeficiency virus (SIV)-infected macaques treated with antiretroviral therapy (ART) showed similar impairments and, if so, to elucidate potential underlying mechanisms. Myoblasts were isolated from muscle at 11 mo after SIV infection from CBA/SIV macaques and from time-matched sucrose (SUC)-treated SIV-infected (SUC/SIV) animals and age-matched controls. Myoblast differentiation and myogenic gene expression were significantly decreased in myoblasts from SUC/SIV and CBA/SIV animals compared with controls. SIV and CBA decreased muscle-specific miR-206 in plasma and muscle and SIV decreased miR-206 expression in myoblasts, with no statistically significant changes in other muscle-specific miRs. These findings were associated with a significant increase in histone deacetylase 4 (HDAC4) and decrease in myogenic enhancer factor 2C (MEF2C) expression in CBA/SIV muscle. Transfection with miR-206 inhibitor decreased myotube differentiation, increased expression of HDAC4, and decreased MEF2C, suggesting a critical role of miR-206 in myogenesis. Moreover, HDAC4 was confirmed to be a direct miR-206 target. These results support a mechanistic role for decreased miR-206 in suppression of myoblast differentiation resulting from chronic alcohol and SIV infection. The parallel changes in skeletal muscle and circulating levels of miR-206 warrant studies to establish the possible use of plasma miR-206 as an indicator of impaired muscle function.

2H stable isotope analysis of human tooth enamel: a new tool for forensic human provenancing?

Stable isotope analysis of biogenic tissues such as tooth enamel and bone mineral has become a well-recognised and increasingly important method for determining the provenance of human remains, and it has been used successfully in bio-archaeological studies as well as forensic investigations. In particular, (18)O and (2)H stable isotope signatures of bone and hair, respectively, are well-established proxies of climate (temperature) and source water and are therefore considered as indicators of geographic life trajectories of animals and humans. While the methodology for (2)H analysis of human hair, fingernails, and bone collagen is currently used to determine human provenance, i.e. geographic origin and identify possible migration patterns, studies involving the analysis of (2)H in tooth enamel appear to be nonexistent in the scientific literature. Ground tooth enamel was analysed by continuous-flow isotope ratio mass spectrometry (IRMS) coupled on-line to a high-temperature conversion elemental analyser (TC/EA). An array of tooth enamel samples from archaeological and modern teeth has been analysed under different experimental conditions, and the results of this proof-of-concept study are presented. While no significant differences in (2)H abundance were noted as a result of H exchange studies or different sample preparation protocols, no significant differences or trends in measured δ(2)H-values were observed either with regard to known differences in geographical provenance. We concluded that the δ(2)H-values obtained from tooth enamel could not be used as proxy for a person's geographical origin during adolescence.

Single molecule detection of double-stranded DNA in poly(methylmethacrylate) and polycarbonate microfluidic devices

