Sex specific effects of buprenorphine on adult hippocampal neurogenesis and behavioral outcomes during the acute phase after pediatric traumatic brain injury in mice

Traumatic brain injury (TBI) in children often causes cognitive and mental dysfunctions, as well as acute and chronic pain. Adult hippocampal neurogenesis plays a key role in cognition, depression, and pain. Adult hippocampal neurogenesis can be modulated by genetic and environmental factors, such as TBI and opioids. Buprenorphine (BPN), a semisynthetic opioid, is commonly used for pain management in children, however, the effects of BPN on adult hippocampal neurogenesis after pediatric TBI are still unclear. This study investigated the sex-specific effects of BPN on adult hippocampal neurogenesis during acute phase after pediatric TBI. Male and female littermates were randomized on postnatal day 20-21(P20-21) into Sham, TBI+saline and TBI+BPN groups. BPN was administered intraperitoneally to the TBI+BPN mice at 30 min after injury, and then every 6-12 h (h) for 2 days (d). Bromodeoxyuridine (BrdU) was administered intraperitoneally to all groups at 2, 4, 6, and 8-h post-injury. All outcomes were evaluated at 3-d post-BrdU administration. We found that TBI induced significant cognitive impairment, depression, and reduced adult hippocampal neurogenesis in both male and female mice, with more prominent effects in females. BPN significantly improved adult hippocampal neurogenesis and depression in males, but not in females. We further demonstrated that differential expressions of opioid receptors, transcription factors and neuroinflammatory markers at the neurogenic niche might be responsible for the differential effects of BPN in males and females. In conclusion, this study elucidates the effects of BPN on adult hippocampal neurogenesis and behavioral outcomes at the acute phase after pediatric TBI.

Racial/ethnic differences in dietary intake among a diverse sample of adolescents: An experimental study

BACKGROUND

African-American (AA) and Hispanic/Latina (HL) females have higher obesity prevalence than do non-Hispanic Whites (NHW); this may be due to AA and HL consuming more energy-dense foods in response to stressors.

OBJECTIVES

This study examined racial/ethnic differences in dietary intake under controlled conditions (relaxation and stress) in a diverse sample of adolescent females.

METHODS

Participants included 120 adolescent females (30% AA, 37% HL and 33% NHW) who participated in a laboratory food intake study. Using a randomized cross-over design, ad libitum food consumption was measured following control/relaxation and social-evaluative stress conditions. Food intake was indexed as consumed calories, added sugars and solid fats.

RESULTS

The effect of laboratory conditions on food intake varied by race/ethnicity, such that AA consumed more energy following relaxation than following stress. For NHW and HL, food intake did not differ between conditions.

CONCLUSIONS

To the best of our knowledge, these findings are the first to directly observe racial/ethnic differences in food intake in response to acute stress, which may contribute to obesity-related health disparities.

Associations Between Placental Corticotropin-Releasing Hormone, Maternal Cortisol, and Birth Outcomes, Based on Placental Histopathology

Preterm birth remains the leading cause of neonatal morbidity and mortality, with complex biochemical pathways requiring continued understanding and assessment. The objective of this study is to assess the associations between maternal cortisol and placental corticotropin-releasing hormone (placental CRH) concentrations with birth outcomes when stratified by placental histopathology. We conducted an analysis of 112 singleton pregnancies who received betamethasone between 23 and 34 weeks' gestation. Maternal blood and saliva were collected prior to betamethasone administration and samples assayed for plasma cortisol (pCort), salivary cortisol (sCort), and placental CRH levels. Placental findings were characterized as inflammatory, maternal vascular underperfusion (MVU), or no pathology, and compared for the outcomes of placental CRH, pCort, and sCort levels, gestational age at birth (GAB), and birthweight percentiles (BWP). Thirty-six subjects were characterized as inflammatory, 38 as MVU, and 38 without placental abnormalities. Histopathology groups differed significantly on placental CRH levels, GAB, and BWP. Post hoc tests suggested that the MVU group had higher placental CRH than the inflammatory or no pathology groups, and despite delivering earlier than the other two groups, the inflammatory group had infants with significantly higher BWP. No differences existed between groups in terms of mean plasma or sCort levels. Higher placental CRH and pCort levels were associated with earlier GAB in the overall sample, but when split by group, these associations remained significant only among the MVU group. Higher placental CRH was also associated with lower BWP in the overall sample but did not remain significant when split by group. Higher sCort was associated with lower BWP only in the MVU group. There is differentiation of placental CRH, cortisol, and birth outcomes when evaluated by placental histopathology. This highlights the importance of evaluating birth outcomes within the context of placental histopathology.

