Detoxification of aqueous zinc using fluorapatite--bearing lean grade rock phosphate

Detoxification of aqueous zinc was studied using the adsorption technique by application of fluorapatite bearing low grade phosphate as a sorbent. The effects of particle size of adsorbent, contact time, initial concentration of zinc and temperature on the adsorption process were studied. Initial rate of adsorption of zinc increases with time up to 30 min and thereafter it reaches equilibrium. Percent adsorption is adversely affected by increase in initial concentration of zinc and increase in particle size of sorbent. Adsorption processes follow first order kinetics and are found to be exothermic.

The role of laparoscopy in second-look evaluations for ovarian cancer

BACKGROUND

The aim of this study was to evaluate the accuracy and safety of laparoscopic second-look operations in patients with ovarian cancer.

METHODS

We retrospectively reviewed the medical records of all patients who have undergone laparoscopic second-look procedures for ovarian cancer at our institution.

RESULTS

From July 1993 to December 1998, 150 patients underwent laparoscopic second-look operations. The mean age of patients was 53 years (range, 25-78 years). The majority of patients (87%) had Stage III or IV disease at initial surgery; the remainder were Stage II or unstaged. Eighty-two patients (54%) had had optimal cytoreduction at the time of their initial surgery. All patients had completed primary chemotherapy and were clinically disease-free based on imaging studies and CA-125 levels at the time of second look. Sixty-nine patients (46%) were found to have pathologically negative second looks; thus, the rate of positive second-look evaluations was 54%. The rate of conversion to laparotomy was 18/150 (12%). In 3 cases this was secondary to bowel injury; one patient sustained a bladder injury; the remainder of conversions to laparotomy were for secondary cytoreduction. There was only 1 case where the patient was found to have extensive adhesions and laparoscopy was abandoned. The overall rate of major complications was 2.7%.

CONCLUSIONS

In our experience, laparoscopy is a safe and accurate method of second-look assessment in patients with ovarian cancer. The incidence of complications is low, particularly in this group of patients, all of whom have undergone prior abdominal surgery. The rate of negative evaluations and the rate of recurrences in patients with negative second looks are equivalent to those described in studies of second-look assessment by laparotomy.

Histoplasma capsulatum in adrenal gland aspirate--a case report

We report a case of disseminated histoplasmosis in a 60-year-old non-immunocompromised patient who presented to us with fever and hepatosplenomegaly. Sonographic & CT examination of the abdomen showed bilateral adrenal masses. Cytological examination of the aspirated material from the mass showed yeast forms of H. capsulatum.

Improved in situ detection method for telomeric tandem repeats in metaphase spreads and interphase nuclei

Peptide nucleic acid technology (PNA) has become an extremely useful tool and promises to impact on molecular biology and diagnostics. These synthetic DNA analogues pair with DNA and RNA molecules according to Watson and Crick base pairing rules. This paper describes a sensitive and quick fluorescent in situ hybridisation (ISH) technique to determine DNA telomere repeat sequences (TTA GGG)n using epifluorescence microscopy. Telomeres are special, repeated structures at the end of each eukaryotic chromosome and serve as protective caps to prevent DNA rearrangements and fusion of chromosomes. A model system has been developed, using stimulated peripheral blood lymphocytes, which facilitates simultaneous detection of telomeres in metaphase as well as in interphase nuclei. A fluorescein isothiocyanate labelled PNA probe (18 mer) directed against complementary telomeric sequences at the end of each chromosome is used. In addition, a simple, easy to perform PNA-ISH protocol is described that overcomes common hybridisation problems encountered using DNA and RNA oligoprobes. Furthermore, the usefulness of a chromogenic immunocytochemical detection system is shown for PNA-ISH.