Single photon burst techniques were used to detect double-stranded DNA molecules in poly(methylmethacrylate) (PM MA) and polycarbonate (PC) microfluidic devices. A confocal epi-illumination detection system was constructed to monitor the fluorescence signature from single DNA molecules that were multiply labeled with the mono-intercalating dye, TOPRO-5, which possessed an absorption maximum at 765 nm allowing excitation with a solid-state diode laser and fluorescence monitoring in the near-infrared (IR). Near-IR excitation minimized autofluorescence produced from the polymer substrate, which was found to be significantly greater when excitation was provided in the visible range (488 nm). A solution containing lambda-DNA (48.5 kbp) was electrokinetically transported through the microfluidic devices at different applied voltages and solution pH values to investigate the effects of polymer substrate on the transport rate and detection efficiency of single molecular events. By applying an autocorrelation analysis to the data, we were able to obtain the molecular transit time of the individual molecules as they passed through the 7 microm laser beam. It was observed that the applied voltage for both devices affected the transport rate. However, solution pH did not alter the transit time for PM MA-based devices since the electroosmotic flow of PMMA was independent of solution pH. In addition, efforts were directed toward optimizing the sampling efficiency (number of molecules passing through the probe volume) by using either hydrodynamically focused flows from a sheath generated by electrokinetic pumping from side channels or reducing the channel width of the microfluidic device. Due to the low electroosmotic flows generated by both PMMA and PC, tight focusing of the sample stream was not possible. However, in PMMA devices, flow gating was observed by applying field strengths > -120 V/cm to the sheath flow channels. By narrowing the microchannel width, the number of molecular events detected per unit time was found to be four times higher in channels with 10 microm widths compared to those of 50 microm, indicating improved sampling efficiency for the narrower channels without significantly deteriorating detection efficiency. Attempts were made to do single molecule sizing of lambda-DNA, M13 (7.2 kbp) and pUC19 (2.7 kbp) using photon burst detection. While the average number of photons for each DNA type were different, the standard deviations were large due to the Gaussian intensity profile of the excitation beam. To demonstrate the sensitivity of single molecule analysis in the near-IR using polymer microfluidic devices, the near-IR chromophore, NN382, wasanalyzed using ourconfocal imager. A detection efficiency of 94% for single NN382 molecules was observed in the PC devices.

Nanoliter-scale sample preparation methods directly coupled to polymethylmethacrylate-based microchips and gel-filled capillaries for the analysis of oligonucleotides

We are currently developing miniaturized, chip-based electrophoresis devices fabricated in plastics for the high-speed separation of oligonucleotides. One of the principal advantages associated with these devices is their small sample requirements, typically in the nanoliter to sub-nanoliter range. Unfortunately, most standard sample preparation protocols, especially for oligonucleotides, are done off-chip on a microliter-scale. Our work has focused on the development of capillary nanoreactors coupled to micro-separation platforms, such as micro-electrophoresis chips, for the preparation of sequencing ladders and also polymerase chain reactions (PCRs). These nanoreactors consist of fused-silica capillary tubes (10-20 cm x 20-50 microns I.D.) with fluid pumping accomplished using the electroosmotic flow generated by the tubes. These reactors were situated in fast thermal cyclers to perform cycle sequencing or PCR amplification of the DNAs. The reactors could be interfaced to either a micro-electrophoresis chips via capillary connectors micromachined in polymethylmethacrylate (PMMA) using deep X-ray etching (width 50 microns; depth 50 microns) or conventional capillary gel tubes using zero-dead volume glass unions. For our chips, they also contained an injector, separation channel (length 6 cm; width 30 microns; depth 50 microns) and a dual fiber optic, near-infrared fluorescence detector. The sequencing nanoreactor used surface immobilized templates attached to the wall via a biotin-streptavidin-biotin linkage. Sequencing tracks could be directly injected into gel-filled capillary tubes with minimal degradation in the efficiency of the separation process. The nanoreactor could also be configured to perform PCR reactions by filling the capillary tube with the PCR reagents and template. After thermal cycling, the PCR cocktail could be pooled from multiple reactors and loaded onto a slab gel or injected into a capillary tube or microchip device for fractionation.

Micromachining in plastics using X-ray lithography for the fabrication of microelectrophoresis devices