Refractory status epilepticus

Refractory status epilepticus is a potentially life-threatening medical emergency. It requires early diagnosis and treatment. There is a lack of consensus upon its semantic definition of whether it is status epilepticus that continues despite treatment with benzodiazepine and one antiepileptic medication (AED), i.e., Lorazepam + phenytoin. Others regard refractory status epilepticus as failure of benzodiazepine and 2 antiepileptic medications, i.e., Lorazepam + phenytoin + phenobarb. Up to 30% patients in SE fail to respond to two antiepileptic drugs (AEDs) and 15% continue to have seizure activity despite use of three drugs. Mechanisms that have made the treatment even more challenging are GABA-R that is internalized during status epilepticus and upregulation of multidrug transporter proteins. All patients of refractory status epilepticus require continuous EEG monitoring. There are three main agents used in the treatment of RSE. These include pentobarbital or thiopental, midazolam and propofol. RSE was shown to result in mortality in 35% cases, 39.13% of patients were left with severe neurological deficits, while another 13% had mild neurological deficits.

The onset and alleviation of learned helplessness in older hospitalized people

The objective of this study was to investigate the relevance of learned helplessness (LH) and learned mastery (LM) theories in the respective development of dependence and independence in older hospitalized people. A two-staged experiment was performed. In stage I, meal-related responses of patient participants (n = 84) were automatically completed by a researcher during two consecutive mealtime events (LH induction). LH effects were then assessed by evaluating participant performance during a controllable meal-task and a non-meal-related psychomotor task. In stage II, "helpless" participants (n = 35) were then given an expectation of future control over the mealtime event followed by two further meals during which the researcher provided no active assistance (LM induction). LM effects were assessed as in stage I. Participants exposed to the LH inducing strategy demonstrated LH effects within both the meal and psychomotor tasks. These effects were alleviated through exposing participants to the LM inducing intervention. Exposing older hospitalized people to uncontrollable or disempowering circumstances may potentially lead them to develop a LH induced dependence. This may be alleviated by increasing patient's expectation of control leading to the development of LM.

Efficacy and safety of a therapeutic interchange from high-dose calcium channel blockers to a fixed-dose combination of amlodipine/benazepril in patients with moderate-to-severe hypertension

BACKGROUND

Recent hypertension trials have demonstrated the importance of achieving goal blood pressures to reduce the risk of target organ damage. In patients with moderate to severe hypertension, the use of high-dose monotherapy and/or combinations of drugs are necessary to achieve these goals. Fixed-dose combination products may be useful in these patients by reducing the number of daily doses required to control blood pressure.

OBJECTIVE

The objective of the present study was to evaluate the efficacy and safety of a therapeutic interchange between high-dose calcium channel blocker therapy and a fixed-dose combination of amlodipine/ benazepril (Lotrel; Novartis Pharmaceuticals, USA) in patients with moderate to severe hypertension.

METHODS

A total of 75 patients were switched from amlodipine (n = 25), felodipine (n = 25), and nifedipine-GITS (n = 25) to amlodipine/benazepril. Twenty-eight of the 75 patients (37%) were taking either a beta-blocker or a diuretic in addition to the high-dose calcium channel blocker prior to the switch. Blood pressure control, side effects and the cost of the therapeutic interchange were evaluated in the year following the therapeutic interchange.

RESULTS

Sixty-six of the 75 (88%) patients were successfully switched with maintenance of blood pressure control and without the development of new dose-limiting side effects. Reasons for treatment failure after the therapeutic interchange included loss of blood pressure control in five patients and the development of new dose-limiting side effects in four patients. These side effects included cough in three patients and rash in one patient. After accounting for differences in drug acquisition cost and costs related to the switch (clinic and emergency room and laboratory tests), a cost savings of $16030 for all 75 patients was realised in the first year. The per patient-per year cost savings was $214.