Acute neuroradiologic findings in young children with inflicted or noninflicted traumatic brain injury

Acute CT/MRI findings were examined in a prospective, longitudinal study of 60 children 0-6 years of age hospitalized for moderate to severe traumatic brain injury (TBI). TBI was categorized as either inflicted (n = 31) or noninflicted (n = 29). Glasgow Coma Scale scores and perinatal history were comparable in both groups. Acute CT/MRI studies were visually inspected by a radiologist blind to group membership. Compared with the noninflicted TBI group, the inflicted TBI group had significantly elevated rates of subdural interhemispheric and convexity hemorrhages as well as signs of pre-existing brain abnormality, including cerebral atrophy, subdural hygroma, and ex vacuo ventriculomegaly. Intraparenchymal hemorrhage, shear injury, and skull fractures were more frequent after non-inflicted TBI. Subarachnoid hemorrhage and infarct/edema occurred with comparable frequency in both groups. Characteristic acute neuroimaging findings of inflicted TBI included multiple extraaxial hemorrhages in addition to the mild atrophy, subdural hygromas, and ventriculomegaly that suggest prior brain abnormality.

Inflicted traumatic brain injury: relationship of developmental outcome to severity of injury

Inflicted traumatic brain injury (TBI) is a frequent consequence of physical child abuse in infants and children. Twenty-eight children who were 2-42 months of age when hospitalized for moderate to severe TBI were enrolled in a prospective, longitudinal study of neurobehavioral outcome following acquired brain injury. Relative to a comparison group, the children with inflicted TBI had significant deficits in cognitive, motor and behavioral domains when assessed with the Bayley Scales of Infant Development-II 1 and 3 months after the injury. Nearly half of the injured children showed persisting deficits in attention/arousal, emotional regulation and motor coordination. Greater injury severity, as indicated by lower coma scale scores, longer periods of unconsciousness and the presence of edema/cerebral infarctions was associated with poorer outcomes in all domains.

Monochloramine directly modulates Ca(2+)-activated K(+) channels in rabbit colonic muscularis mucosae

BACKGROUND & AIMS

Mesenteric ischemia, infection, and inflammatory bowel disease may eventuate in severe colitis, complicated by toxic megacolon with impending intestinal perforation. Monochloramine (NH(2)Cl) is a membrane-permeant oxidant generated during colitis by the large amount of ambient luminal NH(3) in the colon. Reactive oxygen metabolites can modulate smooth muscle ion channels and thereby affect colonic motility, which is markedly impaired in colitis.

METHODS

Effects of NH(2)Cl on ionic currents in the innermost smooth muscle layer of the colon, the tunica muscularis mucosae, were examined using the patch clamp technique. Membrane potential in whole tissue strips was measured using high-resistance microelectrodes.

RESULTS

Whole cell voltage clamp experiments showed that NH(2)Cl (3-30 micromol/L) enhanced outward currents in a dose-dependent manner, increasing currents more than 8-fold at a test potential of +30 mV. Tail current analysis showed that the currents enhanced by NH(2)Cl were K(+) currents. Inhibition by tetraethylammonium and iberiotoxin suggested that these currents represented activation of large-conductance, Ca(2+)-activated K(+) channels. The membrane-impermeant oxidant taurine monochloramine, however, had no effect on whole cell currents. Single-channel studies in inside-out patches showed that NH(2)Cl increased open probability of a 257-pS channel in symmetrical (140 mmol/L) K(+). In the presence of NH(2)Cl, the steady-state voltage dependence of activation was shifted by -22 mV to the left with no change in the single-channel amplitude. The sulfhydryl alkylating agent N-ethylmaleimide prevented NH(2)Cl-induced channel activation. NH(2)Cl also hyperpolarized intact muscle strips, an effect blocked by iberiotoxin.

CONCLUSIONS

NH(2)Cl, at concentrations expected to be found during colitis, may contribute to smooth muscle dysfunction by a direct oxidant effect on maxi K(+) channels.