Micromachining was performed in polymethylmethacrylate (PMMA) using X-ray lithography for the fabrication of miniaturized devices (microchips) for potential applications in chemical and genetic analyses. The devices were fabricated using two different techniques: transfer mask technology and a Kapton mask. For both processes, the channel topography was transferred (1:1) to the appropriate substrate via the use of an optical mask. In the case of the transfer mask technique, the PMMA substrate was coated with a positive photoresist and a thin Au/Cr plating base. Following UV exposure, the resist was developed and a thick overlayer (approximately 3 microns) of Au electroplated onto the PMMA substrate only where the resist was removed, which acted as an absorber of the X-rays. In the other technique, a Kapton film was used as the X-ray mask. In this case, the Kapton film was UV exposed using the optical mask to define the channel topography and following development of the resist, a thick Au overlayer (8 microns) was electrodeposited onto the Kapton sheet. The PMMA wafer during X-ray exposure was situated directly underneath the Kapton mask. In both cases, the PMMA wafer was exposed to soft X-rays and developed to remove the exposed PMMA. The resulting channels were found to be 20 microns in width (determined by optical mask) with channel depths of approximately 50 microns (determined by x-ray exposure time). In order to demonstrate the utility of this micromachining process, several components were fabricated in PMMA including capillary/chip connectors, injectors for fixed-volume sample introduction, separation channels for electrophoresis and integrated fiber optic fluorescence detectors. These components could be integrated into a single device to assemble a system appropriate for the rapid analysis of various targets.

Sanger DNA-sequencing reactions performed in a solid-phase nanoreactor directly coupled to capillary gel electrophoresis

A miniaturized, solid-phase nanoreactor was developed to prepare Sanger DNA-sequencing ladders which was directly interfaced to a capillary gel electrophoresis system. A biotinylated fragment of the rat brain actin gene (1 kbp) was amplified by PCR and attached to the interior wall of an (aminoalkyl)silane-derivatized fused-silica capillary tube via a biotin/streptavidin/biotin linkage. Coverage of the capillary wall with the biotinylated DNA averaged 77 +/- 10%. Stability of the anchored template under pressure (33 nL/s) and electroosmotic flows (11.3 nL/s) were favorable, requiring rinsing for > 150 h to reduce the surface coverage by only 50%. In addition, the immobilized template was stable toward temperatures required for preparing sequencing ladders, even under cycling conditions. Standard Sanger dideoxynucleotide termination performed in a large-volume (approximately 8 microL) solid-phase reactor using the thermally stable polymerase enzymes Taq and Vent and the polymerases T7 and Bst with off-line slab gel electrophoresis and autoradiographic detection indicated that acceptable fragment generation was achieved only in the case of the thermally stable polymerases. Banding was not apparent for T7 and Bst since all reagents were inserted into the column in a single plug at the beginning of the reaction. A small volume reactor (volume approximately 62 nL) was then used to perform DNA polymerase reactions and was coupled directly to a capillary gel column for separation. The capillary reactor was placed inside a thermocycler to control the temperature during chain extension and was directly connected to the gel column via zero dead volume fused-silica connectors. The complementary DNA fragments generated (C-track only) in the reactor were denatured using heat and directly injected onto the gel-filled capillary for size separation with detection accomplished using near-IR laser-induced fluorescence. Extension and single-base separation resolution of the C-track, which was directly injected onto the gel column, was estimated to be > 450 bases from the primer annealing site with plate numbers ranging from 1 x 10(6) to 2 x 10(6)/m.

Is there a role for physician assistants in community mental health?

The authors briefly describe the history and development of the medical discipline of physician assistants (PAs). A careful review of the literature reveals the limited use of PAs in psychiatry, usually only for primary health care needs. A model for using PAs as psychiatric assistants is presented, including the training required and a description of the clinical and administrative functions. The advantages of such a model are multiple. These include: 1) more effective and efficient use of the psychiatrist; 2) reduced costs of service; 3) increased primary medical screening capability in the CMHC; and 4) increased presence of ethnic minorities on the professional staff of the CMHC. Disadvantages of the model relate to training and "turf" issues. In view of the shortage and dissatisfaction of psychiatrists in CMHC settings, and other challenges to the provision of quality mental health care in the community, this model should be considered as a logical and positive response to that challenge. If the model is valid, then training facilities must make a systematic effort to recruit, train, and place psychiatric physician assistants in community agencies.