CONCLUSIONS

Our data indicate that a therapeutic interchange from selected high-dose calcium channel blockers to a fixed-dose combination of amlodipine/ benazepril can be successfully accomplished in the majority of patients.

Effect of ramipril vs amlodipine on renal outcomes in hypertensive nephrosclerosis: a randomized controlled trial

CONTEXT

Incidence of end-stage renal disease due to hypertension has increased in recent decades, but the optimal strategy for treatment of hypertension to prevent renal failure is unknown, especially among African Americans.

OBJECTIVE

To compare the effects of an angiotensin-converting enzyme (ACE) inhibitor (ramipril), a dihydropyridine calcium channel blocker (amlodipine), and a beta-blocker (metoprolol) on hypertensive renal disease progression.

DESIGN, SETTING, AND PARTICIPANTS

Interim analysis of a randomized, double-blind, 3 x 2 factorial trial conducted in 1094 African Americans aged 18 to 70 years with hypertensive renal disease (glomerular filtration rate [GFR] of 20-65 mL/min per 1.73 m(2)) enrolled between February 1995 and September 1998. This report compares the ramipril and amlodipine groups following discontinuation of the amlodipine intervention in September 2000.

INTERVENTIONS

Participants were randomly assigned to receive amlodipine, 5 to 10 mg/d (n = 217), ramipril, 2.5 to 10 mg/d (n = 436), or metoprolol, 50 to 200 mg/d (n = 441), with other agents added to achieve 1 of 2 blood pressure goals.

MAIN OUTCOME MEASURES

The primary outcome measure was the rate of change in GFR; the main secondary outcome was a composite index of the clinical end points of reduction in GFR of more than 50% or 25 mL/min per 1.73 m(2), end-stage renal disease, or death.

RESULTS

Among participants with a urinary protein to creatinine ratio of >0.22 (corresponding approximately to proteinuria of more than 300 mg/d), the ramipril group had a 36% (2.02 [SE, 0.74] mL/min per 1.73 m(2)/y) slower mean decline in GFR over 3 years (P =.006) and a 48% reduced risk of the clinical end points vs the amlodipine group (95% confidence interval [CI], 20%-66%). In the entire cohort, there was no significant difference in mean GFR decline from baseline to 3 years between treatment groups (P =.38). However, compared with the amlodipine group, after adjustment for baseline covariates the ramipril group had a 38% reduced risk of clinical end points (95% CI, 13%-56%), a 36% slower mean decline in GFR after 3 months (P =.002), and less proteinuria (P<.001).

CONCLUSION

Ramipril, compared with amlodipine, retards renal disease progression in patients with hypertensive renal disease and proteinuria and may offer benefit to patients without proteinuria.

A measure of patient empowerment in hospital environments catering for older people

AIM

The principal aim of this research was to develop a valid and reliable measure of patient empowerment and disempowerment in hospital environments catering for older people. Rationale. It is argued that empowerment is linked to Learned Mastery (Peterson, Maier & Seligman 1993) and increasing patient independence, whilst disempowerment is linked to Learned Helplessness (Seligman 1975) and increasing patient dependence. Consequently, the development of a measure of these concepts would represent a valuable quality assurance tool.

METHOD

Measures were developed using the 'act frequency approach' of Buss and Craik (1983) whereby registered nurses (n=38) were asked to nominate empowering and disempowering acts relevant to interactions between staff and older patients. The resulting lists of 98 acts for each disposition were hypothetically judged by older hospitalized people (n=20) as to the extent they would be either 'control giving' (empowering acts) or 'control taking' (disempowering acts) if personally experienced. The twenty highest scoring acts in each category were incorporated into the Patient Empowerment Scale.