Ammonia blockade of intestinal epithelial K+ conductance

Ammonia profoundly inhibits cAMP-dependent Cl- secretion in model T84 human intestinal crypt epithelia. Because colonic lumen concentrations of ammonia are high (10-70 mM), ammonia may be a novel regulator of secretory diarrheal responsiveness. We defined the target of ammonia action by structure-function analysis with a series of primary amines (ammonia, methylamine, ethylamine, propylamine, butylamine, pentylamine, hexylamine, heptylamine, and octylamine) that vary principally in size and lipid solubilities. The amine concentrations required for 50% inhibition of Cl- secretion in intact monolayers and 50% inhibition of outward K+ current (IK) in apically permeabilized monolayers vs. the logs of the respective amine partition coefficients give two plots that are strikingly similar in character. Half-maximal inhibition of short-circuit current (Isc) by ammonia was seen at 6 mM and for IK at 4 mM; half-maximal inhibition for octylamine was 0.24 mM and 0.19 mM for Isc and IK, respectively. The preferentially water-soluble hydrophilic amines (ammonia, methylamine, ethylamine) increase in blocking ability with decreasing size and lipophilicity. Conversely, the preferentially lipid-soluble hydrophobic (propylamine, butylamine, pentylamine, hexylamine, heptylamine, octylamine) amines increase in blocking ability with increasing size and lipophilicity. Ammonia does not affect isolated apical Cl- conductance; amine-induced changes in cytosolic and endosomal pH do not correlate with secretory inhibition. We propose that ammonia in its protonated ammonium form (NH4+) inhibits cAMP-dependent Cl- secretion in T84 monolayers by blocking basolateral K+ channels.

Neuroimaging, physical, and developmental findings after inflicted and noninflicted traumatic brain injury in young children

OBJECTIVE

To characterize neuroimaging, physical, neurobehavioral, and developmental findings in children with inflicted and noninflicted traumatic brain injury (TBI) and to identify characteristic features of inflicted TBI.

METHODS AND PATIENTS

Forty children, 0 to 6 years of age, hospitalized for TBI who had no documented history of previous brain injury were enrolled in a prospective longitudinal study. TBI was categorized as either inflicted (n = 20) or noninflicted (n = 20) based on the assessment of hospital and county protective services. Glasgow Coma Scale scores and neonatal history were comparable in both groups.

OUTCOME MEASURES

Acute computed tomography/magnetic resonance imaging studies and physical findings were evaluated. Glasgow Outcome Scale scores, cognitive development, and motor functioning were assessed an average of 1.3 months after TBI. chi2 analyses assessed differences in the distribution of findings in the inflicted and noninflicted TBI groups.

RESULTS

Signs of preexisting brain injury, including cerebral atrophy, subdural hygroma, and ex vacuo ventriculomegaly, were present in 45% of children with inflicted TBI and in none of the children with noninflicted TBI. Subdural hematomas and seizures occurred significantly more often in children with inflicted TBI. Intraparenchymal hemorrhage, edema, skull fractures, and cephalohematomas were similar in both groups. Retinal hemorrhage was only identified in the inflicted TBI group. Glasgow Outcome Scale scores indicated a significantly less favorable outcome after inflicted than noninflicted TBI. Mental deficiency was present in 45% of the inflicted and 5% of the noninflicted TBI groups.

CONCLUSIONS

Characteristic features of inflicted TBI included acute computed tomography/magnetic resonance imaging findings of preexisting brain injury, extraaxial hemorrhages, seizures, retinal hemorrhages, and significantly impaired cognitive function without prolonged impairment of consciousness.

Childhood autism in tuberous sclerosis

The article reports two cases of childhood autism in tuberous sclerosis (TS). Certain atypical features are highlighted. The probands did not show the common seizure types associated with either TS or autism. No ventricular dilatation, cerebral atrophy or temporal lobe involvement was evident. The high prevalence of childhood autism in TS probands with moderate to severe mental retardation has been emphasized.

Pulmonary lipid peroxidation and antioxidant defenses during exhaustive physical exercise: the role of vitamin E and selenium

Physical exercise is known to induce oxidative stress leading to the generation of free radicals. This increased generation of free radicals might lead to lipid peroxidation and tissue damage, more so under deficient/impaired antioxidant states. In the present study, we report the role of vitamin E and selenium (Se) during exercise-induced oxidative stress in the pulmonary tissue. Vitamin E and/or Se deficiency in female albino rats resulted in generation of free radicals as revealed by electron spin resonance (ESR) spectra in the lung tissue, indicating the onset of oxidative stress. When these animals were subjected to a single bout of exhaustive exercise, there was an additional increase in the generation of oxy-free radicals, which might lead to tissue damage. However, no such signals were recorded in the lung tissue of vitamin E- and Se-supplemented animals, when subjected to a similar exercise program, suggesting that protection is offered by vitamin E and Se in combating oxidative stress.