Quality, cost-effective psychiatric treatment: A CNS--MD collaborative practice model

Health care reform presents an opportunity to design alternative health care delivery models. Psychiatric clinical nurse specialists and psychiatrists are particularly well positioned to work together as full and equal partners, to complement each other's practice and to provide cost-effective care with improved patient outcomes. In this case study, we show that, with the addition of psychotherapy provided by a CNS, the cost of care for the patient decreased from over $40,000 (average hospital cost only) to less than $4,000 per year. In addition, the patient attained competent self-care and an enhanced quality of life. Characteristics of effective collaboration are described. Replication of this design by psychiatric clinical nurse specialists is recommended.

Emergency department patterns in psychiatric visits during the holiday season

STUDY OBJECTIVE

To determine the prevalence of psychopathology during the holiday season and which subpopulations are at greatest risk for holiday decompensation.

DESIGN

A retrospective analysis of emergency department records.

SETTING

ED of a university-affiliated hospital located in a mixed urban-agricultural catchment area in North Carolina.

PARTICIPANTS

Eight thousand seven hundred fifty-six patient visits to the ED, with subsequent triage for psychiatric evaluation, for a 6-year period (1987 to 1993), were analyzed.

RESULTS

We observed seasonal patterns in visits, with a general decrease in visits preceding holidays followed by an increase afterward. Substance abusers, men, and black patients were more likely to visit the ED than expected, particularly during the weeks surrounding Christmas.

CONCLUSION

These results support the existence of a "Christmas effect" on ED visitations by patients with psychiatric symptoms. Understanding of these patterns may help emergency physicians predict the seasonal variation of such patient visits and apply preventive measures accordingly.

Transepithelial phosphate transport in rabbit proximal tubular cells adapted to phosphate deprivation

Both renal and nonrenal cells in culture adapt to deprivation of Pi by increasing Na-dependent Pi uptake. We studied whether this change in uptake is reflected in an increased renal transepithelial Pi transport. We grew primary cultures of rabbit renal cortical cells in plastic flasks and subcultured them onto Millicell-HA filters. This produced cell monolayers, which structurally and functionally resembled proximal tubule. These cells performed Na-dependent net transepithelial transport of 32Pi in the apical-to-basolateral direction that was inhibited by phosphonoformic acid in the apical fluid or by ouabain in the basolateral fluid or by preincubation with parathyroid hormone. Overnight incubation at low Pi concentrations led to a progressive increase in 5-min Na-dependent Pi uptake into cell monolayers. Na-dependent Pi uptake was threefold higher following overnight incubation at 25 microM Pi, compared with 3 mM Pi, and the increase was one-half maximal with incubation at an extracellular Pi concentration ([Pi]) of 300 microM. This was associated with a decrease in Na-dependent transepithelial Pi flux to the basolateral fluid by the same cells, which fell dramatically following incubation at < or = 300 microM Pi. There was no change in Na-dependent uptake or transepithelial transport of L-glutamine. This adaptation to Pi deprivation in vitro appears to serve to restore depleted cell stores of Pi rather than to regulate transepithelial Pi transport.

Religious practices and alcoholism in a southern adult population

OBJECTIVE

The study examined associations between religious variables and alcohol abuse and dependence among 2,969 North Carolina residents aged 18 to 97 who participated in the 1983-1984 National Institute of Mental Health Epidemiologic Catchment Area survey at its Piedmont location.

METHODS

Six-month and lifetime prevalence of alcohol disorders were compared among participants reporting varying levels of religious activity. Data were collected on frequency of Bible reading, prayer, and church attendance; time spent watching or listening to religious programming on television or radio; importance of religion; religious denomination; and identification as "born-again" Christians.

RESULTS

Recent and lifetime alcohol disorders were less common among weekly churchgoers and those who considered themselves born again. Recent, but not lifetime, alcohol disorders were also less common among respondents who frequently read the Bible or prayed privately. Alcohol disorders were more common among those who frequently watched or listened to religious television and radio. Lifetime, but not recent, alcohol disorders were more prevalent among members of Pentecostal denominations.