RESULTS

Using this scale, older hospitalized people (n=102) resident on five different hospital wards were asked to judge how often they had encountered each act over a predetermined period of time. Wards varied in speciality including acute medicine, surgery and elderly care rehabilitation. The ward scoring lowest on the PES (i.e. the least empowering) was the elderly care rehabilitation ward. Moreover, this ward showed an inverse correlation between participant age and exposure to empowering care. Alpha scores ranged from 0.74 to 0.87 for empowerment and 0.65 to 0.87 for disempowerment.

CONCLUSION

The PES is offered as a valid and reliable measure of empowerment and disempowerment in hospital settings catering for older people. It enables the identification of environments which place patients at risk of becoming dependent, or alternatively facilitate increasing independence.

Thoracic aortic dissection in a patient with autosomal dominant polycystic kidney disease

Autosomal dominant polycystic kidney disease is one of the most common hereditary diseases, and frequently has well defined extrarenal manifestations. Very few cases of aortic aneurysms associated with this disorder are described in literature. We report a 42-year-old male with autosomal dominant polycystic kidney disease presenting with dissecting aneurysm of the thoracic aorta.

HEDIS audits: meeting the challenge

The Health Plan Employer Data and Information Set (HEDIS) is a tool to measure and report managed care performance. HEDIS has become the industry standard for assessing and comparing the quality of managed care organizations (MCOs), so it is imperative that MCOs collect and communicate HEDIS data correctly and efficiently. Several primary issues face MCOs in compiling HEDIS data. In particular, this article examines the HEDIS audit process and outlines the preparation required to undergo an audit, common errors uncovered in the audit process, and steps that can be taken to ensure compliance with HEDIS technical specifications.

The Rhnull phenotype in an English individual: haematological, serological and immunological studies

We have characterized the first case of Rhnull phenotype to be identified in England. The red cells were serologically negative for C, c, Cw, D, E, e, f, hr B, Rh17, Lw a, Lw ab and Duclos, while the patient's serum contained anti-Rh29, which was subsequently boosted by transfusion. The Rh phenotype of the patient's son (R1r) confirmed that this was a regulator type of Rhnull in the patient. Follow up studies confirmed the presence of a mild chronic anaemia with stomatocytes and spherocytes; electron microscopy revealed the presence of cells with deep central indentations. Osmotic fragility was increased to a level intermediate between normal and hereditary spherocytic controls. The presence of ongoing haemolysis was indicated by a mild reticulocytosis and splenomegaly. The potent anti-Rh29 has made the provision of compatible blood difficult and autologous units have been frozen. The case illustrates the rare phenomenon of the Rhnull phenotype which not only causes problems for the transfusionist but should also be recognized as a cause of haemolytic anaemia secondary to a membrane defect. Blood film and Rh phenotyping are useful preliminary investigations in suspected cases.

Participant satisfaction in the African American Study of Kidney Disease and Hypertension (AASK) Pilot Study

Seventy-one of the 94 eligible participants of the African American Study of Kidney Disease and Hypertension (AASK) Pilot Study completed a self-administered questionnaire at the end of the study to determine their satisfaction with the study, difficulties encountered during participation, and willingness to join a similar study in the future. Nearly all of the participants (97%) believed that they would directly benefit from the study; treatment and information from physicians (94%), and more knowledge (92%) and closer monitoring (90%) of their physical condition were often cited as the ways in which the AASK Pilot Study helped. The two most commonly reported problems in the study were side effects from antihypertensive drugs (27%) and travel to and from the clinic (25%). Eighty-two percent of those who completed the survey indicated that they would volunteer for a similar study in the future. We conclude that AASK Pilot Study participants believed that they would benefit directly from the trial and that medical aspects of the trial were of major importance. Side effects from antihypertensive drugs and difficulties in travel to and from the clinic were commonly encountered problems and may hinder long-term participation in the AASK Full-Scale Trial.