Characteristics of consecutive in vitro fertilization cycles among patients treated with follicle-stimulating hormone (FSH) and human menopausal gonadotropin versus FSH alone

OBJECTIVE

To compare the endocrine responses of patients who first received hMG plus FSH, then were treated in a subsequent cycle with FSH alone.

DESIGN

Retrospective study.

SETTING

An academic research environment.

PATIENT(S)

Ninety-six women with pituitary down-regulation who underwent two sequential IVF treatments, the first with combined hMG and FSH and the second with FSH alone.

MAIN OUTCOME MEASURE(S)

Duration of stimulation, serum estradiol level on the day of hCG administration, amount of gonadotropin used, number of oocytes retrieved, number of oocytes fertilized, and selected preembryo morphologic features.

RESULT(S)

No difference in the mean duration of stimulation was observed between the treatment cycles among patients who received hMG and FSH (11.9 days) followed by FSH alone (11.7 days). The mean number of oocytes retrieved, the mean number of oocytes fertilized, the percentage of preembryo fragmentation, and the preembryo cell number at transfer did not differ significantly between the stimulation protocols. The cumulative amount of gonadotropin used during stimulation was slightly greater in the cycles stimulated with FSH alone, but this difference was not significant (29.4 ampules of hMG plus FSH versus 31.8 ampules of FSH alone). Serum estradiol levels measured on the day of hCG administration during stimulation with hMG and FSH (1,382 pg/mL) were higher than those measured during stimulation with FSH alone (1,149 pg/mL).

CONCLUSION(S)

Follicular response and preembryo quality were not significantly different when patients were treated first with hMG and FSH and then with FSH alone in a subsequent cycle. Similarities in ovarian response and preembryo characteristics, as well as differences in estradiol patterns seen in each stimulation setting, should be anticipated when patients receive these protocols.

40- and 70-kHz vocalizations of mice (Mus musculus) during copulation

Ultrasonic vocalizations were tape recorded from five pairs of copulating mice and subjected to spectrographic analysis. As expected, the mice emitted numerous 70-kHz vocalizations. At the beginning of the test, before copulation began, 70-kHz calls were emitted almost continuously, while calls with lower spectrographic frequencies were not observed. Subsequently, bursts of 70-kHz calling generally began shortly before mounts and intromissions and persisted until dismount. Intermixed with these 70-kHz calls were additional vocalizations of about 40 kHz. Calling rates were highest just prior to intromission. Once intromissions began, 70-kHz calls continued at a lower rate until dismount; however, 40-kHz calls occurred infrequently. In a second experiment, the male was found to emit the majority of the 70-kHz calls and all of the 40-kHz calls. When the male was devocalized, few calls were detected, regardless of whether the female was able to call. If the male was not devocalized, high rates of calling were detected, even if the female was devocalized.

Congenital cervicovaginal aplasia with septate uterus and functioning endometrium

A 14-year-old adolescent girl presented with primary amenorrhea and uncontrolled pelvic pain. Evaluation using pelvic sonogram, magnetic resonance imaging, and laparoscopy confirmed the diagnosis of cervicovaginal aplasia with functioning endometrium and a vaginal fistulous tract. At age 19 years, hysterectomy and vaginoplasty allowed the patient to be free of pain and to have normal sexual function.

Functional studies of in vitro rat distal colon before and after restitution

BACKGROUND

Epithelial injury occurs in many acute and chronic diseases of the colon and from simple mechanical and chemical injury in the normal colon. Because epithelial repair is so important, we developed a highly reproducible, entirely in vitro model of restitution in rat distal colon.

METHODS

The muscosal surface of colon mounted in Ussing chambers was exposed to 1.5 mol/L NaCl (hypertonic saline, HS) for 10 minutes. Transepithelial potential difference, electrical resistance, and short-circuit current were used to measure return of electrophysiologic characteristics of the tissue during recovery from injury. Recovery of the barrier to transepithelial movement of large molecules was assessed by measuring mannitol and inulin permeability. Na+ and Cl- absorption and forskolin-induced Cl- secretion were used as indicators of functional recovery of the colonic mucosa after HS injury. Morphologic evaluation of tissues was performed by light microscopy and transmission electron microscopy.