CONCLUSIONS

Longitudinal study is necessary to further clarify and explain these relationships between religious practices and alcohol disorders.

Magnetic resonance spectroscopy in social phobia: preliminary findings

Proton localized magnetic resonance spectroscopy was studied in 20 social phobics and 20 age- and sex-matched controls. Stimulated Echo Acquisition Mode volume element localization was used with chemical shift imaging. Choline and creatine signal-to-noise ratios (SNRs) were significantly lower in social phobia than in controls in subcortical, thalamic, and caudate areas. In the social phobic group, N-acetylaspartate (NAA) SNR was significantly lower in cortical and subcortical regions, and ratios of NAA to other metabolites were lower in social phobia. Choline, creatine, and NAA SNRs were inversely correlated to total social phobia and fear symptoms, as measured by the Brief Social Phobia Scale, in the thalamic and noncortical gray areas. In a small number of patients who received clonazepam, posttreatment SNRs generally increased relative to baseline. Our results suggest a promising place for magnetic resonance spectroscopy in social phobia and also indicate potential pharmacodynamic uses of this technique.

Treatment of social phobia with clonazepam and placebo

Clonazepam and placebo were administered in a double-blind pilot study to 75 outpatients with social phobia. The mean maximum dose of clonazepam was 2.4 mg/day at endpoint (range, 0.5 to 3 mg). Treatment was continued for up to 10 weeks. The results of an intent-to-treat analysis indicated superior effects of clonazepam on most measures. Response rates for clonazepam and placebo were 78.3 and 20.0%. Drug effects were apparent on performance and generalized social anxiety, on fear and phobic avoidance, on interpersonal sensitivity, on fears of negative evaluation, and on disability measures. Significant differences were evident by week 1, 2, or 6, depending upon the rating scale used. Clonazepam was well tolerated in general, although unsteadiness and dizziness were more severe and persistent than was the case for placebo subjects.

Should physicians screen for depression in elderly medical inpatients?: Results of a decision analysis

OBJECTIVE

We wish to determine whether or not elderly medical inpatients should be screened for depressive disorder using either 1) a self-rated depression scale (Geriatric Depression Scale), 2) "usual clinical assessment," or 3) neither, assuming that treatment with tricyclic antidepressants (TCAs) is the primary mode of intervention.

METHOD

Based on recent data from epidemiological studies on the prevalence and course of depression, the test characteristics of available screening tests, and the efficacy and side-effects of traditional antidepressants, decision analysis is used to help decide whether or not clinicians should screen for depression in this setting.

RESULTS

These calculations indicate that if screening is done solely to identify depressed patients for treatment with TCAs, then the highest utility lies in not screening; however, the difference in utilities between that decision and the decisions to either screen with GDS or screen by usual clinical assessment was only .04 units on a 0 to 100 scale, making the decision virtually a toss-up. Furthermore, even a small variation in one of several clinical factors or test characteristics could give screening a higher utility. In particular, if psychotherapy is considered as the primary intervention, then the utility of screening exceeds that of not screening.

CONCLUSION

Characteristics of the screening test, clinical setting, types and safety of available treatments, each impact on the usefulness of screening and must be kept in mind when diagnosing and treating depressed medically ill elders hospitalized in acute care settings.

Systematics and body size: implications for feeding adaptations in New World monkeys

The relationship between body size and feeding ecology is well established for primates. It is argued that the evolutionary history of modern New World monkeys and, in particular, the path to attainment of current body size is significant in understanding the similarities and differences between dietary strategies and other ecological parameters of similar-sized monkeys. Current interpretations of New World monkey evolutionary relationships are reviewed. Based on a synthesis of available body weights and the assumption that the earliest New World monkeys weighed close to 1 kg, similar to modern Aotus and Callicebus, predicted patterns of body size change in each lineage are given. Restrictions on directions of body size change in primates are discussed, and it is shown that "Stanley's Rule" offers a good explanation for differing body size ranges in New and Old World anthropoids. Predicted ecological correlates to body size drawn from the mammalian literature are offered and tested using data on New World monkeys, which show some concurrence and several interesting departures from predicted patterns. Sexual dimorphism in body weight of New World monkey species is reviewed, based on the new summary of body weight data given.