Recruitment experience in the African American Study of Kidney Disease and Hypertension (AASK) Pilot Study

Several approaches for recruitment of African American adults with renal insufficiency due to hypertension (glomerular filtration rate between 25 and 70 ml/min/1.73 m2) were explored in the Pilot Study for the African American Study of Kidney Disease and Hypertension (AASK). Over a period of 42 weeks, prescreening information was obtained on 2880 individuals, of whom 498 (17%) were evaluated at a screening visit. Two hundred and twenty-five (8%) had an 125I-iothalamate assessment of glomerular filtration rate. Ninety-four of 97 participants who met all the study eligibility criteria were enrolled in the trial. The most common reasons for ineligibility during screening were absence of renal insufficiency or hypertension, presence of diabetes mellitus, and a body mass index above the acceptable level. Overall, an average of 31 prescreen contacts and 8 screening visits were conducted for every randomization (3.3% yield from prescreening to randomization). Screening in clinical practice was the most efficient method for recruitment (12.6% yield from prescreen contact to randomization compared to 1.1% from mass mailing campaigns, 1.3% from mass media campaigns, and 1.7% from referrals by patients with end-stage renal disease). Randomization yields increased with progressively higher age ranges (2.4%, 3.3%, and 6.0% prescreen to randomization yields for those aged < or = 50, 51-60, and 61-70, respectively). A slight majority (51%) of the prescreen contacts were women, but 75% of the randomized participants were men. Our results suggest that clinic-based screening is an effective approach for recruitment of African Americans with hypertension and renal insufficiency into clinical trials. They also suggest that enrollment of African American women in such studies is a special challenge.

Effect of blood pressure control and antihypertensive drug regimen on quality of life: the African American Study of Kidney Disease and Hypertension (AASK) Pilot Study

The African American Study of Kidney Disease and Hypertension (AASK) Pilot Study evaluated the feasibility of carrying out a randomized, multicenter, 7-year clinical trial to determine the effects of two goal levels of blood pressure control and three antihypertensive drug regimens on decline in glomerular filtration rate in African Americans with clinically diagnosed hypertensive nephrosclerosis. Participants were randomized to either a usual mean arterial blood pressure (MAP) goal group (102-107 mm Hg) or a low-MAP goal group (< or = 92 mm Hg) and to a drug regimen (initial therapy with either atenolol, amlodipine, or enalapril). Quality of life was assessed by the Medical Outcomes Short-Form 36 (MOS SF-36) at baseline and the last follow-up visit for 84 of the 94 participants of the AASK Pilot Study. Symptoms were assessed at baseline and throughout the course of therapy by participant self-report. Mean SF-36 scores increased significantly on physical functioning (9.2), role limitations (physical) (19.0), social functioning (9.0), and vitality dimensions (5.6) from baseline to the last follow-up visit in the usual MAP goal group. Scores for the eight health dimensions assessed by the MOS SF-36 did not change significantly during the same time period either in the low-MAP goal group or in any of the drug regimens. The mean score for general health perception was significantly lower at the last follow-up visit in the enalapril drug regimen (49.9) compared to drug regimens with atenolol (65.4) or amlodipine (63.9). Physical functioning, role limitations (emotional), social functioning, mental health, vitality, and general health perception scores were negatively correlated with self-reported symptoms during treatment. We conclude that selected dimensions of quality of life improved during the AASK Pilot Study only in participants randomized to the usual MAP goal group. Significant differences between MAP goal groups and drug regimens at the end of follow-up were observed for only a few health dimensions.

Immunogenicity of influenza and HSV-1 mixed antigen ISCOMs in mice

Immunostimulating complexes (ISCOMs) were prepared with mixtures of antigens from influenza A virus (A/PR/8/34 or A/Sichuan/2/87) and herpes simplex virus type 1 (HSV-1), and were characterised by enzyme linked immunosorbent assay (ELISA) and electron microscopy using double-labelling immunogold techniques employing monoclonal antibodies to influenza or HSV-1 glycoproteins. The immunogenicity of the mixed antigen ISCOMs was evaluated in mice, following administration by the subcutaneous route, by measuring the total and subclass IgG antibody responses. Protection of these animals against challenge with live influenza A/Sichuan virus or live HSV-1, was compared with that induced by immunization with aqueous mixed antigen preparations. It was found that relatively high humoral responses to both influenza and HSV antigens, and increased levels of protection to both influenza and HSV viruses were elicited in mice receiving the mixed antigen ISCOM preparation compared to those observed in animals receiving the mixed aqueous subunit preparation. The findings also indicate that antigens from more than one virus can be used in an ISCOM formulation to produce immunity and protection.