RESULTS

HS treatment caused marked increases in mannitol and inulin permeability together with exfoliation of colonocytes from the surface and upper crypts, leaving long stretches of denuded basal lamina. Epithelial continuity was morphologically reestablished in 30 to 60 minutes, concomitant with return of permeability to control levels. Potential difference, electrical resistance, and short-circuit current decreased with injury and then gradually recovered, although not to preinjury level. Net Na+ and Cl- absorptions, present in undamaged tissues at approximately equivalent rates, decreased after restitution. Forskolin-stimulated Cl- secretion, present before injury, was abolished after restitution.

CONCLUSIONS

These studies describe a highly reproducible in vitro model of injury and restitution of a fully organized epithelium of rat distal colon. Although morphologic continuity and barrier properties recover after extensive superficial mucosal injury, the surface is repopulated by cells displaying transport properties and ultrastructural characteristics distinct from the surface epithelium of undamaged tissues.

Liver resection for colorectal metastases

PURPOSE

More than 50,000 patients in the United States will present each year with liver metastases from colorectal cancers. The current study was performed to determine if liver resection for colorectal metastases is safe and effective and to evaluate predictors of outcome.

MATERIALS AND METHODS

Data for 456 consecutive resections performed between July 1985 and December 1991 in a tertiary referral center were analyzed.

RESULTS

The perioperative mortality rate was 2.8%, with a mortality rate of 4.6% for resections that involved a lobectomy or more. The median hospital stay was 12 days and only 9% of patients were admitted to the intensive care unit. The 5-year survival rate is 38%, with a median survival duration of 46 months. By univariate analysis, nodal status of the primary lesion, short disease-free interval before detection of liver metastases, carcinoembryonic antigen (CEA) level greater than 200 ng/mL, multiple liver tumors, extrahepatic disease, large tumors, or positive resection margin was predictive of poorer outcome. Sex, age greater than 70 years, site of primary tumor, or perioperative transfusion was not predictive of outcome. By multivariate analysis, positive margin, size greater than 10 cm, disease-free interval less than 12 months, multiple tumors, and extrahepatic disease were independent predictors of poorer outcome. Short disease-free interval or multiple tumors were nevertheless associated with a 5-year survival rate greater than 24%.

CONCLUSION

Liver resection for colorectal metastases is safe and effective therapy and currently represents the only potentially curative therapy for metastatic colorectal cancer. The only absolute contraindication to resection is extrahepatic disease. A randomized trial to examine efficacy of surgical resection cannot ethically be performed. Liver resection should be considered standard therapy for all fit patients with colorectal metastases isolated to the liver.

Amantadine treatment is an independent predictor of improved survival in Parkinson's disease

Amantadine has been used for more than 20 years in the symptomatic treatment of Parkinson's disease (PD). Several recent discoveries suggest that amantadine could also have a neuroprotective effect in PD. We studied survival in all parkinsonism (including PD and other parkinsonian syndromes) patients attending a single clinic, employing standard survival curves and a Cox regression model, to identify independent predictive variables for survival (while taking into account factors potentially associated with both outcome and treatment selection). Amantadine-treated patients (n = 250) were similar to the patients not treated with amantadine (n = 586) in terms of age, gender, type of parkinsonism, Hoehn and Yahr stage and dementia status at initial neurological visit. Amantadine use was an independent predictor of improved survival (p < 0.01). Improved survival was also associated with a higher 10-year expected survival (based on age, gender, and birth year), absence of dementia, type of parkinsonism = PD, and low Hoehn and Yahr stage (I or II) at initial neurologic visit (all p < 0.01); these additional factors occurred in statistically similar proportions in the groups that were and were not treated with amantadine. The association of improved survival with amantadine use may stem from symptomatic benefit or may reflect a "neuroprotective" effect, mediated through N-methyl-D-aspartate (NMDA) receptor antagonism, dopamine uptake blockade activity, or other mechanisms. Our preliminary findings suggest that a prospective, controlled, randomized trial of amantadine's effects on PD progression is warranted.