The Brief Social Phobia Scale

An observer measure of social phobic symptoms, referred to as the Brief Social Phobia Scale, consists of 11 items, 7 evaluating commonly feared or avoided situations and 4 additional items measuring autonomic distress. Symptoms represented by the scale items are found frequently in social phobia, and the instrument demonstrates acceptable interrater and test-retest reliability, internal consistency, concurrent validity against other measures of social phobia, and the ability of patients to change as a result of treatment. It can also detect differences between active treatment and placebo treatment. A comparison of the sensitivity of this scale with other scales in detection of size of effect also is presented.

Long-term treatment of social phobia with clonazepam

Twenty-six socially phobic outpatients were treated with clonazepam for the relief of symptoms. At evaluation, which took place after an average of 11.3 months of continuous treatment, 22 (84.6%) patients showed good improvement and 4 (14.4%) showed no improvement or were not recovered. The dose declined over time, from a peak mean of 2.1 mg/day to a mean of 0.94 mg/day at follow-up. Side effects are described, along with individual case descriptions that illustrate important aspects of the use of benzodiazepines for the treatment of social phobia.

Transepithelial acidification by cultures of rabbit proximal tubules grown on filters

Transepithelial acidification in the proximal tubule occurs by the simultaneous actions of the Na(+)-H+ exchanger in the brush border and the basolateral Na(+)-HCO3- cotransporter. The presence of these systems has been demonstrated for cultured cells; however, their contributions to the transepithelial movement of acid equivalents has not been confirmed in monolayers. To examine transepithelial acidification by intact cells, tubules were grown on membrane filters. Confluent cultures developed a transepithelial pH gradient within 6 h by decreasing the pH of medium in the apical chamber (6.66 +/- 0.03) while raising the basolateral pH to 7.40 +/- 0.02. Cells maintained on plastic did not acidify the medium during this time. Amiloride (10-100 microM) inhibited development of the gradient only when placed in the top chamber. 4-Acetamido-4'-isothiocyanostilbene-2,2'-disulfonic acid (SITS; 10-100 microM), which inhibits basolateral Na(+)-HCO3- cotransport, decreased the gradient only when added to the bottom. These results demonstrate that cultured proximal tubule cells can develop a transepithelial pH gradient and that the polarized distribution of the transport systems is maintained in vitro.

Cine photography of anterior segment fluorescein angiography of iris tumours

A description is given of the apparatus and technique for carrying out cine photography of anterior segment fluorescein angiography with special emphasis on its application in the recording and diagnosis of iris tumours.

Localization and imaging with radioiodine-labeled monoclonal antibodies in a xenogeneic tumor model for human B-cell lymphoma