Severe anemia: a risk factor for glomerular injury in sickle cell disease

Approximately 15% to 20% of patients with sickle cell disease have proteinuria. Proteinuria, particularly albuminuria, is the hallmark of glomerular injury. This study examines risk factors for glomerular injury as indicated by urinary albumin excretion (UAE) 30 microgram/minute, directly related to sickle cell disease. A total of seven patients were enrolled between September 1992 and March 1993. Fasting blood chemistries, complete blood cell count, 24-hour urine for protein and creatinine clearance, and glomerular filtration rate determined by 125 I-iothalamate were obtained for each patient. The results indicated that the lower the hematocrit, the higher the UAE rate. Low hematocrits have served as a protective mechanism in sickle cell disease by reducing blood viscosity and thus decreasing the number of vaso-occlusive crises. However, severe anemia appears to have an indirect adverse effect on the kidney in sickle cell disease.

The pituitary in cirrhosis: ultrastructure, growth hormone, and prolactin concentrations

Micronodular cirrhosis was induced in male SUAH substrain Wistar rats by combined phenobarbitone and carbon tetrachloride treatment. Both pituitary and serum concentrations of growth hormone were significantly reduced in cirrhotic rats compared with age-related untreated rats or those treated only with phenobarbitone. Ultrastructurally growth hormone-secreting cells (somatotrophs) of pituitaries of cirrhotic rats appeared relatively inactive, having few hormone-containing granules, sparse rough endoplasmic reticulum, and small nuclei with areas of condensed chromatin. The cells themselves were smaller than similar cells of untreated rats with a reduced cytoplasmic area. In addition immunocytochemistry of pituitaries at light microscope level, using sheep anti-rat growth hormone antibody, showed that somatotrophs of cirrhotic rats were more heteromorphic and disorganized than those in controls. There was marked development of the folliculo-stellate cell system in pituitaries of cirrhotic rats, the cells were enlarged with distinct golgi, and numerous microvilli were projecting into dilated follicular lumena.

Hypersensitivity angiitis associated with naproxen

A 52-year-old male developed cutaneous necrotizing vasculitis, renal failure, massive proteinuria, and elevated serum IgE levels following oral naproxen therapy. Renal biopsy specimen revealed cellular crescents in more than 40% of the glomeruli and a rare arteriole displayed thickening and eosinophilia of intima. Electron microscopic examination showed fusion of epithelial foot processes. Discontinuation of naproxen therapy was associated with disappearance of cutaneous lesions and improvement of renal function.

Sexual, seasonal and tissue variation in the encystment of Cotylurus variegatus metacercariae in perch, Perca fluviatilis

All of the 267 perch sampled from Lough Neagh between 1981 and 1983 were infected with the metacercarial cysts of Cotylurus variegatus. Sites of infection were the swim-bladder, pericardium, septum transversum and, to a lesser extent, the visceral cavity. The swim-bladder, particularly the anterior portion, was the site of heaviest infection. Visceral cysts were found chiefly in female fish and this may be related to reduced immunological defence and/or thinner body wall during the breeding season. The number of cysts recorded was not related to host length, suggesting that further parasite invasion is offset by cyst mortality possibly as a result of the host immunological response to the parasite. Highest mean worm burden was recorded between May and June. This corresponded to increased water temperature necessary for development of eggs and the breeding season (April-June) of the perch.

The application of sodium dodecyl sulphate-polyacrylamide gel electrophoresis to the taxonomic identification of the total body protein band profiles of Diplostomum spp. metacercariae (Digenea), parasites of fish eyes