Two MoAbs directed towards human B-cell malignancies have been studied in a preclinical animal model to evaluate their potential for in vivo imaging and therapy of B-cell lymphomas. Anti-B1 reacts with virtually all immunoglobulin-bearing malignancies and non-T acute lymphoblastic leukemia. Anti-J5 reacts with the common acute lymphoblastic leukemia antigen found on non-T acute lymphoblastic leukemia and follicular lymphomas. Anti-T1 which recognizes the CD5 antigen on most T-cell leukemias and lymphomas was used as a control antibody. These monoclonal antibodies were radiolabeled with 125I or 131I by the ICl method. Namalwa (B-cell) and MOLT-4 (T-cell) tumors were grown s.c. in irradiated nude mice. The highest tissue concentration of 125I-labeled anti-J5 in Namalwa-bearing mice was in blood and tumor. The tumor/blood ratio ranged from 0.7-1.2, with the highest ratio 4 days after injection. Pharmacokinetic analysis indicated that the t1/2 beta of anti-J5 from blood and other tissues ranged from 40-50 h, while the t1/2 beta for tumor averaged 65 h. The area under the curve of tumor was 2- to 5-fold higher than the area under the curve of liver, kidney, skin, and muscle. The peak tissue levels of 125I-labeled anti-B1 in Namalwa-bearing mice were again in blood and tumor and 6 days following injection more than 5-fold greater activity was found in tumor compared to normal tissues other than blood. The tumor/blood ratio was 1.2 and 0.7 at 4 and 6 days after injection. 125I-labeled anti-B1 showed minimal uptake in antigen-negative MOLT-4 tumors and 125I-labeled anti-T1 showed little uptake in Namalwa tumors. Scintigraphic images were obtained following the injection of 131I-labeled anti-J5 and anti-B1 in nude mice bearing Namalwa tumors. These results indicate that radiolabeled anti-J5 and anti-B1 show promise as diagnostic and possibly therapeutic agents for human B-cell lymphoma, although there may be a limitation to clinical utility due to cross-reactivity with some normal cells.

Role of desacetylation in the detoxification of cephalothin in renal cells in culture

The toxicity of three cephalosporin antibiotics to rabbit kidney cells in culture was compared to their known nephrotoxic potential in vivo (cephaloridine greater than cefazolin greater than cephalothin). While cephalothin is considered to be a relatively nonnephrotoxic cephalosporin when administered to many species including humans and rabbits, in several in vitro systems involving rabbit renal tissue, cephalothin was comparatively more toxic than anticipated based on in vivo data. Cephalothin is extensively desacetylated in rabbits to a less microbiologically active metabolite, desacetylcephalothin. When a microsomal S9 fraction from rabbit kidney was added to the in vitro assay in cultured rabbit renal cells, cephalothin was desacetylated and its toxicity to kidney cells was reduced. The addition of S9 in vitro provided a toxicity ranking of the cephalosporins that correlated with their known in vivo nephrotoxic potentials (cephaloridine greater than cefazolin greater than cephalothin). The in vitro detoxification of cephalothin by S9 was blocked by the coadministration of the esterase inhibitor, aminocarb. Desacetylcephalothin was relatively nontoxic to rabbit renal tissue in vitro. These results suggest that the desacetylation of cephalothin in vivo represents a previously unrecognized mechanism of detoxification of this cephalosporin antibiotic. Furthermore, this mechanism of detoxification may be applicable to other acetylated cephalosporins.

Transient vasopressin-resistant diabetes insipidus of pregnancy

A case of transient vasopressin-resistant diabetes insipidus is reported which developed during the seventh gestational month. Polyuria reached 4-6 L daily and urine osmolality remained dilute despite 21 hours of water deprivation followed by 5 U intramuscularly of aqueous pitressin, as well as four days of treatment with intranasal DDAVP (0.1-0.5 mL every 12 hours). Urinary excretion of prostaglandin E2, 1384 ng/24 hours, was fourfold that in nongravid subjects and a plasma arginine vasopressin level of 12 pg/mL was recorded. Indomethacin had no effect on urine osmolality but decreased urine volume markedly. Hydrochlorothiazide, also, decreased urine volumes, and this drug was used to manage the patient until delivery. The syndrome remitted in the puerperium, the patient concentrating her urine to 938 mOsm/kg when tested several months postpartum.

Transient vasopressin-resistant diabetes insipidus of pregnancy

A case of transient vasopressin-resistant diabetes insipidus is reported, which developed during the seventh month of pregnancy and remitted postpartum. The patient was resistant to large doses of deamino-D-arginine vasopressin as well as to aqueous pitressin. She was treated with hydrochlorothiazide. Evidence that prostaglandins may play a role in this syndrome is discussed.

Iris atrophy in sickle cell disease

Iris atrophy, of unknown origin and believed to be secondary to the vaso-occlusive process of sickle cell disease, has been observed in 25 eyes of 22 patients (two SS disease, 20 SC disease). The crude prevalence was highest in males with SC disease, in whom 14.7% of patients were affected. Iris atrophy was closely associated with proliferative sickle retinopathy in the same eye. Analysis of haematological indices failed to reveal any significant differences between patients with and without iris atrophy. The characteristics and distribution of iris atrophy are described as well as the histopathology in one 68-year-old male patient with SS disease.

Comment on the evolution of claw-like nails in callitrichids (marmosets/tamarins)

A recently proposed scenario for the evolution of a unified complex of exudativory, vertical clinging, and claw-like nails in callitrichids is examined. Consideration of behaviors and morphologies exhibited by Callimico goeldii leads to a decoupling of this "complex," with the early occurrence of claws and vertical clinging in the callitrichid lineage and only later, in some descendents, the development of exudativory and possible related behaviors.

Subfossil platyrrhine tibia (primates: Callitrichidae) from Hispaniola: a possible further example of island gigantism

A distal right tibia described by G.S. Miller in 1929 (Smithsonian Misc. Coll. 82[5]:1-16) on the island of Hispaniola is shown to be that of a heretofore unknown extinct platyrrhine and is informally referred to as Ceboid M. Its affinities appear to be with the dwarfed callitrichids, especially Saguinus. It is suggested that Ceboid M represents yet another case of gigantism in the Antilles, in response to a lack of both competitors and predators. A reconsideration of the affinities of Xenothrix mcgregori from Jamaica is suggested.

Macular vasculature, visual acuity, and irreversibly sickled cells in homozygous sickle cell disease

Observations of visual acuity and the conjunctival, macular, and perimacular vascularity have been assessed in patients with homozygous sickle cell (SS) disease. There were 17 matched pairs, each consisting of one patient with a high count (greater than or equal to 15%) and one with a low count (less than or equal to 5%) of irreversibly sickled cells (ISCs). The macular vascular bed was assessed by measurements of the foveal avascular zone (FAZ), perimacular avascular zones, and counts of perimacular vascular abnormalities (perimacular counts). Small foveal avascular zones and high perimacular counts were commoner in younger than older patients and there was a significant inverse correlation between size of the FAZ and the perimacular count. These observations were compatible with the hypothesis that perimacular vessel anomalies represent the early vaso-occlusive phase which progresses to ischaemia and the formation and enlargement of avascular areas. Visual acuity was assessed by Snellen's test type and by measuring contrast sensitivity. There was no obvious relationship between acuity measured by the 2 methods and no relationship between acuity and observations of macular vascularity. High ISC counts were significantly related to abnormalities of the conjunctival vasculature, but no relationship was noted with abnormalities of the macular vasculature or with visual acuity.

Choroidal neovascularisation induced by photocoagulation in sickle cell disease

Choroidal neovascularisation occurred in 35 out of 57 (61%) patients during a trial of xenon are photocoagulation in proliferative sickle retinopathy. Nineteen patients manifested abnormal vessel systems in the plane of the retina which tended to be benign, not enlarging, and without complications (choroidoretinal neovascularisation). In 16 patients the abnormal vessel systems grew into the vitreous, tended to increase in size, and to be associated with vitreous haemorrhage and retinal traction (choroidovitreal neovascularisation). Both forms of neovascularisation were significantly more common at younger ages. Treatment was generally unsatisfactory, frequently resulting in further enlargement of the lesions. Although the natural history of choroidal neovascularisation and its ultimate effect on visual function remains to be recorded, these lesions constitute a common and potentially serious complication of xenon are photocoagulation in proliferative sickle retinopathy as currently performed.

Cine photography and video recording of anterior segment fluorescein angiography

A description is given of apparatus and technique for carrying out cine photography and video recording of anterior segment fluorescein angiography. We found cine best for single-frame analysis and video tape recording less expensive.