Sodium dodecyl sulphate-polyacrylamide gel electrophoresis has been used to determine the metacercariae (Mc) total body protein band profiles of different Diplostomum spp. Four species of fish were investigated, roach (Rutilus rutilus) infected with D. spathaceum Mc, gywniad (Coregonus laveratus) infected with D. coregonus Mc, ruff (Gymnocephalus cernua) infected with a Diplostomum species related to D. gasterostei Mc, and perch (Perca fluviatilis) infected with D. gasterostei Mc. The four species of Diplostomum Mc were distinguished by three different bands of molecular weight, Mr 55,500, 53,500 and 52,000. A homology of polypeptide component distribution was evident for D. gasterostei Mc, from P. fluviatilis, and D. coregonus Mc, from C. laveratus, the latter showing reduced protein concentrations between bands Mr 32,000-40,000. Critical analysis of Mc polypeptide patterns showed no evidence of contamination with lens, retina or vitreous humour host eye protein. Gross morphological data for the parasites was also considered in relation to different band profiles obtained for the Diplostomum spp. Mc. Band profile analysis in conjunction with other taxonomic tests proved to be a useful tool in the identification of unknown species.

Acute renal failure following cocaine abuse

Three healthy adult males developed acute renal failure following cocaine abuse. Muscle pain, tenderness, elevated levels of serum muscle enzymes, heme-positive urine and the presence of pigmented granular casts in urine all indicated occurrence of rhabdomyolysis. One of them developed acute compartmental syndrome of the left leg and required emergency fasciotomy. The course of renal failure and fast recovery were suggestive of acute tubular necrosis in all 3 patients. A possible role of cocaine in the aggravation of renal and/or muscle ischemia has been speculated.

Polypeptide patterns obtained by polyacrylamide gel electrophoresis of thylakoid membranes isolated from light and dark grown strains of Chlorogloea fritschii

Sodium dodecyl sulphate-polyacrylamide gel electrophoresis has been used to determine the difference between thylakoid polypeptide patterns of light and dark grown strains of the cyanobacterium Chlorogloea fritschii. There were only 2 prominent bands present in the dark grown strains, polypeptide Mr50,000 and polypeptide Mr90,000, also five fainter bands in the Mr range 45,000-66,200 corresponding to photosystem one, compared with the 32 bands present in the light grown strains. There was no obvious indication of the Mr 33,000 3-(3,4-chlorophenyl)-1,1-dimethyl-urea binding protein. In addition the progressive daily development of the various photosystem components in the light and their relationship in photosynthesis was determined. It was observed that the increase of the relative concentrations of the photosystem two and phycocyanin components indicated their developments are mutually synchronized. The effect of light to dark and dark to light transfer on established strains was investigated. Appreciable loss of photosystem two components and the presence of an additional band Mr22,500 of unknown function in the light to dark transfer, and little reactivation of the photosynthetic capabilities in the dark to light transfer was observed.

Pneumocystis carinii pneumonia following 5-fluorouracil administration

A 54-year-old man who had been treated with monthly courses of 5-fluorouracil for one year developed Pneumocystis carinii pneumonia. No evidence of significant, permanent, immunologic impairment was evident one year after the patient became infected. An infection associated with 5-fluorouracil treatment is implicated.

Electronic counting of dog leucocytes. Discrepancies arising from calibration with Coulter standard 4C and with the haemocytometer

The size distributions of leucocytes in canine blood and in standard 4C are markedly different. The use of 4C to calibrate Coulter counters may result in the selection of a threshold setting for canine leucocytes which is too high. Repeated hand counting may be used as a method of calibration, but regular discrepancies occur between hand and electronic counts which are attributable to the differing lytic actions of the diluents used, acetic acid having a more marked effect than commercial Zapoglobin. Canine leucocytes did not show significantly increased lysis when subjected to Zapoglobin at approximately four times the standard concentration, but did do so on exposure to the standard concentration for longer than five minutes. The degree of discrepancy between hand and electronic counts varied in individual dogs suggesting that there is an inconstant leucocyte subpopulation which behaves differently in response to different lytic agents.

A rapid, semi-automated counting procedure for enumeration of antibody-forming cells in gel and nucleated cells in suspension

A commercially available bacterial colony counter has been modified to permit rapid, highly accurate, semi-automated enumeration of antibody-producing plaque forming cells in semi-solid support medium as well as enumeration of nucleated cells in suspension on a standard hemacytometer chamber. This apparatus should therefore serve as an enormous time-conserving accessory to most modern laboratories involved in immunological research.